3,888 research outputs found

    The hepatic sympathetic nerve plays a critical role in preventing Fas induced liver injury in mice

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    Background: Although previous studies have shown that the hepatic sympathetic nerve controls various physiological functions in the liver, the role of this nerve in liver injury has yet to be clarified.Aims: The purpose of this study was to elucidate the role of this nerve, based on our newly developed technique for selectively removing the activities of the hepatic sympathetic nerve.Subjects and methods: Male C57BL/6 mice were operated on for hepatic sympathetic denervation. Thereafter, mice were intravenously administered 0.25 or 0.35 mg/g weight of the Fas agonist antibody, Jo-2, after which mortality by fulminant hepatitis was evaluated. Apoptosis in the liver was also examined by both terminal deoxynucleotidyl transferase mediated dUTP nick end labelling and caspase-3 assay.Results: Mortality in sympathectomised mice was significantly higher than that in sham operated mice following administration of Jo-2. This result was also supported by apoptosis data in which sympathectomised livers exhibited a significant elevation in the number of apoptotic hepatocytes and caspase-3 activity after Jo-2 treatment compared with sham operated livers. Moreover, pretreatment with norepinephrine dose dependently inhibited the hepatic sympathectomy induced increase in mortality after Jo-2 injection. Antiapoptotic protein levels of FLICE inhibitory protein, Bcl-xL, and Bcl-2 in the liver were significantly lower in sympathectomised mice at one and two hours following Jo-2 treatment than in sham operated animals. In addition, interleukin 6 supplementation dose dependently suppressed the hepatic sympathectomy induced increase in mortality after Jo-2 treatment.Conclusions: These results suggest that norepinephrine released from the hepatic sympathetic nerve plays a critical role in protecting the liver from Fas mediated fulminant hepatitis, possibly via mechanisms including antiapoptotic proteins and interleukin 6

    Inverse regioselectivity in the silylstannylation of alkynes and allenes: copper-catalyzed three-component coupling with a silylborane and a tin alkoxide

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    Silylstannylation of alkynes and allenes has been found to proceed by three-component coupling using a silylborane and a tin alkoxide in the presence of a Cu(I) catalyst. The regioselectivities are completely inverse to those of the conventional silylstannylation under palladium catalysis

    Borylstannylation of alkynes with inverse regioselectivity: copper-catalyzed three-component coupling using a masked diboron

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    A variety of terminal alkynes are facilely convertible into cis-boryl(stannyl)alkenes with inverse regioselectivity to those of the previous borylstannylation by the copper-catalyzed three-component reaction using a masked diboron. The synthetic utility of the resulting boryl(stannyl)alkenes has been demonstrated by chemoselective coupling reactions

    Copper-catalyzed α-selective hydrostannylation of alkynes for the synthesis of branched alkenylstannanes

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    A variety of branched alkenylstannanes can directly be synthesized with excellent α-selectivity by the copper-catalyzed hydrostannylation using a distannane or a silylstannane, irrespective of the electronic and steric characteristics of terminal alkynes employed. Synthetic utility of the resulting branched alkenylstannane has been demonstrated by the total synthesis of bexarotene

    How to obtain the adhesive strength for double lap joint by using single lap joint

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    The testing method of adhesive strength of lap joint is prescribed in Japanese Industrial Standard (JIS K6850). However, it has been reported that the strength of double lap joint (DLJ) is about two times larger than the one of single lap joint (SLJ). Therefore, suitable testing method has been required from industries. In this study, the equivalent conditions of strength for SLJ and DLJ are investigated in terms of the intensity of singular stress field (ISSF) appearing at the interface end. First, in order to minimize the bend effect for SLJ, the effect of the specimen geometry on ISSF and deformation angle at the interface corner is considered under the same adhesive geometry and load P. It is found that the minimum ISSF of SLJ can be obtained when the adherend thickness t1 is large enough, and the deformation angle at interface corner is also smallest when adherend thickness t1 is large enough. Therefore, it is necessary to use the specimen with thicker adherend thickness. Then, the equivalent conditions of strength for SLJ and DLJ is investigated by changing adherend thickness. The results show that the strength of the DLJ in JIS (t1=1.5mm) can be obtained by using the SLJ with adherend thickness t1=7mm. When the adherend thickness t1≥25mm, the strength of SLJ is nearly equal to that of DLJ.6th International Conference on Fracture Fatigue and Wear, 26–27 July 2017, Porto, Portuga

    Intensity of singular stress field for three-dimensional butt joint to evaluate the adhesive strength

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    Adhesive joints are extensively used in various manufacturing processes in different industrial sectors because of its high fatigue resistance. Different materials properties cause the singular stress field, whose intensity is depending on the adhesive joint geometry. Our previous studies show that debonding strength can be expressed as a constant value of the critical intensity of singular stress field (ISSF) by using two-dimensional butt joint models. By considering real specimen geometry, in this paper, the ISSFs on the interface outer edges of three-dimensional butt joints are analysed by varying the adhesive thicknesses. A mesh-independent technique combined with three-dimensional finite element method (FEM) is shown to evaluate the ISSF. The ISSF distributions on the interface outer edges are analysed in comparison with the previous two-dimensional results. It is found that the critical ISSF considered 3D geometry is almost constant independent of the adhesive thickness.2018 5th Global Conference on Polymer and Composite Materials (PCM 2018), April 10th - 13th, 2018, in Kitakyushu City, Kokura region, Japan

    Brueckner Rearrangement Effects in Λ5^5_\LambdaHe and ΛΛ6^6_{\Lambda\Lambda}He

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    Rearrangement effects in light hypernuclei are investigated in the framework of the Brueckner theory. We can estimate without detailed numerical calculations that the energy of the α\alpha-core is reduced by more than 2.5 MeV when the Λ\Lambda adheres to 4^4He to form Λ5^5_\LambdaHe. Similar assessment of rearrangement contributions is essential to deduce the strength of ΛΛ\Lambda\Lambda interaction from experimentally observed ΔBΛΛ\Delta B_{\Lambda\Lambda}. The recently observed experimental value of \sim 1 MeV for the ΔBΛΛ\Delta B_{\Lambda\Lambda} of \hll suggests that the matrix element of in \hll is around -2 MeV.Comment: 7 pages, to appear in Phys. Rev.

    Expression and Localization of the Cell Adhesion Molecule SgIGSF during Regeneration of the Olfactory Epithelium in Mice

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    Spermatogenic immunoglobulin superfamily (SgIGSF) is a cell adhesion molecule originally discovered in mouse testis. SgIGSF is expressed not only in spermatogenic cells but also in lung and liver epithelial cells and in neurons and glia of the central and peripheral nervous systems. In the present study, we examined the expression and localization of SgIGSF in mouse olfactory epithelium before and after transection of the olfactory nerves, by RT-PCR, Western blotting and immunohistochemistry. In normal olfactory mucosa, SgIGSF showed 100 kDa in molecular weight, which was identical with that in the lung but different from that in the brain. SgIGSF was expressed on the membrane of all olfactory, sustentacular and basal cells, but more abundantly in the apical portions of the olfactory epithelium where the dendrites of olfactory cells are in contact with sustentacular cells. After olfactory nerve transection, mature olfactory cells disappeared in 4 days but were regenerated around 7–15 days by proliferation and differentiation of basal cells into mature olfactory cells through the step of immature olfactory cells. During this period, both the mRNA and protein for SgIGSF showed a transient increase, with peak levels at 7 days and 11 days, respectively, after the transection. Immunohistochemistry showed that the enriched immunoreactivity for SgIGSF at 7–11 days was localized primarily to the membrane of immature olfactory cells. These results suggested that, during regeneration of the olfactory epithelium, the adhesion molecule SgIGSF plays physiological roles in differentiation, migration, and maturation of immature olfactory cells

    Anomalous Flux Flow Resistivity in Two Gap Superconductor MgB_2

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    The flux flow resistivity associated with purely viscous motion of vortices in high-quality MgB_2 was measured by microwave surface impedance. Flux flow resistivity exhibits unusual field dependence with strong enhancement at low field, which is markedly different to conventional s-wave superconductors. A crossover field which separates two distinct flux flow regimes having different flux flow resistivity slopes was clearly observed in H//ab-plane. The unusual H-dependence indicates that two very differently sized superconducting gaps in MgB_2 manifest in the vortex dynamics and almost equally contribute to energy dissipation. The carrier scattering rate in two different bands is also discussed with the present results, compared to heat capacity and thermal conductivity results.Comment: 4 pages, 3figure
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