• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.20-24
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• 2007

The effects of phenolic acids on inhibition of browning by the Maillard reaction were investigated with a glucose-glutamic acid model for doenjang with citric acid as the antibrowning agent and phenolic acid as its synergist. Five phenolic acids, cinnamic, coumaric, caffeic, hydroxybenzoic, and protocatechuic acids, were used. In order to investigate the antibrowning capacity, 0.1M glucose, 0.1M glutamic acid, 50mM citric acid, and 1mM phenolic acid were dissolved in 1M phosphate buffer (pH 7.0), heated at $50^{\circ}C$ for 24hr in the presence of 0.2mM $FeCl_{2}$, and stored at $4^{\circ}C$ or $30^{\circ}C$ for four weeks. Phenolic acid addition more efficiently inhibited browning during storage at $30^{\circ}C$ than at $4^{\circ}C$, without changes in pH. Hydroxybenzoic acid was the most efficient and increased the antibrowning capacity by 13% compared to sample without phenolic acids. Although caffeic and protocatechuic acids inhibited most the formation of 3-deoxyglucosone or fluorescence, they increased browning by forming colored complexes between two hydroxy groups of phenolic acids and iron ions. Hydroxybenzoic acid will be able to be a useful synergist of citric acid, an antibrowning agent in doenjang, since it is permitted for doenjang.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.49-54
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• 2014

Background: Hydrogels are a class of polymers that can absorb water or biological fluids and swell to several times their dry volume, dependent on changes in the external environment. In recent years, hydrogels and hydrogel nanocomposites have found a variety of biomedical applications, including drug delivery and cancer treatment. The incorporation of nanoparticulates into a hydrogel matrix can result in unique material characteristics such as enhanced mechanical properties, swelling response, and capability of remote controlled actuation. Materials and Methods: In this work, synthesis of hydrogel nanocomposites containing magnetic nanoparticles are studied. At first, magnetic nanoparticles ($Fe_3O_4$) with an average size 10 nm were prepared. At second approach, thermo and pH-sensitive poly (N-isopropylacrylamide -co-methacrylic acid-co-vinyl pyrrolidone) (NIPAAm-MAA-VP) were prepared. Swelling behavior of co-polymer was studied in buffer solutions with different pH values (pH=5.8, pH=7.4) at $37^{\circ}C$. Magnetic iron oxide nanoparticles ($Fe_3O_4$) and doxorubicin were incorporated into copolymer and drug loading was studied. The release of drug, carried out at different pH and temperatures. Finally, chemical composition, magnetic properties and morphology of doxorubicin-loaded magnetic hydrogel nanocomposites were analyzed by FT- IR, vibrating sample magnetometry (VSM), scanning electron microscopy (SEM). Results: The results indicated that drug loading efficiency was increased by increasing the drug ratio to polymer. Doxorubicin was released more at $40^{\circ}C$ and in acidic pH compared to that $37^{\circ}C$ and basic pH. Conclusions: This study suggested that the poly (NIPAAm-MAA-VP) magnetic hydrogel nanocomposite could be an effective carrier for targeting drug delivery systems of anti-cancer drugs due to its temperature sensitive properties.

• Conservation Science in Museum
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• v.17
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• pp.69-84
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• 2016

Yuso is the term for decorative tassels of a braided string which hangs a scroll painting. This study, drawing on extant research concerning the yuso made for Joseon period portrait scrolls of kings and meritorious retainers, focuses on the yuso created to hang literati portraits. Concretely, It examines yuso of seven portraits in the collection of the National Museum of Korea in order to characterize their appearance and determine their material composition. The study found that most of the yuso are sixteen-strand strings braided into a rounded cross-section(dongdahoe). The seven yuso, of which six are red and one indigo-blue, reflect the popular style associated with Joseon period literati portraits. The yuso for the portrait of Yun Geup(duksu 3503) is made from gilded paper. Analysis showed Fe particles present in a red pigment underlying the gold layer, suggesting the presence of red ochre(seokganju), an iron oxide mineral. The yuso of the portrait of Shin Im(duksu 4846) is used a paper which contains gold as well as traces of Pb, Hg and Ag. The paper in the yuso for the portrait of Yi Seongwon(bongwan 10122) mainly consisted of Ag, indicating silver paper having been used in its fabrication. The inner paper in the yuso of the portrait of Yi Seogu(sinsu 1065) is a leather combined with Ag, Fe, and Br, according to chemical analysis. The FTIR of the leather sample reveals that the spectrum in the fingerprint region is nearly identical to that of sheepskin, indicating the yuso was made from gold-coated sheepskin.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.923-928
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• 1993

The series of solid solutions in the $Sr_{1+x}Ho_{1-x}FeO_{4-y}$ (x = 0.00, 0.25, 0.50, 0.75 and 1.00) systems with $K_2NiF_4$ type structure have been prepared at 1550$^{\circ}$C under an atmospheric air pressure. The X-ray powder diffraction spectra of these samples assign that the crystallographic phases are tetragonal system over the whole x range. The lattice volume was increased with increasing the substitution amount of the $Sr^{2+}$ ion. The mole ratio of the $Fe^{4+}$ ion to total iron ions or ${\tau}$ value has been determined by Mohr salt titration of the sample and then the y value was calculated from x and ${\tau}$ values. The ${\tau}$ and y values have been increased with x values. The nonstoichiometric chemical formula are formulated from the general formula of $Sr_{1+x}Ho_{1-x}Fe^3_{1-}\;^+_{\tau}Fe_{\tau}^{4+}O_{4-y}$ replaced by x,${\tau}$ and y values. Mossbauer spectra show the mixed valence state and coordination state of $Fe^{3+}\;and\;Fe^{4+}$ ions. It is found out that the magnetic property of the samples is paramagnetic at room temperature. Electrical conductivity varied within the semiconductivity range of 1.0 to 1 ${\times}\;10^{-9}{\Omega}^{-1}cm^{-1}$. Activation energy of the electrical conductivity was decreased with the $\tau$ value. The conduction mechanism should be explained by the hopping model of the conduction electrons between the valence states of $Fe^{3+}\;and\;Fe^{4+}$ ions.

• Journal of Nutrition and Health
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• v.40 no.sup
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• pp.9-21
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• 2007

This study aimed to assess the total sugar intake for Korean and to identify major food sources contributing to those food components. Korean adults aged over 20 years old from the Korean National Health and Nutrition Examination Survey (KNHANES) 2001 and 2002 were selected. The data were analyzed to obtain nationally and seasonally representative information on the health and nutritional status of the Korean. Forty food groups were used in identifying food sources of total sugar and energy intake. Total sugar contents of foods in the KNHANES data sets were estimated by food code matching technique with Release 18 of the USDA National Nutrient Database for Standard Reference. Sample weighted means, standard errors, and population percentages were calculated using SAS and SUDAAN. The mean total sugar intake of the Korean was 60.3g in 2001, 40.9g in spring 2002, 45.7g in summer 2002, and 52.1g in fall 2002, which were 30-44% of intake of US people. Fresh fruit was identified as the most significant food source for total sugar intake in Korean population in all age groups and all seasons. The next major food sources following fresh fruits were candy/jelly/syrup/honey, coffee/coffee caream, vegetables, Kimchi, soft drinks, milk, fruit juice, cookie/cracker/cake, and vegetable juice/grain juice, which showed similar results through the seasons. While carbonated soft drink was the most significant food sources for total sugar or added sugar intakes for US people. The total sugar intakes were significantly higher in women, higher educational level, and residing in metropolitan area. As intake of total sugar increased, intakes of protein, fiber, calcium, phosphorus, iron, Vit A, B1, B2, C, niacin showed significantly increased, while high intakes of added sugars showed low intakes of some micronutrients in the US people. Percentages of people who consumed nutrients below EAR were less in higher total sugar intake group than in lower intake group. From these results, we can conclude that the food consumption habits including the total sugar intake of Korean people seems relatively good so far. More reliable database of total sugar and added sugar composition tables in public domain should be established in the future, and also more researches about total sugar and added sugar for Koreans should be continued.

• Analytical Science and Technology
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• v.24 no.3
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• pp.168-172
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• 2011

The iron frame of building could be collapsed or bent at $500^{\circ}C$. Therefore the fire-resistant paint should be applied for safety. This study performed the comparative analysis to show the characteristics of fireresistant paint. And then 12 products of fire resistant paint and 6 products of paints were used as samples. And the samples were analyzed by TGA (Thermogravimetric Analyzer) as analyzer for measuring the variation of weight on temper of weight by heating. When TGA analyzer could measure the variatiature, and FT-IR was measured for analyze gas components on variation on of weight by heating on 12 products of fire resistance, the samples showed to decrease 40% of weight to $800^{\circ}C$, and because paints had 50% to 40% of loss weight, it showed to be equal with loss weight of fire resistance paint on high temperature or was lower loss weight than it of fire resistance paints. However number 6 sample of fire resistance paints could show to decrease 20% of total weight on $800^{\circ}C$. And then in the case of FT-IR, fire resistance paints could show to have the high intensity of $CO_2$ spectrum as complete combustion. However paints could show to have the lower intensity of $CO_2$ spectrum, have the higher intensity of water spectrum. Therefore the TGA graph of result could be much different until $250^{\circ}C$. When it was burned, FT-IR spectrum could show to confirm the characteristics of fire resistance paints, and the characteristic could be confirmed on inorganic paint of fire resistance by weight loss of TGA.

• Journal of Life Science
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• v.23 no.1
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• pp.31-37
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• 2013

The present study aimed to investigate effects of ethanol extracts from Hydropsyche kozhantschikovi on cell and DNA damage caused by oxidative stress. In a radical scavenging assay, compared with ascorbic acid used as a control, the level of DPPH (1,1-diphenyl-2-picrylhydrazyl) and that of hydroxyl radicals in H. kozhantschikovi extracts were 60.0% and 43.7%, respectively. The ferrous iron chelating level was 37.5% compared to the chelating value of EDTA (ethylenediaminetetraacetic acid) as a positive control at the same concentration. To verify inhibitory effects of oxidative cell damage induced by reactive oxygen species (ROS), the relative level of lipid peroxidation and the expression level of the p21 protein were compared in extracts-treated and untreated groups. Lipid peroxidation was completely inhibited in the extracts-treated group compared with the radical-only treated group. The level of p21 protein expression was restored to 92.2% of p21 protein expression in the control sample. In addition, DNA cleavage inhibition in the H. kozhantschikovi extracts was 74.1% compared with that of the control group, suggesting that H. kozhantschikovi extracts repress DNA cleavage induced by ROS. Moreover, the phosphorylation ratio of the H2AX protein was 16.7% in the radical-treated group, indicating that the ethanol extracts inhibited 83.3% of DNA damage. Our findings suggest that ethanol extracts from H. kozhantschikovi are effective not only in repressing the oxidation of free radicals and highly toxic hydroxyl radicals, but also in decreasing cell and DNA damage caused by oxidative stress.

• 보존과학연구
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• s.33
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• pp.109-124
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• 2012

Jangan-eup, located in Busan, South Korea,is a famous pottery-producing area in the Joseon Dynasty period. The aim of this paper was to determine the correlation of the pottery from each kiln site of Jangan-eup by analyzing the ingredients of clay as well as its production technique and firing condition. The materials that were used for the study were fragments of inlaid celadon, white porcelain, and white porcelain painted with underglazed iron excavated from six kiln sites of Jangan-eup:Sil-li, Daeryong-li, Hajangan-li, Sangjangan-li, Yongso-li, and Dumyeong-li. In each of the samples from the six kilns, cristobalite, mullite, and quats were found. The firing temperature distinguished from the crystal structure was higher in the following order: Dumyeongli>Sangjangan-li>Daeryong-li>Hajangan-li>Yongso-li>Sil-li. The samples were divided into four groups based on the ingredients of the clayfound therein: the Sil-li andDaeryong-li group, the Hajangan-li and Sangjangan-li group, the Yongso-li group, and the Dumyeong-li group. It was also found that the sample of Dumyeong-li was made using the most homogeneous clay compared with the other samples. The pottery of Jangan-eup had $40-400{\mu}m$ glaze, had bubbles in their bodies, and had $10-150{\mu}m$ sizes.

• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.173-182
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• 2018

The precipitation and phase transformation processes of iron minerals in acid mine drainage have a great influence on the behavior of trace elements in drainage. However, it is not easy to accurately trace these processes in natural environments, and therefore, most studies have carried out in the laboratory to obtain the information on the precipitation and transformation of those minerals. In this study, the precipitation of minerals and the changes of trace elements in drainage water were investigated at different pH values in actual acid mine drainage collected from the Dalsung mine. The amount of some precipitated minerals was not enough for the mineral identification. However, from the minerals identified, amorphous minerals were formed first, and then goethite was precipitated probably from schwertmannite. When the pH of the sample was high (10), amorphous phases of minerals were still observed at even high pH (pH 10). With increasing time, the pH values decreased by precipitation and transformation of minerals. All the elements showed low concentrations at high pH (8, 10), which might be due to the precipitation of minerals at high pH and the effect of surface charge, and the concentrations of elements gradually increased with time. In the case of sulfur, it also increased in water due to the transformation of schwertmannite to goethite.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1426-1431
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• 2004

This study was performed to investigate the antioxidative effect of ethanol extracts of 5 spices. They were separately extracted in ethanol from dried samples at room temperature, and freeze-dried. In vitro testing were conducted by DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity, inhibition of iron-induced linoleate peroxidation and the inhibition of malondialdehyde (MDA) and bovine serum albumin (BSA) conjugation reaction. The ethanol extracts of clove (92.9%) and cinnamon (89.9%) showed the most effective results among five spices in the DPPH radical scavenging capacities. The inhibition rate of ethanol extract of clove on the lipid peroxidation was 55.8%. The ethanol extracts of mustard, wasabi and black pepper were effective in the inhibition of MDA and BSA conjugation reaction showing 73.2%, 72.2% and 61.6%, respectively. These results suggest that five spices tested in this study may enhance the antioxidative capacity, although the results were different according to the assay method and sample.