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   4506篇
  免费   399篇
  国内免费   9篇
耳鼻咽喉   42篇
儿科学   120篇
妇产科学   60篇
基础医学   817篇
口腔科学   66篇
临床医学   500篇
内科学   609篇
皮肤病学   84篇
神经病学   480篇
特种医学   185篇
外科学   799篇
综合类   130篇
一般理论   6篇
预防医学   375篇
眼科学   52篇
药学   380篇
中国医学   2篇
肿瘤学   207篇
  2023年   26篇
  2022年   63篇
  2021年   130篇
  2020年   73篇
  2019年   143篇
  2018年   169篇
  2017年   150篇
  2016年   138篇
  2015年   113篇
  2014年   173篇
  2013年   259篇
  2012年   391篇
  2011年   419篇
  2010年   209篇
  2009年   185篇
  2008年   335篇
  2007年   323篇
  2006年   299篇
  2005年   234篇
  2004年   190篇
  2003年   162篇
  2002年   170篇
  2001年   43篇
  2000年   43篇
  1999年   31篇
  1998年   29篇
  1997年   20篇
  1996年   23篇
  1995年   29篇
  1994年   13篇
  1992年   23篇
  1991年   19篇
  1990年   25篇
  1989年   15篇
  1988年   14篇
  1987年   15篇
  1986年   16篇
  1985年   17篇
  1981年   11篇
  1979年   10篇
  1978年   8篇
  1975年   12篇
  1974年   9篇
  1972年   11篇
  1971年   11篇
  1970年   9篇
  1969年   7篇
  1966年   7篇
  1960年   7篇
  1958年   7篇
排序方式: 共有4914条查询结果,搜索用时 15 毫秒
1.
2.
3.
Independent forensic neuropsychological examinations are performed by neuropsychologists who are hired as independent contractors by third parties to make determinations regarding neuropsychological functioning. The responsibilities of neuropsychologists when performing independent or court-ordered forensic examinations differ from those of clinical examinations. Because neuropsychological training typically occurs in clinical contexts, the transition to forensic contexts may result in uncertainty about how to negotiate the unique responsibilities of the forensic examiner role. Neuropsychologists are responsible for maintaining the highest standards of professional practice when performing independent and court-ordered forensic examinations. To reach and maintain the highest standards of practice, neuropsychologists must understand the unique relationships with retaining parties and examinees and strive to maintain true independence and objectivity. Although a true neuropsychologist-patient relationship is not considered to exist within the context of a forensic neuropsychological evaluation, neuropsychologists have ethical responsibilities to both the retaining party and the examinee.  相似文献   
4.
5.
6.
Piglets between 1 and 40 days of age were inoculated with varying numbers and with different isolates of Streptococcus suis type 2 by the intranasal, intravenous and subarachnoid routes. Less than 100 organisms of an isolate cultured from apparently normal pigs caused subclinical infection in 1-day-old piglets after intranasal inoculation. This infection was naturally transmitted between litter mates. Intravenous inoculation of a similar isolate in 7-week-old pigs resulted in a sub-clinical bacteraemia in 3 of 8 piglets. One other piglet developed a bacteraemia 7 days after inoculation and concurrently developed signs of lameness and nervous dysfunction. Ten piglets were inoculated by the subarachnoid route with a porcine isolate and two with an isolate from a person with clinical disease. Only the latter two pigs developed the classical signs of nervous disease associated with infection by S. suis type 2. It is concluded that strains of S. suis type 2, of varying pathogenicity for both pigs and man, are endemic in New Zealand. It is suggested that the occurrence of disease is associated with both exposure to a pathogenic strain and other, as yet undetermined, secondary factors.  相似文献   
7.
Based upon the percentage of cases of IgA nephropathy (IgAN) in biopsy series, a lower prevalence has been assumed for African-Americans compared with Americans of European descent. This may be due to a racial difference in the basic underlying pathology of IgAN or to racial differences in patterns of referral and biopsy selection practices. Over the past decade (1985 – 1994), we have found similar incidences of IgAN in Caucasian and African-American children from Shelby County, Tennessee. The incidence was 3.0 cases per million per year for Caucasian and 5.7 cases per million per year for African-American children. IgAN may be more common in African-American children than previously appreciated. Population-based incidence studies will be necessary to determine whether or not our experience has become a more widespread phenomenon. Received August 21, 1996; received in revised form and accepted December 18, 1996  相似文献   
8.
Five new N alpha-(5,8-dideazapteroyl)-L-ornithines have been prepared using multistep synthetic sequences. These include N alpha-[5-(trifluoromethyl)-5,8-dideazapteroyl]-L-ornithine, 3, as well as N alpha-[5-(trifluoromethyl)-5,8-dideazaisopteroyl]-L-ornithine, 4, and its 5-fluoro and 5-chloro analogues. Both of the compounds containing a 5-(trifluoromethyl) group (3 and 4) were found to be excellent inhibitors of homogeneous hog liver folylpolyglutamate synthetase, having Ki values in the same range as N alpha-(5-chloro-5,8-dideazapteroyl)-L-ornithine, 2, (approximately 10 nM). However, the bridge-reversed isomer of 2 was 60-fold less inhibitory than 2.  相似文献   
9.
10.
The effectiveness of Tc-99m bleomycin (BLM) and Tc(V)-99m DMSA are compared with that of Ga-67 citrate, which is currently the most widely used agent. In four patients with lipomatous tumors, the clinical significance of tumor imaging with each of these three agents is discussed and compared. Results indicate that both Tc-99m BLM and Tc(V)-99m DMSA are superior in detecting the extension or localization of liposarcomas.  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