• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.361-368
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• 2021

The objective of this study was to establish technology for removing bacteria with human- and eco-friendly material. Staphylococcus aureus as an important component for balanced equilibrium among microbiomes, was cultured under various concentrations of phosphate. Experimental observation relating to physical properties was performed in an addition of phosphate buffer. Statistically minimum value of size and hardness using atomic force microscope was observed on the matured biofilm at 5 mM concentration of phosphate. As a result of absorbance for the biofilm tagged with dye, concentration of biofilm was reduced with phophate, too. To identify whether this reduction by phosphate at the 5 mM is caused by counter ion or not, sodium chloride was treated to the biofilm under the same condition. To elucidate components of the biofilm counting analysis of the biofilm using time-of-flight secondary ion mass spectrometry was employed. The secondary ions from the biofilm revealed that alteration of physical properties is consistent to the change of extracellular polymeric substrate (EPS) for the biofilm. Viscoelastic characterization of the biofilm using a controlled shear stress rheometer, where internal change of physical properties could be detected, exhibited a static viscosity and a reduction of elastic modulus at the 5 mM concentration of phosphate. Accordingly, bacteria at the 5 mM concentration of phosphate are attributed to removing the EPS through a reduction of elastic modulus for bacteria. We suggest that the reduction of concentration of biofilm induces dispersion which assists to easily spread its dormitory. In conclusion, it is elucidated that an addition of phosphate causes removal of EPS, and that causes a function of antibiotic.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.310-316
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• 2022

In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77℃, and B. cereus was not detected after ≥60 s of hot water sterilization at 100℃. In dishcloths, E. coli was not detected after hot water sterilization at 77℃ for ≥30 s, but B. cereus was detected after hot water sterilization at 100℃ for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100℃ for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100℃ for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.

• 한국노년학
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• v.40 no.4
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• pp.707-727
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• 2020

This study aims to empirically analyze the role that perception of the probability of lonely death among the elderly people living alone plays in the relationship between perceived social support and preference for institutional care based on Andersen's expanded Behavioral Model (2002). The subjects (n=676) of this study were the elderly people living alone, extracted from the "2018 Seoul Aging Survey." With "perceived social support" as an independent variable, "preference for institutional care" as a dependent variable, and "perception of the probability of lonely death" as a mediator variable, we conducted a Binary Logistic Regression to follow the three steps of analyzing mediation effect, as suggested by Baron and Kenny (1986). The results showed that perceived social support has a negative effect on the preference for institutional care and perception of the probability of lonely death among the elderly people living alone; at the same time, perception of the probability of lonely death was found to have a positive effect on their preference for institutional care. Lastly, perception of the probability of lonely death was found to partially mediate the effect of perceived social support among the elderly people living alone in terms of their preference for institutional care. Based on these findings, the practical implications of this study can be summarized as follows. First, various programs and support should be provided to the elderly people living alone in order to enhance the level of perceived social support, a factor that has been confirmed to increase preference for institutional care among the elderly people living alone. Second, as the perception of the probability of lonely death was confirmed to be a psychosocial factor of the preference for institutional care, we need to promote education and support for older people living alone to prepare them for lonely death. These efforts are expected to form a foundations for implementing a community-based integrated care system, "Aging in Place," which is the policy direction required for older people care.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.127-144
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• 2021

The purpose of this study is to derive service factors based on the "Rail Statistical Yearbook" data of railroad service providers from 1990 to 2019, and to analyze the effect of the service factors on the operating profit ratio(OPR), a representative management performance variable of railroad transport service providers. In particular, it has academic significance in terms of empirical research to evaluate whether the management innovation of the KoRail has changed in line with the purpose of establishing the corporation by dividing the research period into the first period (1990-2003) and the latter (2004-2019). The contents of this study investigated previous studies on the quality of railway passenger transportation service and analyzed the contents of government presentation data related to the management performance evaluation of the KoRail. As an empirical analysis model, a research model was constructed using OPR as a dependent variable and service factor variables of infrastructure, economy, safety, connectivity, and business diversity as explanatory variables based on the operation and management activity information during the analysis period 30 years. On the results of research analysis, OPR is that the infrastructure factor is improved by structural reform or efficiency improvement. And economic factors are the fact that operating profit ratio improves by reducing costs. The safety factor did not reveal the significant explanatory power of the regression coefficient, but the sign of influence was the same as the prediction. Connectivity factor reveals a influence on differences between first period and latter, but OPR impact direction is changed from negative in before to positive in late. This is an evironment in which connectivity is actually realized in later period. On diversity factor, there is no effect of investment share in subsidiaries and government subsidies on OPR.

• Korean Journal of Plant Resources
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• v.35 no.5
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• pp.565-573
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• 2022

Gingival inflammation is one of the main causes that can be related to various periodontal diseases. Human gingival fibroblast (HGF) is the major constituent in periodontal connective tissue and secretes various inflammatory mediators, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂), upon lipopolysaccharide stimulation. This study is aimed at investigating the anti-inflammatory and antioxidative activities of Lotus Root extract (LRE) in Porphyromonas gingivalis derived lipopolysaccharide (LPS-PG)-stimulated HGF-1 cells. The concentration of NO and PGE₂, as well as their responsible enzymes, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), was analyzed by Griess reaction, ELISA, and western blot analysis. LPS-PG sharply elevated the production and protein expression of inflammatory mediators, which were significantly attenuated by LRE treatment in a dose-dependent manner. LRE treatment also suppressed activation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response gene 88 (MyD88) and nuclear factor-κB (NF-κB) in LPS-PG-stimulated HGF-1 cells. In addition, one of phase II enzyme, NAD(P)H quinone dehydrogenase (NQO)-1, and its transcription factor, Nuclear factor erythroid 2-related factor 2 (Nrf2), were significantly induced by LRE treatment. Consequently, these results suggest that LRE ameliorates LPS-PG-induced inflammatory responses by attenuating TLR4/MyD88-mediated NF-κB, and activating NQO-1/Nrf2 antioxidant response element signaling pathways in HGF-1 cells.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.237-249
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• 2020

This study analyzed the characteristic factors of musical actor that affect the audience's loyalty to the performance by inducing the audience's sensory presence which is the unique characteristic of the performing arts and analyzed the mediating effects of audience's sensory presence between the characteristics of musical actor and audience's loyalty to the performance. Actor's characteristics which are an independent variable were composed with the appearance of actor, acting skills, sing ability and actor's known degree. Audience's sensory presence which is mediating variable was divided into immersion and identification. Audience's loyalty to the performance which is a dependent variable was set as intention of recommendation and intention of revisit the performance. The result of analysis shows that identification have significant mediating effects in all independent variables except between actor's known degree and the audience loyalty to the performance. It shows immersion have also significant mediating effects among all independent variables and the audience loyalty to the performance. The multiple mediating effects of Immersion and Identification between Actor's characteristics and Loyalty to the performance have significant effects all parts. Especially, The result of this study shows that indirect effects that arrive to the loyalty through immersion or identification are larger than the direct effect that actor's characteristics affect to the loyalty to the performance. Actor's characteristics which affect Audience's loyalty to the performance by mediating Audience's sensory presence are shown in order of appearance of actor, acting skills, sing ability and actor's known degree. These results suggest key factors of musical actor's characteristics which lead loyalty to the performance by mediating Audience's sensory presence to musical producers and directors and actors.

• Journal of Life Science
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• v.31 no.12
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• pp.1110-1119
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• 2021

The purpose of this study was to investigate whether the inflammatory response in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages could be promoted by particulate matter 2.5 (PM_2.5) stimulation. To this end, the levels of inflammatory parameters, reactive oxygen species (ROS) and inflammation-regulating genes were investigated in RAW 264.7 cells treated with PM_2.5 in the presence or absence of LPS. Our results showed that the production levels of pro-inflammatory mediators (nitric oxide and prostaglandin E₂) and cytokines (interleukin-6 and -1β) were significantly increased by PM_2.5 stimulation in LPS-treated RAW 264.7 cells, which was correlated with increased expression genes involved in their production. In addition, when LPS-treated RAW 264.7 cells were exposed to PM_2.5, nuclear factor-kappaB (NF-κB) expression was further increased in the nucleus, and the expression of inhibitor of NF-κB as well as NF-κB in the cytoplasm was decreased. These results suggest that the co-treatment of PM_2.5 and LPS further increases the activation of the NF-κB signaling pathway compared to each treatment alone, thereby contributing to the promotion of transcriptional activity of inflammatory genes. Furthermore, although the generation of ROS was greatly increased by PM_2.5 in LPS-treated RAW 264.7 cells, the NF-κB inhibitor did not reduce the generation of ROS. In addition, when the generation of ROS was artificially suppressed, the production of inflammatory mediators and the activation of NF-κB were both abolished. Therefore, our results suggest that the increase in the NF-κB-mediated inflammatory response induced by PM_2.5 in LPS-treated RAW 264.7 macrophages was a ROS generation-dependent phenomenon.

• Journal of Life Science
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• v.31 no.11
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• pp.987-994
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• 2021

Our previous studies have reported that antimicrobial peptides (AMPs) derived from the larvae of white-spotted flower chafer (Protaetia brevitarsis seulensis) exert anti-inflammatory and neuroprotective activities. This study explored the anti-inflammatory effects of protaetiamycine 9 (CVLKKAYFLTNLKLRG-NH₂), a novel AMP, derived from P. b. seulensis against lipopolysaccharide (LPS)-mediated inflammatory response in RAW264.7 macrophage cells. Protaetiamycine 9 (25, 50, 75, and 100 ㎍/ml) did not cause cytotoxic effects against RAW264.7 cells. The RAW264.7 cells were pre-treated with various concentrations of protaetiamycine 9 (25-100 ㎍/ml) for 1 hr and then exposed to LPS (100 ng/ml) for 24 hr. Protaetiamycine 9 treatments decreased the LPS-induced secretion of inflammatory mediators, such as nitric oxide (NO), in a dose-dependent manner. Protaetiamycine 9 (25-100 ㎍/ml) effectively downregulated the LPS-induced increase in mRNA and the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), which are involved in the production of inflammatory mediators. Protaetiamycine 9 also suppressed the production and gene expression of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, compared to the presence of LPS alone. Furthermore, protaetiamycine 9 inhibited the degradation of inhibitory kappa B alpha (IκB-α) and the phosphorylation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. In conclusion, these results suggest that protaetiamycine 9 exhibits LPS-mediated inflammatory responses by blocking IκB-α degradation and MAPK phosphorylation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.365-372
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• 2022

Cellobiose is a dissacharide constituted by two glucose units joined by a β-('1,4') glycosidic bond that is produced by the decomposition of cellulose. This product exists naturally in plants and has been utilized in different industries as a food sweetener, and as a cosmetic and pharmaceutical material. In this study, the potential of cellobiose as a whitening cosmetic product was evaluated by analyzing autophagy induction and the inhibition of melanin production. A cytotoxicity test conducted in the human melanin-producing cell line MNT-1 with increasing concentrations of cellobiose revealed that this compound did not cause cytotoxicity at 20 mg/mL or less. Based on this, autophagy was firstly evaluated by immunostaining with the autophagy marker microtubule-associated protein 1 light chain 3 (LC3) after treatment with 20 mg/mL of cellobiose. The subsequent confocal microscopy analysis revealed an increase in LC3 puncta, indicating induction of autophagy. In addition, autophagy was further confirmed by western blot analysis, which demonstrated that cellobiose converted LC3-I to LC3- ∏ in a concentration- and time-dependent manners. An analysis of melanin contents after cellobiose treatment at a concentration of 20 mg/mL during 7 days revealed that melanin production was reduced by more than 50%. Additionally, the expression levels of melanogenesis-related proteins TYR and TYRP1 were markedly decreased after cellobiose treatment. Based on these studies, a cosmetic cream formulation containing cellobiose was prepared and the change in formulation was tested for 4 weeks, and it was confirmed that the appearance changed to liquid form at high temperature, but the pH did not change. In conclusion, the present research demonstrated that cellobiose activates autophagy and inhibits melanin production, and showed the potential of this product as a material for whitening cosmetics.

• Journal of Life Science
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• v.32 no.11
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• pp.865-871
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• 2022

Tenebrio molitor larvae is well known as edible insect. Then, although it has been widely studied that Tenebrio molitor larvae has various bioactive functions such as antioxidant, anti-wrinkle, and anticancer. Nevertheless, antioxidant effects of Tenebrio molitor larvae water extract (TMH) has not been well described in Adult Retina Pigment Epithelial cell line (ARPE-19). In this study, we demonstrated that antioxidant effects of TMH against H₂O₂-induced oxidative stress in ARPE-19. Thus, we selected for our studies and performed a series of dose-response assay to determine the working concentration that lead to a consistent and high degree of cytotoxicity, which we defined as the level of H₂O₂ that killed 40% of the ARPE-19 cells. ARPE-19 cells were pre-treated with various concentrations of TMH (0.1 up to 2 mg/ml) before exposure to 300 µM H₂O₂. As we expected, TMH effectively prevented ARPE-19 cells from 300 µM H₂O₂-induced cell death in a dose-dependent manner. Furthermore, TMH inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) such as extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. Overall, the inhibitory effects of TMH on H₂O₂-induced apoptosis and oxidative stress were associated with the protection cleaved caspase-3, Bax, Bcl-2, and HO-1. The TMH suppressed H₂O₂-induced cell membrane leakage and oxidative stress in ARPE-19 cells. Thus, these results suggest that the TMH plays an important role in antioxidant effect in ARPE-19.