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   1336415篇
  免费   95663篇
  国内免费   5040篇
耳鼻咽喉   17699篇
儿科学   41524篇
妇产科学   37379篇
基础医学   191851篇
口腔科学   38617篇
临床医学   117225篇
内科学   263280篇
皮肤病学   30399篇
神经病学   103519篇
特种医学   50865篇
外国民族医学   378篇
外科学   203979篇
综合类   32425篇
现状与发展   1篇
一般理论   447篇
预防医学   93232篇
眼科学   31123篇
药学   99828篇
  4篇
中国医学   4007篇
肿瘤学   79336篇
  2018年   14385篇
  2017年   11097篇
  2016年   12344篇
  2015年   13951篇
  2014年   19225篇
  2013年   28279篇
  2012年   37501篇
  2011年   39491篇
  2010年   23738篇
  2009年   22409篇
  2008年   36923篇
  2007年   39385篇
  2006年   39703篇
  2005年   37753篇
  2004年   36569篇
  2003年   35256篇
  2002年   33945篇
  2001年   71765篇
  2000年   73527篇
  1999年   61223篇
  1998年   15796篇
  1997年   13821篇
  1996年   13543篇
  1995年   12822篇
  1994年   11853篇
  1993年   10956篇
  1992年   46790篇
  1991年   44952篇
  1990年   43941篇
  1989年   42745篇
  1988年   38730篇
  1987年   38416篇
  1986年   35634篇
  1985年   34124篇
  1984年   24783篇
  1983年   20650篇
  1982年   11729篇
  1981年   10381篇
  1979年   21968篇
  1978年   15329篇
  1977年   13067篇
  1976年   11838篇
  1975年   12639篇
  1974年   15178篇
  1973年   14518篇
  1972年   13529篇
  1971年   12729篇
  1970年   11754篇
  1969年   11145篇
  1968年   10251篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.

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   
6.
7.
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   
8.
9.
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   
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