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   1351307篇
  免费   95216篇
  国内免费   2944篇
耳鼻咽喉   19872篇
儿科学   40556篇
妇产科学   39093篇
基础医学   189753篇
口腔科学   40229篇
临床医学   114198篇
内科学   265191篇
皮肤病学   30524篇
神经病学   107845篇
特种医学   54415篇
外国民族医学   435篇
外科学   210507篇
综合类   31144篇
现状与发展   6篇
一般理论   438篇
预防医学   92868篇
眼科学   31884篇
药学   101106篇
  4篇
中国医学   3039篇
肿瘤学   76360篇
  2018年   12044篇
  2016年   10879篇
  2015年   12194篇
  2014年   17136篇
  2013年   25886篇
  2012年   33869篇
  2011年   35736篇
  2010年   21312篇
  2009年   20780篇
  2008年   34443篇
  2007年   37630篇
  2006年   38179篇
  2005年   36937篇
  2004年   35834篇
  2003年   34792篇
  2002年   34326篇
  2001年   63757篇
  2000年   65437篇
  1999年   55536篇
  1998年   14819篇
  1997年   13589篇
  1996年   13063篇
  1995年   12349篇
  1994年   11572篇
  1992年   42844篇
  1991年   41352篇
  1990年   40610篇
  1989年   39597篇
  1988年   37022篇
  1987年   36452篇
  1986年   34946篇
  1985年   33151篇
  1984年   24896篇
  1983年   21101篇
  1982年   12740篇
  1981年   11640篇
  1979年   23958篇
  1978年   17110篇
  1977年   14886篇
  1976年   13424篇
  1975年   15296篇
  1974年   18117篇
  1973年   17590篇
  1972年   16837篇
  1971年   15741篇
  1970年   14939篇
  1969年   14370篇
  1968年   13481篇
  1967年   12036篇
  1966年   11279篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
25.
Setting goals to maintain hope.   总被引:3,自引:0,他引:3  
  相似文献   
26.
27.
28.
29.
30.
BACKGROUND: Three dimensional skin equivalents are widely used in dermatopharmacological and toxicological studies and as autologous transplants in wound healing. In pharmacology, there is tremendous need for monitoring the response of engineered skin equivalents to external treatment. Transplantation of skin equivalents for wound healing requires careful verification of their quality prior to transplantation. Optical coherence tomography (OCT) is a non-contact, non-destructive imaging technique for living tissues offering the potential to fulfill these needs. This work presents an analysis of OCT for high-resolution monitoring of skin equivalents at different stages during the culture process. METHODS: We developed a high-resolution OCT imaging setup based on a commercially available OCT system. A broadband femtosecond laser light source replaces the original superluminescence diode. Tomograms of living skin equivalents were recorded with an axial resolution of 3 mum and correlated with histology and immunofluorescence images. Comparison with standard low-resolution OCT is presented to emphasize the advantages of high-resolution OCT for this application. RESULTS: OCT is particularly able to distinguish between different layers of skin equivalents including stratum corneum, epidermal and dermal layer as well as the basement membrane zone. The high-resolution OCT scans correlate closely with two key benchmarks, histology and immunofluorescence imaging. CONCLUSIONS: This study clearly demonstrates the benefits of high-resolution OCT for identifying living tissue structure and morphology. Compared with the current gold standard histology, OCT offers non-destructive tissue imaging, enabling high-resolution evaluation of living tissue morphology and structure as it evolves.  相似文献   
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