• Journal of Science Education
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• v.39 no.3
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• pp.358-375
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• 2015

The purposes of this study were to investigate the value, necessity and legitimacy of STEAM Education and to propose practical approaching methods for STEAM Education to be applicable in Korea through a variety of literature review, case studies and collecting suggestions from domestic and international educational experts. The research questions are as follows: (1) To investigate the perception, understanding and recognitions of domestic and foreign professionals in STEAM education. (2) To analyze policy implications for an improvement in STEAM. The following aspects of STEAM were found to be challenges in our current STEAM policy after analyzing multiple questionnaires with the professionals and case studies including their experiences, understanding, supports and directions of the policy from the governments. The results indicate that (1) there was a lack of precise and conceptual understanding of STEAM in respect to experience. Training sessions for teachers in this field to help transform their perception is necessary. Development of practical programs with an easy access is also required. It is important to get the aims of related educational activities recognized by the professionals and established standards for an evaluation. The experts perceived that a theme-based learning is the most preferred and effective approaching method and the programs that develop creative thinking and learning applicable to practice are required to promote. (2) The results indicate that there was a lack of programs and inducements for supporting outstanding STEAM educators. It is shown that making an appropriate environment for STEAM education takes the first priority before training numbers of teachers unilaterally, thus securing enough budget seems critical. The professionals also emphasize on developing specialized teaching materials that include diverse inter-related subjects such as science technology, engineering, arts and humanities and social science with diverse viewpoints and advanced technology. This work requires a STEAM network for teachers to link up and share their materials, documents and experiences. It is necessary to get corporations, universities, and research centers participated in the network. (3) With respect to direction, it is necessary to propose policy that makes STEAM education ordinary and more practical in the present education system. The professionals have recommended training sessions that help develop creative thinking and amalgamative problem-solving techniques. They require reducing the workload of teachers and changing teachers' perspectives towards STEAM. They further urge a tight cooperation between departments of the government related with STEAM.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.268-277
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• 2016

This study aimed to investigate the anti-inflammatory effect of the ethanol extract from Chondrus ocellatus Holmes (COHEE) in RAW 264.7 cells and in a mouse ear edema model, by measuring the production of lipopolysaccharide-induced inflammatory response mediators. There were no cytotoxic effects on the proliferation of macrophages treated with COHEE compared with the control. COHEE inhibited the production of nitric oxide and pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor-α, and IL-1β]. The extract also reduced the expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-κB p65, and phosphorylated mitogen-activated protein kinase in a dose-dependent manner. In the croton-oil-induced ear edema model, COHEE decreased the formation of mouse ear edema at the highest dose compared with the control, and histological analysis revealed that the epidermal/dermal tissue thickness and mast cell numbers were reduced. Therefore, these results suggest that COHEE may be a promising topical anti-inflammatory therapeutic material through its action of modulating NF-κB and the MAPK signaling pathway.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.112-119
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• 2015

The anti-inflammatory effect of Sargassum coreanum ethanolic extract (SCEE) was investigated using lipopolysaccharide (LPS)-induced inflammatory responses in this study. It was shown that there was no cytotoxicity in the viability of macrophages treated with SCEE when compared to the control. The production of NO was considerably suppressed by SCEE, approximately up to 50% at 100 μg/ml. This significantly decreased levels of IL-6, TNF-α, and IL-1β. In addition, the expression of iNOS, COX-2, NF-κB was suppressed by SCEE treatment. In in vivo testing, the croton oil-induced mouse ear edema was attenuated by SCEE and there were no mortalities in mice administered with 5000 mg/kg body weight of SCEE over a 2 week observation period. From these results, SCEE inhibits the release of LPS-induced pro-inflammatory cytokines and mediators, suggesting that SCEE could be a potential agent for anti-inflammatory therapies.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.452-460
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• 2016

This study was designed to develop a functional pharma-food using Salicornia europaea (SE). Tiny seeds from the mature SE were collected, and their biological activities were evaluated. The extraction yield of the seed in hot water was found to be 29.6% and the hot water extract (HWE) contained 25.7 mg/g total polyphenol (TP) and 11.5 mg/g total flavonoid (TF), which are similar to those contained in leaf and stem of SE. Among the subsequent organic solvent fractions, the ethylacetate (EA) fraction exhibited the highest content of TP (158.3 mg/g), TF (136.2 mg/g), and total sugar (228.3 mg/g). The EA fraction exhibited broad-range antibacterial activities against gram-positive bacteria, and the butanol fraction exhibited growth inhibitory effect against only Staphylococcus epidermidis. An antioxidation activity assay of the HWE and its fractions showed the EA fraction to have the highest radical scavenging activity with $RC_{50}$ values of 57.0, 29.0, and $28.9{\mu}g/ml$ against DPPH anion, ABTS cation, and nitrite, respectively. The $RC_{50}$ values of vitamin C against DPPH anion, ABTS cation, and nitrite were 10.7, 4.0, and $18.0{\mu}g/ml$, respectively, indicating that the EA fraction of SE has potent antioxidant compounds. In an anticoagulation assay, the EA fraction exhibited a 15-fold extended thrombin time at 5 mg/ml and activated partial thromboplastin time at 7 mg/ml, which are comparable to the activities of aspirin. The HWE and its fractions had no hemolysis activities against human RBCs at up to 1 mg/ml. These results suggest that the EA fraction from SE has a great potential as a new antibacterial and anticoagulation agent.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.18-28
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• 2018

In this study, the antioxidant activities and cytoprotective effects against oxidative stress of Lonicera japonica Thunb. 50% ethanol extract and ethyl acetate fraction were investigated. Using the 1,1-diphenyl-2-picrylhydrazyl assay, the free radical scavenging activity (FSC50) of L. japonica Thunb. 50% ethanol extract and ethyl acetate fraction was determined as 152.00 and $77.25{\mu}g/ml$, respectively. To measure the reactive oxygen species (ROS) scavenging activity, the total antioxidant capacity (OSC50) was determined by using a luminol-dependent chemiluminescence assay. The antioxidant activity of the ethyl acetate fraction ($0.33{\mu}g/ml$) was approximately four times stronger than that of the 50% ethanol extract ($1.12{\mu}g/ml$). The protective effect against $^1O_2$-induced cellular damage of human erythrocytes (${\tau}_{50}$) was 46.0 min at $10{\mu}g/ml$ of the 50% ethanol extract and 52.3 min at $1{\mu}g/ml$ of the ethyl acetate fraction. We also investigated the cytoprotective effects against oxidative stress induced by $H_2O_2$ and the intracellular ROS scavenging activity in response to UVB irradiation and found that the extract and fraction protected human skin cells from damage and reduced ROS. These results confirmed that L. japonica Thunb. was a valuable plant-derived natural antioxidant with potential for development as an antioxidative functional ingredient.

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.110-117
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• 2017

The anti-inflammatory effect of Sargassum patens C. Agardh ethanol extract (SPEE) was examined based on the lipopolysaccharide (LPS)-induced inflammatory response in this study. SPEE treatment was not cytotoxic to macrophages compared to the control. The production of NO was suppressed by SPEE by approximately 28% at $100{\mu}g/ml$, and levels of interleukin-6, tumor necrosis $factor-{\alpha}$, and $interleukin-1{\beta}$ decreased in a dose-dependent manner. In addition, the expression of inducible nitric oxide synthase, cyclooxygenase-2, and nuclear $factor-{\kappa}B$ was suppressed by SPEE treatment. In vivo, croton oil-induced mouse ear edema was attenuated by SPEE and the infiltration of mast cells into the tissue decreased. Based on these results, SPEE inhibits the release of LPS-induced pro-inflammatory cytokines and mediators, suggesting that SPEE is a potential agent for anti-inflammatory therapies.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.250-256
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• 2017

The prevalence of infections due to pathogenic bacteria such as Edwardsiella tarda, Streptococcus parauberis, and Photobacterium phosphoreum in fish farms in Jeju Island and their management by marine-derived biomaterials was studied. In this study, we isolated eight spices type of marine-derived biomaterials from four sea areas of Jeju Island. An antibiotic disc susceptibility test confirmed that the isolated marine-derived biomaterials showed weak resistance only to oxytetracycline and penicillin and sensitivity to the other antibiotics tested, and antimicrobial activity against fish pathogens with the inhibitory zone of 22 mm, 18 mm, and 19 mm for MD-02, MD-04, and MD-06 against E. tarda strains, respectively, and 19 mm, 22 mm, 30 mm, and 29 mm for MD-01, MD-02, MD-04, and MD-06 against S. parauberis strains, respectively, while all the marine-derived biomaterials showed antibacterial activity against P. phosphoreum. Among the eight biomaterials selected, Bacillus subtilis MD-02 displayed the greatest antibacterial activity against the three tested fish pathogens and also displayed susceptibility to antibiotics. The growth of Bacillus subtilis MD-02 was greatest with the carbon source, dextrine; nitrogen source, peptone; and mineral source, $MgSO_4{\cdot}7H_2O$. Hence, the present study confirmed that the isolate B. subtilis MD-02 from Jeju Island could be a potential antimicrobial agent against fish pathogens and a potential pharmacotherapeutic agent.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.2
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• pp.109-120
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• 2017

A discounted cost model for preventive maintenance of armor units of rubble-mound breakwaters is mathematically derived by combining the deterioration model based on a discrete-time stochastic process of shock occurrence with the cost model of renewal process together. The discounted cost model of condition-based maintenance proposed in this paper can take into account the nonlinearity of cumulative damage process as well as the discounting effect of cost. By comparing the present results with the previous other results, the verification is carried out satisfactorily. In addition, it is known from the sensitivity analysis on variables related to the model that the more often preventive maintenance should be implemented, the more crucial the level of importance of system is. However, the tendency is shown in reverse as the interest rate is increased. Meanwhile, the present model has been applied to the armor units of rubble-mound breakwaters. The parameters of damage intensity function have been estimated through the time-dependent prediction of the expected cumulative damage level obtained from the sample path method. In particular, it is confirmed that the shock occurrences can be considered to be a discrete-time stochastic process by investigating the effects of uncertainty of the shock occurrences on the expected cumulative damage level with homogeneous Poisson process and doubly stochastic Poisson process that are the continuous-time stochastic processes. It can be also seen that the stochastic process of cumulative damage would depend directly on the design conditions, thus the preventive maintenance would be varied due to those. Finally, the optimal periods and scale for the preventive maintenance of armor units of rubble-mound breakwaters can be quantitatively determined with the failure limits, the levels of importance of structure, and the interest rates.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.427-439
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• 2019

Natural environmental ecology ofthe environmental impact assessment(EIA)is very much lacking in quantitative evaluation. Thus, this study attempted to evaluate quantitative assessment for ecosystem service in the site of Eco-delta project in Busan. As a part of climate change adaptation, this study evaluated and compared with the value for carbon fixation and habitat quality using the InVEST model before and after development with three alternatives of land-use change. Carbon fixation showed 216,674.48 Mg of C (year 2000), and 203,474.25 Mg of C (year 2015)reducing about 6.1%, and in the future of year 2030 the value was dropped to 120,490.84 Mg of C which is 40% lower than year 2015. Alternative 3 of land use planning was the best in terms of carbon fixation showing 6,811.31 Mg of C. Habitat quality also changed from 0.57 (year 2000), 0.35 (year 2015), and 0.21 (year 2030) with continued degradation as development goes further. Alternative 3 also was the highest with 0.21(Alternative 1 : 0.20, Alternative 2 : 0.18). In conclusion,this study illustrated that quantitative method forland use change in the process of EIA can helpdecision making for stakeholders anddevelopers with serving the best scenario forlow impact of carbon. Also it can help better for land use plan, greenhouse gas and natural environmental assets in EIA. This study could be able to use in the environmental policy with numerical data of ecosystem and prediction. Supplemented with detailed analysis and accessibility of basic data, this method will make it possible for wide application in the ecosystem evaluation.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.337-346
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• 2022

The purpose of this study was to investigate the antioxidant and anti-inflammatory activities of hot water (AMPW) and 70% ethanol (AMPE) extracts of apple mango (Mangifera indica L.) peel. The antioxidant activities were measured using a total polyphenol, electron-donating, 2,2'-azinobis [3-ethylbenzothiazoline6-sulfonic acid] (ABTS) radical scavenging assay. The total polyphenol content of AMPW and AMPE was 66.08 ± 0.62 mg TAE/100 g and 100.13 ± 0.23 mg TAE/100 g, respectively. As a result of measuring the electrondonating ability, at a concentration of 1,000 ㎍/ml, AMPW and AMPE showed an effectiveness of 86% and 94%, respectively. The ABTS assay showed 80% and 98% respective radical scavenging activity for AMPW and AMPE, at a concentration of 1,000 ㎍/ml. The cell viability on macrophage cells was performed using a 3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyl-tetrazoliumbromide (MTT) assay, and the results showed more than 90% cell viability at a 100 ㎍/ml concentration. Anti-inflammatory activity was verified by confirming nitric oxide (NO) production inhibitory activity, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) protein and mRNA expression inhibitory activity from lipopolysaccharide (LPS)-treated RAW 264.7 cells. The NO production inhibitory effects were measured using the Griess assay, which confirmed 45% and 40% inhibition after treatment with AMPW and AMPE, respectively. Moreover, the protein and mRNA expression of inflammatory-related factors iNOS and COX-2, decreased in a concentrationdependent manner. In conclusion, this study showed antioxidant and anti-inflammatory effects of Mangifera indica L. peel and revealed its promising potential for application as an antioxidant and anti-inflammatory agent.