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   2225篇
  免费   172篇
  2023年   24篇
  2020年   61篇
  2019年   37篇
  2018年   61篇
  2017年   63篇
  2016年   73篇
  2015年   43篇
  2014年   65篇
  2013年   265篇
  2012年   90篇
  2011年   71篇
  2010年   67篇
  2009年   65篇
  2008年   102篇
  2007年   82篇
  2006年   79篇
  2005年   46篇
  2004年   43篇
  2003年   45篇
  2002年   47篇
  2001年   54篇
  2000年   59篇
  1999年   47篇
  1998年   27篇
  1997年   18篇
  1996年   37篇
  1995年   35篇
  1994年   25篇
  1993年   20篇
  1992年   41篇
  1991年   29篇
  1990年   31篇
  1989年   28篇
  1988年   30篇
  1987年   32篇
  1986年   30篇
  1985年   27篇
  1984年   22篇
  1983年   16篇
  1982年   21篇
  1981年   17篇
  1979年   21篇
  1978年   31篇
  1977年   31篇
  1976年   18篇
  1975年   23篇
  1974年   18篇
  1971年   17篇
  1968年   23篇
  1966年   15篇
排序方式: 共有2397条查询结果,搜索用时 31 毫秒
211.
212.
213.
Assessment of risk is one of the key issues in the field of responsible conduct of research which covers discourses of research ethics and research integrity. The principle of minimizing risks and balancing of risks and benefits is one of the main requirements of research ethics. In addition, the content of informed consent that is another fundamental principle of research ethics derives from the assessment of risks and benefits related to a particular research project. Risk assessment also plays a crucial role in methodological design of the research project. This is an important point where research ethics and research integrity discourses overlap. Firstly, because the choice of a control group (e.g., placebo control) is a key ethical issue related to the protection of the research subjects' interests. Secondly, because the quality of the research data, that is one of the key elements of research integrity, is closely connected to the choice of research methodology as well. The problem of biased interpretation or manipulation of risk related features of biomedical research should also be taken into account. Despite the importance of the concept of risk to the field of biomedical research, its relevance has not yet attracted a sufficient attention in the responsible conduct of research debate.  相似文献   
214.
The Helsinki Declaration is a very important document regarding the protection of patients’ rights in clinical trials and one of the fundamental sources of operational principles for every ethics committee. Although they have been updated, the international guidelines for ethics committees continually fail to address certain issues pertaining to the protection of patients’ rights in clinical trials. These issues include, most significantly, the method of electing ethics committees (a free, secret ballot should be preferred to direct appointment), the avoidance of conflict of interest during the election of ethics committee members, and the necessary insurance coverage for the participants of clinical trials. Polish law should, on the other hand, be developed in such way as to not limit the effectiveness of ethics committees in protecting patients’ rights in clinical trials. The ideal solution would be to draft a uniform law concerning not only clinical trials, but all medical experiments. The opinions of experts who have been reviewing medical research projects for several years may prove to be especially valuable in this setting. This paper was presented at the 6th International Bioethics Conference on the subject of ‘The Responsible Conduct of Basic and Clinical Research’, held in Warsaw, Poland, 3–4 June 2005. The author is Chairman, Bioethics Committee of the Warsaw Regional Chamber of Physicians and Dentists.  相似文献   
215.
Medicine is a scientific discipline, but it is sometimes difficult to separate what is scientific and what is a clinical, practical activity. Man is the object, but he is always the subject of medical research and therefore these two elements become closely bound together by a thread of moral interdependencies. Every mentor of a young academic and all institutions dealing with the teaching of and research into medicine must understand multidimensional, multifaceted, and multilevel aspects of their activity and give them due regard in the educational process. The educational mission of an academic institution and of the teacher working there may be summed up in one phrase: Teach thinking! At the same time, the task of a school and the individual mentor is to teach the student to distinguish personal freedom from a lack of the feeling of responsibility. The medieval principle “Universitas magistrorum et scholarium”, and thus the corporation, the community of teachers and students, has not lost any of its relevance and value today. The situation is, in its far-reaching consequences, tragic in which the “insufficiently tutored teach”. Both physician and teacher, and especially physician-teacher, are not only professions, but also callings. This paper was presented at the 6th International Bioethics Conference on the subject of ‘The Responsible Conduct of Basic and Clinical Research’, held in Warsaw, Poland, 3–4 June 2005.  相似文献   
216.
The Visual Similes Test II was designed to measure the construct of arousal. This study investigated its factor structure with scores from a sample of 154 African-American elementary school children (7 to 10 years). The initial factor structure was examined using principal axis factor analysis with the promax rotation. Confirmatory factor analysis was then used to evaluate the model-fit of the data with the hypothesized hierarchical model. Results provided support for the two-factor structure in the principal axis factor analysis and the model-fit of the hypothesized model in the confirmatory factor analysis.  相似文献   
217.
BACKGROUND: People with autism or Asperger Syndrome (AS) show altered patterns of brain activity during visual search and emotion recognition tasks. Autism and AS are genetic conditions and parents may show the 'broader autism phenotype.' AIMS: (1) To test if parents of children with AS show atypical brain activity during a visual search and an empathy task; (2) to test for sex differences during these tasks at the neural level; (3) to test if parents of children with autism are hyper-masculinized, as might be predicted by the 'extreme male brain' theory. METHOD: We used fMRI during a visual search task (the Embedded Figures Test (EFT)) and an emotion recognition test (the 'Reading the Mind in the Eyes' (or Eyes) test). SAMPLE: Twelve parents of children with AS, vs. 12 sex-matched controls. DESIGN: Factorial analysis was used to map main effects of sex, group (parents vs. controls), and sexxgroup interaction on brain function. An ordinal ANOVA also tested for regions of brain activity where females>males>fathers=mothers, to test for parental hyper-masculinization. RESULTS ON EFT TASK: Female controls showed more activity in extrastriate cortex than male controls, and both mothers and fathers showed even less activity in this area than sex-matched controls. There were no differences in group activation between mothers and fathers of children with AS. The ordinal ANOVA identified two specific regions in visual cortex (right and left, respectively) that showed the pattern Females>Males>Fathers=Mothers, both in BA 19. RESULTS ON EYES TASK: Male controls showed more activity in the left inferior frontal gyrus than female controls, and both mothers and fathers showed even more activity in this area compared to sex-matched controls. Female controls showed greater bilateral inferior frontal activation than males. This was not seen when comparing mothers to males, or mothers to fathers. The ordinal ANOVA identified two specific regions that showed the pattern Females>Males>Mothers=Fathers: left medial temporal gyrus (BA 21) and left dorsolateral prefrontal cortex (BA 44). CONCLUSIONS: Parents of children with AS show atypical brain function during both visual search and emotion recognition, in the direction of hyper-masculinization of the brain. Because of the small sample size, and lack of age-matching between parents and controls, such results constitute a pilot study that needs replicating with larger samples.  相似文献   
218.
This intervention compared the effects of two procedures on the generalization of a tacting repertoire (labeling) in 6 children with autism spectrum disorder. In one procedure the verbal antecedent stimulus “What is she doing?” appeared together with a person performing an action; in the other procedure, the antecedent stimulus was just the presence of the action. In initial tests, children emitted tacts only when the action was presented with the verbal antecedent. Thereafter, they learned to tact an action without the verbal antecedent and received tests to evaluate generalization to another action. Results indicated that in order to obtain generalization of tacting actions, it was necessary to learn to tact other actions without the verbal antecedent as well as learning to tact the action with the verbal antecedent. These findings have relevance for generalization of tacting actions from control by verbal antecedents to natural conditions and the production of spontaneous language.  相似文献   
219.
The importance of intra- and inter-limb relative motion in modelling a whole body coordination skill was examined. Participants were assigned to one of four groups: Full-Body point light model of a cricket bowler, INTRA-LIMB relative motion of the bowling arm, INTER-LIMB relative motions of the right and left wrists or NO-Relative motion, showing only the motions of the right wrist. During 60 acquisition trials, participants viewed the model five times before each 10-trial block. Retention was examined the following day. Although all groups improved on intra-limb coordination of the bowling arm, the INTRA-LIMB and FULL-BODY groups were more accurate than the INTER-LIMB group in acquisition, although these groups did not differ in retention. For inter-limb coordination, the three groups who received relative motion information performed more like the model than the NO-Relative motion group (even though the INTRA-LIMB group did not see the other limb). The amount of information within a display plays a constraining role on acquisition, perhaps more so than the type of information, such that the acquisition of coordination is more an emergent feature of observational learning, rather than a direct approximation of the model.  相似文献   
220.
Modeling the antecedents of proactive behavior at work   总被引:1,自引:0,他引:1  
Using a sample of U.K. wire makers (N = 282), the authors tested a model in which personality and work environment antecedents affect proactive work behavior via cognitive-motivational mechanisms. Self-reported proactive work behaviors (proactive idea implementation and proactive problem solving) were validated against rater assessments for a subsample (n = 60) of wire makers. With the exception of supportive supervision, each antecedent was important, albeit through different processes. Proactive personality was significantly associated with proactive work behavior via role breadth self-efficacy and flexible role orientation, job autonomy was also linked to proactive behavior via these processes, as well as directly; and coworker trust was associated with proactive behavior via flexible role orientation. In further support of the model, the cognitive-motivational processes for proactive work behavior differed from those for the more passive outcome of generalized compliance.  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