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   1499570篇
  免费   127758篇
  国内免费   6778篇
耳鼻咽喉   18671篇
儿科学   47538篇
妇产科学   40122篇
基础医学   204864篇
口腔科学   40053篇
临床医学   136877篇
内科学   311057篇
皮肤病学   34124篇
神经病学   126614篇
特种医学   60912篇
外国民族医学   287篇
外科学   235915篇
综合类   34374篇
现状与发展   4篇
一般理论   667篇
预防医学   121956篇
眼科学   31704篇
药学   105606篇
  6篇
中国医学   2463篇
肿瘤学   80292篇
  2019年   11776篇
  2018年   16682篇
  2017年   13286篇
  2016年   15622篇
  2015年   17638篇
  2014年   24937篇
  2013年   37076篇
  2012年   47127篇
  2011年   50734篇
  2010年   31129篇
  2009年   29970篇
  2008年   47765篇
  2007年   50910篇
  2006年   51541篇
  2005年   50502篇
  2004年   48367篇
  2003年   46563篇
  2002年   44096篇
  2001年   67415篇
  2000年   68820篇
  1999年   57763篇
  1998年   17883篇
  1997年   15795篇
  1996年   16629篇
  1995年   17643篇
  1994年   16398篇
  1993年   15324篇
  1992年   47954篇
  1991年   46586篇
  1990年   44721篇
  1989年   42508篇
  1988年   39465篇
  1987年   38807篇
  1986年   36588篇
  1985年   35416篇
  1984年   27486篇
  1983年   23215篇
  1982年   15269篇
  1981年   13730篇
  1980年   12924篇
  1979年   24107篇
  1978年   17766篇
  1977年   15067篇
  1976年   13794篇
  1975年   14227篇
  1974年   16594篇
  1973年   15846篇
  1972年   14510篇
  1971年   13307篇
  1970年   12121篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.  相似文献   
5.
6.
7.
8.
Neuroscience and Behavioral Physiology - The question of the involvement of impairments to the metabolism of melatonin and its precursors (tryptophan and serotonin) in the development of...  相似文献   
9.
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   
10.
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a...  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