• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.479-479
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• 2000

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.259-265
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• 2020

Antioxidative activities of 50% ethanolic extracts from Du-zhong (Eucommia ulmoides Oliver) leaf and bark were investigated. Yields of the leaf and bark extract were 8.1±0.31 and 17.4±0.89%, respectively. Polyphenol contents of the leaf and bark extract were 64.1±3.35 and 42.4±2.38 ㎍ gallic acid equivalents/mg, respectively. Flavonoid contents of the leaf and bark extract were 24.0±3.15 and 36.7±3.18 ㎍ quercetin equivalents/mg, respectively. As concentration of the leaf and bark extract increased, their antioxidative activities proportionally increased. EC₅₀ values of the leaf and bark extract for cation radical scavenging were 560.6±17.65 and 1,357.4±8.45 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for free radical scavenging were 574.2±14.70 and 2,103.1±108.59 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for ferric reducing antioxidant power were 319.9±13.42 and 705.9±26.08 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for nitrite scavenging were 2,329.2±35.11 and 5,467.6±243.92 ㎍/mL, respectively. In the presence of 74.8 ㎍/mL of the leaf extract and 177.2 ㎍/mL of the bark extract, linoleic acid peroxidation was inhibited by 70.0 and 79.1%, respectively. The Du-zhong leaf extract possessed higher antioxidative activities than its bark extract.

• Journal of Plant Biology
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• v.36 no.4
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• pp.377-382
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• 1993

Rice (Oryza saliva L.) calli containing both embryogenic callus (EC) and non embryogenic callus (NEC) regions were initiated from the mature seed on MS medium supplemented with 2.0 mg/L 2,4-D, 0.5 mg/L kinetin. The calli were developed into two callus type which can be distinguished by visual examination depending on color and appearance. In order to illucidate the polypeptide composition between EC and NEC, the total protein extracted from two types of callus was analysed by electrophoresis. By one-dimesional anlaysis of SDS-PAGE and Isoelectric focusing, several protein bands showed quantitative and qualitative difference in each type of callus. The further analysis of the total protein with two-dimensional electrophoresis showed at least 20 EC specific protein and 10 NE specific protein. Also 3 specific protein spots showing micro heterogeneity of 90, 65, 50 kD were detected in EC, while a series of acidic heterologous protein spots were visualized in NEC.in NEC.

• Journal of the Korean Home Economics Association
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• v.50 no.2
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• pp.53-64
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• 2012

This study was conducted to study the associations between parents' effortful control (EC), their parenting behavior and infants' EC. Subjects of the present study were 55 infants and their parents. Parents who participated in this study replied to questionnaires, including ECBQ-SF, ATQ-SF and Parenting style scale. There was positive correlations between the parents' EC, affectionate parenting style and infants' EC by zero-order correlation. We also performed Mann-Whitney test on the acquired data and it showed significant differences in the infants' EC by their parents' EC and parenting behavior. More specifically, infants with more affectionate and permissive parents showed higher levels of EC. Finally, we performed a partial correlation analysis and its results revealed that the correlation coefficient between the parents' EC and the infants' EC decreased when the parenting style was controlled. These results are vital to have a better understanding on the developmental pathways to the EC.

• Natural Product Sciences
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• v.2 no.2
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• pp.130-136
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• 1996

Evaluation of plant extracts that might inhibit hepatitis B virus (HBV) replication was performed to find potent anti-HBV agents. Eighty-five species of plants from forty-three families were tested for their anti-HBV activities using HBV-producing HepG2-derived 2.2.15 cells. The anti-HBV activity of plant extracts was measured by slot blot hybridization technique and cytotoxicity was determined by crystal violet staining procedure. All plants were extracted with methanol and the extracts were partitioned into n-hexane, ethyl acetate and aqueous layer. The ethyl acetate fractions of Rhus verniciflua $(stem:\;EC_{50},\;8.2{\mu}g/ml;\;CC_{50},\;9.4{\mu}g/ml)$, Gastrodia elata $(root:\;EC_{50},\;17.7{\mu}g/ml;\;CC_{50},\;>20{\mu}g/ml)$, Raphanus sativus $(seeds:\;EC_{50},\;17.3{\mu}g/ml;\;CC_{50},\;>20{\mu}g/ml)$, and Angelica gigas $(root:\;EC_{50},\;8.3{\mu}g/ml;\;CC_{50},\;15.6{\mu}g/ml)$ revealed the anti-HBV activity in 2.2.15 cell culture system and these fractions are under the process of further sequential fractionation by column chromatography to find the active principles against HBV.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.332-336
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• 2005

The average specific growth rate of C. reinhardtii (${\mu}$) was decreased with increase in biocide concentrations. The toxicity of biocides toward was as follows (in descending order of toxicities): herbicide 〉 pesticide 〉fungicide. $EC_{50}$ in each biocide was 0.0017 mg/L, 1.06 mg/L and 13.3 mg/L for herbicide, pesticide and fungicide respectively. When herbicide and pesticide were mixed, $EC_{50}$ was decreased by $2.7{\times}10^{-7}mg/L$. $EC_{50}$ in effective components of each biocide was 5.26 mg/L, 9.37 mg/L and 20.58 mg/L for herbicide, pesticide and fungicide respectively. Mixed main components of herbicide and pesticide caused to decrease by 3.10 mg/L.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.547-555
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• 2018

In addition to North America and Europe, Korea is also responding to the toxic damage caused by the production and distribution of chemicals. Methods for assessing bio-toxicity of harmful substances have been widely introduced, but it is required of quantitative and speedy information for modeling. For 6 heavy metals, as zinc, copper, chrome, cadmium, mercury and lead, bio-toxicity assessment and kinetics model were constructed using Vibrio fischeri which is widely used luminous bacteria. The degree of luminescence activity and the toxicity of heavy metals were relative limunescence unit, RLU measured as by using a photomultiplier embedded device. The toxicity was assessed by the concentration levels giving under 20% lethality and lethal concentration, $EC_{50}$. In the results, the toxicity order were followed from mercury, lead, copper, chrome, zinc and cadmium. $EC_{{50},{\infty}}$ obtained by trends of $EC_{50}$ by time follows had highly linear agreement with main parameters of bio-toxicity modelling. The average error rates of the reproduced lethality obtained from DAM and TDM model on the basis of body residue, were 10.2% for mercury, lead, copper, chrome and 20.0 for the all 6 methals.

• Journal of Wetlands Research
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• v.13 no.2
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• pp.181-187
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• 2011

The overall objective of this study is to develop the engineering-friendly-methodology which can investigate the fate of antibiotic resistance in environment microbial community. For this purpose, effective concentration (EC) concept was adopted with cultural based method which is currently used in engineering practice. When a tetracyline antibiotic was present as selective pressure agent among microbial community, activated sludge, the $EC_{50}$ and/or $EC_{90}$ of tetracycline in microbial community were statistically increased compared to control, especially higher growth rate and organic loading conditions of SBRs. Therefore, these results strongly suggested that the continuous monitoring of EC in microbial community can be used for characterizing the fate of tetracycline resistance community in environmental samples.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.95-98
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• 1982

The insecticides salithion$(Salithion^{(R)},\;25\;EC)$, decamethrin$(Decis^{(R)}\;1\;EC)$, phenthoate$(Elsan^{(R)},\;47.5\;EC)$, diazinon$(Diaton^{(R)})$, chlorfevinphes$(Birlane^{(R)},\;24\;EC)$, phosalone$(Zolone^{(R)},\;25\;EC)$, and methamidophos$(Tamaron^{(R)},\;60\;SL)$ were evaluated on the effectiveness of single ULV foliar spray for the control of the pine fall midges(Therodiplosis japonensis UCHIDA et INOUYE) when the insecticides diluted with the 50 times of water were applied to the pine trees$(1.5\~2m\;in\;height)$ on June 6 by ULV Sprayer(Battery-type of 12 voltage, devised by Union Carbide). A single ULV foliar spray of salithion, decamethrin, and phethoate among the insecticides tested was significantly effective for the pressure of the gall incidence by the insects.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.11-18
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• 2010

Toxicity assessment of ocean dumping wastes (dye waste, urban sewage, food waste) were examined in the fertilization and embryo development rates of the Sea Urchin, Hemicentrotus pulcherrimus. Spawning was induced by injecting 1 mL of 0.5 M KCl into coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. Experiments were began within 30 min the collection of both gametes. The fertilization and embryo development rates test were performed for 10 min and 64 h after fertilization, respectively. The fertilization and embryo development rates in the control condition (not including ocean dumping wastes sludge elutriate) were greater than 90%, but suddenly decreased with increasing of ocean dumping waste sludge elutriate concentrations. The fertilization and normal embryogenesis rates were significantly inhibited in all waste sludge elutriate from dye waste ($EC_{50}$=4.37; $EC_{50}$=1.76), urban sewage ($EC_{50}$=5.79; $EC_{50}$=2.00) and food waste ($EC_{50}$=7.68; $EC_{50}$=2.16), respectively. The NOEC (<3.13) and LOEC (3.13) of fertiliztion and normal embryogenesis rates very similar in all waste sludge elutriate. These results suggest that biological assay using the fertilization and embryo development rates of H. pulcherrimus are very useful test method for the ecological toxicity assessment of ocean dumping wastes.