• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.667-672
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• 2006

Tyrosinase is an enzyme that catalyzes the biosynthetic pathway of melanin pigments participating in the coloring of skin, hair, and eyes, and is widely distributed in nature. The inhibitory compounds of tyrosinase have been extensively used as a cosmetic agent with a skin-whitening effect. In this paper, several plant extracts were screened using Melan-a cells for the melanin biosynthesis inhibition activity, and Idesia polycarpa was selected. A melanin biosynthesis inhibitor was isolated from I. polycarpa fruits by activity-guided fractionation, and the inhibitor was identified as 6-hydroxy-2-[[[(1-hydroxy-6-oxo-2-cyclohexenl-yl)carbonyl]oxy]methyl]phenyl$\beta$-D-glucopyranoside (idescrapin) by comparing it with reported spectral data. Idescarpin $(IC_{50}=8{\mu}g/ml)$ reduced melanin content compared with the vehicle. In addition, the inhibitory activity of idescarpin for melanin synthesis is mediated by decreasing tyrosinase protein rather than directly inhibiting the tyrosinase activity. These results suggest that idescarpin isolated from I. polycarpa fruits may be used as a skin-whitening agent.

• Restorative Dentistry and Endodontics
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• v.49 no.3
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• pp.23.1-23.10
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• 2024

Objectives: Previous in vitro studies determined the whitening effects of bleaching products on stained resin composite surfaces. This in vitro study aimed to verify the effectiveness of a whitening system on composite resin previously subjected to pigmentation, specifically examining the depth of whitening effectiveness within the material structure. Materials and Methods: A commercially available nano-filled composite resin was used. Specimens were stained using a coffee-based solution and a 10% carbamide peroxide-based gel was employed as the whitening agent. The pigment's penetration and the effect of the bleaching gel were evaluated by measuring color (CieLab values) from the outer edge to the inner part of the specimens. Color measurements were taken at 14 points, starting from 0.1 mm from the external perimeter up to 3.0 mm. Results: Analysis of variance tests showed a statistically significant difference between the Control Group (CG), Pigmentation Group, and Whitening Group. The whitening agent was effective up to 1.5 mm in depth, with Whiteness index (W) values not statistically different from those of CG up to 0.5 mm in depth. Conclusions: Whitening agents on nano-filled resin composite previously pigmented appear effective in restoring the W to values similar to the original, particularly in the superficial layers of the sample.

• Journal of Digital Convergence
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• v.15 no.9
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• pp.533-541
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• 2017

In the rapidly changing 21st century, image management has become more important. Under these circumstances, as a lot of hair colors and beaching agents are used to create diverse hair colors, hair damage resulting from frequent chemical hair coloring has been inevitable. This study investigated how to reduce morphological changes in hair and hair damage after dividing hair into healthy hair('Group A') and damaged hair('Group B'), using the following bleaching agents: basic bleaching agent(a), beaching agent diluted with water(b), oil ingredient-added bleaching agent(c), water-shampoo mixed bleaching agent(d). The results found that even though hair damage can be prevented by a bleaching agent diluted with a mixture of diverse additives, there were better effects on hair texture in both 'Group A(4.83)' and 'Group B(4.41)' at a sensory test when hair was bleached with an addition of Camellia oil, according to blinded experiment, in particular. As a result, hair damage could be reduced. Therefore, this study expects that hair bleaching with an addition of Camellia oil to the mixture of a bleaching agent would bring the development of diverse new materials which can minimize hair damage as well as regulate hair brightness and make a contribution to the development of cosmetology market.

• Journal of Korean Society for Quality Management
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• v.29 no.3
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• pp.166-176
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• 2001

This paper considers a six sigma project for reducing the color variation of the monitor materials in a chemical plant. The project follows a disciplined process of five macro phases: define, measure, analyze, improve, and control (DMAIC). A process map is used to identify process input variables. Three key process input variables are selected by using an input variable evaluation table; a melting pressure, a coloring agent, and a DP color variation. DOE is utilized for finding the optimal process conditions of the three key process input variables. The sigma level of defects rate becomes a 4.58 from a 2.0 at the beginning of the project.

• Carbon letters
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• v.26
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• pp.25-30
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• 2018

The dielectric medium used in electrophoretic displays (EPDs) is required to be an environmentally friendly solvent with high density, low viscosity, and a large electric constant. Hydrofluoroether, a highly fluorinated solvent with eco-friendly characteristics, is regarded as a viable alternative medium for EPDs, owing to the similarity of its physical properties to those of the conventional EPD medium. Surface modification of particles is required, however, in order for it to disperse in the charged solvent. Also, positive/negative charges should be present on the particle surface to enable electrophoretic behavior. In this study, carbon black particles wrapped with positively charged nitrogen (N-CBs) were fabricated by a simple hydrothermal process using a poly(diallyldimethylammonium chloride) solution as a black coloring agent for the EPD. The dispersion behavior of N-CBs was investigated in various solvents.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.538-543
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• 2015

This experiment was conducted to measure the effects of olive leaf powder on performance, egg yield, egg quality and yolk cholesterol level of laying hens. A total of 120 Lohmann Brown laying hens of 22 weeks old were used in this experiment. The birds were fed on standard layer diets containing 0, 1%, 2%, or 3% olive leaf powder for 8 weeks. Egg weight and yield were recorded daily; feed intake weekly; egg quality and cholesterol content at the end of the trial. Olive leaf powder had no effect on feed intake, egg weight, egg yield and feed conversion ratio (p>0.05) while olive leaf powder increased final body weight of hens (p<0.05). Dietary olive leaf powder increased yellowness in yolk color (p<0.01) without affecting other quality parameters. Yolk cholesterol content was tended to decrease about 10% (p>0.05). To conclude, olive leaf powder can be used for reducing egg yolk cholesterol content and egg yolk coloring agent in layer diets.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.522-530
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• 2010

We developed functional synthetic lubricant for internal combustion engine oil, which would improve engine oil performance for internal combustion engine and extend engine life. We made base oil by synthesizing nonanoic acid, 1.1.1-trimethylol propane (which has good bio-degradability) and pentaerythrytol ester. We synthesized catalyst using p-toluene sulfonic acid 0.15 wt% and coloring-prevention agent hypo-phosphorus acid 0.18 wt% at 180-$190^{\circ}C$. Reaction temperature was increased at the rate of $10^{\circ}C$ for every 1 hour. When acid value reached below 3, reaction was completed. After cooling and deoxidization, we washed it by distilled water two times. After dehydration and filtering, we obtained trimethylol propane tripelargonate (TMTP) and pentaerythrytol tetrapelargonate (PETP) at yields of 96 % and 98 % respectively.

• Journal of Fashion Business
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• v.10 no.1
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• pp.120-131
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• 2006

Recently, it has been reported that chemical hair coloring can cause allergic reactions, the toxicity issue of chemical hair color was issued. Therefore, there is an increasing interest in the hair coloration technique using non-toxic and bio-compatible hair color gotten from natural resource. In this study, the possibility using fermented Indigo as natural hair coloring agent was investigated. Bleached hair samples were dyed using Indigo, and the effect of dyeing frequency, the physical change after dyeing, color, surface and cross-section characteristics, and tensile property were also studied. In addition, the protection property of cationic detergent finishing on damaged hair samples were also studied. The following conclusions are made; 1. While bleached hair samples with low value showed the negligible effect of repeated dyeing, bleached hair samples with high value showed the good effect of repeated dyeing. 2. Hair sample dyed with Indigo showed a high light-fastness, however, tensile strength and elongation showed very low values (high damage on hair sample). 3. Cationic detergent finishing did not affect on the colorfastness because of decoloration after dyeing, however, it increased the smoothness of hair sample, and therefore, can use as protectant of damaged hair. 4. Hair scale was damaged after dyeing. It seemed that the alkali, potassium carbonate, increased pH of dyeing bath to 11, as a result, the hair was swollen, weaken, and dissolved on the prolonged dyeing time. Dyed hair sample became stiff and fine. 5. The color difference was 4.62 (a high fastness value) in the test of sunlight exposure, shampoo, cationic detergent finishing, and acid perspiration fastness.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.92-97
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• 2006

Dolomite type $BaSn(BO_3)_2$ ceramics with rhombohedral crystal structure has been synthesized via solid state reaction route. Dielectric properties were measured for the samples sintered at $1050\~1200^{\circ}C$ for 2 h in air. Dielectric constant, loss tangent, and temperature coefficient were increased with sintering temperature due to the evolution of $BaSnO_3$, secondary, phase. Optimum dielectric properties were obtained at the $BaSn(BO_3)_2$ ceramics sintered at $1100^{\circ}C.\;CuO/Bi_2O_3$ was added to $BaSn(BO_3)_2$ ceramics to lower the sintering temperature for LTCC application, then Co and Fe-based coloring agents were added for colorizing the LTCC tape. Typical dielectric properties of $BaSn(BO_3)_2$ ceramics with $5 wt\%\;CuO/Bi_2O_3\;and\;3wt\%$ Co-coloring agent that sintered at $900^{\circ}C$ were $\varepsilon_r=9.89,\;tan{\delta}=0.92\times10^{-3},\;and\;TCC=112ppm/^{\circ}C$. Thus obtained LTCC tape was co-fired with Ag paste for compatibility test and revealed no sign of Ag reaction with the ceramics.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.107-112
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• 2014

Coloring agents in food materials plays important roles in the development of attractive products as well as in the functionality of food such as antioxidant or vitamin supplementation. Carrot has been used as an orange coloring agent in the decoration of food but also a major source of vitamin A complex. Though orange has been considered a typical color of carrot, the Rainbow carrot has been developed recently, which exhibit the various colors such as red, pale yellow, purple, orange or their mixtures. After categorization onto 8 groups by their colors, vitamin A complex (${\beta}$-carotene, lycopene and lutein) and soluble sugars (glucose, fructose, and sucrose) have been analyzed in carrots. The ${\beta}$-carotene was abundant in the groups of orange (Group-O) or groups with the orange color (group-OP, and group-YOP). The content of lycopene content was exclusively high in the red color carrot (group-R). The highest lutein contents were observed from the yellow-purple (group-YP) group. Meanwhile, little amounts of lycopene and ${\beta}$-carotene were observed in yellow-purple (group-YP) nor yellow (group-Y) on yellow (group-Y). Among the reducing sugars in 'rainbow carrots', the amount of sucrose was two times higher than those of fructose and glucose. However, the content of glucose, fructose and sucrose as well as the total reducing sugars did not differ between color groups suggesting little variations on their tastes.