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1.
Alessandro Fantoni Manuela Viera Rodrigo Martins 《Solar Energy Materials & Solar Cells》2002,73(2):148
In this paper a set of one-dimensional simulations of a-Si:H p–i–n junctions under different illumination conditions and with different intrinsic layer are presented. The simulation program ASCA permits the analysis of the internal electrical behaviour of the cell allowing a comparison among the different internal configurations determined by a change in the input set. Results about the internal electric configuration will be presented and discussed outlining their influence on the current tension characteristic curve. Considerations about the drift–diffusion and the generation–recombination balance distributions, outlined by the simulation, can be used to explain the correlation between the basic device output, the i-layer characteristics (thickness and DOS), the incident radiation intensity and photon energy. 相似文献
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Subcellular pharmacokinetics (SP) optimizes biology-related factors in the design of libraries for high throughput screening by defining comparatively narrow ranges of properties (lipophilicity, amphiphilicity, acidity, reactivity, 3D-structural features) of the included compounds. The focusing ensures appropriate absorption, distribution, metabolism, excretion, and toxicity (ADMET) in those test biosystems, which are more complex than isolated receptors, and in humans. The SP deploys conceptual models that include transport and accumulation in a series of membranes, protein binding, hydrolysis, and other reactions with cell constituents. The kinetics of drug disposition is described as a non-linear disposition function of drug structure and properties. The SP capabilities are illustrated here using a model-based quantitative structure-activity relationship of toxicity of phenolic compounds against Tetrahymena pyriformis as dependent on lipophilicity and acidity. The resulting SP models clearly outperform empirical models in predictive ability outside the parameter space, as revealed by the leave-extremes-out cross-validation technique with omission of compounds beyond pre-defined lipophilicity and acidity ranges. The SP models do not change substantially if the parameters space is shrunk within some limits. In contrast, the shapes of empirical models vary widely depending upon the fraction of the data set used for their optimization. Once calibrated for a given biosystem, the SP models provide a detailed recipe for tailoring the drug properties to ensure optimum ADMET. The focusing is more accurate than with traditional empirical QSAR studies, assessment of drug-likeness, or the rules for identification of compounds with permeability problems. 相似文献
5.
J Aristu J Rebollo R Martínez-Monge JM Aramendía JC Viera I Azinovic J Herreros A Brugarolas 《Canadian Metallurgical Quarterly》1997,20(3):276-281
The relation between diet and female colorectal cancer was analyzed in a prospective study of 14,727 women aged 34-65 years, who were enrolled at mammographic screening clinics in New York and Florida from 1985 to 1991. They were followed through the end of 1994 (average 7.1 yrs) by a combination of direct contact through mail and telephone and record linkages with regional tumor registries, resulting in 100 incident cases of colorectal cancer. There was no overall positive or inverse association of colorectal cancer risk with intakes of total calories, total or subclasses of fat, carbohydrate, or dietary fiber, whereas there was an inverse association with total protein. Among major food groups, there was a progressive decline in risk of colorectal cancer with increasing intake of fish and shellfish (relative risk for 4th vs. 1st quartile = 0.49, 95% confidence interval = 0.27-0.89). A similar inverse association was also observed for consumption of dairy products, and this association was explained mainly by calcium, not by other nutrients, such as fat or protein. The results of the present study indicated that certain dietary components of fish or dairy products may protect against colorectal cancer, whereas the relations with red meat or total fat remained unclear. 相似文献
6.
Summary
The effect of the of the reactive modifier 1,3-phenylene dimaleimide (BMI) on the interphase structure of poly(propene) block
copolymer (PPBC)/magnesium hydroxide (Mg(OH)2) composites has been investigated. DRIFTS and DSC studies on hot decane extracted composites confirmed preferential encapsulation
of the filler particles with the ethene based elastomeric phase of the PPBC. This elastomeric interphase structure, formed
efficiently via reactive processing of untreated Mg(OH)2, PPBC and BMI, conferred excellent strength and toughness to the composites. The tensile strength and elongation of a BMI
modified composite containing 60% w/w Mg(OH)2, exceeded the yield stress and strain of the unfilled matrix.
Received: 17 March 2000 /Revised version: 23 October 2001/ Accepted: 23 October 2001 相似文献
7.
R Martínez Monge M Jurado I Azinovic JJ Aristu E Tangco JC Viera JM Berián FA Calvo 《Canadian Metallurgical Quarterly》1993,28(2):127-133
In ten patients with chronic renal failure (CRF) serum concentrations of alpha 1-acid glycoprotein, alpha 1-antitrypsin, prealbumin, hemopexin, transferrin, haptoglobin, C3c and C4 complement components, ceruloplasmin, alpha 2-macroglobulin were determined using Partigen plates before, 30 min. and 2 hours after beginning of HD. Serum concentrations of C3c complement component, prealbumin increased significantly during HD using CU dialyser, but changes during HD using CA dialyser were not significant. Serum concentrations of alpha 1-antitrypsin, hemopexin increased significantly after two hours of HD using CA dialyser, but changes during HD using CU dialyser were again not significant. Serum concentrations of alpha 1-acid glycoprotein, transferrin, haptoglobin, ceruloplasmin, C4 complement component during HD using both dialyzers did not change significantly. Serum concentration of alpha 2-macroglobulin was higher after two hours of HD. The type of dialysis membrane has important influence on changes of serum acute phase proteins during the initial period of HD. 相似文献
8.
In order to establish the prerequisites for the examination of solution properties of poly(di-n-alkyl itaconates), the solubilities of the first 11 members of this polymer homologous series were determined in 70 solvents, and the results correlated with the lengths of the ester substituents of the polymer chain, the solvent solubility parameters and the solvent hydrogen bonding capacities. The relation between solvent strength and the lengths of ester substituents of the monomer units was established quantitatively for several solvents in terms of φ2 crit., the nonsolvent volume fraction in ternary polymer-solvent-nonsolvent θ-mixtures, and evaluated according to a turbidometric titration method proposed by ELIAS 1. Both groups of results are a guideline for the probable existance of θ-conditions for particular polymer-solvent pairs and permit the prediction of solubilities of still higher members of the series. 相似文献
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Andrea Bírov Emil vajdlenka Jn Cvengros Viera Dostlíkov 《European Journal of Lipid Science and Technology》2002,104(5):271-277
This paper presents the results of two methods employed to determine the methyl ester (ME) fraction in mixed fuels prepared from MEs of higher fatty acids and fossil Diesel fuel. The first method is based on determining the ester number of the mixed fuel. The second one utilises the measurement of the carbonyl band intensity in the mixed fuel by infrared (IR) spectroscopy. The ME fraction in the tested mixed fuels was always set to 30 wt‐%. Applying the first method the ester numbers of mixed fuels were determined and the ME fraction was defined using an averaged molar mass of ME. The differences between the values of the measured and real fraction of ME varied between −0.2 and +0.8 wt‐%. If the value of the average molar mass of ME was not known, the molar mass of methyl oleate was used as a reference. Thereby the differences in determining the ME fraction in mixed fuels ranged between −0.1 and +0.9 wt‐%. Employing the IR spectroscopy method the differences between the measured and the real fraction of ME varied between −1.0 and +0.5 wt‐%. Both methods are suitable to determine the ME fraction in mixed fuels. 相似文献