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   1215篇
  免费   68篇
  国内免费   4篇
耳鼻咽喉   19篇
儿科学   20篇
妇产科学   43篇
基础医学   227篇
口腔科学   38篇
临床医学   59篇
内科学   235篇
皮肤病学   17篇
神经病学   64篇
特种医学   21篇
外科学   180篇
综合类   18篇
一般理论   1篇
预防医学   165篇
眼科学   13篇
药学   104篇
中国医学   15篇
肿瘤学   48篇
  2023年   5篇
  2021年   26篇
  2020年   12篇
  2019年   26篇
  2018年   38篇
  2017年   27篇
  2016年   33篇
  2015年   30篇
  2014年   35篇
  2013年   42篇
  2012年   76篇
  2011年   95篇
  2010年   56篇
  2009年   33篇
  2008年   78篇
  2007年   91篇
  2006年   85篇
  2005年   60篇
  2004年   62篇
  2003年   67篇
  2002年   38篇
  2001年   34篇
  2000年   53篇
  1999年   25篇
  1998年   5篇
  1996年   3篇
  1995年   3篇
  1992年   10篇
  1991年   9篇
  1990年   5篇
  1989年   10篇
  1988年   7篇
  1987年   7篇
  1986年   5篇
  1985年   9篇
  1984年   4篇
  1980年   2篇
  1979年   7篇
  1977年   3篇
  1976年   3篇
  1974年   5篇
  1973年   6篇
  1972年   4篇
  1971年   8篇
  1970年   5篇
  1969年   7篇
  1968年   10篇
  1967年   6篇
  1966年   5篇
  1965年   2篇
排序方式: 共有1287条查询结果,搜索用时 15 毫秒
71.
This longitudinal study examines perceived unmet dental need in a nationally representative probability sample of HIV-infected persons in medical care. A logistic regression analysis modeled the relationship between unmet need and explanatory variables. We estimate that 40% of HIV/AIDS patients report an unmet need associated with being male, being unemployed, injecting drugs, being heterosexual, lacking dental insurance, and having less education. Disparities in unmet need are related to socioeconomic status rather than to disease stage or ethnicity.  相似文献   
72.
73.
74.
75.
Osteoporosis in men was not recognized as a major health problem until recently, and increased research in this area resulted in the approval of alendronate for the treatment of osteoporosis in men at the beginning of this decade. Low bone mineral density (BMD) has been demonstrated to be a strong predictor of fracture in men as it is in women. The causes of osteoporosis in men are variable and can be classified as primary or secondary. The aim of these report is to present the response of BMD in 10 Puerto Rican men with secondary causes of osteoporosis treated with alendronate. A significant increase of BMD in spine, total hip, trochanter and intertrochanteric regions were noted. A non-significant increase in femoral neck was observed.  相似文献   
76.
The purpose of this study was to evaluate exposure conditions and acute health effects in subjects participating in the Prestige oil spill cleanup activities and the association between these and the nature of the work and use of protection devices in the regions of Asturias and Cantabria (Spain). The sample comprised 400 subjects in each region, selected from a random sampling of all persons involved in cleanup activities, stratified by type of worker and number of working days. Data were obtained via a structured questionnaire and included information on specific tasks, number of working days, use of protective materials, and acute health effects. These effects were classified into two broad groups: injuries and toxic effects. Data analysis was performed using complex survey methods. Significant differences between groups were evaluated using Pearson's chi(2) test. Unconditional logistic regression was used to compute odds ratios and 95% confidence intervals. Bird cleaners accounted for the highest prevalence of injuries (19% presented with lesions). Working more than 20 days in highly polluted areas was associated with increased risk of injury in all workers. Occurrence of toxic effects was higher among seamen, possibly due to higher exposure to fuel oil and its components. Toxic effects were more frequent among those working longer than 20 days in highly polluted areas, performing three or more different cleaning activities, having skin contact with fuel oil on head/neck or upper limbs, and eating while in contact with fuel or perceiving disturbing odors. No severe disorders were identified among individuals who performed these tasks. However, potential health impact should be considered when organizing cleanup activities in similar environmental disasters.  相似文献   
77.
78.
79.
80.
OBJECTIVE: To establish the relationship between seroprevalence for antibodies against Trypanosoma cruzi and its relationship with biotic and abiotic factors. MATERIAL AND METHODS: A cross-sectional study was conducted between August 2000 and September 2001. The study population consisted of a simple random sample of 390 volunteers residing in Palmar de Bravo, Puebla, Mexico. Sample and data collection procedures included assaying antibodies against T. cruzi with validated assays, and searching for domestic reservoirs and triatomine bugs. The relationship between biotic and abiotic factors with seropositivity was assessed. Statistical analysis was conducted using Kappa values for diagnostic tests; statistical significance was assessed with 2 x 2 tables, chi-squared test with Yates' correction, Fisher exact test, and odds ratios. RESULTS: The seroprevalence of T. cruzi infection in humans was 4%; in domestic reservoirs (horses, pigs, and dogs) only 10% of canine reservoirs were positive. Vector species recognized were T. borberi and T. pallidipennis, with a Dispersion Area Index and a Colonization Index of 55% and 40%, respectively. The most important risk factors associated with positive serology were altitude (>2,150 and <2,180 meters above sea level), presence of triatomines, age, time of residence, and participation in a social assistance program. CONCLUSIONS: T. cruzi infection was identified in human beings, vectors, and possibly in domestic reservoirs, in communities located over 2,000 meters above sea level.  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