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31.
Liu DS Tangpeerachaikul A Selvaraj R Taylor MT Fox JM Ting AY 《Journal of the American Chemical Society》2012,134(2):792-795
The inverse-electron-demand Diels-Alder cycloaddition between trans-cyclooctenes and tetrazines is biocompatible and exceptionally fast. We utilized this chemistry for site-specific fluorescence labeling of proteins on the cell surface and inside living mammalian cells by a two-step protocol. Escherichia coli lipoic acid ligase site-specifically ligates a trans-cyclooctene derivative onto a protein of interest in the first step, followed by chemoselective derivatization with a tetrazine-fluorophore conjugate in the second step. On the cell surface, this labeling was fluorogenic and highly sensitive. Inside the cell, we achieved specific labeling of cytoskeletal proteins with green and red fluorophores. By incorporating the Diels-Alder cycloaddition, we have broadened the panel of fluorophores that can be targeted by lipoic acid ligase. 相似文献
32.
Nucleon emission from high spin fused compound systems is analyzed in the framework of the statistical theory of hot rotating
(STHR) nuclei. This is an elaborate version of our earlier work and we present our results for156Er,166Er,168 Yb and188Hg. We predict an increase in neutron emission for166Er due to the abrupt decrease in neutron separation energy aroundI ≈55ℏ. Since the drop in the separation energy is closely associated with the structural changes in the rotating nuclei, relative
increase in neutron emission probability around certain values of angular momentum may be construed as evidence for the shape
transition. A similar effect is predicted for168Yb aroundI ≈55ℏ. We also extend the microscopic cranked Nilsson method (CNM) to hot nuclear systems and compare the results with that of the
STHR method. The two methods yield different results for triaxially deformed nuclei although for biaxial deformations the
results are identical. This is illustrated for186Hg. 相似文献
33.
Convergence rates for lacunary trigonometric interpolation 总被引:1,自引:0,他引:1
Conditions for the solvability of lacunary trigonometric interpolation have been given by Cavaretta, Sharma, and Varga. When
these conditions are satisfied, linear operators are defined on the space of continuous periodic functions. In this paper,
the saturation rate and class of many of these operators is determined. 相似文献
34.
Selvaraj Munirasu Raghavachari Dhamodharan 《Journal of polymer science. Part A, Polymer chemistry》2004,42(5):1053-1057
The ability to do very rapid bulk atom transfer radical polymerization (ATRP) of benzyl methacrylate using a CuX/PMDETA complex at room temperature was demonstrated in this study. The experimental conditions required to synthesize low‐ and high‐molecular‐weight poly(benzyl methacrylate) with low polydispersity are reported here. The controlled/living nature of the polymerization was demonstrated through kinetic studies, and chain‐extension studies. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1053–1057, 2004 相似文献
35.
The Mitsunobu reaction is a well-established fundamental reaction and has been widely applied in organic synthesis. In this
paper, under Mitsunobu conditions dehydration proceeds between (2-chloroquinolin-3-yl)methanol and nitrogen heterocyclic compounds
such as quinazolinone, pyrimidone, 2-oxoquinoline in dry THF in the presence of triethylamine, triphenylphosphane and diethyl
azodicarboxylate to give the corresponding products. As part of our recent research, we attempted to couple two N-heterocyclic compounds under Mitsunobu reaction conditions to provide efficient building blocks for natural product synthesis. 相似文献
36.
An efficient ligand-free cross-coupling reaction of 2-chloro-3-(chloromethyl)benzo[h]quinoline with N-heterocycles such as piperidin-4-one, 4(3H)-pyrimidone, and ethyl 6-chloro-1,2-dihydro-2-oxo-4-phenylquinoline-3-carboxylate using a catalytic amount of ZnO nanorods
as a recyclable catalyst and KOH as the base in DMSO under reflux at 110°C is reported. 相似文献
37.
Arun Kumar Dorai S. Selvasekarapandian Nithya Hellar Sakunthala Ayyasamy Hema Muthusamy 《Ionics》2010,16(6):481-486
Thin films of ionic conductors have low internal resistance. Hence, it could be used as an electrolyte material in sensors
to operate at ambient temperatures. Cerium fluoride, a unipolar fluoride ion conductor, has got a different application in
electrochemical sensor. In the present work, cerium fluoride thin films have been prepared by physical vapor deposition method
and their electrical properties are studied. X-ray diffraction studies reveal the polycrystalline nature of the prepared thin
films and the structure of the material. Scanning electron microscopy (SEM) images show grain-like structures. Conductivity
analysis of the thin films has been studied by ac impedance analysis and the maximum conductivity value is found to be 1.04 × 10−6 S cm−1. The impedance spectra emphasize intergranular conduction in the prepared thin films. 相似文献
38.
Brualdi’s introduction to the concept of poset metric on codes over \(\mathbb {F}_{q}\) paved a way for studying various metrics on \(\mathbb {F}_{q}^{n}\). As the support of vector x in \(\mathbb {F}_{q}^{n}\) is a set and hence induces order ideals and metrics on \(\mathbb {F}_{q}^{n}\), the poset metric codes could not accommodate Lee metric structure due to the fact that the support of a vector with respect to Lee weight is not a set but rather a multiset. This leads the authors to generalize the poset metric structure on to a pomset (partially ordered multiset) metric structure. This paper introduces pomset metric and initializes the study of codes equipped with pomset metric. The concept of order ideals is enhanced and pomset metric is defined. Construction of pomset codes are obtained and their metric properties like minimum distance and covering radius are determined. 相似文献
39.
Whole cells of Candida parapsilosis ATCC 7330 were used for the resolution of N-acetyl amino acid esters. Excellent enantioselectivities (E = 40 to >500) were achieved for the resolution of N-protected protein and non-protein amino acid esters giving good yields (28–50%) and high enantiomeric excesses (up to >99%) for both enantiomers. 相似文献
40.
For the first time, synthesis of AB ring core of camptothecin synthons such as (2-chloroquinolin-3-yl)methanols (Va-Vg) using zinc oxide nanoparticles is reported. The desired attractive products were obtained in high yields, short reaction
time, using a simple work-up procedure with the purification of products by non-chromatographic methods. 相似文献