• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.210-215
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• 2008

The objective of this study was to develop models to predict SCC (somatic cell count) in unhomogenized milk by visible and near-infrared (NIR) spectroscopic technique. Total of 100 milk samples were collected from dairy farms and preserved to minimize propagation of bacteria cells during transportation. Reductive reagents such as methyl red, methylene blue, bromcresol purple, phenol red and resazurin were added to milk samples, and then colors of milk were changed based on SCC of milk. For optimal reductive reagents, reaction time was controlled at 3 level of reaction time. A spectrophotometer was used to measure reflectance spectra from milk samples. The partial least square (PLS) models were developed to predict SCC of unhomogenized milk. The PLS results showed that milk samples with reductive reagents had a good correlation between predicted and measured SCC at 5 minutes of reaction time in the visible range. The PLS models with resazurin reagent had the best performance in $400{\sim}600\;nm$. The prediction results of milk samples with resazurin had 0.86 of correlation coefficient and 14,184 cell/mL of SEP.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.281-284
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• 2007

Neopentyl arenesulfonates react with secondary alkylmagnesium chlorides in the presence of dppfNiCl2 to produce the corresponding arenes via the reductive cleavage of carbon-sulfur bond. Highest yield is obtained by using three equivalents of Grignard reagent to a mixture of arenesulfonate and dppfNiCl2 in Et2O at room temperature. This reaction represents a novel method allowing the efficient hydrogenolysis of sulfur-containing groups in aromatic compounds.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.66-74
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• 2015

DIP(deinked pulp) was bleached by FAS, $Na_2S_2O_4$ and $H_2O_2$, which are widely used in DIP bleaching process, in order to improve optical properties of DIP, and the bleaching efficiencies of DIP and environmental loads of waste water were compared, depending on bleaching chemical dosages. With the application of different bleaching chemicals, some positive improvements were shown in optical and physical properties of bleached pulp. However, the physical properties of bleached DIP and their characteristics of wastewater were remarkably different, depending on dosages and bleaching reagents. DIP chemicals with FAS and $Na_2S_2O_4$ have higher improvement in optical and physical properties than $H_2O_2$. Also, environmental loads such as pH, turbidity, SCODcr and cationic demand were decreased in reductive bleaching process. Despite of higher effectiveness of reductive bleaching process, there were some environmental problems caused by sulfur ions from FAS and $Na_2S_2O_4$. With the method of sulfur ion controls, it would be more effective than $H_2O_2$ bleaching process.

• Environmental Engineering Research
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• v.10 no.4
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• pp.174-180
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• 2005

Nano-sized iron was synthesized using borohydride reduction of $Fe^{3+}$ in aqueous solution. A wide range of synthesis conditions including varying concentrations of reagents, reagent feeding rate, and solution pH was applied in an aqueous system under anaerobic condition. The reactivity of nano-sized iron from each synthesis was evaluated by reacting the iron with TCE in batch systems. Evidence obtained from this study suggest the reactivity of iron is strongly dependent on the synthesis solution pH. The iron reactivity increased as solution pH decreased. More rapid TCE reduction was observed for iron samples synthesized from higher initial $Fe^{3+}$ concentration, which resulted in lower solution pH during the synthesis reaction. Faster feeding of $BH_4^-$ solution to the $Fe^{3+}$ solution resulted in lower synthesis solution pH and the resultant iron samples gave higher TCE reduction rate. Lowering the pH of the solution after completion of the synthesis reaction significantly increased reactivity of iron. It is presumed that the increase in the reactivity of iron synthesized at lower pH is due to less precipitation of iron (hydr)oxides or less surface passivation of iron.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.1
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• pp.31-43
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• 2017

Together with radiotherapy, chemotherapy using cytotoxic agents is one of the most common therapies in cancer. Metabolic changes in cancer cells are drawing much attention recently, but the metabolic alterations by anticancer agents have not been much studied. Here, we investigated the effects of commonly used cytotoxic agents on lung normal cell MRC5 and lung cancer cell A549. We employed cis-plastin, doxorubicin, and 5-Fluorouracil and compared their effects on the viability and metabolism of the normal and cancer cell lines. We first established the concentration of the cytotoxic reagents that give differences in the viabilities of normal and cancer cell lines. In those conditions, the viability of A549 decreased significantly, whereas that of MRC5 remained unchanged. To study the metabolic alterations implicated in the viability differences, we obtained the metabolic profiles using $^1H$-NMR spectrometry. The $^1H$-NMR data showed that the metabolic changes of A549 cells are more remarkable than that of MRC5 cells and the effect of 5-FU on the A549 cells is the most distinct compared to other treatments. Heat map analysis showed that metabolic alterations under treatment of cytotoxic agents are totally different between normal and cancer cells. Multivariate analysis and weighted correlation network analysis (WGCNA) revealed a distinctive metabolite signature and hub metabolites. Two different analysis tools revealed that the changes of cell metabolism in response to cytotoxic agents were highly correlated with the Warburg effect and Reductive lipogenesis, two pathways having important effects on the cell survival. Taken together, our study addressed the correlation between the viability and metabolic profiles of MRC5 and A549 cells upon the treatment of cytotoxic anticancer agents.

• BMB Reports
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• v.29 no.6
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• pp.493-499
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• 1996

The biochemical properties of purified D-hydruxyisovalerate dehydrogenase from Fusarium sambucinum was elucidated. D-Hydroxyisovalerate dehydrogenase produced solely D-hydroxyisovalerate from 2-ketoisovalerate. The isoelectric point of the purified enzyme was 7.0. The enzyme was highly specific with 2-ketoisovalerate ($K_{m}=0.188$ mM, $V_{max}=8.814$ mmol/min mg) and 2-keto-3-methyl-n-valerate ($K_{m}=0.4$ mM, $V_{max}=1.851$ mmol/min mg) for the reductive reaction. This was also seen by comparing D-hydroxyisovalerate ($K_{m}=1.667$ mM, $V_{max}=0.407$ mmol/min mg) and D-hydroxy-3-methyl-n-valerate ($K_{m}=6.7$ mM, $V_{max}=0.648$ mmol/min mg) for the oxidative reaction. Thiol blocking reagents, such as iodoacetamide, N-ethylmaleimide and p-chloromecuribenzoate inhibited about 80% of enzyme activity at 0.02 mM, 50 mM and 50 mM, respectively. The enzyme activity was also inhibited by the addition of 0.1 mM of various metal ions, such as $Fe^{2+}$ (67%), $Cu^{2+}$ (88%), $Zn^{2+}$ t (76%) and $Mg^{2+}$ (9%). The enzyme was stable over three months in 50 mM potassium phosphate buffer (pH 5~7) at $-80^{\circ}C$. However the purified enzyme lost 30% of its activity in the same buffer after 24 h at $4^{\circ}C$. The studies about thermal inactivation of D-hydroxyisovalerate dehydrogenase exhibit 209.2 kJ/M of activation enthalpy and 0.35 kJ/mol K of activation entropy.