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   2714979篇
  免费   206591篇
  国内免费   8562篇
耳鼻咽喉   35110篇
儿科学   88853篇
妇产科学   73585篇
基础医学   378970篇
口腔科学   76777篇
临床医学   246763篇
内科学   538925篇
皮肤病学   62813篇
神经病学   216693篇
特种医学   105847篇
外国民族医学   561篇
外科学   415800篇
综合类   64361篇
现状与发展   6篇
一般理论   940篇
预防医学   211156篇
眼科学   62164篇
药学   195277篇
  11篇
中国医学   5929篇
肿瘤学   149591篇
  2018年   29760篇
  2017年   22847篇
  2016年   26004篇
  2015年   29412篇
  2014年   41037篇
  2013年   61054篇
  2012年   80098篇
  2011年   85234篇
  2010年   51696篇
  2009年   48977篇
  2008年   79140篇
  2007年   84306篇
  2006年   85592篇
  2005年   82259篇
  2004年   79157篇
  2003年   75895篇
  2002年   72706篇
  2001年   135083篇
  2000年   138732篇
  1999年   115166篇
  1998年   32527篇
  1997年   28642篇
  1996年   29364篇
  1995年   28872篇
  1994年   26718篇
  1993年   24862篇
  1992年   91040篇
  1991年   88344篇
  1990年   85145篇
  1989年   81644篇
  1988年   75011篇
  1987年   73601篇
  1986年   69373篇
  1985年   66347篇
  1984年   49776篇
  1983年   42051篇
  1982年   24956篇
  1981年   22389篇
  1980年   20736篇
  1979年   44326篇
  1978年   31416篇
  1977年   26749篇
  1976年   24781篇
  1975年   25926篇
  1974年   30903篇
  1973年   29774篇
  1972年   27651篇
  1971年   25448篇
  1970年   23509篇
  1969年   22060篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild...  相似文献   
5.
6.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
7.
8.

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   
9.
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   
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