• Membrane Journal
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• v.19 no.4
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• pp.310-316
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• 2009

The degradation characteristics of cross-linked lactide/hyaluronic acid (LA/HA) membranes were investigated for purpose of applying to tissue engineering. The lactide/hyaluronic acid cross-linked with 1,3-butadiene diepoxide (BD) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) was degradated in deionized water in water bath at $37^{\circ}C$. As the LA/HA mole ratio or crosslinking agent concentration decreased, the degradation rate of the crosslinked membranes increased. In order to investigate the structure change of the membrane in the degradation process, the control sample and 3, 6, 9 days-degradated samples were analysed by the nuclear magnetic resonance spectroscopy. In case of the membranes crosslinked with EDC, the HA-EDC bonding structure was degradated slowly whereas the HA-LA bonding structure was degradated quickly and dissappeared completely after 6 days. In case of the membranes crosslinked with BD, all the crosslinked bonding structure degradated slowly. The HA-BD bonding structure maintained its original state about 89, 83% in case of 3, 6 days-degardated samples respectively whereas the HA-LA bonding structure maintained its original state about 83, 65%. The scanning electron microscopy of the degradated membranes showed that the pore density in the surface, and the structure in the surface and cross section, of the before and after-degradation membranes did not change greatly, so the membranes was shown to be applied to materials for tissue engineering.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.211-221
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• 2016

Waste salt generated from a pyro-processing for the recovery of uranium and transuranic elements has high volatility at vitrification temperature and low compatibility in conventional waste glasses. For this reason, KAERI (Korea Atomic Energy Research Institute) suggested a new method to de-chlorinate waste salt by using an inorganic composite named SAP ($SiO_2-Al_2O_3-P_2O_5$). In this study, the de-chlorination behavior of waste salt and the microstructure of consolidated form were examined by adding $B_2O_3$ and $Fe_2O_3$ to the original SAP composition. De-chlorination behavior of metal chloride waste was slightly changed with given compositions, compared with that of original SAP. In the consolidated forms, the phase separation between Si-rich phase and P-rich phase decreases with the amount of $Al_2O_3$ or $B_2O_3$ as a connecting agent between Si and P-rich phase. The results of PCT (Product Consistency Test) indicated that the leach-resistance of consolidated forms out of reference composition was lowered, even though the leach-resistance was higher than that of EA (Environmental Assessment) glass. From these results, it could be inferred that the change in the content of Al or B in U-SAP affected the microstructure and leach-resistance of consolidated form. Further studies related with correlation between composition and characteristics of wasteform are required for a better understanding.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7045-7056
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• 2013

Since the first report of RNA interference (RNAi) less than a decade ago, this type of molecular intervention has been introduced to repress gene expression in vitro and also for in vivo studies in mammals. Understanding the mechanisms of action of synthetic small interfering RNAs (siRNAs) underlies use as therapeutic agents in the areas of cancer and viral infection. Recent studies have also promoted different theories about cell-specific targeting of siRNAs. Design and delivery strategies for successful treatment of human diseases are becomingmore established and relationships between miRNA and RNAi pathways have been revealed as virus-host cell interactions. Although both are well conserved in plants, invertebrates and mammals, there is also variabilityand a more complete understanding of differences will be needed for optimal application. RNA interference (RNAi) is rapid, cheap and selective in complex biological systems and has created new insight sin fields of cancer research, genetic disorders, virology and drug design. Our knowledge about the role of miRNAs and siRNAs pathways in virus-host cell interactions in virus infected cells is incomplete. There are different viral diseases but few antiviral drugs are available. For example, acyclovir for herpes viruses, alpha-interferon for hepatitis C and B viruses and anti-retroviral for HIV are accessible. Also cancer is obviously an important target for siRNA-based therapies, but the main problem in cancer therapy is targeting metastatic cells which spread from the original tumor. There are also other possible reservations and problems that might delay or even hinder siRNA-based therapies for the treatment of certain conditions; however, this remains the most promising approach for a wide range of diseases. Clearly, more studies must be done to allow efficient delivery and better understanding of unwanted side effects of siRNA-based therapies. In this review miRNA and RNAi biology, experimental design, anti-viral and anti-cancer effects are discussed.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.79-86
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• 2007

The aim of the present study was to determine mechanisms of corneal epithelial cell apoptosis in vitro following exposure to anti-FAS and anti-FAS ligand antibody and during infection with mycoplasma sp.. A cultured human corneal epithelial(HCE) cell line was treated with anti-FAS antibody or anti-FAS ligand antibody for 2 and 4 days. The original cell line was found to be contaminated by mycoplasma removal agent(MRA) was used to eliminate the bacterium from the cell line. MRA($0.5{\mu}{\ell}$ tissue culture medium) was added to the cell line and incubated for 1 week. The cell line underwent multiple passages in media not contaminating MRA and cells were grown to 50-80% confluency on coverslips and stained using the Hoechst stain provided in the kit to ensure mycoplasma removal. Apoptosis experiments were performed before and after mycoplasma removal. The apoptotic index of anti-FAS and anti-FAS ligand antibody on mycoplasma contaminated cell line was studied using Hoechst 33342 staining and Annexin V-FITC and Propidium Iodide Staining. In conclusion, anti-FAS antibody induces apoptosis in HCE cells in a time and concentration-dependent mechanism. Cell lines contaminated with mycoplasma have an incresed susceptibility to FAS induced apoptosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.80-87
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• 2003

Recovery conditions and characteristics of a high molecular soluble protein from surimi processing wastewater in marine manufacture using calcium powder of cuttle bone treated with acetic acid (ATC) were examined. Judging from results of total-N, pH, COD, turbidity and yields, optimal treatment concentration of ATC for recovery of high molecular soluble proteins from wastewater was $1.0\%.$ The protein recovered from seafood waste (PRW) was macromolecule weight. The COD value in the wastewater treated with ATC was very high. The PRW had a $78.4\%$ in moisture, $1.0\%$ in crude lipid and $5.7\%$ in crude ash. The proximate composition, except the crude ash, of the PRW was similar to that of commercial surimi. The PRW showed white index and similar in the content and in the composition of total amino acid to those of commercial surimi. From the results of sensory evaluation on white index and texture, the heat-induced surimi gel prepared with $5\%$ subsititution of the PRW for bulking agent of commercial surimi was not significantly different compared to that prepared with the original commercial surimi.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.2
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• pp.460-474
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• 1997

The purpose of this study was to evaluate and compare the effectiveness of various low-viscosity resin systems used as rebonding agents to prevent microleakage at the margins of class I composite resin restorations. Seventy sound human premolars were selected for experiment. Class I cavities were prepared and each cavity was conditioned with a 37% phosphoric acid for 15 sec, rinsed with water for 15 sec, and dried with compressed air. Bonding agent(Scotchbond Multipurpose, 3M Co.) was applied and a hybrid composite resin (Z-100, 3M Co.) was placed using an incremental technic. The excess cured composite resin was carefully removed with Sof-Lex discs(3M Co.) to expose the original margins of the cavity. The following seven groups were established : group 1 was not rebonded and used as control group ; group 2 was rebonded with a Scotchbond Multipurpose(3M Co.) and finished ; group 3 was rebonded with a Fortify(BISCO) and finished ; group 4 was rebonded with a Concise white sealant(3M Co.) and finished ; group 5 was rebonded with a Concise white sealant(3M Co.) and not finished ; group 6 was rebonded with a P&F sealant(BISCO) and finished; group 7 was rebonded with a P&F sealant(BISCO) and not finished. The specimens were then subjected to 500 thermocycles between 5 & 65 with a 10 see dwell time and immersed in 2% methylene blue dye solution for 24 hours and sectioned with low-speed diamond cutter into two part under water condition. The extent of microleakage at rebonded margins was evaluated microscopically and scored for dye penetration according to the following scale : 0=no dye penetration ; 1=dye penetration to half-way along axial wall between enamel surface and DEJ ; 2=dye penetration beyond halfway along axial wall between enamel surface and DEJ ; 3=dye penetration to the full depth of DEJ or beyond DEJ. Selected samples were prepared for SEM observation to determine the depth of penetration of the rebonding agent into the marginal interface. The obtained results were as follows: 1. In the group 2 and 3, which is rebonded with a Scotchbond Multipupose and Fortify, dye penetration score were decreased significantly than that of group 1 (P<0.05), but group 4 and 6 were not statistically different from group 1(P>0.05). 2. There were significant differences between group 4, 6 and group 5, 7 when compared by dye penetration score (P<0.05). 3. In the SEM observation, Scotchbond Multipurpose and Fortify were penetrated within $30-40{\mu}m$ depth of the outermost surface. However, both sealants were failed to penetrate into the debonded interface.

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.331-338
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• 1975

The distribution of $^{51}Cr\;and\;^{128}I$ recoil species following radiative-neutron capture in chromates, dichromates, iodates and periodates has been investigated by using paper-electrophoresis. In view of the effective recoil energy and the effect of the internal conversion, it is unlikely that an atom which has captured a neutron can remain bound in its original molecule. It is also unlikely that the energy of the recoil atom is dissipated in heating a small region of the crystal. However, the results of paper-electrophoresis separation of recoil $^{51}Cr\;and\;^{128}I$ indicated that many more of the recoil atoms were bound in the parent molecule. The disorder model for the reaction was proposed from observations of retention. In considering cations, the greater their radii, the higher is the probability of the recoil atom breaking through the secondary cage. In ammonium salt, the ammonium ion behaved as a reducing agent in the disorder zone and resulted in low retention. Crystal structures with their greater free space have shown low retention.

• The Korean Journal of Pharmacology
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• v.25 no.1
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• pp.109-113
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• 1989

Human neutrophil elastase (HNE, EC 3, 4 21, 11), a major causative factor in the induction of pulmonary emphysema, were purified by two steps of liquid chromatography. Purified elastases were cross-reacted with antibody to human neutrophil elastases. Methicillin and cefamandole, which are known as inhibitors of cell wall synthesis of microorganisms, could inhibit the activity of human neutrophil elastase up to 50% with 10mM of both agents and $IC_{50}$ of methicillin was 9.8 mM. Gentamicin, one of the aminoglycosides, also inhibits human neutrophil elastases up to 60% of original activity with 10 mM of this agent and $IC_{50}$ was 9.0 mM. We could demonstrate similar effects in oxytetracycline. 10 mM of oxytetracycline inhibited 95% of human neutrophil elastase and $IC_{50}$ was 0.3 mM. Overall, oxytetracycline, cefamandole and methicillin are strong inhibitors of human neutrophil elastase, and they could be a drug of cholice for the diseases which were known as pathogenesis related to elastase. We also suggest that the mechanism of action of these antibitics are different from the mechanism of antimicrobial effects like inhibition of both cell wall synthesis and protein synthesis.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.38-46
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• 2009

Lichen-forming fungi (LEF) were isolated from 67 Hungarian lichen species from ascospores or thallus fragments. LFF were successfully isolated from 26 species with isolation rate of 38.8%. Of the total number of isolation from ascospores (27 species) and thallus fragments (40 species), 48% and 32.5% of the species were successfully isolated, respectively. Comparison of rDNA sequences of ITS regions between the isolated LFF and the original thallus confirmed that all the isolates originated from the thallus fragments were LEF. The following 14 species of LEF were newly isolated in this study; Acarospora cervina, Bacidia rubella, Cladonia pyxidata, Lasallia pustulata, Lecania hyaline, Lecanora argentata, Parmelina tiliacea, Parmotrema chinense, Physconia distorta, Protoparmeliopsis muralis, Ramalina pollinaria, Sarcogyne regularis, Umbilicaria hirsuta, Xanthoparmelia conspersa and X. stenophylla. Antifungal activity of the Hungarian LFF was evaluated against plant pathogenic fungi of Colletotrichum acutatum, C. coccodes and C. gloeosporioides, causal agent of anthracnose on hot pepper. Among the 26 isolates, 11 LFF showed more than 50% of inhibition rates of mycelial growth of at least one target pathogen. Especially, LFF of Evernia prunastri, Lecania hyalina and Lecanora argentata were remarkably effective in inhibition of mycelial growth of all the tested pathogens with antibiotic mode of action. On the other hands, five isolates of Cladonia furcata, Hypogymnia physodes, Lasallia pustulata, Ramalina fastigiata and Ramalina pollinaria exhibited fungal lytic activity against all the three pathogens. Among the tested fungal pathogens, C. coccodes seemed to be most sensitive to the LFF. The Hungarian LFF firstly isolated in this study can be served as novel bioresources to develop new biofungicides alternative to current fungicides to control hot pepper anthracnose pathogenic fungi.

• Polymer(Korea)
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• v.25 no.5
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• pp.657-664
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• 2001

In this study. the effects of ${\gamma}$-irradiation on the crosslinking of low density poly ethylene (LLDPE) and linear low density polyethylene (LLDPE) containing crosslinking agents were investigated to find the degree of crosslinking in the polymer. The LDPE and LLDPE specimens were prepared by blending crosslinking agents with each polymers, and by hot-press-molding into a sheet at 13$0^{\circ}C$. The ${\gamma}$-irradiation was conducted at 50 to 150 kGy in nitrogen. The crosslinking percentage in these specimens was measured in relation to the irradiation dose and the type of crosslinking agents. The mechanical properties, thermal properties and crystallinity of specimens were examined as a function of irradiation dose as well. It was found that the degree of crosslinking of the irradiated specimens was increased with increasing irradiation dose and by the addition of crosslinking agents. The mechanical properties and thermal properties of specimens were improved in proportion to an increase in the degree of crosslinking. The crystallinity of original resin was decreased with increasing crosslinking density.