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   1422087篇
  免费   117161篇
  国内免费   3404篇
耳鼻咽喉   18471篇
儿科学   46929篇
妇产科学   41265篇
基础医学   202532篇
口腔科学   38173篇
临床医学   127492篇
内科学   286918篇
皮肤病学   33480篇
神经病学   118529篇
特种医学   54277篇
外国民族医学   464篇
外科学   212420篇
综合类   33120篇
现状与发展   3篇
一般理论   517篇
预防医学   111441篇
眼科学   31865篇
药学   99481篇
  2篇
中国医学   3379篇
肿瘤学   81894篇
  2021年   11013篇
  2019年   11866篇
  2018年   16762篇
  2017年   12841篇
  2016年   14451篇
  2015年   16209篇
  2014年   22888篇
  2013年   33871篇
  2012年   46060篇
  2011年   48734篇
  2010年   28570篇
  2009年   27421篇
  2008年   45007篇
  2007年   47546篇
  2006年   48076篇
  2005年   46550篇
  2004年   44384篇
  2003年   42365篇
  2002年   40846篇
  2001年   73348篇
  2000年   74945篇
  1999年   61905篇
  1998年   17194篇
  1997年   15615篇
  1996年   15757篇
  1995年   14920篇
  1994年   13508篇
  1993年   12714篇
  1992年   46084篇
  1991年   43701篇
  1990年   41741篇
  1989年   39748篇
  1988年   36415篇
  1987年   35544篇
  1986年   33047篇
  1985年   31443篇
  1984年   23967篇
  1983年   20152篇
  1982年   12320篇
  1981年   10888篇
  1979年   20840篇
  1978年   14692篇
  1977年   12182篇
  1976年   11460篇
  1975年   11702篇
  1974年   14092篇
  1973年   13632篇
  1972年   12720篇
  1971年   11550篇
  1970年   10964篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
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   
52.
53.
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   
54.
55.

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   
56.
57.
58.
59.
60.
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