79 research outputs found

    Pressure-induced structural phase transition and new superconducting phase in UTe2

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    We report on the crystal structure and electronic properties of the heavy fermion superconductor UTe2 at high pressure up to 11 GPa, as investigated by X-ray diffraction and electrical resistivity experiments. The X-ray diffraction measurements under high pressure using a synchrotron light source reveal anisotropic linear compressibility of the unit cell up to 3.5 GPa, while a pressure-induced structural phase transition is observed above 3.5-4GPa at room temperature, where the body-centered orthorhombic crystal structure with the space group Immm changes into a body-centered tetragonal structure with the space group I4/mmm. The molar volume drops abruptly at the critical pressure, while the distance between the first-nearest neighbor of U atoms increases, implying a switch from the heavy electronic states to the weakly correlated electronic states. Surprisingly, a new superconducting phase at pressures higher than 7 GPa was detected at Tsc above 2K with a relatively low upper-critical field, Hc2(0). The resistivity above 3.5GPa, thus, in the high-pressure tetragonal phase, shows a large drop below 230 K, which may also be related to a considerable change from the heavy electronic states to the weakly correlated electronic states.Comment: 11 pages, 9 figure

    Effects of drinking hydrogen-rich water on the quality of life of patients treated with radiotherapy for liver tumors

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    <p>Abstract</p> <p>Background</p> <p>Cancer patients receiving radiotherapy often experience fatigue and impaired quality of life (QOL). Many side effects of radiotherapy are believed to be associated with increased oxidative stress and inflammation due to the generation of reactive oxygen species during radiotherapy. Hydrogen can be administered as a therapeutic medical gas, has antioxidant properties, and reduces inflammation in tissues. This study examined whether hydrogen treatment, in the form of hydrogen-supplemented water, improved QOL in patients receiving radiotherapy.</p> <p>Methods</p> <p>A randomized, placebo-controlled study was performed to evaluate the effects of drinking hydrogen-rich water on 49 patients receiving radiotherapy for malignant liver tumors. Hydrogen-rich water was produced by placing a metallic magnesium stick into drinking water (final hydrogen concentration; 0.55~0.65 mM). The Korean version of the European Organization for Research and Treatment of Cancer's QLQ-C30 instrument was used to evaluate global health status and QOL. The concentration of derivatives of reactive oxidative metabolites and biological antioxidant power in the peripheral blood were assessed.</p> <p>Results</p> <p>The consumption of hydrogen-rich water for 6 weeks reduced reactive oxygen metabolites in the blood and maintained blood oxidation potential. QOL scores during radiotherapy were significantly improved in patients treated with hydrogen-rich water compared to patients receiving placebo water. There was no difference in tumor response to radiotherapy between the two groups.</p> <p>Conclusions</p> <p>Daily consumption of hydrogen-rich water is a potentially novel, therapeutic strategy for improving QOL after radiation exposure. Consumption of hydrogen-rich water reduces the biological reaction to radiation-induced oxidative stress without compromising anti-tumor effects.</p

    Magnetic and transport properties of CeT2Al10(T= Fe, Ru, Os) under pressure

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    The results of electrical resistivity ρ measurements for CeT2Al10 (T = Fe, Ru, Os) under pressure are reported. The abrupt increase was observed at T0 ~ 27 K for CeRu2Al10 and 29 K for CeOs2Al10 at ambient pressure. By applying pressure, T0 for CeRu2Al10 and CeOs2Al10 suddenly disappeared at 4 GPa and 2 GPa, respectively. Although the ground state of CeRu2Al10 is metal at ambient pressure, ρ at low temperatures increased and the ground state became semiconductor at 2 GPa. The increase in ρ suppressed above 3 GPa and the ground state became metal above 5 GPa. Magnetic contribution to CeRu2Al10 above 4 GPa shows maximum, which seems to be attributed to Kondo coherence. These systematical change in ρ(T) was also observed in CeFe2Al10 and CeOs2Al10. From the pressure dependence of the temperature of the maximum, we suggests that CeFe2Al10 and CeOs2Al10 is corresponding to 3.2 GPa and 1.3 GPa of CeRu2Al10

    Hydrogen inhalation ameliorates ventilator-induced lung injury

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    Introduction\ud Mechanical ventilation (MV) can provoke oxidative stress and an inflammatory response, and subsequently cause ventilator-induced lung injury (VILI), a major cause of mortality and morbidity of patients in the intensive care unit. Inhaled hydrogen can act as an antioxidant and may be useful as a novel therapeutic gas. We hypothesized that, owing to its antioxidant and anti-inflammatory properties, inhaled hydrogen therapy could ameliorate VILI.\ud \ud Methods\ud VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg without positive end-expiratory pressure, FiO2 0.21). The mice were randomly assigned to treatment groups and subjected to VILI with delivery of either 2% nitrogen or 2% hydrogen in air. Sham animals were given same gas treatments for two hours (n = 8 for each group). The effects of VILI induced by less invasive and longer exposure to MV (tidal volume of 10 ml/kg, 5 hours, FiO2 0.21) were also investigated (n = 6 for each group). Lung injury score, wet/dry ratio, arterial oxygen tension, oxidative injury, and expression of pro-inflammatory mediators and apoptotic genes were assessed at the endpoint of two hours using the high-tidal volume protocol. Gas exchange and apoptosis were assessed at the endpoint of five hours using the low-tidal volume protocol.\ud \ud Results\ud Ventilation (30 ml/kg) with 2% nitrogen in air for 2 hours resulted in deterioration of lung function, increased lung edema, and infiltration of inflammatory cells. In contrast, ventilation with 2% hydrogen in air significantly ameliorated these acute lung injuries. Hydrogen treatment significantly inhibited upregulation of the mRNAs for pro-inflammatory mediators and induced antiapoptotic genes. In the lungs treated with hydrogen, there was less malondialdehyde compared with lungs treated with nitrogen. Similarly, longer exposure to mechanical ventilation within lower tidal volume (10 mg/kg, five hours) caused lung injury including bronchial epithelial apoptosis. Hydrogen improved gas exchange and reduced VILI-induced apoptosis.\ud \ud Conclusions\ud Inhaled hydrogen gas effectively reduced VILI-associated inflammatory responses, at both a local and systemic level, via its antioxidant, anti-inflammatory and antiapoptotic effects

    Pressure Effect on the Structure and Superconducting Transition Temperature of Filled Skutterudites LaT4P12 (T=Fe, Ru)

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    We studied the effect of pressure on the superconducting transition temperature TSC of LaT4P12 (T=Fe, Ru) up to 8 GPa through electrical resistivity measurements in a cubic anvil apparatus. The TSC of LaFe4P12 was also determined through magnetization measurements up to 3.4 GPa with an opposed-anvil pressure cell. In LaFe4P12, TSC increases with pressure at a rate of 0.71 K/GPa from 0 GPa reaching its maximum at approximately 7 GPa. In contrast, the TSC of LaRu4P12 monotonically decreases with pressure. The decrease rate gradually increases from −0.07 to −0.29 K/GPa. The distinct pressure dependences of both TSC\u27s cannot be explained solely from a structural point of view. We propose that the difference between the pressure dependence of TSC for LaFe4P12 and that for LaRu4P12 can be attributed to the difference in the electronic density of states at the Fermi energy between these two compounds

    冷凍パン生地の品質改良に関する研究

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    大豆レシチンと活性グルテンを超音波処理する方法で調製した複合体を,パン生地調製時に添加することによって,生地を冷凍貯蔵した後でもその生地から調製したパンの品質は良好である。本研究では,この複合体の冷凍生地に対する効果,すなわち複合体の冷凍障害防止効果の機構を調べるために行なわれた。複合体の酵母に対する効果につては生地内発酵能,すなわち炭酸ガスの生成能を,生地自体に対する効果は生地の粘着性を測定して調べた。そして,酵母と生地の両方に対する影響は生地の膨化性を測定して調べた。その結果,食パン生地においては複合体を添加することによって,酵母の発酵能の低下が明らかに抑制されることが分かった。しかし,バターロール生地においては対象との差はほとんど見られなかった。膨化性を測定した結果についても同様の傾向を示した。食パン生地の粘着性測定の結果では,冷凍貯蔵による生地のべたつきは,複合体を添加することによって抑制することができた。以上より大豆レシチンと活性グルテンの複合体(LG)の冷凍障害防止効果は,酵母に対する保護作用が主因であると考えられるが,同時に生地自体の劣化も抑制すると推察される

    Structural Phase Transition and Possible Valence Instability of Ce4f-4f Electron Induced by Pressure in CeCoSi

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    X-ray powder diffraction and electrical resistivity measurements were performed on the tetragonal compound CeCoSi under pressure to elucidate the phase boundary of the pressure-induced structural transition and the change in the 4ff electronic state. The temperature-pressure phase diagram has been determined from the shift of the Bragg peaks and from the anomaly in the resistivity. The critical pressure, PsP_{\rm s} \sim 4.9 GPa at 300 K, decreases to PsP_{\rm s} \sim 3.6 GPa at 10 K. The decrease of PsP_{\rm s} is due not only to the decrease in volume of the unit cell but also to an anisotropic shrinkage by cooling. When crossing the boundary to the high-pressure phase, the resistivity shows a significant drop to exhibit a metallic temperature dependence. The results of this study strongly suggest that the structural phase transition can be ascribed to valence instability of Ce-4f4f electron.Comment: 7 pages, 5 figures, submitted to J. Phys. Soc. Jp

    Association between serum lactate level during cardiopulmonary resuscitation and survival in adult out-of-hospital cardiac arrest: a multicenter cohort study

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    We aimed to investigate the association between serum lactate levels during cardiopulmonary resuscitation (CPR) and survival in patients with out-of-hospital cardiac arrest (OHCA). From the database of a multicenter registry on OHCA patients, we included adult nontraumatic OHCA patients transported to the hospital with ongoing CPR. Based on the serum lactate levels during CPR, the patients were divided into four quartiles: Q1 (≤ 10.6 mEq/L), Q2 (10.6–14.1 mEq/L), Q3 (14.1–18.0 mEq/L), and Q4 (> 18.0 mEq/L). The primary outcome was 1-month survival. Among 5226 eligible patients, the Q1 group had the highest 1-month survival (5.6% [74/1311]), followed by Q2 (3.6% [47/1316]), Q3 (1.7% [22/1292]), and Q4 (1.0% [13/1307]) groups. In the multivariable logistic regression analysis, the adjusted odds ratio of Q4 compared with Q1 for 1-month survival was 0.24 (95% CI 0.13–0.46). 1-month survival decreased in a stepwise manner as the quartiles increased (p for trend < 0.001). In subgroup analysis, there was an interaction between initial rhythm and survival (p for interaction < 0.001); 1-month survival of patients with a non-shockable rhythm decreased when the lactate levels increased (p for trend < 0.001), but not in patients with a shockable rhythm (p for trend = 0.72). In conclusion, high serum lactate level during CPR was associated with poor 1-month survival in OHCA patients, especially in patients with non-shockable rhythm

    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

    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
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