Ultrastable 3D Heterogeneous Integration via N-Heterocyclic Carbene Self-Assembled Nanolayers.

The commercialization of 3D heterogeneous integration through hybrid bonding has accelerated, and accordingly, Cu-polymer bonding has gained significant attention as a means of overcoming the limitations of conventional Cu-SiO2 hybrid bonding, offering high compatibility with other fabrication processes. Polymers offer robust bonding strength and a low dielectric constant, enabling high-speed signal transmission with high reliability, but suffer from low thermomechanical stability. Thermomechanical stability of polymers was not achieved previously because of thermal degradation and unstable anchoring. To overcome these limitations, wafer-scale Cu-polymer bonding via N-heterocyclic carbene (NHC) nanolayers was presented for 3D heterogeneous integration, affording ultrastable packing density, crystallinity, and thermal properties. NHC nanolayers were deposited on copper electrodes via electrochemical deposition, and wafer-scale 3D heterogeneous integration was achieved by adhesive bonding at 170 °C for 1 min. Ultrastable conductivity and thermomechanical properties were observed by the spatial mapping of conductivity, work function, and force-distance curves. With regard to the characterization of NHC nanolayers, low-temperature bonding, robust corrosion inhibition, enhanced electrical conductivity, back-end-of-line process compatibility, and fabrication process reduction, NHC Cu/polymer bonding provides versatile advances in 3D heterogeneous integration, indicating that NHC Cu/polymer bonding can be utilized as a platform for future 3D vertical chip architectures.

High-Performance Biscrolled Ni-Fe Yarn Battery with Outer Buffer Layer.

The increasing demand for portable and wearable electronics has promoted the development of safe and flexible yarn-based batteries with outstanding electrochemical properties. However, achieving superior energy storage performance with a high active material (AM) load and long cycle life with this device format remains a challenge. In this study, a stable and rechargeable high-performance aqueous Ni-Fe yarn battery was constructed via biscrolling to embed AMs within helical carbon nanotube (CNT) yarn corridors. Owing to the high load of charge storage nanoparticles (NPs; above 97 wt%) and the outer neat CNT layer, the buffered biscrolled Ni-Fe yarn battery demonstrates excellent linear capacity (0.053 mAh/cm) and cycling stability (60.1% retention after 300 charge/discharge cycles) in an aqueous electrolyte. Moreover, our flexible yarn battery exhibits maximum energy/power densities of 422 mWh/cm3 and 7535 mW/cm3 based on the total volume of the cathode and anode, respectively, which exceed those reported for many flexible Ni-Fe batteries. Thus, biscrolled Ni-Fe yarn batteries are promising candidates for next-generation conformal energy solutions.

Factors Affecting Obesity in Urban and Rural Adolescents: Demographic, Socioeconomic Characteristics, Health Behavior and Health Education.

In this study, we aimed to analyze the demographic factors, socioeconomic factors, health behavior factors, and health education of urban and rural adolescents and their impact on obesity in rural and urban youths. We analyzed data from 60,040 students from 800 schools using the 14th Youth Health Behavior Web-based Survey data for 2018. The mean age of the participants was 15.01 ± 1.77; 30,463 (50.7%) males and 29,577 (49.3%) females. The data were analyzed using a chi-square test and multinominal logistic regression analysis. Rural adolescents had significantly lower parental income, parental education, and academic performance levels. Urban adolescents tended to have a higher rate of breakfast fasting, ate more fast-food, exercised less, had a higher rate of sleep dissatisfaction, and had significantly higher current alcohol intake. Rural adolescents reported more stress and obesity levels than their urban counterparts. Factors influencing the obesity of urban adolescents were grade level, father's education, mother's education, academic performance level, fast-food, exercise, current alcohol intake, and sleep satisfaction. Factors influencing the obesity of rural adolescents were parents' income level, academic performance level, exercise, and sleep satisfaction. To effectively prevent and manage adolescent obesity, which is an indicator of health equity among adolescents, an effort must be made to improve health education and the local environment in both urban and rural areas.

Application of Wastewater Reuse with Photocatalyst Prepared by Sol-Gel Method and Its Kinetics on the Decomposition of Low Molecular Weight Pollutants.

The development of immobilized photocatalyst as a strategy for problematic electronics wastewater reuse is described in this study. The strategy was to perform separate rinsing, mostly consisting of low molecular weight compounds, and to decompose them with a simple process, based on the advanced oxidation process (AOP). Extensive studies were performed on the preparation conditions of immobilized photocatalysts by sol-gel method under various amount of precursor and support, water to precursor ratio, pH, aging time, and calcination conditions. The optimized preparation conditions were chosen by measuring removal efficiencies of isopropyl alcohol as a representative target compound with supportive SEM and XRD analyses. Removal efficiencies with photocatalyst and UV irradiation in synthetic wastewater simulating electronics wastewater were evaluated over time. Removal efficiencies of alcohol, acetone, ethanol, and acetaldehyde reached 97.2%, 71.2%, 99.0%, and 99.0%, respectively, in 2 h. Reaction constants of each compound were determined by fitting experimental data to the first order kinetic equation and the trial and error method with consecutive reaction pathway. As analysis results of reaction constants, UV with prepared photocatalyst was found to be effective and the decomposition of acetone was found to be the rate-determining step. The immobilized photocatalyst developed in this study would be useful for application of wastewater reuse with high removal efficiencies, mild preparation conditions, and mechanical stability.

Prevalence of sexual experience among Korean adolescent: age-period-cohort analysis.

OBJECTIVES: Since exposure to sexual content and early sexual initiation among adolescents have become serious social issues in Korea, an in-depth analysis of trends in the prevalence of sexual experience among Korean adolescents is necessary to project the trends and policies required for the next 10 years. The objective of this study was to identify the contributions of age, period, and birth cohort effects on the prevalence of sexual experience in Korean adolescents. METHODS: We analyzed age-specific, period-specific, and birth cohort-specific trends in the prevalence of sexual experience among 911,502 adolescents (469,593 boys, 51.5%; 441,909 girls, 48.5%) aged 12 years to 17 years from the 2006 to 2017 Korean Youth Risk Behavior Web-based Survey. Joinpoint regression analysis was conducted to examine significant changes in the prevalence of sexual experience and to find the optimal number and location of places where trends changed. RESULTS: The prevalence of sexual experience generally increased with age in all periods in both boys and girls. In boys, the prevalence of sexual experience increased in recent periods, especially in the age group of 12-13 years, while the prevalence of sexual experience decreased in the age group of 16-17 years. In girls, the age group of 12-13 years showed an increased prevalence of sexual experience in recent periods. However, the prevalence showed a decreasing trend in the age group of 16-17 years. CONCLUSIONS: In boys and girls, sexual experience increased with age, although this tendency has slowed in recent cohorts. Therefore, early sex education is needed.

Association between sexual behavior and suicidal ideation among South Korean middle school students.

AIM: To identify the association between sexual behavior and suicidal ideation among South Korean middle school students. METHODS: This study used raw data from the 2013 Korean Youth Risk Behavior Web-Based Survey. Among the data from 72,435 students, the data from 36,530 individuals in middle school were analyzed. The prevalence of sexual behavior and suicidal ideation, according to the participants' general characteristics, and suicidal ideation, according to sexual behaviors, were assessed by using a complex sample Chi-squared test. A complex sample logistic regression was used to examine the association between sexual behavior and suicidal ideation. RESULTS: Overall, 3.8% of the students reported having had sexual intercourse and 17.6% of the students reported suicidal ideation during the past 12 months. Having had sexual intercourse was statistically significantly associated with suicidal ideation. The students who had had sexual intercourse usually used contraception and those who had contracted sexually transmitted diseases were more likely to report suicidal ideation in both the unadjusted and adjusted models. CONCLUSION: This study illustrates the need to develop a prevention program that addresses the common factors between sexual behavior and suicidal ideation in order to effectively reduce both sexual behavior and suicidal ideation in middle school students.

Differences in Factors Associated with Depressive Symptoms between Urban and Rural Female Adolescents in Korea.

PURPOSE: To examine the prevalence of depressive symptoms and differentiate factors associated with them in urban and rural areas by applying the Ecological Models of Health Behavior. METHODS: We employed a cross-sectional design and convenience sample of 460 female adolescents. The instruments included the Adolescent Mental-Health Problem-Behavior Questionnaire (AMPQ-II) and the Beck Depression Inventory (BDI). RESULTS: Depressive symptoms were confirmed in 15.7% of urban adolescents and 22.9% of rural adolescents (p<.05). In the urban group, perception of health and stress associated with school performance were significantly associated with depressive symptoms. In the rural group, academic/internet related problems and rule violations were significantly associated with depressive symptoms (p<.05). General life happiness, worry/anxiety, and mood/suicidal ideation were common factors in both urban and rural areas (p<.05). CONCLUSION: Multiple factors were associated with depressive symptoms, and those significant factors differed between urban and rural female youths. Accordingly, tailored approaches are required considering urban and rural differences. The approaches should include intrapersonal, interpersonal, and organizational levels of interventions.

Behavioral and psychosocial factors associated with suicidal ideation among adolescents.

Suicidal ideation poses a serious threat to the well-being of adolescents and is the strongest risk factor for suicide. Indeed, Korea ranks first among Organisation for Economic Cooperation and Development countries regarding the age-standardized suicide rates. In the present study, we examined multiple levels of factors associated with the suicidal ideation of adolescents in Korea by applying the Ecological Models of Health Behavior. A cross-sectional study was conducted with a convenience sample of 860 adolescents. The instruments included the Beck Depression Inventory and the Adolescent Mental Health and Problem Behavior Questionnaire. The data were analyzed using hierarchical multiple regression. Sixteen percent of participants reported suicidal ideation. Intrapersonal (sleep disturbance, Internet game addiction, destructive behavior, and depressive symptoms) and interpersonal factors (family conflicts and peer victimization) were associated with suicidal ideation. Because multiple factors were associated with suicidal ideation among adolescents, both intrapersonal (sleep disturbance, Internet game addiction, and depression) and interpersonal factors (family conflicts and peer problems) should be considered in the development of suicide-prevention programs. These programs could include campaigns changing the norms (permissive attitudes toward school violence) and the development of strict and rigorous school non-violence policies.

Effects of an obesity management mentoring program for Korean children.

AIM: This research aimed to develop and test a mentored obesity management program guiding physical exercise, improving eating habits, and promoting self-esteem among elementary school learners. METHODS: A nonequivalent control group pretest-posttest design was used. Thirty learners were recruited through convenience sampling from two elementary schools, then evenly assigned to the experimental and control groups. Six nursing students were mentored, receiving 16h of mentorship training. A 10-week mentored obesity management program promoting physical exercise and proper nutrition was developed and provided. RESULTS: The two groups' pretest and posttest body mass index and self-esteem differences were statistically significant. Most participants were satisfied with the program, endorsing its provision in the regular school curriculum. CONCLUSIONS: A mentored obesity management program for elementary school learners would effectively manage weight and improve self-esteem. Programs purportedly curtailing childhood obesity should be expanded, and school policies regulated to enable implementation.

[Sexual behavior and associated factors among Korean junior high school students].

OBJECTIVES: The study purpose was to identify the sexual behavior and associated factors of Korean junior high school students. METHODS: Raw data from the 2013 Korean Youth Risk Behavior Web-Based Survey were used. Among the data from 72,435 students, 36,530 junior high school students were analyzed. Complex sample frequency analysis and complex sample chi-square were used to identify the condition of sexual behavior, and complex sample logistic regression was used to examine the factors related to sexual behavior. RESULTS: Among the students, 3.8% responded that they had experienced sexual intercourse, and the prevalence of sexual intercourse was higher among male students (5.0%) compared to female students (2.5%). Among male students, those who had the following were more likely to have had sexual intercourse: perceived high economic status, living with a relative, experience with a partti-me job, a foreign father, experience with smoking and drinking during the past month, experience with drug use, and depression during the past 12 months. Among the female students who were more likely to have had sexual intercourse, the following were ascertained: higher grades, perceived high economic status, living with a relative or in childcare facilities, experience with a part-time job, a foreign father or mother, experience with smoking and drinking during the past month, and experience with drug use. CONCLUSION: The results suggest that it is important to develop a comprehensive approach program not only focused on sexual behavior but also including mental health or other health behaviors to effectively reduce the likelihood of sexual intercourse among Korean junior high school students.

Association of school, family, and mental health characteristics with suicidal ideation among Korean adolescents.

In a cross-sectional research design, we investigated factors related to suicidal ideation in adolescents using data from the 2013 Online Survey of Youth Health Behavior in Korea. This self-report questionnaire was administered to 72,435 adolescents aged 13-18 years in middle and high school. School characteristics, family characteristics, and mental health variables were analyzed using descriptive statistics, χ(2) tests, and logistic regression. Both suicidal ideation and behavior were more common in girls. Suicidal ideation was most common in 11th grade for boys and 8th grade for girls. Across the sample, in logistic regression, suicidal ideation was predicted by low socioeconomic status, high stress, inadequate sleep, substance use, alcohol use, and smoking. Living apart from family predicted suicidal ideation in boys but not in girls. Gender- and school-grade-specific intervention programs may be useful for reducing suicidal ideation in students.

Factors Affecting Underweight and Obesity Among Elementary School Children in South Korea.

PURPOSE: The purpose of the study was to determine factors associated with underweight and obesity in elementary school children in Korea. METHODS: Study participants included 4,895 children attending 59 elementary schools across Korea. Children were grouped into underweight [< 5% body mass index (BMI)-for-age], normal weight (5%-85% BMI-for-age), and overweight/obese (≥ 85% BMI-for age). The questionnaire included demographic characteristics, health status, and diet and exercise behavior of children, and environmental characteristics of schools. RESULTS: Twelve percent of the children were overweight or obese. The results showed that demographic (age and gender), health status (atopic dermatitis and poor subjective health), and the characteristics of diet and exercise (unbalanced diet and diet experiences) were associated with underweight (p < .05), while demographic (age and gender), health status (poor subjective health), behavioral characteristics (fast food consumption and diet experiences), and school environmental characteristics (rural area) were associated with overweight/obesity (p < .05). CONCLUSIONS: Programs and interventions to reduce underweight and overweight/obesity in Korean elementary schools must consider behavioral and environmental characteristics of children.

Weight perception and dieting behavior among Korean adolescents.

This study examines relationships among weight status, weight perceptions, and dieting behaviors in South Korean adolescents. As perceptions of an ideal body for teens in Korea have changed over time, it is important for school nurses to understand these relationships to help students achieve health. A cross-sectional survey of 3,191 8th and 2,252 11th-grade students from 21 middle and high schools across Korea completed a self-administered questionnaire. The prevalence of overweight among adolescents was 17.5% in males and 6.0% in females. Overall, 65.9% of students perceived their weight status accurately. Females overestimated their weight status 2.3 times more often than males. Male students underestimated their weight status 2.7 times more frequently than females. Approximately one third of participants misperceived their weight status, with variations existing between males and females. Study results suggest the need to develop male- and female-specific interventions to promote healthy body images and body weight.