• Carbon letters
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• v.4 no.3
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• pp.140-145
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• 2003

Antibacterial behaviors of PAN-based activated carbon fibers (ACFs) containing silver metal were investigated. The effects of surface and pore structures of the ACFs were studied by $N_2$/77 K adsorption and D-R plot as a function of silver loading content. The antibacterial activities were investigated by a dilution test against Staphylococcus aureus (S. aureus; gram positive) and Klebsiella pnemoniae (K. pnumoniae; gram negative). As experimental results, the ACFs showed some decreases in specific surface areas, micropore volumes, and total pore volume with an increase of silver content. However, the antibacterial activities of the ACFs were strongly increased against S. aureus as well as K. pnumoniae, which could be attributed to the presence of antibacterial metal in the ACFs system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.105-109
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• 2022

In the field of medical and marine industries, antibacterial surfaces have been emerged as one of the most important issues. Recently, many researchers have been studying antibacterial surfaces to kill bacteria or prevent the adhesion of bacteria. In their researches, various materials and structures are suggested to inhibit the adhesion of bacteria or kill the attached bacteria. However, chemical materials such as antibiotics or metal could be toxic. Moreover, frequent use of antibiotics causes super bacteria having resistance to antibiotics. In this study, nano-pillar structured surface was fabricated using polyurethane acrylate (PUA) and the mechanically induced antibacterial function was confirmed based on the fabricated nanostructures. Nanostructures can damage the bacterial membrane of Gram-negative bacteria through stretching of bacterial membrane via interaction with the nanostructures and the bacterial membrane. Consequently, the proposed transparent, flexible and nanostructured PUA films can be one of promising candidates for antifouling and antibacterial surfaces which can be applied in various industries.

• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.439-445
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• 2023

In this study, silver nanoparticles were synthesized by reducing silver nitrate with PVA, and the solution prepared by adding carboxymethyl cellulose (CMC) to the silver nanoparticles was coated on a PET substrate to prepare a coating film with antibacterial and antifogging function. When the coating films were in contact with water vapor at 80 ℃, the uncoated PET substrate was blurred due to the scattering of light due to the occurrence of fog, while the coating film coated with silver nanosol with CMC remained transparent despite contact with water vapor, showing excellent antifogging function. In addition, the antibacterial properties of the coating films were measured by film adhesion method for Staphylococcus aureus, gram-positive bacteria, and Escherichia coli, gram-negative bacteria. The uncoated PET substrate showed a large number of colonies of Staphylococcus aureus and Escherichia coli, while the coating film coated with the silver nanosol greatly inhibited the growth of Staphylococcus aureus and Escherichia coli, resulting in excellent antibacterial effect.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.43-50
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• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and hydration shell model were carried out on the four-4-aminodiphenyl sulfone analogues of 4, 4'-diamino-2' methyldiphenyl sulfone, 4, 2', 4-triaminodiphenyl sulfone, 4, 4'-diaminodiphenyl sulfone, and 4-aminodiphenyl sulfone as antibacterial agents on Mycobacterium lufu. The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy change of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the contributions of water-accessible volume and the hydration free energy of each group or atom in the lowest-free-energy conformation was calculated and compared each other. From comparison of the computed lowest-free-energy conformations of four analogues with their antibacterial activities, it is known that the conformation and the hydrophobicity of sulfonyl group and its adjacent carbon atom in each compound are the essential factors to show the strong antibacterial activity.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.350-360
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• 1989

The conformation and activity of the four benzenesulfonyl analogues of 4-aminobenzene-sulfonamide, 4-aminobenzenesulfonic acid, 4-methylbenzenesulfonamide, and 4-methylbenzenesulfonic acid with antibacterial activity on Staphylococcus aureus were studied using an empirical potential function (ECEPP/2) and the hydration shell model. The conformational energies were minimized from the starting conformations which included possible combinations of torsion angles in each molecule. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. The conformational entropies of low-free-energy coformation of benzenesulfonly analogues were computed by a harmonic approximation. From the correlation of lowest-free-energy conformation of each compound and its antibacterial activity, it was found that the hydration of sulfonyl groups and the substituents are the decisive factors to show antibacterial activities.

• Biomedical Science Letters
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• v.28 no.1
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• pp.50-57
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• 2022

In this study, we tried to examine the possibility of developing a dental product such as tooth decay prevention and oral hygiene by manufacturing a natural polymer film for oral use. Natural polymer films were prepared from shark byproduct extract (SBE) and gellan gum (GG). As an antibacterial substance, the antibacterial activity of green tea extract against tooth decay-causing bacteria was measured. An film was prepared by adding green tea extract to the composition of SBE and GG. The mechanical, solubility, moisture content and antibacterial function of the prepared film were investigated in detail. Also, the incorporation of GTE into the SBE/GG film improved the physical performance of the film. Increasing the content of GTE improved the antioxidant and antibacterial properties of the film. Formulation of antimicrobial SBE/GG film containing green tea extract was established and these results evidently showed potential for cavity prevention products application.

• The Korean Journal of Community Living Science
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• v.19 no.2
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• pp.213-221
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• 2008

In this study, a dye bath was made using a mixture of distilled water, pine needle extract and bamboo vinegar. Analysis and comparison of various functions of cotton fabrics dyed using bamboo charcoal and gardenia seeds in distilled water and in the dye bath mixture were done. The summary of the results is as follows. Comparing bamboo vinegar and the pine needle extracts, the bamboo vinegar had a higher antibacterial function. In the case of natural dyeing cotton fabrics using bamboo charcoal and gardenia seeds, the additional amount of dyestuff for optimization is 10 g and 20 g respectively per 1 liter of distilled water. The suitable dye bath mixture ratio of distilled water, pine needle extract, and bamboo vinegar considering functionality and economical efficiency of dyed fabrics is 4:3:3. By using the mixture made in this study as a dye bath, improved antibacterial function, deodorization, and colorfastness can be obtained more than distilled water alone.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.83-86
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• 1998

This study was carried out to measure the antibacterial effect of lactoperoxidase system against L. monocytogenes. When the initial inoculum levels ($10^{2},\;10^{4},\;10^{7}\;CFU/ml$), concentration of LP (10 ppm, 20 ppm, 30 ppm), culture media (TSB-YE, UHT milk) and storage temperatures ($5^{\circ}C,\;10^{\circ}C,\;15^{\circ}C$) were set up differently for the experiment and the antibacterial effect was compared, the highest antibacterial effect of LP system was shown at $10^{2}\;cfu/ml$ of initial inoculum level, 10 ppm of LP concentration and $5^{\circ}C$ of incubaction temperature. The antibacterial effect of LPS in UHT milk was similar to that in Tryptic soy broth.

• Fashion & Textile Research Journal
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• v.19 no.3
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• pp.331-336
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• 2017

Bacteria exist everywhere and continuously come into contact with daily surroundings and humans. Super bacterium methicillin-resistant Staphylococcus aureus, resistant to methicillin, has recently appeared. The morbidity and rate of death associated with super bacteria infection has increased. This study investigated the antibacterial activity of fabrics naturally dyed with Chamaecyparis obtusa leaves extract against methicillin-resistant Staphylococcus aureus. Fabrics were left for 15 min in a natural dyeing solution prepared by extraction from C. obtusa leaves using 11.3% (o.w.f) with a fixed liquor ratio of 1:22 at $40^{\circ}C$. The dyeing process was conducted using three different mordants; subsequently, the K/S value of the dyed fabrics increased in the order of None < Cu < Fe < Al. The color fastness property of the fabrics to washing, dry-cleaning, and rubbing was found to be excellent and ranked in the 4-5 grade. The color fastness to light of natural dyeing is low in most cases and has the problem that the dye color soon becomes bleached. Yet, in most cases cloth dyed with retinispora leaves, the color fastnezz to light was good with a third to fourth grade. Non-mordant fabrics, aluminum mordants, and copper mordants also showed better antibacterial properties (99.9% reduction) against methicillin-resistant Staphylococcus aureus, compared to the control fabrics. The dyed fabrics showed the same antibacterial activity even after three washes. The results highlight the strong potential of fabrics naturally dyed with C. obtusa-extract as a medicinal material with excellent antibacterial function against methicillin-resistant Staphylococcus aureus.

• Herbal Formula Science
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• v.28 no.1
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• pp.41-51
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• 2020

Objectives : US extract is a mixture of each extract of Ulmi cortex and Smilacis rhizoma. In this study, we investigated the antioxidant, anti-inflammatory, antibacterial, and ovoprotective effects of US extract in in vitro model to identify potential candidates for improving female reproductive function. Methods : The antioxidant activity of US extract was measured using 1,1-diphenyl- 2-picrylhydrazyl free radical and superoxide anion radical scavenging assays. The anti-inflammatory effect of US extract on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were determined with a nitric oxide (NO) assay, enzyme linked immunosorbent assays, and western blots analysis. The antibacterial activity of US extract against vaginitis infection microorganisms were determined with disc diffusion and minimum inhibitory concentration assays. The ovoprotective effect of US extract on 4-vinylcyclohexene diepoxide (VCD)-induced ovotoxicity in CHO-K1 cells were evaluated with a cell viability assay. Result : US extract showed good antioxidant capacity and inhibited LPS-induced NO production as well as iNOS and COX-2 expression and secretion of pro-inflammatory cytokine IL-6 without affecting the cell viability. It showed significant clear zones for Staphylococcus aureus and Candida albicans but did not indicate the clear zones for Escherichia coli and Enterococcus faecium. VCD-induced ovotoxicity in CHO-K1 cells was significantly reduced by US extract pre-treatment. Conclusions : These results demonstrate that US extract has antioxidant activity, anti-inflammatory effects on the LPS-stimulated macrophages, antibacterial activity against vaginitis infection microorganisms, and protective effects on the ovarian cells against VCD-induced ovotoxicity. These findings suggest that the US extract can be used as new prescriptions, supplements, functional foods, and cosmetics for improving female reproductive function.