• Korean Journal of Medicinal Crop Science
• /
• v.23 no.3
• /
• pp.231-236
• /
• 2015

Skin anti-wrinkle activities of the stems and leaves of Abeliophyllum distichum Nakai were evaluated by the extracts obtained from various extraction processes such as using hot water at $100^{\circ}C$, 70% ethanol at $85^{\circ}C$, and 70% ethanol with ultrasonication at $60^{\circ}C$ The ultrasonicated extract showed 95.62% of the highest cell viability in addition of $0.3mg/m{\ell}$ of the extracts into the normal human fibroblast cell, CCD-986sk. For antioxidant activities, the extracts using ultrasonicated extract showed the highest DPPH free radical scavenging as 80.27%, followed by 75.88% and 62.44% for the extracts using ethanol extract and water extract. The ultrasonicated extract also showed the highest elastase inhibition activity as 25.32%, compared to ethanol extract and water extract based method at 22.01% and 12.88%, respectively. MMP-1 production was most effectively decreased down to $2908.1pg/m{\ell}$ with ultrasonicated extract while $6640.8pg/m{\ell}$ with water extract and $3609.3pg/m{\ell}$ with ethanol extract, in addition of $0.3mg/m{\ell}$. Collagen production was increased up to $154.7ng/m{\ell}$ in addition of ultrasonicated extract, and followed by $121.4ng/m{\ell}$ and $31.2ng/m{\ell}$ for ethanol extract and water extract, respectively. These results indicate that the ethanol extract should have skin anti-wrinkling activities and can be improved by the ultrasonication process that high energy input elute more amounts of bioactive substances eluting more amounts of bioactive substances from the high energy input of ultrasonication.

• Applied Biological Chemistry
• /
• v.26 no.1
• /
• pp.41-46
• /
• 1983

The characteristics of crude polyphenol oxidase extracted from mushroom[Tricholoma matsutake(S. Ito et Imai) Sing.] were investigated. The enzyme showed highest affinity to pyrogaroll among trihydroxyphenols. Except for o-diphenols the enzyme was inactive in di-and monophenols. The optimum pH was about 4 and the optimum temperature ranged from 45 to $55^{\circ}C$. The enzyme activity was completely inhibited by $70^{\circ}C$ heat treatment for 2 min. $Cu^{++}$, $Fe^{++}$ and $Mg^{++}$ activated the enzyme at low concentration($10^{-1}mM$), but inhibited at high concentration (1mM). The most potent inhibitors were Na-diethyldithiocarbamate, L-ascorbic acid, L-cysteine and NaCl. The Km value with pyrogaroll was 0.88mM.

• Applied Biological Chemistry
• /
• v.26 no.1
• /
• pp.58-64
• /
• 1983

The fatty acid composition of phospholipid from the leaves of rice plants grown at $28^{\circ}C$ and harvested at the 3-4 leaf stage was determined for 8 cultivars. Change among cultivars observed in the composition has been found to be correlative to the chilling susceptivity of the plants at the given leaf-stage. The chilling-resistant cultivars contain phospholipid with higher degree of unsaturation and larger relative proportion of unsaturated fatty acids than the chilling-sensitive ones. The indices for unsaturation of phospholipid from a cultic-ar are well in accordance with its resistance to cold damage. clearly demonstrating that the fluidity of biomembrane which is generally regarded as the prerequisite for a cell to maintain its membrane-related physiological activity at a low temperature is exclusively controlled by the fatty acid composition of phospholipid. Also identified were the components of phospholipid, which are phosphatidyl serine and phosphatidyl coline as major components and phosphatidyl inositol as minor component plus 3 phospholipids in trace proportion, from every cultivar at the early growth-stage.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.6
• /
• pp.987-996
• /
• 2018

Bacterial programmed cell death is regulated by the toxin-antitoxin (TA) system. YhaV (toxin) and Pr1F (antitoxin) have been recently identified as a type II TA system in Escherichia coli. YhaV homologs have conserved active residues within the C-terminus, and to characterize the function of this region, we purified native YhaV protein (without denaturing) and constructed YhaV proteins of varying lengths. Here, we report a new low-temperature method of purifying native YhaV, which is notable given the existing challenges of purifying this highly toxic protein. The secondary structures and thermostability of the purified native protein were characterized and no significant structural destruction was observed, suggesting that the observed inhibition of cell growth in vivo was not the result of structural protein damage. However, it has been reported that excessive levels of protein expression may result in protein misfolding and changes in cell growth and mRNA stability. To exclude this possibility, we used an [$^{35}S$]-methionine prokaryotic cell-free protein synthesis system in vitro in the presence of purified YhaV, and two C-terminal truncated forms of this protein (YhaV-L and YhaV-S). Our results suggest that the YhaV C-terminal region is essential for mRNA interferase activity, and the W143 or H154 residues may play an analogous role to Y87 of RelE.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.25 no.4
• /
• pp.160-165
• /
• 2015

Lead-free piezoelectric materials have been actively studied to substitute for conventional PZT based solid solution, $Pb(Zr_xTi_{1-x}O_3)$, which occurs unavoidable PbO during the sintering process. Among them, Bismuth Sodium Titanate, $Na_{0.5}Bi_{0.5}TiO_3$ (abbreviated as NBT) based solid solution is attracted for the one of excellent candidates which shows the strong ferroelectricity, Curie temperature (Tc), remnant polarization (Pr) and coercive field (Ec). Especially, the solid solution of rhombohedral phase NBT with tetragonal perovskite phase has a rhombohedral - tetragonal morphotropic phase boundary. Modified NBT with tetragonal perovskite at the region of MPB can be applied for high frequency ultrasonic application because of not only its low permittivity, high electrocoupling factor and high mechanical strength, but also effective piezoelectric activity by poling. In this study, solid state ceramic processing of NBT and modified NBT, $(Na_{0.5}Bi_{0.5})_{0.93}Ba_{0.7}TiO_3$ (abbreviated as NBT-7BT), at the region of MPB using 7 % $BaTiO_3$ as a tetragonal perovskite was introduced and the structure between NBT and NBT-7BT were analyzed using rietveld refinement. Also, the ferroelectric and piezoelectric properties of NBT-7BT such as permittivity, piezoelectric constant, polarization hysteresis and strain hysteresis loop were compared with those of pure NBT.

• Journal of Hydrogen and New Energy
• /
• v.22 no.6
• /
• pp.905-912
• /
• 2011

In this study, the novel concept catalytic reactor was designed for water-gas shift reaction (WGS) under high pressure. The novel concept catalytic reactor was composed of an autoclave, the catalyst, and liquid water. Cu-ZnO/$Al_2O_3$ as the low temperature shift catalyst was used for WGS reaction. WGS in the novel concept catalytic reactor was carried out at the ranges of 150~$250^{\circ}C$ and 30~50 atm. The liquid water was filled at the bottom of the autoclave catalytic reactor and the catalyst of pellet type was located at the gas-liquid water interface. It was concluded that WGS reaction occurred over the surface of catalysts partially wetted with liquid water. The conversion of CO for WGS was also controlled with changing content of Cu and ZnO used as the catalytic active components. Meanwhile, the catalyst of honey comb type coated with Cu-ZnO/$Al_2O_3$ was used in order to increase the contact area between wet-surface of catalyst and the reactants of gas phase. It was confirmed from these experiments that $H_2$/CO ratio of the simulated coal gas increased from 0.5 to 0.8 by WGS at gas-liquid water interface over the wet surface of honey comb type catalyst at $250^{\circ}C$ and 50 atm.

• Journal of the Korean Institute of Gas
• /
• v.16 no.2
• /
• pp.60-66
• /
• 2012

With diversification of research and development activity according to fusion of state-of-the-art technology, potential hazard and risk factors in new forms have been increased in the laboratories. Also, as there are many cases where the experimental condition is extremely high/low temperature and pressure, many many accidents producing loss of life and/or injuries occur due to the extreme condition. In this study, The common fact questionnaire as the survey tool for the establishment of the accident prevention countermeasure in laboratory have been developed to safety security of the laboratory workers. The current status of chemical materials and the realization of important on laboratory safety management using the questionnaire investigated by an electronic mail and visiting survey in the laboratories and universities. The collected data was analyzed with Excel program and it can be utilized as basic data for accident prevention in laboratories.

• Journal of Digital Convergence
• /
• v.13 no.9
• /
• pp.515-521
• /
• 2015

In this study, we tried to analyze arterial stiffness of Jeju female divers who diver into cold water without the assistance of oxygen. For this purpose we measured pulse wave velocity and ankle-brachial index of Jeju female divers and same aged females who didn't have any cardiovascular risk for comparing the vascular stiffness. The results were the following : First, the light-femoral pulse wave velocity of Jeju female divers was significantly lower than normal women of the same ages. Second, Jeju female divers's ABI showed higher tendency than normal same aged women. These result showed that Jeju female divers' body had been completed for adaptation to low temperature and high pressure water environment through a long-term immersion activities in old age, as well as due to higher physical activity levels of Jeju female divers peripheral vascular resistance was not reduced.

• Archives of Pharmacal Research
• /
• v.28 no.4
• /
• pp.502-508
• /
• 2005

Titrated extract of Centella asiatica (TECA) contains three principal ingredients, asiaticoside (AS), asiatic acid (AA), and madecassic acid (MA). These components are known to be clinically effective on systemic scleroderma, abnormal scar formation, and keloids. However, one problem associated with administration of TECA is its low solubility in aqueous as well as oil medium. In this study, various nonionic surfactants and bile salts as anionic surfactant were tested and screened for solubilizing TECA with a view to developing topical hydrogel type of ointment which is stable physicochemically, and has better pharmacological effects. When TECA was incorporated into various nonionic surfactant systems, labrasol had the most potent capacity for solubilizing TECA. In cases of bile salt systems, Na-deoxycholate (Na-DOC) had foremost solubilizing capacity, even more than labrasol. In differential scanning calorimetric study, the peaks of AA, MA, AS and Na-DOC disappeared at the coprecipitate of $1\%$ TECA and $1\%$ Na-DOC, suggesting the optimum condition of Na-DOC for solubilizing TECA. When the physicochemical stability of hydrogel containing this mixture was assessed, it was stable at room temperature for at least one month. Pharmacologically it significantly decreased the size of wound area at the $9^{th}$ day when applied to the wound area of rat dorsal skin. Taken together, solubility of TECA was dramatically improved by using non ionic and anionic surfactant systems, and Na-DOC was found to be the most effective solubilizer of TECA in formulating a TECA-containing hydrogel typed ointment. Moreover this gel was considered to be applicable to clinical use for wound healing effect.

• Journal of Electrochemical Science and Technology
• /
• v.9 no.1
• /
• pp.28-36
• /
• 2018

Metal-organic frameworks have recently been considered very promising modifiers in electrochemical analysis due to their unique characteristics among which tunable pore sizes, crystalline ordered structures, large surface areas and chemical tenability are worth noting. In the present research, $Cu(btec)_{0.5}DMF$ was electrodeposited on the surface of glassy carbon electrode at room temperature under cathodic potential and was initially used as the active materials for the detection of $H_2O_2$. The cyclic voltammogram of $Cu(btec)_{0.5}DMF$ modified GC electrode shows distinct redox peaks potentials at +0.002 and +0.212 V in 0.1 M phosphate buffer solution (pH 6.5) corresponding to $Cu^{(II)}/Cu^{(I)}$ in $Cu(btec)_{0.5}DMF$. Acting as the electrode materials of a non-enzymatic $H_2O_2$ biosensor, the $Cu(btec)_{0.5}DMF$ brings about a promising electrocatalytic performance. The high electrocatalytic activity of the $Cu(btec)_{0.5}DMF$ modified GC electrode is demonstrated by the amperometric response towards $H_2O_2$ reduction with a wide linear range from $5{\mu}M$ to $8000{\mu}M$, a low detection limit of $0.865{\mu}M$, good stability and high selectivity at an applied potential of -0.2 V, which was higher than some $H_2O_2$ biosensors.