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   20296篇
  免费   1313篇
  国内免费   70篇
耳鼻咽喉   233篇
儿科学   733篇
妇产科学   580篇
基础医学   2368篇
口腔科学   249篇
临床医学   3511篇
内科学   3476篇
皮肤病学   201篇
神经病学   1945篇
特种医学   309篇
外科学   1594篇
综合类   198篇
一般理论   85篇
预防医学   3106篇
眼科学   710篇
药学   1017篇
中国医学   11篇
肿瘤学   1353篇
  2023年   81篇
  2022年   133篇
  2021年   292篇
  2020年   208篇
  2019年   357篇
  2018年   404篇
  2017年   313篇
  2016年   368篇
  2015年   447篇
  2014年   587篇
  2013年   1018篇
  2012年   1398篇
  2011年   1466篇
  2010年   806篇
  2009年   688篇
  2008年   1310篇
  2007年   1518篇
  2006年   1483篇
  2005年   1474篇
  2004年   1419篇
  2003年   1319篇
  2002年   1271篇
  2001年   175篇
  2000年   124篇
  1999年   200篇
  1998年   273篇
  1997年   222篇
  1996年   188篇
  1995年   162篇
  1994年   178篇
  1993年   147篇
  1992年   93篇
  1991年   105篇
  1990年   88篇
  1989年   79篇
  1988年   73篇
  1987年   73篇
  1986年   72篇
  1985年   72篇
  1984年   97篇
  1983年   99篇
  1982年   114篇
  1981年   123篇
  1980年   107篇
  1979年   64篇
  1978年   58篇
  1977年   56篇
  1976年   47篇
  1975年   44篇
  1973年   36篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians.  相似文献   
2.
The aim of the study was to determine the effect of exogenous melatonin treatment on circulating prolactin levels in red deer. Melatonin was administered from 12 June 1984 (day 1) to lactating and non-lactating hinds in the feed daily at 1600 h, and to non-lactating hinds by a subcutaneous implant. Average concentrations (ng/ml) of prolactin in plasma taken serially over 15-h periods were significantly higher for untreated hinds than for melatonin-treated animals on day 15 whether lactating (66-133 v. 23-28, P less than 0.05) or non-lactating (28-174 v. 8-13, P less than 0.01), remained higher on day 36 (lactating: 41-152 v. 15-21, P less than 0.05; non-lactating: 21-50 v. 1-7, P less than 0.001) but had decreased to similar levels on day 72 (lactating: 5-24 v. 7-17; non-lactating: 2-9 v. 0-4). The advanced reduction in plasma prolactin for all melatonin-treated hinds was associated with an advanced onset of seasonal breeding activity.  相似文献   
3.
4.
5.
This paper reviews the evidence of inborn temperament individuality in children, which affects the child-caretaker interaction and can be a source of differential treatment approaches. Focus on the dynamic interaction between individual characteristics and environmental demands views the child as a contributor to his or her own development and parent behavior as often reactive rather than the cause of various childhood disturbances.When this article was written, the author was with the Department of Sociology, Social Work, and Anthropology at Utah State University.  相似文献   
6.
Relocation mortality has been cited as an important factor when considering the placement of elderly patients. This study describes the fate of dementia patients relocated to facilitate the move to a new hospital. Some wards were moved as intact units—that is, the patients were kept together and there was little change in the nursing or medical staff. Two other wards were closed, and these patients were dispersed to several existing and new wards and experienced changes of nursing and medical staff. All patients underwent prerelocation and postrelocation orientation programmes. The mortality figures for the total patient group before and after the relocation do not show any statistically significant increase in mortality postrelocation. However, for wards that were closed and where the patients suffered maximum disruption to patient group and nursing staff, there was a significant increase in mortality rates.  相似文献   
7.
Using the concepts of stigma, NIMBY and place, this paper examines the difficulties of finding a place for needle exchange programs (NEPs). Data were drawn from semi-structured interviews with NEP staff (Ontario, Canada) that focused on operational policies and routines. An iterative, inductive analytic process was used. NEPs, their staff and clients are not always welcome additions to organizations or communities because of concerns about the ‘dangerousness’ of clients and the potential contamination of communities and workplaces by stigmatized individuals and their artefacts (e.g. contaminated injection equipment). Public parks where a lot of drug ‘action’ takes place are good destinations for outreach workers but these places are contentious sites for NEP activities, particularly when residents do not perceive a need for the program and/or want to redefine their neighbourhoods. Issues of ‘place’ are further complicated when service delivery is mobile. Finding a place within organizations is difficult for NEPs because of concerns about the diversion of limited financial and spatial resources to ‘non-core’ activities and ‘undesirable’ clients. Workers respond to these challenges by contesting the social and spatial boundaries of who is an acceptable client or neighbour and refuting the perceived ‘differentness’ of injection drug users. Implementation of an unpopular service involves a delicate balancing act of interests, understanding of the dynamics of particular communities and a willingness to reinvent and redefine programs. The sociospatial stigmatization of injection drug use has had a negative impact on NEPs, and perhaps limits HIV prevention efforts.  相似文献   
8.
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