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   1488500篇
  免费   117592篇
  国内免费   6675篇
耳鼻咽喉   19427篇
儿科学   48543篇
妇产科学   40349篇
基础医学   204852篇
口腔科学   40664篇
临床医学   131886篇
内科学   304881篇
皮肤病学   36130篇
神经病学   124265篇
特种医学   63063篇
外国民族医学   296篇
外科学   235030篇
综合类   32522篇
现状与发展   2篇
一般理论   446篇
预防医学   113708篇
眼科学   32417篇
药学   104342篇
  5篇
中国医学   2546篇
肿瘤学   77393篇
  2018年   15907篇
  2017年   12699篇
  2016年   15651篇
  2015年   17484篇
  2014年   23281篇
  2013年   34485篇
  2012年   43661篇
  2011年   45795篇
  2010年   28472篇
  2009年   27183篇
  2008年   43271篇
  2007年   46443篇
  2006年   47541篇
  2005年   46550篇
  2004年   44399篇
  2003年   43430篇
  2002年   41277篇
  2001年   71023篇
  2000年   72919篇
  1999年   60956篇
  1998年   18058篇
  1997年   16103篇
  1996年   16844篇
  1995年   16878篇
  1994年   15721篇
  1993年   14728篇
  1992年   49018篇
  1991年   47668篇
  1990年   45885篇
  1989年   43579篇
  1988年   40292篇
  1987年   39599篇
  1986年   37242篇
  1985年   36003篇
  1984年   27411篇
  1983年   22952篇
  1982年   14448篇
  1981年   12977篇
  1980年   12242篇
  1979年   24699篇
  1978年   17927篇
  1977年   15100篇
  1976年   13810篇
  1975年   14645篇
  1974年   17050篇
  1973年   16269篇
  1972年   15034篇
  1971年   13897篇
  1970年   12633篇
  1969年   11811篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.

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   
23.
24.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
25.
26.
27.
28.
29.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
30.
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