X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 angstrom. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si-OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra

Production and crystallization of lobster muscle tropomyosin expressed in Sf9 cells

AbstractA new form of muscle tropomyosin crystal has been obtained, by employing new strategies in protein preparation and crystallization. Non-polymerizable tropomyosin was prepared by removing 11 amino acids at the C-terminus. The truncated tropomyosin was expressed in Sf9 insect cells by use of the baculovirus-based expression system, to obtain highly homogeneous protein preparations. By routinely monitoring homogeneity by mass spectrometry, we found that the homogeneity played a key role in obtaining good crystals. The crystal quality was also dependent on isoforms; the crystals raised from a slow muscle-specific isoform diffracted to a higher resolution, compared with a fast muscle-specific counterpart. For crystallization, a high concentration of organic solvent was used as the precipitant; in the presence of 35% DMSO, tetragonal crystals were formed, which belong to space group P43(1)212 with cell constants of a = b = 105.6 Å, c = 506.9 Å. The crystals gave rise to reflections the intensities of which were characteristically determined by the transform of α-helical coiled-coil. Thus in the region of 10-5.5 Å resolution along the c∗-axis, the reflections were weak. For accurate measurement of these reflection intensities, beam-line ID2 in ESRF Grenoble was advantageous owing to the high brilliance and a low background. There the crystals diffracted to beyond 3.0 Å along the c∗-axis, whereas along the a∗–b∗-plane reflections were limited to 6.6 Å. Data analysis is under way on a data set from a PtCl4 derivative

ゴルジノラクトンの合成研究

講演番号：4ⅢL 2

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

Validation of ozone data from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES)

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) onboard the International Space Station provided global measurements of ozone profiles in the middle atmosphere from 12 October 2009 to 21 April 2010. We present validation studies of the SMILES version 2.1 ozone product based on coincidence statistics with satellite observations and outputs of chemistry and transport models (CTMs). Comparisons of the stratospheric ozone with correlative data show agreements that are generally within 10%. In the mesosphere, the agreement is also good and better than 30% even at a high altitude of 73km, and the SMILES measurements with their local time coverage also capture the diurnal variability very well. The recommended altitude range for scientific use is from 16 to 73km. We note that the SMILES ozone values for altitude above 26km are smaller than some of the correlative satellite datasets; conversely the SMILES values in the lower stratosphere tend to be larger than correlative data, particularly in the tropics, with less than 8% difference below similar to 24km. The larger values in the lower stratosphere are probably due to departure of retrieval results between two detection bands at altitudes below 28km; it is similar to 3% at 24km and is increasing rapidly down below

Non-destructive assay of nuclear materials using a self-indication method

The integrity test applicable to TRU fuel containing MA with high radioactivity and high decay heat is important for safety. Neutron resonance transmission analysis is adapted for identification and quantification of nuclides in fuels by neutron time-of-flight measurement. In this work, a self-indication method was applied to the measurement of the transmitted neutron. The validation of the self-indication method was performed by using a pulsed neutron source and natural uranium samples at the KURRI-LINAC. The results show that the target areal density can be easily determined from the reduction of the counting rate around the resonances with and without sample. It was confirmed that the reduction ratio due to the neutron resonance absorption can be estimated to within 10%. The numerical estimation showed that the areal density of fuel material can be determined in the range from 10−6 to 10−2 (b−1) using multiple resonances and suitable thickness self-indicator

Immunotoxin-Mediated Tract Targeting in the Primate Brain: Selective Elimination of the Cortico-Subthalamic “Hyperdirect” Pathway

Using a neuron-specific retrograde gene-transfer vector (NeuRet vector), we established immunotoxin (IT)-mediated tract targeting in the primate brain that allows ablation of a neuronal population constituting a particular pathway. Here, we attempted selective removal of the cortico-subthalamic “hyperdirect” pathway. In conjunction with the direct and indirect pathways, the hyperdirect pathway plays a crucial role in motor information processing in the basal ganglia. This pathway links the motor-related areas of the frontal lobe directly to the subthalamic nucleus (STN) without relay at the striatum. After electrical stimulation in the motor-related areas such as the supplementary motor area (SMA), triphasic responses consisting of an early excitation, an inhibition, and a late excitation are usually detected in the internal segment of the globus pallidus (GPi). Several lines of pharmacophysiological evidence suggest that the early excitation may be derived from the hyperdirect pathway. In the present study, the NeuRet vector expressing human interleukin-2 receptor α-subunit was injected into the STN of macaque monkeys. Then, IT injections were made into the SMA. In these monkeys, single-neuron activity in the GPi was recorded in response to the SMA stimulation. We found that the early excitation was largely reduced, with neither the inhibition nor the late excitation affected. The spontaneous firing rate and pattern of GPi neurons remained unchanged. This indicates that IT-mediated tract targeting successfully eliminated the hyperdirect pathway selectively from the basal ganglia circuitry without affecting spontaneous activity of STN neurons. The electrophysiological finding was confirmed with anatomical data obtained from retrograde and anterograde neural tracings. The present results define that the cortically-driven early excitation in GPi neurons is mediated by the hyperdirect pathway. The IT-mediated tract targeting technique will provide us with novel strategies for elucidating various neural network functions

Anti-myeloma Activity by Thiazolidine-2,4-dione compounds

Proviral Integrations of Moloney virus 2 (PIM2) kinase is overexpressed in multiple myeloma (MM) cells, and regarded as an important therapeutic target. Here, we aimed to validate the therapeutic efficacy of different types of PIM inhibitors against MM cells for their possible clinical application. Intriguingly, the thiazolidine 2,4 dione family compounds SMI 16a and SMI 4a reduced PIM2 protein levels and impaired MM cell survival preferentially in acidic conditions, in contrast to other types of PIM inhibitors, including AZD1208, CX 6258 and PIM447. SMI 16a also suppressed the drug efflux function of breast cancer resistance protein, minimized the sizes of side populations, and reduced in vitro colony forming capacity and in vivo tumorigenic activity in MM cells, suggesting impairment of their clonogenic capacity. PIM2 is known to be subject to ubiquitination-independent proteasomal degradation. Consistently, the proteasome inhibitors bortezomib and carfilzomib increased PIM2 protein levels in MM cells without affecting its mRNA levels. However, SMI 16a mitigated the PIM2 protein increase and cooperatively enhanced anti MM effects in combination with carfilzomib. Collectively, the thiazolidine 2,4 dione family compounds SMI 16a and SMI 4a uniquely reduce PIM2 protein in MM cells, which may contribute to their profound efficacy in addition to their immediate kinase inhibition. Their combination with proteasome inhibitors is envisioned