• Journal of the Korean Chemical Society
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• v.48 no.1
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• pp.17-27
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• 2004

A procedure based on solid phase microextraction extraction(SPME)-GC/MS has been developed for the simultaneous analysis of plasticizers. The plasticizers investigated in this study are dimethyl phthalate(DMP), diethyl phthalate(DEP), dibutyl phthalate(DBP), benzylbutyl phthalate(BBP), diethylhexyl phthalate (DEHP), di-n-octyl phthalate(DnOP). The limit of detection(LOD) was 0.163~0.299 with relative standard deciation(RSD) of 5.85~15.80% for these compounds. At water reserviors of Han, Geum, Nakdong and Sumjin rivers, only DBPand DEHP were detected at trace level, 0.192~1.270 ng/ml for DBP and 0.077~1.102 ng/ml for DEHP depending on the river.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.6
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• pp.570-576
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• 2014

LFG (Land-Fill Gas) includes components of $CH_4$, $CO_2$, $O_2$, $N_2$, and water. The preparation of synthesis gas from LFG as a DME (Dimethyl Ether) feedstock was studied by methane reforming of $CO_2$, $O_2$ and steam over NiO-MgO-$CeO_2$/$Al_2O_3$ catalyst. Our experiments were performed to investigate the effects of methane conversion and syngas ratio on the amount of LFG components over NiO-MgO-$CeO_2$/$Al_2O_3$ catalyst. Results were obtained through the activity reaction experiments at the temperature of $900^{\circ}C$ and GHSV of 4,000. The results were as following; it has generally shown that methane conversion rate increased with the increase of oxygen and carbon dioxide amounts. Highly methane conversion of 92~93% and syngas ratio of approximately 1.0 were obtained in the feed of gas composition flow-rate of 243ml/min of $CH_4$, 241ml/min of $CO_2$, 195ml/min of $O_2$, 48ml/min of $N_2$, and 360ml/min of water, respectively, under reactor pressure of 15 bar for 50 hrs of reaction time. Also, it was shown that catalyst deactivation by coke formation was reduced by excessively adding oxygen and steam as an oxidizer of the methane reforming.

• Journal of the Korean Society of Food Culture
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• v.8 no.3
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• pp.295-299
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• 1993

This research was carried out to investigate the changes of volatile substances which influence on liquor flavor while keeping the Hong-Ju on storage. The contents of total acid and ethanol were reduced on long storage. The volatile components in the Hong-Ju were shown in the order of acetaldehyde, fusel oil, acetate, furfural and methanol after a year, while other substances were increased except furfural, and methanol was not detected. After two years, the content of acetaldehyde was $21.4{\sim}58.4\;mg%$ which is the similar level of that of one year. However, fusel oil, whose main components are n-propanol, 2-methyl-1-propanol and 2-methyl-1-butanol was reduced to $0.71{\sim}1.03\;mg/ml$ which is about $4{\sim}6$ times than that of initial content, while furfural was reduced to $0.01{\sim}0.02\;mg/ml$.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1908-1919
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• 2015

This work investigated the potential of curcumin (CCM) and (-)-epigallocatechin gallate (EGCG) to inhibit N-acyl homoserine lactone (AHL)-mediated biofilm formation in gram-negative bacteria from membrane bioreactor (MBR) activated sludge. The minimum inhibitory concentrations (MICs) of CCM alone against all the tested bacteria were 200-350 μg/ml, whereas those for EGCG were 300-600 μg/ml. Biofilm formation at one-half MICs indicated that CCM and EGCG alone respectively inhibited 52-68% and 59-78% of biofilm formation among all the tested bacteria. However, their combination resulted in 95-99% of biofilm reduction. Quorum sensing inhibition (QSI) assay with known biosensor strains demonstrated that CCM inhibited the expression of C4 and C6 homoserine lactones (HSLs)-mediated phenotypes, whereas EGCG inhibited C4, C6, and C10 HSLs-based phenotypes. The Center for Disease Control biofilm reactor containing a multispecies culture of nine bacteria with one-half MIC of CCM (150 μg/ml) and EGCG (275 μg/ml) showed 17 and 14 μg/cm² of extracellular polymeric substances (EPS) on polyvinylidene fluoride membrane surface, whereas their combination (100 μg/ml of each) exhibited much lower EPS content (3 μg/cm²). Confocal laser scanning microscopy observations also illustrated that the combination of compounds tremendously reduced the biofilm thickness. The combined effect of CCM with EGCG clearly reveals for the first time the enhanced inhibition of AHL-mediated biofilm formation in bacteria from activated sludge. Thus, such combined natural QSI approach could be used for the inhibition of membrane biofouling in MBRs treating wastewaters.

• The Korean Journal of Pain
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• v.11 no.2
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• pp.268-272
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• 1998

Background: Postoperative bleeding is a common complication in transurethral resection of prostate (TURP). Some patients become restless and combative after operation, particularly when in pain, producing bleeding from the prostatic bed. So many patients may be necessary to pain control for reduce bleeding. The purpose of this study is to compare recently used two Methods for post-operative analgesia. Methods: We studied 40 patients, ASA physical staus 1, 2, undergone TURP under general anesthesia. The patients divided into two groups: continuous epidural pain control group (I, n=20) received an epidural bolus of morphine 2 mg and 1% lidocaine 10 ml followed by a epidural 0.08% bupivacaine 40 ml and morphine 4.5 mg (basal infusion rate 0.5 ml/hr), intravenous patient-controlled analgesia (IV-PCA) group (II, n=20) received an intravenous bolus of fentanyl $50\sim100{\mu}g$ followed by a IV-PCA morphine 30 mg, ketorolac 180 mg and droperdol 2.5 mg (basal infusion rate 0.5 ml/hr, bolus 0.5 ml, lock-out interval 15 min). This study conducted the analgesic efficacy, side effect and patient's satisfaction for 1 day after TURP. Results: Continuous epidural pain control group had more significant analgesia than IV-PCA at postoperative 30, 60 min, but no significant difference was observed later in both group. Nausea and pruritus were scantly developed in both group but the incidence was no significant differeance. Patients responded good satisfaction over 70% in both group. Conclusions: Postoperative continuous epidural pain block and IV-PCA are both effective Methods of postoperative pain control with lower incidence of side effects.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.366-369
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• 2004

Myristica fragrans Houtt were extracted in 80% aq. MeOH and solvent fractionated sing $CHCl_3$, EtOAc, n-BuOH and water, successively. The n-BuOH fraction gave three phenylpropanoids through application of silica gel column chromatographies. The chemical structures of the phenylpropanoids were determined by the interpretation of several spectral data, including NMR and MS as meso-dihydroguaiaretic acid (1), nectandrin B (2) and syringin methyl ether (3). Compound 1, which was first isolated from this plant by authors, showed inhibitory activities with $60.0{\pm}2.1%\;(100\;{\mu}g/ml),\;42.6{\pm}0.9%\;(140\;{\mu}g/ml)\;and\;12.2{\pm}0.2%\;(200\;{\mu}g/ml)$ on ACAT(acyl-CoA:Cholesterol Acyltransferase), chitin synthase III and HMG-CoA reductase (3-hydroxy-3-methylglutaryl coenzyme A reductase), respectively. Compound 3 showed inhibitory activities with $27.2{\pm}0.9%\;(100\;{\mu}g/ml),\;45.5{\pm}0.8%\;(200\;{\mu}g/ml)$ on ACAT and chitin synthase III.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.42-47
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• 1961

A titration of a small amount of iron with standard potassium ferrocyanide using potassium thiocyanate as indicator has been studied. A sample solution containing $0.1{\sim}1.0$ mg. $Fe^{3+}$ in 60 ml. is pipeted into 100 ml. Erlenmyer flask and the pH of the solution is adjusted to $1.5{\sim}3.0$ with 0.1 N or 1 N $HNO_3$ and $NH_4OH.$ To this solution one ml. of 1 M KCNS solution as indicator is added. The solution colored by iron thiocyanate complex is titrated with 1/200 M or 1/400 M standard solution of potassium ferrocyanide from a 5 ml. micro-buret. Near the end point, when the color of sample changes from deep red to green, about 20 ml. of ether is added and shake the flask vigorously. The red color is extracted to the ether layer. To settle the ether layer a few drops of ethanol is added and then standard solution is added dropwise and shake vigorously. The end point is reached when the color of the ether layer disappears owing to the quantitative formation of $Fe_4[Fe(CN)_6]_3.$ In this titration, 0.lmg. of $Fe^{3+}$ can be determined within 1.0% of titration error, provided the following optimum conditions, i.e., pH $1.5{\sim}3.0$, final concentration of KCNS indicator; $0.01{\sim}0.02M$, at room temperature. The titration found to be interfered by the presence of slightly soluble salts, stable complex forming ions and the ions which would be reduced by ferrocyanide or oxidized by ferric ion.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.5
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• pp.477-483
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• 2015

LFG (Land-Fill Gas) includes components of $CH_4$, $CO_2$, $O_2$, $N_2$, and water. The preparation of synthesis gas from LFG as a DME (Dimethyl Ether) feedstock was studied by methane reforming of $CO_2$, $O_2$ and steam over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Our experiments were performed to investigate the effects of methane conversion and syngas yield on the amount of LFG components over $NiO-MgO-CeO_2/Al_2O_3$ catalyst. Results were obtained through the methan reforming experiments at the temperature of $900^{\circ}C$ and GHSV of 8,800. The results were as following; it has generally shown that syngas yield increase with the increase of oxygen and steam amounts and then decrease. Highly methane conversion of above 98% and syngas yield of approximately 60% were obtained in the feed of gas composition flow-rate of 243ml/min of $CH_4$, 241ml/min of $CO_2$, 195ml/min of $O_2$, 48ml/min of $N_2$, and 450ml/min of steam, respectively, under reactor pressure of 1 bar for 200 hrs of reaction time. Also, it was shown that catalyst deactivation by coke formation was reduced by excessively adding oxygen and steam as an oxidizer of the methane reforming.

• Journal of Plant Biology
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• v.34 no.1
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• pp.37-43
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• 1991

Mesophyll protoplasts of Nicoliana labacum ($NR^{-}/SR^{+}$) and N glulinosa were electrofused with AC field of 0.5 MHz and 1 kV DC pulse for 2 ms. Fused protoplasts were selected and cultured to the green cell clusters in $MSNO_3$ medium containing 1.2 mg!ml streptomycin sulfate. Four plant lines regenerated from selected colonies showed both parental morphological characteristics of leaf and flower and these plant lines were confirmed as somatic hybrids based on electrophoretic patterns of leaf peroxidase. In XhoI restriction patterns of chloroplast DNA, these hybrid plant lines expressed both parent common restriction sites and parent specific sites. One of these hybrid lines exhibited interspecific pattern of both parental chloroplast genomes. indicating nine both parent common sites, one N labacum specific site and two N glutinosa specific sites. sites.

• The Korean Journal of Ecology
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• v.28 no.3
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• pp.129-134
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• 2005

The monthly variations of physico-chemical and microbiological water quality were investigate in the artificial Lake Geumgang near estuary barrage. Sixty heterotrophic bacteria were isolated and identified by amplification and sequencing of 16S rDNA. Water temperature, pH, and inorganic nutrients($NH_4$-N, $NO_2$-N, $NO_3$-N, $PO_4$-P) were measured. Concentrations of DO, BOD, and inorganic nutrients were lower than in the middle-stream of Geum river The population densities of heterotrophic bacteria and total coliforms varied from $4.1{\pm}1.0\times10^2$ to $6.7{\pm}1.1{\times}10^3\;cfu\;ml^{-1}$, and 0 to $2.3{\pm}0.6{\times}10^2\;cfu\;ml^{-1}$, respectively. Among the measured numbers of physiological groups of bacteria, cellulolytic bacteria showed higher population densities than those of other physiological groups. Bacterial community structure was analysed based on 16S rDNA partial sequencing. Among 60 isolates, dominant genus was Pseudomones (20 strains).