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1.
Arnaud C. Feron P. Boustimi M. Grosso P. Bosc D. Guignard P. 《Electronics letters》2003,39(17):1249-1250
Numerical results on polymer surrounded by an air micro-ring coupled to waveguides are presented. The FDTD method predicts a filter width of 1.4 nm and an extraction efficiency of almost 80% for a gap of 0.15 /spl mu/m. 相似文献
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Marko J. Tadjer Michael A. Mastro José M. Rojo Alberto Boscá Mojena Fernando Calle Francis J. Kub Charles R. Eddy Jr. 《Journal of Electronic Materials》2014,43(4):1188-1193
Manganese dioxide films were grown on large area flexible carbon aerogel substrates. Characterization by x-ray diffraction confirmed α-MnO2 growth. Three types of films were compared as a function of hexamethylenetetramine (HMTA) concentration during growth. The highest concentration of HM TA produced MnO2 flower-like films, as observed by scanning electron microscopy, whose thickness and surface coverage lead to both a higher specific capacitance and higher series resistance. Specific capacitance was measured to be 64 F/g using a galvanostatic setup, compared to the 47 F/g-specific capacitance of the carbon aerogel substrate. Such supercapacitor devices can be fabricated on large area sheets of carbon aerogel to achieve high total capacitance. 相似文献
3.
M Velasco MJ Díaz-Guerra P Martín-Sanz A Alvarez L Boscá 《Canadian Metallurgical Quarterly》1997,272(37):23025-23030
Lipopolysaccharide (LPS) administration to mice elicited the activation of nuclear factor kappaB (NF-kappaB) in several tissues including liver and macrophages. Maximal activation was observed 1 h after treatment but declined at 3 and 6 h. The levels of IkappaBalpha and IkappaBbeta were analyzed during this period in an attempt to correlate NF-kappaB activity with IkappaB resynthesis. Degradation of IkappaBalpha was very rapid and was followed by recovery 1 h after LPS administration. IkappaBbeta degradation, which has been associated with persistent NF-kappaB activation, was complete at 1 h. However, a rapid recovery of IkappaBbeta in these tissues was observed at 3 h in parallel with the abrogation of NF-kappaB activity. Immunolocalization of newly synthesized IkappaBbeta by confocal microscopy revealed its preferential accumulation in the cytosol. Analysis of IkappaBbeta by Western blot using high resolution polyacrylamide gel electrophoresis showed the presence of two bands in cytosolic extracts of LPS-treated macrophages at 3 h, but only one band with the same mobility as the control was detected at 6 h. Moreover, treatment of extracts of resynthesized IkappaBbeta with alkaline phosphatase resulted in the accumulation of the protein of slightly higher electrophoretic mobility, indicating the prevalence of a rapid phosphorylation of the newly synthesized IkappaBbeta. At the mRNA level, up-regulation of IkappaBbeta was observed in macrophages stimulated for 1 h with LPS. When the effect of pro-inflammatory cytokines was investigated, tumor necrosis factor alpha, but not interleukin-1 or interferon-gamma, promoted an important degradation of IkappaBbeta followed by an increase in the mRNA at 1 h. These results suggest the existence of LPS- and tumor necrosis factor alpha- specific pathways involved in a rapid IkappaBbeta degradation and resynthesis and might explain the transient period of activation of NF-kappaB in these tissues upon stimulation with these factors. This rapid control of NF-kappaB function may contribute to the attenuation of the inflammatory response of these cells. 相似文献
4.
Vincent Rouessac Arie van der Lee Florence Bosc Jean Durand Andr Ayral 《Microporous and mesoporous materials》2008,111(1-3):417-428
Three characterization techniques are described for studying the open nanoporosity, i.e. the open free volume, the microporosity, the mesoporosity and the thickness variation of thin deposited films during gas adsorption and condensation. They are all based on the coupling of the sorption of a probe gaseous molecule at room temperature and a physical characterization tool of thin deposited films: the quartz crystal microbalance, ellipsometry and X-ray reflectometry, giving the mass uptake, the refractive index variation and the electronic density variation, respectively, of the film due to the adsorbate intrusion inside the open free volume and pores. The film thickness evolution during the sorption can also be followed by the two last techniques. These techniques are complementary because each one can bring specific properties and can validate the results of another one. Both static and dynamic measurements can be carried out to characterize the porosity, the contraction or the swelling of the film and the penetration rate of the gas. 相似文献
5.
About projection-selection-join queries addressed to possibilistic relational databases 总被引:1,自引:0,他引:1
This work deals with databases containing ill-known attribute values represented by possibility distributions. Any such database has a canonical interpretation as a set of regular databases, but it is well known that their manipulation raises a number of problems, in particular with respect to the soundness of querying operations and the tractability of the evaluation process. In This work, we propose a query language including three operators which are soundly defined on extended possibilistic (compact) relations, which is the key for tractability. The originality of the approach is twofold: 1) a nesting mechanism is introduced in the data model in order to support the expression of the result of some of the operations allowed, and 2) a joint operation enables to compose possibilistic relations under some reasonable hypotheses. 相似文献
6.
In traditional database management systems, queries are intended to retrieve data which satisfy crisp criteria. In some cases, this lack of flexibility leads to empty answers. That is one of the reasons why we have been investigating the extension of these systems so that they become able to support imprecise querying capabilities. In this article, the introduction of imprecise queries in a particular nonrelational system (Information Warehouse) is presented. One of the main interesting aspects of this work resides in the specific data model for which the semantics of fuzzy queries firstly has to be defined. © 1994 John Wiley & Sons, Inc. 相似文献
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8.
Chao TH Lam T Vong BG Través PG Hortelano S Chowdhury C Bahjat FR Lloyd GK Moldawer LL Boscá L Palladino MA Theodorakis EA 《Chembiochem : a European journal of chemical biology》2005,6(1):133-144
The synthesis and the biological evaluation of a new family diterpenes are presented. The synthetic studies were inspired by the structural framework of acanthoic acid (1) and yielded a family of compounds that were evaluated as anti-inflammatory agents. Among them, compounds 2, 10, 12, and 16 exhibited a very low nonspecific cytotoxicity and inhibited the synthesis of TNF-alpha with greater than 65 % efficacy at low micromolar concentrations. Cytokine-specificity studies revealed that these compounds also inhibited the synthesis of the proinflammatory cytokines IL-1beta and IL-6, while inhibition of IL-1ra and IL-8 synthesis was marginal and only occurred at high concentrations. Further studies, through EMSA and Western blot analyses, indicated that these compounds decreased the extent of phosphorylation of IkappaBalpha; this suggests that they exert their anti-inflammatory profile by inhibiting NF-kappaB-mediated cytokine synthesis. These findings imply that these diterpenes represent promising leads for the development of novel anti-inflammatory agents. 相似文献
9.
Fructose 2,6-bisphosphate concentration, 6-phosphofructo 2-kinase/fructose 2,6-bisphosphatase (PFK-2/FBPase2) activity, and messenger RNA decreased in maternal rat liver during the last days of gestation, and the recovery started after delivery. Phospho(enol)pyruvate carboxykinase activity and messenger RNA increased in contrast to PFK-2 changes. Measurement of the glycolytic capacity in isolated hepatocytes prepared from rats 1 h after parturition showed a low glucose consumption and an impaired capacity to metabolize glucose. These results stress the relevance of the PFK-2/fructose 2,6-bisphosphate system in the control of the glycolytic flux in liver, and these changes are intended to prevent glucose consumption by maternal liver and contribute to allow gluconeogenesis to proceed at the end of gestation. The physiological basis of this adaptation may lay on the diversion of glucose from maternal to fetal metabolism. 相似文献
10.
Nicolas Keller Elodie Barraud Florence Bosc David Edwards Valerie Keller 《Applied catalysis. B, Environmental》2007,70(1-4):423-430
The photocatalytic behavior of different TiO2-based photocatalysts was reported for gas-phase toluene removal under both UV and visible light illumination, and compared to that of commercial P25 (Degussa) TiO2. Promotion by sulfates and the use of nanosized anatase TiO2 were reported to strongly increase the toluene removal efficiency under UV illumination. Nanosized-anatase was prepared by a protecting group sol–gel synthesis using hexamethyldisilazane as crystallite growth inhibitor. Sulfates played a double positive role, with photogenerated electrons transfer effects limiting charge recombination and as repulsive species for strongly adsorbed aromatic intermediates that act as poisons. The decrease in particle size obtained on nanosized anatase TiO2 (5 nm) yielded a considerable enhancement in the toluene removal efficiency. Pure high surface area rutile has been synthesized at low temperature by a polyethylenglycol-containing sol–gel method for visible light activation purposes. A two-way semiconductor coupling phenomenon, consisting of a reciprocal electron/hole transfer between two visible light-activated oxides, rutile TiO2 and WO3, was proposed to explain the large gain in efficiency when adding low amounts of WO3 to rutile TiO2. 相似文献