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Assessment and Surgical Correction of Posterior Tibial Slope in Revision Anterior Cruciate Ligament Surgery: An International Expert Delphi Consensus Statement
No full textInternational audiencePurpose: The aim was to provide international guidelines to enhance decision-making regarding the definition and evaluation of increased posterior tibial slope (PTS) and the role of anterior closing wedge high tibial osteotomy (ACWHTO) in the setting of revision anterior cruciate ligament reconstruction (ACLR). Methods: This guideline is based on responses from 46 international orthopedic surgeons with expert experience in knee pathologies and osteotomy. Based on a literature review, each expert drafted and commented on a set of core statements. The provided comments were blinded and discussed within the working group to refine the statements. In a subsequent round of surveys, all experts discussed with the final 32 statements. Consensus was achieved when at least 80% of survey respondents fully agreed. Results: With respect to ACWHTO for PTS reduction, there was consensus achieved for using the medial plateau as a measurement for PTS measuring, aiming for PTS correction of 5 - 7 degrees, individualizing osteotomy wedge thickness, and performing ACWHTO and revision ACLR in a single stage. There was no consensus on the type of radiographs to be used, a cut-off value for increased PTS, an absolute indication for ACWHTO the osteotomy technique, nor type of fixation. The International consensus statements aim to bridge the gap between research and clinical application to enhance clinicians’ decision-making in revision ACLR management and to focus future areas of required research. Conclusion: The literature review confirmed a paucity of evidence to guide clinicians in the diagnosis and surgical management of increased PTS. An agreement could be achieved for 25/32 statements (78%) on the definition and assessment of PTS, indication, planning, surgical decision-making, and peri- and postoperative management for ACWHTO. While no consensus could be achieved for the definition of a cut-off value for pathological PTS, consensus was reached for a variety of statements on diagnostic and surgical aspects
Phase Behavior of CO2 + 2,2-dimethylbutane and CO2 + 2-methylpentane from 293 K to 363 K and at Pressures up to 11 MPa
No full textInternational audienceThis study is a continuation of a series of works concerning the acquisition of new experimental data related to binary mixtures of branched alkanes with CO 2 . A synthetic method was employed to measure phase transition pressures for the systems CO 2 + 2,2-dimethylbutane and CO 2 + 2-methylpentane with an adjustable-volume high-pressure cell. To our knowledge, these binary systems were investigated for the first time in this work. Bubble and dew point pressures were obtained by visual detection at constant composition with an expanded uncertainty ranging from (0.04 to 0.08) MPa. Mixtures were investigated at temperatures ranging from (293.15 to 363.15) K with pressures up to 11 MPa. The Peng-Robinson equation of state was used to correlate the experimental data. An accurate representation of the results has been obtained by using classical mixing rules with temperature-dependent binary interaction parameters regressed against experimental data. The predictive model PPR78 has also provided satisfactory results
Exploring the thermophysical properties of biodiesel: high-pressure density and speed of sound prediction with PC-SAFT and ester composition models
No full textInternational audienceThis paper presents comprehensive experimental data on the density (ρ), the speed of sound (c), the isentropic compressibility (κ s ), and the acoustic impedance (Z) for three methyl biodiesels derived from coconut, sucupira, and canola oils. Measurements were carried out over a broad range of pressure (0.1 to 200 MPa) and temperature (293.15 to 373.15K), providing valuable insights into the thermophysical properties of biodiesel under extreme conditions. Speed of sound was measured via the pulse-echo technique in the full p,T range. Density was measured using a U-shaped vibrating tube densimeter and up to 100MPa and extended to 200 MPa by integrating the speed of sound data. The experimental data were compared to PC-SAFT equation of state calculations, and to the predictions of two specific models developed to calculate the thermophysical properties (density, speed of sound, isentropic compressibility, and acoustic impedance) of methyl biodiesel up to 200 MPa, based solely on the fatty acid methyl ester composition. Both the experimental and modeling results contribute to a deeper understanding of biodiesel's behavior under high-pressure conditions at varied temperatures, enhancing its practical application in advanced fuel injection systems and supporting its potential as a sustainable alternative fuel.</div
Chitosan-based coatings to prevent Nitratidesulfovibrio vulgaris influenced (bio)corrosion on aluminium alloy
No full textInternational audienceChitosan, a natural polymer derived from chitin, is widely recognized for its biocompatibility, biodegradability, and in particular antimicrobial properties. This study investigates the effectiveness of chitosan grafted onto aluminium Al 2024 alloy substrates in preventing (bio)corrosion, specifically in the presence of the sulfate-reducing bacterium Nitratidesulfovibrio vulgaris (formerly Desulfovibrio vulgaris), a model organism for biocorrosion. Chitosan-based coatings of micrometer thickness were applied using a dip-coating method, which is easy to implement in industrial settings. The coatings were applied to both mirror-polished aluminum substrates, with and without triethoxysilylpropylsuccinic anhydride (TESPSA) for functionalization. Weight loss analysis, profilometry, epifluorescence microscopy, and X-ray photoelectron spectroscopy (XPS) were conducted on the chitosan-coated aluminium alloy before and after microbial incubation. The results showed that chitosan coatings, particularly those functionalized with TESPSA, significantly reduce (bio)corrosion and microbial growth. Notably, the 2 % w/v chitosan coating demonstrated strong adhesion, with less than 5 % detachment under tape tests and no detachment observed after five weeks of exposure to N. vulgaris, and substantial (bio)corrosion resistance. Epifluorescence microscopy revealed a nearly tenfold decrease in bacterial coverage compared to the uncoated substrate. XPS showed minimal impact from N. vulgaris on the 2 % w/v chitosan-coated aluminium, with a stable C/N ratio of 7.4 + /- 0.2 before and after incubation. Electrochemical corrosion tests indicated that the combination of chitosan coatings and TESPSA functionalization significantly decreases the corrosion rate, despite a minor increase in susceptibility to corrosion. These findings highlight the potential of chitosan-based coatings, especially when paired with surface treatments like TESPSA functionalization, to effectively combat corrosion and (bio)corrosion of aluminum alloys
Mixing of Two Microbial Consortia in the Search for Stimulating Chromium Depletion
No full textInternational audienceTwo bacterial consortia (C55 and C33), obtained from an industrial residue contaminated with hexavalent chromium (Cr(VI)), were used to study the behavior of their mixture for depleting this ion in liquid media. In the absence of Cr(VI), C55 showed a greater growth rate than C33, while the latter exhibited biofilm formation. In the presence of this ion, C55 showed resistance up to 800 mg·L −1 and an ability to diminish up to 400 mg·L −1 of the Cr(VI) from the medium, while for C33, these concentrations were 400 and 200 mg·L −1 , respectively. Bacterial synergism between these consortia was evaluated using different compound ratios (C55:C33 ratios of 1:1, 1:2, and 2:1), growing at 50, 100, and 200 mg·L −1 Cr(VI). The best half‐lives of Cr(VI) decrease were 16, 31, and 98 h, respectively, for the 1:1 mixture. The ability of C33 and the mixed consortia to form biofilms was verified. MiSeq sequencing revealed 4 major populations for C55 (in a total of 14) and 3 for C33 (8), most of which were common. After an isolation process, 2 bacterial strains were obtained from C55 and 4 from C33. Three of these strains (QRePLB33E, similar to Oceanobacillus profundus ; QRePLB33G, to Shouchella clausii ; and QRePLB55C, to Cellulosimicrobium funkei ) showed resistance to Cr(VI) and the ability to remove 100% of it at least up to 300 mg·L −1 . Thus, synergism between different bacterial consortia obtained from the same site is possible and can improve, by complementing their capacities, both the growth rate and the ability to diminish the xenobiotic from the medium
Glycogenic hepatopathy in a primitive teleost fish model: the inductive effect of high carbohydrate diet and the alleviating role of betaine
No full textInternational audienceCarbohydrate-induced glycogenic hepatopathy is underdiagnosed and difficult to discriminate from hepatic steatosis in humans. The present study used liver biopsy and other diagnostic tools, and adopted metabolomic technology to identify glycogenic hepatopathy rather than hepatic steatosis in largemouth bass induced by high carbohydrate diet (HC). HC induced obvious liver injury in largemouth bass with disarranged hepatocytes, partial cell membrane damage, and irregular distribution of nuclei, accompanied by increased serum ALT and AST activities. PAS staining and glycogen content analysis detected significant increases in liver glycogen content, whereas intrahepatic triglyceride content and programmed cell death were not affected. Metabolomic analysis indicated that up-regulated metabolites were mainly enriched in glycogen synthesis precursors, whereas betaine and unsaturated fatty acids were down-regulated, confirming that HC induced glycogenic hepatopathy rather than hepatic steatosis in largemouth bass. The significantly decreased betaine in both serum and liver of largemouth bass served as a potential key regulator in such disease, whose supplementation could alleviate HC-induced liver injury and serum ALT activity. Betaine supplementation increased betaine and carnitine contents in liver and serum, resulting in decreased hepatic glycogen deposition and cortisol content in largemouth bass. Further study showed that dietary betaine significantly improved the capacity of largemouth bass to resist against ammonia stress. Therefore, our study established a glycogenic hepatopathy-inducing and evaluation model in a primitive teleost and also identified the betaine as the key metabolic marker and prevent strategy, which help advance the understanding of human liver diseases
Une collection de monnaies au musée de Foix : du commun à l'insolite
No full textCentre Jean Clottes, Parc de la Préhistoire, Tarascon-sur-Ariège (27 avril 2024)International audienc
Three‐Phase PV Pumping System With Advanced Control for Enhanced Efficiency and Robustness: Modeling, Experimental Validation, and Optimization
No full textInternational audienceThis paper presents a detailed study of a three‐phase photovoltaic pumping system (PVPS), comprising a 1.5‐kW three‐phase induction motor for water pumping, a three‐phase voltage source inverter (VSI), and a DC‐DC boost converter designed to maximize power extraction from a 1.88‐kWp photovoltaic generator (PVG). The system is characterized by its cost‐effectiveness, high efficiency, and robust performance. To reduce overall system costs, the inductor current of the boost converter and the rotational speed of the induction motor are estimated rather than measured directly. A nonlinear neural network observer (NNO) is employed to estimate the inductor current, whereas a sliding mode observer (SMO) is utilized to estimate the motor speed. To enhance the system's resilience against internal and external disturbances, a hybrid incremental conductance super‐twisting sliding mode controller (InC‐STSMC) is implemented for maximum power point tracking (MPPT) from the PVG, and a flux‐oriented sliding mode vector control (FO‐SMC) is adopted for precise regulation of the motor speed. The effectiveness of the proposed control strategy is evaluated through model‐in‐the‐loop (MIL) simulations conducted in the MATLAB‐Simulink environment, demonstrating significant improvements in dynamic performance, particularly in terms of stability and robustness, compared to conventional proportional‐integral (PI) control methods. The practicality and suitability of the proposed InC‐STSMC combined with the NNO scheme are further validated through a processor‐in‐the‐loop (PIL) test using the STM32F769I board, highlighting its potential for real‐world applications
Expertise in futurum et monopole du représentant de la masse des obligataires
No full textInternational audienceNote sous Cour de cassation, com., 9 octobre 2024, no 23-10.645 (F-B
