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Combining gold(I/III) complexes and ferrociphenol scaffold for the generation of bimetallic complexes with anticancer activity
No full textInternational audienceA series of eleven heterobimetallic Au/Fe complexes featuring [Au(I)-thioglucose tetraacetate], [Au(I)-NHC], [(C^N)Au(III)Cl], [(C^N^C)Au(III)] or [(C^C)Au(III)Cl] fragments and (diphenylphosphino)ferrociphenol or (diphenylphosphino)ferrocene ligands have been synthesized. The compounds were fully characterized by NMR, high-resolution mass spectrometry, elemental analysis, as well as by X-ray diffraction for the representative Au-carbene complex. The electrochemical behavior of the complexes was studied by cyclic voltammetry. While the compounds resulting from (diphenylphosphino)ferrocene displayed a reversible, ferrocene-centered redox process, their analogs obtained from (diphenylphosphino)ferrociphenol showed additional irreversible multielectron redox transitions attributable to the redox-active ferrociphenol fragment. The antiproliferative activity of the complexes was evaluated in vitro on lung (A549) and triple-negative breast (MDA-MB-231) cancer cells and compared to non-cancerous breast cells (MCF-10A). Coordination of the gold fragments by (diphenylphosphino)ferrocene led to the buildup of antiproliferative activity with EC50 down to the submicromolar level. Comparatively, the antiproliferative activities of the analogous bimetallic complexes containing the (diphenylphosphino)ferrociphenol ligand were slightly lower. The ability of the complexes to inhibit thioredoxin reductase (TrxR), an established target of both gold complexes and ferrociphenol, was also investigated, including in oxidative conditions. Bimetallic complexes featuring exchangeable ligands, such as in Au(I)−chlorido, thiolato, and (C^N) cyclometallated Au(III) fragments, showed half-maximal effective concentrations (EC50) values in the nanomolar range, typical of related gold complexes. In contrast, bimetallic complexes bearing stable scaffolds such as Au(I)-NHC (NHC = N-heterocyclic carbene) and bis-cyclometallated (C^N^C) Au(III) required oxidation of the ferrociphenol moiety to induce significant thioredoxin reductase inhibition
Brownian dynamics simulations of electric double-layer capacitors with tunable metallicity
No full textInternational audienceWe introduce an efficient description of electrodes, characterized by their Thomas–Fermi screening length inside the metal, for Brownian dynamics (BD) simulations of capacitors. Within a Born–Oppenheimer approximation for the electron charge density inside the electrodes, we derive the effective many-body potential for ions in an implicit solvent between Thomas–Fermi electrodes, taking into account the constraints of applied voltage and of global electro-neutrality of the system, as well as the 2D periodic boundary conditions along the electrode surfaces. We derive the average charge and the fluctuation–dissipation relation for the differential capacitance, highlighting the contribution of the fluctuations of the net ionic dipole moment, as well as those from the solvent polarization and of the electron density, whose fluctuations are suppressed within the Born–Oppenheimer description. We demonstrate the relevance of this model by validating its predictions against known results for the force on ions as a function of the ion-surface distance in simple geometries. The equilibrium ionic density profiles from BD simulations are in excellent agreement with those from an explicit electrode model for perfect metals and are obtained at a significantly lower computational cost. Finally, we discuss with the present model the effect of the Thomas–Fermi screening length on the equilibrium ionic density profiles and the capacitance. While limited to parallel plate capacitors, the present simulation method allows us to consider larger systems, lower concentrations, and longer time scales than molecular simulations in order to predict the electrochemical properties of Thomas–Fermi capacitors and correlate them with the ion dynamics
BIOCARE - Polymères BIOsourcés pour la Consolidation et la réduction de l'Acidité des papiers fRagilEs
No full textInternational audiencePreserving many industrial papers, particularly those from the mid-19th to mid-20th centuries, is a major challenge due to their mechanical fragility caused by acidification, which develops quickly after production. A well-established solution is to neutralise the acids through a deacidification treatment. However, the simultaneous addition of a consolidant, which allows for safe handling while limiting irreversible material loss, is a practice that is rarely used due to a lack of effective solutions. The depletion of oil reserves and plastic pollution are also encouraging the use of bio-based and/or biodegradable materials, including for the conservation and restoration of heritage.The BIOCARE thesis explores the eco-design of sustainable treatments for the mechanical reinforcement of fragile heritage papers. We will study the use of nanocellulose and bio-based amino polymers (PBAs). The latter carry functional groups that are potentially capable of deacidifying paper. Unlike PBAs, which have been little or not at all explored for application to paper and for which this study is therefore pioneering, nanocelluloses are increasingly used in conservation for the consolidation of cellulosic substrates, using films or dispersions, either mixed with alkaline particles or not. However, the wide variety of morphological and mechanical characteristics of nanocellulose is never taken into account. The most effective formulations will be applied to several historical industrial papers and well-characterised, artificially aged model papers to approximate the state of preservation of ancient papers. The long-term effectiveness of the formulations will be evaluated through physicochemical analyses (mechanical tests, colorimetry, pH).La préservation de nombreux papiers industriels, particulièrement de la période mi- XIXe – mi-XXe siècles, représente un défi de taille en raison de leur fragilité mécanique causée par l’acidification qui se développe rapidement après leur production. Une solution bien établie consiste à neutraliser les acides par un traitement de désacidification. L’ajout simultané d’un consolidant, permettant une manipulation sécuritaire tout en limitant des pertes de matière irréversibles, est en revanche une pratique peu exploitée faute de solutions efficaces. L'épuisement des réserves pétrolières et la pollution plastique incitent également au recours à des matériaux biosourcés et/ou biodégradables, y compris pour la conservation-restauration du patrimoine.La thèse BIOCARE explore l’écoconception de traitements durables de renforcement mécanique de papiers patrimoniaux fragiles. Nous étudierons l'utilisation de nanocelluloses et de polymères biosourcés aminés (PBAs). Ces derniers portent des groupes fonctionnels potentiellement capables de désacidifier le papier. Contrairement aux PBAs, peu voire pas explorés pour une application au papier et pour laquelle cette étude est donc pionnière, les nanocelluloses sont de plus en plus utilisées en conservation pour la consolidation de supports cellulosiques, à l’aide de films ou de dispersions en mélange ou non avec des particules alcalines. Cependant la grande variété des caractéristiques morphologiques et mécaniques des nanocelluloses n’y est jamais prise en compte. Les formulations les plus performantes seront appliquées sur plusieurs papiers industriels historiques, et des papiers modèles bien caractérisés et artificiellement vieillis pour approcher les états de conservation de papiers anciens. L’efficacité des formulations sur la durée sera évaluée par des analyses physico- chimiques (essais mécaniques, colorimétrie, pH)
Dimensionality Control in Superlattices from Copper Sulfide Nanocrystals
No full textInternational audienceThree-dimensional nanocrystal superlattices have garnered considerable research interest due to their remarkable collective properties and promising applications. The control of the dimensionality of superlattices remains a significant challenge, with no established synthetic protocol to tune the shape of superlattices. The present article manifests a straightforward and efficient single-step chemical synthesis route for modulating the dimensionality of Cu1.8S nanocrystals superlattices. The resulting superlattices exhibit distinct stability within several solvents (hexane, toluene and benzene) over an extended period of several months. Furthermore, we unveil the growth mechanism of these superlattices through comprehensive small-angle X-ray scattering (SAXS) experiments. This method addresses several drawbacks (multi step synthesis, structural fragility, reproducibility, long-range order instability, etc) associated with previously reported self-assembly methods, the superlattices generated by this technique are efficient to fabricate devices in the future.</div
Impact of MAPbI3 Phase Transitions on Solar Cell Performance: Everything you need to know about ab-initio methods in device performance
No full textThis paper presents a first step toward a pragmatic phenomenological multiscale approach to evaluate perovskite solar cell performance which determines material properties at the atomistic scale with first-principles calculations, and applies them in macro-scale device models. This work focuses on the MAPbI3 (MA = CH3NH3) perovskite and how its phase transitions impact on its optical, electronic, and structural properties which are investigated at the first-principles level. The obtained data are coupled to a numerical drift-diffusion device model enabling evaluation of the performance of corresponding single junction devices. The first-principles simulation applies a hybrid exchange-correlation functional adapted to the studied family of compounds. Validation by available experimental data is presented from materials properties to device performance, justifying the use of the approach for predictive evaluation of existing and novel perovskites. The coupling between atomistic and device models is described in terms of a framework for exchange of optical and electronic parameters between the two scales. The obtained results are systematically discussed in terms of first-principles levels of approximation performances
Macrophages restrict tumor immune infiltration by controlling collagen topography
No full textInternational audienceDuring tumorigenesis, the extracellular matrix is extensively remodeled. While the impact of such remodeling on tumor growth and invasion is well-described, the consequences on immune infiltration are not well-understood. Combining tissue imaging and machine learning, we show that immune cell localization in tumors can be predicted by the local topography of fibrillar collagens. Such topographies are dictated by a fibrotic pathway driven by transcription factor 4 (Tcf4) in both cancer and stromal cells, which promotes collagen III deposition and results in intermingled collagen networks that favor intratumoral infiltration of T cells and neutrophils. Macrophages inhibit this pathway, highlighting their key structural role in shaping the tumor extracellular matrix. Re-analysis of data from human solid tumors revealed a strong correlation between TCF4, COL3A1, and T cell and neutrophil signatures. Together, our data identify collagen network topographies as a key regulator of tumor-infiltrating immune cells.
Le mystère des pépites vertes (enfin résolu!) – A la source des matières colorantes des sites paléolithiques de la vallée de l’Ardèche
No full textNational audienceLes opérations archéologiques menées dans la vallée de l’Ardèche et du Chassezac ont livré un corpus remarquable de matières colorantes. Parmi elles, plusieurs fragments à inclusions vertes ont été identifiés à la grotte aux Points (30), à l’abri des Pêcheurs (07) et au Mas d’Aiguillon (07). Des matériaux similaires, mais sans inclusions, proviennent d’Huchard et de la Baume d’Oulen (07). L’étude pétrographique révèle une matrice argilo-ferrugineuse fine, associant hématite en feuillets et aluminosilicates, témoignant d’une origine probablement hydrothermale.Ces caractéristiques suggèrent qu’une stratégie de sélection a guidée la collecte des matières colorantes.Deux approches complémentaires ont été menées : la première, analytique (microscopie, Raman, DRX), pour déterminer la nature minéralogique des inclusions vertes ; la seconde, dans le cadre du PCR Pigmentothèque, pour rechercher des affleurements compatibles. Les prospections de 2024 ont abouti à la découverte, d’un affleurement présentant toutes les caractéristiques pétrographiques recherchées : matrice argilo-ferrugineuse et… pépites vertes
Engineering materials for electrochemical energy storage via ionic liquid and deep eutectic solvent synthesis media
No full text"ADC - Accord Couperin / American Chemical Society (2024-2026)".International audienceThe development of high-performance electrode and solid electrolyte materials is crucial for the advancement of next-generation electrochemical energy storage systems. Among emerging synthesis strategies, ionic liquids (ILs) and deep eutectic solvents (DESs) have gained increasing attention as alternative reaction media due to their unique physicochemical properties, including high thermal stability, a wide electrochemical stability window, low vapor pressure, and tunable composition and polarity. These features offer unprecedented control over particle morphology, composition, and surface chemistry, enabling the formation of novel or metastable phases, as well as in situ surface functionalization or generation of homogeneous carbon coatings through postannealing treatments. Despite these promising attributes, the implementation of ILs and DESs at an industrial scale remains to date limited. Major challenges include high viscosity, recycling difficulties, high costs, and a lack of large-scale proofs of concept. After introducing ILs and DESs, and their specific properties, this review critically evaluates the potential and limitations of IL- and DES-based synthesis methods in comparison to conventional techniques such as solid-state and hydrothermal approaches. The benefits and impacts of these uncommon solvents on material morphology and functional properties are discussed along with a systematic comparison with the electrochemical performance of similar materials synthesized via classical methods. This review further discusses the prospects for industrial integration and highlights key areas where further research is essential. Finally, this review provides some perspectives that would allow for mastering these synthesis approaches and developing optimized materials for electrochemical energy storage.</p
Defect Suppression and Efficiency Enhancement of Slot-Die-Coated Formamidinium Lead Iodide Solar Devices via Ambient Air Annealing
No full textInternational audienc
Enhancing ion‐electron transport in positive electrode of solid‐state lithium metal batteries with multifunctional catholyte made of polymer mixed ionic‐electronic conductor PEDOT:PSSTFSI and Li3InCl6
No full textOpen access publication funding provided by COUPERIN CY26.International audienceThe development of positive electrode composites (PECs) with improved ionic and electronic conductivity is critical for high-performance all-solid-state batteries (ASSBs). Conventional strategies rely on tuning the ratio of cathode active material (CAM) to solid electrolyte (SE) or introducing electronic conductive additives, yet both often induce interfacial instabilities limiting long-term performance. Here, mixed ionic-electronic conductor, poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonyl(trifluoromethylsulfonyl)imide) (PEDOT:PSSTFSI), is incorporated as a functional polymer (FP) binder in Li3InCl6 (LIC), forming multifunctional catholytes in a single step via one-pot aqueous synthesis. Owing to π–π stacking and the TFSI− functional group, PEDOT:PSSTFSI enhances electronic and ionic conductivity within the catholyte. Compared to the polymer-free NMC-based PEC, the incorporation of 5 wt.% FP markedly increases electrode compactness, reducing the porosity by 41.8% and yielding a twelvefold increase in effective electronic conductivity. In parallel, ionic conductivity improves substantially—up to 15-fold, with the highest reached at 0.6 wt.% of FP in the PEC. When tested in ASSB cells, PECs containing FP show enhanced rate capability, especially at 1 C rate with full reversibility, and deliver up to 30% higher discharge capacity at a C/20 rate compared to polymer-free NMC-LIC references. This study highlights mixed conducting binders as a versatile system to improve conducting pathways while enhancing electrode integrity.</p