Immunohistochemical localization of collagen types I and VI in human skin wounds

A total of 74 human skin wounds were investigated and collagen types I and VI were localized in the wound area by immunohistochemistry. Collagen type I appeared in the form of ramifying string-like structures after approximately 5–6 days, but positive reactions in the form of a spot-like staining around isolated fibroblasts also occurred in a skin wound aged 4 days. Collagen VI was detectable after a post-infliction interval of at least 3 days showing a strongly positive reacting network associated with fibroblasts in the wound area. Both collagens appeared almost constantly after a wound age of 6–7 clays and could also be found in wounds aged a few months. Therefore, although a positive reaction for collagen type I in the form of string-like and ramifying structures around wound fibroblasts indicates a wound age of at least 5–6 days, a spot-like positive staining for collagen type I cannot exclude a wound age of at least 4 days. A positive staining for collagen type VI represents a post-infliction time of 3 days or more. The almost constant appearance of these collagen types suggests that negative results in a sufficient number of specimens indicate a wound age of less than 6–7 days, but cannot completely exclude longer post-infliction intervals. Since collagen type I and VI are also found in the granulation/scar tissue of lesions with advanced wound age, the immunohistochemical analysis of these proteins provides no further information for an age determination of older skin wounds

Some Features of the Curvature of a Two-Dimensional Detonation Shock Front at a Simple Refraction Locus

We present a theoretical study of the interaction of a constant-velocity two-dimensional detonation wave with its surrounding medium. For the case of pure refraction, we obtain exact expressions for the interface curvatures of the shock fronts in both the explosive (X) and its confinement (C) in terms of the detonation velocity D, the material properties of X and C and, if the flow is cylindrically symmetric, the radius of the explosive charge. These relations are obtained from the constraints imposed on the flow derivatives of the pressure P and the flow turning angle θ by the conservation laws, the boundary conditions at the curved shock fronts and the contact conditions matching P and θ along the interface. This model is used in our numerical analysis of a polytropic explosive with a pressure-dependent decomposition rate and a polytropic confinement. We find that, for a given D, the explosive's interface curvature Cx decreases as the confinement's density increases

Traitement de surface par explosif du cuivre polycristallin : caractérisation microstructurale et comportement en fatigue plastique

A new surface treatment technique with a primary explosive deposited in thin layer was applied to a polycrystalline pure copper. After treatment, surface roughness remains of high quality especially when compared to shot peened surfaces. The treated zone extends over several hundreds microns in depth and the microhardness profile exhibits a significant increasing of hardness with a maximum reaching 100% at the surface. The transmission electron microscopy shows a microstructure which changes with depth : below the surface, there is a thin recrystallized layer with very small grains followed by a region with numerous mechanical twins the density of which decreases when depth increases. Tested in fatigue with a constant plastic strain amplitude, the treated copper specimens exhibit a strong hardening from the first cycles compared to the untreated specimen ; however this initial hardening erases after 2% of the fatigue life. The fatigue resistance is not modified by the treatment.
Une nouvelle technique de traitement de surface à l'aide d'un explosif primaire déposé en couche mince a été utilisée sur du cuivre pur polycristallin. L'état de surface après traitement reste de très bonne qualité, surtout comparé aux surfaces grenaillées. La zone traitée s'étend sur une profondeur de quelques centaines de microns et le profil de microdureté montre une importante augmentation de dureté avec un maximum en surface pouvant atteindre 100%. La micrcrostructure, observée par microscopie électronique en transmission, est caractérisée par une fine recristallisation en surface, puis par un abondant maclage dont la densité décroît lorsque la profondeur augmente. Testé en fatigue à déformation plastique imposée, le cuivre traité présente un fort écrouissage initial dès les premiers cycles, mais qui s'efface progressivement au cours du cyclage après 2% de la durée de vie, cette dernière n'étant pas modifiée par le traitement

Proprietés mécaniques de surface d'un acier inoxydable traité par explosif

A new surface treatment technique by primary explosive was used on a 316L type austenitic stainless steel. Two explosive compositions, inducing a pressure of 1 GPa and 4 GPa respectively, were deposited in a thin layer on plane samples. The detonation induced effects have been characterized by different techniques. The surface roughness increases with the applied pressure, but remains lower than that obtained after shot peening. The microbardness profiles along a direction perpendicular to the treated surface and the microstructural study exhibit a marked hardening on several hundred micrometers associated with a profuse twinning. Moreover, for the 4 GPa pressure a very thin surface layer of fine recrystallized grains appears. In both cases, tensile residual stresses are measured at the surface and compressive stresses beyond 10$~\mu$m. The microstructure in the surface layers results of a noticeable thermal effect. The wear resistance of this stainless steel is improved by a factor 10 to 200 depending on the treatment conditions.Une technique de traitement de surface utilisant un explosif primaire a été utilisée sur un acier inoxydable austénitique de type 316L. Deux compositions explosives délivrant des pressions respectives de 1 GPa et 4 GPa ont été déposées en couche mince sur des échantillons plans. Les effets induits par la détonation ont été caractérisés par différentes techniques. La rugosité en surface augmente avec la pression appliquée mais reste très inférieure à celle obtenue après grenaillage. Les profils de microdureté suivant un axe perpendiculaire à la surface traitée et l'étude microstructurale montrent un écrouissage marqué sur quelques centaines de micromètres associé à un maclage important auquel s'ajoute, pour la pression de 4 GPa, une fine recristallisation en surface. Dans les deux cas, les contraintes résiduelles sont de tension en surface et passent en compression au-delà de 10$~\mu$m. La microstructure des couches superficielles témoigne d'un effet thermique notable. La résistance à l'usure de cet acier est améliorée d'un facteur 10 à 200 suivant les conditions de traitement

Realistic Simulations for the Evaluation of Monomodal Registration Algorithms of 3D Pelvic Ultrasound Images

International audienceMotivation: to propose a simulation framework to validate ultrasound registration algorithms.Methodsthe proposed framework is composed of 4 steps: (1) an ultrasound image is simulated from a real one, (2) the scatterers are displaced with a known transformation and (3) a new ultrasound image is generated from this transformed scatterer map. Finally (4), registration is performed between the images simulated at steps 1 and 3. Registration results are compared to the applied transform (step 2).Resultsthe experts admitted the simulated images were highly realistic. The mean registration errors were -0.8±1.3 mm, -1.2±2.6 mm in anterior-posterior and superior-inferior directions, respectively

Impact of probe pressure variability on prostate localization for ultrasound-based image-guided radiotherapy

International audiencePurpose/Objective: For effective delivery of new radiotherapy techniques providing highly conformal dose distributions, the accurate positioning of the patient and the localization of the irradiated structures are crucial. For prostate cancer, a soft tissue imaging modality is required to setup the patient before irradiation sessions. The use of a three-dimensional transabdominal ultrasound system (3D-TA-US) could be a better alternative to X-ray based modalities because US based imaging is non-invasive,non-irradiating and allows for differentiation between soft tissues. Two issues related to an intramodality US imageguidance system for prostate cancers were investigated: 1. Impact of probe pressure on prostate localization, 2. Variability of the probe pressure during treatment sessions

Recalage automatique d'images ultrasonores tridimensionnelles transabdominales pour le repositionnement inter-séances de patients traités par radiothérapie ayant subis une prostatectomie radicale

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Recent findings in the epidemiology, diagnosis and treatment of superficial-vein thrombosis

International audienc