This study examined the electrical properties of Ti/MnO2/Pt devices with stable and reproducible bipolar resistive switching behavior. The dependency of the memory behavior on the cell area and operating temperature suggest that the conducting mechanism in the low resistance states is due to the locally conducting filaments formed. X-ray photoelectron spectroscopy showed that nonlattice oxygen ions form at the MnO2 surface. The mechanism of resistance switching in the system examined involves the generation and recovery of oxygen vacancies with the nonlattice oxygen ions.

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BackgroundThe coronavirus disease‐2019 (COVID‐19) outbreak has presented unique dermatologic challenges due to respiratory protective equipment (RPE)–related skin conditions.ObjectiveTo objectively evaluate the effects of RPE including medical masks and respirators on the skin barrier by measuring various physiological properties of the skin.MethodsA cross‐sectional study was designed. Twenty healthy healthcare workers were included in this study. Skin parameters including skin hydration, transepidermal water loss (TEWL), erythema, sebum secretion, pH, and skin temperature were measured in the RPE‐covered and RPE‐uncovered areas of the face 4 and 8 hours after wearing RPE and 14 hours after not wearing RPE.ResultsSkin hydration, TEWL, erythema, pH, and skin temperature increased in the RPE‐covered areas after wearing RPE for 4 and 8 hours. By contrast, in the RPE‐uncovered areas, skin hydration decreased and TEWL, erythema, and pH showed minimal changes over time. Based on the repeated‐measure analysis, the changes in skin physiological properties over time were significantly different between RPE‐covered and RPE‐uncovered areas.ConclusionWe observed that skin physiological characteristics change with the prolonged use of RPE such as medical masks and respirators. These changes may lead to various adverse skin reactions after long‐term use.

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