National Institute of Technology, Hiroshima College

We converted perhydropolysilazane into SiO2 at a temperature below 65 °C by irradiating it with a low-temperature plasma jet composed of argon and water vapor. We evaluated the electrical properties of the SiO2 thin films obtained by using this method through capacitance–voltage and current density–electric field measurements on MOS capacitors. The results showed that the SiO2 thin films exhibited performance comparable with thermal oxides formed at 1000 °C. Based on these findings and the results of Fourier transform infrared spectroscopy measurements, we identified the film formation mechanism as interface-driven self-organization, which explains why the PHPS-converted SiO2 films exhibit thermal-oxide-like quality.

This study focused on exploring the relationship between antimicrobial use indicators, including the modified antibiotic heterogeneity index (mAHI), and the carbapenem susceptibility in Pseudomonas aeruginosa. Survey-based observational study conducted across multiple facilities. Public community hospital institutions. This survey was conducted in 15 community hospitals in Japan. Indicators, such as the defined daily doses (DDDs), days of therapy (DOTs), antibiotic heterogeneity index (AHI), and mAHI, were analyzed for P. aeruginosa carbapenem susceptibility using Spearman's rank correlation. The predictive accuracies of the AHI and mAHI for carbapenem susceptibility were compared using DeLong's test for the 2 correlated receiver operating characteristic curves. No significant correlations were observed between DDDs or DOTs and carbapenem susceptibility. However, a significant correlation was observed between carbapenem susceptibility and the mAHI (r = 0.261, P = .02), which also demonstrated a higher predictive accuracy for high susceptibility rates than that of the AHI (area under the curve: 0.75 vs 0.58, p < .01). The optimal mAHI cutoff value for predicting 90% susceptibility was 0.765, with a sensitivity of 67.7% and specificity of 76.5%. The mAHI may be a better predictor of carbapenem susceptibility than other commonly used indicators. This study underscores the utility of the mAHI as an effective indicator of antimicrobial usage patterns for managing carbapenem susceptibility in P. aeruginosa. Incorporating the mAHI into antimicrobial stewardship programs could enhance the effectiveness of antimicrobial interventions across diverse healthcare settings.

TcXyn30A from Talaromyces cellulolyticus, which belongs to subfamily 7 of the glycoside hydrolase family 30 (GH30-7), releases xylose from the reducing end of xylan and xylooligosaccharides (XOSs), the so-called reducing-end xylose-releasing exoxylanase (ReX). In this study, the crystal structures of TcXyn30A with and without xylose at subsite +1 (the binding site of the xylose residue at the reducing end) were determined. This is the first report on the structure of ReX in the family GH30-7. TcXyn30A forms a dimer. The complex structure of TcXyn30A with xylose revealed that subsite +1 is located at the dimer interface. TcXyn30A recognizes xylose at subsite +1 composed of amino acid residues from each monomer and blocks substrate binding to subsite +2 by dimer formation. Thus, the dimeric conformation is responsible for ReX activity. The structural comparison between TcXyn30A and the homologous enzyme indicated that subsite -2 is composed of assembled three stacked Trp residues, Trp49, Trp333, and Trp334, allowing TcXyn30A to accommodate xylan and any branched XOSs decorated with a substitution such as α-1,2-linked 4-O-methyl-d-glucuronic acid or α-1,2- and/or -1,3-linked L-arabinofuranose. These findings provide an insight into the structural determinants for ReX activity of TcXyn30A.

In recent years, the impact of the deterioration of the marine environment on ecosystems has become the problem. One of the causes of water quality deterioration is the hardening of sand and mud on the seafloor. Eelgrass beds, which provide a habitat for young fish, have been decreasing in number due to these effects. In this study, we focused on seabed tillage as a means of improving the hardening of sand and mud on the seafloor and creating an environment conducive to the growth of eelgrass. Currently, large-scale tillage using vessels is the mainstream, and it is not easy for a single organization to perform. This research aims to develop a small-scale subsea tillage robot that can be handled by an individual. Previous research until last year confirmed the rotation of the blades of the submarine tillage robot. However, a problem emerged in the mobility performance. In this report, we describe the process of manufacturing an underwater crawler and confirming its operation in order to improve its mobility.

The practical use of high-temperature superconducting bulk electric rotating machines is limited, despite their increased power densities over permanent magnet machines, by the magnetization process of the bulks. A fast and effective magnetization process is needed to promote the practical application of superconducting machines. This is why we developed a method for magnetizing bulk superconductors and trapping high magnetic flux density using a single pulsed field magnetization (PFM). The method of magnetization of the superconducting bulk magnet by controlling the applied magnetic field has been tested previously at 77 K and 70 K. We tried during this study to trap high magnetic flux density in a GdBaCuO bulk at 60 K, to confirm that the method is effective at a lower temperature. Moreover, we tried to improve the method by using negative feedback of the magnetic flux density on the growth sector, to control the chopping of the current flowing through the magnetizing coils. We managed to reduce the temperature rise during the pulse by 10 K compared to a passive PFM and trapped a maximum of 2.17 T in the center of the bulk sample, the improvements compared to passive PFM at 60 K are remarkable.

The purpose of this study was to idetify the pros and cons of the online system in the merchant marine school and the educational effects of on-demand health and physical education classes in order to understand the actual conditions and issues faced by students in the COVID-19 pandemic. The following two findings were revealed: (a) The exercise habits of the merchant marine students during the COVID-19 pandemic and the actual situation of the online class showed that the exercise and sports habits were drastically reduced and the educational effects of the online system were generally satisfactory, but some students were not able to participate in the system. (b) Distance education using ICT and online tools in the COVID-19 pandemic was effective in carrying out highly specialized classes, providing quality learning, connecting students and teachers, and serving as a means of exchange among families, schools, and communities. It was also an opportunity for teachers to train each other and build their own ICT competence.