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   5787篇
  免费   347篇
  国内免费   29篇
耳鼻咽喉   56篇
儿科学   172篇
妇产科学   72篇
基础医学   909篇
口腔科学   573篇
临床医学   380篇
内科学   1362篇
皮肤病学   177篇
神经病学   460篇
特种医学   80篇
外科学   616篇
综合类   19篇
预防医学   544篇
眼科学   80篇
药学   392篇
中国医学   31篇
肿瘤学   240篇
  2024年   5篇
  2023年   58篇
  2022年   111篇
  2021年   217篇
  2020年   166篇
  2019年   226篇
  2018年   215篇
  2017年   183篇
  2016年   158篇
  2015年   217篇
  2014年   266篇
  2013年   313篇
  2012年   477篇
  2011年   576篇
  2010年   327篇
  2009年   271篇
  2008年   412篇
  2007年   364篇
  2006年   332篇
  2005年   287篇
  2004年   244篇
  2003年   214篇
  2002年   154篇
  2001年   34篇
  2000年   37篇
  1999年   37篇
  1998年   31篇
  1997年   20篇
  1996年   19篇
  1995年   14篇
  1994年   13篇
  1993年   10篇
  1992年   14篇
  1991年   11篇
  1990年   17篇
  1989年   12篇
  1988年   15篇
  1987年   7篇
  1986年   12篇
  1985年   9篇
  1984年   8篇
  1983年   6篇
  1982年   7篇
  1980年   4篇
  1979年   6篇
  1977年   4篇
  1973年   3篇
  1972年   4篇
  1969年   2篇
  1968年   3篇
排序方式: 共有6163条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Cecal intubation is a critical aspect of effective, complete colonoscopy. Difficult colonoscopy is most often considered as one in which it is challenging or impossible to reach the cecum. It may be a common occurrence due to patient and/or endoscopist factors. Incomplete colonoscopies should be avoided, since patients in this context present an important prevalence of lesions that escape examination. The approach to successful cecal intubation should depend on characterization of the problem as redundant colon or difficult sigmoid colon. Most patients with a prior incomplete colonoscopy can be colonoscoped successfully, if careful attention is paid to technique, using a variety of scopes, colonoscopy methods and additional equipment. Sufficient time should be allotted to make the attempt.  相似文献   
9.
OBJECTIVE: The authors tested the effect of blood sampling (skin versus venous puncture) on some biochemical and hematological blood parameters in athletes to answer whether skin puncture could be used as a substitute for venous puncture. DESIGN: Comparative study of 2 methods of blood samples collection. SETTING: The blood was collected in the same athletes at 3 different moments of the preparatory training phase. PARTICIPANTS: Fourteen male indoor soccer players (22 +/- 1 years old) and 7 female handball players (18 +/- 1 years old) participated. MAIN OUTCOME MEASUREMENT: Blood was collected in heparin and K3EDTA by Vacutainer BD or Microvette Sarstedt system for biochemical and hematological analyses, respectively. RESULTS: There were no significant statistical differences between the 2 methods for the values of creatine kinase, urea, creatinine, lymphocytes, and platelets. The other hematological analyzes and uric acid exhibited significant higher values in skin blood, although they were all within the normal expected range. A high degree of correlation was observed between the 2 techniques for all parameters. CONCLUSIONS: Skin puncture is a reliable, easy, accurate, and less invasive sampling method for assessing hematological and some biochemical parameters in athletes, respecting that blood samples should always be obtained from the same site, especially in follow-up studies.  相似文献   
10.

Background  

Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.  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