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N<sub>2</sub>-broadening coefficients and their temperature exponents for ethylene lines: A semi-empirical approach for (exo)planetary studies
No full textInternational audienceNitrogen-broadening coefficients for ethylene absorption lines in the ν 7 band are computed theoretically to fill in the enormous gaps existing in available experimental data. A semiempirical method relying on the Anderson theory is employed for this purpose, with the model parameters adjusted on some rare room-temperature measurements and used further for calculations in extended temperature ranges. The spectroscopically active molecule C2H4 is rigorously treated as an asymmetric top, and its energy levels and wavefunctions are accurately computed by a quantum-chemistry methodology based on ab initio potential energy surfaces. Theoretical broadening values are obtained for the temperature range 100-1000 K relevant to studies of planetary and exoplanetary atmospheres. These values are further analyzed by the traditional power law to get the associated temperature-dependence exponents. Comparisons of the computed theoretical results with previous measurements and calculations are provided at a low temperature of 173 K to validate the theoretical method chosen. Since the power law describes perfectly the considered temperature range, the sets of reference-temperature broadening coefficients and their temperature exponents can be safely used for higher temperatures where semi-classical approaches applicability only grows. These data are provided for the quantum numbers 0 ≤ J ≤ 47, K ≤ 26 and the three P -, Q-, R-branches of the ν7 band, i.e. represent the most comprehensive up-to-date description of N2-broadened ethylene linewidths suitable for integration into spectroscopic databases and high-temperature simulations of (exo)planetary atmospheres.</div
Processing of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) Using Acetic Acid: An Eco-friendly Alternative to Chloroform
No full textInternational audienceAbstract The pervasive accumulation of plastic waste in terrestrial and aquatic environments has become a critical environmental issue, largely due to the resistance of petroleum-derived polymers to microbial degradation. This persistence leads to the long-term generation of microplastics and widespread ecosystem contamination. As a response, biodegradable and bio-based materials such as polyhydroxyalkanoates (PHA) have emerged as promising sustainable alternatives. Among them, poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) is a microbial polyester that exhibits excellent biodegradability, biocompatibility, and tunable mechanical properties. Owing to these characteristics, P(3HB-co-4HB) can be employed in a wide range of applications, from environmentally friendly packaging to biomedical devices. However, its processing has traditionally relied on toxic solvents such as chloroform. In this study, acetic acid is evaluated as a green alternative solvent for producing P(3HB-co-4HB) films and porous gels. Compared with chloroform, acetic acid caused moderate reductions in molecular weight (–12% for 10 mol% 4HB and − 5% for 34 mol% 4HB) and slight decreases in thermal stability, while degradation kinetics remained unaffected. DSC analyses revealed enhanced melting enthalpy for P(3HB-co-10 mol%4HB) films and the emergence of additional crystalline populations for P(3HB-co-34 mol%4HB). Mechanical tests showed moderate reductions in ductility and modulus at low 4HB content, whereas high 4HB content was unaffected. FTIR spectra confirmed the absence of solvent-induced chemical modifications. In addition, a simple thermally induced phase separation method produced highly porous (≈ 90%) gels. Overall, this study demonstrates that acetic acid offers a sustainable processing route for P(3HB-co-4HB), while preserving key material properties comparable to those obtained with chloroform
Former à la diversité des contextes, deux modélisations pour une professionnalisation réflexive en FLE
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Mid-Holocene wet optimum and Early-Late Holocene arid phases shaped steppe-forest vegetation and human societies of Uzbekistan: Multi-proxy evidences from Lake Fazilman
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Evidence for the absence of a relationship between inflammation and cognition in a cohort of 1565 individuals with bipolar spectrum disorders: a Bayesian analysis of network
No full textInternational audiencePrevious studies have reported variable associations between peripheral inflammatory markers and cognitive functioning in individuals with bipolar spectrum disorders (BSD), with some identifying significant links and others finding no relationship. Such inconsistencies raise important questions about the role of inflammation in cognitive impairment among individuals with BSD. This study aims to investigate the relationship between peripheral inflammatory markers and cognitive function in a clinical sample of individuals with BSD using a Bayesian network analysis framework. We analyzed data from a large cohort (n = 1565) focusing on hsCRP and a subsample (n = 249) that included concurrent assessments of additional cytokines including Interleukin-6 and Tumor Necrosis Factor-alpha. A Bayesian approach was utilized to quantify uncertainty regarding the presence or absence of associations between inflammation and cognitive function. Our findings revealed no significant associations between inflammatory markers and cognitive performance in both samples. Strong evidence was found supporting the absence of association, with network analysis indicating distinct clusters for cognitive and inflammatory variables, suggesting they function as independent constructs with limited interactions. In our clinical sample of individuals with BSD, our findings do not support a direct association between some inflammatory markers and cognition, aligning with studies that found minimal or no associations. Our study emphasizes the importance of utilizing Bayesian methods to assess these relationships rigorously and suggests further exploration of individual differences and subgroup effects in future research
Comparative analysis of recent sedimentation histories for Longemer and Gérardmer lakes in Vosges, France: a geochronological study using 210Pb, 137Cs and 241Am
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Macrophages Are Critical Inducers of Bleomycin-Induced Fibrosis in a Systemic Scleroderma Model
No full textInternational audienceMacrophages are critical regulators of inflammation with an essential role in maintaining and re-establishing homeostasis after inflammatory insults. However, excessive macrophage activation could promote fibrosis, highlighting their potential as a therapeutic target in chronic inflammatory diseases. Two preclinical models of systemic sclerosis, bleomycin-induced systemic scleroderma and sclerodermatous graft-versus-host disease, were used to analyze the role of macrophages in the establishment of fibrosis. In both models, macrophage numbers increase in the skin and lungs, in association with elevated collagen content and correlating with fibrosis development. These macrophages had a Ly6clowCD206+MerTk+ phenotype, suggesting a profibrotic role during disease progression. Using macrophage depletion and differentiation blocking approaches, this work shows that reduced macrophage accumulation effectively prevented bleomycin-induced fibrosis development. Direct profibrotic activity of bleomycin-exposed macrophages was revealed by s.c. macrophage injections in naïve mice, which was sufficient to induce systemic fibrosis. Finally, bleomycin-treated primary mouse and human macrophages display reduced clearance of apoptotic cells and secrete factors that promote fibroblast activation and collagen production. Metabolic and mitochondrial dysfunction, changes in receptor shedding, and cytoskeletal reorganization in bleomycin-treated macrophages further contribute to their impaired efferocytosis and enhanced profibrotic activity. Collectively, this work identifies macrophages as critical promoters of tissue fibrosis and suggests that inhibition of macrophage activation represents a new potent therapeutic avenue in efforts to reverse fibrosis associated with chronic inflammation
Validation methodology on real data of reversible Kalman Filter for state estimation with Manifold
No full textThis work extends a previous study that introduced an algorithm for state estimation on manifolds within the framework of the Kalman filter. Its objective is to address the limitations of the earlier approach. The reversible Kalman filter was designed to provide a methodology for evaluating the accuracy of existing Kalman filter variants with arbitrary precision on synthetic data. It has favorable numerical properties on synthetic data, achieving arbitrary precision without relying on the small-velocity assumption and depending only on sensor noise. However, its application to real data encountered difficulties related to measurement noise, which was mitigated using a heuristic. In particular, the heuristic involved an event detection step switching between reversible Kalman filter and classical Kalman variant at chosen moments. In the present work, we propose a study of this detection step and propose a methodology to prove at which moment the reversible Kalman approach improves on classical multiplicative variant
Impaired endotoxin inactivation, rather than gut translocation, is associated with organ injury in cardiac surgery with cardiopulmonary bypass
No full textInternational audienceBACKGROUNDS In patients with cardiac surgery under cardiopulmonary bypass (CPB), postoperative inflammation is a driver of adverse outcomes. Endotoxaemia is one of the factors thought to trigger this inflammatory response. The mechanism behind high endotoxin activity (increased translocation vs. reduced inactivation capacity) has never been elucidated and may imply different therapeutic candidates. OBJECTIVES We aimed to evaluate, in patients with cardiac surgery with prolonged CPB, mechanisms and consequences of endotoxaemia and the efficacy of haemo-adsorption to reduce the endotoxin burden. DESIGN Ancillary analysis of a randomised controlled trial. Patients scheduled for cardiac surgery with prolonged CPB were assigned to receive either intra-operative haemo-adsorption or standard of care. Endotoxin mass and activity were measured before surgery, at the end of CPB, 6, 24 and 48 h after the end of surgery. SETTING Operating room, Amiens University Hospital. PATIENTS Adults scheduled for cardiac surgery under CPB with an expected CPB time more than 90 min. INTERVENTION Patients were randomised to receive either haemo-adsorption or standard care during CPB. MAIN OUTCOME MEASURES Endotoxin activity. RESULTS Two hundred and ninety-five samples from 66 patients were analysed. Following CPB, we observed a reduction in endotoxin mass accompanied by a relative increase in endotoxin activity. High postoperative endotoxin activity was associated with intra-operative dobutamine requirement, increased postoperative inflammatory biomarkers and organ injury. Endotoxin plasma concentration and activity were not lower in patients treated with haemo-adsoprtion. CONCLUSION The capacity of individuals to inactivate endotoxin rather than raw endotoxin mass (i.e. Quantity) seemed to be a determinant of endotoxin noxious effect in cardiac surgery and CBP. Haemo-adsorption was not associated with a reduction of endotoxin plasma mass or activity in patients with cardiac surgery under CPB. TRIAL REGISTRATION ClinicalTrials.gov, NCT04201119NCT0420111