• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1191-1200
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• 2023

The lithium ion battery has applied to various fields of energy storage systems such as electric vehicle and potable electronic devices in terms of high energy density and long-life cycle. Despite of various research on the electrode and electrolyte materials, there is a lack of research for investigating of the binding materials to replace polymer based binder. In this study, we have investigated petroleum pitch/polymer composite with various ratios between petroleum pitch and polymer in order to optimize the electrochemical and physical performance of the lithium-ion battery based on petroleum pitch/polymer composite binder. The electrochemical and physical performances of the petroleum pitch/polymer composite binder based lithium-ion battery were evaluated by using a charge/discharge test, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and universal testing machine (UTM). As a result, the petroleum pitch(MP-50)/polymer(PVDF) composite (5:5 wt % ratio) binder based lithium-ion battery showed 1.29 gf mm^-1 of adhesion strength with 144 mAh g^-1 of specific dis-charge capacity and 93.1 % of initial coulombic efficiency(ICE) value.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.173-178
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• 2022

A lateral flow immunoassay (LFIA) method using carbon nanodot@silica as a signaling material was developed for analyzing the concentration of retinol-binding protein 4 (RBP4), one of the lung cancer biomarkers. Instead of antibodies mainly used as bioreceptors in nitrocellulose membranes in LFIA for protein detection, aptamers that are more economical, easy to store for a long time, and have strong affinities toward specific target proteins were used. A 5' terminal of biotin-modified aptamer specific to RBP4 was first reacted with neutravidin followed by spraying the mixture on the membrane in order to immobilize the aptamer in a porous membrane by the strong binding affinity between biotin and neutravidin. Carbon nanodot@silica nanoparticles with blue fluorescent signal covalently conjugated to the RBP4 antibody, and RBP4 were injected in a lateral flow manner on to the surface bound aptamer to form a sandwich complex. Surfactant concentrations, ionic strength, and additional blocking reagents were added to the running buffer solution to optimize the fluorescent signal off from the sandwich complex which was correlated to the concentration of RBP4. A 10 mM Tris (pH 7.4) running buffer containing 150 mM NaCl and 0.05% Tween-20 with 0.6 M ethanolamine as a blocking agent showed the optimum assay condition for carbon nanodot@silica-based LFIA. The results indicate that an aptamer, more economical and easier to store for a long time can be used as an alternative immobilizing probe for antibody in a LFIA device which can be used as a point-of-care diagnosis kit for lung cancer diseases.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.181-188
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• 1993

Frozen korean traditional poultries(Manyker, Korean native fowl, Ogol fowl and Pheasant) were thawed at $5^{\circ}C$, and $20^{\circ}C$ in the air, and using a microwave oven. Effect of thawing methods on the quality of Korean poultry was investigated. The pH of the poultry muscle was lowered after thawing in all treatments. The pH of the muscle thawed by microwave oven was the lowest. The quantity of drip released after thawing was the least in a microwave thawing. The quantity of drip in Maniker and Pheasant was loss than Ogol fowl. The relationship between pH and water binding capacity showed highly significant, and the drip quantity after thawing increased as the pH decreased. Leg muscle has higher strength than breast muscle in all the Korean poultry. Shear strength of all the poultry muscle showed closely relative related to the pH. As the pH lowered, the shear strength of the muscle was also decreased.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1519-1526
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• 2010

The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.73-78
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• 2011

Purpose: For periodontal tissue engineering, it is a primary requisite and a challenge to select the optimum types of cells, properties of scaffold, and growth factor combination to reconstruct a specific tissue in its natural form and with the appropriate function. Owing to fundamental disadvantages associated with using a two-dimensional substrate, several methods of seeding cells into three-dimensional scaffolds have been reported and the authors have asserted its usefulness and effectiveness. In this study, we explore the cell attachment of periodontal ligament fibroblasts on nanohydroxyapatite (n-HA) scaffold using avidin biotin binding system (ABBS). Methods: Human periodontal ligament fibroblasts were isolated from the health tooth extracted for the purpose of orthodontic procedure. HA nanoparticles were prepared and $Ca(NO_3)_2-_4H_2O$ and $(OC_2H_5)_3P$ were selected as precursors of HA sol. The final scaffold was 8 mm in diameter and 3 mm in height disk with porosity value of 81.55%. $1{\times}10^5$ periodontal ligament fibroblasts were applied to each scaffold. The cells were seeded into scaffolds by static, agitating and ABBS seeding method. Results: The number of periodontal ligament fibroblasts attached was greater for ABBS seeding method than for static or agitating method (P<0.05). No meaningful difference has been observed among seeding methods with scanning electron microscopy images. However, increased strength of cell attachment of ABBS could be deduced from the high affinity between avidin and biotin ($Kd=10^{-15}\;M$). Conclusions: The high-affinity ABBS enhances the ability of periodontal ligament fibroblasts to attach to three-dimensionally constructed n-HA scaffold.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.157-165
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• 2016

It is possible to achieve high strength ranging from 40 MPa to 70 MPa in alkali-activated slag concrete (AASC), and AASC is also known to have a finer pore structure due to its high latent hydraulicity and fineness of slag cement, which makes it difficult for chloride ions to penetrate. Electrophoresis is mostly used to calculate the effective diffusion coefficient of chloride ions, and then to evaluate resistance to salt damage. Few studies have been conducted on the fixation capacity of chloride ions in AASC. For this reason, in this study the chloride fixation within the hardened paste was evaluated according to the type and the amount of alkaline activators. As a result, it was revealed that among the test specimens, the chloride fixation was greatest in the paste containing $Na_2SiO_3$. In addition, it was found that as more activator was added, a higher level of chloride fixation was observed. Through this analysis, it can be concluded that the type and the amount of alkaline activators have a high correlation with the amount of C-S-H produced.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.629-646
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• 2023

Host rock of Cheonjeon-ri petroglyph is shale belonging to the Daegu Formation of Cretaceous Gyeongsang Supergroup. The rocks were hornfelsified by thermal alteration, and shows high density and hardness. The petroglyph forms weathered zone with certain depth, and has difference in mineral and chemical composition from the unweathered zone. As the physical deterioration evaluations, most of cracks on the surface appear parallel to the bedding, and are concentrated in the upper part with relatively low density. Breakout parts are occurred in the upper and lower parts of the petroglyph, accounting for 6.0% of the total area and occurs to have been created by the wedging action of cracks crossing. The first exfoliation parts occupying the surface were 23.8% of the total area, the second exfoliations covered with 9.3%, and the exfoliation parts with three or more times were calculated as 3.4%. It is interpreted that this is not due to natural weathering, and the thermal shock caused by the cremation custom here in the past. As the ultrasonic properties, the petroglyph indicates highly strength in the horizontal direction parallel to bedding, and the area with little physical damage recorded mean of 4,684 m/s, but the area with severe cracks and exfoliations showed difference from 2,597 to 3,382 m/s on average. Physical deterioration to the Cheonjeon-ri petroglyph occurred to influence by repeated weathering, which caused the rock surface to become more severe than the inside and the binding force of minerals to weaken. Therefore, it can be understood that when greater stress occurs in the weathered zone than in the unweathered zone, the relatively weathered surface loses its support and exfoliation occurs.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.659-664
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• 2011

Staphylococcus aureus (SA) bacteremia is associated with high mortality, and often results in metastatic infections. The methicillin-resistant SA (MRSA) is an urgent health care issue, as nosocomial infections with these bacteria represent limited treatment alternatives. Samples of whole blood containing challenge inoculums of SA and MRSA strains were passed through columns packed with surfaceheparinized polyethylene beads. The bound bacteria were eluted and quantitatively determined by culturing and by real-time PCR. Significant amounts of both SA and MRSA adhered to the heparinized beads (more than 65% of inoculated bacteria). After rinsing with buffer at high ionic strength, viable bacteria or bacterial DNA were eluted from the columns, indicating that the binding was specific. The conclusions that can be made from these experiments are that, as earlier reported in the literature, the high affinity of SA to heparin is retained in whole blood, and MRSA in whole blood binds to heparin with similar or higher affinity than SA. It should be possible to lower the amount of SA and/or MRSA from the blood of infected patients to levels that could be taken care of by the immune system. In previous studies, we have shown that passing blood from septic patients over beads coated with end-point-attached, biologically active heparin is a useful technique for regulating the levels of heparinbinding cytokine. These findings in combination with the present findings indicate the possibility of creating an apheresis technology for treatment of sepsis caused by SA and/or MRSA.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.199-205
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• 2009

Wet noodles with different percentages of Curcuma Ionga L. powder(CLP) as an additive were generated and their cooking characteristics were evaluated. Wheat flour with 8% CLP had the highest water binding capacity and breakdown, while setback was reversed. Cooked noodle characteristics, weight, volume and tensile strength decreased as CLP content of wheat flour increased, but turbidity of the soup was reversed. L value of wet noodles was higher than cooked noodles, while b value, and texture of wet noodles were lower than cooked noodles. Hunter color value and texture measurements demonstrated decreasing L value, springiness and cohesiveness but increasing b value, hardness, gumminess and chewiness with increasing CLP content. In sensory evaluations, noodles made with 4% CLP were most highly preferred, while noodles made with 2% and 8% CLP were less preferred than CLP-free prepared noodles.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.4
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• pp.365-373
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• 2007

We optimized the compositions of electrolyte and additives for anode in Ni-MH battery to improve the electrode characteristics at ambient and low temperatures using response surface method(RSM). Among various additives for anode, PTFE exhibited the greatest influence on the discharge capacity of the anode. Through response optimization process, we found the optimum composition of the additives to exhibit the greatest discharge capacity. When the amount of additives was too small, the anode was degraded with time due to the low binding strength among alloy powders and the resultant separation of powders from the current collector. In contrast, the addition of large amount of the additives increased in the resistance of the electrode. In addition, the discharge capacity of the anode at $-18^{\circ}C$ increased with decreasing the concentration of KOH, NaOH and LiOH in design range of electrolyte. The resistance and viscosity of electrolyte appear to affect the discharge capacity of the anode at low temperature.