• Biomolecules & Therapeutics
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• v.31 no.5
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• pp.573-582
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• 2023

Muscle atrophy is characterized by the loss of muscle function. Many efforts are being made to prevent muscle atrophy, and exercise is an important alternative. Methylglyoxal is a well-known causative agent of metabolic diseases and diabetic complications. This study aimed to evaluate whether methylglyoxal induces muscle atrophy and to evaluate the ameliorative effect of moderate-intensity aerobic exercise in a methylglyoxal-induced muscle atrophy animal model. Each mouse was randomly divided into three groups: control, methylglyoxal-treated, and methylglyoxal-treated within aerobic exercise. In the exercise group, each mouse was trained on a treadmill for 2 weeks. On the last day, all groups were evaluated for several atrophic behaviors and skeletal muscles, including the soleus, plantaris, gastrocnemius, and extensor digitorum longus were analyzed. In the exercise group, muscle mass was restored, causing in attenuation of muscle atrophy. The gastrocnemius and extensor digitorum longus muscles showed improved fiber cross-sectional area and reduced myofibrils. Further, they produced regulated atrophy-related proteins (i.e., muscle atrophy F-box, muscle RING-finger protein-1, and myosin heavy chain), indicating that aerobic exercise stimulated their muscle sensitivity to reverse skeletal muscle atrophy. In conclusion, shortness of the gastrocnemius caused by methylglyoxal may induce the dynamic imbalance of skeletal muscle atrophy, thus methylglyoxal may be a key target for treating skeletal muscle atrophy. To this end, aerobic exercise may be a powerful tool for regulating methylglyoxal-induced skeletal muscle atrophy.

• Journal of Korean Association for Spatial Structures
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• v.23 no.3
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• pp.87-94
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• 2023

Chloride is one of the most common threats to reinforced concrete (RC) durability. Alkaline environment of concrete makes a passive layer on the surface of reinforcement bars that prevents the bar from corrosion. However, when the chloride concentration amount at the reinforcement bar reaches a certain level, deterioration of the passive protection layer occurs, causing corrosion and ultimately reducing the structure's safety and durability. Therefore, understanding the chloride diffusion and its prediction are important to evaluate the safety and durability of RC structure. In this study, the chloride diffusion coefficient is predicted by machine learning techniques. Various machine learning techniques such as multiple linear regression, decision tree, random forest, support vector machine, artificial neural networks, extreme gradient boosting annd k-nearest neighbor were used and accuracy of there models were compared. In order to evaluate the accuracy, root mean square error (RMSE), mean square error (MSE), mean absolute error (MAE) and coefficient of determination (R2) were used as prediction performance indices. The k-fold cross-validation procedure was used to estimate the performance of machine learning models when making predictions on data not used during training. Grid search was applied to hyperparameter optimization. It has been shown from numerical simulation that ensemble learning methods such as random forest and extreme gradient boosting successfully predicted the chloride diffusion coefficient and artificial neural networks also provided accurate result.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.221-221
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• 2020

Curcumin, a hydrophobic polyphenol derived from turmeric, has been used a food additive and as a herbal medicine for the treatment of various diseases. In the present study, we found the functional role of a nanosphere loaded with curcumin (CN) in the promotion of the motility of human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) during the wound closure. We found that the efficacy of hUCB-MSCs migration induced by CN was 1000-fold higher than that of curcumin powder. CN significantly increased the motility of hUCB-MSCs by activating c-Src, which is responsible for the phosphorylation of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK). CN induced the expression levels of α-actinin-1, profilin-1 and filamentous-actin, as regulated by the phosphorylation of nuclear factor-kappa B during its promotion of cell migration. In a mouse skin excisional wound model, we found that transplantation of UCB-MSCs pre-treated with CN enhances wound closure, granulation, and re-epithelialization at mouse skin wound sites. These results indicate that CN is a functional agent that promotes the mobilization of UCB-MSCs for cutaneous wound repair.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.92-92
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• 2022

Under the COVID-19 pandemic, interest in immune enhancement is increasing. Although the immune-enhancing activity of plants of the genus Hibiscus has been reported, there is no study on the immune-enhancing activity of H. syriacus. Thus, in this study, we investigated the immune-enhancing activity of Hibiscus syriacus leaves (HSL) in mouse macrophages, RAW264.7 cells, and immunosuppressed mice. HSL increased the production of immunostimulatory factors such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) and activated the phagocytosis in RAW264.7 cells. The HSL-mediated production of immunostimulatory factors was dependent on toll-like receptor 4 (TLR4), p38, and c-Jun N-terminal kinase (JNK) in RAW264.7 cells. In the immunosuppressed mouse model, HSL increased the spleen index, the levels of the cytokines, and the numbers of lymphocytes, neutrophils, and monocytes. Taken together, HSL may be considered to have immune-enhancing activity and be expected to be used as a potential immune-enhancing agent.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.1001-1020
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• 2023

As massive increase in remote work since COVID-19, the boundaries between the inside and outside of corporate networks have become blurred. As a result, traditional perimeter security has stagnated business productivity and made it difficult to manage risks such as information leakage. The zero trust architecture model has emerged, but it is difficult to apply to IT environments composed of various companies. Therefore, using the remote work system configuration as an example, we presented a configuration and methodology that can apply zero trust models even in various network environments such as on-premise, cloud, and network separation. Through this, we aim to contribute to the creation of a safe and convenient cyber environment by providing guidance to companies that want to apply zero trust architecture, an intelligent system that actively responds to cyber threats.

• Smart Media Journal
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• v.12 no.9
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• pp.124-133
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• 2023

Currently, Korea shares culture, economy, and society together as a member of the international community along with rapid economic growth. In particular, in the 2000s, the construction of local cultural performance halls has been promoted through efforts and methods for the development of local culture. As a result, many local governments built medium-sized or larger performance halls, and achieved both quantitative and qualitative effects by satisfying citizens and attracting visitors. However, this study aims to analyze the safety of the space used by many visitors at the same time and whether an effective evacuation plan is applied to frequent disasters and disaster situations in recent years.

• Journal of the Korean Society of Food Culture
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• v.39 no.1
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• pp.74-81
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• 2024

Ulcerative colitis (UC) is a chronic inflammatory intestinal disease characterized by an imbalance in immune function and the overexpression of inflammatory cytokines and mediators. Vitamin B2, also known as riboflavin (Libof), is an essential water-soluble vitamin with numerous beneficial properties, including antioxidant, anti-aging, anti-inflammatory, anti-nociceptive, and anti-cancer effects. In this study, we aimed to investigate the protective effects of Libof on dextran sulfate sodium (DSS)-induced experimental colitis. The C57BL/6 mice were used as the in vivo model of chronic colitis to investigate the anti-inflammatory effects of Libof. RAW 264.7 cells were used for the in vitro investigation of the molecular mechanisms underlying these effects. In vivo, Libof alleviated the DSS-induced disease activity index (DAI), colon length shortening, and colonic pathological damage. In vitro, Libof inhibited lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 production in RAW 264.7 cells. Moreover, Libof inhibited LPS-induced nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells. In conclusion, these findings indicate that Libof shows potential as an agent for the treatment of UC.

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.3
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• pp.131-139
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• 2024

Crew Transfer Vessels (CTVs) are primarily used for the maintenance of offshore wind farms. Despite being manually operated by professional captains and crew, collisions with other ships and marine structures still occur. To prevent this, the introduction of autonomous navigation systems to CTVs is necessary. In this study, research on the obstacle avoidance system of the autonomous navigation system for CTVs was conducted. In particular, research on obstacle avoidance simulation for CTVs using deep reinforcement learning was carried out, taking into account the currents and wind loads in offshore wind farms. For this purpose, 3 degrees of freedom ship maneuvering modeling for CTVs considering the currents and wind loads in offshore wind farms was performed, and a simulation environment for offshore wind farms was implemented to train and test the deep reinforcement learning agent. Specifically, this study conducted research on obstacle avoidance maneuvers using MATD3 within deep reinforcement learning, and as a result, it was confirmed that the model, which underwent training over 10,000 episodes, could successfully avoid both static and moving obstacles. This confirms the conclusion that the application of the methods proposed in this study can successfully facilitate obstacle avoidance for autonomous navigation CTVs within offshore wind farms.

• Journal of Web Engineering
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• v.14 no.10
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• pp.2164-2174
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• 2022

Obesity treatment efficiency can be increased by targeting both central and peripheral pathways. In a previous study, we identified two natural compounds (hispidulin and p-synephrine) that affect adipocyte differentiation. We tested whether obesity treatment efficiency may be improved by adding an appetite-controlling agent to the treatment in the present study. Alkaloids, such as p-octopamine, are adrenergic agonists and are thus used as dietary supplements to achieve weight loss. Here, we assessed anti-obesity effects of a mixture of p-synephrine, p-octopamine HCl, and hispidulin (SOH) on murine preadipocyte cells and on mice receiving a high-fat diet (HFD). SOH showed stronger inhibition of the formation of red-stained lipid droplets than co-treatment with hispidulin and p-synephrine. Moreover, SOH reduced the expression of adipogenic marker proteins, including CCAAT/enhancer-binding protein alpha, CCAAT/enhancer-binding protein beta, and peroxisome proliferator-activated receptor gamma. In the HFD-induced obesity model, body weight and dietary intake were lower in mice treated with SOH than in the controls. Additionally, liver weight and the levels of alanine aminotransferase and total cholesterol were lower in SOH-treated mice than in the controls. In conclusion, our results suggest that consumption of SOH may be a potential alternative strategy to counteract obesity.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.399-404
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• 2000

The adjuvant effect of a muramyl dipeptide (MDP) derivative, MDP-Lys(L18), on enhancing of antitumor immunity induced by X-irradiated tumor cells against highly metastatic B16-BL6 melanoma cells was examined in mice. Mice immunized intradermally (i.d.) with a mixture of X-irradiated B16-BL6 cells and MDP-Lys (L18) [Vac+MDP-Lys (L18)] followed by an intravenous (i.v.)inoculation of $10^4$ viable tumor cells 7 days after immunization, showed a significant inhibition of experimental lung metastasis of B16-BL6 melanoma cells. The most effective immunization for the prophylactic inhibition of tumor metastasis was obtained from the mixture of $100{\;}\mu\textrm{g}$ of MDP-Lys (L18) and $10^4$ X-irradiatied tumor vaccine. Furthermore, immunization of mice with Vac+MDP-Lys(L18), 3 days after tumor challenge, resulted in a significant inhibition of lung metastasis of B16-BL6 melanoma cells in an experimental lung metastasis model. Similarly, the administration of Vac+MDP-Lys(L18), 1 or 7 days after tumor removal, markedly inhibited tumor metastasis of B16-BL6 in a spontaneous lung metastasis model. When Vac+MDP-Lys (L18) was i.d. administered 3 days after subcutaneous (s.c.) inoculation of tumor cells ($5{\times}10^5/site$) on the back, mice treated with Vac+MDP-Lys(L18) showed inhibition of significantly tumor growth on day 20. These results suggest that MDP-Lys (L18) is able to enhance antitumor activity induced by X-irradiated tumor vaccine to reduce lung metastasis of tumor cells, and is a potent immunomodulating agent which may be applied prophylactically as well as therapeutically to treatment of cancer metastasis.