Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Sustainable and Scalable Enzymatic Production, Structural Elucidation, And Biological Evaluation of Novel Phlorizin Analogues
No full textInternational audienceIt is not unusual for naturally occurring compounds to be limited for their use in cosmetics due to their low water solubility. Recently, aiming at accessing novel phlorizin (a glycosylated bioactive recovered from apple tree wood and already used in cosmetics as antioxidant ingredient) analogues, we reported the synthesis of very promising – but low water‐soluble – biomass‐derived chalcones (CHs) and dihydrochalcones (DHCs) exhibiting antioxidant and anti‐tyrosinase activities. Glycosylating bioactive compounds being one of the most common strategies to increase their water solubility, herein we report the enzymatic glycosylation of the CHs mentioned above, as well as DHC using cyclodextrin glycosyltransferases (CGTase), enzymes well‐known for catalyzing the selective α(1→4) transglycosylation. Indeed, while most natural glycosides are β‐glycosides (such as phlorizin), the selected enzyme produces selectively new α‐glycosides, thus expanding their structural diversity. A first step of separation using Centrifugal Partition Chromatography (CPC) led to mono‐, di‐ or triglycosides‐enriched fractions, which were then submitted to a comprehensive purification strategy for an in‐depth chemical profiling of the synthesized α‐glycosides, revealing that the major compounds were glycosylpyranosides. Surprisingly, among the diglycosides characterized, besides the expected maltoside compounds, nigeroside derivatives were also identified in significant amounts, depending on the starting compound structure. Finally, evaluating the antiradical, anti‐tyrosinase and antimicrobial activities of the major glycosides revealed them as potential sustainable alternatives to current petro‐sourced cosmetic ingredients
"Les indemnités dues en raison de la résiliation unilatérale d’un contrat d’entreprise sont-elles soumises à la TVA ?"
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Pour le fonctionnaire, simuler n'est pas servir
No full textInternational audienceNote sous CAA Marseille, 14 juin 2024, no 23MA0153
Composite preforming defects classification, involved mechanisms and induced mechanical properties
No full textInternational audienceThe inclusion of composite materials in different fields and applications is advancing with time. The demand is for higher-performing functional parts, which induces the need to optimize the manufacturing processes of composite materials for higher-quality products, especially for parts with complex geometries. The forming process of fabrics, that provide rigidity to the composite, can be challenging because of the onset of defects. Multiple defects appearing on the fabric are referenced and studied in the literature with a growing interest over the last decade, which indicates the importance of the problem. They appear on different scales and are related to different deformation types and mechanisms. A defect in the structure creates a local anomaly, which poses a risk of disturbing the mechanical properties of the composites. This chapter proposes a summary of the preforming defects with the analysis of their mechanisms and the induced mechanical behavior proposed on composite materials
Nature, Predictors, and Outcomes of Workers’ Longitudinal Workaholism Profiles
No full textInternational audienceThis research relies on a combination of variable- and person-centered approaches to help improve our understanding of the dimensionality of the workaholism construct. Our results showed that employees’ workaholism ratings simultaneously reflected a global overarching construct co-existing with four specific dimensions (behavioral, motivational, emotional, and cognitive workaholism) among a sample of 432 workers who completed a questionnaire twice over a three-month period. We also examined the profiles taken by workaholism dimensions, and documented their stability over time as well as the associations between these profiles and theoretically-relevant predictors and outcomes. Furthermore, we examined whether these associations differ as a function of working remotely or onsite. Four profiles were identified and found to be highly stable over time: Unplugged, Plugged In, Moderately Unplugged with Externalized Workaholism, and Moderately Unplugged with Cognitive Workaholism. Personal life orientation, telepressure, and interpersonal norms regarding work-related messages were related to the likelihood of profile membership. Remote working also reinforced the positive effects of personal life orientation and the negative effects of interpersonal norms regarding work-related messages. Finally, employees’ work-to-family guilt, job satisfaction, family satisfaction, and life satisfaction also differed as a function of their profile
Imager les parcours migratoires après la guerre civile du Surinam (1986-1992) .: Mémoires_traces, postures_parcours sensibles, espaces-produits_marques.
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Hydro-ecological controls on dissolved organic matter production, mineralization into greenhouse gases, and export in a temperate peatland: the Frasne case study, Jura mountains, France.
No full textInternational audiencePeatlands can be viewed as a nexus of water, organic material, and specific biodiversity, allowing long-term (millennial-scale) storage of significant volumes of carbon. Spatial or temporal modification of one of the three pillars of this nexus may alter the capacity of peatlands to retain carbon in the soil and promote the production of greenhouse gases such as CO₂ and CH₄.This study illustrates these relationships by analyzing atmospheric CO₂/CH₄ concentration variations measured using an Unmanned Aerial Vehicle over the 7 ha Frasne peatland (Jura Mountains, France), which is part of the French Observatory of Peatlands (SNO Tourbières). These data were compared with vegetation and topographic characteristics, as well as hydrogeochemical information (Dissolved Organic Carbon-DOC, Fluorescence Index-FI, Biological Index-BIX, aromaticity, δ¹³C-DOC) from pore waters sampled across a network of piezometers throughout the ecosystem.Preliminary results suggest a multiscale control of potential GHG emissions. At the ecosystem scale, we observe a positive relationship between [CO₂] and [CH₄], which appears to reflect a general upstream–downstream gradient in peat surface elevation and vegetation type. The indicators of pore water DOC quality ((aromaticity, FI, BIX) also present upstream-downstream gradient suggesting molecules of lower weight and greater microbial activities origin in the downstream where atmospheric greenhouse gases concentrations were the highest. At a more local scale, CH₄ and CO₂ concentrations are anticorrelated, suggesting a dominant influence of water-table depth and the content and quality of pore water DOC. These findings highlight the importance of considering both spatial scale and hydroecological conditions when assessing GHG dynamics over peatlands. Continued integration of UAV-based gas monitoring with field-based geochemical and ecological data offers a promising approach for improving our understanding of the complex feedbacks driving peatland carbon emissions
Osmolality of compounded oral liquids for pediatrics
No full textInternational audienceCompounding oral liquids is a common practice in pediatrics given the scarcity of medications suitable for children. However, compounded products are unlicensed. Their safety, effectiveness and quality are not assessed by regulatory agencies. Then, the assessment of critical characteristics of compounded medications relies on compounding pharmacies. Since the osmolality of oral liquids may contribute to gastrointestinal complications, this study aimed to evaluate the osmolality of compounded oral liquid medications. The osmolality of compounded liquid medications listed in the formulary of our institution was measured. The source of the active pharmaceutical ingredient and the vehicle of each compounded medication were collected. Results showed that 61% of the 28 compounded medications exceeded the recommended threshold of 450 mOsm/kg. The primary determinant of osmolality was found to be the vehicle used in compounding, with commercial vehicles being associated with higher osmolality values. The active pharmaceutical ingredient had minimal influence on the osmolality.Conclusion: These findings underscore the importance of the vehicle in the osmolality of compounded oral liquids. Careful selection of compounding vehicles is required to minimize the risks associated with high-osmolality medications, especially for vulnerable populations such as enterally fed neonates. The systematic assessment of osmolality of compound medication would support the implementation of strategies to mitigate the risks associated with high osmolality and improve the safety of compounded pediatric medications.What is known: • Compounded oral liquid medications are widely used in pediatrics due to the limited availability of commercial pediatric formulations. • High osmolality in liquid oral medications may contribute to adverse effects.What is new: • This study highlighted the significant impact of the compounding vehicle on the osmolality of compounded oral liquid medications. • Careful selection of compounding vehicles is important, especially for vulnerable children
Débats autour de la scolarisation du yoga : pratique de bien-être ou d’optimisation corporel(le) ?
No full textInternational audienceEn janvier 2019, l’EPS française intègre officiellement le yoga dans la liste nationale des activités proposées au lycée. Cette intégration peut sembler aller de soi, au regard de l’évolution des pratiques sociales, notamment la place grandissante dans nos sociétés occidentales des pratiques corporelles de bien-être. En effet, en 2021, 15 % de la population active (soit 7,6 millions de personnes) pratique régulièrement le yoga (Garcia et al., 2023). En France, cette intégration concorde avec les évolutions récentes de l’école et de la discipline EPS : injonction institutionnelle au bien-être (Collinet et Delalandre, 2014) et à la santé des élèves au sein de l’école (Salaméro et al., 2024) ; développement des activités d’entretien de soi (Combaz et Hoibian, 2009) ; préoccupations sanitaires autour de la sédentarité des élèves (Klein, 2015).Cependant, les pratiques de yoga cristallisent un ensemble de critiques ou vigilances : vigilances vis-à-vis de possibles dérives sectaires ; critiques autour de pratiques d’optimisation de soi (Röcke, 2024), de normalisation des comportements (Garcia et al., 2023) et d’injonction au bien-être selon une logique entrepreneuriale (Paintendre et Schirrer, 2024 ; Rail, 2016) ; de pratiques vues comme « caisse de résonance de l’idéologie néolibérale » (Fashi, 2023) et vectrices de normes corporelles strictes, notamment à travers des réseaux comme Instagram (Hinz et al., 2021). Pourtant, de nombreux/ses pratiquant·es sont « animés de convictions très critiques contre l’ordre établi, avec des discours volontiers anticonsuméristes » (Fashi, 2023).Face à cette ambivalence, nous posons la question de la réception en France de cette scolarisation « par le haut du yoga » en 2019 ? Comment cette intégration est-elle réceptionnée, appropriée, critiquée par les différent·es acteurs/trices de l’EPS ?Douze entretiens semi-dirigés ont été réalisés avec une diversité d’acteurs/trices de la discipline : corps d’inspection, formateurs/trices en STAPS/INSPE, enseignant·es d’EPS, enseignant·es impliqué·es dans le monde syndical.L’analyse de leurs propos révèle des points de consensus et de débats (Schirrer et Paintendre, 2022). Le yoga apparaît légitime en EPS pour le bien-être qu’il procure aux élèves et la connaissance de son corps qu’il autorise. Seul·es les acteurs/trices universitaires ou syndiqué·es formulent une critique du yoga comme pratique d’optimisation de soi dans une logique néo-libérale (Röcke, 2024). Le yoga est critiqué car il ne serait pas assez « physique » et difficile, voire impossible à évaluer. Enfin, la formation des enseignant·es est jugée inexistante
