• Journal of Life Science
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• v.29 no.8
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• pp.895-903
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• 2019

The aim of the present study was to improve the cell viability of human dental papilla derived single-induced pluripotent stem cells (iPSCs) using a Rho-associated protein kinase (ROCK) inhibitor, Y-27632. The iPSCs were produced using an episomal plasmid-based reprogramming method. After cell separation using trypsin, the iPSCs were treated with 0, 0.5, 1, 2.5, 5, 7.5, or $10{\mu}M$ Y-27632 for 5 d. Cell viability increased significantly following the $5{\mu}M$ Y-27632 treatment (p<0.05). When the iPSCs were exposed to medium containing $10{\mu}M$ Y-27632 for 0, 1, 2, 3, 4, and 5 d, the cell viability rate increased significantly in accordance with the cell viability rate (p<0.05). To evaluate the effect of the Y-27632 treatment on stemness characteristics, the expression of stem cell-specific transcripts and telomerase activity were investigated in the iPSCs treated with $10{\mu}M$ Y-27632 for 5 d. The expression levels of stem cell-specific transcripts, such as OCT-4, NONOG, and SOX-2, and telomerase activity were not significantly different in the iPSCs treated with $10{\mu}M$ Y-27632 as compared with those of untreated control iPSCs (p>0.05). Taken together, the results demonstrated that cell viability can be improved by treatment with the ROCK inhibitor Y-27632, without losing iPSC stemness characteristics.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.23-33
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• 2019

After making tea by steaming the Burdock(Arctium lappa) nine times and drying it nine times, the ingredients and functions of the Burdock tea were compared to those of M company. The tea's calories were 346.48kcal/100g, carbohydrates were 72.75g/100g, crude protein was 11.98g/100g, and crude ash was 5.01g/100g. The total of free sugars were 31.93mg/100, among them, fructose was 26.27, sucrose was 1.27 mg/100g. The inorganic material contents were 1,476.21mg/100g of potassium, 255.96 mg/100g of calcium and 311.41 mg/100g of magnesium. The saturated fatty acids were 40.73mg/100g and the unsaturated fatty acids were 59.27mg/100g, among which the linoleic acid was 41.28mg/100g, the palmitic acid was 33.11mg/100g, the oleic acid was 10.07mg/100g and linolenic acid was 7.92mg/100g. DPPH radical scavenging was 33.9% of teas that were developed, 2.3% of M's tea for comparison, and 37.2% of indiex material. ABTS radical scavenging were 90.7% of teas developed, 85.9% of M's tea and 37.2% of index materials, and SOD like activities were 11.3% of teas developed and 50.5% of M's teas. The flavonoid content was 2.6 fold of the tea developed, 2.9 fold of M's tea and 1.7 fold of index material. The polyphenol content was 33.8 fold of teas developed, 38.9 fold of the M's tea and 13.8 fold of the index material. The sensory evaluation compare to the one-time extract and the five-time extract. Based on the one-time extract, the color were 65.9 % of the five-time extract tea were developed, 12.8 % of the M's tea. Flavour were 78.0% of the tea developed and 33.3% of the M's tea, tastes were 71.4% of the tea developed, 20.7% of the M's tea. The cart for comparison showed that while the extract decreased as we developed it, the overall symbolism decreased to 21.4% after five time extracts, the developed tea decreased to 72.1%. We believe that the developed tea will have a greater effect on preventing and improving diseases as it has a stronger antioxidant function, more effective substances, and a higher level of symbolism than the comparative M squared tea and surface substance.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.95-101
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• 2019

Purpose: The aim of this study is to evaluate the effects of various primers on the microtensile bond strength (${\mu}TBS$) of resin cements to cobalt-chromium (Co-Cr) dental casting alloy. Materials and methods: Four adhesive primers (Universal primer, Metal primer II, Alloy primer, and Metal/Zirconia primer) and two resin cements (Panavia F2.0, G-CEM LinkAce) were tested. One hundred fifty Co-Cr beams were prepared from Co-Cr ingots via casting ($6mm\;ength{\times}1mm\;width{\times}1mm\;thick$). The metal beams were randomly divided into ten groups according to the adhesive primers and resin cements used; the no-primer groups served as the control (n = 15). After sandblasting with aluminum oxide ($125{\mu}m$ grain), the metal and resin cements were bonded together using a silicone mold. Prior to testing, all metal-resin beams were examined under stereomicroscope, and subjected to the ${\mu}TBS$ test. The mean value of each group was analyzed via one-way ANOVA with Tukey's test as post hoc (${\alpha}=.05$) using SPSS software. Results: The mean ${\mu}TBS$ of all groups was ranged from 20 to 28 MPa. There is no statistically significant difference between groups (P > .05). Mixed failure, which is the combination of adhesive and cohesive failures, is the most prevalent failure mode in both the Panavia F2.0 and G-Cem LinkAce groups. Conclusion: The ${\mu}TBS$ of all tested groups are relatively high; however, the primers used in this study result in no favorable effect in the ${\mu}TBS$ of Panavia F2.0 and G-Cem LinkAce resin cement to Co-Cr alloy.

• Journal of Life Science
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• v.29 no.1
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• pp.18-28
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• 2019

Recent studies reported that obesity upregulated the expression of neuronal nitric oxide synthase (nNOS) and regulated particular behavior patterns in animal models. They also reported that ameliorated the increase in nNOS expression and decreased depression and anxiolytic effects. Thus, exercise seems to be an effective strategy for improving brain function by downregulating nNOS. However, the immune response differs greatly, depending on the exercise intensity. The aim of the present study was to investigate differences in brain nNOS expression in obese C57BL/6 mice that performed exercise of different intensities. Obesity was induced in 6-wks-old mice (n=35) by feeding a 60%-fat diet for 6-wks. A control (CON) group (n=14) was fed a normal diet. At the end of the induction 6-wks period of obesity, seven animals in the CON group and obesity-induced group were sacrificed to confirm obesity induction (preliminary experiments and confirmation of visceral fat accumulation). The remaining animals were then used in an 8-wks exercise intervention. Other than the CON (n=7), the obesity-induced animals were divided into the following groups: high-fat diet (HFD, n=7), HFD-low intensity (HFD-LI, n=7, 12 m/min for 75 min), HFD-moderate intensity (HFD-MI, n=7, 15 m/min for 60 min), and HFD-high intensity (HFD-HI, n=7, 18 m/min for 50 min). The exercise was performed on an animal treadmill. The expression of the nNOS protein in the hippocampus was significantly higher in the HFD group as compared with that in the CON group (p<0.01). However, there was no difference in the hippocampal expression of the nNOS protein in the other exercise groups as compared with that in the CON group. In contrast, nNOS expression in the HFD-HI group was significantly lower than that in the HFD-LI group (p<0.05). The expression of phosphorylated Akt (pAkt) was significantly higher in all the exercise groups as compared with that in the CON and HFD groups. There was no difference in the expression of pAkt in the cerebral cortex among groups, and the expression of pAkt in the cerebellum was significantly higher in the HFD-HI group as compared with that in the CON group (p<0.05). There were also no between-group differences in pAkt expression in the cerebellum among the various exercise groups. In conclusion, nNOS seems to be overexpressed in response to obesity, and it appears to be downregulated by exercise. Relatively high-intensity exercise may be effective in improving brain function by downregulating nNOS.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.204-212
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• 2019

The optimal application rate of a controlled release fertilizer (CRF) on the growth, yield, and seeding time of rice grown on seedling trays was investigated. The experimental field was located at $37^{\circ}22^{\prime}10^{{\prime}{\prime}}N$ latitude and $127^{\circ}03^{\prime}85^{{\prime}{\prime}}E$ longitude in Hwaseong, Gyeonggi-do, Republic of Korea. The soil in the paddy field was a clay loam. The CRF used in the experiment contained $300g\;kg^{-1}$ of nitrogen, $60g\;kg^{-1}$ of phosphate, and $60g\;kg^{-1}$ of potassium, respectively. The CRF was applied at the rate of 0, 200, 300, 400, 500, and 600 grams on rice seedling tray compared with the field application based on soil testing (control), respectively. The CRF can be applied as single application(which can replace basal fertilizer application and two top dressing application) directly to the seedling tray, and showed the minimum release at the seedling period. Considering the plant growth, nitrogen use efficency and yield of rice, the optimal application rate of developed CRF was 500 g per seedling tray and the yield of rice at this application rate was $4.92{\sim}5.04Mg\;ha^{-1}$. The regression formula between the rice yield and application rates of CRF was as follows ; "$Y=0.0002{\chi}^2+0.0963{\chi}+411.6$($R^2$ : 0.9922) in 2010 and $Y=8E-6{\chi}^2+0.2723{\chi}+344.04$($R^2$:0.9864) in 2011, Y : Rice yield ($Mg\;ha^{-1}$), ${\chi}$ : Application rate (grams) of controlled release fertilizer". The optimum application rates of CRF per rice seedling tray by regression formula was 498 grams in 2010 and 513 grams in 2011.

• Journal of Life Science
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• v.31 no.3
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• pp.330-337
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• 2021

This study was conducted to investigate the potential of Stewartia koreana as oral healthcare materials. The antibacterial activity of ethanol extracts from leaves and branches of S. koreana against oral bacteria was confirmed. The leaf and branch extracts (1 mg/disc) showed antibacterial activity against P. gingivalis only among several tested oral bacteria. The leaf extracts showed higher antibacterial activity, with values similar to those of chlorhexidine, which was used as a positive control. The MIC of the leaf extract against P. gingivalis was 0.4 mg/ml and showed bacteriostatic action. The inhibitory effects of the extract on biofilm formation and on gene expression related to biofilm formation by P. gingivalis were determined by biofilm biomass staining, scanning electron microscopy (SEM), and qRT-PCR analysis. The biofilm production rate and cell growth of P. gingivalis in the cultures treated with 0.2-2.0 mg/ml of S. koreana leaf extracts were significantly decreased in a concentration-dependent manner. The inhibitory effect on the formation of P. gingivalis biofilms at concentrations of 1 mg/ml was confirmed by SEM. The qRT-PCR analysis showed concentration-dependent suppression of the fimA and fimB gene expression associated with fimbriae formation in the cultures treated with 0.2-2.0 mg/ml S. koreana leaf extract. These results support the conclusion that S. koreana leaf extracts can be used as oral healthcare materials derived from natural materials, as demonstrated by the antibacterial action and inhibition of biofilm formation of P. gingivalis.

• (The) Korean Journal of Educational Psychology
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• v.32 no.3
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• pp.571-596
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• 2018

Objectives: This study investigated the challenges of young cross-cultural individuals (CCIs) through the cultural homelessness (CH) framework. Methods: Through a survey of 151 CCIs, the study empirically examined the relationship between CH and psychological well-being (PWB), as well as the moderating role of emotional clarity (EC). Results: Results indicated that CH was significantly and negatively associated with PWB, especially on the Positive Relations with Others and Environmental Mastery dimensions. Individuals with high CH tended to have less satisfactory relationships and a reduced sense of control over daily life situations, regardless of their EC level. A significant interaction effect between CH and EC was found, specifically in Positive Relations with Others (PR) and Personal Growth (PG). For individuals with high CH, however, satisfactory relationships were dependent on their EC level; they reported more positive relationships with others when their EC levels were high. Interestingly, individuals with high CH were likely to report a high desire for personal growth regardless of their EC level, indicating that they may appear ambitious but may be experiencing unclear emotions. Conclusions: These findings suggest that CH and EC are issues that need to be dealt with simultaneously. As individuals' PWB depends not only on their CH level, but also on their EC, reducing the level of CH should not be the only goal in promoting the well-being of CCIs. Increasing individuals' EC would be just as important, as high EC, along with low CH, predicts important dimensions of PWB.

• Journal of Life Science
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• v.31 no.5
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• pp.475-480
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• 2021

Interest in edible insects such as Protaetia brevitarsis has increased rapidly, and several insect producers use these insects in industrialized mass production. However, mass rearing of insects can cause insect diseases. Sprouted barley is a valuable source of nutrients and has antioxidant, antimicrobial, anti-inflammatory, and anti-cancer effects. This study was conducted to investigate the effect of sprouted barley as a feed additive for producing healthy P. brevitarsis larvae. P. brevitarsis larvae were fed feeds with or without sprouted barley, and their body weight and larval period wewe checked weekly. To confirm the antibacterial effects of sprouted barley, in vitro bioassays were performed by counting Serratia marcescens colonies, and in vivo bioassays were performed by determining the survival rate and body weights of the S. marcescens-infected larvae. Larvae fed different feeds were analyzed for their nutrient compositions (i.e., such as proximate composition, minerals, amino acids, and heavy metals). Larvae fed 5% and 10% sprouted barley had maximum weight increases of 19.2% and 23.1%, respectively. Both treatment groups had significantly shorter larval periods than those of the control group. Sprouted barley markedly inhibited the growth of entomopathogenic S. marcescens. Furthermore, larvae fed sprouted barley exhibited higher Cu, Zn, and K levels. Seventeen amino acids were present in larvae fed sprouted barley, of which, tyrosine and glutamic acid were predominant. No heavy metals were detected in any of the investigated groups. Therefore, sprouted barley may be a suitable feed additive for producing high-quality P. brevitarsis larvae.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.188-197
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• 2020

Termites play an important role as decomposers of the forest ecosystem, while simultaneously causing enormous damage to wooden structures. Currently, two species of subterranean termites have been reported in Korea, and termite damage to historical wooden buildings is occurring nationwide due to climate change, forest fertility, and the locational characteristics of historical wooden buildings. Subterranean termites make their nests underground or inside timber. Termites move underground and access wooden structures through the lower parts of the buildings, adjacent to the ground. Once termites attack the wooden structures, it not only spoils the authenticity of cultural heritage structure, but also hampers structural stability due to the decrease in the strength of the material. Therefore, it is important to prevent termite damage before it occurs. Chemical treatments are mainly used in Korea to control and prevent the damage. In foreign countries, physical barriers are also used to prevent entry to wooden buildings, along with chemical treatments. Physical barriers involve installing nets or particles that termites cannot pass through in the lower part of the building, around the pipes, and between the edges of the building or exterior walls and interior materials. Advantages of a physical barrier are that it is an eco-friendly method, maintains long-term effect after installation, and does not require the use of chemical treatments. Prior to applying physical barriers, studies into the characteristics of termite species must be undertaken. In this study, we evaluated the minimum passage size that each caste of Reticulitermes speratus kyushuensis can move through. We found that workers, soldiers, and secondary reproductive termites were able to pass through diameters of 0.7mm, 0.9mm, and 1.1mm respectively. Head height of termites was an important factor in determining the minimum passing size. Results from the current study will be used as a basis to design the mesh size for physical barriers to prevent damage by termites in historical wooden buildings in Korea.

• Journal of Life Science
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• v.31 no.6
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• pp.559-567
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• 2021

This study compared the nutritional characteristics and antioxidant effects of sea mustards sourced from five different areas (Barammaegi, Gultongmeori, Chanmulgae, Johongtaek, and Goraedeung) in Taejongdae, Youngdo, Busan. The contents of total flavonoids and phenols and fatty acid composition were measured. To evaluate their antioxidant effects, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays were used. Acetone/methylene chloride (A+M) extracts from all the sea mustards contained higher amounts of total flavonoids and phenols than methanol (MeOH) extracts. Among the sea mustards obtained from the different areas, the total flavonoid and total phenolic content of the A+M extract of the sea mustard from Gultongmeori was 1.44±0.04 mg/g and 1.72±0.06 mg/g, respectively. In terms of the fatty acid composition, the Gultongmeori sea mustard had higher percentages of total n-6, total n-3, eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) than the sea mustards from the other areas. The A+M extract of the sea mustard from Gultongmeori was more effective in terms of scavenging free radicals as compared with that of the other sea mustards, as assessed by the DPPH and ABTS assays (p<0.05). In a 120-minute reactive oxygen species (ROS) production assay, all the extracts tested decreased cellular ROS production induced by H₂O₂ compared to that produced by exposure to an extract-free control (p<0.05). The extracts from Barammaegi and Gultongmeori had a greater inhibitory effect on cellular ROS production. These results indicated that the antioxidant effects of sea mustards might be associated with a higher amount of flavonoids and phenols. This study suggests that food-processed products from sea mustard can be developed as functional foods for promoting health in the local population.