• Journal of Hydrogen and New Energy
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• v.24 no.1
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• pp.29-35
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• 2013

A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.105-110
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• 2009

Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. Erythropoietin (Epo) has been shown to exert neuroprotective effects in various brain injury models although the exact mechanisms through which Epo functions are not completely understood. This study investigates the effect of Epo on hypoxic-ischemic (HI) brain injury and the possibility that its neuroprotective actions may be associated with iron-mediated metabolism. Methods : HI brain injury was produced in 7-day-old rats by unilateral carotid artery ligation followed by hypoxia with 8% oxygen for 2 h. At the end of HI brain injury, the rats received an intraperitoneal injection of 5,000 units/kg erythropoietin. Random premedication with iron, deferoxamine, iron-deferoxamine, or saline were performed 23 d before HI brain injury. The severity of the brain injury was assessed at 7 d after HI. Results : Single Epo treatment post-HI brain injury reduced the gross and histopathological findings of brain injury. Iron premedication did not increase the incidence or severity of the injury as measured by the damage score. Deferoxamine administration before HI brain injury improved the brain injury as compared to no treatment or Epo treatment. Conclusion : These findings indicate that Epo provides neuroprotective benefits after HI in the developing brain. These findings suggest that Epos neuroprotective actions may involve reducing iron in tissues that mediate the formation of free radicals.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.104-111
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• 1993

Background: Gram-negative bacterial endotoxin induced septicemia is known to be a leading cause in the development of adult respiratory distress syndrome(ARDS). The mechanism of endotoxin induced lung injury is mainly due to the activated neutrophils which injure the capillary endothelial cells by releasing oxidant radical and resulted in pulmonary edema. We studied the change of antioxidant enzyme in the case of large or small, intermittant dose of endotoxin infused rat lungs. Methods: Endotoxin was given to the rat through the peritoneal cavity in the dose of 7 mg/kg body weight in the large dose group and 1 mg/kg for 10 days in the small dose group. Bronchoalveolar lavage (BAL) was done and rats were killed at 6, 12, 24 hours after single endotoxin injection in the large dose group and 3, 7, 10 days after daily endotoxin injection for 10 days in the small dose group. The lungs were perfused with normal saline through the pulmonary artery to remove the blood and were homogenized in 5 volume of 50 mM potassium phosphate buffer containing 0.1 mM EDTA. After centrifuging at 100,000 g for 60 minute, the supernatent was removed and stored at $-70^{\circ}C$ until measuring for superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and protein. Results: We observed the following results. 1) The lung wet/dry weight ratio and albumin concentration in the BAL fluids were increased to peak at 12 hours and neutrophil number in the BAL fluids were peak at 6 hours after endotoxin injection in the large dose group. 2) Cu, Zn SOD (IU/mg protein) was significantly decreased after 6, 12 hours after endotoxin injection in the large dose group. 3) There were no singnificant change in the level of Mn SOD, catalase, GSH-Px after endotoxin injection in both groups. Conclusion: Endotoxin in the large dose group produced the acute pulmonary edema and decreased the Cu, Zn SOD in the lung tissue after injecting endotoxin at 6 and 12 hours. These phenomenon may be due to the cell membrane damage by endotoxin. Further research would be necessary whther giving SOD by intratracheal route or method to increase the synthesis of SOD may lessen the acute lung injury by endotoxin.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.989-995
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• 2003

Purpose : Dexamethasone is frequently administered to prevent or treat chronic lung disease in human neonates who are also prone to hypoxic-ischemic(HI) insults. Recently, meta-analysis of the follow-up studies reveals a significantly increased odd ratio for the occurrence of cerebral palsy or an abnormal neurologic outcome, and there is conflicting evidence regarding the impact of dexamethasone exposure on HI brain injury. This study was conducted to explore the effect of post-HI dexamethasone administration on neuronal injury in neonatal rats. Methods : HI was produced in seven-day-old rats by right carotid artery ligation followed by two hours of 8% oxygen exposure. At the end of HI, the animals were injected intraperitoneally either with dexamethasone(0.5 mg/kg) or saline. Neuronal injury was assessed seven days after the HI by the area of infarction, TUNEL reactivity, Bcl-2 and Bax expression in brain. Results : Post-insult dexamethasone administration resulted in reduction of weight gain and a higher mortality rate during seven days after HI. Dexamethasone treatment revealed no effect on the size of brain infarction induced by HI. Bax protein expression increased in dexamethasone treated brain but Bcl-2 protein expression and TUNEL reactivity revealed no significant differences between dexamethasone treated and non treated brain. Increased Bax protein expression suggest upregulation of the apoptosis by dexamethasone. Conclusion : The result suggests the adverse role of Post-HI administration of dexamethasone in neonatal HI.

• Radiation Oncology Journal
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• v.13 no.3
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• pp.205-214
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• 1995

Purpose : To investigate the effect of Ginkgo biloba extract (GBE) on hypoxic cell fraction and metabolic status in fibrosarcoma (FSa II) of C3H mouse. Materials and Methods : Fibrosarcoma (FSa II) 6 mm in diameter, growing in the right hindleg muscle of C3H mouse was used for estimation of hypoxic cell fraction using comparison of $TCD_{50}$. Radiation was given one hour after administration of GBE (100 mg/kg. i.p.) with or without priming dose of GBE (100 mg/kg, i.p.) given 24 hours earlier. Radiation was also given under air breathing condition or clamp hypoxia without GBE as controls. $^{31}p$ NMR spectroscopy was performed before and one hour after administration of GBE with or without priming dose of GBE. Results : $TCD_{50/120's}$ were 81.7 (77.7-86.0) Gy when irradiated under clamped hypoxia 69.6 (66.8-72.5) Gy under air breathing condition. 67.5 (64.1-71.1) Gy with a single dose of GBE (100 mg/kg) given one hour before irradiation, and 62.2 (59.1-65.5) Gy with two doses of GBE given at 25 hours and one hour before irradiation. The hypoxic cell fractions, estimated from $TCD_{50/120's}$, were $10.6{\%}$ under air breathing condition, $7.2{\%}$ after a single dose of GBE, and $2.7{\%}$ after two doses of GBE. The results of $^{31}P$ NMR spectroscopy were as follow. PCr/Pi ratio was $0.27{\pm}0.04$ and $0.40{\pm}0.04$ before and one hour after a single dose of GBE (p<0.05), respectively, without priming dose and $0.30{\pm}0.02$ and $0.71{\pm}0.04$, respectively, with priming dose (p<0.01). These findings indicate that the metabolic status is slightly improved after a single dose and markedly after repeated administrations. Conclusion : GBE decreases the hypoxic cell fraction and imprvoes the meta bolic status of tumor, probably by increasing the blood flow and delivery of oxygen and nutrients, resulting in increased radiosensitivity of tumor.

• Applied Microscopy
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• v.31 no.3
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• pp.275-285
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• 2001

The pulmonary alveolar macrophage is thought to play an important role in the mediation of acute inflammatory lung injury by secretory products including degraded enzymes, cytokines, and reactive oxygen metabolites . This study was conceived to understand the role of alveolar macrophage in oxidative stress induced acute lung injury. To examine the alveolar macrophages and xanthine oxidase (XO) activity in bronchoalveolar lavage fluid (BALF), time-dependent changes of numbers of alveolar macrophages, monocytes and neutrophils in alveolar cavity were counted in association with ultrastructural and cytochemical observations of lung tissue and alveolar cells. The number of monocytes was increased (p<0.001) at 1h after IL-1 treatment compared with that of sham. At 2h after instillation of IL-1, the number of alveolar macrophages was the highest, XO activity in BALF was elevated at 2h after IL-1 instillation and the activity was markedly elevated(p<0.05) at 3h after IL-1 treatment. On the basis of these experimental results, it is suggested that, during early phase of acute lung injury induced by IL-1, alveolar macrophage-derived XO contributes to lung injury earlier than the neutrophilic respiratory burst.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.53-61
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• 2006

When routine behavior control is impossible, midazolam is often used for sedation, because it has wide margin of safety, relatively few side-effects and multiple route of administration. Although intramuscular administration of all administration route is frequently used, it is a major source of anxiety, discomfort, and trauma in children. To the contrary, oral administration of midazolam is easily administered and accepted by children. But, it's therapeutic drug concentration has not been established. The purpose of this study was to compare sedation effect and physiologic parameter of oral midazolam which palliate demerits of intramuscular administration in sedating young pediatric patients with intramuscular midazolam Twelve negative children, mean age 62.5 months, who needed at least two separate restorative visits, requiring local anesthesia participated in this study On every visit, one of the following 2 different sedative regimen was given : (1) 0.30mg/kg midazolam by intramuscular administration (2) 0.75mg/kg by oral administration. Physiologic parameter(oxygen saturation, heart rate) was recorded by ten procedure and behavior was videotaped and rated using Ohio State University Behavior Rating Scale and Automated Counting System by one investigator, blind to administration route The analyzed sedative effect of oral midazolam resulted in good sedative effect, comparing to intramuscular route, And there is no statistically difference between oral and intramuscular administration of midazolam (p>0.05).

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.117-124
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• 2003

This study was designed to test the effect of Korean traditional tea materials on oxygen-free radical metabolism in lead (Pb) -administered rats. Male rats were divided into normal, Pb-control (Pb-Con) and Pb-water extract of green tea (Camellia sinensis; GT) , persimmon leaf (Diospyros kaki; PL) , safflower seed (Carhamus tinctorius: SS) , Du-Zhong (Eucommia ulmoides; EU) groups, respectively. Pb intoxication was induced by administration of lead acetate (25 mg/kg. B.W., oral) weekly. The extract was administered based on 1.26 g of raw material/kg B.W./day for 4 weeks. When the GT, PL, SS and EU were supplemented to the Pb-administered rats, hepatic lipid peroxide levels were significantly lower compared to the Pb-Con group. Hepatic cytochrom P-450 content and aminopyrine N-demethylase activity was lower in the Pb-Con group than in the normal group, whereas xanthine oxidase activity was significantly elevated in Pb-administered rats. The water extract of GT, PL, SS and EU supplementation attenuated changes in enzyme activities generating reactive oxygen species in the liver. Hepatic superoxide dismutase, catalase and glucose 6-phosphate dehydrogenase activities were significantly higher in the Pb-Con group than in the normal group, while monoamine oxidase activity also tended to increase in the Pb-administered rats. However, glutathione peroxidase and glutathione S-transferase activities, and glutathione content significantly decreased through Pb intoxication. The supplementation of GT, PL, SS and EU induced alleviation changes of hepatic antioxidant enzyme activity.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.111-120
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• 2014

Purpose: This study was to investigate changes in the thickness of cornea, curvature of cornea, and aberration depending on the water contents, materials, and refractive power of contact lens. Methods: The differences in the corneal thickness between pre- and post-wearing the lenses were compared using 5 kinds of lenses. The changes in the corneal thickness, the curvatures of the anterior and posterior cornea, and high order aberration (HOA) before and after wearing the lenses were investigated at the center of the cornea, and the different distance and the direction away from the center of the cornea. For the equipments of measurement, ORB ScanII (Bausch & Lomb Inc, ver 3.14) was used to measure the corneal topography and thickness, and Zywave (Bausch & Lomb Inc, ver 5.20) was used to analyze the high order aberration. Results: Five (S1, S2, S3, T1, T2) of the lens was used for this study, excluding the lens T2 lens has four lenses and the thickness of the corneal shape, but the impact is minimal. In the case of the hydrogel soft contact lenses (T2 lens) with low oxygen permeability, the corneal thickness showed distinct increasing patterns. The high order aberration and coma aberration were most changed in the silicon hydrogel toric lens, while the depth of anterior was most changed in the hydrogel toric lens. Conclusion: Among the 5 kinds of contact lenses with different water contents, materials, and refractive power used for this study, the corneal shape change was small for the lenses with an oxygen permeability (Dk) of more than 28, and the largest for the lenses with a very low oxygen permeability.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.407-411
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• 2015

Dense ceramic membranes have been prepared using the commercial perovsikite $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$, powders synthesized by the solid state reaction method. The as-synthesized powders were compressed into disks with 1.0 mm of thickness and the disk was sintered at $1,100^{\circ}C$ for 2 hr. The oxygen permeation flux of $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ membrane increased with the increasing temperature and oxygen partial pressure. The activation energy for oxygen permeation was increased with the increasing oxygen partial pressure. Oxygen permeation flux at $950^{\circ}C$ were measured at various flow rates of feed and sweep gas. It has been demonstrated that oxygen permeability increased at elevated flow rates of both gases, but the sweep gas is more influential.