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21.
M P Vaquero M Veldhuizen W van Dokkum C J A van den Hamer G Schaafsma 《Journal of the science of food and agriculture》1994,64(4):475-481
The influence of drinking tea on copper bioavailability is unclear, particularly when tea is consumed with food. A breakfast meal containing white bread, margarine, strawberry jam, cheese and tea, with or without milk, was digested in; vitro and the dialysis of copper investigated. Reference breakfasts were prepared with water and water with milk. Copper dialysability (percentage of copper dialysed) was markedly increased by tea. The influence of adding milk to tea was not significant. A second study was carried out in rats using the breakfasts containing tea and water. They were spiked with 64Cu and given orally to the animals in a single dose. Whole-body 64Cu retention was measured over a 4-day period after administration. In order to determine the true absorption of 64Cu a control group of rats received the dose intraperitioneally. The results in vivo indicate a tendency to higher absorption and retention of 64Cu with tea. Liver 64Cu retention was significantly elevated by tea. Therefore, the presence of tea in a breakfast meal favours the formation of soluble low-molecular-weight ligands which can be absorbed and retained by rats. The concomitant increase in liver copper retetition may be associated with higher bioavailability and/or lower copper mobilisation. 相似文献
22.
23.
Bellens R. de Schrijver E. Van den Bosch G. Groeseneken G. Heremans P. Maes H.E. 《Electron Devices, IEEE Transactions on》1994,41(3):413-419
A continued fast interface trap generation is observed in n-channel MOS transistors after termination of the hot-carrier stress. The magnitude of this post-stress effect is strongly dependent on the conditions of the preceding stress, on the post-stress conditions and on the process parameters. For measurements at 293 K, a simple model is proposed which is based on the release of hydrogen by the thermal detrapping of holes, and which can explain the observed dependencies. The importance of the post-stress Dit-generation is illustrated for the case of dynamic stress conditions where it can lead to an apparently deviating degradation behavior 相似文献
24.
The levels of bacterial blood endotoxin, antiendotoxin antibodies and the overall immunity were studied in 48 females with inflammatory genital diseases complicated by pelvioperitonitis. The severest pelvioperitonitis-complicated abnormality was shown to characterized by high concentrations of endotoxin and low levels of antibodies. Endotoxinemia was found to be of diagnostic and prognostic value. 相似文献
25.
Simulations with regional climate models (RCMs), carried out for the Rhine basin, have been analyzed in the context of implications of the possible future discharge of the Rhine river. In a first analysis, the runoff generated by the RCMs is compared to observations, in order to detect the way the RCMs treat anomalies in precipitation in their land surface component. A second analysis is devoted to the frequency distribution of area averaged precipitation, and the impact of selection of various driving global climate models. 相似文献
26.
Zwanborn A.P.M. van den Berg P.M. 《Antennas and Propagation, IEEE Transactions on》1991,39(2):224-228
A number of electromagnetic field problems for planar structures can be formulated in terms of a hypersingular integral equation, in which a grad-div operator acts on a vector potential. The vector potential is a convolution of the free-space Green's function and some surface current density over the domain of interest. A weak form of this integral equation is obtained by testing it with subdomain basis functions defined over the plate domain only. As a next step, the vector potential is expanded in a sequence of subdomain basis functions and the grad-div operator is integrated analytically over the plate domain only. For the problem of electromagnetic scattering by a plate, the method shows excellent numerical performance. The numerical difficulties encountered in some previous conjugate gradient fast Fourier transform (CGFFT) methods have been eliminated 相似文献
27.
A procedure is described by which the length of a tendon at the onset of loading is determined objectively. The procedure includes the fitting of third-order polynomial functions on the load-elongation data. The onset of loading is detected by an increasing fit of the polynomial by selective data reduction of the initial part of the load-elongation curve. The procedure results in an objective and reproducible definition of the zero strain level of a tendon. 相似文献
28.
A system for the removal and control of dissolved oxygen (DO) from freshwater was designed and constructed with aquarium-type fish studies in mind. Degassed water was obtained using a partial vacuum of -14 psi, and DO regulated at an aquarium scale using electronically controlled aeration with timed partial water renewal. The degassing system was capable of producing water with approximately 1.7 mg L(-1) DO within 10 min of operation, and 0.55 mg L(-1) after 2h. The control system was capable of maintaining DO levels of ca 0.8 mg L(-1) over 48 h in the absence of aeration and further capable of precisely controlling DO levels as low as 1.16+/-0.002 mg L(-1) (mean+/-SEM) with aeration over a 48 h period. 相似文献
29.
GI Kempen MJ van Heuvelen RH van den Brink AC Kooijman M Klein PJ Houx J Ormel 《Canadian Metallurgical Quarterly》1996,25(6):458-464
Molecular electrostatic potential (MEP) maps of certain 3-methoxy flavone derivatives having different anti-picornavirus activities have been studied. Geometries of the molecules were optimised and charge distributions computed using the AM1 molecular orbital method. Hybridization displacement charges (HDC) were combined with the L?wdin charge distributions to compute the MEP maps. Reliability of the method of computing MEP maps was tested by studying certain other molecules for which ab initio MEP results are available. The anti-picornavirus activities of the flavones have been shown to be related with negative MEP values in two regions, one near the 3-methoxy group and another in a diagonally opposite region near the substituent attached to the C7 atom of the molecules. 相似文献
30.