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   204篇
  免费   24篇
  2020年   3篇
  2018年   3篇
  2017年   4篇
  2016年   4篇
  2015年   7篇
  2014年   13篇
  2013年   8篇
  2012年   15篇
  2011年   10篇
  2010年   6篇
  2009年   12篇
  2008年   1篇
  2007年   15篇
  2006年   7篇
  2005年   7篇
  2004年   3篇
  2003年   6篇
  2002年   10篇
  2001年   4篇
  2000年   7篇
  1999年   6篇
  1998年   6篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   3篇
  1991年   3篇
  1990年   5篇
  1989年   4篇
  1988年   8篇
  1987年   4篇
  1986年   2篇
  1985年   3篇
  1984年   4篇
  1983年   2篇
  1980年   1篇
  1979年   2篇
  1976年   1篇
  1974年   1篇
  1972年   4篇
  1971年   3篇
  1970年   1篇
  1968年   2篇
  1967年   1篇
  1965年   2篇
  1961年   2篇
  1960年   1篇
  1959年   1篇
排序方式: 共有228条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
The quantity of research on the effects of stress on disease has increased substantially in recent years, but little effort has been devoted to examining the effects of cultural influences in the stress process. A model is proposed in this paper in which cultural context exerts a modifying influence on the relationship between sociocultural stressors and psychosomatic symptoms, specifically in the context of modernization. In change situations involving increasing modernization there is increased differentiation in systems of social stratification within a community, due to increased potential for upward social mobility. The individuals who are upwardly mobile adopt a particular style of life, involving the acquisition of western consumer goods, as symbolic of their success. Lower class individuals strive to attain this same style of life as a claim to a higher status social identity, but their lower economic condition results in stressful incongruities and higher psychosomatic symptoms. Individuals who are successful in upward mobility are confronted by a different set of stressors that are primarily intrapsychic in nature. Events and circumstances perceived as threats to their self-identity are related to more psychosomatic symptoms. Thus, the meaning of specific stressors changes depending on the sociocultural context of the individual, and this meaning serves as a bridge between environmental circumstances and physiological outcomes. This model receives substantial empirical support in two field studies. Limitations of the model and implications for future research are discussed.Research in St. Lucia was supported by the Connecticut Research Foundation and the University of Connecticut Health Center. Research in the U.S. was supported by Research Grant MH 33943 from the Center for the Study of Minority Group Mental Health, National Institute of Mental Health. Drs. Arthur Kleinman, Lee Badger, H. B. M. Murphy, James Bindon, and Laurence Watkins kindly commented on previous drafts of this paper. Dr. Michael Murphy deserves a special note of gratitude for reading several drafts of the paper and for patiently sitting through several lengthy discussions of it. I alone am responsible for the errors and shortcomings.  相似文献   
5.
Some males of a mutant strain of King-Holtzman rats exhibit an anomalous heritable defect manifested as either unilateral or bilateral ectopic testes. In the adult, these testes contain seemingly immature Sertoli and Leydig cells, seminiferous tubules greatly reduced in diameter, and exhibit arrested spermatogenesis. Thus, the affected testis is essentially sterile. An inability to produce normal amounts of testosterone and androstenedione by these gonads is probably a reflection of changes that have been effected in their Leydig cells. Thus, this study suggests that abnormal function of the Leydig and Sertoli cells and seminiferous tubule failure in these mutant animals result from the physiologically cryptorchid condition.  相似文献   
6.
7.
The generaAmblostoma, Lanium, andStenoglossum are discussed, and it is concluded that all three should be included inEpidendrum.Lanium is treated as a section, and new names are proposed for two species whose epithets are preoccupied inEpidendrum: E. macrum (forAmblostoma gracile) andE. stiliferum (forLanium subulatum).  相似文献   
8.
9.
10.
Sampling properties of DNA sequence data in phylogenetic analysis   总被引:26,自引:6,他引:20  
We inferred phylogenetic trees from individual genes and random samples of nucleotides from the mitochondrial genomes of 10 vertebrates and compared the results to those obtained by analyzing the whole genomes. Individual genes are poor samples in that they infrequently lead to the whole-genome tree. A large number of nucleotide sites is needed to exactly determine the whole-genome tree. A relatively small number of sites, however, often results in a tree close to the whole-genome tree. We found that blocks of contiguous sites were less likely to lead to the whole-genome tree than samples composed of sites drawn individually from throughout the genome. Samples of contiguous sites are not representative of the entire genome, a condition that violates a basic assumption of the bootstrap method as it is applied in phylogenetic studies.   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