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Purine-based chemical probe with HOMO switching for intracellular detection of mercury ions
No full textInternational audienceThe detailed photophysical characterization of 2-piperidinyl-6-triazolylpurine derivatives and their complexes with metal ions is presented. The studied compounds contain two electron donating units -piperidine and methoxyphenyl, while triazolyl-purine acts as an electron acceptor. These derivatives possess good fluorescence quantum yields in both aprotic and aqueous environments. All piperidine-triazole-purine compounds exhibited a fluorescence "turn-off" sensing behavior to different metal ions, including Hg 2+ . We are discussing the changes in photophysical properties occurring upon complexation including switching between highest occupied molecular orbitals (HOMOs) of different electron donating units and the entire electron charge shift possibility in the complex with mercury ion. The sensing concept was further applied for newly synthesized water-soluble compounds, that demonstrated better selectivity toward Hg 2+ in aqueous media. Further, the selected 2-piperidinyl-6triazolylpurine water-soluble derivative was employed as a "turn-off" chemical probe for mercury ion detection in living cells
Enquêter le genre en prison. La non-binarité comme ressource épistémologique
No full textInternational audienceThis article explores how the non-binarity of the researcher serves as a unique epistemological resource for studying gender in prison. The author, a non-binary person, analyzes the constraints and adaptive strategies implemented during their investigation in the strictly binary environment of the prison. The text demonstrates how the penitentiary institution reinforces binary gender norms, affecting incarcerated individuals, staff, and researchers alike. Finally, it highlights that a queer research ethics, grounded in the positionality of the researcher, allows for a more nuanced understanding of power dynamics and epistemic injustices within the prison system.Cet article explore comment la non-binarité de l’enquêteur·ice sert de ressource épistémologique unique pour étudier le genre en prison. L’auteur·ice, une personne non binaire, analyse les contraintes et les stratégies d’adaptation mises en place lors de son enquête dans l’environnement strictement binaire de la prison. Le texte démontre comment l'institution pénitentiaire renforce les normes de genre binaires, affectant à la fois les personnes incarcérées, le personnel et les chercheur·se·s. Enfin, il met en avant qu'une éthique de recherche ancrée dans la positionnalité de la personne chercheuse permet une compréhension plus nuancée des dynamiques de pouvoir et des injustices épistémiques au sein du système carcéral
Les Capucins : “du ventre de Bordeaux” à “un mini Château Rouge”, le rôle de la diaspora camerounaise dans la constitution d’une centralité commerciale africaine
No full textInternational audienc
La gouvernance territoriale est-elle soluble dans la transition écologique ? Réflexions à partir des politiques d’aménagement et d’urbanisme et de la place qu’elles font aux enjeux environnementaux
No full textMaryse Condé et sa sœur à Conakry, au cœur des sociabilités militantes guinéennes
No full textInternational audienc
Aux origines de l’utopie (pan)africaine. Fondements théoriques et approches
No full textIntervention dans le cadre de la Session 4 : "Réécriture de l’histoire et panafricanisme à l’épreuve du temps"International audienc
Analyse comportementale des sols de chaussée à dominante argileuse sous l’effet de sécheresse
No full textThe shrink–swell behavior of clayey soils (RGA) is a major challenge for the durability of road infrastructures, particularly in France where nearly half of the territory is exposed to this geotechnical hazard. Highly sensitive to moisture variations, these soils undergo successive drying and rewetting cycles that induce significant volumetric deformations, weakening pavements and generating high maintenance costs. The objective of this thesis is to experimentally and multi-scalely analyze the hydro-mechanical behavior of clayey soils beneath pavements and to evaluate the effectiveness of an innovative stabilization technique using nano-silica injection. First, several natural and industrial clays were characterized in terms of their geotechnical properties, microstructure (SEM/EDS), and mineralogical composition (XRD), complemented by porosity analyses (X-ray tomography and mercury intrusion porosimetry). These investigations highlighted the key role of mineralogy and pore structure in the water sensitivity of soils. Second, the hydro-mechanical behavior of soils subjected to monotonic and cyclic drying–wetting solicitations was investigated. The tests showed that shrink–swell deformations and surface cracking are strongly correlated with the content of swelling minerals. Digital Image Correlation (DIC) monitoring revealed that cracks develop at the early stages of desiccation, even before full desaturation, and evolve cumulatively over successive cycles. Finally, the effect of nano-silica as a stabilizing agent was analyzed, together with an environmental and economic assessment. The results showed partial pore filling and a microstructural reorganization from a dispersed to a flocculated structure, improving compactness and cohesion. The addition of nano-silica reduced shrink–swell amplitudes by 40 to 55% during the first cycles, with optimal performance obtained for moderate dosages. Long-term stability was also assessed through leaching tests, which confirmed the very low mobility of nano-silica, demonstrating its effective immobilization within the clay matrix and its efficiency for mitigating shrink–swell phenomena.Le retrait-gonflement des sols argileux (RGA) constitue un enjeu majeur pour la durabilité des infrastructures routières, notamment en France où près de la moitié du territoire est exposée à ce risque géotechnique. Sensibles aux variations hydriques, ces sols subissent des cycles de dessiccation et de ré-humidification qui induisent des déformations volumiques importantes fragilisant les chaussées et générant des coûts de maintenance élevés. L’objectif de cette thèse est d’analyser, de manière expérimentale et multi-échelle, le comportement hydromécanique des sols argileux sous chaussée et d’évaluer l’efficacité d’une stabilisation innovante par injection de nano-silice. Dans un premier temps, plusieurs argiles naturelles et industrielles sont caractérisées, en termes de propriétés géotechniques, de microstructure (MEB/EDS) et de composition minéralogique (DRX), complétées par une analyse de la porosité (tomographie X et porosimétrie au mercure). Ces investigations ont mis en évidence le rôle déterminant de la minéralogie et de la structure poreuse dans la sensibilité hydrique des sols. Dans un second temps, le comportement hydromécanique des sols soumis à des sollicitations monotones et cycliques de séchage-humidification est étudié. Les essais montrent que les déformations de retrait-gonflement et la fissuration de surface sont fortement corrélées à la teneur en minéraux gonflants. Le suivi par corrélation d’images numériques (CIN) révèle que les fissures apparaissent dès les premiers stades de dessiccation, avant même la désaturation complète, et évoluent de manière cumulative au fil des cycles. Finalement, l’effet de la nano-silice comme stabilisant est analysé avec une évaluation environnementale et économique. Les résultats montrent un comblement partiel des pores et une réorganisation microstructurale, passant d’un état dispersé à une structure floculée, améliorant la compacité et la cohésion. L’ajout de nano-silice réduit de 40 à 55 % les amplitudes de retrait-gonflement au cours des premiers cycles, avec un effet optimal pour des dosages modérés. La stabilité à long terme a été aussi évaluée par des essais de lixiviation. Les résultats confirment une très faible mobilité de la nano-silice, témoignant de sa bonne immobilisation dans la matrice argileuse et sa performante pour les RGA
Echocardiographic Outcomes After Transcatheter Edge-to-Edge Repair in Patients With Isolated Tricuspid Regurgitation
No full textInternational audienceBackground: The relationships among tricuspid regurgitation (TR) reduction after tricuspid transcatheter edge-to-edge repair (T-TEER), changes in right-sided heart function, and outcomes are poorly explored.Objectives: This study aims to explore the relationship between functional remodeling and subsequent outcomes and the associations among T-TEER, residual TR, and outcomes.Methods: Changes in echocardiographic parameters from baseline to 1 year, overall and according to TR reduction were evaluated by a centralized echocardiographic core laboratory in patients included in the Tri.Fr (Evaluation of Tricuspid Valve Percutaneous Repair System in the Treatment of Severe Secondary Tricuspid Disorders) trial.Results: A total of 300 patients (aged 78 ± 5 years; 53.7% women) were enrolled; 152 patients were allocated to the T-TEER + guideline-directed medical therapy (GDMT) group, and 148 were allocated to the GDMT group. Patients in the T-TEER + GDMT group demonstrated a significant decrease in most of parameters of right ventricular (RV) function, whereas patients in the GDMT group exhibited no significant changes in RV metrics at 1 year. The clinical composite score improved progressively with each successive grade of TR reduction. The positive effect of T-TEER on the composite clinical score was observed irrespective of baseline right atrial volume but only in patients with normal RV-pulmonary artery coupling (defined by a tricuspid annular plane systolic excursion-to-systolic pulmonary artery pressure ratio ≥0.40). At 1 year, patients with an improved clinical composite score had a lower right atrial volume index compared with patients whose clinical score remained unchanged or worsened (median 112 mL/m2 [Q1-Q3: 78.0-146 mL/m2] vs median 141 mL/m2 [Q1-Q3: 107-173 mL/m2]; P = 0.004).Conclusions: Although T-TEER can decrease TR severity, its impact on conventional RV function parameters and RV-pulmonary artery coupling remains limited. RV functional recovery has a smaller influence on clinical outcomes at 1 year compared with achieving optimal reduction in TR severity. (Evaluation of Tricuspid Valve Percutaneous Repair System in the Treatment of Severe Secondary Tricuspid Disorders [Tri.Fr]; NCT04646811)
nexus: Sourcing Archaeological Materials by Chemical Composition
No full textExploration and analysis of compositional data in the framework of Aitchison (1986). This package provides tools for chemical fingerprinting and source tracking of ancient materials
