• Molecules and Cells
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• 제26권5호
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• pp.486-489
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• 2008

Curcumin (diferuloylmethane), a pigment derived from turmeric, has anti-oxidant and anti-inflammatory activities. Accumulating evidence points to a biochemical link between increased oxidative stress and reduced bone density. Osteoclast formation was evaluated in co-cultures of bone marrow stromal cells (BMSC) and whole bone marrow cells (BMC). Expression of receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) was analyzed at the mRNA and protein levels. Exposure to curcumin led to dose-dependent suppression of osteoclastogenesis in the co-culture system, and to reduced expression of RANKL in $IL-1{\alpha}$-stimulated BMSCs. Addition of RANKL abolished the inhibition of osteoclastogenesis by curcumin, whereas the addition of prostaglandin $E_2$ ($PGE_2$) did not. The decreased osteoclastogenesis induced by curcumin may reduce bone loss and be of potential benefit in preventing and/or attenuating osteoporosis.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.49-54
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• 2004

Detailed flame structures of the opposed flames formed for different oxidant compositions are studied numerically. The detailed chemical reactions are modeled by using the CHEMKIN code. Only the $CO_2$ and $H_2O$ are assumed to participate by absorbing the radiative energy while all other gases are assumed to be transparent. The discrete ordinates method and the narrow band based WSGGM with a gray gas regrouping technique are applied for modeling the radiative transfer through non-homogeneous and non-isothermal combustion gas mixtures generated by the opposed flow flames. The results show that the different radiation model can cause different results for flame structures and the WSGGM with gray gas regrouping is successful in modeling the opposed flames with non-gray gas mixture. The numerical results show that the increases in $CO_2$ and $H_2O$ compositions cause to reduce the flame temperature and the NO formation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.384-384
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• 2012

We report nonvolatile memory properties of poly (3, 4-ethylenedioxythiophene) (PEDOT) thin films grown by vapor phase polymerization using FeCl3 as an oxidant. Liquid-bridge-mediated transfer method was employed to remove FeCl3 for generation of pure PEDOT thin films. From the electrical measurement of memory device, we observed voltage induced bipolar resistive switching behavior with ON/OFF ratio of 103 and reproducibility of more than 103 dc sweeping cycles. ON and OFF states were stable up to 104 seconds without significant degradation. Cyclic voltammetry data illustrates resistive switching effect can be attributed to formation and rupture of conducting paths due to oxidation and reduction of PEDOT. The maximum current before reset process was found to be increase linearly with increase in compliance current applied during set process.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.71-75
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• 2005

Green tea and their major constituents such as catechins are famous materials for their anti-oxidative and anti-carcinogenic activity, but many compounds with reducing power can promote the oxidation in their oxidized form or in the presence of metal ion. We investigated the pro-oxidative effect of the ethanol extract equivalent up to 30mg of dried weight of green tea leaves in four in vitro systems which could be used for detecting DNA damage. Although ethanol extract of green tea did not show significant mutagenicity in Salmonella typhimurium TA102, which is sensitive strain to oxidative stress, it degraded deoxyribose extensively in the presence of $FeCl_3-EDTA$ complex, promoted 8-oxoguanine formation in the live bacteria cell, Salmonella typhimurium TAI04, and cleaved super coiled DNA strand with the help of copper ion. It suggested that green tea, famous anti-oxidative material, can be pro-oxidant according to the condition of extraction or metal existence.

• 대한화학회지
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• 제56권5호
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• pp.591-596
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• 2012

Preparation of $AlPMo_{12}O_{40}$ (AlPMo) salts, supported on mesostructured SBA-15 silica, by the reaction deposition strategy causes the formation of isolated AlPMo nanocrystals inside the nanotubular channels. The remarkable characteristic of the SBA-15 structure is that all the cylindrical pores are connected by some small channels. This makes the whole pore system in SBA-15 three-dimensional. We have used 2D hexagonal SBA-15 silicas as hard templates for the nanofabrication of AlPMo salt nanocrystal. The oxidation of alcohols occurs effectively and selectively with $H_2O_2$ as the oxidant. AlPMo salt nanocrystal was used as the catalyst.

• Environmental Engineering Research
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• 제10권6호
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• pp.269-282
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• 2005

The novel behavior of ferrate(VI) has received an increased attention for its possible applications in various purposes particularly in the treatment of waste/effluent waters. It possess relatively high oxidizing capacity and the reduced ferrate(VI) into Fe(III) again an important and useful precipitant, coagulant, flocculants and likely to be a good adsorbent via the formation of ferric hydroxide for various metal cations. Moreover, the non-toxic effect makes it a 'green chemical' and further enhances its widespread uses in various purposes. Here an attempt has been made to review the applications of ferrate(VI) in the treatment of waste waters and also its possible future applications in the wastewater treatment technology.

• 생약학회지
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• 제48권2호
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• pp.155-159
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• 2017

Cudrania tricuspidata Bureau (Moraceae) is a traditional oriental medicine that has been widely used as anti-oxidant, anti-inflammatory and immunomodulatory in Korea. This study was performed that the 70% ethanol extract of the roots of C. tricuspidata (CTE) suppressed receptor activator of NF-${\kappa}B$ ligand (RANKL)-induced osteoclastogenesis, actin ring formation in RAW 264.7 cell lines. CTE significantly inhibited the JNK/mitogen-activated protein kinase (MAPK) signaling pathway without affecting ERK and p38 signaling in RANKL-stimulated RAW 264.7 cells. Also, CTE inhibited RANKL-induced expression of c-Fos, an upstream activator of NFATc1. Consequently, CTE suppresses osteoclast differentiation by inhibiting RANKL induced MAPK signaling pathways and disrupts the actin rings in mature osteoclasts. Thus, CTE can be used for the development of osteoporosis treatment drug with a natural material.

• 약학회지
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• 제56권6호
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• pp.390-394
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• 2012

A series of new pyridazinyl sulfoxides 3a~e and pyridazinyl sulfones 4a were synthesized for development of candidates to retain anticancer activity. The utility of sulfoxides and sulfones in both laboratory and industrial practice was quickly recognized, and these species have been extensively utilized, including as pharmaceutical intermediates and anticancer agents. Alkylthiopyridazines 2a~e were prepared from the 3,6-dichloropyridazine using allylthiolation with alkyl mercaptan. Sulfides could be oxidized to sulfoxides or sulfones using 1~3 equivalents of hydrogen peroxide as an oxidant. The oxidation of sulfoxides to sulfones was also accomplished with aqueous hydrogen peroxide. Formation of 3a~e and 4a was undertaken with stirring using 35% hydrogen peroxide at room temperature in acetic acid for 18~72 h. Synthetic compounds were identified using NMR spectrum.

• Archives of Pharmacal Research
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• 제29권7호
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• pp.577-581
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• 2006

Oxidative mechanisms are thought to have a major role in cataract formation and diabetic complications. Antioxidant enzymes play an essential role in the antioxidant system of the cells that work to maintain low steady-state concentrations of the reactive oxygen species. When HLE-B3 cells, a human lens cell line were exposed to 50-100 mM glucose for 3 days, decrease of viability, inactivation of antioxidant enzymes, and modulation of cellular redox status were observed. Significant increase of cellular oxidative damage reflected by lipid peroxidation and DNA damage were also found. The glycation-mediated inactivation of antioxidant enzymes may result in the perturbation of cellular antioxidant defense mechanisms and subsequently lead to a pro-oxidant condition and may contribute to various pathologies associated with the long term complications of diabetes.

• 대한의생명과학회지
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• 제27권4호
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• pp.231-238
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• 2021

Several structural proteins present in keratinocytes of the skin are known to play an important role in the formation of epidermal tissue and barrier function, and the absence of structural proteins in keratinocytes causes various skin diseases. In this study, 42 types of tetrapeptides derived from the sequence of Loricrin, a kind of terminally differentiating structural protein, were synthesized, and skin anti-aging properties were measured by measuring the elastase inhibition, proliferation of skin cells. The anti-aging efficacy was verified and, based on this, it succeeded in selecting one of the most excellent peptides. It is expected that the selected tetrapeptide can be used as a raw material for various cosmetics and quasi-drugs based on anti-aging and skin cell proliferation effects.