• Title/Summary/Keyword: Protection mechanisms

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XPS STUDY ON DNA DAMAGE BY LOW-ENERGY ELECTRON IRRADIATION

  • Noh, Hyung-Ah;Cho, Hyuck
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.190-194
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    • 2011
  • After the first report that electrons with sub-ionization energy of DNA could cause single strand breaks or double strand breaks to DNA, there have been various studies to investigate the mechanisms of DNA damage by low-energy electrons. In this paper, we examined the possibility of using X-ray photoelectron spectroscopy (XPS) to analyze the dissociation patterns of the molecular bonds by electron irradiation on DNA thin films and tried to establish the method as a general tool for studying the radiation damage of biomolecules by low energ yelectrons. For the experiment, pBR322 plasmid DNA solution was formed into the films on tantalum plates by lyophilization and was irradiated by 5-eV electrons. Un-irradiated and irradiated DNA films were compared and analyzed using the XPS technique.

Broadcasting System Compliant with MPEG-2/4 IPMPX

  • Cho, Yong-Ju;Seok, Jong-Won;Hong, Jin-Woo;Ahn, Chie-Teuk
    • ETRI Journal
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    • v.26 no.2
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    • pp.83-91
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    • 2004
  • In this paper, we present an intellectual property management and protection (IPMP) system in a broadcasting environment to provide mechanisms for copyright and contents protection that are compliant with the MPEG-2 and MPEG-4 IPMP Extension (IPMPX) specifications. The technology for processing IPMP related information was exploited, and a terminal model has been successfully designed and implemented. In addition, interoperability, which is the main objective of MPEG-2/4 IPMPX, has been addressed in detail. The experimental results show that the implemented system performs the IPMP process well, meeting the requirements of a broadcasting environment.

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Protective Effects of Alpinia katsumadai Extract Against Oxidative Stress

  • Lee, Eul-Jae;Kim, Jeong-Hee
    • International Journal of Oral Biology
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    • v.36 no.3
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    • pp.149-154
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    • 2011
  • In the present study, total methanol extracts prepared from Alpinia katsumadai showed significant protective effects against the oxidative stress induced by hydrogen peroxide, UV-C or ${\gamma}$-ray irradiation. These protective effects were substantially increased by treatment with 20~100 ${\mu}g$/ml of the extract. The A. katsumadai total methanol preparation was further fractionated into n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these five fractions, the ethylacetate and butanol fractions of A. katsumadai showed the strongest protective effects against oxidative stress induced by UV-C and ${\gamma}$-ray irradiation. These fractions also showed high DPPH radical scavenging and lipid peroxidation inhibitory activities. In addition, both fractions displayed cell proliferation activation effects, as evidenced by significant increases in colony formation. Our current data thus suggest that the mechanisms underlying the protective effects of A. katsumadai against oxidative damage may include radical scavenging, protection against cell membrane damage and stimulation of cell proliferation.

Protection and Restoration of GMPLS LSP using CR-LDP Detours (CR-LDP 우회를 통한 GMPLS LSP의 보호 및 복구)

  • 김진형;정재일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.12B
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    • pp.1051-1059
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    • 2003
  • The key feature of GMPLS is the provision of network resources and the automatic set-up of a path. And the mechanism of protection and restoration of a path is presented when network component fails. This paper suggests CR-LDP Static Detour Mechanism and Dynamic Detour Mechanism. CR-LDP Detours are a mechanism to set up detour paths automatically at every node to protect working path. Hence suggested mechanism performance is compared with existing mechanisms by computer simulation.

Rule Protecting Scheme for Snort

  • Son, Hyeong-Seo;Lee, Sung-Woon;Kim, Hyun-Sung
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.259-262
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    • 2005
  • This paper addresses the problem of protecting security policies in security mechanisms, such as the detection policy of an Intrusion Detection System. Unauthorized disclosure of such information might reveal the fundamental principles and methods for the protection of the whole network. In order to avoid this risk, we suggest two schemes for protecting security policies in Snort using the symmetric cryptosystem, Triple-DES.

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MOLECULAR MECHANISMS OF CARDIOPROTECTION BY A NOVEL GRAPE SEED PROANTHOCYANIDIN EXTRACT

  • Bagchi, Debasis;Preuss, Harry G.;Das, Dipak K.
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.20-21
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    • 2001
  • Free radicals and oxidative stress playa crucial role in the pathophysiology of a broad spectrum of cardiovascular diseases including congestive heart failure, valvular heart disease, cardiomyopathy, hypertrophy, atherosclerosis and ischemic heart disease. We have demonstrated that IH 636 proanthocyanidin extract (GSPE) provides excellent protection against free radicals in both in vitro and in vivo models, and exhibits significantly better efficacy as compared to vitamins C, E and $\beta$-carotene.(omitted)

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Study on the Countermeasure to Induced AC Voltage for Protection to Corrosion of Underground Pipelines (지하 매설 배관의 부식방지를 위한 교류유도 저감대책에 관한 연구)

  • Kim, Dae-Kyeong;Bae, Jeong-Hyo;Lee, Hyun-Goo
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.803-806
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    • 1997
  • The AC induced voltage on underground pipelines not only do harm to workers and instruments, but also cause big trouble in some case. This paper gives the mechanisms, examples, and countermeasure for the AC induced voltages which are caused by the resistive coupling between the grounding system of the 22.9kV distribution power system and the underground pipeline.

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Hepatoprotective Effects of the Acteoside on Carbon tetrachloride Induced Liver damage in Mice

  • Lee, Kyung-Jin;Woo, Eun-Rhan;Choi, Chul-Yung;Jeong, Hye-Gwang
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.174.1-174.1
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    • 2003
  • The protective effects of acteoside, a phenylethanoid glycoside, on cabon tetrachloride-induced hepatotoxicity and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with acteoside prior to the administration of carbon tetrachloride significantly prevented the increased serum enzymatic activities of alanine and aspartate aminotransferase in a dose-dependent manner. (omitted)

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Characteristics of Lightning Overvoltages Coming in Low-Voltage Power Distribution Systems

  • Lee, Bok-Hee;Lee, Dong-Moon;Lee, Su-Bong;Jeong, Dong-Cheol;Lee, Jae-Bok;Myung, Sung-Ho
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.3
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    • pp.91-98
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    • 2003
  • The importance of improving the quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and systems. The transient over-voltages on low-voltage power distribution systems are induced by direct or indirect lightning return strokes. These can cause damage and/or malfunction of the utility systems for home automation, office automation, factory automation, medical automation, etc. The behaviors of lightning overvoltages transferred through the transformer to the low-voltage distribution systems using a Marx generator were experimentally investigated. Furthermore, the coupling mechanisms of lightning overvoltages transferred to the low-voltage systems were clearly illustrated through a theoretical simulation using a Pspice program. The overvoltages in low-voltage ac power systems are rarely limited by the application of the surge arrester to the primary side of the distribution transformer. A superior surge protection scheme is to install surge protection devices at the service entrance switchboard and/or at the load devices in TN power systems.