We will study a new concept in heterogeneous catalysis based on "core-shell" structures, where the active phase (metallic nanoparticles) is covered by an oxide that is used as a support. This system contrasts from most of the reported studies. Our preliminary results highlight that TiO2@Au@SiO2 core-shell catalysts surprisingly show superior performances in photocatalytic hydrogen generation (10-fold higher activity) and selective oxidation of furfural (3 times better). The objective of INGENCat is to provide fundamental understanding of such core-shell catalysts and identify the corresponding active sites. Our ambition is to solve the mystery around the superior activity of these catalysts as compared to the supported materials. We intend also to shed the light around their versatile properties in heterogeneous and photocatalysis processes in the liquid phase selective oxidation of furfural. The DFT analysis of the studied materials and reaction will be further performed.

Cytokine storm is a hallmark of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which causes coronavirus disease 2019 (COVID-19). As a consequence some patients could develop severe inflammatory diseases some of which leading to cardiac failure. Tumor Necrosis Factor alpha (TNF-a), High Mobility Group Box 1 (HMGB1) protein, and type I interferon (IFN-I) are major pro-inflammatory cytokines associated with COVID-19. Signaling pathways triggered by the cytokines end up in the nucleus modifying the transcriptome of the infected and non-infected cells through epigenetic regulation. Promyelocytic Leukemia (PML) Nuclear Bodies (NBs) are sensors of these signaling pathways, and together with the histone H3.3 variant HIRA chaperone complex, they contribute to the regulation of the expression of at least the IFN stimulated genes (ISGs). The CHROMACoV project proposes to decipher the impact of the TNF-a HMGB1, and IFN-I cytokines secretion together with the PML NBs/HIRA/H3.3 axis in the onset of the molecular and biological events leading to inflammatory complications associated to the COVID-19.

Predicting both climate and temperature evolution requires, among other parameters, to quantify properly the contribution of clouds through a better understanding of their formation. Clouds form by condensation of water vapor on particles (aerosols) of varying morphology and chemical composition and with sizes down to a sub-micron level. WATEM will study the early stages of this process in situ in a Transmission Electron Microscope (TEM). Providing the required spatial resolution, the TEM also brings morphological (2D/3D), structural and chemical information. The challenge to control thermodynamic conditions for condensation of liquid droplets from a humid gaseous environment will be taken up in a dedicated Environmental TEM (ETEM) working at a variable partial pressure (< 20 mbar as in ESEM: Environmental Scanning EM). We will develop a tip for a sample holder based on a Peltier cooled micro-device allowing observing solid, liquid and vapor phases at the same time, and evolution at their interfaces, as well as pure liquid without sealing membranes. Based on this technological development, WATEM will highlight the scientific expertise of three teams whose expertise are both complementary and with sufficient overlap so that effective communication and exchanges can take place together with effective intra- and inter-team work thus providing a solid basis for the success of the project: IRCELYON (atmospheric chemistry, liquid/gas ETEM, liquid/gas ESEM), MATEIS (liquid/gas ETEM, liquid/gas ESEM, electronic tomography, specific sample holders), MAJULAB (micro/nano devices, specific sample holders, ESEM/ETEM). WATEM will revolve around 5 scientific/technological WP (in addition to the WP concerning the project management). WP1 concerns the realization of the Peltier cooled micro-device adaptable both to an ESEM and to an existing sample holder in an ETEM. This original solution will be completed by other existing alternatives a priori less effective from the point of view of fine control of the temperature, and therefore of the conditions of condensation of water on the aerosols. These alternatives allow nevertheless to manageable the risk of delay in the development of our prototype. In WP3, WP4 and WP5 particular attention will be given to the effects of irradiation so as to minimize their effect on the observed phenomena and to develop relevant experiment protocols. WP3 will validate and calibrate the Peltier micro-device in the ESEM by studying the water condensation on large collections of model artificial aerosols (statistical studies) thus taking advantage of the space existing in the ESEM chamber and in order to facilitate the experiments to be carried out in the ETEM; tomography approaches in ESEM, under condensation conditions, will also be tested. A similar approach in ETEM will be performed in WP4, taking advantage of the results acquired in WP3: validation of the Peltier micro-device in ETEM on the same model aerosols and measurements of the deliquescence (DRH) and efflorescence (ERH) relative humidity. We will also study the role of the mixed nature of aerosols (for instance: inorganic/organic) on hygroscopicity using analytical methods (EDX/EELS), complementary to imaging, as well as electronic tomography. Finally, in WP5 we will tackle the study of natural aerosols (atmospheric sampling) in ETEM; here the main challenge will be to be able to follow in real-time the evolution of the solid/liquid and liquid/vapor interfaces essential for an understanding of the growth phenomena of water nanodroplets and their implication in cloud formation. The successful development of the approach an strategy proposed in WATEM will allow extension to studies in other fields: suspension of nano-objects in liquid, crystallogenesis in nano-confined media, evolution of biological sub-micron systems, …

The scientific interest for h-BN material is growing every year due to its potential use in various domains such as microelectronic. The presented project aims to develop and study a new atomic layer deposition (ALD) approach for boron nitride very thin films. Indeed, the few existing ALD processes being mostly based on ammonia and/or halide precursors, new ALD approach using alternative precursors is proposed to avoid corrosive and/or irritant reactant and by-product as well as to improve the film quality especially in term of crystallinity. Regarding an eventual industrial application, low energy consumption and environmentally friendly process is sought after. The polymer derived ceramics route will thus be transposed to ALD. No process combining these two synthetic routes has been reported up to now. Elaboration of well crystallized h-BN ultra-thin films is motivated among others by further study of BN/graphene heterostructures, which are highly promising in microelectronics.

Due to sanitary risks associated with the presence of the Asian tiger mosquito Ae. albopictus in recently invaded urban areas, better knowledge is needed to evaluate the social (behavior, practices) and environmental (human impact on the environment) factors as risk factors on the emergence of vector-borne diseases. Indeed, the urban mosaic provides a wide range of water containers suitable for larval development. It was suggested for certain mosquito species that anthropogenic disturbances of the environment can have a direct effet on the physiology of mosquitoes but also an indirect effect by impacting their microbiota. However, it is now admitted that those microorganisms, which are predominantly acquired and influenced by water of breeding sites, play a key role in mosquito biology and their ability to transmit pathogens. By combining in situ observations and experiments in controlled environments, this project aims to assess the combined impact of human practices (via a survey of opinion and practices) and human activities (emission of pollutants) on the proliferation of the Asian tiger mosquito in urban areas. Improving our knowledge of the biotic and abiotic factors involved in the ecology of the tiger mosquito in urban environments could lead to a new reflection for the implementation of recommendations applicable to the inhabitants and to the actors of health and the city in order to create a durable habitat that is poorly favorable to the colonization by this mosquito.