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91.
Dr. Chetan Kumar Arya Swati Yadav Dr. Jonathan Fine Dr. Ana Casanal Dr. Gaurav Chopra Prof. Dr. Gurunath Ramanathan Dr. Kutti R. Vinothkumar Prof. Dr. Ramaswamy Subramanian 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17109-17114
N,N-dimethyl formamide (DMF) is an extensively used organic solvent but is also a potent pollutant. Certain bacterial species from genera such as Paracoccus, Pseudomonas, and Alcaligenes have evolved to use DMF as a sole carbon and nitrogen source for growth via degradation by a dimethylformamidase (DMFase). We show that DMFase from Paracoccus sp. strain DMF is a halophilic and thermostable enzyme comprising a multimeric complex of the α2β2 or (α2β2)2 type. One of the three domains of the large subunit and the small subunit are hitherto undescribed protein folds of unknown evolutionary origin. The active site consists of a mononuclear iron coordinated by two Tyr side-chain phenolates and one carboxylate from Glu. The Fe3+ ion in the active site catalyzes the hydrolytic cleavage of the amide bond in DMF. Kinetic characterization reveals that the enzyme shows cooperativity between subunits, and mutagenesis and structural data provide clues to the catalytic mechanism. 相似文献
92.
JPC – Journal of Planar Chromatography – Modern TLC - The separation and estimation of natural products by chromatographic techniques such as high-performance liquid chromatography... 相似文献
93.
James J. Powers David A. Favor Trent Rankin Chetan Pandit Samarendra N. Maiti 《Tetrahedron letters》2009,50(12):1267-731
The synthesis of a series of methyl-, fluoro-, and chloro-substituted 6-hydroxyisoindolin-1-ones is described. 相似文献
94.
Chetan Nayak 《General Relativity and Gravitation》1991,23(6):661-669
We consider the loop space representation of Rovelli and Smolin as the starting point for the analysis of quantum gravity in 2+1 dimensions. To do so, we introduce observables directly within this representation and consider the problem of its Lagrangian formulation. The implications of this framework for the issue of time are discussed and the extension of these results to 3+1 gravity is also considered. 相似文献
95.
Chetan K. Modi Parthiv M. Trivedi Jiten A. Chudasama Haresh D. Nakum Digvijaysinh K. Parmar Sanjeev K. Gupta 《Green Chemistry Letters and Reviews》2014,7(3):278-287
The intriguing research toward the exploitation of zeolite-Y-based hybrid nanocatalysts for catalytic oxidation reactions has been growing significantly. In the present investigation, we describe the synthesis of zeolite-Y entrapped transition metal complexes of the general formulae [M(SFCH)·xH2O]-Y (where, M = Mn, Fe, Co, Ni (x = 3) and Cu (x = 1)); H2SFCH = (E)-N′-(2-hydroxybenzylidene)furan-2-carbohydrazide]. These nanocatalysts have been characterized by various physicochemical techniques. Density functional theory calculations are performed to address the relaxed geometry, bond angle, bond length, dihedral angle, highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap, and electronic density of states of H2SFCH ligand and their neat transition metal complexes. The observed HOMO–LUMO gap and the Fermi energy is higher for Cu(II) complexes, which demonstrates the better catalytic activity of this nanocatalyst. The catalytic activity was performed in liquid-phase oxidation of cyclohexane using hydrogen peroxide as oxidant to give cyclohexanone (CyONE) and cyclohexanol (CyOL). Among them, [Cu(SFCH)·H2O]-Y catalyst has the highest selectivity toward CyONE (84.5%). 相似文献
96.
97.
We study the coupling between a quantum dot and the edge of a non-Abelian fractional quantum Hall state which is spatially separated from it by an integer quantum Hall state. Near a resonance, the physics at energy scales below the level spacing of the edge states of the dot is governed by a k-channel Kondo model when the quantum Hall state is a Read-Rezayi state at filling fraction nu=2+k/(k+2) or its particle-hole conjugate at nu=2+2/(k+2). The k-channel Kondo model is channel isotropic even without fine-tuning in the former state; in the latter, it is generically channel anisotropic. In the special case of k=2, our results provide a new venue, realized in a mesoscopic context, to distinguish between the Pfaffian and anti-Pfaffian states at filling fraction nu=5/2. 相似文献
98.
We explain how (perturbed) boundary conformal field theory allows us to understand the tunneling of edge quasiparticles in non-Abelian topological states. The coupling between a bulk non-Abelian quasiparticle and the edge is due to resonant tunneling to a zero mode on the quasiparticle, which causes the zero mode to hybridize with the edge. This can be reformulated as the flow from one conformally invariant boundary condition to another in an associated critical statistical mechanical model. Tunneling from one edge to another at a point contact can split the system in two, either partially or completely. This can be reformulated in the critical statistical mechanical model as the flow from one type of defect line to another. We illustrate these two phenomena in detail in the context of the ν=5/2 quantum Hall state and the critical Ising model. We briefly discuss the case of Fibonacci anyons and conclude by explaining the general formulation and its physical interpretation. 相似文献
99.