• Journal of Power Electronics
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• v.1 no.2
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• pp.65-70
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• 2001

Transmission System Operators are governed by operational security standards that are applied in real time. During system disturbances, the System Operators must rely on the installed protection and control equipment, prior to human intervention. New power electronic solutions bring rapid and repeatable responses to disturbances, which will help System Operators to guarantee a stable system. Last year, Alstom completed the world's first competitively bid STATCOM to support the voltage on National Grid's 400kV network that supplies London and the Southeast from the north of the UK. It is rated ${\pm}75MVAr$ and forms part of a Static Var System (SVS) with a total rating of 0 to 225MVAr. This paper will describe the reasons for its size, location, its chain-link configuration and give examples of its operating performance. The paper will also describe the features that allow this STATCOM to deliver much more than reactive compensation in support of a wider transmission service objective, as system conditions require.

• 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.

• Radiation Oncology Journal
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• v.31 no.2
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• pp.57-65
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• 2013

Beta-lapachone (${\beta}$-Lap; 3,4-dihydro-2, 2-dimethyl-2H-naphthol[1, 2-b]pyran-5,6-dione) is a novel anti-cancer drug under phase I/II clinical trials. ${\beta}$-Lap has been demonstrated to cause apoptotic and necrotic death in a variety of human cancer cells in vitro and in vivo. The mechanisms underlying the ${\beta}$-Lap toxicity against cancer cells has been controversial. The most recent view is that ${\beta}$-Lap, which is a quinone compound, undergoes two-electron reduction to hydroquinone form utilizing NAD(P)H or NADH as electron source. This two-electron reduction of ${\beta}$-Lap is mediated by NAD(P)H:quinone oxidoreductase (NQO1), which is known to mediate the reduction of many quinone compounds. The hydroquinone forms of ${\beta}$-Lap then spontaneously oxidizes back to the original oxidized ${\beta}$-Lap, creating futile cycling between the oxidized and reduced forms of ${\beta}$-Lap. It is proposed that the futile recycling between oxidized and reduced forms of ${\beta}$-Lap leads to two distinct cell death pathways. First one is that the two-electron reduced ${\beta}$-Lap is converted first to one-electron reduced ${\beta}$-Lap, i.e., semiquinone ${\beta}$-Lap $(SQ)^{{\cdot}-}$ causing production of reactive oxygen species (ROS), which then causes apoptotic cell death. The second mechanism is that severe depletion of NAD(P)H and NADH as a result of futile cycling between the quinone and hydroquinone forms of ${\beta}$-Lap causes severe disturbance in cellular metabolism leading to apoptosis and necrosis. The relative importance of the aforementioned two mechanisms, i.e., generation of ROS or depletion of NAD(P)H/NADH, may vary depending on cell type and environment. Importantly, the NQO1 level in cancer cells has been found to be higher than that in normal cells indicating that ${\beta}$-Lap may be preferentially toxic to cancer cells relative to non-cancer cells. The cellular level of NQO1 has been found to be significantly increased by divergent physical and chemical stresses including ionizing radiation. Recent reports clearly demonstrated that ${\beta}$-Lap and ionizing radiation kill cancer cells in a synergistic manner. Indications are that irradiation of cancer cells causes long-lasting elevation of NQO1, thereby sensitizing the cells to ${\beta}$-Lap. In addition, ${\beta}$-Lap has been shown to inhibit the repair of sublethal radiation damage. Treating experimental tumors growing in the legs of mice with irradiation and intraperitoneal injection of ${\beta}$-Lap suppressed the growth of the tumors in a manner more than additive. Collectively, ${\beta}$-Lap is a potentially useful anti-cancer drug, particularly in combination with radiotherapy.

• Animal cells and systems
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• v.15 no.4
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• pp.259-267
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• 2011

This study was undertaken to produce a $F_{ab}$ fragment of a human monoclonal antibody reactive to oxidized and carbamylated low-density lipoprotein (oxLDL and cLDL) using phage display technology. An analysis of DNA sequences of this $F_{ab}$, termed plaque 15,16-46 $F_{ab}$, revealed that the rearranged $V_H$ was highly mutated. Complementarity-determining regions of the $V_H$ showed a very high R/S ratio and contained many positively charged amino acids. In direct binding and competitive ELISA, the $F_{ab}$ reacted strongly with both MDA-LDL and Cu-oxLDL forms of oxLDL, and also showed high affinity for cLDL. Immunofluorescence and immunohistochemical analyses showed that this $F_{ab}$ positively stained atherosclerotic aortic plaques in $ApoE^{-/-}$ mice as well as those in patients with atherosclerosis. The $F_{ab}$ also showed positive staining in placental decidua from patients with preeclampsia. It is suggested that the plaque 15,16-46 $F_{ab}$ against oxLDL and cLDL might possibly be applicable for developing a diagnostic reagent for both human and rodent animal research to detect and characterize atherosclerotic disease progression in atherosclerotic lesions as well as exploring the pathogenesis of atherogenic diseases such as preeclampsia.

• Korean Journal of Materials Research
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• v.2 no.1
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• pp.35-42
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• 1992

Thermal behavior of residue and damaged layer formed by reactive ion etching (RIE) in $CHF_3/C_2F_6$ were investigated using X-ray photoelectron spectroscopy(XPS) and secondary ion mass spec-trometry(SIMS) techniques. Decomposition of polymer residue film begins at $200^{\circ}C$ and above $400^{\circ}C$ carbon compound as graphite mainly forms by in-situ resistive heating. It reveals that thermal decomposition of residue can be completed by rapid thermal anneal treatment above $800^{\circ}C$ under nitrogen atmosphere and out-diffusion of carbon and fluorine of damaged layer is observed.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.83-83
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• 2000

Alkylketene dimer was known as a cellulose reactive or alkaline size because it does not require to fix to the fiber as do the traditional rosin sizes. A proposed sizing mechanism of AKD was the formation of P -ketoester bond between AKD and cellulose which provides the permanent attachment and the orientation of the hydrophobic alkylchains outward. However, some questions about the reaction had arisen and thus, the sizing mechanism of AKD has been a subject of controversy for several decades. The major concern of the controversy is that AKD is really reactive with cellulose or not in the papermaking conditions. In this study, reaction between AKD and pulp fiber was investigated, in order to find out whether AKD forms P-ketoester with pulp fiber during aging under no catalyzed neutral condition with obvious spectroscopic evidence. In addition, effect of aging treatment on the sizing development was studied. It has been disclosed that, in absence of water, AKD reacted with cellulose to form P -ketoester linkage under no catalyzed neutral condition, while, in presence of water, most of AKD was hydrolyzed to a dialkyl ketone or P -ketoacid. In addition, during the aging treatment of AKD-sized paper, its typical IR spectra bands gradually were reduced, completely disappeared after 6hr aging, and formed new absorption bands at 1707cm-' and shoulder peak at 1700cm-' which refer to the typical dialkylketone absorption bands. Therefore, the formation of P -ketoester between AKD and pulp fiber is impossible in the practical papermaking process. It could be suggested that the sizing development of AKD-sized paper is obtained by next two mechanism: 1) formation of a thin-layer of AKD on the fiber surface through melting and spreading of AKD emulsion particles by heat and 2) the hydrolysis of AKD to dialkyl ketone which has higher melting point, during drying and storage of AKD sized papers.

• Journal of Pharmacopuncture
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• v.17 no.1
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• pp.59-69
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• 2014

Objectives: In homeopathy, it is claimed that more homeopathically-diluted potencies render more protective/curative effects against any disease condition. Potentized forms of Condurango are used successfully to treat digestive problems, as well as esophageal and stomach cancers. However, the comparative efficacies of Condurango 6C and 30C, one diluted below and one above Avogadro's limit (lacking original drug molecule), respectively, have not been critically analyzed for their cell-killing (apoptosis) efficacy against lung cancer cells in vitro, and signalling cascades have not been studied. Hence, the present study was undertaken. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were conducted on H460-non-small-cell lung cancer (NSCLC) cells by using a succussed ethyl alcohol vehicle (placebo) as a control. Studies on cellular morphology, cell cycle regulation, generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential (MMP), and DNA-damage were made, and expressions of related signaling markers were studied. The observations were done in a "blinded" manner. Results: Both Condurango 6C and 30C induced apoptosis via cell cycle arrest at subG0/G1 and altered expressions of certain apoptotic markers significantly in H460 cells. The drugs induced oxidative stress through ROS elevation and MMP depolarization at 18-24 hours. These events presumably activated a caspase-3-mediated signalling cascade, as evidenced by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot and immunofluorescence studies at a late phase (48 hours) in which cells were pushed towards apoptosis. Conclusion: Condurango 30C had greater apoptotic effect than Condurango 6C as claimed in the homeopathic doctrine.

• Molecules and Cells
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• v.39 no.3
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• pp.242-249
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• 2016

A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1-240) and truncated (residues 19-240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2518-2520
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• 1998

Silicon can be reactive ion etched (RIE) either isotropically or anisotropically. In this paper, a new micromachining technology combining these two etching characteristics is proposed. In the proposed method, the fabrication steps are as follows. First. a polysilicon layer, which is used as the bottom electrode, is deposited on the silicon wafer and patterned. Then the silicon substrate is etched anisotropically to a few micrometer depth that forms a cavity. Then an PECVD oxide layer is deposited to passivate the cavity side walls. The oxide layers at the top and bottom faces are removed while the passivation layers of the side walls are left. Then the substrate is etched again but in an isotropic etch condition to form a round trench with a larger radius than the anisotropic cavity. Then a sacrificial PECVD oxide layer is deposited and patterned. Then a polysilicon structural layer is deposited and patterned. This polysilicon layer forms a pivot structure of a rocker-arm. Finally, oxide sacrificial layers are etched away. This new micromachining technology is quite simpler than conventional method to fabricate joint structures, and the devices that are fabricated using this technology do not require a flexing structure for motion.

• Biomedical Science Letters
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• v.24 no.3
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• pp.196-205
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• 2018

Reactive oxygen species (ROS) generated from metabolic reactions cause oxidative DNA damage, which results in oxidative tissue injury. Therefore, there is an increasing demand in the intake of high antioxidant sources in order to maintain a healthy environment in cells. In this study, we investigated the antioxidant and anti-inflammatory activities of Malus domestica (apple), Pyrus communis L. (pear), Daucus carota L. (carrot), Brassica oleracea var. (broccoli), Brassica oleracea var. capitata (cabbage), and Raphanus sativus L. (radish) obtained from the local market. Since these are common fruits and vegetables that are widely consumed, we aimed to investigate their beneficial properties, placing particular emphasis on their antioxidant and anti-inflammatory properties. The samples were processed via an indirect heating method and their properties were compared to their raw forms. Based on DPPH and ABTS assays, processed samples showed better antioxidant activities when compared to raw samples and processed pear samples exhibited the best antioxidant activity. The anti-inflammatory activities of the samples were also investigated in LPS-treated RAW 264.7 cells. mRNA expression of pro-inflammatory mediators and cytokines (iNOS, COX-2, $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6) was assessed using RT-PCR. As expected, processed samples exhibited better iNOS inhibition when compared to their raw forms and processed broccoli and cabbage samples exhibited outstanding anti-inflammatory effects. The samples, up to 1 mg/mL concentration, did not exhibit cytotoxicity against RAW 264.7 cells as demonstrated by cell viability assays. Altogether, processed broccoli and cabbage samples exhibited the strongest anti-inflammatory properties.