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   59646篇
  免费   3947篇
  国内免费   239篇
耳鼻咽喉   771篇
儿科学   1384篇
妇产科学   1121篇
基础医学   7548篇
口腔科学   1400篇
临床医学   6243篇
内科学   13264篇
皮肤病学   619篇
神经病学   5955篇
特种医学   2370篇
外国民族医学   3篇
外科学   9137篇
综合类   560篇
一般理论   42篇
预防医学   4033篇
眼科学   958篇
药学   4018篇
中国医学   65篇
肿瘤学   4341篇
  2023年   302篇
  2022年   534篇
  2021年   1257篇
  2020年   782篇
  2019年   1211篇
  2018年   1460篇
  2017年   1098篇
  2016年   1161篇
  2015年   1414篇
  2014年   2035篇
  2013年   2859篇
  2012年   4250篇
  2011年   4590篇
  2010年   2639篇
  2009年   2446篇
  2008年   4124篇
  2007年   4215篇
  2006年   4025篇
  2005年   4039篇
  2004年   3672篇
  2003年   3510篇
  2002年   3218篇
  2001年   568篇
  2000年   397篇
  1999年   547篇
  1998年   761篇
  1997年   587篇
  1996年   490篇
  1995年   476篇
  1994年   388篇
  1993年   356篇
  1992年   270篇
  1991年   267篇
  1990年   231篇
  1989年   222篇
  1988年   200篇
  1987年   188篇
  1986年   197篇
  1985年   212篇
  1984年   246篇
  1983年   245篇
  1982年   281篇
  1981年   244篇
  1980年   247篇
  1979年   135篇
  1978年   155篇
  1977年   135篇
  1976年   105篇
  1975年   113篇
  1974年   94篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
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   
3.
4.
5.
ObjectivesTo fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.ConclusionsMoving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns.  相似文献   
6.
7.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
8.

Cerebellar mutism syndrome (CMS) occurs in one out of four children after posterior fossa tumor surgery, with open questions regarding risk factors, pathophysiology, and prevention strategies. Because of similarities between several cerebellar syndromes, a common pathophysiology with damage to the dentato-thalamo-cortical and dentato-rubro-olivary pathways has been proposed. Hypertrophic olivary degeneration (HOD) is an imaging correlate of cerebellar injury observed for instance in stroke patients. Aim of this study was to investigate whether the occurrence and severity of CMS correlates with the extent of damage to the relevant anatomical structures and whether HOD is a time-dependent postoperative neuroimaging correlate of CMS. We performed a retrospective single center study of CMS patients compared with matched non-CMS controls. CMS occurred in 10 children (13% of the overall cohort) with a median age of 8 years. Dentate nucleus (DN) injury significantly correlated with CMS, and superior cerebellar peduncle (SCP) injury was associated by tendency. HOD was observed as a dynamic neuroimaging phenomenon in the postoperative course and its presence significantly correlated with CMS and DN injury. Children who later developed HOD had an earlier onset and tended to have longer persistence of CMS. These findings can guide surgical measures to protect the DN and SCP during posterior fossa tumor resections and to avoid a high damage burden (i.e., bilateral damage). Development of intraoperative neuromonitoring of the cerebellar efferent pathways as well as improved preoperative risk stratification could help to establish a patient-specific strategy with optimal balance between degree of resection and functional integrity.

  相似文献   
9.
10.
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