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1.
Bhamidi V Varanasi S Schall CA 《Langmuir : the ACS journal of surfaces and colloids》2005,21(20):9044-9050
Fundamental understanding of protein crystal nucleation facilitates crystallization of biological macromolecules for structure determination and control of crystal size distribution. In the studies presented here, nucleation kinetics of hen egg-white lysozyme crystals were measured at solution conditions that exhibited equal solubility by adjusting pH, temperature, or sodium chloride concentration. It was observed that solution conditions that lead to equal solubility resulted in equal nucleation rates and hence kinetic parameters. Since the solubility of globular proteins correlates with the osmotic second virial coefficient, B(22), an integral measure of the protein pair interaction potential, this observation indicates that the protein pair interaction plays a key role in determining nucleation kinetic parameters. 相似文献
2.
Magnetic nanoparticle‐tethered Schiff base–palladium(II): Highly active and reusable heterogeneous catalyst for Suzuki–Miyaura cross‐coupling and reduction of nitroarenes in aqueous medium at room temperature 下载免费PDF全文
K. Manjunatha Tuhin S. Koley Vishal Kandathil Ramesh B. Dateer Geetha Balakrishna B. S. Sasidhar Shivaputra A. Patil Siddappa A. Patil 《应用有机金属化学》2018,32(4)
As a continuation of our efforts to develop new heterogeneous nanomagnetic catalysts for greener reactions, we identified a Schiff base–palladium(II) complex anchored on magnetic nanoparticles (SB‐Pd@MNPs) as a highly active nanomagnetic catalyst for Suzuki–Miyaura cross‐coupling reactions between phenylboronic acid and aryl halides and for the reduction of nitroarenes using sodium borohydride in an aqueous medium at room temperature. The SB‐Pd@MNPs nanomagnetic catalyst shows notable advantages such as simplicity of operation, excellent yields, short reaction times, heterogeneous nature, easy magnetic work up and recyclability. Characterization of the synthesized SB‐Pd@MNPs nanomagnetic catalyst was performed with various physicochemical methods such as attenuated total reflectance infrared spectroscopy, UV–visible spectroscopy, inductively coupled plasma atomic emission spectroscopy, energy‐dispersive X‐ray spectroscopy, field‐emission scanning electron microscopy, transmission electron microscopy, powder X‐ray powder diffraction, thermogravimetric analysis and Brunauer–Emmett–Teller surface area analysis. 相似文献
3.
Pei Li Qichao Zhao Jared L. Anderson Sasidhar Varanasi Maria R. Coleman 《Journal of polymer science. Part A, Polymer chemistry》2010,48(18):4036-4046
Block copolyimides based on aromatic dianhydrides and diamines copolymerized with diamino room temperature ionic liquid (RTIL) monomers were synthesized over a range of compositions. Specifically, two diamino RTILs, 1,3‐di(3‐aminopropyl) imidazolium bis[(trifluoromethyl)sulfonyl] imide ([DAPIM] [NTf2]) and 1,12‐di[3‐(3‐aminopropyl) imidazolium] dodecane bis[(trifluoromethyl) sulfonyl] imide ([C12 (DAPIM)2] [NTf2]2) were synthesized using a Boc protection method. The two RTILs were reacted with 2,2‐bis(3,4‐carboxylphenyl) hexafluoropropane dianhydride (6FDA) to produce 6FDA‐RTILs oligomers that formed the RTIL component for the block copolyimides. The oligomers were reacted with 6FDA and m‐phenylenediamine (MDA) at oligomer concentration from 6.5 to 25.8 mol % to form block copolyimides. Increasing the concentration of the 6FDA‐RTIL oligomer in the block copolyimides resulted in a decrease in the thermal degradation temperature, glass transition temperature and an increase in the density. The gas permeability of the RTIL based block copolyimide decreased but the ideal permeability selectivity for CO2/CH4 gas pair increased relative to the pure 6FDA‐MDA. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4036–4046, 2010 相似文献
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Sasidhar Chavali Philip M. Birch Rupert Young Chris Chatwin 《Optics and Lasers in Engineering》2007,45(3):413
Achieving phase only modulation from a spatial light modulator (SLM) is useful for many optical processing tasks. In this paper, we demonstrate a simple method of decoupling phase and amplitude modulation in a twisted nematic liquid crystal (TNLC) SLM using a double pass technique. A Jones calculus model is developed which matches our experimental data. 相似文献
6.
Rupam Sarma Pradip Chowdhury Chaitanya Bikkina Sasidhar Gumma Jubaraj B. Baruah 《Journal of chemical crystallography》2010,40(10):892-896
Abstract
The structural aspects of one-dimensional coordination polymer (1) of nickel(II) with 1,3,5-benzene tricarboxylate and a three-dimensional interpenetrating coordination polymer (2) of zinc(II) with 1,4-benzenedicarboxylate ligand are studied by single crystal X-ray diffraction analysis. Coordination polymer (1) forms a hydrogen bonded three dimensional network structures. The coordination polymer 1 having a composition [Ni3(TMA)2(H2O)12] n where (TMA = trimesate anion), crystallizes in monoclinic crystal system with C2 space group and has a/?, 17.3387(4); b/?, 12.8748(4); c/?, 6.5302(2); β/°111.620(2); V/?3, 1355.20(7). The zinc coordination polymer 2 crystal system is orthorhombic, with space group Pbca. It has a/?, 14.5049(3); b/?, 17.1616(3); c/?, 18.1389(4); V/?3, 4515.27(16). The 1,4-benzenedicarboxylate three dimensional coordination polymer of zinc(II) comprises of novel hydroxo bridged tetranuclear zinc(II) secondary building units and has a composition [Zn2(C6H4C2O4)1.5{(CH3)2SO}2(OH)] n . Topological analysis of the three dimensional coordination polymer 2 shows that it has a two fold interpenetrating net topology. 相似文献7.
The enantiospecific synthesis of angular triquinanes has been developed starting from the readily available (S)-campholenaldehyde. Two alternate strategies have been used, one employing a Johnson’s orthoester Claisen rearrangement followed by an intramolecular cyclopropanation and regioselective cyclopropane ring cleavage, and a second one based on a RCM reaction. 相似文献
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Adusumilli Srikrishna Vijendra H. Pardeshi Konda Mahesh 《Tetrahedron: Asymmetry》2010,21(20):2512-2516
The enantiospecific total synthesis of two epimers of the sesquiterpene isocalamusenone has been accomplished starting from the readily available monoterpene (R)-limonene, which of the natural product established the stereostructure and the absolute configuration. 相似文献
9.
Nirudodhi S Parsonage D Karplus PA Poole LB Maier CS 《International journal of mass spectrometry》2011,302(1-3):93-100
This is the first comprehensive HX-MS study of a "robust" 2-Cys peroxiredoxin (Prx), namely Salmonella typhimurium AhpC (StAhpC). Prx proteins control intracellular peroxide levels and are abundant antioxidant proteins in eukaryotes, archaea and bacteria. Crystal structural analyses and structure/activity studies of several bacterial and mammalian 2-Cys Prxs have revealed that the activity of 2-Cys Prxs is regulated by redox-dependent oligmerization and a sensitivity of the active site cysteine residue to overoxidation. The propensity to overoxidation is linked to the conformational flexibility of the peroxidatic active site loop. The HX-MS results emphasize the modulation of the conformational motility of the active site loop by disulfide formation. To obtain information on the conformational impact of decamer formation on the active site loop motility, mutants with Thr77 substituted by Ile, a decamer-disrupting mutation or by Val, a decamer-stabilizing mutation, were studied. For the isoleucine mutant, enhanced mobility was observed for regions encompassing the α4 helix located in the dimer-dimer interface and regions surrounding the peroxidatic loop. In contrast, the T77V mutation resulted in an increase in conformational stability in most regions of the protein except for the active site loop and the region encompassing the resolving cysteine. 相似文献
10.
Vishal Kandathil Aisha Siddiqa Abhinandan Patra Bhakti Kulkarni Manjunatha Kempasiddaiah B.S. Sasidhar Shivaputra A. Patil Chandra Sekhar Rout Siddappa A. Patil 《应用有机金属化学》2020,34(11):e5924
N-heterocyclic carbene (NHC)-palladium(II) complex (GO@NHC-Pd) was synthesized on graphene oxide (GO) support via a simple and cost-effective multistep approach. The spectroscopic, microscopic, thermal, and surface analyses of GO@NHC-Pd confirmed the successful formation of the catalyst. The investigation of catalytic activity showed that GO@NHC-Pd was very effective in Suzuki–Miyaura as well as Hiyama cross-coupling. Being heterogeneous in nature, GO@NHC-Pd was recovered after each reaction cycle easily and reused for up to nine and six cycles in Suzuki–Miyaura and Hiyama cross-coupling, respectively, without significant loss of activity. Further exploration of the supercapacitor performance of GO@NHC-Pd catalyst assembled in a two-electrode cell configuration shown a maximum attained capacitance of 105.26 F/g at a current density of 0.1 A/g with good cycling stability of 96.89% over 2,500 cycles. 相似文献