• Journal of Acupuncture Research
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• v.19 no.4
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• pp.190-199
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• 2002

Objective : This study was performed to determine if Scutellaria balicalensis Georgi extract (SbGE) prevents oxidant-induced membrane transport dysfunction in renal tubular cells. Methods : Membrane transport function was estimated by measuring $Na^+$-dependent inorganic phosphate transport in opossum kidney (OK) cells. $H_2O_2$ inhibited phosphate transport in a dose-dependent manner. Results : The inhibitory effect of $H_2O_2$ was significantly prevented SbGE over concentration range of 0.005-0.05%. $H_2O_2$ caused ATP depletion, which was prevented by SbGE. $H_2O_2$ induced the loss of mitochondrial function as evidenced by decreased MTT reduction and its effect was prevented by SbGE. The $H_2O_2$-induced inhibition of phosphate transport was not affected by a potent antioxidant DPPD, but the inhibition was prevented by an iron chelator deferoxamine, suggesting that $H_2O_2$ inhibits $Na^+$-dependent phosphate transport via an iron-dependent nonperoxidative mechanism in renal tubular cells. Conclusion : These data suggest that SbGE may exert the protective effect against oxidant-induced membrane transport dysfunction by a mechanism similar to iron chelators in renal epithelial cells. However, furher studies should be carried out to find the active ingredient(s) of SbGE that exerts the protective effect.

• Journal of Acupuncture Research
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• v.18 no.3
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• pp.69-78
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• 2001

목적 : 본 연구는 최근 임상에서 많이 사용하는 자하차(紫河車) 약침액(藥鍼液)이 과산화수소($H_2O_2$)로 야기된 송과선 세포의 apoptosis에 있어서 세포 보호에 미치는 영향과 그 기전을 분석하였다. 방법 및 결과 : MTT assay를 이용하여 분석한 결과 처리 시간 및 농도에 따른 세포 독성의 효과가 $H_2O_2$ 투여로부터 관찰되었다. 또한 자하거 약침액은 세포 증식 효과를 나타내었고 자하거 약침액을 전처치하고 $H_2O_2$를 처치하였을 때 세포 독성이 크게 감소되었다. DAPI staining에서 자하거 약침액 투여군은 $H_2O_2$ 투여군에 비해 fragmentation이 억제되었다. TUNEL assay를 통하여 자하거 약침액 투여군은 $H_2O_2$ 투여군에 비하여 TUNEL 양성세포의 발현이 감소되었다. Flow cytometry를 통하여 자하거 약침액 투여군은 $H_2O_2$ 투여군에 비하여 세포주기 중 sub G1 분획의 증가가 억제되었다. 결론 : 이상의 결과를 통하여 자하거 약침액이 $H_2O_2$로 유발된 apoptosis에서 세포보호 효과가 있음이 확인되었다.

• Biomedical Science Letters
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• v.8 no.4
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• pp.251-256
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• 2002

This study was undertaken to determine the underlying mechanisms of reactive oxygen species-induced cell injury in renal epithelial cells and whether there is a difference in the role of lipid peroxidation between freshly isolated renal cells and cultured renal cells. Rabbit renal cortical slices were used as a model of freshly isolated cells and opossum kidney (OK) cells as a model of cultured cells. Cell injury was estimated by measuring lactate dehydrogenase (LDH) release in renal cortical slices and frypan blue exclusion in OK cells. $H_2O$$_2$ was used as a drug model of reactive oxygen species. $H_2O$$_2$ induced cell injury in a dose-dependent manner in both cell types. However, renal cortical slices were resistant to $H_2O$$_2$ approximately 50-fold than OK cells. $H_2O$$_2$-induced cell injury was prevented by thiols (glutathione and dithiothreitol) and iron chelators (deferoxamine and phenanthroline) in both cell types. $H_2O$$_2$-induced cell injury in renal cortical slices was completely prevented by antioxidants N,N-diphenyl-p -phenylenediamine and Trolox, but the cell injury was not affected by these antioxidants in OK cells. $H_2O$$_2$ increased lipid peroxidation in both cell types, which was completely inhibited by the antioxidants. These results suggest that $H_2O$$_2$ induces cell injury through a lipid peroxidation-dependent mechanism in freshly isolated renal cells, but via a mechanism independent of lipid peronidation in cultured cells.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.113-118
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• 1977

Into the precontaminated farm milk hydrogen peroxide ($H_2O$$_2$) was added at the concentrations ranging from 0.01％ to 0.05％ and kept at 3$0^{\circ}C$ for 16 hours with periodical determinations for viable counts, residual $H_2O$$_2$, and lactic acid. Under the tested conditions the initial level of contaminated bacteria could be arrested from growing at least for 8, 12, and 16 hours by treating the milk with 0.01, 0.02. and 0.03 per cent of $H_2O$$_2$, respectively. Furthermore, when the $H_2O$$_2$concentrations ware limited within the level of 0.03 Per cent the added $H_2O$$_2$was completely decomposed within 12 hours without the aid of external catalase and the decomposition time decreased in parallel with the $H_2O$$_2$ concentrations. A safer use of $H_2O$$_2$for preserving farm milk temporarily by limiting its concentration has been discussed.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.442-447
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• 2001

The charge-transfer compound (OMTTF)AuCl$_4$ was prepared from the direct reaction of octamethylenethiafulvalene (OMTTF) with HAuCl$_4{\cdot}xH_2$O in THF. (OMTTF)$_2PtCl_4$, (OMTTF)_2IrCl_6{\cdot}2H_2$O, and (OMTTF)Os$Cl_5{\cdot}THF$ were also formed using $H_2PtCl_6{\cdot}xH_2O$, $H_2IrCl_6{\cdot}xH_2O$ and $H_2OsCl_6$, respectively. The prepared compounds were characterized by magnetic (EPR, magnetic susceptibility), spectroscopic (IR, UV-Vis), electrochemical (CV) methods, and the powdered electrical conductivity measurement. The powdered electrical conductivities at room temperature were ~$10^{-7}S{\cdot}cm^{-1}$. The experimental results show that $OMTTF^+$ monocation radicals exist in all of the prepared compounds. The redox potential of OMTTF supports that $OMTTF^+$ is relatively stable. The magnetic properties indicate that there are significant magnetic interactions between the localized odd electrons on the central metal (Ir and Os) ions and the odd electrons resided on $OMTTF^+$ cation radicals in both (OMTTF) $_2IrCl_6{\cdot}2H_2O$ and (OMTTF)$OsCl_5{\cdot}THF$.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.51-56
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• 2000

The Photocatalytic decolorization and degradation of commercial dyes were studied using a batch reactor. Degussa P25 titanium dioxide and $H_2O_2$ were used as the photocatalyst and proved to be effective for dyes degradation when they were irradiated with UV light. The light source was a 20W low pressure mercury lamp. Three different kinds of dyes, such as direct dye(congo red), acid dye (acid black) and disperse dye(disperse blue) were tested. Extending the UV only treatment up to 120min, direct dye was decolorized to 60% and degraded to 30% as COD. On the other side, acid and disperse dyes were eliminated less than 10% as color and COD. But, color and COD were eliminated about 90% for all of the three dyes by $UV/H_2O_2$ system. And then the most effective decolorization was done for direct dye with 96% removal efficiency by $UV/TiO_2$ system at 120min with 500mg/L of $TiO_2$.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.1
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• pp.39-47
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• 2016

Background: Oxidative stress occurs during the aging process and other conditions such as bone fracture, bone diseases, and osteoporosis, but the role of oxidative stress in bone remodeling is unknown. Propofol exerts antioxidant effects, but the mechanisms of propofol preconditioning on oxidative stress have not been fully explained. Therefore, the aim of this study was to evaluate the protective effects of propofol against $H_2O_2$-induced oxidative stress on a human fetal osteoblast (hFOB) cell line via activation of autophagy. Methods: Cells were randomly divided into the following groups: control cells were incubated in normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$) without propofol. Hydrogen peroxide ($H_2O_2$) group cells were exposed to $H_2O_2\;(200{\mu}M)$ for 2 h, propofol preconditioning (PPC)/$H_2O_2$ group cells were pretreated with propofol then exposed to $H_2O_2$, 3-methyladenine (3-MA)/PPC/$H_2O_2$ cells were pretreated with 3-MA (1 mM) and propofol, then were exposed to $H_2O_2$. Cell viability and apoptosis were evaluated. Osteoblast maturation was determined by assaying bone nodular mineralization. Expression levels of bone related proteins were determined by western blot. Results: Cell viability and bone nodular mineralization were decreased significantly by $H_2O_2$, and this effect was rescued by propofol preconditioning. Propofol preconditioning effectively decreased $H_2O_2$-induced hFOB cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol. In western blot analysis, propofol preconditioning increased protein levels of collagen type I, BMP-2, osterix, and TGF-${\beta}1$. Conclusions: This study suggests that propofol preconditioning has a protective effect on $H_2O_2$-induced hFOB cell death, which is mediated by autophagy activation.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.269-274
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• 2010

The solubility and the physicochemical property (refractive index) in the NaCl-$CaCl_2$-$H_2O$ and KCl-$CaCl_2$-$H_2O$ systems were determined at $50^{\circ}C$ and the phase diagrams and the diagrams of physicochemical property vs composition were plotted. One invariant point, two univariant curves, and two crystallization zones, corresponding to sodium Chloride (or potassium chloride), dihydrate ($CaCl_2{\cdot}2H_2O$) showed up in the phase diagrams of the ternary systems. The mixing parameters ${\theta}_{M,Ca}$ and ${\Psi}_{M,Ca,Cl}$ (M = Na or K) and equilibrium constant $K_{sp}$ were evaluated in NaCl-$CaCl_2-H_2O$ and KCl-$CaCl_2-H_2O$ systems by least-squares optimization procedure, in which the single-salt Pitzer parameters of NaCl, KCl and $CaCl_2$ ${\beta}^{(0)}$, ${\beta}^{(1)}$, ${\beta}^{(2)}$ and $C^{\Phi}$ were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

• Microbiology and Biotechnology Letters
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• v.8 no.3
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• pp.181-191
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• 1980

For the purpose of studies on the citric acid production, some experiments were carried out with isolated strains. The results obtained were as follows. 1) The optimal culture media of the strain M-80 in surface culture contained 140g of sucrose, 3.0g of (N $H_4$)$_2$S $O_4$, 1.5g of K $H_2$P $O_4$, 0.2g of MgS $O_4$.7$H_2O$, 3.0mg of F $e^{++}$, 1.0mg of Z $n^{++}$, 0.5N HCI to a pH of 5.0 and distilled water to 1.0 liter; and that of the strain M-315 in surface culture contained 140g of sucrose, 2.0g of N $H_4$N $O_3$, 1.0g of K $H_2$P $O_4$, 0.25g of MgS $O_4$. 7$H_2O$, 2.0mg of F $e^{++}$, 2.0mg of Z $n^{++}$, 0.05mg of C $u^{++}$, 0.5N HCI to a pH of 4.5 and distilled water to 1.0 liter. While that of the strain M-315 in submerged culture contained 140g of sucrose, 2.5g of N $H_4$N $O_3$, 1.5g of K $H_2$P $O_4$, 0.3g of MgS $O_4$. 7$H_2O$, 3.0mg of F $e^{++}$, 0.1mg of C $u^{++}$, 0.5N HCI to a pH of 4.5 and distilled water to 1.0 liter. The optimal temperature and size of inoculum were mostly 28-3$0^{\circ}C$, 10$^{7}$ -10$^{8}$ spores/50ml, respectively. 2) Through the course of citric acid production, the growth of strains had nearly been completed, pH value was rapidly decreased below 2.0 and the content of sugar was also reduced, while the accumulation of citric acid in media was remarkably begun in about 3-4 days. The yields of citric acid generally reached the maximum level in 8-10 days in surface or submerged fermentation process. 3) Methanol was effective citric acid production when they were added to fermentation media. In the case of surface culture, by addition of 2％ (strain M-80), 3％ (strain M-315), the yields of citric acid was increased 6.5％, 20.6%, respectively and 5.0% yield was increased by addition of 3% methanol in submerged culture media of the strain M-315. 4) Chromatography analysis of culture broth after fermentation under optimal culture conditions detected that the majority of acid in media was citric acid. 72.1mg/ml, 98.1mg/ml, of citric acid were determined in surface culture media by strains of M-80, M-315, and 59.8 mg/ml of citric acid was contained in the submerged culture media by the strain M-315. strain M-315.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.407-410
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• 2012

The properties of Al-doped ZnO (AZO) films were investigated as a function of H2/(Ar + H2) gas ratio using an AZO (2 wt% Al2O3) ceramic target in a radio frequency (RF) magnetron sputtering system. The deposition process was done at 200 ℃ and in 2 × 10-2Torr working pressure and with various ratios of H2/(Ar + H2) gas. During the AZO film deposition process, partial H2 gas affected the AZO film characteristics. The electron resistivity (~ 9.21 × 10-4 Ωcm) was lowest and mobility (~17.8 ㎠/Vs) was highest in AZO films when the H2/(Ar + H2) gas ratio was 2.5%. When the H2/(Ar + H2) gas ratio was increased above 2.5%, the electron resistivity increased and mobility decreased with increasing H2/(Ar + H2) gas ratio in AZO films. The carrier concentration increased with increasing H2/(Ar + H2) gas ratio from 0% to 7.5%. This phenomenon was explained by reaction of hydrogen and oxygen and additional formation of oxygen vacancy. The average optical transmission in the visible light wavelength region over 90% and an orientation of the deposition was [002] orientation for AZO films grown with all H2/(Ar + H2) gas ratios.