Quantum wells (QWs), enabling effective exciton confinement and strong light-matter interaction, form an essential building block for quantum optoelectronics. For two-dimensional (2D) semiconductors, however, constructing the QWs is still challenging because suitable materials and fabrication techniques are lacking for bandgap engineering and indirect bandgap transitions occur at the multilayer. Here, we demonstrate an unexplored approach to fabricate atomic-layer-confined multiple QWs (MQWs) via monolithic bandgap engineering of transition metal dichalcogenides and van der Waals stacking.
View Article and Find Full Text PDFInt J Environ Res Public Health
February 2021
Health behavior is a critical measure in controlling the coronavirus disease 2019 (COVID-19) pandemic. We estimated the effect of health behaviors against air pollution on reducing the risk of COVID-19 during the initial phase of the pandemic. The attack rates of COVID-19 in 159 mainland Chinese cities during the first 2 weeks after the closure of major cities was estimated; air pollution level as a surrogate indicator of the mask-wearing rate.
View Article and Find Full Text PDFUnc-51-like autophagy activating kinase 1 (ULK1), a mammalian homolog of the yeast kinase Atg1, has an essential role in autophagy induction. In nutrient and growth factor signaling, ULK1 activity is regulated by various posttranslational modifications, including phosphorylation, acetylation, and ubiquitination. We previously identified glycogen synthase kinase 3 beta (GSK3B) as an upstream regulator of insulin withdrawal-induced autophagy in adult hippocampal neural stem cells.
View Article and Find Full Text PDFThe Hebei Spirit oil spill (HSOS) occurred on the west coast of South Korea (Taean county) on December 7, 2007, and studies revealed that exposure to the oil spill was associated with various adverse health issues in the inhabiting population. However, no studies evaluated the association between crude-oil exposure and epigenetic changes. This study aimed to investigate the HSOS exposure-associated longitudinal and cross-sectional variations in global DNA methylation (5-mc) and/or hydroxymethylation (5-hmc) and expression profiles of related genes in Taean cohort participants from 2009 (AH-baseline) and 2014 (AH-follow-up) relative to the reference group (AL).
View Article and Find Full Text PDFObjectives: The optimal treatment option for carbapenem-resistant Acinetobacter baumannii (CRAB) is still limited. This study investigated the efficacy of three or more antibiotic types and regimens for treatment of CRAB infection in high CRAB endemic areas.
Methods: A multicentre retrospective study was conducted to evaluate the efficacy of treatment types and regimens of CRAB infections in 10 tertiary hospitals in the Republic of Korea.
To provide a nationwide representative dataset for the study on health impact of air pollution, we combined the data from the Korea National Health and Nutrition Examination Survey with the daily air quality and weather data by matching the date of examination and the residential address of the participants. The database of meteorological factors and air quality as sources of exposure data were estimated using the Community Multiscale Air Quality model. The linkage dataset was merged by three ways; administrative district, si-gun-gu (city, county, and district), and geocode (in latitude and longitude coordinate units) based on the participants' residential address, respectively.
View Article and Find Full Text PDFACS Appl Mater Interfaces
February 2021
The power conversion efficiency (PCE) of solution-processed organic-inorganic hybrid perovskite solar cells has been drastically improved. Despite this considerable progress, systematic research on precursor solution chemistry and its effects on photovoltaic parameters has been limited thus far. Herein, we report on the tracking of changes in chemical species in a precursor solution under solar illumination and investigate the correlation between the equilibrium change and the corresponding perovskite film formation.
View Article and Find Full Text PDFWe performed polarized Raman spectroscopy on mechanically exfoliated few-layer MoTe samples and observed both 1T' and T phases at room temperature. Few-layer 1T' and T MoTe exhibited a significant difference especially in interlayer vibration modes, from which the interlayer coupling strengths were extracted using the linear chain model: strong in-plane anisotropy was observed in both phases. Furthermore, temperature-dependent Raman measurements revealed a peculiar phase transition behavior in few-layer 1T' MoTe.
View Article and Find Full Text PDFKorean red pine needle (RPN) exhibits various biological and pharmacological activities. Among the various compounds of RPN, we isolated dehydroabietic and 4---communic acid. At first, we confirmed that two compounds inhibited angiotensin converting enzyme (ACE) and induced p-Akt in human umbilical vein endothelial cells (HUVEC).
View Article and Find Full Text PDFThe purpose of this study was to determine whether the fluoroquinolone (FQ) minimum inhibitory concentration (MIC) for the causative agent influences the clinical response of FQ treatment at 72 h in patients with community-acquired acute pyelonephritis (CA-APN). We prospectively collected the clinical data of women with CA-APN from 11 university hospitals from March 2010 to February 2012 as well as isolates from the urine or blood. In total, 78 patients included in this study received FQ during the initial 72 h, and the causative was detected.
View Article and Find Full Text PDFInt J Environ Res Public Health
December 2020
Shigellosis is a major diarrheal disease in low- and middle-income countries. Although the incidence of such diseases in South and Southeast Asia has been associated with climate fluctuations linked to the El Niño-Southern Oscillation (ENSO), the impact of ENSO on shigellosis infections remains unknown. Data reported to being infected with shigellosis while traveling abroad from 2004 to 2017 were obtained from the Korea Centers for Disease Control and Prevention.
View Article and Find Full Text PDFBackground: Hepatitis B is known to cause several forms of liver diseases including chronic hepatitis B (CHB), and hepatocellular carcinoma. Previous genome-wide association study of CHB risk has demonstrated that rs12614 of complement factor B (CFB) was significantly associated with CHB risk. In this study, fine-mapping study of previously reported GWAS single nucleotide polymorphism (SNP; CFB rs12614) was performed to validate genetic effect of rs12614 on CHB susceptibility and identify possible additional causal variants around rs12614 in a Korean population.
View Article and Find Full Text PDFBackground: Lung cancer is the leading cause of cancer-related deaths worldwide. Copy number variation (CNV) in several genetic regions correlate with cancer susceptibility. Hence, this study evaluated the association between CNV and non-small cell lung cancer (NSCLC) in the peripheral blood.
View Article and Find Full Text PDFInt J Environ Res Public Health
December 2020
Previous studies have demonstrated that ambient air pollution leads to a decrease in mental and physical function. Although studies on the relationship between long-term exposure to air pollution and health-related quality of life have been conducted, the impact of short-term exposure has rarely been reported. This study explored the association between short-term exposure to air pollution and EuroQol-visual analog scale (EQ-VAS) scores, an indicator of health-related quality of life, using repeated measures.
View Article and Find Full Text PDFObjectives: This study aimed to develop hypotheses on trends in malaria incidence in North Korea using malaria incidence among South Korean visitors to North Korea.
Methods: The number of South Korean tourists who visited Mount Kumgang from 2000 to 2008 and the number of South Korean employees at the Kaesong Industrial Complex from 2005 to 2015 were obtained from the Korean Statistical Information Service. The number of malaria cases among South Koreans who visited North Korea was obtained from a previous report.
Curr Opin Neurobiol
December 2020
Visually guided decision-making requires integration of information from distributed brain areas, necessitating a brain-wide approach to examine its neural mechanisms. New tools in Drosophila melanogaster enable circuits spanning the brain to be charted with single cell-type resolution. Here, we highlight recent advances uncovering the computations and circuits that transform and integrate visual information across the brain to make behavioral choices.
View Article and Find Full Text PDFProtein dimerization or oligomerization resulting from swapping part of the protein between neighboring polypeptide chains is known to play a key role in the regulation of protein function and in the formation of protein aggregates. Glutaredoxin-1 from (cGrx1) was used as a model to explore the formation of multiple domain-swapped conformations, which were made possible by modulating several hinge-loop residues that can form a pivot for domain swapping. Specifically, two alternative domain-swapped structures were generated and analyzed using nuclear magnetic resonance (NMR), X-ray crystallography, circular-dichroism spectroscopy and hydrogen/deuterium-exchange (HDX) mass spectrometry.
View Article and Find Full Text PDFJ Korean Med Sci
November 2020
Background: Hearing loss (HL) in children may adversely affect their development. HL is more prevalent in patients with chronic kidney disease (CKD) than in the general population. This study evaluated the prevalence of HL and its underlying diseases in patients with childhood-onset in CKD.
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