Molecular-based light-activated thyristor

A photoinduced electrical conductivity switching is observed in the molecular conductor of alpha-[bis(ethylenedithio)tetrathiafulvalene](2)I-3 at different temperatures with different irradiation light intensities. The threshold voltage for the differential-negative-resistance effect appearing in the current-voltage characteristic curve decreases and increases, respectively, as the light intensity is increased and as the temperature decreases below the insulator-metal phase transition. The potential application of molecular conductor in bidirectional light-activated thyristor devices is demonstrated. (c) 2007 American Institute of Physics

Reversible photoswitching behavior in bulk resistance and in color of polycrystalline AgI at room temperature

A photoinduced reversible change in bulk resistance of polycrystalline AgI is observed at room temperature. The original yellow color of the sample changes to dark brown with UV (308 nm) photoirradiation, associated with the small decrease in the bulk resistance. A reversible switching of color between dark brown and yellow is observed by alternative UV-visible photoirradiation, associated with a switching between high and low resistance states. The observed reversible photoswitching is interpreted in terms of the photoinduced reversible change in the beta-gamma-polytype stacking structure of the polycrystalline AgI

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

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Magnetic field effects on electro-photoluminescence of photoinduced electron transfer systems in a polymer film

Magnetic field effects on photoluminescence (PL) in the presence of external electric fields have been examined for a variety of electron donor and acceptor pairs, either linked with methylene chain or randomly distributed in polymethyl methacrylate (PMMA) films, which show intermolecular photoinduced electron transfer (PIET). Application of electric fields changes the energy separation among different electronic states, because the electric dipole moment at the state under consideration is usually different from the others. The energy levels within the same spin multiplicity are also shifted or splitted by application of magnetic field. Then, simultaneous application of electric field and magnetic field induces interesting effects on PL which cannot be observed when only electric field or magnetic field is applied to molecules. In this article, experimental results of the magnetic field effect of the electric field effect both on LE fluorescence and on exciplex fluorescence resulting from PIET are presented, and the mechanism of the synergy effects of the electric and magnetic fields on PL are discussed. The hyperfine interaction of the various radical-ion pairs produced by PIET has been also determined on the basis of the synergy effects on PL, and the results are compared with the calculated values

Photo- and field-induced charge-separation and phosphorescence quenching in organometallic complex Ir(ppy)3

Electric field effects on absorption and photoluminescence (PL) spectra of organometallic phosphorescent emitter Ir(ppy)3, {tris[2-phenylpyridinato-C2,N] iridium (III)} doped in a film of polymethyl methacrylate (PMMA) have been confirmed at temperatures in the range of 40-295 K. Field-induced quenching of PL observed for Ir(ppy)3 is attributed to the decrease both of emitting state population and of the lifetime of PL. The quenching is independent of excitation energy as well as temperature. Field-assisted charge separation or dissociation of electron-hole (e-h) pair produced by photoexcitation may decrease the population of the emitting state. The Stark shifts on absorption and PL spectra have also been analyzed