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   1370190篇
  免费   114021篇
  国内免费   6456篇
耳鼻咽喉   17164篇
儿科学   43739篇
妇产科学   37131篇
基础医学   187421篇
口腔科学   36902篇
临床医学   123793篇
内科学   285730篇
皮肤病学   32252篇
神经病学   113547篇
特种医学   56789篇
外国民族医学   275篇
外科学   215690篇
综合类   31713篇
现状与发展   2篇
一般理论   431篇
预防医学   108513篇
眼科学   28485篇
药学   95533篇
  5篇
中国医学   2270篇
肿瘤学   73282篇
  2018年   14317篇
  2017年   11273篇
  2016年   13461篇
  2015年   15098篇
  2014年   21123篇
  2013年   31353篇
  2012年   38632篇
  2011年   41429篇
  2010年   25804篇
  2009年   25296篇
  2008年   38583篇
  2007年   41112篇
  2006年   42070篇
  2005年   40596篇
  2004年   38639篇
  2003年   37634篇
  2002年   35441篇
  2001年   66286篇
  2000年   68062篇
  1999年   56793篇
  1998年   17055篇
  1997年   15275篇
  1996年   16203篇
  1995年   16419篇
  1994年   15260篇
  1993年   14306篇
  1992年   47184篇
  1991年   45831篇
  1990年   44036篇
  1989年   41874篇
  1988年   38807篇
  1987年   38125篇
  1986年   35902篇
  1985年   34690篇
  1984年   26433篇
  1983年   22184篇
  1982年   13925篇
  1981年   12515篇
  1980年   11779篇
  1979年   23573篇
  1978年   17102篇
  1977年   14408篇
  1976年   13200篇
  1975年   13740篇
  1974年   16113篇
  1973年   15414篇
  1972年   14189篇
  1971年   13044篇
  1970年   11890篇
  1969年   11104篇
排序方式: 共有10000条查询结果,搜索用时 0 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.
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   
4.
5.
6.
7.
8.
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   
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