• Title/Summary/Keyword: oxygen species

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Supplementation of cryoprotective extender with resveratrol decreases apoptosis index and reactive oxygen species levels in post-thaw dog sperm

  • Bang, Seonggyu;Tanga, Bereket Molla;Qamar, Ahmad Yar;Fang, Xun;Seong, Gyeonghwan;Nabeel, Abdelbagi Hamad Talha;Yu, Iljeoung;Cho, Jongki
    • Korean Journal of Veterinary Research
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    • v.61 no.4
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    • pp.29.1-29.7
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    • 2021
  • Resveratrol (RSV, 3,5,4'-trihydroxytrans-stilbene) protects sperm from cryo-induced damage in various animal and human species. In this study, we aimed to assess the effect of dog sperm cryoprotective extender containing RSV on the quality of post-thaw dog sperm. Sperm were collected from 4 Beagles and supplemented with different concentrations of RSV (0, 100, 200, and 400 µM). After thawing, apoptosis index, and reactive oxygen species (ROS) levels were assessed to determine post-thaw sperm quality. Dog sperm cryopreserved with 400 µM RSV showed significant improvement in post-thaw sperm quality with lower apoptosis index and ROS levels (p < 0.05). Our results showed that the supplementation of dog sperm cryoprotective extender with RSV at a concentration of 400 µM improved the post-thaw dog sperm quality in the term of sperm ROS production and apoptosis. In addition, we emphasize the necessity of testing the ROS levels and apoptosis index using flow cytometry to determine the quality of post-thaw semen.

An Experimental Study on Flammability Limits and Combustion Characteristics of Synthetic Gas in a Constant Combustion Chamber (정적연소기를 이용한 합성가스의 가연한계 및 연소특성에 관한 실험적 연구)

  • Cho, Yong-Seok;Lee, Seang-Wock;Won, Sang-Yeon;Park, Young-Joon;Kim, Duk-Sang
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.14-21
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    • 2008
  • Synthetic gas is defined as reformed gas from hydrocarbon-based fuel and the major chemical species of the synthetic gas are $H_2$, CO and $N_2$. Among them, hydrogen from synthetic gas is very useful species in chemical process such as combustion. It is a main reason that many studies have been performed to develop an effective reforming device. Furthermore, other technologies have been studied for synthetic gas application, such as the ESGI(Exhaust Synthetic Gas Injection) technology. ESGI injects and burns synthetic gas in the exhaust pipe so that heat from hydrogen combustion helps fast warmup of the close-coupled catalyst and reduction of harmful emissions. However, it is very hard to understand combustion characteristic of hydrogen under low oxygen environment and complicated variation in chemical species in exhaust gas. This study focuses on the characteristics of hydrogen combustion under ESGI operating conditions using a CVC(Constant Volume Chamber). Measurements of pressure variation and flame speed have been performed for various oxygen and hydrogen concentrations. Results have been analyzed to understand ignition and combustion characteristics of hydrogen under lower oxygen conditions. The CVC experiments showed that under lower oxygen concentration, amount of active chemicals in the combustion chamber was a crucial factor to influence hydrogen combustion as well as hydrogen/oxygen ratio. It is also found that increase in volume fraction of oxygen is effective for the fast and stable burning of hydrogen by virtue of increase in flame speed.

Optimal oxygen saturation in premature infants

  • Chang, Mea-Young
    • Clinical and Experimental Pediatrics
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    • v.54 no.9
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    • pp.359-362
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    • 2011
  • There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation ($SpO_2$) is 90 to 93% with an intermittent review of the correlation between $SpO_2$ and the partial pressure of arterial oxygen tension ($PaO_2$). Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

Seasonality Study of Shellfish Gathering using Oxygen Isotope Analysis (산소동위원소 분석을 이용한 조개채집의 계절성 연구)

  • 안덕임;이인성
    • The Korean Journal of Malacology
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    • v.12 no.2
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    • pp.105-108
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    • 1996
  • In archaeology, oxygen isotope analysis using marine shells has been used to reconstruct past environment and determine the season of shellfish-gathering activities in the past. Modern oysters(Crassostrea gigas) from Solsum ao the mouth of Chonsu Bay were anayzed to examine the potential of the species for determining seasonality by oxygin isotope analysis. As a result, it appears that the species can be used for this purpose.

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TETRAHYDROPAPAVEROLINE INDUCES DNA DAMAGE AND APOPTOTIC CELL DEATH THROUGH GENERATION OF REACTIVE OXYGEN SPECIES

  • Shin, Mi-Hyun;Jang, Jung-Hee;Lee, Jeong-Sang;Surh, Young-Joon
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.05a
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    • pp.124-124
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    • 2001
  • Tetrahydropapaveroline(THP), a dopamine-derived 6,7-dihydroxy-l-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydrosioquinoline, has been suspected as a possible dopaminergic neurotoxin to elicit Parkinsonism. Autoxidation or monoamine oxidase-mediated oxidation of THP and subsequent generation of reactive oxygen species (ROS) may contribute to the degeneration of dopaminergic neurons induced by this isoquinoline alkaloid.(omitted)

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Arachidonic Acid Liberated through Activation of $iPLA_2$ Mediates the Production of Reactive Oxygen Species and Apoptosis Induced by N-Ethylmaleimide in HepG2 Human Hepatoma Cells

  • Lee, Yong-Soo
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.242.2-243
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    • 2002
  • We have previously reported that activation of $K^{+}$-$Cl^{-}$-cotransport (KCC) by N-ethylmaleimide (NEM) induces apoptosis through generation of reactive oxygen species (ROS) in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of phospholipase $A_2$($PLA_2$)-arachidonic acid (AA) signals in the mechanism of the NEM actions. (omitted)

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Role of Reactive Oxygen Species In Capsaicin-Induced Apoptosis in MBT -2 Murine Bladder Cancer Cells

  • Chang, Jong-Sun;Jin, Da-Qing;Beak, Sung-Mok;Kim, Jung-Ae
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.137-137
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    • 2002
  • Capsaicin has been reported to induce apoptosis in various cancer cells. However, its effect on bladder cancer cells has not been studied. In this study, we investigated whether capsaicin induces apoptosis in murine orthotopic bladder cancer MBT-2 cells and reactive oxydative species(ROS) are involved in capsaicin-induced apoptotic process.(omitted)

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Induction of Reactive Oxygen Species and Malignant Transformation by Tcdd Through Metabolic Formation of Catechol Estrogens

  • Na, Hye-Kyung;Chen, Zhi-Hua;Kim, Jung-Hwan;Surh, Young-Joon
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.10b
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    • pp.188-188
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    • 2003
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a prototype of halogenated aromatic hydrocarbons, is a persistent environmental contaminant and one of the most powerful tumor promoters. The molecular mechanism underlying induction of tumor promotion by TCDD has not been elucidated.(omitted)

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