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   15755篇
  免费   1234篇
  国内免费   66篇
耳鼻咽喉   98篇
儿科学   367篇
妇产科学   347篇
基础医学   1983篇
口腔科学   232篇
临床医学   2355篇
内科学   2973篇
皮肤病学   204篇
神经病学   1504篇
特种医学   484篇
外国民族医学   1篇
外科学   2337篇
综合类   243篇
现状与发展   1篇
一般理论   16篇
预防医学   1576篇
眼科学   247篇
药学   1146篇
中国医学   52篇
肿瘤学   889篇
  2023年   67篇
  2022年   112篇
  2021年   302篇
  2020年   174篇
  2019年   273篇
  2018年   364篇
  2017年   266篇
  2016年   261篇
  2015年   301篇
  2014年   491篇
  2013年   662篇
  2012年   977篇
  2011年   1168篇
  2010年   557篇
  2009年   556篇
  2008年   907篇
  2007年   1057篇
  2006年   910篇
  2005年   952篇
  2004年   853篇
  2003年   822篇
  2002年   793篇
  2001年   258篇
  2000年   288篇
  1999年   282篇
  1998年   203篇
  1997年   165篇
  1996年   169篇
  1995年   140篇
  1994年   119篇
  1993年   124篇
  1992年   173篇
  1991年   148篇
  1990年   155篇
  1989年   135篇
  1988年   132篇
  1987年   138篇
  1986年   115篇
  1985年   148篇
  1984年   130篇
  1983年   101篇
  1982年   95篇
  1981年   98篇
  1980年   81篇
  1979年   93篇
  1978年   81篇
  1977年   74篇
  1976年   60篇
  1974年   47篇
  1972年   50篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual.  相似文献   
2.
3.
4.
5.
6.
On May 14, 2013, Angelina Jolie disclosed she carries BRCA1, which means she has an 87% risk of developing breast cancer during her lifetime. Jolie decided to undergo a preventative bilateral mastectomy (PBM), reducing her risk to 5%. The purpose of this study was to analyze the type of information individuals are exposed to when using the Internet to search health information regarding Jolie’s decision. Qualitative content analysis revealed four main themes—information about genetics, information about a PBM, information about health care, and information about Jolie’s gender identity. Broadly, the identified websites mention Jolie’s high risk for developing cancer due to the genetic mutation BRCA1, describe a PBM occasionally noting reasons why she had this surgery and providing alternatives to the surgery, discuss issues related to health care services, costs, and insurances about Jolie’s health decision, and portray Jolie as a sexual icon, a partner to Brad Pitt, a mother of six children, and an inspirational humanitarian. The websites also depict Jolie’s health decision in positive, negative, and/or both ways. Discussion centers on how this actress’ health decision impacts the public.  相似文献   
7.
Rates of smoking during pregnancy remain high in Canada, and cessation rates are low among women who are younger than 24 years and who are socially disadvantaged, that is, have few social and economic resources because of poverty, violence, or mental health issues. On the basis of findings from literature reviews and consultation with policy makers, we developed and operationalized four approaches that can be used by health care providers to tailor interventions for tobacco use in pregnancy. These four approaches are woman centered, trauma informed, harm reducing, and equitable. Public health initiatives that address smoking in young and socially disadvantaged women could be more sharply focused by shifting to such tailored approaches that are grounded in social justice aims, span pre- and postpregnancy periods, and can be used to address women’s social contexts and concerns.  相似文献   
8.
OBJECTIVE: This study employed EEG source localisation procedures to study the contribution of motor preparatory and attentional processing to foreperiod activity in an S1-S2 motor priming task. METHODS: Behavioural and high-density event-related potential (ERP) data were recorded in an S1-S2 priming task where participants responded to S2 with a left or right-hand button press. S1 either provided information about response hand (informative) or ambiguous information (uninformative). RESULTS: Responses were significantly faster in informative trials compared with uninformative trials. Dipole source analysis of foreperiod lateralized ERPs revealed sources of motor preparatory activity in the dorsolateral premotor cortex (PMd) in line with previous work. In addition, two spatial attention components (ADAN, LDAP) were identified with generators in the PMd and occipitotemporal visual areas in the middle temporal (MT) region, respectively. Separation of motor-related and attentional PMd source locations was reliable along the rostral-caudal axis. CONCLUSIONS: The presence of attentional components in a motor priming paradigm supports the premotor theory of attention which suggests a close link between attention and motor preparatory processes. Separation of components in the premotor cortex is in accord with a functional division of PMd into rostral (higher-order processing) and caudal (motor-related processing) areas as suggested by imaging work. SIGNIFICANCE: A prime for response preparation is a trigger for separate, but closely linked, attention-related activity in premotor areas.  相似文献   
9.
10.
A retrospective review was conducted of 1,230 human poison exposures in which syrup of ipecac was administered to determine the availability of this emetic. Ipecac was available in 41.1% of the homes, while 42.5% obtained it from the pharmacy. Eight and two tenths percent were referred to a health care facility, 2.9% obtained ipecac from a neighbor, 2.3% went to an emergency room prior to calling the poison center, and 3% obtained ipecac from other sources. A randomly selected sample of 150 of these 1,230 cases were contacted 6 months after their initial call to the poison center to determine any changes in the availability of syrup of ipecac in the home. Although almost 30% more homes had syrup of ipecac than previously, 22.2% of homes still did not have ipecac available, despite the previous poisoning experience. Greater effort should be made during follow-up to educate the public regarding ipecac and its use.  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