In classical guitar, playing technique affects the tone and expression. The results of FFT(Fast Fourier Transform) analysis and calculation of overtone content rate showed that the fundamental tone is emphasized in the apoyando technique, while the overtones are more abundant in the al-aire technique. In addition, the overtones were divided into consonant interval components and dissonant interval components, and the consonant interval factor was calculated to evaluate the balanc e between the two components. The results showed that the al-aire technique had higher factor. We believe that scientific clarification of the difference in tone between the al-aire technique and the apoyando technique will enable more effective improvement of tone.

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The measles virus is a highly contagious pathogen responsible for causing measles, for which no effective treatment is currently available. Consequently, the development of therapeutic drugs remains a pressing need. Recently, inhibitors targeting the measles virus fusion protein—a critical factor in the virus's pathogenicity—have been identified and are considered promising candidates for therapeutic drug development. In this study, we employed fragment molecular orbital (FMO) calculations to elucidate the interaction mechanism between AS-48, a representative inhibitor, and the fusion protein.

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The development of efficient hydrogen recovery methods for fusion reactor divertor materials is key to their long-term stability. In this work, a novel hydrogen recovery technique using solid-state diffusion was investigated, focusing on the intrinsic hydrogen solubility properties of metals.A tungsten (W) substrate was coated with a Niobium (Nb) thin film by ion plating, followed by Deuterium plasma irradiation under ITER-relevant conditions (fluence: 5.3×10²⁶ /m²). The structural evolution was evaluated by analysing the changes in lattice constants using X-ray diffraction (XRD).The results showed lattice expansion in the W substrate and unexpected contraction in the Nb thin film. This behaviour is attributed to the supersaturation of hydrogen in the W substrate, generating tensile stress in the confined Nb film due to volume expansion. The observed structural changes extended throughout the 1 mm thick substrate, suggesting significant hydrogen transport.These results indicate that while hydrogen permeation into Nb is thermodynamically favourable, the mechanical interaction between substrate and film must be carefully controlled. This work provides important insights for the design of effective hydrogen recovery systems in fusion reactor environments.

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Avian influenza is a disease that primarily affects birds but is rarely transmitted to humans. The fatality rate of infection with the highly pathogenic H5N1 avian influenza virus is particularly high. Oseltamivir is known to be an effective antiviral agent against both human and avian influenza. However, an Asn-to-Ser mutation in the N1 neuraminidase has been reported to confer resistance to oseltamivir, and accurate analysis to identify the cause of drug resistance is needed. In this study, fragment molecular orbital (FMO) calculations were performed to gain insight into the electronic mechanism of oseltamivir resistance in avian influenza neuraminidase. The FMO method is an innovative approach that enables quantum mechanical calculations of entire biomolecules, such as proteins. The amino acid residues involved in ligand binding can be identified through the interfragment interaction energies (IFIEs) derived from FMO calculations. The IFIE results suggest that one of the factors contributing to oseltamivir resistance in the N294S mutant is a reduction in the interaction energy between oseltamivir and ASP151, ARG152, and GLU277 in the N1 mutant. The Asn-to-Ser mutation at position 294 does not directly have a significant impact.

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2-nonenal is a volatile chemical component of body odor, known for the correlation between its concentration and the degree of aging. Because the concentration of 2-nonenal changes according to the aging-related metabolism change, measuring 2-nonenal in skin gas has a potential on biochemical evaluation of aging. However, highly selective 2-nonenal sensor has not been developed so far. In this study, we developed a biofluorometric gas sensor (bio-sniffer) that utilize NADPH-dependent enone reductase (ER) for selective detection of 2-nonenal. This sensor detects 2-nonenal by measuring the decrease in autofluorescence of NADPH (ex: 340 nm, fl: 490 nm), which occurs when ER reduces the α, β-unsaturated bond of 2-nonenal. The ER biosensor consists of an ER-immobilized membrane and a fiberoptic NADPH fluorescence detection unit having UV-LED and photomultiplier tube. We evaluated the performance of the ER biosensor using the primary substrate, ethyl vinyl ketone (EVK), and target molecule, 2-nonenal.The selectivity of the ER biosensor on 2-nonenal was also evaluated. The experimental result showed that the ER biosensor can quantify EVK from 100 nM to 1 mM, and it also showed significantly high fluorescence signal on 2-nonenal compared to other aldehydes.

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Continuous measurement of volatile organic compounds is expected for non-invasive monitoring of metabolic functions and screening of diseases. Especially, acetone emitted through the skin is known for its correlation to lipid metabolism and promising for detection of diabetes mellitus. However, the concentration of transdermal acetone is estimated to be sub-ppb level, which requires highly sensitive and selective sensor . Additionally, accurate standard acetone gas at sub-ppb level is also essential for evaluation of these sensors. In our previous study, we developed a biofluorometric acetone gas sensor based on nicotinamide adenine dinucleotide (NADH, excitation 340 nm, emission 490 nm)-dependent secondary alcohol dehydrogenase. In this study, we evaluated the accuracy of concentration of acetone gas at the sub-ppb level, prepared by a flow rate-based continuous dilution method. Then, the reliability of the acetone bio-sniffer was also evaluated by correlation analysis between the signal obtained by gas chromatography-mass spectrometer (GC-MS) and the acetone bio-sniffer at the same acetone gas. The outputs in both measurement methods showed linear correlation (R² = 0.996), indicating the reliability of the acetone bio-sniffer. In the future works, continuous measurement of transdermal acetone at various locations on the body surface will be conducted by using the acetone bio-sniffer.

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