• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.782-788
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• 2018

Submicron copper-silver core-shell (Cu@Ag) particles were synthesized using the sonochemical combined transmetallation reaction and the application to printed electronics as a low cost conductive paste was evaluated. $Cu_2O$ of the $Cu_2O/Cu$ composite used as a core in the reaction for the synthesis of core-shell was sonochemically reduced to Cu, and Cu atoms functioned as a reducer for silver ions in transmetallation to achieve the copper-silver core-shell structure. The characterization of submicron particles by TEM-EDS and TG-DSC confirmed the core-shell structure. Conductive pastes in which 70 wt% Cu@Ag was dispersed in solvents were prepared using a binder and wetting agents, and coated on the polyamide film using a screen-printing method. Printed paste films containing synthesized Cu@Ag particles with 8 at% and 16 at% Ag exhibited low resistivity of 96.2 and $38.4{\mu}{\Omega}cm$ after sintering at $180^{\circ}C$ in air, respectively.

• Korean Journal of Metals and Materials
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• v.47 no.8
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• pp.488-493
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• 2009

Direct syntheses of bulk $Ti_3Al$ via electro-discharge-sintering (EDS) of a stoichiometric elemental powder mixture were investigated. A capacitor bank of $450{\mu}F$ was charged with three input energies, 0.5, 1.0, and 1.5 kJ. The charged capacitor bank was then instantaneously discharged through 0.3 g of a Ti-25.0 at.%Al powder mixture for consolidation. Complete phase transformation occurred in less than $200{\mu}sec$ by the discharge and a bulk $Ti_3Al$ compact was obtained. Compared with consolidated samples fabricated by conventional methods such as high vacuum sintering and casting, the electro-discharge-sintered $Ti_3Al$ compact shows a very fine microstructure with a hardness value of 425 Hv. Electro-discharge-sintering under a $N_2$ atmosphere successfully modified the surface Ti oxide of the $Ti_3Al$ compact into Ti nitride, which concurred with the synthesis and consolidation of $Ti_3Al$. Complete conversion yielding a single phase $Ti_3Al$ is primarily dominated by the fast solid state diffusion reaction.

• The Korea Journal of Herbology
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• v.28 no.1
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• pp.9-14
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• 2013

Objectives： Bletillae Rhizoma, the roots of Bletilla striata, is used to restrain the leakage of blood and stop bleeding. It can cure the sores, ulcers, and chapped skin. This study was designed to investigate the collagen metabolism, elastase and tyrosinase activity of Bletillae Rhizoma extract (BR). Methods : The effects of BR on type I procollagen production and collagenase activity in human normal fibroblasts Hs68 after UVB (312 nm) irradiation were measured by ELISA method. The elastase activity, tyrosinase activity, and L-DOPA oxidation after treatment of BR were measured as well. Results : In the present study, the collagen production (type I procollagen) was significantly increased to $15.7{\pm}1.8$ ng/ml at a concentration of BR 100 ${\mu}g/ml$ in UVB damaged Hs68 cells. The increased collagenase activity after UVB damage was significantly recovered to $42.7{\pm}0.7%$, $54.5{\pm}3.5%$, and $38.4{\pm}0.9%$ by BR 10, 30, and 100 ${\mu}g/ml$. The activities of BR 10 mg/ml on tyrosinase activity was significantly reduced to $45.1{\pm}8.4%$ as well. However, there were no significant effects on the elastase activity and the L-DOPA oxidation. Conclusion : BR showed the promoting effects of collagen synthesis and inhibitory effects of collagenase activity in Hs68, human normal fibroblast cells. And these could be thought to have the anti-wrinkle effects and whitening effects in vitro. These results suggest that BR may have potential as an anti-aging ingredient in cosmetic treatment.

• Journal of Life Science
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• v.28 no.8
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• pp.900-907
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• 2018

This study was carried out to evaluate the possibility of unripe apple peel water extracts as cosmetic materials and to evaluate the biological activities of the antioxidant and whitening effects of the samples. The antioxidative properties of the samples were confirmed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation radical scavenging ability. To evaluate the whitening effect of the samples, several analytical techniques were used, including toxicity evaluations of the samples by MTT assays. Measurements of the inhibition rates of cellular tyrosinase, melanin synthesis rates, and expression rates of whitening-related proteins and genes were confirmed using melanoma (B16F10 cell). At equivalent unripe apple peel water concentrations ($1,000{\mu}g/ml$), the DPPH radical scavenging and the ABTS cation radical scavenging activities were 77.3% and 93.1%, respectively. The whitening activity evaluation showed that tyrosinase activity and melanin synthesis were inhibited by 19.8% and 17.3%, respectively, at unripe apple peel water extract concentrations of $50{\mu}g/ml$. In B16F10 cells induced by ${\alpha}$-MSH, the expression of tyrosinase, TRP-1, and TRP-2 decreased. Also, the activity of the transcription factor MITF was inhibited. In real-time PCR experiments, the expression of related genes at the upstream signal level was also found to be progressively lowered as the concentration of unripe apple peel water extracts increased. From these results, it was confirmed that the unripe apple peel water extracts showed excellent whitening efficacy and could be used as safe, natural, raw cosmetic material in the future.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.317-322
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• 2009

In the present study, the effect of ethanol extracts of leaf and root of Rosa multiflora on the proliferation of B16 cells, tyrosinase activity and melanin synthesis were investigated. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide(MTT) assay demonstrated that the cell viability upon treatment with Rosa multiflora extract(0-200 ${\mu}g$/ml) was similar to that of untreated control. Treatment with leaf or root extracts(200 ${\mu}g$/ml) decreased the in vitro tyrosinase activity to about 65% of that in untreated control. Similarly, the intracellular tyrosinase activity of B16 cells decreased in a concentration-dependent manner. Furthermore, the melanin synthesis of B16 cells decreased by the two extracts in a concentration dependent manner. However, the extracts did not change the level of tyrosinase mRNA, as determined by RT-PCR. These results demonstrated that the Rosa multiflora extracts inhibit the tyrosinase dependent melanin biosynthesis, and therefore, are candidates for skin-whitening agents.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.69-75
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• 2005

To investigate the morphological effect on synthesis of aluminum nitride by SHS Process, two type of Al Powder (granular and flacky shape) with the mean size of 34 $\mu$m and the diluent AIN powders of four different mean sizes.0.12, 9.7, 39.3, 50.5 $\mu$m, were used to prepare green compact. The packing density was fixed to $35 TD\%. The initial pressure of $N_{2}$ and diluent fraction was varied in the range of $1\~10 MPa,\;0.4\~0.7$, respectively. AlN with high purity of $98\% or over and large particle size of about several tens fm can be synthesized by SHS reaction as a consequence of adjusting particle size of AlN dilutent similarly to that of Al reactant. This may be caused by improvement of $N_{2}$ gas permeation to compact after passing the propagation wave. In the case of flaky-shape aluminum used as reactant, instead of granular Al-powder, unstable combustion would be occurred. As the result, irregular propagation of combustion wave and falling-off of maximum temperature would be observed during the reaction.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.257-263
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• 2009

In order to search for new whitening cosmetic ingredients from Chinese herbal extracts including Chinese herbs and complex prescriptions from TCM (Traditional Chinese Medicine), we screened about 47 TCM extracts collected from China. We tested their inhibitory effects on melanogenesis by using in vitro tyrosinase inhibition assay and B16 melanoma cells. We selected Siphonostegia chinensis and Salvianic miltiorrhiza Bunge. We isolated Danshensu ($\alpha$,3,4-trihydroxybenzenepropanoic acid sodium salt) from Salvianic miltiorrhiza Bunge extract and tested its inhibitory effect on melanin formation in B16-F10 melanoma cells. Danshensu suppressed melanin synthesis up to about 50% at a concentration of $100\;{\mu}g/mL$. Siphonostegia chinensis suppressed melanin synthesis up to about 60% at a concentration of $300\;{\mu}g/mL$. The results showed that these extracts could be used as new natural active ingredients for whitening cosmetics.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.4
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• pp.1-15
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• 2018

Objectives: Osteoporosis is considered a serious human disease. We developed an extract of mixed herbs containing root of Platycodon grandiflorum (ExMH-PGR), which is expected to be effective in preventing or treating osteoporosis. The aim of this study was to investigate the anti-osteoporotic effect of ExMH-PGR in osteoblastic MC3T3-E1 cells and osteoclastic RAW 264.7 cells. Methods: To examine the anti-osteoporotic effect of ExMH-PGR, osteoblast and osteoclast differentiation were induced and cultured with various concentrations of ExMH-PGR. Alkaline phosphatase (ALP) activity, collagen synthesis, osteocalcin production, and mineralization in MC3T3-E1 cells were analyzed. Tartrate-resistant acid phosphatase (TRAP) activity and the formation of actin ring in RAW 264.7 cells were analyzed. Results: ExMH-PGR at concentration up to $25{\mu}g/mL$ significantly increased ALP activity, collagen synthesis, osteocalcin production, and mineralization in MC3T3-E1 cells. ExMH-PGR at 50 to $200{\mu}g/mL$ significantly inhibited TRAP activity and the formation of actin ring in RAW 264.7 cells. Conclusions: These results demonstrate that ExMH-PGR stimulates osteoblastic activities and inhibits osteoclastic activities in in vitro systems, suggesting that ExMH-PGR might be considered as an anti-osteoporotic candidate for treatment of osteoporosis disease.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.2
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• pp.115-124
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• 2017

The objective of this study was to investigate skin whitening effect of Resorcinol dipentyl ether [1,3-di(pentyloxyl)benzene] by in vitro experiments. Resorcinol dipentyl ether was prepared by alkylation of resorcinol with 1-bromopentane. The reaction products were confirmed by NMR, MS and other analytical equipments. In order to evaluate the skin safety of resorcinol dipentyl ether, the cytotoxicity of the cells constituting the skin (keratinocyte, melanocyte, fibroblast) was analyzed and similar cell viability was observed in all cell lines as compared with the control group. Inhibition of extracellular melanin synthesis effect of resorcinol dipentyl ether was approximately 65.75% at $20{\mu}g/mL$ and inhibition of intracellular melanin synthesis effect of resorcinol dipentyl ether was approximately 53.89% at $20{\mu}g/mL$. The real-time PCR and western blot analysis of mRNA expression and protein expression of tyrosinase, TRP-1, and TRP-2 related to melanogenesis revealed that melanin inhibitory effect of resorcinol dipentyl ether was inhibited from the transcription stage respectively. Finally, this study suggested applicability of Resorcinol dipentyl ether [1,3-di(pentyloxyl)benzene] as a whitening functional cosmetic new material.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.129-135
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• 2008

In this study, the potential anti-aging properties of Prunella vulgaris extract were investigated. According to our results, Prunella vulgaris extract increased collagen synthesis(74.7% at 250 ${\mu}g/mL$) and decreased on MMP-1 synthesis(90.2% at 200 ${\mu}g/mL$) and elastase activity(43.7% at 2.0%). Furthermore, it also showed free radical scavenging activity(76.9% at 2.0%) and reduced $H_2O_2$-induced cytoxicity(49.9% at 2.0%). A double-blind clinical study to investigate the effect of Prunella vulgaris extract on the skin's surface was conducted with 22 healthy volunteers, aged 34 to 48 years. The volunteers applied a cream formula with 4.0% of Prunella vulgaris extract, or placebo cream, on each crow's feet twice a day for 12 weeks. Skin wrinkles were evaluated with the naked eye and instrumental image analysis of silicone replicas, followed by statistical analysis. Twelve weeks after application of cream formula with 4.0% of Prunella vulgaris extract, we found significant improvement of facial wrinkle. Moreover, silicone replica analysis confirmed notable improvement in average of R2 and R3 at 12 weeks(p<0.05). These results demonstrate that Prunella vulgaris provides a remarkable and significant tensor and anti-wrinkle effect on the skin, which could be of great use in anti-aging skin care products.