• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.105-112
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• 2011

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of thirteen kinds of natural plant pigments. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging and nitrite scavenging ability activity. The free radical scavenging activity by method using stable free radical DPPH was the highest in the red cabbaged pigment. Addition of ethanol extract 1mg/ml from onion peel pigment displayed remarkable effect on nitrite scavenging ability about 91.9%. Antioxidative enzyme activity was evaluated in terms of superoxide dismutase(SOD), catalase(CAT), and ascorbate peroxidase(APX) activity. The bitter melon pigment had the highest SOD activity of 87.3%. The activities of CAT and APX were higher in the mulberry leave pigment compared with other natural plant pigments. In contrast, CAT activity of plant pigment samples were unaffected. These results suggest that natural plant pigment had the potent biological activities such as antioxidant enzyme activities, and that their activities exhibited differently depending on each kind of pigments.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.69-76
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• 2016

Purpose: The study was conducted to determine that photoreceptors of mouse having pigment in RPE(retinal pigment epithelium) can be damaged by blue-light and apoptosis of specific cells among photoreceptors are induced by blue-light, and to assist the investigation of AMD(Age-related macular degeneration) mechanisms and development of AMD drugs. Methods: C57Black mice were injured by irradiating $2800{\pm}10lux$ of 463 nm LED for 6 hours after 24 hours dark adaptation and eyes were enucleated 1, 3, 7 days. Damage of retina induced by blue-light was determined by western blotting GFAP(Glial fibrillary acidic protein) expression. In the light-injured retina, cell death of photoreceptors was determined by TUNEL(Terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. ERK(Extracellular signal-regulated kinases), JNK, and SRC(sarcoma) expression were assessed by western blotting to determine regulated pathway. Blue light-injured retina were immunostained with antibodies against Opsin and Rhodopsin as markers of photoreceptors to compared the damage cone cells with rod cells. Results: After 1, 3 and 7 days from exposure to blue-light, thickness of retina was more decreased than control, and more decreased at nuclear layer than at outer plexiform layer and GFAP expression was increased day 1 after blue-light injured. While phosphorylated ERK and SRC protein expressions at day 1 were increased after blue-light injured, phosphorylated c-JUN was decreased. Fluorescence intensity analysis showed that markers of cone and rod cells were decreased after blue-light injured and Opsin was more decreased than Rhodopsin. Conclusions: The study suggests possibilities that the blue-light promotes retinal damage and causes apoptotic cell death via ERK and SRC pathway in mouse retina, and blue-light retinal damage is more induced cone cells apoptosis than rod cells directly.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.36-43
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• 2003

This study was carried out to evaluate the fungicidal, anti-sapstain and termiticidal efficacy of commercial Dan-Chung which are currently being used for painting to decorate and to provide durability with structures of temples. Two binders (Polysol and Gelatine), and eleven pigments (Iron Oxide Red, Lead Red, Toluidine Red, Chrome Yellow, Titanium Dioxide, Ultramarine Blue, Chrome Oxide Green, Permanent Black, Cyanine Green and Ho-bun(Chalk)) were applied for the evaluation. The fungicidal and anti-sapstain activity of each pigment were depended on the types of binders. When the Polysol was used as a binder, the fungicidal efficacy of Toluidine Red treated specimen was close to the standard value (above 80) with grater than 70 against to two wood decay fungi (T. palustris and T. versicolor). The anti-sapstain efficacy of Lead Red treated specimens was excellent against to three sapstain fungi (P. funiculosum, T. viride and R. nigricans), and that of Ultramarine Blue treated specimens was also excellent to T. viride. The other pigments had little efficacy to these micro-organisms. Although there were some different trends of the effectiveness depending on the types of binders, the anti-termite effectiveness of Chrome Oxide Green and Chrome Yellow was outstanding to termite tests.

• Korean Journal of Materials Research
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• v.24 no.7
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• pp.370-374
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• 2014

Inorganic pigments have high thermal stability and chemical resistance at high temperature. For these reasons, they are used in clay, paints, plastic, polymers, colored glass and ceramics. $CoAl_2O_4$ nano-powder was synthesized by reverse-micelle processing the mixed precursor(consisting of $Co(NO_3)_2$ and $Al(NO_3)_3$). The $CoAl_2O_4$ was prepared by mixing an aqueous solution at a Co:Al molar ratio of 1:2. The average particle size, and the particle-size distribution, of the powders synthesized by heat treatment (at 900; 1,000; 1,100; and $1,200^{\circ}C$ for 2h) were in the range of 10-20 nm and narrow, respectively. The average size of the synthesized nano-particles increased with increasing water-to-surfactant molar ratio. The synthesized $CoAl_2O_4$ powders were characterized by X-ray diffraction analysis(XRD), field-emission scanning electron microscopy(FE-SEM) and color spectrophotometry. The intensity of X-ray diffraction of the synthesized $CoAl_2O_4$ powder, increased with increasing heating temperature. As the heating temperature increased, crystal-size of the synthesized powder particles increased. As the R-value(water/surfactant) and heating temperature increased, the color of the inorganic pigments changed from dark blue-green to cerulean blue.

• Conservation Science in Museum
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• v.28
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• pp.109-136
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• 2022

This study analyzes the , one of the three panels of 《Welcoming Banquets for the Governor of Pyeong-an》, a documentary painting of the late Joseon Dynasty, with the aim to identify the coloring materials used in the painting. The painting was first imaged at each wavelength in order to minimize the potential problems in the process of analyzing specific parts. This study applied X-rays to identify ink, gold, and organic and inorganic pigments and used infrared rays to find ink and copper-based pigments. It also applied hyperspectral imaging to distinguish organic pigments from black, blue, and green materials. It also analyzed spots selected for each color to identify the following materials: white lead (white), ink/indigo (black), a combination of red lead and cinnabar (red), pink dye, purple dye, iron oxides (brown), orpiment/dye (yellow), malachite/malachite and yellow dye/indigo (green), azurite/white lead and indigo/indigo (blue), indigo and cochineal (violet), and gold leaf (gold). It is expected that more efficient analysis will be made possible by securing a sufficient library for each wavelength.

• Korean Journal of Materials Research
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• v.23 no.5
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• pp.271-275
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• 2013

Cobalt (Co) compounds have been used for centuries to impart rich blue color to glass, glazes and ceramics. Cobalt monoxide (CoO), an oxide of Co, is an inorganic compound that has long been used as a coloring agent in the ceramic industry. Unlike other coloring agents, CoO can be used to develop colors other than blue, and several factors such as its concentration in the glaze and firing condition have been suggested as possible mechanisms. For example, CoO produces a typical blue color called "cobalt blue" at very low concentrations such as 1 wt% in both oxidation and reduction firing conditions; a higher concentration of CoO (5 wt%) develops a darker blue color under the same firing conditions. Interestingly, CoO also develops a purple color at high concentrations above 10 wt%. In this study, we examined the applicability and mechanism of a novel purple glaze containing cobalt(II, III) oxide, one of the well characterized cobalt oxides. Experimental results show that an Augite crystal isoform (Augite-Fe/Co) in which Fe was replaced with Co is the main component contributing to the formation of the purple color. Based on these results, we developed a glaze using chemically synthesized Augite-Fe/Co crystal as a color pigment. Purple color glaze was successfully developed by the addition of 6~15 wt% of $Co_3O_4$ to magnesia lime.

• Journal of Environmental Impact Assessment
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• v.10 no.1
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• pp.1-8
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• 2001

Detection of red tides by satellite remote sensing can be done either by detecting enhanced level of chlorophyll pigment or by detecting changes in the spectral composition of pixels. Using chlorophyll concentration, however, is not effective currently due to the facts: 1) Chlorophyll-a is a universal pigment of phytoplankton, and 2) no accurate algorithm for chlorophyll in case 2 water is available yet. Here, red band algorithm, classification and PCA (Principal Component Analysis) techniques were applied for detecting patches of Cochlodinium polykrikoides red tides which occurred in Korean waters in 1995. This dinoflagellate species appears dark red due to the characteristic pigments absorbing lights in the blue and green wavelength most effectively. In the satellite image, the brightness of red tide pixels in all the three visible bands were low making the detection difficult. Red band algorithm is not good for detecting the red tide because of reflectance of suspended sediments. For supervised classification, selecting training area was difficult, while unsupervised classification was not effective in delineating the patches from surrounding pixels. On the other hand, PCA gave a good qualitative discrimination on the distribution compared with actual observation.

• 보존과학연구
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• s.24
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• pp.131-152
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• 2003

In ancient times, many kinds of different inorganic pigments were used as colorants for making objects. These pigments are still evidentin well known objects such as Danchung, mural painting and Buddhist painting. This study discusses the results obtained from an analysis of the pigments used on the Buddha pigments. The results can be briefly summarized as below; Firstly, the microcrystalline structures revealed on the cross section of analyzed pigments, samples of which were taken from various parts of Buddha pigments show that different sizes and shapes of pigment particle were used for different purposes such as coloring, toning of the pigments. The arrangement of pigments and their usages are varied according to the owner temples and the place where it was created. Secondly, a result of the analysis on the composition and structure of the pigments shows that the main components in their composition are: Red pigments - Red lead($Pb_3O_4$) and Cinnabar(HgS)Green pigments - Malachite[$CuCO_3$.$Cu(OH)_2$] and Prussian Blue[$Fe4(Fe(CN)_6)_2$]Gold pigments - pure gold(Au)Yellow pigments - Orpiment($A_s2S_3)White pigments - Lead Cyanamide[$Pb_3(CO_3)_2(OH)_2]Ultramarine pigments - Azulite[$Cu_3(CO_3)_2(OH)_2]Especially, we knew that pigments used on the Ssanggye temple not repaired to the artificial synthetic pigment

• Applied Biological Chemistry
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• v.41 no.5
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• pp.399-404
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• 1998

Genipin was obtained from hydrolysis of geniposide isolated from gardenia fruits with ${\beta}-glucosidase$. Reaction of genipin with glycine, alanine, histidine, lysine, phenylalanine and glutamate in aqueous buffer solution converted colorless starting materials to blue pigments. Effect of pH for the formation of blue pigments was tested using UV/Vis spectrophotometer. The optimum pH for the formation of blue pigments was 7.0. No pigment and trace amounts were formed at acidic (pH 3.0) and alkaline (pH 12.0) conditions, respectively. The amount and tincture of blue color were distinct with different amino acids. In contrast with lysine $({\lambda}_{max}=573\;nm)$, glycine $({\lambda}_{max}=595\;nm)$, phenylalanine $({\lambda}_{max}=602\;nm)$ and alanine $({\lambda}_{max}=595\;nm)$, the reaction of genipin with histidine $({\lambda}_{max}=601\;nm)$ and glutamate $({\lambda}_{max}=601\;nm)$ produced relatively small amounts of blue pigments. Rate constants for the formation of blue pigments from genipin with amino acids at various temperatures $(60,\;70,\;80,\;90^{\circ}C,\;pH\;7.0\;phosphate\;buffer)$ were obtained. Rate constants of genipin with basic amino acids were larger than neutral or acidic amino acids. Arrhenius activation energies of the formation of blue pigments indicated that activation energy of glycine $(E_A=9.8\;kcal/mol)$ was especially lower than those of other amino acids $(E_A=13.3{\sim}15.4\;kcal/mol)$.

• Journal of Life Science
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• v.27 no.11
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• pp.1349-1356
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• 2017

Potassium channel openers (KCOs) produce physiological and pharmacological defense mechanisms against cell injuries caused by oxidative stress of diverse origins. Openings of mitochondrial and plasmalemmal $K^+$ channels are involved in the defense mechanisms. This study tested whether NS 1619, an opener of large-conductance BK channels, has a similar beneficial influence on the pigment epithelial cells of retinas. The human retinal pigment epithelial cell line ARPE-19 was exposed to $H_2O_2$-induced oxidative stress in the absence and presence of NS 1619. The degrees of the cells' injuries were assessed by analyzing the cells' trypan-blue exclusion abilities and TUNEL staining. NS 1619 produced remarkable protections against cell injuries caused by $H_2O_2$. It prevented apoptotic and necrotic cell deaths. The protective effect of NS 1619 was significantly diminished when the cells were treated with NS 1619 in combination with the BK channel-blocker paxilline. NS 1619 significantly ameliorated cellular ATP deprivations in $H_2O_2$-treated cells. It helped mitochondria preserve their functional integrity, which was estimated by their MTT reduction abilities and mitochondrial membrane potential. In conclusion, it was suggested that NS 1619 had a beneficial effect on mitochondria in regards to preserving their functional integrity under oxidative stress, and it produces defense mechanisms against oxidant-induced cell injuries in ARPE-19 cells.