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   2596683篇
  免费   185214篇
  国内免费   7573篇
耳鼻咽喉   34354篇
儿科学   85468篇
妇产科学   71775篇
基础医学   364663篇
口腔科学   70016篇
临床医学   235527篇
内科学   516976篇
皮肤病学   62584篇
神经病学   214378篇
特种医学   100263篇
外国民族医学   736篇
外科学   387485篇
综合类   50432篇
现状与发展   5篇
一般理论   976篇
预防医学   197092篇
眼科学   56745篇
药学   188767篇
  8篇
中国医学   5342篇
肿瘤学   145878篇
  2021年   20086篇
  2019年   20757篇
  2018年   29573篇
  2017年   22847篇
  2016年   26489篇
  2015年   29699篇
  2014年   40669篇
  2013年   60897篇
  2012年   80806篇
  2011年   85152篇
  2010年   51326篇
  2009年   49350篇
  2008年   79635篇
  2007年   84541篇
  2006年   86149篇
  2005年   82292篇
  2004年   79233篇
  2003年   76608篇
  2002年   73833篇
  2001年   128602篇
  2000年   131590篇
  1999年   110640篇
  1998年   31303篇
  1997年   27955篇
  1996年   28245篇
  1995年   27422篇
  1994年   25114篇
  1993年   23450篇
  1992年   85199篇
  1991年   81589篇
  1990年   78814篇
  1989年   76095篇
  1988年   69500篇
  1987年   68026篇
  1986年   63569篇
  1985年   60546篇
  1984年   44985篇
  1983年   37983篇
  1982年   22497篇
  1981年   20025篇
  1979年   38981篇
  1978年   27461篇
  1977年   23272篇
  1976年   21509篇
  1975年   22830篇
  1974年   26803篇
  1973年   25392篇
  1972年   23755篇
  1971年   21963篇
  1970年   20191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.
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