• Biomolecules & Therapeutics
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• 제6권1호
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• pp.9-13
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• 1998

ln an attempt to define the effects of hyperbaric oxygen treatment on the lipid peroxidation and oxygen See radical reactions in rats exposed to carbon monoxide, we studied malondialdehyde(MDA) level and activities of catalase and superoxide dismutase in the heart of the rats exposed to carbon monoxide. Male Sprague-Dawley albino rats weighing 240 to 260gm were used. Experimental groups consist of Control group (=breathing with air), HBO group(=exposed to hyperbaric oxygen(HBO, 3ATA, 100%) after air breath), CO group(=exposed to CO(3,970 ppm) after air breath), CO-Air group(=exposed to CO after air breath followed by air breath) and CO-HBO group(=exposed to CO after ai. breath followed HBO treatment). The CO group showed significantly higher MDA level, catalase activity and SOD activity as compared to that of control group. The CO-HBO group showed significantly lower MDA level as compared to that of CO group, and did not show significantly lower catalase activity and SOD activity as compared to that of CO group. These results suggest that the excessive oxygen free radicals is an important determinant in pathogenesis of Co-induced cardiotoxicity and HBO inhibits the lipid peroxidation caused by excessive oxygen free radicals in the heart of the rats exposed to carbon monoxide.

• Biomolecules & Therapeutics
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• 제7권2호
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• pp.121-126
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• 1999

In an attempt to define the effects of hyperbaric oxygen treatment on the lipid peroxidation and oxygen free radical reactions in rats exposed to carbon monoxide, we studied malondialdehyde (MDA) level and activities of catalase and superoxide dismutase in the kidney of the rats exposed to carbon monoxide. Male Sprague-Dawley albino rats weighing 240 to 260 gm were used. Experimental groups consist of Control group (=breathing with air), HBO group (=exposed to hyperbaric oxygen 〔HBO, 3ATA, 100%〕 after air breath), CO group (=exposed to CO〔3,970 ppm〕after air breath), CO-Air group (=exposed to CO after air breath followed by air breath) and CO-HBO group (=exposed to CO after air breath followed HBO treatment). The CO group showed significantly higher MDA level, catalase activity and SOD activity as compared to that of control group. The CO-HBO group showed significantly lower MDA level as compared to that of CO group, and did not show significantly lower catalase activity and SOD activity as compared to that of CO group. These results suggest that the excessive oxygen free radicals is an important determinant in pathogenesis of CO-induced nephrotoxicity and HBO inhibits the lipid peroxidation caused by excessive oxygen free radicals in the kidney of the rats exposed to carbon monoxide.

• 한국연소학회지
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• 제8권2호
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• pp.1-6
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• 2003

Numerical simulations are conducted at atmospheric pressure in order to understand the effect of the oxygen enrichment level on structure of $CH_4/O_2/N_2$ premixed flames. Under several equivalence ratios the flame speeds are calculated and compared with those obtained from the experiments, the results of which are in good agreement. The effects of the oxygen enrichment are investigated on flames under fuel-rich conditions. As the oxygen enrichment level is increased from 0.21 to 1, the flame speed and the temperature are increased. The emission index of $CO_2$ is decreased in cases of flames for fuel rich mixtures, so the efficiency of combustion may be decreased. The maximum emission index of NO is obtained for 0.6 of the oxygen enrichment level.

• BMB Reports
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• 제32권1호
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• pp.25-27
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• 1999

Otitis media with effusion (OME) is an inflammatory disease of the middle ear cleft. Oxygen free radicals have been implicated in a variety of inflammatory disorders. Oxygen free radicals may also be involved in the pathogenesis of OME. To evaluate the involvement of oxygen free radicals in the pathogenesis of OME, the level of malondialdehyde, which gives an index of lipid peroxidation by oxygen free radicals, was measured by the reaction with thiobarbituric acid. Malondialdehyde level in the middle ear fluid from the OME group was higher than that in the normal control group. Malondialdehyde level in the middle ear fluid from a mucoid subgroup was higher than that in the serous subgroup. Malondialdehyde levels in the middle ear fluid from the serous subgroup was significantly correlated with symptom duration. The Pearson correlation coefficient between malondialdehyde levels in the middle ear fluid from the serous subgroup and symptom duration was 0.842 (P<0.05). These results indicate that lipid peroxidation by oxygen free radicals may be involved in the pathogenesis of human OME.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.197-201
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• 2001

Measuring of the dissolved oxygen is widely used for the environmental control of natural waters, sewage waste treatment, medical and biochemical studies, soil husbandry, food and drug process control, and prevention of corrosion in boilers. Especially, a power plants need special management for preventing accidents from corrosion, therefore, it is essential to measure the concentration of dissolved oxygen in real-time. In this paper we present a method of measuring dissolved oxygen very accurately up to ppb units. This method, called polarographic method, is based on the measures of the electric current generated by the oxidation process in cathode and de-oxidation process in anode, assuming that the amount of the current is proportional to the density of dissolved oxygen.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.529-536
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• 1998

용존산소(D.O.) level은 유기산 및 포도당을 혼합한 배지에서 Azotobacter vinelandii UWD의 생장 및 생분해성 고분자(PHBV) 생성에 큰 영향을 주었다. 용존산소 level이 높은 경우(5% D.O.)는 낮은 경우(1% D.O.)에 비해 세포의 생장속도가 약 2배 증가하였으나 PHBV 생성은 D.O.가 낮은 경우 62.3 wt%로 D.O.가 높은 경우에 비해 약 17배 증가하였다. 그러나 B.O. level은 통기(aeration)에 의한 A. vinefandii UWD의 발효특성 연구에 적합한 기준이 아니었다. 공기공급속도를 고정하고 교반속도만을 변화시키는 통기법으로 산소전달속도를 감소시켰을 때 이 균주는 산소소모속도를 그에 따라 대응 감소시킴으써 겉보기 D.O.를 높게(5%) 유지할 수 있었고 이 때 생장이 느려지고 PHBV 양은 57.3 wt%로 증가하였다. 통기가 세포생장 및 PHBV 생성에 미치는 영향을 일관성 있게 설명할 수 있는 기준은 D.O. level이 아니라 산소전달속도였으며 비생장속도는 산소전달속도에 비례하여 증가하였고 PHBV 생산량은 산소전달속도에 반비례하였다.

• 한국정밀공학회지
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• 제22권1호
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• pp.193-198
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• 2005

Changes in visuospatial cognitive performance, blood oxygen saturation and heart rate due to the highly concentrated oxygen administration were observed in this study. Six male ($25.8 \pm$1.0) and six female (($23.8 \pm$ 1.9) adults were asked to perform 20 visuospatial tasks with the same level of difficulties by supplying two different oxygen levels (21%, 30%). Experiment consisted of Rest1 (1 min.), Control (1 min.), Task (4 min.), and Rest2 (4 min.) and physiological signals such as blood oxygen saturation and heart rate were measured through each stage. The result showed the accuracy of task performance increased significantly at 30% oxygen concentration compared with 21%, which means oxygen supply has positive effects on visuospatial cognitive performance. When 30% oxygen was supplied, blood oxygen saturation during control and task phases was increased and heart rate was decreased compared with 21%. It means that 30% oxygen can stimulate brain activities by directly increasing the actual level of blood oxygen concentration during cognitive performance, and enough oxygen supply during cognitive performance make heart rate decrease.

• Safety and Health at Work
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• 제6권1호
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• pp.18-24
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• 2015

Background: In 2006, three farmers died at the bottom of an agricultural shallow well where the atmosphere contained only 6% oxygen. This study aimed to document the variability of levels of oxygen and selected hazardous gases in the atmosphere of wells, and to identify ambient conditions associated with the low-oxygen situation. Methods: A cross-sectional survey, conducted in June 2007 and July 2007, measured the levels of oxygen, carbon monoxide, hydrogen sulfide, and explosive gas (percentage of lower explosive limit) at different depths of the atmosphere inside 253 wells in Kamphaengphet and Phitsanulok provinces. Ambient conditions and well use by farmers were recorded. Carbon dioxide was measured in a subset of wells. Variables independently associated with low-oxygen condition (<19.5%) were identified using multivariate logistic regression. Results: One in five agricultural shallow wells had a low-oxygen status, with oxygen concentration decreasing with increasing depth within the well. The deepest-depth oxygen reading ranged from 0.0% to 20.9%. Low levels of other hazardous gases were detected in a small number of wells. The low-oxygen status was independently associated with the depth of the atmosphere column to the water surface [odds ratio (OR) = 13.5 for 8-11 m vs. <6 m], depth of water (OR = 0.17 for 3-<8 m vs. 0-1 m), well cover (OR = 3.95), time elapsed since the last rainfall (OR = 7.44 for >2 days vs. <1 day), and location of well in sandy soil (OR = 3.72). Among 11 wells tested, carbon dioxide was detected in high concentration (>25,000 ppm) in seven wells with a low oxygen level. Conclusion: Oxygen concentrations in the wells vary widely even within a small area and decrease with increasing depth.

• 사상체질의학회지
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• 제18권3호
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• pp.155-165
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• 2006

1. Objectives The purpose of this research is to find out the Constitutional difference of Oxidative stress by Free oxygen radicals. 2. Methods We enrolled 55 patients who visited our hospital for medical examination from February 1, 2006 to May 31, 2006. This research investigated the Constitutional difference of Oxidative stress by Free oxygen radicals. 3. Results and Conclusions l) The Sasang Constitutional distribution of patients have oxidatative stress by Free oxygen radicals was Taeunmin 30%(8persons of total 27persons), Soeumin 56%(9persons of total 16persons), Soyangin 33%(4persons of total 12persons). The rate of patients have oxidatate stress was high in Soeumin. The Sasang Constitution had significance relation with oxidatative stress by Free oxygen radicals. 2) Triglyceride on the average of Taeumin patients have oxidatative stress by Free oxygen radicals is ststistical significantly higher than Triglyceride on the average of controlled normal persons in Taeumin(p-value=0.010) and Soyangin(p-value=0.015). Blood uric acid level on the average of patients have oxidatate stress by Free oxygen radicals is ststistical significantly lower than Blood uric acid level on the average of controlled normal persons in Taeumin(p-value=0.004) and Soyangin(p-value=0.037). This research has shown that there is a statistical significance between the Triglyceride level, Blood uric acid level and oxidatate stress by Free oxygen radicals.

• 한국안전학회지
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• 제22권6호
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• pp.87-90
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• 2007

최근 의료분야에서 인체의 생리학적 조직에 정자계가 영향을 미치는 것으로 밝혀짐에 따라 정자계를 사용하는 의료장비의 중요성이 대두되고 있다. 본 연구의 목적은 자속의 영향에 의한 혈중 산소 포화 농도의 변화를 평가하는 것이다. 본 연구의 결과는 검지 손가락에 정자계 쌍극자가 맞추어졌을 때 혈중 산소포화 농도가 증가한다는 것을 보여준다.