• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.157-157
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• 2003

To evaluate an effect of pathological liver damage on the cyclohexane metabolism, rats were pretreated with 50% $CCl_4$ dissolved in olive oil (0.1$\mell$/100g body weight) 10 or 17 times intraperitoneally at intervals of every other day. On the basis of liver function and histological findings, the animals pretreated with $CCl_4$ 10 times were identified as acutely liver damaged ones and the animals pretreated with $CCl_4$ 17 times were identified as severly liver damaged ones, with fibrosis, biliary abnormality and mild injury both in the kidneys and the lungs. To these liver damaged animals, cyclohexane (a single dose of 1.56g/kg body weight, i.p.) was administrated at 48 hours after the last injection of $CCl_4$. The rats were sacrificed at 4 or 8 hours after injection of cyclohexane. The cyclohexane metabolites; cyclohexanol (CH-ol), cyclohexane-1, 2-diol (CH-1, 2-diol), cyclohexane-l, 4-diol (CH-1, 4-diol), and their glucuronyl conjugates and cyclohexanone (CH-one) were detected in the urine of cyclohexane treated rats. After cyclohexane treatment, the serum levels of CH-ol and CH-one were remarkably increased at 4 hours and then decreased at 8 hours in normal group. Whereas in liver damaged rats, these cyclohexane metabolites were higher at 8 hours than at 4 hours. The excretion rate of cyclohexane metabolites from serum into urine was more decreased in liver damaged animals than normal group, with the levels of excretion rate being lower in $CCl_4$ 17 times injected animals than 10 times injected ones. However, it was interesting that the urinary concentration of cyclohexane metabolites was generally more increased in liver damaged animals than normal ones, and the increasing rate was higher in $CCl_4$ 17 times injected rats than 10 times injected ones. And liver damaged rats, especially $CCl_4$ 17 times treated ones, had an enhanced ability of glucuronyl conjugation to cyclohexanol analogues compared with normal group. Futhermore, CH-1, 2 and 1, 4-diol were all conjugated with glucuronic acid in $CCl_4$ 17 times injected animals. In conclusion, the metabolic rate of cyclohexane was unexpectably accelerated and it may be caused by physiological adaptation of adjacent intact hepatocyte in damaged liver.

• Applied Chemistry for Engineering
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• v.1 no.2
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• pp.190-196
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• 1990

The biological active monomer, 1-(methacryloyloxymethyl)-5-fluorouracil(MAOMFU) was synthesized from 2, 4-bis(trimethylsilyloxy)-5-fluoropyrimidine. Poly(MAOMFU) poly(1-methacryloyloxymethyl-5-f1uorouracil-co-methyl methacrylate), and poly(MAOMFU-co-MMA) were also obtained by radical polymerization at $60^{\circ}C$. The monomer reactivity ratios, $r_1$ and $r_2$ were determined by $Kelen-T\ddot{u}d\ddot{o}s$ method ; $r_1(MAOMFU)=0.72$, and $r_2(MMA)=1.24$. These reactivity values imply that the copolymerization was mainly affected by the steric hindrance of MAOMFU. It was found from kinetic measurements that the rate constants of solvolysis are given as $6.42{\times}10^{-5}sec^{-1}$ and $7.40{\times}10^{-6}sec^{-6}$, respectively, for MAOMFU and poly(MAOMFU).

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.236-242
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• 2005

To develop a new detection method using irradiation-induced volatile marker compounds of red pepper powder (RP), the volatile compounds of irradiated RP (0, 1, 3, 5, and 10 kGy) were analyzed by purge and trap (P&T)/solid phase microextraction (SPME)/gas chromatography/mass spectrometry (GC/MS) methods. A total of 51 and 31 compounds were detected in IRP by SPME and P&T methods, respectively. Among these, 25 compounds, which were composed of 4 hydrocarbons, 7 aldehydes, 1 ketone, 3 alcohols, 4 aromatic compounds, 2 esters and 4 miscellaneous compounds, showed irradiation dependent manner with significant positive correlation (p<0.01 or p<0.05) between irradiation dose and relative concentration. However, all compounds except 1,3-bis(1,1-dimethylethyl)benzene were not suitable as marker compounds because of their low determination coefficients ($R^2$<0.80) between irradiation dose and their concentrations, and detectablilty in nonirradiated sample. Therefore, only one compound, 1,3-bis(1,1-dimethylethyl)benzene, was tentatively identified as a volatile marker compound to detect irradiated RP.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.196-201
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• 2004

Volatile components in flower and seed of safflower were identified. Volatile flavor compounds of safflower (Carthamus tinctorius L.) was extracted by simultaneous steam distillation and extraction method using Likens and Nickerson's extraction apparatus. Concentrated extract was analyzed and identified by gas chromatography and GC-mass spectrometry. Main volatile components in flower were terpene compounds, including p-cymene, limonene, ${\alpha}-phellandrene$, ${\gamma}-terpinene$, camphor, 4-terpineol, selinene, ${\beta}-caryophyllene$, torreyol, ${\beta}-eudesmol$, and 10 acids including 3-methylbutanoic acid, 2-methylbutanoic acid, and acids of $C_{2},\;C_{5}-C_{11}$. Main volatile components in seed and safflower were 20 aldehydes including hexanal (7.17%), (E)-2-heptenal (1.10%), (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.903-913
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• 2021

Three-type PVC membranes denoted by AEM-1, AEM-2, and AEM-3 with a cross-linked anion-exchange group were prepared by substitution reaction of PVC with triethyldiamine (TEDA), 1,4-dimethylpiperazine (DMP), and 1,4-bis(imidazol-1-ylmethyl)benzene (BIB) in cyclohexanone, respectively. We confirmed the successful preparation of the AEM-1, AEM-2, and AEM-3 via ionic conductivity (S/cm), water uptake (%), contact angle, ion-exchange capacity (m_eq/g), thermal properties, SEM and XPS analysis, respectively. The electrochemical capacitor experiments using PVC membrane with cross-linked anion-exchange group in organic electrolytes were performed. The prepared AEM-1, AEM-2 AEM-3 have a good stability by charge and discharge performance in organic electrolyte. As a result, the AEM-2 and AEM-3 membrane based on PVC prepared by the solvent casting method after substituent reaction is suitable for the use as a separator in organic electrochemical capacitor (supercapacitor).

• Clean Technology
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• v.30 no.2
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• pp.145-156
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• 2024

Carbon has a large specific area and excellent chemical stability, so research on its use as a catalyst support is actively conducted. When using carbon as a support, the pretreatment process is essential. Through pretreatment of carbon, the growth of metal nanoparticles can be controlled and the bonding strength between the support and metal particles can be improved. In this study, carbon was pretreated for surface modification and 5 wt% Pd/C catalysts were synthesized using it as a support. Catalytic activity was evaluated through phenol hydrogenation. To compare with nitric acid, which is commonly used in carbon pretreatment, carbon pretreatment was performed using organic acid. Pd/C treated with gluconic acid showed the highest activity, with 94.93% phenol conversion and 92.76% cyclohexanone selectivity. Therefore, it is expected that pretreatment of the carbon support using organic acid will not only overcome the disadvantages of inorganic acid treatment but also improve catalyst performance.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.1
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• pp.31-38
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• 2024

In this study, vinyl waste, which is the cause of environmental pollution, is recycled via an electrospinning method and applied as a separator that can be employed for energy storage devices. In detail, vinyl wastes are dissolved in a solution containing p-xylene and cyclohexanone, followed by electrospinning to obtain a vinyl waste-derived separator(VWS), and then the hydrophilic functional groups on the surface of VWS are introduced using a plasma treatment to improve wettability. Scanning electron microscopy analysis have verified that the shape and thickness of as-spun VWS vary depending on the concentration of vinyl waste. The surface hydrophility of VWS is modified by plasma treatment with applied powers ranging from 80 to 120W. The lowest contact angle is observed when the 100W power is applied to VWS(VWS-100W). In electrochemical analysis, the VWS-100W-based supercapacitor device shows the highest specific capacitance of 57.9 F g^-1. This is ascribed to the high porosity achieved by electrospinning as well as the introduction of hydrophilic functional groups by the oxygen plasma treatment. In conclusion, vinyl waste is successfully recycled into separators for energy storage devices, suggesting a new way to reduce environmental pollution.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.241-246
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• 2007

Purpose: $[^{11}C]6-OH-BTA-1$ ([N-methyl-$^{11}C$]2-(4'-methylaminophenyl)-6-hydroxybenzothiazole, 1), a -amyloid imaging agent for the diagnosis of Alzheimer's disease in PET, can be labeled with higher yield by a simple loop method. During the synthesis of $[^{11}C]1$, we found the formation of by-products in various solvents, e.g., methylethylketone (MEK), cyclohexanone (CHO), diethylketone (DEK), and dimethylformamide (DMF). Materials and Methods: In Automated radiosynthesis module, 1 mg of 4-aminophenyl-6-hydroxybenzothiazole (4) in 100 l of each solvent was reacted with $[^{11}C]methyl$ triflate in HPLC loop at room temperature (RT). The reaction mixture was separated by semi-preparative HPLC. Aliquots eluted at 14.4, 16.3 and 17.6 min were collected and analyzed by analytical HPLC and LC/MS spectrometer. Results: The labeling efficiencies of $[^{11}C]1$ were $86.0{\pm}5.5%$, $59.7{\pm}2.4%$, $29.9{\pm}1.8%$, and $7.6{\pm}0.5%$ in MEK, CHO, DEK and DMF, respectively. The LC/MS spectra of three products eluted at 14.4, 16.3 and 17.6 mins showed m/z peaks at 257.3 (M+1), 257.3 (M+1) and 271.3 (M+1), respectively, indicating their structures as 1, 2-(4'-aminophenyl)-6-methoxybenzothiazole (2) and by-product (3), respectively. Ratios of labeling efficiencies for the three products $([^{11}C]1:[^{11}C]2:[^{11}C]3)$ were $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ in MEK, $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$ in CHO, $9.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$ in DEK and $7.6{\pm}0.5%:0.0%:0.0%$ in DMF, respectively. Conclusion: The labeling efficiency of $[^{11}C]1$ was the highest when MEK was used as a reaction solvent. As results of mass spectrometry, 1 and 2 were conformed. 3 was presumed.