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   1296篇
  免费   70篇
  国内免费   4篇
耳鼻咽喉   3篇
儿科学   50篇
妇产科学   12篇
基础医学   110篇
口腔科学   8篇
临床医学   167篇
内科学   184篇
皮肤病学   3篇
神经病学   276篇
特种医学   13篇
外科学   29篇
综合类   39篇
一般理论   4篇
预防医学   391篇
眼科学   7篇
药学   55篇
肿瘤学   19篇
  2024年   1篇
  2023年   17篇
  2022年   40篇
  2021年   52篇
  2020年   53篇
  2019年   55篇
  2018年   42篇
  2017年   54篇
  2016年   38篇
  2015年   44篇
  2014年   61篇
  2013年   125篇
  2012年   42篇
  2011年   52篇
  2010年   61篇
  2009年   66篇
  2008年   59篇
  2007年   72篇
  2006年   45篇
  2005年   42篇
  2004年   36篇
  2003年   33篇
  2002年   31篇
  2001年   43篇
  2000年   18篇
  1999年   17篇
  1998年   27篇
  1997年   12篇
  1996年   8篇
  1995年   10篇
  1994年   16篇
  1993年   6篇
  1992年   15篇
  1991年   9篇
  1990年   15篇
  1989年   4篇
  1988年   6篇
  1987年   5篇
  1986年   12篇
  1985年   5篇
  1984年   5篇
  1983年   2篇
  1982年   3篇
  1981年   3篇
  1980年   3篇
  1979年   4篇
  1974年   1篇
排序方式: 共有1370条查询结果,搜索用时 31 毫秒
1.
《Cancer cell》2022,40(8):835-849.e8
  1. Download : Download high-res image (220KB)
  2. Download : Download full-size image
  相似文献   
2.
3.
BACKGROUND: Early environment is a major determinant of long-term mental health, evidenced by the relationship between early-life neglect or abuse and chronically increased vulnerability to developmental psychopathology, including major depressive disorder (MDD). Animal studies can increase understanding of environmentally mediated causal risk processes. We describe how daily deprivation of biological parenting in primate infants disrupts development of homeostatic and reward systems central to MDD. METHODS: Nine breeding pairs of marmoset monkeys provided control twins (CON) and early-deprived twins (ED); the latter were socially isolated for 30-120 min/day on days 2-28. During the first year of life, basal urinary norepinephrine (NE) titers and cardiophysiologic activity were measured. At the end of year 1 (adolescence), automated neuropsychologic tests were conducted to measure responsiveness to changes in stimulus-reward association (simple/reversed visual discrimination learning) and to reward per se (progressive ratio [PR] reinforcement schedule). RESULTS: The ED monkeys exhibited increased basal urinary NE titers and increased systolic blood pressure relative to CON siblings. The ED monkeys required more sessions to reinstate stimulus-oriented behavior following reversal, suggesting increased vulnerability to perceived loss of environmental control; ED monkeys also performed less PR operant responses, indicating that reward was less of an incentive and that they were mildly anhedonic relative to CON. CONCLUSIONS: In marmoset monkeys, neglect-like manipulation of ED leads to chronic changes in homeostatic systems, similar to those in children and adolescents exposed to early-life adversity and in MDD, and to responses to environmental stimuli similar to those that characterize MDD.  相似文献   
4.
Over the past decade, the unfortunate reality is that the income gap has widened between Canadian families. Educational outcomes are one of the key areas influenced by family incomes. Children from low-income families often start school already behind their peers who come from more affluent families, as shown in measures of school readiness. The incidence, depth, duration and timing of poverty all influence a child’s educational attainment, along with community characteristics and social networks. However, both Canadian and international interventions have shown that the effects of poverty can be reduced using sustainable interventions. Paediatricians and family doctors have many opportunities to influence readiness for school and educational success in primary care settings.  相似文献   
5.
Cognitive models of depression propose that negative schemas contribute to depressive symptoms. Early experiences, particularly parenting, have been proposed to influence cognitive schemas and have also been shown to correlate with depression. This study explores the concurrent relationship between retrospective reports of parenting, Early Maladaptive Schemas (EMSs) described by J. E. Young (1994), and symptoms of depression in a sample of undergraduate students (N = 194). The EMSs of defectiveness/shame, insufficient self-control, vulnerability, and incompetence/inferiority were associated with perceptions of parenting and depressive symptomatology. There was evidence that these four EMSs partially mediate the relationship between parental perceptions and depressive symptomatology. Results are discussed in relation to previous findings, theory, and the measurement of EMSs.  相似文献   
6.
中国贫困医疗救助模式的制度缺陷及其改进思路   总被引:2,自引:0,他引:2  
讨论现行国内医疗救助模式的基本经验与存在的缺陷。现行国内医疗救助模式无论在制度设计还是具体实施中部存在许多缺陷,如在制度设计方面,救助标准与水平总体上都比较低,大病痛种的规定大大限制和缩小了贫困医疗救助的范围,而定点医院限制了救助对象选择的空间等。  相似文献   
7.
In recent decades, there has been a dramatic increase in unhealthy weight for both children and adults. The Canadian standard of living has changed in favour of more easily prepared, calorie-dense foods and sedentary practices. Many family characteristics have also changed over the past 50 years. More Canadian families are living in disadvantaged situations, forecasting a host of unhealthy behaviours and attitudes in adults. The poor are not only getting poorer, they are also becoming heavier. Children from disadvantaged families seem to be leading the trend in increasing prevalence of unhealthy weight. Because they live in neighbourhoods that are perceived as unsafe, these children are likely spending more time indoors. This is associated with watching more television, which not only displaces other forms of educational and active entertainment but also places them at risk of learning inaccurate information about proper eating. Social science research helps identify factors contributing most to the rise in excess weight within this population, thus providing essential clues for effective approaches to its eradication.  相似文献   
8.
9.
医疗领域的数据由过去的封闭系统存储逐渐转向了局域网、广域网通信与传输,DICOM标准是目前应用最为广泛的医疗数据传输与储存协议。该标准的某些版本存在着一个已知的引言漏洞,可能会导致dcm文件被捆绑恶意代码。  相似文献   
10.
BackgroundChildren born of low birth weight (LBW) and/or premature may have developmental delays and difficulties. The vulnerability, without early intervention, would have detrimental lifelong effects.ObjectivesThis study examined 1) the relationship between LBW and prematurity and the occurrence and timing of children's receipt of developmental and special education services; and 2) whether poverty intersects with LBW and prematurity affecting service receipt.MethodsThis population-based study used cross-sectional data from the National Survey of Children's Health which consisted of approximately 52,000 participants aged 1–17 between 2017 and 2018 in the United States. We conducted logistic regression to analyze the predictive relationship of LBW/prematurity and the occurrence of receiving developmental and special education services. We then conducted ordered logistic regression to examine whether LBW and prematurity predicted the timing of receiving developmental and special education services. Further, we conducted moderating analyses to examine whether the predictive relationships above varied with poverty. The analyses listed above were weighted to reflect the population drawn.ResultsChildren born with LBW and prematurity were more likely to receive developmental and special education services and they tended to receive services earlier than those born at normal weight and term. Educational disparities were evident among children in low-income families. Children of LBW in low-income families were less likely to receive earlier services than those in affluent families.ConclusionsThis study indicates developmental and special education needs of children born LBW and/or premature. With restrained assets, low-income families may need more assistance to promote optimal development for their children.  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