• Analytical Science and Technology
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• v.25 no.1
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• pp.14-18
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• 2012

Rn-222 was used as a natural radioactive isotope tracer to evaluate non-aqueous phase liquid(NAPL) contaminated soil and aquifer. In the case of soil sample, Rn-222 concentration was inversely decreased with diesel concentration in the granite soil sample and it was decreased about 30% at the 13% diesel contaminated soil. For evaluating trichloroethylene (TCE) contaminated aquifer, the natural radioisotope Rn-222 was used as naturally occurring partitioning tracer for the approximate localization and semiquantitative assessment of the TCE source zone. Rn-222 was analyzed for the estimation of TCE contamination ranges of the acquifer in the contaminated site at Wonju in Korea.

• Fisheries and Aquatic Sciences
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• v.21 no.6
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• pp.16.1-16.7
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• 2018

Background: Matrix metalloproteinases (MMPs) are linked with several complications such as metastasis of cancer progression, oxidative stress, and hepatic fibrosis. Brown seaweeds are being extensively studied for their bioactive molecule content against cancer progression. In this context, Sargassum horneri was reported to possess various bioactivities including antiviral, antimicrobial, and anti-inflammatory partly due to its phenolic compound content. Methods: In this study, potential of S. horneri was evaluated through anti-MMP effect in HT1080 fibrosarcoma cells. S. horneri crude extract was fractionated with organic solvents, namely, water ($H_2O$), n-buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and n-hexane. The non-toxicity of fraction samples (Sargassum horneri solvent-partitioned extracts (SHEs)) was confirmed by cell-viability assay. SHEs were tested for their ability to inhibit MMP enzymatic activity through gelatin digestion evaluation and cell migration assay. Expressions of MMP-2 and MMP-9 and tissue inhibitors of MMP (TIMPs) were evaluated by reverse transcription and Western blotting. Results: All fractions inhibited the enzymatic activities of MMP-2 and MMP-9 according to gelatin zymography. Except $H_2O$ fraction, fractions hindered the cell migration significantly. All tested fractions suppressed both mRNA and protein levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. Conclusion: Overall, current results suggested that S. horneri has potential to be a good source for anti-MMP agents, and further investigations are underway for better understanding of the action mechanism and isolation and elucidation of the bioactive molecules.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.147-148
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• 2009

The water-like ionic liquids have been widely used to enable the proton conduction in ionic liquid based membranes at high temperature and anhydrous PEFCs. In this study, we synthesized various kinds of composite membranes based on hydrocarbon polymers having good thermal and mechanical stabilities at high temperatures and ionic liquids. The composite membrane consisting of hydrocarbon polymer and ionic liquid was characterized by thermogravimetric analyzer (TGA) and impedance spectroscopy. Consequently the non-aqueous composite membranes of a variety of hydrocarbon polymer and ionic liquids have good conductivity and thermal stability at high temperature conditions.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.205-208
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• 2015

A 6-year old, neutered male, Maltese dog was presented in Veterinary Medical Teaching Hospital, Seoul National University. As hyphema and aqueous flare in the right eye were found, medical treatment for uveitis was started. Four months later, anterior displacement of dorsotemporal iris was observed. A mass originating from ciliary body of the right eye was revealed by ocular sonography. There was no evidence of metastasis on thoracic and abdominal radiographic imaging. Enucleation was performed on the right eye due to the enlargement of the mass and deteriorating uveitis. On histopathological evaluation, anterior uveal melanocytoma with chronic hemorrhage was confirmed. This case suggests adequate removal of intraocular neoplasm by enucleation can be curative in case of continuous hemorrhage or inflammation in the eye that cannot be controlled by non-surgical medications.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.399-409
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• 2012

Effects of pretreatment and extraction conditions on total polyphenol yield from licorice root were investigated using statistical method. For pretreatment, heat treatment at $121^{\circ}C$ for 10 min was applied. Licorice root content in solvent (10, 20, and 30%) ethanol concentration (20, 40, and 60%) and reaction time (1, 2, and 3 h) were used as variables for extraction conditions. Two experiments, with heat treated and no treated licorice, were prepared with same experimental design. Box behnken design was employed and produced a total of 15 trials. Total polyphenol yield from licorice root was not affected by heat treatment. Among variables, licorice content in solvent showed most significant effect regardless of other variables (p<0.05). Finally, optimum conditions for the extraction of total polyphenol from licorice root was detected as following: 10% of licorice in solvent, 52% ethanol as solvent, 2 h of reaction time and non-heat treatment and the extraction yield from optimized condition was 17.6 mg/g licorice root.

• Journal of the Mineralogical Society of Korea
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• v.24 no.3
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• pp.189-194
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• 2011

Martian satellite missions indicate that Martian equatorial plains are covered by ferric iron oxide. As a non-destructive technique, low-temperature treatment of remanent magnetization is effective in identifying magnetic minerals in rocks. In the present study, four sets of ferric iron oxides were prepared by aqueous alteration of ferrihydrite at warm conditions and four others by dehydration of goethite. As the amount of aluminous trivalent cations increases, crystallographic lattice parameters and N$\acute{e}$el temperatures decrease. Such declines originate from lattice distortion as the smaller aluminous trivalent cations substitue the larger terric irons. Whilst high remanence memory was observed for aqueously produced ferric iron oxide, low remanence memory was observed for dehydrated ferric iron oxide. In the future. magnetic remanence memory would be powerful in diagnosing the origin of ferric iron oxide.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.88.1-88.1
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• 2012

Silicon nanowires (SiNWs), due to their unusual quantum-confinement effects that lead to superior electrical and optical properties compared to those of the bulk silicon, have been widely researched as a potential building block in a variety of novel electronic devices. The conventional means for the synthesis of SiNWs has been the vapor-liquid-solid method using chemical vapor deposition; however, this method is time consuming, environmentally unfriendly, and do not support vertical growth. As an alternate, the electroless etching method has been proposed, which uses metal catalysts contained in aqueous hydrofluoric acids (HF) for vertically etching the bulk silicon substrate. This new method can support large-area growth in a short time, and vertically aligned SiNWs with high aspect ratio can be readily synthesized with excellent reproducibility. Nonetheless, there still are rooms for improvement such as the poor surface characteristics that lead to degradation in electrical performance, and non-uniformity of the diameter and shapes of the synthesized SiNWs. Here, we report a facile method of SiNWs synthesis having uniform sizes, diameters, and shapes, which may be other than just cylindrical shapes using a modified nanosphere lithography technique. The diameters of the polystyrene nanospheres can be adjustable through varying the time of O2 plasma treatment, which serve as a mask template for metal deposition on a silicon substrate. After the removal of the nanospheres, SiNWs having the exact same shape as the mask are synthesized using wet etching technique in a solution of HF, hydrogen peroxide, and deionized water. Different electrical and optical characteristics were obtained according to the shapes and sizes of the SiNWs, which implies that they can serve specific purposes according to their types.

• Journal of Pharmaceutical Investigation
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• v.39 no.4
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• pp.249-255
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• 2009

The main object of this study was to prepare of w/o emulsion including glyceryl monooleate(GMO) and to evaluate its stability by using the recently developed $Turbiscan^{(R)}LAB$. GMO is the polar oily surfactant with the low HLB value, and it forms the gel phase of cubic structures after dissolves in aqueous media. Phosphate buffer solution (PBS) of pH 7.4 was prepared as the water phase and Marcol 52(mineral oil) was used as the oil phase in this study. GMO was used as the surfactant of W/O emulsion. W/O emulsion using GMO alone as a surfactant was very unstable. But the emulsion using both GMO and poloxamer 407 was more stable. The stability of W/O emulsions was evaluated after centrifuging the emulsions. But it was difficult with naked eye because an opaque and concentrated system like W/O emulsion was very turbid. So $Turbiscan^{(R)}LAB$ was used to detect the destabilization phenomena in non-diluted emulsion. As a result, the W/O emulsion using the proper amounts of GMO and poloxamer 407 was more stable among them using GMO of various amounts. But it seems that the other element for the stability of W/O emulsion including GMO was required. Furthermore, the $Turbiscan^{(R)}LAB$ was a very efficient analyzer for evaluating the physical stability of emulsion.

• Fibers and Polymers
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• v.7 no.2
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• pp.129-138
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• 2006

Using a strain-controlled rheometer, the steady shear flow properties of aqueous xanthan gum solutions of different concentrations were measured over a wide range of shear rates. In this article, both the shear rate and concentration dependencies of steady shear flow behavior are reported from the experimentally obtained data. The viscous behavior is quantitatively discussed using a well-known power law type flow equation with a special emphasis on its importance in industrial processing and actual usage. In addition, several inelastic-viscoplastic flow models including a yield stress parameter are employed to make a quantitative evaluation of the steady shear flow behavior, and then the applicability of these models is also examined in detail. Finally, the elastic nature is explained with a brief comment on its practical significance. Main results obtained from this study can be summarized as follows: (1) Concentrated xanthan gum solutions exhibit a finite magnitude of yield stress. This may come from the fact that a large number of hydrogen bonds in the helix structure result in a stable configuration that can show a resistance to flow. (2) Concentrated xanthan gum solutions show a marked non-Newtonian shear-thinning behavior which is well described by a power law flow equation and may be interpreted in terms of the conformational status of the polymer molecules under the influence of shear flow. This rheological feature enhances sensory qualities in food, pharmaceutical, and cosmetic products and guarantees a high degree of mix ability, pumpability, and pourability during their processing and/or actual use. (3) The Herschel-Bulkley, Mizrahi-Berk, and Heinz-Casson models are all applicable and have equivalent ability to describe the steady shear flow behavior of concentrated xanthan gum solutions, whereas both the Bingham and Casson models do not give a good applicability. (4) Concentrated xanthan gum solutions exhibit a quite important elastic flow behavior which acts as a significant factor for many industrial applications such as food, pharmaceutical, and cosmetic manufacturing processes.

• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.151-160
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• 1999

Nitric oxide(NO) is synthesized via the oxidation of L-arginine by a family of nitric oxide synthases(NOS), which are either constitutive(cNOS) or inducible(iNOS). The induction of iNOS in tissues can lead to the sustained production of high concentrations of NO which may exert pro-inflammatory effects including vasodilation. edema, cyototoxicity, and its activity can be mediated by various pro-inflammatory cytokine, including interferon ${\gamma}(INF-{\gamma})$. tumor necrosis factor, IL- 1 and IL-6. The enzyme, iNOS, became a new target for pharmacologcal research with the aim to find new substances for the treatment of chronic inflammatory disorders. Murine macrophages produce large amounts of NO when activated with $TFN-{\gamma}$ plus LPS. The murine macrophage-like cell line, RAW 264.7, is a suitable cell model on which to perform vitro studies regarding the iNOS system. Semen jugrandis is a fatty walnut seed found in Korea. The walnut have been used in foik medicine to improve virility, to relieved asthma, and to relieve constipation. Sesquiterpenelactones were isolated from this plant. In the course of screening for NO inhibitory activity from medicnial plants, the aqueous extract of this plant was found to have a significant activity. The result are summarized as followings. 1. The viability of cells incubated in the presence of semen jugrandis increased mare than non incubated cells. 2. Semen jugrandis suppressed the production of NO in tissues dependent on density. 3. Semen jugrandis suppressed the induction of iNOS in tissues dependent on density can lead to reduced production of NO. 4. Semen jugrandis suppressed the production of superoxide in tissue depend on density. According to the above mentioned results, semen jugrandis could be applied production of NO and superoxide can lead to reduction of chronic inflammatary. And as a depence matter come into a virus of microbe and tumor cells.