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The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, ) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550-3554, ) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor-liquid-solid (VLS) grown rough SiGe nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough SiGe nanowire is an order of magnitude lower than that of bulk SiGe and around a factor of four times lower than that of smooth SiGe nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering. [ABSTRACT FROM AUTHOR]

Potassium channels allow K+ ions to diffuse through their pores while preventing smaller Na+ ions from permeating. Discrimination between these similar, abundant ions enables these proteins to control electrical and chemical activity in all organisms. Selection occurs at the narrow selectivity filter containing structurally identified K+ binding sites. Selectivity is thought to arise because smaller ions such as Na+ do not bind to these K+ sites in a thermodynamically favorable way. Using the model K+ channel KcsA, we examined how intracellular Na+ and Li+ interact with the pore and the permeant ions using electrophysiology, molecular dynamics simulations and X-ray crystallography. Our results suggest that these small cations have a separate binding site within the K+ selectivity filter. We propose that selective permeation from the intracellular side primarily results from a large energy barrier blocking filter entry for Na+ and Li+ in the presence of K+, not from a difference of binding affinity between ions. [ABSTRACT FROM AUTHOR]

Sarcopenia, a condition characterized by muscle weakness and mass loss, poses significant risks of accidents and complications. Traditional diagnostic methods often rely on physical function measurements like handgrip strength which can be challenging for affected patients, including those with stroke. To address these challenges, we propose a novel sarcopenia diagnosis model utilizing stimulated muscle contraction signals captured via wearable devices. Our approach achieved impressive results, with an accuracy of 93% and 100% in sarcopenia classification for male and female stroke patients, respectively. These findings underscore the significance of our method in diagnosing sarcopenia among stroke patients, offering a non-invasive and accessible solution., Competing Interests: Conflict of Interest: The authors have no potential conflicts of interest to disclose., (Copyright © 2024. Korean Society for Neurorehabilitation.)

Recently, high-efficiency III-nitride photonic emitters (PEs) for next-generation displays have been studied. Although micro-light-emitting diodes (μ-LEDs), one of the III-nitride PEs, have attracted considerable attention because of their high efficiency and size flexibility, they have encountered technical limitations such as high defect rate, high processing cost, and low yield. To overcome these drawbacks of μ-LEDs, a lot of research on PEs using one-dimensional (1D) gallium nitride-related nanorods (GNRs) capable of horizontally self-positioning on the electrodes has been carried out. The degree of array of GNRs on the interdigitated electrodes (IDEs) is an important factor in the efficiency of the PEs using GNRs to obtain excellent single-pixel characteristics. Therefore, in this study, we demonstrate that the improved performance of self-arrayed GNRs was realized using the dielectrophoresis technique by changing the thickness of IDEs. In addition, the shape and size of vertically aligned GNRs were controlled by the wet process, and GNR-integrated PEs (GIPEs) were driven by perfectly horizontally self-arrayed GNRs on IDEs. The electroluminescence (EL) intensity of the GIPEs was measured at 4-20 V and showed a maximum intensity value at 15 V. Over the injection voltage at 20 V, the EL intensity decreased due to the high current density of GIPEs. The external quantum efficiency (EQE) property of the GIPEs showed a similar efficiency droop as that of conventional III-nitride PEs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)