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   3373491篇
  免费   263432篇
  国内免费   6957篇
耳鼻咽喉   47673篇
儿科学   106056篇
妇产科学   92269篇
基础医学   473309篇
口腔科学   96000篇
临床医学   307711篇
内科学   660590篇
皮肤病学   72706篇
神经病学   284655篇
特种医学   130572篇
外国民族医学   1246篇
外科学   502190篇
综合类   78976篇
现状与发展   4篇
一般理论   1373篇
预防医学   276436篇
眼科学   79120篇
药学   246830篇
  5篇
中国医学   7003篇
肿瘤学   179156篇
  2019年   27270篇
  2018年   39473篇
  2017年   29735篇
  2016年   32732篇
  2015年   36893篇
  2014年   51656篇
  2013年   78494篇
  2012年   108774篇
  2011年   114428篇
  2010年   66306篇
  2009年   62366篇
  2008年   106635篇
  2007年   113262篇
  2006年   113507篇
  2005年   110482篇
  2004年   105803篇
  2003年   101441篇
  2002年   98807篇
  2001年   152639篇
  2000年   157433篇
  1999年   132682篇
  1998年   38816篇
  1997年   35146篇
  1996年   34785篇
  1995年   33342篇
  1994年   31003篇
  1993年   29038篇
  1992年   104631篇
  1991年   100542篇
  1990年   96822篇
  1989年   93047篇
  1988年   86368篇
  1987年   84920篇
  1986年   80066篇
  1985年   76469篇
  1984年   58427篇
  1983年   49761篇
  1982年   30507篇
  1981年   27113篇
  1979年   54025篇
  1978年   38137篇
  1977年   32034篇
  1976年   30056篇
  1975年   31373篇
  1974年   38584篇
  1973年   36920篇
  1972年   34641篇
  1971年   31844篇
  1970年   30132篇
  1969年   28075篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
Abstract

Supporting patients in making informed healthcare decisions is a cornerstone of ethical medical practice. Surgeons frequently draw for and show images to patients when consenting them for operations but the value of this practice in informed decision-making is unclear. An audit was conducted in a General Surgery Department. 244 patients completed questionnaires on the value of visual materials when giving consent for surgery. The complexity of the operations was classified into “simple”, “moderate” or “complex”. 100% of patients felt they had given informed consent to surgery. 62% of patients received at least one form of visual material during the consenting process. All patients who received a drawing, and 99% of those provided with other images, valued these resources. Visual materials were considered more useful to patients when giving consent for moderate or complex operations than simple ones. Approximately one third of patients who did not receive visual materials would have appreciated these when making an informed decision. This research highlights the value of surgeons drawing for, and providing other visual resources to, their patients as part of the consent process. There is a role for further research and training materials in drawing skills for surgeons.  相似文献   
43.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
44.
45.
46.
47.
48.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  相似文献   
49.
50.
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