• Journal of the Korean institute of surface engineering
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• v.42 no.6
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• pp.287-293
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• 2009

The passivation films with epoxy layer on LiF, $SiN_x$ and LiF/$SiN_x$ inorganic layer were fabricated on OLED to protect device from the direct damage of $O_2$ and $H_2O$ and to apply for a buffer layer between OLED device and passivation multi-layer with organic/inorganic hybrid structure as to diminish the thermal stress and expansion. Red OLED doped with 1 vol.% Rubrene in $Alq_3$ was used as a basic device. The device structure was multi-layer of ITO(150 nm) / ELM200_HIL(50 nm) / ELM002_HTL(30 nm) / $Alq_3$: 1 vol.% Rubrene(30 nm) / $Alq_3$(30 nm) / LiF(0.7 nm) / Al(100 nm). LiF/epoxy applied as a protective layer didn't contribute to the improvement of life time. While in case of $SiN_x$/epoxy, damage was done in the passivation process because of difference in heat expansion between films which could occur during the formation of epoxy film. Using LiF/$SiN_x$/epoxy improved lifetime significantly without suffering damage in the process of forming films, therefore, the best structure of passivation film with inorganic/epoxy layers was LiF/$SiN_x$/E1.

• Molecules and Cells
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• v.28 no.4
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• pp.389-395
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• 2009

We previously observed that the transcription of some flagellar genes decreased in Salmonella Typhimurium tdcA mutant, which is a gene encoding the transcriptional activator of the tdc operon. Since flagella-mediated bacterial motility accelerates the invasion of Salmonella, we have examined the effect of tdcA mutation on the invasive ability as well as the flagellar biosynthesis in S. Typhimurium. A tdcA mutation caused defects in motility and formation of flagellin protein, FliC in S. Typhimurium. Invasion assays in the presence of a centrifugal force confirmed that the defect of flagellum synthesis decreases the ability of Salmonella to invade into cultured epithelial cells. In addition, we also found that the expression of Salmonella pathogenicity island 1 (SPI1) genes required for Salmonella invasion was down-regulated in the tdcA mutant because of the decreased expression of fliZ, a positive regulator of SPI1 transcriptional activator, hilA. Finally, the virulence of a S. Typhimurium tdcA mutant was attenuated compared to a wild type when administered orally. This study implies the role of tdcA in the invasion process of S. Typhimurium.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.75-85
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• 2021

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.47-47
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• 2010

Over the past 20 years, constant progress in noise and vibration (NVH) engineering has enabled to constantly advance quality and comfort of operation and use of really any products - from automobiles to aircraft, to all kinds of industrial vehicles and machines - to the extend that for many products, supreme NVH performance has becomes part of its brand image in the market. At the same time, the product innovation agenda in the automotive, aircraft and really many other industries, has been extended very much in recent years by meeting ever more strict environmental regulations. Like in the automotive industry, the drive towards meeting emission and CO2 targets leads to very much accelerated adoption of new powertrain concepts (downsizing of ICE, hybrid-electrical...), and to new vehicle architectures and the application of new materials to reduce weight, which bring new challenges for not only maintaining but further improving NVH performance. This drives for innovation in NVH engineering, so as to succeed in meeting a product brand performance for NVH, while as the same time satisfying eco-constraints. Product innovation has also become increasingly dependent on the adoption of electronics and software, which drives for new solutions for NVH engineering that can be applied for NVH performance optimization of mechatronic products. Finally, relentless pressure to shorten time to market while maintaining overall product quality and reliability, mandates that the practice and solutions for NVH engineering can be optimally applied in all phases of product development. The presentation will first review the afore trends for product and process innovation, and discuss the challenges they represent for NVH engineering. Next, the presentation discusses new solutions for NVH engineering of products, so as to meet target brand values, while at the same time meeting ever more strict eco constraints, and this within a context of increasing adoption of electronics and controls to drive product innovation. NVH being very much defined by system level performance, these solutions implement the approach of "Model Based System Engineering" to increase the impact of system level analysis for NVH in all phases of product development: - At the Concept Phase, to be able to do business case analysis of new product concepts; to arrive at an optimized and robust product architecture (e.g. to hybrid powertrain lay-out, to optimize fuel economy); to enable target cascading, to subsystem and component level. - In Development Phase, to increase realism and productivity of simulation, so as to frontload virtual validation of components and subsystems and to further reduce reliance on physical testing. - During the final System Testing Phase, to enable subsystem testing by a combination of physical testing and simulation: using simulation models to simulate the final integration context when testing a subsystem, enabling to frontload subsystem testing before final system integration is possible. - To interconnect Mechanical, Electronical and Controls engineering, in all phases of development, by supporting model driven controls engineering (MIL, SIL, HIL). Finally, the presentation reviews examples of how LMS is implementing such new applications for NVH engineering with lead customers in Europe, Asia and US, with demonstrated benefits both in terms of shortening development cycles, and/or enabling a simulation based approach to reduce reliance on physical testing.