• Journal of Ginseng Research
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• v.37 no.4
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• pp.401-412
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• 2013

Korean Red Ginseng (KRG) is an oriental herbal preparation obtained from Panax ginseng Meyer (Araliaceae). To expand our understanding of the action of KRG on central nervous system (CNS) function, we examined the effects of KRG on tissue plasminogen activator (tPA)/plasminogen activator inhibitor-1 (PAI-1) expression in rat primary astrocytes. KRG extract was treated in cultured rat primary astrocytes and neuron in a concentration range of 0.1 to 1.0 mg/mL and the expression of functional tPA/PAI-1 was examined by casein zymography, Western blot and reverse transcription-polymerase chain reaction. KRG extracts increased PAI-1 expression in rat primary astrocytes in a concentration dependent manner (0.1 to 1.0 mg/mL) without affecting the expression of tPA itself. Treatment of 1.0 mg/mL KRG increased PAI-1 protein expression in rat primary astrocytes to $319.3{\pm}65.9%$ as compared with control. The increased PAI-1 expression mediated the overall decrease in tPA activity in rat primary astrocytes. Due to the lack of PAI-1 expression in neuron, KRG did not affect tPA activity in neuron. KRG treatment induced a concentration dependent activation of PI3K, p38, ERK1/2, and JNK in rat primary astrocytes and treatment of PI3K or MAPK inhibitors such as LY294002, U0126, SB203580, and SP600125 (10 ${\mu}M$ each), significantly inhibited 1.0 mg/mL KRG-induced expression of PAI-1 and down-regulation of tPA activity in rat primary astrocytes. Furthermore, compound K but not other ginsenosides such as Rb1 and Rg1 induced PAI-1 expression. KRG-induced up-regulation of PAI-1 in astrocytes may play important role in the regulation of overall tPA activity in brain, which might underlie some of the beneficial effects of KRG on CNS such as neuroprotection in ischemia and brain damaging condition as well as prevention or recovery from addiction.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.125-130
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• 2001

Experimental and analytical researches have been conducted on the twin-fluid atomizers for better droplet breakup during the past decades. But, the studies on the disintegration mechanism still present a great challenge to understand the drop behavior and breakup structure. In an effort to describe the aerodynamic behavior of the sprays issuing from the internal mixing counter-swirling nozzle, the spatial distribution of axial (U) radial (V) and tangential (W) components of droplet velocities are investigated across the radial distance at several axial locations of Z=30, 50, 80, 120 and 170mm, respectively. Experiments were conducted for the liquid flow rates which was kept constant at 7.95 g/s and the air injection pressures were varied from 20 kPa to 140 kPa. Counter-swirling internal mixing nozzles manufactured at angles of $15^{\circ},\;30^{\circ},\;45^{\circ}$ and $60^{\circ}$ the central axis with axi-symmetric tangential-drilled holes was considered. The distributions of velocities and turbulence intensities are comparatively analyzed. PDPA is installed to specify spray flows, which have been conducted along the axial downstream distance from the nozzle exit. Ten thousand of sampling data was collected at each point with time limits of 30 second. 3-D automatic traversing system is used to control the exact measurement. It is observed that the sprays with all swirl angle have the maximum SMD for on air injection pressure of 20 kPa and 140 kPa with centerline, respectively. The nozzle with swirl angle of $60^{\circ}$ has vest performance.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.113-118
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• 1992

To elucidate a part of phosphorus cycle an'd the nutritional status of phosphorus. the degradation rates of organic phosphate by phosphatase activity (PA). were studied at the water column of Lake Soyang. from March 1900 to April 1991. Phosphatase activity showed the range of 1-2220 nMillhr. Its maximum value was recortled on August and minimum during October and November. The PA and chlorophyll u v~luess howed high correlation coefficent (0.69). and the values of specific astivity was highest during Winter, 45-12\ulcorner nMihripg chl. a, and lowest on October. 2 nMl hripg chl. 11. The values of PA and bioavailable dissolved inorganic phosphate (DIP) showed negative correlation in surface water. During destratification period (Oct. and Nov. 1990). the values of PA were about 11240 times lower than those during August albeit high concentration of chlorophyll a (1.7- 7.2 mglm'). Such results seem to be cause'd by DIP supply from the metalimnion. hypolimnion ant1 sediment. With these results. phosphate was sufficient to sustain the biomass in Autumn. and internal loading of phosphate shoultl accelerate the eutrophication in Lake Soyang.

• Korean Journal of Materials Research
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• v.3 no.3
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• pp.215-222
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• 1993

Malononitrile(MN) as a reactive additive was added to Diglycidyl ether of bisphenol A (DGEBA)/Methylene dianiline (MDA) system in order to modify a thermosetting epoxy resin. Cure ki. netics and cure mechanism of this modified system were investigated by using DSC(differential scanning calorimetry) and FT-IR(fourier transform infrared spectrometry). Cure kinetics gave an information that the DGEBA/MDA system modified with MN should cure at over $110^{\circ}C$ after curing at about $80^{\circ}C$ for the complete curing. The activation energy of the first cure was nearly constant and that of the second cure was increased as the MN content was increased. Cure mechanism for the system was investigated with the samples cured every $30^{\circ}C$, from $80^{\circ}C$ to $170^{\circ}C$, for Ihr. It was known that the cure reactions of the epoxy-diamine system were composed of PA -E, SA - E and E-OH reactions. Beside these three reactions, in the DGEBA/MDA/MN system PA-CN and CN-OH reaction was found.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.213-219
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• 2011

The metastatic effect of Eupatorium japonicum extract (EJE) on MDA-MB-231 human breast cancer cells was investigated. MDA-MB-231 cells were treated with various concentrations of EJE (0, 5, 10 and $20{\mu}g/mL$). EJE inhibited cell migration, invasion and adhesion of MDA-MB-231 cells in dose-dependent manners. Gelatin zymography exhibited that EJE significantly down regulated secretion of matrix metalloproteinase (MMP)-9 and MMP-2. EJE decreased the protein levels of tissue inhibitor of metalloproteinase (TIMP)-1 but increased TIMP-2 levels. Additionally, EJE reduced the protein and mRNA levels of urokinase-type plasminogen activator (uPA), vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM). In several solvent fractions of EJE, the hexane fraction markedly decreased MDAMB-231 cell migration. Thus, these finding suggest that EJE may be a potential antimetastatic agent, which can considerably inhibit the metastatic and invasive capacity of breast cancer cells.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.15-20
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• 2006

EDTA is known to have bacteriocidal effect on Vibrio vulnificus, pathogen of septicemia by osmotic shock in seafoods. Attempts were made to elucidate the bacteriocidal effect of phytic acid (PA) as a substitute for EDTA against V. vulnificus and its inhibition effect on the septicemia, which induces liver damage of the mice by the pathogen. Viable cells of V. vulnificus with the initial titre of $1.7{\times}10^6$ c.f.u. $ml^{-1}$ decreased by 90.6% after 1 min and 99.6% after 5 min in distilled water. The titre decreased by 65.9% and 94.5% in 2 mM solution of $Mg^{2+}$. In 0.1 mM solution of PA, the rate of decrease in titre was 97.4% after 1 min of incubation and 99.8% after 5 min, compared to 95.7% and 99.8% in 0.1 mM solution of EDTA. The bacteriocidal effect of PA solution at a concentration of 1 mM was marked: the rate of decrease in titre was 99.9% after 1 min. In relation to the bacteriocidal effect, PA was evaluated as a potential therapeutic agent for V. vulnificus septicemia in mouse. When the survival periods of mice were investigated by PA and EDTA treatment after the pathogen injection, the group of mice which infected by a low concentration of the strain survived longer than that inoculated at high concentration; also, the ratio of survival was 1.3 times higher in PA than in EDTA, showing that the fatal rate depended on the inoculation concentration. Although survival periods of mice induced with liver damage by carbon tetrachloride and then inoculated with the strain showed a similar trend, the fatal rate of mice was 2 times faster than those inoculated with only pathogen into normal liver, These results indicate that the infection by V. vulnificus was more fatal to those with liver disease. Also, symptoms of hemorrhage and inflammation on the mice with induced liver damage were reduced in case there was phytic acid treatment at each concentration.

• Biomolecules & Therapeutics
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• v.15 no.3
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• pp.150-155
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• 2007

In the present study, we have tested the effect of dioleoyl phosphatidic acid (PA) on intracellular $Ca_{2+}$ concentration ($[Ca^{2+}]_{i}$) in two human colon cancer cell lines (HCT116 and HT29). PA and lysophosphatidic acid (LPA), a bioactive lysolipid, increased $[Ca^{2+}]_{i}$ in both HCT116 and HT29 cell lines. Increases of $[Ca^{2+}]_{i}$ by PA and LPA were more robust in HCT116 cells than in HT29 cells. A specific inhibitor of phospholipase C (U73122), however, was not inhibitory to the cell responses. Pertussis toxin, a specific inhibitor of $G_{i/o}$ type G proteins, however, had an inhibitory effect on the responses except for an LPA-induced one in HT29 cells. Ruthenium red, an inhibitor of the ryanodine receptor, was not inhibitory on the responses, however, 2-APB, a specific inhibitor of inositol 1,4,5-trisphosphate receptor, completely inhibited both lipid-induced $Ca^{2+}$ increases in both cell types. Furthermore, by using Ki16425 and VPC32183, two structurally dissimilar specific antagonists for $LPA_{1}/LPA_{3}$ receptors, an involvement of endogenous LPA receptors in the $Ca^{2+}$ responses was observed. Ki16425 completely inhibited the responses but the susceptibility to VPC32183 was different to PA and LPA in the two cell types. Expression levels of five LPA receptors in the HCT116 and HT29 cells were also assessed. Our data support the notion that PA could increase $[Ca^{2+}]_{i}$ in human colon cancer cells, probably via endogenous LPA receptors, G proteins and $IP_{3}$ receptors, thereby suggesting a role of PA as an intercellular lipid mediator.

• Journal of the Korean Wood Science and Technology
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• v.45 no.2
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• pp.223-231
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• 2017

This work was conducted to investigate on the effect of urea-formaldehyde (UF) resin viscosity on plywood adhesion. The viscosity of UF resin was controlled either by adjusting the condensation reaction during its synthesis to obtain different target viscosities (100, 200 and 300 mPa.s) at two levels of formaldehyde/urea (F/U) mole ratios (1.0 and 1.2) or by adding different amounts (10, 20 and 30%) of wheat flour into the resins for the manufacture of plywood. When the viscosity of UF resin increased by the condensation reaction, the adhesion strength of plywood bonded with UF resin of 1.2 F/U mole ratio consistently increased, while those bonded with the 1.0 F/U mole ratio resin slightly decreased, suggesting a difference in the adhesion in plywood. However, the adhesion strength of plywood decreased as the viscosity increased by adding wheat flour, regardless of F/U mole ratio. The manipulation of UF resin viscosity by adjusting the condensation reaction was much more efficient than by adding wheat flour in improving the adhesion performance of plywood. These results indicated that a way of controlling the viscosity of UF resin adhesives has a great influence to their adhesion in plywood.

• Journal of The Korean Astronomical Society
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• v.25 no.2
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• pp.105-109
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• 1992

We show that spacing patterns of planets and satellites in the solar system are formulatable in a single form. It is suggested that a possible explanation for the rule might be the orbital resonance effect, which has existed at an earlier epoch of the solar (planet) system. By extrapolating the formulated spacing patterns beyond the sun-Pluto distance, we find the sun-Planet X distance falls in a range ($46{\sim}79$) A. U..

• Archives of Pharmacal Research
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• v.1 no.1
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• pp.41-54
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• 1978

Aspirin is one of the oldest synthetic drugs and remains the most widely used medical agent. It is a household remedy effective in treating such common ailments as headache, minor muscular pain and fever. Aspirin is the drug choice for rheumatic fever and arthritis which some five million Americans suffer. Lately it has been established by double-blind and randomized clinical studies that regular aspirin intake reduces the incidence of mild strokes and heart attackes.