• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.51-57
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• 2008

Mixed matrix membranes of poly(vinyl alcohol) (PVA), loaded with phosphomolybdic heteropolyacid (HPA) and crosslinked with glutaraldehyde have been prepared by the solution casting technique. Pervaporation (PV) experiments have been performed at $30^{\circ}C$ to separate water-isopropanol feed mixtures containing 10 to 40 wt.% of water. The membranes were characterized by DSC and DMTA to understand their thermal behavior and mechanical strength properties. At high content (i.e. 7 wt.% with respect to weight of PVA) of HPA, the mixed matrix membranes could extract water efficiently on the permeate side with a selectivity of 90,000 and a flux of 0.032 $kg/m^2h$ for 10 wt.% of water containing feed mixture (the lowest feed composition of water studied). Flux of the mixed matrix membranes decreased with increasing concentrations of HPA.

• Korea-Australia Rheology Journal
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• v.19 no.2
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• pp.81-88
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• 2007

Blends of collagen dispersion (COL) with poly(vinyl alcohol) (PVA) in different weight ratios were investigated by oscillatory rheometry, Fourier transform-infrared spectroscopy and scanning electron microscopy. It was found that even with 80% of PVA, the COL/PVA blends behaved more like collagen dispersion than pure PVA solution in the dynamic thermal and frequency processing, for instance, a dominant elastic appearance (G'>G"), a similar shear thinning behavior and the thermal denaturation below $40^{\circ}C$. However, influence on the blend behaviour by PVA was noticeable, for instance, an increase of dynamic denaturation temperature, the decreasing intensity of amide I, II and III bands as well as the diminishing irregular pores on the surface of blends. The interaction between collagen and PVA could be observed, especially at the regions with low content or high content of PVA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.362-365
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• 2002

This paper, experiment manufactures device of Metal/Poly-${\gamma}$ Benzyl $_D$-GlutamateOrganic Films/Metal structure using PBDG and I-V properties and C-F properties. The I-V characteristic is measured that approve voltage from 0 to +2[V] of device and the distance between electrode is larger, could know that small current flow and thin film could know that had insulation property. C-F characteristic has each other affinity between the polarization amount and frequency. Permittivity of MIM device could know by dipole that is voluntary polarization of LB film that polarization is happened. The capacitor properties of a thin film is better as the distance between electrodes is smaller.

• Toxicological Research
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• v.14 no.4
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• pp.465-474
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• 1998

This study was examined on the effect of ex-vivo immunotherapy in 7, 12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinogenesis. Sprague-Dawley female 40 rats were divided into Jour groups. As a positive control, Group I was intubated with DMBA, 5 mg /100 g body weight and single dose, at experimental onset. Group II was treated ex-vivo immunotherapy with polyinosinic-polycytidylic acid (Poly I : C) and Group III was treated with Interleukin-2 (IL-2). Group IV was negative control. All rats were sacrificed at 16 weeks after DMBA intubation. Mammary gland wet weight, dry fat free tissue weight, incidence of tumor, and the number of lobules, alveolar buds, terminal end buds, and terminal ducts were examined. Morphological changes of the mammary gland after treated with DMBA were analyzed by whole mount and histopathological method. As results, the induced mammary tumors of Group I, II and III were 60%, 33% and 0%, respectively. Histopathological types of induced-mammary tumors were adenoma, adenocarcinoma and carcinosarcoma. In analysis of the whole mount method, the number of the terminal end buds, terminal ducts and lobules were significantly lower in Group II (p<0.01) and III (p<0.01) than DMBA alone treated Group I. In microscopic observation, hyperplastic alveolar nodules were significantly lower in Group III than Group I (p<0.01). In conclusion, IL-2 had strong inhibitory effect on the mammary gland tumorigenesis induced by DMBA in rats. Whole mount method may be a useful technique to assess the mammary carcinogenesis. Moreover, hyperplastic alveolar nodules were very sensitive parameter to assess the mammary carcinogenesis.

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.42-48
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• 1999

We have performed a quantum-chemical investigation on the conformations and electronic properties of a variety of methoxy-substituted poly(p-phenylenevinylenes) (PPVs) to elucidate the effects of alkoxy substitution. Geometrical parameters for the polymers were fully optimized through Austin Model I (AM I) semi-empirical Hartree-Fock (HF) band calculations. Electronic properties of the polymers were obtained by applying the AM I optimized structures to the modified extended Huckel method. To confirm validity of the AM I conformational results, we also carried out ab initio HF calculations with the 6-31G (d) basis set for a variety of methoxy-substituted divinylbenzenes. It is found that the potential energy surfaces of alkoxy-substituted PPVs are quite shallow around the planar conformations, suggesting that the prepared films possess a variety of conformations with different torsion angle in the solid state, depending on the synthetic conditions. When two alkoxy groups are concurrently substituted at the adjacent sites in the phenylene ring, these groups are subject to rotating around the C(sp2)-O bonds by 70-80° to avoid the strong steric repulsion between them. Consequently, the overlap between the π-type p orbital of oxygen and the π molecular orbitals of the polymer decreases. This leads to a wide gap and a high oxidation potential for tetramethoxy-substituted PPV, compared to those of dialkoxy-substituted PPV.

• Journal of Nutrition and Health
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• v.13 no.3
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• pp.145-149
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• 1980

To study the rancidity of dried yellow carlbina oil by oxidation during the storage period general properties of the oil and composition of its fatty acid were analysed quantitatively with gas chromatography The results indicated that I) The dried yellow carbina oil was involved in drying oil of high degree of unsaturation with IV 138 and consisted of higher-fatty acid with SV 194. 2) The composition of the fatty acids were composed of 18 fatty acids involving 6 unknown fatty acids and comprised poly-unsaturated fatty acid with $C_{18}^{:3}\:and\:C_{22}^{:5}$ 3) After three morths storage of dried yellow carbina the content of malonaldehyde was about 12mg/kg in its exterior part, but 6mg/kg in interior part, which indicateing that the degree of rancidity of poly unsaturated glycerides in exterior part of carbina were two times as much as that of interior part.

• Macromolecular Research
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• v.16 no.1
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• pp.51-56
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• 2008

Spherical micelles of poly(styrene-b-isoprene) (SI) diblock copolymers in selective solvents have been reported to pack onto either face-centered cubic (fcc) or body-centered cubic (bcc) lattices. The selection rule for fcc and bcc lattices has been understood in terms of the intermicellar potentials, and they have been quantified using the ratio of the corona layer thickness to the core radius, $L/R_c$, as suggested by McConnell and Gast. In order to test the validity of the McConnell-Gast criterion, this study compared the $L/R_c$ values from various solutions i.e. nine SI copolymers in several different selective solvents. The McConnell-Gast criterion was not found to be a determining factor, even though it could explain the fcc/bcc selection qualitatively. From the phase diagrams, the transition between fcc and bcc phases was also considered as a function of concentration and temperature, and their physical mechanisms are discussed based on the recent mean-field calculation reported by Grason.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1587-1589
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• 2000

In this paper the weight loss, surface potential decay, surface resistivity and dielectric constant are measured to investigate the surface properties, insulation characteristic changes of PET film according to the discharge treatment. As a result of the test, up to the 10[min] the surface potential decay and surface resistivity have increased. Also, from the result of dielectric constant has decreased. On the other hand, the insulation characteristic of PET film have decreased after 10[min] in the discharge treatment.

• Biomedical Science Letters
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• v.19 no.2
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• pp.112-117
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• 2013

Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2). Triptolide (TP), a natural component of Tripterygium wilfordii Hook. F, has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that TP inhibits the NF-${\kappa}B$ activation induced by polyriboinosinic polyribocytidylic acid (Poly[I:C], TLR3 agonist) and lipopolysaccharide (LPS, TLR4 agonist). TP also inhibits COX-2 expression induced by Poly[I:C] and LPS. These results suggest that TP can modulate the immune responses regulated by TLR3 and TLR4 signaling pathways.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.11
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• pp.57-62
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• 1998

In this paper, tunable transconductor shows good linearity over a wide input voltage range are proposed. The proposed transconductor employ operating in the nonsaturation(ie., linear) region to improve circuit simplicity and tunability and 6.8V$\_$p-p/ wide input range. Also the circuit employ source-coupled differential pair to provide true differential input and can achieve both positive and negative transconductance values. The proposed circuits are implemented using a 1.2 $\mu\textrm{m}$ single poly double metal n-well CMOS technology. The THD characteristic of proposed circuit is less than 1% for a differential input voltage of up to 6V$\^$p-p/ when supply bias condition is V$\_$DD/=-V$\_$ss/=5V, I$\_$B/=20, 40${\mu}$A, and frequency of input signal is 1KHz.