• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.123-133
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• 2023

Wastewater generated in the secondary battery production process contains lithium and high-concentration sulfate. Recently, as demand as demand for high-Ni precursors with high-energy density has surged, nickel emission is also a concern. Lithium and sulfate are not included in the current water pollutant discharge standard, so if they are not properly processed and discharged, the negative effect on future environment may be great. Therefore, in this study, the ecotoxicity of lithium, nickel, and sulfate, which are potential contaminants that can be discharged from the secondary battery production process, was evaluated using water flea (Daphnia magna) and luminescent bacteria (Aliivibrio fischeri). As a result of the ecotoxicity test, 24-hour and 48-hour D. magna EC₅₀ values of lithium were 18.2mg/L and 14.5mg/L, nickel EC50 values were 7.2mg/L and 5.4mg/L, and sulfate EC₅₀ values were 4,605.5mg/L and 4,345.0mg/L, respectively. In the case of D. magna, it was found that there was a difference in ecotoxicity according to the contaminants and exposure time (24 hours, 48 hours). Comparing the EC₅₀ of D. magna for lithium, nickel, and sulfate, the EC₅₀ of nickel at 24h and 48h was 39.6-37.2% compared to lithium and 0.1-0.2% compared to sulfate, which was the most toxic among the three substances. The difference appeared to be at a similarlevelregardless of the exposure time. The EC₅₀ of sulfate was 253.0-299.7% and 639.5-804.6%, respectively, compared to lithium and nickel, showing the least toxicity among the three substances. The 30-minute EC₅₀ values of luminescent bacteria forlithium, nickel, and sulfate were 2,755.8mg/L, 7.4mg/L, and 66,047.3mg/L,respectively. Unlike nickel, it was confirmed that there was a difference in sensitivity between D. magna and A. fischeri bacteria to lithium and sulfate. Studies on the mixture toxicity of these substances are needed.

• Research in Plant Disease
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• v.30 no.2
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• pp.131-138
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• 2024

The effects of five fungicides on the spore growth phase of Alternaria dauci, which causes carrot leaf blight, were tested using the spore viability assay (SVA) and agar dilution method (ADM). The average EC₅₀ values for chlorothalonil against seven isolates of A. dauci examined by SVA and ADM were 14.21 ㎍/ml and more than 100 ㎍/ml. Dithianon and folpet also had lower EC₅₀ values in SVA than in ADM, while iminoctadine trisalbesilate had lower EC₅₀ value in ADM. For fluazinam, the EC₅₀ values of SVA and ADM were 1.63 and 2.40 ㎍/ml, respectively. As EC₅₀ values of five fungicides according to the spore growth phase of A. dauci KACC 42997, the efficacy of each fungicide as chlorothalonil, dithianon, and folpet decreased when treated after spore germination rather than when treated with spores before germination. However, iminoctadine tris-albesilate was more effective when treated after spores germinated than when treated before treatment. The excellent effect of fluazinam on the pathogen was maintained until A. dauci KACC 42997 was cultured in potato dextrose broth for 6 hr and the germ tube grew beyond the size of the spore. However, when treated with iminoctadine tris-albesilate and fluazinam after culturing for 12 hr, as the EC₅₀ values of the two fungicides increased to 8.87 and 20.65 ㎍/ml, their efficacies decreased. The results of this study show that the treatment time of the fungicide should be determined by considering the effect of the fungicide on the spore growth phase of pathogens.

• 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.

• Clean Technology
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• v.21 no.1
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• pp.39-44
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• 2015

This study investigated the effects of six metal oxide nanoparticles (NPs: CuO, NiO, TiO₂, Fe₂O₃, Co₃O₄, ZnO) on seed germination and germination index (G.I) for five types of seeds: Brassica napus L., Malva verticillata L., Brassica olercea L., Brassica campestris L., Daucus carota L. NPs of CuO, ZnO, NiO show significant toxicity impacts on seed activities [CuO (6-27 mg/L), ZnO (16-86 mg/L), NiO (48-112 mg/L)], while no significant effects were observed at > 1000 mg/L of TiO₂, Fe₂O₃, Co₃O₄. Tested five types of seed showed different sensitivities on seed germination and root activity, especially on NPs of CuO, ZnO, NiO. Malva verticillata L. seed was highly sensitive to toxic metal oxide NPs and showed following EC₅₀s : CuO 5.5 mg/L, ZnO 16.4 mg/L, NiO 53.4 mg/L. Mostly following order of toxicity was observed, CuO > ZnO > NiO > Fe₂O₃ ≈ Co₃O₄ ≈ TiO₂, where slightly different toxicity order was observed for carrot, showing CuO > NiO ≈ ZnO > Fe₂O₃ ≈ Co₃O₄ ≈ TiO₂.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.79-86
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• 2016

BACKGROUND: This study was initiated to quantitatively evaluate the effects of five heavy metals on the growth and P removal efficiencies of Alcaligenes sp., known as the Phosphorus Accumulating Organisms (PAOs). It was cultivated in the batch system with five heavy metals, such as Cd, Cu, Zn, Pb and Ni, added in single and binary mixtures, respectively.METHODS AND RESULTS: IC₅₀ (half of inhibition concentration of bacterial growth) and EC₅₀ (half of effective concentration of phosphorus removal Efficiencies) were used to quantitatively evaluate the effects of heavy metals on the growth and phosphorus removal Efficiencies of Alcaligenes sp. In addition, Additive Index Value (A.I.V.) method was used to evaluate the interactive effects between Alcaligenes sp. and heavy metals. As a result, as the five heavy metals were singly added to Alcaligenes sp., the greatest inhibitory effects on the growth and P removal efficiencies of each bacteria was observed in the cadmium (Cd). In the binary mixture treatments of heavy metals, the treatments of lowest IC₅₀ and EC₅₀ were the Cd + Cu treatment. Based on the IC₅₀ and EC₅₀ of the binary mixtures of heavy metals treatments, most interactive effects between the heavy metals were found to be antagonistic.CONCLUSION: Based on the results obtained from this study, it appears that they could provide the basic information about the toxic effects of the respective treatments of single and binary mixtures of heavy metals on the growth and P removal efficiencies of Alcaligenes sp. through further study about the characterization of functional proteins involved in toxic effects of heavy metals.

• Herbal Formula Science
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• v.31 no.1
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• pp.11-19
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• 2023

Objectives : The purpose of this study was to examine the effects of herbal medicines on pacemaker potentials of large intestinal interstitial Cells of Cajal (ICC) in mice. Methods : We made the ICC culture in large intestine in mice and used the electrophysiological method to record pacemaker potentials. Also we used MTT assay to check cell viability and examined the ICC protein expression by western blot. Results : 1.Glycyrrhiza uralensis Fischer (GF) (50-150 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 58.95 ㎍/ml. Angelica gigas (AG) (50-200 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 77.22 ㎍/ml. Poncirus fructus (PF) (10-100 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 13.39 ㎍/ml. Citrus unshiu S. Marcov. (CU) (10-500 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 139.80 ㎍/ml. Gardenia jasminoides J. Ellis (GJ) (100-500 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 78.70 ㎍/ml. Coptis chinensis (CC) (100-1000 ㎍/ml) induced pacemaker depolarization and decreased frequency with concentration-dependent manners. EC₅₀ is 138.10 ㎍/ml. Scutellaria baicalensis (SB) (10-100 ㎍/ml) had no effects on pacemaker potentials and decreased frequency with concentration-dependent manners. IC₅₀ is 18.34 ㎍/ml. Atractylodes macrocephala koidzumi (AM) (10-100 ㎍/ml) induced pacemaker hyperpolarizations and decreased frequency with concentration-dependent manners. IC₅₀ is 18.54 ㎍/ml. 2. PF, SB and AM had no effects on cell death in large ICC. 3. PF increased the ANO1 and c-kit protein expression and SB and AM increased the c-kit protein expression in large ICC. Conclusions : These results suggest that PF, SB, and AM are likely to be the optimal combination of herbal medicines that can be used to treat diseases such as gastrointestinal motility disorders such as irritable bowel syndrome.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.407-411
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• 2021

In vitro antioxidant potential of 30% (v/v) ethanolic extracts from Panax ginseng and Panax notoginseng roots was investigated. The polyphenol contents of Panax ginseng and Panax notoginseng extracts were 10.3±0.3 and 10.4±0.4 mg/g-extract, respectively. The extracts of Panax ginseng and Panax notoginseng possessed an antioxidant potential in a concentration-dependent manner. EC₅₀ values of Panax ginseng and Panax notoginseng extracts for cation radical, reducing power, and nitrite were 4.76±0.12 and 6.24±0.14 mg/mL, 1.99±0.01 and 3.13±0.05 mg/mL, and 4.78±0.31 and 3.52±0.10 mg/mL, respectively.

• Journal of Life Science
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• v.26 no.9
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• pp.1074-1081
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• 2016

Mistletoes are hemi-parasitic plant growing on different host tree and shrubs. They are traditionally used in folkloric medicine for the treatment of diarrhea, cough, diabetes, hypertension, cancer and skin infection. The purpose of this study was to determine the contents of phenolics and antioxidant activity of 70% ethanol, 100% methanol and hot water extracts of Jeju camellia mistletoe (Korthalsella japonica Engl.). Ethanol was most effective in extracting total phenols (7,427 mg gallic acid equivalent (GAE)/100 g) and flavonoid (1,777 mg rutin equivalent (RE)/100 g). The free radical scavenging activity, 1,1-diphenyl-2-picryl hydrazyl (DPPH) (EC₅₀ = 7.8 mg/ml) and hydrogen peroxide (H₂O₂) (EC₅₀ = 1.4 mg/ml), and the capacity for chelating metal ions (EC₅₀ = 8.0 mg/ml) and reducing power (EC₅₀ = 14.9 mg/ml) of the samples also higher in ethanolic extracts. The strong correlation (r² = −0.996～−0.881) between antioxidant capacities and the phenolic contents implied that phenolic compounds are a major contributor to the antioxidant activity of the ethanolic extracts of Jeju camellia mistletoe. As conclusions, Jeju camellia mistletoe contains bioactive substances with a potential for reducing the physiological as well as oxidative stress and this could explain the suggested cancer preventive effect of these plants as well as their protective role on other major diseases.

• Research in Plant Disease
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• v.26 no.2
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• pp.79-87
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• 2020

Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae (Fof) is the most important diseases of a strawberry field in Korea. We surveyed phylogenetic analysis, pathogenicity test, and fungicide response about Fof isolates isolated from Korea. Twenty-seven isolates of F. oxysporum isolated from strawberry plants were conducted in this study. Specific amplification by Fof specific primer was confirmed in all 26 isolates except Fo080701 isolate. The nuclear ribosomal intergenic spacer region and the translation elongation factor EF-lα gene sequences of isolates revealed three main lineages. Most of all isolates were contained DNA lineage group 1, but 2 and 3 group was shown only one and three isolates, respectively. All isolates were shown in pathogenicity with cv. Seolhyang. The EC₅₀ mean values of prochloraz ranged 0.02-0.1 ㎍/ml except for Fo080701 and effectively inhibited mycelial growth at low concentrations. The EC₅₀ value of metconazole was also 0.04-0.22 ㎍/ml, showing a similar inhibitory effect to that of prochloraz. The EC₅₀ value of pyraclostrobin was 0.23-168.01 ㎍/ml, which was different according to the strain. In the field trial, boscalid+fludioxonil, fluxapyroxad+pyraclostrobin, and prochloraz manganese were selected as the effective fungicides for controlling Fusarium wilt.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.281-289
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• 2022

Fusarium head blight is an important disease of small grains. It is mainly caused by members of the Fusarium graminearum species complex (FGSC). Barley and wheat growers spray fungicides, especially demethylation-inhibitor fungicides, to suppress the disease. The objective of this study was to examine the changes in the sensitivity of the FGSC population to the triazole fungicide, propiconazole. A total of 124 and 350 isolates of FGSC were obtained from barley and wheat in Jeolla Province during 2010-2016 and 2020-2021, respectively. The species identity and trichothecene chemotypes of the FGSC isolates were determined based on polymerase chain reaction assays targeting translation elongation factor 1-alpha and TRI12 genes, respectively. Sensitivity to propiconazole was determined based on the effective concentration that reduced 50% of the mycelial growth (EC₅₀) using the agar dilution method. Of all isolates, F. asiaticum with the nivalenol chemotype was the most common (83.9% in 2010-2016 and 96.0% in 2020-2021), followed by F. asiaticum with the 3-acetyl deoxynivalenol chemotype (12.1% in 2010-2016 and 2.9% in 2020-2021). The EC₅₀ values of the isolates collected in 2010-2016 and 2020-2021 ranged from 0.0180 to 11.0166 ㎍/mL and 1.3104 to 17.9587 ㎍/mL, respectively. The mean EC₅₀ value of the isolates increased from 3.8648 ㎍/mL in 2010-2016 to 5.9635 ㎍/mL in 2020-2021. The baseline resistance to propiconazole was determined to be 7 ㎍/mL, based on the EC₅₀ value of isolates collected in 2010-2016, and the ratio of resistant isolates increased from 9.7% in 2010-2016 to 28.6% in 2020-2021.