• Journal of the Korean Geotechnical Society
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• v.38 no.4
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• pp.21-32
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• 2022

Steel pile foundations are widely used for offshore constructions due to their high bearing capacity and efficiency. Typically, offshore structures that have reached the end of their design life are required to be demolished. However, pile foundations are often left on site due to technical and economic limitations. The pile left on the site not only pollutes the environment, but can also cause obstacles for the construction of new structures. Therefore, research is required to completely eliminate these foundations at the site. In this study, a new type of double-wall pile foundation that can drastically reduce the pull-out load was conceptually proposed, and a series of model tests were performed to validate the performance of the double-wall pile foundation. The installation and extraction of the double-wall pile were simulated in dry sand in the model test, and the measured up-lift load was compared to that of the conventional pile. According to the result, the maximum up-lift load induced by the decommissioning of the double-wall pile was reduced by 45% when compared to the traditional pile in dense sand. This study verified the mechanism for reducing the up-lift load of the double-wall foundation and confirmed the possibility of completely decommissioning a pile that has reached the end of its nominal service life.

• BMB Reports
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• v.55 no.4
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• pp.198-203
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• 2022

As negative regulators of cytokine signaling pathways, suppressors of cytokine signaling (SOCS) proteins have been reported to possess both pro-tumor and anti-tumor functions. Our recent studies have demonstrated suppressive effects of SOCS1 on epithelial to mesenchymal signaling in colorectal cancer cells in response to fractionated ionizing radiation or oxidative stress. The objective of the present study was to determine the radiosensitizing action of SOCS1 as an anti-tumor mechanism in colorectal cancer cell model. In HCT116 cells exposed to ionizing radiation, SOCS1 over-expression shifted cell cycle arrest from G2/M to G1 and promoted radiation-induced apoptosis in a p53-dependent manner with down-regulation of cyclin B and up-regulation of p21. On the other hand, SOCS1 knock-down resulted in a reduced apoptosis with a decrease in G1 arrest. The regulatory action of SOCS1 on the radiation response was mediated by inhibition of radiation-induced Jak3/STAT3 and Erk activities, thereby blocking G1 to S transition. Radiation-induced early ROS signal was responsible for the activation of Jak3/Erk/STAT3 that led to cell survival response. Our data collectively indicate that SOCS1 can promote radiosensitivity of colorectal cancer cells by counteracting ROS-mediated survival signal, thereby blocking cell cycle progression from G1 to S. The resulting increase in G1 arrest with p53 activation then contributes to the promotion of apoptotic response upon radiation. Thus, induction of SOCS1 expression may increase therapeutic efficacy of radiation in tumors with low SOCS1 levels.

• Journal of Ginseng Research
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• v.46 no.4
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• pp.561-571
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• 2022

Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through its action on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liver steatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulin resistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectin expression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO) mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as well as insulin sensitivity was measured. The activation of AMPK was also detected in the liver and hepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium (CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partly attenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TG content, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulin sensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatment significantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise, the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosis and insulin resistance, which further elucidates a new mechanism underlying the beneficial effects of GRb1 on obesity.

• Journal of Ginseng Research
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• v.46 no.4
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• pp.515-525
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• 2022

Background: The incidence of ischemic cerebrovascular disease is increasing in recent years and has been one of the leading causes of neurological dysfunction and death. Ginsenoside Rg1 has been found to protect against neuronal damage in many neurodegenerative diseases. However, the effect and mechanism by which Rg1 protects against cerebral ischemia-reperfusion injury (CIRI) are not fully understood. Here, we report the neuroprotective effects of Rg1 treatment on CIRI and its possible mechanisms in mice. Methods: A bilateral common carotid artery ligation was used to establish a chronic CIRI model in mice. HT22 cells were treated with Rg1 after OGD/R to study its effect on [Ca²⁺]_i. The open-field test and poleclimbing experiment were used to detect behavioral injury. The laser speckle blood flowmeter was used to measure brain blood flow. The Nissl and H&E staining were used to examine the neuronal damage. The Western blotting was used to examine MAP2, PSD95, Tau, p-Tau, NOX2, PLC, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging was used to test the level of [Ca²⁺]_i. Results: Rg1 treatment significantly improved cerebral blood flow, locomotion, and limb coordination, reduced ROS production, increased MAP2 and PSD95 expression, and decreased p-Tau, NOX2, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging results showed that Rg1 could inhibit calcium overload and resist the imbalance of calcium homeostasis after OGD/R in HT22 cells. Conclusion: Rg1 plays a neuroprotective role in attenuating CIRI by inhibiting oxidative stress, calcium overload, and neuroinflammation.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.243-254
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• 2021

This study analyzed the abuse of authority among the types of power abuse in educational institutions in order to create an educational climate in which democracy and equality are respected and to create a better education and an equal society. First, we analyzed the concept and cause of power abuse through literature research, and then explored the cases of members of educational institutions according to the type of abuse of authority through qualitative research to derive implications. As a result, abuse of authority within educational institutions were found as follows: additional work without consultation, transfer of duties, coercive and unilateral instructions using status, instructions violating laws and guidelines, private instructions for personal convenience, specific institutions, personal rights, and privacy. Based on this analysis, a policy was proposed. First, an agreed standard for abuse of authority, an institutional mechanism to mediate conflicts and complaints over abuse of authority, mandatory installation and legislation of the best decision body, active and transparent disclosure of information, and a shift to open and listening administration are needed. Second, analyzing and seeking ways to reduce overuse of authority in educational institutions will be the cornerstone for leading education's democracy and equality by creating a culture of mutual respect and communication among members of the organization. Hope that follow-up studies will be carried out and that the Gap-jil in educational institutions will be reduced to create a better educational environment.

• Nutrition Research and Practice
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• v.16 no.1
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• pp.33-45
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• 2022

BACKGROUND/OBJECTIVES: Ginseng extract (GSE) and taurine (TR) are widely used antifatigue resources in functional foods. However, the mechanism underlying the antifatigue effects of GSE and TR are still unclear. Hence, we investigated whether GSE and TR have synergistic effects against fatigue in mice. MATERIALS/METHODS: L6 cells were treated with different concentrations of TR and GSE, and cell viability was determined using 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium. Oxidative stress was analyzed by immunocytochemistry using MitoTracker^TM Red FM and an anti-8-oxoguanine antibody. Respiratory gas analysis was performed to investigate metabolism. Expression of an activated protein kinase was analyzed using immunohistochemistry. Gene expression of cluster of differentiation 36 and pyruvate dehydrogenase lipoamide kinase isozyme 4 was measured using reverse transcription-polymerase chain reaction. Mice were orally administered TR, GSE, or their combination for 30 days, and then fatigue-related parameters, including lactate, blood urea nitrogen, and glycogen, were measured after forced swimming. RESULTS: TR and GSE reduced oxidative stress levels in hydrogen peroxide-stimulated L6 cells and enhanced the oxygen uptake and lipid metabolism in mice after acute exercise. After oral administration of TR or GSE for 30 days, the fatigue-related parameters did not change in mice. However, the mice administered GSE (400 mg/kg/day) alone for 30 days could swim longer than those from the other groups. Further, no synergistic effect was observed after the swimming exercise in mice treated with the TR and GSE combination for 30 days. CONCLUSIONS: Taken together, our data suggest that TR and GSE may exert antifatigue effects in mice after acute exercise by enhancing oxygen uptake and lipid oxidation.

• Journal of Life Science
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• v.32 no.1
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• pp.63-69
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• 2022

The thioredoxin reductase (TrxR) system is essential for cell survival and function by playing a pivotal role in maintaining homeostasis of cellular redox and regulating signal transduction pathways. The TrxR system comprises thioredoxin (Trx), TrxR, and nicotinamide adenine dinucleotide phosphate. Trx reduced by the catalytic reaction of the TrxR enzyme reduces downstream proteins, resulting in protection against oxidative stress and regulation of cell differentiation, growth, and death. Cancer cells survive by improving their intracellular antioxidant capacity to eliminate excessively generated reactive oxygen species (ROS) due to infinite cell proliferation and a high metabolic rate. Therefore, cancer cells have high dependence and sensitivity to antioxidant systems, suggesting that focusing on TrxR, a representative antioxidant system, is a potential strategy for cancer therapy. Several studies have revealed that TrxR is expressed at high levels in various types of cancers, and research on anticancer activity targeting the TrxR system is increasing. In this review, we discuss the feasibility and value of the TrxR system as a strategy for anticancer activity research by examining the relationship between the function of the intracellular TrxR system and the development and progression of cancer, considering the anticancer activity and mechanism of TrxR inhibitors.

• Nutrition Research and Practice
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• v.16 no.6
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• pp.729-744
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• 2022

BACKGROUND/OBJECTIVES: 4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of ⳑ-methionine in rats. MATERIALS/METHODS: Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of ⳑ-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated. RESULTS: Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed ⳑ-methionine, which were attributed to the stimulation of GST by ⳑ-methionine. With decreasing HNE levels, ⳑ-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by ⳑ-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by ⳑ-methionine. The anti-inflammatory action of ⳑ-methionine was also reflected by the up-regulation of IL-10. CONCLUSIONS: This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to ⳑ-methionine availability. The anti-inflammatory mechanism exerted by ⳑ-methionine was to inhibit NF-κB activation and to up-regulate GST.

• The Korea Journal of Herbology
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• v.28 no.1
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• pp.23-31
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• 2013

Objectives : The purpose of this study was to determine the anti-obesity effect and molecular mechanism of YY312, a herbal extract composed of Imperatae Rhizoma, Citri Unshius Pericarpium Immaturus, and Evodiae Fructus, on a high-fat diet-induced animal model and on 3T3-L1 cells. Methods : C57BL/6 mice were fed for 6 weeks with a normal diet or a high-fat diet (HFD). Then they orally administered daily with 300 mg/kg YY312 for next 10 weeks. Body weight and food consumption were recorded weekly and daily, respectively. Tissue weights, serum lipid, and glucose levels were analyzed at the end of the study. Additionally, the effects of YY312 on adipocyte differentiation in 3T3-L1 cells were examined. After differentiating 3T3-L1 cells were treated with YY312, Oil-red O staining, RT-PCR, and Western blotting were performed for lipid accumulation, mRNA expression of adipogenesis gene, and AMP-activated protein kinase (AMPK) phosphorylation, respectively. Results : YY312-administered mice showed a significant reduction of body weights and abdominal adipose tissue weights. YY312 also reduced the serum levels of triglycerides and total cholesterol, compared with the HFD group. Treatment with YY312 inhibited lipid accumulation and blocked expression of adipogenic transcription factors and lipogenesis genes, including peroxisome proliferator-activated receptor ${\gamma}$, CCAT/enhancer binding protein ${\alpha}$ and fatty acid synthase. YY312 increased AMPK phosphorylation in 3T3-L1 adipocytes. Conclusions : This study showed that herbal extract YY312 has an anti-obesity effect in vitro and in vivo. Thus, YY312 could be developed as a supplement for reduction of body weight gain induced by an HFD.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.71-78
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• 2018

Objectives : This study was fulfilled to investigate nominee materials as anti-inflammatory agent from ethanol extract of Chinese medicinal plants in Yanjin. Among the 20 candidates, we selected most effective one, the ethanol extract of Cicuta virosa L. (CVL). The mechanism underlying the anti-inflammatory effects of CVL is not clearly identified as yet. Accordingly, we clarified the anti-inflammatory effects of CVL and its underlying molecular mechanisms in LPS-stimulated RAW 264.7 macrophages. Methods : RAW264.7 macrophages were incubated with CVL (12.5, 25, or $50{\mu}M$) and/or lipopolysaccharide (LPS) ($1{\mu}g/m{\ell}$). Cytotoxicity was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and the level of nitric oxide (NO) production was measured with Griess reagent. The prostaglandin $E_2$ ($PGE_2$) production was measured with enzyme immunoassay kits and the protein expression of inducible nitric oxide synthase (iNOS) was determined using Western blot analysis. Results : Among the 20 ethanol extract of Chinese medicinal plants of Yanjin tested, CVL significantly reduced the production of NO in a dose-dependent manner via inhibition the protein expressions of iNOS without cytotoxicity on the LPS-stimulated RAW 264.7 macrophages. In addition, CVL also effectively declined the production of $PGE_2$ in LPS-simulated RAW 264.7 macrophages. Conclusions : Taken together, these data presented in this study demonstrate that CVL possesses anti-inflammatory activity by suppressing the production of pro-inflammatory mediators NO and $PGE_2$, and pro-inflammatory protein iNOS expression in LPS-stimulated RAW 264.7 macrophages.