• Biomedical Science Letters
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• v.16 no.4
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• pp.271-277
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• 2010

This study was conducted to investigate the biological activities of Areca catechu L. The antioxidative, fibrinolytic, thrombin inhibitory, and ${\alpha}$-glucosidase inhibitory activities of Areca catechu L extracted with hexane, $CHCl_3$, ethyl acetate, butanol, and water were measured. The water fraction showed the highest extraction yield at 3.65% (w/w). The butanol, $CHCl_3$, water, and ethyl acetate fractions showed strong antioxidative activities at 81.6%, 87.1%, 88.0%, and 89.5%, respectively. The fibrinolytic activity was strong only in the ethyl acetate fraction at 0.84 plasmin units/ml. The 100-fold dilution of the water fraction had the strongest thrombin inhibitory activity at 59.2%. The 100-fold dilution of butanol fraction displayed the strongest ${\alpha}$-glucosidase inhibitory activity at 88.6%. In conclusion, the extracts of Areca catechu L hold promise for use in the development of biofunctional foods to prevent cardiovascular diseases.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1675-1686
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• 2016

We characterized the probiotic properties of Lactobacillus helveticus strains KII13 and KHI1 isolated from fermented cow milk by in vitro and in vivo studies. The strains exhibited tolerance to simulated orogastrointestinal condition, adherence to Caco-2 cells, and antimicrobial activity. Both L. helveticus strains produced bioactive tripeptides, isoleucylprolyl-proline and valyl-prolyl-proline, during fermentation of milk. KII13 showed higher in vitro cholesterol-lowering activity (47%) compared with KHI1 (28%) and L. helveticus ATCC 15009 (22%), and hence, it was selected for in vivo study of cholesterol-lowering activity in atherogenic diet-fed hypercholesterolemic mice. For the study, mice were divided into four groups (viz., normal diet control group, atherogenic diet control group (HCD), KII13-atherogenic diet group (HCD-KII13), and Lactobacillus acidophilus ATCC 43121-atherogenic diet group (HCD-L.ac) as positive control). The serum total cholesterol level was significantly decreased by 8.6% and 7.78% in the HCD-KII13 and HCD-L.ac groups (p < 0.05), respectively, compared with the HCD group. Low-density lipoprotein cholesterol levels in both HCD-KII13 and HCD-L.ac groups were decreased by 13% and 11%, respectively, compared with the HCD group (both, p < 0.05). Analysis of cholesterol metabolism-related gene expression in mice liver showed increased expression of LDLR and SREBF2 genes in mice fed with KII13. By comparing all the results, we conclude that L. helveticus KII13 could be used as a potential probiotic strain to produce antihypertensive peptides and reduce serum cholesterol.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.48-55
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• 2015

1-Deoxynojirimycin (DNJ) has been extensively investigated for its applications as an a-glucosidase inhibitor in postprandial hyperglycemia, and has been applied to nutraceuticals and medicines to prevent or delay the progression of type 2 diabetes. However, the amount of DNJ in mulberry leaves is low (approximately 0.1%), therefore, a more effective extraction method is needed. In this study, microbial DNJ production was developed as an alternative to chemical methods. We identified fermented sericultural products and bacteria that produce DNJ in large quantities using high performance liquid chromatography and thin layer chromatography. The inhibition of a-glucosidase activity was examined with respect to DNJ production or non-production. Crude DNJ from the isolated strains exhibited greater than 70% a-glucosidase activity. An investigation of the effect of mulberry leaf powder concentration (1~5%), using high DNJ producing bacteria, provided evidence for microbial mass production of DNJ.

• Journal of the Korean Ceramic Society
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• v.55 no.4
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• pp.381-391
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• 2018

In this work, photocatalytic $CO_2$ reduction over a CdSe-graphene-$TiO_2$ nanocomposite has been studied. The obtained material was successfully fabricated via ultrasonic technique. The physical properties of the as-synthesized materials were characterized by some physical techniques. The $TiO_2$ and CdSe dispersed graphene nanocomposite showed excellent results of strong reduction rates of $CO_2$ compared to the results of bare $TiO_2$ and binary CdSe-graphene. An outstanding point of the combination of CdSe-$TiO_2$ and graphene appeared in the form of great photocatalytic reduction capability of $CO_2$. The photocatalytic activity of the asfabricated composite was tested by surveying for the photoreduction of $CO_2$ to alcohol under UV and visible light irradiation, and the obtained results imply that the as-prepared CdSe-graphene-$TiO_2$ nanocomposite is promising to become a potential candidate for the photocatalytic $CO_2$ reduction.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.477-487
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• 2021

The purpose of this study is to develop textbooks that can be used in education for developing easy-to-read materials for people with developmental disabilities. The textbook was developed through the steps of analysis of guidelines for making easy-to-read materials, confirmation of the course, development of textbook contents, and verification of validity. The final developed materials were developed as textbooks, including reader classification, vocabulary, symbols, layout, and production practice for the development of easy-to-read materials with a total of 7 sessions. The important characteristics of the textbook developed in this study are: First, it classified readers who read easy-to-read materials for the first time in Korea and introduced them as Plain Language readers and Easy to Read readers. Second, the guideline that can be referenced while developing easy-to-read materials was developed as a checklist, so that it can be checked by itself. Third, thematic activity sheets and workbooks were developed so that they can be used as activity-oriented textbooks.

• The Korean Journal of Mycology
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• v.40 no.3
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• pp.159-163
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• 2012

This study was performed to investigate the biological activities of Hericium erinaceus fruiting body, including antioxidative, fibrinolytic, thrombin inhibitory and ${\alpha}$-glucosidase inhibitory activities. The water extract of H. erinaceus was fractionated into hexane, chloroform, ethyl acetate, butanol and water fractions, and each of these fractions was individually assayed. The water extract showed high antioxidative activity at 87.78%. The water fraction showed the highest extraction yield at 35.68% (w/w). In the fraction activity tests, butanol and water fractions showed strong antioxidative activities at 87.91% and 92.27%, respectively. Assays for fibrinolytic activity indicated that only the ethyl acetate fraction has significant efficacy at 2.96 plasmin units/mL. The 10-fold dilution of hexane fraction showed high thrombin inhibitory activity, and ${\alpha}$-glucosidase inhibitory activity at 77.67% and 90.53%, respectively. In conclusion, solvent fractions of H. erinaceus can be used as materials for the development of biofunctional foods to prevent cardiovascular diseases.

• Korean Journal of Materials Research
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• v.22 no.8
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• pp.421-425
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• 2012

Two types of Pt nanoparticle electrocatalysts were composited on Pt nanowires by a combination of an electrospinning method and an impregnation method with NaBH4 as a reducing agent. The structural properties and electrocatalytic activities for methanol electro-oxidation in direct methanol fuel cells were investigated by means of scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry. In particular, SEM, HRTEM, XRD, and XPS results indicate that the metallic Pt nanoparticles with polycrystalline property are uniformly decorated on the electro-spun Pt nanowires. In order to investigate the catalytic activity of the Pt nanoparticles decorated on the electro-spun Pt nanowires, two types of 20 wt% Pt nanoparticles and 40 wt% Pt nanoparticles decorated on the electro-spun Pt nanowires were fabricated. In addition, for comparison, single Pt nanowires were fabricated via an electrospinning method without an impregnation method. As a result, the cyclic voltammetry and chronoamperometry results demonstrate that the electrode containing 40 wt% Pt nanoparticles exhibits the best catalytic activity for methanol electro-oxidation and the highest electrochemical stability among the single Pt nanowires, the 20 wt% Pt nanoparticles decorated with Pt nanowires, and the 40 wt% Pt nanoparticles decorated with Pt nanowires studied for use in direct methanol fuel cells.

• Research in Plant Disease
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• v.24 no.1
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• pp.33-40
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• 2018

This study was conducted to evaluate the antifungal activity of 19 agro-materials that have been registered for organic cultivation in Korea, after inoculation of pear leaves with Venturia nashicola and Gymnosporangium asiaticum. In V. nashicola, most of the nine agro- materials containing sulfur and copper completely inhibited spore germination, and some of the spores that germinated did not form appressoria. However, in only lime sulfur, Neobordeaux (cupric sulfate), and Wheengaris (sulfur)showed antifungal activity against G. asiaticum. Among the agro-materials containing plant extracts, Wheengarujaba (wood vinegar+spirits+rhubarb) inhibited conidial germination in V. nashicola and G. asiaticum by 100% and 71.6%, respectively. Among the agro-materials containing antifungal microorganisms, Cheongotan (Streptomyces griseus) reduced spore germination rate of V. nashicola to 88.8%; moreover, formation of appressoria or intracellular accumulation was not observed. Application of Topsid (Paenibacillus polymyxa) reduced spore germination rates in V. nashicola and G. asiaticum to 71.0% and 90.6%, respectively, and the formation of appressoria was not observed. Studying the antifungal activity of agro-materials because of cumulative applications under the field conditions is necessary, owing to their contact fungicidal effect and the induced-resistance by microbial metabolites and natural compounds.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.672-673
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• 2003

• Biomedical Science Letters
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• v.16 no.3
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• pp.161-167
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• 2010

In this study, the biological activities of Glycyrrhiza uralensis were investigated, including antioxidative, fibrinolytic, thrombin inhibitory, and a-glucosidase inhibitory activity. The hot water extract of Glycyrrhiza uralensis was fractionated into hexane, $CHCl_3$, ethyl acetate, butanol, and water fractions, and each of these fractions were assayed individually. The water fraction showed the highest extraction yield of 19.45% (w/w). Using the DPPH method, the free radical scavenging activity was to be the strongest in the $CHCl_3$ fraction at 89.3%. Using the fibrin plate method, only the butanol fraction showed a substantial plasmin activity of 0.62 units/ml. In thrombin inhibitory activity tests, a 100-fold dilution of the ethyl acetate fraction showed the strongest activity of 46.9%. In the a-glucosidase inhibitory activity assay, a 100-fold dilution of the $CHCl_3$ fraction showed the strongest activity of 80.6%. In conclusion, the combined results of this study demonstrate that the extracts of Glycyrrhiza uralensis can be used as a material for the development of biofunctional foods for diabetics.