Plant viruses and viroids in Japan

An increasing number of plant viruses and viroids have been reported from all over the world due largely to metavirogenomics approaches with technological innovation. Herein, the official changes of virus taxonomy, including the establishment of megataxonomy and amendments of the codes of virus classification and nomenclature, recently made by the International Committee on Taxonomy of Viruses were summarized. The continued efforts of the plant virology community of Japan to index all plant viruses and viroids occurring in Japan, which represent 407 viruses, including 303 virus species and 104 unclassified viruses, and 25 viroids, including 20 species and 5 unclassified viroids, as of October 2021, were also introduced. These viruses and viroids are collectively classified into 81 genera within 26 families of 3 kingdoms (Shotokuvirae, Orthornavirae, Pararnavirae) across 2 realms (Monodnaviria and Riboviria). This review also overviewed how Japan’s plant virus/viroid studies have contributed to advance virus/viroid taxonomy

100m疾走の後半における走スピード, ピッチおよびストライドの変化

本研究では, 成人男子7名を被験者にして, 100m疾走中の後半における走スピード, ピッチ数およびストライド長の変化を明らかにした。本研究で得られた結果は, 次のように要約できる。1) 100m疾走後半の50mから100mまで, 走スピードは減少し続けた。2) 100m疾走後半の50mから100mまで, ピッチ数は減少し続けた。3) 100m疾走後半の50mから90mまでストライド長はほぼ一定を保ったが, 90mから100mまでの区間ではストライド長は急激に増加した。The purpose of this study was to measure running speed, stride length and step frequecny in the latter half of 100m sprint running. The subjects used in this study were four collegiate jumpers, 2 graduate students and an assistant of Chukyo University. All were healthy males. Each run was filmed at 50 frames/sec with Photosonics and Bolex 16mm cameras. Stride length and step frequency was measured from film analysis. Resultes obtanied from this study were summarized as follows. 1. Running speed and step frquency were gradually decreased in the latter half 50m of 100m sprint running. 2. Stride length was almost constant from 50m to 90m. After that, however, it was significantly decreased

Electroabsorption spectra of PbSe nanocrystal quantum dots

The quantum-confined Stark effect of PbSe nanocrystal quantum dots (QDs) in a polymer film has been studied for the near-infrared absorption in the region of 1300-1600 nm (corresponding to diameters of 4.0-7.0 nm) by using electric field modulation spectroscopy. Electroabsorption spectra of QDs show the electric-field-induced energy shift in the exciton state, resulting in the spectral broadening given by the second derivative of the absorption spectra. It is shown that the magnitude of the change in electric dipole moment following excitation into the first exciton state increases with an increase in the size of QDs

Molecular-Simulation–Inspired Synthesis of [6]-Prismane via Photoisomerisation of Octafluoro[2.2]paracyclophane

Prismanes have been attracting interest for nearly 50 years because of their geometric symmetry, highly strained structures, and unique applications due to their high carbon densities and bulky structures. Although [3]-, [4]-, and [5]-prismanes have been synthesised, [6]-prismanes and their derivatives remain elusive. Herein, fluorine chemistry, molecular mechanics, molecular orbital package, and density functional theory calculations were used to design and implement the photoisomerisation of octafluoro[2.2]paracyclophane (selected based on the good overlap of its lowest unoccupied molecular orbitals and short distance between the benzene rings) into octafluoro-[6]-prismane. Specifically, a dilute solution of the above precursor in CH3CN/H2O/dimethyl sulfoxide (DMSO) (2:1:8, v/v/v) solution was irradiated with ultraviolet light, with the formation of the desired product confirmed through the use of nuclear magnetic resonance spectroscopy and gas chromatography–mass spectrometry. The product was thermally stable in solution but not under work-up conditions, which complicated the further analysis and single-crystal preparation. The key criteria for successful photoisomerisation were the presence of fluorine substituents in the cyclophane structure and DMSO in the solvent system. A more stable derivative design requires the isolation of prismane products. The proposed fluorination-based synthetic strategy is applicable to developing novel high-strain molecules/materials with three-dimensional skeletons

Role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of focal hepatic lesions

AIM: To evaluate the utility of diffusion-weighted imaging (DWI) in screening and differential diagnosis of benign and malignant focal hepatic lesions