RESUMO
Oxygen-vacancy-induced topotactic phase transformation between the ABO2.5brownmillerite structure and the ABO3perovskite structure attracts ever-increasing attention due to the perspective applications in catalysis, clean energy field, and memristors. However, a detailed investigation of the electronic-structure evolution during the topotactic phase transformation for understanding the underlying mechanism is highly desired. In this work, multiple analytical methods were used to explore evolution of the electronic structure of SrFeO3-xthin films during the topotactic phase transformation. The results indicate that the increase in oxygen content induces a new unoccupied state of O 2pcharacter near the Fermi energy, inducing the insulator-to-metal transition. More importantly, the hole states are more likely constrained to thedx2-y2orbital than to thed3z2-r2orbital. Our results reveal an unambiguous evolution of the electronic structure of SrFeO3-xfilms during topotactic phase transformation, which is crucial not only for fundamental understanding but also for perspective applications such as solid-state oxide fuel cells, catalysts, and memristor devices.
RESUMO
This study examined ionizing radiation-induced tumor necrosis factor (ligand) superfamily, member 4 (TNFSF4) mRNA expression changes in human peripheral blood cells and their distribution in a normal population. The results showed that expression level of TNFSF4 mRNA exhibited a dose-dependent response after different irradiation doses, but that was independent of incubation time post-irradiation. Moreover, it was not affected by age and gender in 51 healthy donors. Our studies indicate that TNFSF4 can be considered as a candidate gene to develop a new biodosimeter.