• 대한본초학회지
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• 제26권4호
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• pp.23-30
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• 2011

Objectives : This study aimed to evaluate the effect of Atractylodis Rhizoma Alba water extract on streptozotocin (STZ)-induced diabetes in rats. Methods : Male Sprague-Dawley rats were divided into four groups ; normal, STZ-control and Atractylodis Rhizoma Alba (A) water extract-administrated group. Rats in which diabetic was induced by intraperitonal injection with STZ(60 mg/kg body weight). STZ-induced diabetic rats were orally administrated A extract daily for 5 weeks at doses of 200 or 500 mg/kg. Fasting blood glucose, total cholesterol, triglyceride and blood urea nitrogen were measured in sera of rats. Total volume of urine and urinary creatinine were also measured. Histopathological examination and immunohistochemical staining for the expression of insulin and ${\alpha}$-SMA in pancreas and kidney were performed, respectively. Results : There were no differences in body and kidney weights between STZ-control and A extract-administrated groups. However, serum triglyceride level was significantly decreased in A extract-administrated groups compared with those of STZ-control group. Histopathological analysis of pancreas and kidney revealed increased the number of islets and insulin-positive beta-cells in pancreas, and decreased morphological changes of glomerulus and ${\alpha}$-SMA expression in kidney after the administration of A extract. Conclusions : These results suggest that Atractylodis Rhizoma Alba has a biological action on STZ-induced diabetes in rats via decreasing the serum levels of total triglyceride, and suppressing the morphological changes of pancreas and kidney.

• Nuclear Engineering and Technology
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• 제40권6호
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• pp.467-476
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• 2008

To keep the superconducting (SC) magnet coils of KSTAR at proper operating conditions, not only the coils but also other cold components, such as thermal shields (TS), magnet structures, SC bus-lines (BL), and current leads (CL) must be maintained at their respective cryogenic temperatures. A helium refrigeration system (RRS) with an exergetic equivalent cooling power of 9 kW at 4.5 K without liquid nitrogen ($LN_2$) pre-cooling has been manufactured and installed. The main components of the KST AR helium refrigeration system (HRS) can be classified into the warm compression system (WCS) and the cryogenic devices according to the operating temperature levels. The process helium is compressed from 1 bar to 22 bar passing through the WCS and is supplied to cryogenic devices. The main components of cryogenic devices are consist of cold box (C/B) and distribution box (D/B). The C/B cool-down and make the various cryogenic helium for the KSTAR Tokamak and the various cryogenic helium is distributed by the D/B as per the KSTAR requirement. In this proceeding, we will present the commissioning results of the KSTAR HRS. Circuits which can simulate the thermal loads and pressure drops corresponding to the cooling channels of each cold component of KSTAR have been integrated into the helium distribution system of the HRS. Using those circuits, the performance and the capability of the HRS, to fulfill the mission of establishing the appropriate operating condition for the KSTAR SC magnet coils, have been successfully demonstrated.

• 한국자원식물학회지
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• 제24권2호
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• pp.208-213
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• 2011

둥근마 기내 식물체의 증식을 위해서는 고체배지보다 액체배지에서 액아수, 초장, 생체중, 괴경형성의 수가 높아 기내식물체 증식에 효과적이었다. 배지의 무기염류 농도는 MS 기본 염류의 배지에서 액아수와 생체중이 각각 28.8개, 3.6 g로 기본 염류의 양을 반으로 줄이거나 두 배로 늘인 배지에서보다 높았다. 당원으로는 sucrose가 glucose 보다 더 효과적이었고, sucrose의 농도는 60 $g{\cdot}L^{-1}$에서 액아수와 괴경형성수가 가장 높아 효율적이었다. 질소원은 $NH_4NO_3$와 $KNO_3$의 조성 비율이 $1{\times}{\frac{1}{2}}$인 것이 다른 처리에 비해 생육이 우수한 것으로 나타났다. 배지내 수소이온 농도는 pH 4.8 ~ 6.8 범위내에서 pH간에 뚜렷한 유의 차이를 보이지 않았다. 생장시기별 생장량에 있어서 엽수, 마디수 및 초장은 접종후 2주부터 5주까지 급격히 증가하고 12주까지는 서서히 증가하는 유사한 경향을 보였다. 반면, 생체중은 접종 3주에서 11주까지 꾸준하게 증가하여 최고치에 달했다. 괴경은 접종 2주부터 형성되기 시작하여, 5~8주 사이에 높은 증가율을 가지며 11주에 최고 형성수가 되었다.

• 한국재료학회지
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• 제22권11호
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• pp.609-614
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• 2012

We report on the NO gas sensing properties of non-directional ZnO nanofibers synthesized using a typical electrospinning technique. These non-directional ZnO nanofibers were electrospun on an $SiO_2$/Si substrate from a solution containing poly vinyl alcohol (PVA) and zinc nitrate hexahydrate dissolved in distilled water. Calcination processing of the ZnO/PVA composite nanofibers resulted in a random network of polycrystalline ZnO nanofibers of 50 nm to 100 nm in diameter. The diameter of the nanofibers was found to depend primarily on the solution viscosity; a proper viscosity was maintained by adding PVA to fabricate uniform ZnO nanofibers. Microstructural measurements using scanning electron microscopy revealed that our synthesized ZnO nanofibers after calcination had coarser surface morphology than those before calcination, indicating that the calcination processing was sufficient to remove organic contents. From the gas sensing response measurements for various NO gas concentrations in dry air at several working temperatures, it was found that gas sensors based on electrospun ZnO nanofibers showed quite good responses, exhibiting a maximum sensitivity to NO gas in dry air at an operating temperature of $200^{\circ}C$. In particular, the non-directional electrospun ZnO nanofiber gas sensors were found to have a good NO gas detection limit of sub-ppm levels in dry air. These results illustrate that non-directional electrospun ZnO nanofibers are promising for use in low-cost, high-performance practical NO gas sensors.

• 한국재료학회지
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• 제22권11호
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• pp.575-580
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• 2012

The purpose of this study is to investigate the crystalline structure and optical properties of (GaZn)(NO) powders prepared by solid-state reaction between GaOOH and ZnO mixture under $NH_3$ gas flow. While ammoniation of the GaOOH and ZnO mixture successfully produces the single phase of (GaZn)(NO) solid solution within a GaOOH rich composition of under 50 mol% of ZnO content, this process also produces a powder with coexisting (GaZn)(NO) and ZnO in a ZnO rich composition over 50 mol%. The GaOOH in the starting material was phase-transformed to ${\alpha}$-, ${\beta}-Ga_2O_3$ in the $NH_3$ environment; it was then reacted with ZnO to produce $ZnGa_2O_4$. Finally, the exchange reaction between nitrogen and oxygen atoms at the $ZnGa_2O_4$ powder surface forms a (GaZn)(NO) solid solution. Photoluminescence spectra from the (GaZn)(NO) solid solution consisted of oxygen-related red-emission bands and yellow-, green- and blue-emission bands from the Zn acceptor energy levels in the energy bandgap of the (GaZn)(NO) solid solutions.

• 한국축산식품학회지
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• 제32권1호
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• pp.77-83
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• 2012

미역, 파래, 톳 등 해조류의 우수한 기능성을 육제품에 활용하기 위한 기초 자료를 얻기 위하여 이들의 첨가(1, 2, 4%)가 돈육 패티의 물리 화학적 특성과 저장성 및 관능에 미치는 영향을 살펴보았다. 파래, 미역, 톳 등 모든 해조분말 첨가 패티에서 해조 첨가량이 많을수록 조회분함량이 증가하고, 패티의 CIE $L^*$, $a^*$ 및 $b^*$ 값이 감소하였다. 패티를 중심온도 $72^{\circ}C$에서 15분간 가열하였을 때 가열 감량을 측정한 결과 해조 분말 첨가량이 증가할수록 돈육 패티의 가열감량이 감소하는 결과를 보였으며, 특히 미역 첨가가 가장 큰 폭의 가열감량 감소를 보였다. VBN 값은 파래, 미역, 톳 등 모든 해조류 첨가군이 대조구 패티에 비해 낮았다. 해조류 분말 첨가는 패티의 다즙성을 증가시켰으며, 향미와 종합기호도에는 큰 영향을 미치지 않았다. 이상의 결과로 보아 돈육 패티 제조 시 해조류의 첨가는 패티의 회분함량을 증가시켜 돈육에 부족한 무기질 함량을 보충해주며, 패티의 가열감량 감소, 다즙성 증가 및 VBN 감소 등 긍적적 효과가 기대된다.

• 한국축산식품학회지
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• 제36권6호
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• pp.760-768
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• 2016

The present study was performed to determine the effect of dietary supplementation with processed sulfur on the quality and stability of vacuum packaged pork during aging time. All groups were designated into two groups; NP, a group fed basal diet and SP, a group fed basal diet and processed sulfur, 3 g/kg feed. Following vacuum packaging, Longissimus dorsi muscles were vacuum-packaged and stored under refrigerated condition ($1-2^{\circ}C$) for 21 d. Weight loss of the SP group was lower (p<0.05) than that of the NP group. Interaction effect of shear force and cooking loss was observed (p<0.05). Redness values of the SP group at 14 and 21 d after storage were higher than those of the NP group (p<0.05). Lipid oxidation and volatile basic nitrogen (VBN) levels in the SP group were retarded (p<0.05) compared to that of the NP group during storage. Aspartic and glutamic acid in SP were higher than in NP (p<0.1). There was no significant (p>0.05) difference in TPC between the both groups during storage. Therefore, vacuum packaged pork from pigs fed processed sulfur had better aging yield and storage stability than pork from pigs fed basal diet.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 춘계 총회 및 학술발표회
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• pp.99-101
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• 1998

1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

• 한국미생물·생명공학회지
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• 제42권4호
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• pp.339-346
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• 2014

가정에서 제조된 된장으로부터 lactose를 glucose와 galactose로 가수분해하는 균체외 ${\beta}$-galactosidase의 생산균이 분리되었다. 분리균 YB-1414는 형태적 특성, 생화학적 성질 및 16S rRNA 유전자 염기서열에 근거하여 Bacillus licheniformis로 확인되었다. 탄소원과 질소원으로 밀기울 (1%)과 yeast extract (2.5%)를 사용하였을 때 B. licheniformis YB-1414의 ${\beta}$-galactosidase 생산성이 최대 6.2 U/ml에 이르렀다. 특히 밀기울의 불용성 성분이 수용성 성분보다 ${\beta}$-galactosidase 생산성을 더 증가 시키는 것으로 확인되었다. ${\beta}$-galactosidase의 para-nitrophenyl-${\beta}$-D-galactopyranoside 가수분해 활성은 pH 6.0과 $55-60^{\circ}C$에서 가장 높았으며, 낮은 농도의 galactose에 의해서도 크게 저해를 받았다. 그러나 glucose에 의해서는 ${\beta}$-galactosidase의 가수분해 활성이 약하게 저해를 받으며 400 mM glucose가 존재하여도 최대 활성의 85%에 해당하는 가수분해 활성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.351-356
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• 2013

A high ${\beta}$-glucosidase (BGL)-producing strain, Stereum hirsutum, was identified and isolated and showed a maximum BGL activity (10.4 U/ml) when cultured with Avicel and tryptone as the carbon and nitrogen sources, respectively. In comparison with other BGLs, BGL obtained from S. hirsutum showed a higher level of activity to cellobiose ($V_{max}$ = 172 U/mg, and $k_{cat}$ = 281/s). Under the optimum conditions (600 rpm, $30^{\circ}C$, and pH 6.0), the maximum BGL activity of 10.4 U/ml with the overall productivity of 74.5 U/l/h was observed. BGL production was scaled up from a laboratory scale (7-L fermenter) to a pilot scale (70-L fermenter). When S. hirsutum was cultured in fed-batch culture with rice straw as the carbon source in a 70-L fermenter, a comparable productivity of 78.6 U/l/h was obtained. Furthermore, S. hirsutum showed high levels of activity of other lignocellulases (cellobiohydrolase, endoglucanase, xylanase, and laccase) that are involved in the saccharification of biomasses. Application of S. hirsutum lignocellulases in the hydrolysis of Pinus densiflora and Catalpa ovata showed saccharification yields of 49.7% and 43.0%, respectively, which were higher than the yield obtained using commercial enzymes.