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   2377620篇
  免费   195288篇
  国内免费   4212篇
耳鼻咽喉   34343篇
儿科学   72914篇
妇产科学   63020篇
基础医学   335219篇
口腔科学   67551篇
临床医学   215833篇
内科学   469118篇
皮肤病学   47988篇
神经病学   201014篇
特种医学   96055篇
外国民族医学   886篇
外科学   360715篇
综合类   56313篇
现状与发展   1篇
一般理论   979篇
预防医学   190870篇
眼科学   55512篇
药学   177709篇
  4篇
中国医学   4368篇
肿瘤学   126708篇
  2018年   24260篇
  2016年   20642篇
  2015年   23343篇
  2014年   33607篇
  2013年   50954篇
  2012年   68885篇
  2011年   72438篇
  2010年   42558篇
  2009年   40942篇
  2008年   68911篇
  2007年   73302篇
  2006年   74157篇
  2005年   72212篇
  2004年   69489篇
  2003年   67160篇
  2002年   66395篇
  2001年   112528篇
  2000年   116595篇
  1999年   98392篇
  1998年   27891篇
  1997年   25556篇
  1996年   25472篇
  1995年   24639篇
  1994年   23176篇
  1993年   21576篇
  1992年   79432篇
  1991年   76465篇
  1990年   73612篇
  1989年   70883篇
  1988年   65888篇
  1987年   64833篇
  1986年   61362篇
  1985年   58430篇
  1984年   44255篇
  1983年   37677篇
  1982年   22908篇
  1981年   20361篇
  1980年   19054篇
  1979年   41319篇
  1978年   29009篇
  1977年   24363篇
  1976年   22845篇
  1975年   23981篇
  1974年   29655篇
  1973年   28061篇
  1972年   26252篇
  1971年   24161篇
  1970年   22763篇
  1969年   21096篇
  1968年   19147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