81 research outputs found

    Multilayer graphene shows intrinsic resistance peaks in the carrier density dependence

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    Since the advent of graphene, a variety of studies have been performed to elucidate its fundamental physics, or to explore its practical applications. Gate-tunable resistance is one of the most important properties of graphene and has been studied in 1-3 layer graphene in a number of efforts to control the band gap to obtain a large on-off ratio. On the other hand, the transport property of multilayer graphene with more than three layers is less well understood. Here we show a new aspect of multilayer graphene. We found that four-layer graphene shows intrinsic peak structures in the gate voltage dependence of its resistance at zero magnetic field. Measurement of quantum oscillations in magnetic field confirmed that the peaks originate from the specific band structure of graphene and appear at the carrier density for the bottoms of conduction bands and valence bands. The intrinsic peak structures should generally be observed in AB-stacked multilayer graphene. The present results would be significant for understanding the physics of graphene and making graphene FET devices

    Two Cases of Increased Gastrointestinal Polyps in Familial Adenomatous Polyposis following Antiacid Agent Intake

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    Introduction: Familial adenomatous polyposis (FAP), a hereditary disorder of the gastrointestinal tract, is an autosomal dominant inherited condition caused by germline mutations in the adenomatous polyposis coli (APC) gene. It is characterized by the development of hundreds to thousands of colorectal adenomatous polyps, which, if left untreated, can eventually develop into colorectal carcinomas. Representative extracolonic tumors in FAP include multiple duodenal adenomas and desmoid tumors. Moreover, multiple fundic gland polyps are frequently identified in the stomachs of patients with FAP. Case Presentation: Herein, we report the two cases. A 52-year-old woman who underwent total colectomy for FAP, and pancreatoduodenectomy was initiated on esomeprazole for the treatment of anastomotic erosion. Esophagogastroduodenoscopy performed 42 months later showed an increased number and size of gastric fundic gland polyps, which subsequently decreased after replacing esomeprazole with ranitidine. Similarly, a 39-year-old woman with FAP was initiated on vonoprazan for the treatment of reflux symptoms. Esophagogastroduodenoscopy and colonoscopy performed 14 months later indicated an increase in the number of gastric fundic gland polyps and colorectal polyps, which subsequently decreased after vonoprazan discontinuation. In these two cases, the increase and decrease in the number and size of fundic gland polyps and colon adenoma were associated with serum gastrin levels. Conclusion: Gastric fundic gland polyps and colon polyps may rapidly increase in number and size due to increased gastrin levels induced by proton pump inhibitor/potassium-competitive acid blocker use. Hence, these drugs should be prescribed with caution

    Immunological detection of D-β-aspartate-containing protein in lens-derived cell lines

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    Alpha-crystallin is the major protein of the mammalian lens and its average molecular weight is approximately 800 kDa. It is composed of two kinds of structurally and functionally related polypeptides, αA-and αB-crystallin subunits, each with a molecular weight of 20 kDa Recently, we prepared a polyclonal antibody against peptide Gly-Leu-D-β-Asp-Ala-Thr-Gly-Leu-D-β-Asp-Ala-ThrGly-Leu-D-β-Asp-Ala-Thr (anti-peptide 3R antibody) that corresponded to three repeats of positions 149-153 in human αA-crystallin [11]. This antibody cross-reacted specifically with D-β-Asp-151-containing αA-crystallin. Because formation of D-Asp is accompanied by isomerization to form the β-Asp (isoaspartate) residue, three isomers of Asp residues, L-β-Asp, D-α-Asp and D-β-Asp isomers, are formed in the protein Cell culture systems are used widely for the analysis of cellular functions related to particular organ systems. For lens research, it is of particular interest to find conditions that reflect the situation within this organ. In order to establish whether the D-β-Asp-containing protein is present in cultured lens cells, we cultured two cell lines, αTN4-1 and N/N1003A, which are commonly used in lens research Conclusions: The results indicate that the N/N1003A cell line expressed a 50 kDa D-β-Asp-containing protein, which may share a common amino acid sequence with αA-and αB-crystallin

    Low Oxygen Enhances Primitive and Definitive Neural Stem Cell Colony Formation by Inhibiting Distinct Cell Death Pathways

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    Neural stem cells (NSCs) can be derived from single mouse embryonic stem cells (ESCs) in the absence of instructive factors. Clonal primitive NSC (pNSC) colonies are formed first, and then give rise to clonal, fibroblast growth factor-dependent definitive neural stem cells (dNSCs). We tested low-oxygen culture as a potential method of alleviating the extensive cell death seen in pNSCs and dNSCs. Culture in low (4%) oxygen promoted survival of pNSCs by inhibiting apoptosis-inducing factor (AIF)-dependent cell death, although pNSCs undergo both AIF- and caspase-mediated cell death in 20% oxygen. In contrast, survival of dNSCs in low oxygen was increased by inhibition of caspase-dependent cell death. In normoxia, AIF is implicated in promoting dNSC survival. Neither survival effect was dependent on the main transcriptional effector of hypoxia, hypoxia-inducible factor 1. Low-oxygen concentrations may be involved in expansion of early NSC populations by inhibiting cell death through different pathways in these sequential pNSC and dNSC populations. Stem Cells 2009;27:1879–188

    ゼンシッカン オ タイショウ トスル リハビリテーション ノ ガイネン : シッカン ニ カカワラナイ ソウキ ドウニュウ ノ ユウコウセイ

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    The right Japanese translation of rehabilitation is a “return” and is not the meaning “training.” It is a cure aiming at returning to the state before suffering from the illness in the body, soul, and social environment. Therefore, the rehabilitation should be performed to not only bone and joint diseases and apoplexy but also other diseases or states including infectious diseases and the state after surgery. Patients who are compulsorily stayed on the bed for a long time, especially in an acute care ward, easily become bedridden with various complications such as gait or eating disorder. It is important to try for all the staff in connection with medical care to have a rehabilitation concept, and to return a patient to the former condition falling ill

    Reference Grade Characterization of Polymorphisms in Full-Length HLA Class I and II Genes With Short-Read Sequencing on the ION PGM System and Long-Reads Generated by Single Molecule, Real-Time Sequencing on the PacBio Platform

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    Although NGS technologies fuel advances in high-throughput HLA genotyping methods for identification and classification of HLA genes to assist with precision medicine efforts in disease and transplantation, the efficiency of these methods are impeded by the absence of adequately-characterized high-frequency HLA allele reference sequence databases for the highly polymorphic HLA gene system. Here, we report on producing a comprehensive collection of full-length HLA allele sequences for eight classical HLA loci found in the Japanese population. We augmented the second-generation short read data generated by the Ion Torrent technology with long amplicon spanning consensus reads delivered by the third-generation SMRT sequencing method to create reference grade high-quality sequences of HLA class I and II gene alleles resolved at the genomic coding and non-coding level. Forty-six DNAs were obtained from a reference set used previously to establish the HLA allele frequency data in Japanese subjects. The samples included alleles with a collective allele frequency in the Japanese population of more than 99.2%. The HLA loci were independently amplified by long-range PCR using previously designed HLA-locus specific primers and subsequently sequenced using SMRT and Ion PGM sequencers. The mapped long and short-reads were used to produce a reference library of consensus HLA allelic sequences with the help of the reference-aware software tool LAA for SMRT Sequencing. A total of 253 distinct alleles were determined for 46 healthy subjects. Of them, 137 were novel alleles: 101 SNVs and/or indels and 36 extended alleles at a partial or full-length level. Comparing the HLA sequences from the perspective of nucleotide diversity revealed that HLA-DRB1 was the most divergent among the eight HLA genes, and that the HLA-DPB1 gene sequences diverged into two distinct groups, DP2 and DP5, with evidence of independent polymorphisms generated in exon 2. We also identified two specific intronic variations in HLA-DRB1 that might be involved in rheumatoid arthritis. In conclusion, full-length HLA allele sequencing by third-generation and second-generation technologies has provided polymorphic gene reference sequences at a genomic allelic resolution including allelic variations assigned up to the field-4 level for a stronger foundation in precision medicine and HLA-related disease and transplantation studies

    平成29年度 国際教育推進委員会活動報告

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    本校では、10年前に国際教育推進委員会を発足してから、各方面で声高に叫ばれている「グローバル人材の育成」を目指し、筑波大学附属坂戸高等学校では総合学科の特長を生かしながらさまざまな国際教育・ESDの取り組みを行ってきた。平成26年度には、スーパーグローバルハイスクール(SGH)に指定され、平成29年2月には国際バカロレア日本語DP認定校となり、平成30年度からその1期生が入学する。今後、本校の国際教育活動がどのように動いていくか、すべてが見通せるまではしばらくの時間を要すると思われる。本稿frは、本年度はじめてジャカルタで実施した、第1回インドネシア日本高校生SDGsミーティングおよび、10回目を迎えた海外卒業研究支援制度について報告した
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