A CROSS-SECTIONAL STUDY OF GENDER DIFFERENCES IN PULLING STRENGTH OF TOW FOR JAPANESE ELEMENTARY SCHOOL CHILDREN

The aim of this study was to obtain the data of gender differences of pulling strength during experimentally executed TOW for Japanese elementary school children. In mean back strength, gender difference was small from 1st grade to 4th grade, but on 5th and 6th grade, gender difference became large. In mean pulling strength, gender difference was large in 5th and 6th grade. But no tendency was found from 1st grade to 4th grade. In male children, sum of pulling strength increases substantially when the grade changes from 4th to 5th. But pulling strength tended to grow constantly. On the other hand, in female children, sum of pulling strength increases substantially when the grade changes from 2nd to 3rd. And from 4th to 6th, sum of back strength and rope tension were very close to each other. Results suggested that though male children get grow for muscles, female children get motor function more than male children

Near-Shore Aggregation Mechanism of Electrolyte Decomposition Products to Explain Solid Electrolyte Interphase Formation

To get insight of the formation mechanism of solid electrolyte interphase (SEI) film in Lithium-ion battery (LIB), we examine a probable scenario, referred to as “surface growth mechanism,” for electrolyte involving ethylene carbonate (EC) solvent and vinylene carbonate (VC) additive by using density functional theory (DFT). We first extracted stable SEI film components (SFCs) for the EC/VC electrolyte and constructed probable SFC aggregates via DFT molecular dynamics. We then examined their solubility in the EC solution, their adhesion to a model graphite electrode, and the electronic properties. The results showed that the SFC aggregates are characterized by “unstable adhesion” to the graphite surface and “high electronic insulation” against the EC solution. These characteristics preclude explaining SEI growth up to a typical thickness of several tens of nanometers based on the surface growth mechanism. With the present results, we propose “near-shore aggregation” mechanism, where the SFCs formed at the electrode surface desorb into the near-shore region and form aggregates. The SFC aggregates coalesce and come into contact with the electrode to complete the SEI formation. The present model provides a novel perspective for the long-standing problem of SEI formation

Methamphetamine induces Shati/Nat8L expression in the mouse nucleus accumbens via CREB- and dopamine D1 receptor-dependent mechanism

Shati/Nat8L significantly increased in the nucleus accumbens (NAc) of mice after repeated methamphetamine (METH) treatment. We reported that Shati/Nat8L overexpression in mouse NAc attenuated METH-induced hyperlocomotion, locomotor sensitization, and conditioned place preference. We recently found that Shati/Nat8L overexpression in NAc regulates the dopaminergic neuronal system via the activation of group II mGluRs by elevated Nacetylaspartylglutamate following N-acetylaspartate increase due to the overexpression. These findings suggest that Shati/Nat8L suppresses METH-induced responses. However, the mechanism by which METH increases the Shati/Nat8L mRNA expression in NAc is unclear. To investigate the regulatory mechanism of Shati/Nat8L mRNA expression, we performed a mouse Shati/Nat8L luciferase assay using PC12 cells. Next, we investigated the response of METH to Shati/Nat8L expression and CREB activity using mouse brain slices of NAc, METH administration to mice, and western blotting for CREB activity of specific dopamine receptor signals in vivo and ex vivo. We found that METH activates CREB binding to the Shati/Nat8L promoter to induce the Shati/Nat8L mRNA expression. Furthermore, the dopamine D1 receptor antagonist SCH23390, but not the dopamine D2 receptor antagonist sulpiride, inhibited the upregulation of Shati/Nat8L and CREB activities in the mouse NAc slices. Thus, the administration of the dopamine D1 receptor agonist SKF38393 increased the Shati/Nat8L mRNA expression in mouse NAc. These results showed that the Shati/ Nat8L mRNA was increased by METH-induced CREB pathway via dopamine D1 receptor signaling in mouse NAc. These findings may contribute to development of a clinical tool for METH addiction

To Break or not to break: Mechanisms of DMSO decomposition in aprotic LiO2 battery electrolytes

Aprotic Li-O2 batteries offer an appealing opportunity to make use of our immediate environment; harvesting the air for oxygen and further reducing and combining it with Li+ to form LiO2 or Li2O2 at the cathode/electrolyte interface. Although the electrochemistry of such a device could in principle be operated reversibly, side-reactions interfere with the main reactions and limit the lifetime of practical Li-O2 cells – so far operated only in pure O2. Preventing these parasitic reactions, in particular by developing more stable solvents/electrolytes, is critical for progress. Dimethyl sulfoxide (DMSO) is a promising solvent for Li-O2 battery applications [1], but there are conflicting opinions on the long-term stability of DMSO. Experimental work by Kwabi et al. [2] and computational results by Laino et al. [3] suggest that DMSO is readily oxidized to dimethyl sulfone (DMSO2) at Li2O2 surfaces – also forming LiOH. These results have, however, recently been challenged by Schroeder et al. [4], claiming that DMSO is sufficiently stable in the presence of Li2O2, as long as there are no sources of acidic protons present (e.g. from water impurities or carbon electrodes) that can initiate decomposition by forming more reactive hydroperoxy species. More fundamental research on the reaction mechanisms of DMSO with reduced oxygen species is needed to resolve this contradiction. In this work we make use of quantum chemistry calculations to model alternative DMSO decomposition mechanisms in gas, solution phase, and at surfaces. We present reaction energies and barriers to reactions for proton abstraction (DMSO-H), methyl abstraction (DMSO-CH3), and addition reactions (DMSO2) with the aim of better understanding the relative importance of different reaction pathways and the impact of the reactants immediate environment

To Break or not to break: Mechanisms of DMSO decomposition in aprotic LiO2 battery electrolytes

Aprotic Li-O2 batteries offer an appealing opportunity to make use of our immediate environment; harvesting the air for oxygen and further reducing and combining it with Li+ to form LiO2 or Li2O2 at the cathode/electrolyte interface. Although the electrochemistry of such a device could in principle be operated reversibly, side-reactions interfere with the main reactions and limit the lifetime of practical Li-O2 cells – so far operated only in pure O2. Preventing these parasitic reactions, in particular by developing more stable solvents/electrolytes, is critical for progress. Dimethyl sulfoxide (DMSO) is a promising solvent for Li-O2 battery applications [1], but there are conflicting opinions on the long-term stability of DMSO. Experimental work by Kwabi et al. [2] and computational results by Laino et al. [3] suggest that DMSO is readily oxidized to dimethyl sulfone (DMSO2) at Li2O2 surfaces – also forming LiOH. These results have, however, recently been challenged by Schroeder et al. [4], claiming that DMSO is sufficiently stable in the presence of Li2O2, as long as there are no sources of acidic protons present (e.g. from water impurities or carbon electrodes) that can initiate decomposition by forming more reactive hydroperoxy species. More fundamental research on the reaction mechanisms of DMSO with reduced oxygen species is needed to resolve this contradiction. In this work we make use of quantum chemistry calculations to model alternative DMSO decomposition mechanisms in gas, solution phase, and at surfaces. We present reaction energies and barriers to reactions for proton abstraction (DMSO-H), methyl abstraction (DMSO-CH3), and addition reactions (DMSO2) with the aim of better understanding the relative importance of different reaction pathways and the impact of the reactants immediate environment

Life of superoxide in aprotic Li-O-2 battery electrolytes: simulated solvent and counter-ion effects

Li-air batteries ideally make use of oxygen from the atmosphere and metallic lithium to reversibly drive the reaction 2Li + O-2 <-> Li2O2. Conceptually, energy throughput is high and material use is efficient, but practically many material challenges still remain. It is of particular interest to control the electrolyte environment of superoxide (O-2(star-)) to promote or hinder specific reaction mechanisms. By combining density functional theory based molecular dynamics (DFT-MD) and DFT simulations we probe the bond length and the electronic properties of O-2(star-) in three aprotic solvents -in the presence of Li+ or the much larger cation alternative tetrabutylammonium (TBA(+)). Contact ion pairs, LiO2 star, are favoured over solvent-separated ion pairs in all solvents, but particularly in low permittivity dimethoxyethane (DME), which makes O-2(star-) more prone to further reduction. The Li+-O-2(star-) interactions are dampened in dimethyl sulfoxide (DMSO), in relation to those in DME and propylene carbonate (PC), which is reflected by smaller changes in the electronic properties of O-2(star-) in DMSO. The additive TBA+ offers an alternative, more weakly interacting partner to O-2(star-), which makes it easier to remove the unpaired electron and oxidation more feasible. In DMSO, TBA(+) has close to no effect on O-2(star-), which behaves as if no cation is present. This is contrasted by a much stronger influence of TBA(+) on O-2(star-) in DME -comparable to that of Li+ in DMSO. An important future goal is to compare and rank the effects of different additives beyond TBA(+). Here, the results of DFT calculations for small-sized cluster models are in qualitative agreement with those of the DFT-MD simulations, which suggests the cluster approach to be a cost-effective alternative to the DFT-MD simulations for a more extensive comparison of additive effects in future studies