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   2375229篇
  免费   195068篇
  国内免费   4211篇
耳鼻咽喉   34267篇
儿科学   72753篇
妇产科学   62934篇
基础医学   334945篇
口腔科学   67537篇
临床医学   215554篇
内科学   468729篇
皮肤病学   47935篇
神经病学   200802篇
特种医学   95968篇
外国民族医学   886篇
外科学   360428篇
综合类   56218篇
现状与发展   1篇
一般理论   977篇
预防医学   190674篇
眼科学   55559篇
药学   177555篇
  4篇
中国医学   4370篇
肿瘤学   126412篇
  2018年   24211篇
  2016年   20586篇
  2015年   23292篇
  2014年   33542篇
  2013年   50843篇
  2012年   68758篇
  2011年   72310篇
  2010年   42485篇
  2009年   40871篇
  2008年   68791篇
  2007年   73129篇
  2006年   74054篇
  2005年   72065篇
  2004年   69367篇
  2003年   67042篇
  2002年   66297篇
  2001年   112456篇
  2000年   116539篇
  1999年   98348篇
  1998年   27866篇
  1997年   25525篇
  1996年   25453篇
  1995年   24612篇
  1994年   23162篇
  1993年   21557篇
  1992年   79395篇
  1991年   76399篇
  1990年   73586篇
  1989年   70852篇
  1988年   65853篇
  1987年   64804篇
  1986年   61336篇
  1985年   58405篇
  1984年   44224篇
  1983年   37663篇
  1982年   22892篇
  1981年   20332篇
  1980年   19036篇
  1979年   41301篇
  1978年   28987篇
  1977年   24348篇
  1976年   22835篇
  1975年   23969篇
  1974年   29648篇
  1973年   28048篇
  1972年   26235篇
  1971年   24159篇
  1970年   22754篇
  1969年   21091篇
  1968年   19139篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
43.
44.
45.
46.
47.
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   
48.
49.
50.
Glutathione-S-transferase (GST) genes encode a family of detoxification enzymes that offer protection against endogenous and exogenous sources of reactive oxygen species (ROS). Germline variations in GST genes may alter the catalytic efficiency of GST isoenzymes leading to a potential increase in susceptibility to the genotoxic effects of ROS and electrophilic substances. A nested case-control study design was used to examine the association between the polymorphic GST genes and prostate cancer risk among Finnish male smokers of the ATBC Cancer Prevention Study. A case-case analysis was used to determine the association between these genetic polymorphisms and prostate cancer progression. Germline DNA was obtained from 206 prostate cancer cases and 194 controls frequency matched on age, intervention group and study clinic. Cases and controls were genotyped for three GST genes using MALDI-TOF mass spectrometry or multiplex polymerase chain reaction (PCR). Relative to the wild-type genotype, we observed a 36% reduction in prostate cancer risk associated with the GST-M1-null genotype (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.43, 0.95). Unlike GST-M1, GST-T1-null (OR 0.74, 95% CI 0.42, 1.33) and GST-P1*B (OR 1.10, 95% CI 0.72, 1.69) were not strongly associated with prostate cancer risk. We did not observe any significant associations between the selected polymorphic GST genes and tumour grade or stage. In conclusion, we did not observe a direct association between polymorphic GST-T1 or GST-P1 and prostate cancer risk. Our observation of a relatively strong inverse association between the GST-M1-null genotype and prostate cancer risk needs to be confirmed in larger association studies.  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