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   2380837篇
  免费   199740篇
  国内免费   4230篇
耳鼻咽喉   34454篇
儿科学   73141篇
妇产科学   63481篇
基础医学   335221篇
口腔科学   68234篇
临床医学   217343篇
内科学   468907篇
皮肤病学   48248篇
神经病学   201591篇
特种医学   96585篇
外国民族医学   886篇
外科学   362458篇
综合类   56294篇
现状与发展   1篇
一般理论   996篇
预防医学   191244篇
眼科学   55672篇
药学   178769篇
  4篇
中国医学   4284篇
肿瘤学   126994篇
  2018年   24962篇
  2017年   19526篇
  2016年   21341篇
  2015年   23899篇
  2014年   34260篇
  2013年   52166篇
  2012年   70471篇
  2011年   74137篇
  2010年   43426篇
  2009年   41671篇
  2008年   70341篇
  2007年   74724篇
  2006年   75495篇
  2005年   73503篇
  2004年   70598篇
  2003年   68117篇
  2002年   67253篇
  2001年   112727篇
  2000年   116781篇
  1999年   97997篇
  1998年   26309篇
  1997年   23914篇
  1996年   23840篇
  1995年   24559篇
  1994年   23150篇
  1993年   21534篇
  1992年   79356篇
  1991年   76474篇
  1990年   73600篇
  1989年   70875篇
  1988年   65876篇
  1987年   64834篇
  1986年   61377篇
  1985年   58475篇
  1984年   44258篇
  1983年   37647篇
  1982年   22891篇
  1981年   20301篇
  1979年   41296篇
  1978年   28980篇
  1977年   24305篇
  1976年   22798篇
  1975年   23946篇
  1974年   29602篇
  1973年   28022篇
  1972年   26216篇
  1971年   24154篇
  1970年   22735篇
  1969年   21078篇
  1968年   19130篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
1.
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of...  相似文献   
2.
3.
4.
5.
6.
7.
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   
8.
9.

Background

Hyperglycaemia is common in patients with acute brain injury admitted to an intensive care unit (ICU). Many studies have found associations between development of hyperglycaemia and increased mortality in hospitalised patients. However, the optimal target for blood glucose control is unknown. We want to conduct a systematic review with meta-analysis and trial sequential analysis to explore the beneficial and harmful effects of restrictive versus liberal glucose control on patient outcomes in adults with severe acute brain injury.

Methods

We will systematically search medical databases including CENTRAL, Embase, MEDLINE and trial registries. We will search the following websites for ongoing or unpublished trials: http://www.controlled-trials.com/ , http://www.clinicaltrials.gov/ , www.eudraCT.com , http://centerwatch.com/ , The Cochrane Library's CENTRAL, PubMed, EMBASE, Science Citation Index Expanded and CINAHL. Two authors will independently review and select trials and extract data. We will include randomised trials comparing levels of glucose control in our analyses and observational studies will be included to address potential harms. The primary outcomes are defined as all-cause mortality, functional outcome and health-related quality of life. Secondary outcomes include serious adverse events including hypoglycaemia, length of ICU stay and duration of mechanical ventilation, and explorative outcomes including intracranial pressure and infection. Trial Sequential Analysis will be used to investigate the risk of type I error due to repetitive testing and to further explore imprecision. Quality of trials will be evaluated using the Cochrane Risk of Bias tool, and quality of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

Discussion

The results of the systematic review will be disseminated through peer-reviewed publication. With the review, we hope to inform future randomised clinical trials and improve clinical practice.  相似文献   
10.
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