• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.223-226
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• 2003

Due to the potential application to ultra-high strength fibers and excellent properties such as high mechanical properties, excellent thermal endurance and chemical stability, thermotropic liquid crystal polymers (TLCPS) are attractive in recent years [1, 2]. Furthermore, the melt blends of TLCPS and conventional thermoplastics have been extensively investigated because of their easy processing and high performance [3-6]. Since high performance polymers generally has high melt viscosity, introduction of the relatively low viscosity components may be one of the more effective techniques to improve processability through the decrement of melt viscosity in melt processing. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.179-182
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• 2003

Chitin is the most abundant natural amino polysaccharide and is estimated to be produced annually almost as much as cellulose. It has become of great interest not only as an under utilized resource, but also as a new functional material of high potential in various fields. In addition, chitin and chitosan are recommended as suitable functional materials, because these natural polymers have excellent properties such as biocompatibility, biodegradability, non-toxicity and adsorption properties, etc. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.94-94
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• 2003

Cross-linked polystyrene (PS) particles with carboxyl and/or poly(ethylene glycol) units on surface were formed by an emulsifier-free emulsion polymerization using styrene, methacrylic acid (MA), and poly(ethylene glycol) dimethacrylate (PEG-diMMA) at pH 7, and followed by freeze-drying to give the corresponding powders. Monodisperse polymer particles could be obtained at a concentration of PEG-diMMA 1 mol% relative to styrene. Zeta potential of polymer surface was measured to be 91 mV at a polymer of PEG-diMMA 1 mol% and was dropped as the content of MA increased.

• BMB Reports
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• v.38 no.2
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• pp.161-166
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• 2005

Functional protein of MB78 bacteriophage having apparent molecular weight of 22 kDa is expressed from 1.7 kb HindIII G fragment. The nucleotide sequence of this fragment showed two open reading frames of 222 and 196 codons in tail-to-tail orientation separated by a 62-nucleotide intercistronic region. The ORF of 22 kDa protein is present in opposite orientation, i.e. in the complementary strand, preceded by a strong ribosomal binding site and a promoter sequence. Another ORF started from the beginning of the fragment whose promoter region and translational start site lies in the 0.45 kb HincII U fragment which is located next to the HindIII G fragment, that has the sequence for DNA bending. 3' end of the fragment has high sequence homology to the EaA and EaI proteins of bacteriophage P22, a close relative of MB78 phage.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.691-709
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• 2007

Concerns on environmental waste problems caused by non-biodegradable petrochemical-based plastic packaging materials as well as consumer's demand for high quality food products has caused an increasing interest in developing biodegradable packaging materials using annually renewable natural biopolymers such as polysaccharides and proteins. However, inherent shortcomings of natural polymer-based packaging materials such as low mechanical properties and low water resistance are causing a major limitation for their industrial use. By the way, recent advent of nanocomposite technology rekindled interests on the use of natural biopolymers in the food packaging application. Polymer nanocomposites, especially natural biopolymer-layered silicate nanocomposites, exhibit markedly improved packaging properties due to their nanometer size dispersion. These improvements include increased mechanical strength, decreased gas permeability, and increased water resistance. Additionally, biologically active ingredients can be added to impart the desired functional properties to the resulting packaging materials. Consequently, natural biopolymer-based nanocomposite packaging materials with bio-functional properties have huge potential for application in the active food packaging industry. In this review, recent advances in the preparation and characterization of natural biopolymer-based nanocomposite films, and their potential use in food packaging applications are addressed.

• International Journal of Oral Biology
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• v.30 no.1
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• pp.31-37
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• 2005

Treponema maltophilum, a Group IV oral spirochete, is associated with periodontitis and endodontic infections. In this study we analyzed the functional role of the major surface protein of this organism (MspA) in human gingival fibroblasts (HGFs). The full-length gene encoding MspA was cloned and expressed in Escherichia coli by using the expression vector pQE-30. The recombinant protein (rMspA) was purified by affinity chromatography with nickel-nitrilotriacetic acid agarose and possible contamination of E. coli endotoxin in rMspA was removed by using polymyxin B-agarose. rMspA significantly induced the expression of pro inflammatory cytokines like IL-6 and IL-8 and intercellular adhesion molecule (ICAM)-1 in HGFs, when analyzed by reverse transcription-PCR, flow cytometry, and enzyme-linked immunosorbent assay. Our results indicate that MspA of T. maltophilum may play an important role in amplifying the local immune response by upregulating the expression of proinflammatory cytokines and ICAM-1.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.320-325
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• 1998

To elucidate of role(s) of tTA as a repressor in the tTA-mediated gene repression system, we introduced mutations into the acidic domain of VP16 and examined the effects of such various mutations. In the transient repression experiment, a region containing 34 amino acids of the activation domain of VP16 (412-456) which interacts with TFIIB was found to be necessary and sufficient for the tTA-mediated repression of gene expression. However, in the experiment to investigate the fact that tTA-regulated repression is related to the activation function of VP16, we found that the repression abilities of tTA derivatives did not correlate exactly with their activation abilities. Therefore, we conclude that increased mass of VP16 in tTA might be also important for efficient repression in addition to functional domain of VP16.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1569-1571
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• 1996

The role of ESR spectroscopy in the characterization of functional LB films is discussed. Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly dependant on the combination of dyes. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. In structural studios, ESR is of particular important in the analysis of molecular orientation of LB films. Development of new functional LB films may provide more cases where ESR spectroscopy will clarify the nature of such films.

• Korean Journal of Pharmacognosy
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• v.28 no.2
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• pp.65-71
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• 1997

This study was carried out to purify and to characterize various bioactive material acemannan from Aloe vera. Purified acemannan was mannose (67%) and acetyl group (23%), and the rest of glucose was galactose that consists of long chain polydispered beta-(1, 4) linked mannan polymers. The sugar and acetyl group in the molecule were linked by molar ratio of 3 : 1. This polysaccharide from Aloe vera may provide functional flood and potential drug source with antiviral and immunomodulating properties.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1545-1547
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• 2009

The fiber-rich fractions including enzyme treated insoluble dietary fiber, alcohol insoluble solid, and water insoluble solid were prepared from the peel of soft ripe persimmon, and to evaluate and compare the yields, proximate compositions, monosaccharide profiles, and functional properties. The results showed that uronic acid was the main sugar followed by glucose, which indicated that all insoluble fibers were mainly composed of pectic substances and cellulose. The presence of xylose and fucose indicated the occurrence of hemicellulose. All fiber-rich fractions were exhibited high yield and functional properties. Thus, the peel of ripe persimmon could be used as fiber supplements.