37 research outputs found
Long-Term Alterations of Cytokines and Growth Factors Expression in Irradiated Tissues and Relation with Histological Severity Scoring
PURPOSE: Beside its efficacy in cancer treatment, radiotherapy induces degeneration of healthy tissues within the irradiated area. The aim of this study was to analyze the variations of proinflammatory (IL-1α, IL-2, IL-6, TNF-α, IFN-Îł), profibrotic (TGF-ÎČ1), proangiogneic (VEGF) and stem cell mobilizing (GM-CSF) cytokines and growth factors in an animal model of radiation-induced tissue degeneration. MATERIALS AND METHODS: 24 rats were irradiated unilaterally on the hindlimb at a monodose of 30 Gy. Six weeks (n=8), 6 months (n=8) and 1 year (n=8) after irradiation the mediators expression in skin and muscle were analyzed using Western blot and the Bio-PlexÂź protein array (BPA) technology. Additional histological severity for fibrosis, inflammation, vascularity and cellularity alterations scoring was defined from histology and immnunohistochemistry analyses. RESULTS: A significant increase of histological severity scoring was found in irradiated tissue. Skin tissues were more radio-sensitive than muscle. A high level of TGF-ÎČ1 expression was found throughout the study and a significant relation was evidenced between TGF-ÎČ1 expression and fibrosis scoring. Irradiated tissue showed a chronic inflammation (IL-2 and TNF-α significantly increased). Moreover a persistent expression of GM-CSF and VEGF was found in all irradiated tissues. The vascular score was related to TGF-ÎČ1 expression and the cellular alterations score was significantly related with the level of IL-2, VEGF and GM-CSF. CONCLUSION: The results achieved in the present study underline the complexity and multiplicity of radio-induced alterations of cytokine network. It offers many perspectives of development, for the comprehension of the mechanisms of late injuries or for the histological and molecular evaluation of the mode of action and the efficacy of rehabilitation techniques
IRSUTE, a small satellite for water budget estimate with high resolution infrared imagery
International audienc
Failure Analysis of ESD-stressed SiC MESFET
International audienceReliability studies are required for SiC device development. In a previous work we studied the intrinsicESD robustness of a SiC MESFET. The failure mechanism was related to the triggering of an NPN parasitictransistor. In this work, a new MESFET layout is considered, which optionally include a Zener diode for internalprotection. TLP testing and failure analysis has been carried out. Two new failure mechanisms are evidenced.Based on this knowledge, solutions are proposed to further improve the ESD robustness
Atmospheric Science from Space using Fourier Transform Spectroscopy (ASSFTS15)
International audienc
Atmospheric Science from Space using Fourier Transform Spectroscopy (ASSFTS15)
International audienc