Portail HAL UPEC
Not a member yet
55480 research outputs found
Sort by
Characterization and Treatment Outcomes of Malignant Histiocytoses in a Retrospective Series of 141 Cases in France
No full textInternational audienceMalignant histiocytoses (MH) are rare and poorly understood cancers, with no established therapeutic guidelines. We conducted a national retrospective study of MH diagnosed in France between 2000 and 2023. All cases underwent centralized histological review, and several malignant tumors with a stroma highly enriched in histiocytes were excluded. In total, 141 patients were included, with a median age of 62 years (range, 1-87). The cases comprised either primary MH (64%) or MH associated with other hematologic malignancies (36%). Phenotypes corresponded to histiocytic (43%), interdigitating dendritic cell (37%) or Langerhans cell (12%) sarcomas, or high-grade indeterminate dendritic cell tumors (10%), as per the World Health Organization classification. Tumor cells were almost universally positive for CSF1R and PU.1, and 85% showed phosphorylated extracellular signal-regulated kinase positivity. Next-generation sequencing was performed in 75 cases. Mutations in the MAPK pathway were more frequent in secondary compared with primary MH (90% vs 55%; P = .0012). PTPN11 mutations were exclusively observed in primary MH (P = .0035). Mutations in genes related to DNA methylation mechanisms (TET2, ASXL1, DNMT3A) and TP53 were present in 20% and 14% of cases, respectively. Although therapeutic regimens varied considerably, our results demonstrate that surgical resection in localized cases, and the use of BRAF or MEK inhibitors achieved the highest complete response rates, at 63% and 21%, respectively. The prognosis remains poor, with a 5-year overall survival rate of 31%, which is comparable to that of T/natural killer cell lymphomas. Prospective follow-up and a standardized treatment approach in specialized reference centers are crucial to improving patient survival. This trial was registered at www.clinicaltrials.gov as #NCT04437381
Study of conformational changes in biliverdin within the phytochrome using hybrid all-atom/coarse-grained simulations
No full textInternational audiencePhytochromes are a large family of photoreceptor proteins composed of two domains: PAS (Per-ARNT-Sim) and GAF (cGMP-phosphodiesterase/adenylate cyclase/FhIA [1]. The PAS domain binds a linear tetrapyrrole chromophore via a cysteine residue. The biliverdin chromophore, a bile pigment derived from the breakdown of the heme [2], is present in various organisms. Biliverdin absorbs and emits light in a specific range, making it important in the study of light-sensitive proteins and their applications in biotechnology and medicine. A deeper understanding of this system will offer valuable insights for designing new devices that emit red-colored photons, thereby producing light signals that are more easily detectable within the human body [3].In this research, we aim to construct the energy profile that connects two protein structures including biliverdin in two distinct conformations: compacted and extended, which absorb at different wavelength. This analysis is important for understanding the molecular mechanisms behind conformational changes in phytochromes. For that, we performed umbrella sampling [4] simulations with hybrid AA/CG (All-Atom/Coarse-Grained) representation using SIRAH force field [5] for the coarse-grained part and homemade force field for the all-atom part. The energy profile provides us information on the feasibility of the conformational transition, revealing key factors that govern this process. Additionally, molecular dynamics simulations allow us to analyse the trajectories of the protein over time, offering a detailed view of how interactions between the protein and biliverdin stabilize one conformation over another. By identifying the driving process behind the conformation transitions, we can better understand how phytochromes function and the way for future applications in designing light-sensitive biomolecular tools
Comprehensive analysis of sickle β+-thalassemia genotypes and their associated HbA levels in France
No full textInternational audienceWe retrospectively reviewed the clinical records of 228 HbS/β+-thal patients. The different genotypes were distributed into three groups according to their mean residual HbA levels: <10 % (group 1; n = 22), between 10 and 20 % (group 2; n = 175) and > 20 % (group 3; n = 31). Routine red blood cells and hemoglobin parameters were compared between the three groups. Sixteen different sickle β+-thal genotypes were identified but only four of them were associated with a residual HbA level below 10 %. Patients of this group exhibited a more severe anemia (Hb < 10 g/dL; reticulocytes >200 G/L) compared to the two other groups. However, no difference could be observed on those parameters between patients of group 2 and 3, as well as for the main RBC parameters. According to our study, >80 % of the sickle β+-thalassemia patients in France have a residual HbA level beyond 10 % and a mild to moderate anemia. Only four β+-thal variations (all affecting the splicing process) would lead to a potentially severe SCD syndrome in association with HbS (HbA < 10 %) but this result should be confirmed in a prospective clinical study
Investigating the Impact of Alignment Angle Between Copper Turns and Magnetic Core on Magnetic Field Coupling in PCB Integrated Inductors
No full textInternational audienceThis study investigates the influence of copper trace alignment relative to the magnetic core in PCB-embedded inductors, focusing on the effects of the alignment angle on perpendicular magnetic flux density that shall cause eddy currents in AC applications. Although aligning traces at right angles is common in traditional inductor winding, it may not be feasible for PCB designs due to manufacturing constraints. The study proposes an investigation of the angular-shift effects on magnetic flux while maintaining practical PCB manufacturability in potential applications like static power converters. By evaluating how the angular shift impacts magnetic flux behavior in copper traces, this research is part of a study that aims to address efficiency losses and heating caused by eddy currents. Through Finite Element Method (FEM) simulations using Ansys Maxwell software and experimental validation, the results demonstrate that smaller alignment angles, particularly at 0°, reduce perpendicular flux what shall mitigate eddy current formation in AC applications, improving inductor performance
Magnetic field measurement for contactless current sensing in power electronic converters
No full textInternational audienceCurrent sensing plays an important role in power electronics for both protection and control of power electronic converters. This paper proposes an approach for detecting short-circuit (SC) events through the measurement of the magnetic field radiated by power converters. Two magnetic field sensor technologies (AMR and induction coils) were evaluated. The magnetic field mapping over the PCB is carried out to estimate favorable positions for detecting SC events. The obtained results show that the induction coil is a promising candidate, not only for detecting a SC event but also for performing contactless current measurement in power converters. This work plans to develop the integration of contactless current sensors for power converters, or for intelligent drivers integrating protection against SC event (or over-currents), especially dedicated to wide band gap devices such as GaN and SiC materials which could have lower SC robustness compared to silicon
Transcatheter Edge-to-Edge Repair in Patients With Primary Tricuspid Regurgitation
No full textInternational audienceBackground: Tricuspid regurgitation (TR) leads to right heart congestion and increased mortality risk. Unlike secondary TR, primary TR results from leaflet degeneration. Transcatheter edge-to-edge repair (TEER) is widely used for TR. However, its feasibility primary TR remains uncertain.Objectives: The aim of this study was to assess the safety and feasibility of TEER in patients with primary TR.Methods: The primary TR registry is a multicenter cohort study of patients with primary TR undergoing TEER. Echocardiographic assessment classified leaflet pathology into type 1 (flail), type 2 (billowing prolapse), type 3 (perforation), and type 4 (restricted mobility). The primary endpoint was TR reduction to moderate or less at discharge.Results: From December 2016 to April 2023, 114 patients (mean age 79.9 years, 53.5% men) were included. Most patients were in NYHA functional class III or IV (83.3%), with a median TRI-SCORE of 5.0. The TR pathologies were type 1 (28.1%), type 2 (61.4%), and type 4 (10.5%), with no type 3 cases. Device deployment was achieved in 95.6%, and 83.3% showed TR reduction to moderate or less. In-hospital mortality was 1.8%, and single-leaflet device attachment occurred in 3.5%. At 1 year, 79.7% of patients had TR moderate or less, with significant reductions in vena contracta (-5.0 mm; P < 0.001), annular diameter (-2.0 mm; P = 0.003), and mid right ventricular diameter (-3.0 mm; P < 0.001). NYHA functional class also improved significantly (NYHA functional class I or II: 17.1% at baseline vs 66.5% at follow-up; P < 0.001).Conclusions: TEER is a safe and effective option for primary TR, promoting right heart reverse remodeling and symptomatic relief, offering a vital alternative to surgery in selected patients
Nécessité écologique de changements transformateurs en aménagement et essai de croisements disciplinaires
No full textInternational audienceLe colloque Contre Nature s’est tenu à Paris en janvier 2025. Il a exploré les tensions entre aménagement du territoire et conservation de la nature, face à l’urgence écologique et environnementale globale. Centré sur les modèles de land sparing (séparation stricte des espaces naturels et anthropisés) et land sharing (intégration de la nature dans les espaces aménagés), il a interrogé leur pertinence dans des configurations et des contextes spatiaux variés. Cinq sessions ont croisé sciences sociales et sciences de la nature, analysant les politiques publiques, les dynamiques paysagères, les conflits d’usages et les récits d’une transition écologique qui pourrait advenir. L’événement a aussi mis en débat les défis de traduction et d’adaptation de ces concepts pour repenser l’aménagement à l’ère des changements globaux
QUANTITATIVE OBSERVABILITY FOR ONE-DIMENSIONAL SCHR ÖDINGER EQUATIONS WITH POTENTIALS
No full textInternational audienceIn this note, we prove the quantitative observability with an explicit control cost for the 1D Schrödinger equation over R with real-valued, bounded continuous potential on thick sets. Our proof relies on different techniques for low-frequency and high-frequency estimates. In particular, we extend the large time observability result for the 1D free Schrödinger equation in Theorem 1.1 of Huang-Wang-Wang [20] to any short time. As another byproduct, we extend the spectral inequality of Lebeau-Moyano [27] for real-analytic potentials to bounded continuous potentials in the one-dimensional case
Qu'est-ce que la productivité ?
No full textCette vidéo a été produite dans le cadre du "Dico du management" de la FNEGE (https://fnege-medias.fr/dico/). Elle répond à l'entrée "Productivité" de ce dictionnaire et synthétise le contenu d'un chapitre d'ouvrage écrit par les deux présentateurs de la vidéo
Transformation of banana peels into banana peel wood
No full textThis study aims to establish a sustainable valorization pathway for banana peel, an abundant agro-industrial residue, by converting it into a high-performance, wood-like biocomposite material. Using a simple and scalable processing method and with water as the only additive, banana peels were transformed into a dense, brown, and hydrophobic biocomposite. The material was evaluated for its mechanical properties, water repellency, density, and compatibility with conventional woodworking techniques. The biocomposite exhibits a Young’s modulus ranging from 0.8 to 3 GPa, and densities up to 1.2 g/cm³—values that are respectively comparable to those of light commercial woods and similar to that of ebony and a contact angle between 75° and 102°. It can be carved, shaped, and assembled with standard tools. Considering that banana production generates over 50 million tons of peel annually, this approach could yield up to 2 million tons of biocomposite each year. This work highlights the potential of agricultural waste as a renewable resource for producing wood alternatives. It supports the circular bioeconomy and offers a sustainable substitute for certain endangered tropical wood species