@article { ISI:000320746200022, title = {Biochemical characterization of recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala}, journal = {International Journal of Biological Macromolecules}, volume = {58}, year = {2013}, month = {JUL}, pages = {154-159}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) protein from Leucaena leucocephala was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. Optimum pH for forward and reverse reaction was found to be 6.5 and 7.8 respectively. The enzyme was most stable around pH 6.5 at 25 degrees C for 90 min. The enzyme showed k(cat)/k(m) for feruloyl, caffeoyl, sinapoyl, coumaroyl CoA, coniferaldehyde and sinapaldehyde as 4.6, 2.4, 2.3, 1.7, 1.9 and 1.2 (x10(6) M-1 s(-1)), respectively, indicating affinity of enzyme for feruloyl CoA over other substrates and preference of reduction reaction over oxidation. Activation energy, E-a for various substrates was found to be in the range of 20-50 kJ/mol. Involvement of probable carboxylate ion, histidine, lysine or tyrosine at the active site of enzyme was predicted by pH activity profile. SAXS studies of protein showed radius 3.04 nm and volume 49.25 nm(3) with oblate ellipsoid shape. Finally, metal ion inhibition studies revealed that Ll-CCRH1 is a metal independent enzyme. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Activation energy, Cinnamoyl CoA esters, Cinnamoyl CoA reductase 1, SAXS, stability}, issn = {0141-8130}, doi = {10.1016/j.ijbiomac.2013.03.050}, author = {Sonawane, Prashant and Vishwakarma, Rishi Kishore and Khan, Bashir Mohammad} } @article { ISI:000315306200009, title = {Effect of clay and of electrospinning on the polymorphism, structure and morphology of poly(vinylidene fluoride)}, journal = {European Polymer Journal}, volume = {49}, number = {1}, year = {2013}, month = {JAN}, pages = {90-99}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Electrospun poly(vinylidene fluoride) (PVDF) fibers, containing different amounts of montmorillonite clay were produced, in order to study the effect of clay and of the electrospinning process on the polymorphism, structure and morphology of the PVDF matrix, Clay acted as a processing aid agent, avoiding the formation of beads and improving the quality of the fibers. Clay and the electrospinning process acted synergically on the chain mobility, favoring the formation of beta phase of PVDF, the most valuable for its piezoelectric properties, and shaping its semicrystalline morphology. Electrospinning did not significantly aid the dispersion of clay within the matrix. The interplay of formulation and processing in these composites allowed to obtain PVDF-based materials with varying polymorphism, structure and morphology, offering the possibility to ultimately control their functional properties. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Composite, electrospinning, Poly(vinylidene fluoride), Polymer, polymorphism, SAXS}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2012.09.023}, author = {Neppalli, Ramesh and Wanjale, Santosh and Birajdar, Mallinath S. and Causin, Valerio} } @article { ISI:000335620500016, title = {Effect of self-assembly on triiodide diffusion in water based polymer gel electrolytes: an application in dye solar cell}, journal = {Journal of Colloid and Interface Science}, volume = {425}, year = {2014}, month = {JUL}, pages = {110-117}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The preparation of ordered polymer gels from the amphiphilic block copolymers, Pluronic (R) F77, P123 and polyethylene glycol in the presence of ionic liquid, iodine and organic additives is presented. At 35\%(w/w) concentration these copolymers (F77 and P123) self-assembled into cubic liquid crystalline phase in aqueous solution and characterized by using SAXS and AFM measurements. The effects of micellar aggregation formed by polymers on the ionic transport and triiodide diffusion have been studied by electro-chemistry and SANS experiments. The ionic migration or triiodide diffusion through these polymer gels is found to be affected by the PEO/PPO content in the polymer backbone. These gels were successfully employed as an electrolyte in a dye sensitized solar cell. A remarkable solar to electricity conversion efficiency and good stability was obtained using Pluronic (R) F77 based gel, which is attributed to its thermoreversible sol to gel transition. (C) 2014 Elsevier Inc. All rights reserved.

}, keywords = {Amphiphilic block copolymer, Dye solar cell, Micellar nanochannels, SANS, SAXS, Self-assembly, Water based gel electrolytes}, issn = {0021-9797}, doi = {10.1016/j.jcis.2014.03.047}, author = {Soni, S. S. and Fadadu, K. B. and Vekariya, R. L. and Debgupta, Joyashish and Patel, K. D. and Gibaud, A. and Aswal, Vinod K.} } @article {45637, title = {Highly stable In-SBA-15 catalyst for vapor phase Beckmann rearrangement reaction}, journal = {Microporous and Mesoporous Materials}, volume = {234}, year = {2016}, month = {NOV }, pages = {293-302}, type = {Article}, abstract = {

The Indium doped SBA-15 material was prepared by sol-gel method and tested for vapor phase Beckman rearrangement reaction. Among three indium loading, In/Si ratio of 2/100 was found as an optimum composition in terms of caprolactam selectivity (100\%) and cyclohexanone oxime conversion (100\%). The catalysts were characterized by N-2 adsorption, small-angle X-rays/neutron scattering (SAXS/SANS), XRD, FESEM, HRTEM, EDX, UV, FTIR and NH3-TPD techniques. In-situ SANS experiment was performed on the adsorption of CO2 to detect the micropores in the mesopore wall. All catalysts samples have highly ordered hexagonal structure with well dispersed indium in the silica matrix. The fine tuning of weak and strong acid sites were found in indium doped SBA-15 (In/Si = 2/100) catalyst. The same catalyst showed optimum catalytic performance, high space time yield 114.4 mol/h/g(cat) and high stability till 6 h of reaction without deactivation. The micro-kinetic analysis showed that there were no external and internal diffusion limitations in the SBA-15 catalyst. The reaction mechanism of Beckmann rearrangement over In-SBA-15 has been elucidated. (C) 2016 Elsevier Inc. All rights reserved.

}, keywords = {e-Caprolactam, In-situ SANS, indium, SAXS, SBA-15}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2016.07.024}, author = {Kumar, Rawesh and Shah, Sneha and Bahadur, Jitendra and Melnichenko, Yuri B. and Sen, Debasis and Mazumder, S. and Vinod, Chathakudath P. and Chowdhury, Biswajit} } @article {46006, title = {Mapping fusogenicity of ciprofloxacin-loaded liposomes with bacterial cells}, journal = {AAPS Pharmscitech}, volume = {20}, year = {2019}, month = {JUL}, pages = {180}, type = {Article}, abstract = {

The process of liposome fusion with cellular membrane plays key role in delivering encapsulated drug molecule into the cell. This process becomes very important for molecules having low permeability as they fail to reach the site of action located inside the cell. Ciprofloxacin (CIP), a broad-spectrum BCS class IV antibiotic, has poor permeability. In the present work, CIP-loaded liposomes were prepared using solvent evaporation method and optimized by 3(2) factorial design approach. The optimized batch of CIP-loaded liposomes was characterized for size, entrapment efficiency, zeta potential, FTIR, and microbial susceptibility study on Staphylococcus aureus (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). Confocal microscopy was used to study the fusogenicity process of CIP-loaded liposomes with bacterial cells. Additionally, the kinetics of fusogenicity process was studied using SAXS for the first time. Surprisingly, the rate of fusion of CIP-loaded liposomes with cell wall of S. aureus was twice when compared to the cell wall of E. coli. It is believed that the current work can act as a roadmap in selection of proper excipients while developing formulations which would expedite the fusogenicity and may execute pharmacological activity of poorly penetrable drug molecules at lower dose.

}, keywords = {ciprofloxacin, confocal microscopy, fusion, liposomes, SAXS}, issn = {1530-9932}, doi = {10.1208/s12249-019-1381-4}, author = {Patil, Runali and Torris, Arun and Bhat, Suresh and Patil, Sharvil} } @article {47360, title = {Process-induced microstructure in viscose and lyocell regenerated cellulose fibers revealed by SAXS and SEM of acid-etched samples}, journal = {ACS Applied Polymer Materials}, volume = {3}, year = {2021}, month = {MAY }, pages = {2598-2607}, type = {Article}, abstract = {

Regenerated cellulose fibers represent an important class of bioderived commercial fibers. The traditional viscose process requires the use of environmentally harmful carbon disulfide solvent to produce fibers. Lyocell fibers, produced using a more sustainable recent process, exhibit differences in properties from viscose. These differences arise from their semicrystalline microstructure, formed during fiber spinning. It is widely believed that regenerated cellulose fibers predominantly form fringed fibrillar crystals. We optimize acid etching, followed by SEM as an experimental tool to visualize this fibrillar structure. Acid etching provides sufficient topological contrast to directly visualize similar to O(10 nm) fibrils using field-emission scanning electron microscopy (SEM). We combine SEM with small-angle X-ray scattering (SAXS) to reveal other microstructural details. We observe a Bragg peak, indicating the coexistence of stacked lamellar structure with crystalline fibrils for viscose fibers, but not for lyocell. Viscose and lyocell fibers are characterized by partially oriented semicrystalline microstructure. We present a methodology to calculate the Lorentz correction for such microstructure and employ this to analyze the lamellar scattering from viscose fibers using a 1D correlation function approach. We characterize the lamellar microstructure after swelling viscose fibers with water and observe expansion of the Bragg spacing due to water absorption in the amorphous regions. Our data suggest that the water-induced plasticization of amorphous regions is inhomogeneous. Lamellar stacks that are more misoriented from the fiber direction exhibit lower swelling than those along the fiber direction. The experimental methods described in this work reveal interesting details of semicrystalline microstructure in regenerated cellulose fibers, with important implications for the mechanical response of dry and wet fibers. The methods developed here might find use in investigations of other polymer fibers as well.

}, keywords = {acid etching, crystalline lamellae, fibers, fibrils, Lorentz correction, Regenerated cellulose, SAXS}, issn = {2637-6105}, doi = {10.1021/acsapm.1c00204}, author = {Sharma, Aakash and Wankhede, Parnashri and Samant, Roopali and Nagarkar, Shailesh and Thakre, Shirish and Kumaraswamy, Guruswamy} }