Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa

We have constructed a pressure$-$temperature ($P-T$) phase diagram of $P$-induced superconductivity in EuFe$_2$As$_2$ single crystals, via resistivity ($\rho$) measurements up to 3.2 GPa. As hydrostatic pressure is applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at $T_\mathrm{0}$ shifts to lower temperatures, and the corresponding resistive anomaly becomes undetectable for $P$ $\ge$ 2.5 GPa. This suggests that the critical pressure $P_\mathrm{c}$ where $T_\mathrm{0}$ becomes zero is about 2.5 GPa. We have found that the AF order of the Eu$^{2+}$ moments survives up to 3.2 GPa without significant changes in the AF ordering temperature $T_\mathrm{N}$. The superconducting (SC) ground state with a sharp transition to zero resistivity at $T_\mathrm{c}$ $\sim$ 30 K, indicative of bulk superconductivity, emerges in a pressure range from $P_\mathrm{c}$ $\sim$ 2.5 GPa to $\sim$ 3.0 GPa. At pressures close to but outside the SC phase, the $\rho(T)$ curve shows a partial SC transition (i.e., zero resistivity is not attained) followed by a reentrant-like hump at approximately $T_\mathrm{N}$ with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like strain component is applied using a solid pressure medium, the partial superconductivity is continuously observed in a wide pressure range from 1.1 GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B, selected as "Editors' Suggestion

児童生徒の食習慣と健康状態の実態調査 : 「朝孤食」と「朝共食」の比較(自然科学編)

児童生徒や保護者の食に関する実態や意識などの現状を把握し, 家庭, 学校における今後の食育推進のあり方を考察するための基礎資料を得ることを目的に調査した.今回は「朝孤食」と「朝共食」の食習慣, 健康状態等との比較を行った. 「朝孤食」は「朝食を一人で食べる」, 「朝共食」は『朝食を「家族全員」と「大人もいるが全員ではない」と「子どもだけ」』の該当者を全て加えた. 今回の調査では, 孤食を避け, 誰かと共に食卓を囲むこと「子どもだけで食べる」でも心身の健康には十分効果があることが推察でき, 一般的には「子どもだけで食べる」は孤食に分類1)されるが本調査では『共食』に値すると判断しこのような群に分け検討した.正しい食習慣の育成や食文化の伝承などは, 大人と一緒に食べる『共食』に期待したい.児童生徒の「朝孤食」の割合は, 小学生9.1%, 中学生25.7%と差がみられ, 朝食の共食状況と心身の不調との関係では, 「朝孤食」は「朝共食」に比べ「身体がだるい」, 「目覚めが悪い」, 「イライラする」等の順で割合が高かった. 今回の調査で, 「朝孤食」は就寝時刻が遅いことで, 夜食の摂取が多くなり, 朝食の欠食につながり, 身体の不調に現れていることが推察できた.また, 保護者の食意識では, 「一人で食べさせない」と回答したのは, 「朝共食」の児童生徒の保護者60.2%に比べ「朝孤食」のそれは36.5%と親の意識に大きな差がみられた.今回の調査で「朝孤食」の健康に及ぼす影響や食習慣上の問題点が明らかになり, 「朝共食」が心身の健康にとって好ましいことが分かった

保健師学生の関わりからみたB地区自主防災活動の課題

B地区における8年間の保健師学生の防災活動の取り組みについて分析し、地域の自主防災活動の課題を明らかにした。①学生が作成した既存資料等の分析、②防災対策関係者と学生の意見交換、③2町内における防災講習会の実施と自主防災活動への意識調査、④防災対策関係者への聞き取り調査を行った。その結果、①リーダーの積極的かつ先駆的な働きかけのもとに、町内単位やコミュニティセンター活動を活かして自主防災活動の啓発を行う。②時間の経過とともに防災意識が薄れる中で学生が継続的に介入し、地域の防災行動の普及・啓発を図る。③専門職や他地区の自主防災組織等と連携、協働の上、自主防災組織の繋がりをさらに強化する

S-(1,2-Dicarboxyethyl)glutathione and Glutathione in Lens and Liver of Naphthalene-Treated Rabbits

Peer Reviewe

Chromosome aberrations do not Persist in the Lymphocytes or Bone Marrow Cells of Mice Irradiated in Utero or Soon after Birth.

Mice were exposed at various ages to 1 Gy or 2 Gy of X rays, and translocation frequencies in peripheral blood T cells, spleen cells, and bone marrow cells were determined with FISH painting of chromosomes 1 and 3 when the animals were 20 weeks old. It was found that the mean translocation frequencies were very low (0.8%) in mice exposed in the fetal or early postnatal stages. However, with the increase in animal age at the time of irradiation, the frequency observed at 20 weeks old became progressively higher then reached a plateau (about 5%) when mice were irradiated when 6 weeks old. A major role of p53 (Trp53)-dependent apoptosis for elimination of aberrant cells was not suggested because irradiated fetuses, regardless of the p53 gene status, showed low translocation frequencies (1.8% in p53−/− mice and 1.4% in p53+/− mice) compared to the frequency in the p53−/− mother (7.4%). In contrast, various types of aberrations were seen in spleen and liver cells when neonates were examined shortly after irradiation, similar to what was observed in bone marrow cells after irradiation in adults. We interpreted the results as indicating that fetal cells are generally sensitive to induction of chromosome aberrations but that the aberrant cells do not persist because fetal stem cells tend to be free of aberrations and their progeny replace the pre-existing cell populations during the postnatal growth of the animals

Discovery of fossil asteroidal ice in primitive meteorite Acfer 094

隕石中に小惑星の氷の痕跡を発見 --氷が抜けてできた空間を放射光X線CTで発見--. 京都大学プレスリリース. 2019-11-25.Carbonaceous chondrites are meteorites believed to preserve our planet’s source materials, but the precise nature of these materials still remains uncertain. To uncover pristine planetary materials, we performed synchrotron radiation–based x-ray computed nanotomography of a primitive carbonaceous chondrite, Acfer 094, and found ultraporous lithology (UPL) widely distributed in a fine-grained matrix. UPLs are porous aggregates of amorphous and crystalline silicates, Fe─Ni sulfides, and organics. The porous texture must have been formed by removal of ice previously filling pore spaces, suggesting that UPLs represent fossils of primordial ice. The ice-bearing UPLs formed through sintering of fluffy icy dust aggregates around the H2O snow line in the solar nebula and were incorporated into the Acfer 094 parent body, providing new insight into asteroid formation by dust agglomeration