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   2642790篇
  免费   214811篇
  国内免费   4943篇
耳鼻咽喉   36089篇
儿科学   88094篇
妇产科学   75104篇
基础医学   375366篇
口腔科学   75922篇
临床医学   237447篇
内科学   518087篇
皮肤病学   58910篇
神经病学   216659篇
特种医学   103691篇
外国民族医学   897篇
外科学   398073篇
综合类   64947篇
现状与发展   6篇
一般理论   984篇
预防医学   207785篇
眼科学   61348篇
药学   193749篇
  2篇
中国医学   5505篇
肿瘤学   143879篇
  2018年   28084篇
  2017年   21489篇
  2016年   24177篇
  2015年   27455篇
  2014年   38557篇
  2013年   58029篇
  2012年   78521篇
  2011年   82903篇
  2010年   48891篇
  2009年   46725篇
  2008年   77779篇
  2007年   82145篇
  2006年   83318篇
  2005年   80772篇
  2004年   78294篇
  2003年   74808篇
  2002年   72642篇
  2001年   126117篇
  2000年   129709篇
  1999年   109035篇
  1998年   30604篇
  1997年   27683篇
  1996年   27634篇
  1995年   26562篇
  1994年   24571篇
  1993年   23189篇
  1992年   86360篇
  1991年   83275篇
  1990年   80724篇
  1989年   77583篇
  1988年   71913篇
  1987年   70586篇
  1986年   66705篇
  1985年   63954篇
  1984年   48338篇
  1983年   41379篇
  1982年   24768篇
  1981年   22072篇
  1979年   44793篇
  1978年   31292篇
  1977年   26333篇
  1976年   24802篇
  1975年   25772篇
  1974年   31493篇
  1973年   30416篇
  1972年   28085篇
  1971年   26149篇
  1970年   24442篇
  1969年   22764篇
  1968年   21068篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
93.

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   
94.
95.
96.
97.
98.
99.
100.
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