HAL - Normandie Université
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Quand les calebasses se sont tues : quelles voies pour une histoire des objets de musique amérindiens antillais (XVIIe-XVIIIe siècle) ?
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LIM kinase/inhibitor binding study in cell lysates using microscale thermophoresis in the red spectrum
No full textInternational audienceBackground: Cellular function depends on complex molecular interactions that activate signaling pathways - central to drug discovery projects. LIM kinases (LIMKs) are attractive therapeutic targets implicated in various diseases, yet no clinically approved LIMK inhibitors exist, likely due to limited understanding of their molecular behavior under near-physiological conditions. This breach stems in part from the difficulty in purifying these proteins. To address this, there is a crucial need for a simple and rapid method to determine LIMK-inhibitor binding affinities (Kd values) directly in cell lysates, bypassing challenging purification and immobilization steps.Results: The monomeric near-infrared fluorescent protein miRFP670 (excitation/emission: 640/680 nm) is an advantageous fluorescent tag for microscale thermophoresis (MST) assays in cell lysates. The miRFP670-tagged LIMKs were successfully overexpressed in HEK293 cells, characterized, and validated by western blotting. MST assay conditions - including MST buffer composition and target storage - were carefully optimized and negative controls were consistently used to ensure data reproducibility as well as assay specificity. The MST conditions were as follows: miRFP670-kinases at a fixed concentration of a few tens of nM in cell lysate supplemented with 30 % (v/v) glycerol for convenient storage; 0.005 % (v/v) DMSO in the MST buffer; 37 ◦C; 20 % LED power; medium MST power; and standard capillaries. The presence of 0.1 % Triton X-100 in the MST buffer was essential to prevent protein aggregation, as evidenced by smooth MST time traces. The reproducibility and stability of signals across all capillaries attest to the optimality of the incubation conditions and the attainment of a stable binding equilibrium. This consistency also validates the robustness of the assay. MST analysis of cell lysates yielded Kd values for full-length and kinase domains and show strong agreement with literature where available. Notably, sub-micromolar Kd values were confirmed for the reference inhibitors LX7101, BMS-5, and TH-257, with slight differences observed between full-length LIMKs and their kinase domains - differences often overlooked in the literature.Significance and novelty: This work establishes the first detailed production, characterization, and use of miRFP670 in MST-based evaluation of biomolecular interactions under near-native conditions. miRFP670 operates in a spectral region (red) with minimal cellular autofluorescence, enhancing signal specificity and sensitivity. This approach offers a straightforward and broadly applicable, purification-free platform for early-stage drug discovery
Parameter estimation algorithm for a PEM electrolyzer equivalent circuit model under current ripple conditions
No full textInternational audienceUnknown parameter estimation for electrical models of proton exchange membrane (PEM) electrolyzers is important for optimal hydrogen production and storage in power systems. Algorithms for correctly identifying parameters for different models, including equivalent circuit models (ECM), have been reported. These are important for analyzing the transient dynamics of the PEM electrolyzer connected to grid-tied power electronics sources. However, no method has been reported to correctly estimate the ECM parameters when subjected to current ripple from power electronics. Current ripple is an important issue requiring further investigations since they are responsible for the accelerated aging of electrolyzers. In this work, an algorithm has been developed to estimate the parameters of an ECM for the electrolyzer voltage under input current ripple. Furthermore, based on the gradient method, this algorithm allows adapting the parameters with the values of the proposed electronic components, i.e., resistors, capacitors, and voltage sources. The proposed algorithm has been validated using two voltage–current databases obtained from a commercial PEM electrolyzer system NMH2 1000. Thus, by efficiently estimating the ECM parameters, the proposed algorithm facilitates the design and construction of power converters coupled to the electrolyzer under current ripple constraints
Comparisons of optimal medical treatment between men and women in patients with lower extremity peripheral artery disease and exertional limb symptoms
No full textInternational audienceBackground: Patients with lower-extremity peripheral artery disease (PAD) are undertreated with women being less likely than men to receive the optimal medical treatment (OMT). The main objective was to compare the prescription of OMT between men and women in PAD patients with exertional limb symptoms. Secondary objectives were to perform these comparisons in PAD patients with history of lower-extremity revascularization (LER) and in PAD patients with coronary artery disease (CAD).Methods: This single-center observational retrospective study included PAD patients with exertional limb symptoms. OMTbi was defined as antithrombotic therapy and lipid-lowering therapy. OMTtri was defined as OMTbi associated with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Comparisons between men and women were performed at 3 levels: in all PAD patients, in PAD patients with LER, and in PAD patients with CAD.Results: Among the 877 included patients, 182 (20.8%) were women. In all PAD patients, PAD patients with LER, and PAD patients with CAD, OMTbi were 73.2%, 77.8%, 88.1%, respectively; whereas, OMTtri were 52.0%, 53.1%, 69.7%, respectively. After adjustments, in all PAD patients, no statistical differences were found between men and women for OMTbi (75.0% vs. 66.5%, P = 0.2838) and OMTtri (53.7% vs. 45.6%, P = 0.8446). Similar results were found in PAD patients with LER and in PAD patients with CAD.Conclusion: The findings of this study indicated that there was no statistically significant difference between men and women in terms of OMTbi or OMTtri. PAD Patients with CAD were the best treated. The number of patients who received OMTbi and OMTtri needs to be improved
Infinitely many saturated travelling waves for a degenerate Fisher-KPP equation not in divergence form
No full textInternational audienceWe consider an epidemic model with distributed-contacts. When the contact kernel concentrates, one formally reaches a very degenerate Fisher-KPP equation with a diffusion term that is not in divergence form. We make an exhaustive study of its travelling waves. For every admissible speed, there exist not only a unique non-saturated (smooth) wave but also infinitely many saturated (sharp) ones. Furthermore their tails may differ from what is usually expected. These results are thus in sharp contrast with their counterparts on related models
Torrefied biomass (Biotorr) potential for agricultural applications. A review
No full textInternational audienceCrop residue management has gained attention for its potential to increase soil organic matter and improve soil health in agricultural systems. For these purposes, pyrolysis of crop residues, to produce biochar, and its impacts on soils have been extensively studied, but torrefied biomass (biotorr), produced by torrefaction between 200 and 300 • C represents a promising alternative. Torrefaction offers advantages such as higher mass yields and lower production costs, which could make it an accessible and cost-effective soil conditioner.This review synthesises current knowledge on the effects of torrefaction on the properties of biotorr and assesses its potential as a soil conditioner. The results showed that torrefaction affects the composition of biotorr differently depending on the feedstock and the torrefaction parameters. While the yield of biotorr decreased with increasing torrefaction temperature, it was still higher than that of biochar. Compared to the feedstock, the carbon content and stability of biotorr improved significantly. Our analysis also indicated higher levels of P and K in biotorr, although further research is needed to determine their bioavailability.Given these results, biotorr shows a strong potential as a soil conditioner to improve soil health and support sustainable agriculture. However, it is now necessary to further investigate the potential of biotorr for agricultural application through field experiments, especially to assess how biotorr affects soil nutrient dynamics and carbon sequestration.</p
Revealing the promoting effect of ZnO on Cu clusters-embedded in self-pillared pentasil zeolites for CO2 hydrogenation to methanol
No full textInternational audienceDespite extensive studies on Cu-ZnO catalysts for CO2 hydrogenation, the atomic-level understanding of Cu-ZnO interfacial synergy remains elusive due to challenges in controlling the size and spatial distribution of Cu clusters. Well-dispersed Cu clusters with an average diameter of 1.8–3.6 nm, successfully anchored in the mesopores of the self-pillared pentasil zeolite (SPP) with a narrow size distribution, were prepared using the traditional impregnation method. The abundant surface-OH groups in SPP zeolite not only facilitated the high dispersion of Cu clusters but also effectively suppressed undesirable agglomeration of the Cu clusters under reaction conditions. The highest turnover frequency (TOF) of CO2 conversion (1.64 h−1) and space-time yield (STY) of methanol (12.7 mgMeOH × h−1gcata−1) was achieved on Cu9.4-SPP. The incorporation of ZnO significantly enhanced methanol selectivity and CO2 conversion of CuZn-SPP. The methanol STY over it reached 45.3 mgMethanol × h−1×gcata−1, which is 3.6 times that of Cu9.4-SPP. Quasi-in situ XPS and in situ FTIR results reveal the strong synergistic effect between partial oxidation of the Cu clusters and an interfacial ZnO, enhancing the stability of adsorbed bidentate HCOO∗ species. The set of experimental results revealed that the bidentate formate formation and consumption rates were accelerated by the addition of ZnO in the formate mechanism, which could be used for further optimization of CO2 hydrogenation catalysts
Le monde de l'opéra, et le nôtre
No full textInternational audienceL’opéra n’est pas seulement une œuvre musicale, mais une œuvre fictionnelle où les personnages parlent en chantant (parlare cantando, selon l’expression de Monteverdi), et où la musique instrumentale est présente presque continûment. Aussi l’opéra, contrairement aux autres formes de théâtre musical, a-t-il été accusé d’invraisemblance. Or pour aimer l’opéra, il faut en comprendre la vraisemblance propre, et ne pas faire du chant une convention arbitraire. Ce n’est pas malgré le chant, mais grâce au chant que l’opéra raconte de bonnes histoires, pouvant surpasser le médium théâtral (qu’on songe à Don Giovanni, Pelléas et Mélisande ou à Dialogues des carmélites). Mais alors, quel est le monde de l’opéra, et en quoi diffère-t-il du nôtre ? Quelles sont les implications pour la mise en scène d’opéras