• Analytical Science and Technology
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• v.20 no.2
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• pp.109-114
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• 2007

In this study, soxhlet extraction and dissolution-precipitation method are used for separating analyte from polymer materials. In soxhlet extraction efficiency test, it has been found that the DCM, Toluene, THF, and mixtures Acetone/Hexane (1:4, v/v) gave good extraction efficiency, while the use of the ethyl ether, acetone/ethyl ether (1:4, v/v), acetone/hexane (1:1, v/v), DCM/hexane (1:1, v/v) resulted in significantly lower values. In case of dissolution-precipitation method, there is no considerable difference with used different dissolving solvent. The elution amount of multi layer silica and Florisil column were determined with hexane 250 mL and 70 mL of hexane, respectively. Range of PBDE in real waste plastics was N.D.~1,028 ppm.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.51-55
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• 2007

The fractions of Ulva lactuca were studied to verify the antioxidant activities. The fractions from the ethanol extract of U. lactuca were prepared by the systematic extraction procedure with the solvents such as hexane, ethyl ether, ethyl acetate, butanol and $H_2O$. Furthermore, ethyl ether, ethyl acetate and aqueous fractions of U. lactuca were purified using HPLC. The antioxidant activities of purified samples from ethyl ether, ethyl acetate, and aqueous fractions were investigated using 1,1-diphenyl-2-picryl-hydrazil (DPPH). L-ascorbic acid, a positive control showed the highest DPPH radical scavenging activity. In addition, purified sample from aqueous fraction also showed relatively high activity. Purified sample from ethyl acetate fraction showed moderate activity, but purified sample from ethyl ether fraction showed the lowest activity. Dose dependent patterns were observed on all three samples tested. The lipid peroxidation inhibition activities of these three purified samples were also investigated. Purified sample from ethyl ether fraction of U. lactuca showed the highest activity and as strong activity as that of $\alpha-tocopherol$, a positive control. These results suggest that U. lactuca may be a useful candidate for a natural antioxidant agent.

• Natural Product Sciences
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• v.11 no.3
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• pp.150-154
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• 2005

The radical scavenging effect of the MeOH extract of Fraxini Cortex on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The $CH_2Cl_2$-and n-BuOH-soluble fractions of MeOH extract showed the promising DPPH radical scavenging effects, and further purified by silica gel, Sephadex LH-20 column chromatography, and reversed-phase C-18 MPLC to yield five coumarins, esculetin (1), fraxidin (2), fraxetin (3), fraxidin $8-O-{\beta}-D-glucopyranoside$ (fraxin methyl ether) (5), esculin (6), and a secoiridoid oleuropein (4), and a coumarin-secoiridoid escuside (7). Compounds 1, 3, and 4 showed potent DPPH radical scavenging effects, exhibiting $IC_{50}$ values of 14.68, 9.64, and $22.03\;{\mu}M$, respectively. Compounds 6 and 7 also showed moderate effects with $IC_{50}$ values of 147.79 and $72.73\;{\mu}M$, respectively. L-Ascorbic acid was used as a positive control and exhibited the $IC_{50}$ value of $50.31\;{\mu}M$.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.75-80
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• 1994

Flexural properties and thermal stability have been studied as a function of blend composition in bifunctional DGERA (diglycidyl ether of hisphenol A)/tetrafunctional TGDDM(tetrag1ycidyl diamino diphenyl methane) cured with DDM(4, 4'-diamino diphenyl methane). The flexural modulus and the glass transition temperature increase with an increase of TGDDM and show discontinuous dependence on blend composition around the composition range of 80/20~60/40(L)GEBA/TGDDM). This can be explained with a structural phase inversion (ductile-to-brittle) in crosslinking networks. With increasing TGDDM, the maximum decomposition temperature(Ts) increases, whereas the activation energy during thermal degradation decreases.

• Journal of Chest Surgery
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• v.20 no.4
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• pp.659-672
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• 1987

Nitrofen [2,4-dichlorophenyl-P-nitrophenyl ether] is a diphenyl ether herbicide used for pre and post-emergent control of broad leafed weeds. This chemical was known to induce a variety of congenital cardiovascular anomalies with diaphragmatic hernia and hydronephrosis in the rate fetuses. The present study was conducted to produce congenital cardiovascular anomalies in the rat fetuses by oral nitrofen administration at the indicated doses and days of gestation, and to find the characteristics of nitrofen-induced cardiovascular anomalies. All the observed fetuses were removed from the pregnant Sprague-Dawley rats sacrificed on the twenty-first day of gestation. They were preserved in 10 per cent formalin and dissection for examination were carried out under a dissecting microscope using forceps and scissors. Following results and conclusion were based on dissecting microscopic findings on 482 offsprings. 1. The eleventh day of gestation was the most sensitive day for nitrofen induction of congenital cardiovascular anomalies in the rat. This incidence was dose-related in rats exposed on the eleventh day of gestation. 2. Ventricular septal defect was the most common single anomaly that represented more than half of the total cardiovascular anomalies, followed by aortic arch anomalies and tetralogy of Fallot. 3. Cardiac anomalies derived from infundibular maldevelopment such as tetralogy of Fallot and pulmonary atresia with ventricular septal defect were only observed in the eleventh gestation day treated group. 4. Aortic arch anomalies were found in high frequency and the great majority were characteristically anomalous right subclavian artery with left aortic arch. Key words; nitrofen, congenital cardiovascular anomalies.

• IMMUNE NETWORK
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• v.10 no.2
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• pp.64-74
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• 2010

Background: The present study was undertaken to examine the immunological effects of pentabrominated diphenyl ether (penta-BDE) and decabrominated diphenyl ether (deca-BDE) on the immune system of the dams and the developmental immune system of the offsprings. Methods: In this study, mated female C57BL/6J mice were orally administered penta-BDE, deca-BDE or corn oil for 5 weeks, from gestational day 6 to lactational day 21. Results: The body weight of PND21 exposed to penta-BDE was significantly decreased relative to control mice, but that of post-natal day 63 (PND63) were recovered. Orally dosed dams with penta-BDE had significantly smaller absolute and relative spleen masses than control mice. Absolute and relative spleen and thymus masses of PND21 exposed to penta-BDE were significantly decreased over control. The exposure of dams and PND21 with penta-BDE reduced the number of splenocytes and thymocytes. As results of hematologic analysis, percentage WBC and percentage neutrophils increased in dams with deca-BDE. Splenic T cell proliferation in dams and PND21 exposed to penta-BDE was increased, and there were no significant difference in splenic B cell proliferation in all treatment groups. As results of flow cytometric analysis of splenocyte, percentage total T cell, Th cell and Tc cell in PND21 exposed to penta-BDE was slightly increased, and percentage macrophage in dams and PND21 exposed to deca-BDE was decreased. The ELISA results of antibody production show no significant difference in all treatment groups relative to controls. Conclusion: These results imply that PBDEs given to the dam were transferred to the offspring during gestation and lactation, and PBDEs transferred from the dam affect immune system of offspring.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.237-245
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• 1998

The transgenic tobacco (Nicotiana tabacum cv. Xanthi) plants containing Bacillus subtilis protoporphyrinogen oxidase gene with cauliflower mosaic virus 35S promoter have recently been generated by using Agrobacterium-mediated gene transformation. The nontransgenic and the transgenic tobacco plants were compared with respect to responses to diphenyl ether herbicide oxyfluorfen and under various environmental conditions. Both cellular leakage and lipid peroxidation caused by oxyfluorfen were found to be less in the transgenic than in the nontransgenic plants. Growth responses of the transgenic plants under various temperature, light, and water conditions were almost the same as those of the nontransgenic plants, although the transgenic plants exhibited slightly more retarded growth under low light or saturated water condition. These results revealed that the transgenic tobacco plants containing B. subtilis protoporphyrinogen oxidase gene under cauliflower mosaic virus 35S promoter were relatively resistant to oxyfluorfen and exhibited normal growth pattern. Possible mechanism of resistance to oxyfluorfen in the transgenic plants is also discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.3017-3021
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• 2011

Two chiral stationary phases (CSPs) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 bonded covalently to silica gel were applied for the first time to the resolution of racemic vigabatrin and its analogue ${\gamma}$-amino acids and the resolution results were compared to those on the commercially available Crownpak CR(+) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 coated dynamically onto octadecylsilica gel. While vigabatrin was not resolved at all on Crownpak CR(+), it was resolved quite well on the two CSPs. Among four vigabatrin analogue ${\gamma}$-amino acids, only two were resolved on Crownpak CR(+), but three were resolved on the CSP (CSP 1) containing residual silanol groups and all of four were resolved on the CSP (CSP 2) containing residual silanol group-protecting n-octyl groups. The improved lipophilicity in CSP 2 was proposed to be responsible for its superiority to CSP 1 for the resolution of vigabatrin and analogue ${\gamma}$-amino acids. In addition, the composition of aqueous mobile phase was found to affect the chiral recognition behaviors for the resolution of vigabatrin and analogue ${\gamma}$-amino acids on CSP 2.

• The Korean Journal of Community Living Science
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• v.23 no.3
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• pp.255-263
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• 2012

Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs), which are used in a variety of consumer products. Several of those are produced in large quantities. Their chemical structure similarities to polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs), as well as their toxicity, has been studied. PBDEs are persistent and lipophilic, which results in their bioaccumulation in the fatty tissues of organisms and enrichment throughout food chains. In addition, a number of studies also reported high levels of PBDEs in animals and food resulting from the use of contaminated animal feed Public concern about PBDEs levels in animals and food has been raised. Feed contamination by toxic chemicals has been the cause of the contamination of poultry products. The purpose of this study was to evaluate PBDEs in pig feed to search the origin chase of POPs in pigs. Feed samples were obtained wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1614. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Quantification was carried out by the isotopic dilution method. The analysis of ${\Sigma}PBDEs$ involved 22 PBDE congeners, including BDE-17, 28, 47, 49, 66, 71, 77, 85, 99, 100, 119, 126, 138, 153, 154, 156, 183, 184, 190, 191, 196 and 197.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.10
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• pp.1436-1442
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• 2002

In this paper, the effect of the loess and mud of an inorganic substance dyed on cotton knitting fabrics have been studied The structure and chemical composition of loess and mud was analyzed. And the Far-Infrared emissivity and emission power, colorfastness, anti-bacterial properties cotton knitting fabrics dyed with loess and mud were also evaluated. The structure and chemical composion of loess and mud was almost identical structure and to be alike main components were SiO$_2$, Al$_2$0$_3$ and Fe$_2$O$_3$. The cotton hitting fabrics dyed with loess and mud have good colorfastness and anti-bacterial properties. when the dyed fabrics was after-treated with diphenyl ether, the anti-bacterial property were improved. Far-Infrared emissivity and emission power cotton knitting fabrics dyed with loess and mud have very good.