28 research outputs found

    Persistent effectivity of gas plasma-treated, long time-stored liquid on epithelial cell adhesion capacity and membrane morphology

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    Research in plasma medicine includes a major interest in understanding gas plasma-cell interactions. The immediate application of gas plasma in vitro inhibits cell attachment, vitality and cell-cell contacts via the liquid. Interestingly, in our novel experiments described here we found that the liquid-mediated plasma effect is long-lasting after storage up to seven days; i. e. the liquid preserves the characteristics once induced by the argon plasma. Therefore, the complete Dulbecco's Modified Eagle cell culture medium was argon plasma-treated (atmospheric pressure, kINPen09) for 60 s, stored for several days (1, 4 and 7 d) at 37°C and added to a confluent mouse hepatocyte epithelial cell (mHepR1) monolayer. Impaired tight junction architecture as well as shortened microvilli on the cell membrane could be observed, which was accompanied by the loss of cell adhesion capacity. Online-monitoring of vital cells revealed a reduced cell respiration. Our first timedependent analysis of plasma-treated medium revealed that temperature, hydrogen peroxide production, pH and oxygen content can be excluded as initiators of cell physiological and morphological changes. The here observed persisting biological effects in plasma-treated liquids could open new medical applications in dentistry and orthopaedics

    A Q-Band Pulsed ENDOR Spectrometer for the Study of Transition Metal Ion Complexes in Solids

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    We describe the design of a pulsed electron nuclear double resonance (ENDOR) spectrometer operating at Q-band frequencies (35 GHz) for studies of transition metal ion complexes in the temperature range between 4.2 and 297 K. Specific features of the spectrometer are a microwave IMPATT generator, a homebuilt cavity, and a commercial Bruker magnet. Standard Davies and Mims ENDOR sequences have been implemented. The performance of the spectrometer is demonstrated for a broad radio frequency range by 1H, 14N, 31P, 133Cs, and 207Pb pulsed ENDOR experiments of Cu 2+, Cr 5+, and V 4+ transition metal ion complexes in both single crystals and disordered materials

    EPR, ESE and pulsed ENDOR study of nitrogen related centers in 4H-SiC wafers grown by different technologies

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    D-band electron paramagnetic resonance (EPR) measurements as well as X and Q-band field-swept Electron Spin Echo (ESE) and pulsed Electron Nuclear Double Resonance (ENDOR) studies were performed on a series of n-type 4H-SiC wafers grown by different techniques including sublimation sandwich method (SSM), physical vapor transport (PVT) and modified Lely method. Depending on the C/Si ratio and the growth temperature the n-type 4H-SiC wafers revealed, besides a triplet due to nitrogen residing on the cubic site (Nc), two nitrogen (N) related EPR spectra with g||=2.0055, g⊄=2.0010 and g||=2.0063, g⊄=2.0005 with different intensities. In the samples with low C/Si ratio the EPR spectrum with g||=2.0055, g⊄=2.0010 consists of a triplet with low intensity which is tentatively explained as a N-related complex, while in the samples with high C/Si ratio the triplet is transformed into one structureless line of high intensity, which is explained as being due to an exchange interaction between N donors. In the samples grown at low temperature with enhanced carbon concentration the EPR line with g||=2.0063, g⊄=2.0005 and a small hyperfine (hf) interaction dominates the EPR spectrum. It is attributed to N on the hexagonal lattice site. The interpretation of the EPR data is supported by activation energies and donor concentrations obtained from Hall effect measurements for three donor levels in this series of 4H-SiC samples

    A Q-Band Pulsed ENDOR Spectrometer for the Study of Transition Metal Ion Complexes in Solids

    No full text
    We describe the design of a pulsed electron nuclear double resonance (ENDOR) spectrometer operating at Q-band frequencies (35 GHz) for studies of transition metal ion complexes in the temperature range between 4.2 and 297 K. Specific features of the spectrometer are a microwave IMPATT generator, a homebuilt cavity, and a commercial Bruker magnet. Standard Davies and Mims ENDOR sequences have been implemented. The performance of the spectrometer is demonstrated for a broad radio frequency range by 1H, 14N, 31P, 133Cs, and 207Pb pulsed ENDOR experiments of Cu 2+, Cr 5+, and V 4+ transition metal ion complexes in both single crystals and disordered materials

    A Q-Band Pulsed ENDOR Spectrometer for the Study of Transition Metal Ion Complexes in Solids

    Get PDF
    We describe the design of a pulsed electron nuclear double resonance (ENDOR) spectrometer operating at Q-band frequencies (35 GHz) for studies of transition metal ion complexes in the temperature range between 4.2 and 297 K. Specific features of the spectrometer are a microwave IMPATT generator, a homebuilt cavity, and a commercial Bruker magnet. Standard Davies and Mims ENDOR sequences have been implemented. The performance of the spectrometer is demonstrated for a broad radio frequency range by 1H, 14N, 31P, 133Cs, and 207Pb pulsed ENDOR experiments of Cu 2+, Cr 5+, and V 4+ transition metal ion complexes in both single crystals and disordered materials

    A Q-Band Pulsed ENDOR Spectrometer for the Study of Transition Metal Ion Complexes in Solids

    No full text
    We describe the design of a pulsed electron nuclear double resonance (ENDOR) spectrometer operating at Q-band frequencies (35 GHz) for studies of transition metal ion complexes in the temperature range between 4.2 and 297 K. Specific features of the spectrometer are a microwave IMPATT generator, a homebuilt cavity, and a commercial Bruker magnet. Standard Davies and Mims ENDOR sequences have been implemented. The performance of the spectrometer is demonstrated for a broad radio frequency range by 1H, 14N, 31P, 133Cs, and 207Pb pulsed ENDOR experiments of Cu 2+, Cr 5+, and V 4+ transition metal ion complexes in both single crystals and disordered materials

    The ASSET Architecture - Integrating Media Applications and Products through a Unified API

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    Applications and products currently available for the broadcasting market are vertically integrated or proprietary. They are based on components requiring specific and costly development to interoperate and do rely typically on a single manufacturer or system integrator. Hence they are not fully compliant with broadcasters' requirements. ASSET is a European funded project whose main goal is to overcome the limitations of custom specific implementations of a digital system for TV content creation. These limitations are generally due to the misfit of interfaces between software layers, proprietary APIs of equipment from different vendors and the lack of a generalised middleware for multimedia content management with openly defined interfaces. Besides presenting the ASSET proposed architecture and concepts, this paper describes the prototype under development to test and demonstrate the project proposals

    EPR, ESE and pulsed ENDOR study of nitrogen related centers in 4H-SiC wafers grown by different technologies

    No full text
    D-band electron paramagnetic resonance (EPR) measurements as well as X and Q-band field-swept Electron Spin Echo (ESE) and pulsed Electron Nuclear Double Resonance (ENDOR) studies were performed on a series of n-type 4H-SiC wafers grown by different techniques including sublimation sandwich method (SSM), physical vapor transport (PVT) and modified Lely method. Depending on the C/Si ratio and the growth temperature the n-type 4H-SiC wafers revealed, besides a triplet due to nitrogen residing on the cubic site (Nc), two nitrogen (N) related EPR spectra with g||=2.0055, g⊄=2.0010 and g||=2.0063, g⊄=2.0005 with different intensities. In the samples with low C/Si ratio the EPR spectrum with g||=2.0055, g⊄=2.0010 consists of a triplet with low intensity which is tentatively explained as a N-related complex, while in the samples with high C/Si ratio the triplet is transformed into one structureless line of high intensity, which is explained as being due to an exchange interaction between N donors. In the samples grown at low temperature with enhanced carbon concentration the EPR line with g||=2.0063, g⊄=2.0005 and a small hyperfine (hf) interaction dominates the EPR spectrum. It is attributed to N on the hexagonal lattice site. The interpretation of the EPR data is supported by activation energies and donor concentrations obtained from Hall effect measurements for three donor levels in this series of 4H-SiC samples
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