Hiroshima University

About: Hiroshima University is a education organization based out in Hiroshima, Japan. It is known for research contribution in the topics: Population & Cancer. The organization has 33602 authors who have published 69290 publications receiving 1495648 citations. The organization is also known as: Hiroshima Daigaku.

Radio-Loud Narrow-Line Seyfert 1 as a New Class of Gamma-Ray Active Galactic Nuclei

Abstract: We report the discovery with Fermi/LAT of gamma-ray emission from three radio-loud narrow-line Seyfert 1 galaxies: PKS 1502+036 (z=0.409), 1H 0323+342 (z=0.061) and PKS 2004-447 (z=0.24). In addition to PMN J0948+0022 (z=0.585), the first source of this type to be detected in gamma rays, they may form an emerging new class of gamma-ray active galactic nuclei (AGN). These findings can have strong implications on our knowledge about relativistic jets and the unified model of AGN.

Heme regulates the dynamic exchange of Bach1 and NF-E2-related factors in the Maf transcription factor network

Abstract: Small Maf proteins serve as dual-function transcription factors through an exchange of their heterodimerization partners. For example, as heterodimers with hematopoietic cell-specific p45 NF-E2 or NF-E2-related factors (Nrf), they activate the β-globin or antioxidative stress enzyme heme oxygenase 1 (HO-1) genes, respectively. In contrast, together with Bach1, they repress these same genes. However, the signals leading to this partner exchange are not known. Using chromatin immunoprecipitation assays in NIH 3T3 cells, we show that heme, an inducer of ho-1, promotes displacement of Bach1 from the MafK-occupied ho-1 enhancers, which is followed by Nrf2 binding to these elements. Whereas histone H3 at the ho-1 enhancers and promoter is hyperacetylated irrespective of gene activity, exposure of cells to heme results in de novo hyperacetylation and hypermethylation of histone H3 in the transcribed region. These data indicate that, under normal conditions, the chromatin structure of ho-1 is in a preactivation state, but transcription is repressed by Bach1. Heme induces switching of Maf dimers, resulting in ho-1 expression. Heme also promotes displacement of Bach1 from the β-globin locus control region without affecting MafK binding in murine erythroleukemia cells. Thus, heme functions as a signaling molecule for gene expression in higher eukaryotes.

The spectrum and morphology of the Fermi bubbles

Abstract: The Fermi bubbles are two large structures in the gamma-ray sky extending to 55 deg above and below the Galactic center. We analyze 50 months of Fermi Large Area Telescope data between 100 MeV and 500 GeV above 10 deg in Galactic latitude to derive the spectrum and morphology of the Fermi bubbles. We thoroughly explore the systematic uncertainties that arise when modeling the Galactic diffuse emission through two separate approaches. The gamma-ray spectrum is well described by either a log parabola or a power law with an exponential cutoff. We exclude a simple power law with more than 7 sigma significance. The power law with an exponential cutoff has an index of 1.90+/-0.2 and a cutoff energy of 110+/- 50 GeV. We find that the gamma-ray luminosity of the bubbles is 4.4(+)2.4(-0.9 ) 10(exp 37) erg s-1. We confirm a significant enhancement of gamma-ray emission in the south-eastern part of the bubbles, but we do not find significant evidence for a jet. No significant variation of the spectrum across the bubbles is detected. The width of the boundary of the bubbles is estimated to be 3.4(+)3.7(-)2.6 deg. Both inverse Compton (IC) models and hadronic models including IC emission from secondary leptons t the gamma-ray data well. In the IC scenario, the synchrotron emission from the same population of electrons can also explain the WMAP and Planck microwave haze with a magnetic field between 5 and 20 micro-G.

Alkylated dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophenes (Cn-DNTTs): Organic semiconductors for high-performance thin-film transistors

Abstract: Organic thin-fi lm transistors (OTFTs) have attracted great interest for their potential use in several electronic applications, including active-matrix displays, electronic paper, and chemical sensors. [ 1 ] Among the many semiconducting materials evaluated in the TFT confi guration, pentacene is the best as it shows the highest fi eld-effect mobility ( > 3.0 cm 2 V − 1 s − 1 ). [ 2 , 3 ] On the other hand, new organic semiconductors are being actively investigated to further improve the performance of OTFTs. In fact, superior unconventional organic semiconductors used to produce high-performance OTFTs have been recently reported, including picene (3.2 cm 2 V − 1 s − 1 ), [ 4 ] trans -1,2-dithieno[2,3b ′ :3,2d ′ ]thiophene ethene (DTTE, 2.0 cm 2 V − 1 s − 1 ), [ 5 ] dithieno[2,3d ;2 ′ ,3 ′ d ′ ]benzo[1,2b ;4,5b ′ ]dithiophene (DTBDT, 1.7 cm 2 V − 1