• Clinical and Experimental Pediatrics
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• 제52권1호
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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.

• Applied Chemistry for Engineering
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• 제24권4호
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• pp.433-437
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• 2013

Electrical discharge plasma created in a multi-channel porous ceramic membrane-supported catalyst was applied to the decomposition of a volatile organic compound (VOC). For the purpose of improving the oxidation capability, the ceramic membrane used as a low-pressure drop catalyst support was loaded with zinc oxide photocatalyst by the incipient wetness impregnation method. Alternating current-driven discharge plasma was created inside the porous ceramic membrane to produce reactive species such as radicals, ozone, ions and excited molecules available for the decomposition of VOC. As the voltage supplied to the reactor increased, the plasma discharge gradually propagated in the radial direction, creating an uniform plasma in the entire ceramic membrane above a certain voltage. Ethylene was used as a model VOC. The ethylene decomposition efficiency was examined with experimental variables such as the specific energy density, inlet ethylene concentration and zinc oxide loading. When compared at the identical energy density, the decomposition efficiency obtained with the zinc oxide-loaded ceramic membrane was substantially higher than that of the bare membrane case. Both nitrogen and oxygen played an important role in initiating the decomposition of ethylene. The rate of the decomposition is governed by the quantity of reactive species generated by the plasma, and a strong dependence of the decomposition efficiency on the initial concentration was observed.

• Journal of Life Science
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• 제17권8호통권88호
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• pp.1147-1151
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• 2007

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke and chemicals. Free radicals and reactive oxygen species caused by them play critical roles in cellular damage. They not only injure the skin structure but also participate in the immensely complex inflammatory reaction. Anti-wrinkle effects of the Oriental herb extracts(OHE) were evaluated by the determination of anti-oxidation, collagenase inhibition and collagen synthesis in normal human fibroblast. OHE showed antioxidative activity as high as vitamin C, trolox and DL-penicillamine. Also OHE showed promotive effect on collagen synthesis and inhibitory effect on collagenase activity. These results demonstrated that OHE could be useful as an anti-wrinkle cosmetic ingredient.

• Journal of Life Science
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• 제19권10호
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• pp.1352-1359
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• 2009

We designed this study to investigate the effects of continuous strenuous aerobic exercise on the respiratory system in a rat model. After exercise for 8 weeks, rats' weights were higher in the exercise groups than in the Control group (non-exercise). Rats in Exercise-120 min group (Ex-120 group) had the lowest weights. Total leukocyte counts in bronchoalveolar lavage fluid (BALF) were higher in exercise groups than in Control group. The Ex-30 and Ex-120 groups had higher neutrophil counts, whereas that in the Ex-60 group was lower than in the Control group, and that in the Ex-30 group was the highest. Lymphocyte and monocyte counts were higher in all exercise groups than in the Control group, and those in the Exercise-120 min group were the highest. Interleukin-6 (IL-6) level was the highest, while IL-10, interferon-$\gamma$ and nitric oxide (NO) levels were the lowest in the Ex-120 group when compared to the Control and other exercise groups. These findings suggest that strenuous aerobic exercise for short periods (30 min) may have a beneficial effect on decrease in body weight, whereas prolonged-strenuous aerobic exercise (>1 hr) may be adverse to leukocyte and immune levels in the bronchoalveolar system, as well as result in an increased production of oxygen free radicals.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.211-211
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• 1999

Titanium nitride (TiN) thin films have useful properties including high hardness, good electrical conductivity, high melting point, and chemical inertness. The applications have included wear-resistant hard coatings on machine tools and bearings, decorative coating making use of the golden color, thermal control coatings for widows, and erosion resistant coatings for spacecraft plasma probes. For all these applications as feature sizes shrink and aspect ratios grow, the issue of good step coverage becomes increasingly important. It is therefore essential to manufacture conformal coatings of TiN. The growth of TiN thin films by chemical vapor deposition (CVD) is of great interest for achieving conformal deposition. The most widely used precursor for TiN is TiCl4 and NH3. However, chlorine impurity in the as-grown films and relatively high deposition temperature (>$600^{\circ}C$) are considered major drawbacks from actual device fabrication. To overcome these problems, recently, MOCVD processes including plasma assisted have been suggested. In this study, therefore, we have doposited Ti(C, N) thin films on Si(100) and D2 steel substrates in the temperature range of 150-30$0^{\circ}C$ using tetrakis diethylamido titanium (TDEAT) and titanium isopropoxide (TIP) by pulsed DC plamsa enhanced metal-organic chemical vapor deposition (PEMOCVD) method. Polycrystalline Ti(C, N) thin films were successfully grown on either D2 steel or Si(100) surfaces at temperature as low as 15$0^{\circ}C$. Compositions of the as-grown films were determined with XPS and RBS. From XPS analysis, thin films of Ti(C, N) with low oxygen concentration were obtained. RBS data were also confirmed the changes of stoichiometry and microhardness of our films. Radical formation and ionization behaviors in plasma are analyzed by optical emission spectroscopy (OES) at various pulsed bias and gases conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameter and the effect of N2 and NH3 gases as reactive gas is also evaluated in reduction of C content of the films. In this study, we fond that He and H2 mixture gas is very effective in enhancing ionization of radicals, especially N resulting is high hardness. The higher hardness of film is obtained to be ca. 1700 HK 0.01 but it depends on gas species and bias voltage. The proper process is evident for H and N2 gas atmosphere and bias voltage of 600V. However, NH3 gas highly reduces formation of CN radical, thereby decreasing C content of Ti(C, N) thin films in a great deal. Compared to PVD TiN films, the Ti(C, N) film grown by PEMOCVD has very good conformability; the step coverage exceeds 85% with an aspect ratio of more than 3.

• The Journal of Korean Medicine
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• 제26권3호
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• pp.27-42
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• 2005

Objectives : Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disease characterized by amyloid plaques and neurofibrillary tangles. These plaques are associated with degenerating neuronal processes and consist primarily of fibrillary aggregates of beta-amyloid$ protein, generated from amyloid precursor protein (APP). Another amyloidogenic fragment, the carboxyl terminus (CT) of APP, which is composed of 99-105 amino acid residues containing the complete $A{\beta}$ sequence, also appears to be toxic to neurones. Recent evidence suggest that CT105, carboxy terminal 105 amino acids peptide fragment of APP, may be an important factor causing neurotoxicity in AD. Methods : Although a variety of oriental prescriptions including Pinelliae rhizoma have traditionally been utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet been fully elucidated. In the present study, we investigated effects of the dichloromethane extract of Pinelliae rhizoma (PINR) on neurotoxicity and the formation of reactive oxygen species (ROS) and nitric oxide (NO) in SK-N-SH cells overexpressed with CT105. In addition, we evaluated its radical scavenging activity and effects on acetylcholinesterase (AChE) activity. Furthermore, effects on cognitive deficits induced by scopolamine treatment in rats were evaluated. Results ; We found in this study that PINR significantly inhibited apoptotic neuronal death induced by CT105 overexpression in SK-N-SH cells. Based on morphological examinations by phase-contrast microscopy, PINR reversed apoptotic changes of CT105-expressed cells. It was also found that PINR significantly promoted neurite outgrowth and inhibited formation of ROS nd NO. PINR was shown to scavenge DPPH radicals and noncompetitively inhibit AChE activity. Furthermore, it reduced scopolamine-induced memory impairment in rata, assessed by passive avoidance test. Conclusions : Taken together, these results demonstrate that PINR exhibits neuroprotective, antioxidant, and memory enhancing effects, and therefore may bs beneficial for the treatment of AD.

• Reproductive and Developmental Biology
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• 제35권4호
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• pp.441-447
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• 2011

The study aim is to investigate the free radicals scavenging and spermatogenic potentials, as well as to analyze any reproductive toxicity of ethanolic extract of Mucuna prureins (M. pruriens) Linn. in spermatozoa, under different dosages in normal male rat. Normal rats were randomly selected and suspension of the extract was administered orally at the dosages of 150, 200 and 250 mg/kg body weight of the different groups of male rats (n=6) once in a day for 60 days and grouped as group II, III and IV respectively. Saline treated rats served as control -group I. On the $60^{th}$ day the animals were sacrificed and the epididymal sperm were subjected to various analyses like level of ROS production, LPO, enzymatic and non enzymatic antioxidant, morphology, morphometry, chromosomal integrity and DNA damage. Results showed significant reduction in ROS production and peroxidation and significant increase in both enzymic and non-enzymic antioxidants in all concentration treated groups when compared with control. Results from all the drug treated groups showed good sperm morphology, increased sperm count and motility. There was no DNA damage and showed normal chromosomal integrity even in 250 mg/kg dose. When compared with control all the three extract treated groups showed increased ROS scavenging activity. However, group II (200 mg/kg) showed significant changes in all the parameters. From the present study it was confirmed that the M. pruriens has potential to improve the sperm qualitatively and quantitatively through scavenging the excess ROS with any adverse side effects. These observations suggest that ethanolic seed extract of M. pruriens may serve as anti-oxidant that can exploit to treat the oxidative stress mediated male factor infertility.

• Korean Journal of Food Science and Technology
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• 제20권3호
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• pp.287-292
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• 1988

The inhibition mechanism of DNA damage by lipid peroxidation was studied through the reaction systems of plasmid pBR322 DNA, linoleic acid and the ethanol extracts obtained from ginger and garlic. The DNA damage was greatly inhibited by the addition of ginger and garlic extracts, and their scavenging effects of active oxygens were also great. It is considered that the inhibitory effects of these extracts on the DNA damage are mainly due to their scavenging effects of active oxygen radicals.

• Journal of Physiology & Pathology in Korean Medicine
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• 제19권6호
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• pp.1557-1562
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• 2005

A mechanism of hair cell damage caused by noise and ototoxic agents is mediated through generation of free radicals and reactive oxygen species (ROS). It is known that most of animals have defense systems to protect against ROS, and the cochlea of inner ear in animals also has ROS defense systems including several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH), which efficiently detoxifying ROS generated under normal condition. Steamed roots of Rehmannia glutinosa have been traditionally used in Oriental medicine for the treatment of auditory disease such as tinnitus, vertigo, and hearing loss as well as inflammatory diseases, hectic fever, night sweat, and headache. In the present study, we showed that the ethanol extract from steamed roots of R. giutinosa (ESRG) increased the antioxidant enzymes such as SOD, CAT, GPX, and GR activities and GSH level in HEI-OC1 auditory cells. This extract itself did not show any significant cytotoxicity up to $50{\mu}g/ml$. Our results further support the view that ESRG is promising sources of potential antioxidants. Future studies will be aimed at investigating the effects of ESRG on the regulation of cellular mechanisms and isolating and identifying the substances responsible for the regulation of antioxidant enzyme system from the plant extracts.

• Korean Journal of Medicinal Crop Science
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• 제26권5호
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• pp.391-400
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• 2018

Background: Atractylodes radix is a well-known medicinal crop having many physiological effects. This study was conducted to select useful Atractylodes japonica ${\times}$ Atractylodes macrocephala (AJM) cultivars by comparing anti-oxidative and anti-inflammatory efficacies. Methods and Results: Seven extracts from AJM cultivars were used to treat lipopolysacchride (LPS)-treated BV2 cells, and the effects on cell viability and inhibition on reactive oxygen species (ROS) and nitric oxide (NO) production were analyzed. In vitro scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and peroxynitrite ($NOO^-$) radicals were also investigated. Contents of total phenol, atractylenolide I, and atractylenolide III in the AJM extracts were measured using high performance liquid chromatography (HPLC) or spectrophotometry. The experiments show that none of the seven extracts was cytotoxic above 89.2% at $20-250{\mu}g/m{\ell}$. Extracts of Gowon, Dawon, Sangchul, and Huchul inhibited ROS generation in a dose-dependent manner, and Sangchul extract showed the highest inhibition on ROS production. All the AJM extracts showed effective inhibitory activity after on NO release in the LPS-treated BV2 cells, and Sangchul extract showed the highest activity. Sangchul extract had the most potent scavenging activities for $NOO^-$ and had some DPPH radical scavenging effect. Sangchul extract also had the highest content at total phenol and atractylenolide I content. Atractylenolide III was not detected in the AJM extracts. Conclusions: The results suggested that Sangchul was the most useful anti-oxidative and anti-inflammatory resource among the AJM cultivars.