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Muraoka D.,Tokyo Metroplitan University | Zhang L.,Tokyo Metroplitan University | Suzuki Y.,The Institute of Physical and Chemical Research | Kawakami H.,Tokyo Metroplitan University
Journal of Membrane Science | Year: 2011

In this study, we focused on the effects of the carbon structures on the gas permeability and selectivity of the asymmetric polyimide membranes prepared by He+-irradiation using iron (III) acetylacetonate (AAI) as the catalyst. The irradiated asymmetric membranes consisted of a defect-free carbonized ultrathin skin layer and indicated a molecular sieving-like effect due to the surface carbonization similar to carbon molecular membranes. The Raman spectrum of the irradiated membranes included two well-known D (1360cm-1) and G (1580cm-1) peaks and two additional new peaks around 1150 and 1500cm-1. Interestingly, the graphitic and amorphous structures at 1580 and 1500cm-1 in the membranes increased with an increase in the AAI content. Especially, it was found that the catalyst had a profound effect on the graphitic and amorphous structures of the ion-irradiated membrane. Finally, we concluded that the amorphous structure in the membrane had an influence on the gas permeability and that the graphitic structure formed a barrier to the gas permeability and had an influence on the gas selectivity. © 2011 Elsevier B.V.

Meng X.,Harbin Medical University | Meng X.,Shiga University of Medical Science | Kondo M.,Shiga University of Medical Science | Morino K.,Shiga University of Medical Science | And 9 more authors.
Biochemical and Biophysical Research Communications | Year: 2010

Down-regulation of insulin receptor substrate-1 (IRS-1) expression could modify the ability of IRS-1 to fulfill its functions. It has been proposed that the phosphorylation of IRS-1 on serine residues could promote its degradation. However, few studies have investigated the transcriptional regulation of IRS-1 in the pathogenesis of insulin resistance. Genotyping for genome-wide single nucleotide polymorphisms revealed that the transcription factor activating enhancer-binding protein-2β (AP-2β) is a novel candidate gene for conferring susceptibility to obesity and type 2 diabetes. AP-2β is expressed in adipose tissue and its expression is increased during the maturation of adipocytes. Overexpression of AP-2β leads to adipocyte hypertrophy, directly inhibits adiponectin expression, and enhanced the expression of inflammatory adipokines such as IL-6 and MCP-1. In this study, we found that overexpression of AP-2β in 3T3-L1 adipocytes impaired the promoter activity of IRS-1, and subsequently decreased mRNA and protein expression. Electrophoretic mobility shift assays showed that AP-2β bound specifically to the IRS-1 promoter region. Furthermore, site-directed mutagenesis of the AP-2 binding site located at -362 to -351, relative to the transcription start site, markedly decreased AP-2-induced suppression of IRS-1 promoter activity, whereas other putative AP-2 binding sites did not. Our results clearly showed that AP-2β directly decreased IRS-1 expression by binding to its promoter. Based on these findings, we speculate that the AP-2β transcriptional factor is a unique regulator of IRS-1 and a candidate gene for insulin resistance. © 2010 Elsevier Inc. All rights reserved.

Matsumoto H.,Saga University | Tsuzuki S.,Saga University | Date-Ito A.,University of Tokyo | Ohnishi A.,The Institute of Physical and Chemical Research | Hayakawa Y.,Saga University
Insect Biochemistry and Molecular Biology | Year: 2012

Growth-blocking peptide (GBP) is a member of an insect cytokine family with diverse functions including growth and immunity controls. Members of this cytokine family have been reported in 15 species of Lepidoptera, and we have recently identified GBP-like peptides in Diptera such as Lucilia cuprina and Drosophila melanogaster, indicating that this peptide family is not specific to Lepidoptera. In order to extend our knowledge of this peptide family, we purified the same family peptide from one of the tenebrionids, Zophobas atratus,. 11Zophobas atratus Zmc mRNA for cytokine, AB243070. isolated its cDNA, and sequenced it. The Z. atratus GBP sequence together with reported sequence data of peptides from the same family enabled us to perform BLAST searches against EST and genome databases of several insect species including Coleoptera, Diptera, Hymenoptera, and Hemiptera and identify homologous peptide genes. Here we report conserved structural features in these sequence data. They consist of 19-30 amino acid residues encoded at the C terminus of a 73-152 amino acid precursor and contain the motif C-x(2)-G-x(4,6)-G-x(1,2)-C-[KR], which shares a certain similarity with the motif in the mammalian EGF peptide family. These data indicate that these small cytokines belonging to one family are present in at least five insect orders. © 2012 Elsevier Ltd.

Ozaki S.,The Institute of Physical and Chemical Research
Biology and Medicine | Year: 2015

Signal transduction is carried out by inositol trisphophate IP3Earlier, we supported the signal transduction by synthesis of various compounds such as IP3, and phosphoinositide PIPx. IP3-binding protein was thoroughly investigated, the materials concerning signal transduction are playing a vital role in medicine discovery. During our previous work, DAB was found to be a, regulator of Ca2+ release and consequent cellular process. Cathetel ablation of tricuspid valve and insertion of stent wear effective for heart disease. © 2015 Ozaki S.

Molholt T.E.,University of Iceland | Mantovan R.,CNR Institute for Microelectronics and Microsystems | Gunnlaugsson H.P.,University of Aarhus | Naidoo D.,University of Witwatersrand | And 11 more authors.
Hyperfine Interactions | Year: 2010

We present a method to describe the temperature dependence of emission Mössbauer spectra showing slow spin-lattice relaxations of Fe3+ in MgO single crystals, obtained after implantation of 57Mn at ISOLDE/CERN. The analysis is based on the Blume-Tjon model for the line-shape of relaxing paramagnetic sextets with the spin relaxation rate, τ-1 as a parameter. The temperature dependent spin relaxation rate of Fe3+ in MgO is found to increase to ~108 s-1 at 647 K by assuming a relaxation rate of τ-1 < 106 s-1 at 77 K. The results are in accordance with those obtained by electron paramagnetic resonance spectroscopy demonstrating the possibility of retrieving spin-lattice relaxation rates of dilute Fe3+ from emission Mössbauer spectroscopy of Mn/Fe-implanted oxides. © 2010 Springer Science+Business Media B.V.

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