• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.43-48
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• 1996

We investigated the energistics of the physiological heart model by comparing predictive indexes of the myocardial oxygen consumption (MOC), such as tension-time index (R), tension-time or force-time inteual (FTI), rate-pressure product (RPP), pressure-work index, and systolic pressure-volume area (PVA) when using the electro-hydraulic left ventricular device (LVAD). We developed the model of LVAD incorporated the closed-loop cardiovascular system with a baroreceptor which can control heart rate and time-varying elastance of left and right ventricles. On considering the benefit of the LVAD, the effects of various operation modes, especially timing of assistance, were evaluated using this coupled computer model. Overall results of the computer simulation shows that our LVAD can unload the ischemic (less contractile) heart by decreasing the MU and increasing coronary flow. Because the pump ejection at the end diastolic phase of the natural heart may increase the afterload of the left ventricle, the control scheme of our LVAD must prohibit ejecting at this time. Since the increment of coronary flow is proportional to the peak aortic pressure after ventricle contraction, the LVAD must eject immediately following the closure of the aortic valve to increase oxygen availability.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.159-163
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• 2005

We screened the anti-oxidative effect on V79-4 hamster lung fibroblast cells induced by hydrogen peroxide with fifteen herbal extracts. Uncariae rhynchophylla JACKS and Rheum coreanum NAKAI were found to show DPPH radical scavenge activity (25 and 29% compared to control). Rheum coreanum NAKAI and Siegesbeckia orientalis L. were shown to scavenge intracellular reactive oxygen species (57 and 55% compared to control) which is measured by dichlorodihydrofluorescin diacetate method (DCHF-DA). Rheum coreanum NAKAI which showed the most strong intracellular reactive oxygen species scavenging activity had low DPPH radical scavenging activity compared to Uncariae rhynchophylla JACKS.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.135-140
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• 1999

This study was designed to investigate the effects of mulberry leaf extract (MLE) on oxygen radicals and their scavenger enzymes in serum of rats. Sprague-Dawley (SD) male rats (160${\pm}$10g) were fed experimental diets (MLE-100 and MLE-300 groups) added 100 and 300mg/kg BW/day for 6weeks. Triglyceride (TG) levels were significantly inhibited (10% and 20%) in MLE-100and MLE-300 groups, but there were no significant differences in total, LDL-and HDL- cholesterol levels in both MLE-100 and MLE-300 groups. Hydroxyl radical ($.$OH) formations resulted in a marked decreases(20∼25%) in MLE-100 and MLE-300 groups compared with control group, while superoxide radical (O2.-)and hydrogen peroxide formations resulted in a considerable decreases(7∼10% and 5∼10%) in MLE-100 and MLE-300 groups compared with control group. Lipid peroxide (LPO)and oxidized protein(>C=O group) productions resulted in a significant decreases (10% and 6∼10%) in MLE-100 and MLE-300 groups compared with control group. Superoxide dismutase (SOD)and catalase (CAT) activities were remarkably increased (30% and 40∼55%) in MLE-100 and MLE-300 groups, but glutathione peroxidase (GSHPX) activities were significantly increased (10∼15%) in MLE-100 and MLE-300 groups compared with control group. These results suggest that anti-aging effect of mulberry leaf extract (MLE) may play a pivotal role in attenuating a various agerelated changes.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.343-346
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• 2001

The effect of agitation speed and aeration rate on mTG production and cell growth by Streptoverticillum morbarense was investigated. Dissolved oxygen was controlled by on-line computer-controlled fermentation system. The agitation speed and aeration rate of 2.5 L fermentor ranged from 330 to 360 게m and 1 vvm to 4 vvm, respectively. The highest mTG production was 2.1 U/mL when dissolved oxygen level was 20%, and it was improved almost 1.1 times in comparison with that without dissolved uxygen control.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1473-1475
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• 1996

In this paper, we propose the method to find the active region of flame which is produced within the gap between an oxygen blown converter and a skirt. For real-time image processing, basic region segmentation algorithms such as thresholding and XORing are used to segment the active region of flame. The result of this processing may be useful to clear the relationship between hood pressure and flame.

• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1031-1034
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• 1999

Tin oxide films have been grown employing the chemical vapor deposition technique under reduced pressure conditions using tetramethyltin as the precursor and oxygen as the oxidant. An activation energy derived for the deposition reaction under representative deposition conditions has a value of 89±3 kJ mol-1, suggesting a typical kinetic control. Deposition rates of tin oxide films exhibit a near first order dependence on tetramethyltin partial pressure and a zeroth order dependence on oxygen partial pressure. This study provides the first quantitative information about the growth kinetics of tin oxide films from tetramethyltin by the cold-wall low-pressure chemical vapor deposition.

• The Journal of Korean Obstetrics and Gynecology
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• v.26 no.4
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• pp.123-139
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• 2013

Purpose: Cold hypersensitivity is regarded to be associated with blood circulation. This study is aims to evaluate the effects and safety of oxygen chamber therapy on cold hypersensitivity by comparing the temperature and Visual Analogue Scale. Methods: 42 outpatients who visited ${\bigcirc}{\bigcirc}$ University Oriental Hospital from July 11th, 2013 to August 28th, 2013 were analyzed. Patients were subjected to thermometer, and those with thermal difference greater than $0.3^{\circ}C$ between upper arm and palm and also with more than VAS 4 of cold hypersensitivity were diagnosed with cold hypersensitivity. 42 outpatients diagnosed with cold hypersensitivity are divided into two groups, one is the experimental group consisted of 21 patients and other was control group consisted of 21 patients. The experimental group had oxygen chamber therapy 10 times for 4 weeks. Thereafter the effects of oxygen chamber therapy on cold hypersensitivity was analyzed with t-text using SPSS for Windows version 21. Results: After the oxygen chamber therapy, experimental group had considerable improvement on cold hypersensitivity, in consequence of decreasing rate of thermal difference and VAS of cold hypersensitivity. Ear deafness and hand numbness were reported as an adverse effects in experimental group, but there was no serious adverse effects. Conclusions: This clinical trial showed oxygen chamber therapy could be effective and safe to reduce cold hypersensitivity.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.434-438
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• 1998

The antioxidant effects of 700 ppm ginseng extract, 100ppm caffeic acid, ferulic acid, vanillic acid, or ${\alpha}-topherol$ on the 1% linoleic acid aqueous buffer system was studied by measuring malondialdehyde (MDA) and headspace oxygen. The compounds showed antioxidant activities in the following order: $caffeic\;acid{\geq}ferulic\;acid\;>\;{\alpha}-tocopherol$>ginseng extract>vanillic acid, with the oxidation inhibition ratio of 63.5, 62.9, 52.3, 51.2 and 5.6% of the control according to MDA results. The mixture of 100 ppm caffeic acid, 100 ppm ${\alpha}-tocopherol$ and 700 ppm ginseng extract had a high oxidation inhibition ratio of 91.2%. Headspace oxygen results had a similar trend with the MDA results. Headspace oxygen results showed that the antioxidant activities were in order of ferulic acid>caffeic acid>${\alpha}-tocopherol$>ginseng extract>vanillic acid and headspace oxygen contents were 18.56, 17.78, 17.17, 16.65 and 15.95%, respectively.

• Journal of Biomedical Engineering Research
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• v.39 no.5
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• pp.175-182
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• 2018

The purpose of this study is to evaluate the reliability and effectiveness of hyperbaric oxygen chamber on alcohol-induced oxidative stress and hangover. In order to evaluate them, 20 healthy adults were tested for blood and hangover stress tests. When an exponential change was examined after 3 interventions (hangover drink, hyperbaric oxygen chamber, and normal chamber as placebo effect) of 1 hour, the heart rate of subjects experiencing a hyperbaric oxygen chamber showed a statistically significant decrease (p < 0.001). The tests of blood alcohol concentration (BAC) as for exquisite hematology analysis, glucose, creatinine, and AST (aspartate aminotransferase) as well as ALT (alanine aminotransferase) used as liver-damage indicator show that the hyperbaric chamber has the effective effect. In the test of lactic acid, CRP (c-reactive protein), cortisol, and creatinine, the hyperbaric chamber shows much more excellent effect than the hangover drink and normal chamber as control groups. Further studies on hyperbaric oxygen chamber intervention including this study could be very helpful for improving lives of both the patients and healthy people.

• Biomedical Science Letters
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• v.5 no.1
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• pp.51-58
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• 1999

To evaluate an effect of liver damage on the dermal oxygen free radical metabolizing enzyme activities, the $CCl_4$ (0.1 ml/ 100 g body wt., 50% $CCl_4$ in olive oil) was intraperitoneally given to the rats every other day for 2 weeks. Based on the histopathological findings, liver weight (%), serum alanine aminotransferase, xanthine oxidase activities and hepatic lipid peroxide contents, the animals were induced severe liver damage. In the present liver damaged animal, all the activities of dermal scavenging enzymes such as superoxide dismutase, catalase and glutathione peroxidase were significantly decreased compared with central. And under the cytochemical electron microscopy the more coarse granules of cerrous perhydroxide were found compared with the control. In conclusion, the $CCl_4$-induced liver damage may influence upon the activities of some dermal oxygen free radical scavenging enzymes.