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   2672534篇
  免费   204378篇
  国内免费   26606篇
耳鼻咽喉   35084篇
儿科学   79470篇
妇产科学   67810篇
基础医学   387968篇
口腔科学   69489篇
临床医学   256669篇
内科学   506259篇
皮肤病学   54902篇
神经病学   203998篇
特种医学   100162篇
外国民族医学   702篇
外科学   387435篇
综合类   98664篇
现状与发展   88篇
一般理论   872篇
预防医学   202715篇
眼科学   64026篇
药学   208424篇
  345篇
中国医学   22188篇
肿瘤学   156248篇
  2022年   21138篇
  2021年   34977篇
  2020年   23547篇
  2019年   30169篇
  2018年   38384篇
  2017年   30250篇
  2016年   31999篇
  2015年   39790篇
  2014年   53652篇
  2013年   69214篇
  2012年   97038篇
  2011年   104781篇
  2010年   62860篇
  2009年   56661篇
  2008年   91332篇
  2007年   96397篇
  2006年   97139篇
  2005年   94383篇
  2004年   84897篇
  2003年   81369篇
  2002年   77692篇
  2001年   116558篇
  2000年   120192篇
  1999年   102878篇
  1998年   32725篇
  1997年   29306篇
  1996年   28448篇
  1995年   26696篇
  1994年   24158篇
  1993年   21873篇
  1992年   75202篇
  1991年   72821篇
  1990年   70873篇
  1989年   67980篇
  1988年   62284篇
  1987年   60888篇
  1986年   56733篇
  1985年   54258篇
  1984年   40045篇
  1983年   33973篇
  1979年   36189篇
  1978年   25781篇
  1977年   21363篇
  1976年   20446篇
  1975年   21930篇
  1974年   26290篇
  1973年   24938篇
  1972年   23333篇
  1971年   22146篇
  1970年   20355篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
106.
107.
Nidogen 1 (NID1) is a glycoprotein found in basement membranes involved in cross-linking collagen IV and laminin. The role of NID in breast cancer has only been evaluated in a small number of studies and the findings of these studies have been inconsistent. Our previous work revealed that highly tumorigenic murine mammary tumor cells express high levels of Nid1 while weakly tumorigenic mammary tumor cells express low levels of Nid1. To investigate Nid1, two stable knockdown lines were created, and Nid1 knockdown was confirmed at both the mRNA and protein level. Nid1 knockdown significantly reduced cell proliferation and migration/invasion and these reductions in proliferation and migration/invasion could be rescued by conditioned media containing NID1 protein. The reduced migration/invasion observed in the Nid1 knockdown cells was not associated with significant alterations in the epithelial gene Cdh1 or the mesenchymal genes Snai1, Snai2, Twist1, Twist2, Zeb1 and Zeb2. Therefore, suppression of Nid1 expression reduces proliferation and migration/invasion in claudin-low murine mammary tumor cells.  相似文献   
108.
Since the new round of health care reform in 2009, the vertical integration of hospitals and primary health institutions has become widely implemented in China as an efficient method for improving quality of primary care. This study aimed to answer the following questions: (a) What is the perceived quality of township health centres (THCs) under integration? (B) What differences could be observed among the three typical integration models, namely, private hospital-THC integration, public hospital-THC integration, and loose collaboration? Two rounds of cross-sectional surveys were conducted from November 2016 to June 2018. The Chinese version of the Primary Care Assessment Tool was used to evaluate perceived quality of sample THCs, and 1118 adult patients were interviewed in total. Multiple linear regressions were employed to compare the quality scores between two survey rounds and among different integration models after controlling for potential confounders. The results revealed that the quality of care significantly improved under private hospital-THC integration as observed by comparing two survey rounds, while no change or slight changes were observed in the other two models. The difference observed among the three models was that the perceived quality of THCs integrated with private hospitals was worse than that of THCs integrated with public hospitals and THCs under loose collaboration, while no significant difference was observed between public hospital-THC integration and loose collaboration. Increased attention should be given to highlighting the tight integration between hospitals and THCs and the different roles played by private and public hospitals in the current reform.  相似文献   
109.
110.
患者男,64岁,因头颅增大、面部变长,颧骨隆起、下颌增大、双手掌肥厚、双手指粗短30余年,乳房肿物1年余就诊。患者30余年前无明显诱因出现渐进性手足增大,双手掌肥厚,嘴唇变厚,下颌增大,眉弓及颧骨突出,皮肤增厚,无乳腺增大、泌乳,未诊治……  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