Effects of teaching motor skills to others on the persistence of motor learning

The purpose of this study was to examine the effects of teaching motor skills to others on the survivability of motor learning effects. 20 healthy adults were randomly assigned to two conditions a teaching conditions and reading a magazine condition (control conditions). The number of times of turning was measured before and after each condition. In both conditions, the number of ball rotations and the number of improvements increased 30 minutes after the task was completed compared to before the task. Additionally, the number of improvements in ball rotation was significantly higher in the teaching condition than in the control condition. In the teaching condition, the number of ball turnings significantly increased 30 minutes after the end of the condition compared to before the condition. These results suggested that task for teaching motor skill to others might be useful for improving motor learning

A reversible oxygen redox reaction in bulk-type all-solid-state batteries

An all-solid-state lithium battery using inorganic solid electrolytes requires safety assurance and improved energy density, both of which are issues in large-scale applications of lithium-ion batteries. Utilization of high-capacity lithium-excess electrode materials is effective for the further increase in energy density. However, they have never been applied to all-solid-state batteries. Operational difficulty of all-solid-state batteries using them generally lies in the construction of the electrode-electrolyte interface. By the amorphization of Li₂RuO₃ as a lithium-excess model material with Li₂SO₄, here, we have first demonstrated a reversible oxygen redox reaction in all-solid-state batteries. Amorphous nature of the Li₂RuO₃-Li₂SO₄ matrix enables inclusion of active material with high conductivity and ductility for achieving favorable interfaces with charge transfer capabilities, leading to the stable operation of all-solid-state batteries

Electrode performance of amorphous MoS3 in all-solid-state sodium secondary batteries

All-solid-state Na–S secondary batteries that use sodium and sulfur, both available in abundance, are the most attractive next-generation batteries. In this study, two types of amorphous MoS3 (a-MoS3) were prepared as electrode active materials for use in all-solid-state sodium secondary batteries using the thermal decomposition (TD) of (NH4)2MoS4 and mechanochemical (MC) processes, denoted a-MoS3 (TD) and a-MoS3 (MC), respectively. X-ray diffraction, thermogravimetric-differential thermal analysis, and X-ray photoelectron spectroscopy (XPS) analyses revealed that a-MoS3 (TD) and a-MoS3 (MC) had different local structures. The a-MoS3 (TD) and a-MoS3 (MC) electrodes showed high reversible capacities of 310 mAh g−1 and 260 mAh g−1, respectively, for five cycles in all-solid-state sodium secondary batteries. XPS analysis of the discharge–charge products suggested that the dissociation and formation of disulfide bonds occurred during the discharge–charge reaction. The results show that a-MoS3 is a promising active electrode material for all-solid-state sodium batteries

All-Solid-State Na/S Batteries with a Na₃PS₄ Electrolyte Operating at Room Temperature

Bulk-type all-solid-state Na/S cells, which are expected to have high capacity, be highly safe, and have low material cost, were fabricated using a Na₃PS₄ glass-ceramic as a solid electrolyte. The sulfur composite electrodes were prepared by mechanical milling of sulfur active material, a conductive additive (acetylene black), and a Na₃PS₄ glass-ceramic electrolyte. The all-solid-state Na/S cells used the reaction up to the final discharge product of sulfur active material, Na₂S, and achieved a high capacity of ∼1100 mAh (g of S)⁻¹ at room temperature. The rate of utilization of sulfur active material was ∼2 times higher than that of high-temperature-operating NAS batteries (commercially available NAS batteries, Na/sintered β″-alumina/S), where Na₂S_<i>x</i> melts with bridging sulfurs contribute to redox in the sulfur electrodes. The open circuit potential curve of the discharge process of the Na/S batteries operating at room temperature was similar to that of the NAS batteries operating at high temperatures; X-ray diffraction and X-ray photoelectron spectroscopy measurement indicated that amorphous Na₂S_<i>x</i> with a structure similar to the structure of these melts contributed to sulfur redox reaction in the all-solid-state Na/S cells. A galvanostatic intermittent titration technique and impedance measurement suggested that the overpotential during the discharge process in the all-solid-state Na/S cells was mainly derived from the sodium diffusion resistance in the solid sulfur active material. The finding would be an effective guide for achieving higher performance for all-solid-state Na/S cells

Mechanochemical Synthesis of Pyrite Ni1−xFexS2 Electrode for All-solid-state Sodium Battery

All-solid-state sodium secondary batteries are expected to be low-cost, next-generation batteries. NiS2 and FeS2 are potential candidates as positive electrode materials owing to their high theoretical capacities. However, it is difficult to achieve sufficient capacity with bulk FeS2. In this study, pyrite Ni1−xFexS2 (x = 0, 0.3, 0.5, 0.7, 0.9, and 1) electrodes are prepared by a mechanochemical process. The all-solid-state sodium cells with Ni1−xFexS2 show higher discharge–charge potentials than those with NiS2, and higher capacities than those with FeS2. In addition, Ni1−xFexS2 exhibits a higher rate performance than those of NiS2 and FeS2. The all-solid-state cells using Ni1−xFexS2 (x = 0.3, 0.5, and 0.7) are discharged and charged with a high capacity of approximately 390 mAh g−1, without significant capacity fading for at least 30 cycles. The solid-solution formation of NiS2 and FeS2 results in lower material cost, higher rate performance, higher discharge–charge potential than those of NiS2, and higher capacity than that of FeS2. Pyrite Ni1−xFexS2 is a promising positive electrode material for all-solid-state sodium secondary batteries

Lithium-Ion-Conducting Argyrodite-Type Li₆PS₅X (X = Cl, Br, I) Solid Electrolytes Prepared by a Liquid-Phase Technique Using Ethanol as a Solvent

Argyrodite-type crystals, Li₆PS₅X (X = Cl, Br, I), are promising solid electrolytes (SEs) for bulk-type all-solid-state lithium-ion batteries with excellent safety and high energy densities because of their high ionic conductivities and electrochemical stabilities. However, these advantageous features alone are not sufficient to achieve good cell performance. It is also critically important to have a simple and effective synthetic route to SEs and techniques for forming favorable solid–solid interfaces with large contact areas between the electrode and electrolyte particles. Here, we report an effective route for the preparation of argyrodite-type crystals using a liquid-phase technique via a homogeneous ethanol solution to improve cell performance using an SE-coating on the active material. The preparation conditions, such as appropriate halogen species and alcohol solvents, dissolution time, and drying temperature, are examined, finally resulting in Li₆PS₅Br with a lithium-ion conductivity of 1.9 × 10^–4 S cm^–1. Importantly, the obtained solution forms a favorable solid–solid electrode–electrolyte interface with a large contact area in the all-solid-state cells, resulting in a higher capacity than conventional techniques such as hand mixing using a mortar

Periodontal Condition Is Correlated with Deep and Subcortical White Matter Hyperintensity Lesions in Japanese Adults

Deep and subcortical white matter hyperintensity (DSWMH) lesions are a small-vessel disease of the brain. The aim of this cross-sectional study was to investigate the relationship between DSWMH lesions and periodontal status in Japanese adults who participated in a health check. We enrolled 444 consecutive participants (mean age, 54.5 years) who received both brain and oral health evaluation services at the Asahi University Hospital. Magnetic resonance imaging was used to detect DSWMH lesions. Periodontal status was assessed using the community periodontal index. Of the study participants, 215 (48.4%) had DSWMH lesions. Multivariate logistic regression showed that the presence of DSWMH lesions was significantly related to age &ge; 65 years (vs. &lt; 65 years, odds ratio [OR] = 2.984, 95% confidence interval [CI] = 1.696&ndash;5.232), systolic blood pressure &ge; 140 mmHg (vs. &lt; 140 mmHg, OR = 2.579, 95% CI = 1.252&ndash;5.314), the presence of &ge; 28 teeth (vs. &lt; 28 teeth, OR = 0.635, 95% CI = 0.420&ndash;0.961), and probing pocket depth (PPD) &ge; 6 mm (vs. PPD &lt; 6 mm, OR = 1.948, 95% CI = 1.132&ndash;3.354) after adjustment for confounding factors. Having PPD &ge; 6 mm may be a risk factor for DSWMH lesions in Japanese adults