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   83篇
  免费   0篇
  2024年   1篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2018年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   5篇
  2012年   4篇
  2011年   6篇
  2010年   6篇
  2009年   2篇
  2008年   1篇
  2007年   3篇
  2006年   6篇
  2005年   3篇
  2004年   5篇
  2003年   3篇
  2002年   4篇
  2001年   3篇
  2000年   4篇
  1998年   1篇
  1996年   1篇
  1995年   2篇
  1992年   3篇
  1991年   1篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1978年   3篇
  1973年   1篇
排序方式: 共有83条查询结果,搜索用时 15 毫秒
1.
Human fetal cardiac responses (36-39 weeks gestational age) to brief, repeated vocal stimuli (male or female voice uttering the same sentence), given at 90-95 dB SPL ex utero (around 20-30 dB less in utero) during a state of low fetal heart rate (FHR) variability, were examined using highly conservative statistical criteria taking into account each subject's prestimulus FHR variability. Subjects exposed to either of the two stimuli displayed significantly more decelerative heart rate (HR) changes compared to control subjects receiving no stimulation. The decelerative changes started during the first seconds following the onset of stimulation and reached their amplitude peak within 10 or 20 sec, depending on the subject. The directions—HR acceleration or deceleration—and the amplitude of the response depended on prestimulus HR variability only, not on prestimulus level. No major difference was found between the effects of the two voices. The data are compared to previous studies demonstrating fetal decelerative changes to acoustic stimuli of less than 105 dB SPL. The choice of an objective criterion to define an HR response and the possible orienting response nature of the decelerative change are discussed.  相似文献   
2.
Code-switching occurs regularly in the input to bilingual children. Yet, the effect of code-switched input on language development is unclear. To test whether word learning would be affected by code-switching, Spanish–English bilingual children (= 45, 19 boys, MeanAge = 5.05 years; ethnicity: 37 Hispanic/Latino, six Non-Hispanic/Latino, two unreported) were taught English-like novel words in two conditions. In the English-only condition, definitions for novel words were provided entirely in English. In the code-switch condition, definitions for novel words were provided in English and Spanish, incorporating code-switches. Children required fewer exposures to retain novel words in the code-switch than the English-only condition and this effect was not moderated by children's language ability or exposure to code-switching, suggesting that code-switched input does not pose word-learning risks to bilingual children, including children with lower levels of language ability.  相似文献   
3.
4.
Five hundred and fifty-eight cigarette smokers (mean 31 cigarettes/day) were randomized in four groups: Acupuncture, Behaviour Therapy, Placebo Medication and Waiting-list Control. The life-table analysis of smoking cessation showed, at a 12-month follow-up, no difference between Acupuncture, Behaviour Therapy and Placebo. Differences appeared only in an analysis of the abstinent subjects at each data point. Behaviour Therapy and Acupuncture accounted for significantly more abstinent subjects than Placebo at the end of the 2-week therapeutic phase. However at 9 and 12 months Acupuncture had a statistically-significant greater number of abstinent subjects than Behaviour Therapy, but there was no difference between Acupuncture and Placebo. The percentage decrease in smoking from baseline appeared significantly greater at 12 months in the first three groups than in the Control conditions. However, as in most smoking-cessation studies, the overall effect was small and non-specific. The results reflect the importance of maintenance programmes and of the prevention of addiction.  相似文献   
5.
Approximations form an essential part of scientific activity and they come in different forms: conceptual approximations (simplifications in models), mathematical approximations of various types (e.g. linear equations instead of non-linear ones, computational approximations), experimental approximations due to limitations of the instruments and so on and so forth. In this paper, we will consider one type of approximation, namely numerical approximations involved in the comparison of two results, be they experimental or theoretical. Our goal is to lay down the conceptual and formal foundations of a local theory of partial truth. This is done by introducing and exploring the concept of truth space.  相似文献   
6.
7.
8.
Social disruption (SDR) is an effective model of social stress associated with an enhanced inflammatory reactivity of the immune system. The aim of the present study was to further describe SDR effects on cytokine production by spleen cells, testing selectively monocyte and T cell functions as a result of this stressor. For this purpose, splenocytes from control mice (C) and mice socially stressed for 7 days (SDR) were cultured in the presence of lipopolysaccharide (LPS) or concanavalin A (Con A). Splenocyte proliferation, cytokine production and sensitivity of spleen cells to corticosterone were assessed in vitro. The humoral response to keyhole limpet hemocyanin (KLH) immunization was assessed. SDR induced splenomegaly and enhanced splenocyte basal proliferation. The pro-inflammatory influence of SDR was confirmed by an increased release of interleukin-6 (IL-6) by LPS-stimulated cultures and by a reduced sensitivity of spleen cells to the anti-inflammatory effect of corticosterone. The mechanism increasing cytokine production in response to LPS was cytokine specific, since among inflammatory cytokines, IL-6 but not interferon-gamma (IFN-gamma) was enhanced by stress. In stressed mice, the increase in IL-6 and IFN-gamma and the decrease in IL-10 release in Con A-stimulated cultures indicate that SDR did not modify the Th1/Th2 cytokine balance but globally activated T cells. Plasma anti-KLH antibody levels were similar in both groups. Wounded and non-wounded mice presented similar responses to stress. This study shows that social disruption stress enhances the reactivity of cells from both the acquired and innate immune systems.  相似文献   
9.
Reviewing the publications of prominent American rabbis who have (extensively) published on Jewish biomedical ethics, this article highlights Orthodox, Conservative and Reform opinions on a most pressing contemporary bioethical issue: euthanasia. Reviewing their opinions against the background of the halachic character of Jewish (biomedical) ethics, this article shows how from one traditional Jewish textual source diverse, even contradictory, opinions emerge through different interpretations. In this way, in the Jewish debate on euthanasia the specific methodology of Jewish (bio)ethical reasoning comes forward as well as a diversity of opinion within Judaism and its branches.  相似文献   
10.
This study presents the validation of the Authentic Leadership Questionnaire (ALQ) in a sample of more than 600 Spanish employees. This questionnaire measures four distinct but related substantive components of authentic leadership. These components are: self-awareness, relational transparency, balanced processing, and internalized moral perspective. Structural equation modeling confirmed that the Spanish version of ALQ has high reliability and predictive validity for important leadership outputs such as perceived effectiveness of leadership, followers' extra effort and satisfaction with the leader.  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