Publications by authors named "H Nagara"

The maintenance and improvement of balance and walking function in patients with Parkinson’s disease (PD) is essential. Toe dysfunction in patients with PD is related to balance and walking. Recently, insoles have been developed to improve toe function, but their effects on the physical functions of patients with PD remain unclear.

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Stable oxygen sites on a PdO film over a Pd(100) thin structure with a [Formula: see text] surface unit cell are determined using the first-principles electronic structure calculations with the generalized gradient approximation. The adsorbed monatomic oxygen goes to a site bridging two twofold-coordinated Pd atoms or to a site bridging a twofold-coordinated Pd atom and a fourfold-coordinated Pd atom. Estimated reaction energies of CO oxidation by reduction of the oxidized PdO film and N(2)O reduction mediated by oxidation of the PdO film are both exothermic.

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High-pressure structures of Ar(H(2))(2) are studied with possible molecular dissociation and metallization using density functional theory in the local density approximation (LDA) and generalized gradient approximation (GGA) for the exchange-correlation energy. We have estimated the transition pressure from the low-pressure MgZn(2)-type structure to the high-pressure AlB(2)-type structure to be around 240 GPa. The band gap of the MgZn(2)-type structure does not close, while the band gap of the AlB(2) closes at 420 GPa, which is much higher than the pressure of the band gap closure in pure hydrogen obtained by the same GGA.

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We have studied the ζ-phase of solid oxygen using the generalized gradient approximation in the density functional approach. Calculations of total energies and pressures have been carried out for the prototype of diatomic ζ-phase and other hypothetical monoatomic crystal structures. The diatomic phase was found to be stable over a wide range of pressure (100-2000 GPa).

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We explore the unknown structure of phosphorus in phase IV (P-IV phase) based on first-principles calculations using the metadynamics simulation method. Starting from the simple cubic structure, we find a new modulated structure of the monoclinic lattice. The modulation is crucial to the stability of the structure.

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