• Korean Journal of Materials Research
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• v.23 no.1
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• pp.1-6
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• 2013

A simple thermal oxidation of Cu thin films deposited on planar substrates established a growth of vertically aligned copper oxide (CuO) nanorods. DC sputter-deposited Cu thin films with various thicknesses were oxidized in environments of various oxygen partial pressures to control the kinetics of oxidation. This is a method to synthesize vertically aligned CuO nanorods in a relatively shorter time and at a lower cost than those of other methods such as the popular hydrothermal synthesis. Also, this is a method that does not require a catalyst to synthesize CuO nanorods. The grown CuO nanorods had diameters of ~100 nm and lengths of $1{\sim}25{\mu}m$. We examined the morphology of the synthesized CuO nanorods as a function of the thickness of the Cu films, the gas environment, the oxidation time, the oxidation temperature, the oxygen gas flow rate, etc. The parameters all influence the kinetics of the oxidation, and consequently, the volume expansion in the films. Patterned growth was also carried out to confirm the hypothesis of the CuO nanorod protrusion and growth mechanism. It was found that the compressive stress built up in the Cu film while oxygen molecules incorporated into the film drove CuO nanorods out of the film.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1989-1992
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• 2012

We present a low temperature (${\approx}70^{\circ}C$) method to prepare anatase, vertically aligned feather-like $TiO_2$ (VAFT) nanowire arrays $via$ reactive pulsed DC magnetron sputtering. The synthesis method is general, offering a promising strategy for preparing crystalline nanowire metal oxide films for applications including gas sensing, photocatalysis, and 3rd generation photovoltaics. As an example application, anatase nanowire films are grown on fluorine doped tin oxide coated glass substrates and used as the photoanode in dye sensitized solar cells (DSSCs). AM1.5G power conversion efficiencies for the solar cells made of 1 ${\mu}m$ thick VAFT have reached 0.42%, which compares favorably to solar cells made of the same thickness P25 $TiO_2$ (0.35%).

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1204-1210
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• 2011

Objective of this study was to examine the effect of sodium nitroprusside (SNP), a nitric oxide (NO) donor on steroid synthesis, growth and apoptosis of buffalo granulosa cells (GCs) in vitro. Follicular fluid of antral follicles (3-5 mm diameter) was aspirated and GCs were cultured in 0 (control), $10^{-3}$, $10^{-5}$, $10^{-7}$, $10^{-9}\;M$ of SNP for 48 h. To evaluate whether this effect was reversible, GCs were cultured in presence of $10^{-5}\;M$ SNP+1.0 mM $N^{\omega}$-nitro-L-arginine methyl ester (L-NAME) a NO synthase (NOS) inhibitor or hemoglobin (Hb, $1.0{\mu}g$) as NO scavenger. Nitrate/nitrite concentration was evaluated by Griess method, progesterone and estradiol concentrations by RIA and apoptosis by TUNEL assay. SNP ($10^{-3}$, $10^{-5}$, $10^{-7}\;M$) significantly (p<0.05) inhibited estradiol and progesterone synthesis, growth, disorganized GCs aggregates and induced apoptosis in a dose dependent manner. However, $10^{-9}\;M$ SNP induced the progesterone synthesis and stimulated GCs to develop into a uniform monolayer. Combination of SNP $10^{-5}$ M+L-NAME strengthened the inhibitory effect while, SNP+Hb together reversed these inhibitory effects. In conclusion, SNP at greater concentrations ($10^{-3}$, $10^{-5}$ and $10^{-7}\;M$) has a cytotoxic effect and it may lead to cell death whereas, at a lower concentration ($10^{-9}\;M$) induced progesterone synthesis and growth of GCs. These findings have important implications that NOS derived NO are involved at physiological level during growth and development of buffalo GCs which regulates the steroidogenesis, growth and apoptosis.

• Journal of Life Science
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• v.22 no.8
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• pp.1092-1098
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• 2012

This study was carried out to discover the skin wrinkle reducing components in the seeds of Arctium lappa. The isolation of a methylene chloride-soluble fraction of 70% ethanol extract from the seeds of Arctium lappa using a procollagen type-1 synthesis and MMP-1 activity resulted in the isolation and identification of four lignin compounds: arctiin, arctigenin, matairesinol, and diarctigenin. All structures were confirmed via NMR and MS spectroscopic data. To determine cell viability and procollagen type-1 synthesis, human dermal fibroblasts were treated with 10-100 ${\mu}M$. As a result, none of the four compounds showed cytotoxicity up to 50 ${\mu}M$. We also investigated their procollagen type-1 synthesis and MMP-1 inhibition activity and found that arctiin had the highest activity in terms of both procollagen synthesis and MMP-1 inhibition among all four compounds. Putting all the data together, we suggest that arctiin be used in cosmetics as an anti-wrinkle material.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.247-252
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• 2015

ZSM-5 crystals grew on the surface of ${\alpha}$-SiC and ${\beta}$-SiC particles by hydrothermal synthesis method. SiC particles which were > $50{\mu}m$ of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on ${\beta}$-SiC at $900^{\circ}C$ in air, and it was controlled to grow ZSM-5 grew from the ${\beta}$-SiC surface with $150^{\circ}C$ synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of ${\beta}$-SiC. When the synthesis temperature was $200^{\circ}C$, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.6
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• pp.812-817
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• 2012

This study was performed to investigate the antioxidant activities and the melanin inhibitory effects of Hippophae rhamnoides L. fruit extracts. Two in vitro methods were used; the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method to determine antioxidant activity and measurements of the inhibitory effects of tyrosinase activity to determine melanogenesis in B16/F10 melanoma cells. The radical scavenging activity of the extract was 56.0% at $700{\mu}g/mL$, similar to ascorbic acid (56.9%), in the DPPH assay. The tyrosinase inhibitory activity of the extract was 52.1% and 73.4% at 100 and $500{\mu}g/mL$, which is also similar to ascorbic acid. In B16/F10 mouse melanoma cells, the extract inhibited melanin synthesis by 56% at $500{\mu}g/mL$, a more prominent inhibition of melanin synthesis compared to extracts from arbutin. These results suggest that extracts from H. rhamnoides L. have antioxidant activity and skin-whitening effects; allowing their application in cosmetics as a natural product.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1276-1284
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• 1996

Ultrafine calcim carbonate powders with the size of 0.05~0.1 ${\mu}{\textrm}{m}$ and the calcite phase were prepared by the nozzle spouting method which was conducted by spouting calcium hydroxide slurry in reactor filled with CO2 gas. Well dispersed ultra-fine particles were synthesized in condition of high Ca(OH)2 concentration of the slurry ( 0.5wt%) synthesized calcium carbonate powder was shown the large particle size with agglo-meration.

• Electrical & Electronic Materials
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• v.9 no.9
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• pp.906-910
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• 1996

Ferroxplana N $i_{2}$Y(B $a_{2}$N $i_{2}$F $e_{12}$ $O_{22}$ ) magnetic particles, which is one of the hexagonal ferrite were synthesized by a coprecipitation method. The coprecipitates were prepared by adding aqueous solution of BaC $I_{2}$ - 2 $H_{2}$O, NiC $I_{2}$ - 6 $H_{2}$O and FeC $I_{3}$ - 6 $H_{2}$O(of which the mole ratio is $Ba^{+2}$ : N $i^{+2}$ : F $e^{3+}$= 1 : 1 : 6) to a mixture of NaOH and N $a_{2}$C $O_{3}$. The shape of Ferroxplana N $i_{2}$Y magnetic particles obtained at 1, 100(.deg. C) was hexagonal plate-like, average particle size and aspect ratio were 2(.mu.m) and 7, respectively.y.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.95-100
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• 2006

Synthesis of the non-swelling property micas was carried out by hydrothermal method. In order to artificially induce the diffusion of ions, a rotating system was attached to the hydrothermal apparatus and by adding 0.7 mm zircon beads, synthesis of the non-swelling property micas could be performed in a low temperature area. The hydrothermal conditions for the preparation of micas were a reaction temperature of $260^{\circ}C$, for 72 hrs, using $1K_2O,\;1Al(OH)_3,\;4Mg(OH)_2\;and\;6SiO_2$ as the starting materials and a 8M-KOH solution as the hydrothermal solvent. The micas obtained under these conditions were a plate shape with a size of $2.89{\mu}m$ and showed a whiteness of over 97 %. Also, through the FT-IR analysis, because the absorption peak of the $Mg_3OH$ vibration was observed at approximately $3700cm^{-1}$, it could be known that it was phlogopite of non-swelling property showing the chemical composition of $KMg_3AlSi_3O_{10}(OH)_2$. This result was very consistent with the EDS analysis where O (41.34 %), Mg (3.88 %), Al (11.45 %), Si (17.62 %) and K (25.71%) elements were detected.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.440-444
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• 1998

A series of 6-(N-arylamino)-7-methylthio-5,8-quinolinedione derivatives 4a-4l was newly synthesized for the evaluation of antifungal activity. 6-(N-Arylamino)-7-methylthio-5,8-quinolinediones were prepared by regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinediones with arylamines in the presence of $Ce^{3+}$, and $Na_2$S/dimethylsulfate. The MIC values of 4a-4l were determined for antifungal susceptibility in vitro against Candida species by agar streak method. The derivatives 4a-4l had generally potent antifungal activities against all human pathogenic fungi. Especially they had the most potent activity against C. krusei at 12.5-0.8 $\mu\textrm{g}$/ml. Compounds 4d, 4g, 4h, 4j and 4k had more potent antifungal activities than fluconazole. Compounds 4g and 4h completely inhibited the fungal growth at 0.8-6.3 $\mu\textrm{g}$/ml against all Candida species, while fluconazole inhibited the growth at 25 $\mu\textrm{g}$/ml. The compounds such as 4g and 4h containing an N-(4-bromo-2-methylphenyl)- or N-(4-bromo-3methylphenyl)amino substituent exhibited the most potent antifungal activities.