首页 | 官方网站   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   321570篇
  免费   15630篇
  国内免费   575篇
医药卫生   337775篇
  2023年   1700篇
  2022年   1133篇
  2021年   4806篇
  2020年   2831篇
  2019年   5516篇
  2018年   10276篇
  2017年   6595篇
  2016年   6547篇
  2015年   7600篇
  2014年   8040篇
  2013年   12972篇
  2012年   21869篇
  2011年   21980篇
  2010年   11139篇
  2009年   8304篇
  2008年   18550篇
  2007年   19845篇
  2006年   18644篇
  2005年   18504篇
  2004年   17154篇
  2003年   15800篇
  2002年   14885篇
  2001年   8608篇
  2000年   8833篇
  1999年   7607篇
  1998年   1330篇
  1997年   997篇
  1996年   996篇
  1992年   4248篇
  1991年   3839篇
  1990年   3634篇
  1989年   3304篇
  1988年   3095篇
  1987年   2937篇
  1986年   2783篇
  1985年   2551篇
  1984年   1897篇
  1983年   1591篇
  1979年   1720篇
  1978年   1144篇
  1977年   1040篇
  1975年   1111篇
  1974年   1463篇
  1973年   1428篇
  1972年   1301篇
  1971年   1258篇
  1970年   1256篇
  1969年   1287篇
  1968年   1149篇
  1967年   986篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Patients admitted to intensive care after cardiac arrest are at risk of circulatory shock and early mortality due to cardiovascular failure. The aim of this study was to evaluate the ability of the veno-arterial pCO2 difference (∆pCO2; central venous CO2 – arterial CO2) and lactate to predict early mortality in postcardiac arrest patients. This was a pre-planned prospective observational sub-study of the target temperature management 2 trial. The sub-study patients were included at five Swedish sites. Repeated measurements of ∆pCO2 and lactate were conducted at 4, 8, 12, 16, 24, 48, and 72 h after randomization. We assessed the association between each marker and 96-h mortality and their prognostic value for 96-h mortality. One hundred sixty-three patients were included in the analysis. Mortality at 96 h was 17%. During the initial 24 h, there was no difference in ∆pCO2 levels between 96-h survivors and non-survivors. ∆pCO2 measured at 4 h was associated with an increased risk of death within 96 h (adjusted odds ratio: 1.15; 95% confidence interval [CI]: 1.02–1.29; p = .018). Lactate levels were associated with poor outcome over multiple measurements. The area under the receiving operating curve to predict death within 96 h was 0.59 (95% CI: 0.48–0.74) and 0.82 (95% CI: 0.72–0.92) for ∆pCO2 and lactate, respectively. Our results do not support the use of ∆pCO2 to identify patients with early mortality in the postresuscitation phase. In contrast, non-survivors demonstrated higher lactate levels in the initial phase and lactate identified patients with early mortality with moderate accuracy.  相似文献   
5.
6.
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to...  相似文献   
7.
8.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
9.
Clinical Oral Investigations - To determine the usefulness of Serum C-terminal telopeptide cross-link of type 1 collagen (sCTX) as a preoperative marker for predicting the risk of developing...  相似文献   
10.
The set of guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents was developed following an international consensus conference in Copenhagen in 1996 (Viby-Mogensen et al., Acta Anaesthesiol Scand 1996, 40 , 59–74); the guidelines were later revised and updated following the second consensus conference in Stockholm in 2005 (Fuchs-Buder et al., Acta Anaesthesiol Scand 2007, 51 , 789–808). In view of new devices and further development of monitoring technologies that emerged since then, (e.g., electromyography, three-dimensional acceleromyography, kinemyography) as well as novel compounds (e.g., sugammadex) a review and update of these recommendations became necessary. The intent of these revised guidelines is to continue to help clinical researchers to conduct high-quality work and advance the field by enhancing the standards, consistency, and comparability of clinical studies. There is growing awareness of the importance of consensus-based reporting standards in clinical trials and observational studies. Such global initiatives are necessary in order to minimize heterogeneous and inadequate data reporting and to improve clarity and comparability between different studies and study cohorts. Variations in definitions of endpoints or outcome variables can introduce confusion and difficulties in interpretation of data, but more importantly, it may preclude building of an adequate body of evidence to achieve reliable conclusions and recommendations. Clinical research in neuromuscular pharmacology and physiology is no exception.  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-23

京公网安备 11010802026262号