• Title/Summary/Keyword: Defense Mechanisms

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A Study of Testing Embedded System Software Based on Failure Mechanisms (고장메커니즘 기반의 임베디드 시스템 SW 테스트 방법에 관한 연구)

  • Jeong, Si-Young;Jang, Joong-Soon;Lee, Sang-Yong
    • Journal of Applied Reliability
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    • v.7 no.4
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    • pp.137-148
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    • 2007
  • Rapid increase of embedded systems in electronic and mechanical control systems requires reliable and error-free embedded software. State-based testing methods like FSM are usually used to assure the reliability of embedded software. However, because of possibility of explosion of test cases, only partial test cases are considered in practical tests, which cannot guarantee that all the possible errors are investigated. This study proposes a test procedure based on failure mechanisms that may occur in embedded systems, which can not only assure that certain kinds of possible errors are detected but reduce the testing time. The proposed procedure is applied to vehicle air control system.

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Host Innate Immunity against Hepatitis E Virus and Viral Evasion Mechanisms

  • Kang, Sangmin;Myoung, Jinjong
    • Journal of Microbiology and Biotechnology
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    • v.27 no.10
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    • pp.1727-1735
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    • 2017
  • Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

Proteomic Approach Analysis of Mammary Membrane Proteins Expression Profiles in Holstein Cows

  • Yang, Yong-xin;Cao, Sui-zhong;Zhang, Yong;Zhao, Xing-xu
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.6
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    • pp.885-892
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    • 2009
  • To investigate host defense mechanisms for protecting the mammary gland from mastitis infection, the membrane fraction of mammary tissues from Holstein cows was purified by differential velocity centrifugation, and then the sodium dodecyl sulfate-polyacrylamid gel electrophoresis (SDS-PAGE) separated proteins were identified by ion trap mass spectrometer equipped with a Surveyor high performance liquid chromatography (HPLC) system. A total of 183 proteins were identified. Bioinformatics software was applied to analyse physicochemical characteristics of the identified proteins and to predict biochemical function. These data may provide valuable information to investigate the mechanisms of mammary gland milk secretion and infectious disease, and enable a clear identification of proteins and potential protein targets for therapies.

Bacterial Quorum Sensing and Anti-Quorum Sensing (세균의 적정밀도 인식을 통한 신호전달 및 신호전달 차단 연구)

  • 박순양;이정기
    • Microbiology and Biotechnology Letters
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    • v.32 no.1
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    • pp.1-10
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    • 2004
  • Many bacteria monitor their population density and control the expression of specialized gene sets in response to bacterial cell density based on a mechanism referred to as quorum sensing. In all cases, quorum sensing involves the production and detection of extracellular signaling molecules, auto inducers, as which Gram-negative and Gram-positive bacteria use most prevalently acylated homoserine lactones and processed oligo-peptides, respectively. Through quorum-sensing communication circuits, bacteria regulate a diverse array of physiological functions, including virulence, symbiosis, competence, conjugation, antibiotic production, motility, sporulation, and biofilm formation. Many pathogens have evolved quorum-sensing mechanisms to mount population-density-dependent attacks to over-whelm the defense responses of plants, animals, and humans. Since these AHL-mediated signaling mechanisms are widespread and highly conserved in many pathogenic bacteria, the disruption of quorum-sensing system might be an attractive target for novel anti-infective therapy. To control AHL-mediated pathogenicity, several promising strategies to disrupt bacterial quorum sensing have been reported, and several chemicals and enzymes have been also investigated for years. These studies indicate that anti-quorum sensing strategies could be developed as possible alternatives of antibiotics.

Molecular and Cellular Mechanisms of Syndecans in Tissue Injury and Inflammation

  • Bartlett, Allison H.;Hayashida, Kazutaka;Park, Pyong Woo
    • Molecules and Cells
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    • v.24 no.2
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    • pp.153-166
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    • 2007
  • The syndecan family of heparan sulfate proteoglycans is expressed on the surface of all adherent cells. Syndecans interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors and extracellular matrix components, through their heparan sulfate chains. Recent studies indicate that these interactions not only regulate key events in development and homeostasis, but also key mechanisms of the host inflammatory response. This review will focus on the molecular and cellular aspects of how syndecans modulate tissue injury and inflammation, and how syndecans affect the outcome of inflammatory diseases in vivo.

Update of Pathophysiology in GERO/LPR (위식도역류질환과 인후두역류질환의 대한 최신지견)

  • Woo, Jeong-Sao
    • Korean Journal of Bronchoesophagology
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    • v.16 no.2
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    • pp.83-90
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    • 2010
  • The pathophysiology of Gastroesophageal reflux disease (GERD) has been known that it is developed when the offense-primarily the gastric acid-pepsin content of the refluxate-overcomes a 3-tiered esophageal protective defense. consisting of antireflux mechanisms, luminal clearance mechanisms, and tissue resistance. Laryngopharyngeal reflux (LPR), which is known as an extraesophageal variant of GERD, has been considered to be developed by transient lower esophageal sphincter relaxation (TLESR), direct mucosal injury by gastric contents, more sensitive mucosa compared to esophagus, and absence of buffering effect and aggravation of the injury due to pepsin. However, hypothesis of the pathophysiology in both entities are numerous and still lack of understanding for being a theory. There is no conflict that understanding the pathophysiology is necessary for resolving the problems of these diseases and numerous studies and results have been releasing. This review could provide clinicians dealing with GERD and LPR with applicable new information and help for overcoming the clinical obstruction.

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Design and Implementation of an Enhanced Secure Android-Based Smartphone using LIDS

  • Lee, Sang Hun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.3
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    • pp.49-55
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    • 2012
  • Recently, with the rapid development of android-based smartphones, it is becomes a major security issue that the case of Android platform is an open platform. so it is easy to be a target of mobile virus penetration and hacking. Even there are a variety of security mechanisms to prevent the vulnerable points of the Android platform but the reason of most of the security mechanisms were designed at application-level that highly vulnerable to the attacks directly to the operating system or attacks using the disadvantages of an application's. It is necessary that the complementary of the android platform kernel blocks the kernel vulnerability and the application vulnerability. In this paper, we proposed a secure system using linux-based android kernel applied to LIDS(Linux Intrusion Detection and Defense System) and applied a smart phone with s5pc110 chip. As a result, the unauthorized alteration of the application was prevented with a proposed secure system.

Glycation-induced Inactivation of Antioxidant Enzymes and Modulation of Cellular Redox Status in Lens Cells

  • Shin, Ai-Hyang;Oh, Chang-Joo;Park, Jeen-Woo
    • Archives of Pharmacal Research
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    • v.29 no.7
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    • pp.577-581
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    • 2006
  • Oxidative mechanisms are thought to have a major role in cataract formation and diabetic complications. Antioxidant enzymes play an essential role in the antioxidant system of the cells that work to maintain low steady-state concentrations of the reactive oxygen species. When HLE-B3 cells, a human lens cell line were exposed to 50-100 mM glucose for 3 days, decrease of viability, inactivation of antioxidant enzymes, and modulation of cellular redox status were observed. Significant increase of cellular oxidative damage reflected by lipid peroxidation and DNA damage were also found. The glycation-mediated inactivation of antioxidant enzymes may result in the perturbation of cellular antioxidant defense mechanisms and subsequently lead to a pro-oxidant condition and may contribute to various pathologies associated with the long term complications of diabetes.

The soma-germline communication: implications for somatic and reproductive aging

  • Gaddy, Matthew A.;Kuang, Swana;Alfhili, Mohammad A.;Lee, Myon Hee
    • BMB Reports
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    • v.54 no.5
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    • pp.253-259
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    • 2021
  • Aging is characterized by a functional decline in most physiological processes, including alterations in cellular metabolism and defense mechanisms. Increasing evidence suggests that caloric restriction extends longevity and retards age-related diseases at least in part by reducing metabolic rate and oxidative stress in a variety of species, including yeast, worms, flies, and mice. Moreover, recent studies in invertebrates - worms and flies, highlight the intricate interrelation between reproductive longevity and somatic aging (known as disposable soma theory of aging), which appears to be conserved in vertebrates. This review is specifically focused on how the reproductive system modulates somatic aging and vice versa in genetic model systems. Since many signaling pathways governing the aging process are evolutionarily conserved, similar mechanisms may be involved in controlling soma and reproductive aging in vertebrates.

Anticancer Effects of Gut Microbiota-Derived Short-Chain Fatty Acids in Cancers

  • Mi-Young Son;Hyun-Soo Cho
    • Journal of Microbiology and Biotechnology
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    • v.33 no.7
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    • pp.849-856
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    • 2023
  • Short-chain fatty acids (SCFAs), such as butyrate, propionate, and acetate produced by the gut microbiota have been implicated in physiological responses (defense mechanisms, immune responses, and cell metabolism) in the human body. In several types of cancers, SCFAs, especially butyrate, suppress tumor growth and cancer cell metastasis via the regulation of the cell cycle, autophagy, cancer-related signaling pathways, and cancer cell metabolism. In addition, combination treatment with SCFAs and anticancer drugs exhibits synergistic effects, increasing anticancer treatment efficiency and attenuating anticancer drug resistance. Therefore, in this review, we point out the importance of SCFAs and the mechanisms underlying their effects in cancer treatment and suggest using SCFA-producing microbes and SCFAs to increase therapeutic efficacy in several types of cancers.