3,873 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

    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 fields of an embedded fibre under pull-out force

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    Previous experimental studies of fibre pull-out test show two dangerous points on the interface. Failure usually occurs at the bonded end of the fibre (Point A) or at the entry point on the surface of the matrix (Point E). Both points have different singular stress fields which causes crack initiation, crack propagation, and final failure. In this paper, intensity of singular stress fields (ISSF) at the fibre bonded end A and ISSF at the intersection point E of the fibre and the surface are discussed. The analysis method focuses on calculating the finite element method (FEM) stress radio by using a reference model and an unknown model. In the unknown model and the reference model, same FEM mesh pattern is applied. To analyse the ISSF at A, the body force method solution is used as the reference model. To analyse the ISSF at E, the reciprocal work contour integral method (RWCIM) solution is used as the reference model. Then, the two ISSFs are compared and discussed by varying the fibre embedded length l in. When l in is shorter, the singular stress at A is larger than the singular stress at E. When l in is longer, the singular stress at E is larger than the ISSF at A.2018 5th Global Conference on Polymer and Composite Materials (PCM 2018), April 10th - 13th, 2018, Kitakyushu, Japa

    Spatial Current Patterns, Dephasing and Current Imaging in Graphene Nanoribbons

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    Using the non-equilibrium Keldysh Green's function formalism, we investigate the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In particular, we demonstrate that the spatial current patterns associated with discrete transmission resonances sensitively depend on the GNRs' geometry, size, and aspect ratio, the location and number of leads, and the presence of dephasing. We identify a relation between the spatial form of the current patterns, and the number of degenerate energy states participating in the charge transport. Furthermore, we demonstrate a principle of superposition for the conductance and spatial current patterns in multiple-lead configurations. We demonstrate that scanning tunneling microscopy (STM) can be employed to image spatial current paths in GNR with atomic resolution, providing important insight into the form of local charge transport. Finally, we investigate the effects of dephasing on the spatial current patterns, and show that with decreasing dephasing time, the current patterns evolve smoothly from those of a ballistic quantum network to those of classical resistor network.Comment: 25 pages, 12 figure

    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

    Cooperative damping mechanism of the resonance in the nuclear photoabsorption

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    We propose a resonance damping mechanism to explain the disappearance of the peaks around the position of the resonances higher than the Δ\Delta resonance in the nuclear photoabsorption. This phenomenon is understood by taking into account the cooperative effect of the collision broadening of Δ\Delta and NN^{*}, the pion distortion and the interference in the two-pion photoproduction processes in the nuclear medium.Comment: 11 pages, uses revtex.sty. To appear in Phys. Rev. Let

    Association Study of Two Cannabinoid Receptor Genes, CNR1 and CNR2, with Methamphetamine Dependence

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    Several studies have suggested that the endocannabinoid system plays significant roles in the vulnerability to psychiatric disorders including drug abuse. To examine the possible association of the CNR1 and CNR2 genes, which encode cannabinoid receptors CB1 and CB2, with methamphetamine dependence, we investigated three single nucleotide polymorphisms (SNPs) (rs806379, rs1535255, rs2023239) in intron 2 of the CNR1 gene and a nonsynonymous SNP, Q63R, in the CNR2 gene. The study samples consisted of 223 patients with methamphetamine dependence and 292 age- and sex- matched controls. There were no significant differences between the patients and controls in genotypic or allelic distribution of any SNP of the CNR1 and CNR2 genes. We also analyzed the clinical features of methamphetamine dependence. Rs806379 of the CNR1 gene showed a significant association with the phenotype of latency of psychosis after the first consumption of methamphetamine. Patients with the T allele or T-positive genotypes (T/T or A/T) may develop a rapid onset of psychosis after methamphetamine abuse. The present study suggests a possibility that genetic variants of the CNR1 gene may produce a liability to the complication of psychotic state after abuse of methamphetamine; however, our findings need to be confirmed by future replications

    Nuclear Photoabsorption at Photon Energies between 300 and 850 Mev

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    We construct the formula for the photonuclear total absorption cross section using the projection method and the unitarity relation. Our treatment is very effective when interference effects in the absorption processes on a nucleon are strong. The disappearance of the peak around the position of the D13D_{13} resonance in the nuclear photoabsorption can be explained with the cooperative effect of the interference in two-pion production processes,the Fermi motion, the collision broadenings of Δ\Delta and NN^*, and the pion distortion in the nuclear medium. The change of the interference effect by the medium plays an important role.Comment: 22pages,7figures,revtex

    Association Between 5HT1b Receptor Gene and Methamphetamine Dependence

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    Several lines of evidence implicate serotonergic dysfunction in diverse psychiatric disorders including anxiety, depression, and drug abuse. Mice with a knock-out of the 5HT1b receptor gene (HTR1B) displayed increased locomotor response to cocaine and elevated motivation to self-administer cocaine and alcohol. Previous genetic studies showed significant associations of HTR1B with alcohol dependence and substance abuse, but were followed by inconsistent results. We examined a case-control genetic association study of HTR1B with methamphetamine-dependence patients in a Japanese population. The subjects were 231 patients with methamphetamine dependence, 214 of whom had a co-morbidity of methamphetamine psychosis, and 248 age- and sex-matched healthy controls. The three single nucleotide polymorphisms (SNPs), rs130058 (A-165T), rs1228814 (A-700C) and rs1228814 (A+1180G) of HTR1B were genotyped. There was no significant difference in allelic and genotypic distributions of the SNPs between methamphetamine dependence and the control. Genetic associations of HTR1B were tested with several clinical phenotypes of methamphetamine dependence and/or psychosis, such as age at first abuse, duration of latency from the first abuse to onset of psychosis, prognosis of psychosis after therapy, and complication of spontaneous relapse of psychotic state. There was, however, no asscocation between any SNP and the clinical phenotypes. Haplotype analyses showed the three SNPs examined were within linkage disequilibrium, which implied that the three SNPs covered the whole HTR1B, and distribution of estimated haplotype frequency was not different between the groups. The present findings may indicate that HTR1B does not play a major role in individual susceptibility to methamphetamine dependence or development of methamphetamine-induced psychosis

    ACTIN CYTOSKELETON STRUCTURE AND ITS LOCALIZATION IN Gongronella butleri, Mucor javanicus AND Absidia cylindrospora (Mucorales -Zygomycetes)

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    Mediante estudios de microscopia óptica de fluorescencia se describe y caracteriza la estructura, dislribución y localización de la actina, en tres especies de hongos de la clase Zygomycetes: Absidia cylilndrospora, Gongronella butleri y Mucor javanicus. La estruclura de  la actina fue analizada utilizándose el marcador FITC-Phalloidina, específico para actina, en muestras fijadas con forlmaldehido. En los resultados se observan diferencias en la estruclura. distribución y localización de esta proleina en las especies analizadas. Filamentos, aglomerados, placas o aglomerados periféricos y gránulos, fueron las formas más comunes encontradas en los hongos, con prevalencia de los aglomerados observados en todos los citoplasma de las hifas. La tinción de aclina en los ápices de las hilas, solo se observó en Mucor javanicus, esta diferencia en la estructura de la actina podria estar asociada a zonas de expansión de la pared celular de los hongos
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