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   1539篇
  免费   66篇
  国内免费   1篇
  1606篇
  2021年   18篇
  2019年   26篇
  2018年   39篇
  2017年   28篇
  2016年   55篇
  2015年   24篇
  2014年   27篇
  2013年   116篇
  2012年   52篇
  2011年   67篇
  2010年   34篇
  2009年   36篇
  2008年   49篇
  2007年   44篇
  2006年   45篇
  2005年   35篇
  2004年   51篇
  2003年   43篇
  2002年   47篇
  2001年   45篇
  2000年   36篇
  1999年   33篇
  1998年   23篇
  1997年   18篇
  1996年   14篇
  1995年   17篇
  1994年   21篇
  1993年   20篇
  1992年   20篇
  1991年   25篇
  1990年   24篇
  1989年   18篇
  1988年   17篇
  1987年   18篇
  1986年   21篇
  1985年   26篇
  1984年   21篇
  1983年   18篇
  1982年   20篇
  1981年   19篇
  1979年   26篇
  1978年   18篇
  1977年   17篇
  1975年   16篇
  1974年   24篇
  1973年   22篇
  1972年   19篇
  1971年   21篇
  1969年   18篇
  1967年   14篇
排序方式: 共有1606条查询结果,搜索用时 0 毫秒
991.
The Service Delivery Model Task Force (SDMTF) was appointed in 2009 by the leadership of the National Society of Genetic Counselors (NSGC) with a charge to research and assess the capacity of all existing service delivery models to improve access to genetic counseling services in the context of increasing demand for genetic testing and counseling. In approaching this charge, the SDMTF found that there were varying interpretations of what was meant by "service delivery models" and the group held extensive discussions about current practices to arrive at consensus of proposed definitions for current genetic service delivery models, modes of referral and components of service delivery. The major goal of these proposed definitions is to allow for conversations to begin to address the charge to the committee. We propose that current models of service delivery can be defined by: 1) the methods in which genetic counseling services are delivered (In-person, Telephone, Group and Telegenetics), 2) the way they are accessed by patients (Traditional referral, Tandem, Triage, Rescue and Self-referral) and 3) the variable components that depend upon multiple factors unique to each service setting. This report by the SDMTF provides a starting point whereby standardized terminology can be used in future studies that assess the effectiveness of these described models to overcome barriers to access to genetic counseling services.  相似文献   
992.
Facioscapulohumeral muscular dystrophy (FSHD), is a dominantly inherited, late onset, progressive disease. At present, no treatment or prevention of symptoms are available. There is considerable clinical variability, even within families. The gene whose defect causes FSHD has not been identified, but molecular diagnosis can be made by analyzing D4Z4 repeat length on chromosome 4q35. The results can support or rule out the clinical diagnosis of FSHD, but there are also "gray zone", non-conclusive results. During the years 2000-6, 66 individuals (including 7 asymptomatic individuals), were tested in our institute for D4Z4 repeat number. In 77% of the cases the results were conclusive: two thirds of them supported a diagnosis of FSHD while in a third this diagnosis was ruled out. In 23% the results were in the gray zone. Cognitive involvement was rare, occurring only when the D4Z4 repeat size was very small (<15 kb). Maximal utilization of the existing molecular test for FSHD demands detailed clinical and family pedigree information. We recommend that comprehensive genetic counseling always be given before and after molecular testing for FSHD, in addition to the neurological follow-up. Presymptomatic testing should only be offered when complete molecular evaluation can be offered, including 4qA and 4qB variant analysis.  相似文献   
993.
Diminished expression of speech is a pernicious feature of both schizophrenia and schizotypy--defined as the personality organization reflecting a putative genetic schizophrenia liability. As yet, the mechanism underlying diminished expression is unclear. We tested the hypothesis that diminished expression reflects a cognitive resource issue--that is, as cognitive resources are depleted, expression becomes diminished in individuals with psychometrically defined schizotypy. Acoustic analysis of natural speech was procured during experimentally manipulated baseline and high cognitive-load dual tasks and examined in 38 individuals with psychometrically defined schizotypy and 34 controls. For both groups, expression significantly decreased as a function of increased task demands, although there were no group differences in expression or magnitude of change across baseline to high cognitive-load conditions. Participants with self-reported constricted affect showed significant reductions in expression under high-load versus baseline speaking conditions relative to other schizotypal and control participants. Moreover, psychometrically defined schizotypal participants with poor cognitive performance on the high-load task, suggestive of depleted cognitive resources, also showed expressivity reductions compared with other participants. These findings suggest that diminished expression occurs as a function of limited cognitive resources in psychometrically defined schizotypy.  相似文献   
994.
Bridging the literatures on social dilemmas, intergroup conflict, and social hierarchy, the authors systematically varied the intergroup context in which social dilemmas were embedded to investigate how costly contributions to public goods influence status conferral. They predicted that contribution behavior would have opposite effects on 2 forms of status-prestige and dominance-depending on its consequences for the self, in-group and out-group members. When the only way to benefit in-group members was by harming out-group members (Study 1), contributions increased prestige and decreased dominance, compared with free-riding. Adding the option of benefitting in-group members without harming out-group members (Study 2) decreased the prestige and increased the dominance of those who chose to benefit in-group members via intergroup competition. Finally, sharing resources with both in-group and out-group members decreased perceptions of both prestige and dominance, compared with sharing them with in-group members only (Study 3). Prestige and dominance differentially mediated the effects of contribution behavior on leader election, exclusion from the group, and choices of a group representative for an intergroup competition. Taken together, these findings show that the well-established relationship between contribution and status is moderated by both the intergroup context and the conceptualization of status.  相似文献   
995.
Attribution theory has long enjoyed a prominent role in social psychological research, yet religious influences on attribution have not been well studied. We theorized and tested the hypothesis that Protestants would endorse internal attributions to a greater extent than would Catholics, because Protestantism focuses on the inward condition of the soul. In Study 1, Protestants made more internal, but not external, attributions than did Catholics. This effect survived controlling for Protestant work ethic, need for structure, and intrinsic and extrinsic religiosity. Study 2 showed that the Protestant-Catholic difference in internal attributions was significantly mediated by Protestants' greater belief in a soul. In Study 3, priming religion increased belief in a soul for Protestants but not for Catholics. Finally, Study 4 found that experimentally strengthening belief in a soul increased dispositional attributions among Protestants but did not change situational attributions. These studies expand the understanding of cultural differences in attributions by demonstrating a distinct effect of religion on dispositional attributions.  相似文献   
996.
We investigated how the availability of self-control resources affects risk-taking inclinations and behaviors. We proposed that risk-taking often occurs from suboptimal decision processes and heuristic information processing (e.g., when a smoker suppresses or neglects information about the health risks of smoking). Research revealed that depleted self-regulation resources are associated with reduced intellectual performance and reduced abilities to regulate spontaneous and automatic responses (e.g., control aggressive responses in the face of frustration). The present studies transferred these ideas to the area of risk-taking. We propose that risk-taking is increased when individuals find themselves in a state of reduced cognitive self-control resources (ego-depletion). Four studies supported these ideas. In Study 1, ego-depleted participants reported higher levels of sensation seeking than non-depleted participants. In Study 2, ego-depleted participants showed higher levels of risk-tolerance in critical road traffic situations than non-depleted participants. In Study 3, we ruled out two alternative explanations for these results: neither cognitive load nor feelings of anger mediated the effect of ego-depletion on risk-taking. Finally, Study 4 clarified the underlying psychological process: ego-depleted participants feel more cognitively exhausted than non-depleted participants and thus are more willing to take risks. Discussion focuses on the theoretical and practical implications of these findings.  相似文献   
997.
Meaning in life has been identified as an important element of well-being. Recently attention has been directed to examining the differences between having meaning in life and searching for meaning in life. Theory has speculated that if an individual is searching for meaning in life, he/she may be distressed. Researchers of late have begun to focus on the process of searching for meaning in life to gain a better understanding of the individual differences which may exist. Interest has also been directed towards exploring whether any moderators of the possible negative effects of the searching process may exist. This research investigated the hypothesised negative link between high levels of searching for meaning in life and subjective well-being and the positive moderating effects of presence of meaning in life while also exploring the influence of the demographic variables which were treated as control variables. From an exploratory stance further analysis examined the hypothesised positive moderating effects of self-actualisation, self-efficacy and achievement motives on the relationship between searching for meaning and subjective well-being. One study (n?=?500) was conducted to assess the hypothesized relationships. The study confirmed the negative relationship between high levels of searching for meaning in life and subjective well-being and positive moderating effects that presence of meaning in life and self-actualisation have on happiness scores when individuals are searching for meaning in life. Self-efficacy and achievement motives were shown to have no significant moderating effects on searching for meaning in life and subjective wellbeing. Overall the results suggest that individuals who record high levels of searching for meaning in life are protected from the negative outcomes of this process by holding high levels of presence of meaning in life and self-actualisation.  相似文献   
998.
Beyond its immediate effects, experiences of sexual abuse in childhood have long been analyzed with regard to possible long-term consequences. Based mainly on reviews and meta-analyses, this paper provides an overview on the state of research. Long-term effects of child sexual abuse have been researched with regard to numerous somatic, emotional, cognitive, behavioural and social characteristics. Research also touches upon questions of interindividual variability of long-term effects and factors influencing type, severity, stability and development of sexual abuse in childhood effects. The paper addresses typical research problems related to establishing connections between symptoms found in victim populations and victim experiences made years or decades ago.  相似文献   
999.
A number of prior fMRI studies have focused on the ways in which the midbrain dopaminergic reward system coactivates with hippocampus to potentiate memory for valuable items. However, another means by which people could selectively remember more valuable to-be-remembered items is to be selective in their use of effective but effortful encoding strategies. To broadly examine the neural mechanisms of value on subsequent memory, we used fMRI to assess how differences in brain activity at encoding as a function of value relate to subsequent free recall for words. Each word was preceded by an arbitrarily assigned point value, and participants went through multiple study–test cycles with feedback on their point total at the end of each list, allowing for sculpting of cognitive strategies. We examined the correlation between value-related modulation of brain activity and participants’ selectivity index, which measures how close participants were to their optimal point total, given the number of items recalled. Greater selectivity scores were associated with greater differences in the activation of semantic processing regions, including left inferior frontal gyrus and left posterior lateral temporal cortex, during the encoding of high-value words relative to low-value words. Although we also observed value-related modulation within midbrain and ventral striatal reward regions, our fronto-temporal findings suggest that strategic engagement of deep semantic processing may be an important mechanism for selectively encoding valuable items.  相似文献   
1000.
A common recommendation for teaching skills to children with autism is to apply differential reinforcement by reserving high-quality reinforcement for unprompted responses (Sundberg and Partington in Teaching language to children with autism or other developmental disabilities, Behavior Analysts Inc., Pleasant Hill, 1998). Earlier research focuses primarily on schedules or quality of reinforcement, rather than magnitude of reinforcement, when evaluating the use of differential reinforcement in practice. The utility of magnitude-based differential reinforcement may be dependent upon evidence that a learner responds differentially to large and small amounts of reinforcement such that he or she selects the large amount of reinforcement over the small amount of reinforcement and engages in more responses that produce the relatively larger magnitude reinforcement. Three individuals with autism participated in a treatment comparison of differential reinforcement. The manipulation of magnitude of differential reinforcement in a skill acquisition program did not have an appreciable effect on the rate of acquisition for any of the three participants.  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