999 resultados para 478-2


Relevância:

40.00% 40.00%

Publicador:

Resumo:

Vorbesitzer: Dominikanerkloster Frankfurt am Main

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A model (NADH-phenazine methosulfate-O2) formally similar to pyridine nucleotide-dependent flavoprotein hydroxylases catalyzed the hydroxylation of several aromatic compounds. The hydroxylation was maximal at acid pH and was inhibited by ovine Superoxide dismutase, suggesting that perhydroxyl radicals might be intermediates in this process. The stoichiometry of the reaction indicated that a univalent reduction of oxygen was occurring. The correlation between the concentration of semiquinone and hydroxylation, and the inhibition of hydroxylation by ethanol which inhibited semiquinone oxidation, suggested the involvement of phenazine methosulfate-semiquinone. Activation of hydroxylation by Fe3+ and Cu2+ supported the contention that univalently reduced species of oxygen was involved in hydroxylation. Catalase was without effect on the hydroxylation by the model, ruling out H2O2 as an intermediate. A reaction sequence, involving a two-electron reduction of phenazine methosulfate to reduced phenazine methosulfate followed by disproportionation with phenazine methosulfate to generate the semiquinone, was proposed. The semiquinone could donate an electron to O2 to generate O2 which could be subsequently protonated to form the perhydroxyl radical.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

An integrated multiwavelength grating cavity (MGC) laser fabricated by selective area regrowth is demonstrated. In addition to allowing wavelength conversion, the device can perform various important network functions such as space switching and multiplexing. The use of the device for these functions offers several advantages from a wavelength division multiplexing (WDM) network, such as flexibility, reduced component count, size, and the associated cost reduction.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

于2010-11-23批量导入

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The multilayer Langmuir-Blodgett (LB) films of pr,ly 3-(2-(5-chlorobenzotriazole)ethyl) thiophene (PCBET) blended with amphibious arachidic acid (AA) were prepared and characterized. The photoluminescence intensity of the blend film was enhanced as the AA increased by a certain amount. The PCBET excimers were not formed in the blend LB films.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

生物吸附法是处理含重金属废水的一种新兴的处理技术。微生物所分泌的胞外聚合物(EPS)在微生物吸附重金属中起重要作用。硫酸盐还原菌(SRB)混合菌群分泌的EPS能有效的吸附水溶液中的Cu^2+,Langmuir等温方程和Freundlich等温方程都能拟合实验所得吸附数据,最大吸附容量达到478.47mg/gEPS。水溶液的初始pH值对EPS吸附Cu^2+影响明显,在pH为7时,吸附效率最高,pH增减,吸附效率明显下降。SRB混合茵群分泌的EPS的FT—IR分析表明,EPS对Cu^2+的吸附主要在于EPS中的蛋白质的酰胺(Ⅱ)、羧基、多聚糖的C-O-C、OH和脂类等基团对Cu^2+的强络合能力.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A hardware performance analysis of the SHACAL-2 encryption algorithm is presented in this paper. SHACAL-2 was one of four symmetric key algorithms chosen in the New European Schemes for Signatures, Integrity and Encryption (NESSIE) initiative in 2003. The paper describes a fully pipelined encryption SHACAL-2 architecture implemented on a Xilinx Field Programmable Gate Array (FPGA) device that achieves a throughput of over 25 Gbps. This is the fastest private key encryption algorithm architecture currently available. The SHACAL-2 decryption algorithm is also defined in the paper as it was not provided in the NESSIE submission.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aims/hypothesis: Glycation of insulin, resulting in impaired bioactivity, has been shown within pancreatic beta cells. We have used a novel and specific radioimmunoassay to detect glycated insulin in plasma of Type 2 diabetic subjects.

Methods: Blood samples were collected from 102 Type 2 diabetic patients in three main categories: those with good glycaemic control with a HbA1c less than 7%, moderate glycaemic control (HbA1c 7–9%) and poor glycaemic control (HBA1c greater than 9%). We used 75 age- and sex-matched non-diabetic subjects as controls. Samples were analysed for HbA1c, glucose and plasma concentrations of glycated insulin and insulin.

Results: Glycated insulin was readily detected in control and Type 2 diabetic subjects. The mean circulating concentration of glycated insulin in control subjects was 12.6±0.9 pmol/l (n=75). Glycated insulin in the good, moderate and poorly controlled diabetic groups was increased 2.4-fold (p<0.001, n=44), 2.2- fold (p<0.001, n=41) and 1.1-fold (n=17) corresponding to 29.8±5.4, 27.3±5.7 and 13.5±2.9 pmol/l, respectively.

Conclusion/interpretation: Glycated insulin circulates at noticeably increased concentrations in Type 2 diabetic subjects. [Diabetologia (2003) 46:475–478]

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Este projeto teve como principal objetivo continuar o desenvolvimento do quiosque multimédia FNAC. Filial do Grupo Pinault Printemps, a FNAC é líder europeu na distribuição de bens tecnológicos e culturais. Nesta fase do desenvolvimento, o foco do projeto centrou-se na procura da melhor forma de mostrar ao utilizador a localização de um produto na loja FNAC Madeira, expansão das funcionalidades aos restantes produtos e o redesenho da interface do quiosque multimédia FNAC. Por forma a identificar uma forma eficaz de dar a conhecer ao utilizador a localização de um produto dentro da loja FNAC Madeira, foi efetuado um estudo que consistiu em questionários e testes com utilizadores para comparar duas formas de localização, por planta da loja ou por vídeo em tempo real. A primeira versão do quiosque multimédia FNAC apenas possuía suporte a livros, pelo que foi necessário tornar a aplicação o mais abstrata possível por forma a gerar as categorias de produtos em runtime recorrendo a ficheiros XML. Por fim, para redesenhar a interface do quiosque multimédia FNAC, foram efetuadas análises às interfaces da primeira versão, utilizando as heurísticas de Nielsen e os “Principles of good form” de Larry Constantine. Após a fase de análise as interfaces foram redesenhadas tendo por base a análise efetuada, o guia de norma FNAC 2011 e breves testes de usabilidade com utilizadores. Do estudo realizado, na procura pela melhor forma de localização, foram identificados alguns problemas relacionados com a utilização de um vídeo em tempo real para a identificação, tal como as interferências externas por parte dos outros clientes do espaço comercial e foi possível constatar um melhor desempenho e aceitação da localização por planta. A localização por planta mostrou-se suficiente para os utilizadores conseguirem identificar o local onde o produto estava exposto, pois permitia-lhes identificar o local onde encontravam-se e obter uma localização mais precisa do local, necessitando apenas de olhar em volta para conseguir relacionar o que era possível visualizar na planta com aquilo que os rodeava na loja.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A submodel of the so-called conformal affine Toda model coupled to the matter field (CATM) is defined such that its real Lagrangian has a positive-definite kinetic term for the Toda field and a usual kinetic term for the (Dirac) spinor field. After spontaneously broken the conformal symmetry by means of BRST analysis, we end up with an effective theory, the off-critical affine Toda model coupled to the matter (ATM). It is shown that the ATM model inherits the remarkable properties of the general CATM model such as the soliton solutions, the particle/soliton correspondence and the equivalence between the Noether and topological currents. The classical solitonic spectrum of the ATM model is also discussed. (C) 2001 Elsevier B.V. B.V. All rights reserved.