47 research outputs found

    Polyamide 66 microspheres metallised with in situ synthesised gold nanoparticles for a catalytic application

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    A simple concept is proposed to metallise polyamide 66 (PA66) spherulite structures with in situ synthesised gold nanoparticles (Au NPs) using a wet chemical method. This cost-effective approach, applied to produce a PA66/Au NP hybrid material, offers the advantages of controlling the nanoparticle size, the size distribution and the organic-inorganic interactions. These are the key factors that have to be controlled to construct consistent Au nanostructures which are essential for producing the catalytic activities of interest. The hybrid materials obtained are characterised by means of scanning electron microscopy, transmission electron microscopy, attenuated total reflection-Fourier transform infrared spectrometry and X-ray diffraction spectrometry. The results show that PA66 microspheres obtained via the crystallisation process are coated with Au NPs of 13 nm in size. It was found that controlling the metal coordination is the key parameter to template the Au NPs on the spherulite surfaces. The preparation processes and the key factors leading to the formation of PA66 spherulites coated with Au NPs are discussed. Moreover, the efficiency of the coated spherulites as a potential catalyst is proved by demonstrating the reduction of methylene blue via UV-visible spectrometry

    Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing.

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    Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity. A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay. Fifteen laboratories returned results, obtained using a wide range of wet-lab and informatics methods. Six of 25 target viruses were detected by all laboratories, with the remaining viruses detected by 4-14 laboratories. Six non-target viruses were detected by three or more laboratories. The study demonstrated that a wide range of methods are currently used for adventitious virus detection screening in biological products by deep sequencing and that they can yield significantly different results. This underscores the need for common reference materials to ensure satisfactory assay performance and enable comparisons between laboratories

    The GenTree Platform: growth traits and tree-level environmental data in 12 European forest tree species

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    Background: Progress in the field of evolutionary forest ecology has been hampered by the huge challenge of phenotyping trees across their ranges in their natural environments, and the limitation in high-resolution environmental information. Findings: The GenTree Platform contains phenotypic and environmental data from 4,959 trees from 12 ecologically and economically important European forest tree species: Abies alba Mill. (silver fir), Betula pendula Roth. (silver birch), Fagus sylvatica L. (European beech), Picea abies (L.) H. Karst (Norway spruce), Pinus cembra L. (Swiss stone pine), Pinus halepensis Mill. (Aleppo pine), Pinus nigra Arnold (European black pine), Pinus pinaster Aiton (maritime pine), Pinus sylvestris L. (Scots pine), Populus nigra L. (European black poplar), Taxus baccata L. (English yew), and Quercus petraea (Matt.) Liebl. (sessile oak). Phenotypic (height, diameter at breast height, crown size, bark thickness, biomass, straightness, forking, branch angle, fructification), regeneration, environmental in situ measurements (soil depth, vegetation cover, competition indices), and environmental modeling data extracted by using bilinear interpolation accounting for surrounding conditions of each tree (precipitation, temperature, insolation, drought indices) were obtained from trees in 194 sites covering the species’ geographic ranges and reflecting local environmental gradients. Conclusion: The GenTree Platform is a new resource for investigating ecological and evolutionary processes in forest trees. The coherent phenotyping and environmental characterization across 12 species in their European ranges allow for a wide range of analyses from forest ecologists, conservationists, and macro-ecologists. Also, the data here presented can be linked to the GenTree Dendroecological collection, the GenTree Leaf Trait collection, and the GenTree Genomic collection presented elsewhere, which together build the largest evolutionary forest ecology data collection available

    Between but not within species variation in the distribution of fitness effects

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    New mutations provide the raw material for evolution and adaptation. The distribution of fitness effects (DFE) describes the spectrum of effects of new mutations that can occur along a genome, and is therefore of vital interest in evolutionary biology. Recent work has uncovered striking similarities in the DFE between closely related species, prompting us to ask whether there is variation in the DFE among populations of the same species, or among species with different degrees of divergence, i.e., whether there is variation in the DFE at different levels of evolution. Using exome capture data from six tree species sampled across Europe we characterised the DFE for multiple species, and for each species, multiple populations, and investigated the factors potentially influencing the DFE, such as demography, population divergence and genetic background. We find statistical support for there being variation in the DFE at the species level, even among relatively closely related species. However, we find very little difference at the population level, suggesting that differences in the DFE are primarily driven by deep features of species biology, and that evolutionarily recent events, such as demographic changes and local adaptation, have little impact

    From palladium-catalyzed cross-coupling reactions to organic electronics

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    Les appareils de haute technologie (ordinateurs, tĂ©lĂ©visions, tĂ©lĂ©phones, 
) sont fabriquĂ©s Ă  partir de composants relativement simples (transistors, diiodes Ă©lectroluminescentes, 
) qui utilisent du silicium comme semiconducteur. En Ă©lectronique molĂ©culaire, les composĂ©s organiques π- conjuguĂ©s qui ont un Ă©cart HOMO-LUMO faible peuvent prĂ©senter cette propriĂ©tĂ©. Dans le cadre de ce travail, nous avons Ă©tudiĂ© la synthĂšse de nouveaux semiconducteurs organiques parpolymĂ©risation par mĂ©tathĂšse d’alcynes. Pour cela, des composĂ©s de type dialcynylaromatique ont Ă©tĂ© prĂ©parĂ©s. Leur Ă©tude en polymĂ©risation ainsi que leurs propriĂ©tĂ©s Ă©lectroniques ont Ă©tĂ© rĂ©alisĂ©es dans des laboratoires collaborateurs d’un projet ANR (CADISCOM). Dans une seconde partie, indĂ©pendante de la premiĂšre, les couplages croisĂ©s catalysĂ©s par le palladium sont d’une importance capitale dans la chimie organique de synthĂšse actuelle. De nombreux travaux ont Ă©tĂ© menĂ©s sur le partenaire organomĂ©tallique de la rĂ©action, mais trĂšs peu en ce qui concerne le partenaire Ă©lectrophile. Lors de ce travail, nous avons Ă©laborĂ© un nouveau groupe partant Ă  partir de prĂ©curseurs trĂšs peu onĂ©reux que nous avons pu appliquer dans les quatre "grands couplages" les plus utilisĂ©s (Suzuki, Stille, Sonogashira et Heck).High-technology devices (computers, TV, mobile phones, 
) are manufactured from simple components (transistors, LED, 
) which use silicium as semiconductor. In organic electronics, π- conjugated organic compounds with low HOMO-LUMO gap can show this property. This work is dealing with the synthesis of new organic semiconductors via alkyne metathesis polymerization.Dialkynyl compounds were synthetized. Their polymerization studies as well as electronic characterization were conducted by collaborating groups in an ANR project (CADISCOM). In an independent second part, palladium-catalyzed cross-coupling are of great importance in actual organic synthesis. Many studies have been focused on the organometallic partner of the reaction,but the electrophilic partner have received much less attention. In this work, we developed a new leaving group from cheap precursors that we applied in the four most well-known couplings (Suzuki, Stille, Sonogashira, Heck)

    From palladium-catalyzed cross-coupling reactions to organic electronics

    No full text
    Les appareils de haute technologie (ordinateurs, tĂ©lĂ©visions, tĂ©lĂ©phones, 
) sont fabriquĂ©s Ă  partir de composants relativement simples (transistors, diiodes Ă©lectroluminescentes, 
) qui utilisent du silicium comme semiconducteur. En Ă©lectronique molĂ©culaire, les composĂ©s organiques π- conjuguĂ©s qui ont un Ă©cart HOMO-LUMO faible peuvent prĂ©senter cette propriĂ©tĂ©. Dans le cadre de ce travail, nous avons Ă©tudiĂ© la synthĂšse de nouveaux semiconducteurs organiques parpolymĂ©risation par mĂ©tathĂšse d’alcynes. Pour cela, des composĂ©s de type dialcynylaromatique ont Ă©tĂ© prĂ©parĂ©s. Leur Ă©tude en polymĂ©risation ainsi que leurs propriĂ©tĂ©s Ă©lectroniques ont Ă©tĂ© rĂ©alisĂ©es dans des laboratoires collaborateurs d’un projet ANR (CADISCOM). Dans une seconde partie, indĂ©pendante de la premiĂšre, les couplages croisĂ©s catalysĂ©s par le palladium sont d’une importance capitale dans la chimie organique de synthĂšse actuelle. De nombreux travaux ont Ă©tĂ© menĂ©s sur le partenaire organomĂ©tallique de la rĂ©action, mais trĂšs peu en ce qui concerne le partenaire Ă©lectrophile. Lors de ce travail, nous avons Ă©laborĂ© un nouveau groupe partant Ă  partir de prĂ©curseurs trĂšs peu onĂ©reux que nous avons pu appliquer dans les quatre "grands couplages" les plus utilisĂ©s (Suzuki, Stille, Sonogashira et Heck).High-technology devices (computers, TV, mobile phones, 
) are manufactured from simple components (transistors, LED, 
) which use silicium as semiconductor. In organic electronics, π- conjugated organic compounds with low HOMO-LUMO gap can show this property. This work is dealing with the synthesis of new organic semiconductors via alkyne metathesis polymerization.Dialkynyl compounds were synthetized. Their polymerization studies as well as electronic characterization were conducted by collaborating groups in an ANR project (CADISCOM). In an independent second part, palladium-catalyzed cross-coupling are of great importance in actual organic synthesis. Many studies have been focused on the organometallic partner of the reaction,but the electrophilic partner have received much less attention. In this work, we developed a new leaving group from cheap precursors that we applied in the four most well-known couplings (Suzuki, Stille, Sonogashira, Heck)

    Être sur le terrain, regarder ensemble, Ă©changer et Ă©couter: La marche comme outil d’analyse du territoire

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    Entretien menĂ© par JĂ©rĂ©my ChevalPropos issus du Mercredi de l’AnthropocĂšne produit par l’École urbaine de Lyon le 18 mars 2020 et animĂ© par JĂ©rĂ©my Cheval
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