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   112篇
  免费   0篇
系统科学   1篇
理论与方法论   2篇
现状及发展   69篇
研究方法   10篇
综合类   28篇
自然研究   2篇
  2019年   1篇
  2016年   1篇
  2014年   1篇
  2012年   5篇
  2011年   2篇
  2010年   2篇
  2008年   4篇
  2007年   4篇
  2006年   4篇
  2005年   3篇
  2004年   6篇
  2003年   1篇
  2002年   1篇
  2000年   3篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1992年   2篇
  1991年   2篇
  1990年   6篇
  1989年   1篇
  1988年   4篇
  1987年   2篇
  1985年   4篇
  1984年   3篇
  1978年   3篇
  1977年   8篇
  1976年   4篇
  1975年   5篇
  1974年   3篇
  1973年   1篇
  1972年   7篇
  1971年   2篇
  1968年   1篇
  1967年   3篇
  1966年   1篇
  1965年   3篇
  1961年   1篇
排序方式: 共有112条查询结果,搜索用时 15 毫秒
21.
Biotechnology: surrogate broodstock produces salmonids   总被引:1,自引:0,他引:1  
Takeuchi Y  Yoshizaki G  Takeuchi T 《Nature》2004,430(7000):629-630
A worldwide decline in the number of wild salmonids calls for strategies to restore endangered populations. Here we show that germ cells can be transplanted between two different salmonid species, with the subsequent production of xenogenic, donor-derived offspring. This pioneering xenotransplantation technology may eventually find applications in facilitating the production of commercially valuable fish, as well as in species conservation.  相似文献   
22.
Summary 3, 5-Dichloro-2,4-dihydroxybenzanilide, an inhibitor of histidine decarboxylase, inhibited skin tumor promotion induced by 12-O-tetradecanoylphorbol-13-acetate in mice.Acknowledgments. The authors wish to thank Miss H. Iwami for technical assistance and members of the Central Research Laboratory of Sanraku-Ocean Co., Ltd for supplying lecanoric acid analogues. This work was supported in part by the Grantsin-Aid for Cancer Research from the Ministry of Education, Science and Culture and the Ministry of Health and Welfare of Japan.  相似文献   
23.
Tight junctions (TJs) create a paracellular permeability barrier. Although reactive oxygen species have been implicated as mediators of inflammation in inflammatory bowel diseases, their influence on the function of colonic epithelial TJs remains unknown. Oxidative stress-mediated colonic epithelial permeability was significantly attenuated by a p38 mitogen-activated protein (MAP) kinase inhibitor, SB203580. Although the amount of TJ proteins was not altered, hydrogen peroxide (H2O2) changed the localization of claudin-4 protein from an NP-40 insoluble fraction to a soluble fraction and from an apical TJ to lateral membrane. The p38 MAP kinase inactivator Wip1 significantly attenuated phosphorylation of p38 MAP kinase, and oxidative stress mediated permeability. H2O2-induced changes in claudin-4 localization were abolished by SB203580 pretreatment as well as Wip1-expressing adenovirus infection. This is the first study to demonstrate that exogenous Wip1 functions to protect oxidative stress-mediated colonic mucosal permeability and that H2O2-induced claudin-4 dislocalization is abolished by Wip1. Received 14 June 2007; received after revision 8 October 2007; accepted 8 October 2007  相似文献   
24.
Chronic kidney disease (CKD), impairment of kidney function, is a serious public health problem, and the assessment of genetic factors influencing kidney function has substantial clinical relevance. Here, we report a meta-analysis of genome-wide association studies for kidney function-related traits, including 71,149 east Asian individuals from 18 studies in 11 population-, hospital- or family-based cohorts, conducted as part of the Asian Genetic Epidemiology Network (AGEN). Our meta-analysis identified 17 loci newly associated with kidney function-related traits, including the concentrations of blood urea nitrogen, uric acid and serum creatinine and estimated glomerular filtration rate based on serum creatinine levels (eGFRcrea) (P < 5.0 × 10(-8)). We further examined these loci with in silico replication in individuals of European ancestry from the KidneyGen, CKDGen and GUGC consortia, including a combined total of ~110,347 individuals. We identify pleiotropic associations among these loci with kidney function-related traits and risk of CKD. These findings provide new insights into the genetics of kidney function.  相似文献   
25.
The genome of the model plant Arabidopsis thaliana has been sequenced by an international collaboration, The Arabidopsis Genome Initiative. Here we report the complete sequence of chromosome 5. This chromosome is 26 megabases long; it is the second largest Arabidopsis chromosome and represents 21% of the sequenced regions of the genome. The sequence of chromosomes 2 and 4 have been reported previously and that of chromosomes 1 and 3, together with an analysis of the complete genome sequence, are reported in this issue. Analysis of the sequence of chromosome 5 yields further insights into centromere structure and the sequence determinants of heterochromatin condensation. The 5,874 genes encoded on chromosome 5 reveal several new functions in plants, and the patterns of gene organization provide insights into the mechanisms and extent of genome evolution in plants.  相似文献   
26.
27.
Zusammenfassung Die Körperfarbe des männlichen d-rR Medaka ist wegen des in Xanthophor enthaltenen Carotinoid-Pigments orange, die der weiblichen wegen seiner Abwesenheit uni. Die Färbung erfolgt im allgemeinen nach der Ausbrütung. Wird das rote Carotinoid des Paprikas unmittelbar nach der Befruchtung injiziert, so wird die dorsale Körperoberfläche des männlichen Embryos durch das Pigment gefärbt, was die Feststellung des erblichen Geschlechts schon vor der Ausbrütung erlaubt. Beurteilungsfehler konnten bis auf weniger als 10% herabgedrückt werden.  相似文献   
28.
Zusammenfassung Es wird gezeigt, dass die Dopamin--Hydroxylase-Aktivität im Serum bei spontan hypertonischen Ratten im Vergleich zu normotonen Kontrollen nicht verändert ist.  相似文献   
29.
30.
Signal transduction through Toll-like receptors (TLRs) originates from their intracellular Toll/interleukin-1 receptor (TIR) domain, which binds to MyD88, a common adaptor protein containing a TIR domain. Although cytokine production is completely abolished in MyD88-deficient mice, some responses to lipopolysaccharide (LPS), including the induction of interferon-inducible genes and the maturation of dendritic cells, are still observed. Another adaptor, TIRAP (also known as Mal), has been cloned as a molecule that specifically associates with TLR4 and thus may be responsible for the MyD88-independent response. Here we report that LPS-induced splenocyte proliferation and cytokine production are abolished in mice lacking TIRAP. As in MyD88-deficient mice, LPS activation of the nuclear factor NF-kappaB and mitogen-activated protein kinases is induced with delayed kinetics in TIRAP-deficient mice. Expression of interferon-inducible genes and the maturation of dendritic cells is observed in these mice; they also show defective response to TLR2 ligands, but not to stimuli that activate TLR3, TLR7 or TLR9. In contrast to previous suggestions, our results show that TIRAP is not specific to TLR4 signalling and does not participate in the MyD88-independent pathway. Instead, TIRAP has a crucial role in the MyD88-dependent signalling pathway shared by TLR2 and TLR4.  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