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   3374682篇
  免费   249996篇
  国内免费   8853篇
耳鼻咽喉   45709篇
儿科学   110276篇
妇产科学   91946篇
基础医学   474482篇
口腔科学   94457篇
临床医学   309760篇
内科学   662895篇
皮肤病学   77316篇
神经病学   278075篇
特种医学   131124篇
外国民族医学   952篇
外科学   504081篇
综合类   73027篇
现状与发展   5篇
一般理论   1297篇
预防医学   266649篇
眼科学   74932篇
药学   247219篇
  11篇
中国医学   6629篇
肿瘤学   182689篇
  2019年   26219篇
  2018年   36965篇
  2017年   28372篇
  2016年   32626篇
  2015年   36840篇
  2014年   50998篇
  2013年   77051篇
  2012年   101942篇
  2011年   108131篇
  2010年   65138篇
  2009年   62346篇
  2008年   100809篇
  2007年   107326篇
  2006年   109123篇
  2005年   104917篇
  2004年   101156篇
  2003年   97539篇
  2002年   93951篇
  2001年   162119篇
  2000年   166573篇
  1999年   140110篇
  1998年   40481篇
  1997年   35992篇
  1996年   36467篇
  1995年   35434篇
  1994年   32687篇
  1993年   30573篇
  1992年   110446篇
  1991年   106645篇
  1990年   103295篇
  1989年   99450篇
  1988年   91362篇
  1987年   89791篇
  1986年   84477篇
  1985年   80720篇
  1984年   60482篇
  1983年   51183篇
  1982年   30450篇
  1981年   27270篇
  1979年   53984篇
  1978年   38341篇
  1977年   32383篇
  1976年   30055篇
  1975年   32082篇
  1974年   38070篇
  1973年   36332篇
  1972年   33929篇
  1971年   31496篇
  1970年   28968篇
  1969年   27550篇
排序方式: 共有10000条查询结果,搜索用时 0 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