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The purposes of this study were to compare the use of contraception by monocultural and multicultural adolescents and identify the multidimensional factors in an ecological model. This study was cross-sectional design with a secondary data analysis using national data from the 2018 Korea Youth Risk Behavior Survey, including 3,031 participants (81 multicultural and 2,950 monocultural adolescents with sexual activity). The monocultural adolescents reported significantly higher rates of contraceptive use (61.66%) than multicultural adolescents (39.39%, p < 0.001). Monocultural adolescents' contraception use was significantly associated with intrapersonal factors (gender, drinking, and using substances) and school factors (school location, grade, and sex education). School factors also associated with multicultural adolescents' contraception use. To promote contraception use by multicultural adolescents with sexual activity, sex education should be tailored to meet specific cultural needs. In addition, risky behavior prevention should be part of comprehensive health promotion and sex education for monocultural adolescents.

Electrolyte additives with multiple functions enable the interfacial engineering of Li‐metal batteries (LMBs). Owing to their unique reduction behavior, additives exhibit a high potential for electrode surface modification that increases the reversibility of Li‐metal anodes by enabling the development of a hierarchical solid electrolyte interphase (SEI). This study confirms that an adequately designed SEI facilitates the homogeneous supply of Li+, nonlocalized Li deposition, and low electrolyte degradation in LMBs while enduring the volume fluctuation of Li‐metal anodes on cycling. An in‐depth analysis of interfacial engineering mechanisms reveals that multilayered SEI structures comprising mechanically robust LiF‐rich species, electron‐rich P–O species, and elastic polymeric species enabled the stable charge and discharge of LMBs. The polymeric outer SEI layer in the as‐fabricated multilayered SEI could accommodate the volume fluctuation of Li‐metal anodes, significantly enhancing the cycling stability Li||LiNi0.8Co0.1Mn0.1O2 full cells with an electrolyte amount of 3.6 g Ah−1 and an areal capacity of 3.2 mAh cm−2. Therefore, this study confirms the ability of interfacial layers formed by electrolyte additives and fluorinated solvents to advance the performance of LMBs and can open new frontiers in the fabrication of high‐performance LMBs through electrolyte‐formulation engineering. [ABSTRACT FROM AUTHOR]

Currently, commercial lithium (Li) ion batteries (LIBs) do not meet the energy density (>350 W h kg−1) required for vehicle electrification; therefore, alternative materials are required. Lithium metal batteries (LMBs) are promising secondary battery candidates for next-generation, eco-friendly energy conversion given their high theoretical gravimetric capacities (3862 mA h g−1). However, strong reduction by Li metal electrochemically decomposes the electrolytes, reducing battery performance, safety, and stability. To overcome these potential issues, the LMB electrolyte must be very resistant to oxidation. Here, we used leakage current tests to investigate the oxidation stability of organic electrolytes for LMBs. We performed quantum and molecular dynamics simulations to clarify the effects of gel polymers added to the electrolyte. We focused on changes in the behaviors of free organic molecules after the addition of polymers, and the highest/lowest occupied molecular orbital energy levels of various molecular configurations. The leakage current tests revealed improvements to the oxidation stability of an organic-based electrolyte. In addition, polymer addition resulted in a decrease in free organic molecule levels, improving the oxidation stability of the entire system as revealed by the highest occupied molecular orbital energy values of the various molecular configurations. [ABSTRACT FROM AUTHOR]

The purposes of this study were to compare the use of contraception by monocultural and multicultural adolescents and identify the multidimensional factors in an ecological model. This study was cross-sectional design with a secondary data analysis using national data from the 2018 Korea Youth Risk Behavior Survey, including 3,031 participants (81 multicultural and 2,950 monocultural adolescents with sexual activity). The monocultural adolescents reported significantly higher rates of contraceptive use (61.66%) than multicultural adolescents (39.39%, p <.001). Monocultural adolescents' contraception use was significantly associated with intrapersonal factors (gender, drinking, and using substances) and school factors (school location, grade, and sex education). School factors also associated with multicultural adolescents' contraception use. To promote contraception use by multicultural adolescents with sexual activity, sex education should be tailored to meet specific cultural needs. In addition, risky behavior prevention should be part of comprehensive health promotion and sex education for monocultural adolescents. [ABSTRACT FROM AUTHOR]