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   3379050篇
  免费   264363篇
  国内免费   6981篇
耳鼻咽喉   47741篇
儿科学   106224篇
妇产科学   92539篇
基础医学   474069篇
口腔科学   96164篇
临床医学   308161篇
内科学   662083篇
皮肤病学   73013篇
神经病学   285119篇
特种医学   130669篇
外国民族医学   1246篇
外科学   503037篇
综合类   79017篇
现状与发展   4篇
一般理论   1373篇
预防医学   277125篇
眼科学   79188篇
药学   247213篇
  5篇
中国医学   7032篇
肿瘤学   179372篇
  2019年   27580篇
  2018年   39679篇
  2017年   29843篇
  2016年   32849篇
  2015年   37000篇
  2014年   51974篇
  2013年   78879篇
  2012年   109185篇
  2011年   114867篇
  2010年   66603篇
  2009年   62677篇
  2008年   106982篇
  2007年   113576篇
  2006年   113790篇
  2005年   110766篇
  2004年   106054篇
  2003年   101681篇
  2002年   99015篇
  2001年   152739篇
  2000年   157537篇
  1999年   132774篇
  1998年   38872篇
  1997年   35191篇
  1996年   34810篇
  1995年   33373篇
  1994年   31022篇
  1993年   29048篇
  1992年   104662篇
  1991年   100554篇
  1990年   96846篇
  1989年   93072篇
  1988年   86382篇
  1987年   84946篇
  1986年   80085篇
  1985年   76480篇
  1984年   58439篇
  1983年   49774篇
  1982年   30514篇
  1981年   27118篇
  1979年   54031篇
  1978年   38140篇
  1977年   32039篇
  1976年   30066篇
  1975年   31378篇
  1974年   38593篇
  1973年   36929篇
  1972年   34656篇
  1971年   31857篇
  1970年   30139篇
  1969年   28093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.
48.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
49.
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   
50.
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   
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