Portail HAL de l'Université Picardie Jules Verne
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Theoretical and Computational Advances in Solvent Effect on NMR Spectroscopy
No full textInternational audienceAccurate computational prediction of NMR chemical shifts requires proper treatment of solvent effects, which influence nuclear shielding through electrostatic polarization, hydrogen bonding, and dispersion interactions. This review examines computational methodologies from continuum solvation models (PCM, COSMO) to explicit approaches incorporating ab initio molecular dynamics and QM/MM schemes. We evaluate method performance and provide practical guidelines for methodology selection based on solute-solvent interaction types and system size. Emerging machine learning approaches are discussed. While significant progress has been achieved, quantitative accuracy requires careful integration of quantum mechanical theory, statistical mechanics, and validation against experimental data
Evidence for a full clausal (CP) structure in nominalizations: tense and evidentials in Karitiana complement clauses.
No full textInternational audienc
Lyon ESD Dissection score: A pre-procedure prediction model for operating time in colorectal endoscopic submucosal dissection
No full textInternational audienceBackground and aimsColorectal endoscopic submucosal dissection (ESD) is an effective curative technique for superficial colorectal lesions but remains technically demanding, with variable procedure times. This study aimed to develop and validate a pre-procedure predictive model for colorectal ESD duration in the era of traction-assisted strategies.MethodsWe retrospectively analyzed prospectively collected data from patients who underwent colorectal ESD at Edouard Herriot Hospital (Lyon, France). The derivation cohort included 423 cases (January–December 2024) and an independent temporal validation cohort 148 cases (January–May 2025). A generalized linear model with a gamma distribution and log-link function identified independent pre-procedural predictors of ESD duration. Variables were selected based on univariate significance and the Akaike Information Criterion. Model calibration and discrimination were assessed using R2, mean absolute error, and classification accuracy at predefined thresholds (60, 90, 120 minutes). A point-based score (Lyon ESD Dissection Score, LEDs) and nomogram were derived from model coefficients.ResultsMedian procedure time in the derivation cohort was 50 minutes (IQR 30–90). Independent predictors of ESD duration included dissection speed of endoscopists, lesion location (flexures, appendix, cecum, ileocecal valve), predicted lesion size, and suspected fibrosis (all p < 0.05). The LEDs provides a direct estimation of the expected procedure time in minutes based on these variables, showing a strong correlation between predicted and observed durations (R2 = 0.52). Classification accuracy was 76.1%, 82.2%, and 88.1% for thresholds of 60, 90, and 120 minutes, respectively. Validation confirmed good performance (R2 = 0.48) with 91.8% accuracy for procedures ≥120 minutes.ConclusionThis validated pre-procedure scoring system accurately predicts colorectal ESD duration, especially for longer procedures. It may facilitate scheduling, optimize resource use, and improve workflow in endoscopy units
How French vascular physicians treat cancer associated superficial vein thrombosis?
No full textInternational audienceBackgroundSuperficial vein thrombosis (SVT) is a common and well-known condition. Active cancer increases the risk of thrombosis, particularly for SVT associated with catheters in the upper limbs. Despite its frequency, cancer-associated SVT management is not addressed by current evidence-based guidelines, leading to heterogeneous clinical practices.ObjectiveTo describe the current management strategies for cancer-associated SVT among French vascular physicians.MethodsWe conducted a national cross-sectional declarative survey distributed to all the members of both the French Society of Vascular Medicine and the French Association for Oncological Supportive Care. The questionnaire explored demographics and clinical approaches to SVT associated with cancer, both in the lower and upper limbs, through proposed scenarios.ResultsA total of 136 physicians responded, of whom 132 (97.1%) were vascular specialists. SVT of the lower limbs was considered cancer-associated in 15% of cases in daily practice. Among respondents, 102 (75.7%) declared modifying their treatment strategy in the presence of cancer. Fondaparinux 2.5 mg/day (44.1%) and curative-dose low molecular weight heparin (30.9%) were the most common initial treatments. Treatment lasted six weeks in 50.7% of cases and was extended as long as cancer remained active in 38.7%. Oral relay was considered in 19.1% of cases, mainly with apixaban. For upper limb SVT, 27.7% were considered cancer-related, and one third were catheter-associated. Treatment was commonly stopped upon catheter removal.ConclusionThis survey reveals substantial variability in the treatment of cancer-associated SVT. The absence of dedicated trials and specific recommendations highlights the urgent need for prospective studies to guide management in this complex clinical setting
MoS2 quantum dots based next-generation micro-supercapacitors
No full textInternational audienceThe drive for compact, high-performance energy storage has spurred research on quantum-engineered materials with ultrafast, reversible ion-electron dynamics. In this context, we demonstrate a mixed-phase 1 T/2H-MoS2 quantum dot (QD)-based electrode prepared via a pulsed electrodeposition method, with precise control over the composition and morphology, as a potential supercapacitance. When evaluated in 0.5 M H2SO4 electrolyte, the optimized electrode delivered an exceptional specific capacitance of 741 F·g−1, accompanied by remarkable cycling stability, maintaining 89.6% of the initial capacitance over 35,000 charge-discharge cycles. Furthermore, symmetric MoS2 QDs devices implemented in a parallel-plate configuration exhibited a capacitance of 272 F·g−1, an impressive energy density of 112 Wh·kg−1, a power density of 3712 W·kg−1, and a retaining capacitance of 77% after 20,000 cycles. These results underscore the efficacy of the electrodeposition approach for tailoring mixed-phase MoS2 QDs with synergistic metallic and semiconducting domains, enabling rapid ion diffusion and superior charge-storage characteristics. Overall, this work establishes a scalable, solution-based route toward high-performance symmetric micro-supercapacitors, paving the way for their integration into next-generation flexible and miniaturized energy storage systems
Ferroelectric and dielectric studies of a ferroelectric liquid crystal (FLC) dispersed ferroelectric nanoparticles (NPs) : Impact of NP dispersions on the rotational viscoelastic properties of the FLC
No full textInternational audienceThis study focuses on the effects of dispersing tin thiohypodiphosphate ferroelectric nanoparticles (Sn2P2S6) on the structural, ferroelectric, and dielectric properties of a ferroelectric liquid crystal (SmC*) phase. Our findings show that nanoparticle dispersion leads to modifications in phase transition temperatures, spontaneous polarization, and dielectric relaxation modes associated with ferroelectricity. These effects are attributed to changes in the viscoelastic parameters of the SmC* phase. Two concentration regimes were identified: at low concentrations, nanoparticles are well-dispersed, introducing local defects in the smectic layers and distortions in the helical structure, thereby enhancing the viscoelastic properties of the FLC. At higher concentrations, aggregation of nanoparticles reduces the dispersion effects, and the nanocomposite behavior tends to resemble that of the pure liquid crystal
Investigation of the lithium extraction mechanism from LiNi0.6Mn0.2Co0.2O2 by using operando neutron diffraction in an all-solid-state battery
No full textInternational audienceAll‐Solid‐State Batteries (ASSBs) are promising emerging devices for meeting high‐energy demands and an in‐depth understanding of the reaction mechanisms occuring during their operation will help in their design for better performance. In this context, neutrons, with their high penetration depth and sensitivity to light elements such as lithium, provide a powerful tool for investigating the structural mechanisms occurring in bulk ASSBs, while the electrochemical operation of large batteries (required for neutron diffraction) remains a challenge. In this study, we demonstrate the reversible electrochemical Li + extraction/insertion within a 2.5 mm thick ASSB system comprising 140 mg of LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622) as the positive electrode material (238 mWh energy density), Li 5.4 PS 4.4 BrCl 0.6 (LPSClBr) as the solid electrolyte and Li 0.5 In as the negative electrode. Thanks to the use of the newly‐designed ILLBAT#5 electrochemical cell, we were able to perform operando neutron powder diffraction (NPD) of the system, which coupled with ex situ diffraction, allowed us to gain valuable insights into the structural evolution of NMC622 within the ASSB as well as to probe the structural stability of the Argyrodite solid electrolyte throughout the initial cycle. Herein, we report on the formation and the co‐existence of H1‐H2 phases in NMC622, attributed to system inhomogeneity
Development of a generic physiologically based pharmacokinetic (PBPK) model for female mouse including gestation: application to PFOA to link environmental levels to new approaches methodologies (NAMs) results for environmental risk assessment
No full textInternational audiencePerfluorooctanoic acid (PFOA) has been widely detected in human serum, umbilical cord blood and breast milk, indicating potential prenatal and lactational exposure of the general population. Experimental studies in animal models have raised concerns regarding developmental and neurotoxic effects of PFOA. Mice are commonly used in developmental neurotoxicity studies to investigate the effect of exposure to pollutants. Neurodevelopmental research frequently relies on neurobehavioral observations, without measuring or evaluating the corresponding internal concentrations of pollutants within the offspring's brain. Physiologically Based Pharmacokinetic (PBPK) models allow predicting the toxicokinetic behavior of xenobiotics in an organism, based on chemical and physiological properties. In this study, a generic mouse PBPK model including gestation and lactation has been developed. This model comprises six compartments for dams and five for the pup including the brain compartment. It describes the dam's growth from birth and pup from the early embryonic stages, as well as the changes in organ volumes and blood flows. The generic mouse model has been parametrized for PFOA. This model enables the simulation of PFOA distribution and its internal concentration in the offspring's brain resulting from maternal oral exposure. Our case study demonstrates the use of a mouse-specific PBPK model, incorporating gestation and lactation in an in vitro in vivo extrapolation (IVIVE) context, to integrate New Approach Methodologies (NAMs) into neurotoxicity assessment