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   211008篇
  免费   4218篇
  国内免费   1946篇
耳鼻咽喉   1690篇
儿科学   7108篇
妇产科学   3813篇
基础医学   20547篇
口腔科学   2093篇
临床医学   16624篇
内科学   36828篇
皮肤病学   1469篇
神经病学   18237篇
特种医学   10140篇
外国民族医学   17篇
外科学   32262篇
综合类   7204篇
现状与发展   4篇
一般理论   7篇
预防医学   20541篇
眼科学   3536篇
药学   13101篇
  24篇
中国医学   2492篇
肿瘤学   19435篇
  2024年   83篇
  2023年   490篇
  2022年   1166篇
  2021年   1544篇
  2020年   1124篇
  2019年   1185篇
  2018年   23087篇
  2017年   18370篇
  2016年   20468篇
  2015年   2466篇
  2014年   2725篇
  2013年   2700篇
  2012年   9701篇
  2011年   23888篇
  2010年   20686篇
  2009年   12951篇
  2008年   21510篇
  2007年   23600篇
  2006年   2522篇
  2005年   4072篇
  2004年   4700篇
  2003年   5560篇
  2002年   3525篇
  2001年   1185篇
  2000年   1244篇
  1999年   900篇
  1998年   648篇
  1997年   608篇
  1996年   417篇
  1995年   405篇
  1994年   369篇
  1993年   254篇
  1992年   361篇
  1991年   365篇
  1990年   338篇
  1989年   244篇
  1988年   242篇
  1987年   195篇
  1986年   144篇
  1985年   145篇
  1984年   102篇
  1983年   64篇
  1982年   49篇
  1981年   35篇
  1980年   60篇
  1979年   34篇
  1970年   36篇
  1938年   63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 31 毫秒
31.
32.
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   
33.
34.
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   
35.
36.
37.
While decreasing trend in gender differences in alcohol use disorders was reported in Western countries, the change in Asian countries is unknown. This study aims to explore the shifts in gender difference in alcohol abuse (AA) and dependence (AD) in Korea. We compared the data from two nation-wide community surveys to evaluate gender differences in lifetime AA and AD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Face-to-face interviews using the Composite International Diagnostic Interview (CIDI) were applied to all subjects in 2001 (n=6,220) and 2011 (n=6,022). Male-to-female ratio of odds was decreased from 6.41 (95% CI, 4.81-8.54) to 4.37 (95% CI, 3.35-5.71) for AA and from 3.75 (95% CI, 2.96-4.75) to 2.40 (95% CI, 1.80-3.19) for AD. Among those aged 18-29, gender gap even became statistically insignificant for AA (OR, 1.59; 95% CI, 0.97-2.63) and AD (OR, 1.18; 95% CI, 0.80-2.41) in 2011. Men generally showed decreased odds for AD (0.55; 95% CI, 0.45-0.67) and women aged 30-39 showed increased odds for AA (2.13; 95% CI 1.18-3.84) in 2011 compared to 2001. Decreased AD in men and increased AA in women seem to contribute to the decrease of gender gap. Increased risk for AA in young women suggests needs for interventions.  相似文献   
38.
39.
40.
Serum lactate is a non-specific marker of tissue hypoperfusion. Elevated serum lactate is used in the differential diagnosis of acute intestinal ischemia. Although this practice is controversial, in the absence of other validated markers lactate is still used because of its high sensitivity.We present the cases of two patients who developed acute mesenteric ischemia as a post-surgical complication. The patients reported moderate abdominal pain —a non-specific symptom in the postoperative context— and tests showed progressively increasing serum lactate levels, which facilitated suspicion and subsequent diagnostic confirmation through an imaging test.These cases highlight the physiopathological importance of lactate elevation in the perioperative context and of performing a differential diagnosis of its possible causes, including mesenteric ischemia. Although the outcome was negative in the first case, early suspicion allowed us to make an effective diagnosis and administer appropriate treatment in the second patient.  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