Associations of multicultural status with depressive mood and suicidality among Korean adolescents: the roles of parental country of birth and socioeconomic position

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Background The mental health of the offspring of immigrants is a major public health concern. In this study, we examined associations of multicultural status and parental country of birth with adolescent mental health in South Korea, and assessed the effect of socioeconomic position (SEP) on these associations. Methods We used four waves of the Korea Youth Risk Behavior Web-based Survey (KYRBS) between 2011 and 2014, including 294,324 participants (149,219 boys and 145,105 girls aged 13–18 years) as study subjects. KYRBS is a cross-sectional survey conducted annually by the Korea Centers for Disease Control and Prevention. The participants in the KYRBS were drawn as stratified multistage clustered samples from Korean middle schools and high schools. We calculated the age-adjusted 12-month prevalence of depressive mood and suicidal behaviors by parental country of birth, and estimated the effects of SEP indicators on the relationship. Results The age-standardized prevalence of suicidality (suicide ideation, plans, and attempts) was significantly different between multicultural and non-multicultural boys. The impact of multicultural status on mental health varied with parental foreign-born status and maternal country of birth. Compared with non-multicultural counterparts, boys with Japan-born mothers showed lower prevalence ratios (PRs) of suicidal plans (PR = 0.34, 95% CI 0.16–0.70). Girls with Japan-born mothers also showed lower PRs of depressive mood (PR = 0.77, 95% CI 0.63–0.95) and suicidal ideation (PR = 0.59, 95% CI 0.41–0.83), while adolescents with Korean-Chinese mothers showed similar PRs. Boys with foreign-born fathers as well as boys with two foreign-born parents were at a greater risk of suicidality than non-multicultural boys. The magnitude of the relationship between multicultural status and mental health outcomes was generally attenuated after adjusting for SEP indicators. Conclusions In general, adolescents with Japan-born mothers showed lower PRs of depressive mood and suicidality than non-multicultural adolescents, while those with Korean-Chinese mothers showed similar PRs. Boys who had foreign-born fathers generally showed greater PRs of depressive mood and suicidality than non-multicultural boys. To ensure the effective implementation of policies to reduce mental health problems among multicultural adolescents in South Korea, detailed information should be considered regarding the cultural and socioeconomic backgrounds of families, such as parental country of birth and SEP

Enhanced Thermoelectric Properties in Bulk Nanowire Heterostructure-Based Nanocomposites through Minority Carrier Blocking

To design superior thermoelectric materials the minority carrier blocking effect in which the unwanted bipolar transport is prevented by the interfacial energy barriers in the heterogeneous nanostructures has been theoretically proposed recently. The theory predicts an enhanced power factor and a reduced bipolar thermal conductivity for materials with a relatively low doping level, which could lead to an improvement in the thermoelectric figure of merit (ZT). Here we show the first experimental demonstration of the minority carrier blocking in lead telluride–silver telluride (PbTe–Ag_2Te) nanowire heterostructure-based nanocomposites. The nanocomposites are made by sintering PbTe–Ag_2Te nanowire heterostructures produced in a highly scalable solution-phase synthesis. Compared with Ag_2Te nanowire-based nanocomposite produced in similar method, the PbTe–Ag_2Te nanocomposite containing ∼5 atomic % PbTe exhibits enhanced Seebeck coefficient, reduced thermal conductivity, and ∼40% improved ZT, which can be well explained by the theoretical modeling based on the Boltzmann transport equations when energy barriers for both electrons and holes at the heterostructure interfaces are considered in the calculations. For this p-type PbTe–Ag_2Te nanocomposite, the barriers for electrons, that is, minority carriers, are primarily responsible for the ZT enhancement. By extending this approach to other nanostructured systems, it represents a key step toward low-cost solution-processable nanomaterials without heavy doping level for high-performance thermoelectric energy harvesting

Composition Modulation of Ag_2Te Nanowires for Tunable Electrical and Thermal Properties

In this article, we demonstrated that composition modulation of Ag_2Te nanowires can be achieved during the self-templated transformation of Te nanowires into Ag_2Te nanowires during solution phase synthesis, which provides a mean to tune the carrier density of the Ag_2Te nanowires. Both nearly stoichiometric and Ag-rich nanowires have been synthesized, which give rise to p-type and n-type Ag_2Te nanocomposites after hot press, respectively. The electrical and thermal properties of the two kinds of samples have been measured. Theoretical modeling based on the near-equilibrium Boltzmann transport equations has been used to understand the experimental results. We found that ZT of the heavily doped n-type sample reaches 0.55 at 400 K, which is the highest ZT value reported for Ag_2Te at the same temperature mainly due to the reduced thermal conductivity by the nanostructures. Theoretical analysis on the carrier transport shows that the power factor is also very well optimized in the doped Ag_2Te sample considering the reduced carrier mobility by the nanostructures

"Detachment of the carinal hook following endobronchial intubation with a double lumen tube"

<p>Abstract</p> <p>Background</p> <p>Carinal hooks increases difficulty at endotracheal intubation. Amputation of the carinal hook during passage and malpositioning of the tube to the hook are some of the potential problems related with left-sided Carlens double lumen tube (DLT). This article reports an amputation of the hook during a difficult selective intubation and aimed at calling the attention to complications associated with DLTs and the importance of fiberoptic bronchoscopy.</p> <p>Case presentation</p> <p>A 68 year-old woman was scheduled for right-sided thoracotomy in whom blind DLT insertion was performed. Narrowed trachea causes difficulty in rotating the DLT 90° counter-clockwise. After carinal hook was noticed upon visual inspection of the DLT, fiberoptic bronchoscopy was used to remove the missing part (with the use of forceps) from the right mainstem bronchus.</p> <p>Conclusion</p> <p>Insertion of DLTs with carinal hook is associated with technical problems and potentially life-threatening hazards have discouraged their use. Fiberoptic evaluation and repositioning solves most of the problems. Although amputation of the carinal hook has not been previously reported, clinicians should be alert. This case report emphasizes the utility of the fiberoptic bronchoscopy in the operating theatre for placement, positioning and inspection of the carinal hook DLT.</p

One-dimensional steady-state structures at relativistic interaction of laser radiation with overdense plasma for finite electron temperature

One-dimensional steady-state plasma-field structures in overdense plasma are studied assuming that the electron temperature is uniform over plasma bulk and the ions are stationary. It is shown that there may exist solutions for electron distributions with cavitation regions in plasma under the action of ponderomotive forceComment: 6 pages, 4 figure