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   540877篇
  免费   36154篇
  国内免费   650篇
耳鼻咽喉   7154篇
儿科学   17778篇
妇产科学   14274篇
基础医学   88722篇
口腔科学   15177篇
临床医学   47195篇
内科学   99429篇
皮肤病学   12631篇
神经病学   38632篇
特种医学   19373篇
外国民族医学   63篇
外科学   80784篇
综合类   8648篇
一般理论   138篇
预防医学   41564篇
眼科学   12490篇
药学   42532篇
中国医学   1047篇
肿瘤学   30050篇
  2018年   5878篇
  2017年   4560篇
  2016年   4956篇
  2015年   5221篇
  2014年   6837篇
  2013年   11073篇
  2012年   14928篇
  2011年   16489篇
  2010年   9309篇
  2009年   8385篇
  2008年   15496篇
  2007年   16541篇
  2006年   16639篇
  2005年   15917篇
  2004年   15467篇
  2003年   14778篇
  2002年   14601篇
  2001年   24897篇
  2000年   26028篇
  1999年   21105篇
  1998年   5582篇
  1997年   4849篇
  1996年   5139篇
  1995年   4741篇
  1994年   4432篇
  1992年   15879篇
  1991年   16482篇
  1990年   16543篇
  1989年   15942篇
  1988年   14715篇
  1987年   14545篇
  1986年   13710篇
  1985年   13145篇
  1984年   9780篇
  1983年   8369篇
  1982年   4664篇
  1979年   9521篇
  1978年   6915篇
  1977年   5846篇
  1976年   5642篇
  1975年   6456篇
  1974年   7671篇
  1973年   7167篇
  1972年   6984篇
  1971年   6711篇
  1970年   6202篇
  1969年   5914篇
  1968年   5584篇
  1967年   5036篇
  1966年   4465篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.

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 We will search the following websites for ongoing or unpublished trials: http://www.controlled-trials.com/ , http://www.clinicaltrials.gov/ , www.eudraCT.com , http://centerwatch.com/ , The Cochrane Library's CENTRAL,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   
4.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
5.
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies.  相似文献   
6.
7.
8.
9.
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