DAVincCCHeaP answers research issues about clean and sustainable energies as well as reduction of primary energy consumption. Combining theoretical, numerical (CFD) and experimental approaches, this project will support French innovations in the field of regenerative thermal machines. There is great interest in intelligent equipment that supplies several energy sources simultaneously. Scientific issues are addressed through a unique test bench whose data will feed a predictive modelling tool allowing the development of such machines. Heat transfer, multi-scale physics and innovative thermodynamic cycles are the main keys to improve the performance and competitiveness of industrial equipment. Technological advances will benefit to a large range of applications from domestic heat pumps and engines to space cryocoolers. This project with high dissemination potential will promote technological innovation and address the energy and environmental challenges of tomorrow's society.

*Context* Reward is essential for motivation and learning, but can also lead to maladaptive behaviors such as addiction. Reward processing in the brain has been described at various levels, with a large part of the animal literature focusing on subcortical dopamine, while the human literature has relied more strongly on blood oxygen level dependent (BOLD) fMRI. An important challenge is to integrate these levels of description, in order to provide a more unified picture of the healthy and dysfunctional mechanisms underlying reward processing in the brain. In addition, the recent advent of dimensional psychiatry has emphasized the multi-factorial nature of psychiatric disorders and the importance of going beyond single cognitive dysfunctions –such as reward processing– in order to improve the current nosography and treatment strategies. *Objectives and methodology* This project is at the crossroads of fundamental and clinical neuroscience, pursuing two main goals. First, we will attempt to bridge molecular and functional levels of description of the brain mechanisms supporting reward processing in healthy humans. Specifically, we will address the question of how reward-induced dopamine release in the striatum is (i) regulated by top-down prefrontal control and (ii) coupled with striatal BOLD activity. We will address these questions using a state-of-the-art technique –simultaneous PET-fMRI– combined with a machine learning approach and the novel ‘lp-ntPET’ analytical framework optimized for tracking dynamic changes in dopamine release (Axis 1). Then, building on this knowledge and multi-modal approach, we will focus on gambling addiction, a psychiatric disorder that has been associated with impaired reward-related dopamine functioning. Despite the popularity of this hypothesis, supporting evidence remains inconsistent. To resolve these inconsistencies, we propose to test a novel model of gambling addiction which (i) explicitly takes into account individual differences, and (ii) posits an interaction between abnormal reward processing and threat reactivity in the brain. Importantly, we will test the ecological validity of this neurobiological model, by examining its predictive value for real-life gambling behavior using Ecological Momentary Assessment (Axis 2). *Impact* This project has the potential to make an impact at three levels. At a fundamental level, this project will provide a multi-level description of reward processing in the brain. This should help refine models that relate striatal dopaminergic transmission with hemodynamic changes in the human brain, and inform our understanding of how top-down prefrontal control of reward behaviors is implemented within cortico-striatal loops. At a methodological level, the combined use of simultaneous PET-fMRI and machine learning should allow us to derive a proxy measure of striatal dopamine release based on BOLD fMRI. Given that fMRI is much cheaper and less invasive than PET, such a proxy measure would be highly valuable for assessing subcortical dopamine dysfunctions across a range of psychiatric disorders, such as addiction, depression or schizophrenia. Finally, at the clinical level, this project should bring the first proof-of-concept that a model of gambling addiction explicitly accounting for individual differences and a multi-factorial etiology can reconcile previous inconsistent findings, and make predictions about real-world behavior. This approach relying on cognitive dimensions, as opposed to rigid categorical diagnoses, should eventually contribute an improved biological definition of addiction, and pave the way to more personalized treatment strategies.

The 'Polymer Materials Engineering' (IMP, UMR 5223, Lyon) and the 'Léon Brillouin Laboratory' (LLB, UMR 12, Saclay) are the two CNRS partners involved in this highly interdisciplinary project. Electrostatically driven LbL self-assembly is the most studied and applied technique for the elaboration of multilayer coatings. Although more developed on planar (2D) substrates, significant efforts have been focused on the elaboration of multilayer architectures on spherical (3D) substrates. This process relies on the specific and sequential interactions between a 2D or 3D substrate with oppositely charged polyelectrolytes. It allows for an easy tuning of the properties/applications of these multilayer architectures from the choices of the substrate, the nature of the polyelectrolytes, counter-ions and various organic, inorganic or bioinspired charged architectures. Even if it generally involves environmentally friendly water based processes, LbL assembly using charged and polar materials is also a main limitation of this technology. Indeed, counter-ion mobility and reversibility of the electrostatic interactions must be considered. Also, this process excludes an important part of macromolecular materials, i.e. uncharged polymers. This can be explained by the specificity and the easy processing of this method which mainly relies on consecutive immersions of charged substrates in aqueous solutions of oppositely charged polymers/architectures. The proposal associated to this request for ANR funding is based on an innovative method for the elaboration of organic and hybrid multilayer thin films and nanoparticles, each layer being associated covalently by click chemistry. This versatile chemistry is based on the catalyzed irreversible cycloaddition of an alkyne (R-CCH) and an azide (R-N3), yielding a 1,2,3-triazole aromatic ring. This chemical pathway is playing an important role in the evolution of functional macromolecular materials. Indeed, its high specificity, selectivity and quantitativity, the absence of residuals and by-products, the high tolerance in aqueous, hydro-alcoholic or organic media will allow this project to be successful. Linear macromolecules having alkyne or azide functionalities randomly distributed along their backbone, and platinum nanoparticles having alkyne functionalities covering their surface will be prepared as the organic and inorganic parts of the targeted 2D and 3D hybrid multilayer architectures. Sequential click chemistry processes will be then applied to covalently bound the elementary bricks described above from the 2D or 3D substrates. Beside the characterization techniques fully accessible at the IMP and LLB laboratories (e.g. NMR, UV, IR, SEC, TGA, DSC, ellipsometry, SFM, TEM, SEM, XPS, DLS...) neutron scattering and reflectivity experiments will be performed for the detailed characterization of the different multilayer architectures prepared, using contrast matching between different alternating layer systems. These 2D and 3D processes will be then extended to other objects issued from a tailored library of azide and alkyne functionalized organic and inorganic components. Compared to the usual methods for the elaboration of multilayer thin films, the use of click chemistry will significantly expand the chemical nature and the diversity of the components of these new coatings as well as their applications/properties. These objectives will be achieved by the close and complementary collaboration between the young researchers organized as a team for this project. This project will imply an interdisciplinary methodology as well as realistic and clearly identified objectives. This ambitious and outstanding project will have a significant impact in the field of functional coatings and hybrid nanoparticles and will be a valuable contribution in term of innovation to the themes developed by the IMP and the LLB. This highly benefic collaborations will lead in the future to other joined actions involving research, teaching, mobility and exchanges. The combination of the partners involved will allow for the development of an innovative approach impossible to realize without such complementary synergies. The defined project will be conducted in a privileged scientific environment involving close collaborations (e.g. mobility and meetings...) between outstanding research laboratories in the field of polymer materials. These will be important assets for the professional perspective of the future recruited post-doctorate.