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   1847100篇
  免费   136661篇
  国内免费   3746篇
耳鼻咽喉   24228篇
儿科学   60457篇
妇产科学   51032篇
基础医学   279847篇
口腔科学   48189篇
临床医学   167678篇
内科学   358801篇
皮肤病学   42819篇
神经病学   143185篇
特种医学   70095篇
外国民族医学   512篇
外科学   275688篇
综合类   38888篇
现状与发展   5篇
一般理论   586篇
预防医学   143076篇
眼科学   41853篇
药学   133639篇
  2篇
中国医学   4184篇
肿瘤学   102743篇
  2019年   14636篇
  2018年   20867篇
  2017年   15711篇
  2016年   18022篇
  2015年   20109篇
  2014年   28016篇
  2013年   41522篇
  2012年   57515篇
  2011年   61881篇
  2010年   36160篇
  2009年   33876篇
  2008年   56930篇
  2007年   60932篇
  2006年   61042篇
  2005年   59069篇
  2004年   56760篇
  2003年   54270篇
  2002年   52416篇
  2001年   89379篇
  2000年   91399篇
  1999年   75654篇
  1998年   21148篇
  1997年   18852篇
  1996年   18981篇
  1995年   18058篇
  1994年   16317篇
  1993年   15546篇
  1992年   57308篇
  1991年   56606篇
  1990年   54856篇
  1989年   52812篇
  1988年   48465篇
  1987年   47598篇
  1986年   44266篇
  1985年   42276篇
  1984年   31985篇
  1983年   26991篇
  1982年   15855篇
  1979年   28639篇
  1978年   20264篇
  1977年   16691篇
  1976年   16357篇
  1975年   17684篇
  1974年   20795篇
  1973年   20066篇
  1972年   18704篇
  1971年   17297篇
  1970年   16330篇
  1969年   15070篇
  1968年   14312篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
62.
63.
AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXsmiR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXsmiR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.  相似文献   
64.
65.

Researchers have highlighted numerous sociocultural factors that have been shown to underpin human appearance enhancement practices, including the influence of peers, family, the media, and sexual objectification. Fewer scholars have approached appearance enhancement from an evolutionary perspective or considered how sociocultural factors interact with evolved psychology to produce appearance enhancement behavior. Following others, we argue that evidence from the field of evolutionary psychology can complement existing sociocultural models by yielding unique insight into the historical and cross-cultural ubiquity of competition over aspects of physical appearance to embody what is desired by potential mates. An evolutionary lens can help to make sense of reliable sex and individual differences that impact appearance enhancement, as well as the context-dependent nature of putative adaptations that function to increase physical attractiveness. In the current review, appearance enhancement is described as a self-promotion strategy used to enhance reproductive success by rendering oneself more attractive than rivals to mates, thereby increasing one’s mate value. The varied ways in which humans enhance their appearance are described, as well as the divergent tactics used by women and men to augment their appearance, which correspond to the preferences of opposite-sex mates in a heterosexual context. Evolutionarily relevant individual differences and contextual factors that vary predictably with appearance enhancement behavior are also discussed. The complementarity of sociocultural and evolutionary perspectives is emphasized and recommended avenues for future interdisciplinary research are provided for scholars interested in studying appearance enhancement behavior.

  相似文献   
66.
67.
68.
69.
70.
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