• Journal of Life Science
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• v.33 no.7
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• pp.586-592
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• 2023

Oxidative stress is a critical factor affecting the quality and viability of sperm during boar semen storage. Oxidative stress is also a significant concern during the process of freezing semen. The process of semen storage involves exposing the sperm to various stressors, including temperature changes, cryoprotectants, and extended periods of incubation. In addition, oxidative stress can lead to the production of reactive oxygen species (ROS) within the sperm, resulting in oxidative damage to cellular components, such as lipids, proteins, and DNA. Striking a balance between ROS production and the antioxidant defense system is crucial for maintaining sperm viability and functionality during semen storage. Moreover, the prolonged storage of boar semen leads to an increase in ROS levels, which can impair sperm motility, membrane integrity, and DNA integrity. ROS-induced lipid peroxidation affects the fluidity and stability of sperm membranes, leading to decreased sperm motility. Moreover, oxidative damage to the DNA can result in DNA fragmentation, compromising the genetic integrity of the sperm. In conclusion, oxidative stress is a significant challenge in maintaining sperm quality during boar semen storage. Understanding the mechanisms underlying oxidative stress and their impacts on sperm function is crucial for developing effective strategies to minimize oxidative damage and improve sperm storage outcomes.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.570-576
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• 2003

The remarkable change of phenomenon induced by stress increase energy metabolism that can induce many reactive oxygen species (ROS) production. ROS can peroxidize cellular macromolecules including lipid and protein. The object of this study was to investigate whether stress may induce cellular damage by producing ROS and whether vitamin E, as a strong lipid-soluble antioxidant, can protect cells against reactive oxygen species produced by noise and immobilization stress in SD rats. The stress group increased 5-hydroxyindole aceti acid (5-HIAA) , one of the stress hormone, in brain tissue and free fatty acid in plasma. Vitamin I treatment had no effect on 5-HIAA but free fatty acid contents decreased with a fortified vitamin I diet. Furthermore, the body weight of vitamin I-treated rats increased more than that of the stress group. Lipid peroxidation and protein degradation as an index of oxidative damage in brain tissue decreased with the use of the fortified vitamin I diet supplement. The results suggest that vitamin I supplements have a protective effect against noise and immobilization stress-induced oxidative damage in brain tissue.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.2
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• pp.38-45
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• 1997

In this paper, the three-dimensional stress effect of thermal oxide is simulated. We developed a three-dimensional finite element numerical simulator including three-dimensional adaptive mesh generator that is able to refine and eliminate nearby moving boundary of oxide, and oxidation solver with stress model. To investigate the behavior of thermal oxidation the simulations of thermal oxidation for island and hole structures are carried out assuming silicon wafer of <100> direction, temperature of $1000^{\circ}C$, oxidation time of 60min, wet ambient, initial oxide thickness of $300\AA$, and nitride thickness of $2, 000\AA$. The main effect of deformation at the corner area of oxide is due to distribution of oxidant, but the deformation of oxide is affected by the stressin theoxide. In the island structure which is the structure mostly covered with nitride and a coner is opended to oxidation, oxidation is reduced at the coner by compressive stress. In the hole structure which is the structure mostly opedned to oxide and a coner is convered with nitride, however, oxidation is increased at the coner by tensile stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1532-1536
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• 2011

In this study, the antioxidative activity of Artemisia capillaris T. extract on the proliferation and differentiation of MC3T3-E1 cells under $H_2O_2$-induced oxidative stress was investigated in order to determine its protective effect against oxidative stress as well as its availability as an antioxidant material related to treatment of bone diseases. As a result, the total polyphenol content of A. capillaris extract was 90.10 mg/g, whereas the flavonoid content was 4.45 mg/g. A. capillaris extract increased proliferation of MC3T3-E1 cells under $H_2O_2$-induced oxidative stress, and also increased the proliferation of differentiated osteoblast cells under oxidative stress. In addition, two differentiation markers, alkaline phosphatase activity and mineralization level, in A. capillaris extract tended to increase. These results indicate that A. capillaris extract suppresses the damage to osteoblasts caused by oxidative stress, which demonstrates its availability as an antioxidant material for preventing bone diseases.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.124-129
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• 2011

The role of the ferric uptake regulator (Fur) of Helicobacter pylori in the oxidative stress was investigated in this study. A fur knockout mutant of H. pylori was constructed by replacing the fur gene with an aphA (kanamycin resistant marker) gene. Photodynamic therapy using methylene blue (MB) and 660 nm light was chosen to induce oxidative stress. The bactericidal effect of photodynamic therapy (PDT) was compared between wild type H. pylori and fur knockout mutant H. pylori. The degree of oxidative damage of DNA was confirmed using alkaline gel electrophoresis and an assay of 8-hydroxy-2-deoxyguanosine (8-OHdG). In control groups, the number of viable cells was maintained constantly during experiment. After PDT, the mutant H. pylori showed 10,000 times decreased viable cell number compared with wild type H. pylori. Depending on the exposure time of 660 nm light, the 3-fold increase in the concentration of 8-OHdG was observed in mutant H. pylori. The results of this study showed that H. pylori's Fur protein may play a role in oxidative stress induced by PDT.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.4
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• pp.335-340
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• 2002

In this paper, the stress induced leakage currents of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between 113.4${\AA}$ and 814${\AA}$, which have the gate area $10^3cm^2$. The stress induced leakage currents will affect data retention and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses.

• Journal of Life Science
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• v.17 no.11
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• pp.1571-1575
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• 2007

This research was carried out to investigate the effects of Hambag mushroom on the oxidative stress in diabetic rats, Sprague-Dawley. The diabetic rats induced by streptozotocin were fed with hambag mushroom-powder(G. frondosa) for 6 weeks. For the level of oxidative stress in liver and pancreas tissues, it was studied by measuring LPO (lipid oxide) level as an indicator of lipid peroxidation, XOD(xanthine oxidase) as one of important sources for free radicals and the levels of GSH and GST as anti-oxidant systems. Also, as an indicator of liver damaged by oxidative stress, the activities of serum ALT and AST were measured. It was observed that the levels of ALT, AST, LPO and XOD were higher by about two times in both tissues from diabetic rats than in those from control rats. This indicates that the oxidative stress induced by diabetes caused the tissues damages. However, these levels were decreased in the tissues from rats with hambag mushroom-powder. Futhermore, the activity of GST were higher in both tissues from diabetic rats fed with hambag mushroom-powder than in those from diabetic rats. Thus, it is considered that the hambag mushroom-powder decreases the level of oxidative stress by increasing activity of anti-oxidant system such as GSH and GST. It is suggested that the hambag mushroom-powder can be useful for preventing the tissues damaged by diabetes-induced oxidative stress.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.1-4
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• 2013

The present study evaluated the systemic oxidative stress status during major orthopedic surgery in dogs. Sixteen dogs presented with various orthopedic diseases involving fractures or luxation of limbs. All patients underwent orthopedic surgery for treatment of fractures or luxation of limbs. A significant increase in the plasma total oxidant status (TOS) and oxidative stress index (OSI) levels in dogs after surgery was observed. Plasma total antioxidant status (TAS) levels were significantly decreased in dogs after surgery. The results of this study suggested that association or relationship in serum between TOS or TAS levels and redox imbalance were caused by surgical trauma in orthopedic disease conditions.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.103-109
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• 2008

Purpose: This review illustrates an importance of oxidative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation in association with eye disease, especially of cataract, and discusses an important role of lipid peroxide as a mediator of oxidative stress-related ocular dysfunction. Methods: Oxidative stress, resulted from the cellular production of ROS and RNS, is known to cause various forms of cellular damages such as protein oxidation, DNA breaks, apoptosis, and lipid peroxidation. These damages can be developed to human diseases. Accumulating evidence strongly suggests that continuous or constant exposure of eye tissues to oxidative stress is a main cause of cataractogenesis. Therefore, we investigated the action of oxidative stress in ocular dysfunction. Results: The ocular lens is continuously attacked by ROS inevitable generated from the process of cellular metabolism and the chronic exposure to ultraviolet. Excessive generation of ROS, resulting in degradation, oxidation, crosslinking and aggregation of lens proteins, is regarded as an important factor in development of cataract. Conclusions: These oxidative stress and oxidant/antioxidant imbalance produces the excess ROS which can lead to eye dysfunction. Even though known results, it should be noted that there is limited information on the molecular mechanism which can be better defined with the interrelation of oxidative stress and optic abnormalities.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.241-250
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• 2004

본 연구는 건전지나 플라스틱 등 산업물질, 식품, 흡연 그리고 공기, 물 등을 통해 인간과 생태계에 노출되고 있는 중금속 카드뮴을 인간 유방암 세포 MCF-7에 처리하였을 때 일어나는 현상을 살펴보고 나아가 카드뮴의 독성기전을 규명하기 위해 시행되었다. 카드뮴으로 인한 아폽토시스는 DNA분절 현상과 핵의 쪼개짐, 세포주기에 있어서 sub-G1의 출현 그리고 아폼토시스시에 발현되는 단백질 caspase의 발현, 특히 산화적 스트레스상태에서 마이토콘드리아가 손상을 입었을 때 발현되는 caspase-9의 발현을 통해 확인하였다. 카드뮴으로 인한 산화적 스트레스는 활성 산소종이 대조군에 비해 증가하고 이를 방어하기 위한 항산화효소 superofide dismutase, catalase, glutathion redurtase가 감소함을 통하여 확인하였다. 이 상의 결과들을 통해 카드뮴은 인간 유방암 세포 MCF-7에서 산화적 스트레스를 유발시켜 아폼토시스를 일으키는 것으로 추정할 수 있다.