• Journal of Life Science
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• v.22 no.1
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• pp.126-131
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• 2012

Physiological activities of hot water (BRW) and 80% ethanol (BRE) extracts from brown rice were investigated in this study. The highest activity (94.9%) of nitrite reductase was observed for BRE at 1 mg/ml at pH 1.2, while the activity for BRW was about 75.4% under the same conditions. The inhibitory effects of BRW and BRE on xanthine oxidase activity were about 39.0 and 72.9% at 10 mg/ml, respectively. The digestibility of starch was lower for brown rice than for milled rice and the highest inhibition (93.1%) of ${\alpha}$-glucosidase activity occurred with BRE. Superoxide dismutase (SOD)-like activities of BRW and BRE were weakly increased in a dose-dependent manner and were about 56.4 and 44.9% at 10 mg/ml, respectively. The influences of BRW and BRE on alcohol metabolizing activity were determined by measuring the generation of reduced nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). Increases in ADH and ALDH activities were only detected with BRE.

• Applied Microscopy
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• v.17 no.1
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• pp.47-64
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• 1987

Morphological difference of the renal glomerulus at different age groups have been studied in young (three month-old), adult (twelve month-old) and old (thirty month-old) Fisher strain 344 rats. Pieces of the tissues were taken from renal corticies prefixed with 2.5% glutaraldehyde-1.5% paraformaldehyde (0.1 M Millonig's phosphate buffer, pH 7.3), following by post-fixation with 1% osmium tetroxide (0.1 M Millonig's phosphate buffer, pH 7.3) and embedded within Araldite. The ultrathin sections contrasted with uranyl acetate and lead citrate were observed under a JEM 100CX electron microscope. The mean thickness of glomerular basal lamina and Bowman's capsule were determined by measuring the thinnest portion of basal lamina, and by taking the average of 50 readings from electron micrographs at different ages. The numerical changes of the slit pores were compared based upon the numbers over the length of 10um of glomerular basal lamina. The results were as follow: 1. The thickness of glomerular basal lamina is increased during aging; 140.4 nm in young rats, 270.0 nm in adult ones, and 437.8 nm in old ones. 2. The thickness of basal lamina of parietal cells of Bowman's capsule is 187.5 nm in young rats, 914.0 nm in adult ones, and 2850.0 nm in old ones. 3. The numbers of the slit pores of basal lamina are reduced during aging, 30.3 slit pores/$10{\mu}m$ in adult ones, and 24.2 slit pores/$10{\mu}m$ in old ones. 4. Accumulation of dense intracytoplasmic filamentous material in the parietal cells of Bowman's capsule is increased in the vicinity of the basal lamina during aging. The proximal tubule-like epithelial cell in Bowman's capsule is observed at one glomerulus in a young rat. 5. The endothelial cells are edematous and form balloon-like structure protruding into capillary lumen in young and old rats. 6. Cytoplasm of the podocyte shows a variety of alteration during aging, such as swelling of mitochondria and of endoplasmic reticulum, and increase of microtubules, microfilaments, lysosomes and lamellated myelin structures, etc. Accumulation of dense intracytoplasmic material in the foot processes is increased in the vicinity of the basal lamina during aging. The podocytic membrane-like structures are seen in young and o]d rats. 7. The mesangial matrices and mesangial cells are increased during aging, and slight swelling of endoplasmic reticulum and Golgi cisternae in young and old rats.

• Culinary science and hospitality research
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• v.19 no.2
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• pp.40-51
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• 2013

In this study, frozen mulberries were dried with the methods of freeze-drying and hot-air drying and powdered to make healthy functional bagels by adding 0% (control), 1%, 3%, 5%, and 7% of mulberry powder. After measuring the general ingredients, physiochemical property, total polyphenol content and DPPH radical scavenging of frozen mulberries, the physiochemical property test and sensory test of manufactured bagels were carried out. The pH of the bagels appeared to be higher in the group with the addition of hot-air dried mulberry powder than in the group with the addition of freeze-dried mulberry powder. Luminosity (value L) and yellowness index (value b) appeared to be higher in the group with the addition of hot-air dried mulberry powder than in the group with the addition of freeze-dried mulberry powder. Redness index (value a) appeared to be higher when freeze-dried mulberry powder was added than when hot-air dried mulberry powder was added. Hardness showed a significant difference in the group with the addition of freeze-dried mulberry powder while the group with the addition of hot-air dried mulberry powder showed the opposite result. Elasticity did not have any significant difference in the group with the addition of hot-air dried mulberry powder while it showed a significant difference in the group with the addition of freeze-dried mulberry powder. Cohesiveness did not show any significant difference and gumminess showed the tendency of decrease as the added quantity of freeze-dried mulberry powder and hot-air dried mulberry powder increased. The preference of the group with the addition of 5% freeze-dried mulberry powder and the group with the addition of 3% hot-air dried mulberry powder appeared to be the highest.

• Journal of the Korean Electrochemical Society
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• v.14 no.3
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• pp.131-137
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• 2011

A simple and rapid electrochemical method for the quantitative analysis of $Mn^{2+}$ ion is demonstrated with a view to examine the $Mn^{2+}$ dissolution behavior of $LiMn_2O_4$. The method described herein is based on the oxidation reaction of $Mn^{2+}$ to $Mn^{4+}(MnO_2)$ in aqueous buffer solution. Under the optimum condition (pH 8.9 0.04 M $NH_3-NH_4Cl$ buffer solution and glassy carbon working electrode), the linear range of $5{\mu}M-100{\mu}M$ (0.275-5.5 ppm) [$Mn^{2+}$] is obtained for the Linear sweep voltammetry(LSV) and $0.2{\mu}M-10{\mu}M$ (0.011-0.55 ppm) [$Mn^{2+}$] for the differential pulse voltammetry (DPV), respectively. It is also noted that the oxidation reaction of $Mn^{2+}$ ion is reduced with increasing amount of the electrolyte ($LiPF_6$, EC, EMC) added to the measuring solution, which is found to be mainly due to $LiPF_6$ and EC rather than EMC.

• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.31-38
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• 1998

Multi-channel sensors can be used to increase the reliability and remove the random iloise in ion-sensitive field effect transistors(ISFETs). Multi-channel sensors is also an essential step toward potential fabrication of sensors for several ionic species in one device. However, when the multi-channel sensors are separately biased, the biasing problems become difficult, that is to say, the bias circuit is needed as many sensors. In this work, a circuit for biasing the four pH-ISFETs in null-balance method, where bias voltages are switched, was proposed. The proposed concept is need only one bias circuit for the four sensors. Therefore it has advantages of smaller size and lower power consumption than the case that all sensors are separately biased at a time. The proposed circuit was tested with discrete devices and its performance was investigated. In the recent trend, sensor systems are implemented as portable systems. So the verified measurement circuit was integrated by using the CMOS circuit. Fortunately, ISFET fabrication process can be compatible with CMOS process. Full circuit has a mask area of $660{\mu}m{\times}500{\mu}m$. In the future, this step will be used for developing the smart sensor system with ISFET.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.417-426
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• 1997

Rice bran protein hydrolysates were prepared and some of their physicochemical properties were investigated to utilize rice bran as starting material for functional food ingredient. Rice bran proteins (RBP) were prepared from defatted rice bran by alkaline extraction and isoelectric precipitation. The enzyme for hydrolysis of RBP was selected through measuring relative activity by pH-drop method and comparing the degree of hydrolysis (DH) of hydrolysates. The enzymatic hydrolysates prepared by $Esperase^{\circledR}$ treatment were partitioned into two fractions by ultrafiltration(UF) with a 10 kDa molecular weight cut-off membrane. Each fraction was applied to a cholic acid-conjugated ${\omega}-aminohexyl$ Sepharose 4B column and the bile acid-binding components were obtained by eluting with deoxycholate. Gel permeation chromatography on a Sephadex G-50 column revealed that molecular weight of the bile acid-binding fraction of UF permeate was distributed in ranges of $2\;kDa{\sim}10\;kDa$ and $0.2\;kDa{\sim}0.6\;kDa$. Three peaks (R-1, R-2 and R-3) were obtained by prep-HPLC of bile acid-binding fraction of UF retentate and analyzed for total and free amino acid composition. The results showed that proline content of the bile-acid binding polypeptides and peptides was four times as much as that of rice bran protein and that the peak corresponding to higher average hydrophobicity had a higher free amino acid content. Average hydrophobicity slightly increased with enzymatic hydrolysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.961-966
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• 2006

This study was worked out to investigate antioxidant activity of solvent extracts from wild grape skin by measuring electron donating ability (EDA), reducing power, superoxide dismutase (SOD)-like activity, thiobarbituric acid reactive substances (TBARS) and nitrite scavenging ability. Total phenolic compound and flavonoids contents were the highest in ethyl acetate extract, $54.4{\pm}1.18\;mg/100\;g$ and $645.1{\pm}5.05\;mg/100\;g$, respectively. The EDA and reducing power of solvent extracts from wild grape skin were proportionally increased with concentration and ethyl acetate extract $(79.2{\pm}0.06%)$ showed the stronger than BHT $(74.1{\pm}0.15%)$ at concentration of $100\;{\mu}g/mL$, especially. SOD-like ability of ethyl acetate $(25.1{\pm}0.41%)$ and butanol $(20.2{\pm}0.13%)$ extracts were stronger than other extracts at concentration of $100\;{\mu}g/mL$. TBARS of ethyl acetate extract was higher than ascorbic acid. Nitrite scavenging ability of solvent extracts from wild grape skin (pH 2.5, $1000\;{\mu}g/mL$) were in order of ethyl acetate $(90.5{\pm}0.75%)$>butanol $(65.9{\pm}2.16%)$>hexane $(58.1{\pm}1.74%)$>chloroform $(55.4{\pm}1.02%)$>water $(40.9{\pm}0.35%)$. Antioxidant activity of solvent extracts from wild grape skin was the highest in ethyl acetate extract from the results of our experiments.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.43-52
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• 2000

A portion of mitochondria1 COI gene (438 bp) was sequenced from the sampls of Plutella xylostella from four localities in Korea to investigate the population genetic structure and characteristics by measuring the magnitude of genetic diversity and the degree of gene flow among populations. Thirteen haplotypes ranging in nucleotide divergence 0.3% to 1.4%, were obtained from 21 individuals. The nucleotide divergence was similar to the other related studies, but haplotype diversity was substantially higher (mean h = 0.81). The genetic distance among geographically remote Cheju Island population and the two Kimhae populations, distant 1 lkm to each other, was not statistically significant (p<0.05). Instead, a substantial or high female gene flow was detected (Nm = 2-30). One Hawaiian haplotype of the diamondback moth obtained through GenBank search also was genetically similar to the ones obtained from this study. Collectively, the genetic population structure of the diamondback moth in Korea can be characterized into two aspects. First, the diamondback moths in Korea possesses overall moderate genetic divergence based on a high number of haplotypes. Second, a high haplotype diversity within each population due to the long distance dispersal with a substantial dispersal power and the resultant genetic similarity among geographic populations is characteristic.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.205-213
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• 2013

This study was to improve cosmetical activity of thiamine di-lauryl sulfate (TDS) by encapsulation of nanoparticle with lecithin. Results showed that most of the nanoparticles containing the TDS were well formed in round shape with below 150 ~ 200 nm diameter as well as they were fairly stable in various pH ranges by measuring zeta potentials. The nanoparticles of TDS resulted in 85% cell viability of human normal fibroblast cells (CCD-986sk) when added at the highest concentration (1.0 mg/mL). The nanoparticles of Acer mono sap showed highest free radical scavengering effect as 88.1% in adding sample (1.0 mg/mL), compared to TDS solution of non-encapsulation (81.6%). The nanoparticles of TDS reduced the expression of MMP-1 on UV-irradiated CCD-986sk cells down to as 41.4%. The TDS solution and nanoparticles showed significant anti-microbial activities agaionst the salmonella typhimurium and listeria monocytogenes at 5 and 6 days as compared with control. Anti-microbial activities of TDS nanoparticles were similar to positive control. These results indicated that TDS nanoparticles may be a source for functional cosmetic agents capable of improving cosmetical activity such as antioxidant, whitening, and anti-wrinkling effects and can be further developed as natural preservative in cosmetics.

• Journal of the Korean Chemical Society
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• v.37 no.3
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• pp.327-333
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• 1993

A method was developed for the determination of trace elements in seawater by precipitate flotation preconcentration and subsequent flame atomic absorption detection. In order to quantitatively coprecipitate trace ions such as Cd(II), CuI(II), Fe(III), Mn(II), Pb(II) and Pd(II), 2.0 ml of 1.0M cerium(III) solution was added to 1.0l of seawater and the pH was adjusted to 9.5 with 5.0 M sodium hydroxide solution while stirring with a magnetic stirrer. The precipitate was floated with the aid of surfactant solution (1.0 ml of 0.3% sodium oleate) by bubbling nitrogen gas through a porous (No. 4) fritted glass disk. The floats was collected in a small Erlenmeyer flask by suction. The washed precipitate was dissolved in 8.0 M nitric acid and marked with deionized water in the volumetric flask of 10.0 ml. The analyte was determined by measuring the atomic absorbances in 100-fold concentrated solution. Above all analytes in Kangnung (East Sea) and Kanghwado (West Sea) sea waters were found to be under the detection limit of this method. The recoveries of over 92% for all analytes spiked into seawater samples showed that this method was applicable to the analysis of real seawater.