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   3263318篇
  免费   225766篇
  国内免费   8442篇
耳鼻咽喉   44900篇
儿科学   108037篇
妇产科学   90365篇
基础医学   458871篇
口腔科学   89629篇
临床医学   296639篇
内科学   634471篇
皮肤病学   78113篇
神经病学   263933篇
特种医学   125949篇
外国民族医学   918篇
外科学   486588篇
综合类   65582篇
现状与发展   6篇
一般理论   1178篇
预防医学   246322篇
眼科学   73927篇
药学   243598篇
  13篇
中国医学   7093篇
肿瘤学   181394篇
  2019年   25547篇
  2018年   36087篇
  2017年   27938篇
  2016年   32253篇
  2015年   36210篇
  2014年   49707篇
  2013年   74384篇
  2012年   99242篇
  2011年   104906篇
  2010年   63096篇
  2009年   60274篇
  2008年   97794篇
  2007年   104010篇
  2006年   105903篇
  2005年   101568篇
  2004年   97542篇
  2003年   94102篇
  2002年   90854篇
  2001年   159453篇
  2000年   163489篇
  1999年   137615篇
  1998年   38908篇
  1997年   34540篇
  1996年   34720篇
  1995年   33572篇
  1994年   30581篇
  1993年   28692篇
  1992年   106491篇
  1991年   102494篇
  1990年   99663篇
  1989年   96437篇
  1988年   88096篇
  1987年   86085篇
  1986年   80973篇
  1985年   77061篇
  1984年   57199篇
  1983年   48212篇
  1982年   28338篇
  1981年   25137篇
  1979年   50634篇
  1978年   35299篇
  1977年   30633篇
  1976年   27828篇
  1975年   30164篇
  1974年   35409篇
  1973年   33801篇
  1972年   31915篇
  1971年   29677篇
  1970年   27287篇
  1969年   26269篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.

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   
52.
53.
54.
55.
56.
57.
58.
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   
59.
60.
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