• 전기화학회지
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• 제24권3호
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• pp.35-41
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• 2021

본 연구에서는, 양쪽이온성 계면활성제가 구리전해도금에 미치는 영향을 cyclic voltammetry를 이용해 분석해보았다. 대표적인 양쪽이온성 계면활성제인(dodecyldimethylammonio)propanesulfonate (DDAPS)를 전해도금액에 첨가할 경우, Cu²⁺의 환원반응이 억제되는 것을 확인할 수 있었으며, 이러한 억제 효과는 음이온성 계면활성제가 아닌 양이온성 계면활성제와 유사한 특성에 해당한다. 뿐만 아니라, DDAPS는 염소이온과 상호작용을 나타내었고, 억제효과가 물질전달 조건에 따라 변화하는 특성을 가지고 있었으며, 구리도금막의 거칠기 또한 미약하게 감소시켰다. 이러한 특성은, 양이온성 계면활성제의 특성과 유사하나 다소 약화된 모습이었으며, 이를 통해 DDAPS의 작용은 양전하의 친수성 머리에 의해 주도되며, 이 양전하는 음전하 친수성 머리에 의해 shielding 되어 있음을 확인할 수 있었다.

• Corrosion Science and Technology
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• 제14권2호
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• pp.85-92
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• 2015

An on-line corrosion rate measurement system was developed using a personal computer, a data acquisition board and program, and a 2-electrode corrosion probe. Reliability of the developed system was confirmed with through comparison test. With this system, the effect of sodium nitrite ($NaNO_2$) as a corrosion inhibitor were studied on iron and aluminum brass that were immersed in sodium chloride (NaCl) solution. Corrosion rate was measured based on the linear polarization resistance method. The corrosion rates of aluminum brass and iron in 1% NaCl solutions were measured to be 0.290 mm per year (mmpy) and 0.2134 mmpy, respectively. With the addition of 200 ppm of $NO{_2}^-$, the corrosion rates decreased to 0.0470 mmpy and 0.0254 mmpy. The addition of $NO{_2}^-$ caused a decrease in corrosion rates of both aluminum brass and iron, yet the $NO{_2}^-$ acted as a more effective corrosion inhibitor for iron. than aluminum brass.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1188-1192
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• 2003

In order to study the role of residue in the active site of glutathione S-transferase (GST), Tyr 108 residue in human GST P1-1 was replaced with alanine, phenylalanine and tryptophan by site-directed mutagenesis to obtain mutants Y108A, Y108F and Y108W. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Tyr108 significantly affected $K_m^{CDNB}$ and $K_m^{ETA}$, whereas scarcely affected $K_m^{GSH}$. The substitutions of Tyr108 also significantly affected $I_{50}$ of ETA, an electrophilic substrate-like compound. The effect of these substitutions on kinetic parameters and the response to inhibition suggests that tyrosine 108 in hGST P1-1 contributes to the binding of the electrophilic substrate and a major determinant in the binding of CDNB is the aromatic ring of Tyr108, not its hydroxyl group.

• 상하수도학회지
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• 제19권5호
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• pp.639-646
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• 2005

In this research, we tried to develop the application method to water management and treatment using toxicity test method. When we measure the toxicity of environmental samples, we have to decide whether we take some countermeasures to reduce the toxicity or not. The first issue is how to set these action levels in each bioassays. A new idea was attempted to authorize indirect approach of each bioassays through the response characteristics against mixture of chemicals in water quality standard. The significant response in the cell-growth-inhibition bioassay was detected for standards-mixture(STDs). For acute toxicity assay, STDs-based implicit correlation between risks to humans and bioassay data showed a rational approach to set action levels in practical management. A simple model was proposed to describe and predict the changes in the total toxicity based on the concentrations of toxic-controlling chemicals during the ozonation of landfill leachates. On the basis of this simple model, toxicity reduction was predicted for pre-aggregation treatment before ozonation and ozone concentration during the ozonation. The method proposed in this study would be useful in optimizing water treatment processes and their running conditions in terms of the toxicity reduction efficacy.

• 약학회지
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• 제40권6호
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• pp.679-683
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• 1996

The current study evaluates the capacity of eugenol to regulate immediate allergic reaction by control of histamine release. Administrations of eugenol (1M/kg, i.p.) at 60 min b efore and 5, 10 min after the compound 48/80 treatment (8mg/kg, i.p.) were shown the mortality rates as 0, 44.4, and 77.8%, respectively. A 60 min before administered group revealed a significant inhibition of serum histamine release compared with those of 5 and 10 min after the compound 48/80 injection. Eugenol (6-48mM) was also showed a dose-dependent activity on the compound 48/80-induced histamine release from the highly purified population of Alcian Blue-positive peritonea] mast cells. These results indicate that in vitro treatment with exogenous eugenol inhibited the active response of mast cell populations and modulated its characteristics.

• 한국연초학회지
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• 제14권1호
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• pp.12-23
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• 1992

This experiment was conducted to determine the optimum dosage of gamma rays for inducing artificial mutation of several mutant characters in the flue-cured tobacco. 1) In Hicks and BY 104, the gammarays irradiation has no significantly different effect on seed germination from the control. However, the average dosage for 50% growth inhibition was 25-30kr for all the varieties tested, which inhibition 46-52% and 43-57% of the seedling growths for Hicks and BY 104, respectively. 2) A mutant line 83H-5 was selected from Hicks by irradiation gamma ray at the level of 30kr. It has white flower, more resistance to bacterial wilt, Pssudomonas solanacearum, lower plant and stalk height, narrower leaf width, larger leaf shape index(lento width) and later days to flower when compared with the original variety Hicks. 3) White flower was recessive to pink flower in F, and Br (F1 X Hicks) progenies. F2 population of the cross gave segregation ratio of 3 pink flower:1 white flower, and B, (F1 X 83H-5) Population gave 1:1 ratio. Results showed that the white flower character is governed by a single recessive gene.

• 대한한의학회지
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• 제22권3호
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• pp.63-73
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• 2001

Objectives : The objective of the current study is to determine the protective effect of Ukyium(Yougui-yin) on the apoptosis induced by zinc. Methods : Zinc is known to generate reactive oxygen species (ROS), including superoxide anion ($O_2$) and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. We investigated the viablity of cells, $H_2O_2$ generation, chromatin condensation and nuclear fragmentation in Hoechst dye staining and $IkB-{\alpha}$ degradation in C6 glial cells of $ZnCl_2$ between pretreatment- and not pretreatment-group with Ukyium. The former methods were researched by Time- and Dose-dependent manners. Results : We demonstrated that pretreatment with Ukyium prevented zinc-induced cell death of C6 glial cells and apoptotic characteristics including chromatin condensation and nuclear fragmentation. Ukyium also prevented $H_2O_2-induced$ cell death. We further confirmed that Ukyium decreased zinc-induced generation of $H_2O_2$ and inhibited degradation of $IkB-{\alpha}$ by zinc in C6 glial ceHs. Conclusions : These data indicated that Ukyium (Yougui-yin) prevents zinc-induced apoptotic death of C6 glial cells via inhibition of ROS generation, such as $H_2O_2$ as well as inhibition of $IkB-{\alpha}$ degradation.

• Journal of Pharmaceutical Investigation
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• 제36권4호
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• pp.283-286
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• 2006

The present study aimed to investigate the interaction of nucleoside analogs with human organic anion transporter 1 and 3(hOAT1 and hOAT3) that play a primary role in the tubular uptake of endogenous and exogenous organic anions in the kidney. The interactions of ddC, ara-C, ara-A and ara-U with hOAT1 and hOAT3 were examined using MDCK cells stably overexpressing hOAT1 or hOAT3. Among the tested drugs, ddC showed the highest affinity to hOAT1 with $IC_{50}$ values of 5.2 mM, while ara-A, ara-C and ara-U weakly inhibited the cellular uptake of $[^3H]-PAH$ in MDCK-hOAT1 cells at 1 mM. In contrast, all the tested drugs did not have any inhibition effect on the cellular uptake of $[^3H]-estrone$ sulfate in MDCK-hOAT3 cells over the drug concentration of 0.01-2 mM, implying that they might not interact with hOAT3. Taken all together, the present study suggests that hOAT1 could weakly interact with nucleoside analogues such as ddC, ara-C, ara-A and ara-U but the interaction with hOAT3 during the urinary excretion of these nucleoside analogues may be negligible in the kidney.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1140-1146
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• 1997

Storage stability of ginger paste product was investigated from the standpoint of the inhibition of nonenzymatic browning and loss of gingerol contents. For the experimentations, control, 0.04% of N-acetyl-L-cysteine in ginger paste(NAcCys), and combination treatment of NAcCys, 0.92 of water activity and 6.30 of pH in ginger paste (mixed treatment) were stored at 3$0^{\circ}C$ for 40 days and analyzed for browning and gingerol contents. In addition the changes in sugars, organic acids, ascorbic acids, amino acids, and sensory quality were determined. The results revealed that the mixed treatment agent was effective in preventing both nonenzymatic browning and loss of gingerol contents. The inhibition by combination treatment might be resulted from the control of radical formations by sulfhydryl groups of NAcCys and the increase of diffusion resistance in lower water activity. Browning development and total gingerol contents were found to be correlated to some physicochemical characteristics of ginger paste; that is, browning development to amino acid and color value in sensory evaluation, and total gingerol contents to flavor in sensory evaluation.

• The Plant Pathology Journal
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• 제35권2호
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• pp.137-148
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• 2019

In search of an effective biological control agent against the tomato pathogen Fusarium oxysporum f. sp. lycopersici, rhizospheric soil samples were collected from eight agro-ecological zones of Bangladesh. Among the bacteria isolated from soil, 24 isolates were randomly selected and evaluated for their antagonistic activity against F. oxysporum f. sp. lycopersici. The two promising antagonistic isolates were identified as Brevundimonas olei and Bacillus methylotrophicus based on morphological, biochemical and molecular characteristics. These two isolates were evaluated for their biocontrol activity and growth promotion of two tomato cultivars (cv. Pusa Rubi and Ratan) for two consecutive years. Treatment of Pusa Rubi and Ratan seeds with B. olei prior to inoculation of pathogen caused 44.99% and 41.91% disease inhibition respectively compared to the untreated but pathogen-inoculated control plants. However, treatment of Pusa Rubi and Ratan seeds with B. methylotrophicus caused 24.99% and 39.20% disease inhibition respectively. Furthermore, both the isolates enhanced the growth of tomato plants. The study revealed that these indigenous bacterial isolates can be used as an effective biocontrol agent against Fusarium wilt of tomato.