01799nas a2200169   4500008004100000022001400041245013900055210006900194260008000263300001400343490000700357520107100364100001601435700002801451700001901479856013101498       2006                        eng d  a0957-448400aConstruction of conductive multilayer films of biogenic triangular gold nanoparticles and their application in chemical vapour sensing0 aConstruction of conductive multilayer films of biogenic triangul  aDIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcMAY  a2399-24050 v173 a<p>Metal nanoparticles are interesting building blocks for realizing films for a number of applications that include bio- and chemical sensing. To date, spherical metal nanoparticles have been used to generate functional electrical coatings. In this paper we demonstrate the synthesis of electrically conductive coatings using biologically prepared gold nanotriangles as the building blocks. The gold nanotriangles are prepared by the reduction of aqueous chloroaurate ions using an extract of the lemongrass plant (Cymbopogon flexuosus) which are thereafter assembled onto a variety of substrates by simple solution casting. The conductivity of the film shows a drastic fall upon mild heat treatment, leading to the formation of electrically conductive thin films of nanoparticles. We have also investigated the possibility of using the gold nanotriangle films in vapour sensing. A large fall in film resistance is observed upon exposure to polar molecules such as methanol, while little change occurs upon exposure to weakly polar molecules such as chloroform.</p>1 aSingh, Amit1 aChaudhary, Minakshi, V.1 aSastry, Murali  uhttps://library.ncl.res.in/content/construction-conductive-multilayer-films-biogenic-triangular-gold-nanoparticles-and-their-002031nas a2200229   4500008004100000022001400041245013900055210006900194260007700263300001200340490000600352520119500358653001801553653000901571653001801580653001201598653001601610100001601626700001901642700001901661856012101680       2007                        eng d  a1613-681000aSpider silk as an active scaffold in the assembly of gold nanoparticles and application of the gold-silk bioconjugate in vapor sensing0 aSpider silk as an active scaffold in the assembly of gold nanopa  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAR  a466-4730 v33 a<p>Spider silk is being viewed with interest by materials scientists due to its excellent resilience and mechanical properties. In this paper we show that spider silk is an excellent scaffold for the one-step synthesis and assembly of gold nanoparticles. Formation of a gold nanoparticle-spider-silk bioconjugate material is accomplished by simple reaction of the fibers with aqueous chloroauric acid. The gold nanoparticles thus formed are strongly bound to the spider-silk fiber surface enabling study of the electrical properties of the nano bioconjugate. Using the well-known contraction/expansion behavior of the fibers in solvents of varying polarity, we show that exposure of the gold nanoparticle-spider silk bioconjugate to vapors of methanol and chloroform leads to changes in electrical transport through the nanoparticles and thus, the possibility of developing a vapor sensor. The bioconjugate shows excellent response time and cycling efficiency to methanol vapors. The activation energy of electron transport from one gold nanoparticle to another in the nanobiocojugate was determined from temperature-dependent electron-transport measurements to be approximately 1.7 eV.</p>10abioconjugates10aGold10aNanoparticles10asensors10aspider silk1 aSingh, Amit1 aHede, Shantesh1 aSastry, Murali  uhttps://library.ncl.res.in/content/spider-silk-active-scaffold-assembly-gold-nanoparticles-and-application-gold-silk02567nas a2200217   4500008004100000022001400041245014700055210006900202260009500271300001200366490000800378520168700386653002902073653002302102653003202125653001802157100001902175700001602194700001902210856012002229       2009                        eng d  a0021-979700aShape and size selective separation of gold nanoclusters by competitive complexation with octadecylamine monolayers at the air-water interface0 aShape and size selective separation of gold nanoclusters by comp  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcMAY  a380-3880 v3333 a<p>The paper presents a time-dependent study of shape-dependent preferential complexation of gold nanoparticles to the octadecyl amine (ODA) monolayers at the air-water interface. Room temperature reduction of chloroaurate ions using lemon grass leaf extract yields a Mixture of spherical and triangular nanoparticles, which were used for this study. These nanoparticles have a net negative charge on their surface due to the presence of biomolecules from plant extract and thus a strong attractive electrostatic interaction with the positively charged ODA monolayers drives the complexation process. The extent of preferential complexation of the gold nanoparticles to the ODA monolayers is a function of the charge on the particles and the relative mobility of the nanoclusters in the medium. The complexation process has been followed in real time by a host of techniques such as surface pressure-area (pi-A) isotherms, UV-vis-NIR spectroscopy and Brewster angle microscopy. The charge and mobility of the gold nanoparticles was confirmed by measurement of their electrophoretic mobility. Langmuir-Blodgett films of the nanogold-ODA composites have been characterized by UV-vis-NIR spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. These measurements clearly indicate that the cluster mobility and complexation increase with decreasing cluster size. In the competitive complexation process of large and small gold particles, it was observed that some bigger gold particles were also incorporated into the amine matrix even though the cluster mobility is higher for smaller gold particles. (c) 2009 Elsevier Inc. All rights reserved.</p>10aCompetitive complexation10agold nanoparticles10aLangmuir-Blodgett technique10aODA monolayer1 aPasricha, Renu1 aSingh, Amit1 aSastry, Murali  uhttps://library.ncl.res.in/content/shape-and-size-selective-separation-gold-nanoclusters-competitive-complexation-003256nas a2200685   4500008004100000022001400041245005700055210005200112260007100164300001400235490000700249520122200256100002801478700002001506700002301526700001901549700002401568700003001592700002501622700002401647700001801671700002501689700002501714700002101739700002701760700001701787700002501804700002101829700002001850700001801870700001801888700001901906700002201925700002101947700002301968700001601991700002502007700001902032700001702051700002802068700002202096700002102118700002002139700001502159700001802174700001602192700002302208700002402231700002002255700002502275700002602300700002302326700001902349700002202368700002502390700002302415700002102438700002702459856008402486       2012                        eng d  a1528-748300aPolymorphs, salts, and cocrystals: what's in a name?0 aPolymorphs salts and cocrystals whats in a name  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a2147-21520 v123 a<p>The December 2011 release of a draft United States Food and Drug Administration (FDA) guidance concerning regulatory classification of pharmaceutical cocrystals of active pharmaceutical ingredients (APIs) addressed two matters of topical interest to the crystal engineering and pharmaceutical science communities: (1) a proposed definition of cocrystals; (2) a proposed classification of pharmaceutical cocrystals as dissociable ``API-excipient'' molecular complexes. The Indo U.S. Bilateral Meeting sponsored by the Indo-U.S. Science and Technology Forum titled The Evolving Role of Solid State Chemistry in Pharmaceutical Science was held in Manesar near Delhi, India, from February 2-4, 2012. A session of the meeting was devoted to discussion of the FDA guidance draft. The debate generated strong consensus on the need to define cocrystals more broadly and to classify them like salts. It was also concluded that the diversity of API crystal forms makes it difficult to classify solid forms into three categories that are mutually exclusive. This perspective summarizes the discussion in the Indo-U.S. Bilateral Meeting and includes contributions from researchers who were not participants in the meeting.</p>1 aAitipamula, Srinivasulu1 aBanerjee, Rahul1 aBansal, Arvind, K.1 aBiradha, Kumar1 aCheney, Miranda, L.1 aChoudhury, Angshuman, Roy1 aDesiraju, Gautam, R.1 aDikundwar, Amol, G.1 aDubey, Ritesh1 aDuggirala, Nagakiran1 aGhogale, Preetam, P.1 aGhosh, Soumyajit1 aGoswami, Pramod, Kumar1 aGoud, Rajesh1 aJetti, Ram, R. K. R.1 aKarpinski, Piotr1 aKaushik, Poonam1 aKumar, Dinesh1 aKumar, Vineet1 aMoulton, Brian1 aMukherjee, Arijit1 aMukherjee, Gargi1 aMyerson, Allan, S.1 aPuri, Vibha1 aRamanan, Arunachalam1 aRajamannar, T.1 aReddy, Malla1 aRodriguez-Hornedo, Nair1 aRogers, Robin, D.1 aRow, T., N. Guru1 aSanphui, Palash1 aShan, Ning1 aShete, Ganesh1 aSingh, Amit1 aSun, Changquan, C.1 aSwift, Jennifer, A.1 aThaimattam, Ram1 aThakur, Tejender, S.1 aThaper, Rajesh, Kumar1 aThomas, Sajesh, P.1 aTothadi, Srinu1 aVangala, Venu, R.1 aVariankaval, Narayan1 aVishweshwar, Peddy1 aWeyna, David, R.1 aZaworotko, Michael, J.  uhttps://library.ncl.res.in/content/polymorphs-salts-and-cocrystals-whats-name-002045nas a2200661   4500008004100000022001400041245008000055210006900135260007100204300001400275490000700289100002800296700002000324700002300344700001900367700002400386700003000410700002500440700002400465700001800489700002500507700002500532700002100557700002700578700001700605700002500622700002100647700002000668700001800688700001800706700001900724700002200743700002100765700002300786700001600809700002500825700001900850700001700869700002800886700002200914700002100936700002000957700001500977700001800992700001601010700002301026700002401049700002001073700002501093700002601118700002301144700001901167700002201186700002301208700002101231700002701252856010401279       2012                        eng d  a1528-748300aPolymorphs, salts and cocrystals: what's in a name? (vol 12, pg 2147, 2012)0 aPolymorphs salts and cocrystals whats in a name vol 12 pg 2147 2  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a4290-42910 v121 aAitipamula, Srinivasulu1 aBanerjee, Rahul1 aBansal, Arvind, K.1 aBiradha, Kumar1 aCheney, Miranda, L.1 aChoudhury, Angshuman, Roy1 aDesiraju, Gautam, R.1 aDikundwar, Amol, G.1 aDubey, Ritesh1 aDuggirala, Nagakiran1 aGhogale, Preetam, P.1 aGhosh, Soumyajit1 aGoswami, Pramod, Kumar1 aGoud, Rajesh1 aJetti, Ram, R. K. R.1 aKarpinski, Piotr1 aKaushik, Poonam1 aKumar, Dinesh1 aKumar, Vineet1 aMoulton, Brian1 aMukherjee, Arijit1 aMukherjee, Gargi1 aMyerson, Allan, S.1 aPuri, Vibha1 aRamanan, Arunachalam1 aRajamannar, T.1 aReddy, Malla1 aRodriguez-Hornedo, Nair1 aRogers, Robin, D.1 aRow, T., N. Guru1 aSanphui, Palash1 aShan, Ning1 aShete, Ganesh1 aSingh, Amit1 aSun, Changquan, C.1 aSwift, Jennifer, A.1 aThaimattam, Ram1 aThakur, Tejender, S.1 aThaper, Rajesh, Kumar1 aThomas, Sajesh, P.1 aTothadi, Srinu1 aVangala, Venu, R.1 aVishweshwar, Peddy1 aWeyna, David, R.1 aZaworotko, Michael, J.  uhttps://library.ncl.res.in/content/polymorphs-salts-and-cocrystals-whats-name-vol-12-pg-2147-2012-001931nas a2200169   4500008004100000022001400041245008900055210006900144260011000213300001400323490000800337520123800345100001601583700002001599700001901619856012301638       2012                        eng d  a0003-265400aUltra-low level optical detection of mercuric ions using biogenic gold nanotriangles0 aUltralow level optical detection of mercuric ions using biogenic  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a3083-30900 v1373 a<p>Mercury is a serious environmental pollutant known to have detrimental health effects in all life forms. Here, we report the use of biologically synthesized aqueous gold nanotriangles for sensitive and selective optical detection of femto-molar levels of mercury ions by exploiting the high amalgamation tendency of mercury metal towards gold. Aqueous chloroaurate ions were reduced using lemongrass (Cymbopogon flexuosus) leaf extract at room temperature to form gold nanotriangles. Mercuric (Hg2+) ions were reduced in the presence of these triangles to facilitate amalgamation and the optical properties were monitored. We observe a significant change in the longitudinal plasmon absorption band of the nanotriangles even at femto-molar concentrations of mercuric ions. High-resolution transmission electron microscopy confirms changes in particle morphology at such low concentrations. This protocol shows no sensitivity to other environmentally relevant metal ions, including Pb2+, Zn2+, Cd2+, Fe2+, Ni2+, Sr2+, Ca2+, Mn2+, and Cu2+, confirming further that change in the optical properties of gold nanotriangles in the presence of reduced mercuric ions is solely due to the strong amalgamation tendency of mercury metal.</p>1 aSingh, Amit1 aPasrichax, Renu1 aSastry, Murali  uhttps://library.ncl.res.in/content/ultra-low-level-optical-detection-mercuric-ions-using-biogenic-gold-nanotriangles-002084nas a2200289   4500008004100000022001400041245009100055210006900146260000800215300001600223490000700239520114900246100001701395700001901412700003301431700002201464700001901486700001601505700002501521700001701546700002101563700002301584700002601607700001601633700002501649856012001674       2025                        eng d  a0022-262300aMycobacteria-specific prodrug to overcome phenotypic AMR in mycobacterium tuberculosis0 aMycobacteriaspecific prodrug to overcome phenotypic AMR in mycob  cDEC  a24935-249520 v683 a<p>
	Most front-line tuberculosis (TB) drugs are ineffective against hypoxic nonreplicating Mycobacterium tuberculosis (Mtb), largely due to poor permeability, leading to reduced drug accumulation and target engagement. To overcome this phenotypic antimicrobial resistance (AMR), we developed nitroheteroaryl prodrugs for Moxifloxacin (MXF), a front-line TB drug. These prodrugs are activated by bacterial nitroreductases (NTR), which are overexpressed in hypoxic Mtb. NTR-mediated electron transfer and protonation facilitate rapid cleavage of the protective group, releasing active MXF. The lead prodrug exhibited comparable efficacy to MXF in replicating Mtb and significantly enhanced lethality in nonreplicating Mtb. Drug accumulation studies confirmed a modest but significant increase in MXF levels in nonreplicating Mtb treated with the prodrug, suggesting improved permeability. A mathematical model integrating growth and drug-killing kinetics further elucidated how permeability differences impact lethality. Together, these findings highlight enzyme-activated prodrugs as a promising strategy to address phenotypic AMR in Mtb</p>
1 aKumar, Anand1 aBirua, Shalini1 aMallojjala, Sharath, Chandra1 aMukherjee, Piyali1 aSingh, Samsher1 aKaul, Grace1 aRamachandran, Aparna1 aAkhir, Abdul1 aChopra, Sidharth1 aGadgil, Chetan, J.1 aHirschi, Jennifer, S.1 aSingh, Amit1 aChakrapani, Harinath  uhttps://library.ncl.res.in/content/mycobacteria-specific-prodrug-overcome-phenotypic-amr-mycobacterium-tuberculosis