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   29627篇
  免费   3804篇
  国内免费   335篇
耳鼻咽喉   90篇
儿科学   800篇
妇产科学   474篇
基础医学   2287篇
口腔科学   634篇
临床医学   8287篇
内科学   2458篇
皮肤病学   205篇
神经病学   1901篇
特种医学   327篇
外国民族医学   2篇
外科学   2843篇
综合类   3128篇
现状与发展   1篇
一般理论   4篇
预防医学   6443篇
眼科学   152篇
药学   1833篇
  146篇
中国医学   522篇
肿瘤学   1229篇
  2024年   99篇
  2023年   674篇
  2022年   983篇
  2021年   1553篇
  2020年   1735篇
  2019年   1649篇
  2018年   1519篇
  2017年   1489篇
  2016年   1464篇
  2015年   1396篇
  2014年   2042篇
  2013年   2943篇
  2012年   1562篇
  2011年   1597篇
  2010年   1277篇
  2009年   1361篇
  2008年   1345篇
  2007年   1389篇
  2006年   1140篇
  2005年   1002篇
  2004年   826篇
  2003年   666篇
  2002年   593篇
  2001年   511篇
  2000年   468篇
  1999年   362篇
  1998年   328篇
  1997年   294篇
  1996年   212篇
  1995年   190篇
  1994年   156篇
  1993年   137篇
  1992年   126篇
  1991年   117篇
  1990年   89篇
  1989年   64篇
  1988年   73篇
  1987年   51篇
  1986年   39篇
  1985年   35篇
  1984年   39篇
  1983年   27篇
  1982年   23篇
  1981年   27篇
  1980年   19篇
  1979年   10篇
  1978年   19篇
  1977年   12篇
  1976年   8篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
BACKGROUND: Studies have shown that alcoholics have smaller brain volumes than non-alcoholic cohorts, but an effect of family history (FH) of heavy drinking on brain volume has not been demonstrated. We examined the relationship between an FH of heavy drinking and both brain shrinkage as measured by the ratio of brain volumes to intracranial volume (ICV) as well as maximal brain growth as measured by ICV in early-onset and late-onset alcoholics. METHODS: With T1-weighted resonance imaging, we measured ICV, brain volume, and white and gray matter volume in adult treatment-seeking late-onset and early-onset alcoholics with either a positive or a negative FH of heavy alcohol use, and in healthy control subjects. We also calculated brain shrinkage using a ratio of soft tissue volumes to ICV. RESULTS: The FH positive alcoholic patients had significantly smaller ICVs than FH negative patients, suggesting smaller premorbid brain growth. Brain shrinkage did not correlate with FH. Late-onset alcoholics showed a greater difference in ICV between FH positive and FH negative patients than early-onset alcoholics. Late-onset FH positive patients also had significantly lower IQ scores than late-onset FH negative patients, and IQ scores were correlated with ICV. CONCLUSIONS: These data provide evidence that parental alcohol use might increase risk for alcoholism in offspring in part by a genetic and/or environmental effect that might be related to reduced brain growth.  相似文献   
72.
The danger management strategies of low‐income African American women who live in a public housing community characterized by chronic violence are examined. Based on qualitative interviews with 18 single mothers, we explored the violent community dangers with which women contend, the nature of this violence, the strategies used to deal with community violence, and their benefits and costs to family and community life. Findings show that multiple types of violence characterized life in the community and that this violence has specific physical locations, a particular set of actors, and a temporal rhythm. Women's responses to violence were nonconfrontational and family focused in nature. These efforts were effective in keeping women and their children safe, but did not reduce the prevalence of violence.  相似文献   
73.
74.
关于医学生外科临床实习质量的探讨   总被引:2,自引:0,他引:2  
外科是一门实践性很强的学科,如何培养实用型医学人才是摆在我们面前的首要问题。本文分析了外科临床实习中存在的问题,并提出一些应对措施。  相似文献   
75.
Objective   This study evaluated the Impact on Sibling scale, a six-item measure of parents' perception of the effects of a child's illness on healthy siblings.
Methods   Participants were 122 parents of a child with chronic illness, developmental disability, or autism spectrum disorder, and a well sibling aged 4–13 years. Parents completed the Impact on Sibling scale and the Child Behavior Checklist about the sibling, and completed the revised Impact on Family scale and the Brief Symptom Inventory about themselves.
Results   The Impact on Sibling score was correlated with measures of sibling, parent and family functioning. The internal consistency of the Impact on Sibling scale was higher for families with children with chronic illness compared with the other two diagnostic groups.
Conclusion   The Impact on Sibling scale is a brief set of items that can help identify siblings who are negatively affected by a brother/sister's illness. Findings support further research on the Impact on Sibling scale, particularly with families of children with chronic illnesses.  相似文献   
76.
Purpose  The present investigation looks in detail at the causes and types of health incidents reported by 6,300 mainly smallholder agrochemical users in 24 countries during 2005 and 2006. Methods  The investigation is based on a questionnaire survey of knowledge, attitude and practice that concentrated on the sequence of events from purchasing the pesticide to disposal. Information was also collected about health problems experienced while using agrochemicals. The survey targeted mainly smallholder knapsack spray operators who were expected to be at a highest risk of exposure. Results  In the 12 months prior to interview, 1.2% of users reported an agrochemical-related incident that required hospital treatment, 5.8% reported an incident requiring at least trained medical treatment but not hospitalisation and 19.8% reported only a minor sign or symptom. Users who had experienced an incident involving agricultural equipment were 3.38 (95% CI 2.29–4.99) times more likely to experience an agrochemical-related health incident, but confident users who felt that their use of personal protective equipment while spraying was best practice were 0.60 (95% CI 0.44–0.84) times less likely to experience such an incident. Over 80% of product-related incidents were caused by insecticides and the incidence rate per spraying time for incidents linked to insecticides was significantly higher than that for fungicides or herbicides. Headache/dizziness and nausea/vomiting, often smell related, were the most common symptoms reported by users who listed agrochemical products that had caused them health problems (52 and 38% of product mentions, respectively). Conclusions  In most countries, the incidence of serious health effects was low; however, there was a high incidence of minor signs and symptoms in a few countries, especially in Africa. A disproportionate number of incidents occurred during insecticide use relative to the time that they were sprayed. Failure to exercise caution as indicated by whether users had incidents involving agricultural equipment or livestock, and lack of confidence in their practices were the most important predictors of agrochemical-related incidents.  相似文献   
77.
张謇的教育思想十分丰富 ,并且具有鲜明的时代特点。他在江苏南通的教育实践成就卓著 ,极富特色。他较早地提出了教育为地方经济社会发展服务的思想 ,创造了“以实业辅助教育 ,以教育促进实业”的成功模式 ,反映了教育从边缘走向经济中心这一历史发展的趋势。张謇的教育思想与实践在近代中国教育史上有重要地位  相似文献   
78.
Major progress in clinical pain assessment and management has been achieved in the last decade. More effective analgesic drugs and improved techniques for pain management have been introduced. However, medical reports published during the last few years on postoperative pain management (POPM) indicate that moderate or even severe pain is still rather commonly experienced by surgical patients in the early postoperative period and that worst-pain-episodes may occur even in the late postoperative phase. Insufficient relief of postoperative pain seems a more common problem on surgical wards than on a postanaesthesia care unit (PACU). The aims of POPM are to inhibit autonomic trauma-induced nociceptive impulses that may result in functional disturbances of vital organs and thereby affect the incidence of potentially severe complications influencing clinical outcome. Considering that recent studies continue to show sub-optimal pain management despite the availability of effective drugs and analgesic techniques it must be considered essential to identify possible barriers to effective pain management in clinical practice so that necessary improvements in POPM routines can be carried out.  相似文献   
79.
Against the theoretical background of the effort–recovery model and the action regulation theory, the author presents a cross‐sectional questionnaire study testing hypotheses about the relationship between work‐related time pressure, cognitive and emotional irritation, work–family conflict and psychosomatic complaints. Subjects were 576 female home care nurses. Results of a path analysis show that the relation of time pressure and psychosomatic complaints is partially mediated by experiencing a work–family conflict; also the relation of time pressure and work–family conflict is partially mediated by cognitive and emotional irritation. It is argued that cognitive and emotional irritation are fruitful concepts for a more comprehensive understanding of the relationship between work stressors and the development of strain‐based work–family conflict. Implications for the prevention of work–family conflict are outlined. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
80.
保守氨基酸残基在生物进化过程中具有较强的稳定性,一般不会发生太大的变化;生物信息学认为:氨基酸序列决定蛋白质结构,蛋白质结构决定蛋白质功能。因此,作者基于氨基酸的生化特性、几何特性和动态特性描述了一个新颖的算法去发现蛋白酶家族中的保守氨基酸残基,而保守氨基酸残基将对蛋白质的结构和功能的研究具有重要的意义。  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