• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.467-472
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• 2009

Seedling growth test is used to assess toxicity of nanoparticles (NPs). This study evaluates toxicity of zinc, zinc oxide NPs on Cucumis sativus using two methods; phytagel and filter paper. From the comparison, phytagel method prevents precipitation of water insoluble NPS. Seeding length was negatively related to the exposed concentration of Zn, ZnO NPs in filter method. The median effective concentrations (EC50) for C. sativus exposed to Zn, ZnO NPs were estimated about 598, 600 mg/L in filter method. Bioaccumulation increased with the exposed concentration of Zn, ZnO NPs in only filter method. The results showed that the filter paper method was much better protocol than phytagel method.

• KSBB Journal
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• v.7 no.1
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• pp.33-37
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• 1992

This study is to investigate the ethanol tolerance of yeast strains related to fatty acid composition and intracellular ethanol concentration for various fermentation temperatures. The maximum accumulation of ethanol in the cells was decreased by lowering the fermentation temperature, while unsaturated fatty acid content was increased by decreasing the fermentation temperature. Thus, we found that the increase of ethanol accumulation in cells resulted in the decrease of unsaturated fatty acid content. Therefore, it was suggested that the composition of unsaturated fatty acids in the cell membrane be strongly related to the diffusion of ethanol from cell to medium.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.142-148
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• 2003

The aim of the study was to determine Pb and Cd accumulation and to assess its trends in relation to age categories in feral pigeons from urban (Seoul) and industrial complex (Ansan) areas. This study shows that Pb and Cd concentrations in bone, kidney, liver, and lung increase with different developmental stages in feral pigeons. Particularly, Pb in the bones and Cd in the kidneys of birds were highly increased from chicks to adults. Mean Pb concentrations in pigeons from Seoul were three times higher in chicks than in eggs and six times greater in adults than in chicks. For Cd concentrations, pigeons in Seoul contained two times higher in chicks than in eggs and seventeen times higher in adults than in chicks. It indicates that Pb and Cd concentrations increase with age, and these are apparent to the results in Seoul than in the Ansan colony.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.391-392
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• 2000

Tobacco cells transformed with hGM-CSF gene produced $162\;{\mu}g/L$ of hGM-CSF, a valuable therapeutic protein in seven days after inoculation. The protein concentration decreased after the maximum point. It is evidenced that the environment of cell culture was inappropriate for the stability of the protein(e.g., low osmolarity which can cause cell lysis).

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.81-88
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• 2019

In order to understand the effects of the main components of antifoaming agents on the marine benthic ecosystem when silicone-based antifoaming agents are discharged into marine environments, eco-toxicity testing was performed on silicone and alcohol-based antifoaming agent by using benthic amphipod (Monocorophium acherusicum) and luminescent bacteria (Vibrio fischeri). The toxic effects of Polydimethylsiloxane (PDMS) as a main component of silicone-based antifoaming agents on aquatic organisms were also researched. In the results of the eco-toxicity test, luminescent bacteria showed a maximum of 9 times more toxic effects than benthic amphipod for alcohol-based antifoaming agents, and silicone-based antifoaming agents showed a maximum of 400 times more toxic effects than alcohol-based. The $LC_{50}$ and $EC_{50}$ values of PDMS ranged from 10 to $44,500{\mu}g/L$ in phytoplankton, invertebrate, and fish. In the results of applying PBT (P: persistency, B: bioaccumulation, T: toxicity) characteristics as an index showing the qualitative characteristics of PDMS, persistency (P) and bioaccumulation (B) were confirmed. Thus, when PDMS is discharged to marine environments, it could accumulate in the upper trophic level through bioaccumulation and the food chain, which could have negative effects on benthic organisms. The results of this study may be used for objective and scientific risk assessment, considering the major components of antifoaming agents when investigating the effects of various discharged antifoaming agents in marine ecosystem.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.204-210
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• 2006

The purple color in flesh of 'Jasim' potato (Solanum tuberosum L.) tubers is due to an accumulation of anthocyanin. The experiment was conducted to determine what is the key factor among cultural environments that affect the accumulation of anthocyanin in 'Jasim' potato tubers, and the effect of nitrogen fertilization levels on that. Through analysis of anthocyanin content of purple-fleshed tubers produced under the different cultural environments of three localities and two planting dates, we determined that lower temperature during 30days before harvesting resulted in higher anthocyanin accumulation of 'Jasim' potato tubers. In the experiment of different level of nitrogen fertilization, 'Jasim' potato tubers produced in highland (Daegualryeong) showed higher content of anthocyanin in the treatment of recommended level than in treatment of lower or higher level as compared with the recommended level. However, significant difference of anthocyanin content among different nitrogen fertilization levels was not observed in lowland (Gangnung). These results suggest that the selection of locality or cropping system and the optimal fertilization management are very important factors for production of higher pigmented tubers in purple-fleshed potato.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.237-246
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• 2015

Heavy metal pollution in soil, such as lead contamination, has become an area of interest in Korea because of urbanization and atmospheric deposition from neighboring countries. Therefore, in this research, eco-physiological responses such as chlorophyll contents, antioxidant enzyme activity, photosynthetic rate, biomass and phytoaccumulation abilities were investigated for 4 commonly used native roadside tree species to suggest suitable tree species to cope with lead contamination. The target species, Ginkgo biloba, Prunus yedoensis, Zelkova serrata and Chionanthus retusus showed lead toxicity by significant changes of chlorophyll contents and antioxidant enzyme activities on treatments over 200 mg Pb/kg. However, biomass and photosynthetic rates only showed significant responses of plants in the highest level (5,000 mg/kg) treatment. Especially, G. biloba did not show any significant changes of antioxidant enzyme activity, photosynthetic rate, and biomass even in the highest level treatment. In low level - environmentally realistic treatments, G. biloba and P. yedoensis showed the highest phytoaccumulation rate of lead from soil. Selecting and planting species like G. biloba which have good phytoaccumulation abilities and resistance to lead contamination by further research will be required to deal with emerging lead contamination.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.367-367
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• 2022

토지이용의 고도화에 따라 비점오염원 부하는 증가하는 추세이며 기후변화에 따른 강우강도 증가 등으로 지표면에 축적된 고농도의 비점오염물질이 하천으로 유출, 수질오염을 가중시키고 있어 비점오염원 관리가 필요하다. LID 기법은 자연적 기작(mechanisms)과 공정(process)을 이용하여 생태계의 물질순환(물순환 포함)과 에너지 흐름이 원활하도록 조성하는 기법으로, 불투수층면에서 발생되는 강우유출수를 관리 가능하다. LID 시설에는 전처리 시설을 두어 초기 고농도의 입자상 물질을 저감시키고, 강우유출수 저류공간을 통한 유출저감, 첨두유량 등을 저감시킨다. 이러한 전처리 시설에는 유기물질 및 영양소의 생물학적 제거를 위한 미생물 서식공간의 제공 등의 역할을 수행하기 위하여 다양한 여재를 적용하고 있다. 본 연구는 비점오염물질 유입이 LID 기법 전처리 시설 내 여재층의 물리·화학적 및 생물학적 환경을 평가하였다. 3개 시설 모두 100%의 불투수층에서 발생되는 강우유출수를 처리하는 LID 시설을 연구대상으로 선정하였으며, 각각의 전처리 시설에는 자갈, 우드칩, 쇄석 등이 적용되어 있다. 퇴적물의 경우 가장 상부에 존재하는 층으로 퇴적물의 오염물질 농도는 2~10.7배 이상 매우 높게 나타났다. 우드칩의 경우 다른 여재에 비해 높은 함수량과 유기물 함량을 보였으며 이는 우드칩의 수분을 보유하는 능력과 거친 표면공극에 오염물질이 부착되기 때문으로 나타났다. 또한, 같은 무기성 여재인 쇄석과 자갈의 경우 여재 크기의 차이를 보임에도 불구하고 미생물의 군집구성과 함수량의 차이를 보이는 것으로 평가되었다. 유기물의 함량이 낮은 강우유출수의 생물학적 처리능력을 향상시키기 위해서는 유기성 여재가 필요하며, 다공성 무기 멀칭재를 적용하고 하부의 토양은 적정 유기물을 배합하여 질산화 및 탈질화 유도가 가능하도록 설계가 필요한 것으로 분석되었다.

• KSBB Journal
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• v.22 no.3
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• pp.168-173
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• 2007

To clarify the usefulness of fluorescent diagnosis for cancer, we investigated the optimal method of administrating 5-aminolevulinic acid (5-ALA), 5-aminolevulinic acid methyl ester (ALA-methyl ester) by analyzing fluorescence signal of Protoporphyrin IX (PpIX) in the cultured normal and cancer cells. 5-ALA and ALA-methyl ester was injected as a photosensitizer to the cancer liver cells (HepG2) and normal liver cells (Chang). Chang and HepG2 cells were incubated with various concentrations of 5-ALA and ALA-methyl ester (0-800 ${\mu}g/mL$). The accumulation of PpIX induced by 5-ALA and ALA-methyl ester was in HepG2 and Chang. The cell viability was measured by MTT assay. Fluorescence of PpIX in HepG2 cell was excited at a wavelength ($\lambda$ = 410 nm) and showed an emission spectrum at 603.2 nm, 660.8 nm and 603.2 nm, 661.4 nm which could be related to the PpIX generation induced by the applied 5-ALA and ALA-methyl ester, respectively. The experimental results showed that fluorescence signal of PpIX was proportional to the concentration of 5-ALA and ALA-methyl ester in tumor cells, but measured with low concentration in normal cells. Another results showed that the PpIX formation rate induced by ALA-methyl ester is higher than that of 5-ALA.

• KSBB Journal
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• v.11 no.4
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• pp.389-397
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• 1996

The growth of recombinant E. coli and formation of the by-products were investigated. Ammonium phosphate is known to affect the cell growth as well as the enzyme formation. When initial ammonium phosphate concentration was 0.5g/L, cell mass was 4.1g/L. By adding tryptone to the medium, acetic acid formation increased while lactic acid formation decreased. In cultivating recombinant E. coli, lactic acid and acetic acid turned out to be important by-products which affected cell yield and growth rate. Initial ammonium phosphate and tryptone concentration were optimized in our research and can be applied for other culture of recombinant E. coli.