• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.43-54
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• 2013

In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.23-31
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• 2009

To compare the effects of nanometer-sized silver ions and support materials (nano-silver coating material, NM-silver) and silver ions, we exposed zebrafish embryos to both types of nano-silver ions and compared the acute responses during embryogenesis. The amount of silver in the NM-silver (17.16%) was greater than that in the silver ion (4.56%). Both of these materials have different atomic compositions. The silver ion-exposed groups (10 and 20 ppt) showed lower survival rates than the NM-silver-exposed groups (10 and 20 ppt). NM-silver penetrated the skin and blood tube of zebrafish larvae as aggregated particles, whereas, silver ions penetrated the organelles, nucleus and yolk in a spread-out pattern. Micro-array analysis of RNA from zebrafish larvae (72 hours post-fertilization) that were treated with either NM-silver or silver ions, showed alteration in expression of the BMP, activin, TGF-$\beta$, and $GSK3{\beta}$ genes pathway. Additionally, $GSK3{\beta}$ gene pathway for apoptosis that was related with left-right asymmetry. Gene expression changes in the NM-silver or silver ions-treated zebrafish embryo led to phenotypic changes in the hatched larvae, reflecting increased apoptosis and incomplete formation of an axis.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.134-141
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• 2021

This study was conducted to investigate the potential of the neutral extract (NE) prepared by treating P. radiata bark with aqueous NaHCO3 solution as a natural dyestuff. Silk and cotton fabrics were dyed at four different NE concentrations, 0.5%, 1.0%, 1.5%, and 2.0% o.w.b. (on the weight of bath). The fabric to liquid ratio of 1 : 50, dyeing temperature of 90℃, and dyeing time of 90 min were used as the fixed condition. The appropriate NE dyeing concentration of silk and cotton fabrics was 1.5% o.w.b. Colors of the dyed silk and cotton fabrics were brown and light brown, respectively. From colorfastness assessment, both dyed silk and cotton showed good washing and rubbing fastness, but poor light fastness. NE dyed fabrics exhibited excellent ammonia deodorization property and antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. Therefore, NE of P. radiata bark could have the potential for use as a functional brown dyestuff.

• BMB Reports
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• v.42 no.9
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• pp.586-592
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• 2009

The bactenecin is an antibacterial peptide with an intramolecular disulfide bond. We recently found that homodimeric bactenecin exhibits more potent antibacterial activity than the monomeric form and retains its activity at physiological conditions. Here we assess the difference in the modes of antibiotic action of homodimeric and monomeric bactenecins. Both monomeric and dimeric bactenecins almost completely killed both Staphylococcus aureus and E. coli within 10-30 min at concentrations of $8-16\;{\mu}M$. However, exposure to liposomes elicited an increase in the fluorescence quantum yield from a tryptophan-containing monomeric analog, while the homodimeric analog showed a significant reduction in fluorescence intensity. Moreover, unlike the monomer, the homodimer displayed apparent membrane-lytic activity enabling release of various sized dyes from liposomes, and rapidly and fully depolarized the S. aureus membrane. Together, our results suggest that homodimeric bactenecin forms pores in the bacterial membrane, while monomeric one penetrates through the membrane to target intracellular molecules/organelles.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.28-36
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• 2014

We studied the green synthesis and antibacterial activity of paper coated with chitosan-silver (Ag) green nanocomposites for packaging applications. Green synthesis of Ag nanoparticles (AgNPs) was achieved by a chemical reaction involving a mixture of chitosan-silver nitrate ($AgNO_3$) in an autoclave at 15 psi, $121^{\circ}C$, for 30 min. AgNPs and their formation in chitosan was confirmed by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). As-prepared chitosan-AgNPs composite materials were coated on manila paper using Meyer rod. Surface morphology and Ag contents in coating layer were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). The mechanical properties such as tensile strength and elongation were significantly affected by coating with chitosan-AgNPs. The antibacterial test of coated paper was performed qualitatively and quantitatively against Escherichia coli (E. coli). It was shown to be effective in suppressing the growth of E. coli with increasing Ag contents on the surface of coated paper and more than 95 R (%) of antimicrobial rate was obtained at chitosan-AgNPs coated papers.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.639-646
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• 2004

Metal treated activated carbons are prepared using various metals. Adsorption behaviors, morphologies, as well as antibacterial effects of metal treated samples are compared before and after solvent washing. Adsorption isotherms are used to characterize the porous structure of metal treated activated carbons before and after the solvent washing with acetone or ethyl alcohol. From these data, it is noticed that the changes in physicochemical properties of metal treated activated carbons depend on the solvents employed. Similar results are observed from BET data obtained from nitrogen adsorption isotherms. From scanning electron microscopy (SEM) studies, the changes in shape and size of metal particles are observed after the samples are washed with solvents. These changes result in different blocking effects, which, in turn, affect the adsorption behavior of metal treated activated carbons. X-ray diffraction (XRD) patterns of the samples treated with different metals are different each other. High intense sharp peaks attributed to metals are observed from silver treated samples, while the peaks are not observed from copper treated samples. To compare thermodynamic behavior of metal treated activated carbons washed with different type of solvents, differential scanning calorimetric (DSC) analysis is carried out. The analysis shows similar endothermic curves for all of the samples. Finally, antibacterial effects of metal treated activated carbon against Escherichia coli are discussed. Comparing the effects among the metals employed, highest effects are obtained from Cd, while lowest effects are obtained from Cu. Antibacterial activity becomes higher with the increase of the amount of metals treated, Optimum concentrations of metals to treat activated carbons, obtained from a shake flask test, are known to be 0.4, 0.1, and 0.6 moles for Ag, Cd, and Cu, respectively.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.54-59
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• 2017

Objectives: The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis (E. faecalis) to that of NaOCl. Materials and Methods: The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply). A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI) broth. The teeth were submerged in the suspension of E. faecalis and were incubated at $37^{\circ}C$ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used (n = 8). Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply). Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU) analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Results: Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups (p < 0.05). Conclusions: The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.401-411
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• 2006

The cationic chitosan is prepared in this paper. This kind of cationic chitosan is a good retention aid for bleached hardwood pulp, the filler retention increased by 33.0% when the cationic chitosan (DS=1.27) dosage was 0.05%. Because many of the materials used in papermaking process are excellent microbiological nutrients, these nutrients will result in the growth of bacteria; uncontrolled growth of bacteria and fungi in the papermaking process adversely affects machine runnability. According to the standard methods of microbe growth inhibition test, cell counting was conducted after proper cultivated time. This paper explored the factors that affecting the cationic chitosan's antibacterial effect.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.731-737
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• 2013

A convenient synthesis of bifunctional sulfonamide-amide derivatives was reported. Amide coupling of 4-methyl benzoic acid 1 followed by reaction with chlorosulfonic acid produce ethyl-4-(3-(chlorosulfonyl)-4-methylbenzoyl)piperazine-1-carboxylate 4. The resulted compound on further treatment with various anilines produces the title sulfonamide-amide derivatives 5a-n. The configurations of these compounds were established by elemental analysis, IR, $^1H$ NMR, mass spectra, and by their preparation from the corresponding 4-methyl benzoic acid 1 and chlorosulfonic acid. All these new compounds demonstrate significant in vitro antibacterial and antifungal activities against all bacterial and fungal strains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.691-697
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• 1999

The pharmacological effects of hydrocooked(110oC, 5 hours) extracts of Bastard halibut have been investigated. All of the hydrocooked extracts showed the measurable contractile effect on the isolated rat duodenum and decreased the normal blood pressure in anesthetized rat. The hydrocooked extracts also exhibited a dose dependent relaxation on the isolated rat aorta precontracted with phenylephrine. Only RM 60 fraction of these extracts had the cytotoxic effect against MCF7 cell(human breast adenocarcinoma cell line), but the other fractions showed neither antibacterial activity nor antitumor activity. Although fish extracts fed group of rat maintained their original body weight, there were no notable changes in the hematological parameters, except that the levels of high density lipoprotein was significantly increased. These results suggest that the hydrocooked extracts of bastard halibut may contain a variety of bioactive materials.