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Photoelectrochemical Charge Transfer Imaging at Nanoscale Catalysts
No full textInternational audienceSemiconductor (SC)-based photoelectrodes, employed for the production of solar fuels such as H 2 or small organic molecules, have garnered significant attention and extensive studies because they could play a crucial role in addressing the global energy crisis. While macroscopic photoelectrochemical (PEC) studies of these systems are routinely employed to monitor the overall activity of these systems, the spatiotemporal resolution of local PEC activity down to the nanoscale remains a challenge that could lead to considerable improvement in photoelectrode design and engineering. Here, model Si-based photoanodes precisely coated with water-splitting Ni catalysts of various sizes are studied by photoinduced electrochemiluminescence (PECL) microscopy. Our results demonstrate that this method allows precise imaging of hole-driven photoelectrochemical reactivity down to a scale of ~50 nm, making PECL microscopy a valuable tool for elucidating charge transfer and local interfacial activity of photoelectrodes employed in PEC solar energy conversion processes
Reducing Hofmann 3D network into 1D ladder-like topology: interplay between spin crossover and phase transitions
No full textInternational audienceMetal-Organic Frameworks based on [M(CN)4]2- units, such as the Hofmann clathrates and their derivatives..
Microduplications of ARID1A and ARID1B cause a novel clinical and epigenetic distinct BAFopathy
No full textInternational audiencePurpose: ARID1A/ARID1B haploinsufficiency leads to Coffin-Siris syndrome, duplications of ARID1A lead to a distinct clinical syndrome, whilst ARID1B duplications have not yet been linked to a phenotype.Methods: We collected patients with duplications encompassing ARID1A and ARID1B duplications.Results: 16 ARID1A and 13 ARID1B duplication cases were included with duplication sizes ranging from 0.1 to 1.2 Mb (1-44 genes) for ARID1A and 0.9 to 10.3 Mb (2-101 genes) for ARID1B. Both groups shared features, with ARID1A patients having more severe intellectual disability, growth delay, and congenital anomalies. DNA methylation analysis showed that ARID1A patients had a specific methylation pattern in blood, which differed from controls and from patients with ARID1A or ARID1B loss-of-function variants. ARID1B patients appeared to have a distinct methylation pattern, similar to ARID1A duplication patients, but further research is needed to validate these results. Five cases with duplications including ARID1A or ARID1B initially annotated as duplications of uncertain significance were evaluated using PhenoScore and DNA methylation reanalysis, resulting in the reclassification of 2 ARID1A and 2 ARID1B duplications as pathogenic.Conclusion: Our findings reveal that ARID1B duplications manifest a clinical phenotype, and ARID1A duplications have a distinct episignature that overlaps with that of ARID1B duplications, providing further evidence for a distinct and emerging BAFopathy caused by whole-gene duplication rather than haploinsufficiency
Impact de l'ouverture d'un centre médical de soins immédiats sur les urgences de Dax
No full textObjective:to study the impact of opening an immediate care medical center on emergency department visits in Dax. Materials and Methods: a retrospective observational study comparing emergency department visits in Dax between 8 a.m. and 8 p.m. for CCMU 1 and 2 patients, between June and November 2023 (before the opening of the immediate care medical center) and June and November 2024 (after the opening). The primary outcome was the reduction in the number of CCMU 1 and 2 visits to the Dax emergency department between 8 a.m. and 8 p.m. before and after the opening of the immediate care center. The secondary outcome was the reduction in the number of visits based on age and reason for admission. Results: between June–November 2023 and June–November 2024, a significant decrease in the average number of CCMU 1 and 2 visits between 8 a.m. and 8 p.m. was observed. A significant reduction in trauma-related visits was noted across all age groups, except for those over 75 years old, where the decrease was not significant. For consultations categorized as medical, no significant decrease was observed across all age groups, except for those over 75 years old, where a significant increase was noted. Conclusion: the immediate care medical center may have an impact on the number of emergency department visits in Dax, particularly for patients under 75 years old and for trauma-related consultations. However, this study has too many limitations to draw robust conclusions.Objectif : étudier l’impact de l’ouverture d’un centre médical de soins immédiats sur les passages aux urgences de Dax. Matériel et méthode : étude observationnelle rétrospective comparant les passages aux urgences de Dax entre 8 h et 20 h pour les patients CCMU 1 et 2, entre juin et novembre 2023 (avant l'ouverture du CMSI) et juin et novembre 2024 (après l'ouverture). Le critère de jugement principal était la diminution du nombre de passages relevant d’une CCMU 1 ou 2 aux urgences de Dax de 8 h à 20 h avant et après l’ouverture du centre de soins immédiats. Le critère de jugement secondaire était la diminution du nombre de passages en fonction de l’âge et du motif d’admission. Résultats : entre la période de juin à novembre 2023 et celle de juin à novembre 2024, il est observé une diminution significative du nombre moyen de passages CCMU 1 et 2 entre 8 h et 20 h. Il a été observé une diminution significative des passages concernant la traumatologie pour toutes les tranches d’âge, sauf chez les plus de 75 ans, pour lesquels cette diminution n’est pas significative. Pour les consultations catégorisées en médecine, il n’est pas noté de diminution significative pour toutes les tranches d’âge, sauf chez les plus de 75 ans, pour lesquels une augmentation significative est notée. Conclusion : le CMSI pourrait avoir un impact sur le nombre de passages aux urgences de Dax, notamment chez les moins de 75 ans et pour des motifs de consultation relevant de la traumatologie. Mais cette étude contient trop de limites pour pouvoir en tirer des conclusions robustes
Intermediate-Dose Cytarabine as Postinduction AML Therapy
No full textInternational audienceBackground: We conducted a randomized controlled trial to compare intermediate doses (IDAC) with high doses of cytarabine (HDAC) as postinduction therapy in patients 18 to 60 years of age with newly diagnosed acute myeloid leukemia (AML). The main objectives were to evaluate noninferiority in overall survival (OS) after IDAC and safety.Methods: Patients 18 to 60 years of age with newly diagnosed AML, except those with core-binding factor, acute promyelocytic, Philadelphia chromosome-positive, or post-myeloproliferative neoplasm AML, were eligible. After the induction course, we randomly assigned patients to either IDAC (1500 mg/m2/12 hours) or HDAC (3000 mg/m2/12 hours). Patients with intermediate- and adverse-risk AML were eligible for allogeneic hematopoietic stem cell transplantation (HSCT) in first remission. The primary end point was OS in a predefined per-protocol analysis population. The primary analyses were performed in 1132 randomly assigned patients, with a noninferiority outcome adjusted on the European Leukemia Net (ELN) 2022 risk group, the use of induction anthracycline, the response to induction, and HSCT as a function of time following treatment.Results: At 5 years, OS was estimated at 59.3% (95% confidence interval [CI], 55.0 to 63.3) in the IDAC group versus 57.5% (95% CI, 53.3 to 61.5) in the HDAC group (adjusted hazard ratio, 0.96; 95% CI, 0.80 to 1.15; noninferiority test, P=0.0042). A preplanned analysis was unable to detect any interaction between IDAC or HDAC treatment effect and patient subgroups, including those defined by the ELN 2022 risk group or response to induction prior to random assignment. In addition, the severity of chemotherapy-induced myelosuppression and the incidence of related adverse events were lower after IDAC.Conclusions: Our trial shows noninferior outcomes in patients 18 to 60 years of age with newly diagnosed AML treated with low- versus high-dose cytarabine; this occurred with similar or lower toxicities.(Funded by the Regional Clinical Research Office, Angers and others; EudraCT number, 2014-000699-24; ClinicalTrials.gov number, NCT02416388)
Graphe des dépendances pour une marche aléatoire à pas borné sur un groupe libre.
No full textThis article is one of a triptych composed with [Che25a] and [Che25b], that aims at proving an asymptotic expansion to any order of the passage probability of an irreducible equivariant finite range random walk on a tree. In this text we study the analytic and geometric properties of the objects introduced in [Che25b]. To do so we introduce the definition of a "flooded cavern tree" enabling a precise study of some dependency digraph associated with a given irreducible finite-range random walk on a free group.Cet article constitue l’un des volets d’un triptyque, avec [Che25a] et [Che25b], dont l’objectif est d’établir un développement asymptotique à tout ordre de la probabilité de passage d’une marche aléatoire irréductible, équivariante, à pas borné sur un arbre. Dans ce texte, nous étudions les propriétés analytiques et géométriques des objets introduits dans [Che25b]. Pour ce faire, nous introduisons la notion "d’arbre caverne submergée" (flooded cavern tree), qui permet une étude fine d’un graphe de dépendance associé à une marche aléatoire à pas borné sur un groupe libre
Single-cell SNP-DNA sequencing precisely maps genotoxic events in CRISPR-edited primary cells
No full textGenome editing by CRISPR-Cas9 is promising for genetic disease and cancer gene therapy. However, safety concerns are still present, particularly the ON-target genotoxicity for protocols using nucleases. Quality control of edited cells before and after graft is mandatory, especially to assay megabase-scale genomic rearrangements induced at the targeted locus . These unintended events are fortunately rare but potentially deleterious. Classical PCR-based bulk approaches do not detect them or underestimate their frequency. Single-cell approaches are promising but RNA sequencing only estimates copy number variation of the genome. Here, we propose single-cell DNA sequencing to accurately evaluate and monitor CRISPR-mediated genotoxicity in primary cells (human fibroblasts and hematopoietic stem/progenitor cells). We designed a homemade panel using single nucleotide polymorphisms to detect, map and characterize induced-losses of heterozygosity (terminal, interstitial, copy-loss and copy-neutral). This innovative approach revealed intense genotoxicity linked to the double strand break. The risk was associated with DNA repair modulators in particular DNA-PKcs inhibitor AZD7648. Importantly, the CDK4/6 inhibitor palbociclib prevented these rearrangements in hematopoietic stem/progenitor cells. This work strongly suggests that single-cell DNA sequencing should be routinely implemented in clinical applications before CRISPR-edited cell infusions. Graphical abstrac
Wrapped Gaussian on the manifold of Symmetric Positive Definite Matrices
No full textInternational audienceCircular and non-flat data distributions are prevalent across diverse domains of data science, yet their specific geometric structures often remain underutilized in machine learning frameworks. A principled approach to accounting for the underlying geometry of such data is pivotal, particularly when extending statistical models, like the pervasive Gaussian distribution. In this work, we tackle those issue by focusing on the manifold of symmetric positive definite (SPD) matrices, a key focus in information geometry. We introduce a non-isotropic wrapped Gaussian by leveraging the exponential map, we derive theoretical properties of this distribution and propose a maximum likelihood framework for parameter estimation. Furthermore, we reinterpret established classifiers on SPD through a probabilistic lens and introduce new classifiers based on the wrapped Gaussian model. Experiments on synthetic and real-world datasets demonstrate the robustness and flexibility of this geometry-aware distribution, underscoring its potential to advance manifold-based data analysis. This work lays the groundwork for extending classical machine learning and statistical methods to more complex and structured data
Black elites and the civilizing of French colonial frameworks. Sociological Lessons from Louis Vignon’s Contested Lecture at the École Coloniale (1890-1927)
No full textInternational audienceWhile the process by which "things once allowed are now reproved" can be empirically tracked through longitudinal studies of educational materials (Elias, 1939) or declared values (Inglehart & Norris, 2003), the social forces driving these shifts are often more postulated than demonstrated. In particular, more inclusive sensibilities toward subaltern groups are frequently explained through theories of cultural change that sometimes under-examine the role of contingent emancipatory struggles and actions (Linklater, 2016, Go 2017)). Drawing on the investigation of the increasingly contested "French Colonization" class at the École Coloniale from 1890 to 1927, this communication sheds light on how less unequal power dynamics and collective action from outsiders led to a fragile yet existing constraint towards self-constraint when addressing racialized and colonized people from the 1900s onwards. First, I present the contextual elements that led Louis Vignon to lecture at the École Coloniale. This higher education institution, aimed at training future colonial administrators (Collier, 2018), welcomed a diverse student body from the Antilles, West Africa, Indochina and Metropolitan France, who recurrently opposed the course content, both for its reliance on racialist theories and its overtly anti-assimilationist stance on the colonial project. Based on the available archives of the "Vignon incident", I then explore how these protests took shape up until 1927, and how both the administration and the professor navigated these critiques. In sum, I highlight how shifting power dynamics and growing interdependence with colonized elites, even at the heart of the colonial project, exerted ongoing pressure on socially acceptable attitudes and discourse. However, this example of extra-European influences creating new demands for affective regulation reveals more about European cultural mutations than on the brutal reality of the colonial order, which was increasingly masked by a modernized vocabulary
Development of co-sputtered amorphous Ge–Bi–Se films for nonlinear infrared photonic applications
No full textInternational audienceRF magnetron cosputtered amorphous Ge–Bi–Se films were fabricated using polycrystalline GeSe2 and Bi2Se3 targets. Their structural, linear, and nonlinear optical properties were studied to understand compositional influence for future photonic applications. A broader Ge–Bi–Se amorphous region with a noticeably high bismuth atomic percentage (up to at % Bi = 36%) is observed using this deposition method compared to ≤16 at % in the conventional Ge20Se80–xBix bulk glass synthesis [Ikari, T. Phys. Rev. B 1993, 47(9), 4984]. The structural characteristics of the cosputtered films were analyzed using Raman spectroscopy, where increasing bismuth concentration shifted all vibrational bands to the lower energy side with reduced intensity. A decrease in optical band gap energy values from 2.04 (±0.02) eV (Bi atom % = 0) to 0.73 (±0.02) eV (Bi atom % = 36) and the corresponding increase in refractive index value n from 2.41 (±0.01) to 4.09 (±0.01) at telecommunication wavelength indicate the strong influence of bismuth on the optical properties of the films. Third-order nonlinear optical parameters were calculated from linear parameters using semiempirical equations and Sheik-Bahae formalism in order to allow their prediction according to the film composition and taking into account the wavelength of use. Following these simulations, which enabled the selection of promising compositions in terms of optical nonlinearity applications, this work also focused on demonstrating the feasibility of manufacturing ridge waveguides from these cosputtered films by RF magnetron using dry etching with the aim of offering Ge–Bi–Se-based integrated optical circuits