Hiroshima Institute of Technology

Field-angle-resolved specific-heat measurements were performed on a clean single crystal of a spin-triplet superconductor UTe$_2$ with $T_{\rm c}=2.1$ K and a low residual electronic specific heat. At low temperatures, the specific heat exhibits a linear dependence on the magnetic field when the field is applied precisely along the $b$ axis, in stark contrast to its rapid increase at low fields for other orientations. This pronounced anisotropy suggests the presence of nodal quasiparticle excitations with the Fermi velocity predominantly aligned along the $b$ axis. Considering the characteristic field-angle dependences of both the specific heat and the upper critical field, these observations are broadly compatible with theoretical models that assume a superconducting gap structure featuring either point nodes consistent with $B_{\rm 2u}$ symmetry, allowed in the infinitely strong spin-orbit coupling scheme, or line nodes confined to flat regions of the quasi-two-dimensional Fermi surface, consistent with $^3B_{\rm 3u}$ symmetry in the finite spin-orbit classification scheme. These results yield crucial hints for resolving the pairing symmetry of UTe$_2$, paving the way for a deeper understanding of its spin-triplet superconductivity.

ABSTRACT The purpose of this study was to evaluate the precision of various heart rate variability (HRV) analysis parameters during postural changes between sitting and upright postures, with a particular focus on Tone–Entropy analysis, and to verify the absolute evaluability and high reproducibility of Tone–Entropy analysis. Fifteen healthy young men (age 20.7 ± 1.5 years) from two different groups participated in the study, and their heart rates (HRs) were recorded during sitting and upright postures. The postural changes were repeated twice, and each posture was maintained for 2 min. Precision was evaluated by defining the error rate for each HRV index. As a result, Entropy showed almost the same precision as HR. On the other hand, standard frequency domain indices such as low frequency (LF), high frequency (HF), and LF/HF ratio showed consistently low precision. Furthermore, our results support the usefulness of Tone–Entropy analysis to date, as it can allow absolute evaluation in Tone–Entropy space even for different groups of subjects and experimental conditions, and the reproducibility of Entropy is also high. In conclusion, it is suggested that Tone–Entropy analysis has high reliability and reproducibility and that frequency power spectrum analysis lacks sufficient precision to be applied to long‐term monitoring analyses in young male subjects.

In this letter, we propose a reconfigurable 1-bit reflectarray antenna (RAA ) with a novel varactor diode mounted multi-via mushroom-type (VDMM ) structure for heterogeneous networks (HetNets ). Specifically, its reflection phase and operating frequency band are controlled by changing a reverse bias voltage applied to a varactor diode mounted on the unit cell. Moreover, the proposed VDMM structure reduces frequency dependency in each operating frequency band by introducing multiple vias into the metasurface. As a result, the 1-bit RAA with the proposed VDMM structure can adaptively control the reflection direction and operating frequency band.

In order to examine appropriate VR space according to the purpose, we clarified the following: “Characteristics of VR space suitable for arousing the intention to visit” and “Characteristics of VR space sufficient to obtain satisfaction with sightseeing”. We created VR spaces with varying amounts of experience and mobility. After allowing the subjects to freely tour in one of the VR spaces, we asked them to evaluate the content of the experience and the sightseeing spots, and then compared the results.

Effects of two kinds of electroless Ni-P plating and a baking treatment after plating on the temperature-dependent hydrogen desorption behavior, tensile properties, and fatigue properties of 6061-T6 aluminum alloys were investigated, and the results were discussed. Thermal desorption analysis (TDA) revealed that each plating causes hydrogen absorption into the substrate, which was found to reduce the mechanical properties. After plating, the baking treatment significantly reduced the hydrogen amount in the substrate and improved the mechanical properties. The fatigue strength of the low-phosphorus type plated specimen was increased to 160 MPa by the baking treatment, and a fatigue ratio of over 50% was obtained.

This paper analyzes coefficient sensitivity for state-space descriptions of a second-order recursive notch digital filter. To this end, second-order recursive notch digital filters are realized by a lattice-form or direct-form based state-space description. The coefficient sensitivities for each state-space description are then analyzed to derive the improved l2-sensitivity measure. Moreover, adaptive recursive notch digital filters are presented by the lattice-form or direct-form based description. Finally, the coefficient sensitivity of the lattice-form based state-space description is compared with that of the direct-form based counterpart by means of numerical experiments. The simulation results clarify that the lattice-form based state-space description has much lower improved l2-sensitivity than the direct-form based counterpart.

Abstract We analyzed the propagation of atmospheric waves generated by the eruption of Hunga Tonga–Hunga Ha’apai on January 15, 2022 using infrared images acquired by Himawari-8. We used a sequence of high-frequency scanning imagery of the Japan region having a time interval of 2.5 minutes. We calculated the anomaly of the brightness temperature (Tbb) through temporal double integration after taking the second-order time derivative of Tbb. From the temporal–horizontal distribution of the Tbb anomaly, we searched for waveforms by data stacking. As a result, we detected Lamb mode in all infrared channels from Band 7 to Band 16. The Pekeris mode was visualized behind the Lamb mode in Band 12 and the Band 12 − Band 13 difference but was difficult to see in Bands 8, 9, and 10 corresponding to the mid-troposphere. The wave train as an internal gravity wave (IG-train) behind the Pekeris mode was visualized in each band, especially clearly in Band 12 and the Band 12 − Band 13 difference. The IG-train had a period range of 10–15 minutes, corresponding to that of the observed ground pressure. The phase velocity of the IG-train was estimated to be 199.1 ± 10.0 m/s, which is a typical speed of the tsunami phase propagating in the Pacific Ocean. The passage of the IG-train corresponded well with ground pressure variations and the peak tidal oscillations observed as volcanic meteotsunamis along Japan's Pacific coastline.

Plasma membrane transporters are increasingly recognized as potential drug targets for oral cancer, particularly oral squamous cell carcinoma (OSCC). These transporters play crucial roles in cancer cell metabolism, drug resistance, and the tumor microenvironment, making them attractive targets for therapeutic intervention. Among the two main families of plasma membrane transporters, ATP-binding cassette (ABC) transporters have long been known to be involved in drug efflux and contribute to chemoresistance in cancer cells. On the other hand, solute carriers (SLCs) are also a family of transporters that facilitate the transport of various substrates, including nutrients and drugs, and have recently been shown to contribute to cancer chemosensitivity, metabolism, and proliferation. SLC transporters have been identified as potential cancer biomarkers and therapeutic targets, and their expression profiles suggest that they could be utilized in precision oncology approaches. We summarize previous reports on the expression and role of ABC and SLC transporters in oral cancer and discuss their potential as therapeutic targets.

Abstract Chronic hepatitis B (HBV) and hepatitis D (HDV) viral infections pose serious global health challenges, and the lack of curative therapies calls for the development of new antiviral approaches. Recently, we have identified the Kinesin Family Member 4 (KIF4) as a crucial regulator of the surface transport for NTCP (HBV/HDV entry receptor). Our research has shown that the pan-RXR agonist, Bexarotene, suppresses KIF4 expression and inhibits HBV/HDV infections. However, the clinical use of Bexarotene is limited by poor physicochemical and pharmacokinetic (PK) properties and significant side effects. Here we investigated chemically diverse RXR modulators with tuned activity, and identified the RXR agonist S169 as a novel HBV/HDV entry inhibitor. S169 effectively blocks HBV and HDV infections in primary human hepatocyte (PXB) cultures without evident cytotoxicity. S169’s suppressive effect on HBV infection was confirmed by reduction of secreted HBsAg and HBeAg, as well as inhibition of HBV cccDNA, pregenomic RNA, and intracellular HBV DNA. Mechanistically, S169 suppressed FOXM1-mediated KIF4 expression, leading to decreased NTCP surface levels and a marked decrease in HBV preS1 peptide binding to the hepatocyte cell surface. S169 is reported to exhibit enhanced oral bioavailability, favorable PK parameters, lower toxicity compared to Bexarotene. Interestingly, S169 induced a modest inhibition of NTCP-mediated bile acid transport up to 10 μM, which remained unchanged at higher concentrations. Furthermore, S169 significantly impeded HBV spread in HBV infected long-time cultured PHHs (PXB). We speculate that S169 can be a promising seed for the development of novel oral HBV and HDV antiviral therapeutics.