The stratigraphic sequence of calcimicrobialite facies at the Permian-Triassic (P/Tr) boundary has well recorded the biotic and environmental transition across the end-Permian catastrophic events. The biostratigraphy,...The stratigraphic sequence of calcimicrobialite facies at the Permian-Triassic (P/Tr) boundary has well recorded the biotic and environmental transition across the end-Permian catastrophic events. The biostratigraphy, microfacies, carbon isotopes, and fossil records across the P/Tr boundary have been studied at the Kangjiaping Section in Cili County, Hunan Province. Three biostratigraphic zones, Palaeofusulina-Colaniella Zone, Hindeodus parvus Zone, and Isarcicella staeschei Zone, are identified. The excursion of δ13Ccarb exhibits a sharp negative shift in the calcimicrobialite at the P/Tr boundary, which is roughly accordant with the abrupt bioclastic decline. In addition, five types of microfacies are recognized, including algal-foraminifer bioclastic limestone, algal-laminated calcimicrobial limestone, oolitic grainstone, vermiculate limestone, and intraclastic wackstone. The results indicate that the changeover of ecosystem from metazoan reef to calcimicrobialite in Cili is a classic case of marine ecological evolution during the Paleozoic-Mesozoic transition.展开更多
目的观察腹腔注射盐酸氨溴索对气管内注射阿米卡星后大鼠气管黏膜损伤的超微结构的影响。方法将30只Wistar大鼠经气管穿刺注入阿米卡星,随机分为对照组(阿米卡星组,15只)及氨溴索干预组(15只),经大鼠腹腔注射盐酸氨溴索注射液,在2、4、8...目的观察腹腔注射盐酸氨溴索对气管内注射阿米卡星后大鼠气管黏膜损伤的超微结构的影响。方法将30只Wistar大鼠经气管穿刺注入阿米卡星,随机分为对照组(阿米卡星组,15只)及氨溴索干预组(15只),经大鼠腹腔注射盐酸氨溴索注射液,在2、4、8、24及48 h 5个时间点处死大鼠各3只。取气管下1/3段的腹侧部,采用扫描电镜观察气道表面结构。结果阿米卡星组均出现不同程度的黏液分泌增加,黏稠度增加,纤毛倒伏、粘着在一起、排列紊乱、部分断裂缺失,恢复较慢,2、4、8、24及48 h受损面积百分比分别为98.2%、98.5%、97.5%、92.7%及82.1%。氨溴索干预组上述改变较轻,修复较快,2、4、8、24及48 h受损面积百分比分别为85.7%、81.9%、73.0%、61.9%及50.2%,恢复明显较对照组快。经气管注药在各时间点阿米卡星组纤毛受损面积明显高于氨溴索干预组(P<0.01)。结论阿米卡星可对大鼠气道黏膜表面结构造成严重损害,氨溴索可促进气管黏膜的修复,氨溴索注射液法治疗气管损伤效果理想,值得临床推广使用。展开更多
基金National Natural Science Foundation of China (Grant Nos. 40830212, 40621002, 40730209)National Basic Research Program of China (Grant No. 2006CB80640)
文摘The stratigraphic sequence of calcimicrobialite facies at the Permian-Triassic (P/Tr) boundary has well recorded the biotic and environmental transition across the end-Permian catastrophic events. The biostratigraphy, microfacies, carbon isotopes, and fossil records across the P/Tr boundary have been studied at the Kangjiaping Section in Cili County, Hunan Province. Three biostratigraphic zones, Palaeofusulina-Colaniella Zone, Hindeodus parvus Zone, and Isarcicella staeschei Zone, are identified. The excursion of δ13Ccarb exhibits a sharp negative shift in the calcimicrobialite at the P/Tr boundary, which is roughly accordant with the abrupt bioclastic decline. In addition, five types of microfacies are recognized, including algal-foraminifer bioclastic limestone, algal-laminated calcimicrobial limestone, oolitic grainstone, vermiculate limestone, and intraclastic wackstone. The results indicate that the changeover of ecosystem from metazoan reef to calcimicrobialite in Cili is a classic case of marine ecological evolution during the Paleozoic-Mesozoic transition.
文摘目的观察腹腔注射盐酸氨溴索对气管内注射阿米卡星后大鼠气管黏膜损伤的超微结构的影响。方法将30只Wistar大鼠经气管穿刺注入阿米卡星,随机分为对照组(阿米卡星组,15只)及氨溴索干预组(15只),经大鼠腹腔注射盐酸氨溴索注射液,在2、4、8、24及48 h 5个时间点处死大鼠各3只。取气管下1/3段的腹侧部,采用扫描电镜观察气道表面结构。结果阿米卡星组均出现不同程度的黏液分泌增加,黏稠度增加,纤毛倒伏、粘着在一起、排列紊乱、部分断裂缺失,恢复较慢,2、4、8、24及48 h受损面积百分比分别为98.2%、98.5%、97.5%、92.7%及82.1%。氨溴索干预组上述改变较轻,修复较快,2、4、8、24及48 h受损面积百分比分别为85.7%、81.9%、73.0%、61.9%及50.2%,恢复明显较对照组快。经气管注药在各时间点阿米卡星组纤毛受损面积明显高于氨溴索干预组(P<0.01)。结论阿米卡星可对大鼠气道黏膜表面结构造成严重损害,氨溴索可促进气管黏膜的修复,氨溴索注射液法治疗气管损伤效果理想,值得临床推广使用。
