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991.
992.
R Fleming F Lloyd M Herbert J Fenwick T Griffiths A Murdoch 《Canadian Metallurgical Quarterly》1998,13(7):1788-1792
The effects of profound suppression of circulating luteinizing hormone (LH) during the follicular phase of in-vitro fertilization cycles were explored in normal women during treatment with a gonadotrophin-releasing hormone analogue and exogenous purified follicle stimulating hormone. Ovarian responses to treatment and the capacity of supernumerary embryos to undergo blastocyst formation were examined in groups of patients defined by the concentration of plasma LH in the mid-follicular phase. Concentrations < or = 0.5 IU/I diagnosed the group with profoundly suppressed LH (相似文献
993.
J Herbert 《Canadian Metallurgical Quarterly》1998,8(2):39-41
Platelet hemostasis was studied in 23 patients with chronic alcoholism (CA) stage II at rest and under muscular exercise. At rest, the patients had elevated spontaneous aggregation of platelets and more active start of adrenaline and ristomycin aggregation. Exercise stimulated spontaneous platelet aggregation, enhances adrenaline and ristomycin aggregation. According to adrenalin test 32% of the examinees had platelet dysfunction. According to ristomycin aggregation, vascular endothelium was impaired in 95.7%of the patients. Thus, it is evident that CA stage II patients develop disorder of platelet hemostasis and vascular endothelium. Such patients are at high risk of thrombogenesis. 相似文献
994.
Im Rahmen der vorgelegten Arbeit wurden praktische und theoretische Untersuchungen an Wassermodellen von bodengeblasenen metallurgischen Pfannen durchgeführt. Um die Strömungsverhältnisse herauszuarbeiten, wurden zunächst Lichtschnittuntersuchungen durchgeführt. Dabei wurden das H/D-Verhältnis und der Gasdurchsatz in weiten Bereichen variiert. Die Lichtschnittuntersuchungen vermittelten Erkenntnisse über die Abhängigkeit der Vermischungsvorgänge von den Versuchsparametern. In gleicher Weise wurden Farbspur- und vor allem Laser-Doppler-Anemometer-Versuche zur Ermittlung der lokalen Strömungsgeschwindigkeiten durchgeführt. Besondere Beachtung wurde dem Bodenbereich geschenkt, der durch die Partikeleinstreumethode nochmals gesondert untersucht wurde. Der Vergleich von berechneten Strömungsverläufen mit den tatsächlich beobachteten zeigt, daß tendenziell vergleichbare Zusammenhänge bestehen. Im einzelnen ist aber für die Beurteilung von Reaktorteilräumen die Erfassung der Strömungsverhältnisse, Teilraumgrößen und Konzentrationsverläufe aus unmittelbaren Messungen notwendig. Die theoretischen Berechnungen der Konzentrationsverläufe aus einer mathematischen Beschreibung des Pfannenmodells mit Hilfe von drei ideal gemischten Teilräumen ergab qualitativ vergleichbare Zeitabhängigkeiten, wie die unmittelbaren gemittelten Messungen an verschiedenen Stellen im Pfannenmodell. Die Durchmischung wird hiernach durch den Umlaufstrom bzw. die Massenaustauschströme zwischen den Teilräumen, die Teilraumgrößen und ihre Anordnungen bestimmt. Die physikalischen Bedingungen wie Rühren bzw. Antrieb durch das Gas bestimmen sowohl die Massenströme als auch die Ausbildungsformen und Größen der Teilräume. 相似文献
995.
Herbert L. Holland 《Catalysis Today》1994,22(3):427-440
The various models that have been proposed for microbial biotransformations involving carbon hydroxylation and sulfide oxidation are reviewed. From these data, those substrate features that are important in controlling the regiochemistry and stereochemistry of these oxidative bioconversions are identified. 相似文献
996.
997.
998.
The potential performance of SiGe waveguide avalanche photodiodes is analyzed for operation at a wavelength of 1.3 μm. It is found that response speeds in excess of 5 Gbit/s with gains of ~40 should be readily achievable in the absence of carrier trapping effects. Analysis of the electron initiated avalanche current shows an initial low-noise fast pulse due to primary ionization. This is followed by a noisy tail involving hole initiated processes. Structures for future experimental study are proposed 相似文献
999.
The colour resulting from the partial overlap of tiny dots of cyan, magenta, and yellow inks in a matrix is difficult to predict. A method of simulating it on the macro-scale has been devised by measuring discs with coloured sectors using a spectrophotometer. Here the separate colours are mixed within the integrating sphere of the instrument. Although subtractive mixing occurs where colours overlap, the overall result to the eye/brain is interpreted by additive means. The result of mixing known areas of coloured surfaces additively was predicted successfully by Maxwell in the last century. His method, combined with the use of the CIE System, has been successfully used to predict the coordinates of the mixture of coloured sectors measured on the spectrophotometer. The theoretical model developed applies to trichromatic or polychromatic printing, whatever the substrate. © 1995 John Wiley & Sons, Inc. 相似文献
1000.
The relaxing effect of coagulation factor Xa on phenylephrine-contracted rat aortic rings was compared with the effect of thrombin and trypsin. All three proteases induced a dose-dependent relaxation in the presence of an intact endothelium. EC50 values were 3 +/- 1, 24 +/- 9, and 16 +/- 1 nmol/L for thrombin, trypsin, and factor Xa, respectively. Whereas thrombin induced rapid relaxations followed by partial recontraction, trypsin and factor Xa induced slower sustained effects. Factor Xa-induced relaxations were not affected by hirudin at high concentrations (1 mumol/L) but were abolished by DX9065A, a specific inhibitor of the catalytic activity of factor Xa. Furthermore, no relaxations to factor Xa could be elicited in the presence of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (100 mumol/L), whereas relaxations were not altered in the presence of the inactive enantiomer N omega-nitro-D-arginine methyl ester (100 mumol/L). Addition of factor Xa together with thrombin induced relaxations that were larger than those induced by thrombin alone, whereas factor Xa had no additional effects on trypsin-induced relaxations. Further-more, factor Xa relaxed thrombin-desensitized aortic rings but was ineffective in trypsin-desensitized tissues. These data suggest that factor Xa acts on a cleavable endothelial receptor that induces NO release, resulting in the relaxation of precontracted rat aortic rings. Factor Xa does not act through endothelial thrombin receptors but may activate another cleavable trypsin-sensitive receptor. 相似文献