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High‐Chroma, High‐Contrast Tunable Color Coatings Using Sb2S3 in a Metal‐Dielectric Stack
No full textInternational audienceThin-film coatings are a versatile option for creating color. These coatings can be made tunable by introducing phase-change materials (PCMs), whose optical response changes due to an external signal. However, commonly used PCMs such as Ge2Sb2Te 5 (GST) are limited in their applications for color coatings, due to high absorption of visible light. Here, the alternative PCM Sb2S3 is used, and a novel coating design is demonstrated, which incorporates the PCM layer into an asymmetric Fabry-Perot cavity with Ag, SiO2 and Ti layers. Simulations are used to show that this design yields high-chroma colors in a wide range of hues, which exhibit a large tunable hue shift when the phase of the Sb2S3 layer changes. Three coatings are deposited to experimentally verify these results, which give good agreement with the simulations. The phase change of the Sb2S3 layer is demonstrated using direct heating using a hotplate, and also using laser annealing, which allows microscale image writing to be realized on the coatings
Effect of a multicomponent HPV intervention on self-reported HPV vaccine uptake and intention among French adolescents and parents: results from the national, cluster-randomised PrevHPV trial
No full textInternational audienceBackground : Human papillomavirus (HPV) infections cause several cancers, including nearly all cervical cancer cases. While there are safe and effective vaccines, the adolescent HPV vaccine coverage in France is low (<50%). Thus, we studied the effect of municipality-wide interventions to increase HPV vaccine uptake and intention among middle school students. Methods : This cluster-randomised trial used an incomplete factorial design to arrange three components (in-school education, motivation, mobilisation (EMM); in-school vaccination; and local general practitioner (GP) trainings) into six intervention conditions, which were randomly assigned to 91 participating French municipalities. We assessed HPV vaccine status using online self-reported questionnaires that students (typically aged 13–14) and parents completed at baseline and 5-month follow-up. Using adjusted linear regression, we estimated differences in (1) vaccine uptake and (2) uptake and intention to vaccinate, both by randomisation arm and by intervention component. We explored subgroup effects by at-home multilingualism, gender, age and parental education. Results : 2047 of 2664 (74%) students were unvaccinated against HPV at baseline. The 5-month probability of first-dose vaccine uptake in the control group was 0·09 (95% CI 0.06 to 0.11). Vaccine campaigns alone contributed a 24-percentage-point (0.18, 0.30) increase in uptake compared with the control group. EMM was only effective in increasing vaccine uptake among monolingual francophone students, and we detected no effect from GP training. Vaccine campaigns and EMM both increased the combined outcome of vaccine intention and first-dose uptake, but EMM had the same subgroup effect. Questionnaire data from parents (N=236) were sparser but demonstrated similar overall trends. Conclusions : Our results demonstrate that in-school HPV vaccine campaigns effectively increase HPV vaccine uptake among adolescents without exacerbating extant disparities in vaccine uptake. EMM can also be a useful tool to increase HPV vaccine intention but must be improved to bridge disparities in its effectiveness. GP training results were inconclusive
Developing International Consensus on Key Indicators for a 24-Hour Movement Behaviour Report Card in Early Childhood: A Twin-Panel Delphi Study
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In situ study of double yielding in PA11: Role of the amorphous and crystalline fractions
No full textInternational audienceIt is shown that polyamide 11 (PA11), a semicrystalline polymer (SCP), exhibits two well-distinct successive yield points on its characteristic stress-strain curve during tensile deformation below Tg (cf. figure 1). This phenomenon, denoted as double yielding (DY), has been observed in other SCPs like PA6[1][2]. Previous work has demonstrated an intimate relationship between the first yield point σy1 and molecular dynamics in the amorphous phase. The second yield point σy2 is more sensitive to morphological changes in the crystalline phase. Studying the origin of DY is pivotal to provide more insights into the complex and hierarchical deformation mechanisms in SCPs.The purpose of this work is to investigate more thoroughly the origin of such phenomenon and to relate it to the deformation mechanisms occurring in the amorphous and crystalline phases of PA11. Particularly, we wish to highlight the specific deformation scenario and the chronology of the deformation events happening between the two yield points. In that regard, we aim at understanding the specific roles both phases play in the onset of plastic (and thus permanent and heterogeneous) deformation and the initiation of damage mechanisms such as cavitation or lamellar fragmentation. A macroscopic mechanical analysis by the means of tensile, creep and recovery tests is carried out and supported by a microstructural examination using in situ USAXS/SAXS/WAXS techniques performed at ESRF. Such fine methods are necessary to monitor real-time microstructural evolution and damage mechanisms during tensile deformation at the scale of lamellar stacks and uncover the co-dependent involvement of crystalline lamellae and inter-lamellar amorphous regions in the appearance of DY.On one hand, the main results demonstrate the connection between σy1 and the onset of plastic flow in the amorphous phase as modelled by a thermally activated process. On the other hand, σy2 marks the onset of crystalline lamellae de-structuration. Between the two yield points, deformation seems to be governed by both amorphous and crystalline mechanisms operating interdependently. These finding also address crucial comprehension elements regarding the onset of heterogenous and irreversible deformation in PA11. Finally, we address the influence of the test temperature on DY and the underlining deformation and damage mechanisms
Who’s afraid of the early modern sceptic? A Polemical Note on Dmitri Levitin’s The Kingdom of Darkness.
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Sylvain Rode, Écologiser l’urbanisme. Pour un ménagement de nos milieux de vie partagés, Lormont, Éd. Le Bord de l’eau, coll. En anthropocène, 2023, 206 pages
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Toxic microbiome and progression of chronic kidney disease: insights from a longitudinal CKD-Microbiome Study
No full textInternational audienceBACKGROUND: The gut microbiota has been linked to non-communicable diseases, including chronic kidney disease (CKD). However, the relationships between gut microbiome composition changes, uraemic toxins (UTs) accumulation, and diet on CKD severity and progression remain underexplored. OBJECTIVE: To characterise relationships between gut microbiome composition and functionality, UTs diet, and CKD severity and progression, as well as assess microbial contributions to UTs accumulation through mice faecal microbiota transplantation (FMT). DESIGN: This study profiled the gut microbiome of 240 non-dialysis patients with CKD (CKD-REIN cohort) using shotgun metagenomics, with follow-up in 103 patients after 3 years, with comparisons with healthy volunteers from the Milieu Intérieur cohort. A multiomics approach identifies features associated with CKD severity (and progression), with validation in an independent Belgian cohort. Experimental models used FMT to test CKD gut microbiome effects on UTs and kidney fibrosis. Changes in gut microbiome over time were evaluated, and the impact of diet on these changes was assessed. RESULTS: Compared with matched healthy controls, patients with CKD exhibited gut microbiota alteration, with enrichment of UT precursor-producing species. Patients with severe CKD exhibited higher UT levels and greater enrichment of UT (precursor)-producing species in the microbiota than patients with moderate CKD. Over time, UT (precursor)-producing species increased, and a plant-based low protein diet appeared to mitigate these changes. FMT from patients with CKD to antibiotic-treated CKD model mice increased serum UT levels and exacerbated kidney fibrosis. CONCLUSIONS: This study highlights the role of the microbiome and UTs in CKD, suggesting a potential therapeutic target to slow disease progression
Mitigation of indoor pollution events by lime-cement plasters: Full-scale assessment
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Le Caire et sa nouvelle capitale : un mégaprojet aux risques sanitaires et environnementaux
No full textLe Monde arabe connaît depuis une vingtaine d'années une multiplication de mégaprojets urbains à grands renforts de communication et d'images de synthèse illustrant ce que d'aucuns appellent des fantaisies urbaines (Watson 2014), des PowerPoint-cities (Côté-Roy et Moser 2021) ou un urbanisme fictionnel (Stadnicki 2021). Qu'il s'agisse d'opération de rénovation urbaine (souvent en zone péricentrale) comme le projet d'aménagement des rives du Bou-Regreg à Rabat-Salé ou bien de création urbaine ex-nihilo comme le projet Neom en Arabie Saoudite, ces actions de planification urbaine se signalent par une surenchère de gigantisme, une financiarisation appuyée sur des partenariats publics-privés (révélatrice d'alliances géopolitiques), une gouvernance top-down (urbanisme autoritaire) et une rhétorique intégrant les canons urbanistiques dominants tels ceux de ville verte, ville intelligente ou ville durable. Le Caire, capitale de l'Égypte située à l'apex du delta du Nil, n'est pas en reste dans cette compétition avec le démarrage en 2016 du chantier d'une nouvelle capitale administrative (NCA) sur son flanc oriental, à environ 40 km du centre-ville (fig.1). Seconde ville du continent africain et première ville arabe par son poids démographique, la mégapole compte près de 22 millions d'habitants en 2025 et rassemble près d'un quart de la population égyptienne dans un État hypercentralisé. Motivé par le récit officiel d'une croissance urbaine non maîtrisée menaçant les terres agricoles, par la description d'un Caire hyperdense, saturé et pollué, ainsi que par un discours moderniste et développementaliste, le mégaprojet urbain égyptien se concrétise avec l'érection de bâtiments ministériels et l'installation des fonctionnaires depuis l'automne 2023. Pourtant, la construction de cet ensemble urbain d'envergure pose question et pas seulement en termes de coût, de choix politique ou de gouvernance. Le chantier est la partie visible d'une forte relance de l'industrie de la construction qui est le premier secteur d'activité industrielle du pays (l'industrie manufacturière représente 16 % du PIB en 2022-2023) 1 . Cet article propose une analyse du mégaprojet cairote à l'aune de la (sur-)consommation de ressources qu'il implique, notamment en termes de matériaux de construction (marbre, granit, sable) en pointant sa dimension extractiviste. Celle-ci occasionne des risques sanitaires et environnementaux au niveau local
Multiscale modeling of the spatial structure of stem cells in neuroblastoma patient-derived tumoroids reveals a critical role for a short-range diffusive process
No full textInternational audienceNeuroblastomas are heterogeneous pediatric tumors of the sympathetic nervous system for which treatments are still limited. Fundamental and applied approaches have been enabled thanks to the generation of patient-derived tumoroids (PDTs), ex vivo 3D structures used as avatars of the original tumor.We generated neuroblastoma PDTs and quantified the spatial distribution of CD133 + cancer stem cells using immunohistochemistry. We observed that those cells tend to aggregate in the PDT.In order to better understand the set of rules needed for generating such structures, we implemented a multiscale agent-based neuroblastoma tumoroid model.Model rules specify single cell's fate based on its intracellular content, which dynamically evolves according to a stochastic gene regulatory network. The state of this network can be modulated by cell-to-cell signalling through neighbor cells fate decisions and, possibly, spatial location.We first observed that in the absence of any spatial rules for inter-cellular interactions, no spatial structure emerged. The addition of simple rules (signalling by cell-to-cell contact or differential cell adhesion) only marginally improved the quantitative agreement to the experimental dataset. In sharp contrast, the addition of short-range pro-stem cell diffusive signalling among stem cells produced very realistic 3D PDT-like structures. This works highlights the power of our multiscale approach to discard too simplistic rules and to propose a minimal set of hypotheses required to reproduce qualitatively and quantitatively experimentally observed spatial structures. In the case of neuroblastomas-derived PDTs, short-range spatial diffusion of stem-to-stem cell signalling proved to play a key role in successfully reconstructing the spatial structure