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   3162098篇
  免费   229846篇
  国内免费   4464篇
耳鼻咽喉   43601篇
儿科学   103116篇
妇产科学   86068篇
基础医学   465787篇
口腔科学   88630篇
临床医学   290280篇
内科学   608070篇
皮肤病学   69438篇
神经病学   251361篇
特种医学   118196篇
外国民族医学   726篇
外科学   466201篇
综合类   66420篇
现状与发展   14篇
一般理论   1292篇
预防医学   254423篇
眼科学   73903篇
药学   234438篇
  17篇
中国医学   5820篇
肿瘤学   168607篇
  2019年   25567篇
  2018年   34912篇
  2017年   26292篇
  2016年   29334篇
  2015年   33403篇
  2014年   47056篇
  2013年   71304篇
  2012年   97617篇
  2011年   104040篇
  2010年   61549篇
  2009年   58386篇
  2008年   98007篇
  2007年   104528篇
  2006年   105044篇
  2005年   102191篇
  2004年   97927篇
  2003年   94260篇
  2002年   91491篇
  2001年   139758篇
  2000年   143127篇
  1999年   120836篇
  1998年   35470篇
  1997年   31376篇
  1996年   31786篇
  1995年   30080篇
  1994年   27912篇
  1993年   26090篇
  1992年   94887篇
  1991年   92835篇
  1990年   90450篇
  1989年   87527篇
  1988年   80667篇
  1987年   79101篇
  1986年   74688篇
  1985年   71493篇
  1984年   53681篇
  1983年   46235篇
  1982年   27698篇
  1979年   50324篇
  1978年   36231篇
  1977年   30196篇
  1976年   28701篇
  1975年   30955篇
  1974年   37312篇
  1973年   35862篇
  1972年   33817篇
  1971年   31861篇
  1970年   29738篇
  1969年   28308篇
  1968年   26149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.
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   
46.
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index.  相似文献   
47.
48.
49.
50.
Constitutional trisomy 21 is the most prominent predisposing factor to childhood leukemia, whereas the t(12;21)(p13;q22) with its molecular genetic counterpart, the TEL/AML1 fusion gene, is the most common acquired chromosomal rearrangement in childhood B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). Thus, it was somewhat surprising that according to the currently available literature the incidence of TEL/AML1+ BCP ALL is extremely low in patients with Down syndrome (DS). To further investigate this issue in a population-based fashion, the authors retrospectively assessed the number of DS patients with a TEL/AML1+ ALL in two consecutive Austrian ALL multicenter trials. Accordingly, they were able to analyze 8 of 10 individuals with DS and a BCP ALL, including 2 who suffered from a TEL/AML1+ leukemia. Based on this observation we concluded that individuals with a constitutional trisomy 21 may have the similar likelihood to develop a TEL/AML1+ leukemia as BCP ALL patients without this specific predisposing factor.  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