• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.2
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• pp.51-56
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• 2018

Azeotropic drying process is routinely applied to enhance nucleophilicity of $[^{18}F]$fluoride ion during the nucleophilic production of PET radiotracers; however, the drying process requires usually 15-25 min. Due to the high demand of employing fluorine-18 ($t_{1/2}=109.8min$) in PET radiopharmaceutical production, several research groups have focused on the method development, obviating tedious removal process of the residual target water ($[^{18}O]H_2O$) for $[^{18}F]$fluoride ion complex to be used in radiofluorination. Some development in radiofluorination in a mixed organic solvent system was demonstrated with various aliphatic substrates, but only kryptand as a phase transfer agent was utilized in the reported method. Here, we extend to investigate the development scope of applicability with basic alkyl ammonium salt as a phase transfer agent through the extensive elution efficiency study and radiofluorination outcome for aliphatic radiofluorination.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.278-282
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• 2010

In this study, the antibacterial activity and component analysis of Persicaria perfoliata extracts were investigated. MIC (Minimum Inhibitory Concentration) values of ethyl acetate fraction from P. perfoliata on Escherichia coli, Propionibacterium acnes, and Staphylococcus aureus were 0.25%, equally. The results showed that the antibacterial activity of the ethyl acetate fraction was the highest in the S. aureus and P. acnes. Ethyl acetate fraction from P. perfoliata extracts showed 5 bands in TLC and 8 peaks in HPLC (320nm). In HPLC chromatogram of ethyl acetate fraction, first main peak 2 (24.99%) and peak 3 (22.65%) were identified as quercetin-3-o-glucuronide and isoquercitrin in the order of elution time. Also, in HPLC chromatogram of deglycosylated fraction, main peak 2 (76.93%) was identified as quercetin in the order of elution time. And these components are very effective as antioxidants. Thus, these results indicate that extract/fractions of P. perfoliata can be applicable to new functional cosmetics for antioxidant, antibacterial activity.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.619-624
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• 2002

The purpose of this study is to manufacture sintered lightweight aggregate for non-structural concrete using sewage sludge, organic waste matter is produced to a sewage treatment plant. It is tested for basic property and strength of artificial aggregate according to addition ratio of sewage sludge, and the results are compared with imported aggregate from Spain. As the results of experiment, the manufactured lightweight aggregate could be used for non-structural concrete. Also, it was favorably comparable to those of the imported aggregate. When it is manufactured with aggregate, it is safe environmentally because of protecting elution of harmful heavy metals.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.269-272
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• 1989

In order to obtain monoclonal antibody from ascites fluid at sufficiently high purity using a single hydroxylapatite chromatography (HA) a further optimization on its operating variables was carried out. By adjusting the pH of the eluent, the sodium phosphate buffer, to 6.0 from 6.8 and adding CaCl$_2$to 1 mM at the column inlet, the elution molarities (M$_{elu}$) for the desired monoclonal antibody and contaminating proteins can be distinguished from each other with enough resolution. Previously these two groups of proteins co-eluted at the same time at pH 6.8 and without CaCl$_2$. This sin81e step hydroxylapatite chromatography yields the desired antibody pure enough for diagnostic use.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.383-389
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• 1999

To determine the optimum condition for buckwheat noodle making, we prepared noodle from com posite flours of buckwheat, wheat and corn starch, and those physical properties and sensory evalua tion were investigated. The weights of cooked noodle became lower with increasing buckwheat content level indicating that elution of its components to soup was high. Wheat flour in the composite flours probably caused to drop gelatinization temperature and maximum viscosity compared to buck wheat flours. Corn starch in the composite flours increase gelatinization temperature and maximum viscosity compared to buckwheat flours. From the result of farinogram, buckwheat flour lower water absorption ability, and increased dough development time compared to composite flours. Adhesiveness of the cooked noodle with wheat flour was decreased. Cohesiveness of the cooked noodle was decrea sed with increasing buckwheat flour level. In sensory evaluation, chewing and softness of noodle with 100% buckwheat flour was evaluated the best. In taste, BW1 and BSW1 noodles showed slightly higher preference although there was no significant differences.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.45-50
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• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.57-61
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• 2021

Saikosaponin derivatives such as saikosaponins A, B1, B2, B3, B4, C, and D present in Bupleurum falcatum were analyzed by a high performance liquid chromatograph equipped with an evaporative light scattering detector, using different extraction solvents (water and 70% ethanol). The samples were injected into a YMC Pack Pro C18 column and separated using a gradient elution system with a mobile phase composed of acetonitrile and water at a flow rate of 1.1 mL/min. The content of saikosaponin derivatives was higher in 70% ethanol extract than in water extract. This study provides an efficient analytical method for determining the optimal conditions for extraction of saikosaponin derivatives, which can be used as a basis for development of functional foods and pharmaceutical products from B. falcatum.

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.211-216
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• 2016

In the course of our continuing search for biologically active components from Korean medicinal plants, we isolated the main compound, luteolin 5-glucoside from aqueous fraction of Ajuga spectabilis. The structure was elucidated by the basis of $^1H$ and $^{13}C$ NMR and TOF ESI-MS data. Quantitative analysis of luteolin 5-glucoside was carried out on a XBridge C18 column ($S-5{\mu}m$, $4.6{\times}250mm$) with gradient elution composed of acetonitrile:water. The results exhibit that the average content of main compound in A. spectabilis were 0.048%. Oxidative stress plays a major role Alzheimer's disease (AD) and other neurodogenerative disease. AD is major health problem and there is currently no clinically accepted treatment to cure or stop its progression. Pretreatment with luteolin 5-glucoside markedly attenuated $H_2O_2$-induced cell viability loss in a dose-dependent manner. Luteolin 5-glucoside also inhibited the formation of intracellular reactive oxygen species in SH-SY5Y. The results suggest that luteolin 5-glucoside from A. spectabilis has protective effects against oxidative stress-induced cytotoxicity, which might be a potential therapeutic compound for treating and/or preventing neurodegenerative disease implicated with oxidative stress.

• Journal of the Korea Institute of Building Construction
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• v.6 no.3 s.21
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• pp.91-97
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• 2006

Sewage facilities are positively necessary for environment improvement such as rainwater removal, sewage disposal, preservation of the qualify of water and health of the citizens in present-day. Meanwhile, a deterioration of the concrete sewer pipe is increasing rapidly due to the chemical and physical attack and especially biochemical attack that is to say biodeterioration. In this study, researches for the development of antibiotics and antimicrobial concrete were conducted to reduce biochemical corrosion of sewage concrete. First of all, desired performance, such as watertightness, antibiosis, homogeneity, workability and harmlessness, was proposed and performance of antibiotics and antimicrobial concrete were evaluated by them. And developed antimicrobial concrete was applied to actual construction field. As results of this study, dispersibility and antibiosis of liquid antibiotics superior to powdery antibiotics. Antibiosis of antimicrobial concrete was verified, and amount of elution of harmful and effective ingredients was little. In workability, setting time of antimicrobial concrete was delayed. Compressive strength and resistance to carbonation of antimicrobial concrete were more increased than ordinary concrete. Finally, as there were no problems in quality and construction progress of antimicrobial concrete produced in plant, applicability of antimicrobial concrete to actual construction field was verified.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.121-128
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• 2011

Long-term water treatment performance analysis was conducted for the constructed wetland treating agricultural tailwater. Studied wetland was established in 2001 and operated from June, 2002 to November, 2010. Wetland vegetation cover was shown over 90 % coverage after 2005. According to vegetation development, accumulation of sediment nutrient was observed; Organic Carbon, T-P and T-N. In addition, DO concentration and temperature was decreased in the constructed wetland output. An infiltration rate also significantly decreased due to compaction of wetland soil. A runoff coefficient was increased due to the low infiltration rate after 2005. A T-N, TSS and Chl.a removal rate was maintained constantly. However, the T-P removal rate was slightly decreased along to wetland operation because low DO concentration could increase elution of phosphorus from sediment. After constructing open water, the T-P removal rate was increased. This is because open water could accelerate the reaearation process. Consequently, over three years of vegetation development could be helpful for wetland performance. In addition, DO concentration is important factor to maintain the T-P treatment.