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   251985篇
  免费   17856篇
  国内免费   1130篇
耳鼻咽喉   2787篇
儿科学   6495篇
妇产科学   4595篇
基础医学   32936篇
口腔科学   4559篇
临床医学   25324篇
内科学   53599篇
皮肤病学   3383篇
神经病学   24275篇
特种医学   8398篇
外国民族医学   11篇
外科学   38454篇
综合类   3456篇
一般理论   318篇
预防医学   21401篇
眼科学   6559篇
药学   16966篇
  6篇
中国医学   361篇
肿瘤学   17088篇
  2023年   1339篇
  2022年   2411篇
  2021年   5438篇
  2020年   3261篇
  2019年   5300篇
  2018年   5951篇
  2017年   4470篇
  2016年   4958篇
  2015年   5828篇
  2014年   8603篇
  2013年   11794篇
  2012年   18009篇
  2011年   18897篇
  2010年   10575篇
  2009年   9426篇
  2008年   16594篇
  2007年   17448篇
  2006年   17299篇
  2005年   17275篇
  2004年   16187篇
  2003年   15038篇
  2002年   14055篇
  2001年   2101篇
  2000年   1596篇
  1999年   2316篇
  1998年   3065篇
  1997年   2560篇
  1996年   2183篇
  1995年   2095篇
  1994年   1744篇
  1993年   1571篇
  1992年   1256篇
  1991年   1150篇
  1990年   999篇
  1989年   973篇
  1988年   966篇
  1987年   945篇
  1986年   951篇
  1985年   964篇
  1984年   1217篇
  1983年   1123篇
  1982年   1364篇
  1981年   1312篇
  1980年   1146篇
  1979年   703篇
  1978年   747篇
  1977年   635篇
  1976年   584篇
  1975年   469篇
  1974年   472篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
An interview study investigating attitudinal and other factors influencing the selection of primary medical care (PMC) agency is described. It focuses on adult patients excluding those with trauma of medical/surgical emergencies and was conducted in part of the Western Region of Melbourne in late 1983, the period immediately prior to the introduction of Medicare. It is based on a cross-sectional survey of in-hours attenders of eight general practices (GP), the Western Region (Community) Health Centre (WRCHC) and the general clinic of the casualty department at the Western General Hospital (WGH). Attenders of these different services differed significantly in their socio-demographic characteristics. WGH attenders were significantly younger and had migrated from non-English speaking countries significantly more often. Male attenders at the WGH had significantly lower socioeconomic status. 71 per cent being not in the workforce. The most commonly stated reasons for attendance at particular services generally were “closeness to home, work”, “recommendation” and “good service”. Reasons given by attenders at the different clinics generally were similar. However GP attenders offered “good service” significantly more often as a reason for choice; WGH attenders offered “cheap/economic reasons” significantly more often and “recommendation” significantly less so. WRCHC attenders offered “workers' compensation” significantly more often. Thirty per cent of attenders overall had attended other than their current clinic during their past three to four illness episodes. While a large majority of patients still attend GP for PMC it is concluded that a pluralist model recognising the legitimacy of different PMC arrangements and multiple use of them by individuals best meets community need. This is likely to be even more true under Medicare. It is concluded that instrumental factors and social networks are important in the selection of PMC, particularly given the limited knowledge of respondents about health services. It is also concluded that cost and economic factors have been given undue weight in selection of primary medical care agency. The use of the WGH casualty department by groups not in the work force, given no real financial advantage in doing so, requires further study.  相似文献   
152.
153.
154.
A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development.  相似文献   
155.
156.
Social violence is a kind of violence which is applied by one individual to another. It is a stake in the field of public health because of an increasing number of children with such behaviors. In addition to environmental factors, the occurrence of abnormal social behavior before 9 years of age seems to precede social violence for the subsequent 20 years of life. One must therefore identify an inadequate attitude towards the parents and/or the teachers, or a poor child's self-esteem and self-respect. These phenomena are based on parental authority, on the ethical development of the child, on his verbalization capacity, on his socialization and his affective development. It is therefore important to stimulate ethical capacities and feelings in the child not only to provide autonomy but also to allow reflexive distinction of language, behavior and judgment, which enable him to understand, consider and respect other individuals.  相似文献   
157.
Objectives.To test the safety, efficacy, and toxicity of gene therapy using wild-type p53-expressing adenovirus (Ad-CMV-p53) in a nude mouse model with intraperitoneal (ip) 2774 human ovarian cancer cell line that contains a p53 mutation.Study design.An initial study of adenovirus tolerance was determined in nude mice by a single ip injection of increasing doses of Ad-CMV-p53. Nude mice were implanted with an LD100dose of 1 × 107cells. To study the efficacy and specificity of Ad-CMV-p53 treatment, the mice received treatment with different adenovirus constructs. One group received Ad-CMV-p53 and another group received a control adenovirus construct, Ad-CMV-βgal. To study the treatment response to Ad-CMV-p53, the mice were divided into groups and received various treatment schedules of 1 × 108pfu of Ad-CMV-p53.Results.The mice tolerated Ad-CMV-p53 without adverse effects at doses of 1 × 108pfu. The response to Ad-CMV-p53 showed significant survival duration in each dose regimen, with a survival time greater than that of untreated animals (P= 0.0173). However, no statistically significant survival advantage was observed between Ad-CMV-p53- and Ad-CMV-βgal-treated mice.Conclusions.These studies show that at the adenovirus dose and administration regimen used, there is effective but not specific 2774 tumor growth inhibitionin vivo.Efficient introduction of biologically active genes into tumor cells would greatly facilitate cancer therapy. Thus, although promising, these results caution that much effort will be required to realize the potential for clinical application of adenovirus-based ovarian cancer gene therapy.  相似文献   
158.
159.
160.
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