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   4556篇
  免费   335篇
  国内免费   14篇
耳鼻咽喉   35篇
儿科学   170篇
妇产科学   97篇
基础医学   535篇
口腔科学   69篇
临床医学   620篇
内科学   833篇
皮肤病学   50篇
神经病学   441篇
特种医学   101篇
外科学   686篇
综合类   68篇
一般理论   26篇
预防医学   540篇
眼科学   32篇
药学   278篇
中国医学   8篇
肿瘤学   316篇
  2023年   69篇
  2022年   119篇
  2021年   279篇
  2020年   126篇
  2019年   239篇
  2018年   248篇
  2017年   152篇
  2016年   132篇
  2015年   135篇
  2014年   184篇
  2013年   260篇
  2012年   341篇
  2011年   402篇
  2010年   174篇
  2009年   151篇
  2008年   249篇
  2007年   214篇
  2006年   199篇
  2005年   202篇
  2004年   176篇
  2003年   133篇
  2002年   120篇
  2001年   41篇
  2000年   32篇
  1999年   26篇
  1998年   28篇
  1997年   18篇
  1996年   18篇
  1995年   17篇
  1994年   13篇
  1993年   17篇
  1992年   30篇
  1991年   27篇
  1990年   36篇
  1989年   21篇
  1988年   23篇
  1987年   29篇
  1986年   24篇
  1985年   13篇
  1984年   13篇
  1983年   11篇
  1982年   14篇
  1981年   11篇
  1980年   10篇
  1979年   20篇
  1978年   9篇
  1977年   8篇
  1976年   12篇
  1971年   10篇
  1970年   10篇
排序方式: 共有4905条查询结果,搜索用时 0 毫秒
1.
2.
3.
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use.  相似文献   
4.
5.
6.
7.
8.
9.
Myositis is a rare complication following renal transplantation and is most commonly the result of drug-mediated myotoxicity. Other causative disorders include viral infection, electrolyte imbalance and myositis of autoimmune origin. We describe a 60-year-old patient who developed acute polymyositis 4 weeks after a 000 human leukocyte antigen (HLA) mismatch cadaveric renal transplant. Following an uncomplicated transplant course with maintenance triple immunosuppression (prednisolone, mycophenolate mofetil and cyclosporine), the patient presented with severe symmetrical proximal muscle weakness associated with a rise in serum creatine kinase to 46800 U/L. Electromyography confirmed myopathic changes and muscle biopsy demonstrated extensive muscle-fiber necrosis with an inflammatory infiltrate. There were no obviously culpable drugs and viral studies were negative. Prompt initiation of high-dose steroid therapy led to clinical and biochemical recovery. Acute polymyositis may occur following renal transplantation. Potential mechanisms include viral antigen transmission or a localized form of graft vs. host disease.  相似文献   
10.
BACKGROUND: Abnormalities in the limbic-hypothalamic-pituitary-adrenal (LHPA) axis have been implicated in the pathogenesis of obsessive-compulsive disorder (OCD). To our knowledge, however, no prior study has measured pituitary gland volume in OCD. METHODS: Volumetric magnetic resonance imaging studies were conducted in 31 psychotropic drug-na?ve children (10 boys, 21 girls) aged 8-17 years and 31 case-matched healthy comparison subjects. RESULTS: Pituitary volume was significantly smaller in patients with OCD as compared with healthy control subjects (11% smaller). Smaller pituitary volume in patients with OCD was associated with increased compulsive but not obsessive symptom severity. Boys with OCD had smaller pituitary gland volumes compared with control boys (20% smaller). No significant differences in pituitary volume were observed between girls with OCD and control girls. Boys with OCD had significantly smaller pituitary volumes than girls with OCD (31% smaller), whereas control boys also had smaller pituitary gland volumes compared with control girls (21% smaller). CONCLUSIONS: These findings provide new evidence of reduced pituitary volume in pediatric OCD that seems to be more prominent in male patients. The observed alterations in pituitary volume are consistent with neuroendocrine studies that have reported abnormalities in the LHPA axis in OCD.  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