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   191852篇
  免费   12489篇
  国内免费   1307篇
耳鼻咽喉   2487篇
儿科学   4096篇
妇产科学   4644篇
基础医学   27506篇
口腔科学   3721篇
临床医学   20898篇
内科学   35864篇
皮肤病学   4678篇
神经病学   15096篇
特种医学   8668篇
外国民族医学   1篇
外科学   24825篇
综合类   2439篇
现状与发展   6篇
一般理论   130篇
预防医学   14063篇
眼科学   4730篇
药学   15448篇
中国医学   1630篇
肿瘤学   14718篇
  2023年   1170篇
  2022年   3053篇
  2021年   5385篇
  2020年   2870篇
  2019年   4214篇
  2018年   5180篇
  2017年   3769篇
  2016年   4794篇
  2015年   6264篇
  2014年   7863篇
  2013年   9904篇
  2012年   14846篇
  2011年   14614篇
  2010年   8486篇
  2009年   7156篇
  2008年   11370篇
  2007年   11441篇
  2006年   10592篇
  2005年   10128篇
  2004年   9107篇
  2003年   8096篇
  2002年   7200篇
  2001年   4590篇
  2000年   4204篇
  1999年   3539篇
  1998年   1673篇
  1997年   1296篇
  1996年   1189篇
  1995年   1132篇
  1994年   960篇
  1993年   849篇
  1992年   1701篇
  1991年   1702篇
  1990年   1485篇
  1989年   1344篇
  1988年   1254篇
  1987年   1124篇
  1986年   1102篇
  1985年   985篇
  1984年   767篇
  1983年   689篇
  1982年   542篇
  1981年   515篇
  1980年   455篇
  1979年   574篇
  1978年   476篇
  1977年   448篇
  1976年   389篇
  1974年   395篇
  1973年   348篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
15.
16.
17.
Potential for widespread transmission of HIV/AIDS among American Indian (AI) adolescents exists, yet no evidence-based interventions (EBIs) have been adapted and evaluated with this population. Intensive psychoeducation may improve knowledge and decision-making which could potentially translate to reductions in HIV risk behaviors. A peer group randomized controlled comparison of an adapted EBI vs. control was delivered over an eight-day summer basketball camp in one reservation-based tribal community to adolescents ages 13–19. Outcome data were gathered immediately post-camp and at 6 and 12 months follow-up. Self-selected peer groups were randomized to intervention (n = 138) or control (n = 129) conditions for a total sample of 267 participants (56.2% female), mean age 15.1 years (SD = 1.7). Intervention participants had better condom use self-efficacy post-camp (Adjusted Mean Difference [AMD] = ?0.75, p < 0.005) and at 6 (AMD = ?0.44, p < 0.005) and 12 months (AMD = ?0.23, p < 0.05) follow-up. Intervention participants also had higher HIV prevention and transmission knowledge (post-camp: AMD = 0.07, p < 0.01; 6 months: AMD = 0.06, p < 0.01) were more likely to believe condoms prevent sexually transmitted infections (post-camp: RR = 1.41, p < 0.005; 6 months: RR = 1.34, p < 0.05), to talk with an adult about HIV/AIDS (post-camp: RR=1.78, p < 0.005; 6 months: RR = 1.14, p < 0.005), had higher partner negotiation efficacy related to substance use during sex (post-camp: AMD = 0.37, p < 0.01), and were more likely to intend to use a condom (post-camp: RR = 1.39, p < 0.01). The adapted intervention had short- and medium-term impacts on AI adolescent risk for HIV/AIDS, but attenuated at 12 months. Intervention delivery through a community-based camp is feasible and acceptable with strong retention. Additional study is needed to evaluate the adapted intervention's impact on sexual risk behaviors and if booster sessions and parent involvement translate to long-term impacts.  相似文献   
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