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SSCI-VIDE+ATARI+VFO:GPO:AAU; National audience; L’acroléine est très utilisée par l’industrie chimique. Sa forte réactivité en fait un intermédiaire de choix pour de nombreuses synthèses telles que la méthionine, l’acide acrylique ou les biocides. Majoritairement obtenue par oxydation du propylène, de nombreux nouveaux procédés de synthèse de l’acroléine utilisant la biomasse sont en cours de développement. Un de ces procédés innovants est le couplage oxydant d’un mélange d’alcools. Cette réaction est composée de deux étapes. La première implique l’oxydation d’un mélange de méthanol et d’éthanol en formaldéhyde et acétaldéhyde suivie par une aldolisation croisée des aldéhydes puis une déshydratation en acroléine.Le but de ce travail est de produire de l’acroléine à partir d’alcools en une seule étape grâce au développement de catalyseurs présentant un équilibre judicieux entre sites acides et basiques. Afin d’accroître la sélectivité envers l’acroléine sans pour autant produire trop de CO+CO2, des spinelles Mg-Al et modifiés par l’ajout de métaux (Fe, Zn, Cu, Co, Mn) ont été étudiés. Les propriétés acido-basiques ont été déterminées par microcalorimétrie d’adsorption de SO2 et NH3 afin d’obtenir le nombre, la force et la distribution de force des sites.La figure 1 présente les chaleurs différentielles d’adsorption de SO2 et NH3 en fonction du volume adsorbé de molécule sonde pour les spinelles dont le rapport Al/Mg varie de 1 à 12. Les réactions catalytiques ont été menées en présence d’oxygène en vue de comprendre comment les propriétés acido-basiques peuvent influencer la production et la sélectivité en acroléine.Le spinelle avec ajout de Mn montre les meilleurs rendement et sélectivité (30 et 39%) à 215 °C, avec une VVH de 5000 h-1 et une production de CO+CO2 de 9%. Cependant, une plus haute température favorise les réactions d’oxydation limitant la possibilité d’améliorer la production d’acroléine en augmentant la température. Pour les spinelles dont le ratio Al/Mg varie, 1Al2O3 1MgO est le meilleur catalyseur avec 27% de rendement en acroléine. Le ratio alumine/magnésie ne semble pas avoir d’influence sur la production d’acroléine et assez peu sur l’acidité. Le rôle et l’influence de la coopération entre sites acides et basiques sur la production d’acroléine sera discuté.

SSCI-VIDE+ATARI+VFO:GPO:AAU; International audience; Acrolein is widely used in the chemical industry. Its high reactivity, due to the conjugation of carbonyl and vinyl groups, makes it a very good intermediate for numerous syntheses such as methionine, acrylic acid or biocides. Nowadays, acrolein is obtained by oxidation of propylene. Recently, due to the need of reducing greenhouse gas emission and finding more environmental friendly methods of production, new processes have been developed to produce acrolein starting from renewable resources [1-2]. One of these promising ways is the oxidative coupling of biosourced alcohols. In this two-step process, the first stage involves the oxidation of a mixture of methanol and ethanol to formaldehyde and acetaldehyde which is directly followed by an aldolisation and dehydration of aldehydes to get acrolein [3-4].The aim of the present research is to produce acrolein in a single step from alcohols (methanol/ethanol) thanks to the development of catalysts with a good balance between acidic and basic sites. In order to increase selectivity in acrolein without formation of too much CO+CO2, catalysts based on mixed oxides with various Mg/Al ratios and modified spinels with various guest metals (Fe, Zn, Cu, Co, Mn) were investigated (table 1). The basic and acidic properties of the catalysts have been monitored by adsorption microcalorimetry of SO2 and NH3 respectively, to obtain the concentration, strength and strength distribution of the active sites. Then, catalytic reaction has been performed in presence of oxygen to study how the acidic and basic properties can influence the activity and selectivity towards acrolein. Among spinels, manganese spinel shows the best acrolein yield and selectivity (respectively 30 and 39%) at 215°C and 5000 h-1 of GHSV and CO+CO2 production of 9%. However, at higher temperature, side oxidation reaction was promoted, increasing CO+CO2 production and limiting the possibility to increase the temperature to improve acrolein yield. Iron spinel is the second best catalyst with 26% yield of acrolein but 19% of CO+CO2 production. Copper and cobalt spinels appear to only promote side oxidation reaction transforming products and reactants in CO+CO2. For Mg-Al samples, 1Al2O3 1MgO is the best catalyst with 27% yield of acrolein. The ratio of alumina to magnesia seems to have no impact on the acrolein production. The role and the influence of the cooperation between acidic and basic sites on the acrolein production will be discussed. [1] W.G. Etzkorn “Acrolein and Derivatives” in Kirk-Othmer Encyclopedia of Chemical Technology, 2009, 1[2] R.K. Grasselli, Top. Catal., 2002, 21, 79[3] A. Lilić, S. Bennici, J.-F. Devaux, J.-L. Dubois, A. Auroux, ChemSusChem 2017, 10, 1916. [4] A. Lilić, T. Wei, S. Bennici, J.-F. Devaux, J.-L. Dubois, A. Auroux, ChemSusChem 2017, 10, 3459.

National audience; Les projets impliquant l'ingénierie écologique sont, la plupart du temps, mono-objectifs, alors que répondre à plusieurs finalités est souvent la vocation et la plus-value de l'ingénierie écologique. Cet ouvrage à destination des décideurs de la gestion de l'eau et des milieux aquatiques, met en évidence, pour les projets d'ingénierie écologique appliqués aux milieux aquatiques, les bénéfices ainsi que les bénéficiaires associés, en mettant l'accent sur le caractère multi-bénéfices de ces projets. En effet, les actions d'ingénierie écologique peuvent engendrer divers bénéfices, c'est-à-dire des gains, des profits ou des avantages d'ordres écologique, social ou économique. Elles sont multifonctionnelles et génèrent ainsi plusieurs bénéfices d'ampleurs différentes pour plusieurs bénéficiaires. Lors de la conception d'un projet d'ingénierie écologique, l'identification des bénéfices (et des inconvénients) qui pourront être développés par la solution préconisée, qu'ils soient écologiques, sociaux ou économiques, est importante. Ces bénéfices peuvent être qualitatifs ou quantitatifs. Ils peuvent également être évalués monétairement ou non. L'identification des bénéficiaires potentiels d'un projet passe par une identification des changements de fonctionnement du milieu, à l'origine des préjudices subis par des personnes. L'identification, la caractérisation et la priorisation des bénéficiaires peut permettre de définir le ou les plus importants pour les décideurs. La présentation de 17 retours d'expériences vient illustrer quatre sous-chapitres de cet ouvrage dont l'objet est de mettre en avant le caractère multi-bénéfices des projets d'ingénierie écologique à travers quatre grands types d'actions, correspondant chacun à un domaine d'application de l'ingénierie écologique : la restauration du lit d'un cours d'eau et la lutte contre les inondations, la gestion des eaux pluviales en milieu urbain et péri-urbain, l'amélioration de la qualité de l'eau des milieux aquatiques à l'interface péri-urbain/agricole, la création d'habitats en zone portuaire le long des petits fonds côtiers.

International audience; Context. The so-called Hα third emission occurs around pulsation phase ϕ = 0.30. It has been observed for the first time in 2011 in some RR Lyrae stars. The emission intensity is very weak, and its profile is a tiny persistent hump in the red side-line profile.Aims. We report the first observation of the Hα third emission in RR Lyr itself (HD 182989), the brightest RR Lyrae star in the sky.Methods. New spectra were collected in 2013−2014 with the AURELIE spectrograph (resolving power R = 22 700, T152, Observatoire de Haute-Provence, France) and in 2016−2017 with the eShel spectrograph (R = 11 000, T035, Observatoire de Chelles, France). In addition, observations obtained in 1997 with the ELODIE spectrograph (R = 42 000, T193, Observatoire de Haute-Provence, France) were reanalyzed.Results. The Hα third emission is clearly detected in the pulsation phase interval ϕ = 0.188−0.407, that is, during about 20% of the period. Its maximum flux with respect to the continuum is about 13%. The presence of this third emission and its strength both seem to depend only marginally on the Blazhko phase. The physical origin of the emission is probably due to the infalling motion of the highest atmospheric layers, which compresses and heats the gas that is located immediately above the rising shock wave. The infalling velocity of the hot compressed region is supersonic, almost 50 km s-1, while the shock velocity may be much lower in these pulsation phases.Conclusions. When the Hα third emission appears, the shock is certainly no longer radiative because its intensity is not sufficient to produce a blueshifted emission component within the Hα profile. At phase ϕ = 0.40, the shock wave is certainly close to its complete dissipation in the atmosphere.

The chronic inflammatory neuropathies (CINs) are rare, very disabling autoimmune disorders that generally respond well to immune therapies such as intravenous immunoglobulin (IVIg). The most common forms of CIN are chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy, and polyneuropathy associated with monoclonal gammopathy of unknown significance. The field of CIN has undergone a major advance with the identification of IgG4 autoantibodies directed against paranodal proteins in patients with CIDP. Although these autoantibodies are only found in a small subset of patients with CIDP, they can be used to guide therapeutic decision-making, as these patients have a poor response to IVIg. These observations provide proof of concept that identifying the target antigens in tissue-specific antibody-mediated autoimmune diseases is important, not only to understand their underlying pathogenic mechanisms, but also to correctly diagnose and treat affected patients. This state-of-the-art Review focuses on the role of autoantibodies against nodes of Ranvier in CIDP, a clinically relevant emerging field of research. The role of autoantibodies in other immune-mediated neuropathies, including other forms of CIN, primary autoimmune neuropathies, neoplasms, and systemic diseases that resemble CIN, are also discussed.

SSCI-VIDE+ATARI+ALI:SBE:AAU; International audience; n the third decade of the past century, acrolein, a key intermediate in the synthesis of two important commodity chemicals, namely acrylic acid and methionine, was industrially produced by aldolisation of acetaldehyde and formaldehyde. Later, another synthetic way based on propylene oxidation was applied and largely studied. More recently, due to the raw materials diversification and the need to decrease the greenhouse gas emissions, new processes starting from renewable feedstock have been considered [1,2].With the aim of minimizing the investment on the existing plants, the oxidation of biosourced alcohols is a promising way to produce acrolein when compared to glycerol dehydration. In this work, the oxidation of a mixture of methanol and ethanol to formaldehyde and acetaldehyde on FeMoOx and simultaneous aldol-condensation and dehydration to acrolein on Na,K,Ca,Mg/SiO2, was carried out; while most of research works published previously, were considering each reaction individually.In the present study, a series of oxide catalysts obtained by deposition of basic oxides (Na2O, K2O, MgO, CaO) on a silica support has been considered in the oxidative coupling of alcohols to produce acrolein. The addition of different guest oxides of the first and second group of the periodic table, allowed to tune the acidity and basicity of the catalyst surface.The basic and acidic properties of the catalysts have been investigated respectively by sulphur dioxide and ammonia adsorption calorimetry in order to obtain the number, strength and strength distribution of the active sites. Finally, the catalytic reaction has been performed with the aim to verify how in oxidizing conditions the acid/base properties can impact the activity and selectivity towards acrolein.Good performances were obtained for Na/SiO2 catalyst with 25% acrolein yield and 10% CO+CO2 yield. K/SiO2 and Ca/SiO2 showed the lower acrolein production; they promoted side oxidation reactions that overoxidized acrolein (or reactants) into CO and CO2, due to the presence of oxygen. At 5000 h-1 GHSV and a temperature of 280 °C for K/SiO2 and of 320 °C for Ca/SiO2, the CO+CO2 yields were already higher than 10 mol%, thus limiting the possibility to further increase the reaction temperature to enhance acetaldehyde conversion and acrolein selectivity.Mg/SiO2 presented the best results (at 320 °C and 5000 h-1 GHSV) with 29% and 38% of acrolein yield and selectivity, respectively, and a CO+CO2 yield of 7% (see Figure). The presence of both acid and basic sites seems to increase the selectivity towards acrolein.References1. JL Dubois, C. Duquenne, W. Hölderich, J Kervennal, Patent US7655818 BB, Arkema France,20062. D. Stosic, S. Bennici, J.-L. Couturier, J.-L. Dubois, A. Auroux, Catal. Commun. 17 (2012) 23-28.Acknowledgements: the present research has received support from ADEME BIOMA+.

SSCI-VIDE+ATARI+ALI:SBE:AAU; National audience; Acrolein, the simplest unsaturated aldehyde, is widely used in chemical industry as intermediate for the synthesis of various widely used chemical products as biocides, acrylic acid, methionine and other numerous chemicals [1,2]. With the aim to find renewable materials easy to transform into acrolein, minimizing the investment on the existing plants, the oxidation of biosourced alcohols has been recently proposed. In this process, the oxidation of methanol and ethanol to formaldehyde and acetaldehyde and the aldol-condensation and dehydration of the two aldehydes to acrolein, are carried out simultaneously, contrarily to most of research works published up to now.The acid-base properties of the solid catalysts play a key-role in the aldol condensation reactions. Basic sites are essential to increase the activity and selectivity of aldolisation reactions, but their strength plays also an important role in side reactions. The quantification of the acid/base sites concentration and strength on the surface of oxide catalysts is even more crucial when the reaction is carried out in presence of oxygen, thus leading to over-oxidation reactions.In the present study, a series of oxide catalysts obtained by deposition of basic oxides (Na2O, K2O, MgO, CaO) on a silica support has been considered in the cross-condensation of aldehyde and formaldehyde to produce acrolein. The addition of different guest oxides of the first and second group of the periodic table, allowed to tune the acidity and basicity of the catalyst surface. The basic and acidic properties of the catalysts have been investigated by adsorption calorimetry (see Figure) in order to obtain the concentration, strength and strength distribution of the active sites. Finally, the catalytic reaction has been performed in presence of oxygen with the aim to verify how in oxidizing conditions the acid/base properties can impact the activity and selectivity towards acrolein.

SSCI-VIDE+ATARI+ALI:TWE:SBE:AAU; National audience; Acrolein, the simplest unsaturated aldehyde, is widely used in chemical industry as intermediate for the synthesis of various chemical products as biocides, acrylic acid, methionine and other numerous chemicals [1]. Production of acrolein starting from the oxidation of biosourced alcohols has been proposed recently [2].In the present work, production of acrolein from a mixture of alcohols (methanol and ethanol) is studied in a two-stage gas-phase process, in order to understand the reaction mechanism. Oxidation of methanol and ethanol on FeMoOx (Iron-Molybdate) catalyst takes place in the first stage reactor [2]; then the formaldehyde and the acetaldehyde produced feed the second stage reactor where acrolein is produced by aldol condensation (in the presence of O2 and other 1st stage reaction gases) on silica-supported CaO, MgO, Na2O and K2O catalysts [3]. We characterized acidity and basicity of the catalysts surface by adsorption calorimetry, using NH3 and SO2 respectively as probe molecules (Fig.1). The other physico-chemical properties were determined as well using complementary techniques like XRD, XPS, N2-adsorption at 77K.The catalytic reaction has been performed with the aim to verify how in oxidizing conditions the acid/base properties can impact the activity and selectivity towards acrolein. We tested the catalysts at different temperatures in order to maintain the CO+CO2 yield below 10 mol %. Good performances were obtained for Na/Si catalyst with 25% acrolein yield and 10% CO+CO2 yield. K/Si and Ca/Si catalysts showed the lowest acrolein production; they promoted side oxidation reactions that overoxidized acrolein (or reactants) into CO and CO2, due to the presence of oxygen. Mg/Si presented the best results (at 320 °C and 5000 h-1 GHSV) with 29% and 38% of acrolein yield and selectivity, respectively, and a CO+CO2 yield of 7% (Fig.2). The presence of both acid and basic sites seems to increase the selectivity towards acrolein. The fine tuning of the surface properties is necessary to improve the acrolein selectivity and to minimize the over oxidation behavior.

SSCI-VIDE+ATARI+ALI:SBE:AAU; International audience; We studied the production of acrolein from a mixture of alcohols in a two stages gas-phase process to understand and decouple the reaction mechanism. Oxidation of methanol and ethanol on FeMo catalyst takes place in the first stage reactor [1]; then the formaldehyde and the acetaldehyde produced feed the second stage reactor where acrolein is produced by aldol condensation (in the presence of O2 and other 1st stage reaction gases) on silica-supported CaO, MgO, Na2O and K2O catalysts [2]. We characterized the catalysts for their acid and base surface properties, by adsorption calorimetry, using NH3 and SO2 respectively as probe molecules (Fig.1). The other physico-chemical properties were also determined by complementary techniques as XRD, XPS, N2-adsorption at 77K.We tested the catalysts couples at temperatures chosen in order to maintain the CO+CO2 yield below 10 mol %. K-Si and Ca-Si catalysts showed the highest oxidation features and could not be tested above 270 and 300 °C, respectively, despite the acrolein selectivity that might improve at higher temperatures. In each case, the catalysts produced mainly acrolein, acetaldehyde, formaldehyde, CO and CO2.MgO-containing catalyst (Mg-Si) is the most promising and shows the highest acrolein selectivity and the highest amount of both acid and base strong sites (>100 kJ/mol) (Fig.2). Strong basic and acidic sites, as well as a good dispersion of the active oxides on the silica surface, drive the catalytic performances. The fine tuning of the surface properties is crucial to improve the acrolein selectivity and to minimize the over oxidation behavior.

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International audience; The impact of the Cyanobacteria Microcystis aeruginosa on zooplankton dynamics was studied in the hypertrophic Villerest Reservoir (France). Samples were collected and their biochemical composition and calorific content examined. Three most abundant zooplankton species in the reservoir were considered: the cladoceran Daphnia longispina and the copepods Cyclops vicinus and Eudiaptoinus gracilis. The three species were differently affected by the Microcystis aeruginosa blooms. Daphnia longispina did not seem to suffer from the proliferation of the M. aeruginosa, although its biomass decreased concomitantly to the bloom. This collapse would be attributable to the lack of nutritional value of algae. Cyclops vicinus seemed to move away when Microcystis invaded the superficial layers of the reservoir. Because this zooplankter had migratory abilities, it reached the littoral zone where food was available. The energetic costs linked to this migration were clearly pointed out when the species recovered the pelagial zone in early fall. The behaviour of Eudiaptomus gracilis was not clear. This species underwent diapause as M. aeruginosa proliferated. This suggests that Eudiaptomus gracilis moved away from the pelagial zone over the cyanobacterial blooms. In most cases, the cyanobacterial toxins affected the growth of zooplankton and the potential to use herbivorous zooplankton as a means to combat Microcystis proliferation in the Villerest reservoir seems limited