• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.

• Journal of Life Science
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• v.32 no.12
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• pp.979-988
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• 2022

Halophytes have been reported to possess a variety of physiological activities, such as anti-cancer, anti-oxidant, anti-diabetes, anti-inflammatory, and anti-obesity. Studies on the roots of the halophyte Rosa rugosa, in particular, have shown a variety of physiological activities and are known to be effective for nursing diabetic complications in traditional Korean medicine. In this study, the effect of R. rugosa on adipogenesis was investigated in 3T3-L1 pre-adipocytes treated with crude extract and solvent fractions (H₂O, n-BuOH, 85% aq. MeOH, and n-Hex) obtained from R. rugosa roots. Treatment with extract and the solvent fractions inhibited the formation of intracellular lipid droplets in differentiated 3T3-L1 adipocytes compared to the untreated group. In particular, n-BuOH and 85% aq. MeOH fractions effectively decreased the expression of adipogenic transcription factors: peroxisome proliferator activated receptor-γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1c (SREBP1c) in both mRNA and protein levels. In conclusion, these results suggest that R. rugosa contains anti-adipogenic molecules that can be utilized as a nutraceutical against obesity. Further refining of n-BuOH and 85% aq. MeOH fractions and analysis of their action mechanisms could yield potential therapeutic agents with anti-adipogenic effects.

• Resources Recycling
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• v.31 no.2
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• pp.20-32
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• 2022

This study implemented a chelating agent (Ethylenediaminetetraacetic acid, EDTA) in purification to obtain high-purity vanadium pentoxide (V₂O₅) for use in VRFB (Vanadium Redox Flow Battery). V₂O₅ (powder) was produced through the precipitation recovery of ammonium metavanadate (NH₄VO₃) from a vanadium solution, which was prepared using a low-purity vanadium raw material. The initial purity of the powder was estimated to be 99.7%. However, the use of a chelating agent improved its purity up to 99.9% or higher. It was conjectured that the added chelating agent reacted with the impurity ions to form a complex, stabilizing them. This improved the selectivity for vanadium in the recovery process. However, the prepared V₂O₅ powder exhibited higher contents of K, Mn, Fe, Na, and Al than those in the standard counterparts, thus necessitating additional research on its impurity separation. Furthermore, the vanadium electrolyte was prepared using the high-purity V₂O₅ powder in a newly developed direct electrolytic process. Its analytical properties were compared with those of commercial electrolytes. Owing to the high concentration of the K, Ca, Na, Al, Mg, and Si impurities in the produced vanadium electrolyte, the purity was analyzed to be 99.97%, lower than those (99.98%) of its commercial counterparts. Thus, further research on optimizing the high-purity V₂O₅ powder and electrolyte manufacturing processes may yield a process capable of commercialization.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.437-448
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• 2021

The purpose of this study is to analyze morphological characteristics of maxillary primary molar's root and root canal. 268 children aged 3 - 7 years (175 boys, 93 girls) who had CBCT (152 children) and 3D CT (116 children) taken in Seoul National University Dental Hospital from January 2006 to April 2020 were included. The number of roots and root canals were analyzed in 1002 teeth without any root resorption or periapical pathologies. Curvature, angulation, length of root and root canal, as well as cross-sectional shapes of the root canal were analyzed in 218 teeth. By using Mimics and 3-Matics software, volume, surface area, and volume ratio of root canal was analyzed in 48 teeth. More than half of maxillary primary molars have 3 roots and 3 root canals. The degree of symmetry of root canal type was about 0.63 (Cohen's kappa coefficient). The most frequent shape of roots and canals was linear in 1^st primary molars and curved in 2^nd primary molars. Angulation, length of root and root canals was the largest on palatal roots. Most teeth showed ovoid or round shapes at apex. The largest root canal volume, surface area, volume ratio was found in the palatal roots.

• Korean Journal of Poultry Science
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• v.49 no.1
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• pp.1-8
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• 2022

We investigated the effects of stunning methods and gas treatments during slaughter on the quality characteristics of chicken breast and small intestine. Broilers (Ross 308) were stunned and slaughtered using halal, CO₂, or N₂ gas stunning methods (for 10 birds). After slaughter, the pH, proximate composition, color, water-holding capacity, cooking loss, and shear force of chicken breast muscle and small intestine were determined. Compared with the halal treatment, CO₂ treatment resulted in higher pH and lower cooking loss (P<0.05), and the pH, color, and shear force of chicken breast muscle with N₂ treatment were similar to those of the halal treatment (P>0.05). Compared with the halal treatment, the gas treatments resulted in lower pH and lightness and higher redness, yellowness, thickness, and shear force of the small intestine (P<0.05). However, compared with the CO₂ treatment, the N₂ treatment resulted in lower pH, redness, and yellowness, and higher lightness, thickness, and shear force. Overall, compared with the halal method, our results suggest that the use of N₂ gas suppresses the discoloration and deterioration of the texture of chicken meat and small intestine caused by CO₂ gas treatment in the gas stunning method.

• Journal of Korean Home Economics Education Association
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• v.34 no.1
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• pp.131-149
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• 2022

The purpose of this study is to explore what value home economics education should pursue to be established as an essential subject in the 'with-/post Covid-19 era', and to suggest directions for the development of the future. To this end, first of all, changes in the future society symbolized by the with-/post- Covid-19 era were diagnosed through literature review. Moreover, the 'OECD Education 2030' project and Korea's 'Educational Vision 2045', which identified the purpose of education in response to changes in the future, were considered. Furthermore, the teleology of education of John White, a British educational philosopher, was contemplated. As a result, the purpose of education for the future society is considered to be changing toward the well-being of society and individuals, and efforts such as the development of a well-being subject are being made in various countries for this purpose. While several a number of strategies are possible for the implementation of well-being education in Korea, this study argues that the easiest way is to strengthen home economics education that already exists as a subject. In addition, the main value of home economics education as an essential subject in the with-/post-Covid-19 era is evaluated to lie in the fact that this subject helped society and individuals cultivate diverse competencies necessary to pursue well-being. Finally, this study suggests a conceptual framework necessary to develop a discourse on home economics education as 'happiness and well-being education.' Additionally, a conceptual framework describing the unique thinking and execution process that learners will represent in the course of learning of home economics that implements well-being education is suggested. In the follow-up studies, it is expected that the discourse on well-being education in home economics education will be verified by empirical studies.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.511-519
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• 2022

In order to develop an air-stripping based remediation process to remove the TOC (Total Organic Carbon) in groundwater around the underground LPG storage cavern, the laboratory scale experiments at various conditions (change of air injection volume and temperature, the application of ultrasonic treatment, etc.) for two types of groundwater (initial TOC concentration of 608 mg/L and 153 mg/L, respectively). From results of experiment, as the air injection rate for stripping into groundwater increased from 2 L/min to 11 L/min and as the air-stripping time increased from 1 hour to 24 hour, the TOC removal efficiency of air-stripping increased. However, the TOC concentration of treated groundwater was higher than the discharge tolerance limit (100 mg/L) even after 24 hour stripping at the maximum air injection rate of 11 L/min. The main compounds of the TOC in groundwater were identified as methanol and propane and the long stripping time (more than 24 hour) was needed to separate the methanol from groundwater because of the affinity between water and methanol. At 20℃ and 4 L/min of air injection, the TOC removal efficiency increased to 59.1% after 24 hour air-stripping. When the temperature of groundwater increased to 30℃ and 40℃, the TOC removal efficiency increased up to 80.0% and 82.8%, suggesting that more than 24 hour air-stripping at 40℃ is needed to lower the TOC concentration to below 100 mg/L and the additional TOC removal process as well as the air-stripping is necessary. When the temperature increased to 60℃ and the ultrasonic treatment was conjugated with the air-stripping, the TOC removal efficiency increased to 87.8% within 5 hour stripping and the final TOC concentration (72.4 mg/L) was satisfied with the TOC discharge tolerance limit. The TOC removal efficiency for groundwater having low TOC concentration (153 mg/L) also showed similar removal efficiency of 89.7% (the final TOC concentration: 18.9 mg/L). Results in this study supported that the air-stripping conjugated with the ultrasonic treatment could remove successfully the TOC in groundwater around the underground LPG strorage cavern.

• Korean Journal of Poultry Science
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• v.49 no.3
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• pp.139-144
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• 2022

This study was conducted to investigate the effect of three different photoperiods on growth performance, blood properties, and stress indicators in broiler chicks between 1-7 days after hatching. Two hundred and fifty-two 1-day-old male broiler chicks (57.0±0.12 g) were divided into three treatments, with 4 replicates per treatment and 22 birds per replicate subjected to three different photoperiods of 24L, 22L/2D and 18L/6D. A light-emitting diode bulb served as the light source, with an illuminance of 30 lx. As an experimental diet, a commercial feed based on a corn-soybean meal, with 22% CP and 3,150 kcal/kg ME diet, and water were fed ad libitum. Body weight gain, feed conversion ratio, and liver weight ratio showed a statistically significant difference between the 18L/6D and 24L treatments (P<0.05), but with no significant difference between the 22L/2D treatment and either the 24L or 18L/6D treatment. The breast meat ratio was 5.59% in the 18L/6D treatment group, which was lower than that of other treatment groups (P<0.05). The triglyceride levels were highest (P<0.05) in the 18L/6D treatment among treatments, but alanine aminotransferase levels were significantly higher (P<0.05) in the 22L/2D treatment than in the 24L treatment. Levels of cytokines, i.e., Interleukin-6 and Tumor Necrosis Factor-α did not show a significant difference among the treatments, but corticosterone content was significantly higher (P<0.05) in the 24L treatment than in the 18L/6D treatment. In conclusion, 22 hours of lighting is appropriate between 1~7 days after hatching, considering growth performance and the overall health of broiler chicks.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.1-13
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• 2023

The study was carried out to investigate the effects of dietary combined supplementation of antioxidants as catechin and vitamin C on growth performance, meat quality, blood profiles and stress responses of broilers exposed to high temperature. For this experiment, a total of 360 21-day-old male Ross 308 broilers were used. Treatments were assigned with 6 replicates per treatment and 10 birds per replicate in a 2 × 3 factorial design with vitamin C (0, 250 mg/kg) and catechin (0, 600, 1,200 mg/kg). The heat stress environment was maintained at temperature 32±1℃ and relative humidity 60±5% for 24 hours until the end of the experiment. The supplemented antioxidants had no significant difference in weight gain, feed intake and feed conversion ratio (P>0.05). The content of total cholesterol in blood had no interaction, but decrease (P<0.01) in the supplemented catechin group. Also, the supplementation with catechin showed increase in the SOD activity of blood, and lower corticosterone and IgM levels of broilers. The contents of HSP70 and MDA in liver decrease (P<0.05) with the supplementation of antioxidants, and HSP70 showed an interaction between groups. DPPH radical scavenging ability in breast meat increased (P<0.01) in catechin, but meat quality did not show difference according to treatments. Respiratory rate decreased (P<0.05) in catechin, but no interaction with vitamin C. In conclusion, the combination of vitamin C and catechin can alleviate stress under high temperature, such as HSP70 and MDA, but further study on the optimal supplemental level is needed.

• Journal of The Korean Association For Science Education
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• v.43 no.1
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• pp.1-15
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• 2023

As the social and economic value of living modified organisms (LMOs) increase, so do the potential risks they pose to humans and the environment. Therefore, all laboratories using LMOs must establish an LMO laboratory in accordance with the standards required by regulations. Recently, in high school, LMO-related experimental programs have been developed for their educational effects. Also, in this case, it is necessary to comply with the regulation for LMO laboratories. However, high schools are still unfamiliar with the LMO laboratory, and it is difficult for teachers to manage an LMO laboratory because its implementation applies the same standards to general research institutes. In this study, we used causal chain analysis to discover the difficulties each teacher faced while setting up an LMO laboratory by examining three cases. The difficulties experienced by teachers are as follows: the first problem is "reluctance to set up an LMO laboratory," because of "administrative tasks for laboratory registration" and "difficulty in persuading colleagues." The second problem is a difficulty for teachers to operate LMO laboratory in blind spots, due to "inflexible installation and closure," "medical waste disposal," and "LMO education that does not fit the school context." Through this study, although the difficulty of running an LMO laboratory is caused by a lack of necessity and insufficient consideration of the school context, the more fundamental cause was a lack of collaborative planning between the educational field and the operating institutions. The teachers who participate in this research suggest that "using shared LAB" and "preparing opportunities for knowledge sharing" can be considered as strategies for operating the school's LMO laboratory. We feel that this study will provide a useful reference for teachers or schools planning to build an LMO laboratory.