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Suivi à 1 an de l’accumulation de fer dans les noyaux gris centraux en IRM R2* : un biomarqueur de progression de la maladie de Parkinson ?
No full textCONTEXTE : les techniques d'imagerie, telles que la relaxométrie IRM utilisant la mesure du R2*, ont été explorées en tant que biomarqueurs de la maladie de Parkinson (MP). Si le R2* est utile pour le diagnostic précoce de la MP, son rôle dans le suivi de la progression de la maladie reste incertain à différents stades de la MP. OBJECTIF : cette étude vise à évaluer le potentiel du R2* en tant que biomarqueur de la progression de la maladie de Parkinson sur un an dans une grande cohorte, en tenant compte des différents stades de la maladie. MÉTHODE : une étude française longitudinale et multicentrique a examiné les changements du signal R2* des ganglions de la base (ΔR2*) sur un an chez 93 patients atteints de la maladie de Parkinson, regroupés selon la durée de la maladie (< 5, 5-10, 10-15 et > 15 ans), et 65 témoins sains. Des données cliniques motrices et non motrices ont également été recueillies à des fins de comparaison. RÉSULTATS : les patients atteints de la maladie de Parkinson ont présenté une augmentation plus importante du signal R2* dans la substance noire (SN) par rapport aux témoins (p < 0,001) au départ, le signal augmentant sur un an à tous les stades de la maladie et en corrélation avec la durée de la maladie. Cependant, les variations de R2* dans la SN sur un an n'ont pas été corrélées avec les changements dans les scores cliniques moteurs ou non moteurs. CONCLUSION : nos résultats ont démontré une augmentation significative du signal R2* dans la substance noire (SN) des patients atteints de la maladie de Parkinson par rapport aux témoins, avec des changements observés à tous les stades de la maladie. Cependant, aucune corrélation n'a été trouvée entre les variations de R2* et les scores cliniques moteurs ou non moteurs. L'absence de corrélation avec les symptômes cliniques peut être due à des mécanismes neuronaux compensatoires, à la variabilité individuelle de la progression de la maladie ou aux limites de la sensibilité de l'échelle d'évaluation clinique sur une période aussi courte. Des études à plus long terme sont nécessaires pour clarifier ces relations et faire du R2* un biomarqueur robuste de la progression de la maladie de Parkinson
Myeloid neoplasms risks for germline DDX41 pathogenic variants carriers
No full textInternational audienceMonoallelic germline DDX41 pathogenic variants (PV) are responsible for the most frequent monogenic predisposition to myeloid neoplasms (MN), i.e., to myelodysplastic syndrome and acute myeloid leukemia. MN are rare clonal diseases affecting hematopoietic tissues, and curative approaches frequently implicate hematopoietic stem cell transplantation, requesting testing for relatives of DDX41-mutated MN patients. Establishing the penetrance of germline DDX41 PV is crucial to determine how to monitor the unaffected relatives who carry the familial DDX41 PV. Our study aims to assess the risk of MN in relatives of affected DDX41 carriers using the Genotype-Restricted-Likelihood (GRL) approach. We identified 63 families with probands carrying a germline DDX41 PV (ACMG class 4 or class 5 variant) affected with MN, from 11 French centers. One hundred and sixty relatives, including 73 males (46%), were genotyped at the median age of 51 [range: 15-84] years, 80 of them (50%) being carriers of the familial DDX41 PV. The cumulative risk of MN at 70 years for DDX41 PV carriers was estimated at 19.5% [95% CI: 5.8%-62.5%], corresponding to a relative risk compared to the general population of 55 [95% CI: 16.4-176.5]. This risk appeared higher in males, although the difference did not reach statistical significance. Based on these findings, we suggest yearly complete blood count from the age of 50 for DDX41 PV carriers. Of note, we observed cases before the age of 50 in females, which could suggest sex-differentiated monitoring
Is income enough to understand farm diversification strategies ? Unraveling farmers’ labor engagement
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A Highly Emissive Molecular Material with Tunable Emission Color: Investigations as Phosphor for the Elaboration of a Hybrid White-Light-Emitting Diode
No full textInternational audience4,4′-([2,2′-Bipyrimidine]-5,5′-diyl)bis[N,N-bis(4-methoxyphenyl)aniline] (1), a molecular compound built by connecting an electron-deficient 2,2′-bipyrimidine core to two electron-rich triarylamine derivatives further enriched with electron-donating methoxy groups, was designed and synthesized for luminescent purpose. The X-ray crystal structure obtained from tetrahydrofuran (THF) and a dichloromethane (DCM)/hexane mixture revealed that 1 could adopt slightly different conformations in the solid state. Indeed, the bipyrimidine core is almost planar when the molecule is recrystallized from DCM/hexane and forms dimers, while a twist angle of 28.20°between the two pyrimidine rings and the formation of infinite π-stacks were found upon recrystallization from THF. Because of the donor-acceptor-donor structure and the resulting charge transfer, the molecule possesses some polarity in the excited state that makes it sensitive to its surroundings. As a consequence, solutions emitting from blue to red could be obtained by solubilizing 1 in solvents of various polarities. The presence of aromatic units is responsible for π-π-stacking interactions, as revealed by X-ray diffraction, leading to aggregation in solution and in the solid state, which also impacts the photophysical properties. A maximized phenomenon of aggregation-enhanced emission was observed in a THF solution containing 75% water. This sensitivity of 1 to the solvents in terms of photophysical properties was also demonstrated on films deposited from different solvents. These studies revealed the appropriate experimental conditions in which 1 can be highly emissive either in solution or in the solid state. Especially, a photoluminescence quantum yield as high as 82.2% was obtained in a film of 1 doped into poly(methyl methacrylate) at a rate of 10 wt %. Investigations on the photostability of 1 were performed under accelerated aging conditions (375 nm, 300 mW cm -2 ). Lowering the power resulted in an increase in stability and makes the molecular material an interesting candidate for luminescence purposes
A Science of Things. The Jesuits and the Introduction of American Materia Medica in Europe
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Probing the sensitivity of semi-visible jets to current LHC measurements using the CONTUR toolkit
No full textInternational audienceSemi-visible jets arise from a hypothetical, strongly interacting ``dark sector''-- a dark counterpart of quantum chromodynamics whose partial decays back to Standard Model particles introduce new types of collider BSM signature. CMS and ATLAS have have searched for semi-visible jets in the resonant and non-resonant production modes and set constraints on mediator mass values. In this work, indirect constraints on various model parameters, such as dark hadron masses and coupling strengths, are explored using LHC measurements
Angular analysis of decays
No full textInternational audienceAn angular analysis of decays is presented using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb. The analysis is performed in the region of the dilepton invariant mass squared of 1.1-6.0 GeV. In addition, a test of lepton flavour universality is performed by comparing the obtained angular observables with those measured in decays. In general, the angular observables are found to be consistent with the Standard Model expectations as well as with global analyses of other processes, where is either a muon or an electron. No sign of lepton-flavour-violating effects is observed
Évaluation de modèles d'apprentissage automatique pour la prévision de la survenue d'accidents du travail à partir de séries temporelles binaires
No full textInternational audienceWorkplace accidents represent a significant human and economic challenge, but current prevention strategies lack proactive anticipation. Data from field reports, nearmisses, and organizational factors remain underutilized. This study proposes a generic framework for short-term accident prediction, based on binary time series and incorporating covariates. A time-series-specific cross-validation methodology and evaluation using aggregated periods ensure the robustness of the models. Several machine learning algorithms were compared. The results confirm the relevance of the approach and help identify the most effective models for preventing workplace accidentsLes accidents du travail représentent un enjeu humain et économique important, mais les stratégies actuelles de prévention manquent d'anticipation proactive. Les données issues des remontées terrain, quasi-accidents et facteurs organisationnels sont sousexploitées. Cette étude propose un cadre générique de prévision à court terme des accidents, basé sur des séries temporelles binaires et intégrant des covariables. Une validation croisée spécifique aux séries temporelles et une évaluation par périodes agrégées assurent la robustesse des modèles. Plusieurs algorithmes d'apprentissage automatique ont été comparés. Les résultats confirment la pertinence de l'approche et aident à identifier les modèles les plus efficaces pour prévenir les accidents du travail