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   274867篇
  免费   7188篇
  国内免费   447篇
耳鼻咽喉   2257篇
儿科学   9136篇
妇产科学   4791篇
基础医学   28924篇
口腔科学   3308篇
临床医学   22963篇
内科学   50891篇
皮肤病学   2035篇
神经病学   26472篇
特种医学   12794篇
外国民族医学   4篇
外科学   44892篇
综合类   3438篇
一般理论   136篇
预防医学   26053篇
眼科学   4823篇
药学   15842篇
中国医学   728篇
肿瘤学   23015篇
  2023年   577篇
  2022年   943篇
  2021年   2136篇
  2020年   1351篇
  2019年   2142篇
  2018年   24141篇
  2017年   18969篇
  2016年   21206篇
  2015年   3176篇
  2014年   4241篇
  2013年   5511篇
  2012年   14434篇
  2011年   28689篇
  2010年   23058篇
  2009年   15496篇
  2008年   26287篇
  2007年   28807篇
  2006年   7740篇
  2005年   9048篇
  2004年   10054篇
  2003年   10339篇
  2002年   8166篇
  2001年   1173篇
  2000年   1030篇
  1999年   1127篇
  1998年   1434篇
  1997年   1138篇
  1996年   853篇
  1995年   799篇
  1994年   690篇
  1993年   651篇
  1992年   542篇
  1991年   525篇
  1990年   512篇
  1989年   420篇
  1988年   385篇
  1987年   374篇
  1986年   319篇
  1985年   356篇
  1984年   363篇
  1983年   300篇
  1982年   377篇
  1981年   303篇
  1980年   273篇
  1979年   139篇
  1978年   165篇
  1977年   139篇
  1976年   109篇
  1974年   112篇
  1973年   125篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
33.
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   
34.
35.
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   
36.
37.
38.
Digestive Diseases and Sciences - To determine whether the presence of portal vein thrombosis (PVT) where venous flow within the liver may be altered may delay the diagnosis of HCC and be...  相似文献   
39.
40.
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