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   3123250篇
  免费   219809篇
  国内免费   8674篇
耳鼻咽喉   42731篇
儿科学   102533篇
妇产科学   87313篇
基础医学   438593篇
口腔科学   85905篇
临床医学   281061篇
内科学   615133篇
皮肤病学   73249篇
神经病学   255375篇
特种医学   121218篇
外国民族医学   1019篇
外科学   470539篇
综合类   63832篇
现状与发展   5篇
一般理论   1170篇
预防医学   238105篇
眼科学   70416篇
药学   227112篇
  8篇
中国医学   6371篇
肿瘤学   170045篇
  2019年   24181篇
  2018年   34088篇
  2017年   26358篇
  2016年   30238篇
  2015年   34027篇
  2014年   47258篇
  2013年   71182篇
  2012年   94584篇
  2011年   100136篇
  2010年   60614篇
  2009年   58028篇
  2008年   94006篇
  2007年   99628篇
  2006年   101516篇
  2005年   97631篇
  2004年   93842篇
  2003年   90761篇
  2002年   87831篇
  2001年   148390篇
  2000年   151897篇
  1999年   128550篇
  1998年   36862篇
  1997年   32903篇
  1996年   33039篇
  1995年   31732篇
  1994年   29274篇
  1993年   27554篇
  1992年   100141篇
  1991年   96245篇
  1990年   93386篇
  1989年   90360篇
  1988年   82862篇
  1987年   81250篇
  1986年   76567篇
  1985年   72934篇
  1984年   54530篇
  1983年   46317篇
  1982年   27615篇
  1981年   24521篇
  1979年   48570篇
  1978年   34328篇
  1977年   29053篇
  1976年   27141篇
  1975年   29015篇
  1974年   34400篇
  1973年   32883篇
  1972年   30856篇
  1971年   28508篇
  1970年   26608篇
  1969年   25487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.
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.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  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