• Journal of Surface Science and Engineering
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• v.51 no.6
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• pp.344-353
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• 2018

Plasma electrolytic oxidation of Ti-25Ta-xHf alloy in electrolyte containing Ca and P for dental implants was investigated using various experimental techniques. Ti-25Ta-xHf (x=0 and 15 wt.%) alloys were manufactured in an arc-melting vacuum furnace. Micropores were formed in PEO films on Ti-25Ta-xHf alloys in 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at 240 V, 270 V and 300 V for 3 min, respectively. The microstructure of Ti-25Ta-xHf alloys changed from (${\alpha}^{\prime}+{\alpha}^{{\prime}{\prime}}$) phase to (${\alpha}^{{\prime}{\prime}}+{\beta}$) phase by addition of Hf. As the applied potential increased, the number of pore and the area ratio of occupied by micro-pore decreased, whereas the pore size increased. The anatase phase increase as the applied potential increased. Also, the crystallite size of anatase-$TiO_2$ can be controlled by applied voltage.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Food Science and Preservation
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• v.19 no.4
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• pp.604-610
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• 2012

The nutritional composition and in vitro anti-oxidant activities of blueberry (Vaccinium ashei) leaf extract were investigated to examine their physiological characteristics. Calcium was the most abundant mineral. The principal free sugars were glucose, sucrose, maltose, and fructose. The amino acids were mainly composed of glutamic acid and aspartic acid. The fatty acids consisted mainly of 40.94% saturated fatty acid and 54.35% unsaturated fatty acid. In addition, the 112.64 mg% of vitamin C was analyzed as a natural anti-oxidant. Based on the bioactivity-guided isolation principle, the resulting ethanolic extracts from the blueberry leaf were divided into several fractions of n-hexane, chloroform, ethyl acetate, and water. The ethyl acetate fraction showed the greatest total phenolic content. The total phenolics and flavonoid were 50.51 mg of GAE /g and 13.09 mg%, respectively. The ABTS-radical-scavenging activity of the ethyl acetate fraction was 97.53% at a concentration of 500 ${\mu}g/mL$. The ferric-reducing anti-oxidant power of the ethyl acetate fraction increased in a dose-dependent manner. The results suggest that the ethyl acetate fraction of the blueberry leaf extract has good in vitro anti-oxidant activities and excellent nourishment, and can thus be useful food resources.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.6
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• pp.319-327
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• 2004

This study was aimed at evaluating the effect of defibrotide on the development of the surgically induced reflux esophagitis, on gastric secretion, lipid peroxidation, polymorphonuclear leukocytes (PMNs) accumulation, polymorphonuclear leukocytes adherence, superoxide anion and hydrogen peroxide production in PMNs, scavenge of hydroxyl radical and hydrogen peroxide, cytokine (interleukin-1 ${\beta}$, tumor necrosis $factor-{\alpha}$) production in blood, and intracelluar calcium mobilization in PMNs. Defibrotide did not inhibit the gastric secretion and not change the gastric pH. Treatment of esophagitis rats with defibrotide inhibited lipid peroxidation, and myeloperoxidase (MPO) in the esophagus in comparison with untreated rats. Defibrotide significantly decreased the PMN adherence to superior mesenteric artery endothelium in a dose-dependent manner, Superoxide anion and hydrogen peroxide production in $1{\mu}M$ formylmethionylleucylphenylalanine (fMLP)- or $0.1{\mu}g/ml$ N-phorbol 12-myristate 13-acetate (PMA)-activated PMNs was inhibited by defibrotide in a dose-dependent fashion. Defibrotide effectively scavenged the hydrogen peroxide but did not scavenge the hydroxyl radical. Treatment of esophagitis rats with defibrotide inhibited interleukin-1 ${\beta}$ production in the blood in comparison with untreated rats, but tumor necrosis $factor-{\alpha}$ production was not affected by defibrotide. The fMLP-induced elevation of intracellular calcium in PMNs was inhibited by defibrotide. The results of this study suggest that defibrotide may have partly beneficial protective effects against reflux esophagitis by the inhibition lipid peroxidation, PMNs accumulation, PMNs adherence to endothelium, reactive oxygen species production in PMNs, inflammatory cytokine production(i.e. interleukin-1 ${\beta}$), and intracellular calcium mobilization in PMNs in rats.

• Journal of Evidence-Based Herbal Medicine
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• v.1 no.1
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• pp.13-18
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• 2008

Polygoni cuspidati Rhizoma (PCRH) has been used in treatment of menoxenia, skin burn, gallstone, hepatitis, hyperlipidaemia, favus athlete's foot, supperative dermatitis and inflammation. However, its effect in experimental models remains unknown. In this present study, the effect of PCRH for stability on mast cell was analyzed. Two g/kg PCRH inhibited the compound 48/80-induced anaphylaxis by 75%. In addition, PCRH inhibited the tumor necrosis factor-$\alpha$ and interleukin-8 secretion as compared with the phorbol 12-myristate 13-acetate plus calcium ionophore A23187 stimulated human mast cell line, HMC-1 cells. These results suggested PCRH may inhibit mast cell-mediated anaphylactic reaction.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.2
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• pp.111-115
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• 2004

Roundabout (Robo) is the transmembrane receptor for slit, the neuronal guidance molecule. In this study, the tyrosine phosphorylation of Robo was observed in Robo-transfected human embryonic kidney cells and developing rat brains, and found to be increased by the treatment with protein kinase A activator, forskolin. In contrast, protein kinase C activation by phorbol-12-myristate-13-acetate decreased the phosphorylation of Robo. Intracellular calcium was required for the tyrosine phosphorylation. Furthermore, the transfection of an Eph receptor tyrosine kinase dramatically enhanced the tyrosine phosphorylation. These findings indicate that the tyrosine phosphorylation of Robo is regulated by multiple mechanisms, and that Eph receptor kinases may play a role in the regulation of tyrosine phosphorylation of Robo in the rat brain.

• Natural Product Sciences
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• v.15 no.3
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• pp.139-143
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• 2009

The anaphylactic allergic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. In this report, I investigated the effect of ripe fruits of Rubus coreanus Miq. (Rosaceae) (RFRC) on the anaphylactic allergic reaction and studied its possible mechanisms of action. RFRC inhibited compound 48/80-induced systemic anaphylactic reaction in mice. RFRC dose-dependently decreased the IgE-mediated passive cutaneous anaphylaxis. In addition, RFRC decreased the gene expression and production of tumor necrosis factor-$\alpha$ (TNF-$\alpha$) and interleukin (IL)-6 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated human mast cells. These findings provide evidence that RFRC could be a candidate as an anti-allergic agent.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.54.1-54.1
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• 2011

Porous hydroxyapatite has been widely used as clinical implanted material. However, it has poor mechanical properties. To increase the strength as well as the biocompatibility of the porous HAp based artificial bone, it was fabricated by multi-extrusion process. Hydroxyapatite and graphite powders were mixed separately with ethylene vinely acetate and steric acid by shear mixing process. Hydroxyapatite composites containing porous microstructure were fabricated by arranging it in the die and subject it to extrusion process. Burn-out and sintering processes were performed to remove the binder and graphite as well as increase the density. The external and internal diameter of cylindrical hollow core were approximately 10.4 mm and 4.2 mm, respectively. The size of pore channel designed to increase bone growth (osteconduction) was around 150 ${\mu}m$ in diameter. X-ray diffraction analysis and SEM observation were performed to identity the crystal structure and the detailed microstructure, respectively.

• The Journal of Pediatrics of Korean Medicine
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• v.26 no.2
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• pp.13-24
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• 2012

Objectives NJ is being used to treat inflammatory diseases in Korea. In this study, we attempted to evaluate the effects of NJ on atopic dermatitis (AD)-like lesions and mast cell-mediated allergy inflammation in vivo and in vitro. Methods and Results We investigated to ascertain the pharmacological effects of NJ on 2,4-dinitrofluorobenzene (DNFB)-induced allergic reactions under in vivo conditions. Additionally, to find possible explanations for the anti-inflammatory mechanisms of NJ, we evaluated the regulatory effects of NJ on the level of inflammatory mediators in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated human mast cells (HMC-1). Conclusions NJ inhibited the production of the inflammatory cytokines (IgE, IL-6, IL-8 and TNF-${\alpha}$) significantly in vivo and in vitro.

• Natural Product Sciences
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• v.10 no.1
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• pp.24-28
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• 2004

The effects of aqueous extract of Artemisia iwayomogi (Compositae) (AIAE) on the mast cell-dependent allergic and inflammatory reactions were investigated. AIAE (0.05 to 1 g/kg) dose-dependently inhibited systemic allergic reaction induced by compound 48/80 in mice. AIAE (0.1 and 1 g/kg) also significantly inhibited local allergic reaction activated by anti-DNP IgE. AIAE (0.001 to 1 mg/ml) dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80. Moreover, AIAE inhibited the secretion of interleukin (IL)-6 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cell line (HMC-1) cells. These results provide evidence that AIAE may be beneficial in the treatment of allergic diseases.