• Journal of Life Science
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• v.19 no.7
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• pp.994-1002
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• 2009

A bacteriocin-producing bacterium identified as Bacillus licheniformis was isolated from soybean sauce. Antibacterial activity was confirmed by paper disc diffusion method, using Micrococcus luteus as a test organism. The bacteriocin also showed antibacterial activities against Bacillus sphaericus, Lactobacillus bulgaricus, Lactobacillus planiarum, Paenibacillus polymyxa, and Pediococcus dextrinicus. Optimal culture conditions for the production of bacteriocin was attained by growing the cells in an MRS medium at a pH of 6.5~ 7.0 and a temperature of 37$^\circ$C for 36$\sim$48 hr. Solvents such as chloroform, ethanol, acetone, and acetonitrile had little effect on bacteriocin activity. However, about 50% of bacteriocin activity diminished with treatment of methanol and isopropanol at the final concentration of 50% at 25$^\circ$C for 1 hr. It was stable against a pH variation range from 3.0 and 7.0, but the activity reduced to 50% at a pH range from 9.0 to 11.0. It's activity was not affected by heat treatment at 100$^\circ$C for 30 min and 50% of activity was retained after heat treatment at 100$^\circ$C for 60 min, showing high thermostability. The bacteriocin was purified to a homogeneity through ammonium sulfate precipitation, SP-Sepharose ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (HPLC). The entire purification protocol led to a 75-fold increase in specific activity and a 13.5% yield of bacteriocin activity. The molecular weight of purified bacteriocin was estimated to be about 2.5 kDa by tricine-SDS-PAGE.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.245-258
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• 1991

In order to determine the antigenic localization in the tissues of the adult Metagonimus yokegawai, immunogoldlabeling method was applied using serum immunoglobulins (IgG) of cats which were infected with isolated metacercariae from Plecoglossus altivelis. The sectioned worm tissue was embedded in Lowicryl HM 20 medium and stained with infected serum IgG and protein A gold complex (particle size: 12 nm) , It was observed by electron microscopy at each tissue of the worm. The gold particles were observed on the tegumental syncytium as well as cytoplasm of tegumental cells and epithelial lamella of the caecum. The gold particles were not observed on the basal lamina of the tegument, interstitial matrix of the parenchyma, the muscle tissue and mitochondria of the tegument. The gold particles were specifically labeled in the secretory granules in the vitelline cells. They were also labeled on the lumen of bladder and egg shell. The above findings showed that antigenic materials in the tissue of adult worms were specifically concentrated on the tegumental syncytium as well as cytoplasm of tegumental cells and epithelial lamella of the caecum.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.235-244
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• 1991

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg Positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1, 262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11 9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2~32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4~5 days interval were higher (70.8%) than those from single anal swabs (50.0~59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%) . 5. A total of 2, 609 (male : female=1 : 12.4) worms were collected from 17 egg-positive cases treated with anthelinintics. The mean number of worms per child was 153 (range: 4-824) . 6. The egg-positive cases in several studied groups (180 children) were treated with anthelmintics 6 times at 3-week intervals. In this case, the overall positive rate was decreased from 54.8% to 2.2% at 15 weeks after the treatments, but no complete negative conversion was experienced. However, in a group of children (154 children) including egg Positive and negative cases who were both treated with anthelmintics at 3-week interval, a complete egg-negative conversion was observed in the 9th week after treatments. 7. The egg-detection rate in the brothers or sisters of egg Positive children was 70.0% (28 out of 40 examined), and the egg-positive rate according to the family unit was 69.7%. In summarizing the above results, it is concluded that Enterobius vermicularis infection is still highly prevalent among children in Korea, and that repeated mass treatments of more than 3 times will be effective for control of this infection.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.93-102
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• 1993

Carbonized rice hull, neutralized by dilute nitric acid, was evaluated possibility as a bed matrial for sanitary cultivation. The growth response of Chinese Cabbage, lettuce, and spinach on the carbonized rice hull supplemented with different kinds and concentrations of available nutrition solution was accessed. The ideal nitrogen concentration of nutrition solution was 126 mg/l. Both solutions of compound fertilizer and nutrition containing microelements showed no difference in growth and chemical components of vegetables. Therefore, compound fertilizer was thought to be better than nutrition owing to the convenience of handling in practice. The gravel was also evaluated as supporting material of carbonized rice hull. Because of lasting latent heat in gravel, the mixing treatment of carbonized rice hull and gravel(7~10cm in diam.) was efficient to the growth resulting in the highest dry weight per plant, but the heavy weight of gravel made the handling very difficult. Light carbonized rice hull showed the better plant growth and ease handling, compared to the mixture of soil and compost, and had enough supporting capacity. Therefore, carbonized rice hull was thought to be a desirable bed material for environmentally controlled cultivation.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.265-270
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• 2010

Adipogenesis has been one of the most intensely studied models of cellular differentiation. During adipogenesis, differential expression of many adipogenesis related genes lead to profound changes in cellular, morphological, and physiological characteristics of the differentiating cells. The aim of the present study was to examine the expression levels of adipogenic candidate genes, cAMP early repressor (ICER), nephroblastoma over-expressed protein (NOV), heat shock protein beta 1 (HSPB1) and succinate dehydrogenase (SDH), during adipogenesis of bovine mesenchymal stem cells (BMSC). The BMSC were cultured in DMEM / low glucose medium with adipogenic inducers for 6 days and the expression of various candidate genes which seemed related to adipogenesis were measured by real-time PCR. This study showed that the expression of peroxisome proliferator activated receptor ${\gamma}$(PPAR${\gamma}$) and fatty acid binding protein 4 (FABP4) genes as adipogenic indicators were increased to 3.11 and 3.11 folds on day 6 than on day 0, respectively (p<0.05). To determine whether candidate genes were related to adipogenesis, the expression levels of ICER, NOV, HSPB1, and SDH genes were measured during adipogenesis in BMSC. Our results showed that the expression level of ICER gene was significantly increased to 4.12 folds (0.01729 vs. 0.07138; p<0.05), whereas NOV, HSPB1, and SDH genes were decreased to 2.89, 3.18 and 2.36 folds, respectively, on day 6 when compared to day 0. These results suggest that these candidate genes have stimulatory or inhibitory effects on adipogenesis in BMSC, indicating that these genes may be directly or indirectly related to the adipogenic event of adipose precursor cells.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.24-38
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• 2019

Due to the dramatic spatial changes caused by industrialization, environmental problems such as air pollution and urban heat island phenomenon, etc. are occurring in cities. In this case, the wind corridor, which is a passage through which fresh and cool air generated in forests outside cities move to the downtown, can be used as a spatial planning method for improving urban environmental problems. Cold air is determined by the characteristics of the flow depending on the topography and land use of cities, and based on this, the medium- and long-term plan should be established. Therefore, this study analyzed the flow of cold air at night through the KLAM_21 model in Suwon-si, Gyeonggi-do, to prepare the basic data required to apply the wind corridors. As a result, it turned out that cold air of Suwon-si was mainly generated from Gwanggyo Mountain that is a large mountain area in the north, and flowed into the urbanization promotion area, and about three hours after sunset, cold air flowed into the downtown. By district, the depth, wind speed, and direction of the cold air layer were formed differently according to the characteristics of the topography and land use. In the areas where large forests were adjacent, the flow of cold air was active. There are three main wind corridors where cold air flows to the downtown of Suwon-si, all of which are formed around rivers. Especially, if the connection between rivers and the surrounding green areas is high, the effect of wind corridors is found to be significant. In order to utilize the wind corridors of Suwon-si, based on the results of this study, it is necessary to make climate maps through actual survey and complex analysis of cold air flow and establish mid-to-long-term plans for the conservation and expansion of major wind corridors.

• Journal of Life Science
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• v.25 no.12
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• pp.1408-1414
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• 2015

In this study, to retain a stable bacterial inoculant, Bacillus strains showing antifungal activity were screened. The improved production, antifungal mechanism, and stability of the antifungal metabolite by a selected strain, AF4, a potent antagonist against phytopathogenic Botrytis cinerea, were also investigated. The AF4 strain was isolated from rhizospheric soil of hot pepper and identified as Bacillus subtilis by phenotypic characters and 16S rRNA gene analysis. Strain AF4 did not produce antifungal activity in the absence of a nitrogen source and produced antifungal activity at a broad range of temperatures (25-40℃) and pH (7-10). Optimal carbon and nitrogen sources for the production of antifungal activity were glycerol and casein, respectively. Under improved conditions, the maximum antifungal activity was 140±3 AU/ml, which was higher than in the basal medium. Photomicrographs of strain AF4-treated B. cinerea showed morphological abnormalities of fungal mycelia, demonstrating the role of the antifungal metabolite. The B. subtilis AF4 culture exhibited broad antifungal activity against several phytopathogenic fungi. The antifungal activity was heat-, pH-, solvent-, and protease-stable, indicating its nonproteinous nature. These results suggest that B. subtilis AF4 is a potential candidate for the control of phytopathogenic fungi-derived plant diseases.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.136-142
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• 2016

Lespedeza species are mainly used for wildlife food and cover and for erosion control. The germination of these species can be enhanced after a fire occurrence in forest, which is known as fire-activated seeds to germinate. While the heat treatment could break seed dormancy of Lespedeza, its germination rate was quite low. We investigated that chemical scarification could promote germination of L. tomentosa. Seeds were soaked in 100% sulfuric acid (H₂SO₄) for 0, 1, 3, 6, 12, 24, 48, 96, 192, and 384 min, and then washed in distilled water for 24 h. Very few seeds were germinated in control (H₂SO₄ for 0 min). More than 90% of seeds were germinated in H₂SO₄ for 24, 48, and 92 min. However, some damage was observed in roots and cotyledons of seedling dipped in H₂SO₄ for a long time. To search the optimal soaking time in H₂SO₄ without defects, seeds scarified in H₂SO₄ for 30, 60, 90, 120, 150, 180, and 300 min were sown the commercial soil medium. Seeds treated with H₂SO₄ for 90 min and 150 min emerged by about 92% and 84%, respectively. Therefore, H₂SO₄ treatment could break the seed dormancy of Lespedeza species, and especially in case of L. tomentosa the optimal treatment time in sulfuric acid was one to two hours. Germination of L. tomentosa began promptly following the scarification and was completed within about one month, indicating that seeds has no physiological dormancy, just has physical dormancy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.619-624
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• 2011

Tea extract (TE) has been shown to have anti-tumor properties in a wide variety of experimental systems. We evaluated green tea extract (GTE) as a biochemical modulator for the antitumor activity of cisplatin and doxorubicin in the treatment of human lung cancer A549 cells. Cells were grown in RPMI-1640 medium supplemented with 10% (v/v) heat-inactivated fetal bovine serum and two antibiotics (100 units/mL penicillin and $100\;{\mu}g$/mL streptomycin). Two types of TE, epigallocatechin galate (EGCG) and GTE, were used in this experiment. The cells were seeded at $1{\times}10^4$ cells/well in the RPMI-1640 media with or without TE ($100\;{\mu}g$/mL) and then treated with different concentrations of doxorubicin ($0{\sim}14\;{\mu}g$/mL) or cisplatin ($0{\sim}35\;{\mu}g$/mL). After incubation in 5% $CO_2$ at $37^{\circ}C$ for 24 hr, cell viability was determined with a MTT assay. We used a Western blot to detect the influence of EGCG and GTE on the expression of p53 and caspase-3 genes in the A549 cells. A549 cell viability decreased to 15% with a $10\;{\mu}g$/mL concentration of cisplatin, and to 21% with a $8\;{\mu}g$/mL concentration of doxorubicin, as measured with the MTT assay. However, pre-treatment of the cells with EGCG ($100\;{\mu}g$/mL) or GTE ($100\;{\mu}g$/mL) resulted in decreased cell viability with $6\;{\mu}g$/mL of cisplatin and $4\;{\mu}g$/mL of doxorubicin. There was no apparent change in cell viability between EGCG or GTE administration in cisplatin- or doxorubicin-induced cytotoxicity in A549 cells. The levels of p53 and caspase-3 in the A549 cells increased with both EGCG and GTE treatment. We found that GTE could potentially affect cisplatin- or doxorubicin-induced cytotoxicity of A549 cells, which may be useful in the chemotreatment of cancer.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.957-963
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• 1998

Several medicinal herbs, which are nontoxic and have been used widely in traditional folk medicine, were extracted and antimicrobial activity of the extracts was investigated against various foodborne pathogens or food poisioning microorganisms. The ethanol extract of Sansa, Hwangryun, Cheukbaek, and Seokchangpo showed strong antimicrobial activities against Gram postive and Gram negative bacteria, whereas those of Sakunja, Sukjihwang and Baekji had little antimicrobial activities on microorganisms tested. Among medicinal herb extracts, ethanol extract of Coptis chinensis Franch (hwangryun) showed the strongest antimicrobial activity. Antimicrobial activity of ethanol extract of Coptis chinensis Franch was not destroyed by heating at $100^{\circ}C$ for 60 min and at $121^{\circ}C$ for 30 min, which is very stable over heat. The pH effect on minimal inhibitory concentrations (MIC) of the extract of Coptis chinensis Franch indicated that MIC was reduced with increasing the pH value of the medium. The inhibitory effect of partially purified substance from the ethanol extract of Coptis chinensis Franch on the growth of Listeria monocytogenes and Staphylococcus aureus was investigated. Growth of those strains occurred at the concentration of $100{\;}{\mu}g/mL$ and were inhibited at $500{\;}{\mu}g/mL$, whereas those strains was completely inactivated in the presence of $1000{\;}{\mu}g/mL$.