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131.
Adeline Perro Fabrice Meunier Véronique Schmitt Serge Ravaine 《Colloids and surfaces. A, Physicochemical and engineering aspects》2009,332(1):57-62
For the first time, large amount of Janus silica particles as small as 100 nm in diameter were prepared through a simple method based on the elaboration of Pickering emulsions of wax-in-water. Controlling the kinetic stabilization of wax droplets allows the fabrication of gram-sized quantities of regular asymmetric inorganic particles with high yield. In fact, our method is based on a limited coalescence process, which allows one to predict the quantity of interface which is produced when working with a known mass of wax, and thus to be sure that all introduced silica particles are adsorbed on the wax surface. To this end, the hydrophilic surface of the silica particles was made partially hydrophobic by adsorbing a known amount of surfactant: cetyltrimethylammonium bromide (CTAB). Varying the concentration in surfactant results in tuning the penetration rate of the particles in the wax droplets, leading to various dimension of the modified area. The broken spherical symmetry of the particle surface was thereafter revealed by the selective adsorption of gold nanoparticles on the amino-modified surface. 相似文献
132.
133.
Serge Kokot 《中国化学快报》2010,21(8):963-967
<正>The interactions of carbofuran and DNA were studied using voltammetry and fluorescence spectroscopy.The formation of carbofuran-DNA makes the current peak of DNA decreased by voltammetry method.The binding number(n) and constant(K_a) for complex carbofuran-DNA were calculated to be 1.06±0.04 and 0.11±0.03mol~(-1) L,respectively by fluorescence measurement.Chemometrics approach,such as singular value decomposition(SVD) was used to evaluate the number of spectral species in the drug-DNA binding process.And the pure spectra and concentration profiles in the kinetic system were clearly deduced by multivariate curve resolution alternating least squares(MCR-ALS) with the initial estimates by evolving factor analysis(EFA). 相似文献
134.
We report on the easy and fast immobilization of glucose oxidase (GOD) and laccase by mechanical compression with graphite particles to form disc electrodes. The electrical wiring of GOD and laccase was efficiently carried out by their co-inclusion with ferrocene (Fc) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) respectively. A glucose/air compartment-less biofuel cell was constructed based on the association of GOD-ferrocene-graphite disc and laccase-ABTS – graphite disc electrodes as bioanode and biocathode respectively. Such biofuel cell yielded a power density of 23 μW cm?2 at 0.33 V as well as an open-circuit voltage and a short-circuit current of 0.63 V and 166 μA, respectively. 相似文献
135.
Jessica Baur Michael Holzinger Chantal Gondran Serge Cosnier 《Electrochemistry communications》2010,12(10):1287-1290
A novel and simple immobilization strategy for biotinylated biological macromolecules onto electropolymerized poly(pyrrole-nitrilotriacetic acid)(NTA)–Cu2+ films without avidin as connecting bridge is reported. After complexation of Cu2+ by the polymerized NTA chelator, biotinylated biomolecules were immobilized by coordination of the biotin groups on the NTA–Cu2+ complex. The anchoring of biotinylated glucose oxidase was demonstrated by fluorescent characterization via FITC-labeled avidin and amperometric measurement of glucose. The resulting calibration curve led to a sensitivity and maximum current density values of 0.6 mA mol?1 L cm? 2 and 13.2 μA cm? 2, respectively. Thus, biotinylated polyphenol oxidase was fixed leading to a catechol sensor with a sensitivity of 656 mA mol?1 L cm? 2 and maximum current density of 25.4 μA cm? 2. This system was also applied to the efficient immobilization of biotinylated DNA, illustrated by impedimetric detection of the formation of the DNA duplex. 相似文献
136.
Clementine Cailleteau Ludovic Micallef Clemence Lepage Philippe Jean-Paul Cardot Jean-Louis Beneytout Bertrand Liagre Serge Battu 《Analytical and bioanalytical chemistry》2010,398(3):1273-1283
Differentiation therapy could be one strategy for stopping cancer cell proliferation. A plant steroid, diosgenin, is known
to induce megakaryocytic differentiation in human erythroleukemia (HEL) cells. In recent studies, the use of sedimentation
field-flow fractionation (SdFFF) allowed the preparation of subpopulations that may differ in regard to sensitivity to differentiation
induction. The specific goal of this study was to determine the relationship between cell cycle stage and sensitivity to megakaryocytic
differentiation induction of HEL cells. After first confirming the capacity of diosgenin to specifically select targets, hyperlayer
SdFFF cell sorting was used to prepare fractions according to cell cycle position from crude HEL cells. The sensitivities
of these fractions to diosgenin-induced differentiation were then tested. The coupling of SdFFF cell separation to imaging
flow cytometry showed that G1-phase cells were more sensitive to differentiation induction than S/G2M-phase cells, confirming
the relationship between cell status at the start of induction, the extent of the biological event, and the potential of SdFFF
in cancer research. 相似文献
137.
Aline Staub Sylvain Giraud Martial Saugy Serge Rudaz Jean‐Luc Veuthey Julie Schappler 《Electrophoresis》2010,31(2):388-395
CE is a powerful analytical tool used to separate intact biomolecules such as proteins. The coupling of CE with TOF/MS produces a very promising method that can be used to detect and identify proteins in different matrices. This paper describes an efficient, rapid, and simple CE‐ESI‐TOF/MS procedure for the analysis of endogenous human growth hormone and recombinant human growth hormone without sample preparation. Operational factors were optimized using an experimental design, and the method was successfully applied to distinguish human growth hormone and recombinant human growth hormone in unknown samples. 相似文献
138.
Nathalie Dupré Pauline Rémy Dr. Kévin Micoine Dr. Cécile Boglio Dr. Serge Thorimbert Dr. Emmanuel Lacôte Dr. Bernold Hasenknopf Prof. Max Malacria Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(24):7256-7264
The preparation of new organosoluble Lewis acidic polyoxometalates (POMs) is reported. These complexes were prepared by the incorporation of Zr, Sc, and Y atoms into the corresponding monolacunary Dawson [P2W17O61]10? and Keggin [PW11O39]7? polyoxotungstates. The catalytic activity of these compounds was evaluated for C? C bond formation in the Diels–Alder, Mannich, and Mukaiyama‐type reactions. Comparisons with previously described Lewis acidic POMs are reported. Competitive reactions between imines and aldehydes or between various imines demonstrated that fine tuning of the reactivity could be reached by varying the metal atom incorporated into the polyanionic framework. A series of experiments that employed pyridine derivatives allowed us to distinguish between the Lewis and induced Brønsted acidity of the POMs. These catalysts activate imines in a Lewis acidic way, whereas aldehydes are activated by indirect Brønsted catalysis. 相似文献
139.
Excepted for the very short terms the frequency stability of ultra-stable oscillators is mainly limited by the resonator noise. In this work we proposed a parametric model of the bulk acoustic wave (BAW) resonator phase noise based on an equivalent circuit. This model explains phase noise generated by a BAW crystal from a point of view of parametric fluctuations and proves the f−1 dependences of the crystal noise. The model performance is verified with simulation. Simulation results are compared to experimental data and discussed. Comparison of three existing models is made. 相似文献
140.
The classification of simple biset functors is known, but the evaluation of a simple biset functor at a finite group G may be zero. We investigate various situations where this happens, as well as cases where this does not occur. We also prove a closed formula for such an evaluation under some restrictive conditions on G. 相似文献