• Korean Journal of Microbiology
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• v.49 no.3
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• pp.297-300
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• 2013

EPS producing bacteria were enumerated in ginseng root system (rhizosphere soil, rhizoplane, inside of root). EPS producing bacterial density of rhizosphere soil, rhizoplane and inside of root were distributed $9.0{\times}10^6$ CFU/g, $7.0{\times}10^6$ CFU/g, and $1.4{\times}10^3$ CFU/g, respectively. Phylogenetic analysis of the 24 EPS producing isolates based on the 16S rRNA gene sequences, EPS producing isolates from rhizosphere soil (RS) belong to genus Arthrobacter (6 strains) and Rhizobium (1 strain). EPS producing bacteria from rhizoplane (RP) were Arthrobacter (6 strains), Rhodococcus (1 strain) and Pseudomonas (1 strain). EPS producing bacteria from inside of root (IR) were categorized into Rhzobium (6 strains), Bacillus (1 strain), Rhodococcus (1 strain), and Pseudomonas (1 strain). Phylogenetic analysis indicated that Arthrobacter may be a member of representative EPS producing bacteria from ginseng rhizosphere soil and rhizoplane, and Rhizobium is typical EPS producing isolates from inside of ginseng root. The yield of EPS was 10.0 and 4.9 g/L by Rhizobium sp. 1NP2 (KACC 17637) and Arthrobacter sp. 5MP1 (KACC 17636). The purified EPS were analyzed by Bio-LC and glucose, galactose, mannose and glucosamine were detected. The major EPS sugar of these strains was glucose (72.7-84.9%).

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.61-66
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• 2012

Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.375-380
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• 2009

Polyepichlorohydrin rubber was treated with sodium azide (Na$N_3$) to replace its chlorine by azide ($N_3$). Then, the azidated polyepichlorohydrin rubber (Az-PECH) was blended with thermoplastic styrene-acrylonitrile copolymer with the rubber/plastic ratio of 80/20, 70/30 and 60/40 (wt/wt). The miscibility, mechanical and dynamic mechanical properties as well as elastic recovery properties of the blends were evaluated by DMA (Dynamic Mechanical Analyzer) and tensile tests. When azidation level in azidated PECH was upto 50%, the blends exhibited excellent miscibility, manifested by a single $T_g$, and fairly good elastic recovery. When azidation level was 75%, the blends showed phase separation. The miscible Az-PECH/SAN blends exhibited typical thermoplastic elastomer like properties, ie. melt processibility and high extensibility as well as good elastic recovery rate. It was also observed from combustion test that higher energy is released with the increase in the azidation level of the Az-PECH in the blends.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.499-503
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• 2018

Transglutaminase (TGase), which forms linkages among proteins, has been used to improve food quality. In the current study, quality characteristics such as color values, texture profile parameters, and sensory profiles of the frozen surichwi (Synurus deltoids) rice cake made using transglutaminase (TGase) treated-rice flour were investigated, with a view to producing high-value rice products. The results indicate that Hunter color values (L and b) and TPA parameter values (hardness, gumminess and chewiness) of frozen surichwi rice cake made with TGase-treated rice flour were significantly changed, and that these properties may be applied to improve the sensory qualities of final products. Also, the sensory acceptability scores related to color, appearance, taste and texture, as well as overall acceptability of the TGase-treated frozen surichwi rice cake, were found to be significantly higher compared to controls. In conclusion, the results clearly indicate that TGase-treated rice flour carries the potential to improve the overall quality of frozen rice cake, and that surichwi is an effective ingredient for sensory profiles.

• Journal of Nutrition and Health
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• v.40 no.1
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• pp.14-23
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• 2007

Elevated plasma homocysteine (Hcy) is a risk factor for cognitive dysfunction and Alzheimer disease, although the mechanism is still unknown. Both folate and betaine, a choline metabolite, play essential roles in the remethylation of Hcy to methionine. Choline deficiency may be associated with low folate status and high plasma Hcy. Alterations in DNA methylation also have established critical roles for methylation in development of the nervous system. This study was undertaken to assess the effect of choline and folate deficiency on Hcy metabolism and genomic DNA methylation status of the liver and brain. Groups of adult male Sprague Dawley rats were fed on a control, choline-deficient (CD), folate-deficient (FD) or choline/folate-deficient (CFD) diets for 8 weeks. FD resulted in a significantly lower hepatic folate (23%) (p<0.001) and brain folate (69%) (p<0.05) compared to the control group. However, plasma and brain folate remained unaltered by CD and hepatic folate reduced to 85% of the control by CD (p<0.05). Plasma Hcy was significantly increased by FD $(18.34{\pm}1.62{\mu}M)$ and CFD $(19.35{\pm}3.62{\mu}M)$ compared to the control $(6.29{\pm}0.60{\mu}M)$ (p<0.001), but remained unaltered by CD. FD depressed S-adenosylmethionine (SAM) by 59% (p<0.001) and elevated S-adenosylhomocysteine (SAM) by 47% in liver compared to the control group (p<0.001). In contrast, brain SAM levels remained unaltered in CD, FD and CFD rats. Genomic DNA methylation status was reduced by FD in liver (p<0.05) Genomic DNA hypomethylation was also observed in brain by CD, FD and CFD although it was not significantly different from the control group. Genomic DNA methylation status was correlated with folate stores in liver (r=-0.397, p<0.05) and brain (r = -0.390, p<0.05), respectively. In conclusion, our data demonsoated that genomic DNA methylation and SAM level were reduced by folate deficiency in liver, but not in brain, and correlated with folate concentration in the tissue. The fact that folate deficiency had differential effects on SAM, SAH and genomic DNA methylation in liver and brain suggests that the Hcy metabolism and DNA methylation are regulated in tissue-specific ways.

• Korean Journal of Crystallography
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• v.16 no.1
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• pp.38-42
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• 2005

The crystal structure of Bis(ethylenediamine) cuprate(II)$\cdot$dichromate, $Cu(C_2H_8N_2)_2{\cdot}Cr_2O_7$, has been determined by X-ray crystallography. Crystal data: a=5.682(2), b=8.567(3), c=14.839(3) ${\AA},\;{\alpha}=97.50(2),\;{\beta}=101.06(1),\;{\gamma}=109.38(2)^{\circ}$ Triclinic, P-1 (SG No=2), Z=2, V=653.9(2) ${\AA}^3,\;D_c=2.030gcm^{-3},\;{\mu}=3.273mm^{-1}$. The structure was solved by Patterson method and refined by full matrix least-square methods uslng unit weights. The final R and S values were $R_1=0.0256,\;R_w=0.0708,\;R_{all}=0.0316,\;S=1.151$ for the observed 2291 reflections. The two cupper complex ion has the usual distorted octahedral structure with mean four Cu-N distances of 2.010(3) $\AA$ and the longer mean Cu-O distance of 2.525(2) $\AA$. The Cu-complex and dichromate ions are linked to form infinite chain arranged alternatively along the [111]-direction. The neighboring chains in the (0-11) plane are connected with N1-O5 and N3-O1 hydrogen bonds.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.103-108
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• 2020

Shiga toxin-producing Escherichia coli (STEC) is an important pathogenic bacteria and can cause severe foodborne disease. For STEC detection, conventional culture methods have disadvantages in the fact that conventional culture takes a long time to detect and PCR can also detect dead bacteria. To overcome these problems, we suggest a bacteriophage amplification assay, which utilizes the ability of bacteriophages to infect living cells and their high specificity. We used a combination of six bacteriophages infecting E. coli to make the bacteriophage cocktail and added ferrous ammonium sulfate as a virucidal agent to remove free-bacteriophages. When cherry tomato and paprika were artificially inoculated with the cocktail at a final concentration of around 3 log CFU/mL and were enriched for at least 5 h in mTSB broth with Novobiocin, approximately 2-3 log PFU/mL were detected through the bacteriophage amplification assay. Therefore, bacteriophage amplification assay might be convenient and a useful method to detect STEC in a short period of time.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.140-146
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• 2012

The commercial product "pyto-patch" prepared as nano sized silver particle less than 5 nm, has effective antifungal activity against Collectotrichum gloeosporioides, Botrytis cinerea, Sclerotinia sclerotiorum in vitro. As a fungal growth inhibiton mechanism, it can reduce spore germination rate and mycelial growth. As s promising fungicide, Phyto-patch can control anthracnose effectively. The spore of C. gloeosporioides dipped in 5 ppm phyto-patch dilute suppressed germination rate to 13.2%, and mycelial growth stopped for 15 days at 10 ppm. The spore postinoculated on 10 ppm phyto-path smeared PDA surface could not germinate for 3 days and prohibit pathogen infection effectively. In field test, the anthracnose development of 4 ppm phyto-patch treated plot was less than 7% after 21 days compaired to 40% of it in untreated plot. In heavy rainfall season, pepper anthracnose effectivly contrrolled by regular 10 ppm phytopatch spraying every 7 days. The diseased pepper fruit decreased to 5.8% compaired to 94.6% in untreated plot. During drying period, the diseased pepper fruit havested in phyto-patch treated plot was 24.2%, but pepper fruit havested in untreated plot destroyed to 100% within 3 days. The nano silver particle coated on multching textile prevented late blight of pepper effectively and disease occurance delayed about month.

• KSBB Journal
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• v.21 no.4
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• pp.255-259
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• 2006

The biodegradable hyaluronic acid(HA) membranes cross-linked with lactide using the crosslinking agent, 1-ethyl-3(3-dimethyl aminopropyl) carbodiimide(EDC) were prepared as a potential biocompatible material for tissue engineering. HA membranes having different mechanical properties were synthesised by varying degree of the mole ratio of lactide to HA, EDC concentration, and crosslinking temperature. HA membranes were degradable in water solution and the degradation became slower with the increasing mole ratio of lactide to HA. HA membranes were sterilized using ethylene oxide gas and extracted with cell culture medium for 24 h at $37^{\circ}C$ and 200 rpm. Cytotoxicity of the extract was tested using NIH/3T3 mouse embryo fibroblast as a model cell. Growth inhibition was not observed in the extracts of HA membranes with the mole ratios of lactide to HA, 5 or 10, and 10% EDC concentration, however 11% of growth inhibition was observed in the extract with the mole ratio of 13. Growth inhibition was not observed in the extracts of HA membranes prepared with 5% EDC or 10% EDC and the mole ratio of lactide to HA, 10, however 12% of growth inhibition was observed in the extract with 20% EDC. Cytotoxicity was not observed in the extracts of HA membranes prepared at varying crosslinking temperatures, $15^{\circ}C,\;25^{\circ}C,\;and\;28^{\circ}C$ with the mole ratio of lactide to HA, 10 and 10% EDC.

• Clean Technology
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• v.13 no.1 s.36
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• pp.34-45
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• 2007

Phase behavior of the ternary systems of water-insoluble simvastatin drug, which is well known to be effective drugs for hypercholesterolemia therapy, in solvent mixtures of dichloromethane and supercritical carbon dioxide was investigated to present a guideline of establishing operating conditions in the particle formation of the drugs by a supercritical anti-solvent recrystallization process utilizing dichloromethane as a solvent and carbon dioxide as an anti-solvent. The solubilities of simvastatin in the mixtures of dichloromethane and carbon dioxide were determined as functions of temperature, pressure and solvent composition by measuring the cloud points of the ternary mixtures at various conditions using a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The solubility of the drug increased as the dichloromethane composition in solution and the system pressure increases at a fixed temperature. A lower solubility of the drug was obtained at a higher temperature. The second half of this work is focused on the particle formation of the simvastatin drug by a supercritical anti-solvent recrystallization process in a cylindrical high-pressure vessel equipped with an impeller. Microparticles of the simvastatin drug were prepared as functions of pressure (8 MPa to 12 MPa), temperature (303.15 K, 313,15 K), feed flow rate of carbon dioxide, and stirring speed (up to 3000 rpm), in order to observe the effect of those process parameters on the size and shape of the drug microparticles recrystallized.