This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting o...This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting of the section are briefly introduced. Changhsingian to ＂Griesbachian＂ conodont and ammonoid zonations, the most perfect Permo-Triassic zonations over the world, are presented, with a short discussion on the age of Otoceras, The Changhsingian to ＂Griesbachian＂ strata are subdivided into three 3rd order sequences, and the sedimentary structure of each sequence is indicated. The paper presents a correlation of the Changhsingian to ＂Griesbachian＂ magneetostratigraphy of the Meishan section with the general scale, and informed the negation of a short magnetic reversal at the PTB suggested by Zhu and Liu （1999）. Recent developments of chemostratigraphy of δ^13C and δ^34S are introduced, especially the discovery of more than one negative δ^13C excursions across the PTB. Two important molecular researches reveal the profound changes at the base of eco-system, the microbial catastrophy, and the euxinic conditions in the photic zone during the Permian-Triassic superanoxic event. The paper reports the changes in dating the age of PTB since 2001. According to recent achievements, the age of volcanogenic claybed 25, 14 cm below the PTB, is now set at 252.4±0.3 Ma. A discussion on the eventostratigraphy concludes that, although there is a major event episode at beds 25-26, the events across the PTB at Meishan are multi-episodic and commenced prior to the Event Beds 25-26, thus the possibility that the mass extinction was mainly induced by an exterrestrial impact is largely excluded.展开更多
Objective: To evaluate the effect of chewing sugar-free gum on gastrointestinal function recovery after cesarean section. Methods: Randomized controlled trials comparing the use of chewing gum in postoperative recover...Objective: To evaluate the effect of chewing sugar-free gum on gastrointestinal function recovery after cesarean section. Methods: Randomized controlled trials comparing the use of chewing gum in postoperative recovery with a control group were retrieved from the databases including Pubmed, Cochrane Library, Science Direct, Web of Science, CBM, CNKI, Wanfang and VIP, et al. After screening literatures, evaluating the quality of studies, extracting data, the RevMan5.3 software was used for data analysis. Results: A total of 13 RCTs including 2233 patients were analyzed in the study. The results showed that chewing gum after cesarean delivery can effectively shorten the recovery time of bowel sounds, passage of flatus and first defecation (all P Conclusion: Chewing sugar-free gum after cesarean section can promote the early recovery of gastrointestinal function, but the side effects of chewing gum are still unclear, which needs more clinical, large sample and high-quality studies to further verify.展开更多
目的:系统评价糖尿病足病人就诊延迟情况。方法:计算机检索PubMed、EMbase、the Cochrane Library、Web of Science、中国知网、万方数据库、中国生物医学文献数据库和维普数据库建库至2022年7月3日有关糖尿病足病人就诊延迟的研究。由...目的:系统评价糖尿病足病人就诊延迟情况。方法:计算机检索PubMed、EMbase、the Cochrane Library、Web of Science、中国知网、万方数据库、中国生物医学文献数据库和维普数据库建库至2022年7月3日有关糖尿病足病人就诊延迟的研究。由2名评价员独立筛选文献、提取资料并评价纳入研究的偏倚风险,采用Stata 15.0软件进行Meta分析。结果:共纳入12项横断面研究,涉及22920例糖尿病足病人。Meta分析结果显示,糖尿病足病人就诊延迟率为64%,95%CI(52%,75%)。结论:现有证据显示,糖尿病足病人就诊延迟率较高,受纳入研究的数量和质量的限制,研究结论尚需要更多高质量研究予以验证。展开更多
基金The work was supported by the National Natural Science Foundation of China(project no.40232025).
文摘This paper provides a synthetic review of researches on Meishan Section D, the Global Stratotype Section and Point of the Permian-Triassic Boundary （PTB）. The history of research, geographic and geological setting of the section are briefly introduced. Changhsingian to ＂Griesbachian＂ conodont and ammonoid zonations, the most perfect Permo-Triassic zonations over the world, are presented, with a short discussion on the age of Otoceras, The Changhsingian to ＂Griesbachian＂ strata are subdivided into three 3rd order sequences, and the sedimentary structure of each sequence is indicated. The paper presents a correlation of the Changhsingian to ＂Griesbachian＂ magneetostratigraphy of the Meishan section with the general scale, and informed the negation of a short magnetic reversal at the PTB suggested by Zhu and Liu （1999）. Recent developments of chemostratigraphy of δ^13C and δ^34S are introduced, especially the discovery of more than one negative δ^13C excursions across the PTB. Two important molecular researches reveal the profound changes at the base of eco-system, the microbial catastrophy, and the euxinic conditions in the photic zone during the Permian-Triassic superanoxic event. The paper reports the changes in dating the age of PTB since 2001. According to recent achievements, the age of volcanogenic claybed 25, 14 cm below the PTB, is now set at 252.4±0.3 Ma. A discussion on the eventostratigraphy concludes that, although there is a major event episode at beds 25-26, the events across the PTB at Meishan are multi-episodic and commenced prior to the Event Beds 25-26, thus the possibility that the mass extinction was mainly induced by an exterrestrial impact is largely excluded.
文摘Objective: To evaluate the effect of chewing sugar-free gum on gastrointestinal function recovery after cesarean section. Methods: Randomized controlled trials comparing the use of chewing gum in postoperative recovery with a control group were retrieved from the databases including Pubmed, Cochrane Library, Science Direct, Web of Science, CBM, CNKI, Wanfang and VIP, et al. After screening literatures, evaluating the quality of studies, extracting data, the RevMan5.3 software was used for data analysis. Results: A total of 13 RCTs including 2233 patients were analyzed in the study. The results showed that chewing gum after cesarean delivery can effectively shorten the recovery time of bowel sounds, passage of flatus and first defecation (all P Conclusion: Chewing sugar-free gum after cesarean section can promote the early recovery of gastrointestinal function, but the side effects of chewing gum are still unclear, which needs more clinical, large sample and high-quality studies to further verify.
