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排序方式: 共有396条查询结果,搜索用时 171 毫秒
21.
Marcelo T. Oliveira Ana Flávia L. Specian Célia G.T.J. Andrade Emanuele J.G. Fran?a Luciana Furlaneto-Maia Marcia C. Furlaneto 《Micron (Oxford, England : 1993)》2010,41(6):604-608
Candida parapsilosis is found frequently as commensal organism on epithelial tissues, and is also an increasing cause of nosocomial infection. Scanning electron microscope (SEM) observations were used to analyse the capability of C. parapsilosis cells to adhere and grow as biofilm on human natural substrates and to compare the adherence pattern of isolates exhibiting distinct phenotypes. Cells from the crepe phenotype are predominantly elongated and form pseudohyphae whereas cells from the smooth phenotype are yeast-shaped, either in liquid cultures or on human nail and hair surfaces. The electron micrographs revealed that C. parapsilosis cells from the smooth phenotype adhered in higher number to both surfaces compared to the observed for the crepe phenotype. SEM analysis of human hair surface revealed that cells from the smooth phenotype appear as clumped blastoconidia of uniform morphology embedded in a flocculent extracellular material forming biofilm. The extracellular material and biofilm were seeing in a less extension in the crepe phenotype. A distinct adherence pattern was observed when human nail was used as substrate. Here C. parapsilosis cells seem to be linked to surface structures of human nail plate. Fibrillar extracellular material was observed connecting neighbouring cells as well as nail surface. 相似文献
22.
23.
Piazza R Pierno M Vignati E Venturoli G Francia F Mallardi A Palazzo G 《Physical review letters》2003,90(20):208101
Solubilization of membrane proteins requires surfactants, whose structural properties play a crucial role in determining the protein phase behavior. We show that ionization of a pH-sensitive surfactant, lauryldymethylamino-N-oxide, bound to the bacterial photosynthetic Reaction Center, induces protein phase segregation in micrometric "droplets." Liquid-liquid phase separation takes place in a narrow pH range, is promoted by increasing temperature, and vanishes by adding salt. After a fast initial droplet growth, the nearly arrested kinetics at a later stage leaves the system in a finely divided, long-lasting emulsified state. 相似文献
24.
Vendruscolo M Paci E Dobson CM Karplus M 《Journal of the American Chemical Society》2003,125(51):15686-15687
We present a method for determining the ensembles of native protein structures that result from the large fluctuations of low probability revealed by hydrogen-exchange experiments. The measured protection factors are used to bias Monte Carlo simulations to sample the structures of the exchange competent species. The approach is illustrated by its application to the case of alpha-lactalbumin. 相似文献
25.
Vittorio Emanuele Galafassi 《Annali di Matematica Pura ed Applicata》1948,27(1):135-151
Sunto. In relazione a curve trigonali reali (di genere e specie assegnati) vengono svolte alcune questioni di realità, ed in particolare
quella concernente il numero dei circuiti della parte reale ed il loro comportamento rispetto alla g
3
4
il che dà luogo ad una classificazione di tali curve. Sono perciò riprese od introdotte svariate considerazioni che potrebbero
anche venire più largamente utilizzate. 相似文献
26.
Antonio I. Carbone F. Paolo Cavasino Emanuele Di Dio Carmelo Sbriziolo 《国际化学动力学杂志》1986,18(6):609-621
The stopped-flow technique has been used to study the effect of cationic (CTAN), nonionic (Triton X-100), andanionic (SDS) micelles on the rate of the reaction between nickel(II) ion and the ligand pyridine-2-azo-p-dimethylaniline (PADA) at 20.0°C and ionic strength 0.03 mol dm?3. The complex formation reaction is markedly inhibited by both CTAN and Triton X-100 micelles. The kinetic dataare found to conform to a reaction mechanism which implies only partitioning of the ligand between water and the micellar phase, the estimated bindingconstant of PADA being significantly larger in the presence of CTAN aggregates. Anionic micelles strongly speed the complexation reaction, Which occurs in the micellar phase with the same rate and the same mechanism as in water. The extent of binding of PADA to anionic micelles is similar to that found for the cationic micellar aggregates. 相似文献
27.
E. Costa A. Emanuele A. Rubini E. Massaro G. Matt G. Medici G. C. Perola M. Salvati 《Il Nuovo Cimento C》1990,13(2):431-436
Summary We describe a high sensitivity X-ray Thomson polarimeter for astrophysical research, particularly designed for the XMM mission.
The efficiency, the modulation factor and the performances of this instrument have been estimated by means of a Monte Carlo
simulation. The predicted sensitivity for the high eccentricity Orbit of XMM should allow the detection of the Crab Nebula
polarization (3σ, (5÷11)keV) in 15 seconds only.
To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee. 相似文献
28.
29.
Ranieri A Monari S Sola M Borsari M Battistuzzi G Ringhieri P Nastri F Pavone V Lombardi A 《Langmuir : the ACS journal of surfaces and colloids》2010,26(23):17831-17835
Mimochrome VI (MC-VI) is a synthetic heme peptide containing a helix-heme-helix sandwich motif designed to reproduce the catalytic activity of heme oxidases. The thermodynamics of Fe(III) to Fe(II) reduction and the kinetics of the electron-transfer process for MC-VI immobilized through hydrophobic interactions on a gold electrode coated with a nonpolar SAM of decane-1-thiol have been determined through cyclic voltammetry. Immobilization slightly affects the reduction potential of MC-VI, which under these conditions electrocatalytically turns over molecular oxygen. This work sets the premise for the exploitation of totally synthetic mimochrome-modified electrode surfaces for clinical and pharmaceutical biosensing. 相似文献
30.
We study the coupling of massive scalar fields to matter in orbit around rotating black holes. It is generally expected that orbiting bodies will lose energy in gravitational waves, slowly inspiraling into the black hole. Instead, we show that the coupling of the field to matter leads to a surprising effect: because of superradiance, matter can hover into "floating orbits" for which the net gravitational energy loss at infinity is entirely provided by the black hole's rotational energy. Orbiting bodies remain floating until they extract sufficient angular momentum from the black hole, or until perturbations or nonlinear effects disrupt the orbit. For slowly rotating and nonrotating black holes floating orbits are unlikely to exist, but resonances at orbital frequencies corresponding to quasibound states of the scalar field can speed up the inspiral, so that the orbiting body sinks. These effects could be a smoking gun of deviations from general relativity. 相似文献