• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.248-254
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• 2008

Candida magnoliae, an osmotolerant and erythritol producing yeast, prefers D-fructose to D-glucose as carbon sources. For the investigation of the fructophilic characteristics with respect to sugar transportation, a sequential extraction method using various detergents and ultracentrifugation was developed to isolate cellular membrane proteins in C. magnoliae. Immunoblot analysis with the Pma1 antibody and two-dimensional electrophoresis analysis coupled with MS showed that the fraction II was enriched with membrane proteins. Eighteen proteins out of 36 spots were identified as membrane or membrane-associated proteins involved in sugar uptake, stress response, carbon metabolism, and so on. Among them, three proteins were significantly upregulated under the fructose supplying conditions. The hexose transporter was highly homologous to Ght6p in Schizosaccharomyces pombe, which was known as a predominant transporter for the fructose uptake of S. pombe because it exhibited higher affinity to D-fructose than D-glucose. The physicochemical properties of the ATP-binding cassette transporter and inorganic transporter explained their direct or indirect associations with the fructophilic behavior of C. magnoliae. The identification and characterization of membrane proteins involved in sugar uptake might contribute to the elucidation of the selective utilization of fructose to glucose by C. magnoliae at a molecular level.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.66-78
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• 2019

Purpose: Thallium (TI+) autometallography is often used for the imaging of neuronal metabolic activity in the rodent brain under various pathophysiologic conditions. The purpose of this study was to apply a thallium autometallographic technique to observe changes in neuronal activity in the forebrain of rats following acute carbon monoxide (CO) intoxication. Methods: In order to induce acute CO intoxication, adult Sprague-Dawley rats were exposed to 1100 ppm of CO for 40 minutes, followed by 3000 ppm of CO for 20 minutes. Animals were sacrificed at 30 minutes and 5 days after induction of acute CO intoxication for thallium autometallography. Immunohistochemical staining and toluidine blue staining were performed to observe cellular damage in the forebrain following intoxication. Results: Acute CO intoxication resulted in significant reduction of TI+ uptake in major forebrain structures, including the cortex, hippocampus, thalamus, and striatum. In the cortex and hippocampal CA1 area, marked reduction of TI+ uptake was observed in the cell bodies and dendrites of pyramidal neurons at 30 minutes following acute CO intoxication. There was also strong uptake of TI+ in astrocytes in the hippocampal CA3 area following acute CO intoxication. However, there were no significant histological findings of cell death and no reduction of NeuN (+) neuronal populations in the cortex and hippocampus at 5 days after acute CO intoxication. Conclusion: The results of this study suggest that thallium autometallography can be a new and useful technique for imaging functional changes in neural activity of the forebrain structure following mild to moderate CO intoxication.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.455-463
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• 2021

The adsorption process using GAC is one of the most secured methods to remove of phosphate from solution. This study was conducted by impregnating Cu(II) to GAC(GAC-Cu) to enhance phosphate adsorption for GAC. In the preparation of GAC-Cu, increasing the concentration of Cu(II) increased the phosphate uptake, confirming the effect of Cu(II) on phosphate uptake. A pH experiment was conducted at pH 4-8 to investigate the effect of the solution pH. Decrease of phosphate removal efficiency was found with increase of pH for both adsorbents, but the reduction rate of GAC-Cu slowed, indicating electrostatic interaction and coordinating bonding were simultaneously involved in phosphate removal. The adsorption was analyzed by Langmuir and Freundlich isotherm to determine the maximum phosphate uptake(q_m) and adsorption mechanism. According to correlation of determination(R²), Freundlich isotherm model showed a better fit than Langmuir isotherm model. Based on the negative values of q_m, Langmuir adsorption constant(b), and the value of 1/n, phosphate adsorption was shown to be unfavorable and favorable for GAC and GAC-Cu, respectively. The attempt of the linearization of each isotherm obtained very poor R². Batch kinetic tests verified that ~30% and ~90 phosphate adsorptions were completed within 1h and 24 h, respectively. Pseudo second order(PSO) model showed more suitable than pseudo first order(PFO) because of higher R². Regardless of type of kinetic model, GAC-Cu obtained higher constant of reaction(K) than GAC.

• Korean Journal of Exercise Nutrition
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• v.15 no.4
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• pp.163-171
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• 2011

The effects of a high-fat diet and fasting on resting energy expenditure and energy substrate utilization were examined using the method of measuring whole body energy metabolism and oxygen uptake. Eight 4-week old male Sprague-Dawley rats were used for the high-fat diet experiment. Energy metabolism was measured using acrylic metabolic chambers over 24 hours. After 1-week of preliminary feeding, 4 rats were fed a chow diet, whereas the remaining 4 rats were fed a high-fat diet (HF) ad libitum, which contained 40% (w/w, calorie base 60%) more fat than that in the chow diet. The flow rate to measure energy metabolism inside the chamber was controlled at a mean of 3.5 L/min, and five chambers were subjected to measurement. One of the five chambers was used to correct errors by measuring the atmosphere. As a result of 5 weeks of control diet and high-fat diet feeding, body weight of the high-fat diet group tended to increase more than that in the control diet fed group, but the difference was not significant. Oxygen uptake and carbon dioxide production changed as time went on over the 24 hr. The respiratory exchange ratio also changed during the 24 hr, and the difference between the groups was significant. The control group showed significantly more carbohydrate oxidation than that of the high-fat diet fed group. A fasting experiment was conducted using six 7-week old Sprague-Dawley male rats. Energy metabolism measurements were performed using the same method as that used in the high-fat diet experiment; resting metabolism was measured prior to fasting, and a fasting condition began from 9:00 am the next day for 3 days to calculate energy metabolism. Both body weight and 24-hour oxygen uptake decreased significantly as a result of 3-day fasting. Total oxygen uptake in the first day decreased, and declined significantly on day 3 of fasting. Total 24-hour carbon dioxide production decreased significantly over the 3 days. The mean 24-hour respiratory exchange ratio decreased significantly. Additionally, energy expenditure during the dark period (20:00-08:00), which is the active period for rats, decreased significantly with fasting, whereas energy expenditure during the light period (08:00-20:00) did not increase by fasting.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1411-1416
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• 2009

Several adsorbents were tried to remove the selenium ions from industrial wastewater and the following ascending order of the adsorption performance for the selenium at pH 9 was observed: cation exchange resin < chelate resin < zeolite < brown marine algae < granular activated carbon < anion exchange resin. Initial concentration of selenium(146 mg/L) in industrial wastewater was reduced to 63 mg/L of selenium at pH 9 by neutralization process. The maximum uptake of Se calculated from the Langmuir isotherm with anion exchange resin was 0.091 mmol/g at pH 10 and that with granular activated carbon was 0.083 mmol/g at pH 6. The affinity coefficients of Se ion towards anion exchange resin and granular activated carbon were 3.263 L/mmol at pH 10 and 0.873 L/mmol at pH 6, respectively. The sorption performance of anion exchange resin at the low concentration of Se, namely, was much better than that of granular activated carbon. The Se ions from industrial wastewater throughout neutralization process and two steps of adsorption using anion exchange resin was removed to 97.7%.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.307-318
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• 1988

Properties of succinate transport were examined in basolaterat membrane vesicles (BLMV) isolated from rabbit renal cortex. An inwardly directed $Na^+$ gradient stimulated succinate uptake and led to a transient overshoot. $K^+,{\;}Li^+,{\;}Rb^+$ and choline could not substitute for $Na^+$ in the uptake process. The dependence of the initial uptake rate of succinate on $Na^+$ concentration exhibited sigmoidal kinetics, indicating interaction of more than one $Na^+$ with transporter Hill coefficient for $Na^+$ was calculated to be 2.0. The $Na^+-dependent$ succinate uptake was electrogenic, resulting in the transfer of positive charge across the membrane. The succinate uptake into BLMV showed a pH optimum at external pH $7.5{\sim}8.0$, whereas succinate uptake into brush border membrane vesicles (BBMV) did not depend on external pH. Kinetic analysis showed that a Na-dependent succinate uptake in BLMV occurred via a single transport system, with an apparent Km of $15.5{\pm}0.94{\;}{\mu}M$ and Vmax of $16.22{\pm}0.25{\;}nmole/mg{\;}protein/min$. Succinate uptake was strongly inhibited by $4{\sim}5$ carbon dicarboxylates, whereas monocarboxylates and other organic anions showed a little or no effect. The succinate transport system preferred dicarboxylates in trans-configuration (furmarate) over cis-dicarboxylates (maleate). Succinate uptake was inhibited by the anion transport inhibitors DIDS, SITS and furosemide, and $Na^+-coupled$ transport inhibitor harmaline. These results indicate the existence of a $Na^+-dependent$ succinate transport system in BLMV that may be shared by the other Krebs cycle intemediates. This transport system seems to be very similar to the luminal transport system for dicarboxylates.

• Journal of Soil and Groundwater Environment
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• v.24 no.6
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• pp.16-25
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• 2019

Anthropogenic polycyclic aromatic hydrocarbons (PAHs) are formed by the incomplete combustion of fuels and industrial waste. PAHs can be widely exposed to the environment (water, soil and groundwater). PAHs are potentially toxic, mutagenic and/or carcinogenic. Fundamental studies such as biota uptake (e.g., earthworm and plant) of PAHs are highly needed. It is necessary to develop alternative ways to evaluate bioavailability of PAHs instead of using living organisms because it is time-consuming, difficult to apply in the field, and also exaction method is tedious and time-consuming. In this study, sorption behaviors of phenanthrene were evaluated to predict the fate of PAHs in soils. Moreover, bioaccumulation of PAHs in an artificially contaminated soil was evaluated using pea plant (Pisum sativum) as a bioindicator. A novel passive sampler, organic-diffusive gradient in thin-film (o-DGT) for PAHs was newly synthesized, tested as a biomimic surrogate and compared with plant accumulation. Sorption partitioning coefficient (K_P) and sorption capacity (K_F) were in the order of natural soil > loess corresponding to the increase in organic carbon content (f_oc). Biota-to-soil accumulation factor (BSAF) and DGT-to-soil accumulation factor (DSAF) were evaluated. o-DGT uptake was linearly correlated with pea plant uptake of phenanthrene in contaminated soil (R²=0.863). The Tenax TA based o-DGT as a biomimic surrogate can be used for the prediction of pea plant uptake of phenanthrene in contaminated soil.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.3
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• pp.38-45
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• 2001

This study quantified annual $CO_2$, SO$_2$ and NO$_2$ uptake and annual $O_2$ production by trees in Yongin´s urban ecosystem, and explored values of urban tree plantings in atmospheric purification. Woody plant cover was only 7.7% with planting density of 1. trees/100$m^2$, and the tree-age structure was largely characterized by a young, growing tree population. Annual per capita pollutant emissions from fossil fuel consumption were 7.3t/yr for $CO_2$, 7.6kg/yr for SO$_2$, and 26.6kg/yr for NO$_{x}$. Carbon dioxide storage per unit urban area by trees was 13.1t/ha and the economic value for $CO_2$ storage was ￦6.6millions/ha. Annual atmospheric purification was 2.0t/ha/yr for $CO_2$ uptake, 2.0kg/ha/yr for SO$_2$ uptake, 4.0kg/ha/yr for NO$_2$ uptake and 1.5t/ha/yr for $O_2$ production, and the annual economic value for the atmospheric purification was ￦1.5millions/ha/yr. Urbantrees stored an amount of $CO_2$ equivalent to about 3.1% of the total annual $CO_2$ emissions, and annually offset total $CO_2$ emissions by 0.5%. Annual SO$_2$ and NO$_2$ uptake by trees equaled 0.5% of total SO$_2$ emissions and 0.3% of total NO$_{x}$ emissions, respectively. Urban trees also played an important role through producing annually 9.2 of the $O_2$ requirement for Yongin´s total population, despite relatively poor tree plantings. Future active plantings and greenspace enlargement in the study city could enhance the role of atmospheric purification by urban trees. The results from this study are expected to be useful in emphasizing environment benefits of urban trees, and in urging the continuous necessity for tree planting and management budget.get.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.571-576
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• 2004

Since anaerobic/anoxic/oxic process, which is a typical mainstream biological nitrogen and phosphorus removal process, utilizes influent organic matter as an external carbon source for phosphorus release in anaerobic or anoxic stage, influent COD/T-P ratio gives a strong influence on performance of phosphorus removal process. In this study, a bench scale experiment was carried out for SBR process to investigate nitrogen and phosphorus removal at various influent COD/T-P ratio and nitrate loadings of 23~73 and 1.6~14.3g $NO_3{^-}-N/kg$ MLSS, respectively. The phosphorus release and excess uptake in anoxic condition were very active at influent COD/T-P ratios of 44 and 73. However, its release and uptake was not obviously observed at COD/T-P ratio of 23. Consequently, phosphorus removal efficiency was decreased. In addition, the phosphorus release and uptake rate in anoxic condition increased as the nitrate loading decreased. Specific denitrification rate had significantly high correlation with organic materials and nitrate loadings of the anoxic phase too. The rate of phosphorus release and uptake in the anoxic condition were $0.08{\sim}0.94kg\;S-P/kg\;MLSS{\cdot}d$ and $0.012{\sim}0.1kg\;S-P/kg\;MLSS{\cdot}d$, respectively.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.485-492
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• 2011

Sorption of cyanide on granular activated carbon and attenuation of the cyanide by UV-light over a wide range of conditions such as pH and concentration were investigated through batch experiments. Cyanide uptake by activated carbon is much effective at $[CN]_{ini}$ < 2 mg/L. The sorption of cyanide on activated carbon at pH 7.0 is greater than that of pH 9.0. It is found that the ratio of CN uptake to CN in solution increases at pH 9.0 whereas at pH 7.0 the ratio decreases, suggesting that reactivity of activated carbon increases as a function of pH. The sorption of cyanide rapidly increases during the first 30 min, followed by sharp desorption until 3hr, and then the sorption increases and reaches the maximum sorption during the duration of experiments, implying that the sorption mode could be changed through conformational change during the initial stage of the cyanide uptake by activated carbon. Total amount of cyanide desorbed from the activated carbon during the period of desorption experiments is less than 1.5% of total sorbed cyanide, indicative of strong and stable sorption of cyanide on the activated carbon. The sorption with mixture of activated carbon and Ham-Baek sludge shows less effective on the removal of the cyanide. It is noted that UV-light is much effective on the removal of cyanide but also the attenuation is achieved until $[CN]_{tot}$ is up to 10 mg/L. Our findings demonstrate that both activated carbon and UV-light are very effective on the attenuation of cyanide over a wide range of environmental conditions.