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   2330847篇
  免费   171995篇
  国内免费   5619篇
耳鼻咽喉   30428篇
儿科学   75834篇
妇产科学   64716篇
基础医学   344549篇
口腔科学   65056篇
临床医学   223456篇
内科学   448498篇
皮肤病学   48364篇
神经病学   191545篇
特种医学   84981篇
外国民族医学   603篇
外科学   325585篇
综合类   50454篇
现状与发展   4篇
一般理论   979篇
预防医学   198192篇
眼科学   52142篇
药学   171608篇
  12篇
中国医学   4785篇
肿瘤学   126670篇
  2019年   19182篇
  2018年   26313篇
  2017年   20060篇
  2016年   21779篇
  2015年   24981篇
  2014年   34685篇
  2013年   53565篇
  2012年   73148篇
  2011年   77881篇
  2010年   45256篇
  2009年   42564篇
  2008年   72133篇
  2007年   76796篇
  2006年   76526篇
  2005年   74425篇
  2004年   71284篇
  2003年   68035篇
  2002年   65844篇
  2001年   101872篇
  2000年   104487篇
  1999年   88023篇
  1998年   25252篇
  1997年   22954篇
  1996年   23000篇
  1995年   21822篇
  1994年   20379篇
  1993年   19107篇
  1992年   70325篇
  1991年   69261篇
  1990年   67173篇
  1989年   64278篇
  1988年   59591篇
  1987年   58426篇
  1986年   55724篇
  1985年   53145篇
  1984年   40155篇
  1983年   34795篇
  1982年   20874篇
  1979年   37567篇
  1978年   27239篇
  1977年   22478篇
  1976年   21557篇
  1975年   22601篇
  1974年   27615篇
  1973年   27208篇
  1972年   25375篇
  1971年   23736篇
  1970年   22216篇
  1969年   20618篇
  1968年   19445篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Pharmaceutical Chemistry Journal - Three extracts were produced from the above-ground part of the meadowsweet Filipendula ulmaria (L.) Maxim. using water, 40% ethanol, and 70% ethanol. Comparative...  相似文献   
44.
Caring for patients with end-stage kidney disease (ESKD) in the United States is challenging, due in part to the complex epidemiology of the disease's progression as well as the ways in which care is delivered. As CKD progresses toward ESKD, the number of comorbidities increases and care involves multiple healthcare providers from multiple subspecialties. This occurs in the context of a fragmented US healthcare delivery system that is traditionally siloed by provider specialty, organization, as well as systems of payment and administration. This article describes the role of care fragmentation in the delivery of optimal ESKD care and identifies research gaps in the evidence across the continuum of care. We then consider the impact of care fragmentation on ESKD care from the patient and health system perspectives and explore opportunities for system-level interventions aimed at improving care for patients with ESKD.  相似文献   
45.
46.
47.
As millions of people turn to social media for health information, better understanding the factors that guide health-related judgments and perceptions in this context is imperative. We report on two Web experiments (n > 400 total) examining the power of society’s widespread weight bias and related stereotypes to influence nutrition judgments in social media spaces. In Experiment 1, meals were judged as lower in nutritional quality when the person who recommended them (the source) was depicted as obese rather than of normal weight, an effect mediated by stereotypic beliefs about the source as a generally unhealthy person. Experiment 2 replicated this effect, which—notably—remained significant when controlling for objective nutritional information (calories and fat content). Results highlight spillover effects of weight bias that extend beyond person perception to color impressions of objects (here, food) that are associated with stigmatized attributes. Implications for everyday nutrition judgments and public health are considered.  相似文献   
48.
49.
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   
50.
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