The Temperature Dependence of the Resistivity of Liquid Alkali Metals at Constant Volume

The temperature dependence of the resistivity of liquid alkali metals at constant volume and at constant pressure was measured. The residual resistance obtained by extrapolating the resistivity curve plotted at constant volume against temperature to absolute zero is small for liquid Na, and becomes larger proceeding to the heavier alkali metals. The temperature dependence of the resistivity at constant volume and at constant pressure is discussed in the term of the temperature variation of the correlation function α(K)

Photodarkening of amorphous selenium under high pressure

The photodarkening phenomena of amorphous Se have been studied by the optical absorption coefficient, sound velocity and attenuation measurements. The light illumination at low temperatures induces the photodarkening, and the photodarkened state is completely recovered by annealing near 306 K corresponding to the glass transition temperature. The photodarkening is enhanced by application of pressure. The sound velocity decreases and the sound attenuation increases by the illumination at low temperature. These suggest that a structural disorder increases in the photodarkened state. Three stages are observed for the recovery process of the photodarkened specimen. The photodarkening and the recovery process are discussed on the basis of VAP (valence alternative pair) model.<br /

The Effect of the Electron Correlation on the Electrical Resistivity of Liquid Metals

An elementary theory of the electrical resisitivity of monovalent liquid metals is given. On using the theory of the plasma oscillations of conduction electrons, the electron-ion interactions are separated into two parts : one gives the effective electron-ion interactions which are screened as the result of the effects of the plasma oscillations of the conduction electrons and contributes directly to the electrical resistivity ; the other describes the interactions between the ions and the plasma oscillations. The screened electron-ion interaction is defined as the pseudo-potential of the ion. The theory constructed on the basis of the free-electron model is applied in the first instance to estimate the electrical resistivity of liquid sodium near the melting point. Callaway\u27s potential and the correlation function of ions determined from neutron diffraction experiments are used and the mean free path of a conduction electron is calculated numerically. Therefore, in our theory the "plasma term" and the "structure term" of Ziman\u27s theory are not treated separately

Synthetic RNA-protein complex shaped like an equilateral triangle.

Synthetic nanostructures consisting of biomacromolecules such as nucleic acids have been constructed using bottom-up approaches. In particular, Watson-Crick base pairing has been used to construct a variety of two- and three-dimensional DNA nanostructures. Here, we show that RNA and the ribosomal protein L7Ae can form a nanostructure shaped like an equilateral triangle that consists of three proteins bound to an RNA scaffold. The construction of the complex relies on the proteins binding to kink-turn (K-turn) motifs in the RNA, which allows the RNA to bend by ∼ 60° at three positions to form a triangle. Functional RNA-protein complexes constructed with this approach could have applications in nanomedicine and synthetic biology

Establishment of an Epicutaneously Sensitized Murine Model of Shellfish Allergy and Evaluation of Skin Condition by Raman Microscopy

Background: Shellfish allergy is one of the most common food allergies. Recent studies have shown that sensitization to allergens via the skin is involved in the development of food allergies. In this study, a mouse model of shrimp allergy was generated by epicutaneous sensitization and used to identify skin conditions associated with susceptibility to sensitization. Methods: Four-week-old female BALB/c mice were sensitized by repeated application of 0.1 mg of tropomyosin to tape-stripped skin on days 0, 7, and 15, followed by a challenge on days 28 and 35. Results: Epicutaneously sensitized mice exhibited higher serum levels of tropomyosin-specific IgE on day 15 than control mice. After the oral challenge, model mice had higher anaphylaxis scores and lower rectal temperature. After three tape-strip treatments for sensitization, the skin was analyzed by Raman microscopy. The sensitized mice exhibited lower relative intensities of Raman bands at 399, 915, and 1073 cm−1 than control mice, which could be helpful noninvasive markers in screening for potential sensitization via the skin. Conclusions: An epicutaneous sensitization shellfish allergy model was generated. This model will be useful in studies to elucidate the pathogenesis of skin sensitization. Raman microscopy may also be valuable for capturing subtle skin changes leading to sensitization

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「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

「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