• Korean Journal of Materials Research
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• v.21 no.8
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• pp.450-455
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• 2011

[ $Al_2TiO_5$ ]has a high refractive index and good solubility of the chromophore in the $Al_2TiO_5$ lattice, which allows this structure to be a good candidate for the development of new ceramic pigments. However, pure $Al_2TiO_5$ is well known to decompose on firing at $900{\sim}1100^{\circ}C$. However, this process can be inhibited by the incorporation of certain metal cations into its crystalline lattice. In this study, the synthesis of gray ceramic pigment was performed by doping cobalt on the $Al_2TiO_5$ crystal structure. The $Al_2TiO_5$ was synthesized using $Al_2O_3$ and $TiO_2$, and doped with $Co_3O_4$ as a chromophore material. In order to prevent the thermal decomposition during the cooling procedure, MgO was added to samples by 0.05 mole, 0.1 mole, and 0.15 mole as a stabilizer. The samples were fired at $1500^{\circ}C$ for 2 hours and cooled naturally. The crystal structure, solubility limit, and color of the synthesized pigment were analyzed using XRD, Raman spectroscopy, UV, and UV-vis. $Al_2O_3$ was available for the formation of $CoAl_2O_4$, which should also be considered in order to explain the small amount of this phase detected in the sample with the higher $Co^{2+}$ content (${\geq}$ 0.03 mole). It was found that the solubility limit of $Co^{2+}$ in the $Al_2TiO_5$ crystal was 0.02 mole% through an analysis of Raman spectroscopy. Through the addition of a pigment with 0.02 mole% of $Co^{2+}$ to lime-barium glaze, stabilized gray color pigments with 66.54, -2.35, and 4.68 as CIE-$L^*a^*b^*$ were synthesized.

• Conservation Science in Museum
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• v.15
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• pp.66-77
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• 2014

A gujangbok is a king's silk ceremonial robe embroidered with nine symbols that represent the essential virtues that a king needs to govern his country. The National Museum of Korea currently own a gujangbok worn by King Gojong in the late Joseon Dynasty. The robe is painted with various colors, including red, yellow, blue, green, and gray. μ-XRF and analysis was conducted on the pigments, and it was found that the red color was made from cinnabar, the yellow color was gold and brass, the blue color was a blue organic pigment and white lead, the green color was a synthetic pigment composed of copper and arsenic, and the gray color pigment was silver. Also, the pigments were compared to those used to make the patterns of a queen's ceremonial robe and a front cloth panel, both made around the same time and also owned by the National Museum of Korea. The comparative analysis revealed clear differences and similarities between the various pigments. The resulting data expect to serve as a useful foundation research for future studying of the pigments used by the Joseon royal court in the late nineteenth century.

• Journal of the Korean Ceramic Society
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• v.49 no.1
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• pp.84-89
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• 2012

Attempts were made to develop a stable gray pigment at reducing atmosphere, substituting Ti in $ZrTiO_4$ with Mn, Fe, Co and Cu The pigment synthesized at $1300~1500^{\circ}C$ by solid state method with the composition of $ZrTi_{1-x-y}A_xB_yO_4$ (x = y = 0.005, 0.015, 0.035, 0.055, 0.075, 0.095, 0.115, 0.135, 0.155, 0.175 and 0.195 mole, A = Mn(III), Fe(III), Co(II, III) and Cu(II) (chromophores), B = Sb (counterion). The pigments were fired at $1400^{\circ}C$ for 3 h with substitute amount changes of Mn, Fe, Co and Cu to $ZrTiO_4$ crystals, and analyzed by Raman spectroscopy to figure out substitute limits. Results indicated 0.035 mole for Mn, 0.115 mole for Fe, 0.015 mole for Co and 0.015 mole for Cu as substitute limits, respectively. Figs. 1, 2, 3, and 4 represent each substitute pigments of Mn, Fe, Co and Cu. Synthesized pigment was applied to a lime and a lime-magnesia glaze at 7 wt% each, and fired at reducing atmosphere of $1240^{\circ}C$, soaking time 1h. Gray color was obtained with CIE-$L^*a^*b^*$ values at 44.55, -0.65, 1.19(Mn), 40.36, -0.90, 0.30(Fe), 42.63, -0.03, -1.49(Cu) and -40.79, -0.28, -0.91(Co), respectively.

• The Korean Journal of Mycology
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• v.19 no.2
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• pp.136-142
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• 1991

Colonial morphology of the various yeasts grown on the yeast morphology agar me­dium containing orange-yellow pigments extracted from the fruits of Gardenia jasminoides (GJPM) was investigated in hopes of the differential identification of yeasts on primary cultures. Colonies of Candida lusitaniae and Ca. guilliermondii on GJPM turned to prussian blue within three days of incubation and Ca. tropicalis and Ca. viswanathii turned to bluish gray but the latter species turned to deep blue after 7 days. Ca. krusei, Saccharomyces cerevisiae, and Torulopsis glabrata showed neutral gray, grayish green, and baby blue respectively after one or two weeks. However, the colonies of Ca. albicans and parapsilosis remained unchanged even after 20 days. Colonial color of Cryptococ­cus neoformans showing brown to purple brown was distinguishable not only from buff color of Cr. laurentii after one or two weeks incubation but also from those of Candida spp. Growth of certain species was promoted on GJPM. The findings clearly showed that Ga. jasminoides pigments medium was useful to the morphological differentiation of medically important yeasts which were often encountered in sputum or other clinical specimens.

• Korean Journal of Veterinary Service
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• v.30 no.4
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• pp.533-538
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• 2007

A 16-year-old female mixed dog was submitted for examination at the pathology division of national veterinary research and quarantine service (NVRQS). Grossly, white or grayish spherical, multinodular, firm to friable masses were present in the tibiofibula to the pharenge area of the right limb, and dysphagia, breathing difficulties and tachypnea were shown. Various-sized white or grayish black masses were scattered in lungs and diaphragm and one mass was observed in the trachea and in the jejunum, respectively. Histopathologically, the neoplastic cells were composed of polygonal or spindle shaped cells with various sized round to oval nuclei and abundant cytoplasm. These cells formed lobules or nests separated by fine connective tissue and contained little amount of melanin pigments. Melanin pigments were stained dark gray or black with Fontana-Masson method. Melanosomes were also ultrastructurally demonstrable by electron microscopy. Based on above results, the present case was diagnosed as canine malignant melanoma originating from the lower limb and digit.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.212-219
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• 2016

Forty-nine pigments were extracted from the collections of 106 pigment producing bacteria from the plant rhizosphere soil. Antibacterial activity test was performed in the subjects of the extracted pigments with plant pathogenic bacteria including Xanthomonas axonopodis and Xanthomonas campestris, and with plant pathogenic fungi including Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum. The yellow pigment by Chryseobacterium sp. RBR9 and the red pigment by of Methylobacterium sp. RI13 showed the antibacterial activities against Xanthomonas axonopodis and Xanthomonas campestris. The violet pigment by Collimonas sp. DEC-B5 showed the antibacterial activity as well as the antifungal activities against Botrytis cinerea and Fusarium oxysporum. Especially, the violet pigment inhibited the growth of Botrytis cinerea more than 65% at MIC $20{\mu}M$. Upon the HPLC analysis result for the isolation of pigment with antifungal activity, violacein (91.6%) and deoxyviolacein (8.4%) were isolated for the pigment by Collimonas sp. DEC-B5. The production amount of the pigment was increased more than 10 times higher when D-mannitol 1.5% and yeast extract 0.2% were added as the nitrogen source to SCB medium. This study suggests that produced violacein by Collimonas sp. DEC-B5 will be effective to control strawberry gray-mold rot fungi by its preventive activity.

• Journal of the Korean Ceramic Society
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• v.48 no.4
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• pp.298-302
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• 2011

This study developed a pigment by doping Cr to Pyrochlore-type stannate crystals and investigated the chromogenic relationship in a glaze. Crystal phases of the pigment according to firing temperatures were analyzed by XRD, and the doping relationship was analyzed by Raman Spectroscopy. Color and reflection rate of the pigment were measured by UV-vis Spectrophotometer. Consequently, stannate characteristic band appeared at 307, 408, 505 and $755cm^{-1}$ until 0.1 mole substitution of $Cr_2O_3$. However, as amount of $Cr_2O_3$ increased, the stannate characteristic peak was decreased and shift happened at the left hand side due to Cr-dope. In composition of 0.12~0.14 mole substituted, the unreacted $Cr_2O_3$ stannate characteristic peak, which was not engaged, was shown. This result shows the maximum limit of solid solution was 0.1 mole $Cr_2O_3$. The color of the glaze, which was produced by adding 6 wt% of $Y_2Sn_{1.94}Cr_{0.06}O_7$ pigment in a lime or a lime-magnesia glaze and fired the mixture at $1260^{\circ}C$, was grayish pink with $L^*$ 70.29, $a^*$ 5.68 and $b^*$ 6.27. It showed gray with $L^*$ 68.82, $a^*$ 3.07and $b^*$ 8.13 for $Y_2Sn_{1.9}Cr_{0.1}O_7$.

• The Korean Journal of Cytopathology
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• v.8 no.1
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• pp.93-97
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• 1997

A case of cervical chordoma diagnosed by fine needle aspiration is discussed. A 41year-old male was admitted due to dyspnea on neck flexion. Radiologic image revealed a retrotracheal superior mediastinal solid mass. Aspiration cytology showed many clusters of oval or large polygonal cells having abundant eosinophilic or bubbly cytoplasm in an amorphous blue-gray mucoid background. The nuclei were round and showed size variation, coarse granular chromatin, and indistinct nucleoli. Some cells contained brown granular pigments in the cytoplasm. Mitoses were rarely found. The cytoplasm was strongly positive for PAS stain. Immunohistochemical stains using cell block revealed positive reaction for cytokerain, EMA, vimentin, and S-100 protein. The confirmative diagnosis was made by following excisional biopsy. Electron microscopic study revealed large pools of intracytoplasmic glycogen and microfilaments. This is the first case of cervical chordoma diagnosed by aspiration cytology to our knowledge in Korean literature.

• Korean Journal of Materials Research
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• v.24 no.2
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• pp.93-97
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• 2014

In this study, a cobalt sulfate ceramic coating was sintered on various clays at $1250^{\circ}C$. The specimen characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), TG-DTA, UV-vis spectrophotometer, and HRDPM. The ceramic coating had a constant thickness of thousands ${\mu}m$, and the surface was confirmed to be densely fused. Other new compounds were produced by the cobalt sulfate sintering process and reactions. These compounds were a $CoAl_2O_4$ phase, $Co_2SiO_4$ phase, anorthite($CaAl_2Si_2O_8$) phase, and $FeAl_2O_4$ phase, respectively. UV properties of the coated specimen were investigated, celadon clay specimen in 530-550 nm band is showing a dark gray color. The white clay and white mix clay specimen in 460-500 nm band is showing a blue color. The cobalt-aluminate($CoAl_2O_4$) spinel and the cobalt-silicate olivine($Co_2SiO_4$) were the strongest of the ceramic pigments, producing a very pure, navy blue color.

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.402-408
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• 1997

The antibiotic-producing strain HW-003 was screened from soil and found to be effective against the multidrug-resistant Staphylococcus aureus. The spore chain of HW-003 was retinaculiaperti, and the spore surface was spiny. Strain HW-003 has a LL-diaminopimelic acid isoform in the cell wall. The aerial mass color of the strain was gray, and the reverse side was yellow-brown. The strain produced melanin, but did not produce soluble pigments. According to the Taxon program, HW-003 showed best match with Streptomyces cyaneus. Antibiotic production reached a maximum after 72-h cultivation. The antibiotic was purified with silica gel column chromatography, octadecylsilyl column chromatography, and HPLC. The purified antibiotic, AMRSA1, showed strong inhibitory activity against multidrug-resistant Staphylococcus aureus and gram-positive bacteria. The molecular weight of AMRSA1 was about 1, 100. AMRSA1 was a peptide antibiotic containing alanine and serine.