• Applied Chemistry for Engineering
• /
• v.18 no.5
• /
• pp.433-437
• /
• 2007

Bis(dithiobenzil) metal complex, used as functional NIR absorbing dye and photostabilizer, was synthesized using bezoin and anisoin as intermediate compounds. And squarylium, a charge generation material, was synthesized to find its photostability effect. The structure of the product was determined by $^1H-NMR$ and FT-IR and the thermal property was analyzed by DSC and TGA. Optical property and photostability were determined by UV-Vis-NIR spectroscopy. High absorbance was obtained in the NIR range and maximum absorbing wavelength was shifted depending on the nature and position of substituent in the bis(dithiobenzil) metal complex. The photofading effect of squarylium decreased by the addition of bis(dithiobenzil) metal complex.

• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.566-569
• /
• 2005

The extracellular polysaccharide...(EPS) has been used in a wide variety of industrial applications because of gel formation, emulsion stability, control of the surface tension, water absorption and film formation etc. In this study, inhibitory activity on tyrosinase and inhibitory activity on angiotensin converting enzyme...(ACE) are determined. UV adsorption wavelength, beads formation of EPS were investigated. In the result, in 1%(w/v) EPS concentration, EPS had inhibitory activity of 71.8% on tyrosinase and inhibitory activity of 61.5% on angiotensin converting enzyme in 1.5% EPS concentration. Adsorption wavelength of EPS was UV-B,C . Beads based on EPS were prepared by w/o emulsion method and the shape of EPS beads observed by SEM was spherical and uniform.

• Applied Biological Chemistry
• /
• v.27 no.3
• /
• pp.151-157
• /
• 1984

Skyrin was extracted from Penicillium islandicum cultivated on synthetic Czapek-Dox medium. A preliminary experiment in Penicillium islandium using $[^{14}C]$-acetate proved the incorporation of $[^{14}C]$ into skyrin. In the cell-free system using the fungus $[^3H]$-emodin and $[^3H]$-emodinanthrone were shown to give some reliable evidences far the biosynthesis of skyrin. The incorporation of $[^3H]$-emodin was less significant than that of $[^{3}H]$-emodinanthrone. As a result of the cell-free experiment, the biosynthetic pathway of skyrin by the fungus was suggested as follows: $emodinanthrone{\rightarrow}emodin{\rightarrow}skyrin$.

• The Korean Journal of Malacology
• /
• v.9 no.2
• /
• pp.94-102
• /
• 1993

동양달팽이(Nesiohelix samarangae)의 자성생식기 중 정자낭(spermatheca)의 미세구조를 투과전자현미경을 이용하여 관찰하였다. 성체의 정자낭의 내강에서는 정자와 이와 관련된 물질들 또는 상피로부터의 분비물질들이 관찰되었다. 정자낭의 내강을 둘러싸고 있는 벽의 상피는 단층원주상피로서 내강과 연한 세포의 원형질막은 미세융모를 가지고 있었으며 섬모는 가지고 있지 않았다. 이 미세융모들의 기부에서는 고배율 하에서 pinocytotic vesicle들이 관찰되었고 때로 세포의 분비물을 세포 밖으로 방출하는 모습도 관찰되었다. 세포들의 상부세포질에는 많은 수의 mitochondria가 있었고, 때로 분비과립과 lysosomd들이 존재하기도 하였다. 이들보다 아래에는 잘 발달한 골지체와 과립소포체(RER)들이 있었다. 이 부위에서 분비과립들이 많이 형성되어 있는 모습이 세포에 따라 관찰되었고, 그 아래에 즉, 각 세포의 하반부 세포질에 상하로 긴 핵이 관찰되었다. 세포의 기부 원형질막은 상부 세포질 내로 깊게 그리고 수없이 많이 주름을 이루고 있어 인접한 세포와의 경계를 구분할 수 없을 정도였다. 기저막의 아래에는 근육다발과 색소세포들이 결합조직 내에서 관찰되었고, 정자낭의 외막은 큰 액포로 인하여 세포질들이 원형질막 주변으로 밀려나 있는 특이한 세포들로 이루어져 있었다. 정자낭의 기능은 정자를 일시 저장하며 정자낭 상피에서 분비되는 소화액들로 정자를 일차적으로 세포외 소화하고 소화되지 않은 물질들을 흡수하여 이차적으로 세포내소화하는 것으로 생각된다.

• Fire Science and Engineering
• /
• v.22 no.5
• /
• pp.61-66
• /
• 2008

In this research, gel compounds containing thermochromic ingredients were manufactured and evaluated to prevent the transition hazards of fire and explosion, which they are one of the methods for detecting abnormal conditions caused by overheating of special materials early. And also, compounds of viscoelastic and brushing types were manufactured as the kind and content of raw materials, and manufacturing process to enlarge the application for overheat-detecting targets. Test methods were conducted as chromism test, viscosity profile, starting time of thermochromism, and FT-IR analysis. Thermochromic gel materials exhibit chromism properties that can detect abnormal conditions effectively, and then they are possible to various applications.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.25 no.2
• /
• pp.45-57
• /
• 1999

Melanocytes, derived from neural crest, make melanin and protect skin from the hazardous ultraviolet light. Melanocytes with dendritic process has similar morphology with neurogenic cells and share growth factor receptors such as neurotrophin receptors. Melanogenesis can be regulated by ultraviolet light and inflammation of the skin. In addition, several factors such as hormone, cytokines, arachidonic acid can affect the proliferation and melanogenesis of melanocytes. For melanogenesis, melanocytes need expression of various genes including tyrosinase, TRP-1, TRP-2. In addition, melanin need to be transferred from melanocytes to surrounding keratinocytes. The biology of melanocytes is complex and mechanism of melanocytes proliferation and melanogenesis is still under the investigation.

• Korean Journal of Microbiology
• /
• v.42 no.3
• /
• pp.235-237
• /
• 2006

When fruit bodies of Coprinellus congregatus were matured, they were autolysed to form black ink. During the developmental changes, cell walls of basidia were degraded. Laccase formed melanin which was the typical black pigment of fungi, and chitinase hydrolyzed the chitin which was a component of fungal cell wall. When laccase and chitinase genes were used as the probe for the Northern analysis to confirm their expression during the fruit body development, both gene expressions were increased as the mushroom was getting matured.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.352-353
• /
• 2007

The spectrum for $0_{\circ}$, $90_{\circ}$-polarized light coincides with the spectrum for non-polarized light and also with the spectrum was observed in the LB film deposited using a fresh solution. And, the formation and dissociation of J-aggregates, anisotropic behavior was no longer observed in the heat treated merocyanine dyes LB films. But, in the optical absorption spectra of same LB films by UV irradiation at room temperature, their were observed only dissociation of J-aggregates, that is decrease of absorbance peak without change spectral shape. On the other hand, in the case of optical absorption spectra of the LB films by the heat treatment at $70^{\circ}C$ in the air, both of the shifted absorption bands decay and a monomer absorption peak of about 530 nm appears instead.

• Applied Chemistry for Engineering
• /
• v.27 no.2
• /
• pp.115-122
• /
• 2016

Melanin is a common name used for a certain type of natural dark pigments existing in living organisms, particularly in human hair, eyes, and skin. The unique free radical scavenging effect of melanine could help protecting cells and tissues from harmful UV light. While their exact molecular structures in nature are not still well defined, their multifunctional properties including electrical and ionic conductivities, antioxidation, wet adhesion, and metal ion chelation, are highlighted for the potential applications in bioorganic electronics including biomedical sensors and devices. In this mini-review, we will discuss sources, synthesis methods, structures and multifunctional properties of melanin materials in addition to current research directions on a wide range of applications.

• Korean Journal of Food Science and Technology
• /
• v.6 no.1
• /
• pp.1-5
• /
• 1974

The extraction mode of orange-yellow pigment from Gardenia is depended upon the extraction time, extraction temperature and volume of solvent. The amounts of the extracted-pigment (C) is proportional to the log ${\theta}^{1.15}$ of extraction time $({\theta}:0{\cdots}{\cdots}{\cdots}60$ min.), the log $T^{3.73}$ of extraction temperature $(T:5{\cdots}{\cdots}{\cdots}60^{\circ}C)$ and the log $S^{3.7}$ of volume of solvent $(S:5{\cdots}{\cdots}{\cdots}50ml)$ at $18^{\circ}C$ for 10 minutes. Finally, the general emperical equation was derived as follows; C=1.15 log ${\theta}$+3.73 log T+3.7 log S-7.0