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   4178360篇
  免费   295710篇
  国内免费   10495篇
耳鼻咽喉   60130篇
儿科学   138397篇
妇产科学   118337篇
基础医学   586300篇
口腔科学   119694篇
临床医学   376680篇
内科学   806628篇
皮肤病学   97530篇
神经病学   335871篇
特种医学   163785篇
外国民族医学   1701篇
外科学   631193篇
综合类   90284篇
现状与发展   12篇
一般理论   1535篇
预防医学   319785篇
眼科学   98069篇
药学   309562篇
  15篇
中国医学   8442篇
肿瘤学   220615篇
  2018年   45063篇
  2017年   35552篇
  2016年   39608篇
  2015年   45458篇
  2014年   61224篇
  2013年   90972篇
  2012年   124522篇
  2011年   128548篇
  2010年   77108篇
  2009年   74603篇
  2008年   119303篇
  2007年   128122篇
  2006年   129468篇
  2005年   131399篇
  2004年   128870篇
  2003年   121530篇
  2002年   114370篇
  2001年   188839篇
  2000年   193374篇
  1999年   165297篇
  1998年   47933篇
  1997年   42496篇
  1996年   42000篇
  1995年   40391篇
  1994年   37465篇
  1993年   35255篇
  1992年   131362篇
  1991年   127972篇
  1990年   124800篇
  1989年   121168篇
  1988年   111934篇
  1987年   110073篇
  1986年   103985篇
  1985年   99271篇
  1984年   74580篇
  1983年   63450篇
  1982年   37439篇
  1981年   33745篇
  1979年   68779篇
  1978年   48558篇
  1977年   41768篇
  1976年   38508篇
  1975年   42484篇
  1974年   50450篇
  1973年   48345篇
  1972年   45691篇
  1971年   42624篇
  1970年   40018篇
  1969年   38105篇
  1968年   35365篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.

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   
84.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
85.
86.
87.
88.

Introduction

Several studies demonstrated that simulator-acquired skill transfer to the operating room is incomplete. Our objective was to identify trainee characteristics that predict the transfer of simulator-acquired skill to the operating room.

Methods

Trainees completed baseline assessments including intracorporeal suturing (IS) performance, attentional selectivity, self-reported use of mental skills, and self-reported prior clinical and simulated laparoscopic experience and confidence. Residents then followed proficiency-based laparoscopic skills training, and their skill transfer was assessed on a live-anesthetized porcine model. Predictive characteristics for transfer test performance were assessed using multiple linear regression.

Results

Thirty-eight residents completed the study. Automaticity, attentional selectivity, resident perceived ability with laparoscopy and simulators, and post-training IS performance were predictive of IS performance during the transfer test.

Conclusions

Promoting automaticity, self-efficacy, and attention selectivity may help improve the transfer of simulator-acquired skill. Mental skills training and training to automaticity may therefore be valuable interventions to achieve this goal.  相似文献   
89.
90.
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