• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.19-34
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• 1996

It has been demonstrated that intracoronal bleaching of pulpless teeth may result in cervical root resorption. Several authors postulated that bleaching agents such as hydrogen peroxide penetrated through the dentinal tubules to damage the surrounding tissues that cause cervical root resorption. The purpose of this study was to suggest on in vitro model for direct determination of hydrogen peroxide penetration through CEJ during nonvital bleaching. In addition, this model permit the quantification of the amount of hydrogen peroxide penetrated during the procedure. Freshly extracted intact premolars, removed for orthodontic reasons were used. Root canal treatment was performed in each tooth. And then the outer surface and crown portion of the teeth was sealed with wax leaving the CEJ. The prepared teeth mounted on the wax laminates were placed in plastic assay tubes containing 1.5ml bidistilled water with their entire root, including the CEJ, submerged in the solution. The teeth were dividied into four groups. Thermo group : thermocatalytic bleaching with superoxol Walk group: walking bleaching with sodium perborate & superoxol Combi group : combination of thermocatalytic & walking bleaching Dw group : walking bleaching with sodium perborate & water The bleaching procedure was performed three times. The bleaching intervals were at 3 days. The hydrogen peroxide present in the assay system was added to ferrous ammonium sulfate resulting in ferric ion release. Upon the addition of potassium thiocyanate a ferrithiocyanate complex results, which absorbs light at the wavelength of 467nm. The radicular penetration of hydrogen peroxide in the four groups was assessed directly using spectrophotometer. The amount of hydrogen peroxide in the samples tested is determined by comparing them with a standard curve generated by known amounts of hydrogen peroxide. The results were obtained as follows : 1. In all experimental groups except the Dw group showed lower penetration amount in day 4 than day 1, there was statistical importance in the difference (P<0.05). 2. After 3rd treatment, Thermo group showed slightly increased value and narrow distribution. Walk group showed much more penetration amount and widely dispersed value. Value of Combi group showed wide distribution without regard to treatment time, but value of Dw group evenly distributed. 3. Thermo group, Walk group and Dw group showed a tendency of increasing penetration amount with increasing treatment times(P<0.01), but Combi group revealed no statistically important differences. 4. Combi group showed the highest degree of penetration. Walk group showed lower penetration than Combi group. Thermo group & Dw group showed lower than Walk group. 5. Cervical root permeability to hydrogen peroxide varied from 0 to 35 %.

• Korean Journal of Food Science and Technology
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• v.49 no.1
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• pp.110-116
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• 2017

${\gamma}-Oryzanol-loaded$ calcium-pectin micro- and nanocapsules were prepared by ionic gelation to improve oxidation stability and the effect of particle size on capsule properties was investigated. The physical properties were influenced by preparation conditions such as concentrations of pectin, $CaCl_2$, ${\gamma}-oryzanol$, and hardening time. Particle sizes of micro- and nanocapsules that showed the maximum encapsulation efficiency and sustained release were $2.27{\pm}0.02mm$ and $347.7{\pm}58.1nm$, respectively. Microcapsules showed higher encapsulation efficiency ($50.73{\pm}1.98%$) than nanocapsules ($17.70{\pm}2.04%$), while nanocapsules showed more sustained release and higher stability than microcapsules. Release of ${\gamma}-oryzanol$ from both microand nanocapsules, which was low in gastric environments and promoted in intestinal environments, showed suitable characteristics for oral administration. Furthermore, antioxidant activity of ${\gamma}-oryzanol$ against autoxidation of linoleic acid was prolonged by both micro- and nanoencapsulation in a ferric thiocyanate test. Therefore, micro- and nanoencapsulation using pectin can be effective for improving biodelivery, stability, and antioxidant activity of ${\gamma}-oryzanol$.

• Food Science and Preservation
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• v.13 no.3
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• pp.413-419
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• 2006

This study was investigated to analyze the antioxidant activity or extracts form Elaeagnus multiflora Thunb for development to the functional materials. The antioxidative activities of water ethanol and methanol extracts from the Elaeagnus multiflora Thunb were analyzed by electron donating ability (EDA), anti-oxidization activity, superoxide dismutase (SOD)-like activity, The superoxide anion radical-scavenging activity, and nitrite scavenging ability. The Etectron donating ability of methanol extract was higher in 1.0 mg/mL of extraction solution than those of ethers. The anti-oxidization activity of ethanol and methanol extracts by thiocyanate method using linolenic acid system was higher than those of the water extract. The SOD-like activity was increased with increase of the extract concentration in each extracts. The SOD-like activity was highest in 2.0 mg/mL of methanol extract. The superoxide anion radical-scavenging activity was increased with increase of the concentration in the ethanol extract and methanol extract. The nitrite scavenging ability of water extracts in 1.0 mg/mL of extraction soiution in pH 1.2 was higher than ethanol extrats and methanol extracts. The nitrite scavenging ability of all extracts was decreased according to increase of pH.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.758-764
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• 2014

Femtosecond vibrational spectroscopy was used to measure the vibrational population relaxation time ($T_1$) of different anions bound to ferric myoglobin ($Mb^{III}$) and hemoglobin ($Hb_{III}$) in $D_2O$ at 293 K. The $T_1$ values of the anti-symmetric stretching (${\nu}_1$) mode of NCS in the $NCS^-$ bound to $Mb^{III}$ ($Mb^{III}$NCS) and $Hb_{III}$ ($Hb_{III}$NCS) in $D_2O$ are $7.2{\pm}0.2$ and $6.6{\pm}0.2$ ps, respectively, which are smaller than that of free NCS. in $D_2O$ (18.3 ps). The $T_1$ values of the ${\nu}_1$ mode of NCO in the $NCO^-$ bound to $Mb^{III}$ ($Mb^{III}$NCO) and $Hb_{III}$ ($Hb_{III}$NCO) in $D_2O$ are $2.4{\pm}0.2$ and $2.6{\pm}0.2$ ps, respectively, which are larger than that of free $NCO^-$ in $D_2O$ ($1.9{\pm}0.2$ ps). The smaller $T_1$ values of the ${\nu}_1$ mode of the heme-bound NCS suggest that intramolecular vibrational relaxation (VR) is the dominant relaxation pathway for the excess vibrational energy. On the other hand, the longer $T_1$ values of the ${\nu}_1$ mode of the heme-bound NCO suggest that intermolecular VR is the dominant relaxation pathway for the excess vibrational energy in the ${\nu}_1$ mode of $NCO^-$ in $D_2O$, and that intramolecular VR becomes more important in the vibrational energy dissipation of the ${\nu}_1$ mode of NCO in $Mb^{III}$NCO and $Hb_{III}$NCO.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.309-316
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• 2016

In this study, performance of hardening accelerator types which promote setting and hardening of cement has been reviewed in order to develop early age strength of concrete with compressive strength of 21~27 MPa after examination of strength development of the concrete at early age according to curing temperature and unit cement(binder) content. As results, soluble mineral salt showed better hardening acceleration effect than organic salt in the scope of this study. Also, hydration reaction accelerating effect of $C_3S$ by Soluble mineral salt is effective on development of early age compressive strength and it was shown that the Pt's hydration reaction accelerating effect was the best. Construction duration reduction can be expected by securing compressive strength for prevention of early aged freezing damage in 25hour-curing time under curing temperature at $15^{\circ}C$. Also, it was shown that compressive strength of specimen cured at $5^{\circ}C$ was similar with plain specimen cured at $10^{\circ}C$. Therefore, it is expected that fuel costs and carbon dioxide can be reduced when the same construction duration is considered.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.423-427
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• 2013

This research was carried out to identify the characteristics of the wastewater from coke oven gas (COG) purification process of the coke plant, and derive optimal operating conditions for the treatment of wastewater. The coke plant wastewater contains highly concentrated $S^{-2}$ and $SCN^-$ that are harmful to microorganisms, and their concentrations were 6.8~11.2 mg/L and 190~320 mg/L, respectively. When the $S^{-2}$ ion concentration was lower than 10 mg/L, $SV_{30}$ of active sludge was 280~ 340 mL and the sludge sedimentation velocity was very fast. But, when the $S^{-2}$ ion concentration was higher than 15 mg/L, $SV_{30}$ of the active sludge was 560~680 mL and the sludge sedimentation velocity was very slow. Also when the $SCN^-$ ion concentration was lower than 300 mg/L, $SV_{30}$ of the active sludge was 245~320 mL and the sludge sedimentation velocity was very fast. But, when the $SCN^-$ ion concentration was higher than 400 mg/L, $SV_{30}$ of the active sludge was 470~ 567 mL and the sludge sedimentation velocity was slow. To treat the wastewater generated by COG purification process of the coke plant effectively and to maintain microorganism activities in good conditions, the ion concentration of $S^{-2}$ and $SCN^-$ should be lower than 15 mg/L and 400 mg/L, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.913-920
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• 2003

Soybean sauce fermented with soybean and wheat, has been a major condiment of Korean diets from centuries ago. Melanoidin, a brown pigment generally found in various food systems, is a final product produced in amino-carbonyl reaction during soybean sauce processing. Antioxidative activities of soybean sauce and melanoidin were investigated in vitro system using linoleic acid emulsion. Soybean sauce and glucose-lysine model melanoidin showed the stronger antioxidative effect than control by ferric thiocyanate and conjugated diene assays. In addition, DPPH radical scavenging effect of soybean sauce was higher than melanoidin, which was ascribed to soluble peptide and low molecular protein existing in soybean sauce. To ascertain antioxidative effect of dietary soybean sauce and melanoidin in vivo, the male Wister rats were fed 10% soybean sauce or 10% glucose-lysine model melanoidin with corn oil or fish oil for 5 weeks. Fatty acid compositions in liver and plasma were influenced by oil source. Therefore, EPA and DHA contents of fish oil group were higher than those of corn oil group. When the inhibitory effect of soybean sauce and melanoidin on lipid peroxidation using TBARS methods was measured, fish oil group (FC) showed higher malondialdehyde (MDA) content than corn oil group (CC). However, supplementation of soybean sauce and melanoidin to fish oil group attenuated MDA formation. In the levels of phosphatidyl choline hydroperoxide (PCOOH) in liver and plasma by CL (chemiluminescence)-HPLC method, PCOOH in FC group was significantly higher than that of CC group both in liver and plasma. Supplementation of soybean sauce to fish oil groups significantly inhibited the formation of PCOOH in plasma and liver, while melanoidin suppressed hepatic PCOOH formation. Based on these results, it can be suggested that soybean sauce possesses stronger antioxidative potential than melanoidin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1072-1078
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• 2012

The potential antioxidant and anti-inflammatory effect of water and ethanol extracts from Flammulina velutipes (Curtis) Singer (FVS) on hydrogen peroxide ($H_2O_2$) and LPS-induced oxidative damage in PC-12 and RAW264.7 cells were investigated. The DPPH radical scavenging activities of the water extract from FVS was the highest, and the 50% inhibitory concentration value was 0.388 mg/mL. Also, the antioxidant activities of water and ethanol extracts were determined by ferric reducing antioxidant power, 2,2'-azino-bis-(3-ethybenzothiazoline-6-sulphonic acid) radical scavenging activity. In addition, water extract from FVS showed a strongly inhibitory effect on lipid peroxidation by measuring ferric thiocyanate values. The water extract decreased cell apoptosis in PC-12 cells against $H_2O_2$-induced oxidative damage. In addition, FVS extracts exhibited the strongest nitric oxide (NO) inhibition activity. It was also found that FVS extract inhibited LPS-induced iNOS and COX-2 expression in RAW264.7 cells. The findings of the present study suggest that extracts of FVS exhibit anti-oxidative and anti-inflammatory activity against oxidative stress and/or stimulated cells.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.148-152
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• 2000

The antioxidative activities of water-soluble extracts from leaves and stem bark of Morus alba and Cudrania tricuspidata were compared in vitro experimental models. Antioxidative activities were measured by inhibition activity against lipid peroxidation of mouse liver microsome, and they were showed in the following order; stem bark of C. tricuspidata(53%)>stem bark of M. alba(43%)>leaves of C. tricuspidata(38%)>leaves of M. alba(43%). In antioxidative activities determined by thiocyanate method and TBA method, the water-soluble extract of stem bark of C. tricuspidata showed the highest antioxidative activity. The water-soluble extracts of leaves were slightly stronger than other extracts in DPPH$({\alpha},{\alpha}'-diphenyl-{\beta}-picrylhydrazyl)$ method. The concentrations of total polyphenolic compound from water-soluble extracts of leaves and stem bark of M. alba and C. tricuspidata were 1.32%, 1.28%, 1.34% and 1.30% respectively. In these results, the water-soluble extract of stem bark from Cudrania tricuspidata showed the highest antioxidative activity.

• Journal of Life Science
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• v.21 no.7
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• pp.1052-1059
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• 2011

The contents of bioactive and antioxidative activities (DPPH (${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl), free radical scavenging activity, peroxidation of linoleic acid and rat hepatocyte microsome, and Fe/Cu reducing power, tyrosinase inhibition activity) were tested by in vitro experimental models using water, hot water, ethanol and methanol extracts of leaves (ASL), roots (ASR), stems (ASS) and fruits (ASF) from Acanthopanax senticosus. Hot water extract from ASL showed the highest extraction yield (16.04%) as well as highest contents of phenolic compounds (2.67%) and flavonoids (1.43%). Major minerals were K, Ca and Mg. In oxidation in vitro models using DPPH free radical scavenging activity, Fe/Cu reducing power, $Fe^{2+}$/ascorbate-induced linoleic acid peroxidation by ferric thiocyanate and thiobarbituric acid (TBA) methods, tyrosinase inhibition activity and autooxidation of rat hepatic microsomes membrane, and antioxidative activities were strong in Acanthopanax senticosus. From these results, ASL extracts were shown to have the most potent antioxidative properties and contain the highest amounts of antioxidative compounds such as phenolic compounds and flavonoids. These results may provide the basic data to understand the biological activities of bio-active materials derived from leaves of Acanthopanax senticosus.