• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.1
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• pp.30-34
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• 2012

The filamentous bacterium Leucothrix mucor, an epiphyte of seaweed, showed antifouling activity against Ulva pertusa spore settlement and germling development. The chemical constituents representing the antifouling activity were identified as giffinisterone B and oleamide based on nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). Approximately 3.6 mg of giffinisterone B and 2.8 mg of oleamide were isolated from 1.6 g of Leucothrix mucor crude extract. Giffinisterone B fully inhibited spore settlement and germling development at $100{\mu}g/mL$. Oleamide inhibited spore settlement at $10{\mu}g/mL$ and germling development at $100{\mu}g/mL$.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.198-204
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• 2016

The characteristics of the flow field of a circular cylinder having a small vertical plate at the upstream side are investigated by measuring the fluid force on the circular cylinder and by visualizing the flow field using particle image velocimetry. The experimental parameters are the width ratios (H/B = 0.2-0.6) of the vertical plates to the circular cylinder's diameter, and the gap ratios (G/B = 0-3) between the circular cylinder and the vertical plate. The drag reduction rate and Strouhal number of the circular cylinder increased and then decreased with G/B in the case of the same H/B. The drag reduction rate increased with H/B in the case of the same G/B. In the case of a circular cylinder having a small vertical plate, the stagnation regions are represented on the upstream and downstream sides of the circular cylinder, and the size of that region on the upstream side increased with H/B.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.40-44
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• 2009

This study was carried for the understanding of infiltration and percolation characteristics of water in agricultural land filled with rock-dust (Technosols). The experiment was performed at two sites (A, B), and soil horizons of the sites were classified with 4 layers, respectively. The soil texture of all soil horizons was analyzed with silt loam (SiL) except for the soil texture, which was loamy sand (LS), at the lowest horizon of measurement site A. The bulk densities at each horizon of two soils were mostly over $1.49g{\cdot}cm^{-3}$, which is very higher than $1.25g{\cdot}cm^{-3}$ of typical medium-textured mineral soil, except for the surface of site A measured immediately after tillage. The concentrations of $P_2O_5$ at surface of two soils s were 1962 (A), 1613 (B) $mg{\cdot}kg^{-1}$, respectively. These concentrations are 3.2~6.5 times of $300{\sim}500mg{\cdot}kg^{-1}$, which is the optimum concentration for crop growth. Infiltration rates at surface of the soils were 3.54 (A), 2.85 (B) cm $hr^{-1}$, but percolation rates at soil horizons under the surface were below 0.3 (A), below 0.003 (B) cm $hr^{-1}$. These results would be because the surface soils were managed by tillage and crop planting etc., but soils under surface were formed with structural problems occurred at the formation time of agricultural land accumulated with rock-dust or a compaction by farm machines.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.534-541
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• 2019

his study assessed microbial contamination of leeks and leek-cultivated soil. Leeks and leek-cultivated soil were collected in A and B regions and accounted for 39 and 33 samples, respectively. All of the samples were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Salmonella spp., E. coli O157:H7, Listeria monocytogenes, and Bacillus cereus. In A and B region, the total aerobic bacteria was in the range of 5.87-8.78 log CFU/g for leeks and 5.94-8.45 log CFU/g for leek-cultivated soil. The coliform in leeks and leek-cultivated soil was in the range of 1.20-7.36 log CFU/g and 2.45-5.87 log CFU/g, respectively. B. cereus was detected from some of the samples while other pathogens were not detected. This study provides important background information on the microbiological safety of fresh vegetable cultivation environments.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.124-129
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• 2006

The grades of burley tobacco stems and scraps were classified followed by the nicotine and nitrate contents by using the cluster analysis. The chemical components of the burley tobacco stems and scraps gathered from 2002 to 2005 were analyzed with auto analyzer. According to the nicotine contents and the nitrate contents, the burley stems and scraps could be classified three groups, respectively. In case of the burley scraps, the AB3T, AB4TR, B1T and B2T grades belonged to the $1^{st}$ a group. The C1W and C2W grades belonged to the $2^{nd}$ group and the CD3W and CD4TR belonged to the $3^{rd}$. In case of the burley stems, the AB3T and AB4TR grades belonged to the $1^{st}$ group. The B1T, B2T, C1W and C2W grades belonged to the $2^{nd}$ group and the CD3W and CD4TR belonged to the $3^{rd}$ group. This classification of raw materials depending on the similarity in the chemical components might be helpful to control the properties of the Reconstituted Tobacco sheet.

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.479-484
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• 2011

A reverse-phase system of HPLC using a linear gradient of acetonitrile and deionized water was developed for the quantification lignans, eleutherosides B and E, in Acanthopanax senticosus. The HPLC system consisted of linear gradient of acetonitrile and deionized water, and UV/VIS detection was set at 210 nm. Both eleutherosides B and E contents in different parts of A. senticosus were determined. As a result, the contents of eleutherosides B and E were measured in the leaves (trace amounts and 0.029 mg/g, respectively), stems (0.107 and 1.015 mg/g, respectively), roots (0.026 and 0.390 mg/g, respectively), and fruits (0.022 and 0.043 mg/g, respectively). Moreover, eleutherosides B and E in the water extract were found 0.011 and 0.171 mg/g, respectively.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.81-86
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• 2011

This study was conducted to evaluate the influence of crown diameter on plant growth after planting and fruit yield. All nursery plants were classified into three classes: A, > 9 mm; B, 8~9 mm; C, < 8 mm. The A-class nursery plant plot showed better root and plant growth after planting compared to the B-class and C-class nursery plants. The A-class nursery plant plot was 10 days faster in first flowering time then those of the B-class and the C-class. Also, the A-class nursery plant plot was 2~3 days faster in the mean flowering time. The accumulative yield of the A-class nursery plant plot was 481 g per plant, that of the B-class was 445 g, and the C 422 g, which the nursery plant plot of A-class yielded more 8.1% and 13.9% respectively than B-class plot and C-class plot per plant. In early yield of to February; A-class nursery plant plot showed 23.3% higher yield than B-class nursery plant plot, and 39.1% higher the C-class nursery plant.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.19-25
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• 2006

Objectives : The aim was to study experimentally the effects of KABHANG-BANG(갑항방) on the hyperthyroidism of rats induced by sodium levothyroxine. Methods : Spargue-Dawley rats were separated into four groups. Except normal group, the other three groups were treated with sodium levothyroxine $32{\mu}g$/200g/days for 5 days by oral administration. Among the three groups, two except one(as control) were treated KHB extract 225mg/200g/days(sample A), 450mg/200g/days(sample B) for 3 days separately. T3-uptake, T3, T4, r-TSH, total cholesterol, total protein change in the Serum of rats were measured after medication of solid extract of KHB. Results : As a result of this study, in the serum T3 and T4 level were decreased in sample A and B compared to controls. The serum r-TSH, total cholesterol and total protein were increase in sample A and B compared to controls. In the serum T3-uptake content, Smple B showed significant decrease in comparison with control group, but Sample A did not show significant decrease. Conclusion : According to the above results, it is suggested that KHB is effective to cure hyperthyroidism.

• The Korean Journal of Ecology
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• v.10 no.1
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• pp.23-31
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• 1987

This study was carried out to investigate by the MGP analysis the composition of oribatid mite in coniferous and broad-leaved forests, Kwang Yng experiment plantation, Chola Nam Do Province, southern part of Korea. In these study area, 157 species of oribatid mites (Acari: Cryptogimata) were identified. Among them 6 species such as; Brachychochthonius jugatus JACOT, B hungaricus BALOGH, Eremulus translamealtus BALOGH et. MAHUNKA, Brachioppiella ctenifera GOLOSOVA, Striatoppia opuntiseta BALOGH et. MAHUNKA, Suctobelba perdentata baculifer BALOGH et. MAHUNKA have not been described in Korea. Species compositions were as follows; Among them 69 species were found in all the six sampling sites, 33 species scattered sporadically in all the area, 12 species found in coniferous forest, 10 species in broad-leaved forest only, and 33 species sampled at one site. According to the MGP analysis I, site B-1, B-2, and B-3 were found to be "Type G" and site C-1, C-2, and C-3 were "Type MG". According to the MGP analysis II, site B were found to be all "Type G". But site C-1 was "Type MG", C-2 was "Type M" and C-3 was "Type G" suggesting that "Group M" increased in the site C.e G" suggesting that "Group M" increased in the site C. in the site C.

• Natural Product Sciences
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• v.16 no.4
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.