• Toxicological Research
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• v.11 no.1
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• pp.117-125
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• 1995

In order to examine the mechanism of asbestos clastogenicity, CHO cells were treated with chrysotile and crocidolite. Crocidolite and chrysotile were able to induce lipid peroxidation in a dose dependent manner. Ultrafiltrate of culture media from CHO cells treated with chrysotile/crocidolite induced sister chromatid exchange in CHO cells. Ultrafiltrate of culture media from CHO cells treated with chrysotile induced chromosome aberration but it was not statistically significant. Simultaneous treatment of 3-Aminobenzamide (3-AB) or cytosine arabinoside (Ara C) with crocidolite had no effect on the frequency of chromosome aberration by crocidolite whetease posttreatment of caffeine significantly increased the chromosomel aberration by crocidolite. This indicated that DNA damage by asbestos took place at late stage of cell cycle. The results suggested that the ultrafiltrate of media contained clastogenic factor (CF) and lipid peroxidation might be involved in the formation of CF.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.511-535
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• 2017

Internet banking is one of many services provided by financial institutions that have become very popular with an increasing trend. Due to the increased amount of usage of the service, Internet banking has become a target from adversaries. One of the points that are at risk of an attack is the login process. Therefore, it is necessary to have a security mechanism that can reduce this risk. This research designs and develops a multi-factor authentication protocol, starting from a registration system, which generates authentication factors, to an actual authentication mechanism. These factors can be categorised into two groups: short term and long term. For the authentication protocol, only three messages need to be exchanged between a client and a financial institution's server. Many cryptographic processes are incorporated into the protocol, such as symmetric and asymmetric cryptography, a symmetric key generation process, a method for generating and verifying digital signatures. All of the authentication messages have been proved and analysed by the logic of GNY and the criteria of OWASP-AT-009. Even though there are additional factors of authentication, users do not really feel any extra load on their part, as shown by the satisfactory survey.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.8
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• pp.392-401
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• 2001

This paper presents the single-stage high power factor AC to DC converter operated in active-clamp mode. The proposed converter is added active-clamping circuit to boost-flyback single-stage power factor corrected power supply. The active-clamping circuit limits voltage spikes, recycles the energy trapped in the leakage inductance, and provides a mechanism for achieving soft switching of the electronic switches to reduce the switching loss. The auxiliary switch of active-clamping circuit uses the same control and driver circuit as the main switch to reduce the additional cost and size. To verify the performance of the proposed converter, a 100W converter has been designed. The proposed converter gives good power factor correction, low line current harmonic distortions, and tight output voltage regulation, as used unity power factor.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.66-67
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• 2003

It is well known that osteoblasts and osteoc1asts playa key role in bone metabolism. They involve in osteoformation or bone destruction which are ragulated by various factors such as thyroid hormone, parathyroid hormone, estrogen, growth factor and cytokine. Recently, it is demonstrated that oxidative stress is one of pathological factors in bone metabolism, but it is left unknown about mechanism between oxidative stress and bone metabolism.(omitted)

• Molecules and Cells
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• v.44 no.5
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• pp.342-355
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• 2021

The microphthalmia-associated transcription factor family (MiT family) proteins are evolutionarily conserved transcription factors that perform many essential biological functions. In mammals, the MiT family consists of MITF (microphthalmia-associated transcription factor or melanocyte-inducing transcription factor), TFEB (transcription factor EB), TFE3 (transcription factor E3), and TFEC (transcription factor EC). These transcriptional factors belong to the basic helix-loop-helix-leucine zipper (bHLH-LZ) transcription factor family and bind the E-box DNA motifs in the promoter regions of target genes to enhance transcription. The best studied functions of MiT proteins include lysosome biogenesis and autophagy induction. In addition, they modulate cellular metabolism, mitochondria dynamics, and various stress responses. The control of nuclear localization via phosphorylation and dephosphorylation serves as the primary regulatory mechanism for MiT family proteins, and several kinases and phosphatases have been identified to directly determine the transcriptional activities of MiT proteins. In different immune cell types, each MiT family member is shown to play distinct or redundant roles and we expect that there is far more to learn about their functions and regulatory mechanisms in host defense and inflammatory responses.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.70-70
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• 2003

Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

• Bioinformatics and Biosystems
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• v.2 no.1
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• pp.24-27
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• 2007

Human cell regulatory mechanism is one of suspicious problems among biologists. Here we tried to uncover the human breast cancer cell regulatory mechanism from gene expression data (Marc J. Van de vijver, et. al., 2002) using a module network algorithm which is suggested by Segal, et. al.(2003) Finally, we derived a module network which consists of 50 modules and 10 tree depths. Moreover, to validate this candidate network, we applied a GO enrichment test and known transcription factor-target relationships from Transfac(R) (V. Matys, et. al, 2006) and HPRD database (Peri, S. et al., 2003).

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.4879-4881
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• 2012

Epidermal growth factor receptor (EGFR) overexpression is associated with resistance to chemotherapy and radiotherapy. The EGFR modulates DNA repair after radiation-induced damage through an association with the catalytic subunit of DNA protein kinase. DNA double-strand breaks (DSBs) are the most lethal type of DNA damage induced by ionizing radiation, and non-homologous end joining is the predominant pathway for repair of radiation-induced DSBs. Some cell signaling pathways that respond to normal growth factors are abnormally activated in human cancer. These pathways also invoke the cell survival mechanisms that lead to resistance to radiation. The molecular connection between the EGFR and its control over DNA repair capacity appears to be mediated by one or more signaling pathways downstream of this receptor. The purpose of this mini-review was not only to highlight the relation of the EGFR signal as a regulatory mechanism to DNA repair and radiation resistance, but also to provide clues to improving existing radiation resistance through novel therapies based on the above-mentioned mechanism.

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.503-509
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• 2021

Marine sources as potential treatment options for various diseases have been a subject of growing interest. However, information on the anti-inflammatory mechanism employed by Undaria pinnatifida (UP) remains limited. The present study was conducted to investigate the mechanisms of UP on the mast cell-mediated inflammatory response. To determine the pharmacological mechanism of UP in inflammatory reaction, we evaluated the effects of UP on interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α production and nuclear factor-κB (NF-κB) and caspase-1 activation in calcium ionophore A23187 plus phorbol 12-myristate 13-acetate-stimulated human mast cells-1 (HMC-1). The results showed that UP suppressed IL-6, IL-8 and TNF-α production in a dose-dependent manner. Moreover, UP significantly attenuated NF-kB/caspase-1 activation in stimulated HMC-1. Collectively, these findings provide experimental evidence that UP may be a useful candidate for the inflammation-related diseases treatment.

• Journal of Applied Reliability
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• v.17 no.3
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• pp.224-235
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• 2017

Purpose: Reliability is the most important factor to detect defects as wind turbines are deployed in large blades. The methods of detecting defects are various, such as non-destructive inspection and thermal imaging inspection. We propose the phased array ultrasonic testing method of non-destructive testing. Methods: We propose the active pressure mechanism for wind power blade. The phase array ultrasonic inspection method is used for fault detection inner blade surface. Controlled pressure of mechanism with respect to z-axis is important for guarantee the result of phase array ultrasonic inspection. The model based control and proposed mechanism are utilized for overall system stability and effectiveness of system. Result: The result of proposed pressure mechanism B is more stable than A. Convergence speed is also faster than A. Conclusion: We confirmed the performance of the proposed constant pressure mechanism through experiments. Non-destructive testing was applied to the specimen to confirm the reliability of detecting defects.