68 research outputs found
A Transport Analysis of the BEEM Spectroscopy of Au/Si Schottky Barriers
A systematic transport study of the ballistic electron emission microscopy
(BEEM) of Au/Si(100) and Au/Si(111) Schottky barriers for different thicknesses
of the metal layer and different temperatures is presented. It is shown that
the existing experimental data are compatible with a recently predicted
bandstructure-induced non-forward electron propagation through the Au(111)
layer.Comment: 5 pages, Latex-APS, 1 postscript figure,
http://www.icmm.csic.es/Pandres/pedro.htm. Phys. Stat. Sol. (b) (to appear),
HCIS-10 Conf, Berlin 199
Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter
Compensation of gain saturation in SOA-gates by interferometric Mach-Zehnder wavelength converters
Two-section semiconductor optical amplifier used as an efficient channel dropping node
All-optical wavelength conversion at bit rates above 10 Gb/s using semiconductor optical amplifiers
WDM cross-connect cascade based on all-optical wavelength converters for routing and wavelength slot interchanging using a reduced number of internal wavelengths
Comparison of proton channel, phagocyte oxidase, and respiratory burst levels between human eosinophil and neutrophil granulocytes.
Robust production of reactive oxygen species (ROS) by phagocyte NADPH oxidase (phox) during the respiratory burst (RB) is a characteristic feature of eosinophil and neutrophil granulocytes. In these cells the voltage-gated proton channel (Hv1) is now considered as an ancillary subunit of the phox needed for intense ROS production. Multiple sources reported that the expression of phox subunits and RB is more intensive in eosinophils than in neutrophils. In most of these studies the eosinophils were not isolated from healthy individuals, and a comparative analysis of Hv1 expression had never been carried out. We performed a systematic comparison of the levels of essential phox subunits, Hv1 expression and ROS producing capacity between eosinophils and neutrophils of healthy individuals. The expression of phox components was similar, whereas the amount of Hv1 was approximately 10-fold greater in eosinophils. Furthermore, Hv1 expression correlated with Nox2 expression only in eosinophils. Additionally, in confocal microscopy experiments co-accumulation of Hv1 and Nox2 at the cell periphery was observed in resting eosinophils but not in neutrophils. While phorbol-12-myristate-13-acetate-induced peak extracellular ROS release was approximately 1.7-fold greater in eosinophils, oxygen consumption studies indicated that the maximal intensity of the RB is only approximately 1.4-fold greater in eosinophils. Our data reinforce that eosinophils, unlike neutrophils, generate ROS predominantly extracellularly. In contrast to previous works we have found that the two granulocyte types display very similar phox subunit expression and RB capacity. The large difference in Hv1 expression suggests that its support to intense ROS production is more important at the cell surface
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