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   2179475篇
  免费   153275篇
  国内免费   3200篇
耳鼻咽喉   31206篇
儿科学   71576篇
妇产科学   62036篇
基础医学   313980篇
口腔科学   61355篇
临床医学   189237篇
内科学   419425篇
皮肤病学   47323篇
神经病学   167999篇
特种医学   86162篇
外国民族医学   564篇
外科学   334947篇
综合类   45181篇
现状与发展   2篇
一般理论   545篇
预防医学   156292篇
眼科学   49905篇
药学   170333篇
  8篇
中国医学   4903篇
肿瘤学   122971篇
  2018年   21391篇
  2016年   18567篇
  2015年   21094篇
  2014年   28867篇
  2013年   43273篇
  2012年   59355篇
  2011年   63354篇
  2010年   37460篇
  2009年   35149篇
  2008年   60313篇
  2007年   65024篇
  2006年   66020篇
  2005年   63968篇
  2004年   61433篇
  2003年   59487篇
  2002年   58056篇
  2001年   107204篇
  2000年   110029篇
  1999年   92589篇
  1998年   24767篇
  1997年   22003篇
  1996年   22125篇
  1995年   20896篇
  1994年   19434篇
  1993年   18125篇
  1992年   72417篇
  1991年   70473篇
  1990年   69514篇
  1989年   67207篇
  1988年   61813篇
  1987年   60415篇
  1986年   57372篇
  1985年   54322篇
  1984年   40047篇
  1983年   34373篇
  1982年   19717篇
  1981年   17419篇
  1979年   37061篇
  1978年   25539篇
  1977年   22413篇
  1976年   20401篇
  1975年   22764篇
  1974年   26657篇
  1973年   25769篇
  1972年   24603篇
  1971年   22959篇
  1970年   21231篇
  1969年   20571篇
  1968年   18852篇
  1967年   16704篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
51.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
52.
53.
54.
55.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
56.
57.
58.
BackgroundSecond-hand smoking or environmental tobacco smoke is a critical health risk. Children are the most vulnerable to second-hand smoking because of their small bronchial ducts, less developed immunity, and low-physical activity.ObjectivesThe purpose of this study was to ascertain the effects of second-hand smoking on lung functions in athlete and non-athlete school-aged children.MethodsThis observational study included forty-six school-aged children, their age was 8–15 years, assigned to three groups; 2 study groups and 1 control group (n=15). The study groups comprised of 16 football players, and of 15 cyclists. Lung functions were evaluated recording forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow using digital spirometer.ResultsAll measures were recorded in definite values and the children were also classified into second-hand smoking (SH), or non-exposed to tobacco smoking (NE). The findings presented a significant increase (p<0.05) of the study groups in forced vital capacity, forced expiratory volume in 1 sec and peak expiratory flow solely for the non-exposed children. However, there were non-significant differences between the cyclists and football players or between the passive smoking children and non-exposed children in any of the two study groups (p>0.05).ConclusionThe outcomes of this study suggest beneficial influences of the sports activity on the lung functions, without different influences of the cyclists and football players on the lung functions.  相似文献   
59.
60.
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