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   1339920篇
  免费   94506篇
  国内免费   2922篇
耳鼻咽喉   19757篇
儿科学   40342篇
妇产科学   38700篇
基础医学   187660篇
口腔科学   39953篇
临床医学   112899篇
内科学   263324篇
皮肤病学   30250篇
神经病学   106655篇
特种医学   53821篇
外国民族医学   435篇
外科学   208900篇
综合类   31056篇
现状与发展   6篇
一般理论   436篇
预防医学   92283篇
眼科学   31419篇
药学   100487篇
  4篇
中国医学   2995篇
肿瘤学   75966篇
  2018年   11808篇
  2015年   11936篇
  2014年   16779篇
  2013年   25379篇
  2012年   33189篇
  2011年   35109篇
  2010年   20852篇
  2009年   20302篇
  2008年   33745篇
  2007年   36872篇
  2006年   37438篇
  2005年   36219篇
  2004年   35273篇
  2003年   34230篇
  2002年   33776篇
  2001年   63736篇
  2000年   65434篇
  1999年   55507篇
  1998年   14703篇
  1997年   13509篇
  1996年   12986篇
  1995年   12260篇
  1994年   11513篇
  1992年   42858篇
  1991年   41380篇
  1990年   40640篇
  1989年   39628篇
  1988年   37039篇
  1987年   36472篇
  1986年   34964篇
  1985年   33167篇
  1984年   24858篇
  1983年   21086篇
  1982年   12686篇
  1981年   11588篇
  1980年   10790篇
  1979年   23948篇
  1978年   17084篇
  1977年   14841篇
  1976年   13391篇
  1975年   15283篇
  1974年   18095篇
  1973年   17569篇
  1972年   16822篇
  1971年   15732篇
  1970年   14927篇
  1969年   14360篇
  1968年   13474篇
  1967年   12025篇
  1966年   11262篇
排序方式: 共有10000条查询结果,搜索用时 15 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