• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.70-70
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• 2003

Active sites and substrate bindings of 1-aminoxyclopropane-1-carboxylate oxidase (MD-ACO1) catalyzing the oxidative conversion of ACC to ethylene have been determined based on site-directed mutagenesis and comparative modeling methods. Molecular modeling based on the crystal structure of Isopenicillin N synthase (IPNS) provided MD-ACO1 structure. MD-ACO1 protein folds into a compact jelly roll shape, consisting of 9 ${\alpha}$-helices, 10 ${\beta}$-strands and several long loops. The MD-ACO1/ACC/Fe(II)/Ascorbate complex conformation was determined from automated docking program, AUTODOCK. The MD-ACO1/Fell complex model was consistent with well known binding motif information (HIS177-ASP179-HIS234). The cosubstrate, ascorbate is placed between iron binding pocket and Arg244 of MD-ACO1 enzyme, supporting the critical role of Arg244 for generating reaction product. These findings are strongly supported by previous biochemical data as well as site-directed mutagenesis data. The structure of enzyme/substrate suggests the structural mechanism for the biochemical role as well as substrate specificity of MD-ACO1 enzyme.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.116-122
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• 1992

This study determined hepatic microsomal lipid peroxide values glucose 6-phosphatase NA-DPH-cytochrome P450 reductase and cytosolic glutathione S-transferase activites to examine the effects of methyl group deficiency on hepatic lipid peroxidation in rats treated with diethylni-trosamine(DEN) and 2-acetylamionfluorene(AAF) Weanling sprague Dawley male rats were fed the diet with methyl group supplemented or deficient. Two weeks after feeding rate were injected with a single of 200mg/kg body weight DEN intraperitoneally and after four weeks 0.02% AAF containing diets were fed for two weeks. Animals were sacrificed at 6th week. Microsomal lipid peroxide values were tended to increase in methyl group deficiency(MD). Especially in case of carcinogen tratments lipid peroxide values were increased significantly in MD. Microsomal glucose 6-phophatase activities were decreased by MD and carcinogens and in MD with carcinogen group (MD+C) the enzyme activites were the lowest Glucose 6-phosphatase activities were negatively correlated with lipid peroxidation. Microsomal NADPH-cytochrome P450 reductase activities were the highest in MD+C and correlated positively with lipid peroxidation. Cytosolic glutathione S-transferase activities were the highest in MD+C Methyl group deficiency induces lipid peroxidation especially in case of being exposed to carcinogens. Therefore the results suggest that lipid peroxidation may be one of the meachanisms of carcinogensis by methyl group deficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2535-2542
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• 2011

This study was researched by practical method in a subjectivity study accessible in-depth, in sloughing off old habit of functional quantity analysis about product-selectivity on role of Home-shopping TV MD. The perception pattern come out in this study were divided into four types in Q-methodology. The result is as follows ; it is that divided '1[(N=9) : No-relationship Type], 2[(N=3) : Experience-oriented Type], 3[(N=5) : Ability-focus Type], 4[(N=1) : Drive-importance Type]'. Like this, it found that is very different type all over. In conclusion, this study is to ascertain acceptance behavior about Reception Type on product-selectivity on role of Home-shopping TV MD ; to offer a developmental suggestion about it.

• Food Science and Preservation
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• v.24 no.7
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• pp.891-897
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• 2017

Apple (Malus domestica) is a climacteric fruit because of its high respiration and ethylene production. Ethylene affects the fruit by decreasing its quality and storability. Md-ACS1 and Md-ACO1 genes are involved in ethylene biosynthesis in apple; the Md-ACS1-2 and Md-ACO1-1 alleles are associated with low ethylene production. We conducted an analysis to study Md-ACS1 and Md-ACO1, and to examine ethylene production and softening rate of fruit at room temperature ($20^{\circ}C$) storage in 'Fuji (FJ)', 'Golden Supreme (GS)', and 5 cultivars of Korean apples ('RubyS (RS)', 'Hongro (HR)', 'Arisoo (AS)', 'Summer King (SK)', 'Greenball (GB)'). The result showed that an increase in the number of the alleles (ACS1-2, ACO1-1) decreased the ethylene production and softening rate. The presence of ACS1-1/1, ACO1-1/2 was confirmed in GS and the highest ethylene production and softening rate was observed. Ethylene production and softening rate of SK and GB expressing ACS1-1/2, ACO1-1/2 were higher than that of HR and AS, expressing ACS1-2/2, ACO1-1/2, but lower than GS. FJ with ACS1-2/2, ACO1-1/1 showed the lowest ethylene production and softening rate among all cultivars except RS. The Md-ACS1 and Md-ACO1 DNA markers could potentially be used to estimate storability and applied in marker assisted selection the improve the efficiency of apple breeding.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1487-1494
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• 2009

The effects of drying temperature (55, 60, and $65^{\circ}C$) and addition levels of maltodextrin (MD) (10, 20, and 30%) on the physicochemical properties and nutritional quality of purple sweet potato flour were investigated. MD-added flours had higher $L^*$ values, water soluble index, total phenolic, and anthocyanin contents than untreated flour. However, $a^*$, $b^*$ values, water absorption index, and swelling capacity were dependent on the drying temperature and MD concentration. On the other hand, untreated flour had a higher ascorbic acid content compared to the MD-treated flour. Ascorbic acid contents decreased, whereas anthocyanin content was not significantly different, with increasing drying temperatures. MD was positively correlated with phenolic content, anthocyanin, hue angle, and water soluble index. However, there was no correlation between quality parameters and glass transition temperature. The best quality product was obtained when samples were pretreated with MD before drying, regardless of drying temperature.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.403-411
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• 2022

Annually, about 48-60% of sediment discharge of the Mekong River is delivered near the mouths of the Mekong River branches which is mostly coinciding with the southwest (SW) monsoon. This sediment budget in turn will be southwestwardly transported along the coast of the Mekong Delta (MD) during the northeast (NE) monsoon. Analysis of monsoonal changes in grain-size distribution (GSD) of surface sediment contributes to a better understanding of erosion and deposition processes along the MD. This study aims to figure out changes in GSD and sediment textures along the MD between SW and NE monsoons based on 183 surficial sediment samples collected along the MD during two field surveys carried-out in October 2016 and February-March 2017. Compared to the GSD during the SW and NE monsoon, the GSD along the MD changed significantly, especially in the estuary areas and along the coast of Bac Lieu and Ganh Hao. Whereas, in the west coast of the MD, GSD seem no changes between the two seasons. These changes in seabed sediment suggest that sediment with grain-sizes ranging from silt to fine sand can be transported during only a NE season.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.1-10
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• 2022

A vegetative filter strip (VFS) is one of the best management practices (BMPs) to reduce pollutant loads. This study aims to assess the effectiveness of VFS in dense upland field areas. The study areas are agricultural fields in the Maedae (MD), Gaa (GA), and Jaun (JU) watersheds, where severe sediment yields have occurred and the Korean government has designated them as non-point management regions. The agricultural fields were divided into three or four clusters for each watershed based on their slope, slope length, and area (e.g., MD1, MD2). To assess the sediment trapping (STE) and pesticide reduction efficiency (PRE) of VFS, the Vegetative Filter Strip Modeling System (VFSMOD) was applied with three different scenarios (SC) (SC1: VFS with rye vegetation; SC2: VFS with rye vegetation and a gentle slope in VFS range; and SC3: VFS with grass mixture). For SC1, there were relatively short slope lengths and small areas in the MD1 and GA3 clusters, and they showed higher pollutant reduction (STE>50%, PRE>25%). For SC2 and SC3, all clusters in GA and some clusters (MD1 and MD3) in MD show higher pollutant reduction (>25%), while the uplands in JU still show a lower pollutant (<25%). With correlation analysis between geographic characteristics and VFS effectiveness slope and slope length showed relative higher correlations with the pollutant efficiency than a area. The results of this study implied that slope and slope length should be considered to find suitable upland conditions for VFS installations.

• Nuclear Engineering and Technology
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• v.36 no.3
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• pp.229-236
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• 2004

Radiation hardening is a multiscale phenomenon involving various processes over a wide range of time and length. We present a multiscale model for estimating the amount of radiation hardening in pressure vessel steel in the environment of a light water reactor. The model comprises two main parts: molecular dynamics (MD) simulation and a point defect cluster (PDC) model. The MD simulation was used to investigate the primary damage caused by displacement cascades. The PDC model mathematically formulates interactions between point defects and their clusters, which explains the evolution of microstructures. We then used a dislocation barrier model to calculate the hardening due to the PDCs. The key input for this multiscale model is a neutron spectrum at the inner surface of reactor pressure vessel steel of the Younggwang Nuclear Power Plant No.5. A combined calculation from the MD simulation and the PDC model provides a convenient tool for estimating the amount of radiation hardening.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.295-301
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• 2006

This study has been designed to evaluate the efficacy of MD in-ovo vaccination in broiler and to find the contamination level of MD virus in broiler farms. A nested PCR test was used to find the level of filed contamination of pathogenic MD virus in the commercial broiler farms. The positive rate of farms contaminated with pathogenic MD virus was 26.09%. And to evaluate the efficacy of MD vaccination, performance factors such as the mortality, feed conversion rate and body weight at market age has been recorded and compared among farms. There was no difference on these factors between vaccinated and non-vaccinated farms except performance. We need further investigation of the film with low performance index. The B/B ratio, which is common index for the evaluation of bursal changes, was calculated and compared between vaccinated and non-vaccinated group There were significant decreases of B/B ratio in the both group without any statistical difference between groups. The reason of decreased bursal size may be due to other infection such as IBD. From this study, we can know that the contamination rate of fm with pathogenic MD virus was very low and not different from previous study. However, the difference of the contamination rate in different locations recommends periodical monitoring on these areas.

• Interaction and multiscale mechanics
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• v.6 no.4
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• pp.395-409
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• 2013

Molecular dynamics (MD) systems are highly nonlinear and nonlocal, and the conventional model order reduction methods are ineffective for MD systems. The RBF-POD method (Lee and Chen, 2013) employed a radial basis function (RBF) approximated potential energies and inter-atomic forces of MD systems under the framework of the proper orthogonal decomposition (POD) method for the reduced-order modeling of MD systems. In this work, we focus on the numerical procedures of the RBF-POD method and demonstrate how to apply this approach to the modeling of ds-DNA molecules under stretching and bending conditions.