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   27027篇
  免费   2275篇
  国内免费   69篇
耳鼻咽喉   364篇
儿科学   994篇
妇产科学   680篇
基础医学   3376篇
口腔科学   437篇
临床医学   3092篇
内科学   4988篇
皮肤病学   412篇
神经病学   3204篇
特种医学   583篇
外科学   2927篇
综合类   379篇
一般理论   13篇
预防医学   3349篇
眼科学   439篇
药学   1835篇
  1篇
中国医学   35篇
肿瘤学   2263篇
  2023年   223篇
  2022年   383篇
  2021年   771篇
  2020年   513篇
  2019年   774篇
  2018年   936篇
  2017年   667篇
  2016年   656篇
  2015年   737篇
  2014年   992篇
  2013年   1417篇
  2012年   1965篇
  2011年   2132篇
  2010年   1109篇
  2009年   954篇
  2008年   1537篇
  2007年   1656篇
  2006年   1462篇
  2005年   1438篇
  2004年   1343篇
  2003年   1201篇
  2002年   1079篇
  2001年   289篇
  2000年   273篇
  1999年   268篇
  1998年   220篇
  1997年   191篇
  1996年   180篇
  1995年   139篇
  1994年   133篇
  1993年   134篇
  1992年   207篇
  1991年   195篇
  1990年   173篇
  1989年   155篇
  1988年   154篇
  1987年   169篇
  1986年   147篇
  1985年   165篇
  1984年   183篇
  1983年   159篇
  1982年   159篇
  1981年   152篇
  1980年   118篇
  1979年   119篇
  1978年   142篇
  1977年   101篇
  1976年   111篇
  1975年   112篇
  1974年   95篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
The recent controversy surrounding the use of the reflex anal dilatation (RAD) sign in cases of suspected sexual abuse is a general illustration of the difficulties clinicians face in determining which symptoms, signs or laboratory tests to use in their daily practice. The evidence required fully to evaluate RAD is incomplete. The specificity in particular is uncertain. Sufficient evidence is, however, available to permit a quantitative examination of the test's performance under various circumstances. Our analysis suggests that, at the prevalence of anal abuse reported in one large series of children referred to paediatricians with suspected sexual abuse (13%), only if the specificity of the test is 99% or greater, may the positive predictive value of RAD be as high as 90%. At the likely prevalence of anal abuse in the general child population (less than 0.5%), however, an even higher specificity of 99.99% would be necessary to achieve a similar positive predictive value.  相似文献   
53.
B Harvey 《Pediatrics》1991,87(1):1-6
Although the federal government has long had an interest in the health of children, action in support of this interest has been limited, fragmented, and inequitable. While health problems are increasing and becoming more complex and while policy leaders, business groups, and the public recognize that action is necessary, no response has been forthcoming. Development of a policy with measurable goals is needed. Resources must be allocated and data collected to periodically evaluate progress toward goals and to appropriately redirect resources.  相似文献   
54.
55.
We examined the relationship between testosterone levels, violent dreams, and REM sleep behavior disorder (RBD) in 31 men with Parkinson's disease (PD): 12 with clinical RBD and 19 without. All PD patients with clinical RBD experienced violent dreams, but none of the 19 non-RBD patients reported violent dreams. While dream content appears to be more aggressive in PD patients with clinical RBD, the presence of violent dreams or clinical RBD is not associated with testosterone levels in men with PD.  相似文献   
56.
57.
Two enzyme immunoassays (EIAs) detecting Chlamydia trachomatis from endocervical swabs, Syva MicroTrak (MT) and Abbott Chlamydiazyme (CZ), were compared with a tissue culture (TC) standard. Initially, 8% (100 of 1250) of specimens were TC positive, yielding sensitivities of 94% (94 of 100) for MT and 79% (79 of 100) for CZ with identical 98% specificities (1129 of 1150 for MT and 1130 of 1150 for CZ). Discrepant specimens were retested by both EIAs and assayed for elementary bodies (EBs) by a fluorescent antibody test. After discrepancy analysis, 9.5% (118) of 1240 patients were either TC or EB positive, yielding sensitivities of 94.1% for MT (111 of 118) and 79.7% for CZ (94 of 118) with identical specificities of 100% (1122 of 1122). These results indicate that the MT is significantly more sensitive (p less than 0.05, McNemar test) than CZ in detecting C. trachomatis from endocervical swabs.  相似文献   
58.
This study investigated relationships between child/parent dissatisfaction with child facial appearance and the self-concept/social competence of 8- to 15-year-old children with (N = 34) and without (N = 34) oral clefts. Children in both groups had normative psychosocial adjustment, but also reported moderate dissatisfaction with facial appearance. Cleft group parents were more likely to agree with their child's dissatisfaction. When cleft group parents were more dissatisfied with child facial appearance, their children reported better quality of life. Results suggest that parents of children with clefts reporting greater dissatisfaction may respond in positive ways that enhance quality of life.  相似文献   
59.
The American Board of Nursing Specialties (ABNS) conducted a survey to determine the value professional nurses place on nursing certification as well as barriers to certification. This article presents an overview of the survey results in general and specifically the views of nephrology nurse participants.  相似文献   
60.
OBJECTIVES: Percentage of deliveries assisted by a skilled birth attendant (SBA) has become a proxy indicator for reducing maternal mortality in developing countries, but there is little data on SBA competence. Our objective was to evaluate the competence of health professionals who typically attend hospital and clinic-based births in Benin, Ecuador, Jamaica, and Rwanda. Methods: We measured competence against World Health Organization's (WHO) Integrated Management of Pregnancy and Childbirth guidelines. To evaluate knowledge, we used a 49-question multiple-choice test covering seven clinical areas. To evaluate skill, we had participants perform five different procedures on anatomical models. The 166 participants came from facilities at all levels of care in their respective countries. Results: On average, providers answered 55.8% of the knowledge questions correctly and performed 48.2% of the skills steps correctly. Scores differed somewhat by country, provider type, and subtopic. Conclusion: A wide gap exists between current evidence-based standards and current levels of provider competence.  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