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   464篇
  免费   0篇
电工技术   1篇
化学工业   4篇
建筑科学   1篇
能源动力   1篇
轻工业   1篇
水利工程   1篇
无线电   1篇
一般工业技术   1篇
冶金工业   452篇
自动化技术   1篇
  2020年   1篇
  2015年   1篇
  2011年   1篇
  2008年   1篇
  2005年   1篇
  2003年   3篇
  2002年   1篇
  1999年   20篇
  1998年   135篇
  1997年   78篇
  1996年   60篇
  1995年   30篇
  1994年   27篇
  1993年   29篇
  1992年   3篇
  1991年   3篇
  1990年   3篇
  1989年   3篇
  1988年   6篇
  1987年   1篇
  1986年   3篇
  1983年   3篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1977年   23篇
  1976年   22篇
排序方式: 共有464条查询结果,搜索用时 5 毫秒
461.
Random samples of nurses in two states which differed in abortion statues were sent questionnaires. Content areas included experience with 12 specific nursing activities associated with abortion, willingness to participate in the same activities, and extent of agreement with statements related to abortion. Attitudes toward abortion were inferred from the willingness-to-participate items and from the agreement section. These two measures correlated highly suggesting a common underlying dimension. However, the two samples differed significantly in extent of agreement but did not differ in willingness to participate. These results were interpreted as supporting the position that attitudes derived from items using situational contexts might bear a better relationship to behavior. The findings also suggest that abortion facilities can probably be staffed without violating personal preferences since so many expressed willingness to participate in at least some of the activities. Comparison across the two samples suggest that increased experience or even the potential for experience with abortion patients tended to increase the favorableness of attitudes toward this issue.  相似文献   
462.
Filarial nematode parasites establish long-term chronic infections in the context of an antiparasite immunity that is strongly biased toward a Th2 response. The mechanisms that lead to this Th2 bias toward filarial antigens are not clear, but one possibility is that the parasites produce molecules that have the capacity to proactively modify their immunological environment. Here we report that filarial parasites of humans secrete a homologue of the human proinflammatory cytokine macrophage migration inhibitory factor (MIF) that has the capability of modifying the activity of human monocytes/macrophages. A cDNA clone isolated from a Brugia malayi infective-stage larva expression library encoded a 12.5-kDa protein product (Bm-MIF) with 42% identity to human and murine MIF. MIF homologues were also found to be expressed in the related filarial species Wuchereria bancrofti and Onchocerca volvulus. Bm-mif was transcribed by adult and larval parasites, and the protein product was found in somatic extracts and in the parasite's excretory-secretory products. Immunohistocytochemistry revealed that Bm-MIF was localized to cells of the hypodermis/lateral chord, the uterine wall, and larvae developing in utero. Unexpectedly, the activities of recombinant Bm-MIF and human MIF on human monocytes/macrophages were found to be similar. When placed with monocytes/macrophages in a cell migration assay, Bm-MIF inhibited random migration. When placed away from cells, Bm-MIF induced an increase in monocyte/macrophage migration that was specifically inhibited by neutralizing anti-Bm-MIF antibodies. Bm-MIF is the first demonstration that helminth parasites produce cytokine homologues that have the potential to modify host immune responses to promote parasite survival.  相似文献   
463.
Even today psychotic depression is connected to a lot of unanswered questions. A self-questionnaire (BFD) was developed in order to evaluate cognitions corresponding to mood congruent depressive delusions. They were assumed to indicate psychotic depression and to be related to severity of the depressive syndrome. 42 depressed inpatients were examined by the BFD, the Hamilton Depression Scale (HAMD) and the Beck Depression Inventory (BDI). BFD scores were found increased in psychotic depression (p = 0.009) and correlated to BDI scores (p = 0.002). 19 re-examined patients showed a significant improvement in HAMD and BDI scores but not concerning the delusion indicating cognitions (BFD), which were significantly correlated to suicidality items of BDI and HAMD (p = 0.005). The results prove the delusion indicating nature of cognitions measured by the BFD and their correlation to severe depression. Differences in treatment response are indicated and persisting or increasing BFD scores seem to be accompanied by more severe suicidal tendency.  相似文献   
464.
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