Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Analysis of Interface Sliding in a Composite I-Steel–Concrete Beam Reinforced by a Composite Material Plate: The Effect of Concrete–Steel Connection Modes
No full textInternational audienceThis study investigates interface sliding behavior in composite I-steel–concrete beams reinforced with a composite material plate by analyzing various connection configurations combining shear stud connectors and adhesive bonding. The degree of composite action, governed by the shear stiffness at the steel–concrete interface, plays a critical role in structural performance. An analytical model was developed based on the elasticity theory and the strain compatibility approach, assuming constant shear and normal stress across the interface. Five connection modes were considered, ranging from fully mechanical (100% shear studs) to fully adhesive (100% bonding), as well as mixed configurations. The model was validated against finite element simulations, demonstrating strong agreement with relative differences between 0.3% and 10.7% across all cases. A parametric study explored the influence of key factors such as interface layer stiffness and composite plate reinforcement material on the overall interface behavior. The results showed that adhesive bonding significantly reduces slippage at the steel–concrete interface, enhancing bond integrity, while purely mechanical connections tend to increase interface slippage. The findings provide valuable guidance for designing hybrid connection systems in composite structures to optimize performance, durability, and construction efficiency
Conséquences des traumatismes faciaux sur les structures dentaires et parodontales : une revue systématique de la littérature
No full textLe massif facial est un ensemble complexe, dans lequel s’articulent des os et structures multiples. Les traumatismes faciaux représentent une catégorie importante de lésions qui peuvent entraîner des répercussions significatives sur la santé bucco-dentaire. Les traumatismes faciaux touchent une majorité d’hommes (2,6 hommes, pour 1,8 femmes). Ils concernent principalement les automobilistes (36%), les conducteurs de deux-roues (24%), ou les piétons et cyclistes (17%). Qu'ils résultent d'accidents de la voie publique, de chutes, ou de violences physiques, ces traumatismes peuvent engendrer des atteintes diverses et variées au niveau des structures dentaires et parodontales, compromettant ainsi les fonctions oro-faciales, telles que la phonation, la mastication ou la respiration. En tant que chirurgien-dentiste, nous devons être à même de gérer les situations d’urgence que représente la prise en charge de patients traumatisés faciaux. Cette gestion doit également se poursuivre avec des séances de contrôles régulières afin d’assurer la pérennité des structures dentaires et parodontales. Cette démarche se fait pour chaque traumatisme, et à tout âge ; que le traumatisme implique des dents temporaires ou permanentes
Prise en charge thérapeutique des dents permanentes expulsées, illustrée par des cas cliniques
No full textDans le cadre de cette thèse, nous abordons le sujet d’un traumatisme oro-facial : l’expulsion dentaire. Dans un premier temps, nous étudions les méthodes de diagnostic, suivi des différentes étapes de traitements, d’urgence, puis de suivi du traumatisme. L’expulsion dentaire représentent 0,5 à 3% des traumatismes de la denture permanente, et est un traumatisme grave, qui nécessite une prise en charge rapide et adaptée. Une distinction importante est à faire entre les dents permanentes immatures expulsées, et les dents permanentes matures expulsées. En effet, la prise en charge immédiate et différée, les traitements, et le suivi du traumatisme différeront grandement en fonction du degré de maturité de la dent. Cette variété de traitements, ainsi que le suivi rigoureux de protocole définis, sont importants à connaître pour le chirurgien-dentiste, afin d’assurer un bon pronostic à la dent traumatisée. Pour illustrer cette thèse, deux cas cliniques ont été choisis, afin de mettre en évidence les difficultés rencontrées en pratique clinique, ainsi que les échecs et réussites des différents traitements
Application des principes ergonomiques au service du design du cabinet, de la gestion des flux de patients et de la prévention des troubles musculosquelettiques
No full textL’augmentation de la complexité de l’environnement du cabinet dentaire influence la productivité et la masse de travail des praticiens. Les nouveautés technologiques et la diversité d’équipements à leur disposition entraînent une nouvelle variété de mouvements à effectuer pendant la réalisation des soins. La densification des protocoles, les nouvelles technologies, l’augmentation de l’importance des démarches administratives et une réglementation toujours plus exigeante forcent le chirurgien-dentiste moderne à repenser sa pratique dans sa globalité. Le design du cabinet, la gestion du flux de patients, la prévention des troubles musculo-squelettiques, deviennent des composantes indispensables à prendre en compte dès la conception du cabinet afin de favoriser un environnement de travail ergonomique et une pratique de qualité
Pulmonary glue embolism after radiological embolization of pelvic varices: a case report
No full textInternational audienceCompeting Interests: Declarations. Ethics approval and consent to participate: We obtained informed written consent from the patient to present this case report. Clinical trial number not applicable. Consent for publication: We obtained informed written consent from the patient to present this case report. Competing interests: The authors declare no competing interests.Background: Non-thrombotic pulmonary embolism (NTPE) is defined as embolization in the pulmonary circulation of biological or non-biological substances and foreign bodies. The migration of glue in the pulmonary circulation during interventional procedures is unusual and has been reported mainly after gastroenterological procedures. The most severe cases of NTPE can be life-threatening.Case Presentation: A 31-year-old woman developed respiratory failure 24 h after radiological embolization of pelvic varices. Glue embolization was detected during the intervention and was confirmed on a chest CT scan showing multiple bilateral hyperdense elements up to sub-pleural regions. The patient developed respiratory symptoms 24 h after the procedure, progressively worsening with oxygen requirement up to 6 L/min. A follow-up chest CT angiography showed a thrombotic pulmonary embolism. Treatments included curative anticoagulation, antibiotherapy, corticosteroids, and oxygen, leading to improvement after 10 days of treatment.Conclusions: This case report highlights that NTPE can occur after all interventional procedures using glue including pelvic procedures and can be complicated by thrombotic pulmonary embolism
Thermoplasticization of Paramylon by Ionic Liquids
No full textInternational audienceParamylon is a rare glucan produced by Euglena gracilis microalgae as intracellular energy storage granules. Its linear macromolecular structure involves β(1-3) glycosidic linkages that induce a triple helix conformation. This structure gives unique bioactive immunomodulating properties with potential anti-inflammatory effects. However, it also results in a native hexagonal crystallinity stabilized by hydrogen bonds, water insoluble and that does not melt below the biopolymer's degradation temperature [1]. At ILMAT 6, we showed how biobased ionic liquids (ILs) could be designed as efficient solvents of paramylon [2]. Since then, we have been exploring the melt processing of paramylon using [Cholinium][Glycinate]/water mixtures as plasticizers [3]. We will show of this approach (Figure 1.a) can be extended to other ILs, in particular containing pharmaceutically active ions, in order to make paramylon-based bioactive thermoplastic materials, that can be shaped as film by hot compression moulding or as rods by extrusion. ILs-plasticized paramylon material's structure and their properties were investigated and will be discussed. Bioactivity was evaluated by using bone marrow derived dendritic cells (Figure 1.b) to assess immunostimulant properties
Unraveling Effects of a Pesticide Mixture on Earthworm Life-Cycle: Toxic Cocktails in our Soils: When Pesticides join Forces against Earthworms
No full textInternational audienceSoils play a critical role in ecosystem functioning, yet they are increasingly threatened by agricultural intensification leading to contamination with persistent mixtures of plant protection products (PPPs). While standard environmental risk assessment typically focuses on single compounds, soil organisms are exposed to complex mixtures of PPP residues, making it crucial to understand their combined effects. Our study aims to develop a DEB-TKTD model to understand the physiological mode of action of a mixture of two prevalent PPPs in agricultural soils: epoxiconazole (fungicide) and imidacloprid (insecticide). Using the earthworm Aporrectodea caliginosa as a model organism, we first characterized the toxicokinetics of both compounds before examining their effects on reproduction through an adapted OECD guideline 222 experiment using a ray design (n = 7 mono-substance doses, n = 21 mixture doses, n = 3 replicates). By monitoring cocoon production, hatching success, and juvenile growth over 28 days, we will gather essential data to parameterize our DEB-TKTD model. The integration of mixture toxicity data into the DEB framework will provide mechanistic insights into how these PPPs interact to affect earthworm life-history traits. This DEB-TKTD model will then be incorporated into an Individual-Based Model to predict long-term effects on population dynamics under realistic exposure scenarios. This multi-level modeling approach will help bridge the gap between individual and population responses to pesticide mixtures, contributing to more environmentally relevant risk assessment procedures
Regards croisés sur la pratique des rites des administrativistes à l'étranger
No full textInternational audienceEspagne, Etats-Unis, Japon, Angleterr
Exploring superposition and interference in state-of-the-art low-parameter vision models
No full textInternational audienceThe paper investigates the performance of state-of-the-art low-parameter deep neural networks for computer vision, focusing on bottleneck architectures and their behavior using superlinear activation functions. We address interference in feature maps, a phenomenon associated with superposition, where neurons simultaneously encode multiple characteristics. Our research suggests that limiting interference can enhance scaling and accuracy in very low-scaled networks (under 1.5M parameters). We identify key design elements that reduce interference by examining various bottleneck architectures, leading to a more efficient neural network. Consequently, we propose a proof-of-concept architecture named NoDepth Bottleneck built on mechanistic insights from our experiments, demonstrating robust scaling accuracy on the ImageNet dataset. These findings contribute to more efficient and scalable neural networks for the low-parameter range and advance the understanding of bottlenecks in computer vision
