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   17849篇
  免费   1297篇
  国内免费   67篇
耳鼻咽喉   128篇
儿科学   548篇
妇产科学   537篇
基础医学   2478篇
口腔科学   291篇
临床医学   2041篇
内科学   3376篇
皮肤病学   478篇
神经病学   1801篇
特种医学   494篇
外科学   1879篇
综合类   115篇
一般理论   7篇
预防医学   1952篇
眼科学   423篇
药学   1054篇
  1篇
中国医学   19篇
肿瘤学   1591篇
  2024年   25篇
  2023年   234篇
  2022年   355篇
  2021年   686篇
  2020年   465篇
  2019年   583篇
  2018年   759篇
  2017年   510篇
  2016年   609篇
  2015年   671篇
  2014年   825篇
  2013年   1111篇
  2012年   1631篇
  2011年   1601篇
  2010年   811篇
  2009年   760篇
  2008年   1163篇
  2007年   1176篇
  2006年   1028篇
  2005年   948篇
  2004年   826篇
  2003年   753篇
  2002年   714篇
  2001年   89篇
  2000年   50篇
  1999年   76篇
  1998年   108篇
  1997年   101篇
  1996年   62篇
  1995年   52篇
  1994年   49篇
  1993年   56篇
  1992年   39篇
  1991年   24篇
  1990年   21篇
  1989年   20篇
  1988年   7篇
  1987年   9篇
  1986年   18篇
  1985年   16篇
  1984年   18篇
  1983年   16篇
  1982年   23篇
  1981年   12篇
  1980年   10篇
  1979年   8篇
  1978年   10篇
  1977年   9篇
  1971年   8篇
  1967年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Infections are an uncommon cause of chronic diarrhoea. Parasites are most likely, including protozoa like giardia, cryptosporidia and cyclospora. Bacteria are unlikely to cause chronic diarrhoea in immunocompetent individuals with the possible exception of Yersinia, Plesiomonas and Aeromonas. Infectious diarrhoea can trigger other causes of chronic diarrhoea, including inflammatory bowel disease, irritable bowel syndrome and “Brainerd-type” diarrhoea. A thorough evaluation should detect most infections causing chronic diarrhoea.  相似文献   
102.
Environmental assessment and exposure reduction are a set of diagnostic and treatment techniques that work in tandem with the traditional medical approach by reducing a patient??s exposure to adverse environmental conditions as part of medical care. Assessment involves identifying the specific exposures to which a patient is sensitive and locating the corresponding contaminants in the patient??s environment. This provides a more complete diagnostic evaluation of a patient??s problem than could be obtained merely by examining the patient alone. Exposure reduction involves reducing the identified triggers to levels that are below thresholds that are associated with increased risk of sensitization and disease morbidity. Assessment of an environment for contaminants focuses on a chain of factors that include contaminant sources such as cockroaches, rodents, dust mites and fungi that excrete contaminants into an environment, facilitative factors such as moisture, food, water and shelter that help sources to thrive, and reservoirs where contaminants can accumulate prior to subsequent transport to occupants. By using this model to guide environmental assessments and their corresponding interventions, the root cause of health problems can be addressed, leading to improved quality of life for patients and reduced need for chronic medications.  相似文献   
103.
104.
We describe Guatemalan birth attendants’ identification of vulnerable newborns, their evaluation of gestational age and anthropometry, and the validity of the Capurro and New Ballard newborn gestational age assessment methods. We interviewed 49 birth attendants and trained 10 of these women to assess 63 newborns. The Capurro and Ballard methods were correlated (Spearman rho = .75, p < .001) and showed agreement (Bland-Altman plot, difference and bias, ?0.33 ± 1.3 weeks). Prematurity was estimated at 27% (Ballard) and 24% (Capurro); low birth weight (LBW) was 30%. Capurro provided a simplified, equivalent estimate of gestational age compared with New Ballard that could be used by birth attendants.  相似文献   
105.
We surveyed cognitively normal teens with and without chronic illness regarding the perceived physical and social impact of various chronic diseases including asthma.

The overall physical impact of asthma was perceived equivalently to diabetes and arthritis, but less than epilepsy, Down's syndrome, leukemia, and human immunodeficiency virus infection. However, asthma was rated to more commonly cause physical disability (p < 0.001) and restrict activities (p < 0.0005). The social impact of asthma was perceived equivalently to diabetes, but more favorably than the other chronic diseases surveyed. Specifically, teens with asthma were perceived as having fewer behavior problems, being more honest, popular, and fun to be around, but less adept at sports. Only 6 of 149 (4%) teens surveyed expressed any degree of reluctance to befriend peers with asthma.  相似文献   
106.
The importance of aeroallergens as triggers for asthma is well recognized, but the relationship between asthma severity and atopic profiles in childhood has not been elucidated. This study assessed the relationship of allergen sensitization to asthma severity in a study of 114 asthmatic children followed for 8 weeks in three Southern California areas. Increased controller medication and β-agonist use were positively associated with number of positive skin tests and allergy to mold and pollens. Mold was associated with increased asthma symptoms. Degree of atopy and reactivity to mold and pollens plays a significant role in asthma severity in asthmatic children.  相似文献   
107.
108.
109.
110.
For traditionally underserved populations, the Web can potentially unlock resources that could fundamentally improve health and wellbeing. However, there are many barriers to using Web-based content. While physical access issues are well documented, there is little understanding of how nonmainstream populations use or will use the Web. Based on an ethnographic study of a group of low-literate adults, we have identified specific navigational and content issues that present barriers to this population. We discuss preliminary assumptions that can be used to inform the development of Web tools for this target audience, and directions for future applied research.  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