• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.236-236
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• 2017

Effluent treated by an NaDCC injection method in Ballast water management system (BWMS) contains reactive chlorine species and disinfection by-products (DBPs). In this study, we conducted whole effluent toxicity (WET) testing and ecological risk assessment (ERA) to investigate its ecotoxicological effects on marine environment. WET testing was carried out for four marine pelagic and freshwater organisms, i.e., diatom Skeletonema costatum, Navicula pellicuosa, chlorophyta Dunaliella tertiolecta, Pseudokirchneriella subcapitata, rotifer Brachionus plicatilis, Brachionus calyciflorus and fish Cyprinodon variegatus, Pimephales promelas. The biological toxicity test revealed that algae was the only biota that showed apparent toxicity to the effluent; it showed no observed effect concentration (NOEC), lowest observable effect concentration (LOEC) and effect concentration of 50% (EC50) values of 25-50%, 50-100% and >100%, respectively, at three water condition, but did not show any significant toxicities on other biota. Meanwhile, chemical analysis revealed that the BWMS effluent contained total residual oxidants (TROs) below $0.03{\mu}g/L$ and a total of 25 DBPs such as bromate, volatile halogenated organic compounds (VOCs), halogenated acetonitriles (HANs), halogenated acetic acids (HAAs), chloropicrin and Isocyanuric acid. Based on ERA, the 25 DBPs were not considered to have persistency, bioaccumulation and toxicity (PBT) properties. The ratio of predicted environmental concentration (PEC) to predicted no effect concentration (PNEC) of the other DBPs did not exceed 1 for General harbor environment. However, four substances (Isocyanuric acid, Tribromomethane, Chloropicrin and Monochloroacetic acid) were exceed 1 for Nearship environment. But observed toxicity in the test water on algal growth inhibition would be mitigated by normal dilution factor of 5 applied for nearship exposure. Thus, our results of WET testing and ERA showed that the BWMS effluent treated by NaDCC injection method would have no adverse impacts on marine environment.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.61-72
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• 2018

Objectives The purpose of this experiment is to evaluate 4 weeks DRF (Dose Rate Finding) and single oral dose toxicity of ChondroT in rats. Methods In 4-week DRF, male and female Sprague-Dawely rats were treated with ChondroT at oral dose of 0, 500, 1000, and 2000 mg/kg. clinical signs, body weight, food consumption, necropsy findings, organ weight, hematological and blood-chemical parameters, and histological findings were monitored for 4 weeks. Also, after single oral administration of ChondroT, mortality, clinical signs, body weight, and necropsy findings were minitored for 2 weeks. Results In 4-week DRF and single dose oral toxicity study of ChondroT in sprague-Dawley rats, ChondroT did not exhibit any toxicity under the study conditions employed. Conclusions The results suggested a no-observed adverse effects level (NOAEL) was over 2,000 mg/kg/day in SD rats after oral administration, this study could be used as basic study of the repeated dose 13-week oral toxicity study of ChondroT.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.21-29
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• 2007

In Korea, we assign the chemical substances of 535 types as toxic substance. Only 10% of the 535 toxic substances are being managed by the Ministry of Environment related with water quality standard. Tar color is also one of chemical substances, but we have the lacks for the information of tar colors about the environmental effects of aquatic ecosystem. This study performed the test of bioassay using Water Fleas and Luminescent Bacteria. The tar has 7 types of colors allowed as the edible color and we evaluate the toxicities of 5 tar colors out of 7 colors and we would like to provide the informations for further study as we perform the toxicity test for the samples of 5 tar colors. We did the toxicity test of using Water Fleas From the results, we obtained the magnitudes of toxicity in order of Red No.2, Yellow No.5, Red No.3, Yellow No.4, Blue No.1. As the result based on Microtox Acute Toxicity Test using Luminescent Bacteria with the standard of 15min-EC50, we obtained in order of Yellow No.5, Food Red No.3, Red No.2, Yellow No.4, Blue No.1. We could expect the tar colors may have different effects on the aquatic ecosystem, respectively and it may influence to the aquatic ecosystem and the human, because of bioconcentration by food chain when toxicity of the tar colors overflow in the aquatic ecosystem.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2051-2057
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• 2011

Several studies have demonstrated that nanoparticles (NPs) have toxic effects on cultured cell lines, yet there are no clear data describing the overall molecular changes induced by NPs currently in use for human applications. In this study, the in vitro cytotoxicity of three oxide NPs of around 100 nm size, namely, mesoporous silica (MCM-41), iron oxide ($Fe_2O_3$-NPs), and zinc oxide (ZnO-NPs), was evaluated in the human embryonic kidney cell line HEK293. Cell viability assays demonstrated that 100 ${\mu}g/mL$ MCM-41, 100 ${\mu}g/mL$ $Fe_2O_3$, and 12.5 ${\mu}g/mL$ ZnO exhibited 20% reductions in HEK293 cell viability in 24 hrs. DNA microarray analysis was performed on cells treated with these oxide NPs and further validated by real time PCR to understand cytotoxic changes occurring at the molecular level. Microarray analysis of NP-treated cells identified a number of up- and down-regulated genes that were found to be associated with inflammation, stress, and the cell death and defense response. At both the cellular and molecular levels, the toxicity was observed in the following order: ZnO-NPs > $Fe_2O_3$-NPs > MCM-41. In conclusion, our study provides important information regarding the toxicity of these three commonly used oxide NPs, which should be useful in future biomedical applications of these nanoparticles.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.169-174
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• 2017

Acute and chronic toxicities of methyl ethyl ketone and methanol were investigated on Paronychiurus kimi (Collembola), for evaluating the potential effects of accidental exposures of these chemical substances on the terrestrial environments. This study was undertaken to establish a toxicity database for these chemical substances, which was required for the preparation of the response compensation and liability act for agricultural production and environmental damage. The 7-d acute toxicity and 28-d chronic toxicity were conducted using the OECD artificial soil spiked with varying, serially diluted concentrations of methyl ethyl ketone and methanol. Mortality was recorded after 7-d and 28-d of exposures, and the number of juveniles were determined after 28-d of exposure in the chronic toxicity test. In both assessments, methanol was more toxic than methyl ethyl ketone in terms of mortality ($LC_{50}$) and reproduction ($EC_{50}$). The 7-d $LC_{50}$ of methyl ethyl ketone and methanol were 762 and $2378mg\;kg^{-1}$ soil dry wt., respectively, and the 28-d $LC_{50}s$ were 6063 and $1857mg\;kg^{-1}$ soil dry wt., respectively. The 28-d $EC_{50}$ of methyl ethyl ketone and methanol were 265 and $602mg\;kg^{-1}$ soil dry wt., respectively. Comparison of results obtained in this study with literature data revealed that P. kimi was more sensitive to methanol than other soil invertebrates. However, given the high volatility of the chemicals tested in this study, further studies are necessary to improve the current test guideline, or to develop new test guidelines for an accurate assessment of chemicals that require toxicity databases for chemical accidents.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.499-513
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• 2020

Among the many studies of carbon-based nanomaterials, carbon-based dots (CDs) have attracted considerable interest owing to their large surface area, intrinsic low-toxicity, excellent biocompatibility, high solubility, and low-cost with environmentally friendly routes, as well as their ability for modification with other nanomaterials. CDs have several applications in biosensing, photocatalysis, bioimaging, and nanomedicine. In addition, the fascinating electrochemical properties of CDs, including high active surface area, excellent electrical conductivity, electrocatalytic activity, high porosity, and adsorption capability, make them potential candidates for electrochemical sensing materials. This paper reviews the recent developments and synthesis of CDs and their composites for the proposed electrochemical sensing platforms. The electrochemical principles and future perspective and challenges of electrochemical biosensors are also discussed based on CDs-nanocomposites.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1101-1102
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• 2008

• YAKHAK HOEJI
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• v.31 no.4
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• pp.236-251
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• 1987

The chemistry, antimicrobial properties, organic soil resistance, toxicity, corrosivity and chemical stability of stabilized alkaline 2%, glutaraldehyde solution(SGS) are discussed. SGS retains the maximum antimicrobial activity of alkaline glutaraldehyde solutions and the chemical stability here to fore observed only with acidic glutaraldehyde solutions. These improvements, along with the inherent resistance of glutaradehyde to neutralization by organic soil, allow SGS to be continuously used for 14 days in situations of high dilution, or 28 days in situations of low dilution.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.997-998
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• 2009

• Journal of Life Science
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• v.16 no.1
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• pp.108-113
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• 2006

To compensate the problems of chemical assay in detoxification of recalcitrant and a practical approach in selection of bioremediation bacteria, a simple and rapid toxicity evaluation system was constructed based on Lumbricus rubellus. Long term-culture and specific equipment are not necessary, and semi-quantitative analysis of toxicity at sub-lethal concentration is possible by measuring of dose-dependent increased yellowish secreted compounds. When the toxicity of endosulfan, its metabolites and structurally related chemicals were measured for 24 h, the results were coincided with previous reports. Toxicity was found in endosulfan, endosulfan sulfate, aldrin, and dieldrin, respectively. Rapid and economic selection of endosulfan-detoxifying bacteria was possible using our system. Klebsiella pneumoniae KE-1, K. oxytoca KE-8 and Pseudomonas sp. KS-2P, reported endosulfan degrading bacteria, ameliorated the endosulfan toxicity, whereas E. coli, B. subtilis and other bacteria failed to protect the toxicity of endosulfan in L. rubellus. Our results suggest that the constructed system is useful to selection of microorganism as well as toxicity evaluation against toxic recalcitrants.