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   1339131篇
  免费   112231篇
  国内免费   6372篇
耳鼻咽喉   16706篇
儿科学   43010篇
妇产科学   36556篇
基础医学   183676篇
口腔科学   36290篇
临床医学   120724篇
内科学   278568篇
皮肤病学   31899篇
神经病学   110568篇
特种医学   55539篇
外国民族医学   274篇
外科学   210393篇
综合类   31546篇
现状与发展   2篇
一般理论   414篇
预防医学   106640篇
眼科学   28093篇
药学   93746篇
  5篇
中国医学   2229篇
肿瘤学   70856篇
  2018年   13389篇
  2017年   10642篇
  2016年   12804篇
  2015年   14306篇
  2014年   19960篇
  2013年   29766篇
  2012年   36254篇
  2011年   38910篇
  2010年   24381篇
  2009年   23904篇
  2008年   36380篇
  2007年   38793篇
  2006年   39915篇
  2005年   38501篇
  2004年   36736篇
  2003年   35836篇
  2002年   33849篇
  2001年   66062篇
  2000年   67932篇
  1999年   56595篇
  1998年   16727篇
  1997年   15018篇
  1996年   16022篇
  1995年   16235篇
  1994年   15098篇
  1993年   14157篇
  1992年   47105篇
  1991年   45752篇
  1990年   43971篇
  1989年   41816篇
  1988年   38759篇
  1987年   38085篇
  1986年   35861篇
  1985年   34636篇
  1984年   26359篇
  1983年   22110篇
  1982年   13849篇
  1981年   12449篇
  1980年   11718篇
  1979年   23547篇
  1978年   17074篇
  1977年   14385篇
  1976年   13186篇
  1975年   13724篇
  1974年   16095篇
  1973年   15397篇
  1972年   14176篇
  1971年   13041篇
  1970年   11882篇
  1969年   11102篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
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   
5.
6.
7.
8.
9.
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   
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