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   1120925篇
  免费   83588篇
  国内免费   3135篇
耳鼻咽喉   14443篇
儿科学   37707篇
妇产科学   30731篇
基础医学   161004篇
口腔科学   30477篇
临床医学   102482篇
内科学   218527篇
皮肤病学   24511篇
神经病学   89940篇
特种医学   43200篇
外国民族医学   305篇
外科学   169159篇
综合类   25534篇
现状与发展   1篇
一般理论   550篇
预防医学   89299篇
眼科学   25309篇
药学   80777篇
  5篇
中国医学   2145篇
肿瘤学   61542篇
  2021年   9126篇
  2019年   9459篇
  2018年   13228篇
  2017年   10120篇
  2016年   11387篇
  2015年   13058篇
  2014年   17992篇
  2013年   27501篇
  2012年   36956篇
  2011年   39235篇
  2010年   23206篇
  2009年   21765篇
  2008年   36253篇
  2007年   38471篇
  2006年   38595篇
  2005年   37447篇
  2004年   36459篇
  2003年   34880篇
  2002年   33705篇
  2001年   48133篇
  2000年   49038篇
  1999年   41581篇
  1998年   12641篇
  1997年   11273篇
  1996年   11271篇
  1995年   10876篇
  1994年   10029篇
  1993年   9423篇
  1992年   33029篇
  1991年   32269篇
  1990年   31713篇
  1989年   30573篇
  1988年   27899篇
  1987年   28031篇
  1986年   26169篇
  1985年   25421篇
  1984年   19241篇
  1983年   16316篇
  1982年   10327篇
  1981年   9459篇
  1979年   17476篇
  1978年   12850篇
  1977年   10868篇
  1976年   10271篇
  1975年   10634篇
  1974年   12797篇
  1973年   12275篇
  1972年   11204篇
  1971年   10439篇
  1970年   9671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