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   1421402篇
  免费   116807篇
  国内免费   3399篇
耳鼻咽喉   18575篇
儿科学   47015篇
妇产科学   41568篇
基础医学   203008篇
口腔科学   37917篇
临床医学   127156篇
内科学   285962篇
皮肤病学   33809篇
神经病学   118313篇
特种医学   54741篇
外国民族医学   472篇
外科学   212733篇
综合类   32833篇
现状与发展   3篇
一般理论   496篇
预防医学   110665篇
眼科学   31816篇
药学   99583篇
  1篇
中国医学   3361篇
肿瘤学   81581篇
  2021年   10880篇
  2019年   11911篇
  2018年   16879篇
  2017年   12913篇
  2016年   14581篇
  2015年   16355篇
  2014年   22973篇
  2013年   33901篇
  2012年   46243篇
  2011年   48813篇
  2010年   28623篇
  2009年   27513篇
  2008年   45042篇
  2007年   47589篇
  2006年   48202篇
  2005年   46651篇
  2004年   44478篇
  2003年   42379篇
  2002年   40859篇
  2001年   73531篇
  2000年   75015篇
  1999年   62008篇
  1998年   17195篇
  1997年   15556篇
  1996年   14671篇
  1995年   14838篇
  1994年   13468篇
  1993年   12644篇
  1992年   46059篇
  1991年   43756篇
  1990年   41781篇
  1989年   39829篇
  1988年   36410篇
  1987年   35643篇
  1986年   33096篇
  1985年   31513篇
  1984年   23988篇
  1983年   20134篇
  1982年   12269篇
  1981年   10828篇
  1979年   20864篇
  1978年   14711篇
  1977年   12180篇
  1976年   11432篇
  1975年   11724篇
  1974年   14117篇
  1973年   13663篇
  1972年   12797篇
  1971年   11628篇
  1970年   11024篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
61.
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