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   43257篇
  免费   3547篇
  国内免费   450篇
耳鼻咽喉   361篇
儿科学   2141篇
妇产科学   456篇
基础医学   4890篇
口腔科学   596篇
临床医学   4842篇
内科学   2845篇
皮肤病学   313篇
神经病学   15346篇
特种医学   438篇
外科学   1408篇
综合类   4434篇
现状与发展   2篇
一般理论   1篇
预防医学   4153篇
眼科学   142篇
药学   3548篇
  21篇
中国医学   1010篇
肿瘤学   307篇
  2024年   185篇
  2023年   995篇
  2022年   1488篇
  2021年   2082篇
  2020年   1996篇
  2019年   1818篇
  2018年   1681篇
  2017年   1803篇
  2016年   1871篇
  2015年   1664篇
  2014年   3083篇
  2013年   3992篇
  2012年   2617篇
  2011年   2980篇
  2010年   2328篇
  2009年   2179篇
  2008年   2211篇
  2007年   2011篇
  2006年   1626篇
  2005年   1332篇
  2004年   1063篇
  2003年   977篇
  2002年   823篇
  2001年   607篇
  2000年   494篇
  1999年   419篇
  1998年   436篇
  1997年   356篇
  1996年   268篇
  1995年   232篇
  1994年   199篇
  1993年   169篇
  1992年   167篇
  1991年   158篇
  1990年   140篇
  1989年   125篇
  1988年   116篇
  1987年   93篇
  1986年   48篇
  1985年   84篇
  1984年   58篇
  1983年   39篇
  1982年   63篇
  1981年   33篇
  1980年   29篇
  1979年   26篇
  1978年   18篇
  1977年   19篇
  1976年   14篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
BackgroundThe positive effect of a father’s involvement in children’s upbringing is now recognised. However, research on fathers raising children with autism spectrum disorder (ASD) are still few. This study examines the relationship between the perception, fathers of children with ASD have of the importance of their role in the development of their children and the feelings (self-efficacy, caregiving burden, satisfaction) they express about their parenting experience.MethodSixty-three Swiss Italian fathers of children with ASD completed The Role of the Father Questionnaire (ROFQ), three sub-scales of the Caregiver Survey, a subtest of the Child Adjustment and Parent Efficacy Scale and a home-made questionnaire measuring Perceived Social Support.ResultsThe results from hierarchical multiple regression analyses show that the importance that fathers attach to the paternal role predicts positively their caregiving satisfaction and their feeling of self-efficacy. The children’s challenging behaviours predict positively the caregiving burden whereas the assessment of social support predicts it negatively.ConclusionsThe perception of the importance of the paternal role needs to be considered in the support offered to families with a child with ASD. A better understanding of the fathers’ feelings could be of value for the programmes.  相似文献   
32.
33.
34.
35.
Children with a specific learning disorder (SLD) are often characterized by marked intellectual strengths and weaknesses. In the last few years, research has focused on a common discrepancy between low working memory and processing speed on the one hand, and high verbal and visuoperceptual intelligence on the other. SLD profiles featuring a specific discrepancy between verbal and visuoperceptual abilities have been only marginally considered, however, and their systematic comparison vis-à-vis typically-developing (TD) populations has yet to be conducted. The present study examined a dataset of 1624 WISC-IV profiles of children with a diagnosis of SLD. It emerged that the proportion of children with a Verbal Comprehension Index (VCI) at least 1.5 SD (22 standardized points) lower than their scores on the Perceptual Reasoning Index (PRI) was larger than the proportion of SLD children with the opposite discrepant profile; it was also larger than the same proportion found among TD children. Comparing the two discrepant profiles revealed that the children also differed by type of learning difficulty, gender, and performance in the WISC-IV Symbol search task. Further examination suggested that children who were discrepant and also distinctly poor in visuoperceptual intelligence were particularly slow in general processing.  相似文献   
36.
37.
38.
《L'Encéphale》2022,48(2):188-195
Depressive disorder is characterized by a polymorphic symptomatology associating emotional, cognitive and behavioral disturbances. One of the most specific symptoms is negative beliefs, called congruent to mood. Despite the importance of these beliefs in the development, the maintenance, and the recurrence of depressive episodes, little is known about the processes underlying the generation of depressive beliefs. In this paper, we detail the link between belief updating mechanisms and the genesis of depressive beliefs. We show how depression alters information processing, generating cognitive immunization when processing positive information, affective updating bias related to the valence of belief and prediction error, and difficultie to disengage from negative information. We suggest that disruption of belief-updating mechanisms forms the basis of belief-mood congruence in depression.  相似文献   
39.
目的 探索珠海地区NRXN1NLGN1基因多态性与儿童孤独症易感性的关系,为孤独症的防治提供科学依据。方法 采用病例对照的研究方法,选取2011-2016年就诊于珠海市妇幼保健院的123例珠海地区的孤独症患儿和506例健康对照。采用口腔拭子采集口腔上皮细胞以提取DNA,采用Sequenom Mass Array platform分型技术对NRXN1基因上的rs1045881和rs11885824以及NLGN1上的rs9855544进行基因分型。结果 NRXN1基因上的rs1045881和rs11885824以及NLGN1上的rs9855544位点基因型分布在孤独症组和健康对照组比较,差异无统计学意义;但NLGN1基因上的rs9855544与NRXN1基因上的rs11885824存在基因与基因间的交互作用(预测准确率为0.480,交叉验证一致性为10/10,P=0.040)。结论 NRXN1基因上的rs1045881和rs11885824以及NLGN1上的rs9855544位点基因多态性可能与孤独症易感性没有关联,但NLGN1基因上的rs9855544与NRXN1基因上的rs11885824之间的交互作用可能是孤独症易感性的影响因素。  相似文献   
40.
Objective: To determine serotonin system abnormalities related to major depression or previous suicidal behavior.

Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.

Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.

Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents.  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