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We report first principles numerical discovery of hydrostatic pressure driven tetragonal to collapsed tetragonal transition in 1111-type material ThMnAsN accompanied by simultaneous magneto-structural, insulator to metal transition together with complete collapse of Mn moment. We present detailed evolution of various structural parameters, magnetism and electronic structures of ThMnAsN with increasing hydrostatic pressure. All the structural parameters show anomalies at a critical pressure P$_c \sim$ 9 GPa; c-lattice parameter, out of plane As-As bond length, anion height (h$_{As}$) undergo drastic modification compared to the in-plane parameters which is manifested in an iso-structural phase transition from tetragonal to a collapsed tetragonal (cT) phase. These modifications in "local structural correlations" due to pressure destroys usually localized nature of Mn moments and gets completely quenched. Apart from that the elastic constant, the electronic structures also bear the finger prints of insulator-metal and magneto-structural transition at higher pressures accompanying a total collapse of magnetic moment at the vicinity of 9 GPa. The critical value of the pressure P$_c$ at which tetragonal to collapse tetragonal phase transition occurs, remains robust with respect to the on-site Hubbard correlation (U). The dynamical stability of the compound at higher pressures are affirmed through detailed computations of phonon dispersion curves endowed with positive phonon frequency through out the Brillouin zone. The effect of magnetic spin structure on the electronic band structures are obtained through band unfolding. The electronic structure of ThMnAsN at higher pressures "orbital selectively" influences bands, band gap and closely resembles with the electronic structure of Fe-based superconductors with the occurrences of orbital selective Lifshitz transition., Comment: 13 pages, 21 figures

International audience; We report on the crystallite growth of nanometric NpO2 and UO2 powders. The AnO2 nanoparticles (An = U and Np) were synthesized by hydrothermal decomposition of the corresponding actinide(IV) oxalates. NpO2 powder was isothermally annealed between 950 °C and 1150 °C and UO2 between 650 °C and 1000 °C. The crystallite growth was then followed by high-temperature X-ray diffraction (HT-XRD). The activation energies for the growth of crystallites of UO2 and NpO2 were determined to be 264(26) kJ mol−1 and 442(32) kJ mol−1, respectively, with a growth exponent n = 4. The value of the exponent n and the low activation energy suggest that the crystalline growth is rate-controlled by the mobility of the pores, which migrate by atomic diffusion along the pore surfaces. We could thus estimate the cation self-diffusion coefficient along the surface in UO2, NpO2 and PuO2. While data for surface diffusion coefficients for NpO2 and PuO2 are lacking in the literature, the comparison with literature data for UO2 supports further the hypothesis of a surface diffusion controlled growth mechanism.

International audience; Rational design and synthesis of low-cost trifunctional electrocatalysts with improved stability and superior electrocatalytic activity for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) are highly desirable but remain as the bottlenecks at the current state of technology. In this paper, the cobalt-iron (Co–Fe) composite supported on nitrogen-doped carbon nanotubes (CoFe composite/NCNTs) is synthesized. The intrinsic OER and HER catalytic activities of this CoFe composite/NCNTs composite are significantly improved with palladium (Pd) nanocluster decoration [Pd-coated (CoFe composite/NCNTs)]. The as-prepared Pd-coated (CoFe composite/NCNTs) catalyst exhibits excellent trifunctional electrocatalytic activity and stability due to the interfacial coupling between Pd and (CoFe composite/NCNTs). This catalyst is successfully employed in the water electrolysis cell as both OER and HER electrode catalysts, flexible rechargeable Zn-air battery as the bifunctional ORR and OER electrode catalyst. The cell voltage of this catalyst-coated electrodes requires only 1.60 V to achieve 10 mA cm−2 current density for water electrolysis cell, which is comparable to and even better than that of Pt/C and Ir/C based cell. The primary Zn-air battery using this catalyst shows a constant high open-circuit voltage (OCV) of 1.47 V and a maximum power density of 261 mW cm−2 in the flooded mode configuration. Most importantly, a flexible Zn-air battery with this catalyst runs very smoothly without a change in voltage gap during flat, bending, and twisting positions.

International audience; The powerful combination of steady state isotopic transient kinetic analysis (SSITKA) and operando infrared spectroscopy (IR) was applied to study the CO oxidation reaction on Pd-supported Al2O3 catalyst at low temperature. The aim was to reveal the true role of hydrogen‑carbonate species in the reaction mechanism. The SSITKA-IR experiments, conducted in presence and absence of CO2 in the gas feed, have confirmed that hydrogen‑carbonate species behave as spectator species in the reaction. Its formation was due to re-adsorption of the CO2 product itself on the alumina surface as confirmed by the direct 12CO2/13CO2 exchange observed on the bare support.

International audience; PurposeHypermobile Ehlers–Danlos syndrome (hEDS) is a connective tissue disorder with many different symptoms such as pain, fatigue, dysautonomia, or respiratory symptoms. Among the respiratory manifestations described, the most frequent are exertional dyspnea and breathing difficulties. Mechanical ventilatory constraints during exercise could participate in these respiratory manifestations. The objective of this study was to explore the response of pulmonary flow-volume loops to exercise in patients with hEDS and to look for dynamic hyperinflation and expiratory flow limitation during exercise.MethodsFor this purpose, breathing pattern and tidal exercise flow-volume loops were recorded at two workloads (30% and 80% of the peak power output) of a constant load exercise test.ResultsTwelve patients were included (11 women, mean age 41 ± 14 years). The results showed a decrease (p = 0.028) in the inspiratory capacity (from 3.12 ± 0.49 L to 2.97 ± 0.52 L), an increase (p = 0.025) in the end-expiratory lung volume (EELV) (from 0.73 ± 0.68 L to 0.88 ± 0.66 L, i.e., from EELV comprising 17 ± 12% to 21 ± 12% of forced vital capacity) between the two workloads in favor of dynamic hyperinflation, and half of the patients had expiratory flow limitations.ConclusionThis exploratory study provides evidence for mechanical ventilatory constraints during exercise in patients with hEDS, which may induce discomfort during exercise and could contribute to the respiratory symptomatology.; IntroductionLe syndrome d'Ehlers-Danlos hypermobile (SEDh) est une maladie du tissu conjonctif qui se manifeste par des symptômes variés tels que la douleur, la fatigue, la dysautonomie ou des symptômes respiratoires. Parmi les manifestations respiratoires décrites, les plus fréquentes sont la dyspnée à l'effort et les difficultés respiratoires. Les contraintes mécaniques ventilatoires survenant à l'exercice pourraient participer à ces manifestations respiratoires. L'objectif de cette étude était d'explorer la réponse des courbes débit-volume pulmonaires à l'exercice chez les patients atteints de SEDh et de rechercher une hyperinflation dynamique et une limitation du débit expiratoire à l'exercice.MéthodeDans ce but, le schéma respiratoire et les courbes débit-volume à l'exercice ont été enregistrés à deux charges de travail (30% et 80% de la puissance maximale) lors d'un test d'endurance à charge constante.RésultatsDouze patients ont été inclus (11 femmes, âge moyen 41 ± 14 ans). Les résultats ont montré une diminution (p = 0,028) de la capacité inspiratoire (de 3,12 ± 0,49 L à 2,97 ± 0,52 L), une augmentation (p = 0,025) du volume pulmonaire de fin d'expiration (VPFE) (de 0,73 ± 0,68 L à 0,88 ± 0,66 L, soit un VPFE compris entre 17 ± 12 % et 21 ± 12 % de la capacité vitale forcée) entre les deux charges de travail en faveur d'une hyperinflation dynamique, et la moitié des patients présentaient des limitations du débit expiratoire.ConclusionCette étude exploratoire fournit des éléments en faveur de l'existence de contraintes mécaniques ventilatoires à l'exercice chez les patients atteints de SEDh, ce qui peut induire un inconfort pendant l'exercice et pourrait contribuer à la symptomatologie respiratoire.

Aqueous hydroaminomethylation (HAM) is an atom economical route for the efficient production of amines in one reaction step, starting from basic chemicals like alkenes. Herein we present the first successful establishment of a continuous process for HAM in an aqueous multiphase system. The green mass transfer agents randomly methylated-β-cyclodextrins (CD) enabled the catalytic system consisting of rhodium/sulfoXantphos to achieve high yields of up to 70% with selectivities of up to 80% in several continuous experiments with a total run time of more than 220 h. The key here is that water and products have large polarity differences, but the reaction still proceeds effectively due to the addition of cyclodextrin, which made the application of solvents obsolete. The main achievements in this way were the investigation of the influence of the randomly methylated-β-cyclodextrin concentration on the reaction rate and the selectivity in batch studies and finding promising operating points in the first continuous experiments. In a final experiment, the separation temperature was investigated. It was shown that the catalyst loss in the product phase is enormously small at 0.003% h−1 of the initial mass (0.24% in total), which is the lowest ever reported value for the HAM on this scale. Within a run time of 78 hours, 2.87 kg of tertiary amine were produced using only 0.2 g (>14 000 : 1) of transition metal, while the loss of rhodium per kg of product produced was mostly around 0.15 mg kg−1, suggesting possible economical applicability. 25;9

IntroductionThe study aimed to interpret the evolution of the physical performance of rugby sevens and rugby union French international players from 2009 to 2020.Methods631 players from the French national teams were divided into three groups: forwards, backs and sevens. The performances evaluated were anthropometric characteristics, strength tests (1 RM bench press and 1 RM pull-up), aerobic capacity (YoYo IR1 test) and speed tests (10 m, 20 m and 50 m). The best performance of each player over a two-year period was kept for the analysis. Fluctuations were observed across the decade.ResultsThe anthropometric characteristics of female rugby sevens players tend to be taller and lighter than rugby union players. In rugby sevens, a moderate increase in maximal aerobic capacity was observed while sprint performances remained similar. Improvements in height and weight were observed over the last 10 years in rugby union players with a difference between the position. A moderate increase in sprinting performances and strength were observed both in backs and forwards.DiscussionThe overall improvement of strength and conditioning performances and anthropometrical evolution reflects the rugby environment characterized by the arrival of professional contracts and the structuration process of the clubs which allows a better quality of training and easier access to the infrastructures of the very high level.

Polymorphic phases of copper pyrovanadate (α- and β-Cu2V2O7) were synthesized by solid state reaction and the mechanisms governing the phase transitions have been highlighted by the ThermoGravimetric Analysis (TGA) and the Differential Scanning Calorimetry (DSC). The thermal evolution of the lattice parameters was determined by high temperature X-ray Diffraction revealing negative thermal expansion coefficients. The thermogravimetric analysis coupled with differential scanning calorimetry was also used to determine the optimal conditions to obtain a dense target in order to produce thin films by the Pulsed Laser Deposition (PLD) technique. Thin films elaborated under different oxygen pressures and temperatures exhibit a β-Cu2V2O7 polycrystalline phase and their band gap indicates absorption in the visible range. These oxides can be used as photoanodes and their photoelectrochemical properties were studied for both bulk (α-Cu2V2O7) and thin films (β-Cu2V2O7), as a function of the wavelength and/or intensity of the luminous flux. The best photocurrent efficiency was obtained under 450 nm illumination. Moreover, in the case of thin films, we have observed a linear evolution of the current density with the luminous flux. Finally, the photostability of thin films was measured and shows a reduction in the photocurrent of 8% after 1 h of measurement. This photocorrosion phenomenon was also highlighted by the elemental mapping performed on thin films by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectrometry (EDS). 13;18

This study aimed to identify predictive variables of performance for a 100-km race (Perf100-km) and develop an equation for predicting this performance using individual data, recent marathon performance (Perfmarathon), and environmental conditions at the start of the 100-km race. All runners who had performed official Perfmarathon and Perf100-km in France, both in 2019, were recruited. For each runner, gender, weight, height, body mass index (BMI), age, the personal marathon record (PRmarathon), date of the Perfmarathon and Perf100-km, and environmental conditions during the 100-km race (i.e., minimal and maximal air temperatures, wind speed, total amount of precipitation, relative humidity and barometric pressure) were collected. Correlations between the data were examined, and prediction equations were then developed using stepwise multiple linear regression analyses. Significant bivariate correlations were found between Perfmarathon (pr = 0.838), wind speed (pr = -0.545), barometric pressure (pr = 0.535), age (p = 0.034, r = 0.246), BMI (p = 0.034, r = 0.245), PRmarathon (p = 0.065, r = 0.204) and Perf100-km in 56 athletes The, 2 prediction equations with larger sample (n = 591) were developed to predict Perf100-km, one including Perfmarathon, wind speed and PRmarathon (model 1, r² = 0.549; standard errors of the estimate, SEE = 13.2%), and the other including only Perfmarathon and PRmarathon (model 2, r² = 0.494; SEE = 14.0%). Perf100-km can be predicted with an acceptable level of accuracy from only recent Perfmarathon and PRmarathon, in amateur athletes who want to perform a 100 km for the first time.

Mixed-anion compounds widen the chemical space of attainable materials compared to single anionic compounds, but the exploration of their structural diversity is limited by common synthetic paths. Especially, oxychlorides rely mainly on layered structures, which suffer from low stability during photo(electro)catalytic processes. Herein we report a strategy to design a new polar 3D tetrahedral framework with composition Zn4Si2O7Cl2. We use a molten salt medium to enable low temperature crystallization of nanowires of this new compound, by relying on tetrahedral building units present in the melt to build the connectivity of the oxychloride. These units are combined with silicon-based connectors from a non-oxidic Zintl phase to enable precise tuning of the oxygen content. This structure brings high chemical and thermal stability, as well as strongly anisotropic hole mobility along the polar axis. These features, associated with the ability to adjust the transport properties by doping, enable to tune water splitting properties for photoelectrocatalytic H2 evolution and water oxidation. This work then paves the way to a new family of mixed-anion solids 135;26

International audience; Modulating the interaction between Mo nanoparticles and their support is an elegant approach to finely tune the structural, physico-chemical, redox and electronic properties of the active site. In this work, a series of molybdenum nitride catalysts supported on TiO2, and SBA-15 has been prepared and fully characterized. The results of characterization confirmed the high dispersion of Mo and the formation of small molybdenum nanoparticles in both the 10-Mo-N/SBA-15 and 10-Mo-N/TiO2 catalysts. In this context, we have shown that the catalytic activity of Mo species was strongly impacted by the nature of the catalytic support. Amongst the studied supports, SBA-15 was found to be the most appropriate for Mo dispersion. In comparison, when supported on a reducible oxide (TiO2), Mo species showed poor catalytic activity in both ammonia synthesis and decomposition and were prone to quick deactivation in the ammonia synthesis reaction. Evidence of charge transfer from the reducible support to the active phase, indicative of possible SMSI behaviour, has been observed by XPS and EPR. Differences in the oxidation states, redox behaviours, and electronic properties have been further studied by means of EPR, H2-TPR and H2-TPD.

Sesquiterpene lactones (STLs) are a large group of terpenoids most commonly found in plants of the Asteraceae family, e.g., in chicory plants, displaying a wide range of interesting biological activities. However, further studies on the biological potential of chicory-derived STLs and analogues are challenging as only four of these molecules are commercially available (as analytical standards), and to date, there are no published or patented simple extraction–purification processes capable of large-scale STLs isolation. In this work, we describe a novel three-step large-scale extraction and purification method for the simultaneous purification of 11,13-dihydrolactucin (DHLc) and lactucin (Lc) starting from a chicory genotype rich in these STLs and the corresponding glucosyl and oxalyl conjugated forms. After a small-scale screening on 100 mg of freeze-dried chicory root powder, the best results were achieved with a 17 h water maceration at 30 °C. With these conditions, we managed to increase the content of DHLc and Lc, at the same time favoring the hydrolysis of their conjugated forms. On a larger scale, the extraction of 750 g of freeze-dried chicory root powder, followed by a liquid–liquid extraction step and a reversed-phase chromatography, allowed the recovery of 642.3 ± 76.3 mg of DHLc and 175.3 ± 32.9 mg of Lc. The two pure STLs were subsequently used in the context of semisynthesis to generate analogues for biological evaluation as antibacterial agents. In addition, other described chicory STLs that are not commercially available were also synthesized or extracted to serve as analytical standards for the study. In particular, lactucin-oxalate and 11,13-dihydrolactucin-oxalate were synthesized in two steps starting from Lc and DHLc, respectively. On the other hand, 11β,13-dihydrolactucin-glucoside was obtained after a MeOH/H2O (70/30) extraction, followed by a liquid–liquid extraction step and a reversed-phase chromatography. Together, this work will help facilitate the evaluation of the biological potential of chicory-derived STLs and their semisynthetic analogues.

Contexte : Les jeunes en situation d’obésité ont un niveau d’activité physique (AP) plus faible que les jeunes normo-pondérés (1). La pratique d’AP en visioconférence pourrait permettre de limiter les barrières à l’AP (transport, temps, motivation) et d’autonomiser les adolescents tout en gardant une pratique collective, encadrée et sécuritaire (2). L’objectif de notre étude est de comparer l’efficacité d’un programme d’activité physique supervisé réalisé en visioconférence versus en présentiel. Méthodologie : Trente jeunes (9-17 ans) en situation d’obésité, divisés en 3 groupes (n=10), ont participé à notre étude : entraînement en visioconférence (Ent_V), entraînement en présentiel (Ent_P) et sans programme d’entraînement (S_Ent). Les adolescents des groupes entraînements ont suivi un programme d’AP composé de 2 séances d’une heure d’AP par semaine pendant 4 mois. Avant (T0) et après la période de quatre mois (T4), les adolescents ont effectué un test sous-maximal d’effort (PWC170) afin d’estimer l’aptitude aérobie. La composition corporelle a été mesurée par une balance impédancemètre. Résultats : Chez le groupe Ent_V, la puissance relative à la masse corporelle développée à 170 Bpm a augmenté à T4 (p=0,007). Aucune différence significative n’a été révélée pour les groupes Ent_P et S_Ent. Concernant l’analyse de la composition corporelle, nous avons noté une stabilisation pour les groupes entraînements. En revanche, la masse corporelle et le pourcentage de masse grasse corporelle ont augmenté significativement entre T0 et T4 pour le groupe S_Ent (respectivement, p = 0,003 et p = 0,006). Conclusion : Un programme d’activité physique de quatre mois réalisés en visioconférence permet de stabiliser le poids corporel et d’améliorer l’aptitude aérobie chez des adolescents en situation d’obésité. Ces résultats préliminaires restent à confirmer avec un nombre plus important de participants.

International audience

International audience

International audience; In this work, zeolitic imidazolate framework-67 (ZIF-67)/chitosan composite beads were prepared by immersing chitosan beads incorporating cobalt (hydr)oxide into a solution containing the organic linker (2-methylimidazole). Compared to the conventional preparation protocols for metal-organic framework/polymer beads, the in-situ growth approach developed herein allows obtaining higher surface area with the shaped composites, up to 1200 m2/g for ZIF-67/CS2:1. The CO2 adsorption capacity of these ZIF-67/chitosan beads was investigated and reached 1.21 mmol/g at 273 K, which represents almost 100% of the adsorption capacity of pure ZIF-67, in line with the preserved surface area despite the incorporation of the 19% of additives included. Importantly, the ZIF-67/chitosan beads with an average bulk (crush) strength of 1.57 N could be easily regenerated, with a retained efficiency above 97% after 6 cycles. Furthermore, a possible mechanism for CO2 adsorption is discussed.

International audience; α-carbonyl homoallylic alcohols have been synthesized in a one-pot reaction from benzaldehyde and allylic alcohols. The nickel-catalyzed allylation of α-hydroxyketones has first been studied and allowed the identification of Ni(cod)2/dppf as the most suitable catalytic system. The tandem reaction that combines the benzoin condensation of aldehydes (synthesis of α-hydroxyketones) promoted by the 1,3-dimethylimidazolium chloride/DBU system and the nickel-catalyzed allylic alkylation with allylic alcohol has been realized in EtOH as green solvent. The reaction is 100 % atom-economical and water is formed as sole by-product. A broad scope of different benzaldehyde derivatives as well as various allylic alcohols is also described.

Contexte - Plusieurs équipes ont exploré la glycémie lors d’épreuves d’ultra-endurance, mais, seulement avec des mesures ponctuelles conduisant à des résultats divergents (baisse[1], hausse[2], ou stabilité de la glycémie[3]). La mesure des variations glycémiques en continu permettrait d’apprécier les variations réelles de glycémies pendant les différentes phases de l’épreuve et à la récupération. La mise en évidence d’éventuels épisodes hypo ou hyperglycémiques pourrait expliquer certaines variations de performances. Méthodes - Cinquante-cinq coureurs (43 hommes, 12 femmes) ont participé à un ultra-trail de 6 boucles de 26km et 1000m D+ à Clécy (France)[4]. La veille de la course, un capteur de glucose interstitiel en continu, en mode masqué, a été placé à l'arrière du bras des participants et porté pendant 14 jours afin d’obtenir les données de repos (de la pose du capteur jusqu’à 06h00 le jour de la course), de course mais aussi de récupération. Des modèles mixtes linéaires ou des régressions logistiques binaires ont permis d’identifier les excursions glycémiques et leurs liens avec les caractéristiques de course. Résultats - Au repos avant la course, le temps passé 140mg.dL-1 est moins élevé que pendant la course (e -5,86; P=0,004). Plus la vitesse de course est élevée lors d’une boucle, plus les coureurs passent de temps >140mg.dL-1 (e -0,1; P=0,003). La variabilité glycémique (coefficient de variation) augmente au fur et à mesure des boucles de course (e +2,55; P140mg.dL-1 a tendance à diminuer le temps de réaction des coureurs lors des tests de vigilance (e -0,01; P=0,071). Conclusion - L’ultra trail s’est accompagné d’un risque hyperglycémique, et non hypoglycémique, accru, d’autant plus lors les boucles où la vitesse était plus élevée, suggérant l’implication des hormones hyperglycémiantes. La suite des analyses explorera les données de récupération.

Maximizing the electrochemical performance of 3D micro-supercapacitors based on pseudocapacitive films is crucial for powering the next generation of miniaturized IoT devices. The films have to be nanostructured, must conform the 3D template, and have uniform deposition. To study the growth mechanism of nanostructured MnO2 films obtained by a pulsed electrodeposition method, in situ Atomic Force Microscopy methods operating in liquid mode, Scanning Electron Microscopy, and electrochemical characterization techniques were used. The impact of ON and OFF times during the pulsed electrodeposition process was investigated. The deposition mechanism in Volmer Weber Island growth mode provided some guidelines to tune the deposit morphology to enhance the electrochemical performance of the 3D electrode based on nanostructured MnO2 films.

National audience; INTRODUCTION. Les déséquilibres glycémiques accompagnant le diabète de type 1 (DT1) peuvent conduire, au long terme, à un léger déclin des fonctions cognitives[1]. Chez les personnes non diabétiques, l’activité physique (AP) est reconnue pour ses effets bénéfiques au niveau cérébral, notamment via l’augmentation de facteurs neurotrophiques (facteur neurotrophique dérivé du cerveau, BDNF, et IGF-1). METHODOLOGIE. Chez 95 adultes DT1, des régressions multiples ascendantes ont été réalisées pour estimer les liens entre les performances à une batterie de tests cognitifs et le niveau habituel d’AP et de sédentarité (questionnaires IPAQ et MAQ) en tenant compte des concentrations sériques de BDNF et d’IGF-1 total (prélèvement sanguin) et des facteurs classiques pouvant influencer les fonctions cognitives (démographiques : âge, sexe, IMC, niveau d’éducation ; liés au DT1 : mode d’administration de l’insuline, glycémie du moment, HbA1c, nombre d’épisodes hypoglycémiques sévères durant la vie, âge du diagnostic du DT1, durée du diabète, complications micro/macrovasculaires). RESULTATS. Le niveau d’AP prédisait positivement la flexibilité mentale (performance au TMT B-A: B– 0,05 ; SE(B) 0,03 ; P=0.05 pour le MAQ, MET-h/sem et B– 0,001 ; SE(B) 0,00 ; P=0.018 pour l’IPAQ, MET-min/sem) et ce indépendamment des niveaux de sédentarité, de BDNF et d’IGF-1.Le niveau d’AP n’influençait pas les autres domaines cognitifs évalués (i.e., la vitesse de traitement et la recherche visuo-spatiale avec le TMT-A, la résistance aux interférences avec le Stroop, la mémoire spatiale avec le SMT, la mémoire de travail avec le OPSPAN). Les autres facteurs qui influençaient la plupart des domaines cognitifs étaient l’âge, le niveau d’éducation, le nombre d’épisodes hypoglycémiques sévères, et les complications macrovasculaires. CONCLUSION. L’association entre le niveau d’AP et la flexibilité mentale chez les adultes DT1 souligne l’importance de mettre en place des programmes d’AP, en vue de préserver les fonctions exécutives au long terme.

Contexte : Les jeunes en situation d’obésité ont un niveau d’activité physique (AP) plus faible que les jeunes normo-pondérés (1). La pratique d’AP en visioconférence pourrait permettre de limiter les barrières à l’AP (transport, temps, motivation) et d’autonomiser les adolescents tout en gardant une pratique collective, encadrée et sécuritaire (2). L’objectif de notre étude est de comparer l’efficacité d’un programme d’activité physique supervisé réalisé en visioconférence versus en présentiel. Méthodologie : Trente jeunes (9-17 ans) en situation d’obésité, divisés en 3 groupes (n=10), ont participé à notre étude : entraînement en visioconférence (Ent_V), entraînement en présentiel (Ent_P) et sans programme d’entraînement (S_Ent). Les adolescents des groupes entraînements ont suivi un programme d’AP composé de 2 séances d’une heure d’AP par semaine pendant 4 mois. Avant (T0) et après la période de quatre mois (T4), les adolescents ont effectué un test sous-maximal d’effort (PWC170) afin d’estimer l’aptitude aérobie. La composition corporelle a été mesurée par une balance impédancemètre. Résultats : Chez le groupe Ent_V, la puissance relative à la masse corporelle développée à 170 Bpm a augmenté à T4 (p=0,007). Aucune différence significative n’a été révélée pour les groupes Ent_P et S_Ent. Concernant l’analyse de la composition corporelle, nous avons noté une stabilisation pour les groupes entraînements. En revanche, la masse corporelle et le pourcentage de masse grasse corporelle ont augmenté significativement entre T0 et T4 pour le groupe S_Ent (respectivement, p = 0,003 et p = 0,006). Conclusion : Un programme d’activité physique de quatre mois réalisés en visioconférence permet de stabiliser le poids corporel et d’améliorer l’aptitude aérobie chez des adolescents en situation d’obésité. Ces résultats préliminaires restent à confirmer avec un nombre plus important de participants.

International audience; Electrochemical lithium (de)intercalation in an atomic layer deposited (ALD) TiO2 anatase thin film deposited on a planar Si /Al2O3/Pt substrate is investigated by Raman spectroscopy. An initial discharge capacity of 63 µAh cm−2 µm−1 (0.5 Li+ mole−1) is reached at C/10 rate, which increases up to 77 µAh cm−2 µm−1 upon further cycles. An excellent capacity retention is achieved over at least 100 cycles, showing the good adherence of the ALD thin film. Raman spectra of LixTiO2 (0 ≤ x ≤ 0.5) thin film electrodes point to the nucleation of the orthorhombic lithiated titanate (LT) Li0.5TiO2 phase from x = 0.1. This LT phase coexists with tetragonal TiO2 in the 0.1 ≤ x ≤ 0.4 composition domain to be pure for x = 0.5. A fully reversible transformation from orthorhombic LT to tetragonal TiO2 is observed upon the charge. The high quality of the Raman spectra allows identifying for the first time 12 modes in the 100–800 cm−1 region for the electrochemically formed LT phase. Furthermore, an appropriate Raman spectra analysis allows a reliable and quantitative determination of the thin film composition during discharge and charge. These results illustrate Raman spectroscopy is a powerful probe to scrutinize the Li insertion/extraction mechanism in TiO2 thin films.

International audience; Hydroxyl groups of several industrial grade lignins are esterified thanks to palladium-catalyzed hydroesterification reactions with CO and olefins, fatty esters or 1,3-butadiene. The reaction is efficient, salt-free and allows introducing aliphatic chains to lignin through ester linkage. Technical and modified lignins are characterized by NMR, IR, SEC and thermal properties are evaluated by DSC. The esterified lignins show modified glass transition temperatures that depend on the substitution degree of the hydroxyl groups and on the nature of the aliphatic chains that have been introduced. The implementation of this catalysis also opens up the possibility of inserting new reactive functionalities such as esters or unsaturations from abundant and/or biobased reactants.

International audience; Supramolecular chemistry based on cyclodextrin receptors as second-sphere ligands contribute to developing non-covalent materials with synergistic functionalities. Herein, we comment on a recent investigation of this concept, describing selective gold recovery through a hierarchical host-guest assembly specifically built from β-CD.

International audience; The capture of gaseous iodine has been deeply studied for trying to mitigate the dangers of nuclear power energy. The UiO family of MOF materials is considered as one of the best candidates for such purpose since it couples high specific surface areas, facility to be chemically modified, great iodine adsorption capacity, and good stability under nuclear accidents conditions. UiO-66 was profoundly evaluated in several works for trapping I2 by using different linkers and metal contents. A transformation of the I2 molecule into I3– inside such porous systems was verified in other studies and is yet to be better elucidated. The comprehension of this transformation can improve the systems used to capture iodine species and guarantee a better stabilization of such pollutants in a long term. For this reason, three UiO-67_NH2 samples with different metal contents (Zr, Zr/Hf, and Hf) were employed to capture iodine and the signature of the different species were evaluated using Raman spectroscopy mappings in and out of resonance conditions (λex = 515, 633 and 785 nm). The UiO-67_NH2(Hf) compound demonstrated the best adsorption capacity after 48 h of contact with gaseous I2 under room temperature, capturing 3428 g.mol-1 of iodine. The other two samples, UiO-67_NH2(Zr/Hf) and UiO-67_NH2(Zr), adsorbed 2835 g.mol-1 and 1658 g.mol-1 in the same conditions, respectively. The I2 transformation into I3– was confirmed by the presence of bands related to “perturbed” I2 and I3– at about 170 and 107 cm-1, respectively. The Raman mapping demonstrated that both the monometallic UiO-67_NH2 samples displayed a homogeneous distribution of the two species after 48 hours of contact with the iodine gas flow, whereas the bimetallic sample exhibited zones with different concentrations of I2 and I3–. This effect was related to the I2 diffusion process through the UiO-67_NH2 crystallites, which could be faster in the monometallic UiO-67_NH2 samples because of their smaller crystal size ( 44 μm and ≈ 51 μm for UiO-67_NH2(Hf) and UiO-67_NH2(Zr), respectively) when compared to the UiO-67_NH2(Zr/Hf) sample (≈ 140 μm). This paper shows the spatial distribution of I2 and I3– along the crystals of UiO-67_NH2 materials and correlates this data with the diffusion process of both species, improving the understanding of the mechanism responsible for the iodine conversion and stabilization in UiO materials; Le captage de l'iode gazeux a été profondément étudié pour tenter de pallier les dangers de l'énergie nucléaire. La famille UiO de matériaux MOF est considérée comme l'un des meilleurs candidats à cet effet car elle couple des surfaces spécifiques élevées, une facilité à être modifiée chimiquement, une grande capacité d'adsorption d'iode et une bonne stabilité dans les conditions d'accidents nucléaires. UiO-66 a été profondément évalué dans plusieurs travaux pour piéger I2 en utilisant différents lieurs et teneurs en métaux. Une transformation de la molécule I2 en I3– à l'intérieur de tels systèmes poreux a été vérifiée dans d'autres études et reste encore à mieux élucider. La compréhension de cette transformation peut améliorer les systèmes utilisés pour capter les espèces iodées et garantir une meilleure stabilisation de ces polluants à long terme. Pour cette raison, trois échantillons UiO-67_NH2 avec différentes teneurs en métal (Zr, Zr/Hf et Hf) ont été utilisés pour capturer l'iode et la signature des différentes espèces a été évaluée à l'aide de cartographies par spectroscopie Raman dans et hors des conditions de résonance (λex = 515, 633 et 785 nm). Le composé UiO-67_NH2(Hf) a démontré la meilleure capacité d'adsorption après 48 h de contact avec de l'I2 gazeux à température ambiante en captant 3428 g.mol-1 d'iode. Les deux autres échantillons, UiO-67_NH2(Zr/Hf) et UiO-67_NH2(Zr), ont respectivement adsorbé 2835 g.mol-1 et 1658 g.mol-1 dans les mêmes conditions. La transformation de I2 en I3– a été confirmée par la présence de bandes liées à I2 et I3– « perturbées » à environ 170 et 107 cm-1, respectivement. La cartographie Raman a démontré que les deux échantillons monométalliques UiO-67_NH2 présentaient une distribution homogène des deux espèces après 48 heures de contact avec le flux de gaz iodé, tandis que l'échantillon bimétallique présentait des zones avec des concentrations différentes en I2 et I3–. Cet effet était lié au processus de diffusion de I2 à travers les cristallites UiO-67_NH2, qui pourrait être plus rapide dans les échantillons monométalliques UiO-67_NH2 en raison de leur taille de cristal plus petite (≈ 44 μm et ≈ 51 μm pour UiO-67_NH2(Hf) et UiO-67_NH2(Zr), respectivement) par rapport à l'échantillon UiO-67_NH2(Zr/Hf) (≈ 140 μm). Cet article montre la distribution spatiale de I2 et I3– le long des cristaux de matériaux UiO-67_NH2 et corrèle ces données avec le processus de diffusion des deux espèces, améliorant la compréhension du mécanisme responsable de la conversion et de la stabilisation de l'iode dans les matériaux UiO.

International audience; The concept of privileged structure has been used as a fruitful approach for the discovery of novel biologically active molecules. A privileged structure is defined as a semi-rigid scaffold able to display substituents in multiple spatial directions and capable of providing potent and selective ligands for different biological targets through the modification of those substituents. On average, these backbones tend to exhibit improved drug-like properties and therefore represent attractive starting points for hit-to-lead optimization programs. This article promotes the rapid, reliable, and efficient synthesis of novel, highly 3-dimensional, and easily functionalized bio-inspired tricyclic spirolactams, as well as an analysis of their drug-like properties.

International audience; The requirements of nanocomposite thin films, having non-aggregated nanoparticles homogeneously dispersed in the matrix, have been realized using a new method of Direct Liquid Reactor-Injector (DLRI) of nanoparticles. In this approach, unlike conventional aerosol-assisted plasma deposition, the nanoparticles are synthesized before their injection as an aerosol into plasma. In our experiments, we have used two different plasma reactors, namely an asymmetric low-pressure RF plasma reactor and a parallel plate dielectric barrier discharge at atmospheric pressure. Our results have shown that DLRI can be easily coupled with various plasma processes as this approach allows the deposition of high-quality multifunctional nanocomposite thin films, with embedded nanoparticles of less than 10 nm in diameter. Hence, DLRI coupled with plasma processes meets the specifications for the deposition of multifunctional coatings.

International audience; We report bulk dilatometry and diffraction data through the T MIT = 427 K metal-insulator transition of the n = 3 member of the V n O 2n-1 Magnéli series. Besides VO 2 , V 3 O 5 is the only other vanadium oxide with a potentially useful MIT transition above room temperature. A narrow (ΔT = 10 K) abrupt negative thermal expansion of α L =-21.4 x 10-6 (dilatometry) and α V =-213 x 10-6 K-1 (crystallographic) is observed. We argue that the combination of the MIT along with the simultaneous vanadium charge ordering are responsible for such large values. The low temperature magnetic properties are also clarified and neutron diffraction measurements show a k = [½ ½ 0] magnetic structure at 1.5 K. DFT calculations of the exchange interactions support the low dimensionality and allow modelling the magnetic susceptibility.

In healthy subjects, at low minute ventilation (V_ E) during physical exercise, the water content and temperature of the airways are well regulated. However, with the increase in V_ E, the bronchial mucosa becomes dehydrated and epithelial damage occurs. Our goal was to demonstrate the correspondence between the ventilatory threshold inducing epithelial damage, measured experimentally, and the dehydration threshold, estimated numerically. In 16 healthy adults, we assessed epithelial damage before and following a 30-min continuous cycling exercise at 70% of maximal work rate, by measuring the variation pre- to postexercise of serum club cell protein (cc16/cr). Blood samples were collected at rest, just at the end of the standardized 10 min warm-up, and immediately, 30 min and 60 min postexercise. Mean V_ E during exercise was kept for analysis. Airway water and heat losses were estimated using a computational model adapted to the experimental conditions and were compared with a literature-based threshold of bronchial dehydration. Eleven participants exceeded the threshold for bronchial dehydration during exercise (group A) and five did not (group B). Compared with post warm-up, the increase in cc16/cr postexercise was significant (mean increase ± SE: 0.48 ± 0.08 ng·L 1 only in group A but not in group B (mean difference ± SE: 0.10 ± 0.04 ng·L 1). This corresponds to an increase of 101 ± 32% [range: 16%–367%] in group A (mean ± SE). Our findings suggest that the use of a computational model may be helpful to estimate an individual dehydration threshold of the airways that is associated with epithelial damage during physical exercise. 132;4

International audience; The use of an extrusion-spheronization process was investigated to prepare robust and highly porous extrudates and granules starting from UiO-66 and UiO-66_NH2 metal–organic framework powders. As-produced materials were applied to the capture of gaseous iodine and the adsorption of xenon and krypton. In this study, biosourced chitosan and hydroxyethyl cellulose (HEC) are used as binders, added in low amounts (less than 5 wt % of the dried solids), as well as a colloidal silica as a co-binder when required. Characterizations of the final shaped materials reveal that most physicochemical properties are retained, except the textural properties, which are impacted by the process and the proportion of binders (BET surface area reduction from 5 to 33%). On the other hand, the mechanical resistance of the shaped materials toward compression is greatly improved by the presence of binders and their respective contents, from 0.5 N for binderless UiO-66 granules to 17 N for UiO-66@HEC granules. UiO-66_NH2-based granules demonstrated consequent iodine capture after 48 h, up to 527 mg/g, in line with the pristine UiO-66_NH2 powder (565 mg/g) and proportionally to the retaining BET surface area (−5% after shaping). Analogously, the shaped materials presented xenon and krypton sorption isotherms correlated to their BET surface area and high predicted xenon/krypton selectivity, from 7.1 to 9.0. Therefore, binder-aided extrusion-spheronization is an adapted method to produce shaped solids with adequate mechanical resistance and retained functional properties.

Growing CO2 emissions lead to global warming, which is currently one of the most challenging environmental phenomena. Direct catalytic hydrogenation to dimethyl ether over hybrid catalysts enables CO2 utilization, hydrogen and energy storage and produces sustainable fuels and an important platform molecule. In this paper, we evaluated structure–performance correlations in the bifunctional hybrid copper–zinc SAPO-34 catalysts for direct synthesis of dimethyl ether via CO2 prepared using zirconia, alumina and ceria used as oxide carriers. Higher copper dispersion and higher CO2 conversion rate were uncovered over the alumina and zirconia supported catalysts followed by ceria supported counterpart. The CO2 hydrogenation seems to be principally favoured by higher copper dispersion and to a lesser extent depends on the concentration of Bronsted acid sites in the studied catalysts. Because of lower reverse water gas-shift activity, the alumina supported catalyst exhibited a higher dimethyl ether yield compared to the zirconia and ceria supported counterparts. 57;5

International audience; Several aryl polycarboxylic ligands (pyromellitic acid, 4,4′-azobenzenedicarboxylic acid and 3,3′,5,5′- azobenzenetetracarboxylic acid) have been used to react with the pentavalent ethoxide niobium(V) precursor Nb(OEt)5. Three new crystalline molecular compounds (1 with pyromellitate, 2 with 4,4′- azobenzenedicarboxylate and 3 with 3,3′,5,5′-azobenzenetetracarboxylate) were isolated from slowcrystallization at room temperature from the mother liquid containing the precursor Nb(OEt)5. They are composed of one polycarboxylate ligand fully coordinated to mononuclear or dinuclear octahedrally- coordinated niobium(V) units. For the dimers, the two adjacent niobium centers are bridged by one μ-O and one μ-OEt groups and complexed by only one of the syn–syn bidentate carboxylate function arms from the polytopic ligand. Compounds 1–3 were characterized in solid state by single-crystal and powder X-ray diffraction analysis. Insight into the formation of the three compounds was supported by the help of infrared and liquid 1H NMR spectroscopy.; Plusieurs ligands aryl polycarboxyliques (acide pyromellitique, acide 4,4′-azobenzènedicarboxylique et acide 3,3′,5,5′-azobenzènetétracarboxylique) ont été utilisés pour réagir avec l'éthoxyde pentavalent niobium(V) précurseur Nb(OEt)5. Trois nouveaux composés moléculaires cristallins (1 avec du pyromellitate, 2 avec du 4,4′-azobenzènedicarboxylate et 3 avec du 3,3′,5,5′-azobenzènetétracarboxylate) ont été isolés à partir decristallisation à température ambiante à partir du liquide mère contenant le précurseur Nb(OEt)5. Ils sont composés d'un ligand polycarboxylate entièrement coordonné à des unités de niobium (V) octaédriquement coordonnées mononucléaires ou dinucléaires. Pour les dimères, les deux centres de niobium adjacents sont pontés par un groupe μ-O et un groupe μ-OEt et complexés par un seul des bras de la fonction carboxylate syn – syn ​​bidentate du ligand polytopique. Les composés 1 à 3 ont été caractérisés à l'état solide par analyse par diffraction des rayons X sur monocristal et sur poudre. La compréhension de la formation des trois composés a été étayée par l'aide de la spectroscopie RMN 1H infrarouge et liquide.

We compared quadriceps oxygenation and surface electromyography (sEMG) responses during the 1-min sit-to-stand (1STS) in 14 people with severe COPD and 12 controls, in whom cardiorespiratory response, near-infrared spectroscopy signals (oxy [Hb-Mb], deoxy [Hb-Mb], total [Hb-Mb], and SmO2) and sEMG signals of the quadriceps were recorded. Time duration of each sit-to-stand cycle and the total work performed during the 1STS were measured. The quadriceps oxygenation parameters were normalized by reporting their values according to the total work during 1STS. The rate of sit-to-stand maneuvers decelerated in people with COPD leading to smaller total work compared with controls. The pattern of quadriceps oxygenation response during 1STS was similar between groups. However, in COPD, the recovery after 1STS was characterized by larger overshoots in oxy [Hb-Mb], total [Hb-Mb], and SmO2. When corrected for the cumulative total work, the increase in muscle O2 extraction (deoxy [Hb-Mb]) during the first 30 s of recovery was greater in people with COPD compared to controls. Quadriceps sEMG changes suggestive of a fatiguing contraction pattern was observed only in people with COPD. All together, these results highlighted physiological misadaptation of people with severe COPD to the 1STS.

International audience; The SCR performance of V2O5-WO3/TiO2 SCR-catalysts characterized by different surface W density (2.1W/nm2 and 9.5W/nm2) and different surface V density varying in the range 1–8V/nm2 has been investigated in order to clarify existing controversies on the preferential involvement of electronic and geometric effects in the catalytic properties. It was found that tungsten has a weak effect on the VOx cluster size distribution through contraction of dilution effect. In contrast, the optimal interaction between W and V, when both reach their highest composition, appears to be a relevant parameter that can enhance their acidic properties and improve the catalytic efficiency in dry conditions. On the other hand, an absence of significant interaction leads to discontinuity due to deactivation. In the presence of steam, acidic properties are averaged, lowering the impact of the V to W ratio. Finally, the critical importance of acidic properties which outperform redox properties in the definition of active site is pointed out in the light of this study.

Global pollution by plastics derived from petroleum has fostered the development of carbon–neutral, biodegradable bioplastics synthesized from renewable resources such as modern biomass, yet knowledge on the impact of bioplastics on ecosystems is limited. Here we review the polylactic acid plastic with focus on synthesis, biodegradability tuning, environmental conversion to microplastics, and impact on microbes, algae, phytoplankton, zooplankton, annelids, mollusk and fish. Polylactic acid is a low weight semi-crystalline bioplastic used in agriculture, medicine, packaging and textile. Polylactic acid is one of the most widely used biopolymers, accounting for 33% of all bioplastics produced in 2021. Although biodegradable in vivo, polylactic acid is not completely degradable under natural environmental conditions, notably under aquatic conditions. Polylactic acid disintegrates into microplastics faster than petroleum-based plastics and may pose severe threats to the exposed biota.

Numerous studies expose the potential of brannerite to become a good matrix, concentrating fission products and actinides. Minerals can complement the data collected from the synthetic materials and offer an advantage of a long-time exposure to radiation. Natural metamict brannerite from Akchatau, Kazakhstan, and its annealed sample were studied by EPMA, Raman spectroscopy, TGA, DSC, XRD and HTXRD. The radioactivity of pristine and annealed samples of brannerite was measured. Brannerite from Akchatau is characterized by the absence of significant amounts of REE and yttrium. The studied brannerite regains its structure at a temperature ~650 °C, revealed by the HTXRD and DSC. HTXRD was also performed on the annealed recrystallized brannerite. The thermal expansion for brannerite has been determined for the first time. The brannerite structure expands anisotropically with temperature increase. All the thermal expansion coefficients are positive except for αβ. The decreasing beta parameter indicates a “shear structural deformation“. The angle between the 1st axis of the tensor and the crystallographic a axis decreases with the increase of the temperature. The structure expands mostly in the α11 direction, approaching the bisector of the β angle. Brannerite has a low CTE at room temperature—αv = 16 × 10−6 °C−1, which increases up to 39.4 × 10−6 °C−1 at 1100 °C. In general, the thermal stability of brannerite is comparable to that of the other perspective oxide radioactive waste-immobilizing matrices (e.g., Ln2Zr2O7, CePO4, CaTiO3, CaZrTi2O7). The calculated thermal expansion of brannerite and the understanding of its underlying crystal chemical mechanisms may contribute to the behavior prediction of the material (both metamict and crystalline) at high temperatures.

Type 2 diabetes (T2D) is a metabolic disorder characterized by loss of pancreatic β- cell function, decreased insulin secretion and increased insulin resistance, that affects more than 400 million people worldwide. Although several treatments are proposed to patients suffering from T2D, long-term control of glycemia remains a challenge. Therefore, identifying new potential drugs and targets that positively affect β-cell function and insulin secretion remains crucial. Here, we developed an automated approach to allow the identification of new compounds or genes potentially involved in β-cell function in a 384-well plate format, using the murine β-cell model Min6. Using MALDI-TOF mass spectrometry, we have implemented a high-throughput screening (HTS) strategy based on the automation of a cellular assay allowing to detect insulin secretion in response to glucose, quantitative detection of insulin, in a miniaturized system. As a proof of concept, we screened siRNA targeting well-know β-cell genes and 1600 chemical compounds and identified several molecules as potential regulators of insulin secretion and/or synthesis, demonstrating that our approach allows HTS of insulin secretionin vitro.

The synthesis of methanol and dimethyl ether (DME) from carbon dioxide (CO2) and green hydrogen (H2) offers a sustainable pathway to convert CO2 emissions into value-added products. This heterogeneous catalytic reaction often uses copper (Cu) catalysts due to their low cost compared with their noble metal analogs. Nevertheless, improving the activity and selectivity of these Cu catalysts for these products is highly desirable. In the present study, a new architecture of Cu- and Cu/Zn-based catalysts supported on electrospun alumina nanofibers were synthesized. The catalysts were tested under various reaction conditions using high-throughput equipment to highlight the role of the hierarchical fibrous structure on the reaction activity and selectivity. The Cu or Cu/ZnO formed a unique structure of nanosheets, covering the alumina fiber surface. This exceptional morphology provides a large surface area, up to ~300 m2/g, accessible for reaction. Maximal production of methanol (~1106 gmethanolKgCu−1∙h−1) and DME (760 gDMEKgCu−1∙h−1) were obtained for catalysts containing 7% wt. Cu/Zn with a weight ratio of 2.3 Zn to Cu (at 300 °C, 50 bar). The promising results in CO2 hydrogenation to methanol and DME obtained here point out the significant advantage of nanofiber-based catalysts in heterogeneous catalysis.

International audience; In this work, surface properties evaluated by catalytic conversion of isopropanol and by ammonia Temperature Programmed Reduction (NH3-TPD) over ferrite spinel nanoparticles was investigated. Bulk NiFe2O4 with specific surface area 114 m2/g and crystallites size 6 nm was prepared by hydrothermal synthesis using nitrates as precursors. X-ray diffraction (XRD), Raman spectroscopy, specific surface area by B.E.T, Scanning Electron Microscopy (SEM) and X-ray energy dispersive microanalysis (EDS), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS) techniques were used for their structural and textural characterizations. The reducibility by hydrogen at variable temperatures was investigated by Temperature Programmed reduction (H2-TPR) and Thermal Gravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC). The total acidity and acid strength distribution was determined by NH3-TPD. The synthesized oxide showed the presence of mixed phases containing the inverse spinel structure NiFe2O4 as the major phase and iron oxide α- Fe2O3 as an additional phase. It was shown that the surface of the powder was richer in Ni2+ species. The surface acidity (Brönsted and Lewis) determined by NH3-TPD showed that the number of acidic sites increased dramatically with the temperature. The catalytic conversion of isopropanol yields both acidic and redox/basic sites were available. A good correlation between textural, structural, redox and acid-base properties of catalyst is established.; Dans ce travail, les propriétés de surface évaluées par conversion catalytique de l'isopropanol et par réduction programmée en température de l'ammoniac (NH3-TPD) sur des nanoparticules de ferrite spinelle ont été étudiées. Le NiFe2O4 massif avec une surface spécifique de 114 m2/g et des cristallites de 6 nm a été préparé par synthèse hydrothermale en utilisant des nitrates comme précurseurs. La diffraction des rayons X (XRD), la spectroscopie Raman, la surface spécifique par B.E.T, la microscopie électronique à balayage (SEM) et la microanalyse dispersive en énergie (EDS), la microscopie électronique à transmission (TEM) et la spectroscopie photoélectronique à rayons X (XPS) ont été utilisées pour leurs caractérisations structurelles et texturales. La réductibilité par l'hydrogène à des températures variables a été étudiée par réduction programmée en température (H2-TPR) et par analyse thermogravimétrique et calorimétrie à balayage différentiel (TGA-DSC). L'acidité totale et la distribution de la force acide ont été déterminées par NH3-TPD. L'oxyde synthétisé a montré la présence de phases mixtes contenant la structure spinelle inverse NiFe2O4 comme phase principale et l'oxyde de fer α- Fe2O3 comme phase supplémentaire. Il a été montré que la surface de la poudre était plus riche en espèces Ni2+. L'acidité de surface (Brönsted et Lewis) déterminée par NH3-TPD a montré que le nombre de sites acides augmentait considérablement avec la température. La conversion catalytique de l'isopropanol donne lieu à la présence de sites acides et de sites redox/basiques. Une bonne corrélation entre les propriétés texturales, structurelles, redox et acide-base du catalyseur est établie.

ObjectivesThe aim of this study was to evaluate the effects of a home-based pulmonary rehabilitation (PR) programme on anxiety and depressive symptoms, general fatigue and burden in informal caregivers of patients with COPD. We also evaluated the baseline characteristics of both patients and caregivers that contributed to the change in caregiver's outcomes after PR.MethodsIn this retrospective study, patients with COPD were referred to an 8-week home-based PR programme consisting of a weekly supervised 90-min session. Informal caregivers were invited to participate in PR according to the patient's preference and its availability. Caregivers received educational support, behavioural therapies and self-management strategies using the same methods as for patients. Burden, anxiety and depressive symptoms, and general fatigue of caregivers were assessed at baseline and at the end of PR.Results241 patients with COPD and 138 (57.3%) caregivers were included. The majority of the caregivers were women (70.5%) and spouses (90.3%) and had at least three comorbidities (57.3%). A large proportion of caregivers showed baseline high burden, anxiety symptoms and abnormal fatigue (40%, 40% and 45%, respectively). Burden, anxiety and depressive symptoms, and general fatigue of informal caregivers were all improved after PR (pConclusionA large proportion of caregivers of patients with COPD showed anxiety symptoms, fatigue and a high burden. These outcomes were improved by integrating the caregiver into a home-based PR programme.

International audience

International audience; Controlled traffic farming (CTF) is used to confine soil compaction to the least possible area of the field, thereby achieving economic and environmental benefits. In the context of climate change, soil erosion is one of the most discussed topics, and there is a research gap in understanding the effects of CTF on soil erosion in Central Europe. The aim of this work was to show the potential of CTF to reduce water erosion, in terms of water runoff and soil loss on steep land. A 16 ha experimental field with a CTF technology implemented since 2009 at the Slovak University of Agriculture was used in this research. Three traffic intensity locations were selected and watered using a rainfall simulator. The results showed that the soil which had not been wheeled for 12 years had the lowest water runoff: its intensity after 20 min of simulated rain was 10 times lower compared to the multiple traffic treatment. The soil loss, expressed as the total soil sediments collected after 35 min, in the no traffic area was lower by 70%, compared to the soil with one-pass treatment and only 25% of the loss in the multiple traffic areas. These results show that CTF can significantly reduce soil loss through water runoff on steep land.

International audience; Purpose:Providing students with enjoyable experiences in Physical Education (PE) is considered a key variable in research on increasing Physical Activity (PA) levels. Designing game formats in PE is relevant to achieving this aim. Coupling principles of Motor Praxeology (MP) and the Constraints Led Approach (CLA) to design three games, the aim of this study was to examine how participants’ sex, age and skill levels (organismic constraints) interacted with varied manipulations of task and environmental constraints in the organisational design of badminton games to increase their enjoyment and PA.Method:Participants were students (n = 55, Mage = 14.0, SD = 2.41, 41.8% girls, aged 11–19) enrolled in a PE unit with three distinct badminton organisational designs for games: Individual Tournament (IT), Team Score (TS) and Personal Challenge (PC). IT challenges students in a group of a homogeneous skill level with a one-on-one competition. TS consists of a series of one-on-one games amongst a group of students with a heterogeneous skill level. PC is a competition between students in a heterogenous-level group, adopting a handicap score system. Enjoyment and level of PA was measured using a pleasure scale and accelerometers.Results:Results indicated little effect of organisational design on pupils’ enjoyment but showed a difference in their PA: younger and skilled boys moved less in the PC design compared to the TS organisational design.Discussion/conclusion:Our results suggest that potential interactions between the format of the organisational design and individual differences in students could be relevant for increasing PA in PE programmes. In exploring the effects of interactions of organisational designs for games, goal tasks and students’ characteristics, a combination of MP and CLA frameworks helps to address some of the prevailing beliefs about pleasure and the commitment made by students in common physical education play and activity formats. Our study showed that there is no ideal organisational design for engaging students, but that the most fruitful formats depend on the specific interests of the students.Practical implications:These theoretical frameworks invite PE teachers to develop organisational designs by providing interaction between goal-oriented tasks and social variables (e.g. relationships between players) to provoke richer experiences in all students from different skill levels.

International audience; The effect of the Co-Cu oxide catalysts composition on their physicochemical properties and performance in the deep oxidation of ethanol was studied. The catalysts with Co:Cu molar ratios of 4:1, 1:1, and 1:4 were obtained by calcination (4 h at 500 °C in air) of the coprecipitated precursors and characterized in detail using powder XRD, Raman spectroscopy, N2 physisorption, H2-TPR, and XPS. The powder XRD and Raman spectroscopy indicated the formation of Co3O4 and CuO mixtures rather than Co-Cu mixed oxides. The CuO promoted the Co3O4 reduction; the Co-Cu catalysts were reduced more easily than the single-component Co and Cu oxides and the main reduction maxima were shifted to lower temperatures with increasing cobalt content in the catalysts. The Co-Cu oxide catalyst with a Co:Cu molar ratio of 4:1 exhibited the best performance in ethanol gas-phase oxidation, showing the lowest T50 (91 °C) and T90(CO2) (159 °C) temperatures needed for 50% ethanol conversion and 90% conversion to CO2, respectively. The excellent catalytic properties of this Co-Cu oxide catalyst were ascribed to the synergistic effect of Co and Cu components. The high activity and selectivity of the Co-Cu catalyst was attributed to the presence of finely dispersed CuO particles on the surface of Co3O4.; L'effet de la composition des catalyseurs à base d'oxyde de Co-Cu sur leurs propriétés physicochimiques et leur performance dans l'oxydation profonde de l'éthanol a été étudié. Les catalyseurs avec des rapports molaires Co:Cu de 4:1, 1:1 et 1:4 ont été obtenus par calcination (4 h à 500 °C dans l'air) des précurseurs coprécipités et caractérisés en détail à l'aide de la XRD des poudres, de la spectroscopie Raman, de la physisorption de N2, de la H2-TPR et de la XPS. La DRX des poudres et la spectroscopie Raman ont indiqué la formation de mélanges de Co3O4 et de CuO plutôt que d'oxydes mixtes Co-Cu. Le CuO a favorisé la réduction du Co3O4 ; les catalyseurs Co-Cu ont été réduits plus facilement que les oxydes de Co et de Cu à composant unique et les principaux maxima de réduction ont été déplacés vers des températures plus basses avec l'augmentation de la teneur en cobalt dans les catalyseurs. Le catalyseur à base d'oxyde de Co-Cu avec un rapport molaire Co:Cu de 4:1 a présenté les meilleures performances dans l'oxydation de l'éthanol en phase gazeuse, affichant les températures T50 (91 °C) et T90(CO2) (159 °C) les plus basses nécessaires à la conversion de 50 % de l'éthanol et à la conversion de 90 % en CO2, respectivement. Les excellentes propriétés catalytiques de ce catalyseur à base d'oxyde de Co-Cu ont été attribuées à l'effet synergique des composants Co et Cu. L'activité et la sélectivité élevées du catalyseur Co-Cu ont été attribuées à la présence de particules de CuO finement dispersées à la surface du Co3O4.

International audience; Tailoring boron–polysaccharide interactions is an important strategy for developing functional soft materials such as hydrogels, fire retardants, and sorbents for environmental remediation, for example, using lignocellulosic biomass. For such applications to be realized, it is paramount to understand the adsorption kinetics of borate anions on cellulose and their local structures. Here, the kinetic aspects of boron adsorption by microcrystalline cellulose, lignin, and polymeric resin are investigated and compared. Borate anions interact with the vicinal diols in the glucopyranoside moieties of cellulose to yield chemisorbed boron chelate complexes. In contrast to cellulose, technical lignin contains fewer cis-vicinal diols, and it does not have a tendency to form such chelate complexes upon treatment with the aqueous boric acid solution. The formation kinetics and stability of these chelate complexes strongly depend on nanoscale structures, as well as reaction conditions such as pH and concentration of the sorbate and sorbent. Specifically, insights into the distinct boron adsorption sites were obtained by solid-state one-dimensional (1D) 11B magic-angle spinning NMR and the local structures and intermolecular interactions in the vicinities of boron chelate complexes are elucidated by analyzing two-dimensional (2D) 1H–13C and 11B–1H heteronuclear correlation NMR spectra. The total boron adsorption capacity of cellulose is estimated to be in the 1.3–3.0 mg range per gram of sorbent, which is lower than the boron adsorption capacity of a polystyrene-based resin, ∼17.2 mg of boron per gram of Amberlite IRA 743. Our study demonstrates that the local backbone and side chain flexibility as well as the structures of polyol groups play a significant role in determining the kinetic and thermodynamic stability of chelate complexes, yielding to different boron adsorption capabilities of lignocellulosic polymers.

International audience; Phosphate tungsten and molybenum bronzes represent an outstanding class of materials displaying textbook examples of charge-density-wave (CDW) physics among other fundamental properties. Here we report on the existence of a novel structural branch with the general formula [Ba(PO4)2][WmO3m−3] (m=3, 4 and 5) denominated ′layered monophosphate tungsten bronzes′ (L-MPTB). It results from thick [Ba(PO4)2]4− spacer layers disrupting the cationic metal-oxide 2D units and enforcing an overall trigonal structure. Their symmetries are preserved down to 1.8 K and the compounds show metallic behaviour with no clear anomaly as a function of temperature. However, their electronic structure displays the characteristic Fermi surface of previous bronzes derived from 5d W states with hidden nesting properties. By analogy with previous bronzes, such a Fermi surface should result into CDW order. Evidence of CDW order was only indirectly observed in the low-temperature specific heat, giving an exotic context at the crossover between stable 2D metals and CDW order.

International audience; The conversion of biomass as a sustainable path to access valuable chemicals and fuels is very attractive for the chemical industry, but catalytic conversions still often rely on the use of noble metals. Sustainability constraints require developing alternative catalysts from abundant and low-cost metals. In this context, NiFe nanoparticles are interesting candidates. In their reduced and supported form, they have been reported to be more active and selective than monometallic Ni in the hydrogenation of the polar functions of organic molecules, and the two metals are very abundant. However, unlike noble metals, Ni and Fe are easily oxidized in ambient conditions, and understanding their transformation in both oxidative and reductive atmospheres is an important though seldom investigated issue to be addressed before their application in catalysis. Three types of NiFe nanoparticles were prepared by an organometallic approach to ensure the formation of ultrasmall nanoparticles (

Application of nanocomposites in daily life requires not only small nanoparticles (NPs) well dispersed in a matrix, but also a manufacturing process that is mindful of the operator and the environment. Avoiding any exposure to NPs is one such way, and direct liquid reaction-injection (DLRI) aims to fulfill this need. DLRI is based on the controlled in situ synthesis of NPs from the decomposition of suitable organometallic precursors in conditions that are compatible with a pulsed injection mode of an aerosol into a downstream process. Coupled with low-pressure plasma, DLRI produces nanocomposite with homogeneously well-dispersed small nanoparticles that in the particular case of ZnO-DLC nanocomposite exhibit unique properties. DLRI favorably compares with the direct liquid injection of ex situ formed NPs. The exothermic hydrolysis reaction of the organometallic precursor at the droplet-gas interface leads to the injection of small and highly dispersed NPs and, consequently, the deposition of fine and controlled distribution in the nanocomposite. The scope of DLRI nanosynthesis has been extended to several metal oxides such as zinc, tin, tungsten, and copper to generalize the concept. Hence, DLRI is an attractive method to synthesize, inject, and deposit nanoparticles and meets the prevention and atom economy requirements of green chemistry.

The potential use of down-sized BFO-xSTO systems (x ≤ 25%) as highly efficient photoanodes for photocatalytic water splitting is investigated. BFO-xSTO is prepared by a solid-state method and subsequently deposited by spray coating. The compounds possess rhombohedral symmetry for x ≤ 15% and phase coexistence for x > 15%, as demonstrated by Raman spectroscopy and transmission electron microscopy. Our findings revealed a drastic grain size decrease with increasing STO content, namely 260 nm for BFO to 50 nm for BFO with 25% STO. Moreover, BFO-xSTO, x > 10% exhibited high optical absorption (> 80%) in the full spectrum and interestingly a very promising band alignment with water redox potentials. Moreover, the photochemical measurements revealed a photocurrent density of ~0.17 μA cm−2 achieved for x = 15% at 0 bias. Using DFT calculations, the substitution effects on the electronic, optical, and photocatalytic performances of the BFO system were investigated and quantified. Surprisingly, a high hydrogen yield (~191 μmol g−1) was achieved by BFO-12.5%STO compared to 1 μmol g−1 and 57 μmol g−1 for BFO and STO, respectively. This result highlights the beneficial effects of both the downsizing and substitution of BFO on the photocatalytic water splitting and hydrogen production performances of Bi1−xSrxFe1−xTixO3 systems.

International audience; Ternary Co3Mo3N nitrides are reported to exhibit high catalytic activity in ammonia synthesis. However, synthesis of ternary nitrides requires thermal treatments at elevated temperatures and reactive atmospheres that lead to unavoidable surface reduction (~ 10 m2 g-1). In this work, we have developed a novel approach to improve the catalytic activity of Co3Mo3N through its dispersion into a high surface area silica-based support (SBA-15). During ammonolysis and ammonia synthesis conditions reaction, SBA-15 demonstrated good thermal and chemical stability maintaining an ordered porous structure and high surface area (> 500 m2 g-1). For application in ammonia synthesis, SBA-15 supported cobalt molybdenum catalysts with different metal loading (10, 20 and 30 wt.%) were prepared by a modified impregnation-infiltration protocol and their catalytic activity studied. The dispersion of CoMo nitride nanoparticles into SBA-15 structures resulted in the improvement of their structural and textural properties of nitrides as evidenced by XRD analysis, STEM-EDS, and N2- physisorption (e.g. 10-CoMo-N/SBA-15: 348 m2 g-1). Nevertheless, the surface composition of CoMo-N/SBA-15 catalysts was found to be similar to the non-supported Co3Mo3N. Furthermore, supported CoMo-N/SBA-15 displayed enhanced catalytic activity in ammonia synthesis (1714, 1429 and 810 μmol gactive phase-1 h-1 corresponding to the CoMo oxide loadings of 10, 20, 30 wt.% respectively) that outperform the classical Co3Mo3N catalyst (298 μmol gcatalyst-1 h-1). The results reported in this work highlights a novel approach for the design of nitride-based catalysts with superior catalytic properties in ammonia synthesis.; Les nitrures ternaires de Co3Mo3N présentent une activité catalytique élevée dans la synthèse d'ammoniac. Cependant, la synthèse de nitrures ternaires nécessite des traitements thermiques à des températures élevées et des atmosphères réactives qui conduisent à une réduction de surface inévitable (~ 10 m2 g-1). Dans ce travail, nous avons développé une nouvelle approche pour améliorer l'activité catalytique du Co3Mo3N grâce à sa dispersion dans un support à base de silice à surface élevée (SBA-15). Au cours de la réaction dans les conditions d'ammonolyse et de synthèse d'ammoniac, le SBA-15 a démontré une bonne stabilité thermique et chimique en maintenant une structure poreuse ordonnée et une surface spécifique élevée (> 500 m2 g-1). Pour une application dans la synthèse d'ammoniac, des catalyseurs au cobalt-molybdène sur support SBA-15 avec différentes charges métalliques (10, 20 et 30 % en poids) ont été préparés par un protocole d'imprégnation-infiltration modifié et leur activité catalytique étudiée. La dispersion des nanoparticules de nitrure de CoMo dans les structures SBA-15 a entraîné l'amélioration de leurs propriétés structurelles et texturales des nitrures, comme en témoignent l'analyse XRD, le STEM-EDS et la physisorption N2 (par exemple 10-CoMo-N/SBA-15 : 348 m2 g-1). Néanmoins, la composition de surface des catalyseurs CoMo-N/SBA-15 s'est avérée similaire à celle du Co3Mo3N non supporté. De plus, le CoMo-N/SBA-15 supporté a affiché une activité catalytique améliorée dans la synthèse d'ammoniac (1714, 1429 et 810 μmol gactive phase-1 h-1 correspondant aux charges d'oxyde CoMo de 10, 20, 30 % en poids respectivement) qui surpassent le catalyseur classique Co3Mo3N (298 μmol gcatalyst-1 h-1). Les résultats rapportés dans ce travail mettent en évidence une nouvelle approche pour la conception de catalyseurs à base de nitrure avec des propriétés catalytiques supérieures dans la synthèse d'ammoniac.