• Journal of dental hygiene science
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• v.11 no.2
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• pp.69-76
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• 2011

The aim of this study was to compare the effects on the resistance to demineralization by the frequency and method of fluoride application in vitro. ninety-one human enamel specimens were embedded in acrylic resin with the labial surfaces exposes. The specimens were divided into 7 groups; (1) non-treated; (2) 1.23% APF gel 1 time; (3) 2% NaF sol 1 time; (4) 2% NaF sol iontophoresis 1 time; (5) 1.23% APF gel 4 time; (6) 2% NaF sol 4 time; (7) 2% NaF sol iontophoresis 4 time. All the groups were immersed in the remineralizing solution (RS) before baseline and divided into 7 test groups of 13 specimens each. All the specimens were exposed to a pH-cycling model which consisted of demineralization (6 hours) and remineralization (18 hours) for 5 days. The Vickers surface micro-hardness number of all the specimens was measured using microhardness tester and the specimen surfaces were observed by scanning electron microscope (SEM). The results were analyzed using one-way ANOVA followed a Tukey's multiple comparison at a significance level of 0.05. The group 7 showed higher level of microhardness after Fluoride application. The group 1 showed lowest level of microhardness but group 7 showed higher level of microhardness after pH-cycling model, there were significant differences between groups. After the modified pH-cycling, the 2% NaF solution with the iontophoresis group showed the best resistance to demineralization(p<0.05). These results were also confirmed by SEM. The fluoride iontophoresis method was the most effective of the regimens in increasing the acid resistance of the enamel.

• Korean journal of food and cookery science
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• v.18 no.3
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• pp.275-279
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• 2002

This study was carried out to investigate the effects of soybean oil and salt on the mechanical texture and sensory characteristics of Dongbu-Mook (Cowpea Starch Gel). As the amount of the soybean oil was increased, the hardness and chewiness of the Mook were decreased. But there were no significant difference in the cohesiveness and springiness. While the Mook samples made with commercial Dongbu-Mook flour didn't show a significant difference, those made with lab-manufactured Dongbu-Mook flour without salt showed higher hardness, chewiness than the ones with salt. The Mook made of commercial Dongbu-Mook flour was found to be higher in the hardness and lower in the cohesiveness than the one made of lab-manufactured Dongbu-Mook flour. In sensory evaluation, as the amount of soybean oil was increased, all the samples showed higher yellowness and greasiness, and lower clarity, hardness and chewiness. For the samples with salt, the yellowness was high, and the hardness was low. The Mook samples made with lab-manufactured Dongbu-Mook flour had low chewiness. There was no significant difference in the clarity and greasiness. Overall, the Mook samples made with commercial Dongbu-Mook flour showed the best quality, when soybean oil was not added and salt was added. For the Mook made with lab-manufactured Dongbu-Mook flour, the sample with 2% oil and salt was the best.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.139-145
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• 2017

The aim of this study was to measure the remineralization effect of APF gel and fluride varnish on artificial enamel caries using CLSM in vitro. The samples were divided into 3 groups: control, 1.23% APF gel, 5% NaF varnish. The specimen surfaces were observed by CLSM and measured average fluorescence of the lesion(AFL). The results were analyzed using one-way ANOVA and Pearson's correlation analysis at a significance level off 0.05(PSWA 18.0, SPSS Inc., USA). There were significant differences between AFL at baseline and 1 day after fluoride application(p<0.05) but there are no significant differences between ${\Delta}$ AFL of all groups (p=0.222). Result of Pearson's correlation analysis, there are no significant correlation between VHN and AFL, but there were significant correlation between AFL at baseline and 1 day after fluoride application(r=0.811, p<0.001). Although AFL decreased after fluoride application, but there was no difference between the groups. In the future, it is necessary to test the oral environment model or in situ experiment supplemented the limitations of this study.

• Journal of Microbiology
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• v.44 no.1
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• pp.92-97
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• 2006

We developed an mPCR assay for the simultaneous detection, in one tube, of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes using species-specific primers. The mPCR employed the E. coli O157:H7 specific primer Stx2A, Salmonella spp. specific primer Its, S. aureus specific primer Cap8A-B and L. monocytogenes specific primer Hly. Amplification with these primers produced products of 553, 312, 405 and 210 bp, respectively. All PCR products were easily detected by agarose gel electrophoresis, and the sequences of the specific amplicons assessed. Potential pathogenic bacteria, in laboratory-prepared and four commercially available kimchi products, were using this mPCR assay, and the amplicons cloned and sequenced. The results correlated exactly with sequences derived for amplicons obtained during preliminry tests with known organisms. The sensitivity of the assay was determined for the purified pathogen DNAs from four strains. The mPCR detected pathogen DNA at concentrations ranging from approximately 0.45 to $0.05\;pM/{\mu}l$. Thus, this mPCR assay may allow for the rapid, reliable and cost-effective identification of four potentially pathogens present in the mixed bacterial communities of commercially available kimchi.

• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.133-140
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• 2012

A novel cry2Ab gene was cloned and sequenced from the indigenous isolate of Bacillus thuringiensis subsp. kurstaki. This gene was designated as cry2Ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kDa and pI value of 8.98. The amino acid sequence of the Cry2Ab25 protein was compared with previously known Cry2Ab toxins, and the phylogenetic relationships among them were determined. The deduced amino acid sequence of the Cry2Ab25 protein showed 99% homology to the known Cry2Ab proteins, except for Cry2Ab10 and Cry2Ab12 with 97% homology, and a variation in one amino acid residue in comparison with all known Cry2Ab proteins. The cry2Ab25 gene was expressed in Escherichia coli BL21(DE3) cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the Cry2Ab25 protein is about 70 kDa. The toxin expressed in BL21(DE3) exhibited high toxicity against Malacosoma neustria and Rhagoletis cerasi with 73% and 75% mortality after 5 days of treatment, respectively.

• The Plant Pathology Journal
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• v.22 no.2
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• pp.131-138
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• 2006

Two strains of Cucumber mosaic virus (CMV) isolated in Kuwait were confirmed their infectivity based on symptomatology and host range on different cultivars of tomato (Lycopersicon esculentum), tobacco(Nicotiana tabacum L.) and squash (Cucurbita pepo). The pattern of symptoms differed for the two CMV strains in tomato and tobacco, showing severe stunting and mosaic symptoms with one strain designated KU2, and almost symptomless with the other strain designated KU1. A satellite RNA 5 (sat-RNA) was found to be associated with the KU1 strain and was characterized as a benign viral satellite RNA. Using reverse transcription and polymerase chain reaction (RT-PCR) with sat-RNA specific primers, an amplified PCR product of about 160bp was determined and analyzed by gel electrophoresis. This naturally occurring benign viral satellite RNA was successfully used as a biological control agent to protect tomato plants against the severe KU2 strain. Tomato plants grown in plant-growth chambers, were preinoculated with KU1 containing the benign viral satellite and then challenge inoculated with the severe KU2 strain at different time intervals. All plants challenged three weeks after preinoculation showed nearly complete protection from subsequent infection by the severe strain. This biological control technology using plant viruses was found protective and could be successfully established sooner after the preinoculation.

• Journal of Magnetics
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• v.21 no.3
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• pp.308-314
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• 2016

Cobalt-, zinc-, and nickel-zinc-substituted nano-size manganese ferrite powders, $MnFe_2O_4$, $Mn_{0.8}Co_{0.2}Fe_2O_4$, $Mn_{0.8}Zn_{0.2}Fe_2O_4$ and $Mn_{0.8}Ni_{0.1}Zn_{0.1}Fe_2O_4$, were fabricated using a sol-gel method, and their crystallographic and magnetic properties were subsequently studied. The $MnFe_2O_4$ ferrite powder annealed at temperatures above 523 K exhibited a spinel structure, and the particle size increased as the annealing temperature increased. All ferrites annealed at 773 K showed a single spinel structure, and the lattice constants and particle size decreased with the substitution of Co, Zn, and Ni-Zn. The $M{\ddot{o}}ssbauer$ spectrum of the $MnFe_2O_4$ ferrite powder annealed at 523 K only showed a doublet due to its superparamagnetic phase, and the $M{\ddot{o}}ssbauer$ spectra of the $MnFe_2O_4$, $Mn_{0.8}Co_{0.2}Fe_2O_4$, and $Mn_{0.8}Zn_{0.2}Fe_2O_4$ ferrite powders annealed at 773 K could be fitted as the superposition of two Zeeman sextets due to the tetrahedral and octahedral sites of the $Fe^{3+}$ ions. However, the $M{\ddot{o}}ssbauer$ spectrum of the $Mn_{0.8}Ni_{0.1}Zn_{0.1}Fe_2O_4$ ferrite powder annealed at 773 K consisted of two Zeeman sextets and one quadrupole doublet due to its ferrimagnetic and paramagnetic behavior. The area ratio of the $M{\ddot{o}}ssbauer$ spectra could be used to determine the cation distribution equation, and we also explained the variation in the $M{\ddot{o}}ssbauer$ parameters by using this cation distribution equation, the superexchange interaction and the particle size. Relative to pure $MnFe_2O_4$, the saturation magnetizations and coercivities were larger in $Mn_{0.8}Co_{0.2}Fe_2O_4$ and smaller in $Mn_{0.8}Zn_{0.2}Fe_2O_4$, and $Mn_{0.8}Ni_{0.1}Zn_{0.1}Fe_2O_4$. These variations could be explained using the site distribution equations, particle sizes and magnetic moments of the substituted ions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.681-688
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• 1996

To investigate the effort of drying methods on the physicochemical properties of agar, gel strength, viscosity, melting and setting point, and phase transition by differential scanning calorimetery (DSC) during its heating were determined. In addition the structural differences of agar powder by scanning electron microscope (SEM) was examined. The most shortest onset temperature of gel strength increase was extruding method among any other methods. Viscosity of agar with hot air method, 400.00 cps at $45^{\circ}C$, was markedly increased, but with spraying and extruding ones were little change. The melting and setting point, and the temperature for maximum endothermic and enthalpy for agar with extruding one, $80.01^{\circ}C,\;36.05^{\circ}C\;and\;61.72^{\circ}C,\;0.73\;cal/g$, respectively, were lowest among the drying ones. But in the case of reheating after gelling, there were little change in all methods. Observing the surface structure of agar with SEM, extruding method showed the most unstable with absorptive property.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.165-170
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• 2014

The stems of Viburnum erosum were extracted with 80% MeOH. The concentrated extract was partitioned with EtOAc, n-BuOH, and $H_2O$. From the EtOAc and n-BuOH fractions, four compounds were isolated through the repeated $SiO_2$, octadecyl silica gel, and Sephadex LH-20 column chromatographies. Based on NMR, MS, and IR spectroscopic data, the chemical structures were determined as betulinic aldehyde (1), koaburside (2), (6R,7E,9R)-9-hydroxymegastigma-4,7-dien-3-one-9-O-${\beta}$-D-glucopyranoside (3), and byzantionoside B (4). All the compounds were isolated for the first time from the stems of Viburnum erosum.

• Macromolecular Research
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• v.11 no.6
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• pp.451-457
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• 2003

Anion-substituted poly(vinyl alcohol) (PVA) membranes, carboxymethylated PVA (C-PVA), and sulfonated PVA (S-PVA) were prepared and the effects of these substitutions on the plasma protein adsorption were studied by one- and two-dimensional gel electrophoresis and immunoblotting. When Cuprophane was used as a negative control, the amount of total proteins bound to samples decreased in the order Cuprophane > PVA > C-PVA > S-PVA, which we attribute to the effects of the surface characteristics of the samples, such as their surface tensions and electrostatic properties, on the adsorption of proteins to the surfaces of the materials. The results revealed that albumin was the most abundant protein in all the samples. The proportion of adsorbed fibrinogen to S-PVA exceeded those of PVA and C-PVA, whereas S-PVA exhibited the lowest IgG adsorption affinity among the samples we studied.