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排序方式: 共有6433条查询结果,搜索用时 31 毫秒
931.
R Malekan ST Kelley Y Suzuki C Reynolds T Plappert MS Sutton LH Edmunds CR Bridges 《Canadian Metallurgical Quarterly》1998,116(5):752-762
OBJECTIVE: Transmyocardial laser revascularization is an investigational technique for revascularizing ischemic myocardium in patients with inoperable coronary arterial disease. This study tests the hypothesis that laser revascularization prevents left ventricular functional deterioration and aneurysm formation after acute anteroapical myocardial infarction. METHODS: An ultrasonic ascending aortic flow probe and snares around the distal left anterior descending and second diagonal coronary arteries were placed in 26 Dorsett hybrid sheep. Ten to 14 days later, snared arteries were occluded to produce an anteroapical infarction of 23% of left ventricular mass. Before infarction 14 animals had 34 +/- 4 transmyocardial perforations in the area of the anticipated infarction made with a carbon dioxide laser. Twelve animals served as controls. Hemodynamic measurements and transdiaphragmatic quantitative echocardiograms were obtained before, immediately after, and 2, 5, and 8 weeks after infarction. Eighteen sheep completed the protocol. RESULTS: All animals had large anteroapical left ventricular aneurysms with massive ventricular enlargement. Immediately after infarction the anterior wall became thinner and dyskinetic in all sheep. At 8 weeks aneurysmal size and shape were indistinguishable between groups. Two days after infarction, laser holes were filled with fibrin. At 5 and 8 weeks the infarct consisted of dense collagen, fibroblasts, scattered calcifications, myocyte fragments, neutrophils, macrophages, and no laser holes. There were no significant differences at any time between groups for cardiac pressures or output, ventricular volumes, ejection fraction, stroke work, and the stroke work-left ventricular end-diastolic pressure index. CONCLUSION: Transmyocardial laser perforations do not revascularize acute myocardial infarction in sheep. 相似文献
932.
The performance of polysilicon thin-film transistors (TFTs) formed by a 600°C process was improved using a two-layer gate insulator of photochemical-assisted vapor deposition (photo-CVD) SiO2 and atmospheric-pressure chemical vapor deposition (APCVD) SiO2. The photo-CVD SiO2, 100 Å thick, was deposited on polysilicon and followed by APCVD SiO2 of 1000 Å thickness. The TFT had a threshold voltage of 8.3 V and a field-effect mobility of 35 cm2/V-s, which were higher than those of the conventional TFT with a single-layer gate SiO2 of APCVD. Hydrogenation by hydrogen plasma was more effective for the new TFT than for the conventional device 相似文献
933.
Mucous barrier was searched by the histochemical method of mucopolysaccharides and by the measurement of precipitated mucus of gastric juice. The neutral polysaccharide stored within the surface epithelial cells must be a source of the mucus of the gastric juice. The storage of the polysaccaride was decreased by a long-term stimulation by histamine, and the precipitated mucus volume was also decreased shortly after the stimulation. Therefore, some kind of the stimulation for the gastric secretion must be avoided for prevention of peptic ulcer. The oral administration of the sulfuric polysaccharide extracted from seaweed prevented the occurrence of experimental ulcer. It may be concluded that the exogeneous polysaccaride can take the place of the endogenous polysaccharide. 相似文献
934.
935.
936.
A novel InP/InGaAsP buried heterostructure laser diode on p-type InP substrate has been developed. The laser has achieved a threshold current as low as 20 mA DC with high power output of 50 mW under CW operation in the fundamental transverse mode. 相似文献
937.
938.
In eight separate experiments with laboratory silos, silages were prepared with 50 mmol caproic (nC6), isocaproic (iC6), valeric (nC5) and isovaleric (iC5) acid additions per kg Italian ryegrass or cocksfoot, and stored at 25°C for 70 days. In the nC6 and iC6 treatments, fermentation was consistently inhibited, and also the contents of water-soluble carbohydrates (WSC) were considerably higher in the silages than in the grasses. This increase in WSC was partly explained by the increase in glucose but the difference between WSC and “glucose + fructose” was clearly larger in the silages than in the grasses. In the nC5 and iC5 treatments, various results were obtained; in some cases, presumably due to high dry matter content, fermentation was inhibited and WSC increased, while, in one case, fermentation was improved with higher lactic acid and lower butyric acid production than in the control silage. According to the results of five experiments with bag silos, although the inhibition of fermentation was observed by the treatment with nC6, little or no increase in WSC during ensilage was found. 相似文献
939.
Johnson Ronald C.; Suzuki Nancy S.; Olds William K. 《Canadian Metallurgical Quarterly》1964,69(2):233
An analysis of previous studies suggested that certain letters and letter combinations occur more often than would be expected by chance in affectively pleasant words, while others are overrepresented in unpleasant words. On the basis of data from these prior investigations, 14 pairs of artificial words were constructed and randomly paired with 7 good and 7 bad adjectives. College, deaf high school, and hearing high school Ss were presented with the task of matching each of the English adjectives with the correct member of the artificial word pair presented with it. The college and hearing high school Ss matched as predicted significantly more often than chance expectancy, which deaf Ss did not. The results are interpreted as supporting the existence of phonetic symbolism of word sounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
940.
This paper summarizes our research on newly-developed multifilamentary V3Ga and Nb3Sn compound superconductors, including their design, processing, and characteristics such as mechanical and superconducting properties, and coil performance. 相似文献