Publications scientifiques de l'Université de Reims Champagne-Ardenne
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[Poster]#132 Exploring the Interactions between drugs and metabolic disturbances in CKD: an example with oral anticoagulants
No full textInternational audienceBackground and Aims The metabolic disturbances associated with chronic kidney disease might alter drug distribution, decrease albumin drug binding, and thus increase the free (unbound) drug concentrations. Along with direct toxic effects on tissues, uremic toxins can affect the pharmacokinetic or pharmacodynamic activity of certain drugs. Vitamin K antagonists (VKA) are interesting candidates for the evaluation of potential interactions between uremic toxins and drugs. The primary objective of the present study was to investigate the association between free VKA concentrations and the decline in the estimated glomerular filtration rate (eGFR). Furthermore, we sought to determine whether this relationship was mediated by protein carbamylation (measured by homocitrulline levels) and/or the accumulation of protein-bound uremic toxins (PBUTs). Method In this prospective cross-sectional study, 389 adult patients treated with VKA were included between May 2021 and June 2023. For each patient, levels of free VKAs, total VKAs, homocitrulline and PBUTs were assayed using liquid chromatography-tandem mass spectrometry. We used a linear regression model to explore the association between kidney function and free VKA levels and used conventional mediation analyses to determine whether the association between kidney function and free VKA levels was mediated (at least partly) by PBUTs and/or protein carbamylation. Results Of the 389 patients included, the median age [IQR] was 75 [66–83]. Patients with an eGFR <40 mL/min/1.73 m² or those on chronic hemodialysis had lower total VKA levels, higher free VKA levels and thus a higher of free/total VKA ratio than those with an eGFR ≥40 mL/min/1.73 m². Kidney function was independently associated with free VKA levels (β1 = 0.31 [0.19; 0.43], P < 0.001). Twenty percent [95% CI, 0.7%–34%] of the association between kidney function and free VKA levels was mediated by homocitrulline. This association was not mediated by PBUTs. Conclusion Our results showed that a decline in kidney function was associated with an elevation in the free drug fraction (taking VKAs as an example). This association was independent of blood albumin levels and appeared to be partly mediated by protein carbamylation
Le séisme profond de Coaraze (ML 4,1 ; 18 mars 2025, Arc de Nice, France) : où est la faille ?
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Conditional expectations in Quantum Mechanics and causal interpretations: the Bohm momentum as a best predictor
No full textGiven a normalized state-vector , we define the conditional expectation of a Hermitian operator with respect to a strongly commuting family of self-adjoint operators as the best approximation, in the operator mean square norm associated to , of by a real-valued function of A fundamental example is the conditional expectation of the momentum operator given the position operator , which is found to be the Bohm momentum. After developing the Bohm theory from this point of view we treat conditional expectations with respect to general , which we apply to non-relativistic spin -particles modeled by the Pauli equation, conditioning with respect and to a component of the spin operator. We derive the dynamics of the conditional expectations of momentum and spin which can be interpreted in terms of a classical two-component fluid whose components carry intrinsic angular momentum. The joint spectrum of the conditioning operators can be interpreted as a space of beables. To arrive at a Bohm-style causal interpretation one additionally needs a particle dynamics on this beable space which is compatible with the time evolution of the Born probability. This can be done for spin particles by combining the de Broglie-Bohm guidance condition with J. Bell's idea of using Markov jump processes when the spectrum is discrete. A basic problem is that such auxiliary particle dynamics are far from unique. We finally examine the relation of with conditional expectations of -algebras when has discrete spectrum. As an application, we derive an evolution equation for when satisfies an abstract Schr\"odinger equation which takes a simple form when Two appendices re-interpret the classical Bohm model as an integrable constrained Hamiltonian system, and provide the details of the two-fluid interpretation
Les moyens numériques pour accompagner les élèves présentant des troubles des apprentissages
No full textProductions des groupes thématiques numériques (Direction du numérique pour l’éducation du Ministère de l'Éducation nationale, de l’Enseignement supérieur et de la Recherche)Ce bulletin de veille est rédigé dans le cadre du groupe de travail GTnum #EBEP (2021-2024), intitulé « Les apports des technologies numériques au développement et aux apprentissages des élèves à besoins éducatifs particuliers », porté par le 2LPN (Université de Lorraine) et le C2S (Université de Reims-Champagne-Ardenne). Le bulletin adopte une approche générale basée sur la littérature scientifique afin d’identifier trois types d’accompagnement en classe : rééducatif, compensatoire et accessibilisant. Bien que ces catégories facilitent l’analyse, elles restent théoriques et souvent imbriquées dans la pratique
« Recension de LA BIGNE Yolaine de, L'animal médecin. Les secrets du soin chez les animaux, Paris, Éditions Alisio, coll. « Alisio Sciences », 2023 »
No full textInternational audienceL’ouvrage dirigé par Yolaine de la Bigne, L’animal médecin (2023), explore la zoopharmacognosie (l'automédication animale) et les liens thérapeutiques inter-espèces. Il réunit des experts (biologistes, vétérinaires) pour reconnaître les savoirs médicaux animaux et leur rôle pour la santé humaine, notamment mentale
« Recension de TISSERAND Chloé, Calais, une médecine de l’exil, Saint-Denis, Presses Universitaires de Vincennes, coll. « Singulières Migrations », 2023 »
No full textInternational audienceRecension d'ouvrage. Chloé Tisserand, dans Calais, une médecine de l’exil (2023), analyse comment le "lieu-frontière" de Calais transforme le soin. Son ethnographie révèle les dilemmes des soignants face à la précarité et aux marques de la violence. Ils réinventent une médecine de l’urgence par le care et l'ingéniosité pour rétablir la dignité des exilés
Refractive indices of Titan, Pluto and Exoplanet photochemical haze analogs from UV to far-IR : a comparative study between the PAMPRE and COSmIC experimental setups
No full textInternational audienceThe observations of planetary atmospheres and surfaces strongly rely on the use of experimental data to understand the interaction between light and particles. The intrinsic optical properties of these particles, also known as the refractive indices, describing light dispersion (i.e., n) and absorption (i.e., k), are required to consider the influence of their chemical composition. Only with these data can we interpret observations and avoid large degeneracy in the retrieval data analyses. Climate modeling is also strongly sensitive to these experimental data as atmospheric particles absorb and scatter radiations, and thus modify the temperature profile.Photochemical hazes are observed in the atmospheres of the different objects in the outer Solar System (Titan, Pluto, Triton, Jupiter, Saturn) as well as in exoplanet atmospheres (e.g., GJ1214 b). The observations of these different objects as well as the modeling suggest that the composition of photochemical hazes varies from one object to the next following changes in the irradiation efficiency, temperature, pressure and gas composition. These differences in composition suggest that the refractive indices of photochemical hazes are also function of pressure, temperature, irradiation efficiency and gas composition. In the present work, we produced laboratory analogs of these hazes from various gas mixtures with controlled abundances. We used 6 different gas compositions to mimic the atmospheric compositions of Titan, Pluto and exoplanets. Among the 6 conditions, we modified the N2/CH4 and CO/CH4 abundance ratios in the gas mixture to assess the influence of N2 and CO on the refractive indices of the haze material. In addition, we compared the influence of the experimental setup by using haze analogs produced with the PAMPRE (LATMOS, France) and COSmIC (NASA Ames, USA) experimental setups. This cross-laboratory comparison allows us to assess the influence of temperature, pressure, gas residence time and irradiation which are changing between PAMPRE and COSmIC. Using several optical measurements, we covered a broad spectral range from UV to far-IR (up to 200 microns) which is essential for climate calculations and to interpret the various remote-sensing observations of these planetary bodies.Our results revealed a significant difference between the refractive indices obtained on PAMPRE and COSmIC analogs, even for similar gas compositions. Based on previous elemental analyses of the haze analogs, we know that the COSmIC analogs are richer in nitrogen relative to carbon compared to the PAMPRE analogs. Here, we show that this difference in composition leads to higher n and k values for the COSmlC analogs in the entire spectral range. We found that changes in the CO/CH4 gas ratio have a rather poor influence on the refractive indices compared to the effect of the N2/CH4 ratio. We also found that hazes produced without nitrogen are more transparent in the entire spectral range from UV to IR with very different mid-IR absorption features that could help distinguish between N-rich and N-poor exoplanet atmospheres. These data should be used for future observational analyses and modeling simulations of sub-Neptune atmospheres and Solar System gas giants
