29 research outputs found

    Linear Trimer Formation by Three-Center-Four-Electron Bonding in RuP

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    In molecules like hydrogen, most chemical bonds are formed by sharing two electrons from each atom in the bonding molecular orbital (two-center-two-electron (2c2e) bonding). There are, however, different kinds of chemical bonding. The I3- molecule, for example, is noteworthy because three iodine atoms are linearly united by sharing four electrons (three-center-four-electron (3c4e) bonding). Some inorganic solids undergo phase transitions that result in the formation of "molecules" in their crystalline frameworks, which are often accompanied by dramatic changes in physical properties; the metal-to-insulator transition (MIT) in vanadium dioxide, for example, occurs with the formation of dimer molecules with 2c2e bonding. We repot the creation of a linear ruthenium trimer with 3c4e bonding in ruthenium monopnictide at its MIT. Charge transfer from polymerized phosphorous to ruthenium produces this unusual molecule, with all conduction electrons trapped by the bonding molecular orbital. Our results demonstrate that molecules are crucial even in solid crystals as they impact their electronic properties.Comment: 12 pages, 9 figures, 3 Table

    Polarity-dependence of the defect formation in c-axis oriented ZnO by the irradiation of an 8 MeV proton beam

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    The polarity dependence of the radiation hardness of single-crystalline ZnO bulk crystals is studied by irradiating the Zn-polar and O-polar c-planes with an 8 MeV proton beam up to the fluence of 4.2 × 1016 p/cm2. To analyze the hardness, radiation-induced defects were evaluated using positron annihilation (PA) analysis, and the recovery by post-annealing was examined using continuous-wave photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements. It was suggested by the PA and PL analyses that the major defects in both polarities were VZnVO divacancies. While the PA data did not show the clear dependence on the polarity, the PL and TRPL results showed that the Zn-polar c-plane had a little higher radiation tolerance than that of the O-polar c-plane, which was consistent with the result that the increase in the electrical resistance by proton beam irradiation was smaller for the former one. Considering these results in total, the polarity dependence is considered to be not so large, but the Zn-polar c-plane has a little higher tolerance than that of the O-polar one

    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

    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

    Renal arteriovenous malformation treated using glue embolization under inflow and outflow control by balloon occlusion

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    A 45-year-old female presented with gross hematuria. Right renal arteriovenous malformation on abdominal contrast-enhanced computed tomography necessitated urgent transcatheter arterial embolization. Right renal digital subtraction angiography revealed a single tortuous and dilated vessel converging to an aneurysmal dilated vein. To selectively embolize the malformation, we closed the arterial side with a microballoon and attempted glue embolization; filling occurred unexpectedly early, and another balloon on the vein side helped control the renal vein blood flow. Glue embolization was performed without adverse events. Glue embolization for high-flow arteriovenous malformation under balloon occlusion-mediated inflow and outflow control can effectively and safely embolize complete target vessels

    A case of blindness caused by Lemierre's syndrome

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    Key Clinical Message We describe a patient who lost her vision because of Lemierre's syndrome. Ophthalmologic complications of Lemierre's syndrome are rare, and very few cases have been reported. Clinicians need to recognize that it is a serious condition that can lead to blindness in some cases. Abstract Lemierre's syndrome is a systemic septic embolism resulting from thrombophlebitis of the internal jugular vein. We report a case of blindness caused by Lemierre's syndrome, despite prompt diagnosis and early treatment. A 36‐year‐old woman was transported to our hospital. She presented with fever, facial swelling, and right visual acuity deterioration. Contrast‐enhanced computed tomography revealed a retropharyngeal abscess and right internal jugular vein thrombosis. Blood culture revealed Fusobacterium necrophorum, suggesting Lemierre's syndrome. The patient had septic shock and disseminated intravascular coagulation. We diagnosed her visual impairment as orbital‐apex syndrome due to spread of inflammation. After 6 weeks of antimicrobial drug treatments, her general condition had improved, and the retropharyngeal abscess had disappeared. On Day 49 of her illness, she was transferred to a rehabilitation hospital, but her visual acuity was not restored. Clinicians should be aware that Lemierre's syndrome can, although rarely, cause blindness
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