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Abstract A glassy carbon (GC) substrate was irradiated with 380 keV argon ions (Ar+), and platinum nanoparticles (Pt NPs) were then deposited on it by a radio-frequency magnetron sputtering method. The interfacial effect of the Ar+-induced defects in the GC substrate on the size and electronic structure of the Pt NPs was investigated. The irradiation defects in the carbon support promoted the growth of the Pt NPs on the substrate, leading to a larger NP size. Density functional theory calculations revealed that the lattice vacancies in the graphitic structure lowered the position of the Pt d-band center via the interfacial charge transfer. This down-shift in the d-band center would be a reason for the higher catalytic activity, which was reported in our previous research. Highlights • The Pt nanoparticles were deposited on a 380 keV Ar+-irradiated carbon support. • The particle sizes on the irradiated and non-irradiated support were investigated. • A Pt electronic structure was modified by the irradiation defects of the carbon support. • We discussed how the Pt size and electronic structure affected the catalytic activity. [ABSTRACT FROM AUTHOR]

Abstract The chemical state and local structure of 2.6-nm-sized platinum (Pt) nanoparticles on an ion-irradiated glassy carbon (GC) substrate were investigated by X-ray absorption fine structure measurements. The partial oxidation of the Pt nanoparticles was confirmed by the peak intensity in the near-edge region of the absorption spectrum. The analysis of the extended region revealed a higher coordination number and shorter bond length of Pt–Pt compared to those of the Pt nanoparticles on the non-ion-irradiated GC. Thus, Pt nanoparticles on the ion-irradiated GC substrate were found to hold a rigid metallic coordination during the oxidation. Highlights • Pt nanoparticles were deposited on a 380 keV Ar+-irradiated carbon support. • The partial oxidation of Pt was confirmed by XANES measurements. • Pt on the irradiated support held a rigid metallic coordination during oxidation. [ABSTRACT FROM AUTHOR]

In this work, coherent phonons in glassy carbon using transient reflection measurements with the pump-probe spectroscopy are investigated. Detection of coherent oscillation of optical phonons in a polished glassy carbon sample is enabled by wavelength-selected measurements for reflected probe pulse. We demonstrate that the G and D mode oscillations occur at 46.8 and 38.2 THz frequency, respectively, and have approximately the same lifetime of 0.17 ps. Furthermore, we find that the D mode peak is anisotropic and spreads towards lower energies. [Display omitted] • Femtosecond transient reflection signal showed a coherent oscillation of optical phonons in a polished glassy carbon. • Wavelength selective detection with an optical bandpass filter enhanced the phonon oscillation. • Both G and D mode oscillations had approximately the same lifetime of 0.17 ps. [ABSTRACT FROM AUTHOR]

Abstract: Reactive oxygen species (ROS) play an important role in diverse vital functions including host defense via anti-viral and anti-bacterial effects, but ROS also lead to peroxynitrite and hydroxyl radical production, which are powerful mediators of brain injury in brain inflammation. It is known that NADPH oxidases (NOX) are the major source of ROS. In the present study, NOX2 expression and distribution were examined after intracranial encephalomyocarditis virus B variant (EMCV-B) infection, which causes encephalitis. The reverse transcriptase (RT)-polymerase chain reaction (PCR) and immunohistochemistry showed that the expression and distribution of NOX2 were significantly up-regulated after EMCV-B infection in microglial cells, which invaded into the surrounding regions where neurons were subjected to oxidative stress. These findings suggest that the oxidative stress generated by NOX2 in activated microglial cells damages neurons and that this is an important process in the pathogenesis of EMCV-B infection. [Copyright &y& Elsevier]