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   12893篇
  免费   857篇
  国内免费   189篇
耳鼻咽喉   148篇
儿科学   263篇
妇产科学   189篇
基础医学   1916篇
口腔科学   210篇
临床医学   1141篇
内科学   2757篇
皮肤病学   491篇
神经病学   736篇
特种医学   933篇
外科学   1634篇
综合类   141篇
一般理论   3篇
预防医学   537篇
眼科学   375篇
药学   1147篇
中国医学   179篇
肿瘤学   1139篇
  2023年   91篇
  2022年   279篇
  2021年   421篇
  2020年   212篇
  2019年   295篇
  2018年   353篇
  2017年   330篇
  2016年   475篇
  2015年   711篇
  2014年   782篇
  2013年   916篇
  2012年   1170篇
  2011年   1109篇
  2010年   782篇
  2009年   679篇
  2008年   743篇
  2007年   668篇
  2006年   635篇
  2005年   557篇
  2004年   401篇
  2003年   353篇
  2002年   295篇
  2001年   50篇
  2000年   56篇
  1999年   55篇
  1998年   108篇
  1997年   125篇
  1996年   131篇
  1995年   80篇
  1994年   79篇
  1993年   74篇
  1992年   60篇
  1991年   40篇
  1990年   46篇
  1989年   33篇
  1988年   39篇
  1987年   34篇
  1986年   34篇
  1984年   17篇
  1983年   18篇
  1982年   18篇
  1978年   21篇
  1976年   17篇
  1959年   23篇
  1958年   63篇
  1957年   61篇
  1956年   59篇
  1955年   52篇
  1954年   43篇
  1949年   26篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Most ureteral tumors are transitional cell neoplasms. Neuroendocrine tumors of the genitourinary tract are extremely rare. To our knowledge, only one ureteral carcinoid tumor has been reported before. We report a second case of ureteral carcinoid tumor found in a 70-year-old female.  相似文献   
2.
Abstract  Gastrointestinal stromal tumor (GIST) is a recently described mesenchymal tumor that can develop in any portion of the gastrointestinal tract. The occurrence of a GIST in the urinary tract is rare, but GIST can present as tumor of the urinary tract or invade the urinary tract. This is the first reported case of GIST in the ileal neobladder, which presented as a submucosal tumor. The patient underwent an open exploration and partial resection of the neobladder pouch.  相似文献   
3.
4.
The Australian government established the Council on Overseas Professional Qualifications (COPQ) in 1969. In response to approaches by the occupational therapy profession, an Expert Panel in Occupational Therapy was established in 1979 in order to develop a screening examination to be used in assessing the competency of overseas trained occupational therapists. This paper describes the development of the COPQ examination for all overseas qualified occupational therapists wishing to work in Australia; the experience of candidates since its inception in 1983; and the problems associated with achieving recognition of the COPQ examination throughout Australia given the lack of uniform recognition procedures in the various States and Territories. The need for a consistent national approach to the policy of recognition and employment of overseas trained occupational therapists is addressed, with stress placed on the need for all employer groups, in both the public and the private sectors, to cooperate with COPQ's assessment procedures.  相似文献   
5.
Summary. Twenty artificial periapical lesions confined to cancellous bone were prepared at the apices of first and second mandibular molars of human cadavers. The lesions emphasized removal of the lamina dura and preparation of a 'halo' lesion surrounding the root apex, plus the addition of a simulated sclerotic border. Radiographs taken before and after creation of the lesions were scored by three examiners for detectable lesions Cross-sections of the lesions were assessed for the extent of bone destruction. Periapical lesions confined to cancellous bone were detected in 80 per cent of cases, and the presence of a sclerotic border tended to enhance visualization, although not in all cases. Intentional cortical involvement also improved detection of lesions. The anatomical features of the periapical area appear to promote the visualization of lesions which might not be detected in other locations.  相似文献   
6.
7.
8.
9.
10.
Transforming growth factor-β1 (TGF-β1) is known to be a potent growth inhibitor for many cell types, including most epithelial cells. In skin keratinocytes, TGF-β1 has been shown to inhibit growth and to rapidly reduce c-mycexpression. However, the molecular mechanism of TGF-β1 action on cell growth of cervical carcinoma has not yet been elucidated. We thus assessed the effect of TGF-β1 on the growth of cervical carcinoma cell lines. Two cervical squamous carcinoma cell lines, CUMC-3 and CUMC-6, were incubated with varying concentrations of TGF-β1, and growth inhibition was evaluated with tetrazolium-based colorimetric assay. After culture in TGF-β1 for 24 h, inhibition of growth was detected in a dose-dependent manner at concentrations of 0.1–10 ng/ml in both cell lines. This effect of TGF-β1 on cultured carcinoma cells was associated with apoptotic process including oligonucleosomal ladder DNA and apoptotic body formations. Northern blot analysis revealed c-mycmRNA expression was suppressed by 10 ng/ml of TGF-β1 following 3 h of treatment in both cell lines. Western blot analysis showed that the level of p27Kip1protein was increased after TGF-β1 treatment in both cell lines. These results suggest that the mechanisms by which TGF-β1 inhibits the growth of cervical carcinoma are complex and may include effects on down-regulation of c-mycgene, and overexpression of p27Kip1protein.  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