• Korean Journal of Microbiology
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• v.41 no.2
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• pp.105-111
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• 2005

Streptomyces produces many kinds of secondary-metabolites including antibiotics. Screening of a new compound and elucidation of a biosynthetic pathway for the secondary metabolites are very important fields of biology, however, there is a main problem that most of the identified compounds are already researched compounds. To solve these problems, a microarray system that is based on the data related to the biosynthetic genes for secondary-metabolites was designed. For the main contents of DNA microarray, the important genes for the bio-synthesis of aminoglycosides, polyenes group, enediyne group, alpha-glucosidase inhibitors, glycopeptide group, and orthosomycin group were chosen. A DNA microarray with 69 genes that were involved in the bio-synthesis for the antibiotics mentioned above was prepared. The usability of the DNA microarray was confirmed with the chromosomal DNA and total RNA extracted from S. coelicolor whose genomic sequence had already been reported.

• Journal of Life Science
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• v.19 no.10
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• pp.1478-1483
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• 2009

A solid-state culture based on grain materials was attempted to produce a fibrinolytic enzyme for blood circulation improvement using Bacillus subtilis BK-17. The spore, rather than vegetative cell inoculation, of B. subtilis BK-17 on the solid-state culture was effective in the production of a fibrinolytic enzyme. Maximum spore production was obtained with a SFM medium (0.8% nutrient broth, 0.05% yeast extract, $10^{-1}$ M $MgCl_2$, $10^{-3}$ M $FeCl_3$, $10^{-4}$ $MnCl_2$, $10^{-5}$ M dipicolic acid, pH 6.5). Optimal pH and temperature were pH 6 and $30^{\circ}C$, respectively. The spore production reached a maximum at 60 hours of incubation. Bacillus subtilis BK-17 on the mung bean solid-state culture produced greater fibrinolytic activity, and less activity was seen in other grains such as kidney bean, soybean and corn. Protein and lipid contents of fermented soybeans were about 10 - 30% more than those of unfermented soybeans. Amino acid content was also 5 - 20% more than that of unfermented soybeans. These results indicated that fermented solid-state culture medium, fermented soybean in this case, can be utilized as a food supplement.

• Journal of Plant Biology
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• v.35 no.2
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• pp.117-123
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• 1992

The effect of benzyladenine (BA) on lipid peroxidation and compositions of total insoluble proteins and chloroplast thylakoid protein from wheat primary leaves during senescence in the dark was studied. BA ($10^{-5}\;M$) treatment prevented conspicuously the loss of chlorophyll content and soluble and insoluble leaf protein contents in senescing wheat leaf segments during 4-day dark incubation. Under the BA treatment, especially, the level of insoluble protein was highly maintained than that of soluble protein. Also, the increase of malondialdehyde (MDA: the peroxidation product of membrane lipids) content was inhibited in the BA treated leaves. Three major polypeptide bands in quantity corresponding to 57, 26 and 12 KD molecular weight were clearly resolved with other minor bands by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) in the insoluble protein fraction. The insoluble protein profiles of the control leaves showed a remarkable decrease in the intensity of the 57 and 12 KD band except for 26 KD band in the 72 h dark incubation. This loss during dark incubation was reduced by BA treatment. More than 20 polypeptides were resolved in the chloroplast thylakoid membrane fraction with the most prominent bands which are 59 and 57 KD ($\alpha\;and\;\beta$ subunit of coupling factor: CF) and 26 KD (apoprotein of LHCP). The changes in thylakoid protein profile during 72 h dark incubation showed the rapid degradation in control, but this degradation was prevented in quantity by BA treatment. The above results suggested that BA would inhibit the peroxidation of membrane lipids, thereby preventing the loss of membrane proteins which led to the maintenance of the membrane integrity including chloroplast thylakoid.

• Journal of Korean society of Dental Hygiene
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• v.15 no.4
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• pp.705-711
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• 2015

Objectives: The purpose of the study is to evaluate the effect of continuing dental care program by elementary school dental clinic in Gimcheon from 2008 to 2013. Methods: The subjects were experimental group of 152 students from three elementary schools having dental clinics and control group of 136 students from three elementary schools of no dental clinics. The six dentists in Gimcheon community health center carried out the regular dental checkups in the elementary schools and four dental hygienists recorded the dental examination results. After receiving WHO dental survey guideline education, the examiners used dental mirror and dental probe under the natural light. The contents of the survey included dental caries in the deciduous and permanent teeth, malocclusion, remaining ratio of sealant, treatment, and follow up. Results: DFT index by grade showed that 3.71 in experimental group and 4.56 in control group and it was remarkable in the 3rd grade. Thus. DFT index in the experimental group was lower than that of control group (p<0.05). DT index by grade was 0.63 in experimental group and 1.28 in control group marked in the 6th grade. DT index in the control group was higher than that of the experimental group (p<0,001). DFT index and DMFT Index by grade showed no significant difference between the control group and the experimental group. DFT and DMFT Index of the control group in the 3rd and 6th grade were lower score than those of experimental group. DFT and DMFT index in the third and 6th grade showed no significant difference between the control group and the experimental group. The remaining ratio of the sealant was 4.89 experimental group in the 6th grade. The remaining ratio of the sealant in the experimental group was higher than that in the control group. Conclusions: The continuing dental care program in the elementary school is very effective method in the treatment of oral disease in the elementary school children. The oral health care and prevention for the elementary school children should be implemented and carried out continuously.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.23-29
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• 2008

The effectiveness of rehabilitation programs for coal mining spoils in Samcheok, Jeongsun, and Mungyung were evaluated based on the physicochemical properties of soil in the rehabilitated areas. These spoils were reclaimed by introducing plants such as black locust (Robinia pseudoacacia), pitch pine (Pinus rigida), birch (Betula platyphylla var. japonica), alder (Alnus hirsuta), bush clover (Lespedeza cyrtobotrya), and grass (Lolium perenne) in planting beds covered with forest soil. In the surface soil, the pH, organic matter, total N, available P, and exchangeable Ca showed significant changes over the years after reclamation. The pH and exchangeable Ca content decreased exponentially over time, whereas organic matter increased linearly and total N and available P increased exponentially. Changes in the physicochemical properties of subsurface soils displayed a different pattern. There were significant changes over time in the organic matter, available P, and exchangeable Ca and Mg contents of the soil. Organic matter increased logarithmically with years since rehabilitation and available P increased exponentially. Meanwhile, exchangeable Ca decreased exponentially, and Mg decreased logarithmically. The changes in the subsurface soil were not as dramatic as those in the surface soil. This result suggests that the ameliorating effects of the establishment and growth of plants more pronounced on the surface soil layer. Stand ordination data showed different relationships with time since rehabilitation in the early and later stages of the rehabilitation process. In the early stages of rehabilitation, stands tended to be arranged in the order of reclamation age. However, in the later stages, there was not a clear relationship between reclamation age and vegetation characteristics. This result suggests that soil amelioration is required for the early stages, after which an autogenic effect becomes more prominent as the vegetation becomes better established.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.762-771
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• 2010

Two experiments were conducted to determine i) the fermentation characteristics of catfish by-product (C) ensiled with rice bran (RB) or sugarcane molasses (M) in different ratios, and ii) the digestibility of the silages in growing pigs. In the ensiling experiment, there were three ratios of C, ensiled with RB or M, of 8:2, 7:3 and 6:4 (wet basis for C and air-dry basis for RB and M). The six treatments were CRB8:2, CRB7:3, CRB6:4, CM8:2, CM7:3 and CM6:4, with 3 replications per treatment and seven sampling times. The pH of CRB7:3 and CRB6:4 decreased (p<0.05) from the first week and stayed stable until 8 weeks of ensiling, but the pH did not decrease in CRB8:2. The pH of CM8:2, CM7:3 and CM6:4 decreased rapidly from the first week until week 8. Dry matter (DM) and crude protein (CP) contents were slightly lower when catfish by-product was ensiled with RB than with M. Ammonia content in all treatments increased (p<0.05) during ensiling. Lactic acid content in silages with molasses increased from the first week, with the highest value at week 4. However, the lactic acid content in CRB8:2 did not increase with time and had the lowest value of all treatments. Acetic acid proportions of total volatile fatty acids were low at day 0, with the highest value at day 7, decreasing slowly until 8 weeks. The butyric acid proportion was highest at day 0 and decreased up to week 8. The proportion of propionic acid increased during ensiling. The digestibility experiment had a 4${\times}$4 Latin-square design and included 4 castrated crossbreed (Yorkshire${\times}$Landrace) male pigs fed four diets. The basal diet (BD) included rice bran, broken rice and maize meal, and the other three diets included fish meal (FMD) or catfish by-product ensiled with rice bran (CRBD) or sugarcane molasses (CMD). The silages chosen were those which gave the best results in the ensiling experiment for each additive. The coefficient of total tract apparent digestibility (CTTAD) of DM and organic matter (OM) was not significantly different among treatments. The CTTAD of CP was not different among the silage diets, but was lower in BD (p<0.01). The CTTAD of ether extract (EE) was higher in the catfish by-product silage diets than in FMD and BD. There was no significant difference in the digestibility of DM, OM, CP and EE between the fish meal and the by-product silages. In conclusion, catfish by-product can be successfully preserved by ensiling. Moreover, the total tract apparent digestibility of OM, CP and EE in ensiled catfish by-product was comparable with that of fish meal.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.1-15
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• 2017

Wetland function assessment is not only a basic step to understand wetland ecosystems in detail but also an important process as a base of the term, ecosystem service to recognize wetland ecosystems as valuable and useful resources and goods for human being. WET (wetland evaluation technique), EMAP (environmental monitoring assessment program)-wetlands, and HGM (hydrogeomorphic method) were developed as pioneer wetland function assessments in U.S. at the end of $20^{th}$-century. RAMs (rapid assessment methods) became a major function assessment tool which is relatively simpler and easier assessment tool at the beginning of $21^{th}$-century. After that, the hierarchy of three levels of assessment (landscape assessment, rapid assessment, and intensive assesment) has been prepared and strategically utilized according to the objectives and purposes of function assessments. In South Korea, RAM and HGM were used to assess wetland functions with reforming a couple of items and contents at 2001. And, modified and reformed function assessments have been developed to complement and improve upon the existing RAMs and HGMs. Via the trend analysis on wetland function assessments, some needs which require supplements in terms of function assessment are pointed out: 1) wetland function assessments using useful indicators such as birds are needed with considering our environmental characteristics. 2) optimized wetland function assessments for coastal wetlands are also needed. 3) the network construction and further expansion to lead communications and co-operations between researchers and policy makers is needed in the field of wetland function assessment.

• Journal of Plant Biotechnology
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• v.42 no.1
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• pp.19-24
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• 2015

Glycine betaine (GB) is one of the compatible solutes that accumulate in the chloroplasts of certain halotolerant plants under salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into GB, has been cloned from a soil bacterium Arthrobacter globiformis. We generated transgenic sweetpotato plants [Ipomoea batatas (L.) Lam] expressing codA gene in chloroplasts under the control of the SWPA2 promoter (referred to as SC plants) and evaluated SC plants under oxidative and drought stresses. SC plants showed enhanced tolerance to methyl viologen (MV)-mediated oxidative stress and drought stress due to induced expression of codA. At $5{\mu}M$ of MV treatment, all SC plants showed enhanced tolerance to MV-mediated oxidative stress through maintaining low ion leakage and increased GB levels compared to wild type plants. When plants were subjected to drought conditions, SC plants showed enhanced tolerance to drought stress through maintaining high relative water contents and increased codA expression compared to wild type plants. These results suggest that the SC plants generated in this study will be useful for enhanced biomass production on global marginal lands.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.373-381
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• 1990

Endocrine cells in the cardiac and fundic regions of the Korean hedgehog were studied ultrastructurally. Five types of endocrine cells classified as EC, ECL, $D_1$. G and A-like cells were identified in these regions. EC cells contained pleomorphic granules, 170~500nm in diameter, with high electron density and highly dense bodies in a dense matrix. ECL cells were characterized by the presence of round or oval granules, 220~450nm in diameter, with high electron density. Some granules of ECL cells showed a small amounts of contents or empty. $D_1$ cells contained round and relatively small granules, 140~400nm in diameter, with low to moderate electron density. G cells were characterized by the presence of round or oval granules, 200~400nm in diameter, with moderate electron density. Some granules of these cells showed a narrow halo between the limiting membrane and the granular matrix. A-like cells contained round granules, 170~260nm in diameter, With high electron density. The granules of these cells showed homogeneous matrix surrounded by the tight membrane.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.209-218
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• 2006

This study was to evaluate microcystin production by two strains of cyanobacteria (Microcystis aeruginosa and Planktothrix agardhii) in response to three different levels of direct (0,4,8 inds.) or indirect (0,25, 50% of zooplankton culture media filtrate) exposures to zooplankton (Daphnia magna and Moina macrocopa). The cell biomass and intracellular microcystin (MC) were measured everyday. The survival rates of zooplankton were evaluated for daily intervals for the direct exposure. The intracellular MC produced peaked on the day 3 or 4, and then decreased over the both exposure experiment. In the direct experiment, the MC values were significantly different among the control and zooplankton treatments (ZT; repeated measures-ANOVA: P< 0.039). The MC contents of P. agardhii strain (No.204) were significantly higher (Tukey test, P< 0.082) in ZT2 (8 inds.) than in ZT2 (4 inds.). On the peak day, the intracellular MC exposed to both zooplanktons was significantly higher than the control (One-way ANOVA, P< 0.021). Higher zooplankton survivals were observed in the M. aeruginosa strain (No. 111) rather than in high toxic P. agardhii strain. In the indirect experiment, the intracellular MC of the M. aeruginosa strain was significantly different among the control and zooplankton culture media filtrate (ZCMF)treatments (rm-ANOVA: P<0.004), The MC exposed ZCMF2 (50%) were significantly higher than in ZCMFI (25%: Tukey test, P< 0.025) for both strains. This study strongly supports the induced-defensive MC production of potentially toxic cyanobacteria in response to the presence of zooplankton.