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   941186篇
  免费   66939篇
  国内免费   1369篇
耳鼻咽喉   13067篇
儿科学   24702篇
妇产科学   23425篇
基础医学   134179篇
口腔科学   28431篇
临床医学   81379篇
内科学   185222篇
皮肤病学   19414篇
神经病学   73045篇
特种医学   37028篇
外国民族医学   79篇
外科学   153645篇
综合类   18116篇
现状与发展   1篇
一般理论   238篇
预防医学   62430篇
眼科学   21432篇
药学   73094篇
  3篇
中国医学   2195篇
肿瘤学   58369篇
  2018年   9257篇
  2017年   7257篇
  2016年   7974篇
  2015年   9100篇
  2014年   12331篇
  2013年   17906篇
  2012年   24650篇
  2011年   25622篇
  2010年   15177篇
  2009年   14584篇
  2008年   25013篇
  2007年   26172篇
  2006年   26924篇
  2005年   25832篇
  2004年   24909篇
  2003年   23922篇
  2002年   23471篇
  2001年   54996篇
  2000年   56816篇
  1999年   47218篇
  1998年   10824篇
  1997年   9545篇
  1996年   9666篇
  1995年   9001篇
  1994年   8358篇
  1993年   7644篇
  1992年   35659篇
  1991年   34085篇
  1990年   32872篇
  1989年   32014篇
  1988年   29100篇
  1987年   28369篇
  1986年   26393篇
  1985年   25219篇
  1984年   17892篇
  1983年   15183篇
  1982年   7819篇
  1981年   6806篇
  1979年   15836篇
  1978年   10638篇
  1977年   9087篇
  1976年   7903篇
  1975年   8654篇
  1974年   10499篇
  1973年   9892篇
  1972年   9382篇
  1971年   8867篇
  1970年   8447篇
  1969年   7945篇
  1968年   7215篇
排序方式: 共有10000条查询结果,搜索用时 3 毫秒
1.
2.

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   
3.
4.
5.
6.
7.
8.
9.
10.
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.  相似文献   
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