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In 1970-72, 456 (53.4%) of 854 drivers responsible for a motor vehicle accident in which either they or other persons were killed had been drinking beforehand. Of surviving culpable drivers tested for blood alcohol concentration 81.7% were found to be legally impaired; however, only 24.8% of these drivers were tested. Because surviving culpable drivers pose a possible future hazard to highway safety it is important that data on this group be collected and analysed. 相似文献
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The carcinoid endocardial plaque; an ultrastructural study 总被引:2,自引:0,他引:2
Ultrastructural studies disclosed that the plaque-like endocardial thickenings in three patients with the carcinoid syndrome were composed of smooth muscle cells embedded in a stroma that was rich in acid mucopolysaccharides, collagen, and microfibrils, but devoid of elastic fibers. The smooth muscle cells contained variable numbers of myofilaments and cisterns of rough surfaced endoplasmic reticulum, and their basement membranes were greatly thickened, reduplicated, and arranged in layers. The endocardial plaques appeared histologically and ultrastructurally similar regardless of their location in the heart. The smooth muscle cells in these plaques appear to have been derived from primitive mesenchymal cells, which normally are present in the subendocardial endothelial space. These observations are interpreted as indicating that the plaques develop as a result of healing of a superficial endocardial injury, which may be initiated by release of bradykinin from hepatic metastases of a carcinoid tumor. 相似文献
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The ruthenate compounds, Gd2–zCe
z
Sr2Cu2RuO10, GdSr2Cu2RuO8, and doped Sr2YRuO6, all superconduct in their SrO layers, which is why they have almost the same 49 K onset temperatures for superconductivity. The sister compound Ba2GdRuO6, either doped or not, does not superconduct, because L = 0, J 0 Gd breaks pairs and destroys superconductivity in the potentially superconducting BaO layers. High-temperature superconductivity resides in the SrO or BaO layers, or in interstitial-oxygen regions of the crystal, not in the cuprate-planes. 相似文献
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Because ideal PrBa2Cu3O7 superconducts at 90 K, it should be replaced by RBa2–u Sr
u
Cu2MO8 (where R is a light-mass rare earth and M is Nb or, preferably, Ta) as the insulator of choice for YBa2Cu3O7 Josephson junction or microstructure technology. Furthermore, (110)- or (100)-oriented substrates of RSr2Cu2MO8 may provide an opportunity for optimal device fabrication. 相似文献