Asymmetric synthesis of aryloxypropanolamines via OsO4-catalyzed asymmetric dihydroxylation - Sayyed, I. A.; Thakur, V. V.; Nikalje, M. D.; Dewkar, Gajanan; Kotkar, S. P.; Sudalai, A. (Tetrahedron, 2005)
A simple and effective procedure for the enantioselective synthesis of several beta-adrenergic blocking agents incorporating the first asymmetric synthesis of celiprolol, is described. The key steps are (i) sharpless asymmetric dihydroxylation of aryl allyl ethers to introduce chirality into the molecules and (ii) conversion of cyclic sulfates into the corresponding epoxides using a three-step procedure. (c) 2005 Elsevier Ltd. All rights reserved.
Keywords: antihypertensive; asymmetric dihydroxylation; cyclic sulfates; epoxides

Characterization of two midgut proteinases of helicoverpa armigera and their interaction with proteinase inhibitors - Telang, M. A.; Giri, Ashok P.; Sainani, Mohini N.; Gupta, Vidya S. (Journal of Insect Physiology, 2005)
Two serine proteinases from the midgut of Helicoverpa armigera have been partially purified and characterized. One proteinase, HGP-1, was capable of hydrolyzing a synthetic substrate of elastase and was inhibited by elastatinal. The second proteinase, HGP-2, was inhibited by a trypsin inhibitor. Molecular weights of HGP-1 and HGP-2 were approximately 26.0 and 29.0 kDa, respectively. Both the proteinases exhibited alkaline pH optima in the range of 10-11. Furthermore, interaction of HGP-1 and HGP-2 with proteinase inhibitors (PIs) from host and non-host plants was studied. HGP-1 was not only insensitive to a PI from chickpea (host) but was also able to degrade it. The same PI from chickpea was able to inhibit over 50% activity of HGP-2. On the contrary, PIs from potato (non-host) showed strong inhibition of both, HGP-1 and HGP-2 and also demonstrated protection of chickpea seed proteins from digestion by both the HGPs. These results could provide important clues in designing strategies for sustainable use of plant PIs in developing insect-tolerant transgenic plants. (C) 2005 Elsevier Ltd. All rights reserved.
Keywords: elastase; Helicoverpa armigera gut proteinases; insect-resistant plants; plant proteinase inhibitors

Cloning, preparation and preliminary crystallographic studies of penicillin V acylase autoproteolytic processing mutants - Chandra, P. M.; Brannigan, James A.; Prabhune, Asmita; Pundle, A.; Turkenburg, J. P.; Dodson, Guy G.; Suresh, C. G. (Acta Crystallographica Section F-Structural Biology and Crystallization Communications, 2005)

Diversity oriented synthesis of tricyclic compounds from glycals using the ferrier and the pauson-khand reactions - Hotha, Srinivas; Tripathi, A. (Journal of Combinatorial Chemistry, 2005)
Diversity oriented synthesis of tricyclic compounds was achieved using a combination of the Ferrier reaction and the Pauson-Khand reaction. Ferrier reaction was effected using NbCl5, and the Pauson-Khand reaction was carried out using CO2(CO)(8), acetonitrile-dimethoxyethane. Michael additions using various alkyl, aryl, and heterocyclic thiols were also performed successfully. The Ferrier, Pauson-Khand, and Michael addition reactions were found to be highly diastereoselective.

Enantioselective synthesis of (S)-alpha-arylpropionic acids via pd-catalyzed kinetic resolution of benzylic alcohols - Thakur, V. V.; Sudalai, A. (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2005)
A convenient synthetic route for the synthesis of three (S)-alpha-propionic acids, (S)-naproxen (90% ee), (S)-ibuprofen (82% ee) and (S)-phenylpropioilic acid (92% ee) is described. Pd-catalyzed oxidative kinetic resolution of the corresponding benzylic alcohols is used as a key step to introduce stereogenicity into the molecule.

First enantiospecific synthesis of (+)-beta-herbertenol - Chavan, Subhash P.; Thakkar, M.; Kharul, Rajendra K.; Pathak, A. B.; Bhosekar, Gaurav V.; Bhadbhade, Mohan M. (Tetrahedron, 2005)
The first enantiospecific synthesis of (+)-beta-herbertenol, from naturally occurring R-(+)-citronellal, employing Taber's diazo decomposition protocol as the key step, is described. (c) 2005 Elsevier Ltd. All rights reserved.
Keywords: citronellal; diazo decomposition; enantiospecific

In vivo and in vitro effect of capsicum annum proteinase inhibitors on helicoverpa armigera gut proteinases - Tamhane, V. A.; Chougule, Nanasaheb P.; Giri, Ashok P.; Dixit, A. R.; Sainani, Mohini N.; Gupta, Vidya S. (Biochimica Et Biophysica Acta-General Subjects, 2005)
Two proteinase inhibitors (PIs), CapA1 and CapA2, were purified from Capsicum annum Linn. Var. Phule Jyoti leaves and assessed for their in vitro and in vivo activity against Helicoverpa armigera gut proteinases (HGPs). Both the inhibitors exhibited molecular weights of about 12 kDa with inhibitory activity against bovine trypsin and chymotrypsin indicating presence of probable two-inhibitor repeats of PIN II family. CapA1 and CapA2 inhibited 60-80% HGP (azocaseinolytic) activity of fourth instar larvae feeding on various host plants while 45-65% inhibition of HGP activity of various instars (II to VI) larvae reared on artificial diet. The partial purification of HGP isoforms, their characterization with synthetic inhibitors and inhibition by C. annum PIs revealed that most of the trypsin-like activity (68-91%) of HGPs was sensitive to C. annum PIs while 39-85% chymotrypsin-like activity of HGPs was insensitive to these inhibitors. The feeding of C. annum leaf extracts and two purified PIs in various doses to H. armigera larvae for two successive generations through artificial diet demonstrated their potential in inhibiting larval growth and development, delay in pupation period and dramatic reduction in fecundity and fertility. This is the first report-demonstrating efficacy of C. annum PIs against insect gut proteinases as well as larval growth and development of H. armigera. (c) 2004 Elsevier B.V. All rights reserved.
Keywords: Capsicum annum; gut proteinase; Helicoverpa armigera; insect resistance; Proteinase inhibitor

Influence of alkali metal doping on selectivity behaviour of platinum catalysts for hydrogenation of 2-butyne-1,4-diol - Telkar, M. M.; Rode, C. V.; Rane, V. H.; Chaudhari, R. (Catalysis Communications, 2005)
Hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol (B(2)D) and butane-1,4-diol (B(1)D) using Pt catalysts doped with alkali metals was studied. These catalysts showed higher selectivity to the olefinic diol (B2D) compared to that with monometallic platinum catalyst. Among various alkali metals, Cs-doped catalyst showed highest selectivity (>99%) to B(2)D. The selectivity to B(2)D increased (up to 99.9%) with increase in the concentration of Cs from 0.25% to 1%. The increase in the basic strength of alkali doped catalysts measured by CO(2)-TPD, would be responsible for the increase in electron density of Pt hence, faster desorption and higher selectivity to the intermediate olefinic diol (B(2)D). The reaction parameters; such as temperature, H(2) pressure and substrate concentration haye strong influence on the catalyst activity but almost no effect on the selectivity to B(2)D. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: 2-butene-1; 2-butyne-1; 4-diol; alkali metal doping; platinum catalysts; Selective hydrogenation

Influence of process pressure on HW-CVD deposited a-Si : H films - Jadkar, Sandesh R.; Sali, J. V.; Kshirsagar, S. T.; Takwale, M. G. (Solar Energy Materials and Solar Cells, 2005)
Hydrogenated amorphous silicon (a-Si:H) films were deposited using pure silane (SiH4) without hydrogen dilution by hot wire chemical vapor deposition (HW-CVD) technique. The electrical, optical, and structural properties of these films are systematically studied as a function of process pressure (P-r). The device quality a-Si:H films with a photosensitivity > 10(5) were deposited at a deposition rate >40 Angstrom/s at low process pressure. However, a-Si:H films deposited at higher process pressures show degradation in their electrical and structural properties. The FTIR spectroscopic analysis showed that a-Si:H films deposited at low process pressure contain hydrogen mainly in mono-hydrogen (Si-H) configuration whereas films deposited at higher process pressure have hydrogen in di-hydrogen (Si-H-2) or poly hydrogen (SiH2)(n) complexes. The hydrogen content (C-H) in the films was found to be less than 4 at.% over the entire range of process pressure studied. This indicates that the growth of a-Si:H films is mainly from the atomic species (Si and H) evaporated from the hot filament and hydrogen gets incorporated in the film via gas-phase reactions and substrate gas interactions. The band gap, however was found similar to1.71 eV or much higher. We attribute high band gap at low hydrogen content may be due to presence of microvoids. Raman spectroscopic analysis showed increase in structural disorder and Rayleigh scattering with increase in the process pressure. (C) 2004 Elsevier B.V. All rights reserved.
2nd International Conference on Cat-CVD (Hot-Wire CVD) Process, DENVER, CO, SEP 10-14, 2002
Keywords: Electrical properties; FTIR spectroscopy; hot wire chemical vapor deposition; hydrogenated amorphous silicon; Raman spectroscopy

Isolation and characterization of an iodide bridged dimeric palladium complex in carbonylation of methanol - Tonde, S. S.; Kelkar, Ashutosh A.; Bhadbhade, Mohan M.; Chaudhari, Raghunath V. (Journal of Organometallic Chemistry, 2005)
Palladium-catalyzed carbonylation of methanol in presence of iodide promoters was investigated. Iodide bridged palladium dimeric complex, [PPh3CH3](2)[Pd2I6] was isolated from the carbonylation reaction mixture and characterized using X-ray crystallography. Reaction mechanism was proposed based on IR and UV spectroscopic characterizations of catalytic species involved in the catalytic cycle. The isolated dimeric palladium species, [Pd2I6](2-) underwent carbonylation to give monomeric species [PdI3CO](-) at atmospheric pressure of carbon monoxide. It was also observed that PPh3 plays an important role to avoid catalyst deactivation at higher temperatures. Turnover frequency (TOF) of 1052 h(-1) was achieved using Pd(OAC)(2)-HI-PPh3 catalyst system at 175 degrees C. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: dirneric palladium; IR spectroscopy; methanol carbonylation; palladium catalyst; reaction mechanism; UV

Isopropyl 2,5-anhydro-3,4-di-O-tert-butyldiphenyl-silyl-L-ribonate - Glawar, A. F. G.; Watkin, D. J.; Sanjayan, G. J.; Tranter, G. E.; Edwards, Alison A.; Fleet, George W. J. (Acta Crystallographica Section E - Structure Reports Online, 2005)
Determination of the crystal structure of the title compound, C40H50O5Si2, firmly established its relative configuration and hence that of some related tetrahydrofuran carboxylates. The material crystallizes with Z' = 2. Except for the chiral centres, the two independent molecules are related by a pseudo-centre of symmetry.

Isothermal kinetic study of nitric oxide adsorption and decomposition on Pd(111) surfaces: molecular beam experiments - Thirunavukkarasu, K; Thirumoorthy, K; Libuda, X; Gopinath, Chinnakonda S. (Journal of Physical Chemistry B, 2005)
The kinetics of NO adsorption and dissociation on Pd(111) surfaces and the NO sticking coefficient (S-NO) were probed by isothermal kinetic measurements between 300 and 525 K using a molecular beam instrument. NO dissociation and N-2 productions were observed in the transient state from 425 K and above on Pd(l 11) surfaces with selective nitrogen production. Maximum nitrogen production was observed between 475 and 500 K. It was found that, at low temperatures, between 300 and 350 K, molecular adsorption occurs with a constant initial SNO of 0.5 until the Pd(I 11) surface is covered to about 70-80% by NO. Then SNO rapidly decreases with further increasing NO coverage, indicating typical precursor kinetics. The dynamic adsorption-desorption equilibrium on Pd(I 11) was probed in modulated beam experiments below 500 K. CO titration experiments after NO dosing indicate the diffusion of oxygen into the subsurface regions and beginning surface oxidation at >= 475 K. Finally, we discuss the results with respect to the rate-limiting character of the different elementary steps of the reaction system.

Larvicidal activity of acacia nilotica extracts and isolation of D-pinitol - a bioactive carbohydrate - Chaubal, Rohini; Pawar, P. V.; Hebbalkar, G. D.; Tungikar, V. B.; Puranik, Vedavati G.; Deshpande, V. H.; Deshpande, N. R. (Chemistry & Biodiversity, 2005)
A low-molecular-weight, sugar-like compound other than glucose, fructose, sucrose, or myo-inositol showing lipophilic nature was isolated from the EtOH extract of Acacia nilotica. The structure of the compound was determined by spectral methods. This alicyclic polyalcohol was found to be D-pinitol (- 3-O-methyl-D-chiro-inositol; 1). The configuration of the compound was confirmed by single-crystal X-ray analysis. The compound I is known from Soybean, Australian mangroves, Fagonia indica, A rachis hypogaea, etc., but we have isolated this compound for the first time from the aerial parts of A. nilotica. Very few references have been cited for compound I for its entomological activity, and there are no reports on mosquitoes. Therefore, the crude extracts of A. nilotica were tested for its biological activity against mosquito larvae. Acetone extract at 500-ppm concentration showed chronic toxicity against Aedes aegypti and Culex quinquefasciatus IVth instar mosquito larvae. Such a biological activity has been observed for the first time for this plant. This study could be a stepping stone to a solution for destroying larval species as well as consumption of such a widely grown, problem weed, A. nilotica. This larvicidal agent, since it is derived from plant, is eco-friendly, cost effective, non-hazardous to nontarget organisms and would be safe unlike commercially available insecticides.

Lignin-carbohydrate complexes from sugarcane bagasse: preparation, purification, and characterization - Singh, R.; Singh, S.; Trimukhe, K. D.; Pandare, K. V.; Bastawade, Kulbhushan B.; Gokhale, D. V.; Varma, Anjanikumar (Carbohydrate Polymers, 2005)
Lignin-carbohydrate complexes were isolated from sugarcane bagasse by a process, which yielded sulfur-free lignins. These could be made carbohydrate-free, if necessary, by treatment with xylanase enzyme. A study of the preparation, purification, and characterization of such lignin-carbohydrate complexes, comparison with commercial lignin samples (wood based as well as bagasse based) and some other lignin derivatives was made by using a variety of analytical tools such as FTIR, HPLC at three different UV-wavelengths, GPC, thermal analysis and elemental analysis. The use of such a diverse range of lignin-carbohydrate complex samples enabled us to predict the sensitivity of the various analytical techniques for characterization of complex polymers containing carbohydrate moieties. Evidence for lignin-carbohydrate complex was detectable by FTIR as well as HPLC studies. Thermal analysis studies showed the crucial effect of carbohydrate groups, the content of aliphatic chains, and the sulfur content of the lignins. Generalized structures of lignin-carbohydrate complexes obtained from various sources using different preparation methods and chemical modifications are presented. This will aid the applications development effort with advantageously using lignins containing low levels of carbohydrate moieties as reactive sites as well as biodegradability inducing sites. (C) 2005 Elsevier Ltd. All rights reserved.
Keywords: biodegradability; hardwood lignins; lignin-carbohydrate complex; softwood lignins; Sugarcane bagasse; sulfur-free lignins; xylanase enzyme

Mitochondrial sequence reveals high levels of gene flow between breeds of domestic sheep from Asia and Europe - Meadows, J. R. S.; Li, K.; Kantanen, J.; Tapio, M.; Sipos, W.; Pardeshi, V.; Gupta, V.; Calvo, J. H.; Whan, V.; Norris, B.; Kijas, J. W. (Journal of Heredity, 2005)
Sequence variation present within the mitochondrial genome was used to investigate genetic diversity within sheep breeds from Asia and Europe. Comparison of 2027 bp of sequence from 121 animals revealed 44 phylogenetically informative nucleotide positions and a single insertion/deletion. A total of 57 haplotypes were observed which formed two distinct clades. Type A haplotypes were found in breeds from Asia (India, Indonesia, Mongolia, and Tibet), while type B haplotypes were observed at the highest frequency in breeds sourced from Europe (nine breeds from Austria, angstrom land, Finland, Spain, and northwestern Russia). The distribution of haplotypes indicates sheep appear to have the weakest population structure and the highest rate of intercontinental dispersal of any domestic animal reported to date. Only 2.7% of the sequence variation observed was partitioned between continents, which is lower than both goat (approximately 10%) and cattle (approximately 50%). Diagnostic restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) tests which distinguish type A and B haplotypes were used to test an additional 223 animals from 17 breeds of European and Asian origin. A mixture of the two lineages was found in every breed except Suffolk and the Indian Garole, indicating introgression has played a major part during breed development and subsequent selection.

Molecular beam study of the NO plus CO reaction on Pd(111) surfaces - Thirunavukkarasu, K; Thirumoorthy, K; Libuda, J; Gopinath, Chinnakonda S. (Journal of Physical Chemistry B, 2005)
Nitric oxide (NO) reduction with carbon monoxide (CO) on the Pd(111) surface was studied under isothermal conditions by molecular beam techniques as a function of temperature, NO:CO beam composition, and beam flux. Systematic experiments were performed under transient and steady state conditions. Displacement of adsorbed CO by NO in the transient state of the reaction was observed at temperatures between 375 and 475 K for all the NO: CO compositions studied. NO accumulation occurs on Pd(l 11) surface under steady state conditions, below 475 K, due to stronger chemisorption of NO. The steady state reaction rates attain a maximum at about 475 K, nearly independent of beam composition. N-2 was found to be the major product of the reduction, along with a minor production of N2O. The production of N2 and N2O indicates molecular and dissociative adsorption of NO on Pd(l 11) at temperatures up to 525 K. Postreaction TPD measurements were performed in order to determine the nitrogen coverage under steady-state conditions. Finally, the results are discussed with respect to the rate-controlling character of the different elementary steps of the reaction system.

NBS-catalyzed hydroamination and hydroalkoxylation of activated styrenes - Talluri, S. K.; Sudalai, A. (Organic Letters, 2005)
N-Bromosuccinimide efficiently catalyzes the hydroamination and hydroalkoxylation of activated styrenes using tosylamides, carbamates, and alcohols as the nucleophiles to afford amino and ether derivatives, respectively. Both the processes give good to excellent yields of the products with 100% regioselectivity (Markovnikov fashion).

Niobium(V) chloride catalyzed microwave assisted synthesis of 2,3-unsaturated O-glycosides by the Ferrier reaction - Hotha, Srinivas; Tripathi, A. (Tetrahedron Letters, 2005)
NbCk catalyzes the Ferrier reaction of per-O-acetylated glycals with primary, secondary, altylic, benzylic and monosaccharide alcohols to give 2,3-unsaturated alpha-glycosides in short reaction times under microwave irradiation conditions. (c) 2005 Elsevier Ltd. All rights reserved.

Response of trichogramma chilonis to infochemicals: an SEM and electrophysiological investigation - Sen, A; Raina, R; Joseph, Mary P.; Tungikar, VB (Biocontrol, 2005)
The external morphology and peripheral olfactory responses of antennal chemoreceptors of Trichogramma chilonis Ishii (Hymenoptera:Trichogrammatidae) to host related stimuli were examined by SEM and EAG technique respectively. The antennae of male and female T. chilonis reveal strong sexual dimorphism in structure as well as in types, density and distribution of individual sensillar types. The female antennae are characterized by the presence of a single uniporous sensilla on the apical tip of the dome and numerous multiporous pitted sensilla. Sensilla common to both males and females include the multiporous plate sensilla, the peg sensilla and trichoid sensilla. Differences between males and females occur with respect to their EAG profiles to 22 chemicals commonly found in plants viz., hexanal, β-pinene, citronellal, terpinene, citronellol, phytol, caryophyllene, R-(+)-limonene, linalool, carvacrol, cis-3-hexen-1-ol, ethanol, α-pinene, trans-2-hexanal, α-phellandrene, amyl acetate, cineole, quinolene, S-(-)limonene, β-myrcene, carvone, terpineol; hexane leaf extracts of three host plants of Helicoverpa armigera (cotton, chickpea and pigeon pea) and hexane scale extracts of adult males and females of H. armigera. Individually, the largest peak amplitudes in females were obtained with citronellal, phytol, caryophyllene, R-(+)-limonene, linalool, carvacrol and citronellol while in males citronellol, caryophyllene, linalool, R-(+)-limonene and amyl acetate caused the highest response. Among the different chemical classes, the largest peak amplitudes in females were obtained with oxygenated monoterpenes, while in males, fatty acid derivatives caused the highest response. In both males and females, the hydrocarbon monoterpenes caused the least response. Thus, the wide spectrum response of Trichogramma chilonis, to a wide group of chemicals belonging to different chemical classes, though varying, nevertheless suggests that using plant information enhances its parasitization efficiency.
Keywords: antennae; Chickpea; cotton; EAG; parasitoid; pigeon pea; scanning electron microscopy; Trichogramma chilonis; Volatiles

Role of a co-metal in bimetallic Ni-Pt catalyst for hydrogenation of m-dinitrobenzene to m-phenylenediamine - Telkar, M. M.; Nadgeri, J. M.; Rode, C. V.; Chaudhari, R. (Applied Catalysis A-General, 2005)
Bimetallic Ni-Pt catalysts supported on carbon were found to give very high turn over frequency numbers and almost complete selectivity to m-phenylenediamine in m-dinitrobenzene hydrogenation as compared to the monometallic nickel catalysts. The XRD and XPS characterization revealed that most of the nickel remains as Ni2+ in a monometallic catalyst while, the addition of platinum leads to the stabilization of Ni-0 state, in case of bimetallic catalysts. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: Bimetallic catalyst; Catalytic hydrogenation; m-dinitrobenzene; m-phenylenediamine; Selective hydrogenation; turn over number; XPS and XRD of nickel

Separability of local reactivity descriptors - Tanwar, A; Pal, S (Journal of Chemical Sciences, 2005)
The size-dependence of different local reactivity descriptors of dimer A(2) and AB type of systems is discussed. We derive analytic results of these descriptors calculated using finite difference approximation. In particular, we studied Fukui functions, relative electrophilicity and relative nucleophilicity, local softness and local philicity. The results are explained using the example of the dimer of BH3NH3.
Keywords: condensed Fukai functions; Local reactivity descriptors; molecular interactions; separability

Studies on the lactic-fermentation of sugar apple (Annona squamosa L.) puree - Tien, Y. Y.; Ng, C. C.; Chang, C. C.; Tseng, W. S.; Kotwal, S.; Shyu, Y. T. (Journal of Food and Drug Analysis, 2005)
Sugar apple (Annona squamosa L.) is a fruit tree of economic importance in Taiwan, with the fruit primarily consumed fresh. Overproduction in recent years, coupled with short shelf life and other practical issues, make practical the research into uses for sugar apples in formats other than fresh. This study presents an exploration of lactic-fermented sugar apple products. The product has a unique sweet aroma and a test panel found its texture to be appealing. For this study, sugar apple puree was used as the substrate for fermentation using mixed starters in a ratio 1:1 or 1:1:1. The high total soluble solid nature (20.5 +/- 4.33 degrees Brix) of sugar apple puree as compared to that of mixed fruit juice (lower than 10 Brix) indicates its potential to be used in fermentation. Following fermentation, the properties and effects of different starter inoculations were recorded and discussed. Fermentation achieved a pH value of 3.8 after 60 hr. The performance of fermented product in the DPPH (alpha,alpha-diphenyl-beta- picrylhydrazyl) decreased from 92% to 78% after 48 hr, followed by a stationary state. Fermented sugar apple puree and fresh sugar apple juice blended in a ratio of 2:8 delivered the highest DPPH scavenging efficiency (88%) and iron chelating ability (49%). The relatively high values of these properties offer the potential for sugar apple juice to be further developed as a novel functional food. Such a development would surely help to ease recent overproduction problems.
Keywords: annonaceae; DPPH scavenging; Fermentation; Lactobacillus

Synthesis and biodegradability of polyaspartic acid: a critical review - Thombre, SM; Sarwade, BD (Journal of Macromolecular Science-Pure and Applied Chemistry, 2005)
Poly(aspartic acid) (PAA) being biodegradable is suitable for various industrial medical and agricultural applications to replace many non-biodegradable polymers in use. Poly(aspartic acid) can be synthesized by different methods with and without catalyst in different forms such as polysuccinimide, either hydrolyzed to acid or salt. The polymer of (aspartic acid) is present in different forms such as alpha, beta and L, D isomers. The conformational analysis of poly(aspartic acid) was done by various analytical methods. Different combinations of these two isomer present in different percentage can be detected by various methods such as Hoffman degradation, IR, and NMR spectroscopic analysis. From the standard test for biodegrad ability, it was shown that the polymer is fully biodegradable. In this review, synthesis and characterization of homo and copolymer derivatives of PAA, along with the application and biodegradability in comparison with the other polymer in use, is discussed briefly.
Keywords: Biodegradation; poly(aspartic acid); Polycondensation; polysuccinimide; synthesis; thermal

Synthesis and characterization of ferrocenylchalcogenopropargyl complexes [Fe(eta(5)-(C5H4ECH2C)-C-I CH)(2)] (E-I = Se, S) and their reactions to form unusual ferrocenyl-containing metal clusters with eclipsed Cp rings and new five-membered (FeECH)-C-I = - Mathur, P.; Singh, V. K.; Mobin, Shaikh M.; Srinivasu, C.; Trivedi, R.; Bhunia, A. K.; Puranik, Vedavati G. (Organometallics, 2005)
{The new bis(chalcogenopropargyl)ferrocene complexes [Fe(eta(5)-C(5)H(4)E(I)CH(2)CdropCH)(2)] (E-I = Se, 1; E-I = S, 2) have been prepared by treatment of the dilithiated [Fe(eta(5)-C5H4Li)(2)] with Se or S powder, followed by reaction with propargyl bromide. Reaction of 1 and 2 with [Fe2M(mu(3)-E)(2)(CO)(9)] (E = S, Se and M = Fe, Ru) forms new clusters which feature an unusual five-membered (FeECH)-C-I=CCH2 ring with a pi bond between the olefinic unit and the Fe atom, and the Cp rings adopt an eclipsed arrangement. The structures of 1 and [Fe(eta(5)-C5H4E(I)-CH(2)CdropCH) (eta(5)-C5H4{Fe2M(CO)(8)(mu-E)((ECHCCH2)-C-I)})] (M = Fe

Synthesis and curing studies of PPG based telechelic urethane methacrylic macromonomers - Asha, S. K.; Thirumal, M.; Kavitha, A.; Pillai, C.K.S. (European Polymer Journal, 2005)
A New class of telechelic urethane methacrylic (TUMA) macromonomers were synthesized by a two-step condensation of 1, 6-hexamethylenediisocyanate (HMDI) with polypropylene glycol (PPG) of various molecular weights and capped with hydroxyl ethyl methacrylate (HEMA). A model compound based on diethylene glycol (DEG)—M-1 was synthesized as a low molecular weight analogue. Another model compound—M-2 was also synthesized by direct coupling of two equivalents of HEMA with HMDI. The structure of the telechelic urethanes were confirmed by 1H, 13C NMR and FTIR spectroscopy. Photopolymerization of these telechelic systems was investigated using 2,2-diethoxy acetophenone as the photoinitiator at 5 wt.%. Trihydroxymethylpropane trimethacrylate (30 parts), PPG diacrylates (25 parts), ethylhexyl acrylate (20 parts) were mixed with the various telechelic urethane methacrylates (25 parts) for curing studies. The kinetics of the curing was monitored by following the disappearance of the methacrylic double bonds at 1628 cm−1 using IR spectroscopy. TUMAPPG-425 had the fastest cure rate among the telechelic urethane methacrylates. This could be accounted for by hydrogen bonding pre-association in these systems. The thermal properties of the cured films were studied using TGA measurements. The cured films of the neat resin had a lower 50 wt.% loss temperature compared with that of the same resin in the formulation.

Textural/structural, stability and morphological properties of mesostructured silicas (MCM-41 and MCM-48) prepared using different silica sources - Gaydhankar, T. R.; Taralkar, U. S.; Jha, Ratnesh Kumar; Joshi, P. N.; Kumar, R (Catalysis Communications, 2005)
A series of MCM-41 and MCM-48 samples have been synthesized under hydrothermal and static conditions using different silica sources (fumed silica, silica sot and ethyl silicate) and characterized by powder XRD, scanning electron microscopy and N-2 adsorption. The silica source reactivity trend observed was as: ethyl silicate > fumed silica > silica sot. However, the extent of contraction caused by calcination, magnitude of the wall thickness and stability were found to depend not only upon the type of silica source used but also on the type of structure formed. Noticeable morphological differences were observed in case of only MCM-41 when silica sources were varied. © 2005 Elsevier B.V. All rights reserved.

Unusual stereochemical outcome of radical cyclization: synthesis of (+)-biotin - Chavan, Subhash P.; Chittiboyina, A. G.; Ramakrishna, G.; Tejwani, R. B.; Ravindranathan, T.; Kamat, Subhash K.; Rai, B.; Sivadasan, L.; Balakrishnan, K.; Ramalingam, S.; Deshpande, V. H. (Tetrahedron, 2005)
An enantioselective synthesis of (+)-biotin 1 starting from naturally available cysteine is described. The key steps are the unusual stereochemical outcome of radical cyclization of compound 10 to prepare 5,5-fused system 11, and the introduction of C4-sidechain at C-6 in 13 via a Grignard reaction. (c) 2005 Elsevier Ltd. All rights reserved.
Keywords: biotin; exocyclization; radical cyclization

Characterization of polydimethylsiloxane rubber upon photochemical, thermal, salt-fog ageings and exposure to acid vapours - Delor-Jestin, Florence; Tomer, N. S.; Singh, R. P.; Lacoste, Jacques (E-Polymers, 2006)
The changes in the chemical structure and the physical properties of a filled crosslinked polydimethylsiloxane rubber were monitored as a function of various ageing factors. The variables included photochemical, thermal, salt-fog ageings and exposure to acid vapours. Unaged and aged samples were studied by IR spectroscopy, hardness measurements, Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) coupled with IR spectroscopy. No significant oxidation was detected after all ageings, except for nitric acid treatment. The presence of aluminium trihydrate was clearly identified as responsible for the observed chemical changes. Then an important vulnerability of this filled silicone rubber towards the cross-linking reactions provoked by usual ageings was also detected. The DSC-thermoporosimetry measurements of the mesh size distribution gave a comparison of cross-linking densities for each ageing. The complementary analysis with TGA-IR allowed us to differenciate the thermal stability of the formulation after various ageings and to acquire new knowledge about thermal decomposition.

COLL 613-Studies on the vapor-phase photo-oxidation of methanol over nano-size titania clusters dispersed in MCM-41 mesoporous silica - Kumar, Dharmesh; Bhattacharyya, Kaustav; Tripathi, Arvind; Varma, Salil; Gupta, Narendra M. (Abstracts of Papers of the American Chemical Society, 2006)

Crystalline phases in nylon-11: studies using HTWAXS and HTFTIR - Nair, S. S.; Ramesh, C.; Tashiro, K. (Macromolecules, 2006)
Nylon-11 was crystallized into different crystalline phases by appropriate methods. The chance in the structure during heating was monitored in situ by wide-angle X-ray scattering (WAXS). The alpha phase obtained by precipitating nylon-11 in 1,4-butanediol started transforming into the pseudohexagonal phase on heating, but the transformation was not fully completed before melting. The melt crystallized sample at 175 degrees C gave the pseudohexagonal phase, which transformed into the alpha' phase on cooling to room temperature at about 100 degrees C. The d spacing of the 00 1 reflection also showed a change at the transition temperature. The melt-quenched sample showed the pseudohexagonal phase, which did not change during heating, but on cooling transformed into alpha' phase. The gamma phase was obtained by casting nylon-11 in trifluoroacetic acid (TFA), and it changed into the pscudohexagonal phase at about 110 degrees C on heating. The d spacing of the 001 reflection depended on the way in which it was obtained. The studies have shown that nylon-11 is one of the few nylons that exhibit an extensive degree of polymorphism. High-temperature Fourier transform infrared spectroscopy (HTFTIR) studies revealed, apart from the conformational differences between various phases of nylon-11, some information on the formation of the gamma phase.

Direct somatic embryogenesis and plant regeneration in Garcinia indica Choiss - Thengane, Shubhada Ratnakar; Deodhar, Swapna R.; Bhosle, S. V.; Rawal, S. K. (Current Science, 2006)
Direct somatic embryogenesis without an intervening callus phase was induced from immature seeds of Gar- cinia indica Choiss. Woody plant medium supplemented with 6-benzyl amino purine (BAP) (4.44-22.19 mu m) alone or in combination with a-naphthaleneacetic acid (2.69 mu m) produces somatic embryos within a period of 2-3 weeks with 80% frequency. Embryo induction was observed all over the explant surface. Origin of the embryo was confirmed histologically from sub-epidermal layer of the seed. Maturation of these embryos was achieved after 12 weeks of culture on a medium containing BAP (16.08 mu m) in combination with indole-3-acetic acid (2.85-5.71 mu m) and/or kinetin (4.65 mu m). About 75% of the regenerated somatic embryos germinated into complete plantlets. The plantlets were acclimatized successfully with 92% survival in greenhouse.
Keywords: Garcinia indica; guttifereae; seeds; somatic embryos

Effect of organic additives on the mitigation of volatility of 1-nitro-3,3 `-dinitroazetidine (TNAZ): next generation powerful melt cast able high energy material - Talawar, M. B.; Singh, Alok; Naik, N. H.; Polke, B. G.; Gore, G. M.; Asthana, S. N.; Gandhe, B. R. (Journal of Hazardous Materials, 2006)
1-Nitro-3,3'-dinitroazetidine(TNAZ) was synthesized based on the lines of reported method. Thermolysis studies on synthesized and characterized TNAZ using differential scanning calorimetry (DSC) and hyphenated TG-FT-IR techniques were undertaken to generate data on decomposition pattern. FF-IR of decomposition products of TNAZ revealed the evolution of oxides of nitrogen and HCN containing species suggesting the cleavage of C/N-NO(2) bond accompanied with the collapse of ring structure. The effect of incorporation of 15% additives namely, 3-amino-1,2,4-triazole(AT), 3,5-diamino-1,2,4-triazole (DAT), carbohydrazide (CHZ), 5,7-dinitrobenzofuroxan (DNBF), bis (2,2-dinitropropyl) succinate (BNPS), triaminoguanidinium nitrate (TAGN), 2,4,6-trinitrobenzoic acid (TNBA) and nitroguanidine (NQ) on the volatility of TNAZ was investigated by undertaking thermogravimetric analysis. The TG pattern brings out the potential of BNPS and TAGN as additives to mitigate the volatility of TNAZ. The influence of additives on thermal decomposition of pattern of TNAZ was also investigated by DSC. The DSC results indicated that the additives did not have appreciable effect on the melting point of TNAZ. Scanning electron microscopic (SEM) studies were carried out to investigate the effect of additives on morphology of TNAZ. This paper also discusses the possible mechanism involved in between the TNAZ and TAGN and BNPS. It appears that the formation of charge transfer complex formation between the TNAZ and TAGN/BNPS. The effect of addition of high explosives such as CL-20, HMX and RDX on thermo-physical characteristics of TNAZ is also reported in this paper. (c) 2005 Elsevier B.V. All rights reserved.
Keywords: melt castable explosive; morphological structure; synthesis; Thermolysis; trinitroazetidine (TNAZ); volatility behavior

Efficient deprotection of dithioacetals to carbonyls using Oxone-KBr in aqueous acetonitrile - Desai, Uday V.; Pore, D. M.; Tamhankar, B. V.; Jadhav, Sushilkumar A.; Wadgaonkar, P. P. (Tetrahedron Letters, 2006)
A simple and efficient method has been developed for the chemoselective dethioacetalization of dithioacetals to aldehydes and ketones using Oxone-KBr in aqueous acetonitrile at room temperature. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: deprotection; dethioacetalization; Oxone

Efficient, solvent-free method for the chemoselective synthesis of acylals from aldehydes and their deprotection catalyzed by silica sulfuric acid as a reusable solid acid catalyst - Desai, Uday V.; Thopate, T. S.; Pore, D. M.; Wadgaonkar, P. P. (Catalysis Communications, 2006)
An efficient method has been developed for the chemoselective synthesis of acylals from aldehydes and acetic anhydride in the presence of silica sulfuric acid as a reusable solid acid catalyst under solvent-free conditions. Ketones are found to remain unaffected under the reaction conditions. The deprotection of acylals has also been achieved using SSA in methanol medium. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: Acylals; aldehydes; Chemoselective; protection and deprotection silica sulfuric acid

First enantiospecific synthesis of (-)-parvifoline and (-)-curcuquinone - Chavan, Subhash P.; Thakkar, Mahesh; Jogdand, Ganesh F.; Kalkote, Uttam R. (Journal of Organic Chemistry, 2006)
The first enantiospecific synthesis of (-)-parvifoline, employing ring-closing metathesis as the key step, and (-)-curcuquinone from naturally occurring (R)-(+)-citronellal is described.

Grapevine DNA polymorphisms revealed by microsatellite-derived markers from soybean and rice - Agrawal, Dinesh C.; Topfer, R.; Zyprian, E. (Vitis, 2006)
We report detection of DNA polymorphisms in grapevine by the use of microsatellite-flanking primer pairs from soybean and rice. These "cross species" microsatellite-derived markers were checked for their inheritance patterns in controlled grapevine crosses. They produced multiple bands that segregated and can be scored as individual genetic markers of dominant type. Employed in genetic mapping studies they offer advantages such as improved reproducibility in comparison to commonly used multi-locus marker systems like RAPDs and AFLPs.
Keywords: 1; 3-dipolar addition; pyrazoles; regiospecific reaction; sydnones

In situ optical emission spectroscopic investigations during arc plasma synthesis of iron oxide nanoparticles by thermal plasma - Banerjee, Indrani; Joshi, N. K.; Sahasrabudhe, S. N.; Kulkarni, Naveen V.; Karmakar, Soumen; Pasricha, R.; Ghorui, S.; Tak, Atul K.; Murthy, Shri P. S. S.; Bhoraskar, S. V.; Das, A. K. (IEEE Transactions on Plasma Science, 2006)
Investigations using in situ precursor spectroscopy during the growth of nanoparticles of iron oxide by thermal plasma induced gas phase condensation method have been shown to be useful for correlating the size of nanoparticles with existing plasma parameters. The relative abundance of ionized Fe species inside the plasma plume is seen to directly establish the relation between particle size, arc current, arc length, and ambient pressure of the reacting oxygen gas. The argon plasma from a transferred arc reactor is made to impinge on the anode that is allowed to vaporize and react with oxygen. The spectral line profiles of both Ar and Fe along the plasma column during the synthesis of nanoparticles have been proved to be useful in understanding the growth mechanism. Band intensities of FeO molecular states indicated the inverse relation with particle sizes that have been correlated to the two competitive processes in which energy is released, namely: 1) one involving the radiative transition and 2) the other that of the growth by coagulation. Atomic Boltzmann plots are used for estimating the temperatures of the zones, whereas particle sizes have been inferred using transmission electron microscopic measurements.
Keywords: plasma arc device; plasma-materials processing applications; spectroscopy

Influence of extended pi-conjugation units on carrier mobilities in conducting polymers - Harima, Yutaka; Kim, D. H.; Tsutitori, Y.; Jiang, Xiaoqing; Patil, R.; Ooyama, Y.; Ohshita, J.; Kunai, A. (Chemical Physics Letters, 2006)
Carrier mobilities in thin films of copolymers with repeat units consisting of oligothiophenes bridged by Si atoms are measured over a range of doping levels, where the numbers of thienylenes in the repeat unit are 7, 8, 10, 12, and 14. The mobilities for these polymer films increased with the increase in doping level and the mobility enhancement followed an increasing order of the pi-conjugation length. The magnitude of the mobility increase for the Si polymer comprising 14 thiophene units reached ca. 10(4), implying that this pi-conjugation length is almost sufficient to reproduce transport properties of polythiophenes. (c) 2006 Elsevier B.V. All rights reserved.

Interaction induced shifts in O-H stretching frequency of water in halide-ion water clusters: a microscopic approach with a bond descriptor - Tanwar, Akhilesh; Bagchi, Biman; Pal, Sourav (Journal of Chemical Physics, 2006)
Based on conceptual density functional theory, two new descriptors, the normalized atom-condensed Fukui functions (NFFs) and bond deformation kernel (BDK), are proposed to describe the O-H stretching frequency shifts in water halide-ion clusters by including local polarizations in the system. NFF, along with BDK, can be successfully used to describe interactions between different atoms, especially in cases where polarizations are quite important. (c) 2006 American Institute of Physics.

Isolation of new straight chain compounds from acacia nilotica - Chaubal, Rohini; Tambe, Amruta; Biswas, Sujata; Rojatkar, Supada; Deshpande, Vishnu; Deshpande, Nirinala (Indian Journal of Chemistry Section B-Organic Chemistry including Medicinal Chemistry, 2006)
A novel diester, pentacosane dioic acid dihexadecyl ester 1 has been isolated for the first time from n-hexane soxhlet extract of Acacia nilotica. Saponification of the diester reveals the presence of an alcohol, hexadecanol and pentacosane dioic acid. The structures of both the compounds are confirmed by GCMS analysis. Saponification of pet-ether extract of Acacia nilotica has been carried out. Unsaponiflable matter is further purified by column chromatography followed by repeated mixed solvent crystallization to afford heptacosan-1,2,3-triol 2.
Keywords: Acacia nilotica; diester; pentacosane dioic acid; saponification

Micropropagation of Indian laurel (Calophyllum inophyllum), a source of anti-HIV compounds - Thengane, Shubhada Ratnakar; Bhosle, S. V.; Deodhar, Swapna R.; Pawar, K. D.; Kulkarni, D. K. (Current Science, 2006)
An efficient protocol for in vitro micropropagtion of Calophyllum inophyllum (Linn.), an evergreen littoral tree, through multiple shoot formation from seed explants was developed. In vitro germination of the seeds was standardized on Woody Plant Medium (WPM) hormone free and/or supplemented with 6-benzylaminopurine (BAP; 2.22 mu M) and on half or full strength MS medium. Multiple shoot formation was achieved on WPM supplemented with BAP (2.22-44.00 mu M) and thidiazuron (TDZ; 0.91-4.54 mu M) from the decapitated seedling explants. The maximum multiple shoots, 20.9 per explant were induced on TDZ (0.91 mu M) after two subcultures. Elongated shoots of size > 4.0 cm were obtained on all media combinations with an average of 2.2-8.7 per explant. Elongation of the stunted shoots induced on BAP and TDZ was done on half strength WPM without any growth hormones. The elongated shoots on half WPM and/or full strength WPM supplemented with indole-3-butyric acid (2.46-24.60 mu M) alone or in combination with BAP (2.22 mu M) resulted in 52% rooting with 1-5 roots per rooted plant. The micropropagated plants were acclimatized successfully with 77% survival rate after five weeks. These plants were planted in the institute campus for ex situ conservation, where 72% plants are showing good growth and development.
Keywords: Calophyllum inophyllum; ex situ conservation; micropropagation; seed

Minimum magnetizability principle - Tanwar, Akhilesh; Pal, Sourav; Roy, Debesh Ranjan; Chattaraj, Pratim Kumar (Journal of Chemical Physics, 2006)

Novel beaded polymers from telechelic methacrylic ether esters - Pujari, N. S.; Trivedi, J.; Ingavle, Ganesh C.; Ponrathnam, S. (Reactive & Functional Polymers, 2006)
A series of telechelic dimethacrylic ether-esters (MEE) were prepared by solventless reaction of alpha,omega-dihydroxy poly(oxytetramethylene) (polytetrahydrofuran, PTHF) with phthalic anhydride and glycidyl methacrylate (GMA). MEE was polymerized with GMA as well as GMA-ethylene dimethacrylate (EGDM) to form porous beads. The terpolymer beads were observed using optical microscopy and SEM and characterized for internal pore volume, equilibrium volume-swelling ratio and dimethyl formamide and aqueous buffer regain. The morphology of the beads was dictated by the mole fraction and molecular weight of MEE in the feed. Porosity was found to increase with increase in molecular weight of MEE. Thus, porosity as high as 49%, 50% and 55% was observed with MEE of molecular weights 1580, 2580 and 3480, respectively. At a specific terpolymerization feed ratio of monomers, the terpolymers formed transform from gel like structure into a macroporous one, with increase in molecular weight of MEE. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: ether-ester dimethacrylates; macroporous; Pore size distribution; porosity; telechelics

Novel series of oligomers from 4-aminomethyl-tetrahydrofuran-2-carboxylates with 2,4-cis and 2,4-trans stereochemistry - Edwards, Alison A.; Sanjayan, Gangadharar J.; Hachisu, Shuji; Tranter, George E.; Fleet, George W. J. (Tetrahedron, 2006)
Two tetrahydrofuran-based y-amino acids [2,4-cis and 2,4-trans] were subjected to iterative peptide-coupling procedures to afford dimeric, tetrameric and hexameric carbopeptoids in good yield. These homooligomers were prepared for secondary structural study-to ascertain the conformational preference inherent in the monomer units. The L-xylo oligomers were protected with triethylsilyl ethers to increase the range of solvents suitable for structural investigation. Initial secondary structure data indicate the presence of hydrogen-bonded conformations in the L-ribo series. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: Foldamers; gamma amino acids; Peptidomimetics; sugar amino acids

Optically transparent magnetic nanocomposites based on encapsulated Fe3O4 nanoparticles in a sol-gel silica network - Thomas, Senoy; Sakthikumar, D.; Joy, Pattayil Alias; Yoshida, Yasuhiko; Anantharaman, Maliemadom R. (Nanotechnology, 2006)
Composite Fe3O4-SiO2 materials were prepared by the sol-gel method with tetraethoxysilane and aqueous-based Fe3O4 ferrofluids as precursors. The monoliths obtained were crack free and showed both optical and magnetic properties. The structural properties were determined by infrared spectroscopy, x-ray diffractometry and transmission electron microscopy. Fe3O4 particles of 20 nm size lie within the pores of the matrix without any strong Si-O-Fe bonding. The well established silica network provides effective confinement to these nanoparticles. The composites were transparent in the 600-800 nm regime and the field dependent magnetization curves suggest that the composite exhibits superparamagnetic characteristics.

Optimization of fermentation media for exopolysaccharide production from lactobacillus plantarum using artificial intelligence-based techniques - Desai, Kiran M.; Akolkar, S. K.; Badhe, Yogesh P.; Tambe, S. S.; Lele, S. S. (Process Biochemistry, 2006)
A Lactobacillus strain was isolated from the fermented Eleusine coracana. This strain was characterized as Lactobacillus plantarum and was found to produce an exopolysaccharide (EPS) in quantitative amounts. The objective of the present paper is to determine optimum media composition and inoculum volume for the stated fermentative production of the EPS. A hybrid methodology comprising the Plackett-Burman (PB) design method, artificial neural networks (ANN) and genetic algorithms (GA) was utilized. Specifically, the PB, ANN and GA forrnalisms were used for identifying influential media components, modeling non-linear process and optimizing the process, respectively. More specifically, the PB method was used to determine those media components, which significantly influence the EPS yield. By ignoring the less influential media components, the dimensionality of the input space of the process model could be reduced significantly. Out of the five media components only three were found influential namely, lactose, casein hydrolysate and triammonium citrate. Next, an ANN-based process model was developed for approximating the non-linear relationship between the fermentation operating variables and the EPS yield. The average % error and correlation coefficient for the developed ANN model were 4.8 and 0.999, respectively. The input parameters of ANN model were subsequently optimized using the GA formalism for obtaining maximum EPS yield in batch fermentation. The optimized media composition has predicted the yield of 7.01 g/l. The GA-optimized solution comprising media composition and inoculum volume was verified experimentally and it comes out be 7.14 g/l. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: Artificial neural network; exopolysaccharide; Fermentation; Genetic algorithm; Lactobacillus plantarum; Media optimization; Plackett-Burman

Photooxidation of vulcanized EPDM/montmorillonite nanocomposites - Morlat-Therias, Sandrine; Fanton, Elisabeth; Tomer, Namrata S.; Rana, Sravendra; Singh, R. P.; Gardette, Jean Luc (Polymer Degradation and Stability, 2006)
The photooxidation of a vulcanized ethylene-propylene-diene monomer (EPDM)/montmorillonite nanocomposite as well as EPDM/nanocomposite with stabilizers was studied under accelerated UV-light irradiation (lambda >= 300 nm, 60 degrees C) for different times. The development of functional groups during oxidation was monitored by infrared spectroscopy. Photodegradation of the neat polymer and composites took place and the increases of absorbance in hydroxyl and carbonyl groups with irradiation times and also the decreases of the EPDM unsaturations were measured. The data indicated that the photooxidation products were not changed in the presence of the nanofiller. However, the presence of MMt was observed to dramatically enhance the rate of photooxidation of EPDM with a shortening of the oxidation induction time, leading to a decrease of the durability of the nanocomposites. On the other hand, it was observed that addition of stabilizers, either Tinuvin P or 2-mercaptobenzimidazole, was efficient in inhibiting the degradative effect of MMt. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: EPDM; Nanocomposite; photooxidation rate; stabilization

Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to alpha,beta-unsaturated ketones at room temperature under solvent-free conditions - Pore, D. M.; Soudagar, M. S.; Desai, Uday V.; Thopate, T. S.; Wadagaonkar, P. P. (Tetrahedron Letters, 2006)
Potassium phosphate and silica sulfuric acid have been found to be useful and highly efficient catalysts for conjugate addition of thiols to alpha,beta-unsaturated ketones under solvent-free conditions, at room temperature. Silica sulfuric acid (SSA) was found to be suitable for electron-deficient enones while potassium phosphate was found to effect thia-Michael addition with both, electron-deficient as well as electron-rich conjugated ketones. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: alpha; beta-unsaturated ketones; chalcones; conjugated enones; Michael addition; Potassium phosphate; silica sulfuric acid; thiols

Preparation and characterization of a series of new organically modified montmorillonite clays using X-ray diffraction, thermogravimetric analysis and FTIR spectroscopy - Natarajan, Upendra; Tiwari, Rajkiran R. (231st National Meeting of the American-Chemical-Society, 2006)
231st National Meeting of the American-Chemical-Society, Atlanta, GA, MAR 26-30, 2006

Preparation and performance evaluation of EPDM nanocomposites under accelerated weathering - Rana, Sravendra; Tevtia, Amit K.; Kumar, Bijendra; Singh, R. P. (Journal of Thermoplastic Composite Materials, 2006)
The degradability of ethylene propylene diene monomer (EPDM) nanocomposites, prepared from organically modified montmorillonite (CMMT), is studied under accelerated UV irradiation (lambda >= 290 nm) for different time intervals. The development of functional groups during degradation is monitored by FT-IR spectroscopy whereas, surface changes are studied by scanning electron microscopy (SEM). The effect of clay modifier and clay concentration on the degradability are studied. The degradation of neat polymer and composites taking place traditionally and an increase in carbonyl and hydroxyl groups are observed with irradiation time. Neat EPDM is found to be less degradable than nanocomposites. Degradation products, as seen by FT-IR in nanocomposites are found to be the same as in neat polymer but are generated at a faster rate. According to the experimental results, one can define that both ammonium ion and neat montmorillonite (MMT) accelerate the photo-oxidation of EPDM.
Keywords: carbonyl index; Degradation; EPDM; layered silicates; Nanocomposites; photooxidation

Repetitive somatic embryogenesis and plant regeneration in Garcinia indica Choiss - Thengane, Shubhada Ratnakar; Deodhar, Swapna R.; Bhosle, S. V.; Rawal, S. K. (In Vitro Cellular & Developmental Biology-Plant, 2006)
Immature seeds of Garcinia indica Choiss. were excised from immature fruits and cultured on Lloyd and McCown (1980), woody plant medium (WPM) with different combinations of auxins and cytokinins. Somatic embryos were obtained on the media supplemented with 6-benzylaminopurine (BA; 2.2-22.1 mu M) alone or in combination with alpha-naphthalene acetic acid (NAA; 2.6 mu M) with 80% frequency within a period of 2-3 wk. Subculture of embryos on medium containing BA (16.0 mu M) supplemented with indole-3-acetic acid (IAA; 2.8-5.7 mu M) and/or kinetin (4.6 mu M) gave rise to clusters of secondary somatic embryos along with maturation of primary embryos. In subsequent subculture on hormone-free half-strength WPM, the embryo clusters germinated with an increase in the number of secondary somatic embryos. About 70% of somatic embryos germinated into complete plantlets, which were successfully established under greenhouse conditions.
Keywords: Garcinia indica; guttifereae; secondary somatic embryos; seeds; somatic embryos

Soft-sensor development for fed-batch bioreactors using support vector regression - Desai, Kiran M.; Badhe, Yogesh P.; Tambe, S. S.; Kulkarni, B. D. (Biochemical Engineering Journal, 2006)
In the present paper, a state-of-the-art machine learning based modeling formalism known as "support vector regression (SVR)", has been introduced for the soft-sensor applications in the fed-batch processes. The SVR method possesses a number of attractive properties such as a strong statistical basis, convergence to the unique global minimum and an improved generalization performance by the approximated function. Also, the structure and parameters of an SVR model can be interpreted in terms of the training data. The efficacy of the SVR formalism for the soft-sensor development task has been demonstrated by considering two simulated bio-processes namely, invertase and streptokinase. Additionally, the performance of the SVR based soft-sensors is rigorously compared with those developed using the multilayer perceptron and radial basis function neural networks. The results presented here clearly indicate that the SVR is an attractive alternative to artificial neural networks for the development of soft-sensors in bioprocesses.
Conference on Atomic Molecular and Optical Physics, Calcutta, INDIA, DEC 13-15, 2005
Keywords: deprotection; Microwave; stannous chloride; tert-butyldimethylsilyl ethers

Stabilization of gamma-sterilized biomedical polyolefins by synergistic mixtures of oligomeric stabilizers - Alariqi, Sameh A. S.; Kumar, A. Pratheep; Rao, B. S. M.; Tevtia, Amit K.; Singh, R. P. (Polymer Degradation and Stability, 2006)
The stabilization of polyolefins against gamma-sterilization has been studied with single or binary additive system. The present attempt is to utilize synergistic mixtures of stabilizers which are approved for food contact applications. Ethylene-propylene (EP) copolymer has been melt-mixed with hindered amine stabilizers (HAS), phenolic antioxidants and organo-phosphites (hydroperoxide decomposer). Samples were sterilized with different doses of gamma-radiation. Stabilization was characterized in terms of changes in the functional groups (oxidation products), tensile properties, yellowing and surface morphology by FTIR spectroscopy, Instron, colorimetry (reflectance) and scanning electron microscopy (SEM), respectively. Results were discussed by comparing the stabilizing efficiency of mixtures with and without phenol system. Among phenol containing systems, where we mostly observe discoloration due to the oxidation of hindered phenol and the combination of secondary HAS, tertiary HAS, organo-phosphite and hindered phenol exhibited improved stabilization efficiency than single or binary additive systems. The mixture of secondary HAS and tertiary HAS, has shown antagonistic effect of stabilization whereas their combination with organo-phosphite has exhibited synergistic effect of stabilization even at higher doses of gamma-sterilization. The effects have been explained through the interaction between the stabilizers. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: Antioxidants; discoloration; ethylene-propylene copolymer; gamma-sterilization; stabilization; tensile properties

Synthesis of 4-aminomethyl-tetrahydrofuran-2-carboxylates with 2,4-cis and 2,4-trans relationships - Edwards, Alison A.; Sanjayan, Gangadhar J.; Hachisu, Shuji; Soengas, Raquel; Stewart, Alistair; Tranter, George E.; Fleet, George W. J. (Tetrahedron, 2006)
Templated tetrahydrofuran-based gamma-azido esters were prepared with the C-2 and C-4 functionalities in cis and trans relative configurations. This was achieved by ring contraction of the suitably protected 2-O-triflates of pentono-1,5-lactones (D-ribose and L-arabinose) with subsequent introduction of the azide via the 4-O-triflate. Access to a corresponding beta-azido ester was achieved in good yield. Little elimination product was observed by introduction of the azide via the 3-O-triflate. These azido esters are scaffolds. which may be predisposed to adopt secondary structural motifs, for example. for use as peptidomimetics; they may also be utilised for the preparation of stereodiverse compound libraries. (c) 2006 Elsevier Ltd All rights reserved.
Keywords: gamma amino acids; Peptidomimetics; scaffolds; sugar amino acids

Analysis of a membrane reactor: influence of membrane characteristics and operating conditions - Tanna, Nikunj P.; Mayadevi, S. (International Journal of Chemical Reactor Engineering, 2007)
Modeling of an esterification reaction in a batch pervaporation membrane reactor (PVMR), and an analysis of the PVMR performance under different reaction conditions for different membrane characteristics are presented. Esterification of ethyl alcohol with acetic acid was considered as the model reaction. The PVMR performance for this reaction could be represented by a 2-step series model. The PVMR performance was similar to that of the batch reactor when both the reactors were in the kinetic regime. However, the performance of the PVMR was superior to that of the batch reactor when both were in the intermediate/equilibrium regime of the reaction. In these regions, the PVMR performance was influenced/limited by the membrane flux and selectivity. The analysis showed that the membrane flux affected the PVMR performance in the intermediate region and the membrane selectivity affected the performance in the equilibrium regime. Further, the limitations introduced by a low-flux membrane could be overcome by appropriate selection of the membrane area and that due to poor selectivity could be compensated to a certain extent by adjusting the feed ratio.
Keywords: comparison; Esterification; membrane reactor; performance; pervaporation membrane

Anhydrous magnesium sulfate mediated solvent-free synthesis of dihydropyrimidin-2(1H)-ones at ambient temperature - Pore, D. M.; Desai, Uday V.; Thopate, T. S.; Wadgaonkar, P. P. (Australian Journal of Chemistry, 2007)
An anhydrous magnesium sulfate mediated solvent-free protocol is described for the synthesis of dihydropyrimidinones (Biginelli compounds) at ambient temperature.

Asymmetric synthesis of (R)-(-)-baclofen via asymmetric dihydroxylation - Thakur, V. V.; Paraskar, A. S.; Sudalai, A. (Indian Journal of Chemistry Section B-Organic Chemistry including Medicinal Chemistry, 2007)
A short and efficient asymmetric synthesis of (R)-(-)-baclofen, a selective GABA(B) agonist has been described with an overall yield of 14% and 85% ee. The Os-catalyzed Sharpless asymmetric dihydroxylation of alpha,beta-unsaturated olefin constitutes the key step in introducing stereogenic centers into the molecule.
Keywords: asymmetric dihydroxylation; baclofen; cyclic sulfate; gamma-aminobutyric acid; Parkinsons' disease

Complex carbohydrate specificity of lectin from fruiting body of ganoderma lucidum. a surface plasmon resonance study - Thakur, Atul; Pal, Lakhan; Ahmad, Absar; Khan, Mohammad Islam (IUBMB Life, 2007)
The thermodynamics and kinetics of binding of glycans and glycoproteins to Ganoderma lucidum lectin was studied using surface plasmon resonance. The lectin showed highest affinity for asialo triantennary N glycan (Ka = 3.52 x 10(5)) among the glycans tested. There was a several fold increase in affinity for glycoproteins compared to their corresponding glycans and coincident increase in contribution from enthalpy (Delta H), suggesting the involvement of hydrogen bonding in the interaction as well as involvement of protein-protein interactions. Increased affinity also showed increase in unfavorable negative binding entropy (Delta S) which was compensated with higher enthalpy. The glycoproteins showed faster association rates (k(1)) and the activation energy (E-1(double dagger)) in the association process was much lower for the glycoproteins than glycans, resulting in their faster associations. These observations elaborate the role of protein matrix in lectin-glycoconjugate interaction.
Keywords: ganoderma lucidum; glycans; Lectin; SPR

Controlled aggregation of gold nanoparticle networks induced by alkali metal ions - Tamang, Sudarsan; Hotha, Srinivas; Bhagavatula L. V. Prasad (Journal of Nanoscience and Nanotechnology, 2007)
Gold nanoparticle networks were obtained by linking them with cysteine modified triethyleneglycols. The oligo-ether linker molecule initially having a linear structure probably adopts a crown ether type structure upon complexation with alkali metal ions that leads to a controlled aggregation of the network. The extent of aggregation depends on the degree of conformational change in the molecule upon complexation with the metal ion, which in turn is governed by the metal ion radius leading to a dependence of red shift of the surface plasmon resonance on the metal ion radius. Since this network is present in the organic solvent they also act as phase transferring agent for the alkali metal ions from aqueous to organic media.
Keywords: Aggregation; Alkali Metal Ions; Au Nanoparticles; Crown Ether; Surface Plasmon Resonance

Controlled synthesis of low-molecular-weight polyethylene waxes by titanium-biphenolate-ethylaluminum sesquichloride based catalyst systems - Umare, Prashant S.; Rao, Karumanchi; Tembe, Gopal L.; Dhoble, Deepa Arun; Trivedi, Bhavna (Journal of Applied Polymer Science, 2007)
Soluble complexes of titanium(IV) bearing sterically hindered biphenols, such as biphenol, 1,1'-methylene di-2-naphthol, 2,2'-methylene bis(4-chlorophenol), 2,2'-methylene bis(6-tert-butyl-4-ethyl phenol), and 2,2' ethylidene bis(4,6-di-tert-butyl phenol), were prepared and characterized. These catalyst precursors, formulated as [Ti((OO)-O-boolean AND)X-2], were active in the polymerization of ethylene at high temperatures in combination with ethylaluminum sesquichloride as a cocatalyst. The ultra-low-molecular-weight polyethylenes (PEs) were linear and crystalline and displayed narrow polydispersities. The catalytic polymerization leading to PE waxes in this reaction exhibited unique properties that have potential applications in surface coatings and adhesive formulations. (c) 2007 Wiley Periodicals, Inc.
Keywords: Catalysts; polyethylene (PE); synthesis; Ziegler-Natta polymerization

Cross-linking assessment after accelerated ageing of ethylene propylene diene monomer rubber - Tomer, N. S.; Delor-Jestin, Florence; Singh, R. P.; Lacoste, Jacques (Polymer Degradation and Stability, 2007)
The ageing of filled and cross-linked ethylene propylene diene elastomer (EPDM) has been studied under accelerated UV irradiation (lambda >= 290 nm) at 60 degrees C, thermal ageing at 100 degrees C and in nitric acid vapours for different time intervals. Hardness measurements were performed. DSC-thermoporosimetry was used to estimate the mesh size distribution and cross-linking densities for each ageing. The development of functional groups was monitored by ATR spectroscopy. An increase in oxidation with exposure time after the different types of ageing was observed. The thermal stability of EPDM was assessed by TGA and evolved volatile gases were identified using FTIR spectroscopy. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: ageing; EPDM; Oxidation; thermal analysis; thermoporosimetry

Deprotonation of 1,2-dialkylpyridinium ions: a DFT study of reactivity and site selectivity - Gupta, Neelima; Garg, Reena; Shah, Kirti Kr.; Tanwar, Akhilesh; Pal, Sourav (Journal of Physical Chemistry A, 2007)
A site-selectivity model, based on the Fukui function as a local reactivity descriptor, has been applied to 1.2-disubstituted pyridinium ions incorporating two competing sites of similar reactivity, i.e., 1-methylene and 2-methylene, which may undergo deprotonation depending on the nature of substituent present on these moieties. Applicability of the local HSAB rule, in context with the Li-Evans' generalized HSAB principle suggesting the hard-hard interactions to be controlled by minimum Fukui function, has been illustrated. Global and local reactivity descriptors have been computed by carrying out DFT calculations at B3LYP/6-31++G** level using Mulliken and NPA methods for charge analysis. A comparison with the calculated deprotonation energies involving two sites indicates that the observed site selectivity in differently substituted pyridinium ions is better explained by the Li-Evans rule of minimum Fukui function for hard-hard interactions.

Diverse forms of pin-II family proteinase inhibitors from capsicum annuum adversely affect the growth and development of helicoverpa armigera - Tamhane, Vaijayantl A.; Giri, Ashok P.; Sainani, Mohini N.; Gupta, Vidya S. (Gene, 2007)
Novel forms of Pin-II type proteinase inhibitor (PIs) cDNAs (CanPIs) having three or four inhibitory repeat domains (IRD) were isolated from the developing green fruits of Capsicum annuum. Deduced amino acid (aa) sequences of the CanPIs showed up to 15% sequence divergence among each other or reported inhibitors (CanPI-1 AF039398, CanPI-2 AF221097). Amino acid sequence analysis of these CanPIs revealed that three IRD Pls have trypsin inhibitory sites, while four IRD CanPIs have both trypsin and chymotrypsin inhibitory sites. Four CanPIs, two having three IRD (CanPI-3 AY986465 and CanPI-5 DQ005912) and two having four IRD (CanPI-7 DQ005913 and CanPI-9 DQ005915), were cloned in Pichia pastoris to express recombinant CanPIs. Recombinant CanPIs inhibited 90% of bovine trypsin (TI), while chymotrypsin inhibition (0) varied with the number of chymotrypsin inhibitory sites in the CanPIs. Recombinant inhibitors inhibited over 70% of the gut proteinase activity of Helicoverpa armigera. H. armigera larvae fed on recombinant CanPIs individually incorporated into artificial diet, showed 35% mortality; in addition, weight gain in H. armigera larvae and pupae was severely reduced compared to controls. Of the four CanPIs, CanPI-7, which has two sites for TI and CI, was the only one to have a consistently antagonistic effect on H. armigera growth and development. We conclude that among the four recombinant Pls tested, CanPIs containing diverse IRDs are best suited for developing insect-resistant transgenic plants. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: insect resistance; IP repeats; PI-insect interaction; Pichia pastoris; potato type 2 inhibitors (Pot-II); Solanaceae

Environmentally benign catalytic hydroformylation-oxidation route for naproxen synthesis - Rajurkar, Kalpendra B.; Tonde, Sunil S.; Didgikar, Mahesh R.; Joshi, Sunil S.; Chaudhari, Raghunath V. (Industrial & Engineering Chemistry Research, 2007)
Hydroformylation of 6-methoxy-2-vinylnaphthalene (MVN), using homogeneous Rh(CO)acac) as a catalyst and a chelating bidentate ligand (1,2-bis-(diphenylphosphino) ethane, dppe), followed by oxidation of the product (2-(6-methoxynaphthyl) propanal, 2-MNP) has been studied as an alternative route for the synthesis Of D,L-naproxen. The feasibility of the MVN hydroformylation route has been demonstrated, and a detailed study has been reported on the key hydroformylation step. The roles of the catalyst, ligands, and solvents, as well as the effect of reaction conditions on the reaction rate and regioselectivity of the product 2-MNP, have been investigated. With Rh(CO)2(acac) as a catalyst and dppe as a ligand, > 98% selectivity to 2-MNP (an important precursor to D,L-naproxen) has been achieved. A possible mechanism to explain the variation in regioselectivity with Rh(CO)(2)(acac) as a catalyst and dppe as a ligand has been discussed. The kinetics of the hydroformylation step has been investigated and a rate equation has been proposed. The second step in the proposed route for naproxen-the oxidation of 2-MNP to 2-(6-methoxynaphthyl) propanoic acid (2-MNPA, or naproxen) - has been studied using Na2WO4 as a catalyst and tetrabutyl ammonium hydrogen sulfate (TBAHS) as the phase-transfer catalyst with H2O2 as the oxidant for the first time. Screening of the catalysts that consisted of the early transition metals, such as salts of tungsten, vanadium, and molybdenum showed that Na2WO4 gives the best performance for the oxidation step with > 80% selectivity to 2-(6-methoxynaphthyl)propanoic acid (2-MNPA/naproxen). This study would be valuable in developing a new environmentally benign route for naproxen synthesis.
Joint 6th International Symposium on Catalysis in Multiphase Reactors/5th International Symposium on Multifunctional Reactors (CAMURE-6/ISMR-5-), Pune, INDIA, JAN 14-17, 2007

Estimation of gross calorific value of coals using artificial neural networks - Patel, Shagufta U.; Kumar, B. Jeevan; Badhe, Yogesh P.; Sharma, B. K.; Saha, Sujan; Biswas, Subhasish; Chaudhury, Asim; Tambe, Sanjeev S.; Kulkarni, Bhaskar D. (Fuel, 2007)
The gross calorific value (GCV) is an important property defining the energy content and thereby efficiency of fuels, such as coals. There exist a number of correlations for estimating the GCV of a coal sample based upon its proximate and/or ultimate analyses. These correlations are mainly linear in character although there are indications that the relationship between the GCV and a few constituents of the proximate and ultimate analyses could be nonlinear. Accordingly, in this paper a total of seven nonlinear models have been developed using the artificial neural networks (ANN) methodology for the estimation of GCV with a special focus on Indian coals. The comprehensive ANN model developed here uses all the major constituents of the proximate and ultimate analyses as inputs while the remaining six sub-models use different combinations of the constituents of the stated analyses. It has been found that the GCV prediction accuracy of all the models is excellent with the comprehensive model being the most accurate GCV predictor. Also, the performance of the ANN models has been found to be consistently better than that of their linear counterparts. Additionally, a sensitivity analysis of the comprehensive ANN model has been performed to identify the important model inputs, which significantly affect the GCV. The ANN-based modeling approach illustrated in this paper is sufficiently general and thus can be gainfully extended for estimating the GCV of a wide spectrum of solid, liquid and gaseous fuels. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: Artificial neural network; gross calorific value (GCV); proximate and ultimate analyses

Fabrication of an effusive molecular beam instrument for surface reaction kinetics - CO oxidation and NO reduction on Pd(111) surfaces - Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S. (Catalysis Letters, 2007)
A simple molecular beam instrument (MBI) was fabricated for measuring the fundamental parameters in catalysis such as, sticking coefficient, transient and steady state kinetics and reaction mechanism of gas/vapor phase reactions on metal surfaces. Important aspects of MBI fabrication are given in detail. Nitric oxide (NO) decomposition and NO reduction with carbon monoxide (CO) on Pd(111) surfaces were studied. Interesting results were observed for the above reactions and they support the efficiency of the MBI to derive the fundamental parameters of adsorption and catalysis. Sustenance of CO oxidation at 400 K is dependent mostly on the absence of CO-poisoning; apparently, CO + O recombination is the rate determining step <= 400 K. NO adsorption measurements on Pd(111) surface clearly indicating a typical precursor kinetics. Displacement of the chemisorbed CO by NO on Pd(111) surfaces was observed directly with NO + CO beams in the transient kinetics. It is also relatively easy to identify the rate-determining step directly from the MBI data and the same was demonstrated for the above reactions.
Keywords: carbon monoxide; catalysis; kinetics; molecular beam; nitric oxide; Pd(111)

First enantiospecific synthesis of (-)-heritol: absolute configuration determination - Chavan, Subhash P.; Thakkar, Mahesh; Kalkote, Uttam R. (Tetrahedron Letters, 2007)
The first enantiospecific synthesis of (-)-heritol, from naturally occurring (R)-(+)-citronellal and confirmation of its absolute configuration, is described. (c) 2006 Elsevier Ltd. All rights reserved.

Gas sorption and transport in polyarylates: effect of substituent symmetry and polarity - Karadkar, Prasad B.; Kharul, Ulhas K.; Bhole, Yogesh S.; Badhe, Yogesh P.; Tambe, Sanjeev S.; Kulkarni, Bhaskar D. (Journal of Membrane Science, 2007)
The gas sorption properties of polyarylates based on bisphenol-A possessing symmetric/asymmetric substitution by nonpolar -CH3 group and symmetrically linked terephthalic acid were examined. The effects of substitution of polar bromine on terephalic acid moiety of polyarylate based on asymmetrically substituted bisphenol were also studied for physical, sorption and transport properties. The estimation of dual mode sorption parameters, solubility and diffusion coefficient revealed that nature of the substituent and substitution type plays a crucial role in depicting permeation properties. An asymmetric substitution by -CH3 group increased solubility coefficient of pure gases (N-2, O-2, CH4 and CO2) up to 27% and symmetric substitution increased the same up to 106%. This was coupled with 7-35% increase in solubility selectivity in both cases of substitution, which ascertained the usefulness of methyl group substitution in polyarylates based on terephalic acid. The pressure dependency of solubility coefficients and solubility selectivity was also investigated for these polyarylates. The sorption and transport properties of these polyarylates correlated well with physical properties of polyarylates and gases studied. The sorption/desorption kinetics of symmetrically substituted TMBisA-T was performed in order to deduce time dependent sorption behavior and to evaluate diffusivity coefficient. The apparent diffusion coefficients from sorption kinetics, desorption kinetics and from steady-states permeation-sorption were compared. The diffusion coefficients of CH4 and N-2 deduced by these methods correlated well with each other. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: Diffusion; kinetics; permeation; polyarylates; Sorption

Geometrical solution to the sharkskin instability - Pol, Harshawardhan V.; Joshi, Yogesh M.; Tapadia, Prashant S.; Lele, Ashish K.; Mashelkar, Raghunath Anant (Industrial & Engineering Chemistry Research, 2007)
We study the effect of die exit divergence on the sharkskin behavior, both experimentally as well as through the use of computational fluid dynamics (CFD) simulations. Sharkskin or surface fracture is known to occur immediately after the die exit, because of the large elongational deformation that a polymer melt experiences as it exits the die. We show that the diverging taper at the die exit postpones or completely removes the occurrence of sharkskin. The corresponding CFD simulations of an equivalent K-BKZ fluid show that the taper at the die exit significantly reduces the severity of the elongational flow, thereby reducing the normal stresses as the polymer melt leaves the die. We believe that, in an extrusion operation, the provision of a diverging taper at the die exit is one of the potential measures by which sharkskin instability can be eliminated on an industrial scale.

Improve polyethylene process control and product quality - using artificial intelligence-based sensors can improve costs - Badhe, Yogesh P.; Lonari, J.; Tambe, S. S.; Kulkarni, B. D.; Valecha, N. K.; Deshmukh, S. V.; Ravichandran, S. (Hydrocarbon Processing, 2007)

Influence of organic modification on mechanical properties of melt processed intercalated poly(methyl methacrylate)-organoclay nanocomposites - Tiwari, Rajkiran R.; Natarajan, Upendra (Journal of Applied Polymer Science, 2007)
The influence of organic modifiers on intercalation extent, structure, thermal and mechanical properties of poly(methyl methacrylate) (PMMA)-clay nanocomposites were studied. Two different organic modifiers with varying hydrophobicity (single tallow versus ditallow) were investigated. The nanocomposites were prepared from melt processing method and characterized using wide angle X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and tensile tests. Mechanical properties such as tensile modulus (E), break stress (sigma(brk)), and 0% break strain (epsilon(brk)) were determined for nanocomposites at various clay loadings. Extent of PMMA intercalation is sufficient and in the range 9-15 angstrom depending on organoclay and filler loading. Overall thermal stability of nanocomposites increases by 16-30 degrees C. The enhancement in T-g of nanocomposite is merely by 2-4 degrees C. With increase in clay loading, tensile modulus increases linearly while % break strain decreases. Break stress is found to increase till 4 wt % and further decreases at higher clay loadings. The overall improvement in thermal and mechanical properties was higher for the organoclay containing organic modifier with lower hydrophobicity and single tallow amine chemical structure. (c) 2007 Wiley Periodicals, Inc.
Keywords: mechanical properties; Nanocomposites; organoclay; structure; Thermal properties

Metal complexes of crosslinked chitosans. part II. an investigation of their hydrolysis to chitooligosaccharides using chitosanase - Trimukhe, K. D.; Bachate, S.; Gokhale, D. V.; Varma, Anjanikumar (International Journal of Biological Macromolecules, 2007)
This paper investigates the behavior of crosslinked chitosans and metal-complexed crosslinked chitosans under similar hydrolytic conditions. Crosslinked chitosans with trimellitic anhydride, diisocyanatohexane, and dibromodecane as crosslinking agents under heterogenous reaction conditions were used as metal complexing agents by equilibrating them with metal salts such as ZnCl2, MnSO4, CuSO4, CdSO4, Pb(NO3)(2), and HgCl2. Crosslinked chitosan without metal complexation had the same hydrolytic behavior as uncrosslinked chitosan. However, when the crosslinked chitosans were complexed with metals, their rates of hydrolysis and extent of hydrolysis were significantly reduced. Thus, while for chitosan about 840 mu g/ml reducing sugar was produced in 4 h time, and 780 mu g/ml was produced for diisocyanatohexane crosslinked chitosan, only 400 mu g/ml and 320 [mu g/ml reducing sugars were produced for cadmium sulfate with crosslinked chitosan and diisocyanatohexane crosslinked chitosan, respectively. Similar results are obtained for other crosslinking agents. Studies on preincubation of the metal with the enzyme show that of the metals studied, Mn has no effect on preincubatioin with the enzyme, Hg, Cd, Pb, and Cu completely deactivates the enzyme, while Zn reduces the enzyme activity by about 43.3%. Preincubation of the metal salts with the chitosan shows that Hg and Cu completely deactivate the molecule from enzyme hydrolysis, Cd and Zn inactivate it to the extent of 56.8% and 43.3%, respectively, while Mn has no effect. Availability of the amino functions seems to be a key feature for the chitosanase to hydrolyze the chitosan polymer. This was also proved by the significant increase in the extent of hydrolysis for chitosan samples with 88% (final value 1120 mu g/ml reducing sugar) and 85% deacetylation (final value 840 mu g/ml reducing sugar). HPIC studies of the products show that a variety of oligomers are produced in the chitosanase enzyme hydrolytic reaction. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: chitooligosaccharides; Chitosan; chitosanase hydrolysis; Crosslinked chitosan; metal-complexed crosslinked chitosan

Organo-catalytic approach to the enantioselective synthesis of (R)-selegiline - Talluri, Siva Kumar; Sudalai, Arumugam (Tetrahedron, 2007)
An efficient enantioselective synthesis of (R)-selegiline has been achieved by two routes, via proline-catalyzed alpha-aminooxylation as well as alpha-amination of phenylpropanaldehyde as the key step. (c) 2007 Elsevier Ltd. All rights reserved.

Polyethylene waxes: catalytic synthesis by ti-biphenolates - Umare, Prashant S.; Rao, Karumanchi; Tembe, Gopal L.; Dhoble, Deepa Arun; Trivedi, Bhavna (Journal of Macromolecular Science Part A‐Pure and Applied Chemistry, 2007)
{Soluble complexes of Ti (IV) bearing biphenol groups such as 1,1'-binaphthelene 2, 2' diol (Binol), 1, 1'-methylene di-2-naphthol, biphenol were prepared and characterized. These catalyst precursors formulated as [
Keywords: fibers; Nanoparticles; Self-assembly

Practical synthesis of (+/-)-venlafaxine - Chavan, Subhash P.; Khobragade, Dushant A.; Thakkar, Mahesh; Kalkote, Uttam R. (Synthetic Communications, 2007)
A practical total synthesis of antidepressant (+/-)-venlafaxine is disclosed.
Keywords: antidepressant; Grignard reaction; Michael addition

Removal of AS(III) and AS (V) from contaminated water sources by sorption onto novel pei-attached poly(hipe) beads", paper presented at international conference on ?role of analytical chemistry in nuclear technology? - Ingavle, Ganesh C.; Tayal, Rajeev; Shaikh, Wasif Abdul Lateef; Chaudhari, Sanjeev; Chavan, Nayaku; Rajan, Chelanattukizhakkemadath Raman; Ponrathnam, Surendra (Role of Analytical Chemistry in Nuclear Technology, 2007)

Simulation of viscoelastic flows of polymer solutions in abrupt contractions using an arbitrary lagrangian eulerian (ALE) based finite element method - Ganvir, Vivek; Lele, Ashish K.; Thaokar, Rochish; Gautham, Basavarsu P. (Journal of Non-Newtonian Fluid Mechanics, 2007)
We present a method for simulation of viscoelastic flows using an Arbitrary Lagrangian Eulerian (ALE) technique based finite element formulation. The ALE technique provides advantages of both Lagrangian and Eulerian frameworks by allowing the computational mesh to move in an arbitrary manner, independent of the material motion. In the present method, a fractional step ALE technique is employed in which the Lagrangian phase of material motion and convection arising out of mesh motion are decoupled. In the first step the relevant flow and constitutive equations are solved in Lagrangian framework. The simpler representation of polymer constitutive equations in a Lagrangian framework avoids the difficulties associated with convective terms thereby resulting in a robust numerical formulation. In the second step the mesh is moved in ALE mode and the associated convection of the stress is performed using a Godunov type scheme. This ALE technique is easy to implement and can accurately simulate the complex viscoelastic behaviour of transient polymer flow through complex geometries. In the present study, steady flows through abrupt contractions of planar and axisymmetric geometries are studied by performing transient flow simulations until steady state is achieved. The proposed method is validated with previously published numerical and experimental studies for polymer solutions obeying the Oldroyd B and Phan Thien Tanner (PTT) models. The simulated corner and lip vortex enhancement mechanism and flow behavior are in good agreement with experimentally obtained flow visualization photographs. The strength of the proposed method lies in its ability to simulate free surface flows such as swell. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: abrupt contraction; Arbitrary Lagrangian Eulerian; finite element; simulations

Spinning wave motion in frontal polymerization - Inamdar, Satish R.; Pujari, N. S.; Karimi, I. A.; Ponrathnam, S.; Tayal, R. K.; Kulkarni, B. D. (Chemical Engineering Science, 2007)
We present a mathematical model describing dynamics of spinning waves which propagate during frontal polymerization reaction taking place in a cylindrical reactor tube. The self-organization of spatio-temporal solution of wave equations due to interplay between thermal diffusion and kinetics gives rise to pattern formation. We begin with a fundamental equation of motion of radial coordinate after defining an asymptotic phase for spinmode. The motion is analyzed near a critical (Hopf) point and a perturbation solution is used to obtain patterns for a case of preparation of poly(2-hydroxyethyl methacrylate) (PHEMA) via frontal polymerization reaction. The model uses the distance as seen in photograph taken using scanning electron microscope (SEM) from which motion begins around core of spiral and calculates pitch of spiral which matches closely with experimental observation in micrograph. Also the model predicts qualitatively the ramp wave and spiral wave motion as observed under SEM. Both these results are reported in open literature for the first time to our best knowledge. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: frontal polymerization; spinning wave; spiral motion; wave dynamics

Stereoselective hydrogenation of tert-butylphenols over charcoal-supported rhodium catalyst in supercritical carbon dioxide solvent - Hiyoshi, Norihito; Rode, Chandrashekhar V.; Sato, Osamu; Tetsuka, Hiroyuki; Shirai, Masayuki (Journal of Catalysis, 2007)
Hydrogenation of 2-, 3-, and 4-tert-butylphenols was studied over a charcoal- supported rhodium catalyst in supercritical carbon dioxide (scCO(2)) solvent, and the results were compared with those in organic solvents. In the hydrogenation of 4-tert-butylphenol, a higher cis ratio for 4-tert-butylcyclohexanol (0.79) was obtained in scCO(2) (10 MPa) than in 2-propanol (0.70) and cyclohexane (0.64) under similar conditions of hydrogen pressure (2 MPa) and temperature (313 K). In the case of 2-tert-butylphenol, the cis ratio for 2-tert-butylcyclohexanol was as high as 0.95 in both scCO(2) and 2-propanol (hydrogen pressure, 2 MPa; reaction temperature, 313 K). In the case of hydrogenation of 3-tert-butylphenol, the cis ratio decreased with the progression of consecutive hydrogenation of 3-tert-butylcyclohexanone intermediate. In addition, the stereoselectivity to cis-tert-butylcyclohexanols in scCO(2) was improved in the presence of hydrochloric acid. It was found that the protons of hydrochloric acid accelerated the hydrogenation of the intermediates, tert-butylcyclohexanones, to the corresponding cis-tert-butylcyclohexanols. The hydrogenation mechanism of tert-butylphenols, particularly the enhanced selectivity to cis-tert-butylcyclohexanols in scCO(2), is postulated based on the observed reaction profiles. (c) 2007 Elsevier Inc. All rights reserved.
Keywords: charcoal-supported rhodium catalyst; stereoselective hydrogenation; supercritical carbon dioxide solvent; tert-butylcyclohexanol

Stereoselective synthesis of 3-alkylidene/alkylazetidin-2-ones from azetidin-2,3-diones - Tiwari, Dharmendra Kumar; Shaikh, Ashif Y.; Pavase, Laxmikant S.; Gumaste, Vikas K.; Deshmukh, Abdul Rakeeb A. S. (Tetrahedron, 2007)
Azetidin-2,3-diones have been used as synthons for the synthesis of C-3 alkylidene/alkylazetidin-2-ones. Some of the 3-alkylazetidin-2-ones are well known for their cholesterol absorption inhibitor activity. A regio and stereoselective Grignard reaction on a keto group followed by dehydration using PPh3/CCl4 reagent is a key step in this synthesis. Hydrogenation of the 3-alkylideneazetidin-2-ones provided stereoselectively cis-3-alkylazetidin-2-ones in very good yields. (c) 2006 Published by Elsevier Ltd.
Keywords: 3-diones; azetidin-2; azetidin-2-ones; beta-lactam; Grignard reaction

Structural evolutions of hydrothermally prepared mesostructured MCM-48 silica using differently manufactured amorphous silica powders - Taralkar, U. S.; Jha, Ratnesh Kumar; Joshi, P. N. (Journal of Non-Crystalline Solids, 2007)
The hydrothermal synthesis of Si-MCM-48 mesoporous molecular sieves was carried out using a ternary SiO2:CTAOH:H2O System wherein differently manufactured amorphous silica powders such as fumed silica (FMDS), spray dried precipitated silica (SDPS) and flash dried precipitated silica (FDPS) were used as silica source materials. The changes in structural/textural properties were evaluated using powder XRD, N-2 adsorption-desorption and scanning electron microscopy techniques. Studies on the progressive development of MCM-48 mesophases revealed that, the reactivity of the silica source follow the trend: FMDS > SDPS > FDPS. MCM-48 synthesized using low cost FDPS has exhibited thicker pore walls but poorer orderness, while MCM-48 prepared from relatively expensive FMDS has thinner pore walls and more ordered structure. Moreover, the extent of contraction caused by calcinations, agglomerate size and structural stability were found to depend on the reactivity of the silica source used. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: long-range order; micelles; scanning electron microscopy; silica; silicates; sol-gels (xerogels); X-ray diffraction

Synthesis and characterization of hindered amine light stabilizers based on end functionalization of polypropylene - Reddy, K. Raghunatha; Kumar, Bijendra; Rana, Sravendra; Tevtia, Amit K.; Singh, R. P. (Journal of Applied Polymer Science, 2007)
A polymeric hindered amine light stabilizer (HALS), where HALS moiety was attached at the terminal end of the polypropylene chain via end-functionalized vinylidine PP through simple organic reactions, was synthesized. It comprises the synthesis of vinylidine-terminated polypropylene by using Cp2ZrCl2/MAO as catalyst system and epoxidation of vinylidene polypropylene. The final product was synthesized by carrying out the reaction between epoxy end functionalized polypropylene and 4-amino-2,2,6,6-tetrametyl piperidine. The final product was characterized by using H-1 NMR, C-13 NMR, and FT-IR spectra. Functionality was calculated by using vapor phase osmometry and H-1 NMR. The solubility and diffusion coefficient of the product were calculated and also its stabilization performance was checked. (c) 2007 Wiley Periodicals, Inc.
Keywords: end functionalization; functionalization of polymers; polymeric HALS; polypropylene; vinylidine and photostabilization

Synthesis and evaluation of antifungal properties of a series of the novel 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and its analogues - Gholap, Atul R.; Toti, Kiran S.; Shirazi, Fazal; Kumari, Ratna; Bhat, Manoj Kumar; Deshpande, Mukund V.; Srinivasan, Kumar V. (Bioorganic & Medicinal Chemistry, 2007)
A series of 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and various analogues have been synthesized in excellent isolated yields starting from various arylidenemalononitrile and 3-amino-2-cyclohexen-1-one in 1-propanol as solvent at reflux temperature in the absence of any added catalyst. All the synthesized compounds were evaluated for their antifungal activity. The relationship between functional group variation and biological activity of the evaluated compounds is discussed in the article. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: Antifungal activity; antiproliferative activity; arylidenemalononitriles; arylquinoline carbonitrile; Michael addition

Unusual trisulphide linkage in bromine-thiourea reaction: crystal structure of formamidinium trisulphide complex with bromine - Tol, Abhaya D.; Natu, Arun D.; Puranik, Vedavati G. (Molecular Crystals and Liquid Crystals, 2007)
{A new complex of formamidinium trisulphide with bromine has been synthesized. Single-crystal X-ray analysis of this compound revealed a novel trisulphide linkage in the formamidinium trisulphide moiety. The crystals belong to orthorhombic space group Fdd2 with a = 14.9119(15)
Keywords: bromine; crystal structure; formamidinium trisulphide; thiourea

Complexation of heavy metals by crosslinked chitin and its deacetylated derivatives - Trimukhe, K. D.; Varma, Anjanikumar (Carbohydrate Polymers, 2008)
Chitin was crosslinked using diisocyanatohexane (HDI), trimellitic anhydride (TMA), and dibromodecane (DBD), then deacetylated in strong aqueous alkali. This led to a product with amine functional groups on the exposed surface of the crosslinked chitin, which could be utilized for complexation with heavy metals. Thus, a key feature of the crosslinked derivatives prepared was that only the hydroxy Groups were utilized in the crosslinking reaction, and the acetylamino groups of chitin were hydrolyzed only after the crosslinking was accomplished. This ensured that all amino groups of the chitosans so produced would be available for metal complexation, and not partially used up in crosslinking. This proposed advantage was proved by the similar binding observed for heavy metals like Hg (348-372 mg/g), Cu (91-119 mg/g), Zn (71-92 mg/g), Mn (3-10 mg/g), Cd (121-160 mg/g), and Pb (32-86 mg/g) using these crosslinked polymers, whereas the control polymer (uncrosslinked chitosan powder) had complexation values for Hg (348-361 mg/g), Cu (100-106 mg/g), Zn (81-92 mg/g), Mn (4-7 mg/g), Cd (135 mg/g), and Pb (25-59 mg/g). Additionally, in a case where chitosan was crosslinked with HDI. the amino groups were consumed in the crosslinking reaction, and the metal complexation capacity has found to be decreased for Cu (91-109 mg/g), Cd (133 mg/g), and Zn (71-77 mg/g), while remaining nearly the same for Hg (362 mg/g). The literature value for Cu complexation is 59.67 mg/g for chitosan crosslinked with glutaraldehyde. The crosslinked derivatives have the added advantage of insolubility even in low pH aqueous media, making their repeated re-use possible. Further, these crosslinked derivatives could be used in powder form, and the additional step of preparing beads was found to be not necessary for ease of separation of the crosslinked powder by filtration. The binding capacity of various crosslinked chitin and deacetylated derivatives for Cu, Cd, Hg, Zn, Mn. and Pb was in the region of 100, 140, 360 88, 5, and 60 mg/g (rounded off values) of polymer, respectively, very close to the values obtained for uncrosslinked chitosan. The metal binding for crosslinked chitosan was slightly lower than that of crosslinked chitin and deacetylated derivatives, due to use of some amino groups in crosslinking. For Cu ions, the Langmuir equation was found to be the best fit for HDI crosslinked deacetylated chitin and TMA crosslinked deacetylated chitin. The morphological studies conducted using WAXRD are in close agreement with the metal complexation data, showing complete loss of original chitosan peaks for the heavily complexed derivatives, and minor changes for the weakly complexed metals. (c) 2007 Elsevier Ltd. All rights reserved.
Keywords: Chitosan; Crosslinked chitosan; deacetylated chitin; metal complexation; Morphology

Conformational preferences of hypermodified nucleoside lysidine (k(2)C) occurring at wobble position in anticodon loop of tRNA(IIe) - Sonawane, Kailas D.; Tewari, Ravindra (Nucleosides Nucleotides & Nucleic Acids, 2008)
Conformational preferences of hypermodified nucleoside, 4-amino-2-(N(6)-lysino)-1-(beta-D-ribofuranosyl) pyrimidinium (Lysidine or 2-lysyl cytidine), usually designated as k(2)C, have been investigated theoretically by the quantum chemical perturbative configuration interaction with localized orbitals (PCILO) method. The zwitterionic, non-zwitterionic, neutral, and tautomeric forms have been studied. Automated geometry optimization using molecular mechanics force field (MMFF), semi-empirical quantum chemical PM3, and ab initio molecular orbital Hartree-Fock SCF quantum mechanical calculations have also been made to compare the salient features. The predicted most stable conformations of zwitterionic, non-zwitterionic, neutral, and tautomeric form are such that in each of these molecules the orientation of lysidine moiety (R) is trans to the N(1) of cytidine. The preferred base orientation is anti (chi = 3 degrees) and the lysine substituent folds back toward the ribose ring. This results in hydrogen bonding between the carboxyl oxygen O(12a) of lysine moiety and the 2'-hydroxyl group of ribose sugar. In all these four forms of lysidine O(12a)...H-C(9) and O(12b)...H-N(11) interactions provide stability to respective stable conformers. Watson-Crick base pairing of lysidine with A is feasible only with the tautomeric form of usual anti oriented lysidine. This can help in recognition of AUA codon besides in avoiding misrecognition of AUG.
Keywords: hypermodified; k(2)C; lysidine; stable conformers

De novo shoot regeneration from root cultures of garcinia indica choiss - Deodhar, Swapna R.; Thengane, R. J.; Thengane, Shubhada Ratnakar (Indian Journal of Experimental Biology, 2008)
Roots of plantlets of Garcinia indica when cultured for long time on half strength MS medium supplemented with BAP (0.44-2.22 mu M) showed production of de novo shoots. Roots attached to mother plant showed more number of shoots, while excised root segments produced lesser shoots. Shoots (0.5-0.8 cm) were transferred to elongation medium consisting of Woody Plant Medium (WPM) supplemented with BAP (4.44-22.69 mu M), IAA (5.71 mu M and kinetin (4.65 mu M). It was observed that shoot length increased to 1-2 cm. WPM medium supplemented with NAA (2.69-10.74 mu M) and IBA (4.90 mu M) induced rooting within 20-25 days. Using the present protocol, 20-25 plantlets could be regenerated from single root explant within 3 to 4 months. The protocol has potential for large scale production of elite plants.
Keywords: Garcinia indica; guttifereae; organogenesis; roots; shoots

Distributed chemical computing using chemstar: an open source java remote method invocation architecture applied to large scale molecular data from pubchem - Karthikeyan, Muthukumarasamy; Krishnan, S.; Pandey, Anil Kumar; Bender, Andreas; Tropsha, Alexander (Journal of Chemical Information and Modeling, 2008)
present the application of a Java remote method invocation (RMI) based open source architecture to distributed chemical computing. This architecture was previously employed for distributed data harvesting of chemical information from the Internet via the Google application programming interface (API; ChemXtreme). Due to its open source character and its flexibility, the underlying server/client framework can be quickly adopted to virtually every computational task that can be parallelized. Here, we present the server/client communication framework as well as an application to distributed computing of chemical properties on a large scale (currently the size of PubChem; about 18 million compounds), using both the Marvin toolkit as well as the open source JOELib package. As an application, for this set of compounds, the agreement of log P and TPSA between the packages was compared. Outliers were found to be mostly non-druglike compounds and differences could usually be explained by differences in the underlying algorithms. ChemStar is the first open source distributed chemical computing environment built on Java RMI, which is also easily adaptable to user demands due to its ``plug-in architecture''. The complete source codes as well as calculated properties along with links to PubChem resources are available on the Internet via a graphical user interface at http://moltable.nel.res.in/chemstar/.

Durability of crosslinked polydimethylsyloxanes: the case of composite insulators - Delor-Jestin, Florence; Tomer, Namrata S.; Singh, Raj Pal; Lacoste, Jacques (Science and Technology of Advanced Materials, 2008)
Most applications of silicones are linked to their hydrophobic properties and (or) their high resistance to ageing (e. g. thermal ageing and photoageing). However, when placed in extreme environments, these materials can fail as in the case of epoxy/fiber glass composite powerlines insulators, where crosslinked polymethylsyloxanes (PDMSs) are used as the protective envelope (housing) of the insulator. We report on the behavior of both pure/noncrosslinked PDMSs and typical formulations used in industrial insulators, i.e. containing peroxide crosslinked PDMS, alumina trioxide hydrated (ATH) and silica. Special attention is paid on both (i) the sources of potential degradation and (ii) the best analytical methods that can be applied to the study of very complex formulations. (i) Aside from conventional types of ageing such as photo-ageing and thermal, hydrolytic, and service life ageings, treatments with acidic vapors, plasma and ozone possibly generating species from the reaction of a high electric field with air were also performed, which allowed to accelerate electrical and out-door ageings and to obtain differently aged materials. (ii) Aside from conventional analytical methods of polymer degradation such as FTIR/ATR spectroscopy and SEC, TG, hardness measurements, more specific methods like photo/DSC, TG/IR, thermoporosimetry, resistivity and density measurements were also performed to characterize the chemical and physical evolutions of polymer materials. In particular, it was found that treatment with nitric acid vapor has detrimental effects on the properties of both fire retardants (e. g. ATH) and PDMSs, affecting the hardness and resistivity of the formulated material.
International Conference on Magneto-Science, Hiroshima, JAPAN, NOV, 2007
Keywords: composite insulators; durability; PDMS; post-crosslinking; silicone

Effect of organic modifiers and silicate type on filler dispersion, thermal, and mechanical properties of ABS-Clay nanocomposites - Tiwari, Rajkiran R.; Natarajan, Upendra (Journal of Applied Polymer Science, 2008)
Acrylonitrile-butadiene-styrene (ABS)-clay composite and intercalated nanocomposites were prepared by melt processing, using Na-montmorillonite (MMT), several chemically different organically modified MMT (OMMT) and Na-laponite clays. The polymer-clay hybrids were characterized by WAXD, TEM, DSC, TGA, tensile, and impact tests. Intercalated nanocomposites are formed with organoclays, a composite is obtained with unmodified MMT, and the nanocomposite based on synthetic laponite is almost exfoliated. An unintercalated nanocomposite is formed by one of the organically modified clays, with similar overall stack dispersion as compared to the intercalated nanocomposites. T, of ABS is unaffected by incorporation of the silicate filler in its matrix upto 4 wt % loading for different aspect ratios and organic modifications. A significant improvement in the onset of thermal decomposition (40-44 degrees C at 4 wt % organoclay) is seen. The Young's modulus shows improvement, the elongation-at-break shows reduction, and the tensile strength shows improvement. Notched and unnotched impact strength of the intercalated MMT nanocomposites is lower as compared to that of ABS matrix. However, laponite and overexchanged organomontmorillonite clay lead to improvement in ductility. For the MMT clays, the Young's modulus (E) correlates with the intercalation change in organoclay interlayer separation (Delta d(001)) as influenced by the chemistry of the modifier. Although ABS-laponite composites are exfoliated, the intercalated OMMT-based nanocomposites show greater improvement in modulus. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110:2374-2383, 2008
Keywords: clay; filler; mechanical; structure characterization; styrene-butadiene

Efficient synthesis of antifungal pyrimidines via palladium catalyzed Suzuki/Sonogashira cross-coupling reaction from Biginelli 3,4-dihydropyrimidin-2(1H)-ones - Gholap, Atul R.; Toti, Kiran S.; Shirazi, Fazal; Deshpande, Mukund V.; Srinivasan, Kumar V. (Tetrahedron, 2008)
An efficient regioselective approach to the synthesis of tetrasubstituted pyrimidines was developed by sequential functionalization of easily available Biginelli 3,4-dihydropyrimidine-2(1H)-ones via dehydrogenation, chlorination followed by palladium catalyzed C-C Suzuki/Sonogashira coupling reaction. All the synthesized compounds were evaluated in vitro for their antifungal activities against Candida albicans, Cryptococcus neoformans, Benjaminiella poitrasii, Yarrowia lipolytica, and Fusarium oxysporum, and antibacterial activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: Antifungal activities; Biginelli compounds; chlorination; Oxidation; Pyrimidines; Suzuki coupling

Environment friendly crosslinked chitosan as a matrix for selective adsorption and purification of lipase of aspergillus niger - Trimukhe, K. D.; Mahadik, N. D.; Gokhale, D. V.; Varma, Anjanikumar (International Journal of Biological Macromolecules, 2008)
Chitosan and its derivatives have been used as affinity matrices for purification of lipase from Aspergillus niger NCIM 1207. Trimellitic anhydride (TMA)-crosslinked deacetylated chitin adsorbed lipase selectively, yielding approximately 5-fold purification of the crude lipase with 70% yield. Further 9-fold purification occurred on eluting through Sephacryl-100. These results suggest that chitosan derivatives can be used as inexpensive biopolymer matrices for the purification of lipases for industrial applications. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Adsorption; Chitosan; Lipase; Matrix; Purification

Hydrogenation activity and selectivity behavior of supported palladium nanoparticles - Nadgeri, J. M.; Telkar, M. M.; Rode, C. V. (Catalysis Communications, 2008)
Enhancement in activity and selectivity of catalytic hydrogenation using supported nanosize palladium catalyst has been investigated. Pd/C catalyst prepared in the presence of polyvinyl pyrrolidone (PVP) as a stabilizer gave Pd particle size in a narrow range of 3-5 nm. While, evaluating for hydrogenation of 2-butyne-1,4-diol, the rate enhancement was found to be 10 times higher as compared to the conventional (bulk) Pd catalysts. A proper choice of stabilizer (PVP) giving small particle size as well as highly dispersed nature of nano particles were the major factors for such a dramatic enhancement of activity. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: butynediol; Catalytic hydrogenation; nanosize palladium; Selective hydrogenation; SEM-EDX analysis; size distribution; supported Pd nanoparticles

Influence of synthesis conditions on structural properties of MCM-48 - Taralkar, U. S.; Kasture, M. W.; Joshi, P. N. (Journal of Physics and Chemistry of Solids, 2008)
The influence of synthesis variables such as time, cetyltrimethyl ammonium hydroxide (CTAOH) concentration, water content, pH, temperature and silica source on the structural properties of Si-MCM-48 is investigated. Time-dependent studies on the progressive development of MCM-48 have indicated that synthesis time is a crucial parameter, which influences the unit cell parameter. The formation of different mesophases was observed when the concentration of CTAOH and pH of the initial gel were varied. The Si-29 MASNMR results showed that the (Q(2) +W-3)/Q(4) ratio decreases with the increase in synthesis temperature. On account of increase in W units at high-temperature synthesis run, Si-MCM-48 with highly polymerized silica walls with lower surface area was obtained when compared with Si-MCM-48 prepared at lower temperature. Such effect was not significant when Si-MCM-48 was synthesized at the same temperature but using silica sol as a source in place of fumed silica. (c) 2008 Elsevier Ltd. All rights reserved.

Intramolecular Diels-Alder reaction in ionic liquids: effect of ion-specific solvent friction - Tiwari, Shraeddha; Khupse, Nageshwar D.; Kumar, Anil (Journal of Organic Chemistry, 2008)
The present work aims at understanding the role of viscosity or solvent friction in ionic liquids for an intramolecular Diels-Alder (IMDA) reaction of (E)-1-phenyl-4-[2-(3-methyl-2-butenyloxy)benzylidene]-5-pyrazolone (1). The results have been analyzed on the basis of the current theoretical models, and their failure to account for the observed trends is discussed in terms of ``effective'' viscosity or microviscosity. The rates of the reaction decrease with the increasing viscosity of the ionic liquids. As evident from the anionic effect, the solute-solvent specific interactions play a role in governing the kinetics of the reaction. The lower viscosities of the bistrifluoromethanesulfonimide [NTf(2)](-) based ionic liquids as compared to those based on tetrafluoroborate [BF(4)](-) anion fail to result in a corresponding acceleration in the rates of the reaction. These contradictory results indicate that solvent microviscosity, rather than the bulk macroscopic viscosity, should be the criteria for selecting the ionic liquids as reaction media.

Local electronic structure and magnetic properties of LaMn(0.5)Co(0.5)O(3) studied by x-ray absorption and magnetic circular dichroism spectroscopy - Burnus, T.; Hu, Z.; Hsieh, H. H.; Joly, V. L. Joseph; Joy, Pattayil Alias; Haverkort, M. W.; Wu, Hua; Tanaka, A.; Lin, H. -J.; Chen, C. T.; Tjeng, L. H. (Physical Review B, 2008)
We have studied the local electronic structure of LaMn(0.5)Co(0.5)O(3) using soft-x-ray absorption spectroscopy at the Co-L(3,2) and Mn-L(3,2) edges. We found a high-spin Co(2+)-Mn(4+) valence state for samples with the optimal Curie temperature. We discovered that samples with lower Curie temperatures contain low-spin nonmagnetic Co(3+) ions. Using soft-x-ray magnetic circular dichroism, we established that the Co(2+) and Mn(4+) ions are ferromagnetically aligned. We also revealed that the Co(2+) ions have a large orbital moment: morb/mspin approximate to 0.47. Together with model calculations, this suggests the presence of a large magnetocrystalline anisotropy in the material and predicts a nontrivial temperature dependence for the magnetic susceptibility.

Molecular genetic mapping of quantitative trait loci associated with loaf volume in hexaploid wheat (Triticum aestivum) - Elangovan, M.; Rai, R.; Dholakia, Bhushan B.; Lagu, Meena D.; Tiwari, R.; Gupta, R. K.; Rao, V. S.; Roeder, M. S.; Gupta, V. S. (Journal of Cereal Science, 2008)
Major efforts in wheat research are being made to improve the yield and quality of wheat. Loaf volume (Lv) is the main quality parameter deciding the bread making potential of wheat. To genetically dissect quantitative trait loci (QTLs) for Lv, a Recombinant Inbred Line (RIL) population (F-8) was developed from a cross between two Indian wheat varieties ``H 1977'' and ``HD 2329''. A total of 914 SSR and 100 ISSR primers were used for molecular analysis and the genetic map comprising 19 chromosomes was constructed with 202 SSR markers and 2 HMW glutenin subunit loci: Glu-B1 and Glu-B1. The phenotypic data were collected from six environments including three different agro-climatic zones for 2 consecutive years. Dissection of Lv through AMMI model revealed significant G x E variance for the trait. QTL analysis was performed using composite interval mapping. A total of 30 QTLs for Lv were detected and significant QTLs were identified on 6B and 6D chromosomes; 1B, 1D, 2A, 3A, 513 and 5D also contributed genetically to Lv. Association between 6B and 6D QTLs and variable expression of gliadins on group 6 chromosomes were discussed. QTLs detected in this study were compared with other QTL analysis in wheat. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: breadmaking; loaf volume; QTL; SSR; wheat quality

Morphological study of heavy metal complexes of chitosan and crosslinked chitosans by SEM and WAXRD - Trimukhe, K. D.; Varma, Anjanikumar (Carbohydrate Polymers, 2008)
Metal complexes of salts of Hg, Cu, Cd, Pb, Zn, and Mn with chitosan and crosslinked chitosans were prepared, and their morphologies were studied using scanning electron microscopy and wide angle X-ray diffraction. The metal ions which were specifically and strongly complexed to the amino functions of chitosans, like Hg, showed smooth surface morphology inspite of large number of ions complexed (372 mg/g of chitosan). The presence of metal ions on the surface of the chitosans could be detected with decrease in metal ion binding, in the following sequence Hg > Cu > Cd > Zn > Pb > Mn. Particularly in the case of Pb ions, the presence of these ions is clearly seen on the surface of the polymer by SEM. The number of ions of Mn complexed on the polymers was too few (5 mg/g of chitosan) to be visible. SEM of Hg and Cu complexes do not show the ``holes'' observed in the crosslinked polymers as they bind specifically to amino groups of chitosan, but for Cd, Zn, Mn, and Pb complexes, these ``holes'' are clearly visible. These results are also in agreement with the morphologies studied by WAXRD. The metal complexation data for each of these metal ions was also in the same sequence. (c) 2007 Elsevier Ltd. All rights reserved.
Keywords: Chitosan; Crosslinked chitosan; metal complex; Morphology; SEM; WAXRD

Multiple weak supramolecular interactions stabilize a surprisingly twisted As2L3 assembly - Pitt, Melanie A.; Zakharov, Lev N.; Vanka, Kumar; Thompson, Ward H.; Laird, Brian B.; Johnson, Darren W. (Chemical Communications, 2008)
A combined crystallographic, DFT and NMR spectroscopic study of a flexible As(2)(3) assembly reveals temperature dependent conformational behavior in solution and a highly asymmetric structure stabilized by As-pi and edge-to-face aromatic interactions.

Multipoint anchoring of the [2.2.2.2]metacyclophane motif to a gold surface via self-assembly: coordination chemistry of a cyclic tetraisocyanide revisited - Toriyama, Masaharu; Maher, Tiffany R.; Holovics, Thomas C.; Vanka, Kumar; Day, Victor W.; Berrie, Cindy L.; Thompson, Ward H.; Barybin, Mikhail V. (Inorganic Chemistry, 2008)
A one-pot transformation of bis(2-isocyano-3-methylphenyl)ethane affords gram quantities of 8,16,24,32-tetraisocyano[2.2.2.2]metacyclophane ( 3). The solid state structure of 3 is remarkably close to the lowest energy conformation found on the potential energy landscape for 3 by DFT. In solution, the structure of metacyclophane 3 is mobile but can be locked in a rectangular gauche- anti- gauche- anti conformation by coordination of the isocyanide substituents to the [W(CO) 5] units to give [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) ( 5). The tetranuclear [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) motif featured in crystallographically characterized 5 may be present in several insoluble complexes of 3 previously described as mononuclear eta (4) species. A self-assembled monolayer of metacyclophane 3 is formed upon exposing a solution of 3 to the gold(111) surface with no precautions to exclude air or light. The monolayer nature of the film was confirmed by optical ellipsometry. The isocyanide stretching band for 3 shifts from 2119 cm (-1) in solution to 2175 cm (-1) upon chemisorption to metallic gold. The FTIR spectrum of the film indicates interaction of 3 with the gold surface via all four of its isocyanide anchors. No gold-facilitated oxidation of the -NC junctions was detected under ambient conditions. The energy cost associated with accessing the conformations of 3 suitable for mu 4-eta (1):eta (1):eta (1):eta (1) interaction of the molecule with the Au(111) surface is under 8 kcal/mol, a value that can be easily offset by formation of a gold-isocyanide bond. Two different mu 4-eta (1):eta (1):eta (1):eta (1) coordination arrangements of 3 with respect to gold atoms on the (111) face of the fcc Au lattice are suggested.

N-doped TiO2 nanoparticle based visible light photocatalyst by modified peroxide sol-gel method - Jagadale, Tushar C.; Takale, Shrikant P.; Sonawane, Ravindra S.; Joshi, Hrushikesh M.; Patil, Shankar I.; Kale, Bharat B.; Ogale, Satishchandra B. (Journal of Physical Chemistry C, 2008)
The peroxide gel route is employed to synthesize N-doped TiO2 nanoparticles (NP) at low temperature using titanium tetraisopropoxide, ethylmethylamine, and hydrogen peroxide as precursors. Structural studies show anatase phase in the undoped titania NPs as well as at 5 at. % N-doped titania NPs, although with a degree of matrix disorder in the latter case. The annealing of N-doped titania NPs at different temperatures shows that above 400 degrees C nitrogen escapes the O-Ti-O matrix and at 500 degrees C the sample becomes crystalline. Transmission electron microscopy reveals that the particle size is in the range of 20-30 nm for the undoped TiO2 but only 5-10 nm for N-doped TiO2. At higher nitrogen concentration (10 at. %) bubble-like agglomerates form. FTIR and photoluminescence quenching also confirm the incorporation of nitrogen in anatase TiO2. Optical properties reveal an extended tailing of the absorption edge toward the visible region upon nitrogen doping. X-ray photoelectron spectroscopy is used to examine the electronic state of doped nitrogen and the associated possible electronic modification of the TiO2 matrix. Under visible light irradiation the undoped TiO2 NPs do not show any significant photocatalytic activity, as expected; however, the 5 at. % N-doped TiO2 NPs show excellent activity.

New poly(phenylene oxide)/polystyrene blend nanocomposites with clay: intercalation, thermal and mechanical properties - Tiwari, Rajkiran R.; Khilar, Kartic C.; Natarajan, Upendra (Journal of Applied Polymer Science, 2008)
We present the first study and results on the preparation and characterization of montmorillonite clay filter based polymer blend nanocomposites of the miscible poly(phenylene oxide)/polystyrene blend. Intercalated nanocomposites, prepared by a melt-processing method with 2-6 wt % commercially available organically modified sodium montmorillonite, have been characterized with wide-angle X-ray diffraction, transmission electron microscopy analysis, thermal analysis (thermogravimetric analysis and differential scanning calorimetry), and mechanical tensile tests. We show that nanocomposites can be successfully prepared in a batch mixer at temperatures much below the conditions conventionally used for this blend without organic degradation. Thermal stability is enhanced by nanoscale hybrid formation. The level of intercalation (change in the d-spacing) does not change with the clay loading. Better dispersion of clay in the blend matrix has been observed at a low level of clay content. The nanocomposites show improved tensile modulus (by 31%) in comparison to the blend, whereas the tensile strength (stress at break) and elongation decrease in the presence of the filler with an increase in the clay loading. The Halpin-Tsai model is able to predict the modulus of the nanocomposites in very good agreement with the experimental data. (c) 2008 Wiley Periodicals, Inc.
Keywords: mechanical properties; Nanocomposites; organoclay; poly(phenylene oxide); Polystyrene; Thermal properties

New route for preparation of luminescent mercaptoethanoate capped cadmium selenide quantum dots - Wankhede, Manoj E.; Inamdar, Shaukatali N.; Deshpande, Aparna; Thete, Aniket R.; Pasricha, Renu; Kulkarni, Sulabha K.; Harani, Santosh K. (Bulletin of Materials Science, 2008)
We report a synthesis of cadmium selenide quantum dots (Q-CdSe) by refluxing a mixture of cadmium acetate, selenium powder, sodium sulfite and 2-mercaptoethanol in N,N'-dimethyl formamide (DMF)/water solution. X-ray and electron diffractions suggest the formation of hexagonal phase of size quantized CdSe. Based on TEM analysis, the formation of nanoparticles with an average diameter of 3.5 +/- 0.5 nm is inferred. Their sols in DMF and dimethyl sulphoxide (DMSO) gave characteristic absorption peaks at 300 nm and 327 nm, which is attributed to the formation of high quality, size quantized CdSe particles. Extracted particles from the sol were readily redispersed in DMF and DMSO, which were diluted further with water without losing their optical and colloidal properties. FTIR spectroscopy suggested the formation of 2-mercaptoethanol thiolate on the particle surface, with free -OH groups available for linkage. Sols in DMSO and their solutions in water displayed an intense photoluminescence (PL).
National Review and Coordination Meeting on Nanoscience and Nanotechnology, Hyderabad, INDIA, 2007
Keywords: chalcogenides; Chemical synthesis; photoluminescence; semiconductor quantum dots

Reaction kinetics of liquid phase air oxidation of p-cresol to p-hydroxybenzaldehyde - Kshirsagar, V. S.; Nadgeri, J. M.; Tayade, P. R.; Rode, C. V. (Applied Catalysis A-General, 2008)
The kinetics of liquid phase oxidation of p-cresol to p-hydroxybenzaldehyde has been investigated using insoluble cobalt oxide (CO3O4) catalyst at oxygen partial pressures in the range 0.1-1.5 MPa, reaction temperatures 333-393 K, p-cresol concentrations 0.49-1.53 kmol/m(3) and catalyst loadings 0.38-3.03 kg/m(3). The effects of oxygen partial pressure, reaction temperature, p-cresol concentration and catalyst loading on the initial rate of reaction have been studied. The initial rate varied linearly with catalyst loading up to 1.5 kg/m(3) beyond which it was independent of the catalyst loading while first-order dependence was observed with variation in oxygen partial pressure. A rate expression has been proposed considering Langmuir-Hinshelwood (LH) type mechanism, based on the initial rate data. A batch reactor model was also developed based on the kinetics studied and the concentration time profile predicted by the model was in good agreement with the experimental data. The activation energy for the liquid phase oxidation of p-cresol was found to be 39.6 kJ/mol. (c) 2008 Elsevier B.V. All rights reserved.
Keywords: Co3O4; kinetics; p-cresol oxidation; XPS; XRD

Role of solvent molecules as a trigger for the crystal phase transition of syndiotactic polystyrene/solvent complex - Gowd, E. Bhoje; Tashiro, Kohji; Ramesh, C. (Macromolecules, 2008)
The phase transitions occurring in the syndiotactic polystyrene-norbornadiene complex were investigated by simultaneous measurements of wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). To understand the effect of norbornadiene molecules on the phase-transition behavior, the delta form samples with different contents of norbornadiene were prepared. By heating these samples, we found that the delta-to-gamma transition occurred well below 100 degrees C in a broad temperature range, and the onset of the transition temperature depended on the content of norbornadiene included in the starting sample. The sample without norbornadiene molecules showed the delta-to-gamma transition to be above 100 degrees C. Upon further heating, the gamma form transformed into a mixture of alpha and beta forms in the presence of norbornadiene molecules, whereas the sample without norbornadiene transformed into only the alpha form. In this way, it has been found that the solvent molecules, which are not completely evaporated from the sample but are transiently trapped in the amorphous region because of the slow diffusion, have a significant role in facilitating the phase transitions as well as the transition temperatures in the crystalline region. On the basis of WAXD and DSC results, a phase-transition model has been reasonably constructed.

Study of a laboratory-scale froth flotation process using artificial neural networks - Kalyani, V. K.; Pallavika; Chaudhuri, Sanjay; Charan, T. Gouri; Haldar, D. D.; Kamal, K. P.; Badhe, Yogesh P.; Tambe, S. S.; Kulkarni, B. D. (Mineral Processing and Extractive Metallurgy Review, 2008)
A three-layer feed-forward artificial neural network (ANN) model, trained using the error back propagation algorithm, has been established to simulate the froth flotation process for the beneficiation of coal fines. The network model validates the experimentally observed qualitative and quantitative trends. The optimal model parameters in terms of network weights have been estimated and can be used to compute the parameters of the coal flotation process over wide-ranging experimental conditions.
Keywords: back propagation algorithm; froth flotation; laboratory-scale; neural network

Synthesis and characterization of novel organo-montmorillonites - Tiwari, Rajkiran R.; Khilar, Kartic C.; Natarajan, Upendra (Applied Clay Science, 2008)
Sodium Montmorillonite (NaMMT) has been modified via cation exchange reaction using three different organic cations. Basal spacings, interlamellar structure and thermal stability of these organo-montmorillonites (OMMT) clays have been characterized using wide angle X-ray diffraction (WARD) and thermogravimetric analysis (TGA) techniques. Increase in the basal spacing due to organic modification is in good agreement with simple theoretical calculations based on van der Waals volume of the cationic ammonium ions. TGA characterization and analysis show that the amount of organic modifier in the OMMT's is in good agreement with theoretically calculated stoichiometric content expected for almost complete exchange of Na+ ions by organic cations. The OMMT's shows stepwise decomposition corresponding to initial weight loss from residual water desorption, followed by decomposition of the organic surfactant and the dehydroxylation of structural water of the montmorillonite layers. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: Montmorillonite; organo-clays; organo-montmorillonite; surfactant

Synthesis of chimeric tetrapeptide-linked cholic acid derivatives: impending synergistic agents - Bavikar, Sudhir N.; Salunke, Deepak B.; Hazra, Braja G.; Pore, Vandana S.; Dodd, Robert H.; Thierry, Josiane; Shirazi, Fazal; Deshpande, Mukund V.; Kadreppa, Sreenath; Chattopadhyay, Samit (Bioorganic & Medicinal Chemistry Letters, 2008)
Tetrapeptides derived from glycine and beta-alanine were hooked at the C-3 beta position of the modified cholic acid to realize novel linear tetrapeptide-linked cholic acid derivatives. All the synthesized compounds were tested against a wide variety of microorganisms (Gram-negative bacteria, Gram-positive bacteria and fungi) and their cytotoxicity was evaluated against human embryonic kidney (HEK293) and human mammary adenocarcinoma (MCF-7) cell lines. While relatively inactive by themselves, these compounds interact synergistically with antibiotics such as fluconazole and erythromycin to inhibit growth of fungi and bacteria, respectively, at 1-24 mu g/mL. The synergistic effect shown by our novel compounds is due to their inherent amphiphilicity. The fractional inhibitory concentrations reported are comparable to those reported for Polymyxin B derivatives. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: Antimicrobial activity; Cholic acid; Cytotoxicity; Synergism; Tetrapeptide

Tetranuclear manganese (III) salicylaldoxime ensemble - Kumbhar, Avinash S.; Mulay, Mahesh P.; Padhye, Subhash B.; Tavale, Sudam S.; Puranik, Vedavati G. (Structural Chemistry, 2008)
Crystal structure of {[Mn(salicylaldoximeH)(salicylaldoxime)](4)} center dot 3CHCl(3) 1 formed by the interaction of MnCl2 center dot 4H(2)O and salicylaldoxime in a 1:1 ratio is described. The compound crystallizes in the orthorhombic space group Pbca (No 61) with the lattice parameters; a = 27.769 (3), b = 22.672 (2), c = 21.650 (2) angstrom, V = 13630 (2) angstrom(3), Z = 8, R-1 = 0.0776, wR(2) = 0.2356, S = 1.164. The cluster with four Mn (III) centers formed by four terminal and four bridging salicylaldoxime ligands results in a central rotating wheel-like core with the Mn-Mn separation varying from 3.531 to 3.576 angstrom and with the diagonal distances being 4.156-4.165 angstrom. Four intramolecular H-bonds between a terminal oxime (NOH) group and the adjacent phenolate oxygen atom of another ligand stabilize the structure of the cluster. Spectral, magnetic, and cyclic voltammetry studies corroborate a stable Mn (III) tetramer.

Thermal and mechanical properties of melt processed intercalated poly(methyl methacrylate)-organoclay nanocomposites over a wide range of filler loading - Tiwari, Rajkiran R.; Natarajan, Upendra (Polymer International, 2008)
BACKGROUND: Poly(methyl methacrylate) (PMMA)-organoclay nanocomposites with octadecylammonium, ion-modified montmorillonite, prepared via melt processing, over a wide range of filler loading (2-16 wt%) were investigated in detail. These hybrids were characterized for their dispersion structure, and thermal and mechanical properties, such as tensile modulus (E). break stress (sigma(brk)), percent break strain (epsilon(brk)) and ductility(J), using wide-angle X-ray diffraction, transmission electron microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile and impact tests. RESULTS: Intercalated nanocomposites were formed even in the presence of 16 wt% clay (high loading) in PMMA matrix. PMMA intercalated into the galleries of the organically modified clay, with a change in d-spacing in the range 11-16 angstrom. TGA results showed improved thermal stability of the nanocomposites. The glass transition temperature (T-g) of the nanocomposites, from DSC measurements, was 2-3 degrees C higher than that of PMMA. The ultimate tensile strength and impact strength decreased with increasing clay fraction. Tensile modulus for the nanocomposites increased by a significant amount (113%) at the highest level of clay fraction (16 wt%) studied. CONCLUSION: We show for the first time the formation of intercalated PMMA nanocomposites with alkylammonium-modified clays at high clay loadings (> 15wt%). Tensile modulus increases linearly with clay fraction, and the enhancement in modulus is significant. A linear correlation between tensile strength and strainat-break is shown. Thermal properties are not affected appreciably. Organoclay can be dispersed well even at high clay fractions to form nanocomposites with superior bulk properties of practical interest. (c) 2007 Society of Chemical Industry.
Keywords: impact strength; mechanical properties; Nanocomposites; PMMA; Thermal properties

Total synthesis of (+)-isolaurepan - Tripathi, Divya; Kumar, Pradeep (Tetrahedron Letters, 2008)
A versatile and efficient method for the enantioselective synthesis of 2,7-cis-disubstituted oxepane 1c, (+)-isolaurepan, using oxidative resolution of a secondary alcohol and highly diastereoselective Et(3)SiH/TMSOTf-promoted reductive cyclization of a hydroxy ketone is described. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Cis-selective cyclization; Cyclic ethers; Isolaurepan; Oxepanes; Oxidative resolution of secondary alcohols

Unusual temperature dependence of salt effects for ``on water'' wittig reaction: hydrophobicity at the interface - Tiwari, Shraeddha; Kumar, Anil (Chemical Communications, 2008)
An unusual variation with temperature of the salt effects in aqueous Wittig reaction is observed, suggesting that hydrophobic acceleration of reactions comprising ``on water'' reactants is fundamentally different from that for reactions with small non-polar solutes.

Use of enantiomerically pure 7-azabicyclo[2.2.1]heptan-2-ol as a chiral template for the synthesis of aminocyclitols - Pandey, Ganesh; Tiwari, Keshri Nath; Puranik, Vedavati G. (Organic Letters, 2008)
Using enantiopure 7-azabicyclo[2.2.1]heptane-2-ol, the synthesis of cis- as well as trans-2-aminocyclohexanols, dihydroconduramine E-1, and ent-conduramine F-1 has been described.

Zinc oxide nanoparticles as novel alpha-amylase inhibitors - Dhobale, Sandip; Thite, Trupti; Laware, S. L.; Rode, C. V.; Koppikar, Soumya J.; Ghanekar, Ruchika-Kaul; Kale, Sangeeta N. (Journal of Applied Physics, 2008)
Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size similar to 18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 mu g/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 mu g/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 degrees C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3009317]

Arthrobacter sp lipase immobilization for preparation of enantiopure masked beta-amino alcohols - Chaubey, Asha; Parshad, Rajinder; Gupta, Pankaj; Taneja, Subhash C.; Qazi, Ghulam N.; Rajan, C. R.; Ponrathnam, S. (Bioorganic & Medicinal Chemistry, 2009)
Recent reports on immobilization of lipase from Arthrobacter sp. (ABL, MTCC 5125; IIIM isolate) on insoluble polymers have shown altered properties including stability and enantioselectivity. Present work demonstrates a facile method for the preparation of enantiopure beta-amino alcohols by modulation of ABL enzyme properties via immobilization on insoluble as well as soluble supports using entrapment/covalent binding techniques. Efficacies of immobilized ABL on insoluble supports prepared from tetraethylorthosilicate/aminopropyltriethoxy silane and soluble supports derived from copolymerization of N-vinyl pyrrolidone-allylglycidyl ether (ANP type)/N-vinyl pyrrolidone-glycidyl methacrylate ( GNP type) for kinetic resolution of masked beta-amino alcohols have been studied vis-a-vis free ABL enzyme/wet cell biomass. The immobilized lipase on different insoluble/soluble supports has shown 21 - 110 mg/g protein binding and 30 - 700 U/g activity for hydrolyzing tributyrin substrate. The findings have shown a significant enhancement in enantioselectivity (ee 99%) vis-a-vis wet cell biomass providing ee 70-90% for resolution of beta-amino alcohols. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: Arthrobacter sp lipase; beta-Aminoalcohol; Enantioselectivity; Immobilization; soluble polymer

Azoic dye hosted in layered double hydroxide: physicochemical characterization of the intercalated materials - Mandal, Sujata; Tichit, Didier; Lerner, Dan A.; Marcotte, Nathalie (Langmuir, 2009)
Intercalation compounds were obtained by introduction of guest methyl orange (MO) into the interlayer space of host Mg/Al and Ni/Al layered double hydroxides (LDHs). Three synthesis methods of organic anion-LDH intercalation compounds, i.e., coprecipitation, reconstruction of the M(II)(Al)O mixed oxides, and anion exchange of LDH were compared. The former Method gives rise to a highly organized MO-intercalated Mg/Al LDH with an interlayer spacing of 2.43 rim and up to seven (001) reflection orders. Reconstruction or the mixed oxide by intercalation with MO in the restored LDH was only achieved with Mg(Al)O. In this case. a competitive adsorption of MO on the external Surface Of the crystals was also seen. On the other hand, intercalation compounds exhibiting interlayer spacing of 2.43 run were obtained with both Mg- and Ni-containing LDH using the anionic exchange method. The equilibrium and kinetic adsorption properties of the compounds were analyzed by UV-visible spectroscopy in anionic exchange experiments. According to the pseudo-second-order adsorption model, the amounts of adsorbed MO reach 3.82 and 2.83 mequiv/g for Mg- and Ni-containing LDHs, respectively, which are close to their respective anionic exchange capacity. The adsorption rates are on the same order of magnitude for the two LDHs (0.10-0.44 g mmol(-1) min(-1)), the equilibrium being reached in less than 60 min. The decomposition of MO by combustion of the organic moieties under an oxidizing atmosphere is delayed in Mg-containing MO-LDH hybrids when compared to the free MO molecule, showing that the thermal stability of MO species is enhanced after intercalation. In Ni-containing LDH, the main decomposition step of MO occurs 300 degrees C below that of Mg-containing LDH. This was rationalized in terms of a catalysis by the Ni-containing oxides formed during the thermal treatment. So these materials exhibit several advantage useful for the development of eco-friendly processes for the removal Of dyes from effluents of textile, plastic, and paper industries.

Catalytic aerobic oxidation of cyclohexane and ethyl benzene over chromium-containing mesoporous organosilicas - Singh, A. P.; Torita, N.; Shylesh, S.; Iwasa, N.; Arai, M. (Catalysis Letters, 2009)
Chromium-containing ethane-bridged hybrid periodic mesoporous organosilicas (Cr-PMO) were synthesized using 1,2-bis(triethoxysilyl) ethane (BTEE) and tetraethyl orthosilicate (TEOS) as silica sources and alkyltrimethyl ammonium salts as surfactants by two different synthesis routes. PXRD and N(2) adsorption-desorption analysis shows that the original structure of the materials is maintained after chromium substitution while spectroscopic study proves the incorporation of chromium in the frame wall positions and show the existence of Cr(2)O(3) species in the mixed silica source (BTEE-TEOS) synthesized chromium samples. The catalytic activity of the newly developed chromium samples was evaluated in the liquid phase oxidation of cyclohexane and ethylbenzene using air as an oxidant. Further, the Cr-PMO samples exhibited better cyclohexane conversion and cyclohexanone selectivity than the conventional Cr-MCM-41 and other metal-containing MCM-41 samples. The exceptional activity of the new chromium-containing molecular sieves is attributed to the hydrophobicity of the materials and to the complementary structural features that facilitates the accessibility of substrate to the active framework chromium sites.
Keywords: Cr-MCM-41; Cyclohexane; Ethyl benzene; Organosilicas; Oxidation

Cellulases from penicillium janthinellum mutants: solid-state production and their stability in ionic liquids - Adsul, Mukund G.; Terwadkar, Asawari P.; Varma, Anjanikumar; Gokhale, Digambar V. (Bioresources, 2009)
The cellulase production by P. janthinellum mutants on lignocellulosic material such as cellulose or steam exploded bagasse (SEB) in combination with wheat bran was studied in solid state fermentation (SSF). One of the mutants, EU2D21, produced the highest levels of endoglucanase (3710 IU g(-1) carbon source) and beta-glucosidase (155 IU g(-1) carbon source). Ionic liquids are so-called green solvents that have become attractive for biocatalysis. Stability of mutant cellulases was tested in 10-50% of the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl). FPA and CMCase were significantly stable in 10% ionic liquid after 5h. beta-glucosidase showed 85% of its original activity after 5 h incubation in 30% ionic liquid and retained 55% of its activity after 24 h. This enzyme preparation hydrolyzed ionic-liquid-treated SEB completely in 15 h in the presence of 20% ionic liquid. These studies revealed that there is no need of regenerating cellulose after ionic liquid treatment, since cellulase of mutant strain was found to be significantly stable in the ionic liquid.
Keywords: Cellulase stability; Ionic liquid; Mutant cellulase; Solid state fermentation

Composites of plasma treated poly(etherimide) films with gold nanoparticles and lysine through layer by layer assembly: a ``friendly-rough'' surface for cell adhesion and proliferation for tissue engineering applications - D'Britto, Virginia; Tiwari, S.; Purohit, V.; Wadgaonkar, P. P.; Bhoraskar, S. V.; Bhonde, Ramesh R.; Bhagavatula L. V. Prasad (Journal of Materials Chemistry, 2009)
A composite film fabricated by plasma treated poly(etherimide) with subsequent deposition of gold nanoparticles and lysine using layer by layer assembly has been demonstrated to be good for cell attachment and proliferation making it an attractive strategy for tissue engineering applications. As compared to the other methods the decrease in contact angle obtained here does not depend much on the plasma treatment thus affecting the polymer structure minimally. A combination of surface roughness provided by the gold nanoparticles and the presence of amine groups of lysine is hypothesized to be the reason for the features observed.

Electronic decoupling of surface layers from bulk and its influence in oxidation catalysis: a molecular beam study - Thirunavukkarasu, Kandasamy; Nagarajan, Sankaranarayanan; Gopinath, Chinnakonda S. (Applied Surface Science, 2009)
Interactions between oxygen and Pd-surfaces have important implications, especially towards oxidation reactions, and influence of subsurface oxygen to oxidation reactions is the focus of the present study. In our efforts to understand the above aspects, CO oxidation reactions have been carried out with mixed molecular beam (MB), consisting CO and O(2), on Pd(1 1 1) surfaces under a wide variety of conditions (T = 400-900 K, CO: O(2) = 7: 1 to 1: 10). A new aspect of the above reaction observed in the transient kinetics regime is the evidence for oxygen diffusion into Pd subsurface layers, and its significant influence towards CO oxidation at high temperatures (>= 600 K). Interesting information derived from the above studies is the necessity to fill up the subsurface layers with oxygen atoms to a threshold coverage (theta(O-sub)), above which the reactive CO adsorption occurs on the surface and simultaneous CO(2) production begins. There is also a significant time delay (G) observed between the onset of oxygen adsorption and CO adsorption (and CO(2) production). Above studies suggest an electronic decoupling of oxygen covered surface and subsurface layers, which is slightly oxidized, from the metallic bulk, which induces CO adsorption at high temperatures and simultaneous oxidation to CO(2). (C) 2009 Elsevier B.V. All rights reserved.
2nd International Conference on Physics at Surfaces and Interfaces (PSI2009), Puri, INDIA, FEB 23-27, 2009
Keywords: Electronic decoupling; heterogeneous catalysis; molecular beam; Oxidation; Pd(111); Subsurface diffusion

Electronic structure and catalytic study of solid solution of GaN in ZnO - Mapa, Maitri; Thushara, K. S.; Saha, Biswajit; Chakraborty, Purushottam; Janet, C. M.; Viswanath, R. P.; Nair, C. Madhavan; Murty, K. V. G. K.; Gopinath, Chinnakonda S. (Chemistry of Materials, 2009)
Solid solutions of GaN in ZnO (Zn1-zGaz)(O1-xNx) (x and z <= 0.15) have been prepared by simple solution combustion method, Except for minor changes in the lattice contraction, no significant change in the Wurtzite structure was observed. Raman and secondary ion mass spectrometry results show the direct Zn-N and Ga-N bonds in (Zn1-zGaz)(O1-xNx). Visible light absorption and XPS results demonstrate that N 2p states of nitride occupy the states above the O 2p valence band, and hence a change in optical band gap reduction occurs to similar to 2.5 eV from 3.37 eV for ZnO. Significant nitrogen fixation catalytic activity through NH3 formation has been observed at ambient pressure oil virgin (Zn1-zGaz)(O1-xNx) material, indicating its potential as a catalyst.

Enantioselective total synthesis of (2S,3R,4R)-D-xylo-phytosphingosine from substituted azetidin-2-one - Pandey, Ganesh; Tiwari, Dharmendra Kumar (Tetrahedron Letters, 2009)
Enantiomerically pure (2S,3R,4R)-D-xylo phytosphingosine is synthesized in 36% overall yield in seven steps from known beta-lactam (8) derived from D-mannitol triacetonide. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: beta-lactam; Enantioselective synthesis; Sphingosine; Wittig reaction

General approach to medium-sized ring ethers via hydrolytic and oxidative kinetic resolutions: stereoselective syntheses of (-)-cis-lauthisan and (+)-isolaurepan - Tripathi, Divya; Pandey, Satyendra Kumar; Kumar, Pradeep (Tetrahedron, 2009)
A short and enantioselective approach to medium ring ethers and its application to the syntheses of (-)-cis-lauthisan and (+)-isolaurepan are described. The synthetic strategy features Jacobson's Hydrolytic Kinetic Resolution (HKR), oxidative resolution of secondary alcohol, and highly diastereoselective Et(3)SiH/TMSOTf-promoted reductive cyclization of a hydroxy ketone to give exclusively the different medium-sized cis-disubstituted cyclic ethers. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: cis-Reductive cyclization; Jacobson's Hydrolytic Kinetic Resolution (HKR); Oxepanes; Oxidative resolution of secondary alcohol; Ring ether

Influence of hormones and medium components on expression of dipyranocoumarins in cell suspension cultures of calophyllum inophyllum L. - Pawar, Kiran D.; Thengane, Shubhada Ratnakar (Process Biochemistry, 2009)
Cell suspension cultures were initiated separately from leaf and nodal/internodal calluses for the study of influence of hormones and medium components on biomass growth and expression of dipyranocoumarins. Highest 6.2 times biomass was enhanced in suspension cultures of nodal/internodal callus supplemented with threefold total sulphate. Picloram 8.28 mu M along with BAP 8.88 mu M enhanced 295.05 times inophyllum A in suspension cultures of leaf callus whereas IBA 14.70 mu M along with BAP 4.44 mu M in suspension cultures of leaf callus enhanced 1065 times inophyllum B. IBA 4.90 mu M alone in suspension cultures of nodal/internodal callus enhanced maximum 616 times inophyllum C. Only IBA 9.80 mu M in suspension cultures of leaf callus enhanced 23.22 times inophyllum P. Variation in nitrate and sulphate had maximum positive influence on expression of inophyllums A and C and vitamins had maximum positive influence on expression of inophyllums A, C and B. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Calophyllum inophyllum; dipyranocoumarins; Expression pattern; HPLC; Medium components; Suspension culture

Interfacial reactivity of ``on water'' reactions in the presence of alcoholic cosolvents - Tiwari, Shraeddha; Kumar, Anil (Journal of Physical Chemistry A, 2009)
A detailed study of the variation in the interfacial reactivity and selectivity of ``on water'' reactions in the presence of increasing amounts of alcoholic cosolvents is discussed in the present work. The initial increase in the rates of ``on water'' reactions on the addition of alcoholic cosolvents is contrary to the sharp decrease in rates observed for homogeneous aqueous reactions. The existing theoretical framework is presented in terms of a typical ``on water'' process to enable a discussion of the experimental observations with reference to changing composition of the reaction medium. On the basis of the interesting observations of reactivity and selectivity variations with composition of the reaction medium, a simple ``signature'' characteristic for ``on water'' reactions is proposed.

Kinetic evidence for the influence of subsurface oxygen on palladium surfaces towards CO oxidation at high temperatures - Gopinath, Chinnakonda S.; Thirunavukkarasu, Kandasamy; Nagarajan, Sankaranarayanan (Chemistry-an Asian Journal, 2009)
Transient state kinetics of the catalytic oxidation of CO with 0, on Pd-surfaces has been measured under isothermal conditions by using a molecular beam approach. Systematic studies were carried out as a function of reaction temperature and CO+O(2) composition. With sufficient kinetic evidence, we have demonstrated the positive influence of subsurface oxygen towards CO-adsorption and oxidation to CO, at high temperatures (600-900 K) on Pd-surfaces, and the likely electronic nature of the surface changes with oxygen in the subsurface. These studies also provide a direct proof for CO-adsorption with a significantly reactive sticking coefficient at high temperatures on Pd-surfaces exhibiting a significant subsurface O-coverage.
Keywords: Adsorption; kinetics; Oxidation; Palladium; surface analysis

Metal complexes of crosslinked chitosans: correlations between metal ion complexation values and thermal properties - Trimukhe, K. D.; Varma, Anjanikumar (Carbohydrate Polymers, 2009)
A series of heavy metal complexes of crosslinked chitosans were evaluated by thermogravimetric studies. The metal complexes with Cu, Cd and Hg ions exhibiting the highest complexing ability to chitosans (Hg 354-364, Cu 100-112, and Cd 121-160, in mg/g chitosan), had the lowest onset of degradation temperatures (range 194-210 degrees C) and the lowest final degradation temperatures (generally less than 294-304 degrees C for Hg, 296-338 degrees C for Cu, and 305-368 degrees C for Cd complexes). Mn ion, with the lowest binding to chitosans (Mn 5-7 mg/g), showed the reverse behavior, having onset (240-248 degrees C) and final degradation temperatures (range 300-368 degrees C). Zn (binding 74-87 mg/g) and Pb (binding 39-62 mg/g) ions have a binding ability intermediate to Cu/Cd/Hg and Mn extremes, and therefore the effects on onset and final degradation temperatures are intermediate to these values. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Chitosan; Crosslinked chitosan; Degradation temperature; Metal complexes; Thermal properties; Thermogravimetry

MgCl2 center dot 4(CH3)(2)CHOH: a new molecular adduct and super active polymerization catalyst support - Thushara, K. S.; Mathew, Renny; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Bhaduri, Sumit; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2009)
A new molecular adduct, MgCl(2 center dot)4(CH3)(2)CHOH, has been synthesized and characterized for structural aspects and demonstrated for super active ethylene polymerization activity with TiCl4 to ultrahigh molecular weight polyethylene in high yield.

Nanoscale particles for polymer degradation and stabilization-trends and future perspectives - Kumar, Annamalai Pratheep; Depan, Dilip; Tomer, Namrata Singh; Singh, Raj Pal (Progress in Polymer Science, 2009)
The field of nanoscience and nanotechnology is extending the applications of physics, chemistry, biology, engineering and technology into previously unapproached infinitesimal length scales. The polymer-nanoparticles/nanocomposites have been the exponentially growing field of research for developing the materials in last few decades and have been mainly focusing on the structure-property relationships and their development. Since the polymer-nanocomposites have been the staple of modern polymer industry, their durability under various environmental conditions and degradability after their service life are also essential fields of research. Thus, this article is intended to review the status of worldwide research in this aspect. Among various nanoparticulates, clay minerals and carbon nanotubes are more often used in enhancing physical, mechanical and thermal properties of polymers. In very few systems, the nano particulates have been incorporated into polymer as `nano-additives' for both purposes: degradation and stabilization of polymers. The degradation and durability of polymers is reviewed in the presence of nanoparticles/nanocomposites under different environmental conditions. Nanoparticle-induced biodegradation of polymers is also discussed. (c) 2009 Elsevier Ltd. All rights reserved.
Keywords: Carbon nanotubes; clay; Degradation and stabilization; Nanocomposites; Nanoparticles; Polymer

Nitric oxide reduction with ethanol on palladium surfaces: a molecular beam study - Nagarajan, Sankaranarayanan; Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S.; Counsell, Jonathan; Gilbert, Lee; Bowker, Michael (Journal of Physical Chemistry C, 2009)
Nitric oxide (NO) reduction with ethanol has been carried out with molecular beam instruments in order to understand the influence of ethanol blended gasoline on NO reduction. Maximum NO reduction and nitrogen production was observed between 500 and 600 K. Oxidation products, CO, CO(2), and H(2)O were also observed. Beam switching experiments have been performed between fuel-rich and fuel-lean compositions to demonstrate that the NO reduction can be managed under net oxidizing conditions on Pd surfaces. Nitrogen production only occurs transiently on the relatively clean Pd surface in the oxygen-rich condition due to slow build up and blockage of the reaction by surface oxygen atoms. This shows the need to maintain relatively oxygen free surfaces to manage NO reduction under net-oxidizing conditions by beam oscillation between fuel-rich and fuel-lean compositions.

Orthogonal activation of propargyl and n-pentenyl glycosides and 1,2-orthoesters - Vidadala, Srinivasa Rao; Thadke, Shivaji A.; Hotha, Srinivas (Journal of Organic Chemistry, 2009)
An orthogonal activation strategy with propargyl and n-pentenyl glycosides has been identified. According to this methodology, n-pentenyl glycosides can be selectively activated with NIS/TMSOTf in the presence of either armed or disarmed propargyl O-glycosides. In addition, we report herein that propargyl 1,2-orthoesters can be selectively activated with AuBr(3) in CH(2)Cl(2) at room temperature in the presence of n-pentenyl glycosides. Similarly, pentenyl 1,2-orthoesters can be selectively activated with NIS/Yb(OTf)(3) in the presence of propargyl glycosides.

Polymeric ladderphanes - Chou, Chih-Ming; Lee, Shern-Long; Chen, Chih-Hsien; Biju, Akkattu T.; Wang, Hsian-Wen; Wu, Yi-Lin; Zhang, Guo-Fu; Yang, Kuang-Wei; Lim, Tsong-Shin; Huang, Min-Jie; Tsai, Po-Yu; Lin, Kin-Chuan; et al. (Journal of the American Chemical Society, 2009)
A new class of polymers, which have a double-stranded polybinorbornene skeleton with multilayer planar oligoaryl linkers, defined as polymeric ladderphanes, are synthesized. The structures of these ladderphanes are determined by spectroscopic means. Photophysical studies and time-resolved fluorescence spectroscopic investigations reveal that there is a strong interaction between the chromophore linkers. Thus, Soret band splitting in the absorption spectrum of the polymer with porphyrin linker (12e), significant fluorescence quenching with oligoaryl linkers (12b−d), and excimer emission with a terphenylene-diethynylene linker (12a) are characteristic photophysical properties of these polymers. Scanning tunneling microscopy shows that polymers 12b and d exhibit a ladder-like morphology and form a supramolecular assembly leading to a two-dimensional ordered array on a highly oriented pyrolytic graphite surface.

Prediction of extrudate swell in polymer melt extrusion using an Arbitrary Lagrangian Eulerian (ALE) based finite element method - Ganvir, Vivek; Lele, Ashish K.; Thaokar, Rochish; Gautham, Basavarsu P. (Journal of Non-Newtonian Fluid Mechanics, 2009)
Accurate prediction of extrudate (die) swell in polymer melt extrusion is important as this helps in appropriate die design for profile extrusion applications. Extrudate swell prediction has shown significant difficulties due to two key reasons. The first is the appropriate representation of the constitutive behavior of the polymer melt. The second is regarding the simulation of the free surface, which requires special techniques in the traditionally used Eulerian framework. In this paper we propose a method for simulation of extrudate swell using an Arbitrary Lagrangian Eulerian (ALE) technique based finite element formulation. The ALE technique provides advantages of both Lagrangian and Eulerian frameworks by allowing the computational mesh to move in an arbitrary manner, independent of the material motion. In the present method, a fractional-step ALE technique is employed in which the Lagrangian phase of material motion and convection arising out of mesh motion are decoupled. In the first step, the relevant flow and constitutive equations are solved in Lagrangian framework. The simpler representation of polymer constitutive equations in a Lagrangian framework avoids the difficulties associated with convective terms thereby resulting in a robust numerical formulation besides allowing for natural evolution of the free surface with the flow. In the second step, mesh is moved in ALE mode and the associated convection of the variables due to relative motion of the mesh is performed using a Godunov type scheme. While the mesh is fixed in space in the die region, the nodal points of the mesh on the extrudate free surface are allowed to move normal to flow direction with special rules to facilitate the simulation of swell. A differential exponential Phan Thien Tanner (PTT) model is used to represent the constitutive behavior of the melt. Using this method we simulate extrudate swell in planar and axisymmetric extrusion with abrupt contraction ahead of the die exit. This geometry allows the extrudate to have significant memory for shorter die lengths and acts as a good test for swell predictions. We demonstrate that our predictions of extrudate swell match well with reported experimental and numerical simulations. (c) 2008 Elsevier BY. All rights reserved.
Keywords: Arbitrary Lagrangian Eulerian; Extrudate (die) swell; Free surface simulations

Responses of midgut amylases of Helicoverpa armigera to feeding on various host plants - Kotkar, Hemlata M.; Sarate, Priya J.; Tamhane, Vaijayanti A.; Gupta, Vidya S.; Giri, Ashok P. (Journal of Insect Physiology, 2009)
Midgut digestive amylases and proteinases of Helicoverpa armigera, a polyphagous and devastating insect pest of economic importance have been studied. We also identified the potential of a sorghum amylase inhibitor against H. armigera midgut amylase. Amylase activities were detected in all the larval instars, pupae, moths and eggs; early instars had lower amylase levels which steadily increased up to the sixth larval instar. Qualitative and quantitative differences in midgut amylases of H. amigera upon feeding on natural and artificial diets were evident. Natural diets were categorized as one or more members of legumes, vegetables, flowers and cereals belonging to different plant families. Amylase activity and isoform patterns varied depending on host plant and/or artificial diet. Artificial diet-fed H. armigera larvae had comparatively high amylase activity and several unique amylase isoforms. Correlation of amylase and proteinase activities of H. armigera with the protein and carbohydrate content of various diets suggested that H. armigera regulates the levels of these digestive enzymes in response to macromolecular composition of the diet. These adjustments in the digestive enzymes of H. armigera may be to obtain better nourishment from the diet and avoid toxicity due to nutritional imbalance. H. armigera, a generalist feeder experiences a great degree of nutritional heterogeneity in its diet. An investigation of the differences in enzyme levels in response to macronutrient balance and imbalance highlight their importance in insect nutrition. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Amylase inhibitors; Diet; Helicoverpa armigera larvae; Midgut amylase; Proteinases

Revisit to carbon monoxide oxidation on Pd(111) surfaces - Nagarajan, Sankaranarayanan; Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2009)
Carbon monoxide (CO) oxidation on Pd(111) surfaces has been studied by molecular beam methods with mixed molecular beams (CO + O(2)) between 400 and 900 K and a CO:O(2) ratio of 7:1 to 1:10. A new aspect of the above reaction observed in the transient kinetics regime is the evidence for oxygen diffusion into Pd(111) subsurface layers and its significant influence toward CO oxidation at high temperatures (>= 600 K). An overall influence of subsurface oxygen on the kinetics of the CO oxidation reaction is addressed. Interesting information derived from the above studies is the necessity to fill up the subsurface layers with oxygen atoms to a threshold coverage (theta(Osub)), above which the reactive CO adsorption occurs on the surface with subsequent CO(2) production. The above observation Was demonstrated with CO-rich reactant compositions (CO + O(2)) above 600 K via instant oxygen adsorption on Pd surfaces; however, onset of CO adsorption as well as CO(2) production occurs after a time delay. theta(Osub) and the time delay in CO adsorption (and CO(2) production) increase with increasing temperature and with CO-rich compositions. theta(Osub) was measured up to 0.3 monlayer (ML) between 500 and 850 K before the onset of CO adsorption; however, theta(Osub) increases from an insignificant value at <500 K to 0.4 ML at 900 K with a pure O(2) beam. Onset of CO adsorption with a significant sticking coefficient on the Pd surfaces, that is, covered with significant subsurface oxygen, underscores a change in the electronic state of Pd surfaces toward mildly oxidized (or Pd(delta+)), and an electronic decoupling occurs between the bulk and the surface. The jellium model is invoked to demonstrate the changes observed. A similar observation with polycrystalline Pd surfaces suggests the defect sites is one of the channels for oxygen diffusion into subsurfaces. Initial sticking coefficient (s(0)) measurements demonstrate that there is no significant competition between CO and O(2) adsorption from the CO + O(2) mixture between 400 and 600 K, and indeed they are largely independent of each other. The maximum steady-state CO(2) formation rate was observed for a 1:1 CO/O(2) beam composition between 500 and 550 K. However, with a significant theta(Osub) the rate of CO(2) Production in the steady state is considerable even at high temperatures (700-850 K), and a broadening of the active CO oxidation regime to high temperature is observed with O(2)-rich compositions.

Spatial and temporal expression patterns of diverse Pin-II proteinase inhibitor genes in Capsicum annuum Linn - Tamhane, Vaijayanti A.; Giri, Ashok P.; Kumar, Pavan; Gupta, Vidya S. (Gene, 2009)
Pin-II type proteinase inhibitor (PI) genes were cloned from fruit and stem tissues of Capsicum annuum L var Phule Jyoti using primers designed from reported CanPI gene sequence (AF039398). In total, 21 novel CanPIs, members of the Pin-II PI family, were identified in the study, with three isoforms of 1-inhibitory repeat domain (IRD), eight isoforms of 2-IRD), three isoforms of 3-IRD, five isoforms of 4-IRD and two partial CanPI sequences. Most of the sequences showed variation (2 to 20%) in the deduced AA sequences which were pronounced close to the reactive site loop. Expression patterns of CanPIs in the fruit and stem tissues of mature C. annuum plants were shown to vary qualitatively and quantitatively using semi-quantitative RT-PCR expression analysis. In the fruit tissue. CanPIs with different IRDs (from 1 to 4) were expressed simultaneously. In stem tissue, 1- and 2-IRD CanPIs were strongly expressed along moderate expression of 3- and 4-IRD genes. Analysis of CanPI protein activity showed a range of active forms across the tissues. CanPI expression was differentially up-regulated upon wounding and insect attack. Although infestation by aphids (Myzus persicae) and lepidopteran pests (Spodoptera litura) specifically induced 4-IRD CanPIs, virus-infected leaves did not affect CanPI expression. Analysis of CanPI protein activity indicated that the up-regulation in CanPI expression was not always correlated with increase in PI activity. Our results demonstrated that CanPI expression is regulated spatially, temporally as well as qualitatively and quantitatively. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: CanPI; Capsicum annuum; Endogenous role; Pin-II; Plant defense; Proteinase inhibitor

Structural characterization of azoic dye hosted layered double hydroxides - Mandal, Sujata; Lerner, Dan A.; Marcotte, Nathalie; Tichit, Didier (Zeitschrift fur Kristallographie, 2009)
The removal of methyl orange (MO) from an aqueous solution was performed using layered double hydroxides (LDHs) in a move to develop cleaning processes of effluents contaminated with dye molecules. The intercalation of the guest anionic MO species into host M(II)/Al(III) LDHs differing by the nature of the divalent cations (M(II) = Mg, Ni or Zn) was achieved by anionic exchange of the initially NO(3)(-) present in the interlayer space and led to MO/LDH intercalation compounds. The exchange process was followed by XRD and UV-visible absorption spectroscopy at different stages. Almost all MO in solution is uptaken by the Mg-containing LDH in the concentration range corresponding to its anionic exchange capacity (AEC). A lower exchange is reached with the Ni- and Zn-containing LDHs, for which the diffusion of MO is limited due to a larger crystallite size. MO-Zn/Al LDH intercalation compounds exhibit the highest crystallinity and display a remarkable stacking of the layers at maximal MO exchange. This behaviour can be assigned to the higher intrinsic charge density of the host layers in agreement with its lower M(II)/Al(III) molar ratio (Zn(II)/Al(III) approximate to 1.5 whereas Mg(II)/Al(III) and Ni(II)/Al(III) = 2). The maximum amount of MO retained by the different LDHs is higher for Mg-containing LDH, than for Ni- and Zn-containing LDH, reaching respectively 1.15, 0.84 and 0.77 g/g.
Keywords: Anionic exchange; Depollution; layered double hydroxides; Methyl orange; X-ray diffraction

Structural phase transitions of syndiotactic polystyrene - Gowd, E. Bhoje; Tashiro, Kohji; Ramesh, C. (Progress in Polymer Science, 2009)
Syndiotactic polystyrene (sPS) exhibits four crystal modifications (alpha, beta, gamma, and delta), along with intermediate forms with different molecular conformations, as well as different chain-packing structures. The extensive literature on the crystal structures exhibited by sPS is reviewed herein, including, the mechanisms of phenomena such as solvent-induced crystallization, thermally induced crystallization and gelation, and the phase transitions among the various crystalline forms. The latter have been studied by static and dynamic wide-angle and small-angle X-ray scattering, infrared and Raman spectra, and neutron scattering, etc., in addition to computer simulations. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: crystal structure; Gelation; phase transition; polymorphism; Solvent-induced crystallization; Syndiotactic polystyrene

Superparamagnetic nanocomposite of magnetite and activated carbon for removal of dyes from waste water - Thakuria, Pankaj; Joy, Pattayil Alias (Nanoscience and Nanotechnology Letters, 2009)
Nanocomposite of superparamagnetic Fe(3)O(4) and activated carbon (AC) is synthesized at room temperature and characterized by various techniques. Magnetic measurements indicated that the Fe(3)O(4) nanoparticles are isolated by the AC particles. The magnetic fluid obtained by dispersion of the nanocomposite in water is found to be relatively stable. The dispersion is found to be very efficient for the removal of methylene blue dye from water. Thus, the nanocomposite is highly suitable for removing dissolved dyes and other contaminants from waste water by a simple magnetic separation process after adsorption on AC.
Keywords: Magnetic Separation; Nanocomposite; Superparamagnetism; Water Purification

Supramolecular synthesis of some molecular adducts of 4,4 `-bipyridine N,N `-dioxide - Arora, Kapildev K.; Talwelkar, Mayura S.; Pedireddi, V. R. (New Journal of Chemistry, 2009)
Molecular adducts (1a-1e) of 4,4'-bipyridine N,N'-dioxide, 1, respectively with cyanuric acid, trithiocyanuric acid, 1,3,5-trihydroxybenzene ( phloroglucinol), 1,3-dihydroxybenzene ( resorcinol) and 1,2,4,5-benzenetetracarboxylic acid have been reported. The major interactions observed in the structures 1a-1e are N-H center dot center dot center dot O, N-H center dot center dot center dot S, O-H center dot center dot center dot O and C-H center dot center dot center dot O, in the form of homomeric and heteromeric patterns of the constituents, either as a single or cyclic hydrogen-bonded motifs. While in the adduct 1a, both homomeric and heteromeric units of both the constituents were observed, no heteromeric interactions were observed in 1b and 1c. In addition, in 1b, homomeric aggregation of molecules of 1 occurred in association with water molecules. However, while heteromeric interactions prevail between the constituents in 1d and 1e, only one of the co-crystallizing species gave homomeric interactions (4,4'-bipyridine N,N'-dioxide in 1d; 1,2,4,5-benzenetetracarboxylic acid in 1e). Further, in either type of the patterns, the cyclic motifs are formed as a pair-wise hydrogen bonds comprising of strong and weak hydrogen bonds (N-H center dot center dot center dot O/C-H center dot center dot center dot O or O-H center dot center dot center dot O/C-H center dot center dot center dot O). In three-dimensions, the ensembles of molecules yield planar sheets, ladders and pseudorotaxane type assemblies.

Susceptibility of aedes aegypti and culex quinquefasciatus larvae to gedunin-related limonoids - Gurulingappa, Hallur; Tare, Vrushali; Pawar, Pushpa; Tungikar, Vijay; Jorapur, Yogesh R.; Madhavi, Sriram; Bhat, Sujata V. (Chemistry & Biodiversity, 2009)
The major non-azadirachtin limonoids such as gedunin (1), epoxyazadiradione (3), nimbocinol (4), and nimolicinol (5) from Azadirachta indica A. Juss ('neem') and their derivatives were evaluated for their toxic action against fourth instar larvae of Aedes aegypti L. and Culex quinquefasciatus SAY. Gedunin exhibited 100% toxic action against both the mosquito larvae at 50 and 10 ppm. Epoxyazadiradione and epoxynimolicinol also showed significant toxicities (>= 50%) against larvae of both mosquito species at 50 ppm. These neem limonoids can have benefits in mosquito-control programs.

Synthesis, characterization and catalytic performance of Sn-MCM-48 in solvent-free Mukaiyama-type aldol condensation reactions - Taralkar, U. S.; Kalita, Pranjal; Kumar, Rajiv; Joshi, P. N. (Applied Catalysis A-General, 2009)
The influence of various synthesis variables on the physico-chemical properties of mesoporous stannosilicate molecular sieves with MCM-48 structure (Sn-MCM-48) has been investigated. Sn-MCM48 has been used as a new heterogeneous catalyst in solvent-free Mukaiyama-type aldol reactions. Invariably, the beta-hydroxy ester selectivity was found to be 100% irrespective of the conversion level. The product yield was found to increase, to reach a maximum (70%), and then to decrease with the increase in tin content. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Characterization; heterogeneous catalysis; Hydrothermal synthesis; Mesoporous molecular sieves; Mukaiyama-aldol condensation; Sn-MCM-48

Synthesis of Si-MCM-41 from ternary SiO2-CTAOH-H2O system via dry gel conversion route - Taralkar, U. S.; Niphadkar, P. S.; Joshi, P. N. (Journal of Sol-Gel Science and Technology, 2009)
Steam assisted dry gel conversion method was employed for the synthesis of Si-MCM-41 from ternary SiO2:CTAOH:H2O systems wherein fumed silica was used as a source of silica. The influence of synthesis time, molar ratios of CTAOH/SiO2 in dry gel and the water content at the bottom of autoclave on the quality and formation of mesophases has been investigated. Powder XRD, N-2 adsorption-desorption, TEM and hydrothermal stability test were the techniques used for sample characterization. Keeping molar ratio of CTAOH/SiO2 constant, shorter synthesis time, lower unit cell parameter and d spacing were observed when steam assisted dry gel conversion method was employed in place of conventional hydrothermal method. There exists an optimum lower limit for water content at the bottom of autoclave for reducing the synthesis period. Keeping synthesis temperature and CTAOH/SiO2 molar ratio fixed, Si-MCM-41 with improved hydrothermal stability was obtained by steam assisted dry gel conversion route.
Keywords: Dry gel conversion; powder diffraction; Si-MCM-41; Sol-gel growth; Structural stability; Textural properties

Visible light induced photoreduction of methyl orange by N-doped mesoporous titania - Joshi, Meenal M.; Labhsetwar, Nitin K.; Mangrulkar, Priti A.; Tijare, Saumitra N.; Kamble, Sanjay P.; Rayalu, Sadhana S. (Applied Catalysis A-General, 2009)
N-doped mesoporous titania was synthesized using templating method. Biopolymer chitosan was used as a template and also as a nitrogen source along with ammonium hydroxide. Three different types of N-doped mesoporous titania were synthesized by varying composition of chitosan and titania precursor. These photocatalysts were characterized using XRD, BET-SA, FTIR, UV-DRS, SEM-EDX and XPS analysis. The photocatalytic activity of mesoporous titania was studied by methyl orange (MO) photoreduction reaction. From the experimental results it was observed that the N-doped mesoporous titania (1:2) gives the highest photocatalytic reduction of MO as compared to N-doped mesoporous titania prepared with (1:1) and (1:3) stoichiometry. This could be due to the optimal level of `N' incorporation in the N-doped mesoporous titania (1:2). Photocatalysts reduce the MO dye into derivative of hydrazine. Photoactivity of N-doped mesoporous titania (1:2) is 1.0721 mg of MO reduced per g of TiO2 vis-a-vis 0.508 mg of MO reduced per g of TiO2 for Degussa P25 photocatalyst. The effect of various operating parameters like photocatalyst loading. initial concentration and intensity of light also has been studied. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: biopolymer; Chitosan; MO photoreduction; N-doped mesoporous titania; Visible active photocatalyst

VLS-like growth and characterizations of dense ZnO nanorods grown by e-beam process - Agarwal, Dinesh C.; Chauhan, R. S.; Avasthi, D. K.; Sulania, I.; Kabiraj, D.; Thakur, P.; Chae, K. H.; Chawla, Amit; Chandra, Ramesh; Ogale, S. B.; Pellegrini, G.; Mazzoldi, P. (Journal of Physics D-Applied Physics, 2009)
We present a new approach to produce ZnO nanorods in a reproducible manner at a temperature lower than other physical vapour deposition techniques, such as the vapour-liquid-solid mechanism. Arrays of well-aligned ZnO nanorods of uniform diameter have been synthesized on the Si substrate precoated with Au, using a simple electron beam evaporation method without the flow of any carrier gas. Scanning electron microscopy and atomic force microscopy characterizations show that as-grown nanorods are well aligned and uniform in diameter. X-ray diffraction measurements and clear lattice fringes in high-resolution transmission electron microscopy image show the growth of good quality polycrystalline hexagonal ZnO nanorods and a < 0 0 2 > growth direction. The polarization-dependent studies of near edge x-ray absorption fine structure (NEXAFS) are performed to investigate the electronic structure of the zinc and oxygen ions. The analysis of NEXAFS spectra at different angles of incidence of photon flux indicates the formation of ZnO nanorods having anisotropic behaviour of O and Zn states. The photoluminescence spectrum exhibits strong ultraviolet emission at 385 nm and the UV-visible spectrum also shows a band-gap transition around 390 nm indicating the good quality of nanorods. The catalytic growth mechanism of the ZnO nanorods is discussed on the basis of experimental results in this work.

Winged bean chymotrypsin inhibitors retard growth of Helicoverpla anmigera - Telang, Manasi A.; Giri, Ashok P.; Pyati, Prashant S.; Gupta, Vidya S.; Tegeder, Mechthild; Franceschi, Vincent R. (Gene, 2009)
Two putative Kunitz-type chymotrypsin inhibitor genes (WC12 and WC15) were isolated from winged bean (Psophocarpus tetragonolobus (L.) DC). While WC12 has previously been characterized, WC15 represents a new member of the WC1 family. WC15 was exclusively expressed in winged bean seeds. Theoretical translation of both the genes resulted into polypeptides of 207 amino acids with 86% sequence similarity. The polypeptide sequences contain four half-cysteine residues and a well-conserved Leu(65)-Ser(66) reactive site, typical for chymotrypsin inhibitors. WC15 and WC12 were expressed in Pichia pastoris and the recombinant proteins were assayed against various proteinases. Both the inhibitors strongly inhibited commercially available bovine chymotrypsin. More importantly, gut proteinases of Helicoverpa armigera larvae that damage many important crop plants, were inhibited by WC12 and WC15. In addition, both proteinase inhibitors demonstrated significant reduction of growth of H. armigera larvae after feeding on inhibitor incorporated artificial diets. The inhibitory effects of WC12 and WC15 on activity of proteinases and larval growth make these proteins and their genes promising candidates for enhancing plant defense against H. armigera using transgenic plants. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Antimetabolic effect; Digestive gut proteinases; Kunitz-type proteinase inhibitor; Organ-specific mRNA expression; Psophocarpus tetragonolobus

Amino-phenol-formaldehyde resins by in-situ generation of catalyst - Dwivedi, Mayank; Rao, Locanindi Hari Sarvothama; Reddy, Krishna Mohan Srinivasulu; Dhanasekharan, Janakiraman; Rao, Bevara Madhusudana; Kumar, Sriperambudur Rajesh; Ponrathnam, Surendra; Chelanattukizhakkemadath, Raman Rajan; Tayal, Rajivkumar; Qureshi, Moham (2010)

Beaded cross linked polymers containing tert-amino functional group moities - Dwivedi, Mayank; Rao, Locanindi Hari Sarvothama; Reddy, Krishna Mohan Srinivasulu; Dhanasekharan, Janakiraman; Rao, Bevara Madhusudana; Kumar, Sriperambudur Rajesh; Ponrathnam, Surendra; Chelanattukizhakkemadath, Raman Rajan; Tayal, Rajivkumar; Qureshi, Moham (2010)

Chronic inflammatory responses to microgel-based implant coatings - Bridges, Amanda W.; Whitmire, Rachel E.; Singh, Neetu; Templeman, Kellie L.; Babensee, Julia E.; Lyon, L. Andrew; Garcia, Andres J. (Journal of Biomedical Materials Research, 2010)

Colossal thermoelectric power in Gd-Sr manganites - Sagar, S.; Ganesan, V.; Joy, Pattayil Alias; Thomas, Senoy; Liebig, A.; Albrecht, M.; Anantharaman, Maliemadom R. (EPL, 2010)
Manganites belonging to the series Gd(1-x)Sr(x)MnO(3) (x=0.3, 0.4 and 0.5) were prepared by wet solid-state reaction and their thermoelectric power was evaluated. Thermoelectric power measurements revealed a peak value at similar to 40 K. All the samples exhibited a colossal thermopower at similar to 40K and in that Gd(0.5)Sr(0.5)MnO(3) exhibited a maximum value of similar to 35 V/K, which is the largest reported for these class of materials at this temperature. Temperature-dependent magnetisation measurements showed that the samples exhibit a phase transition from paramagnetic to spin-glass-like state at these temperatures. Plausible mechanisms responsible for the observed colossal thermoelectric power in Gd-Sr manganites are discussed. Copyright (C) EPLA, 2010

Covalently immobilized triphenylphosphine rhodium complex: synthesis, characterization, and application in catalytic olefin hydrogenation - Wang, Lei; Jia, Mingjun; Shylesh, Sankaranarayanapillai; Philippi, Thomas; Seifert, Andreas; Ernst, Stefan; Singh, Anand Pal; Thiel, Werner R. (Chemcatchem, 2010)
A trimethoxysilane functionalized triphenylphosphine was coordinated to rhodium(I) and the resulting rhodium complex was covalently bound to a mesoporous SBA-15 support. The catalytic activity of this hybrid material was studied for the hydrogenation of 2-cyclohexen-1-one and compared with the corresponding homogeneous catalyst. According to the (31)P-MAS NMR data, the catalytically active species was stable against oxidation; no structural change could be detected after exposing it to air for more than two months. Transmission electron microscopy (TEM) measurements on the used catalyst confirmed that the rhodium species was also stable against reduction to the metal because the formation of rhodium nanoparticles during the catalysis could be excluded. The kinetic curves of the recycled system confirmed that this hybrid catalyst shows excellent activity, selectivity, stability, and reusability, and is truly heterogeneous in the hydrogenation reaction.
Keywords: alkenes; heterogeneous catalysis; Hydrogenation; mesoporous materials; Rhodium

Efficient industrial dye decolorization by Bacillus sp. VUS with its enzyme system - Dawkar, Vishal V.; Jadhav, Umesh U.; Tamboli, Dhawal P.; Govindwar, Sanjay P. (Ecotoxicology and Environmental Safety, 2010)
This work presents role of different enzymes in decolorization of industrial dye Orange T4LL by Bacillus sp. VUS. Bacillus sp. strain VUS decolorized dye Orange T4LL, under static anoxic condition in 24 h. During decolorization of Orange T4LL a significant induction in the activities of lignin peroxidase, tyrosinase, and reductases (NADH-DCIP, azo, and riboflavin) was observed. The biodegradation was monitored by Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and high performance liquid chromatography. The final products 4-methyl-2-o-tolylazo-benzene-1,3-diamine and [3-(phenyl-hydrazono)-cyclohexa-1,4-dienyl]-methanol were characterized by gas chromatography-mass spectroscopy. Phytotoxicity, COD, and BUD revealed non-toxicity of degraded products. Phytotoxicity study demonstrated non-toxicity of the biodegraded products for crop plants with respect to Triticum aestivum and Sorghum bicolor. Bacillus sp. VUS with its enzyme system could be a useful tool for textile effluent treatment. (C) 2010 Elsevier Inc. All rights reserved.
Keywords: Decolorization; GC-MS; Lignin peroxidase; Orange T4LL; Phytotoxicity; Reductases

Fabrication of homogeneous nanoparticle/nanoneedle BaTiO3 and Ba0.8Sr0.2TiO3 smooth thin films by simple dip coating - Saini, Mamta; Vivekanand, K.; Poddar, Pankaj; Murty, K. V. G. K.; Thushara, K. S.; Gopinath, Chinnakonda S. (International Journal of Nanotechnology, 2010)
Ferroelectric BaTiO3 (BTO) and Ba0.8Sr0.2TiO3 (BSTO) thin film materials have been successfully prepared by sol-gel processing and simple dip coating on glass and silicon supports. Above thin films were characterised by x-ray diffraction (XRD), Raman spectroscopy, photoelectron spectroscopy, thermal analysis, atomic force microscopy (AFM) and spectroscopic ellipsometry. Phase identification of BaTiO3 and Ba0.8Sr0.2TiO3 was performed by XRD. XRD and Raman spectroscopy investigations demonstrate that thc Ba0.8Sr0.2TiO3 film exhibits tetragonal structure. AFM analysis demonstrates the elongated nanospherical particles on glass substrate and nanowires on silicon substrate, which represent a strong influence of the crystallinity of underlying substrate on the grain morphology in this technique. The thin films on both the substrates are uniformly coated without any pinhole to significant area (similar to 2.5 cm(2)), and this method might be extended to large area uniform coating. Spectroscopic ellipsometric measurements reveal the exact thickness, refractive index and extinction coefficient of the thin films.
Keywords: barium strontium titanate; barium titanate; dip coating; fabrication; ferroelectric material; large area coating; nanotechnology; thin film

Gold-catalyzed glycosidations: synthesis of 1,6-anhydro saccharides - Thadke, Shivaji A.; Hotha, Srinivas (Tetrahedron Letters, 2010)
Various 1,6-anhydro sugars are synthesized utilizing salient features of gold-catalyzed glycosidations. All the reactions occurred under mild conditions in the presence of 7 mol % of AuBr(3) enabling easy synthesis of 1,6-anhydro sugars from corresponding 6-hydroxy propargyl/methyl monosaccharides, disaccharides, and trisaccharides in good yields. (C) 2010 Elsevier Ltd. All rights reserved.

High room temperature ferromagnetic moment of Ho substituted nanocrystalline BiFeO3 - Thakuria, Pankaj; Joy, Pattayil Alias (Applied Physics Letters, 2010)
Magnetic properties of trivalent rare-earth ion substituted nanocrystalline BiFeO3 have been studied for the compositions Bi0.875R0.125FeO3 (R=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb). All compositions show ferromagnetic characteristics at room temperature, with enhanced magnetization after substitution. Very high magnetization (at 6 T), almost three times that of the unsubstituted composition, is observed for R=Ho, and highest remnant magnetization is obtained for R=Nd and Sm. The magnetic transition temperature is increased by similar to 20 K for R=La. The results show that it is possible to tune the magnetic characteristics of the nanocrystalline multiferroic BiFeO3 by the choice of the rare-earth ion. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3502481]

Identification of two flavin monooxygenases from an effluent treatment plant sludge metagenomic library - Singh, Ajit; Chauhan, Nar Singh; Thulasiram, H. V.; Taneja, Vibha; Sharma, Rakesh (Bioresource Technology, 2010)
Oxygenases are useful for the production of many industrially important molecules. Screening of an effluent treatment plant (ETP) sludge metagenomic library identified two clones encoding proteins, B1 and B2, with similarity to putative Flavin monooxygenases from Mesorhizobium loti and Sphingomonas wittichi, respectively. The deduced amino acid sequences show only 20% identity, but both have a paired Rossman fold and a flavin monooxygenase (FMO) motif. B1 and B2 appear to be members of the Flavin-containing monooxygenase and the Baeyer-Villiger monooxygenases subfamilies, respectively. When expressed in Escherichia coli, the two clones produced activities that oxidized indole to a mixture of indigo and indirubin pigments. These results suggest that B1 and B2 have potential as a biocatalyst in indigo/indirubin production. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Indigo; Indirubin; Metagenome; Metagenomic; Monooxygenase

Interaction of recombinant CanPIs with helicoverpa armigera gut proteases reveals their processing patterns, stability and efficiency - Mishra, Manasi; Tamhane, Vaijayanti A.; Khandelwal, Neha; Kulkarni, Mahesh J.; Gupta, Vidya S.; Giri, Ashok P. (Proteomics, 2010)
Six diverse representative Capsicum annuum (common name: hot pepper; Solanaceae) protease inhibitor genes, viz CanPI-5, -7, -13, -15, -19, and 22 comprising 1-4 inhibitory repeat domains (IRDs), were cloned and expressed in Pichia pastoris. The recombinant proteins were evaluated for their interactions with bovine trypsin, chymotrypsin, and Helicoverpa armigera gut proteases (HGP) using electrophoretic (native and denaturing) and mass spectrometric (MALDI-TOF-MS in combination with intensity fading assays) techniques. These techniques allow qualitative and semiquantitative analysis of multiple and processed IRDs of purified recombinant Capsicum annuum proteinase inhibitor (rCanPI) proteins. rCanPIs showed over 90% trypsin inhibition, varying chymotrypsin inhibition depending on the number of respective IRDs and over 60% inhibition of total HGP. rCanPI-15 that has only one IRD showed exceptionally low inhibition of these proteases. Interaction studies of rCanPIs with proteases using intensity fading-MALDI-TOF-MS revealed gradual processing of multi-IRD rCanPIs into single IRD forms by the action of HGP at the linker region, unlike their interactions with trypsin and chymotrypsin. Intensity fading-MALDI-TOF-MS assay showed that CanPI-13 and -15, possessing single IRD and expressed predominantly in stem tissue are degraded by HGP; indicating their function other than defense. In vitro and in vivo studies on rCanPI-5 and -7 showed maximum inhibition of HGP isoforms and their processed IRDs were also found to be stable in the presence of HGP. Even single amino acid variations in IRDs were found to change the HGP specificity like in the case of HGP-8 inhibited only by IRD-12. The presence of active PI in insect gut might be responsible for changed HGP profile. rCanPI-5 and -7 enhanced HGP-7, reduced HGP-4, -5, -10 expression and new protease isoforms were induced. These results signify isoform complexity in plant PIs and insect proteases.
Keywords: CanPI; H. armigera gut proteases; Intensity fading MALDI-TOF-MS; Pin-II; Plant proteomics; Plant-insect interaction

Investigations of CdS and Ag-CdS nanoparticles by X-ray photoelectron spectroscopy - Thakur, Priya; Joshi, Satyawati S.; Patil, K. R. (Applied Surface Science, 2010)
In the present report, CdS and Ag-CdS nanoparticles were synthesized using cysteine as a capping agent. Surface properties CdS and Ag-CdS nanoparticles were studied by X-ray photoelectron spectroscopy (XPS). XPS study of CdS nanoparticles was carried out as a function of pH and for a refluxed sample at pH 11.2. Effect of dopant concentration on surface properties of Ag-CdS nanoparticles was also studied for as prepared samples as well as for annealed sample at 2% doping. Effect of pH, dopant concentration, and effect of particle size on different sulfur species present in the system was studied. Features of Cd 3d, S 2p and Ag 3d core level have been discussed in detail. (C) 2010 Elsevier B.V. All rights reserved.
Keywords: Ag-CdS; CdS; Cysteine; XPS

Isolation, structure, and functional elucidation of a modified pentapeptide, cysteine protease inhibitor (CPI-2081) from streptomyces species 2081 that exhibit inhibitory effect on cancer cell migration - Singh, Jay Prakash; Tamang, Sudarsan; Rajamohanan, P. R.; Jima, N. C.; Chakraborty, Goutam; Kundu, Gopal C.; Gaikwad, Sushama M.; Khan, Mohammad Islam (Journal of Medicinal Chemistry, 2010)
Cysteine proteases play an important role in cell migration and tumor metastasis. Therefore, their inhibitors are of colossal interest, having potential to be developed as effective antimetastatic drugs for tumor chemotherapy. Traditionally, secondary metabolites from streptomyces show a wide range of diversity with respect to their biological activity and chemical nature. In this article, we have described the characterization of small molecule cysteine protease inhibitor, CPI-2081 (compound 1), a mixture of two novel pentapeptides, compound 1a (736.71 Da), and compound 1b (842.78 Da), isolated from Streptomyces species NCIM2081, following solvent extraction and repeated HPLC based on C18 chemistry, and completely characterized using a variety of both ID and 2D NMR spectroscopy. Further, it was found that nanomolar concentration of compound 1 is able to inhibit papain hydrolytic activity. Also, compound 1 significantly inhibits tumor cell migration at sub cytotoxic concentration, indicating its remarkable potential to be developed as antimetastatic drug, which will make chemotherapy more localized and specific, thereby minimizing the hazardous side effects on normal tissues.

Magnetic, dielectric and complex impedance spectroscopic studies of nanocrystalline Cr substituted Li-ferrite - Hankare, P. P.; Patil, R. P.; Sankpal, U. B.; Garadkar, K. M.; Sasikala, R.; Tripathi, A. K.; Mulla, Imtiaz S. (Journal of Magnetism and Magnetic Materials, 2010)
Nanocrystalline Li0.5Fe2.5-xCrxO4 (2.5 <= x >= 0) ferrites were prepared by a sol-gel autocombustion route. X-ray diffraction was employed to confirm the cubic spinel phase formation of the ferrites. The lattice parameter decreases with increase in Cr content. The saturation magnetization, coercivity and remanance were studied as a function of Cr content. The dielectric constant and dielectric loss were measured as a function of frequency in the frequency range 20 Hz-1 MHz. Frequency dependence of dielectric constant shows dielectric dispersion due to the Maxwell-Wagner type of interfacial polarization. In order to understand the conduction mechanism, complex impedance measurements were carried out. The substitution of chromium plays an important role in changing the dielectric and magnetic properties of lithium ferrites. (C) 2010 Published by Elsevier B.V.
Keywords: Complex impedance; dielectric response; Ferrites; Magnetic hysteresis; Sol-gel synthesis; X-ray diffraction

Molecular electric dipole moments using the GVVPT2 variant of multireference perturbation theory - Theis, Daniel; Khait, Yuriy G.; Pal, Sourav; Hoffmann, Mark R. (Chemical Physics Letters, 2010)
A Lagrangian approach for electric dipoles within second order Generalized Van Vleck Perturbation Theory (GVVPT2) is presented. The Lagrangian approach for this response property requires that only one, perturbation-independent, set of simultaneous equations needs to be solved. The presented formulation is demonstrated numerically on several well studied molecules at their equilibrium bond lengths and on the complete potential energy curves of the ground and first excited states of LiH. Numerical corroboration of the expected continuity for molecular properties for the GVVPT2 method is observed. It is seen that the GVVPT2 electric dipoles are in good agreement with experiment and with other high accuracy theoretical methods. (C) 2010 Elsevier B.V. All rights reserved.

Pd-catalyzed one-pot chemoselective hydrogenation protocol for the preparation of carboxamides directly from azides - Bavikar, Sudhir N.; Salunke, Deepak B.; Hazra, Braja G.; Pore, Vandana S.; Thierry, Josiane; Dodd, Robert H. (Tetrahedron Letters, 2010)
Carboxamides were obtained efficiently in high yields from azides on reaction with the corresponding pre-formed activated carboxylic acids in a single-step reductive transformation using hydrogen atmosphere (balloon) under Pd/BaSO(4) or Pd/CaCO(3) catalysis. The method is highly chemoselective and compatible with extremely labile functional groups such as benzyl carbamates, benzyl ethers, benzyl esters, and olefins. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Azide; Carboxamide; Catalytic hydrogenation; Chemoselective; Palladium; Succinimide ester

Pd-functionalized carbon nanotubes for selective hydrogenation of 2-butyne-1,4-diol - Nadgeri, Jayprakash M.; Garade, Ajit C.; Tambe, Romana A.; Gokhale, Suresh P.; Rode, Chandrashekhar V. (Advanced Science Letters, 2010)
Multiwalled carbon nanotubes were prepared by thermal decomposition method followed by acid treatment and Pd-functionalization with PdCl2 by wet impregnation method. The Pd functionlized carbon nanotubes catalyst was characterized by BET, FT-IR, Raman, XRD, EDX, ICP-OES, SEM and TEM and was evaluated for its activity for hydrogenation of 2-butyne-1,4-diol. It showed higher selectivity (93%) to 2-butene-1,4-diol than Pd supported on commercial carbon (70% selectivity to 2-butene-1,4-diol) for complete conversion of 2-butyne-1,4-diol. The catalyst also exhibited excellent stability as evidenced by the three catalyst recycle experiments.

Photodegradation of methanol under UV-visible irradiation by titania dispersed on polyester cloth - Bhattacharyya, Kaustava; Tripathi, Arvind K.; Gupta, Narendra M.; Tyagi, Avesh K. (Photochemistry and Photobiology, 2010)
Titania supported on polyester fabric (TiO(2)-PY) with varying titania loadings (2-7 wt%) were prepared via the dip-coating method at room temperature using an aqueous slurry of anatase titania. Structural and morphological characterizations by X-ray diffraction and scanning electron microscopy revealed that the titanium dioxide crystallites deposited on the surface of the polyester fabric were in the micrometer range while their phase remained to be anatase. Photocatalytic activity of TiO(2)-PY fabric catalysts was evaluated for vapor-phase oxidation of methanol in air as a test reaction in the presence of UV as well as solar radiation under ambient conditions. These catalysts were found to be quite active in both UV and solar irradiation with activity being higher in the former case. CO(2) yield from photo-oxidation of methanol depended on titania content and also on its dispersion over polyester fabric support.

Process for synthesis of beaded cross linked polymers, water-in-oil-in-water emulsions and post functionalisation - Dwivedi, Mayank; Rao, Locanindi Hari Sarvothama; Reddy, Krishna Mohan Srinivasulu; Dhanasekharan, Janakiraman; Rao, Bevara Madhusudana; Kumar, Sriperambudur Rajesh; Ponrathnam, Surendra; Chelanattukizhakkemadath, Raman Rajan; Tayal, Rajivkumar; Qureshi, Moham (2010)

QTL mapping of multiple foliar disease and root-lesion nematode resistances in wheat - Rebecca S. Zwart; Thompson, J. P.; Milgate, A. W.; Bansal, Urmil K.; Williamson, P. M.; Raman, H.; Bariana, Harbans S. (Molecular Breeding, 2010)
A genetic linkage map, based on a cross between the synthetic hexaploid CPI133872 and the bread wheat cultivar Janz, was established using 111 F(1)-derived doubled haploid lines. The population was phenotyped in multiple years and/or locations for seven disease resistance traits, namely, Septoria tritici blotch (Mycosphaeralla graminicola), yellow leaf spot also known as tan spot (Pyrenophora tritici-repentis), stripe rust (Puccinia striiformis f. sp. tritici), leaf rust (Puccinia triticina), stem rust (Puccinia graminis f. sp. tritici) and two species of root-lesion nematode (Pratylenchyus thornei and P. neglectus). The DH population was also scored for coleoptile colour and the presence of the seedling leaf rust resistance gene Lr24. Implementation of a multiple-QTL model identified a tightly linked cluster of foliar disease resistance QTL in chromosome 3DL. Major QTL each for resistance to Septoria tritici blotch and yellow leaf spot were contributed by the synthetic hexaploid parent CPI133872 and linked in repulsion with the coincident Lr24/Sr24 locus carried by parent Janz. This is the first report of linked QTL for Septoria tritici blotch and yellow leaf spot contributed by the same parent. Additional QTL for yellow leaf spot were detected in 5AS and 5BL. Consistent QTL for stripe rust resistance were identified in chromosomes 1BL, 4BL and 7DS, with the QTL in 7DS corresponding to the Yr18/Lr34 region. Three major QTL for P. thornei resistance (2BS, 6DS, 6DL) and two for P. neglectus resistance (2BS, 6DS) were detected. The recombinants combining resistance to Septoria tritici blotch, yellow leaf spot, rust diseases and root-lesion nematodes from parents CPI133872 and Janz constitute valuable germplasm for the transfer of multiple disease resistance into new wheat cultivars.
Keywords: Pratylenchyus spp; Pyrenophora tritici-repentis; Rust diseases; Septoria tritici blotch; Synthetic hexaploid wheat; Triticum aestivum

Self-organizing maps: a tool to ascertain taxonomic relatedness based on features derived from 16S rDNA sequence - Raje, D. V.; Purohit, H. J.; Badhe, Yogesh P.; Tambe, S. S.; Kulkarni, B. D. (Journal of Biosciences, 2010)
Exploitation of microbial wealth, of which almost 95% or more is still unexplored, is a growing need. The taxonomic placements of a new isolate based on phenotypic characteristics are now being supported by information preserved in the 16S rRNA gene. However, the analysis of 16S rDNA sequences retrieved from metagenome, by the available bioinformatics tools, is subject to limitations. In this study, the occurrences of nucleotide features in 16S rDNA sequences have been used to ascertain the taxonomic placement of organisms. The tetra- and penta-nucleotide features were extracted from the training data set of the 16S rDNA sequence, and was subjected to an artificial neural network (ANN) based tool known as self-organizing map (SOM), which helped in visualization of unsupervised classification. For selection of significant features, principal component analysis (PCA) or curvilinear component analysis (CCA) was applied. The SOM along with these techniques could discriminate the sample sequences with more than 90% accuracy, highlighting the relevance of features. To ascertain the confidence level in the developed classification approach, the test data set was specifically evaluated for Thiobacillus, with Acidiphilium, Paracocus and Starkeya, which are taxonomically reassigned. The evaluation proved the excellent generalization capability of the developed tool. The topology of genera in SOM supported the conventional chemo-biochemical classification reported in the Bergey manual.
Keywords: Curvilinear component analysis; Principal component analysis; self-organizing maps

Small molecule inhibition of phosphatidylinositol-3,4,5-triphosphate (PIP3) binding to pleckstrin homology domains - Miao, Benchun; Skidan, Igor; Yang, Jinsheng; Lugovskoy, Alexey; Reibarkh, Mikhail; Long, Kai; Brazell, Tres; Durugkar, Kulbhushan A.; Maki, Jenny; Ramana, C. V.; Schaffhausen, Brian; Wagner, Gerhard; et al. (Proceedings of the National Academy of Sciences of the United States of America, 2010)
The PI3-kinase (PI3K) pathway regulates many cellular processes, especially cell metabolism, cell survival, and apoptosis. Phosphatidylinositol-3,4,5-trisphosphate (PIP3), the product of PI3K activity and a key signaling molecule, acts by recruiting pleckstrin-homology (PH) domain-containing proteins to cell membranes. Here, we describe a new structural class of nonphosphoinositide small molecule antagonists (PITenins, PITs) of PIP3-PH domain interactions (IC50 ranges from 13.4 to 31 mu M in PIP3/Akt PH domain binding assay). PITs inhibit interactions of a number of PIP3-binding PH domains, including those of Akt and PDK1, without affecting several PIP2-selective PH domains. As a result, PITs suppress the PI3K-PDK1-Akt pathway and trigger metabolic stress and apoptosis. A PIT-1 analog displayed significant antitumor activity in vivo, including inhibition of tumor growth and induction of apoptosis. Overall, our studies demonstrate the feasibility of developing specific small molecule antagonists of PIP3 signaling.
Keywords: Anticancer; PIP3 antagonist

Studies of antimicrobial activity of turmeric (Curcuma Longa L.) leaves and rhizomes collected during plant growth phases - Shirgurkar, M. V.; Thengane, Shubhada Ratnakar (Research Journal of Biotechnology, 2010)
Turmeric is the processed underground rhizome used as spice, herbal medicines, dying agent and cosmetics. The leaves and rhizomes of this plant were collected at periodic intervals. These samples were air dried, powdered and extracted with MeOH and EtOH. Antibacterial activity of these extracts was determined against three different index microbes, gram-positive cocci, gram-negative rod and cocci using well diffusion method with appropriate controls. Antimicrobial activity of the 4-month-old leaves was found to be the maximum while that of mature and fresh rhizomes was the maximum against both gram-positive and Gram-negative bacteria.
Keywords: antibacterial activity; Curcuma longa; Leaf extract; Minimum inhibitory concentration; rhizome extract

Studies of penicillin G acylase immobilization using highly porous cellulose-based polymeric membrane - Adikane, H. V.; Thakar, D. M. (Applied Biochemistry and Biotechnology, 2010)
The different ionic molecules/compounds were used as a ligand for the immobilization of penicillin G acylase on the highly porous cellulose-based polymeric membrane having buffer flux 1,746 LMH (L m(-2) h(-1)) at 0.5 bar pressure. The immobilized enzyme activity around 250 U-App was obtained with the ligand such as proline, tryptophan, casein acid hydrolysate, and brilliant green. Comparatively, proline showed less IMY% (percentage immobilization yield-58) but higher RTA% (percentage of activity retention-71) and specific activity (145 U-App g(-1)). However, the crosslinked preparation of brilliant green obtained using glutaraldehyde showed 82 +/- 2.7% immobilized enzyme activity after the completion of successive five cycles. In comparison with the free enzyme, the enzyme immobilized on the brilliant green coupled membrane showed around 2.4-fold increase in K-m value (47.4 mM) as well as similar optimum pH (7.2) and temperature (40 degrees C). The immobilized enzyme retained almost 50% activity after 107 days and 50 cycles of operation. Almost 50% decrease in buffer flux after enzyme immobilization was observed. At the end of the 30 cycles, flux pattern shows around 38% decrease in buffer flux however, after 16 cycles of operation flux moves closer towards the steady state.
Keywords: Brilliant green; Immobilization; Penicillin G acylase; Polymeric membrane; Proline

Synthesis and characterization of nanocrystalline zinc substituted nickel ferrites - Hankare, P. P.; Sankpal, U. B.; Patil, R. P.; Mulla, Imtiaz S.; Sasikala, R.; Tripathi, A. K.; Garadkar, K. M. (Journal of Alloys and Compounds, 2010)
Nanocrystalline zinc substituted nickel ferrites, Ni(1-x)Zn(x)Fe(2)O(4) (0.0 <= x <= 1.0) have been prepared by citrate gel auto-combustion method. The effect of zinc ion content on structural, electrical transport and magnetic properties has been studied. The X-ray diffraction (XRD) pattern revealed that, all the compositions possess single-phase spinel structure. The nano-sized grain structure formation was confirmed by transmission electron microscopy (TEM). The dc electrical resistivity shows the samples are semiconducting in nature. The magnetic measurements showed that the composition Ni(0.6)Zn(0.4)Fe(2)O(4) has maximum saturation magnetization (M(s)) while high coersivity (Hc) for ZnFe(2)O(4). Thermoelectric power measurement study showed that the compounds, with x <= 0.4 are p-type and for x > 0.4 behaves n-type conduction mechanism. (C) 2010 Published by Elsevier B.V.
Keywords: Electron microscopy; Magnetic; Sintering; X-ray diffraction

Vanadia-titania thin films for photocatalytic degradation of formaldehyde in sunlight - Akbarzadeh, Rokhsareh; Shubhangi B. Umbarkar; Sonawane, Ravindra S.; Takle, Srikant; Dongare, Mohan K. (Applied Catalysis A-General, 2010)
Thin films of vanadia-titania with good adhesion to the substrates have been deposited on various substrates such as glass slides, glass helix and silica raschig rings by simple sol-gel dip coating process using vanadium and titanium peroxide gel. The optimum concentration of vanadia in titania for obtaining good uniform viscous gel was found to be 0.5-4 wt% beyond which the vanadia particles disturb the gel network, resulting in the formation of a gelatinous precipitate. The films of vanadia-titania as well as the dried powder of the bulk gel were characterized by different characterization techniques. Optical characterization by UV-vis spectrophotometer showed a shift in optical absorption wavelength to the visible region that may be due to the incorporation of vanadia into titania structure. The XRD revealed the formation of anatase phase in pure titania as well as titania with up to 2% vanadia loading, whereas formation of rutile as minor phase along with anatase as major phase was observed at higher vanadia loading. The XRD did not show any peaks of vanadia phase up to 5% vanadia loading indicating either incorporation of vanadia into titania structure or high dispersion of amorphous vanadia on titania support. The pure and vanadia doped TiO(2) thin films were evaluated for their photocatalytic activity for degradation of methylene blue as a model pollutant under sunlight. Doping Of V(2)O(5) in TiO(2) showed an increase in the photo-degradation rate of methylene blue by a factor of 3-6.6 times compared to pure TiO(2). The highest rate has been obtained for 4% V(2)O(5)-doped TiO(2) films. Vanadia doped TiO(2) thin films were also found to be very active for photocatalytic degradation of formaldehyde from aqueous solution in sunlight. (c) 2009 Elsevier B.V. All rights reserved.
Keywords: Formaldehyde; Methylene blue; Photocatalysis; Sunlight; Thin films; V(2)O(5)/TiO(2)

Antifungal activity of novel synthetic peptides by accumulation of reactive oxygen species (ROS) and disruption of cell wall against Candida albicans - Maurya, Indresh Kumar; Pathak, Sarika; Sharma, Monika; Sanwal, Hina; Chaudhary, Preeti; Tupe, Santosh; Deshpande, Mukund V.; Chauhan, Virander Singh; Prasad, Rajendra (Peptides, 2011)
In the present work, we investigated the antifungal activity of two de novo designed, antimicrobial peptides VS2 and VS3, incorporating unnatural amino acid alpha,beta-dehydrophenylalanine (Delta Phe). We observed that the low-hemolytic peptides could irreversibly inhibit the growth of various Candida species and multidrug resistance strains at MIC(80) values ranging from 15.62 mu M to 250 mu M. Synergy experiments showed that MIC(80) of the peptides was drastically reduced in combination with an antifungal drug fluconazole. The dye PI uptake assay was used to demonstrate peptide induced cell membrane permeabilization. Intracellular localization of the FITC-labeled peptides in Candida albicans was studied by confocal microscopy and FACS. Killing kinetics, PI uptake assay, and the intracellular presence of FITC-peptides suggested that growth inhibition is not solely a consequence of increased membrane permeabilization. We showed that entry of the peptide in Candida cells resulted in accumulation of reactive oxygen species (ROS) leading to cell necrosis. Morphological alteration in Candida cells caused by the peptides was visualized by electron microscopy. We propose that de novo designed VS2 and VS3 peptides have multiple detrimental effects on target fungi, which ultimately result in cell wall disruption and killing. Therefore, these peptides represent a good template for further design and development as antifungal agents. (C) 2011 Elsevier Inc. All rights reserved.
Keywords: Antifungal peptides; Candida albicans; Cell wall; ROS

Association between chemical and genetic variation in calophyllum inophyllum, a medicinally important tree of the Western Ghats of India - Pawar, Kiran D.; Joshi, Swati P.; Thengane, Shubhada Ratnakar (Plant Systematics and Evolution, 2011)
The objective of the present work is to study the chemical variation in Calophyllum inophyllum growing along the Western Ghats of India. Contents of dipyranocoumarins (inophyllums) in C. inophyllum were determined to assess whether they could be used as a taxonomic marker for C. inophyllum. This study also aims to establish inter simple sequence repeat (ISSR) markers that can be used to study genetic variation within the species and explore correlation between ISSR and chemical markers. The contents of dipyranocoumarins were estimated in seeds collected from 20 locations. Leaves from plants at the same 20 locations were assayed for ISSR variation. A dendrogram based on Nei's genetic distance as well as principal component analysis based on dipyranocoumarins and ISSR variation clustered plants from these 20 locations into three groups that indicated close relationship among ISSR, dipyranocoumarins contents, and geographical position (variation) of locations. Based on this study, two locations of elite plants were identified.
Keywords: Calophyllum inophyllum; Dendrogram; dipyranocoumarins; HPLC; ISSR; Principal component analysis; Western Ghats of India

Auxin signaling and transport promote susceptibility to the root-infecting fungal pathogen fusarium oxysporum in arabidopsis - Kidd, Brendan N.; Kadoo, Narendra Y.; Dombrecht, Bruno; Tekeoglu, Muecella; Gardiner, Donald M.; Thatcher, Louise F.; Aitken, Elizabeth A. B.; Schenk, Peer M.; Manners, John M.; Kazan, Kemal (Molecular Plant-Microbe Interactions, 2011)

Bioactivity of essential oils of zingiber officinalis and achyranthes aspera against mosquitoes - Khandagle, Abhay J.; Tare, Vrushali S.; Raut, Kishor D.; Morey, Rashmi A. (Parasitology Research, 2011)
Due to the global health problems associated with mosquito-borne diseases, over two million people primarily in the tropical countries are at risk. The widely and commonly used chemical method though effective, has some major disadvantages making insect control practically difficult. In view of the above, it is unavoidable to search for new molecules, which are eco-friendly, cheaper, and safer. The present study deals with evaluation of bioactive potential of two commonly occurring plants against mosquitoes presenting an alternative to the conventional chemical methods. Essential oils extracted by steam distillation from rhizome of Zingiber officinalis and leaf and stem of Achyranthes aspera were evaluated for larvicidal, attractant/repellent, and oviposition attractant/deterrent activity against two mosquito species viz. Aedes aegypti and Culex quinquefasciatus. The highest larvicidal activity, i.e., LC(50) = 154 ppm and LC(50) = 197 ppm for A. aegypti and C. quinquefasciatus, respectively was shown by Z. officinalis. This oil also offers 5-h protection at the concentration of 0.5 mg/cmA(2) from both mosquito species. The highest oviposition deterrence activity was exhibited by A. aspera stem oil, i.e., 100% and 85.71%, in case of A. aegypti and C. quinquefasciatus, respectively, at the concentration of 0.1%. These results reveal that both these oils have control potential against A. aegypti and C. quinquefasciatus.

Classification of Indian power coals using K-means clustering and self organizing map neural network - Pandit, Yogesh P.; Badhe, Yogesh P.; Sharma, B. K.; Tambe, Sanjeev S.; Kulkarni, Bhaskar D. (Fuel, 2011)
The present study reports results of the classification of Indian coals used in thermal power stations across India. For classifying these power coals a classical unsupervised clustering technique, namely ``K-Means Clustering'' and an artificial intelligence (AI) based nonlinear clustering formalism known as ``Self-Organizing Map (SOM)'' have been used for the first time. To conduct the said classification, five coal descriptor variables namely moisture, ash, volatile matter, carbon and gross calorific value (GCV) have been used. The classification results thereof indicate that Indian power coals from different geographical origins can be classified optimally into seven classes. It has also been found that the K-means and SOM based classification results exhibit similarity in close to 75% coal samples. Further, K-means and SOM based seven coal categories have been compared with as many grades of a commonly employed Useful Heat Value (UHV) based Indian non-coking coal grading system. Here, it was observed that a number of UHV-based grades exhibit similarity with the categories identified by the K-means and SOM methods. The classification of Indian power coals as provided here can be gainfully used in selecting application-specific coals as also in their grading and pricing. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Coal classification; Indian power coals; K-means clustering; Self-Organizing Map

Comparative and chemical proteomic approaches reveal gatifloxacin deregulates enzymes involved in glucose metabolism - Suresh, Kesavan K.; Bhosale, Santosh D.; Thulasiram, Hirekodathakallu V.; Kulkarni, Mahesh J. (Journal of Toxicological Sciences, 2011)
Gatifloxacin has been associated with increased risks of hypoglycemic and hyperglycemic side effects. In order to understand the molecular mechanism of gatifloxacin induced deregulation of glucose metabolism, a Combination of comparative and chemical proteomic approaches were employed using yeast as a model system. Differential protein expression studies using two dimensional electrophoresis and mass spectrometry reveal that gatifloxacin deregulates the expression of key enzymes involved in glucose metabolism. Furthermore, affinity chromatography and LC-MSE analysis led to identification of enolase, as one of the key gatifloxacin binding proteins. Fluorescence spectrometric studies confirmed that the gatifloxacin indeed binds to enolase. Role of enolase in regulation of gatifloxacin induced dysglycemic effect is discussed.
Keywords: antibiotics; Differential protein expression; Fluoroquinolone; Glycolysis; Yeast

Degradation of tannic acid by cold-adapted klebsiella sp NACASA1 and phytotoxicity assessment of tannic acid and its degradation products - Jadhav, Umesh; Kadu, Sudhir; Thokal, Nilesh; Padul, Manohar; Dawkar, Vishal V.; Chougale, Ashok D.; Salve, Abhay; Patil, Manoj (Environmental Science and Pollution Research, 2011)
The focus of the present study is to know the potential of bacterial isolate for tannic acid degradation at low temperature. Also, we tried to evaluate the suitability of phytotoxicity testing protocol for the determination of tannic acid toxicity. Screening for tannic acid degrading bacterial strains was carried out by using microbial isolation techniques. The 16S rDNA amplicon of the isolate was used to identify the isolate. The effect of different concentrations of tannic acid and its degradation products on germination of Vigna unguiculata was evaluated. The study was carried out to determine total sugar and starch content of the used seeds and even to check the presence of alpha-amylase activity during seed germination. The isolated bacterium was identified as Klebsiella sp NACASA1 and it showed degradation of tannic acid in 40 (+/- 0.85***) h at 15A degrees C and pH 7.0. A gradual decrease in root/shoot length was observed with increasing concentration of tannic acid. There was 95.11 (+/- 0.24**)% inhibition in alpha-amylase activity at 20,000 ppm tannic acid, as compared to control. No such effects were observed on germination, root-shoot length, and alpha-amylase activity with tannic acid degradation products. The results obtained confirmed that tannic acid may act as a toxic agent in plant cells. The simple biodegradation process presented in this study was found to be effective in reducing toxicity of tannic acid. Also, it reveals the potential of soil bacterium to degrade tannic acid at low temperature.
Keywords: Cold-adapted bacterium; Phytotoxicity; Tannic acid degradation

Determination of organic acid impurities in lactic acid obtained by fermentation of sugarcane juice - Qureshi, Mohd Shadbar; Bhongale, Sunil Sitaram; Thorave, Archana K. (Journal of Chromatography A, 2011)
Lactic acid produced by fermentation process mostly contains a number of aliphatic carboxylic acids as impurities. In this work, carboxylic acid impurities in lactic acid samples from a number of sources were determined at ppm levels. A simple HPLC method was developed that utilized a new generation polar embedded reverse phase, 20 mM phosphate buffer at pH 2.20 (+/- 0.05) and UV detection at 210 nm. The method enabled quantitative analysis of the above acids in lactic acid matrix. The experimental conditions for column temperature, mobile phase pH and flow rate were optimized. A detailed validation of the method was performed for linearity, precision, accuracy, selectivity, limit of detection (LOD), limit of quantitation (LOQ), ruggedness and repeatability and reproducibility (R&R). (C) 2011 Elsevier B.V. All rights reserved.
Keywords: Lactic acid; Method validation; Organic acid impurities; Polar embedded RP-HPLC; Sugarcane juice fermentation

Differential induction, purification and characterization of cold active lipase from Yarrowia lipolytica NCIM 3639 - Yadav, K. N. Sathish; Adsul, Mukund G.; Bastawade, Kulbhushan B.; Jadhav, D. D.; Thulasiram, H. V.; Gokhale, D. V. (Bioresource Technology, 2011)
The production, purification and characterization of cold active lipases by Yarrowia lipolytica NCIM 3639 is described. The study presents a new finding of production of cell bound and extracellular lipase activities depending upon the substrate used for growth. The strain produced cell bound and extracellular lipase activity when grown on olive oil and Tween 80, respectively. The organism grew profusely at 20 degrees C and at initial pH of 5.5, producing maximum extracellular lipase. The purified lipase has a molecular mass of 400 kDa having 20 subunits forming a multimeric native protein. Further the enzyme displayed an optimum pH of 5.0 and optimum temperature of 25 degrees C. Peptide mass finger printing reveled that some peptides showed homologues sequence (42%) to Yarrowia lipolytica LIP8p. The studies on hydrolysis of racemic lavandulyl acetate revealed that extracellular and cell bound lipases show preference over the opposite antipodes of irregular monoterpene, lavandulyl acetate. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: Cell bound lipase; Cold active lipase; Extracellular lipase; Lavandulyl acetate; Oligomeric lipase

Effect of blend composition and organoclay loading on the nanocomposite structure and properties of miscible poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) blends - Tiwari, Rajkiran R.; Natarajan, Upendra (Polymer Engineering and Science, 2011)
Organically-modified montmorillonite clay nanocomposites of poly(styrene-co-acrylonitrile) (SAN), poly(methyl methacrylate) (PMMA) and SAN/PMMA miscible blend are investigated. Structure characteristics at the nanoscale and microscale and thermal and tensile properties are studied as a function of polymer blend composition and filler loading fraction. Blend miscibility and T(g) are unaffected by up to 10% by wt. organoclay. Thermal degradation stability increases with SAN content and exhibits an optimum value of clay loading. Stiffness shows significant improvement. Tensile strength and elongation-at-break suffer as a result of nanocomposite formation. Modulus shows a maximum enhancement of 57% (5 +/- 0.06 GPa at 10 wt% filler, 20/80 SAN/PMMA) and varies linearly with clay fraction for all compositions of matrix phase. Predictions of Halpin-Tsai composite model are in excellent agreement with the experimental behavior over full range of polymer blend composition. Fundamental aspects of a polymer blend-clay nanocomposite are clarified, such as lack of additional synergy between clay platelets and matrix, and tensile ductility reduction, compared with polymer-clay system. POLYM. ENG. SCI., 51:979-991, 2011. (C) 2011 Society of Plastics Engineers

Extrudate swell of linear and branched polyethylenes: ALE simulations and comparison with experiments - Ganvir, Vivek; Gautham, Basavarsu P.; Pol, Harshawardhan; Bhamla, M. Saad; Sclesi, Lino; Thaokar, Rochish; Lele, Ashish K.; Mackley, Malcolm (Journal of Non-Newtonian Fluid Mechanics, 2011)
Extrudate swell is a common phenomenon observed in the polymer extrusion industry. Accurate prediction of the dimensions of an extrudate is important for appropriate design of dies for profile extrusion applications. Prediction of extrudate swell has been challenging due to (i) difficulties associated with accurate representation of the constitutive behavior of polymer melts, and (ii) difficulties associated with the simulation of free surfaces, which requires special techniques in the traditionally used Eulerian framework. In a previous work we had argued that an Arbitrary Lagrangian Eulerian (ALE) based finite element formulation may have advantages in simulating free surface deformations such as in extrudate swell. In the present work we reinforce this argument by comparing our ALE simulations with experimental data on the extrudate swell of commercial grades of linear polyethylene (LLDPE) and branched polyethylene (LOPE). Rheological behavior of the polymers was characterized in shear and uniaxial extensional deformations, and the data was modeled using either the Phan-Thien Tanner (PTT) model or the eXtended Pom-Pom (XPP) model. Additionally, flow birefringence and pressure drop measurements were done using a 10:1 contraction-expansion (CE) slit geometry in a MultiPass Rheometer. Simulated pressure drop and contours of the principal stress difference were compared with experimental data and were found to match well. This provided an independent test for the accuracy of the ALE code and the constitutive equations for simulating a processing-like flow. The polymers were extruded from long (L/D=30) and short (L/D=10) capillaries dies at 190 degrees C. ALE simulations were performed for the same extrusion conditions and the simulated extrudate swell showed good agreement with the experimental data. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
Keywords: ALE-FEM; extrudate swell; Flow birefringence; MultiPass Rheometer; PSD; PTT; XPP

Gold catalyzed glycosidations for the synthesis of sugar acrylate/acrylamide hybrids and their utility - Thadke, Shivaji A.; Kar, Mritunjoy; Sen Gupta, Sayam; Hotha, Srinivas (Carbohydrate Research, 2011)
Propargyl glyco 1,2-orthoesters were exploited for the efficient synthesis of interesting glycomonomers such as glyco-acrylates and acrylamides using gold catalysts. It was observed that propargyl glyco 1,2-orthoesters with hydroxyethyl acrylates gives very good yield of the corresponding glyco-acrylates in a single step in the presence of catalytic amount of gold(III) catalyst; whereas, gold catalyzed glycosidation reaction on hydroxyethyl acrylamides was found to yield the corresponding acrylamidoyl 1,2-orthoester which was then converted to the corresponding glycol-acrylamide in the presence of catalytic amount of TMSOTf. Synthesized glyco-acrylate/acrylamide monomers are shown to undergo thiolate addition as well as free radical polymerization (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: carbohydrates; Glycoacrylamides; Glycoacrylates; Glycopolymers; glycosylation; Gold

Increase in efficiency of media utilization for recombinant protein production in Chinese hamster ovary culture through dilution - Thombre, Shreya; Gadgil, Mugdha (Biotechnology and Applied Biochemistry, 2011)
Animal cells are extensively used for the large-scale production of recombinant proteins. Processes and genetically engineered cell lines have been developed to enhance longevity of the culture and increase protein productivity. In this study, we tested the effect of diluting a culture of Chinese hamster ovary (CHO) cells with phosphate-buffered saline (PBS) on cell growth and efficiency of media utilization. An immunoglobulin G-expressing CHO cell line was cultured in CD CHO media followed by dilution of the culture with PBS after the end of the exponential phase. A 28% and 61% increase in protein yield per milliliter of media was observed in the diluted culture in the batch and fed-batch mode with glucose and protein hydrolysate feeding, respectively. To aid in analyzing the potential causes of this observed increase, an unstructured mathematical model was constructed using previously reported kinetics to simulate cell growth, nutrient utilization, and protein production. The model predicts an increase in recombinant protein yield per milliliter of media in PBS diluted cultures under both batch and fed-batch conditions, and suggests that this observed increase could at least partly be due to a decrease in inhibitor concentration in the diluted culture.
Keywords: chemically defined media; culture dilution; glucose consumption; inhibitor formation; recombinant protein yield

Influence of abiotic elicitation on production of dipyranocoumarins in suspension cultures of calophyllum inophyllum L. - Pawar, Kiran D.; Thengane, Shubhada Ratnakar (Acta Physiologiae Plantarum, 2011)
Effects of elicitation with heavy metals such as copper, cadmium, chromium (abiotic elicitation) and supplementation of CaCl(2) on production of dipyranocoumarins (inophyllums) in suspension cultures of leaf and stem callus of Calophyllum inophyllum were studied. The optimum timing for elicitor introduction was found to be the 10th day after initiating the suspension cultures. Cadmium as abiotic elicitor in suspension cultures of stem callus was found best to elicit maximum production of inophyllums A, C, and calophyllolide while cadmium in suspension cultures of leaf callus was found best for eliciting maximum production of inophyllums B and P. Inophyllum D was the only dipyranocoumarin whose highest production was achieved when 1.0 mM chromium was used as abiotic elicitor in suspension cultures of stem callus. Out of the three abiotic elicitors used, none could result biomass growth. Only incorporation of CaCl(2) in suspension cultures resulted biomass growth. A maximum of 35.26-fold biomass growth was achieved when suspension cultures of stem callus were incorporated with 2.0 mM CaCl(2). CaCl(2) was noted to have no positive influence on production of most of the dipyranocoumarins under study.
Keywords: Abiotic elicitation; Calophyllum inophyllum; dipyranocoumarins; Heavy metals; Suspension culture

Influence of endophytic fungal elicitation on production of inophyllum in suspension cultures of Calophyllum inophyllum L. - Pawar, Kiran D.; Yadav, Amit V.; Shouche, Yogesh S.; Thengane, Shubhada Ratnakar (Plant Cell Tissue and Organ Culture, 2011)
The influence of dried cell powder and culture filtrates of endophytic fungi on production of inophyllum in cell suspension cultures of leaf- and stem-derived callus of Calophyllum inophyllum was investigated. Two fungi, Nigrospora sphaerica and Phoma spp., endophytic to C. inophyllum, were isolated from leaf tissues, and were identified by both 18S rRNA gene amplification and sequencing. Elicitation of suspension cultures of both callus types of C. inophyllum with dried cell powder and culture filtrates of both fungi consistently elicited production of inophyllum A, B, C, and P. In comparison to stem-derived callus, suspension cultures of leaf-derived callus enhanced production of most inophyllum. Of the four inophyllum studied, the highest production of inophyllum A, C, and P was achieved in elicited suspension cultures of leaf-derived callus. Suspension cultures of stem-derived callus enhanced production only of inophyllum B. When suspension cultures of leaf-derived callus were elicited with 40 mg dried cell powder of Phoma spp., a level of 751-fold (6.84 mg/100 g elicited biomass) of inophyllum A was produced, compared to control. Whereas, a level of 414-fold (6.22 mg/100 g elicited biomass) of inophyllum B was produced when suspension cultures of stem-derived callus were elicited with 20 mg dried cell powder of N. sphaerica. When compared to control, a 10% culture filtrate of N. sphaerica in suspension cultures of leaf-derived callus elicited inophyllum C and P production by 928-fold (7.43 mg/100 g elicited biomass) and 750-fold (1.5 mg/100 g elicited biomass), respectively.
Keywords: Biotic elicitation; Calophyllum inophyllum; Endophytic fungi; Inophyllum; Suspension cultures

Influence of reactive compatibilization on the structure and properties of PP/LDH nanocomposites - Lonkar, Sunil P.; Therias, Sandrine; Leroux, Fabrice; Gardette, Jean Luc; Singh, Raj Pal (Polymer International, 2011)
Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared by the direct melt intercalation method usingmaleic anhydride grafted polypropylene (PP-g-MAH) as a reactive compatibilizer. The compatibilization effects provided by PP-g-MAH in different weight fractions and their influence on the structure and properties of the final nanocomposites were investigated. The interactions and structural morphology of the nanocomposites were examined by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electronmicroscopy. Thermal, mechanical and rheological properties of these nanocomposites were investigated as a function of compatibilizer concentration. The detailed morphological and X-ray diffraction results revealed that the degree of LDH dispersion increases as the amount of PP-g-MAH increases. Study of the linear viscoelastic properties showed that the storage modulus G' is very sensitive to the microstructure of the nanocomposite. The thermal properties of the nanocomposites were significantly influenced by the weight fraction of PP-g-MAH due to the shielding and nucleating effect of exfoliated layers. Both the tensile strength and modulus showed substantial improvements with increasing PP-g-MAH content, while the elongation at break substantially decreased, although the presence of PP-gMAH somewhat improves these values. The overall results showed that 10 wt% of compatibilizer is optimum to achieve nanocomposites with better performance. (C) 2011 Society of Chemical Industry
Keywords: compatibilization; layered double hydroxides; Nanocomposites; polypropylene; Rheology; thermomechanical properties

Kinetics of nitric oxide adsorption on Pd(111) surfaces through molecular beam experiments: a quantitative study - Nagarajan, Sankaranarayanan; Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S.; Prasad, Sudarsan D. (Journal of Physical Chemistry C, 2011)
A detailed kinetic picture derived by molecular beam studies of the adsorption-desorption of the NO/Pd(111) system is presented. Numerical simulations and detailed kinetic analysis show that the precursor state model of adsorption provides a valid picture of the sticking coefficient variation with surface coverage, especially at low temperatures. At higher temperatures, the precursor model gives way to the Langmuir molecular model of adsorption. All the parameters of the precursor state model have been quantified. Temperature programmed desorption (TPD) studies further show that there is a slight repulsive interaction between adsorbed NO molecules and there is only a negligible fraction of dissociated molecules on the surface for temperatures less than 500 K, as the Pd(111) surface is defect free. A Bragg-Williams (BW) lattice gas model with repulsive interactions, within the framework of mean field approach (MFA), is shown to describe the TPD spectra reasonably well.

MgCl2 center dot 6PhCH(2)OH - a new molecular adduct as support material for ziegler-natta catalyst: synthesis, characterization and catalytic activity - Gnanakumar, Edwin S.; Thushara, K. S.; Bhange, Deu S.; Mathew, Renny; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Bhaduri, Sumit; Gopinath, Chinnakonda S. (Dalton Transactions, 2011)
Benzyl alcohol has been used to prepare a single phase MgCl2 center dot 6BzOH molecular adduct as a support for an ethylene polymerization catalyst (Ziegler catalyst). The structural, spectroscopic and morphological aspects of the MgCl2 center dot 6BzOH molecular adduct and the Ziegler catalyst have been thoroughly studied by various physicochemical characterization techniques. The presence of MgO6 octahedrons due to the interaction of Mg2+ with six -OH groups of the benzyl alcohol is confirmed from a Raman feature at 703 cm(-1), and structural studies. The supported catalyst activity has been evaluated for the ethylene polymerization reaction. The lower polymerization activity of the titanated Ziegler-Natta catalyst compared with a standard catalyst is attributed to the strong interaction of titanium chloride with the support and associated electronic factors.

Novel hybrids of fluconazole and furanones: design, synthesis and antifungal activity - Borate, Hanumant B.; Sawargave, Sangmeshwer P.; Chavan, Subhash P.; Chandavarkar, Mohan A.; Iyer, Ramki; Tawte, Amit; Rao, Deepali; Deore, Jaydeep V.; Kudale, Ananada S.; Mahajan, Pankaj S.; Kangire, Gopinath S. (Bioorganic & Medicinal Chemistry Letters, 2011)
During our efforts to develop new antifungal agents, a number of hybrid molecules containing furanones and fluconazole pharmacophores were designed and synthesized. The new chemical entities thus synthesized were tested for their potential as antifungal agents against various fungal strains and it was observed that the compounds with general structure 7 were potent inhibitors of Candida albicans ATCC 24433, Candida glabrata ATCC 90030, Candida tropicalis ATCC 750 and Candida neoformans ATCC 34664 while the fluconazole analogues 12 exhibited antifungal activity against Candida albicans ATCC 24433 and Candida glabrata ATCC 90030. The structure-activity relationship for these compounds is discussed. The synthetic strategies used in the present work have potential to prepare a large number of compounds for further refinement of structures to obtain molecules suitable for development as antifungal drugs. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: Antifungal activity; Fluconazole; Furanones

Novel pyrazole-3-carboxamide derivatives as cannabinoid-1 (CB1) antagonists: journey from non-polar to polar amides - Sasmal, Pradip K.; Reddy, D. Srinivasa; Talwar, Rashmi; Venkatesham, B.; Balasubrahmanyam, D.; Kannan, M.; Srinivas, P.; Kumar, K. Shiva; Devi, B. Neelima; Jadhav, Vikram P.; Khan, Sanjoy K.; Mohan, Priya; et al. (Bioorganic & Medicinal Chemistry Letters, 2011)
The synthesis and biological evaluation of novel pyrazole-3-carboxamide derivatives as CB1 antagonists are described. As a part of eastern amide SAR, various chemically diverse motifs were introduced. In general, a range of modifications were well tolerated. Several molecules with high polar surface area were also indentified as potent CB1 receptor antagonists. The in vivo proof of principle for weight loss is exemplified with a lead compound from this series. (C) 2010 Elsevier Ltd. All rights reserved.

Numerical and experimental studies on extrudate swell of branched polyethylene through axisymmetric and planar dies - Ganvir, Vivek; Gautham, Basavarsu P.; Thaokar, Rochish; Lele, Ashish K.; Pol, Harshwardhan (Journal of Polymer Engineering, 2011)
Extrudate swell is simulated using an Arbitrary Lagrangian Eulerian (ALE) technique based finite element formulation and the same has been validated by comparing the results with reported numerical and experimental studies. In the present work we compare our ALE simulations with our own experimental data on the extrudate swell of commercial grade low density polyethylene (LDPE) resin. The resins were characterized for their rheological behavior in both shear and uniaxial extension. The polymers were extruded from a capillary under isothermal conditions and the extrudates were observed on-line using a video camera. ALE simulations were performed using molecular constitutive model like eXtended Pom-Pom (XPP) for branched (LDPE). The simulated extrudate swell was a good match with the experimental data. It was found that the swell values of LPDE through planar die are higher than the axisymmetric die.
Keywords: ALE-FEM; extrudate swell; polymer flow simulations; XPP

One-pot three-component kabachnik-fields synthesis of alpha-aminophosphonates using H-beta zeolite catalyst - Tillu, V. H.; Dumbre, Deepa K.; Wakharkar, R. D.; Choudhary, Vasant R. (Tetrahedron Letters, 2011)
One-pot three-component Kabachnik-Fields synthesis of alpha-aminophosphonates with high yields from the reaction between carbonyl compound, primary amine, and substituted phosphite can be carried out in a short period, using H-beta zeolite as a reusable catalyst. (C) 2010 Elsevier Ltd. All rights reserved.
Keywords: Carbonyl compound; H-beta zeolite; Primary amine; Substituted phosphite

Organocatalytic route to the synthesis of (6S)-5,6-dihydro-6-[(2R)-2-hydroxy-6-phenylhexyl]-2H-pyran-2-one and ravensara lactones - Dwivedi, Namrata; Tripathi, Divya; Kumar, Pradeep (Tetrahedron-Asymmetry, 2011)
An organocatalytic enantioselective synthesis of the title compounds has been achieved. The stereogenic centers were generated by the iterative use of proline catalyzed alpha-aminoxylations and HWE olefination of aldehydes while the lactone ring was constructed by ring closing metathesis. (C) 2011 Elsevier Ltd. All rights reserved.

Photoactive RuII-polypyridyl complexes that display sequence selectivity and high-affinity binding to duplex DNA through groove binding - Ghosh, Amrita; Das, Priyadip; Gill, Martin R.; Kar, Prasenjit; Walkar, Michael G.; Thomas, Jim A.; Das, Amitava (Chemistry A European Journal, 2011)
The duplex-DNA binding properties of a nonintercalating polypyridyl ruthenium(II) complex that incorporates a linear extended ligand with a catechol moiety has been probed with a variety of photo- and biophysical techniques. These studies reveal that the complex groove binds to DNA sequences biphasically, and displays binding constants equivalent to those of high-affinity metallointercalators. The complex also displays preferential binding to AT-rich sequences. Changes in the structure of the coordinated catechol ligand and the incorporation of intercalating ancillary ligands into the complex were found to modulate both the optical-binding response and binding parameters of the system, which indicates that the catechol moiety plays a crucial role in the observed enhancement to binding affinities.

Poly(acrylonitrile) based ultrafiltration membranes: optimization of preparation parameters - Lohokare, Harshada R.; Bhole, Yogesh S.; Taralkar, Suyog; Kharul, Ulhas K. (Desalination, 2011)
Supported ultrafiltration (UF) membranes based on poly(acrylonitrile) were prepared while varying crucial parameters responsible for controlling membrane porosity, viz.; polymer concentration, solvent and additives in the dope solution. Insight into membrane porosity and morphology was obtained by water flux, solute rejection, bubble point, pore size distribution, SEM and AFM analyses. It was found that merely increasing polymer concentration does not necessarily reduce pore size of membranes. Among four solvents used for the dope solution preparation, N-methyl pyrrolidone was found to offer membranes with optimal combination of flux and rejection of various solutes. Some of the PAN(17) (17% w/w PAN concentration in the dope solution) membranes prepared using organic acid as the additive (citric acid, tartaric acid or maleic acid) offered 1.2-1.7 times higher flux than the membrane prepared using inorganic salt, ZnCl2 as an additive. The porosity of PAN(17) membrane prepared using CA as an additive was larger as compared to membrane prepared using ZnCl2 as an additive. Atomic force microscopy (AFM) analysis of this membrane exhibited higher surface roughness as compared to the ZnCl2 based membrane. Both these membranes exhibited bacteria (E. Coli) log reduction value (LRV) of at least 6; depicting applicability of these membrane for water disinfection. (C) 2011 Elsevier B.V. All rights reserved.
Keywords: Additive; Bacteria rejection; Poly(acrylonitrile); Pore size distribution; Ultrafiltration

Possible deNO(x) management under net oxidizing conditions: a molecular beam study of (NO)-N-15+CO+O-2 reaction on Pd(111) surfaces - Nagarajan, Sankaranarayanan; Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2011)
Isothermal kinetic measurements of (NO)-N-15 reduction with CO on Pd(111) surfaces were carried out under net-oxidizing conditions with (NO)-N-15 + CO + O-2, using a molecular beam instrument (MBI). Transient state (TS) and steady state (SS) kinetic details of the above reaction were obtained for a wide range of temperature and beam compositions, especially with O-2-rich compositions. Increasing O-2 content, generally, suppresses (NO)-N-15 reduction in the SS; nonetheless, irrespective of O-2 content, N-15(2) was produced in TS, and to a significant extent under SS conditions too. Sustainable N-2 production between 450 and 600 K and with low to moderate amount of oxygen was observed, and the extent of NO decomposition was also quantified. The ratio of N-15(2): (N2O)-N-15 was generally found to be around 8:1 under most of the reaction conditions. Maxima in the SS reaction rates of all products were observed between 500 and 600 K. Compared to other elementary reaction steps, a slow decay observed with N + N -> N-2 step under SS beam oscillation conditions demonstrates its contribution to the rate limiting nature of the overall reaction. Fast beam switching experiments have been performed alternately between O-2-lean and -rich conditions, thus highlighting the effectiveness of (NO)-N-15 reduction in TS, irrespective of the beam composition. Possibly in a future technology initiative, this aspect could be exploited to manage more (NO)-N-15 reduction on Pd-based catalysts.

Purification and characterization of bacterial aryl alcohol oxidase from sphingobacterium sp ATM and Its uses in textile dye decolorization - Tamboli, Dhawal P.; Telke, Amar A.; Dawkar, Vishal V.; Jadhav, Shekhar B.; Govindwar, Sanjay P. (Biotechnology and Bioprocess Engineering, 2011)
Aryl alcohol oxidase (AAO) produced by dye decolorizing bacteria Sphingobacterium sp. ATM, was purified 22.63 fold to a specific activity of 21.75 mu mol/min/mg protein using anion exchange and size exclusion chromatography. The molecular weight of the purified AAO was found to be 71 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and confirmed by zymography of AAO using L-dopa. The enzyme showed substrate specificity towards veratryl alcohol, followed by n-propanol. The optimum pH and temperature of purified AAO were found to be 3.0 and 40 degrees C, respectively. The K(m) and V(max) of AAO was 1.1615 mM and 3.13 mM/min when veratryl alcohol was used as substrate. Sodium azide showed maximum inhibition while ethylenediamine tetra acetic acid (EDTA), L-cysteine and dithiothreitol showed slight inhibition. Metal ions also showed slight inhibition. HPLC analysis confirmed the degradation of Direct Red 5B. The metabolite obtained after decolorization of Direct Red 5B was characterized as 3 diazenyl 7 [-(phenyl carbonyl) amino] naphthalene-2-sulfonic acid using GC-MS analysis.
Keywords: aryl alcohol oxidase; Direct Red 5B; dye decolorization; ion exchange chromatography; Sphingobacterium sp ATM

Recurrent somatic embryogenesis and plant regeneration in Angelica glauca Edgew., a critically endangered medicinal plant of the Western Himalaya - Pandey, Meena; Dhar, Uppeandra; Samant, Sher Singh; Shirgurkar, Mrudul Vijay; Thengane, Shubhada Ratnakar (Journal of Horticultural Science & Biotechnology, 2011)
Secondary somatic embryogenesis and plant regeneration from seedling explants of Angelica glauca, an endangered medicinal plant of the Himalaya, is reported for the first time. Callus was obtained from all the explants tested in the present study (i.e., epicotyls, hypocotyls, and cotyledonary nodes). The highest frequency of callus formation (95.8%) was observed using epicotyl explants on 4.0 mu M 2,4-dichlorophenoxyacetic acid (2,4-D), whereas 70.8% of hypocotyl explants, and 58.3% of cotyledonary nodes produced callus. One-hundred percent embryogenic callus was induced from epicotyl explants in 2.0 mu M 6-benzyladenine (BA) and 2.0 mu M alpha-naphthaleneacetic acid (NAA), together with the maximum number of somatic embryos (34.2 embryos per explant). Cotyledonary nodes did not produce somatic embryos. Histological studies confirmed the induction of somatic embryogenesis. Somatic embryos germinated into plantlets upon transfer to half-strength Murashige and Skoog (MS) medium without added plant growth regulators. We observed 85% survival of these plantlets under field conditions. The development of secondary embryos was also observed when primary embryos were sub-cultured on full-strength MS medium containing 2.0 mu M NAA plus 2.0 mu M BA. This system of recurrent somatic embryogenesis provides a route for gene transfer and also for the large-scale production of this critically endangered medicinal plant.