• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.52-53
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• 2006

A new series of PEO-PPO-PEO and PPO-PEO-PPO copolymers having several hydroxyl groups on the PPO chain segment were synthesized, further modified with various poly(lactic acid) PLA oligomeric chains to confer physical stability after thermo-gelation in the body fluid. Gel stability was endowed by either increasing hydrophobic interaction between PLA chains or inducing stereocomplex formation between enatiomeric isomers of PLA chains. Macromolecular drugs were incorporated within the gels and their release patterns were investigated using Pluronic F127 as a control.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.295-295
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• 2006

In present study, poly(acrylic acid) (PAA) and hydrophobically modified poly(ethylene oxide) (HM-PEO) multilayers based on the hydrogen bonding between the component polymer pair have been prepared by the LbL deposition method. Dip assembled HM-PEO/PAA multilayers yield unique film morphologies in comparison with PEO/PAA multilayers due to the micellar formation of HM-PEO owing to the hydrophobic attraction between alkyl chains end-capped with the PEO chains. Individual HM-PEO micelles were connected through the bridging PEO chains to form temporary networks on multilayer surface and induced peculiar surface morphology on HM-PEO/PAA multilayers above the critical number of bilayers.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1171-1174
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• 2007

We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.40-40
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• 2010

CdSe nanocrystals (NCs) have been decorated on singlewalled carbon nanotubes (SWCNTs) by combining a method of chemically modified substrate along with gate-bias control. CdSe/ZnS core/shell quantum dots were negatively charged by adding mercaptoacetic acid (MAA). The silicon oxide substrate was decorated by octadecyltrichlorosilane (OTS) and converted to hydrophobic surface. The negatively charged CdSe NCs were adsorbed on the SWCNT surface by applying the negative gate bias. The selective adsorption of CdSe quantum dots on SWCNTs was confirmed by confocal laser scanning microscope. The measured photocurrent clearly demonstrates that CdSe NCs decorated SWCNT can be used for photodetector and solar cell that are operable over a wide range of wavelengths.

• Journal of Plant Biology
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• v.38 no.2
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• pp.137-141
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• 1995

We isolated a cDNA clone, BLSC1, encoding 5' exon of ATP synthase CF0 subunit I from broccoli. BLSC1 is 285 nucleotides long which consists of a 5' noncoding region of 34 nucleotides, a 5' exon of 145 nucleotides and an intron of 106 nucleotides. The 5' exon codes for 48 amino acids which reveals mostly hydrophobic. The amino acid sequence deduced from BLSC1 shares 83%, 83% and 91% identities with the genes coding for atpF from wheat, rice and spinach, respectively. Genomic Southern blot analysis for BLSC1 showed a typically strong signal for a gene located in the chloroplast genome. Northern blot analysis identified three major classes of transcripts showing strong positive signals in the leaves, but only trace amounts of the transcripts were identified in the other organs like stems, flowr buds and roots.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.746-754
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• 2010

Response surface methodology was adopted to model and optimize the effects of microbial transglutaminase (TG) and calcium alginate (CA) systems of various ratios on the gelation characteristics of porcine myofibrillar protein (MP) at various salt levels. The CA system consisting of sodium alginate (SA), calcium carbonate (CC) and glucono-$\delta$-lactone (GdL) showed no remarkable changes in the salt-soluble fraction, and only minor effects on electrostatic interactions were observed. Increasing CA concentration caused acid-induced hydrophobic interactions in MPs, resulting in increased MP gel strength. The TG system, containing TG and sodium caseinate (SC), induced cold-set MP gelation by formation of covalent bonding. The main advantage of the combined system was a higher cooking yield when the MP gel was heated. These results indicated that 0.7% TG combined with 0.8% CA system can form a viscoelastic MP gel, regardless of salt levels.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.337-345
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• 1995

Biosurfactants produced by Pseudomonas aeroginosa KK-7 were purified and their properties were studied. The bacterial surfactant was seperated into two sorts of biosufactants (Type I, 11) by silica gel column chromatograpgy. On the basis of physiochemical analysis, Type I was found to be mixture of two glycolipids with M.W. 800, and Type II was peptide with M.W. 1300. The Type 11 biosurfactant was compose of glutamic acid, proline, glycine, leucine, histidine. The crude extract was used to dertermine some properties as a surfactant. The biosurfactant had the properties as stronger emulsification agent and a stronger stabilizing agent emulsion than any other surfactants tested.

• Journal of the Korean Applied Science and Technology
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• v.3 no.1
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• pp.43-47
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• 1986

1.2-bis(aminoacyl)hydrazine derivatives and dipeptides were synthesized by conventional peptide synthesis procedures. Their antioxidant activity were inverstigated by over-storage test using corn oil as substrte. 1.2-bis (aminoacyl) hydrazine derivatives and dipetides containing hydrophobic side chain amino acid showed higher antioxidant activity. A free N-terminal amino group was also found to be important for the appearance of antioxidant activity. 1.2-bis (aminoacyl) hydrazine derivatives showed higher antioxidant activity than dipeptides. Antimicrobial activites of dipeptides and 1.2-bis (aminoacyl) hydrazine derivatives were also examined by the paper disc method. All of these compounds had shown no antimicrobial activity.

• International Journal of Automotive Technology
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• v.5 no.1
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• pp.1-7
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• 2004

In line with the Super Ultra Low Emission Vehicle (SULEV) regulation, the main idea in this study has been focused on the utilization of hydrocarbon adsorber (HCA) to adsorb the excess hydrocarbons emitted during a period of engine cold-start, As main recipes of HCA materials, many types of zeolite as well as the combination of alumina and precious metals were used, Representative physico-chemical factors of zeolite such as acidic and hydrophobic properties were characterized. The optimum recipe of HCA materials was also determined. Among the acid properties of zeolites, the Si/Al ratio was found to be the most important factor to get higher hydrocarbon adsorption capacity.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.30-34
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• 2014

We report a novel approach for fabricating active surface-enhanced Raman scattering (SERS) substrate for sensitive detection. This approach is based on the assembling of gold nanoparticles (AuNPs) onto the electrospun polycaprolactone (PCL) nanofiber film. The hydrophobic surface of PCL nanofiber film was pretreated using UV-inducing graft polymerization with acrylic acid. Afterwards this PCL nanofiber film was incubated with the AuNP solution to promote the assembly of AuNPs onto the PCL nanofibers and the formation of SERS active substrate. 4-aminothiophenol (4-ATP) molecule was used as a test probe for SERS experiments, indicating that the substrate has high sensitivity to SERS response. Our method has great advantage in term of environment-friendly synthesis, large-scale, high stability and good reproducibility. This highly active SERS substrate can be employed to detect the drug molecule, 2-thiouracil.