• Korean Journal of Pharmacognosy
• /
• v.36 no.3 s.142
• /
• pp.164-170
• /
• 2005

In the present study, we investigated the mineral and metabolite composition and antioxidant activities in the flower, stem and root of Aster ciliosus Kitamura in order to detect biologically active substances and develop novel functional resources. The mineral and metabolite compositions differ significantly among the organ of Aster ciliosus Kitamura. The flower is composed of K as 827 mg/100g. while the stem and root are composed of Na as 654.64mg/100g and 771.70mg/100g, respectively. Contents of unsaturated fatty acids, such as oleic, linoleic, and linolenic acid, were higher than those of saturated fatty acid, such as palmitic acid in flower. The contests of phenolic compounds were measured at 285 nm using different solvents: 2.53 and 2.03 optical density (OD) in chloroform and 1.864 and 1.715 in ethanol extracts for the stem and root, respectively. Antioxidant activity was measured in 75% ethanol extracts: 41.3, 42.0 and $45.2\;{\mu}g/ml$ in stem, root and flower at $IC_{50}$ value, respectively. These results suggest that extracts from Aster ciliosus Kitamura can be potentially used as novel resources for antioxidant and biological active substances.

• Journal of Life Science
• /
• v.15 no.6 s.73
• /
• pp.847-850
• /
• 2005

The aim of this study was to increase production of leucocin A, a kind of bacteriocin, in a transformed variety of S. cerevisiae. We investigated optical density, total secreted protein, protease activity, and antibacterial activity for the transformed S. cerevisiae in different carbon sources. The production of leucocin A growth-associated, and antibacterial activity, according to carbon source, was in the order of sucrose, glucose, glycerol, and fructose. Antibacterial activity was $10.6\%$ higher in the presence of sucrose than glucose. This is the first report regarding the effect of carbon sources on the production of leucocin A in transformed S. cerevisiae, as far as we ascertain. Our results could prove useful in the industrial production of natural preservatives.

• Journal of fish pathology
• /
• v.22 no.2
• /
• pp.167-172
• /
• 2009

Antibody-detection enzyme-linked immunosorbent assay (ELISA) was performed to determine whether the absorbance value of ELISA is influenced by the different serum storage conditions of olive flounder Paralichthys olivaceus. Flounder antiserum to bovine serum albumin was stored at -80, -20, 4 and 20${^{\circ}C}$ for 1, 30, 69 and 124 days, respectively. In addition, the flounder antisera were frozen at -80 and -20${^{\circ}C}$, respectively and then repeated 1, 5 and 10 thaw-freeze cycles. No significant difference was shown in ELISA optical density (O.D.) values of sera, which were stored at the above mentioned storage conditions during 124 days. ELISA O.D. values of unfrozen serum samples, which were previously stored at 4${^{\circ}C}$, were almost similar to those of sera undergoing 1, 5, and 10 freeze-thaw cycles after stored at -80 or -20${^{\circ}C}$. In conclusion, the ELISA O.D. values of flounder sera were not affected by various storage conditions: different temperatures (-80, -20, 4 and 20${^{\circ}C}$), durations of storage (1, 30, 69 and 124 days), and repeated thaw-freeze cycles (1, 5, and 10 times).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.12
• /
• pp.1503-1510
• /
• 2007

This study was carried out to investigate antioxidant substances (phenolic compounds and brown pigment), antioxidative effect and nitrite scavenging ability (NSA) of solvent extracts (hexane: HE, methanol; ME, water: WE) from fermented soybean foods, Chungkukjang and Doenjang. The antioxidant activities were determined by the measurements of peroxide value (POV) on the linoleic acid system, electron donating ability (EDA) and superoxide dismutase (SOD)-like activity. The contents of phenolic compounds and total brown pigments in Doenjang were $28.5{\pm}0.3mg/100g$ and optical density (OD) $1.98{\pm}0.03$, respectively, whereas their contents in Chungkukjang were significantly lower with $5.8{\pm}0.3mg/100g$ and OD $0.95{\pm}0.02$. The brown pigment contents of hydrophilic extracts increased more than that of lipophilic extracts through the fermentation and ripening processes. The ME of Doenjang exhibited higher inhibitory effects against the peroxidation of a linoleic acid system than that of Chungkukjang. The EDA and NSA of MEs were higher than those of WEs. Among the MEs, Doenjang showed the highest levels of EDA and NSA. On the other hand, the SOD-like activities of WE were higher than those of ME at the same concentrations and their activities of Doenjang were significantly higher than that of Chungkukjang. In conclusion, the antioxidative effects and NSA of Doenjang was significantly higher than those of Chungkukjang. It seemed that phenolic compounds and brown pigments formed during fermentation and ripening partly affect the antioxidative activities of fermented soybean foods.

• Korean Journal of Remote Sensing
• /
• v.20 no.2
• /
• pp.91-102
• /
• 2004

This paper reflects the estimation of using the EOC(Electro-optical Camera) images supporting GIUH(geomorphological instantaneous unit hydrograph) approach. We have analyzed GIUH in its density and frequency distribution by creating a DEM(digital elevation model) for the sub basin produced from the EOC images and examined topographical and hydrological application possibility of the EOC images. In this process, we have topographical basin characteristic analysis that use the remote sensing technique analyzing the DEM creation process of the EOC stereo images by studying the basic topographical hydrology analysis about abstraction technique since it is flirty complex and is more time-consuming than other method. we executed statistical analysis of a basin size and river length using the frequency function after divided lattice spacing applied have to the sub river basin from the image data and the digital map into 10m intervals ranging from 10m to 100m. After comparing and examining the peak and time to peak of the GIUH, we proceeded with a comparative analysis by lattice concerning the topographical divergence rate, area ratio, length ratio. Accumulating the peak and time to peak of the GIUH is altered to non-linear form in accordance to lattice dimension as well as basin factor. It was proved that the lattice dimension is one of the important factors about the peak and time to peak of the GIUH.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.31 no.4
• /
• pp.154-158
• /
• 2021

The optical transmittance of Mn-doped SnO₂ monolayer film increased gradually from 80.9 to 85.4 % at 550 nm wavelengths upon increasing the O₂/Ar+O₂ concentration rate from 0 to 7.9 % and the band gap energy changed from 3.0 to 3.6 eV. The resistivity tended to decrease from 3.21 Ω·cm to 0.03 Ω·cm, reaching a minimum at 2.7 %, and then gradually increased from 0.03 to 52.0 Ω·cm at higher O₂/Ar+O₂ gas concentration ratio. Based on XPS spectra analysis, the Sn 3d_5/2 peak of Mn-doped SnO₂ single layer shifted slightly from 486.40 to 486.58 and O_1s peak also shifted from 530.20 to 530.33 eV with increase the O₂/Ar+O₂ concentration ratio. Therefore, the XPS spectra results indicate that a multiphase with SnO and SnO₂ coexisted in the sputtered Mn-doped SnO₂ monolayer film.

• Journal of Electrochemical Science and Technology
• /
• v.9 no.4
• /
• pp.282-291
• /
• 2018

The pristine fluorine-doped $SnO_2$ (abbreviated as FTO) inverse opal (IO) was developed using a 410 nm polystyrene bead template. The nanolayered copper tungsten oxide ($CuWO_4$) was decorated on the FTO IO film using a facile electrochemical deposition, subsequently followed by annealing at $500^{\circ}C$ for 90 min. The morphologies, crystalline structure, optical properties and photoelectrochemical characteristics of the FTO and $CuWO_4$-decorated FTO (briefly denoted as $FTO/CuWO_4$) IO film were investigated by field emission scanning electron microscopy, X-ray diffraction, UV-vis spectroscopy and electrochemical impedance spectroscopy, showing FTO IO in the hexagonally closed-pack arrangement with a pore diameter and wall thickness of about 300 nm and 20 nm, respectively. Above this film, the $CuWO_4$ was electrodeposited by controlling the cycling number in cyclic voltammetry, suggesting that the $CuWO_4$ formed during 4 cycles (abbreviated as $CuWO_4$(4 cycles)) on FTO IO film exhibited partial distribution of $CuWO_4$ nanoparticles. Additional distribution of $CuWO_4$ nanoparticles was observed in the case of $FTO/CuWO_4$(8 cycles) IO film. The $CuWO_4$ layer exhibits triclinic structure with an indirect band gap of approximately 2.5 eV and shows the enhanced visible light absorption. The photoelectrochemical (PEC) behavior was evaluated in the 0.5 M $Na_2SO_4$ solution under solar illumination, suggesting that the $FTO/CuWO_4$(4 cycles) IO films exhibit a photocurrent density ($J_{sc}$) of $0.42mA/cm^2$ at 1.23 V vs. reversible hydrogen electrode (RHE, denoted as $V_{RHE}$), while the FTO IO and $FTO/CuWO_4$(8 cycles) IO films exhibited a $J_{sc}$ of 0.14 and $0.24mA/cm^2$ at $1.23V_{RHE}$, respectively. This difference can be explained by the increased visible light absorption by the $CuWO_4$ layer and the favorable charge separation/transfer event in the cascading band alignment between FTO and $CuWO_4$ layer, enhancing the overall PEC performance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.32 no.5
• /
• pp.426-431
• /
• 2019

In this study, we report the effect of pre-treatment of alpha-$Ga_2O_3$ grown on a sapphire substrate by halide vapor phase epitaxy (HVPE). During the pre-treatment process, 10 sccm of GaCl gas was injected to the sapphire substrate at $470^{\circ}C$. The surface morphologies of the alpha-$Ga_2O_3$ layers grown with various pre-treatment time (3, 5, and 10 min) were flat and crack-free. The transmittance of the alpha-$Ga_2O_3$ epi-layers was measured to analyze their optical properties. The transmittance was over 80% within the range of visible light. The strain in the alpha-$Ga_2O_3$ grown with a pre-treat 5 min was measured, and was found to be close to the theoretical XRD peak position. This can be explained by the reduction of strain having caused a lattice mismatch between the alpha-$Ga_2O_3$ layer and sapphire substrate. The calculated dislocation density of the screw and edge were $2.5{\times}10^5cm^{-2}$ and $8.8{\times}10^9cm^{-2}$, respectively.

• Korean Journal of Optics and Photonics
• /
• v.32 no.5
• /
• pp.209-214
• /
• 2021

High-power continuous-wave operation of a Yb-doped double-clad fiber laser at 1018 nm, pumped by high-power diode lasers at 976 nm, is reported. Based on numerical calculation of the gain and laser signal power along the length of the Yb fiber, it is found that robust operation at 1018 nm can be achieved for a high Yb³⁺-ion excitation density greater than 11.5%, accompanied by high suppression of the feedback from the fiber's end facet. The Yb fiber laser constructed in house yields 626 W of continuous-wave output at 1018 nm for 729 W of incident pump power, corresponding to a slope efficiency of 86.6%. The prospect for power scaling is considered.

• Korean Journal of Veterinary Service
• /
• v.43 no.4
• /
• pp.201-209
• /
• 2020

In Korea, bovine tuberculosis (bTB) is a representative zoonotic disease that causes considerable economic loss. In determining the positive bTB, the ELISA method for examining the amount of interferon-gamma (IFN-γ) is included in Korea's diagnostic standard method. Recently, commercially available BIONOTE TB-Feron ELISA Plus (TB-Feron Plus) that detects IFN-γ has been introduced. However, since the scientific basis for the performance is limited, we evaluated performance by comparing it with the results of another IFN-γ ELISA assay kit (BOVIGAM®) certified by Office International des Epizooties. In our research, 42 positive blood samples preliminarily tested with a tuberculin skin test and/or BOVIGAM® and 54 negative blood samples collected from three bTB free farms were subjected to IFN-γ assay using the TB-Feron Plus and the BOVIGAM®, respectively. The result shows that the sensitivity, specificity and accuracy were 81.0% (34/42), 100% (54/54), 91.7% (88/96) in TB-Feron Plus kit and 78.6% (33/42), 100% (54/54), 90.6% (87/96) in BOVIGAM® kit, respectively. Moreover, the overall accordance percentage of the two kits was 99.0% (95/96) and there was almost perfect agreement between two assays (Kappa=0.977, P<0.0001). Furthermore, additional studies confirmed that elevated lymphocyte numbers in blood did not interfere with the results of the TB-Feron Plus kit. And, delayed time from sampling to culture decreased the optical density (OD) value. Therefore, we concluded that the TB-Feron Plus kit was not inferior to BOVIGAM® in performance. High lymphocyte numbers in blood did not impact on TB-Feron Plus results, while delayed time before culture interfered with OD value.