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   197703篇
  免费   2568篇
  国内免费   100篇
耳鼻咽喉   1423篇
儿科学   7215篇
妇产科学   3431篇
基础医学   20007篇
口腔科学   2090篇
临床医学   14546篇
内科学   35430篇
皮肤病学   1252篇
神经病学   19251篇
特种医学   9561篇
外科学   30952篇
综合类   2439篇
一般理论   15篇
预防医学   19895篇
眼科学   3280篇
药学   10839篇
中国医学   701篇
肿瘤学   18044篇
  2024年   38篇
  2023年   221篇
  2022年   427篇
  2021年   740篇
  2020年   491篇
  2019年   705篇
  2018年   22523篇
  2017年   17824篇
  2016年   20079篇
  2015年   1683篇
  2014年   1717篇
  2013年   1893篇
  2012年   8771篇
  2011年   22859篇
  2010年   19776篇
  2009年   12381篇
  2008年   20978篇
  2007年   23149篇
  2006年   1987篇
  2005年   3539篇
  2004年   4645篇
  2003年   5474篇
  2002年   3457篇
  2001年   479篇
  2000年   583篇
  1999年   370篇
  1998年   413篇
  1997年   390篇
  1996年   221篇
  1995年   203篇
  1994年   188篇
  1993年   123篇
  1992年   110篇
  1991年   157篇
  1990年   191篇
  1989年   143篇
  1988年   121篇
  1987年   95篇
  1986年   74篇
  1985年   84篇
  1984年   48篇
  1983年   56篇
  1982年   53篇
  1980年   64篇
  1974年   33篇
  1970年   35篇
  1968年   33篇
  1938年   62篇
  1932年   57篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
Studies on the exposure of children to sugar-sweetened beverages (SSBs) at an early age may contribute to better understand the common causes and the temporal order of the relationships between obesity and asthma in early childhood. The objective of this study was to estimate the association between SSB and child asthma traits in the 2nd year of life, modeling direct and indirect pathways mediated by the highest BMI-z of the child and allergic inflammation. Data from the BRISA cohort, São Luís-MA, Brazil (n = 1140), were obtained from the baseline and from the follow-up performed at the 2nd year of life. The main explanatory variable was the calories from added sugars in SSBs as a percentage of the total daily energy intake. The outcome child asthma traits was a latent variable deduced from four indicators: medical diagnosis of asthma, wheezing, emergency visit due to intense wheezing, and medical diagnosis of rhinitis. A high percentage of daily calories from sugars added to SSBs was directly associated with higher values of child asthma traits (standardized coefficient (SC = 0.073; P = .030)). High levels of eosinophils were also directly associated with child asthma traits (SC = 0.118; P = .049). No mediation pathways were observed via greater BMI-z or eosinophil counts. Therefore, early exposure of children to SSB may contribute to increased risk of childhood asthma, preceding the link between sugar consumption and overweight/obesity, not yet evident in children in the first 2 years of life.  相似文献   
24.
25.
There is some evidence suggesting that Parkinson's disease (PD) patients exhibit lower body weight when compared to age-matched healthy subjects. Low body mass index (BMI) is correlated with low bone mineral density, both of which are major risk factors for hip fractures. Possible determinants of weight loss in PD patients include hyposmia, impaired hand-mouth coordination, difficulty chewing, dysphagia, intestinal hypomotility, depression, decreased reward processing of dopaminergic mesolimbic regions, nausea, and anorexia as the side effects of medication, and increased energy requirements due to muscular rigidity and involuntary movements. It is unclear whether PD patients in general, or only a subgroup of those affected, definitely show lower BMI in the advanced stages of the disease. We therefore recommend that the body weight of PD patients be monitored monthly as the disease progresses, and that a patient's nutrition should be supplemented with sufficient amounts of vitamin D and calcium to reduce the risk of hip fractures and strengthen bone density. Because meal times may coincide with unpredictable off periods associated with akinesia and impaired hand-mouth coordination, PD patients also need flexible food schedules that accommodate the associated symptoms of this disease.  相似文献   
26.
27.
28.
29.
30.
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