178 research outputs found

    Electrochemically active species in aluminum electrodeposition baths of AlCl3/glyme solutions

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    Electrochemically active species in aluminum (Al) electrodeposition baths using AlCl3 and less volatile solvents i.e. glymes were investigated. Raman spectroscopy revealed that all the glyme baths contained AlCl₄⁻ anions and Al-Cl-glyme cations as ionic species. Room temperature conductivities were as high as the order of 10⁻³ S cm⁻¹ for the diglyme (G2), triglyme (G3) and tetraglyme (G4) baths, whereas that for the butyl diglyme (butylG2) bath was only 10⁻⁴ S cm⁻¹ due to a lower concentration of ionic species. Surprisingly, electrochemical measurements showed that, among the glyme baths, only the G2 bath enabled electrodeposition of Al. Consequently, despite the similar structures of Al-Cl-glyme complex cations, only the G2 complex cations are electrochemically active. This suggests that the desolvation of glymes from Al-Cl-glyme cations and their subsequent reduction is exceptionally easy for the G2 complexes

    Caenorhabditis elegans ortholog of the p24/p22 subunit, DNC-3, is essential for the formation of the dynactin complex by bridging DNC-1/p150Glued and DNC-2/dynamitin

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    Dynactin is a multisubunit protein complex required for the activity of cytoplasmic dynein. In Caenorhabditis elegans, although 10 of the 11 dynactin subunits were identified based on the sequence similarities to their orthologs, the p24/p22 subunit has not been detected in the genome. Here, we demonstrate that DNC-3 (W10G11.20) is the functional counterpart of the p24/p22 subunit in C. elegans. RNAi phenotypes and subcellular localization of DNC-3 in early C. elegans embryos were nearly identical to those of the known dynactin components. All other dynactin subunits were co-immunoprecipitated with DNC-3, indicating that DNC-3 is a core component of dynactin. Furthermore, the overall secondary structure of DNC-3 resembles to those of the mammalian and yeast p24/p22. We found that DNC-3 is required for the localization of the DNC-1/p150Glued and DNC-2/dynamitin, the two components of the projection arm of dynactin, to the nuclear envelope of meiotic nuclei in the adult gonad. Moreover, DNC-3 physically interacted with DNC-1 and DNC-2 and significantly enhanced the binding ability between DNC-1 and DNC-2 in vitro. These results suggest that DNC-3 is essential for the formation of the projection arm subcomplex of dynactin

    Student Modelling for ICAI in View of Cognitive Science : Process Driven Model Inference Method

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    本論文では,学生の問題解決過程および誤りに対する認知的競点からの考察に基づいて,学生モデルの記述法であるプロセスモデルと,プロセスモデルで記述された学生モデルを生成するプロセス駆動型モデル推論法を提案する.更に,生成された学生モデルを用いることによって可能となる誤りに対する指導を検討する.プロセスモデルは,学生の知識運用の過程を表現しており,これを用いることにより学生の知識運用上の誤りを表現することができる.知識自体の誤りは,運用の誤りの固定化としてとらえることができる.プロセス駆動型モデル推論法は,問題解決過程のプロセスモデルを摂動することにより,その問題の解決過程で発生する知識運用の誤りをモデル化する.知識運用の誤りの原因は,モデルの生成過程で加えられた摂動により説明できる.本学生モデルを用いることにより,知識運用の誤りに対して,運用の誤りの原因を指摘し,知識を正しく運用するように誘導する指導が可能となる.この指導は.知識自体の誤りに対しては,誤った知識の発生原因に対する指導となっている

    Peretinoin, an acyclic retinoid, improves the hepatic gene signature of chronic hepatitis C following curative therapy of hepatocellular carcinoma

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    BACKGROUND: The acyclic retinoid, peretinoin, has been shown to be effective for suppressing hepatocellular carcinoma (HCC) recurrence after definitive treatment in a small-scale randomized clinical trial. However, little has been documented about the mechanism by which peretinoin exerts its inhibitory effects against recurrent HCC in humans in vivo. METHODS: Twelve hepatitis C virus-positive patients whose HCC had been eradicated through curative resection or ablation underwent liver biopsy at baseline and week 8 of treatment with either a daily dose of 300 or 600 mg peretinoin. RNA isolated from biopsy samples was subjected to gene expression profile analysis. RESULTS: Peretinoin treatment elevated the expression levels of IGFBP6, RBP1, PRB4, CEBPA, G0S2, TGM2, GPRC5A, CYP26B1, and many other retinoid target genes. Elevated expression was also observed for interferon-, Wnt-, and tumor suppressor-related genes. By contrast, decreased expression levels were found for mTOR- and tumor progression-related genes. Interestingly, gene expression profiles for week 8 of peretinoin treatment could be classified into two groups of recurrence and non-recurrence with a prediction accuracy rate of 79.6% (P<0.05). In the liver of patients with non-recurrence, expression of PDGFC and other angiogenesis genes, cancer stem cell marker genes, and genes related to tumor progression was down-regulated, while expression of genes related to hepatocyte differentiation, tumor suppression genes, and other genes related to apoptosis induction was up-regulated. CONCLUSIONS: Gene expression profiling at week 8 of peretinoin treatment could successfully predict HCC recurrence within 2 years. This study is the first to show the effect of peretinoin in suppressing HCC recurrence in vivo based on gene expression profiles and provides a molecular basis for understanding the efficacy of peretinoin

    The minibrain kinase homolog, mbk-2, is required for spindle positioning and asymmetric cell division in early C. elegans embryos

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    AbstractIn the newly fertilized Caenorhabditis elegans zygote, cytoplasmic determinants become localized asymmetrically along the anterior–posterior (A–P) axis of the embryo. The mitotic apparatus then orients so as to cleave the embryo into anterior and posterior blastomeres that differ in both size and developmental potential. Here we describe a role for MBK-2, a member of the Dyrk family of protein kinases, in asymmetric cell division in C. elegans. In mbk-2 mutants, the initial mitotic spindle is misplaced and cytoplasmic factors, including the germline-specific protein PIE-1, are mislocalized. Our findings support a model in which MBK-2 down-regulates the katanin-related protein MEI-1 to control spindle positioning and acts through distinct, as yet unknown factors, to control the localization of cytoplasmic determinants. These findings in conjunction with work from Schizosaccharomyces pombe indicate a possible conserved role for Dyrk family kinases in the regulation of spindle placement during cell division

    Differential interferon signaling in cells in liver lobules and portal areas under treatment for chronic hepatitis C

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    金沢大学医薬保健研究域医学系Background & Aims: The mechanisms of treatment resistance to interferon (IFN) and ribavirin (Rib) combination therapy for hepatitis C virus (HCV) infection are not known. This study aims to gain insight into these mechanisms by exploring hepatic gene expression before and during treatment. Methods: Liver biopsy was performed in 50 patients before therapy and repeated in 30 of them 1 week after initiating combination therapy. The cells in liver lobules (CLL) and the cells in portal areas (CPA) were obtained from 12 patients using laser capture microdissection (LCM). Results: Forty-three patients were infected with genotype 1 HCV, 20 of who were viral responders (genotype 1-Rsp) with treatment outcome of SVR or TR, while 23 were non-responders (genotype 1-nonRsp) with NR. Only seven patients were infected with genotype 2. Before treatment, the expression of IFN and Rib-stimulated genes (IRSGs), apoptosis-associated genes, and immune reaction gene pathways was greater in genotype 1-nonRsp than in Rsp. During treatment, IRSGs were induced in genotype 1-Rsp, but not in nonRsp. IRSG induction was irrelevant in genotype 2-Rsp and was mainly impaired in CLL but not in CPA. Pathway analysis revealed that many immune regulatory pathways were induced in CLL from genotype 1-Rsp, while growth factors related to angiogenesis and fibrogenesis were more induced in CPA from genotype 1-nonRsp. Conclusions: Impaired IRSGs induction in CLL reduces the sensitivity to treatment for genotype 1 HCV infection. CLL and CPA in the liver might be differentially involved in treatment resistance. These findings could be useful for the improvement of therapy for HCV infection. © 2010 European Association for the Study of the Liver

    Hepatic interferon-stimulated genes are differentially regulated in the liver of chronic hepatitis C patients with different interleukin-28B genotypes

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    Pretreatment up-regulation of hepatic interferon (IFN)-stimulated genes (ISGs) has a stronger association with the treatment-resistant interleukin (IL)28B minor genotype (MI; TG/GG at rs8099917) than with the treatment-sensitive IL28B major genotype (MA; TT at rs8099917). We compared the expression of ISGs in the liver and blood of 146 patients with chronic hepatitis C who received pegylated IFN and ribavirin combination therapy. Gene expression profiles in the liver and blood of 85 patients were analyzed using an Affymetrix GeneChip (Affymetrix, Santa Clara, CA). ISG expression was correlated between the liver and blood of the MA patients, whereas no correlation was observed in the MI patients. This loss of correlation was the result of the impaired infiltration of immune cells into the liver lobules of MI patients, as demonstrated by regional gene expression analysis in liver lobules and portal areas using laser capture microdissection and immunohistochemical staining. Despite having lower levels of immune cells, hepatic ISGs were up-regulated in the liver of MI patients and they were found to be regulated by multiple factors, namely, IL28A/B, IFN-λ4, and wingless-related MMTV integration site 5A (WNT5A). Interestingly, WNT5A induced the expression of ISGs, but also increased hepatitis C virus replication by inducing the expression of the stress granule protein, GTPase-activating protein (SH3 domain)-binding protein 1 (G3BP1), in the Huh-7 cell line. In the liver, the expression of WNT5A and its receptor, frizzled family receptor 5, was significantly correlated with G3BP1. Conclusions: Immune cells were lost and induced the expression of other inflammatory mediators, such as WNT5A, in the liver of IL28B minor genotype patients. This might be related to the high level of hepatic ISG expression in these patients and the treatment-resistant phenotype of the IL28B minor genotype. © 2014 by the American Association for the Study of Liver Diseases.This article has Supplemental materrial and methods
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