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   2869364篇
  免费   211165篇
  国内免费   6409篇
耳鼻咽喉   38199篇
儿科学   95818篇
妇产科学   80060篇
基础医学   405356篇
口腔科学   82072篇
临床医学   258545篇
内科学   559682篇
皮肤病学   66099篇
神经病学   226156篇
特种医学   111035篇
外国民族医学   774篇
外科学   432567篇
综合类   64780篇
现状与发展   7篇
一般理论   949篇
预防医学   221511篇
眼科学   67390篇
药学   207047篇
  9篇
中国医学   6691篇
肿瘤学   162191篇
  2019年   22000篇
  2018年   34343篇
  2017年   27080篇
  2016年   29099篇
  2015年   33744篇
  2014年   45272篇
  2013年   64841篇
  2012年   92965篇
  2011年   93983篇
  2010年   54985篇
  2009年   53222篇
  2008年   85183篇
  2007年   90896篇
  2006年   91935篇
  2005年   95410篇
  2004年   93533篇
  2003年   85884篇
  2002年   78934篇
  2001年   140882篇
  2000年   143102篇
  1999年   120735篇
  1998年   32659篇
  1997年   28692篇
  1996年   28780篇
  1995年   27581篇
  1994年   25153篇
  1993年   23409篇
  1992年   93841篇
  1991年   90449篇
  1990年   87485篇
  1989年   84007篇
  1988年   77028篇
  1987年   75259篇
  1986年   70650篇
  1985年   67088篇
  1984年   49854篇
  1983年   42115篇
  1982年   24091篇
  1979年   44587篇
  1978年   30854篇
  1977年   25820篇
  1976年   24174篇
  1975年   25839篇
  1974年   31366篇
  1973年   30065篇
  1972年   28160篇
  1971年   25998篇
  1970年   24490篇
  1969年   22972篇
  1968年   21519篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.

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   
102.
103.
104.
105.
106.
107.
108.
109.
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
110.
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