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   45037篇
  免费   5108篇
  国内免费   74篇
耳鼻咽喉   323篇
儿科学   1318篇
妇产科学   898篇
基础医学   6203篇
口腔科学   1229篇
临床医学   5664篇
内科学   8875篇
皮肤病学   696篇
神经病学   3613篇
特种医学   1987篇
外国民族医学   1篇
外科学   5943篇
综合类   1192篇
一般理论   26篇
预防医学   5236篇
眼科学   843篇
药学   3747篇
  1篇
中国医学   77篇
肿瘤学   2347篇
  2021年   586篇
  2020年   356篇
  2019年   642篇
  2018年   734篇
  2017年   522篇
  2016年   598篇
  2015年   708篇
  2014年   940篇
  2013年   1362篇
  2012年   1993篇
  2011年   1999篇
  2010年   1122篇
  2009年   1097篇
  2008年   1898篇
  2007年   2006篇
  2006年   1971篇
  2005年   1886篇
  2004年   1737篇
  2003年   1662篇
  2002年   1617篇
  2001年   1542篇
  2000年   1468篇
  1999年   1464篇
  1998年   604篇
  1997年   479篇
  1996年   481篇
  1995年   499篇
  1994年   439篇
  1993年   498篇
  1992年   1210篇
  1991年   1127篇
  1990年   1080篇
  1989年   1055篇
  1988年   988篇
  1987年   997篇
  1986年   997篇
  1985年   915篇
  1984年   778篇
  1983年   645篇
  1982年   430篇
  1981年   360篇
  1980年   351篇
  1979年   587篇
  1978年   491篇
  1977年   374篇
  1976年   382篇
  1974年   432篇
  1973年   400篇
  1972年   386篇
  1969年   358篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Burkitt lymphoma (BL) occurs at all ages, but the patterns of Epstein–Barr virus (EBV) positivity in relation to human immunodeficiency virus (HIV), immunoprofiles and age have not been fully explored. BL tissues from residual tissue repositories, and two academic centers in the United States were examined by expert hematopathologists for morphology, immunohistochemistry, MYC rearrangement, EBV‐encoded RNA (EBER), and diagnosed according to the 2008 WHO lymphoma classification. Analysis was done using frequency tables, Chi‐squared statistics, and Student's t‐test. Of 117 cases examined, 91 were confirmed as BL. The age distribution was 26%, 15%, 19%, and 29% for 0–19, 20–34, 35–59, 60+ years, and missing in 11%. MYC rearrangement was found in 89% and EBER positivity in 29% of 82 cases with results. EBER positivity varied with age (from 13% in age group 0–19 to 55% in age group 20–34, and fell to 25% in age group 60+ years, p = 0.08); with race (56% in Blacks/Hispanics vs 21% in Whites/Asians/Pacific Islanders, p = 0.006); and by HIV status (64% in HIV positive vs 22% in HIV negative cases, p = 0.03). EBER positivity was demonstrated in about one‐third of tumors and it was strongly associated with race and HIV status, and marginally with age‐group.  相似文献   
992.
993.
Abstract

The COVID-19 pandemic is a worldwide historical event that will continue to affect nearly every aspect of ordinary life, including affecting our economic, political, and healthcare eco-systems. An effective pandemic response demands a coordinated and integrated response across community healthcare stakeholders, including Public Health and Emergency Management Officials. EMS systems are in a unique position and perform an essential role on the frontlines of COVID-19, including facilitating coordination of response efforts to COVID-19 within their communities while supporting public health mitigation efforts to slow the spread of the SARS-CoV-2. EMS physicians serve their communities at a unique intersection as clinical leaders, population health experts, and advocates. This paper examines and recommends crucial roles for EMS physician leaders as communities work together in pandemic response.  相似文献   
994.
Mycosis fungoides (MF) is an indolent, uncommon, non-Hodgkin T-cell lymphoma of the skin. It classically presents with patches, plaques, and tumors and may rarely show spread to internal organs or bone marrow. Up to 7.5% of MF patients may be diagnosed with a second malignancy. Intravascular large B-cell lymphoma (IVLBCL) is an exceedingly rare non-Hodgkin B-cell lymphoma characterized by predominant growth of large neoplastic cells in the lumina of blood vessels. This case presents with an unusual confluence of two rare diagnoses, MF and IVLBCL, made more remarkable by the presence of both diagnoses on a single skin biopsy sample.  相似文献   
995.
Objective:The purpose of this study was to provide an updated profile of gambling and problem gambling in Canada and to examine how the rates and pattern of participation compare to 2002.Method:An assessment of gambling and problem gambling was included in the 2018 Canadian Community Health Survey and administered to 24,982 individuals aged 15 and older. The present analyses selected for adults (18+).Results:A total of 66.2% of people reported engaging in some type of gambling in 2018, primarily lottery and/or raffle tickets, the only type in which the majority of Canadians participate. There are some significant interprovincial differences, with perhaps the most important one being the higher rate of electronic gambling machine (EGM) participation in Manitoba and Saskatchewan. The overall pattern of gambling in 2018 is very similar to 2002, although participation is generally much lower in 2018, particularly for EGMs and bingo. Only 0.6% of the population were identified as problem gamblers in 2018, with an additional 2.7% being at-risk gamblers. There is no significant interprovincial variation in problem gambling rates. The interprovincial pattern of problem gambling in 2018 is also very similar to what was found in 2002 with the main difference being a 45% decrease in the overall prevalence of problem gambling.Conclusions:Gambling and problem gambling have both decreased in Canada from 2002 to 2018 although the provincial patterns are quite similar between the 2 time periods. Several mechanisms have likely collectively contributed to these declines. Decreases have also been reported in several other Western countries in recent years and have occurred despite the expansion of legal gambling opportunities, suggesting a degree of inoculation or adaptation in large parts of the population.  相似文献   
996.
997.
998.
999.
1000.
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