• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.399-406
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• 2015

In this study, we developed a composite filler comprising cross-linked hyaluronic acid (HA) and human collagen (COL) derived from the human umbilical cord with the aim of improving its biocompatibility and longevity compared with commercially available fillers. After HA/COL composite fillers were made in two different ratios (10:1 and 5:1), the physical properties of the fillers were evaluated. The interior morphologies and in vivo weight change of these hydrogels were also characterized at 1-16 weeks after injection into mice. To evaluate their biocompatibility and durability in vivo, we injected the composite fillers into nude mice subcutaneously. The variations of injected gel weight were measured and compared with the commercial dermal fillers (Restylane and TheraFill). The composites showed improved or similar physical properties (complex viscosity of 19-22 × 10⁵ cP, and injection force of 10-12 N) over the commercial dermal fillers. Sixteen weeks following the injection, the ratio of remaining composite filler weight to initial weight (75.5 ± 16.9%; 10:1) was shown to be greater than that of the commercial fillers (43.2 ± 8.1%, Restylane; 12.3 ± 5.3%, TheraFill). In addition, immunohistochemical analysis with angiogenesis-related markers such as isolectin and vWF revealed newly formed blood vessels and cellular influx into the composite filler, which were not observed in the other fillers. These results clearly suggest that the HA/COL composite filler is a superior candidate for soft tissue reconstruction. The filler we developed may be a suitable candidate as an injectable dermal filler for tissue augmentation in humans.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2004.11a
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• pp.265-271
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• 2004

The interaction network of protein -protein plays an important role to understand the various biological functions of cells. Currently, the high -throughput experimental techniques (two -dimensional gel electrophoresis, mass spectroscopy, yeast two -hybrid assay) provide us with the vast amount of data for protein-protein interaction at the proteome scale. In order to recognize the role of each protein in their network, the efficient bioinformatical and computational analysis methods are required. We propose a systematic and mathematical method which can analyze the protein -protein interaction network rigorously and enable us to capture the biological and physical essence of a topological character and stability of protein -protein network, and sensitivity of each protein along the biological pathway of their network. We set up a Laplacian matrix of spectral graph theory based on the protein-protein network of yeast proteome, and perform an eigenvalue analysis and apply a perturbation method on a Laplacian matrix, which result in recognizing the center of protein cluster, the identity of hub proteins around it and their relative sensitivities. Identifying the topology of protein -protein network via a Laplacian matrix, we can recognize the important relation between the biological pathway of yeast proteome and the formalism of master equation. The results of our systematic and mathematical analysis agree well with the experimental findings of yeast proteome. The biological function and meaning of each protein cluster can be explained easily. Our rigorous analysis method is robust for understanding various kinds of networks whether they are biological, social, economical...etc

• Journal of Pharmaceutical Investigation
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• v.39 no.4
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• pp.249-255
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• 2009

The main object of this study was to prepare of w/o emulsion including glyceryl monooleate(GMO) and to evaluate its stability by using the recently developed $Turbiscan^{(R)}LAB$. GMO is the polar oily surfactant with the low HLB value, and it forms the gel phase of cubic structures after dissolves in aqueous media. Phosphate buffer solution (PBS) of pH 7.4 was prepared as the water phase and Marcol 52(mineral oil) was used as the oil phase in this study. GMO was used as the surfactant of W/O emulsion. W/O emulsion using GMO alone as a surfactant was very unstable. But the emulsion using both GMO and poloxamer 407 was more stable. The stability of W/O emulsions was evaluated after centrifuging the emulsions. But it was difficult with naked eye because an opaque and concentrated system like W/O emulsion was very turbid. So $Turbiscan^{(R)}LAB$ was used to detect the destabilization phenomena in non-diluted emulsion. As a result, the W/O emulsion using the proper amounts of GMO and poloxamer 407 was more stable among them using GMO of various amounts. But it seems that the other element for the stability of W/O emulsion including GMO was required. Furthermore, the $Turbiscan^{(R)}LAB$ was a very efficient analyzer for evaluating the physical stability of emulsion.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.3
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• pp.224-232
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• 2002

CdS-$TiO_2$ nano-composite sol was prepared by the sol-gel method in organic solvents at room temperature and further hydrothermal treatment at various temperatures to control the physical properties of the primary particles. Again, CdS-$TiO_2$ composite particulate films were made by casting CdS-$TiO_2$ sols onto $F:SnO_2$ conducting glass and then heat-treatment at $400^{\circ}C$. Physical properties of these 61ms were further controlled by the surface treatment with $TiCl_4$, aqueous solution. The photo currents and hydrogen production rates measured under the experimental conditions varied according to the $CdS/[CdS+TiO_2]$ mole ratio and the mixed-sol preparation method. For $CdS-TiO_2$ composite sols prepared in IPA, CdS particles were homogeneously surrounded by $TiO_2$ particles. Also, the surface treatment with $TiCl_4$ aqueous solution caused a considerable improvement in the photocatalytic activity, probably as a result of close contacts between the primary particles by the etching effect of $TiCl_4$. It was found that the photoelectrochemical performance of these particulate films could be effectively enhanced by this approach.

• Macromolecular Research
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• v.15 no.3
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• pp.221-224
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• 2007

A silica-magnesium bisupport (SMB) was prepared by a sol-gel method for use as a support for a metal-locene/Ziegler-Natta hybrid catalyst. The prepared $rac-Et(Ind)_2ZrCl_2/TiCl_4$/MAO(methylaluminoxane)/SMB catalyst was applied to the copolymerization of ethylene with l-hexene using a variable triethylaluminum (TEA)/transition-metal (Ti) ratio and fixed MAO/transition-metal (Zr) ratio. The effect of the Al(TEA)/Ti ratio on the physical properties and chemical composition distributions (CCDs) of the ethylene-hexene copolymers produced by the hybrid catalyst was investigated. In the ethylene-hexene copolymers, two melting temperatures attributed to the metal-locene and Ziegler-Natta catalysts were clearly observed. The number of CCD peaks was increased from six to seven and the temperature region in which the peaks for the short chain branches of the ethylene-hexene copolymer were distributed became lower as the Al(TEA)/Ti ratio was increased from 300 to 400. Furthermore, the temperature regions corresponding to the lamellas in the copolymer became lower and those corresponding to the small lamellas in the copolymer became higher as the Al(TEA)/Ti ratio was increased from 300 to 400. In the copolymer produced with Al(TEA)/Ti = 500, however, only four CCD peaks were observed and the short chain branches were poorly distributed.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1444-1451
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• 2018

The surface-to-volume ratio of one-dimensional (1D) semiconductor metal-oxide sensors is an important factor for achieving good gas sensing properties because it offers a wide response area. To exploit this effect, in this study, we determined the optimal calcination temperature to maximize the specific surface area and thereby the sensitivity of the sensor. The $In_2O_3$ nanorods were synthesized by using vapor-liquid-solid growth of $In_2O_3$ powders and were decorated with the Pt nanoparticles by using a sol-gel method. Subsequently, the Pt nanoparticle-decorated $In_2O_3$ nanorods were calcined at different temperatures to determine the optimal calcination temperature. The $NO_2$ gas sensing properties of five different samples (pristine uncalcined $In_2O_3$ nanorods, Pt-decorated uncalcined $In_2O_3$ nanorods, and Pt-decorated $In_2O_3$ nanorods calcined at 400, 600, and $800^{\circ}C$) were determined and compared. The Pt-decorated $In_2O_3$ nanorods calcined at $600^{\circ}C$ showed the highest surface-to-volume ratio and the strongest response to $NO_2$ gas. Moreover, these nanorods showed the shortest response/recovery times toward $NO_2$. These enhanced sensing properties are attributed to a combination of increased surface-to-volume ratio (achieved through the optimal calcination) and increased electrical/chemical sensitization (provided by the noble-metal decoration).

• Journal of Biomedical Engineering Research
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• v.44 no.6
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• pp.465-475
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• 2023

In this study, we demonstrated a silica nanofibrous membrane based on the electrospinning process and evaluated its DNA isolation and purification performance in PCR pretreatment. Generally, silica membranes made of non-woven fabric are used for PCR pretreatment, but this study aimed to improve the efficiency of the pretreatment process by developing a nanofiber-type silica membrane with high specific surface area and porosity. In order to manufacture a nanofiber-shaped silica film while maintaining the original physical properties of silica, nanofiber membranes produced by adding various concentrations of PEO (5 wt%, 8 wt%, and 10 wt%) to silica prepared by the sol-gel method were compared. In terms of nanofiber membrane production, the higher the PEO concentration, the more effective it was in producing nanofiber membranes. The produced silica nanofiber membrane was inserted to a pretreatment device used in commercial PCR equipment, and the pretreatment performance was compared and verified using Salmonella bacteria. When Salmonella was used, samples containing 5 wt% PEO showed superior PCR efficiency compared to samples containing 8 wt% and 10 wt% PEO. These results show that adding 5 wt% of PEO can effectively improve DNA purification and separation by producing a nanofiber-shaped silica film while maintaining the physical properties of silica. We expect that this study will contribute to the development of effective PCR pretreatment technology essential for various molecular biology applications.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.277-287
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• 2007

To understand the effects of the powdered manganese nodule and sea bottom sediment pumped up with nodules on the mining process, the shattering ratio of manganese nodule and their physical properties are analyzed. The self shattering ratio and crushing shattering ratio are about 27% and about 3%, respectively. Then total shattering ratio is about 30%. The initial turbidity of the powdered manganese nodule and the bottom sediment show high, i.e., about 3,100 and 1,850 respectively. But their turbidities decrease rapidly with time. After 1 hour, turbidity of the powdered manganese nodule drops to about 1,570 and that of the bottom sediment to 1,310. The turbidity of Na-bentonite changes from 820 to 730 after 1 h and to 700 after 2 h. The viscosity of powdered manganese nodule is $1.4{\sim}1.5cP$, and the viscosity of bottom sediment is less than 1 cP. The viscosity fo Na-bentonite is initially 37.2 and increase with time to 86.4 cP after 30 min. The high initial turbidity of powdered manganese nodule is due to dark color of the powder. The high specific gravity makes rapid precipitation and then decreases the turbidity rapidly. The bottom sediment shows high initial turbidity because of easy suspension with very fine particle size. But it cannot be hydrated and formed gel in suspension, then it is easily precipitated. However Na-bentonite is hydrated to the expended state and makes gel state, then it shows high turbidity and high viscosity. These physical properties of the powdered manganese nodule suggest that the powder of manganese nodule should not make scaling inside of lifting pipe or pump. And the bottom sediment lifted up with manganese nodule should not play the role of drilling mud shch as Na-bentonite.

• Journal of Applied Biological Chemistry
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• v.44 no.4
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• pp.190-193
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• 2001

Genipin, aglycone of geniposide isolated from fruits of Gardenia jasminoides, was transformed into blue pigments through reaction with glycine and methylamine. The blue pigments formed from glycine-reacted genipin were passed through Bio-Gel P-2 resin yielding fractions GG1 and GG2, and those from methylamine-reacted genipin were separated into fractions GM1-GM4. The first eluted higher molecular-weight fractions, GG1 and GM1, had higher tinctorial strength than the later eluted lower molecular-weight fractions, GG2 and GM2-GM4, respectively. $^1H-NMR$ spectra of GG1 and GM1 showed very broad peaks indicating that structures of the pigments were highly polymeric. $^1H-NMR$ spectra of GG2, GM3, and GM4 showed several sharp peaks at aliphatic and aromatic regions with accompanying broad peaks, although the spectrum of GM2 was rather simple. Determination of the structural and physical nature of the isolated pigments is in progress.

• YAKHAK HOEJI
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• v.29 no.1
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• pp.32-38
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• 1985

The anthelmintic substance of the roasted fruits of Prunas mume against Clonorchis sinensis was isolated and its structure was identified by chemical and physical methods. The results obtained from the experiments are as follows: 1) The methanol extract of the roasted fruits of P. mume was fractionated into four parts: petroleum ether, ethyl ether, ethyl acetate and water soluble part. Among these, etherial fraction was found to have strong wormicidal effect on liberated metacercaria of Clonorchis sinensis. 2) From the etherial fraction, the wormicidal substance was isolated by silica gel, polyamide and sephadex column chromatography and identified to be 5-hydroxymethylfurfural (5-HMF) by chemical and spectral data. 3) 5-HMF was synthesized and administered to the rabbits infected with C. sinensis. On the 2nd day after administration, the EPG (eggs per gram in feces) reached to the maximal value. Among the adult worms isolated from the bile duct of the treated animal, 84% of worms were damaged morphologically. 4) The content of 5-HMF in the fruits of P. mume which were roasted in an oven at $90-110^{\circ}C$ for 52 hours and that in the fresh fruits was evaluated by HPLC. The content of 5-HMF was 0.8% in the roasted fruits and 0.02% in the fresh ones.