• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.541-556
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• 2022

Myocardial fibrosis is a key link in the occurrence and development of diabetic cardiomyopathy. Its etiology is complex, and the effect of drugs is not good. Cardiomyocyte apoptosis is an important cause of myocardial fibrosis. The purpose of this study was to investigate the effect of gaseous signal molecule sulfur dioxide (SO₂) on diabetic myocardial fibrosis and its internal regulatory mechanism. Masson and TUNEL staining, Western-blot, transmission electron microscopy, RT-qPCR, immunofluorescence staining, and flow cytometry were used in the study, and the interstitial collagen deposition, autophagy, apoptosis, and changes in phosphatidylinositol 3-kinase (PI3K)/AKT pathways were evaluated from in vivo and in vitro experiments. The results showed that diabetic myocardial fibrosis was accompanied by cardiomyocyte apoptosis and down-regulation of endogenous SO₂-producing enzyme aspartate aminotransferase (AAT)_1/2. However, exogenous SO₂ donors could up-regulate AAT_1/2, reduce apoptosis of cardiomyocytes induced by diabetic rats or high glucose, inhibit phosphorylation of PI3K/AKT protein, up-regulate autophagy, and reduce interstitial collagen deposition. In conclusion, the results of this study suggest that the gaseous signal molecule SO₂ can inhibit the PI3K/AKT pathway to promote cytoprotective autophagy and inhibit cardiomyocyte apoptosis to improve myocardial fibrosis in diabetic rats. The results of this study are expected to provide new targets and intervention strategies for the prevention and treatment of diabetic cardiomyopathy.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.153-170
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• 2022

Waterjet has been comprehensively used in urban areas owing to a suitable technique for cutting concrete and rock, and low noise and vibration. Recently, the abrasive waterjet technique has been adopted and applied by the Korea Atomic Energy Research Institute to demolish concrete plugging without disturbing and damaging In-situ Demonstration of Engineered Barrier System in the disposal research tunnel. In this study, the use of abrasive waterjet in the tunnel was evaluated for practical applicability and the existing cutting model was compared with the experimental results. As a variable for waterjet cutting, multi-cutting, water flow rate, abrasive flow rate, and standoff distance were selected for the diversity of analysis. As regarding the practical application, the waterjet facilitated path selection for cutting the concrete plugging and prevented additional disturbances in the periphery. The pump's noise at idling was 64.9 dB which is satisfied with the noise regulatory standard, but it exceeded the standard at ejection to air and target concrete because the experiment was performed in the tunnel space. The experimental result showed that the error between the predicted and measured cutting volume was 12~13% for the first cut and 16% for second cut. The standoff distance had a significant influence on the cutting depth and width, and the error tended to decrease with decrement of standoff distance.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.321-333
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• 2022

In this study, the concentration and distribution characteristics of BTEX (benzene toluene, ethylbenzene, and xylene) emitted from Daesan Petrochemical Industrial Complex were examined to determine their potential hazards to local residents. Residents living nearby the complex areas may be exposed to the chemicals through various media (air, water, and soil), especially by air. This study evaluated human health risks by inhalation using both deterministic and probabilistic risk assessment approaches. As a result of the deterministic risk assessment, the non-cancer risk was much lower than the regulation limit of hazard index (HI 1.0) for all the points. However, in case of cancer risk evaluation, it was found that the risk of excess cancer for benzene at point A located in the industrial complex was 2.28×10^-6, which slightly exceeded the standard regulatory limit of 1.0×10^-6. In addition, the probabilistic risk assessment revealed that the percentile exceeding the standard of 1.0×10^-6was found to be 45.3%. The sensitivity analysis showed that exposure time (ET) had the greatest impact on the results. Based on the risk assessment study, it implied that ethylbenzene, toluene, and xylene had little adverse effects on potential human exposure, but benzene often exceeded the cancer risk standard (1.0×10^-6). Further studies on extensive VOCs monitoring are needed to evaluate the potential risks of industrial complex areas.

• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.570-588
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• 2022

We scrutinized the acoustic outputs from the 70 shock wave generators of the 15 product models whose technical documents were available, among the 46 ballistic extracorporeal shock wave therapeutic devices of 11 domestic and 6 foreign manufacturers, approved by the Minster of Food & Drug Safety (Rep. Korea). We found that the acoustic Energy Flux Density (EFD), the most popular exposure parameter, was different by up to 563.64 times among shock wave generators at their minimum output settings and by up to 74.62 times at their maximum settings. In the same product model, the EFD was shown to vary depending on shock wave transmitters by up to 81.82 times at its minimum output setting and by up to 46.15 times at its maximum setting. The lowest EFD 0.013 mJ/mm² at the maximum output settings was much lower (2.1 %) than the maximum value 0.62 mJ/mm² at the minimum settings. The Large acoustic output differences (tens to hundreds of times)from the therapeutic devices approved for the same clinical indications imply that their therapeutic efficacy & safety may not be assured. The findings suggest the regulatory authority to revise her guideline to give clearer criteria for clinical approval and equality in performance, and recommend the authority to initiate a post-approval surveillance as well as a test in conformance between the data in technical documents and the real acoustic outputs clinically used.

• The Korean Journal of Pain
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• v.35 no.4
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• pp.423-432
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• 2022

Background: The decreased expression of mu-opioid receptors (MOR) in the amygdala may be a key molecular in chronic post-surgical pain (CPSP). It is known that miR-339-5p expression in the amygdala of a stressed rat model was increased. Analyzed by RNAhybrid, miR-339-5p could target opioid receptor mu 1 (oprm1) which codes MOR directly. So, the authors hypothesized that miR-339-5p could regulate the expression of MOR via targeting oprm1 and cause the effects to CPSP. Methods: To simulate perioperative short-term stress, a perioperative stress prolongs incision-induced pain hypersensitivity without changing basal pain perception rat model was built. A pmiR-RB-REPORT^TM dual luciferase assay was taken to verify whether miR-339-5p could act on oprm1 as a target. The serum glucocorticoid level of rats was test. Differential expressions of MOR, GFAP, and pERK1/2 in each group of the rats' amygdala were tested, and the expressions of miR-339-5p in each group of rats' amygdalas were also measured. Results: Perioperative stress prolonged the recovery time of incision pain. The expression of MOR was down-regulated in the amygdala of rats in stress + incision (S + IN) group significantly compared with other groups (P < 0.050). miR-339-5p was up-regulated in the amygdala of rats in group S + IN significantly compared with other groups (P < 0.050). miR-339-5p acts on oprm1 3'UTR and take MOR mRNA as a target. Conclusions: Perioperative stress could increase the expression of miR-339-5p, and miR-339-5p could cause the expression of MOR to decrease via targeting oprm1. This regulatory pathway maybe an important molecular mechanism of CPSP.

• Journal of Korean Elementary Science Education
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• v.41 no.1
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• pp.65-78
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• 2022

This study aims to 1) verify the validity of the Science self-efficacy scale and 2) perform a latent mean analysis of the background variables about a pre-service teacher. The study uses pre-tests to analyze data from 187 pre-service teachers, which uses Tark's Science self-efficacy scale (2011). To identify the factor structure, exploratory factor analysis was performed. Based on the results of the pilot test, the expert group council revised the scale for the pre-service teachers to respond to the 3-factor structure. In the main test, 354 data were analyzed through a modified Science self-efficacy scale, and exploratory and confirmatory factor analyses were performed. The results of the study are as follows: First, in the pilot test, the pre-service teacher responded to a 3-factor instrument, but the validity of two items was examined further below. Second, the pre-service teachers responded to a 3-factor instrument on 29 items for the modified Science self-efficacy scale. The total reliability of the instrument was .886 and the reliability of each factor was analyzed as .882-.886. Finally, the latent mean analysis by gender showed that females have a higher self-regulation efficacy factor and males have a higher self-confidence factor (Cohen's d > .3). Furthermore, there is a significant difference in task difficulty preference and self-regulatory efficacy factor (Cohen's d > .8) between the college preparatory and science subject preference. This study provides important insights into and contributions to the accurate scientific self-efficacy diagnosis of pre-service teachers, as well as proposes a curriculum to improve the scientific self-efficacy of prospective teachers.

• Animal Bioscience
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• v.35 no.5
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• pp.763-777
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• 2022

Objective: Excessive lipid accumulation in adipocytes results in prevalence of obesity and metabolic syndrome. Curcumin (CUR), a naturally phenolic active ingredient, has been shown to have lipid-lowering effects. However, its underlying mechanisms have remained largely unknown. Therefore, the study aims to determine the effect of CUR on cellular lipid accumulation in porcine subcutaneous preadipocytes (PSPA) and to clarify novel mechanisms. Methods: The PSPA were cultured and treated with or without CUR. Both cell counting Kit-8 and lactate dehydrogenase release assays were used to examine cytotoxicity. Intracellular lipid contents were measured by oil-red-o staining extraction and triglyceride quantification. Apoptosis was determined by flow cytometry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling assay. Adipogenic and apoptosis genes were analyzed by quantitative polymerase chain reaction and Western blot. Results: The CUR dose-dependently reduced the proliferation and lipid accumulation of PSPA. Noncytotoxic doses of CUR (10 to 20 μM) significantly inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and expression of adipogenic genes peroxisome proliferation-activity receptor-γ (PPAR-γ), CCAAT/enhancer binding protein-α, sterol regulatory element-binding protein-1c, adipocyte protein-2, glucose transporter-4 as well as key lipogenic enzymes fatty acid synthase and acetyl-CoA carboxylase, while ERK1/2 activation significantly reversed CUR-reduced lipid accumulation by increasing PPAR-γ. Furthermore, compared with differentiation induced media treated cells, higher dose of CUR (30 μM) significantly decreased the expression of AKT and B-cell lymphoma-2 (BCL-2), while increased the expression of BCL-2-associated X (BAX) and the BAX/BCL-2 expression ratio, suggesting triggered apoptosis by inactivating AKT and increasing BAX/BCL-2 ratio and Caspase-3 expression. Moreover, AKT activation significantly rescued CUR inhibiting lipid accumulation via repressing apoptosis. Conclusion: These results demonstrate that CUR is capable of suppressing differentiation by inhibiting ERK1/2-PPAR-γ signaling pathway and triggering apoptosis via decreasing AKT and subsequently increasing BAX/BCL-2 ratio and Caspase-3, suggesting that CUR provides an important method for the reduction of porcine body fat, as well as the prevention and treatment of human obesity.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.27-38
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• 2022

In developed countries, the number of accidents has significantly decreased with the introduction of the process safety management system, but it has a regulatory nature and it is difficult to show the actual situation of workplace safety management. Many organizations recommend the use of process safety performance indicators to comprehensively monitor process safety status. In this study, for the application of process safety performance indicators, the related guidelines were compared and analyzed, and the method of using the process safety system of the workplace as an indicator was reviewed. In literature indicators, compliance with procedures is mainly checked, whereas in system-based indicators, procedures or inspections for a specific purpose of the safety system can be clearly identified, and the operation status can be measured and monitored. It can be seen that this characteristic is more advantageous in terms of the clarity of the supplements derived in operating safety management activities. Using this, it is possible to effectively show the level of safety management in the workplace.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.331-342
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• 2022

Obesity is one of the metabolic diseases caused by excessive differentiation and accumulation of adipose tissue due to an imbalance between energy intake and consumption. In this study, we investigated the anti-obesity effect of SliMax, a natural-derived 6 compounds mixture, by using 3T3-L1 cells. As a result, SliMax showed the inhibitory effect on adipocyte differentiation through down-regulation of the PPARγ and C/EBPα expression, which are known to regulate the late adipogenesis stage. In the process of lipolysis on differentiated 3T3-L1 cells, SliMax accelerated decomposition of large-sized unilocular lipid droplet into numerous small-sized multilocular lipid droplets through up-regulation of the expression of lipolysis-related proteins ATGL and HSL. Finally, in order to confirm the effect of SliMax on induction of brown adipocyte, the expression of UCP-1 and the amount of mitochondria were confirmed by immunofluorescent staining, and as a result, SliMax increased the expression of UCP-1 and the amount of mitochondria in fat cells. Taken together, those results suggest that SliMax, a naturally-derived mixture, have a potential to be anti-obesity agent through exerting inhibitory effect on the formation of lipid droplet by suppression of adipogenesis and stimulation of lipolysis, and browning effect associated with generation of heat energy and energy consumption.

• Informatization Policy
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• v.29 no.4
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• pp.26-42
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• 2022

In order to evaluate the usefulness of metaverse learning from the learner's point of view, this study 1) evaluated whether the expectancy-value of the class was satisfied before and after the learner used the metaverse learning platform and 2) verified factors affecting metaverse learning satisfaction with regard to the self-efficacy and expectancy-value of learners. Expectancy-value was evaluated by the learning effect, communication, class involvement, and learning attitude, whereas self-efficacy was evaluated by preference for task difficulty, self-regulation efficacy, and self-confidence. As a result of a study targeting 70 college students who applied for a few courses using the metaverse platform at a university in the northeastern part of Seoul, learners were found to have high expectations and values for learning before using the metaverse platform, but both were not statistically satisfied after use. In addition, the higher the self-efficacy of the learner, the higher the satisfaction with the metaverse learning, and statistically significant results were found in the task-difficulty preference and self-regulatory efficacy among the sub-factors of self-efficacy. There is a negative causal relationship between expectancy-value factors and satisfaction with metaverse learning. This study implies that it is a learner-centered evaluation of metaverse learning, revealing the expectancy-value effect and factors influencing the satisfaction with metaverse learning.