Eu-doped SrAl2O4 is a promising thermoluminescent and mechanoluminescent material with high brightness and stability, making it suitable for various luminescent devices. In this study, SrAl2O4:Eu was synthesized using a solid-state reaction method, and the effects of reducing atmosphere and high-temperature synthesis conditions on its luminescence properties were systematically analyzed. The luminescence characteristics of SrAl2O4:Eu were found to be highly sensitive to synthesis temperature, atmosphere, and Eu doping concentration, and optimal conditions were determined. A comparison of SrAl2O4:Eu synthesized at 1,300 °C under air and reducing atmospheres revealed that the reducing atmosphere plays a critical role in stabilizing Eu2+ ions, forming a single-phase SrAl2O4, and establishing luminescence centers. Notably, SrAl2O4:Eu synthesized at 1,600 °C in a reducing atmosphere achieved a photoluminescence quantum yield (PLQY) of 43 % and a maximum luminance of 2,030 Cd/m2, showing significant improvement in luminescence efficiency compared to samples synthesized at 1,300 °C. When Eu doping concentrations were adjusted from 1 % to 20 %, the highest luminescence performance was observed at 10 % doping, while excessive doping (20 %) increased non-radiative recombination pathways, and no further improvement in luminescence efficiency was observed. X-ray Diffraction (XRD) and Photoluminescence (PL) analyses elucidated the effects of synthesis conditions on the structural stability and luminescence properties of SrAl2O4:Eu, and the optimal reducing atmosphere and high-temperature synthesis conditions are proposed. This study provides a synthesis strategy for enhancing the luminescence properties of Eu-doped SrAl2O4 and lays the groundwork for the development of highperformance thermoluminescent and mechanoluminescent materials.

Pepper is one of the most important vegetables in South Korea. It is a key ingredient in kimchi, the nation’s staple dish, and serves as the primary raw material for producing gochujang, a commonly used condiment in Korean cooking. As a result, numerous pepper varieties have been developed, including those that yield more fruit or have milder pungency. However, farmers who grow peppers tend to prefer varieties that are resistant to pests and diseases. Bacterial wilt (BW) is one of the most devastating diseases affecting peppers and is transmitted through the soil. To breed pepper varieties resistant to bacterial wilt using molecular breeding techniques, it is essential to first identify the Quantitative Trait Locus (QTL) that confers resistance to this disease. This requires conducting locus analysis with resistant cultivars. In this study, an F2 population was developed by selfing F1 hybrids, which were obtained by crossing a resistant cultivar with a susceptible cultivar, to identify QTLs associated with bacterial wilt resistance. Genotyping-by-Sequencing (GBS) analysis will be performed using the F2 population, and the results will be utilized for QTL mapping.

Neural machine translators (NMTs), such as Google Translate, may assist second language (L2) readers with general comprehension. However, previous empirical studies show mix ed r esults r egarding their e ffectiveness. In this study, 145 Korean English learners from a girls’ high school were asked to solve three types of reading comprehension problems (grammar judgment, inferring meaning from context, inferring main idea) under three reading conditions (no aid, MT, glossary). Overall, when using MT, reading comprehension scores were higher than in either the no aid or glossary conditions individually. However, none of the reading aid conditions improved grammar judgment. Only mid-proficiency learners benefited from MT in both inferring meaning from context and inferring main idea tasks. The results suggest that the glossary may have interrupted the flow of the reading process. With the widespread availability of MT as an online reference tool, L2 teachers should consider incorporating MT as a legitimate reading aid for different proficiency levels and reading purposes.

This study examines the effects of the TiO2 content and TiO2 position in the core or shell within tubular carbon nanofibers on the photocatalytic activity under visible light. Core–shell tubular carbon nanofiber composites whose cores are filled with TiO2 nanoparticles (PMTi(10)P) are fabricated through coaxial electrospinning and subsequent heat treatment. The PMTi(10)P composites with well-preserved TiO2 nanoparticles in the core part induce more oxygen vacancies, Ti3+ species, chemisorbed oxygen species, and anatase phases, significantly improving the photocatalytic performance. They act as photoelectron traps, allowing more photoelectrons and holes to participate in the photocatalytic reaction and extending the absorbance of TiO2 to the visible light region. The resulting PMTi(10)P photocatalyst exhibits excellent performance of 100% removal of methylene blue within 30 min and maintains nearly 100% removal of 15 ppm methylene blue over 10 regeneration cycles, indicating consistent and stable photocatalytic performance.

Mo-ODS alloys have excellent mechanical properties, including an improved recrystallization temperature, greater strength due to dispersed oxides, and the ability to suppress grain growth at high temperatures. In ODS alloys, the dispersed Y2O3 and added Ti form Y-Ti-O complex oxides, producing finer particles than those in the initial Y2O3. The complex oxides increase high-temperature stability and improve the mechanical properties of the alloy. In particular, the use of TiH2 powder, which is more brittle than conventional Ti, can enable the distribution of finer oxides than is possible with conventional Ti powder during milling. Moreover, dehydrogenation leads to a more refined powder size in the reduction process. This study investigated the refinement of Yi2Ti2O7 in a nano Mo-ODS alloy using TiH2. The alloy compositions were determined to be Mo-0.5Ti-0.5Yi2O3 and Mo-1.0Ti-0.5Yi2Oi2. The nano Mo-ODS alloys were fabricated using Ti and TiH2 to explore the effects of adding different forms of Ti. The sintered specimens were analyzed through X-ray diffraction for phase analysis, and the microstructure of the alloys was analyzed using scanning electron microscopy and transmission electron microscopy. Vickers hardness tests were conducted to determine the effect of the form of Ti added on the mechanical properties, and it was found that using TiHi2 effectively improved the mechanical properties.

Among the products of the electrocatalytic reduction of carbon dioxide (CO2RR), CO is currently the most valuable product for industrial applications. However, poor stability is a significant obstacle to CO2RR. Therefore, we synthesized a series of bimetallic organic framework materials containing different ratios of tungsten to copper using a hydrothermal method and used them as precursors. The precursors were then subjected to pyrolysis at 800 °C under argon gas, and the M-N bimetallic sites were formed after 2 h. Loose porous structures favorable for electrocatalytic reactions were finally obtained. The material could operate at lower reduction potentials than existing catalysts and obtained higher Faraday efficiencies than comparable catalysts. Of these, the current density of WCu-C/N (W:Cu = 3:1) could be stabilized at 7.9 mA ‧ cm-2 and the FE of CO reached 94 % at a hydrogen electrode potential of -0.6 V (V vs. RHE). The novel materials made with a two-step process helped to improve the stability and selectivity of the electrocatalytic reduction of CO2 to CO, which will help to promote the commercial application of this technology.

Sestrin 2 (SESN2) is a member of the sestrin family of stress-induced proteins that negatively regulate agingassociated biological processes. This study aims to investigate the role of SESN2 in regulating the differentiation potential and senescence of mesenchymal stem cells (MSCs) derived from young and elderly donors. Bulk RNA sequencing revealed a common decline in the SESN2 mRNA levels in MSCs from elderly individuals, which was confirmed via reverse transcription-polymerase chain reaction and western blot analyses. SESN2 knockdown in MSCs from young donors resulted in phenotypic changes similar to those in MSCs from elderly donors, including an enhanced expression of senescence and adipogenic markers and diminished expression of osteogenic markers. To confirm the effect of decreased SESN2 expression on osteogenic and adipogenic differentiation, we induced Sesn2 knockdown in mouse bone marrow-derived MSCs. Sesn2 knockdown suppressed the mRNA expression of osteogenic marker genes, alkaline phosphatase activity, and matrix mineralization. Furthermore, Sesn2 knockdown enhanced mRNA expression of the adipogenic marker genes and intracellular lipid accumulation. These results suggest that a decline in SESN2 expression during aging contributes to the shift of MSC differentiation from osteogenic to adipogenic lineage.

We have intended and preparation of hierarchically absorbent materials were covered with a NiMn2O4 and acts as a catalyst for azo dye degradation. The polyaromatic-based (PA) absorbent compounds were initially constructed by bromomethylated aromatic hydrocarbons which undergo self-polymerization in presence of ZnBr as a reagent and cross linker is bromomethyl methyl ether. The absorbent black materials with a 3D network were prepared by direct carbonization and activation of the as-prepared PA. The hydrothermal method was adapted for the preparation of carbon hybrid material C@NiMn2O4 powder's catalytic activity is effective in reducing p-nitrophenol to p-aminophenol and decolorizing carbon-based dyes like methyl orange (MO), methyl yellow (MY), and Congo red (CR) in aqueous media at 25 °C when NaBH4 is added. UV–visible spectroscopy was used to analyze the dyes' breakdown at regular interval.

In this study, we undertook detailed experiments to increase hydrogen production efficiency by optimizing the thickness of titanium dioxide (TiO2) thin films. TiO2 films were deposited on p-type silicon (Si) wafers using atomic layer deposition (ALD) technology. The main goal was to identify the optimal thickness of TiO2 film that would maximize hydrogen production efficiency while maintaining stable operating conditions. The photoelectrochemical (PEC) properties of the TiO2 films of different thicknesses were evaluated using open circuit potential (OCP) and linear sweep voltammetry (LSV) analysis. These techniques play a pivotal role in evaluating the electrochemical behavior and photoactivity of semiconductor materials in PEC systems. Our results showed photovoltage tended to improve with increasing thickness of TiO2 deposition. However, this improvement was observed to plateau and eventually decline when the thickness exceeded 1.5 nm, showing a correlation between charge transfer efficiency and tunneling. On the other hand, LSV analysis showed bare Si had the greatest efficiency, and that the deposition of TiO2 caused a positive change in the formation of photovoltage, but was not optimal. We show that oxide tunneling-capable TiO2 film thicknesses of 1~2 nm have the potential to improve the efficiency of PEC hydrogen production systems. This study not only reveals the complex relationship between film thickness and PEC performance, but also enabled greater efficiency and set a benchmark for future research aimed at developing sustainable hydrogen production technologies.

Nanoparticles are commonly used to avoid the opaque white color of TiO2 based sunscreen. However, a dispersing agent is typically required because of the tendency of the nanoparticles (NPs) to agglomerate. Stearic acid is one kind of dispersing agent often used for sunscreen products. However, according to the MSDS data sheet on stearic acid, stearic acid is highly hazardous to aquatic life and causes irritation on human skin. To avoid this problem, in this study a safer organic dispersing agent extracted from Korean seaweed has been studied to disperse TiO2 nanoparticles, and further use as an active agent in sunscreen products. The presence of phytochemicals in seaweed extract, especially alginate, can disperse TiO2 nanoparticles and improve TiO2 dispersion properties. Results show that seaweed extract can improve the dispersion properties of TiO2 nanoparticles and sunscreen products. Reducing the agglomeration of TiO2 nanoparticles improves sunscreen properties, by making it less opaque white in color, and increasing UV protection value. It was also confirmed that adding seaweed extract into sunscreen products had no irritating effects on the human skin, making it more desirable for cosmetics application.

Pigs are considered a “mixing vessel” that can produce new influenza strains through genetic reassortments, which threaten public health and cause economic losses worldwide. We performed surveillance of swine influenza virus (SIV) using 114,140 nasal swabs from 11,414 Korean farms from 2009 to 2022, and characterized their genetic evolution at each farm level. A total of 169 farms out of the 11,414 (1.48%) were SIV-positive. The positivity rate for the H1N2 subtype, which is most dominant in the pig population, was 37.87% (64/169). Through hemagglutinin (HA) gene analysis, 64 H1N2-positive farms were classified into Eurasian avian-like (46/64, 71.88%), triple-reassortant (14/64, 21.88%), pdm09 (3/64, 4.69%), and classical swine (1/64, 1.56%) groups. The estimated evolutionary rate of HA in H1N2 from 2009 to 2022 in Korea is 1.5309 × 10-3/site/year (95% HPD intervals from 1.0003 × 10-3 to 2.1735 × 10-3) with an estimated mean growth rate of 0.0114. Estimates of the relative genetic diversity of clades over time suggested that the HA of H1N2 exhibited an increase in population size. The results of this study showed that the Eurasian avian-like-HA of the H1N2 subtype was dominant in the pig population. The continued evolution of the HA of H1N2, which is critical for cell entry, might lead to genetic diversity and the loss of vaccine cross-protection. These results indicate that continus surveillance is imperative for monitoring the evolution of the swine influenza virus.

Uncoupling protein 1 (UCP1) is a unique mitochondrial membranous protein expressed in brown adipose tissue (BAT) in mammals. While its expression in response to cold temperatures and adipogenic inducers is well-characterized in mammals and human infants, the molecular characterization and expression of UCP1 in fish remain unexplored. To address this gap, we analyzed UCP1 expression in response to adipogenic inducers in a fish cell line, rainbow trout gonadal cells (RTG-2), and compared it with UCP1 expression in three mammalian preadipocytes, 3T3-L1, T37i, and WT1 exposed to the Peroxisome proliferator-activated receptor gamma (PPARγ) agonists, rosiglitazone (Rosi). In mammalian preadipocytes, UCP1 protein was highly expressed by Rosi, with an induction of adipogenesis observed in a time-dependent manner. This suggests that UCP1 plays a significant role in adipogenesis in mammals. However, RTG-2 cells showed no response to adipogenic inducers and exhibited only marginal expressions of UCP1. These results imply that RTG-2 cells may lack crucial responsive mechanisms to adipogenic signals or that the adipogenic response is regulated by other mechanisms. Further studies are needed to confirm these phenomena in fish preadipocytes when an appropriate cell line is established in future research.

This paper investigates L2 motivation and demotivation of college English majors in a Korean junior college. The participants’ L2 (de)motivation was explored by the oughtto L2 self, an element of the L2 motivational self system. Data were collected from two rounds of interviews with 59 and 31 students in all four years and analyzed qualitatively. The sources of the ought-to L2 self varied; however, it was a matter of how the participants recognized others’ expectations and pressure (i.e., manageable or beyond control). It was also relevant to how they comprehended and internalized these external influences for their L2 learning and (de)motivation. The findings indicate that the oughtto L2 self could be a contributing factor in sustaining L2 motivation and exerting effort. Finally, this paper calls for more needs to ensure and promote personalized and meaningful L2 learning for college English major students.

최근 여러 연구에서 Hg2+에 선택적으로 반응해 형광을 강화시키거나 소광시키는 thiophene을 기반으로한 probe가 많이 개발되어 왔지만, 이에 따른 분광학적 현상에 대한 정확한 분자적 수준의 이론적 해석이 이루어지지 않 았다. 이에 따라 우리는 Hg2+와 thiophene간 상호작용을 면밀히 분석하기 위해 Hg2+와 thiophene간 거리에 따른 에너 지 포텐셜을 구하였다. Hg2+ 이온에 대한 모든 전자(all electron, AE) basis set인 x2c-TZVPPall와 effective core potential (ECP) 기반인 LANL2DZ는 모두 상대성 효과가 고려된 바닥 상태에서 Hg2+와 thiophene이 결합력이 없이 해 리가 되는 에너지 포텐셜을 보여주었지만, 용매인 물이 고려된 시스템에서는 Hg2+와 thiophene이 결합력을 가지는 것 을 보였으며 이것은 실험적인 결과를 잘 재현하는 것이었다. 따라서 Hg2+ 이온을 포함하는 착화합물 시스템에서 올바 른 에너지 상태를 구하기 위해서는 상대성효과와 더불어 solvent 영향도 잘 고려돼야 함을 알 수 있다.