• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.217-225
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• 1994

In an attempt to define the effects of Biphenyldimethyl dicarboxylate(DDB) on the lipid peroxidation, oxygen free radical scavenging enzymes activities and hepatic functions in ethanol-induced hepatotoxic rats, we studies malondialdehyde(MDA) level and the activities of catalse, superoxide dismutase(SOD), glutamic-oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) in liver of the rats at 24, 48 and 72 hr after the injection of ethanol and DDB. Sprague-Dalwey albino rats weighing 250 to 280gm were injected intraperitoneally with ethanol(2.5 gm/kg ) only and ethanol plus DDB(300mg/kg ). The result obtained can be summarized as follows : 1) The group treated with ethanol showed significantly higher MDA level and lower catalase and SOD activities at 24, 48 and 72hr after the injection as compared with that of control group. 2) The group treated with ethanol showed significantly higher GOT and GPT activities at 24, 48 and 72hr after the injection as compared with that of control group. 3) The group treated with ethanol plus DDB showed significantly lower MDA level and higher catalase and SOD activities at 24, 48 and 72 hr after the injection as compared with that of ethanol group. 4) The group treated with ethanol plus DDB showed significantly lower GOT and GPT activities at 24, 48 and 72 hr after the injection as compared with that of ethanol group. These results suggest that the excessive oxygen free radicals resulting from the depression of the activities of catalase and superoxide dismutase is an important determinant in pathogenesis of ethanol-induced hepatotoxicity and DDB has antioxidant effects.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.350-356
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• 2008

Etiological studies of diabetes and its complications showed that oxidative stress might play a major role. Therefore, many efforts have been tried to regulate free oxygen radicals for treating diabetes and its complications. Cheonghyul-san has been known to be effective for the antidiabetic, antihyperlipidemic and antiobesitic prescription, and composed of four crude herbs. In male ob/ob mouse with severe obesity, hyperinsulinemia, hypergiycemia, hyperlipidemia, the acting mechanisms of Cheonghyul-san were examined. Mice were grouped and treated for 5 weeks as follows. Both the lean (C57/BL6J black mice) and diabetic (ob/ob mice) control groups received standard chow. The experimental groups were fed with a diet of chow supplemented with 7.5, 15 and 30 mg Cheonghyul-san per 1 kg of body weight for 14 days. The effects of Cheonghyul-san extract on the ob/ob mice were observed by measuring the serum levels of glucose, insulin, lipid components, and the kidney levels of reactive oxygen species (ROS), MDA+HAE, GSH and also the enzyme activities involved in polyol pathway. Cheonghyul-san lowered the levels of serum glucose and insulin in a dose dependent manner. Total cholesterol, triglyceride and free fatty acid levels were decreased, while the HDL-cholesterol level was increased, in Cheonghyul-san treated groups. Renal aldose reductase and sorbitol dehydrogenase activities were increased in the ob/ob mice, whereas those were inhibited in the Cheonghyul-san-administered groups. Cheonghyul-san inhibited the generation of ROS in the kidney. Finally, MDA+HAE level was increased and the GSH level was decreased in the ob/ob mice, whereas those were improved in the Cheonghyul-san-administered groups. The results suggested that Cheonghyul-san exerted the antidiabetic and antihyperlipidemic activities by regulating the activities of polyol pathway enzymes, scavenging ROS, regulating the MDA+HAE and GSH levels in the ob/ob mice.

• Journal of Sensor Science and Technology
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• v.19 no.1
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• pp.36-42
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• 2010

This paper describes a multi channel measurement system which can measure the cellular respiration level in a solution containing cells by using a Clark-type sensor with the solution temperature control unit. The Clark-type sensor can measure the cellular respiration level in the solution because it can measure the reduction current depending on the dissolved oxygen level in the solution. This measurement system was maintained the temperature within ${\pm}0.1^{\circ}C$ of the setting temperature value by on/off control method in order to measure the precise cellular respiration level. The measurement system showed that the applied voltage to the working electrode was very stable(-0.8 V$\pm$ 0.0071 V) by using proportional control method. From the current measurement, the response time and the linearity correlation coefficient were 25 sec and 0.94, respectively, which are very close to the results of the commercial product. Using this system and the fabricated Clarktype sensor, the average ratio of the uncoupled OCR(oxygen consumption rate) to the coupled OCR was 1.35 and this is almost the same as that obtained from a commercial systems.

• Biomolecules & Therapeutics
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• v.13 no.4
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• pp.256-262
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• 2005

We examined the signaling molecules involved in the 6-hydroxydopamine (6-OHDA)-induced neuronal cell death and increase in cellular glutathione (GSH) level in SK-N-SH cells. The 6-OH-DA-induced cell death was significantly prevented by the pretreatment with N-acetylcysteine (NAC), a thiol antioxidant, and BAPTA, an intracellular $Ca^{2+}$ chelator. Although 6-OHDA induced ERK phosphorylation, the pretreatment with PD98059, an ERK inhibitor, did not block 6-OHDA-induced cell death. In addition, the 6-OHDA-induced activation of caspase-3, a key signal for apoptosis, was blocked by the pretreatment with NAC and BAPTA. While the level of reactive oxygen species (ROS) was significantly increased in the 6-OHDA-treated cells, the cellular GSH level was not altered for the first 6-hr exposure to 6-OHDA, but after then, the level was significantly increased, which was also blocked by the pretreatment with NAC and BAPTA, but not by PD98059. Depletion of GSH by pretreating the cells with DL-buthionine-(S,R)-sulfoximine (BSO), a glutathione synthesis inhibitor, rather significantly potentiated the 6-OHDA-induced death. In contrast to the pretreatment with NAC, 6-OHDA-induced cell death was not prevented by the post-treatment with NAC 30 min after 6-OHDA treatment. The results indicate that the GSH level which is increased adaptively by the 6-OHDA-induced ROS and intracellular $Ca^{2+}$ is not enough to overcome the death signal mediated through ROS-$Ca^{2+}$ -caspase pathway.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.281-287
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• 1984

In search for a method of evaluating the cardiopulmonary function. 74 male and 33 female volunteers ages $18{\sim}25$ were subjected to this study The subjects walked on a treadmill at speed of 2,4,6 and 8km/hr with 0,5,10,15,20 and 25% grade of inclination, respectively, for a measurement of heart rate and oxygen-pulse. Heart rate was measured every 5 seconds at resting state and during walking by telemetric method using Heart Checker 108 System (Senoh Co., Japan). Oxygen concentration was measured by Douglas bag method collecting expired air for 5 minutes at rest, and for 2 minutes at the end of each walking exercise. Oxygen concentration in an expired air was analyzed with Orzat gas analyser and expressed in terms of STPD. Oxygen-pulse was defined as an amount of oxygen consumed at every heart at a cellular level. The followings were the results obtained from this study. 1. Mean values of oxygen-pulse at resting state was $3.1{\pm}0.11ml/beat$ in male and $2.5{\pm}0.87ml/beat$ in female, respectively. 2. Mean values of oxygen-pulse during treadmill walking were increased in proportion with the load of exercise, namely, the speed and grade of inclination, from minimum of 7.1ml/beat upto maximum of 18.2ml/beat in male and from minimum of 4.2ml/beat upto maximum of 12,7ml/beat in female. 3. Both linear and logarithmic regressional relationships between oxygen-pulse and speed of walking and grade of inclination were observed in both sexes. Predicted values of oxygen-pulse by logarithmic regressional formula on speed and on grade of inclination were better coincided with the measured values than those predicted by the linear regressional formula.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.100-104
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• 1995

Production of $poly-{\beta}-hydroxybutyrate$ (PHB) in a strain of Azotobacter chroococcum, a nitrogen-fixing bacteria, was investigated at various levels of nitrogen and oxygen. Feeding nitrogen source increased both cell growth and PHB accumulation. Oxygen supply appeared to be one of the most important operating parameters for PHB production. Both cell growth and PHB accumulation increased with the sufficient supply of air in the fed-batch fermentation of the strain. However, it was also noted that keeping the oxygen level under limited condition was critical to achieve high PHB productivity. A high titer of PHB (52 g/l) with a high cellular content (60%) was obtained after 48 hr of fed-batch operation by controlling the oxygen supply. Dual limitation of nitrogen and oxygen did not further increase the PHB accumulation probably due to the greater demand for reducing power and ATP for nitrogen fixation.

• Environmental Engineering Research
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• v.12 no.4
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• pp.148-154
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• 2007

The purpose of this research was to investigate the effects of low concentration of oxygen on reduction of perchlorate, especially low perchlorate influent concentrations in a biofilm reactor, as well as the effect of flow pattern in a biofilm reactor. Dissolved oxygen averaging 1 mg/L did not inhibit reduction of influent perchlorate from 23 to $426\;{\mu}g/L$ in the biofilm reactors when sufficient acetate was added, probably due to limitation of oxygen diffusion into the biofilm. Influent perchlorate ranging from 23 to $426\;{\mu}g/L$ was reduced to below detection level ($4\;{\mu}g/L$) in the presence of 1 mg/L dissolved oxygen (DO). Chloride was produced in a ratio of $0.37gCl^-/g{ClO_4}^-$ and $0.35gCl^-/g{ClO_4}^-$ in plug flow and recirculation biofilm reactor which is similar to stoichiometric amount ($0.36gCl^-/g{ClO_4}^-$) indicating complete perchlorate reduction at $426\;{\mu}g/L$ of ${ClO_4}^-$ feeding. At $23\;{\mu}g/L$L influent perchlorate, total biomass solids were 3.18 g and 2.81 g in the plug flow and recirculation biofilm reactors. The most probable number(MPN) analysis for perchlorate-reducing bacteria showed $10^4$ to $10^5\;cells/cm^2$ in both biofilm reactors throughout the experiments. The effluent perchlorate concentrations were not significantly different in the two different flow regimes, plug flow and recirculation biofilm reactors.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.221-227
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• 1987

In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% $O_2$), normobaric oxygenation (NBO=1 ATA,100% $O_2$), hyperbaric aeration (HBA=5 ATA, 21% $O_2$) and normobaric aeration (NBA=1 ATA, 21% $O_2$). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<.01). This finding supports the hypothesis that hyperoxia increases oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial presure difference between the two groups.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2255-2259
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• 2012

Aggregation of titania nanotubes (TNTs) fabricated by hydrothermal method were calcined in air and dry nitrogen; Changes in morphology and crystallinity of the nanotubes were studied by means of TEM, EDX, and XPS. EDX patterns and XPS spectra proved that there were a certain densities of oxygen vacancies in TNTs annealed in $N_2$. The photocatalysis experiments revealed TNTs/$N_2$ possesses significantly higher photocatalytic efficiency than TNTs annealed in dry air to degrade methylene blue. The correlation between oxygen vacancies and photocatalytic property may be attributed to: 1) oxygen vacancies might have affected results on water molecules adsorption and increase of the hydroxyl concentration; and 2) oxygen vacancies resulted in some changes in electronic structure of TNTs/$N_2$ aggregation and Fermi level extends into the conducting band.

• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.298-302
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• 1994

Wistar albino rats were injected subcutaneously with mercuric chloride (5 mg/kg) to define the early biochemical determinants that participate in the pathogenesis of mercuric chloride-induced hepatotoxicity, especially focusing on oxygen free radicals, we studied malondialdehyde(MDA) level and the activities of catalase and superoxide dismutase in the liver of rats at 24, 48 and 72 hr after the injection of mercuric chloride. MDA levels at 24, 48 and 72 hr after the injection of mercuric chloride increased as compared with that of control group. The activities of catalase and superoxide dismutase at 24, 48 and 72hr after the injection of mercuric chloride decreased as compared with that of control group. These results suggest that the depression of the activities of catalase and superoxide dismutase resulting from excessive oxygen free radicals is an important determinant in pathogenesis of mercuric chloride-induced hepatotoxicity.