首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1008347篇
  免费   76275篇
  国内免费   2630篇
耳鼻咽喉   13076篇
儿科学   34779篇
妇产科学   28682篇
基础医学   147054篇
口腔科学   27951篇
临床医学   91616篇
内科学   195543篇
皮肤病学   23122篇
神经病学   80010篇
特种医学   38727篇
外国民族医学   305篇
外科学   150822篇
综合类   24010篇
一般理论   399篇
预防医学   79126篇
眼科学   22739篇
药学   72779篇
  3篇
中国医学   2037篇
肿瘤学   54472篇
  2018年   10733篇
  2017年   8380篇
  2016年   9544篇
  2015年   10771篇
  2014年   14667篇
  2013年   22370篇
  2012年   29470篇
  2011年   31351篇
  2010年   18760篇
  2009年   17719篇
  2008年   29254篇
  2007年   30928篇
  2006年   31458篇
  2005年   30096篇
  2004年   29387篇
  2003年   28216篇
  2002年   27186篇
  2001年   47238篇
  2000年   48342篇
  1999年   40555篇
  1998年   11317篇
  1997年   10206篇
  1996年   10265篇
  1995年   9866篇
  1994年   9175篇
  1993年   8576篇
  1992年   32468篇
  1991年   31682篇
  1990年   31226篇
  1989年   30090篇
  1988年   27370篇
  1987年   27517篇
  1986年   25611篇
  1985年   24778篇
  1984年   18571篇
  1983年   15643篇
  1982年   9380篇
  1981年   8483篇
  1979年   16995篇
  1978年   12349篇
  1977年   10422篇
  1976年   9854篇
  1975年   10263篇
  1974年   12444篇
  1973年   11955篇
  1972年   10967篇
  1971年   10190篇
  1970年   9444篇
  1969年   8806篇
  1968年   8172篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
4.
We report two British cases of liver abscess, due to Klebsiella pneumoniae and associated with synchronous infection elsewhere, which required liver resection for definitive treatment. They illustrate the geographic spread of aggressive K pneumoniae liver infection and demonstrate the importance of early aggressive treatment.  相似文献   
5.
6.
Hepatic NADPH-cytochrome P450 oxidoreductase null (HRN?) mice exhibit normal hepatic and extrahepatic biotransformation enzyme activities when compared to wild-type (WT) mice, but express no functional hepatic cytochrome P450 activities. When incubated in vitro with [14C]-diclofenac, liver microsomes from WT mice exhibited extensive biotransformation to oxidative and glucuronide metabolites and covalent binding to proteins was also observed. In contrast, whereas glucuronide conjugates and a quinone-imine metabolite were formed when [14C]-diclofenac was incubated with HRN? mouse liver, only small quantities of P450-derived oxidative metabolites were produced in these samples and covalent binding to proteins was not observed. Livers from vehicle-treated HRN? mice exhibited enhanced lipid accumulation, bile duct proliferation, hepatocellular degeneration and necrosis and inflammatory cell infiltration, which were not present in livers from WT mice. Elevated liver-derived alanine aminotransferase, glutamate dehydrogenase and alkaline phosphatase activities were also observed in plasma from HRN? mice. When treated orally with diclofenac for 7 days, at 30 mg/kg/day, the severities of the abnormal liver histopathology and plasma liver enzyme findings in HRN? mice were reduced markedly. Oral diclofenac administration did not alter the liver histopathology or elevate plasma enzyme activities of WT mice. These findings indicate that HRN? mice are valuable for exploration of the role played by hepatic P450s in drug biotransformation, but poorly suited to investigations of drug-induced liver toxicity. Nevertheless, studies in HRN? mice could provide novel insights into the role played by inflammation in liver injury and may aid the evaluation of new strategies for its treatment.  相似文献   
7.
8.
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号