• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.223-225
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• 1996

Poly (ethylene glycol) (PEG)macromers terminated with acrylate groups and interpenetrating polymer networks(IPN) composed of poly(hydroxyethyl methacrylate)(PHEMA) or poly(hydroxyethyl methacrylate-co-hydropropyl methacrylate-co-N-vinyl pyrrolidone) [P(HEMA-co-HPMA-co-NVP)] and PEG macromer were synthesized with the aim of obtaining protein adsorption resisatnt soft contact lens. Polymerization of PEG macromer resulted in the formation of cross-linked gels due to the multifunctionality of macromer. Crosslinked P(HEMA) or P(HEMA-co-HPMA-co-NVP) chains were interpenetrated into the cross-linked three-dimensional networks of PEG. It was found that albumin adsorption onto the contact lens prepared by P(HWMA)/PEG IPN decreases with a decrease of molecular weight of PEG whereas its adsorption onto the contact lens prepared by P(HEMA-co-HPMA-co-NVP)/PEG IPN decreases with an increase of molecular weight of PEG. Also, it was found that albumin adsorption onto the both contact lens decreases with an increase of concentration of PEG macromer in the IPN preparation. There are also more adequate in the bioinertness and bioadhesion for the contact lens by P(HEMA)/PEG IPN or P(HEMA-co-HPMA-co-NVP)/PEG IPN than that by P(HEMA) or P(HEMA-co-HPMA-co-NVP).

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.180-185
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• 2010

We investigated genetic diversity among and within the populations of cultivated ginseng (Panax ginseng C. A. Meyer ) using SRAP profiles. A total of 24 ginseng plants were sampled from the three populations (two from China, one from Korea). Since all these populations are previously shown closely related to each other assister groups, we used Panax quinquefolium L. and wild ginseng as a reference species, which is not "within the sister group". All individuals from the three populations were screened with a total of 36 primer pairs with 26 primers generated from 328 SRAP bands of DNA gels. The mean gene diversity ($H_E$) was estimated to be 0.057 within populations (range 0.032-0.067), and 0.086 at the species level. The genetic differentiation (Gst=0.31) indicates that genetic variation apportioned 30% among populations and 70% within populations. Generally, the result of this study indicates that ginseng contains high molecular variation in its populations.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.29-34
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• 2014

Nanogels are internally cross-linked particles of sub-micrometer size made of hydrophilic polymers and are considered a distinct type of macromolecules, compared with linear and branched polymers or macroscopic gels. In this study, we studied a method of radiation induced synthesis of nanogels, which allows us to obtain tailored intra-molecularly crosslinked macromolecules of independently chosen molecular weight and dimensions. Thus, we report the possibility of applying the prepared nanogels using poly(acrylic acid) through electron beam irradiation for potential application as biomaterials. The nanogels were characterized by scanning electron microscopy (SEM). In addition, the size and zeta-potential of nanogels were measured by a particle size analyzer (PSA). The nanogels were prepared at an approximate size of 180 nm at 100 kGy and were spherical in shapes. The size of the nanogels decreased with increasing irradiation doses, and the absolute value of zeta potential increased with increasing irradiation doses.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.588-594
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• 1997

Gelation time, gel structure and volatility of by-products during gelation of PZT sol-gel processing were investigated by FT-IR spectroscopy. FT-IR spectroscopic study was performed on PZT gels with the various H₂O contents (1, 2 and 3 mol) and the several types (HNO₃, NH₄OH) and amounts (0.1, 0.2 mol) of catalysts, monitoring temporal (0, 1, 3, 10 weeks, 3 months and 3 years) and thermal (100-700 ℃) changes of FT-IR spectra. The interpretation of temporal change of the spectra revealed two trends. One is under the condition of 1 mol H₂O, 1 mol H₂O+0.1 mol HNO₃, 3 mol H₂O and the other is for 1 mol H₂O+0.1 mol NH₄OH, 2 mol H₂O, 1 mol H₂O+0.2 mol HNO₃. The gel structures and the gelation times for these conditions were discussed in comparison with the reported results of SiO₂, and we suggested the reaction mechanisms for these structural characteristics. Thermal variation of FT-IR spectra was interpreted as the evolution processes of gel by investigating the evaporation of solvent and the decomposition of organic residues.

• Macromolecular Research
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• v.17 no.3
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• pp.156-162
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• 2009

Supramolecular hydrogels were instantaneously fabricated by mixing aqueous solutions of $\alpha$-cyclodextrins ($\alpha$-CDs) and amphiphilic methoxy (polyethylene glycol) (MPEG)-$\varepsilon$-caprolactone (CL) oligomer, which was synthesized via the ring-opening polymerization of the CL monomer using low-molecular-weight MPEG ($M_n$ of MPEG=2,000 g/mol) as an initiator. The supramolecular structure of the hydrogels was revealed by X-ray diffraction (XRD) analyses. Rheological studies of the hydrogels revealed an elastic character when the number of CL units in the oligomer was more than 2, and the obtained hydrogels showed high storage modulus but relatively low shearing viscosity due to the low-molecular-weight character of the oligomer, which was more preferable for use as an injectable delivery system. The physical properties of the hydrogels could be modulated by controlling the chain morphology and concentration of the oligomers, as well as the feed molar ratio of the oligomer to $\alpha$-CD. The components of the supramolecular hydrogels are biocompatible and can readily be eliminated from the body. These features render the supramolecular hydro gels suitable as drug delivery systems and tissue engineering scaffolds.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.997-1011
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• 2021

The processing characteristics of freeze-dried pork powder as raw meat for comminuted meat products were compared with those of freeze-thawed pork. The tertiary structural properties, oxidation, and solubility of proteins in the freeze-dried pork powder were investigated. In addition, the properties of the emulsion gels manufactured with freeze-dried pork powder (GFD) and freeze-thawed pork (GFT) at 1.5% and 2.0% NaCl were evaluated. The surface hydrophobicity and intrinsic tryptophan fluorescence intensity of myofibrillar proteins between the freeze-dried pork powder and freeze-thawed pork were similar. However, freeze-dried pork powder had higher carbonyl compounds and lower solubility of sarcoplasmic and myofibrillar proteins than freeze-thawed pork (p<0.05). GFD had higher cooking loss than GFT in 2.0% NaCl, and lower hardness and a^* value of GFD were observed regardless of NaCl level (p<0.05). Moreover, GFD had higher malondialdehyde content than GFT at the two NaCl concentrations (p<0.05). Therefore, our study demonstrated that freeze-dried pork powder has lower functional properties than freeze-thawed pork as raw meat for comminuted meat products.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.4
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• pp.15-25
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• 2021

Purpose: The purpose of this study is to form a new cosmetic market through the development of a composition with high skin permeability after adding omega 3 to Aloe Vera soothing gel products. Research design, data and methodology: In this study, omega-3 fatty acids were added to cosmetic products in the form of soothing gels. By applying nanoparticle technology to rapidly increase the penetration of raw materials into the skin, characteristics related to skin moisture and regeneration were determined. Omega-3 was used as a raw cosmetic material. Then 5% and 15% nanoparticle aqueous products containing omega-3 were prepared. The developed water hydrate was subjected to skin permeability test using artificial skin. Results: 53 hours of artificial transdermal penetration of the developed composition, the ethanol-based omega-3 containing nanoparticle solubilized raw material was about three times higher penetration than the ethanol-based omega-3 containing nanoparticle solubilized raw material. Conclusions: The raw material product (SR-1901) containing 5% of omega-3 nanoparticle water hydrate has skin regeneration ability and pain reduction effect. It can be expected that the skin cosmetics market will be reorganized into a new distribution structure and opportunity through omega-3 supplemented soothing gel cosmetics with improved efficacy than existing cosmetics.

• Korean Journal of Metals and Materials
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• v.47 no.8
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• pp.516-521
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• 2009

In this study we report a rapid synthesis of nanoporous organo-functional silica (OFS) with unimodal and bimodal pore structures encompassing pores ranging from meso-to macroscale. The problems of tediousness and high production cost in the conventional syntheses are overcome by co-condensation of an inexpensive inorganic precursor, sodium silicate with an organosilane containing trimethyl groups. The insitu covalent anchoring of the non-polar trimethyl groups to the inner pore walls prohibits irreversible shrinkage of the wet-gel during microwave drying at ambient pressure and thus larger size pores (from ca. 20 to ca. 100 nm) can be retained in the dried silica. The drying process of the silylated wet-gels at an ambient pressure can be greatly accelerated upon microwave exposure instead of drying in an oven or furnace. Using this approach, anoporous and superhydrophobic silicas showing a wide variation in texture and morphology can be readily synthesized in roughly two hours. The effects of various sol-gel parameters solely on the textural properties of the organo-functional silica (OFS) have been investigated and discussed.

• Natural Product Sciences
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• v.27 no.1
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• pp.1-9
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• 2021

Methicillin-resistant Staphylococcus aureus (MRSA) infection often complicates burn wounds. Mupirocin is the antibiotic of choice for superficial MRSA infection, and its resistance is on the rise due to its frequent and widespread use. This study aimed to develop and evaluate Curcuma xanthorriza extract (CXE)-containing gel as a topical agent against MRSA-infected second-degree burn wound in rats. CXE was obtained using maceration with 96% ethanol. Xanthorrhizol level, antibacterial, and antioxidant activity were evaluated using a standardized method. In vivo, the wound's healing and bacterial load were evaluated every three days, whereas the histopathology of the wound was examined on day 12 of treatment. One-Way ANOVA and Kruskal-Wallis test were used to analyze the data. In this study, 27.0% and 7.10% of the obtained CXE were xanthorrhizol and curcumin, respectively. Additionally, an IC50 of 64.27 ppm was shown in antioxidant activity measurement, and MIC against MRSA was 5 mg/ml. Treatment with CXE-containing gels showed a significant reduction in bacterial load and proliferation of connective tissue in a dose-dependent manner. In conclusion, CXE-containing gel showed a greater reduction of bacterial load and more advanced wound healing phase than mupirocin.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.125-131
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• 2022

The microstructure of highly aggregated colloidal dispersions was investigated by probing the rheological behavior of magnetic suspensions. The dynamic moduli as functions of frequency and strain amplitude are shown to closely resemble that of colloidal gels indicating the formation of network structure. The two types of characteristic critical strain amplitudes, γ_c and γ_y, were characterized in terms of the changing microstructure. The amplitude of γ_c indicates the transition from linear to nonlinear viscoelasticity and depends only on particle volume fraction not magnetic interactions. The study of scaling behavior suggests that it is related to the breakage of interfloc, i.e., floc-floc structure. However, yielding strain, γ_y, was found to be independent of particle volume fraction as well as magnetic interaction. It relates to extensive deformation resulting in yielding behavior. The scaling of elastic constant, G_e, implies that this yielding behavior and hence γ_y is due to the breakage of long-range interfloc interactions. Also, the deformation of flocs due to increase strain was indicated from the investigation of the fractal nature.