Upconversion photoluminescence (UCPL) of rare-earth ions has attracted much attention due to its potential application in cell labeling, anti-fake printing, display, solar cell and so forth. In spite of high internal quantum yield, they suffer from very low external quantum yield due to poor absorption cross-section of rare-earth ions. In the present work, to increase the absorption by rare earth ions, we place the emitter layer on a diffractive array of Al nanocylinders. The array is designed to trap the near infrared light in the emitter layer via excitation of the plasmonic-photonic hybrid mode, a collective resonance of localized surface plasmons in nanocylinders via diffractive coupling. The trapped near-infrared light is absorbed by the emitter, and consequently the intensity of UCPL increases. In sharp contrast to the pure localized surface plasmons which are bound to the surface, the hybridization with diffraction allows the mode to extend into the layer, and the enhancement up to 9 times is achieved for the layer with 5.7 µm thick. This result explicitly demonstrates that coupling the excitation light to plasmonic-photonic hybrid modes is a sensible strategy to enhance UCPL from a thick layer.

Hexagonal Y1−xRxMnO3+δ (R: other than Y rare earth elements) oxides have been recently introduced as promising oxygen storage materials that can be utilized in the temperature swing processes for the oxygen separation and air enrichment. In the present work, the average and local structures of Tb- and Ce-substituted Y0.7Tb0.15Ce0.15MnO3+δ and Y0.6Tb0.2Ce0.2MnO3+δ materials were studied, and their oxygen storage-related properties have been evaluated. The fully oxidized samples show the presence of a significant amount of the highly oxygen-loaded the so-called Hex3 phase, attaining an average oxygen content of δ ≈ 0.41 for both compositions. Extensive studies of the temperature swing process conducted in air and N2 over the temperature range of 180–360 °C revealed large and reversible oxygen content changes taking place with only a small temperature differences and the high dependence on the oxygen partial pressure. Significant for practical performance, the highest reported for this class of compounds, oxygen storage capacity of 1900 μmol O g−1 in air was obtained for the optimized materials and swing process. In the combined temperature–oxygen partial pressure swing process, the oxygen storage capacity of 1200 μmol O g−1 was achieved.

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Osmotic stress hampers the growth of Saccharomyces cerevisiae, and this effect is mediated by oxidative stress. A simple test for the biological evaluation of antioxidants was developed on the basis of recovery of growth delay of Cu, Zn-superoxide dismutase-lacking yeast (SOD1Δ) under hyperosmosis. The SOD1Δ strain suffered from growth inhibition in a medium containing 1.7 M sorbitol. Protein oxidation in SOD1Δ cells was greatly increased by exposure to a hypertonic medium, indicating the accumulation of reactive oxygen species followed by oxidation of cellular materials. The hyperosmosis-induced growth arrest of SOD1Δ was abolished by the addition of L-ascorbic acid to the medium; the antioxidant effect depended on the concentration, ranging from 1 to 10 mM. Cysteine, N-acetyl-cysteine, and glutathione were also able to restore the growth of SOD1Δ cells. High concentrations of these thiol compounds proved less effective, probably due to adverse effects of an excess of these antioxidants. No growth restoration was seen for typical polyphenol antioxidants, including curcumin, quercetin and catechin.

The oxygen intake/release characteristics were systematically studied for Ca2AlMnO5+δ samples synthesized under precisely controlled oxygen pressures. Both the oxygen storage capacity (OSC) and operating temperature were systematically lowered as the oxygen pressure in the firing atmosphere increased. Notably, the sample fired under a 1% O2 atmosphere exhibited sufficiently large OSC and superior oxygen intake/release kinetics to the pristine sample synthesized in an anaerobic condition. The high-angle annular dark-field scanning TEM observation revealed that the samples contain defects in their atomic arrangement when fired in oxygen-rich atmospheres. This result indicates that the oxygen intake/release characteristics of Ca2AlMnO5+δ are sensitive to the synthesis condition and widely tunable even without chemical substitutions.