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   24545篇
  免费   1734篇
  国内免费   65篇
耳鼻咽喉   300篇
儿科学   619篇
妇产科学   648篇
基础医学   3224篇
口腔科学   1294篇
临床医学   1796篇
内科学   5494篇
皮肤病学   729篇
神经病学   2129篇
特种医学   490篇
外国民族医学   1篇
外科学   2953篇
综合类   154篇
一般理论   6篇
预防医学   2359篇
眼科学   492篇
药学   2115篇
中国医学   171篇
肿瘤学   1370篇
  2023年   155篇
  2022年   177篇
  2021年   804篇
  2020年   504篇
  2019年   720篇
  2018年   873篇
  2017年   627篇
  2016年   649篇
  2015年   749篇
  2014年   958篇
  2013年   1232篇
  2012年   1799篇
  2011年   1827篇
  2010年   1068篇
  2009年   899篇
  2008年   1463篇
  2007年   1372篇
  2006年   1244篇
  2005年   1208篇
  2004年   1073篇
  2003年   983篇
  2002年   893篇
  2001年   563篇
  2000年   539篇
  1999年   438篇
  1998年   180篇
  1997年   154篇
  1996年   150篇
  1995年   117篇
  1994年   86篇
  1993年   89篇
  1992年   290篇
  1991年   265篇
  1990年   242篇
  1989年   179篇
  1988年   181篇
  1987年   148篇
  1986年   160篇
  1985年   124篇
  1984年   94篇
  1983年   82篇
  1982年   66篇
  1980年   52篇
  1979年   109篇
  1978年   53篇
  1977年   57篇
  1975年   59篇
  1974年   66篇
  1973年   63篇
  1971年   58篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
School Mental Health - A dual approach to mental health in schools has been widely defended, where the assessment of psychological distress and the examination of strengths/well-being are two...  相似文献   
2.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
3.
4.
5.
6.
7.
8.
9.
10.
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   
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