The International MegaGauss Laboratory at ISSP, The University of Tokyo

Recently, much progress has been made in generation of high magnetic fields in the International MegaGauss Science Laboratory at ISSP of the University of Tokyo. The electro-magnetic flux compression method has been improved to establish the world highest indoor-field of about 730 T. In addition to the destructive methods, a new project aiming at the non-destructive generation of both long pulsed- and 100 T-fields is progressing. The long pulse project is introduced. Not only for the highest field but also for various experiments, many kinds of coils have been developed. A microscope imaging system under pulsed fields, and miniature magnets for the X-ray measurements at the synchrotron radiation facility are also presented.     

Electronic structures of β-SiC containing point defects studied by DV-Xα method

The DV-Xα method was used to calculate the bond order between atoms in cubic silicon carbide (β-SiC) with a point defect. Three types of β-SiC cluster models were used: pure cluster, vacancy cluster and interstitial cluster. The bond order was influenced by the kind of defects. The bonds between C interstitial and neighboring C atoms were composed of anti-bonding type interactions, while the bonds between Si interstitial and neighboring C and Si atoms were composed of bonding type interactions. The overlap population of each molecular orbital was examined to obtain detailed information of the chemical bonding. It appeared more difficult to recombine interstitial atoms in a cluster with a C atom vacancy than in a cluster with a Si atom vacancy, due to the stronger Si–Si bonds surrounding the C atom vacancy. The C interstitial atom had C2s and C2p anti-bonding interactions with high energy levels. The Si interstitial had minimal anti-bonding interactions.     

ITGB6-Knockout Suppresses Cholangiocarcinoma Cell Migration and Invasion with Declining PODXL2 Expression

Intrahepatic cholangiocarcinoma (iCCA) is a heterogeneous bile duct cancer with a poor prognosis. Integrin αvβ6 (β6) has been shown to be upregulated in iCCA and is associated with its subclassification and clinicopathological features. In the present study, two ITGB6-knockout HuCCT1 CCA cell lines (ITGB6-ko cells) were established using the clustered regulatory interspaced short palindromic repeats (CRISPR), an associated nuclease 9 (Cas9) system, and single-cell cloning. RNA sequencing analysis, real-time polymerase chain reaction (PCR), and immunofluorescent methods were applied to explore possible downstream factors. ITGB6-ko cells showed significantly decreased expression of integrin β6 on flow cytometric analysis. Both cell lines exhibited significant inhibition of cell migration and invasion, decreased wound-healing capability, decreased colony formation ability, and cell cycle dysregulation. RNA sequencing and real-time PCR analysis revealed a remarkable decrease in podocalyxin-like protein 2 (PODXL2) expression in ITGB6-ko cells. Colocalization of PODXL2 and integrin β6 was also observed. S100 calcium-binding protein P and mucin 1, which are associated with CCA subclassification, were downregulated in ITGB6-ko cells. These results describe the successful generation of ITGB6-ko CCA cell clones with decreased migration and invasion and downregulation of PODXL2, suggesting the utility of integrin β6 as a possible therapeutic target or diagnostic marker candidate.     

Multi-color light-emitting transistors composed of organic single crystals

We report a novel concept for multi-color light emission from an ambipolar organic single-crystal transistor using natural optical waveguides, the self-absorption effect, Davydov splitting and the unique alignment of the transition dipole moments. We used 9,10-bis-(2,2-diphenylvinyl)-anthracene single crystals to produce blue and green light from identical single-crystal transistors. We also observed red light, which corresponds to the emission from in-gap states that are caused by impurities. Importantly, each of these different colors corresponds to a distinguishable light polarization, which enables us to tune the emission color by using a light polarizer.     

Control of an articulated wheeled mobile robot in pipes

We propose a control method in which an articulated wheeled mobile robot moves inside straight, curved and branched pipes. This control method allows the articulated wheeled mobile robot to inspect a larger area. The articulated wheeled mobile robot comprises pitch and yaw joints is and propelled by active wheels attached to the robot. Via the proposed control method, the robot takes on two different shapes; one prevents the robot from slipping inside straight pipes and the other allows movement in a pipe that curves in any direction. The robot is controlled by a simplified model for the robot's joint angles. The joint angles of the robot are obtained by fitting to a continuous curve along the pipe path. In addition, the angular velocity of the robot's active wheels is determined by a simplified model. The effectiveness of the proposed the control method was demonstrated with a physical implementation of the robot, and the robot was able to move inside straight, curved and branched pipes.     

Gasification of coals treated with non-aqueous solvents. 3. Swelling behaviour of a single coal particle

The swelling behaviour of a single coal particle was examined photographically under rapid heating up to 870 K in an atmosphere of nitrogen or hydrogen, to test how treatment with liquid ammonia affected the swelling property of a Japanese bituminous coal. It was found that the treated particle began to swell at higher temperature than the untreated one in either atmosphere, and that the impregnation of the treated coal with a nickel salt appreciably suppressed the swelling of coal particles especially those of smaller particle size.     

Analysis of Iodothyronines in Dietary Supplements Containing Dried Thyroid by HPLC Using a Pre-column Derivative

A new method to determine the iodothyronines, 3,3′,5-triiodo-L-thyronine (T3), 3,3′,5,5′-tetraiodo-L-thyronine (L-thyroxine, T4), and 3,3′,5′-triiodo-L-thyronine (reverse-T3, rT3), in dietary supplements containing dried thyroid by high-performance liquid chromatography was developed using a pre-column derivative with 4-fluoro-7-nitrobenzofurazan (NBD-F) without using LC/MS. T3, T4, and rT3 were released from dried thyroid in dietary supplements by using protease. The protease reaction was finished in 18 h at 37 °C. Iodothyronines released from dried thyroid were treated on a polyvinylpolypyrrolidone (PVPP) column. Iodothyronines adsorbed on PVPP were eluted with 60% acetonitorile. Iodothyronines present in the eluate from the PVPP column were then derivatized with NBD-F. The reaction of iodothyronines with NBD-F was completed in 30 min at 60 °C. These derivatives were measured by HPLC using an octadecylsilane column with a fluorescence detector. Phosphoric acid (0.1%) was added to 630 ml of acetonitrile to a final volume of 1,000 ml, and the mixture was used as the mobile phase. The excitation wavelength on the fluorescence detector was 470 nm, and the emission wavelength was 530 nm. The linearity of iodothyronines as a coefficient of the correlation value was 0.999, and the quantitation limit of iodothyronines was 0.001 μg/ml. The results confirmed that dried thyroid was added to seven dietary supplements. The recovery rate was in the range of 80.8–104.6%, 81.4–103.7%, and 82.2–104.5% for T3, T4, and rT3, respectively. Previously, dried thyroid in dietary supplements was examined by the combination of measuring T3 and T4 by LC/MS and confirmation of epithelial nuclei forming follicles by a microscope. However, microscopic confirmation of epithelial nuclei forming follicles can be complicated by physical alteration during dietary supplement processing. We suggest that the present of dried thyroid in dietary supplements can be confirmed by detecting rT3 without a microscope.     

Evolution of nanoscopic iron clusters in irradiated zirconium alloys with different iron contents

We investigate the distribution of alloying elements in irradiated Zr alloys with different Fe contents using atom probe tomography. Our results showed dense nanoscale regions (clusters) of Fe formed in the matrix. The average diameter of the Fe clusters in alloy with a high Fe content increased under a higher neutron fluence. Conversely, the number density of Fe clusters remained similar in all the Zr alloy specimens. Energy-dispersive X-ray spectrometry showed that the maximum cluster size depended on the Fe content in the secondary phase particles. Fe clusters gathered along the basal plane of the Zr alloys at high fluence, indicating that irradiation defects influence Fe clustering. The solute concentration of Fe was estimated to be approximately 0.1 at%, which is the Fe concentration in the matrix exclusive of Fe clusters.