46 research outputs found

    X-ray Anomalous Scattering of Diluted Magnetic Oxide Semiconductors: Possible Evidence of Lattice Deformation for High Temperature Ferromagnetism

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    We have examined whether the Co ions crystallographically substitute on the Ti sites in rutile and anatase Ti_{1-x}CoCo_{x}OO_{2-delta}thinfilmsthatexhibitroomtemperatureferromagnetism.IntensitiesofthexrayBraggreflectionfromthefilmsweremeasuredaroundthe thin films that exhibit room-temperature ferromagnetism. Intensities of the x-ray Bragg reflection from the films were measured around the KabsorptionedgeofCo.IftheCoionsrandomlysubstituteontheTisites,theintensityshouldexhibitananomalyduetotheanomalousdispersionoftheatomicscatteringfactorofCo.However,noneoftheanataseandrutilesamplesdidexhibitananomaly,unambiguouslyshowingthattheCoionsinTi-absorption-edge of Co. If the Co ions randomly substitute on the Ti sites, the intensity should exhibit an anomaly due to the anomalous dispersion of the atomic scattering factor of Co. However, none of the anatase and rutile samples did exhibit an anomaly, unambiguously showing that the Co ions in Ti_{1-x}CoCo_{x}OO_{2-delta}arenotexactlylocatedattheTisitesofTiO are not exactly located at the Ti sites of TiO_2.TheabsenceoftheanomalyisprobablycausedbyasignificantdeformationofthelocalstructurearoundCoduetotheoxygenvacancy.WehaveappliedthesamemethodtoparamagneticZn. The absence of the anomaly is probably caused by a significant deformation of the local structure around Co due to the oxygen vacancy. We have applied the same method to paramagnetic Zn_{1-x}CoCo_{x}$O thin films and obtained direct evidence that the Co ions are indeed substituted on the Zn sites.Comment: 5 pages, 4 figures, accepted in PR

    NBRP, National Bioresource Project of Japan and plant bioresource management

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    The National BioResource Project has been organized and established to promote research activities using valuable bioresources. A total of twenty-eight bioresources for ten animals, nine plants and nine microorganisms/cell lines developed or collected in Japan were selected for the project. Resources are categorized into several different groups in the project; genetic resources, germplasm, genome resources and their information. Choices of how many resources must be preserved and maintained and in which categories are dependent on the status of the research community of each organism. These resources, if utilized systematically and intelligently, are powerful means for leading new scientific discoveries. Some examples can be seen in this paper. This paper reviews plant bioresources with the main focus on rice resource activities within the project

    Expression of interferon-stimulated gene 20 in vascular endothelial cells.

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    ISG20 is an ribonuclease specific for single-stranded RNA and considered to play a role in innate immunity against virus infections. We herein show that both poly IC, an authentic double-stranded RNA, and IFN-gamma induced ISG20 expression in cultured HUVEC. Poly IC-induced ISG20 expression was inhibited by LY294002, an inhibitor of PI3K, or by RNA interference against IFN regulatory factor three. ISG20 expression was not induced by IFN-beta, loxoribine or CpG oligonucleotide. These results suggest that ISG20 induction by poly IC may not be dependent on the IRF-3-mediated type I IFN induction pathway in HUVEC. ISG20 may be involved in innate immunity against viral infection in vascular endothelial cells
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