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21.
In this article, we apply a novel time‐dependent discrete variable representation (TDDVR) method proposed by Barkakaty and Adhikari to investigate tunneling through an Eckart barrier. This semi‐classical method is theoretically rigorous and straightforward to implement. Among the TDDVR formulations, this report presents the first derivation of a rigorous form of quantum force (QF) for the present perspective. The validity of this semi‐classical approach is demanded based on the excellent agreement of the tunneling probability with the corresponding quantum results. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004 相似文献
22.
Yongzheng Cong Khatereh Motamedchaboki Santosh A. Misal Yiran Liang Amanda J. Guise Thy Truong Romain Huguet Edward D. Plowey Ying Zhu Daniel Lopez-Ferrer Ryan T. Kelly 《Chemical science》2021,12(3):1001
We report on the combination of nanodroplet sample preparation, ultra-low-flow nanoLC, high-field asymmetric ion mobility spectrometry (FAIMS), and the latest-generation Orbitrap Eclipse Tribrid mass spectrometer for greatly improved single-cell proteome profiling. FAIMS effectively filtered out singly charged ions for more effective MS analysis of multiply charged peptides, resulting in an average of 1056 protein groups identified from single HeLa cells without MS1-level feature matching. This is 2.3 times more identifications than without FAIMS and a far greater level of proteome coverage for single mammalian cells than has been previously reported for a label-free study. Differential analysis of single microdissected motor neurons and interneurons from human spinal tissue indicated a similar level of proteome coverage, and the two subpopulations of cells were readily differentiated based on single-cell label-free quantification.The combination of nanodroplet sample preparation, ultra-low-flow nanoLC, high-field asymmetric ion mobility spectrometry (FAIMS) and latest-generation mass spectrometry instrumentation provides dramatically improved single-cell proteome profiling. 相似文献
23.
24.
Syed Mashhood Ali Santosh Kumar Upadhyay Arti Maheshwari Mamoru Koketsu 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(3-4):325-328
1H NMR spectroscopic study of fluvastatin sodium (FLU), β-Cyclodextrin (β-CD) and their mixtures confirmed the formation of FLU/β-CD inclusion complex in solution. The stoichiometry of the complex was determined to be 1:1 and the overall binding constant (K
s) was calculated to be 340 M−1. Two dimensional COSY, ROESY and DEPTO experiments were performed for the unambiguous assignment of aromatic proton resonances and it was found that two isomeric forms of FLU are present in solution. It was confirmed with the help of ROESY spectral data that only F-substituted aromatic ring penetrates the β-CD cavity and there is chiral differentiation by the β-CD as one of the isomer binds more strongly, which is indicated by the intensity of correlation peaks. The mode of penetration of the guest into the β-CD cavity was also established and structure of the complex has been proposed. 相似文献
25.
A regioselective quinazolinone-directed ortho lithiation on an adjacent quinoline moiety has been used as a key step for a short, efficient, and practical synthesis of the human DNA topoisomerase I poison luotonin A and luotonins B and E. The quinazolinoylquinoline 5 on treatment with in situ-generated nonnucleophilic mesityllithium furnished the desired dilithiated intermediate 6, which on treatment with formaldehyde followed by Mitsunobu ring closure reaction gave luotonin A (1a) in very good yield. The reaction of dilithiated intermediate 6 with DMF directly furnished luotonin B (1b) in 81% yield. Luotonin B (1b) on methylation with p-TSA/methanol gave luotonin E (1c) in 82% yield. 相似文献
26.
An amperometric method for the determination of thiocarbamyl sulphonamides has been developed, based on the cleavage of the S-N bond by hydriodic acid. The method can also be applied for the cleavage of the S-S bond in thiuram disulphides and dibenzothiazyl disulphide, and thus provides a useful means for the estimation of these compounds as well. 相似文献
27.
Santosh K. Upadhyay Mahesh C. Agrawal 《Monatshefte für Chemie / Chemical Monthly》1979,110(2):413-418
Osmium(VIII) catalysed oxidation of lysine by ferricyanide in excess ferrocyanide shows a complex kinetics. The order in lysine falls, from 1 to 0 while that in ferricyanide increases from 0 to 2 with large increase in lysine concentration. The rates were directly proportional to [Os(VIII)] and {Const.+[Fe(CN)
6
4
]}. A suitable mechanism is proposed and discussed.
Oxidation von lysin mittels ferricyanid in der gegenwart von osmium(VIII)
Zusammenfassung Die von Os(VIII) katalysierte Oxidation von Lysin mit Ferricyanid in überschüssigem Ferrocyanid zeigt eine komplexe Kinetik. Bei starker Steigerung der Lysinkonzentration fällt die Ordnung bezüglich Lysin von 1 auf 0, während bezüglich Ferricyanid eine Erhöhung, von 0 auf 2 festzustellen ist. Die Geschwindigkeitskonstanten waren direkt proportional zu [Os(VII)] und {Const.+[Fe(CN) 6 4 ]}. Es wird ein möglicher Mechanismus vorgeschlagen und diskutiert.相似文献
28.
Noor-ul H. Khan Santosh Agrawal Rukhsana I. Kureshy Sayed H.R. Abdi Surendra Singh Raksh V. Jasra 《Journal of organometallic chemistry》2007,692(20):4361-4366
An efficient method for the addition of trimethylsilyl cyanide (TMSCN) to various aldehydes and ketones has been described using Fe(Cp)2PF6 (2.5 mol%) as a catalyst under solvent free condition. Excellent yields of trimethylsilylether of cyanohydrin up to (94%) was achieved within 10 min. 相似文献
29.
Kallol K. Ghosh Pokhraj Sharma Samiksha Taramkar Santosh Kumar Sar 《Reaction Kinetics and Catalysis Letters》2004,81(1):161-168
The acid catalyzed hydrolysis of two N-substituted hydroxamic acids (C6H5CON(OH)R, R = C6H5 (PBHA), R = C6H5CH2(BBHA)) in mixed systems containing -cyclodextrin (—CD) and a surfactant (sodium dodecyl sulfate, SDS) has been studied. The reactions are inhibited by —CD. The inhibition is attributed to the formation of inclusion complex and competition between the micellization and complexation processes.This revised version was published online in December 2005 with corrections to the Cover Date. 相似文献
30.
Magnesium perchlorate has been found to be an efficient catalyst for the synthesis of imines and phenylhydrazones by the reaction of carbonyl compounds with amines and phenylhydrazine in high yields at room temperatures and in short times. The condensation of less electrophilic carbonyl compounds with poorly nucleophilic amines affords the imines in excellent yields. 相似文献