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   2402篇
  免费   166篇
  国内免费   1篇
  2023年   23篇
  2022年   25篇
  2021年   36篇
  2020年   82篇
  2019年   71篇
  2018年   106篇
  2017年   100篇
  2016年   124篇
  2015年   86篇
  2014年   96篇
  2013年   290篇
  2012年   156篇
  2011年   136篇
  2010年   97篇
  2009年   96篇
  2008年   119篇
  2007年   96篇
  2006年   67篇
  2005年   59篇
  2004年   86篇
  2003年   48篇
  2002年   50篇
  2001年   37篇
  2000年   31篇
  1999年   21篇
  1998年   17篇
  1997年   15篇
  1996年   13篇
  1993年   12篇
  1992年   20篇
  1991年   26篇
  1990年   11篇
  1989年   12篇
  1988年   17篇
  1987年   12篇
  1986年   12篇
  1985年   16篇
  1984年   11篇
  1983年   10篇
  1981年   10篇
  1980年   11篇
  1979年   15篇
  1978年   13篇
  1977年   10篇
  1976年   15篇
  1975年   16篇
  1974年   14篇
  1973年   16篇
  1971年   9篇
  1966年   17篇
排序方式: 共有2569条查询结果,搜索用时 15 毫秒
181.
182.
Although much has been written on the dead-donor rule (DDR) in the last twenty-five years, scant attention has been paid to how it should be formulated, what its rationale is, and why it was accepted. The DDR can be formulated in terms of either a Don’t Kill rule or a Death Requirement, the former being historically rooted in absolutist ethics and the latter in a prudential policy aimed at securing trust in the transplant enterprise. I contend that the moral core of the rule is the Don’t Kill rule, not the Death Requirement. This, I show, is how the DDR was understood by the transplanters of the 1960s, who sought to conform their practices to their ethics—unlike today’s critics of the DDR, who rethink their ethics in a question-begging fashion to accommodate their practices. A better discussion of the ethics of killing is needed to move the debate forward.  相似文献   
183.
184.
185.
This paper explores patients’ views and experiences of undergoing treatment-focused BRCA1 and BRCA2 genetic testing (TFGT), either offered following triaging to clinical genetics (breast cancer) or as part of a mainstreamed care pathway in oncology (ovarian cancer). Drawing on 26 in-depth interviews with patients with breast or ovarian cancer who had undergone TFGT, this retrospective study examines patients’ views of genetic testing at this point in their care pathway, focusing on issues, such as initial response to the offer of testing, motivations for undergoing testing, and views on care pathways. Patients were amenable to the incorporation of TFGT at an early stage in their cancer care irrespective of (any) prior anticipation of having a genetic test or family history. While patients were glad to have been offered TFGT as part of their care, some questioned the logic of the test’s timing in relation to their cancer treatment. Crucially, patients appeared unable to disentangle the treatment role of TFGT from its preventative function for self and other family members, suggesting that some may undergo TFGT to obtain information for others rather than for self.  相似文献   
186.
Germline genomic testing is increasingly used in research to identify genetic causes of disease, including cancer. However, there is evidence that individuals who are notified of clinically actionable research findings have difficulty making informed decisions regarding uptake of genetic counseling for these findings. This study aimed to produce and pilot test a decision aid to assist participants in genomic research studies who are notified of clinically actionable research findings to make informed choices regarding uptake of genetic counseling. Development was guided by published literature, the International Patient Decision Aid Standards, and the expertise of a steering committee of clinicians, researchers, and consumers. Decision aid acceptability was assessed by self-report questionnaire. All 19 participants stated that the decision aid was easy to read, clearly presented, increased their understanding of the implications of taking up research findings, and would be helpful in decision-making. While low to moderate levels of distress/worry were reported after reading the booklet, a majority of participants also reported feeling reassured. All participants would recommend the booklet to others considering uptake of clinically actionable research findings. Results indicate the decision aid is acceptable to the target audience, with potential as a useful decision support tool for genomic research participants.  相似文献   
187.

An intrinsic part of seeing objects is seeing how similar or different they are relative to one another. This experience requires that objects be mentally represented in a common format over which such comparisons can be carried out. What is that representational format? Objects could be compared in terms of their superficial features (e.g., degree of pixel-by-pixel overlap), but a more intriguing possibility is that they are compared on the basis of a deeper structure. One especially promising candidate that has enjoyed success in the computer vision literature is the shape skeleton—a geometric transformation that represents objects according to their inferred underlying organization. Despite several hints that shape skeletons are computed in human vision, it remains unclear how much they actually matter for subsequent performance. Here, we explore the possibility that shape skeletons help mediate the ability to extract visual similarity. Observers completed a same/different task in which two shapes could vary either in their skeletal structure (without changing superficial features such as size, orientation, and internal angular separation) or in large surface-level ways (without changing overall skeletal organization). Discrimination was better for skeletally dissimilar shapes: observers had difficulty appreciating even surprisingly large differences when those differences did not reorganize the underlying skeletons. This pattern also generalized beyond line drawings to 3-D volumes whose skeletons were less readily inferable from the shapes’ visible contours. These results show how shape skeletons may influence the perception of similarity—and more generally, how they have important consequences for downstream visual processing.

  相似文献   
188.
Adam Pryor 《Dialog》2018,57(1):5-11
Despite the awe and wonder that discoveries related to astrobiology inspire, the sheer volume and diversity of new discoveries related to space science can become overwhelming without meaningful frames of reference by which to organize our understanding of these phenomena. I suggest that a critical feature of the future of “astrotheology” relates to how it serves as an organizing correlate to astrobiology and space research. Considering that the prefix astro‐ has an amplicative and abductive effect on the fields of study to which it is applied, I contend that astrotheology implies a creative and constructive shift in how we conceptualize meaningful human being for theology that parallels how astrobiology effects a creative and constructive shift in how we conceptualize living systems.  相似文献   
189.
Suicide is the second leading cause of death for those ages 13–25 in the United States. Coping is a mediator between stressful life events and adverse outcomes, and coping skills have been incorporated into interventions (e.g., cognitive-behavioral therapy, dialectical behavior therapy, safety-planning interventions) for suicidal populations. However, longitudinal research has not directly examined the prospective associations between multiple coping styles and suicide-related outcomes in high-risk samples. This study identified cross-sectional and 4-month longitudinal associations of coping styles with suicide risk factors (i.e., depression, suicidal ideation, suicidal behavior) in a sample of 286 adolescent and young adult psychiatric emergency patients. Positive reframing was the coping style most consistently associated with positive outcomes, whereas self-blame and disengagement were consistently associated with negative outcomes. Active coping protected against suicidal behavior for males, but not for females. This was the first study to examine longitudinal relationships between coping and suicide-related outcomes in a high-risk clinical sample. Findings suggest that clinical interventions with suicidal adolescents and young adults may benefit from a specific focus on increasing positive reframing and reducing self-blame.  相似文献   
190.
Multilevel modeling provides the ability to simultaneously evaluate the discounting of individuals and groups by examining choices between smaller sooner and larger later rewards. A multilevel logistic regression approach is advocated in which sensitivity to relative reward magnitude and relative delay are considered as separate contributors to choice. Examples of how to fit choice data using multilevel logistic models are provided to help researchers in the adoption of these methods.  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