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排序方式: 共有164条查询结果,搜索用时 156 毫秒
91.
Christoph Kieninger Evelyne Deery Andrew D. Lawrence Maren Podewitz Klaus Wurst Emi Nemoto‐Smith Florian J. Widner Joseph A. Baker Steffen Jockusch Christoph R. Kreutz Klaus R. Liedl Karl Gruber Martin J. Warren Bernhard Krutler 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10869-10873
92.
Antiplasmodial activity of three bisbenzylisoquinoline alkaloids from the tuber of Stephania rotunda
Chea A Bun SS Azas N Gasquet M Bory S Ollivier E Elias R 《Natural product research》2010,24(18):1766-1770
Three bisbenzylisoquinoline alkaloids were isolated for the first time from Stephania rotunda tuber. Their structures were elucidated by spectroscopic methods and their antiplasmodial activity was investigated in vitro on chloroquine resistant Plasmodium falciparum strain W2. These alkaloids were identified as 2-norcepharanthine (1), cepharanoline (2) and fangchinoline (3). In vitro, they displayed significant antiplasmodial activity with inhibitory concentration 50 values of 0.3, 0.2 and 0.3 μM. 相似文献
93.
Julien Hanss Evelyne Veuillet Kamel Adjout Julien Besle Lionel Collet Hung Thai-Van 《BMC neuroscience》2009,10(1):23-11
Background
In normal-hearing subjects, monaural stimulation produces a normal pattern of asynchrony and asymmetry over the auditory cortices in favour of the contralateral temporal lobe. While late onset unilateral deafness has been reported to change this pattern, the exact influence of the side of deafness on central auditory plasticity still remains unclear. The present study aimed at assessing whether left-sided and right-sided deafness had differential effects on the characteristics of neurophysiological responses over auditory areas. Eighteen unilaterally deaf and 16 normal hearing right-handed subjects participated. All unilaterally deaf subjects had post-lingual deafness. Long latency auditory evoked potentials (late-AEPs) were elicited by two types of stimuli, non-speech (1 kHz tone-burst) and speech-sounds (voiceless syllable/pa/) delivered to the intact ear at 50 dB SL. The latencies and amplitudes of the early exogenous components (N100 and P150) were measured using temporal scalp electrodes. 相似文献94.
We consider the Schrödinger system with Newton-type interactions that was derived by R. Klein, A. Majda and K. Damodaran (1995) [17] to modelize the dynamics of N nearly parallel vortex filaments in a 3-dimensional homogeneous incompressible fluid. The known large time existence results are due to C. Kenig, G. Ponce and L. Vega (2003) [16] and concern the interaction of two filaments and particular configurations of three filaments. In this article we prove large time existence results for particular configurations of four nearly parallel filaments and for a class of configurations of N nearly parallel filaments for any N?2. We also show the existence of travelling wave type dynamics. Finally we describe configurations leading to collision. 相似文献
95.
Larcher D Delobel B Dantras-Laffont L Simon E Blach JF Baudrin E 《Inorganic chemistry》2010,49(23):10949-10955
In this paper, we detailed the formation/evolution of precipitates in alcoholic media containing Co(II+) and Li(+) species, together with the evolution of the composition and structure/texture of the resulting solid phases during the aging process at controlled constant temperature. While the end product is found to be well-crystallized HT-LiCoO(2), its formation is shown to result from a two-step process enlisting the initial fast precipitation of β-HCoO(2) and then its slow dissolution followed by recrystallization of the lithium-containing material. These results were obtained through combined X-ray diffraction, Raman and IR spectroscopy, elemental and oxidation-state analysis, and high-resolution transmission electron microscopy/selected-area electron diffraction observations. Depending on the cationic concentration, the size of the precipitated material can be controlled within the nanometric range. The electrochemical performances of these aged materials are slightly improved compared to those of the directly precipitated ones that we previously reported. The main limitation of these materials remains the presence of surface protons. 相似文献
96.
97.
Metabolic phenotyping of human plasma by 1H‐NMR at high and medium magnetic field strengths: a case study for lung cancer
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Evelyne Louis Francois‐Xavier Cantrelle Liesbet Mesotten Gunter Reekmans Liene Bervoets Karolien Vanhove Michiel Thomeer Guy Lippens Peter Adriaensens 《Magnetic resonance in chemistry : MRC》2017,55(8):706-713
Accurate identification and quantification of human plasma metabolites can be challenging in crowded regions of the NMR spectrum with severe signal overlap. Therefore, this study describes metabolite spiking experiments on the basis of which the NMR spectrum can be rationally segmented into well‐defined integration regions, and this for spectrometers having magnetic field strengths corresponding to 1H resonance frequencies of 400 MHz and 900 MHz. Subsequently, the integration data of a case–control dataset of 69 lung cancer patients and 74 controls were used to train a multivariate statistical classification model for both field strengths. In this way, the advantages/disadvantages of high versus medium magnetic field strength were evaluated. The discriminative power obtained from the data collected at the two magnetic field strengths is rather similar, i.e. a sensitivity and specificity of respectively 90 and 97% for the 400 MHz data versus 88 and 96% for the 900 MHz data. This shows that a medium‐field NMR spectrometer (400–600 MHz) is already sufficient to perform clinical metabolomics. However, the improved spectral resolution (reduced signal overlap) and signal‐to‐noise ratio of 900 MHz spectra yield more integration regions that represent a single metabolite. This will simplify the unraveling and understanding of the related, disease disturbed, biochemical pathways. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
98.
Phase-Transfer Catalytic Alkylation of Hydroperoxides: A Convenient Route to Mixed Dialkyl Peroxides
Jean Moulines Marie-Josèphe Bougeois Monique Campagnole Anne-Marie Lamidey Bernard Maillard Evelyne Montaudon 《合成通讯》2013,43(3):349-353
The solid-liquid phase transfer catalytic alkylation of hydroperoxides using solid potassium hydroxide as a base and TEBAC as a phase transfer catalyst is reported. When the alkylating agent is a primary bromide, this reaction represents a simple and quick method for the synthesis of mixed dialkyl peroxides in fair yields. 相似文献
99.
The nucleophilic substitution by primary amines of secondary homoallylic mesylates easily obtained from corresponding alcohols offers a convenient way to prepare homoallylic amines. The relative low yields in pure compounds is counterbalanced by the simplicity of the procedure. 相似文献
100.
Sodium titanate materials are promising inorganic ion exchangers for the adsorption of strontium from aqueous solutions. Sodium
nonatitanate exhibits a layered structure consisting of titanate layers and exchangeable sodium ions between the layers. The
materials used in this study include samples synthesized by a hydrothermal method at temperatures between 60 °C and 200 °C.
Their structure, composition, and morphology were investigated with X-Ray diffraction measurements; thermogravimetric, compositional
and surface area analyses, and scanning electron microscopy. The structure, composition, and morphology depended on the synthesis
temperature. Batch kinetics experiments for the removal of strontium from aqueous solutions were performed, and the data were
fitted by a pseudo-second-order reaction model and a diffusive model. The strontium extraction capacity also depended on the
synthesis temperature and exhibited a maximum for samples synthesized at 100 °C. The sorption process occurs in one or two
diffusion-controlled steps that also depend on the synthesis temperature. These diffusion-limited steps are the boundary-layer
diffusion and intra-particle diffusion in the case of pure nonatitanate synthesized at temperatures lower than 170 °C, and
only intra-particle diffusion in the case of nonatitanate synthesized at 200 °C. 相似文献