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   45198篇
  免费   2538篇
  国内免费   185篇
耳鼻咽喉   612篇
儿科学   1144篇
妇产科学   965篇
基础医学   6079篇
口腔科学   2617篇
临床医学   3130篇
内科学   10571篇
皮肤病学   1417篇
神经病学   4271篇
特种医学   1032篇
外国民族医学   1篇
外科学   5020篇
综合类   258篇
现状与发展   1篇
一般理论   10篇
预防医学   4307篇
眼科学   1033篇
药学   3263篇
中国医学   286篇
肿瘤学   1904篇
  2023年   411篇
  2022年   924篇
  2021年   1772篇
  2020年   939篇
  2019年   1468篇
  2018年   1815篇
  2017年   1148篇
  2016年   1200篇
  2015年   1414篇
  2014年   1961篇
  2013年   2396篇
  2012年   3583篇
  2011年   3688篇
  2010年   2028篇
  2009年   1674篇
  2008年   2749篇
  2007年   2664篇
  2006年   2418篇
  2005年   2272篇
  2004年   2102篇
  2003年   1772篇
  2002年   1623篇
  2001年   826篇
  2000年   781篇
  1999年   689篇
  1998年   262篇
  1997年   183篇
  1996年   168篇
  1995年   149篇
  1994年   128篇
  1993年   112篇
  1992年   265篇
  1991年   255篇
  1990年   223篇
  1989年   173篇
  1988年   181篇
  1987年   159篇
  1986年   126篇
  1985年   118篇
  1984年   108篇
  1983年   100篇
  1982年   41篇
  1981年   45篇
  1980年   45篇
  1979年   77篇
  1978年   61篇
  1972年   41篇
  1971年   51篇
  1969年   40篇
  1967年   58篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
16.
17.
18.
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices  相似文献   
19.
In low and middle-income countries mammographic breast cancer screening is prohibitively expensive and a cheaper alternative option is to use ultrasound as the primary screening test. In 2009, China launched a breast cancer screening programme for rural women aged 35–64 years with clinical breast examination coupled with ultrasound as the primary tool. Our study aimed to analyse the cost-effectiveness of breast screening compared to no screening among Chinese rural women. We developed a Markov model to estimate the lifetime costs and effects for rural women aged 35 years from a societal perspective. Asymptomatic women in the intervention arm were screened every 3 years before age 64 years. Breast cancer in the non-screening arm can only be diagnosed on presentation of symptoms. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. Compared to no screening, breast cancer screening cost $186.7 more and led to a loss of 0.20 quality-adjusted life years (QALYs). Breast screening was more expensive and did harm to health among rural women with an incremental cost-effectiveness ratio (ICER) of $-916/QALY. The sensitivity analysis identified utility loss from false positives as the factor that most influenced the results, but this did not affect the conclusions. In a rural setting with such low breast cancer incidence, screening for asymptomatic disease is not cost-effective with current screening tools. Priority should be given to ensure that symptomatic women have proper access to diagnosis and treatment at an early stage as this will lead to mortality reductions without the usual screening harms.  相似文献   
20.
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