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排序方式: 共有392条查询结果,搜索用时 31 毫秒
331.
Rocco L. Policarpo Hansol Kang Dr. Xiaoli Liao Amy E. Rabideau Mark D. Simon Prof. Bradley L. Pentelute 《Angewandte Chemie (International ed. in English)》2014,53(35):9203-9208
Sortase‐mediated ligation (sortagging) is a versatile, powerful strategy for protein modification. Because the sortase reaction reaches equilibrium, a large excess of polyglycine nucleophile is often employed to drive the reaction forward and suppress sortase‐mediated side reactions. A flow‐based sortagging platform employing immobilized sortase A within a microreactor was developed that permits efficient sortagging at low nucleophile concentrations. The platform was tested with several reaction partners and used to generate a protein bioconjugate inaccessible by solution‐phase batch sortagging. 相似文献
332.
Cover Picture: Inherently Chiral Macrocyclic Oligothiophenes: Easily Accessible Electrosensitive Cavities with Outstanding Enantioselection Performances (Chem. Eur. J. 47/2014)
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Prof. Francesco Sannicolò Prof. Patrizia R. Mussini Prof. Tiziana Benincori Dr. Roberto Cirilli Prof. Sergio Abbate Serena Arnaboldi Simone Casolo Dr. Ettore Castiglioni Prof. Giovanna Longhi Dr. Rocco Martinazzo Dr. Monica Panigati Dr. Marco Pappini Dr. Elsa Quartapelle Procopio Dr. Simona Rizzo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15257-15257
333.
María Magdalena Centeno José Daniel Martínez Mary Lorena Araujo Felipe Brito Edgar Del Carpio Lino Hernández Vito Rocco Lubes 《Journal of solution chemistry》2014,43(6):1011-1018
Solution equilibria of the ternary systems Ni(II)–picolinic acid (Hpic) and the amino acids aspartic acid (H2asp), glutamic acid (H2glu), cysteine (H2cys) and histidine (Hhis), where the amino acids are denoted as H i L, have been studied pH-metrically. The formation constants of the resulting mixed ligand complexes have been determined at 25 °C using a ionic strength 1.0 mol·dm?3 NaCl. In the Ni(II)–Hpic–H2asp and Ni(II)–Hpic–H2glu systems, the complexes [Ni(pic)H2L]+, Ni(pic)HL, [Ni(pic)L]? and [Ni(pic)L(OH)]2? were detected. In the Ni(II)–Hpic–H2cys system the complexes [Ni(pic)H2L]+ and [Ni(pic)L]? are present. Additionally, in the Ni(II)–Hpic–Hhis system the species [Ni(Hpic)HL]2+, Ni(pic)L and [Ni(pic)L(OH)]? were identified. The species distribution diagrams as functions of pH are briefly discussed. 相似文献
334.
Let G be a semisimple and simply connected algebraic group, and let H 0 be the subgroup of points fixed by an involution of G. Let V be an irreducible representation of G with a nonzero vector v fixed by H 0. In this article, we prove a property of the normalization of the coordinate ring of the closure of G·[v] in ?(V). 相似文献
335.
Heloisa Maria Boechat-Roberty Elmar O. Uhl Flavio N. Rodrigues Maria Cristina A. Lopes Maria Luiza M. Rocco Carlos A. Lucas Alexandre B. Rocha Carlos E. Bielschowsky Gerardo Gerson B. de Souza 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2013,67(2):1-6
Electron energy-loss spectra for the butadiene molecule were measured in the scattering angular range of 2.0° to 8.0°, in an energy-loss range from 2 to 50 eV, using 1000 eV incident electrons. The absolute generalized oscillator strength (GOS) and inelastic cross section have been determined for the \hbox{$\tilde{\rm X}^{1}$}?X1A g → 11B u transition. The absolute elastic differential cross section was also determined spanning an angular range from 2.0° to 40.0°. From a small angle electron energy-loss spectrum, the optical oscillator distribution (photoabsorption spectrum) for the butadiene molecule was obtained in the 2 to 100 eV photon energy range. Accurate ab initio calculations have been performed, within the First Born Approximation, for generalized oscillator strength (GOS) and excitation energies for the \hbox{$\tilde{\rm X}^{1}$}?X1A g → 11B u and \hbox{$\tilde{\rm X}^{1}$}?X1A g → 21A g transitions. Our results emphasize the importance of using highly correlated wavefunctions and accurate methodologies in the calculation of the GOS for electron impact-induced electronic transitions in molecules. 相似文献
336.
337.
In this paper, we obtain a rigidity theorem by modifying Cheng–Yau’s technique to linear Weingarten submanifolds in the unit sphere Sn+p(1) with parallel normalized mean curvature vector. As a corollary, we have Theorem 1.3 in Guo and Li (Tohoku Math J 65:331–339, 2013) and Theorem 2 in Li (Math Ann 305:665–672, 1996). 相似文献
338.
Ultrasound (US) “pre-sonication effect” is the beneficial effect of US in the hydrolytic polymerization of ε-caprolactam (CL) mixtures with very low water concentrations (about 0.1–1 wt%). It appears after a mild initial treatment of the mixtures with US [17.5–20 kHz, short times (5–15 min), low temperatures (70–110 °C)] followed by heating at 220–260 °C. An explanation is proposed on the basis of the formation in mild conditions (100 °C) of low concentrations of cyclic oligomers never detected in the literature at those conditions. These, under US irradiation, produce linear amino acid oligomers, which are strong activators of polymerization when the mixture of CL and water, after US irradiation, is heated at the suitable polymerization temperature indicated above. 相似文献
339.
The fate of crude oil under irradiation is studied. After UV irradiation, the fraction present in the highest percentage shifts from the C8-C9 fractions to C13, using gas chromatography-mass spectrometry (GC-MS) analysis in solution. An increase of the relative amount of the C13-C25 fraction is observed, while a decrease in the relative amount of the C7-C12 fractions is present. In headspace solid-phase microextraction (HS-SPME) analysis, the C8-C10 fractions represent 53% of all the compounds detected. A decrease in the relative amount of the C8-C10 fractions is observed, while C11-C15 fractions increase. The irradiation of crude oil with a solar simulator gives a mixture the analysis of which using GC-MS in solution furnishes the same type of results: the relative amounts of linear alkanes and aromatic compounds increase, while a sharp decrease in the relative amounts of branched and cyclic alkanes is observed. In the SPME analysis, a decreased relative amount of branched alkanes and alkenes, and an increase in the relative amounts of cyclic alkanes and aromatic compounds are observed. Analysis of the distribution of the compounds in all the types of compound shows that a dynamic equilibrium between different compounds and different types of compounds is present. To confirm the presence of a dynamic equilibrium, the irradiation of methylcyclohexane in the presence of 2-methylnaphthalene shows the presence in the reaction mixture of a small amount of tetradecane. 相似文献
340.
Rocco G Toledo C Ahumada I Sepúlveda B Cañete A Richter P 《Journal of chromatography. A》2008,1193(1-2):32-36
An efficient continuous pressurized solvent extraction (PSE) method assisted by ultrasound energy was developed for the extraction of polychlorinated biphenyls (PCBs) from biosolids. Analytes were determined in the extracts by gas chromatography-mass spectrometry in selected ion monitoring (SIM) mode. A screening-type experimental design pointing to dynamic extraction time as the only significant variable in the extraction process was carried out to optimize PCB extraction from the biosolids. Final selected conditions for PSE were extraction temperature, 50 degrees C; static extraction time, 0 min; and dynamic extraction time, 30 min. Recovery of the PSE method was 73%, which was significantly improved (103%) when PSE was assisted with 30-min ultrasound (US-PSE). Precision of the overall method, expressed as relative standard deviation, was 3.6% and the detection limit was 0.037 mg/kg. The method was applied to the determination of PCBs in biosolids from different water treatment plants from central Chile. 相似文献