• Journal of Life Science
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• v.24 no.2
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• pp.112-117
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• 2014

We investigated the effects of extracts from Rubus coreanus (RC) and Artemisia princeps var. orientalis (AP) on DNA damage response in ultraviolet B (UVB)-exposed HaCaT cells. Cell activity upon treatment for 24 h with RC or AP alone was similar to or greater than that of the nontreated control. When UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, cell activity increased in a concentration-dependent manner. Nuclear fragmentation analysis showed that postincubation with RC or AP decreased UVB-induced apoptosis by about 20% and 15%, respectively, of that in cells postincubated with growth medium. When UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, the level of cyclobutane pyrimidine dimer decreased in a concentration- dependent manner. Western blot analysis showed that treatment of cells not exposed to UVB with RC or AP alone did not significantly change the levels of phospho-p53 and GADD45 protein. Interestingly, when UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, phospho-p53 and GADD45 levels decreased in a concentration dependent manner. Our results suggest that RC and AP extract assist the survival of UVB-exposed cells in parallel with a decrease in levels of UVB-induced DNA damage and damage-response proteins, such as p53 and GADD45.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.203-208
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• 2005

Thioacetamide (TA) is potent haptotoxincant that requires metabolic activation by mixed-function oxidases. Micrcarray technology, which is massive parallel gene expression profiling in a single hybridization experiment, has provided as a powerful molecular genetic tool for biological system related toxicant. In this study we focus on the use of toxicogenomics for the determination of gene expression analysis associated with hepatotoxicity in rat liver epithelial cell line WB-F344 (WB). The WB cells was used to assess the toxic effects of TA. WB cells were exposed to two concentrations of TA-doses which caused 20% and 50% cell death were chosen and the cells exposed for periods of 2 and 24 h. Our data revealed that following the 2-h exposure at the both of doses and 24-h exposure at the low doses, few changes in gene expression were detected. However, after 24-h exposure of the cells to the high concentration, multiple changes in gene expression were observed. TA treatment gave rise predominantly to up-regulation of genes involved in cell cycle and cell death, but down-regulation of genes involves in cell adhesion and calcium ion binding. Exposure of WB cells to higher doses of the TA gave rise to more changes in gene expression at lower exposure times. These results show that TA regulates expression of numerous genes via direct molecular signaling mechanisms in liver cells.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.3
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• pp.255-263
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• 2013

Carbon dioxide reduction technologies using photosynthetic microorganism were suggested to overcome environmental destruction caused by $CO_2$ in flue gases from power plant and other industries. However, there are many toxic constituents in flue gas including CO, NOx, SOx. Continuous and Excessive supply of these noxious gases to cells will leads to inhibition of microalgal growth along with partial cell death. In this study, we tested the noxious effect of SOx and NOx on the pH and microalgal growth under photoautotrophic culture in three microalgae of Neochloris oleoabundans, Chlorella vulgaris and Haematococcus pluvialis. As a result, SOx concentration more than 50 ppm led to the rapid reduction of pH, thereby inhibiting of the growth in Neochloris oleoabundans and Chlorella vulgaris. NOx concentration more the 100 ppm reduced the exponential growth of N. oleoabundans and C. vulgaris. And H. pluvialis exhibited low sensitivity to SOx and NOx. Consequently, the three microalgae of N. oleabundas, C. vulagaris and H. pluvialis showed the normal vegetative growth in 25 ppm of NOx and SOx. Above all, H. pluvialis was useful for the $CO_2$ sequestration of the flue gas including high concentrations of NOx and SOx.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1309-1314
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• 2011

People spend approximately 80 ~ 90 % of their time in various kinds of indoor spaces. And, in metropolitan area, most people spend more than 1 hour in public transportation everyday. For this reason, people's interest in the indoor air quality is drastically increasing. Among various indoor air pollutants, $CO_2$ is one of the most severe environmental concerns. Ventilation is commonly used to keep low $CO_2$ concentration in the passenger cabin. However, ventilation may worse the indoor air quality problem in case of subway because the tunnel is seriously polluted by particulate matters. In this study, an alternative way to remove $CO_2$ was suggested. The adsorption of $CO_2$ by $CO_2$ adsorbent was studied. Zeolite modified with base was prepared, and $CO_2$ removal performance was tested in $4m^3$ and $24m^3$ environmental chambers. It was found that $CO_2$ adsorbent could effectively remove $CO_2$ in the chambers.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.683-689
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• 2014

Since $CO_2$ concentrations in industrial flue gases are usually 10%-20%, one of the prerequisites for efficient $CO_2$ removal by algae is the level of tolerance of microalgal species to exposure to high concentrations of $CO_2$. A newly isolated microalgal strain, Chlorella sp. MRA-1, could retain growth with high concentrations of $CO_2$ up to 15%. The highest lipid productivity for Chlorella sp. MRA-1 was 0.118 g/l/day with a 5% $CO_2$ concentration. Octadecenoic acid and hexadecanoic acid, the main components of biodiesel, accounted for 70% of the total fatty acids. A lipid content of 52% of dry cell weight was achieved with limited amounts of nitrogen. Chlorella sp. MRA-1 seems to be an ideal candidate for biodiesel production when cultured with high concentrations of $CO_2$.

• Nutritional Sciences
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• v.2 no.2
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• pp.88-92
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• 1999

The purpose of this study was to study the intake of heavy metals such af arsenic, lead and cobalt and the relationship of dietary heavy metals with serum iron, topper, and zinc, which play important roles in hematopoiesis, in healthy college women living in Choongnam Korea, where we have detected heavy metals (As, Pb, Co) in some marine products in previous studies. The nutritional status of the subjects (35 women) was evaluated by anthropometric measurements, 24-hr dietary recall for 3 days. And 3-day diets (by weighing method) and blood were collected to analyze As, Pb, Co, Fe, Cu, Zn, Hb, Hct, and MCHC. The mean age, height, weight, and BMI were 20 years, 158 cm, 55 kg and 22.42 kg/$m^2$, respectively. The mean daily energy intake was 85.85% of RDA for Koreans. The ratio of energy from carbohydrate, protein, and fat was 60 : 24 : 16. The mean daily intake of heavy metals (As, Pb, Co) was 1.77 mg/day, 75.21 $\mu$g/day and 21.12 $\mu$g/day. And the mean daily intake of iron, copper, and Zinc concentrations were 97, 68, and 92% of normal values. The mean serum heavy metals (As, Pb, Co) were 16.14 $\mu$g/dl, 4.32 $\mu\textrm{g}$/dl and 0.02 $\mu$g/dr, respectively Mean blood levels of Fe, Cu, Zn, Hb, Hct, and MCHC were at normal levels. Dietary heavy metals except Co were not significantly different from serum Fe, Cu, Zn and Hb, Hct, and MCHC. However, there was a tendency toward lower serum concentration of Fe, Hb, Hct, and MCHC in the subjects with higher heavy metals (As) intake. Among heavy metals, only dietary Co showed a significant negative correlation with Hb (p< 0.001) and Hct (p < 0.001).

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.319-325
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• 2004

A bioequivalence of $Etodol^{TM}$ tablets (Yuhan corporation) and $Kuhnillodine^{TM}$ tablets (Kuhnil Pharm. Co., Ltd.) was evaluated according to the guideline of Korea Food and Drug Administration (KFDA). Single 200 mg dose of etodolac of each medicine was administered orally to 24 healthy male volunteers. This study was performed in a $2{\times}2$ crossover design. Concentrations of etodolac in human plasma were monitored by a high-performance liquid chromatography. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 24 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was performed using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Etodol^{TM}/Kuhnillodine^{TM}$ were 1.01-1.10 and 0.87-1.06, respectively. This study demonstrated a bioequivalence of $Etodol^{TM}$ and $Kuhnillodine^{TM}$ with respect to the rate and extent of absorption.

• Corrosion Science and Technology
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• v.18 no.1
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• pp.24-32
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• 2019

The effects of zinc coating and heat treatment on the corrosion resistance of aluminum alloys including A1100 and the modified A3003, used as heat exchanger tube were investigated in this study. The grain size of the heat-treated specimen is larger than that of the specimen without heat treatment, but the grain size did not significantly affect the corrosion behavior. The concentration of zinc was noted at 11.3 ~ 31.4 at.% for the as-received Zn-coated samples and reduced to 1.2 ~ 2.4 at.% after the heat treatment, as measured by the scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS) on the surface. The concentration of oxygen is 22 ~ 46 at.% for the zinc coated specimens while noted at 7.4 ~ 12.8 at.% for the specimens after the removal of the coating. The corrosion behavior depended largely on the concentrations of zinc, aluminum, and oxygen on the specimen surface, but not on the Mo content. The corrosion potential was high and the corrosion rate was low for a specimen with a low zinc content, a high aluminum content, and a high oxygen content.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.737-744
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• 2021

An investigation is conducted to study a solid-liquid mixture vertically upward hydraulic transport of solid particles by non-Newtonian fluids in the Mud system. Rheology of particulate suspensions in viscoelastic fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, etc. In this study a clear acrylic pipe was used in order to observe the movement of solid particles. Annular velocities varied from 0.4 m/s to 1.2 m/s. The mud systems which were utilized included aqueous solution of sodium carboxymethyl cellulose (CMC) solutions. Main parameters considered in the study were inner-pipe rotary speed, fluid flow regime and particle injection rate. Solid volumetric concentration and pressure drops were measured for the various parameters such as inclination angle, flow rate, and rotational speed of inner cylinder.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.161-166
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• 2015

To determine the adequate levels of light intensity and $CO_2$ concentration for mango grown in greenhouses, quantitative measurements of photosynthetic rates at various leaf positions in the tree are required. The objective of this study was to develop two-variable leaf photosynthetic models of Irwin mango (Mangifera indica L. cv. Irwin) using light intensity and $CO_2$ concentration at different leaf positions. Leaf photosynthetic rates at different positions (top, middle, and bottom) were measured by a leaf photosynthesis analyzer at light intensities (0, 50, 100, 200, 300, 400, 600, and $800{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) with $CO_2$ concentrations (100, 400, 800, 1200, and $1600{\mu}mol{\cdot}mol^{-1}$). The two-variable model consisted of the two leaf photosynthetic models expressed as negative exponential functions for light intensity and $CO_2$ concentrations, respectively. The photosynthetic rates of top leaves were saturated at a light intensity of $400{\mu}mol{\cdot}^{-2}{\cdot}s^{-1}$, while those of middle and bottom leaves saturated at $200{\mu}mol{\cdot}^{-2}{\cdot}s^{-1}$. The leaf photosynthetic rates did not reach the saturation point at a $CO_2$ concentration of $1600imolmol^{-1}$. In validation of the model, the estimated photosynthetic rates at top and bottom leaves showed better agreements with the measured ones than the middle leaves. It is expected that the optimal conditions of light intensity and $CO_2$ concentration can be determined for maximizing photosynthetic rates of Irwin mango grown in greenhouses by using the two-variable model.