• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.382-398
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• 2017

This study was conducted to identify the potential of Quercus mongolica (QUM), Pinus densiflora (PID) and Pinus rigida (PIR) as a raw material for pellet production. Larix kaempferi (LAK), which has mostly been used for pellet production in Korea, was also used as a control. All specimens contained very minimal amounts of sulfur and chlorine. Ash content of LAK was the lowest, followed by PID, PIR and QUM. For the size distribution, the mass fraction between 0.42 mm and 0.25 mm was the highest in PIR. Most fuel characteristics of the produced wood pellets improved with the use of 12% moisture content (MC) particles and the increase of the ratio of length to diameter of a hole in flat-die (L/D ratio). When the MC, bulk density and durability of QUM, PID, PIR and LAK pellets was compared with the standards of the KFRI and ISO, the use of wood particles of 12% MC and flat-die with an L/D ratio of 5.00 for PID particles are suitable for high-quality pellets in the aspects of all fuel characteristics. For PIR and QUM, further work is needed to seek the optimum conditions for the production of high-quality and durable pellets.

• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.177-186
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• 1986

This study was designed to evaluate the partially purified antigens which were fractionated from crude extract of Paragonimus westermani and to monitor the enzyme-linked immunosorbent assay (ELISA) in experimental cat paragonimiasis during the course of infection as well as before and after chemotherapy. Crude extract of 6-month-old adult P. westermani was fractionated to 5 antigens by successive applications of ammonium sulfate precipitation, ion exchange chromatography and gel filtration. And the cats, 10 in each group, were infected with 60, 30, 15, and 5 metacercariae, then the half of each group was treated with praziquantel 2 times in one day of 100mg per kilogram of weight on 150 days after the infection. Sera were collected every 10 days. ELISA was performed with the concentration of $2{\mu}g/ml$ antigen, 100 times diluted sera and 1,000 times diluted alkaline phosphatase conjugated anti-cat IgG. The results were as follows: 1. Absorbance by ELISA with proteins precipitated by differential concentration of ammonium sulfate was the highest at $51{\sim}65%$ precipitate (PA2), followed by $0{\sim}50%$ precipitate (PAl), $66{\sim}80%$ precipitate (PA3), and $81{\sim}90%$ precipitate (PA4). Unprecipitated protein over 90% ammonium sulfate (PA5) showed the lowest antigenicity. 2. Fractionation of PA1, PA2, and PA3 through the DEAE-cellulose column did not differentiate the antigenic proteins. 3. By passing through the Sephadex G-200 column, PA1 and PA2 were fractionated to high molecular weight proteins and those of low molecular weight which showed high absorbance by ELISA (PA1-I, II and PA2-I, II). But PA3 was shown to have a fraction of high molecular weight proteins (PA3-I) which showed high antigenicity. 4. SDS-polyacrylamide gel electrophoresis of PA1-I, P A1-II, PA2-I, PA2-II, PA3-I, and crude extract was performed. Fraction PA1-I was composed of proteins which had the molecular weight of 270 kilodaltons(KD) to 196 KD; of them 220KD protein was major band. Fraction PA2-I was composed of $255{\sim}225\;KD$, and PA3-I, $255{\sim}240\;KD$, respectively. Fraction PA1-II and fraction PA2-II consisted of 30 KD proteins. 5. Absorbance by ELISA began to increase within $10{\sim}20$ days after the infection and reached the highest on $140{\sim}180$ days, then made plateau thereafter. 6. Absorbance by ELISA decreased after praziquantel treatment. In 60 metacercariae infection group, the absorbance had been decreasing, but remained within the positive range during observation period, while those of 30, 15, and 5 metacercariae infection groups turned to negative range. 7. Fraction PA1-II showed the highest antigenicity in ELISA, then fraction PA2-I, fraction PA1-I, fraction PA2-II, fraction PA3-I and crude extract followed. In early phase of infection, the absorbance of fraction PA1-II showed more rapid increase than those of the other fractions and it came to positive range at $20{\sim}30$ days after infection.

• Ocean and Polar Research
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• v.34 no.4
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• pp.445-451
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• 2012

The EtOH extracts of red seaweeds (Symphyocladia latiuscula, Chondrus ocellatus and Carpopeltis affinis) and solvent partitioned fractions were investigated for their 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects and the total phenolic contents were correlated with ABTS and DPPH radical scavenging activities. The EtOH extracts and their solvent partitioned fractions exhibited strong ABTS and DPPH radical scavenging activities. Among the solvent partitioned fractions obtained from n-Hexane (HX), methylenchloride (MC), ethylacetate (EA), and buthanol (BuOH), the HX fraction from C. affinis showed higher radical scavenging activities than other fractions. Total phenolic contents showed significant correlation ($r^2$ = 0.709) with ABTS radical scavenging activity. The results of this study suggest that the strong radical scavenging activity of HX fraction from C. affinis is a promising natural antioxidant for healthcare products.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.70.2-70.2
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• 2016

Star formation in galaxies is one of the key factors in galaxy evolution. It is believed that star formation is triggered and enhanced by mergers among galaxies or secular evolution. However, how much these two mechanisms contribute on star formation is not well known yet. Recently, many other studies show observational evidences of faint merger features(tidal tails, stellar streams) around nearby galaxies with deep optical imaging. This study aims to investigate the fraction of star forming galaxies exhibiting faint features to total galaxies. We are analyzing samples of 76 star forming galaxies (NUV < -18) to find merger features from stacked B, R band frames taken at Maidanak 1.5m, McDonald 2.1m telescope and g, r frames from Canada-France-Hawaii Telescope (CFHT) MegaCam archival data. With the fraction, we can expect to know the contribution of mergers on star formation to galaxies.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.517-527
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• 2018

The current study investigated in vitro anti-diabetic and neuroprotective effects of the ethyl acetate fraction in Actinidia arguta sprouts (EFAS), on $H_2O_2$ and high glucose-induced cytotoxicity in human neuroblastoma MC-IXC cells. EFAS had high total phenolic and total flavonoid contents. An assessment of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of EFAS, as well as its potential for inhibiting malondialdehyde production, indicated that EFAS may possess significant antioxidant properties. EFAS exerted inhibitory effects on ${\alpha}-glucosidase$ via glycemic regulation which forms advanced glycation end products. In addition, EFAS exhibited significant acetylcholinesterase inhibitory effects. Moreover, EFAS displayed protective effects against $H_2O_2$ and high glucose-induced cell death, and inhibited the generation of reactive oxygen species in MC-IXC cells. Finally, the main physiological compound of EFAS was identified via high performance liquid chromatography as a rutin.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.483-487
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• 2016

The purpose of this study is to investigate whether gold nanoparticles had radiosensitization when combined with gamma and x ray beam. Cytotoxicity was mearsured with comparing survival fraction after incubated time 6,12,18 and 24 hours. Clonogenic assay was employed to assess survival fraction of cells with and without gold nanoparticles treatment following gamma ray irradiation. The most of gold nanoparticles were distributed in the cytoplasm. And the toxicity of gold nanoparticles used this study were found to be non-cytotoxic. And we also observed enhancement by about 40% in RBE value for gamma ray irradiation of cells treated with gold nanoparticles. Dose reduction of about half for gamma ray irradiation is demonstrated for gold nanoparticles treated cells as compared to untreated cells. In cells with exposed to gamma ray, DNA damage was increased when compared to only radiation exposed cells. The study revealed a significant reduction in radiation dose for killing the cells with internalized gold nanoparticles as compared to the cells without gold nanoparticles. The gold nanoparticles treatment resulted in enhancement of radiation effect as evident from increase in relative biological effectiveness values for photon irradiated cells.

• Korean Journal of Materials Research
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• v.14 no.1
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• pp.28-34
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• 2004

IN 738LC, the major material for gas-turbine for power generation, was heat treated at $750^{\circ}C$, $850^{\circ}C$, $950^{\circ}C$ for 1000, 2000, and 4000 hrs and the microstructural evolution and mechanical properties were examined using optical microscope, XRD, SEM/EDS. The results showed ${\gamma}$', the main strengthening elements in this alloy, was about 300 nm in size and was about 56% by area fraction in as-cast samples. The area fraction of ${\gamma}$' peaked at 2000 hours at $750^{\circ}C$. The average diameter of the ${\gamma}$' which was about 300 nm at ascast specimen increased to about 1 $\mu\textrm{m}$ after heat treatment at $950^{\circ}C$ for 4000 hrs. Carbides were formed at dendrite, cell or grain boundaries which was ascribed to the segregation caused by solute redistribution during solidification. It was found that MC type carbides formed at low temperature, whereas carbides of $M_{23}$ /$C_{ 6}$/ type formed at higher temperature or at longer degradation. The hardness and impact energy decreased as the heat treatment temperature or time of retention increased, which was inaccrodance with the area fraction of ${\gamma}$'.

• Journal of Life Science
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• v.29 no.3
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• pp.287-294
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• 2019

Calystegia soldanella is distributed in coastal sand dunes and has high environmental adaptability; it is also known to be effective for anti-oxidant, anti-pyretic, anti-septic, and diuretic action. This study investigated the effect of crude extracts and organic solvent fractions of C. soldanella on MMP-2 and MMP-9 expression, MMP activity, and cell mobility in phorbol-12-myristate-13-acetate (PMA)-induced fibrosarcoma HT-1080 cells. C. soldanella was twice extracted, once with methylene chloride (MC) and once with methanol (MeOH). After the MC and MeOH extracts were combined, their suppressive effects on MMP-2 and MMP-9 expression, MMP enzymatic activity, and gene and protein expression were measured by gelatin zymography, enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and western blot method. Cell mobility for the HT-1080 cells was observed by wound healing assay. The combined crude extracts showed a significant suppressive effects on MMP-2 and MMP-9 expression. To explore active inhibitory elements, the combined extracts were fractionated according to polarity into with n-hexane, 85% aqueous methanol, n-butanol, and water. Across these four solvent fractions, MMP-2 and MMP-9 activity and cell mobility in the HT-1080 cells were all strongly inhibited by the n-hexane fraction. These results suggest that C. soldanella extract and organic solvent fractions could be used as potent MMP inhibitors for effective anti-cancer treatments to suppress cancer invasion and metastasis.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.294-294
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• 2006

Diblock copolymers whose morphology in the bulk is dictated by the volume fraction of the components and segmental interactions were confined within nanoscopic cylindrical pores. Since the confining geometry is nonplanar and nanoscopic, the extreme imposed curvature, comparable to molecular dimensions, places significant packing frustration on the chains. When incommensurability between the repeating period of diblock copolymers and the diameter of nanopore is coupled with the curvature, it causes the marked departures from bulk or even thin film behavior. The entropy penalty from the constraints and the curvature of the physical confinement determines unique nanostructures available only with this curved confinement.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.94.2-94.2
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• 2014

After successful commissioning observations, IGRINS will soon begin its normal scientific operations on the 2.7m Harlan J. Smith telescope at the McDonald Observatory. We will present a working version of the IGRINS operation plan. A fraction of IGRINS guaranteed time will be devoted to a selection of strategic programs with legacy values, whereas the rest of the time will be used for normal programs. We will also describe the current status of the IGRINS data reduction pipeline package and its future development plan.