59 research outputs found

    Crystal structures and superconducting properties of metallic double-chain based cuprate Pr2Ba4Cu7O15-delta

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    We demonstrated the lattice structures and the superconducting phases of metallic double-chain based cuprate Pr2Ba4Cu7O15-delta exhibiting higher Tc. After the oxygen heat treatment on citrate pyrolysis precursors, their reduction treatment followed by a quench procedure caused higher Tc samples with 26.5-30 K. The crystal structural parameters for the superconducting sample (delta = 0.81) were analyzed from the powder synchrotron X-ray diffraction data using RIETAN-FP program. The effect of magnetic field on the superconducting phase of these samples with different oxygen defects (delta =0.73, 0.81 and 0.87) was examined, for our understanding of the superconducting magnetic field-temperature phase diagram. For delta = 0.87 sample with Tc = 30 K, the resistive critical field Hc* was estimated to be 13 T at 4.2 K. The oxygen deficiency dependence on Tc,on for our samples was compared with the data of several other groups.Comment: 8 pages, 6 figure

    Independent association of HLA-DPB1*02:01 with rheumatoid arthritis in Japanese populations

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    ObjectiveRheumatoid arthritis (RA) is a chronic autoimmune disease characterized with joint destructions; environmental and genetic factors were thought to be involved in the etiology of RA. The production of anti-citrullinated peptide antibodies (ACPA) is specifically associated with RA. DRB1 is associated with the susceptibility of RA, especially ACPA-positive RA [ACPA(+)RA]. However, a few studies reported on the independent associations of DPB1 alleles with RA susceptibility. Thus, we investigated the independent association of DPB1 alleles with RA in Japanese populations.MethodsAssociation analyses of DPB1 were conducted by logistic regression analysis in 1667 RA patients and 413 controls.ResultsIn unconditioned analysis, DPB1*04:02 was nominally associated with the susceptibility of ACPA(+)RA (P = 0.0021, corrected P (Pc) = 0.0275, odds ratio [OR] 1.52, 95% confidence interval [CI] 1.16–1.99). A significant association of DPB1*02:01 with the susceptibility of ACPA(+)RA was observed, when conditioned on DRB1 (Padjusted = 0.0003, Pcadjusted = 0.0040, ORadjusted 1.47, 95%CI 1.19–1.81). DPB1*05:01 was tended to be associated with the protection against ACPA(+)RA, when conditioned on DRB1 (Padjusted = 0.0091, Pcadjusted = 0.1184, ORadjusted 0.78, 95%CI 0.65–0.94). When conditioned on DRB1, the association of DPB1*04:02 with ACPA(+)RA was disappeared. No association of DPB1 alleles with ACPA-negative RA was detected.ConclusionThe independent association of DPB1*02:01 with Japanese ACPA(+)RA was identified

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST) : a protocol for a multicentre randomised controlled trial

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    Introduction: The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naive major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. Methods and analysis: We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. Ethics and dissemination: This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016-0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. Trial registration number: The University Hospital Medical Information Network ID: UMIN000025727 Pre-results

    Nanosized Authigenic Magnetite and Hematite Particles in Mature‐Paleosol Phyllosilicates: New Evidence for a Magnetic Enhancement Mechanism in Loess Sequences of China

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    Magnetic enhancement of Chinese loess‐paleosol sequences has been used extensively as a proxy for East Asian summer monsoon variations. However, the pedogenic magnetic particles contributing to this magnetic enhancement are difficult to extract, so it is not clear how they formed. In this study, we reveal pedogenic magnetite and hematite using electron microscopy, synchrotron radiation X‐ray diffraction, and rock magnetic methods. First‐order reversal curves indicate that superparamagnetic/single domain/vortex state magnetic properties dominated both loess and paleosol samples. Samples of muscovite and chlorite, which are paramagnetic, have weak spontaneous magnetization. The 1‐ to 10‐μm‐sized fraction of host silicatesis responsible for most of the magnetic enhancement of paleosols. In the paleosol fraction, we found weathered phyllosilicates (muscovite/chlorite), including many elongated submicron to a few microns authigenic magnetite and hematite particles between layers; however, few such interlayer particles were found in phyllosilicates of the loess fraction. The concentration of magnetite/hematite particles within paleosol muscovite/chlorite grains and in aggregates of phyllosilicate fragments is much higher than that of the submicron iron oxides found on silicate surfaces. Interlayer magnetite particles are dominantly prism‐shaped with aspect ratios >~4. The authigenic magnetite must be mainly responsible for the spontaneous magnetization of the muscovites and chlorites and the paleosol magnetic properties. The protective silicates account for the low extraction efficiency and also the near absence of surface oxidation of pedogenic magnetite. Based on our results, we suggest that magnetite/hematite in weathered phyllosilicates contribute significantly to the magnetic enhancement of mature paleosols
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