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   949138篇
  免费   66704篇
  国内免费   1376篇
耳鼻咽喉   13885篇
儿科学   24932篇
妇产科学   24297篇
基础医学   134972篇
口腔科学   28384篇
临床医学   81519篇
内科学   186605篇
皮肤病学   19426篇
神经病学   73986篇
特种医学   37114篇
外国民族医学   79篇
外科学   153462篇
综合类   18081篇
现状与发展   1篇
一般理论   236篇
预防医学   63029篇
眼科学   21888篇
药学   74988篇
  3篇
中国医学   2201篇
肿瘤学   58130篇
  2018年   9513篇
  2017年   7406篇
  2016年   8177篇
  2015年   9205篇
  2014年   12571篇
  2013年   18383篇
  2012年   25115篇
  2011年   26345篇
  2010年   15501篇
  2009年   14550篇
  2008年   25400篇
  2007年   26849篇
  2006年   27676篇
  2005年   26599篇
  2004年   25813篇
  2003年   24864篇
  2002年   24161篇
  2001年   55165篇
  2000年   57021篇
  1999年   47247篇
  1998年   10825篇
  1997年   9500篇
  1996年   9620篇
  1995年   8946篇
  1994年   8297篇
  1993年   7608篇
  1992年   35538篇
  1991年   33987篇
  1990年   32825篇
  1989年   31930篇
  1988年   29057篇
  1987年   28306篇
  1986年   26346篇
  1985年   25206篇
  1984年   17880篇
  1983年   15189篇
  1982年   7825篇
  1981年   6809篇
  1979年   15823篇
  1978年   10642篇
  1977年   9083篇
  1976年   7906篇
  1975年   8666篇
  1974年   10492篇
  1973年   9879篇
  1972年   9382篇
  1971年   8870篇
  1970年   8448篇
  1969年   7939篇
  1968年   7225篇
排序方式: 共有10000条查询结果,搜索用时 15 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