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   177650篇
  免费   1134篇
  国内免费   8篇
耳鼻咽喉   1163篇
儿科学   6717篇
妇产科学   3066篇
基础医学   16840篇
口腔科学   1632篇
临床医学   12580篇
内科学   31374篇
皮肤病学   672篇
神经病学   16634篇
特种医学   8992篇
外科学   28992篇
综合类   2357篇
一般理论   2篇
预防医学   18236篇
眼科学   2795篇
药学   9604篇
中国医学   624篇
肿瘤学   16512篇
  2021年   37篇
  2019年   51篇
  2018年   21964篇
  2017年   17385篇
  2016年   19531篇
  2015年   903篇
  2014年   829篇
  2013年   817篇
  2012年   7032篇
  2011年   21073篇
  2010年   18835篇
  2009年   11563篇
  2008年   19559篇
  2007年   21731篇
  2006年   588篇
  2005年   2209篇
  2004年   3407篇
  2003年   4395篇
  2002年   2545篇
  2001年   339篇
  2000年   484篇
  1999年   235篇
  1998年   224篇
  1997年   237篇
  1996年   116篇
  1995年   122篇
  1994年   122篇
  1993年   85篇
  1992年   117篇
  1991年   180篇
  1990年   208篇
  1989年   169篇
  1988年   125篇
  1987年   134篇
  1986年   96篇
  1985年   98篇
  1984年   82篇
  1983年   67篇
  1982年   53篇
  1980年   73篇
  1979年   65篇
  1978年   53篇
  1977年   46篇
  1974年   57篇
  1970年   49篇
  1969年   40篇
  1968年   34篇
  1938年   62篇
  1932年   57篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
11.
12.
Contraceptive use is an important strategy for the prevention of unwanted pregnancy and avoidance of induced abortion. Of all the contraception methods, emergency contraceptive (EC) offers the last chance to achieve this. However, few studies have documented the use of EC among young people in Ghana. This study explored knowledge and usage of EC as well as the factors associated with it among University of Cape Coast students. Data were obtained on the knowledge and usage of ECs among University of Cape Coast students in 2013. Logistic regression analysis was used to investigate the association between students’ socio-demographic characteristics and EC knowledge and use. More male students (72 %) than females (59 %) were sexually active. Fifty-seven percent of the respondents had ever heard of EC and 36 % had ever used EC. Although males were more likely to be sexually active, females were more likely to have knowledge of EC use compared to males. The study underscores the need to increase awareness regarding EC among University students in order to offer them the opportunity that EC provides if other forms of contraceptives are missed.  相似文献   
13.
14.
Gastroesophageal reflux is the most common benign disorder of the esophagus and laparoscopic Nissen fundoplication has become the standard surgical treatment for its treatment. In our area, where the use of bougie calibration is debatable, postoperative dysphagia is encountered often after this surgery although it is usually not permanent. The aim of this study was to investigate the effect of using a soft silicone tube 39 F in diameter for esophageal calibration during laparoscopic Nissen fundoplication on the incidence of postoperative dysphagia. We divided cases scheduled to undergo laparoscopic Nissen fundoplication between January 2009 and November 2010 into two groups, each consisting 25 patients. Esophageal calibration with a 39 F silicone orogastric tube was used for the first group while there was no operative calibration in the second group. The surgical duration was recorded; the presence and severity of the postoperative dysphagia was calculated by using a dysphagia severity scoring system during the 1-year postoperative follow-up. The dysphagia severity scores were significantly lower in group 1 than group 2 on the postoperative second day and at the end of the first week and first month. We did not find a significant difference at the end of the 6-month and first year. There was also no significant difference regarding surgery duration. The use of a soft orogastric tube 39 F in diameter for esophagus calibration during laparoscopic Nissen fundoplication has significantly decreased the incidence of postoperative transient dysphagia without affecting the duration of surgery. Although dysphagia gradually resolves in the majority of patients, a safe and easy calibration method for its prevention is worth developing, and we believe that the use of our method in larger series could be beneficial.  相似文献   
15.
16.
17.
18.
19.
20.
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