237 research outputs found

    Systematic Investigation of Very Early-Phase Spectra of Type Ia Supernovae

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    It has been widely accepted that Type Ia supernovae (SNe Ia) are thermonuclear explosions of a CO white dwarf. However, the natures of the progenitor system(s) and explosion mechanism(s) are still unclarified. Thanks to the recent development of transient observations, they are now frequently discovered shortly after the explosion, followed by rapid spectroscopic observations. In this study, by modeling very early-phase spectra of SNe Ia, we try to constrain the explosion models of SNe Ia. By using the Monte Carlo radiation transfer code, TARDIS, we estimate the properties of their outermost ejecta. We find that the photospheric velocity of normal-velocity supernovae (NV SNe) in the first week is \sim15000 km s1^{-1}. The outer velocity, to which the carbon burning extends, spans the range between \sim20000 and 25000 km s1^{-1}. The ejecta density of NV SNe also shows a large diversity. For high-velocity supernovae (HV SNe) and 1999aa-like SNe, the photospheric velocity is higher, \sim20000 km s1^{-1}. They are different in the photospheric density, with HV SNe having higher density than 1999aa-like SNe. For all these types, we show that the outermost composition is closely related to the outermost ejecta density; the carbon burning layer and the unburnt carbon layer are found in the higher-density and lower-density objects, respectively. This finding suggests that there might be two sequences, the high-density and carbon-poor group (HV SNe and some NV SNe) and the low-density and carbon-rich group (1999aa-like and other NV SNe), which may be associated with different progenitor channels.Comment: 22 pages, 11 figures, and 6 tables. Accepted for publication in Ap

    Cell differentiation and development

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    The development of organoid techniques for regenerative therapy has progressed remarkably with the use of tissue-derived stem cells and pluripotent stem cells based on stem cell biology and tissue engineering technology. To realize whole-organ replacement therapy as next-generation regenerative medicine, it is expected that fully functional bioengineered organs can be reconstructed using an in vitro three-dimensional (3D) bioengineered organ germ and organoids by stem cell manipulation and self-organization. In this mini-review, we focused on substantial advances of 3D bioengineering technologies for the regeneration of complex oral organs with the reconstruction of 3D bioengineered organ germ using organ-inductive potential embryo-derived epithelial and mesenchymal cells. These bioengineering technologies have the potential for realization of future organ replacement therapy

    Radiolabeled apoptosis imaging agents for early detection of response to therapy

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    Since apoptosis plays an important role in maintaining homeostasis and is associated with responses to therapy, molecular imaging of apoptotic cells could be useful for early detection of therapeutic effects, particularly in oncology. Radiolabeled annexin V compounds are the hallmark in apoptosis imaging in vivo. These compounds are reviewed from the genesis of apoptosis (cell death) imaging agents up to recent years. They have some disadvantages, including slow clearance and immunogenicity, because they are protein-based imaging agents. For this reason, several studies have been conducted in recent years to develop low molecule apoptosis imaging agents. In this review, radiolabeled phosphatidylserine targeted peptides, radiolabeled bis(zinc(II)-dipicolylamine) complex, radiolabeled 5-fluoropentyl-2-methyl-malonic acid (ML-10), caspase-3 activity imaging agents, radiolabeled duramycin, and radiolabeled phosphonium cation are reviewed as promising low-molecular-weight apoptosis imaging agents

    Radiolabeled Apoptosis Imaging Agents for Early Detection of Response to Therapy

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    Since apoptosis plays an important role in maintaining homeostasis and is associated with responses to therapy, molecular imaging of apoptotic cells could be useful for early detection of therapeutic effects, particularly in oncology. Radiolabeled annexin V compounds are the hallmark in apoptosis imaging in vivo. These compounds are reviewed from the genesis of apoptosis (cell death) imaging agents up to recent years. They have some disadvantages, including slow clearance and immunogenicity, because they are protein-based imaging agents. For this reason, several studies have been conducted in recent years to develop low molecule apoptosis imaging agents. In this review, radiolabeled phosphatidylserine targeted peptides, radiolabeled bis(zinc(II)-dipicolylamine) complex, radiolabeled 5-fluoropentyl-2-methyl-malonic acid (ML-10), caspase-3 activity imaging agents, radiolabeled duramycin, and radiolabeled phosphonium cation are reviewed as promising low-molecular-weight apoptosis imaging agents

    Professional Skills of Expert Teachers in Music Teaching: The Dynamic Nature of Effective Instruction

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     本研究では,音楽科授業において,達人教師たちが子どもたちに効果的に説明しているさまざまな指導場面を切り出し,「即座に反応する応答力」と「音楽に関連する専門的知識」の2つの視点に則って,ワザの個別事例を分析した。その結果,(1)「即座に反応する応答力」は,指導の中で常に行われる学習者理解によって,教育内容を調整しどのような教授行為を行うかという判断を伴うもので,教師個人内の音楽に関する概念的知識と身体知に基づき間断なく行われる。また,(2)「音楽に関連する専門的知識」は,「音楽する」行為がもたらす身体知を教師と学習者が往還させながら教授・学習されるという特徴がある。したがって「達人教師達が効果的に説明する」というのは,教師と学習者の身体知を往還させながら,教授ストラテジーを巧みに選択し「即座に反応する応答力」を発揮していく創造性豊かな教授的行為である,と考えられた

    奈良における侵襲性GBS感染症における臨床的特徴と分子疫学的特徴(2007~2016年)

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    Invasive Streptococcus agalactiae (GBS) infections are increasingly common among neonates and the elderly. Therefore, GBS surveillance for better antibiotic treatment and prophylaxis strategies are needed. We retrospectively evaluated the clinical aspects of invasive infections and the phenotypic and genetic diversity of infectious isolates from Nara, Japan, collected between 2007 and 2016, by using information from hospital records. GBS strains collected from the blood and cerebrospinal fluid cultures were evaluated for capsular types, multi-locus sequence typing (MLST), antibiotic susceptibility, antibiotics resistance gene, and pulsed-field gel electrophoresis. Forty GBS isolates (10 from children and 30 from adults) were analyzed, and the distribution of molecular serotype and allelic profiles varied between children and adults. We found the rates of early-onset disease in neonates with birth complications to be higher than that of previous reports, indicating that there could be relevance between complications at birth and early-onset disease. Standard antibiotic prophylaxis strategies may need to be reconsidered in patients with birth complications. In adults, the mean age of the patients was 68 years (male: 63%). Primary bacteremia was the most common source of infection. In the neonates, six had early-onset diseases and four had late-onset diseases. The most frequently identified strains were molecular serotype Ia ST23 (40%) and molecular serotype Ib ST10 (20%) in children and molecular serotype Ib ST10 (17%), molecular serotype VI ST1 (13%), and molecular serotype V ST1 (13%) in adults. Levofloxacin-resistant molecular serotype Ib strains and molecular serotypes V and VI ST1 were common causes of GBS infection in adults but were rarely found in children. Furthermore, pulsed-field gel electrophoresis in our study showed that specific clone isolates, that tend to have antibiotics resistance were widespread horizontally for a decade. Continuous surveillance and molecular investigation are warranted to identify the transmission route and improve antibiotic treatment strategies.博士(医学)・甲第773号・令和3年3月15日Copyright: © 2020 Hirai et al. This is an open access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    High revivability of vitrified-warmed bovine mature oocytes after recovery culture with alpha-tocopherol

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    online publication: 27 January 2015The objective of this study was to investigate whether developmental competence of vitrified–warmed bovine oocytes can be improved by antioxidant treatment during recovery culture. In experiment 1, one of the two antioxidants (either l-ascorbic acid or α-tocopherol) was added as a supplement to the recovery culture medium to which postwarming oocytes were exposed for 2 h before IVF. The exposure to α-tocopherol had a positive effect on rescuing the oocytes as assessed by the blastocyst yield 8 days after the IVF (35.1–36.3% vs 19.2–25.8% in untreated postwarming oocytes). Quality of expanding blastocysts harvested on Day 8 was comparable between α-tocopherol-treated vitrification group and fresh control group in terms of total cell number and chromosomal ploidy. In experiment 2, level of reactive oxygen species, mitochondrial activity, and distribution of cortical granules in α-tocopherol-treated postwarming oocytes were assessed. No obvious differences from the control data were found in these parameters. However, the treatment with α-tocopherol increased the percentage of zygotes exhibiting normal single aster formation (90.3% vs 48.0% in untreated postwarming oocytes; 10 h post-IVF). It was concluded that α-tocopherol treatment of vitrified–warmed bovine mature oocytes during recovery culture can improve their revivability, as shown by the high blastocyst yield and the higher mean total cell number in the blastocysts.ArticleREPRODUCTION. 149(4):347-355 (2015)journal articl

    日本における基質特異性拡張型β-ラクタマーゼ産生肺炎桿菌の分子遺伝学的特徴:CTX-M-15の優位性と高病原性クローンの出現

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    Objective: To provide data on the molecular characteristics of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae clinical isolates in Japan. Methods: A total of 100 clinical isolates of ESBL-producing K. pneumoniae collected throughout Japan between June and July 2018 were studied. ESBL genes were analyzed using PCR and DNA sequencing. Transferability of ESBL genes was investigated by conjugation experiments. Plasmid replicon types, virulence genes (rmpA, rmpA2, iucA, iroB, and peg-344) associated with hypervirulent K. pneumoniae (hvKp), and capsule types were detected using PCR. Genotyping was performed using multilocus sequence typing. Results: All ESBL-producing isolates carried blaCTX-M genes. The most predominant CTX-M-type identified was CTX-M-15 (n=55). We identified 24 sequence types (STs) among the CTX-M-15 producers, with ST25 (n=8) being the most common. Most of the transconjugants carrying blaCTX-M-15 contained the FIIk replicon. Of the 100 ESBL-producing isolates, 31 were hvKp defined by the presence of the virulence genes. These ESBL-producing hvKp isolates belonged to eight STs (STs 23, 25, 36, 65, 86, 268, 412, and 4492), with five capsule types (K1, K2, K20, K57, and undefined). Conclusions: CTX-M-15 was the predominant ESBL among K. pneumoniae isolates from Japan. This study shows that ESBL-producing hvKp strains comprising various clones are emerging in Japan.博士(医学)・甲第769号・令和3年3月15日© 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    歯の形態形成に関与する新規遺伝子の解明

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    Tooth development is controlled by body plan during the fetal period, the generation of teeth from tooth germ is induced by the epithelial-mesenchymal interaction. Spatiotemporal regulation of tooth morphogenesis is supported by gene expression. Although many of the genes involved in tooth development are known, the molecular mechanism underlying tooth morphogenesis is not completely understood. For a comprehensive understanding of tooth development, the elucidation of unknown genes is necessary. In this study, to identify unknown genes involved in tooth development, we performed genome-wide analysis at each stage of tooth development and identified 17 genes with high levels of expression and large changes in expression. In addition, we performed qPCR and in situ hybridization analyses to elucidate the spatiotemporal regulation, such as the regulation that occurs around or in the entire tooth germ, enamel knots, epithelium, and mesenchyme. These results show that these characteristic genes may play important roles in each time period or region of tooth development, and the elucidation of the functions of these genes will lead to an integrated understanding of the process of tooth development.博士(医学)・甲第790号・令和3年3月15日発行元である日本再生歯科医学会の許諾を得て登録(2021年6月29日付)ジャーナル公式サイト(日本再生歯科医学会HP内):http://www.jarde.jp/zasshi/e/18-2-1.htm
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