両親媒性コニカルフラーレンの自己集合とその気液,液液,および固液界面における挙動

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 中村 栄一, 東京大学教授 小林 修, 東京大学教授 菅 裕明, 東京大学教授 塩谷 光彦, 東京大学准教授 山野井 慶徳University of Tokyo(東京大学

Characteristics of Anemone Active Regions Appearing in Coronal Holes Observed with {\it Yohkoh} Soft X-ray Telescope

Coronal structure of active regions appearing in coronal holes is studied by using the data obtained with the Soft X-Ray Telescope (SXT) aboard {\it Yohkoh} from 1991 November to 1993 March. The following characteristics are found; Many of active regions appearing in coronal holes show a structure that looks like a ``sea-anemone''. Such active regions are called {\it anemone ARs}. About one-forth of all active regions that were observed with SXT from their births showed the anemone structure. For almost all the anemone ARs, the order of magnetic polarities is consistent with the Hale-Nicholson's polarity law. These anemone ARs also showed more or less east-west asymmetry in X-ray intensity distribution, such that the following (eastern) part of the ARs is brighter than its preceding (western) part. This, as well as the anemone shape itself, is consistent with the magnetic polarity distribution around the anemone ARs. These observations also suggest that an active region appearing in coronal holes has simpler (less sheared) and more preceding-spot-dominant magnetic structure than those appearing in other regions.Comment: 11 pages, 3 tables, 4 figure

Sequence divergence and retrotransposon insertion underlie interspecific epigenetic differences in primates

内在性レトロウイルス配列によってヒトのエピゲノムが変化してきたことを発見！ --ヒトとチンパンジーのiPS細胞の比較解析から--. 京都大学プレスリリース. 2022-10-12.Changes in the epigenome can affect the phenotype without the presence of changes in the genomic sequence. Given the high identity of the human and chimpanzee genome sequences, a substantial portion of their phenotypic divergence likely arises from epigenomic differences between the two species. In this study, the transcriptome and epigenome were determined for induced pluripotent stem cells (iPSCs) generated from human and chimpanzee individuals. The transcriptome and epigenomes for trimethylated histone H3 at lysine-4 (H3K4me3) and lysine-27 (H3K27me3) showed high levels of similarity between the two species. However, there were some differences in histone modifications. Although such regions, in general, did not show significant enrichment of interspecies nucleotide variations, gains in binding motifs for pluripotency-related transcription factors, especially POU5F1 and SOX2, were frequently found in species-specific H3K4me3 regions. We also revealed that species-specific insertions of retrotransposons, including the LTR5_Hs subfamily in human and a newly identified LTR5_Pt subfamily in chimpanzee, created species-specific H3K4me3 regions associated with increased expression of nearby genes. Human iPSCs have more species-specific H3K27me3 regions, resulting in more abundant bivalent domains. Only a limited number of these species-specific H3K4me3 and H3K27me3 regions overlap with species-biased enhancers in cranial neural crest cells, suggesting that differences in the epigenetic state of developmental enhancers appear late in development. Therefore, iPSCs serve as a suitable starting material for studying evolutionary changes in epigenome dynamics during development

Germline genes hypomethylation and expression define a molecular signature in peripheral blood of ICF patients: implications for diagnosis and etiology.

International audienceBACKGROUND: Immunodeficiency Centromeric Instability and Facial anomalies (ICF) is a rare autosomal recessive disease characterized by reduction in serum immunoglobulins with severe recurrent infections, facial dysmorphism, and more variable symptoms including mental retardation. ICF is directly related to a genomic methylation defect that mainly affects juxtacentromeric heterochromatin regions of certain chromosomes, leading to chromosomal rearrangements that constitute a hallmark of this syndrome upon cytogenetic testing. Mutations in the de novo DNA methyltransferase DNMT3B, the protein ZBTB24 of unknown function, or loci that remain to be identified, lie at its origin. Despite unifying features, common or distinguishing molecular signatures are still missing for this disease. METHOD: We used the molecular signature that we identified in a mouse model for ICF1 to establish transcriptional biomarkers to facilitate diagnosis and understanding of etiology of the disease. We assayed the expression and methylation status of a set of genes whose expression is normally restricted to germ cells, directly in whole blood samples and epithelial cells of ICF patients. RESULTS: We report that DNA hypomethylation and expression of MAEL and SYCE1 represent robust biomarkers, easily testable directly from uncultured cells to diagnose the most prevalent sub-type of the syndrome. In addition, we identified the first unifying molecular signatures for ICF patients. Of importance, we validated the use of our biomarkers to diagnose a baby born to a family with a sick child. Finally, our analysis revealed unsuspected complex molecular signatures in two ICF patients suggestive of a novel genetic etiology for the disease. CONCLUSIONS: Early diagnosis of ICF syndrome is crucial since early immunoglobulin supplementation can improve the course of disease. However, ICF is probably underdiagnosed, especially in patients that present with incomplete phenotype or born to families with no affected relatives. The specific and robust biomarkers identified in this study could be introduced into routine clinical immunology or neurology departments to facilitate testing of patients with suspected ICF syndrome. In addition, as exemplified by two patients with a combination of molecular defects never described before, our data support the search for new types of mutations at the origin of ICF syndrome

Efficient Separation of Photoexcited Charge at Interface between Pure CeO2 and Y3+-Doped CeO2 with Heterogonous Doping Structure for Photocatalytic Overall Water Splitting

Enhancement of photoexcited charge separation in semiconductor photocatalysts is one of the important subjects to improve the efficiency of energy conversion for photocatalytic overall water splitting into H2 and O2. In this study, we report an efficient separation of photoexcited charge at the interface between non-doped pure CeO2 and Y3+-doped CeO2 phases on particle surfaces with heterogeneous doping structure. Neither non-doped pure CeO2 and homogeneously Y3+-doped CeO2 gave activities for photocatalytic H2 and O2 production under ultraviolet light irradiation, meaning that both single phases showed little activity. On the other hand, Y3+-heterogeneously doped CeO2 of which the surface was composed of non-doped pure CeO2, and Y3+-doped CeO2 phases exhibited remarkable photocatalytic activities, indicating that the interfacial heterostructure between non-doped pure CeO2 and Y3+-doped CeO2 phases plays an important role for the activation process. The role of the interface between two different phases for activated expression was investigated by selective photo-reduction and oxidation deposition techniques of metal ion, resulting that the interface between two phases become an efficient separation site of photoexcited charge. Electronic band structures of both phases were investigated by the spectroscopic method, and then a mechanism of charge separation is discussed

Efficient Separation of Photoexcited Charge at Interface between Pure CeO₂ and Y³⁺-Doped CeO₂ with Heterogonous Doping Structure for Photocatalytic Overall Water Splitting

Enhancement of photoexcited charge separation in semiconductor photocatalysts is one of the important subjects to improve the efficiency of energy conversion for photocatalytic overall water splitting into H2 and O2. In this study, we report an efficient separation of photoexcited charge at the interface between non-doped pure CeO2 and Y3+-doped CeO2 phases on particle surfaces with heterogeneous doping structure. Neither non-doped pure CeO2 and homogeneously Y3+-doped CeO2 gave activities for photocatalytic H2 and O2 production under ultraviolet light irradiation, meaning that both single phases showed little activity. On the other hand, Y3+-heterogeneously doped CeO2 of which the surface was composed of non-doped pure CeO2, and Y3+-doped CeO2 phases exhibited remarkable photocatalytic activities, indicating that the interfacial heterostructure between non-doped pure CeO2 and Y3+-doped CeO2 phases plays an important role for the activation process. The role of the interface between two different phases for activated expression was investigated by selective photo-reduction and oxidation deposition techniques of metal ion, resulting that the interface between two phases become an efficient separation site of photoexcited charge. Electronic band structures of both phases were investigated by the spectroscopic method, and then a mechanism of charge separation is discussed

Acute Effects of Ambient PM2.5 on All-Cause and Cause-Specific Emergency Ambulance Dispatches in Japan

Short-term health effects of ambient PM₂.₅ have been established with numerous studies, but evidence in Asian countries is limited. This study aimed to investigate the short-term effects of PM₂.₅ on acute health outcomes, particularly all-cause, cardiovascular, respiratory, cerebrovascular and neuropsychological outcomes. We utilized daily emergency ambulance dispatches (EAD) data from eight Japanese cities (2007–2011). Statistical analyses included two stages: (1) City-level generalized linear model with Poisson distribution; (2) Random-effects meta-analysis in pooling city-specific effect estimates. Lag patterns were explored using (1) unconstrained-distributed lags (lag 0 to lag 7) and (2) average lags (lag: 0–1, 0–3, 0–5, 0–7). In all-cause EAD, significant increases were observed in both shorter lag (lag 0: 1.24% (95% CI: 0.92, 1.56)) and average lag 0–1 (0.64% (95% CI: 0.23, 1.06)). Increases of 1.88% and 1.48% in respiratory and neuropsychological EAD outcomes, respectively, were observed at lag 0 per 10 µg/m3 increase in PM₂.₅. While respiratory outcomes demonstrated significant average effects, no significant effect was observed for cardiovascular outcomes. Meanwhile, an inverse association was observed in cerebrovascular outcomes. In this study, we observed that effects of PM₂.₅ on all-cause, respiratory and neuropsychological EAD were acute, with average effects not exceeding 3 days prior to EAD onset