• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1749-1756
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• 2014

This study was performed to establish extraction conditions for useful components from sweet potato leaves. Extraction conditions were heating temperature ($40{\sim}60^{\circ}C$), ratio of solvent to sample (10~30 mL/g), and ethanol concentrations (50~90%). The maximum lutein content was $381.88{\mu}g/g$ under the following conditions: 81.23% ethanol concentration, $46.75^{\circ}C$ temperature, and 25.78 mL/g ratio of solvent. The maximum total polyphenol content was 58.44 mg GAE/g under 67.0%, $53.90^{\circ}C$, and 29.10 mL/g, whereas maximum total chlorophyll content was 769.14 mg/100 g under 93.10%, $69.90^{\circ}C$, and 25.98 mL/g, respectively. The highest antioxidant activity of electron-donating ability ($IC_{50}$) was 0.582 mg/mL under 64.56%, $54.63^{\circ}C$, and 19.57 mL/g, whereas total antioxidant activity was 32.54 mg AA eq/g under 64.42%, $44.51^{\circ}C$, and 26.01 mL/g, respectively. Under these conditions, experimental data matched well with the predicted data. Consequently, the present study was carried out to simulate and optimize sweet potato leaves for useful component extraction.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.227-234
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• 2002

In order to investigate the action mechanism of protein kinase C on $K^+$ channel in osteoblastic cell, effects of phorbol 12, 13-dibutyrate on human osteoblast-like cells (G292) were studied by patch clamp technique with cell-attacked configuration. 111 this experiment, 45pS ion channel was dominant in G292 cell line according to their approximate conductances in symmetrical 140mM KCl saline at holding potential of 60mV. In torrent-voltage relationship, reversal potential was 5.5mV at the condition of potassium enriched saline in the pipette and -27 mV at the condition of standard extracellular saline In the pipette. Phorbol 12, 13-dibutyrate 10nM increased the open probability of 45pS channel and staurosporine, an inhibitor of protein kinase C, suppressed this effect. Phorbol 12,13-dibutyrate moved the reversal potential of 45pS channel to more negative potential and increased the single channel current at the same membrame potential. In order to check the activation of protein kinase C in G292 cell by phorbol 12,13-dibutyrate, western blot of protein kinase C was performed. Phorbol 12,13-dibutyrate $0.1{\mu}M$ translocated protein kinase C from cellular compartment to membrane compartment of the cell. These findings suggest that phorbol 12,13-dibutyrate, one of phorbol esters, activate 45pS channel In G292 cell and affect cell membrane potential, that regulate cellular function.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1625-1632
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• 2005

This study was conducted to monitor the extraction yields and functional properties from cabbage by a response surface methodology. The extract yield was maximized as 44.47$\%$ under the temperature of 79.86$^{\circ}C$, ethanol concentration of 56.84$\%$ and solvent to sample ratio 25.58 mL/g . The maximum value of electron donating ability was 85.46$\%$ at 46.38$^{\circ}C$,57.06$\%$ of ethanol concentration and 27.71 mL/g of solvent to sample ratio. The maximum value of tyrosinase inhibitory effect was 69.37$\%$ at 37.5$^{\circ}C$,47.71$\%$ of ethanol concentration and 16.03 mL/g of solvent to sample ratio. The maximum value of SOD-like activity was 48.36$\%$ in 66.12$^{\circ}C$, 70.35$\%$ of ethanol concentration and 29.13 mL/g of solvent to sample ratio. Estimated conditions for the maximized extraction including yield, electron donating ability and SOD-like activity were 20 $\∼$ 30 mL/g in ratio of solvent to sample, 25$\∼$85$\%$ in ethanol concentration, and 40$\∼$90$^{\circ}C$ in extraction temperature.

• Journal of the Korean Mathematical Society
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• v.44 no.1
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• pp.211-235
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• 2007

In this paper, first we introduce the full expression of the curvature tensor of a real hypersurface M in complex two-plane Grass-mannians $G_2(\mathbb{C}^{m+2})$ from the equation of Gauss and derive a new formula for the Ricci tensor of M in $G_2(\mathbb{C}^{m+2})$. Next we prove that there do not exist any Hopf real hypersurfaces in complex two-plane Grassmannians $G_2(\mathbb{C}^{m+2})$ with parallel and commuting Ricci tensor. Finally we show that there do not exist any Einstein Hopf hypersurfaces in $G_2(\mathbb{C}^{m+2})$.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.141-146
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• 1992

A total of 197 fecal specimens was prepared for quantitative examination of helminth eggs by modified Kato's cellophane thick smear (M.C.T.S.) and Stoll's dilution egg counting technique (D.E,C.T.). The comparative effectiveness of two techniques was evaluated and conversion function was deduced. The average time required for the microscopic examination on one slide by M.C.T.S. was 12.6 minutes and that of D.E.C.T. was 14.6 minutes. M.C.T.S. showed lower false negative rate than D.E.C.T in light worm burden cases. Functions to convert the counts obtained by M.C.T.S. to E.P.G. by Stoll's dilution egg counting technique were $47.86{\times}10^{0.87{\;}logM.C.T.S.},{\;}$ in A. lumbricoides, $41.69{\times}10^{0.82{\;}logM.C.T.S.}$ in T. trichiura and $63.10{\times}10^{0.85{\;}logM.C.T.S.}$ in C. sinensis. It was suggested M.C.T.S. be better than D.E.C.T. for the quantitative examination of intestinal helminthiases such as A. lumbricoides, T. trichiura, and C. sinensis infections even in the cases with low worm burden.

• Food Science and Preservation
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• v.17 no.2
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• pp.281-289
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• 2010

We determined the optimum ethanolic conditions for extraction of $\gamma$-oryzanol and other functional components from rice bran, using response surface methodology (RSM). A central composite design was used to investigate the effects of the independent variables of solvent ratio ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables including yield ($Y_1$), total phenolic content ($Y_2$), electron-donating activity ($Y_3$), ferulic acid level ($Y_4$), and $\gamma$-oryzanol concentration ($Y_5$). Solvent ratio and extraction temperature were the most important factors in extraction. The maximum yield was at 22.56 mL/g ($X_1$), 78.19C ($X_2$), and 522.15 min ($X_3$), at the saddle point. Total phenolic levels were little affected by solvent ratio or extraction temperature. The maximum concentration of extracted total phenolics was 90.78mg GAE/100 g at 21.26 mL/g, $94.65^{\circ}C$, and 567.97 min. A maximum electron-donating ability of 54.72% was obtained with the parameters 20.20 mL/g,$81.89^{\circ}C$, and 701.87 min, at the highest point. The maximum level of ferulic acid components was 210.47 mg/100g at 5.22 mL/g, $79.66^{\circ}C$, and 575.24 min. In addition, the maximum $\gamma$-oryzanol concentration was 660.39 mg/100g at 5.10 mL/g, $81.83^{\circ}C$, and 587.39 min. The optimum extraction conditions were a solvent ratio of 10.45 mL/g, $80^{\circ}C$ extraction temperature, and 535 min extraction time. Predicted extraction levels under optimized conditions were in line with experimental values.

• Journal of Environmental Science International
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• v.8 no.5
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• pp.575-586
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• 1999

From the environmental aspects, primary productivity of phytoplankton plays the most improtant role in enhancement of marine culture oyster production. This study may be divided into two branches; one is estimation of maximum oyster meat production per unit facility(Carrying Capacity) under the present enviromental conditions in Kamak Bay, the other is improvement of carrying from increase of primary productivity by changing the environmental conditions that cause not ot form an unfavorable environment such as the formation of oxygen deficient water mass using the eco-hydrodynamic model. By simulation of three-dimensional hydrdynamic model and ecosystem model, the comparison between observed and computed data showed good agreement. The results of sensitivity analysis showed that phytoplankton maximum growth rate was the most important parameter for phytoplankton and dissolved oxygen. The estimation of mean primary productivity of Wonpo, Kamak, Pyongsa, and Kunnae culture grounds in Kamak Bay during culturing period were 3.73gC/$m^2$/d, 2.12gC/$m^2$/d, 1.98gC/$m^2$/d, and 1.26gC/$m^2$/d, respectively. Under condition not ot form the oxygen deficient water mass, four times increasing of pollutants loading as much as the present loading from river increased mean primary productivity of whole culture grounds to 4.02gC/$m^2$/d. Sediment N, P fluxes that allowed for 35% increasing from the present conditions increased mean primary productivity of whole culture grounds to 3.65gC/$m^2$/d. Finally, ten times increasing of boundary loadings from the present conditions increased mean primary productivity of whole culture grounds to 3.95gC/$m^2$/d. The maximum oyster meat production per year and that of unit facility in actual oyster culture grounds under the present conditions were 6,929ton and 0.93ton, respectively. This 0.93ton/unit facility is considered to be the carrying capacity in study area, and if the primary productivity is increased by changing the environmental conditions, oyster production can be increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.848-853
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• 2001

This research was conducted to study the effects on antigenicities (allergenicity) and structural changes of gamma-irradiated hen’s egg albumin (ovalbumin, OVA) by heating. Three groups of OVA solution (2.0 mg/mL) were prepared; 1) heat treatment; 2) irradiation after heating; 3) heating after irradiation. Samples were isothermally heated and/or irradiated at the absorption dose of 10 kGy. Competitive indirect ELISA was individually formatted with egg-allergic patients IgE (P-IgE), and mouse murine monoclonal IgG (M-IgG) and rabbit polyclonal IgG (R-IgG) for evaluating bindinhg abilities of antibodies to OVA in the sample solutions. Binding abilities of antibodies to thermally denatured OVA were changed : R-IgG to the sample treated with above 6$0^{\circ}C$, M-IgG to that above 7$0^{\circ}C$, and P-IgE to that above 8$0^{\circ}C$, respectively. P-IgE did not well recognize OVA heated at 8$0^{\circ}C$ and the above. However, binding abilities of M-IgG and R-IgG highly in creased. Significant differences of binding abilities were not observed in all samples with the combination of heat treatment and irradiation, regardless the order of the treatment. Turbidity of samples in creased both by heating and by irradiation, and the increase by irradiation was much higher than by heating. These results showed that allergenicity of OVA reduced by gamma irradiation was not affected by heating.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.173-181
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• 2015

Fluxes of carbon dioxide ($CO_2$) were measured above crop canopy using the Eddy Covariance (EC) method, and emission rate of methane ($CH_4$) was measured using Automatic Open/Close Chamber (AOCC) method during the 2012-2013 barley and rice growing season in a barley-rice double cropping field of Gimje, Korea. The net ecosystem exchange (NEE) of $CO_2$ in the paddy field was analyzed to be affected by crop growth (biomass, LAI, etc.) and environment (air temperature, solar radiation, etc.) factors. On the other hand, the emission rate of $CH_4$ was estimated to be affected by water management (soil condition). NEE of $CO_2$ in barley, rice and fallow period was -100.2, -374.1 and $+41.2g\;C\;m^{-2}$, respectively, and $CH_4$ emission in barley and rice period was 0.2 and $17.3g\;C\;m^{-2}$, respectively. When considering only $CO_2$, the barley-rice double cropping ecosystem was estimated as a carbon sink ($-433.0g\;C\;m^{-2}$). However, after considering the harvested crop biomass ($+600.3g\;C\;m^{-2}$) and $CH_4$ emission ($+17.5g\;C\;m^{-2}$), it turned into a carbon source ($+184.7g\;C\;m^{-2}$).

• Development and Reproduction
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• v.14 no.1
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• pp.13-19
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• 2010

We developed a novel dicistronic system for the expression of target cDNA sequences in the milk of transgenic animals using goat beta-casein/hGH fusion construct, pGbc5.5hGH (Lee, 2006) and internal ribosome entry site (IRES) sequences of encephalomyocarditis virus (EMCV). Granulocyte colony-stimulating factor (hG-CSF) cDNA was linked to 3' untranslated region of hGH gene in the pGbc5.5hGH via EMCV IRES sequences. Transgenic mice were generated by microinjection and transgene expression was examined in the milk and mammary gland of transgenic mice at 10 days of lactation. Northern blot analysis showed that hGH gene and hG-CSF cDNA were transcribed as a single dicistronic mRNA. The hG-CSF and hGH proteins were independently translated from the dicistronic mRNA and secreted into the milk of transgenic mice. The highest concentration of hG-CSF and hGH in the milk of transgenic mice were $237{\mu}g/m{\ell}$ and $8,990{\mu}g/m{\ell}$, respectively. In contrast, another hG-CSF expression cassette, in which hG-CSF genomic sequences were inserted into a commercial milk-specific expression vector (pBC1), generated a lower level ($91{\mu}g/m{\ell}$) of hG-CSF expression in the milk of transgenic mice. These results demonstrated that the novel pGbc5.5hGH-based dicistronic construct could be useful for an efficient cDNA expression in the milk of transgenic animals.