Prediction of Breathing and Gate-Opening Transitions Upon Binary Mixture Adsorption in Metal−Organic Frameworks

International audienceAmong the numerous applications of metal−organic frameworks (MOFs), a topical class of nanoporous materials, adsorptive separation is gaining considerable attention. Some of the most exciting candidates for gas separation processes exhibit structural transitions, such as breathing and gate opening. While predictive analytical methods are crucial in separation science and have been widely used for rigid nanoporous solids, a lack exists for materials that exhibit flexibility. We propose here a general method predicting, for the first time, the evolution of structural transitions and selectivity upon adsorption of gas mixtures in flexible nanoporous solids

Prosopographie des hommes du livre (La)

Actes du colloque organisé à l\u27enssib, Villeurbanne, par le Centre de Recherche en Histoire du Livre les 22 et 23 avril 2005, sous la coordination scientifique de Frédéric Barbier, École pratique des hautes études et de Dominique Varry, école nationale supérieure des sciences de l\u27information et des bibliothèques, avec la collaboration de Juliette Guilbaud

Double Structural Transition in Hybrid Material MIL-53 upon Hydrocarbon Adsorption: The Thermodynamics Behind the Scenes

International audienceWe rationalize the thermodynamics behind the guest-induced structural transitions of hybrid material MIL-53, showing that the existence of a double transition depends on the relative guest affinities for the two phases, rather than absolute adsorption enthalpies. Based on a simple model, we interpret recent experimental data on alkane adsorption and predict transition pressures

Templated-PISA: Driving Polymerization-Induced Self-Assembly towards the Fibre Morphology

International audienceDispersions of block-copolymer fibres in water have many potential applications and can be obtained by polymerization-induced self-assembly (PISA), but only in very restricted experimental conditions. In order to enlarge this experimental window, we introduced a supramolecular moiety, a hydrogen-bonded bis-urea sticker, in the macromolecular reversible addition-fragmentation chain transfer agent to drive the morphology of the nano-objects produced by RAFT-mediated PISA towards the fibre morphology. This novel concept is tested in the synthesis of a series of poly(N,N-dimethylacrylamide)-b-poly(2-methoxyethyl acrylate) (PDMAc-b-PMEA) diblock copolymers prepared by dispersion polymerization in water. The results prove that the introduction of the templating bis-urea stickers into PISA greatly promotes the formation of fibres in a large experimental window

Thermodynamics of Guest-Induced Structural Transitions in Hybrid Organic−Inorganic Frameworks

International audienc

Bronchial artery embolization for hemoptysis in adult patients with cystic fibrosis: a single-center retrospective study

Background Hemoptysis is a severe complication of cystic fibrosis (CF) for which bronchial artery embolization (BAE) is an efficient primary therapeutic option. However, recurrence is more frequent than for other etiologies of hemoptysis. Purpose To assess the safety and efficacy of BAE in patients with CF and hemoptysis and predictive factors for recurrent hemoptysis Material and Methods This retrospective study reviewed all adult patients with CF treated by BAE for hemoptysis in our center from 2004 to 2021. The primary endpoint was the recurrence of hemoptysis after bronchial artery embolization. Secondary endpoints were overall survival and complications. We introduced the vascular burden (VB) defined as the sum of all bronchial artery diameters measured on pre-procedural enhanced computed tomography (CT) scans. Results A total of 48 BAE were performed in 31 patients. A total of 19 recurrences occurred with a median recurrence-free survival of 3.9 years. In univariate analyzes, percentage of unembolized VB (%UVB) (hazard ratio [HR] = 1.034, 95% confidence interval [CI=1.016–1.052; P &lt; 0.001) and %UVB vascularizing the suspected bleeding lung (%UVB-lat) (HR = 1.024, 95% CI=1.012–1.037; P &lt; 0.001) were associated with recurrence. In multivariate analyzes, only %UVB-lat remained significantly associated with recurrence (HR = 1.020, 95% CI=1.002–1.038; P = 0.030). One patient died during follow-up. No complication of grade 3 or higher was reported according to the CIRSE classification system for complications. Conclusion When possible, unilateral BAE seems sufficient in patients with CF with hemoptysis even in such a diffuse disease involving both lungs. The efficiency of BAE could be improved by thoroughly targeting all arteries vascularizing the bleeding lung. </jats:sec

Unexpected thermo-responsiveness of bisurea-functionalized hydrophilic polymers in water

International audienceHypothesis: Thermoresponsive polymers are important materials for various applications. However, the number of polymers that exhibit this property in the temperature range of interest remains limited. The development of novel rational design strategies through the understanding of the thermal transition’s origin is therefore of utmost importance.Experiments: Bisurea-functionalized water-soluble polymers were synthesized by RAFT polymerization. After direct dissolution in water, the supramolecular assemblies were analyzed by cryo-TEM and SANS. Their temperature-dependent water-solubility was characterized by various techniques, namely DLS, SANS, DSC, IR, to understand the origin of the temperature sensitivity.Findings: The supramolecular assemblies exhibit an unexpected temperature-dependent solubility. For instance, a cloud point of only 39 °C was measured for poly(N,N-dimethylacrylamide) assemblies. This property is not restricted to one specific polymer but is rather a general feature of bisurea-functionalized polymers that form supramacromolecular bottlebrushes in water. The results highlight the existence of two distinct transitions; the first one is a visually perceptible cloud point due to the aggregation of individual micelles, presumably driven by the hydrophobic effect. The second transition is related to the dissociation of intermolecular bisurea hydrogen bonds. Finally, we show that it is possible to widely tune the cloud point temperature through the formation of co-assemblies