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   1525471篇
  免费   121702篇
  国内免费   3426篇
耳鼻咽喉   20344篇
儿科学   50689篇
妇产科学   43867篇
基础医学   218485篇
口腔科学   41675篇
临床医学   135758篇
内科学   305058篇
皮肤病学   36669篇
神经病学   128875篇
特种医学   58907篇
外国民族医学   464篇
外科学   228077篇
综合类   33256篇
现状与发展   3篇
一般理论   522篇
预防医学   116617篇
眼科学   34068篇
药学   106764篇
  1篇
中国医学   3527篇
肿瘤学   86973篇
  2021年   11919篇
  2019年   12883篇
  2018年   19132篇
  2017年   14838篇
  2016年   17034篇
  2015年   18378篇
  2014年   25154篇
  2013年   38150篇
  2012年   51426篇
  2011年   54774篇
  2010年   31990篇
  2009年   29532篇
  2008年   51285篇
  2007年   54242篇
  2006年   54505篇
  2005年   52950篇
  2004年   50379篇
  2003年   48360篇
  2002年   46821篇
  2001年   76860篇
  2000年   79476篇
  1999年   64388篇
  1998年   18215篇
  1997年   16411篇
  1996年   16360篇
  1995年   15448篇
  1994年   14028篇
  1993年   13174篇
  1992年   46428篇
  1991年   43984篇
  1990年   41978篇
  1989年   40056篇
  1988年   36613篇
  1987年   35847篇
  1986年   33280篇
  1985年   31896篇
  1984年   24405篇
  1983年   20527篇
  1982年   12746篇
  1981年   11285篇
  1979年   21145篇
  1978年   14993篇
  1977年   12527篇
  1976年   11741篇
  1975年   12012篇
  1974年   14365篇
  1973年   13832篇
  1972年   12886篇
  1971年   11753篇
  1970年   11168篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  相似文献   

22.
23.
BackgroundThe aim of this study was to estimate the prevalence of dental prosthetic treatment and to investigate the demographic, social, economic and medical factors associated with the use of fixed and removable dentures in a representative sample of adults living in France.MethodsThe data were obtained from the 2002–2003 Decennial Health Survey, a cross-sectional study of a representative sample of the population living in France, which included 29,679 adults. Information was collected by interview. The variables collected were fixed denture, removable denture, age, gender, number of children, area of residence, nationality, educational attainment, family social status, employment status, annual household income per capita, supplementary insurance, chronic disease, eyesight problems/glasses, hearing problems/hearing aids. Multinomial logistic regression models were used to study the relationship between prosthetic treatment and demographic, socioeconomic and medical characteristics unadjusted, adjusted for age and adjusted for all the characteristics.ResultsThe prevalence of prosthetic treatment was 34.6% (95% confidence interval (CI): [34.1; 35.2]) for fixed prosthetic dentures and 13.8% (95% CI: [13.4; 14.2]) for removable prosthetic dentures. We showed a gradient between educational attainment and removable dentures; the odds ratio adjusted for all the variables (aOR) associated with no or primary education compared to post-secondary education was 2.56; 95% CI: [2.09; 3.13]. When annual household income per capita was low, subjects were less likely to report fixed dentures (aOR = 0.68; 95% CI: [0.62; 0.75]) than those with high annual household income per capita. Individuals without insurance less often reported fixed dentures than those with private insurance. Those reporting chronic disease were less likely to report fixed dentures (aOR = 0.87; 95% CI: [0.79; 0.95]) but more likely to report removable dentures (aOR = 1.29; 95% CI: [1.17; 1.43]) than those without chronic disease.ConclusionThis study reveals social, economic and medical inequalities in fixed and removable prosthetic treatment among adults in France.  相似文献   
24.
25.
ABSTRACT

This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities.  相似文献   
26.
27.
28.
29.
30.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  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