• Membrane Journal
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• v.27 no.2
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• pp.154-166
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• 2017

Polymeric films for gas barrier applications such as food packaging and electronic devices have attracted great interest due to their cheap, light and easy processability among gas barrier materials. Especially in electronic devices, extremely low gas permeance is necessary for maintaining the device performance. However, current polymeric barrier films still suffer from relatively high gas permeance than other materials. Therefore, there have been strong needs to enhance the gas barrier performance of polymeric barrier films while keep their own advantages. Recently, graphene is highlighted as a 2D-layered material for gas barrier applications. However, owing to the poor workability and difficulty to produce in engineering scale, graphene oxide (GO) is on the rise. GO consists of oxygen-containing functional groups on surface with intrinsic 2D-layered structure and high aspect ratio, and it can be well-dispersed in aqueous polar solvents like water, resulting in scalable mass production. Here, we prepared GO incorporated polyimide (PI) nanocomposites. PI is widely used barrier polymer with high mechanical strength and thermal and chemical stability. We demonstrated that PI/GO nanocomposites could perform as a gas barrier. Furthermore, surfactants (Triton X-100 (TX) and Sodium deoxycholate (SDC)) are introduced to enhance the gas barrier performance by improving the degree of dispersion of GO in PI matrix. As a result, TX enhanced the gas barrier performance of PI/GO nanocomposites which is similar to predicted value. This finding will provide new insight to polymer nanocomposites for gas barrier applications.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.153-159
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• 2007

In this study, using FIV-based lentivirus vector system, we tried to express hG-CSF in tetracycline-controllable manner. hG-CSF influences the proliferation, differentiation, and survival of cells in the neutrophil lineage. To enhance stability and translation of hG-CSF transcript, WPRE sequence was also introduced into FIV-Tet-On vector at downstream region of either the hG-CSF gene or the sequence encoding rtTA. Primary culture cells (CEF, chicken embryonic fibroblast; PFF, procine fetal fibroblast) infected with the recombinant FIV were cultured in the medium supplemented with or without doxycycline for 48 hours, and induction efficiency was measured by comparing the hG-CSF gene expression level using quantitative real-time PCR, Western blot and ELISA. Higher hG-CSF expression and tighter expression control were observed from the vector in which the WPRE sequence was placed at downstream of the hG-CSF (in CEF) or rtTA (in PEE) gene. This FIV-Tet-On vector system may be helpful in solving serious physiological disturbance problems which has continuously hampered successful production of transgenic animals and gene therapy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5452-5457
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• 2015

Conjugating a phytochemical, a strong antioxidant, with a functional peptide not only compensates for its stability, but also improves its solubility and anti-wrinkle effects, thereby contributing to the possibility of becoming an excellent cosmetic ingredient. Thus, in this study we examined the potential cosmetic use of a phytochemical-peptide derivative using gallic acid, a phytochemical with antioxidant, anti-inflammatory, and anti-cancer effects. To evaluate the antioxidant and wrinkle-improving efficacy of 5 synthesized gallic acids conjugated with LVH, IVH, KTTKS, YGGFM, and YGGFLRKYP respectively, we observed the expression of genes related to wrinkle improvement using DPPH radical scavenging activity and real-time PCR. As a result, all 5 derivatives had excellent free radical scavenging effects. The expression level of genes involved collagen synthesis also increased, and the secreted peptides during collagen production contributed to their antioxidant and wrinkle improving effects. These results mark the potential use of gallic acid peptide derivatives as a cosmetic ingredient for anti-oxidation and wrinkle improvement.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.636-643
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• 1999

Ectodermal dysplasia is a genetic birth defect in which at least abnormally develop two structures derived from the ectoderm. It is usually inherited in autosomal dominant or autosomal recessive pattern. Oral manifestations are oligodontia, anodontia, dysmorphic teeth(conical shape), decreased occlusal vertical dimension and alveolar bone. Extraoral signs may include decreased or absent sweat glands, sparse and fine hair, saddle nose, hearing loss and decreased production of body fluids including saliva. Most affected children require extensive dental treatment to restore their appearance and help the development of a positive self image. The patient's overclosed profile was due to a decreased vertical dimension. The use of overdenture is to preserve erupted teeth, to accomodate the newly constructed occlusal plane, to improve retention and stability of denture and to maintain the remaining alveolar bone. The restoration of vertical dimension improved the child's speech, swallowing, and eating. Growth continue until the age of approximately 18. As child grows, replacement dentures will have to be fabricated primarily to accomodate increasing vertical dimension and changing dentition. Implants may be indicated later if the alveolar bone is adequate. Periodic recall visits are advised, to monitor the dentures during periods of growth and development, and eruption of the permanent teeth.

• Journal of the Korean Electrochemical Society
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• v.23 no.3
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• pp.66-72
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• 2020

In this study, the development of biosensors capable of bi-enzyme reactions by including Horseradish peroxidase and glucose oxidase was carried out for detection of glucose. The sensors were manufactured using electro deposition method to reduce production time, and screen printed electrodes (SPE) were used to produce economical sensors. To check the bienzyme effect, the sensor was compared and analyzed with single enzyme biosensor. The characteristics of the sensor were evaluated using scanning electron microscopy(SEM), cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS), chronoamperometry(CA), and flow injection analysis(FIA). Analysis results from SEM, CV and EIS confirmed that the enzymes are well fixed to the electrode surface. In addition, it was confirmed that bi-enzyme biosensors manufactured from the CA method improved signal performance by 200% compared to single enzyme biosensors. From this results, we were able to explain that HRP and GOD react catalyzed to each other. And the results of FIA showed that the intensity of each current signal was constant when the same concentration of glucose was injected four times. In addition, by analyzing the intensity of current signals for glucose concentrations, the biosensors manufactured in this study showed excellent trends in signal sensitivity, reproducibility and stability.

• Clean Technology
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• v.24 no.2
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• pp.105-111
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• 2018

This study presents a novel and eco-friendly process that can precisely control the location of the patches on the patch particles. The method of manufacturing these anisotropic hexagram patch particles consists of sequential combinations of two separate methods such as a sequential micromolding technique for fabricating patch particles and a selective localization method for controlling the location of patches on the patch particles. The micromolding technique was carried out using physicochemically stable material as a micromold. In order to fabricate the highly stable patch anisotropic hexagram particles, the perfluoropolyether (PFPE) micromold was used to the process of the micromolding technique because they could prevent the problem of diffusion of hydrophobic monomers while conventional poly(dimethylsiloxane) (PDMS) micromold is limited to prevent the problem of diffusion of hydrophobic monomers. Based on combination methods of the micromolding technique and the selective localization method, the reproducibility and stability have been improved to fabricate 12 different types of anisotropic hexagram patch particles. This fabrication method shows the unique advantages in eco-friend condition, easy and fast fabrication due to less number of process, the feasibility of a mass production. We believe that these anisotropic hexagram patch particles can be widely utilized to the field of the directional self-assembly.

• Clean Technology
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• v.12 no.4
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• pp.250-258
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• 2006

CFC compounds such as CFC-113 and 1,1,1-TCE, etc. have been used in various industries due to their excellent chemical stability, thermodynamic characteristics, non-inflammability and anti-corrosiveness. However, in oder to protect the earth environment, "the Montreal Protocol on substances that deplete the ozone layer" was adopted in 1989 for prevention of production and utilization of these CFC compounds and alternative cleaning agent have been required in the industry. The objective of this study is to develop non-aqueous cleaning agents that do not require major change of cleaning system, have excellent cleaning efficiency, are favorable to the environment, are harmless to the human body, and are not generated corrosive materials. In this work, non-aqueous cleaning agents have been formulated with glycol ether series and paraffinic hydrocarbon series with siloxane, and their physical properties and cleaning efficiencies were analyzed and compared with those of regulated materials. As a result of physical properties measurement of the formulated cleaning agents, it is expected that they may have good penetration ability into contaminated materials due to their properties with low density and low surface tension. Measurement of flash point and vapor pressure of the cleaning agents will be helpful for evaluation of their safety and working environment. The experimental results of cleaning flux, solder and grease by the formulated cleaning agents show that their cleaning abilities of soils were good and that there were no residues on the substance after cleaning. Therefore, alternative cleaning agents which have equivalent cleaning ability to regulating materials, good penetration ability and low hazard to human body, have been developed in this work.

• Korean Journal of Veterinary Research
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• v.1 no.1
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• pp.36-53
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• 1961

This experiment was conducted on the fowl pox embryo vaccine for the production immunity, and stability, using an attenuated fowl pox virus (Nakano strin). Burnet's window method was applied, that is, 0.1 ml. of seed virus was inoculated on the chorioallantoic membrane of 12-day old chicken embryos, and incubated for 5 to 6 day, and then the result were read. Four kinds of suspensions of different embyo tissue were prepared and tested for the infectivity in chickens. Finally the suspension of chorioallantoic membrane was used as the vaccine throughout the experiment. Results obtained in this experiment are summarized as follows: (1) Of embryo tissue infected with the vaccine virus, chorioallantoic membrane had the highest virus titer of $10^{-5.4}$ $EID_{50}$, and albumen the lowest titer of $10^{-0.7}$ $EID_{50}$. (2) Suspensions of infected whole embryo with or without saline, and de-embryonated whole egg had about the same virus titer of $10^{-4.4}$ $EID_{50}$, whereas the chorioallantoic membrane had $10^{-5.7}$ EID 50 or higher. The virus titer droped one log from $EID_{50}$ when inoculated into chickens. Takes were observed 35.6% of 500 chickens by stick method and 89% of 500 chickens by brush method. (3) The chorioallantoic membrane conferred almost perfect immunity for chickens by 10 days after vaccination. (4) Satisfactory immunity was observed in the chickens when eruption in a single follicle. (5) Eight of 10 vaccinated chickens revealed durable immunity for 307 days following vaccination. (6) The vacuum-dried vaccine maintained its infectiviy for 899 days at $5^{\circ}C$ or below and maintained the vius titer of $10^{-3.6}$ $EID_{50}$. On the other hand, non-desiccated wet vaccine maintained the titer of $10^{-3.0}$ $EID_{50}$ for 50 days of preservation period at $5^{\circ}$. However, in 50% glycerin-saline the infectivtiy of the same wet vaccine dropped to $10^{-1.5}$ $EID_{50}$ (7) The vartation of virus titer of the vaccine before and after desiccation was $10^{-0.5}$ $EID_{50}$ on the average. (8) As suspending media, 0.85 per cent saline and distilled water showed nearly the same effect on the infectivity of the vaccine by retaining the titer $10^{-3.0}$ $EID_{50}$ after 50 days of preservation both at $5^{\circ}C$ and $20^{\circ}C$, while 50 percent cent glycerine-saline dropped the titer to $10^{-2.5}$ EID and $10^{-1.5}$ $EID_{50}$ respectively at $5^{\circ}C$ and $2^{\circ}C$ after the same period.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.520-525
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• 1994

This study was carried on the garlic-seasoning oil production by autoclaving method and evaporating method in order to research a developed method. The raw, flake, extract states of garlic was added 40%(w/w) of total amounts to corn salad oil. All samples treated with various conditions analyzed the volatile flavor components(VFC) during incubating ($40{\pm}2^{\circ}C$) and heating ($185{\pm}2^{\circ}C$). In the garlicseasoning oils, the contents of propane, pentane, methyl allyl trisulfide and diallyl trisulfide as the major VFC were decreased while the contents of propenal and hexanal increased according to the storage and heat treatment. The order of flavor contents among garlic states were raw>extract>flake, but flavor stability were raw>flake>extract states during storage, while flake>raw>extract states in heat treatment. VFC in garlic-seasoning oil made by evaporating method were about 66.1% level of those made by autoclaving method, but the changing tendency of their content during storage and heat treatment were shown to be similar. According to those results, autoclaving method and evaporating method were thought to the rational method in preparation of garlic-seasoning oil.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.90-95
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• 1986

A comparative study of chemical characteristics, efficacy and relative merits of extruded and coated granules, containing fungicide and insecticide, was conducted under laboratory and field conditions. Probenzole (3-allyloxy-1,2-benzisothiazole 1,1-dioxide) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methyl carbamate) were chosen as toxicants for rice blast(Pyricularia oryzae) and brown planthopper (Nilaparvata lugens) control, respectively. Stability of active ingredients in coated granule was superior to the extruded one under accelerated temperature. Active ingredient dissolution of coated one into distilled water showed slow release pattern. Pesticide residues in rice (Oryzae sativa, Chucheongbyeo) shoot applied with extruded one at the dosage of 3kg/10a retained higher levels than those with coated one on two days after application, while the residue levels were a reversed tendency on eight days after application. Efficacy on rice blast exhibited minute differences between the granules, on the other hand efficacy on brown planthopper by coated one was of higher rank than that by extruded one. Production cost of the combined pesticide granule by coating method could be cut down by 6% as compared to extrusion method.