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Entre indifférence généralisée et reprises localistes : ce que le changement d’échelle nous apprend sur les lieux d’internement poitevins (1939-1945)
No full textLa période de la Seconde Guerre mondiale a recouvert la Vienne, la Charente, la Charente-Maritime et les Deux-Sèvres de plus de 80 lieux d'internement et de détention que nous pouvons aujourd'hui recenser et cartographier
High Efficiency 2-Stage MMIC GaN Doherty Power Amplifiers with More Than 38% Fractional Bandwidth in C Band
No full textInternational audienceThis paper presents and compares two wideband 2-stage inverted Doherty Power Amplifiers (DPAs) covering the entire 4.2–6.2 GHz band, which represents a 38% fractional bandwidth. The first DPA is a full Monolithic Microwave Integrated Circuit (MMIC) based on UMS 0.15-µm GaN HEMT technology, while the second version is made of the same MMIC except that its output combiner is replaced by an external circuit designed on a Printed Circuit Board (PCB). Both DPAs achieve an average Power Added Efficiency (PAE) of 38% and 43%, respectively, over a wide fractional bandwidth
Adaptive Pruning Method of Digital PreDistortion Models Based on DLA Algorithm for LTE/5G Applications
No full textInternational audienc
Long-term aging of SiO 2 /HfO 2 PIAD-deposited Laser Mégajoule polarizer coatings
No full textInternational audienceThe 176 beams of the Laser Mégajoule (LMJ) are equipped with meter-scale polarizers that filter parasitic light generated before amplification. These multilayer dielectric coatings present instabilities over the years that can lead to a significant transmission loss. To evaluate the causes, HfO 2 and SiO 2 coatings were deposited by evaporation with and without plasma-assistance. Our studies show that a spectral redshift of the polarizers over the years is mainly generated by the SiO 2 layers. A correlation between aging and coatings' moisture sensitivity is evidenced and interpreted as a consequence of water diffusion and the hydrolysis of SiO 2 . Hydrothermal treatments successfully accelerated aging, offering a promising method to stabilize the coating before use
Les "doubles suivis" comme situations frontières Pratiques professionnelles et différenciations sociales des jeunes suivis par l'ASE et la PJJ
No full textCe rapport de recherche rend compte des résultats d’une enquête conduite deux ans durant sur les jeunes doublement suivis, c’est-à-dire pris en charge par l’Aide sociale à l’enfance (ASE), au titre de l’enfance en danger, et par la Protection judiciaire de la jeunesse (PJJ), au titre de l’enfance délinquante. Elle fait suite à l’appel à projets « Trajectoires » lancé par la Direction de la protection judiciaire de la jeunesse en 2021 sur la question de « l’analyse des parcours de jeunes faisant l’objet d’un double suivi ».Le cahier des charges de cet appel portait sur la compréhension de ces situations et de ce qui les engendre, et sur les effets sur les parcours des jeunes de ces prises en charg
Structural and electrical properties of tungsten implanted VO2 nanobeams
No full textInternational audienceVanadium dioxide (VO2) is a phase change material that exhibits a near-room-temperature metal-insulator transition (MIT) at 69°C, accompanied by a resistivity change of 4 to 5 orders of magnitude [1]. The MIT is also accompanied by a structural phase transition from a monoclinic (M1) semiconducting phase to a rutile (R) metallic phase. We present the fabrication and structural characterization of single-crystalline VO2 nanobeams that exhibit higher transition temperatures [2] as compared to polycrystalline thin films. To address this characteristic that constitutes a limitation for specific applications, tungsten ion implantation was used to lower the transition temperature of VO2 nanobeams [3]. The nanobeams were synthesized using a modified vapor-liquid-solid (VLS) method and characterized via X-ray diffraction (XRD) and electrical measurements. Tungsten ions were implanted at various fluences (1×10¹⁴, 2×10¹⁵, and 3×10¹⁵ cm-2) at 500 keV using the ARAMIS Tandem Ion accelerator, with an additional irradiation for another of samples at 2.5 MeV to assess the effects of radiation damage. The tungsten concentration implanted in the VO2 beams and the structural damage were evaluated by simulations using the SRIM software. XRD θ-2θ scans revealed a decrease in peak intensities due to structural disorder caused by implantation, although the main <011> crystallographic orientation was preserved. Temperature-dependent XRD measurements demonstrated a reduction in the MIT temperature, with a significant shift from 80°C to 56°C for a fluence of implanted W of 2×10¹⁵ cm-2. These results demonstrate that ion implantation effectively tunes the transition temperature of VO2 nanobeams, creating interesting opportunities for adapting their properties when integrated into advanced nanoelectronic devices.[1].E.-N. Sirjita, A. Boulle, J.-C. Orlianges, R. Mayet, et A. Crunteanu, “Structural and electrical properties of high-performance vanadium dioxide thin layers obtained by reactive magnetron sputtering”, Thin Solid Films, vol. 759, p. 139461, oct. 2022[2] J-C Orlianges et al “Electrical activation of insulator-to-metal transition in vanadium dioxide single-crystal nanobeam and their high-frequency switching performances” “Journal of applied physics”, aug. 2024[3] Tan, X., Yao, T., Long, R. et al. Unraveling Metal-insulator Transition Mechanism of VO2 Triggered by Tungsten Doping. Sci Rep 2, 466 (2012)
Grands principes du droit constitutionnel (5e éd.)
No full textInternational audienceLes points essentiels du droit constitutionnel tels qu'abordés en cours magistral et en travaux dirigés
ASO Author Reflections: PIPAC Nozzles and Therapeutic Impact: Lessons from the NOMOS Study
No full textInternational audienceObjective Intracranial aneurysm (IA) coiling remains the most commonly used endovascular approach for ruptured and unruptured IA, and recanalization is a common drawback that impairs treatment success. Angiographic occlusion and aneurysm healing are not synonymous, and histological evaluation of embolized aneurysms remains a challenge. We propose here an experimental study of coil embolization in animal models by multiphoton microscopy (MPM) in comparison with conventional histological staining. The purpose of his work is to analyze coil healing process using histological sections of aneurysms. Methods Based on a rabbit elastase model, 27 aneurysms were fixed, embedded in resin, and cut in thin histological sections 1 month after coils implantation and after angiographic control. Hematoxylin and eosin (H&S) staining were realized. Non-stained adjacent slices were imaged for multiphoton excited autofluorescence (AF) and second-harmonic generation (SHG) to construct three-dimensional (3D) projections of sequentially and axially acquired images. Results The contrast provided by the combination of these two imaging modalities can be used to distinguish five levels of aneurysm healing, based on a combination of thrombus evolution and increased extracellular matrix (ECM) deposit. Conclusion RDPC:\Users\SHAHUL\RDP6|We have established a novel histological scale from a rabbit elastase aneurysm model after coiling with a classification of five different stages thanks to nonlinear microscopy. This classification is an actualized tool in order to obtain a more precise evaluation of occlusion device efficacy in the scope of new innovative microscopy for research
Microcatheter navigation using a large compliant balloon placed in a cortical vein during transvenous access
No full textInternational audienceTransvenous embolization (TVE) has emerged as the new approach for the curative treatment of brain arteriovenous malformations (bAVMs), though challenges persist in navigating microcatheters through dural venous sinuses. This video article demonstrates a novel balloon-assisted technique to facilitate microcatheter navigation in a complex case of bAVM. A large compliant Copernic RC balloon was temporarily placed in a cortical vein, serving as a buttress to guide the microcatheter into the draining vein. This method enabled the successful cannulation and advancement of a microcatheter in a draining cortical vein using a large compliant balloon without complications. The case highlights the technical feasibility and safety of this approach in TVE for challenging bAVM cases. Video 1 Microcatheter navigation using a large compliant balloon placed in a cortical vein during a transvenous acces
Bioresorbable scaffolds in interventional radiology: Current concepts and future direction
No full textInternational audienceBackground Glenzocimab is a humanized fragment of a monoclonal antibody directed against the human platelet glycoprotein VI, which has shown promising features, including thrombus growth inhibition and minimal bleeding risk. The first inpatient study suggested the benefit of glenzocimab with alteplase in subgroups of patients with acute ischemic stroke (AIS) receiving endovascular treatment (EVT), with increased reperfusion rates and decreased risk of symptomatic hemorrhagic transformation. The objective of the GREEN (Glenzocimab for REperfusion in the setting of Endovascular therapy for brain infarctioN) study is to evaluate the efficacy of glenzocimab with EVT compared with EVT plus placebo, with or without intravenous thrombolysis (IVT), on functional outcome. Methods GREEN is a multicenter, randomized, double blind, placebo controlled study. Participants presenting with AIS and a large vessel occlusion of the anterior circulation (intracranial internal carotid artery or middle cerebral artery, or both), with symptoms onset within 24 hours, will be randomized to one of two groups: intravenous glenzocimab 1000 mg with standard of care (SoC-EVT±IVT) or SoC (EVT±IVT) plus placebo. The main primary efficacy endpoint is functional outcome (assessed by the modified Rankin Scale score) at 90 days. Conclusion This is the first randomized trial evaluating the efficacy of glenzocimab with EVT. This prospective trial aims to determine whether glenzocimab with EVT improves functional outcome. Trial registration ClinicalTrials.gov NCT0555939