Université de Caen Normandie

Ion implantation is introduced as a novel and controllable approach to incorporate hydrogen into α-MoO3 crystals and induce the formation of hydrogen molybdenum bronze phases (HxMoO3) below the implanted layer. By tuning the ion fluence, this technique enables precise defect engineering and phase transformation, offering a versatile and reproducible strategy for tailoring the material functional properties. High-resolution X-ray diffraction (HRXRD) reveals a gradual expansion of the b lattice parameter for fluences up to 1 × 1017 cm-2, attributed to defect-induced lattice distortion. For higher fluences, instead of typical strain saturation, a new diffraction peak emerges, revealing the formation of type-I HxMoO3, as also confirmed by Raman spectroscopy. This phase forms below the implanted layer and extends up to ∼1µm into the material, as confirmed by transmission electron microscopy (TEM). This phase transformation demonstrates reversibility, with the HxMoO3 signature disappearing upon air annealing at 300°C. HRXRD curve fitting enables assessment of strain/damage profiles evolution with fluence, providing insight into the defect creation and accumulation mechanisms. These structural and compositional changes are accompanied by a quasi-linear increase of electrical conductivity with fluence, by several orders of magnitude, attributed to the presence of HxMoO3 phases, extended defects, and new suboxide minority phases.

Therapeutic Communities (TCs) are long-term residential treatment settings for individuals with substance use disorders, who often present with neuropsychological impairments. These impairments may influence treatment retention, yet little is known about their evolution in TCs or their association with dropout. This study aims to: (1) identify early risk factors for dropout; (2) investigate the potential recovery from the risk of neuropsychological impairment during an 8-mont stay in a TC; and 3) identify variables at TC entry that may predict the risk of neuropsychological impairment during follow-up. Fifty-seven residents from 3 French TCs completed clinical, substance use, and medical assessments, along with a neuropsychological screening (BEARNI) at entry. Twenty-four completed the 8-month follow-up. The dropout rate was 47%. The only significant predictor of dropout was the BEARNI total score, with residents at lower risk of neuropsychological impairment more likely to leave the TC prematurely. Among completers, BEARNI total scores improved at follow-up, primarily explained by improvements in balance rather than in cognitive areas. Lower education, unemployment, recent alcohol use, depressive symptoms, and a history of hepatic disease were consistently associated with a higher risk of neuropsychological impairment at both time points. Unlike other treatment settings, the TC care framework may be particularly appropriate and supportive for residents who are more cognitively vulnerable, as they may be better able to benefit from TCs. Motor recovery among those who remain in treatment is encouraging. However, demographic, addiction-related, and comorbidity factors are consistently associated with the risk of neuropsychological impairment, both at baseline and after 8 months, suggesting a stable and persistent influence over time. Not applicable.

Nonparenchymal central nervous system (CNS)-associated macrophages (CAMs) mediate immune responses at brain boundaries. Perivascular and leptomeningeal CAMs are collectively termed subdural CAMs (sdCAMs). Both sdCAMs and juxtaneuronal microglia are derived from embryonic yolk sac precursors, long-living and maintain their populations through self-renewal. Following depletion, microglia autonomously repopulate from single surviving cells. In contrast, the course of sdCAM repopulation remains poorly understood. Here, by combining multilineage fate mapping, multiomic profiling and high-resolution imaging, we demonstrate divergent repopulation dynamics between sdCAMs and microglia. Unlike microglia, sdCAMs do not renew cell-autonomously, but become transiently accessible to CCR2+Ly6C+ monocyte engraftment after niche induction in an integrin-dependent manner. Moreover, replenished monocyte-derived sdCAMs remain transcriptomically, epigenetically and functionally distinct from their embryo-derived counterparts. Finally, we present a protocol enabling selective exchange of sdCAMs, modulating disease response without functionally affecting microglia. These new insights into CNS immune biology suggest new therapeutic avenues for neuroinflammatory and neurodegenerative diseases.

Data are needed on the effect of oxygen delivered through a high-flow nasal cannula, as compared with standard oxygen therapy, on intubation and mortality in patients with acute hypoxemic respiratory failure. In this multicenter, open-label trial, we randomly assigned patients who had acute hypoxemic respiratory failure to receive high-flow-oxygen or standard-oxygen therapy. All the patients had a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen of 200 or less, a respiratory rate of more than 25 breaths per minute, and pulmonary infiltrate on chest imaging. The primary outcome was death by day 28. A total of 1116 patients underwent randomization. Of these patients, 1110 (556 in the high-flow-oxygen group and 554 in the standard-oxygen group) were included in the analysis. Mortality at day 28 was 14.6% (in 81 of 556 patients) in the high-flow-oxygen group and 14.6% (in 81 of 554 patients) in the standard-oxygen group (difference, -0.05 percentage points; 95% confidence interval [CI], -4.21 to 4.10; P = 0.98). The incidence of intubation by day 28 was 42.4% (in 236 of 556 patients) in the high-flow-oxygen group and 48.4% (in 268 of 554 patients) in the standard-oxygen group (difference, -5.93 percentage points; 95% CI, -11.78 to -0.08). Serious adverse events (cardiac arrest or pneumothorax) occurred during spontaneous breathing in 13 patients (2.3%) in the high-flow-oxygen group and in 6 patients (1.1%) in the standard-oxygen group. Among patients with acute hypoxemic respiratory failure, the use of oxygen delivered through a high-flow nasal cannula did not significantly reduce mortality at day 28. (Funded by the French Ministry of Health and Fisher and Paykel Healthcare; SOHO ClinicalTrials.gov number, NCT04468126.).

The Finite Element Method (FEM) is well suited to capture the complex sintering behavior of 3D-printed parts, including anisotropy, shrinkage, and temperature-dependent porous deformation. However, applying FEM directly to real parts is challenging, as intricate geometries require highly refined meshes, leading to long computation times and frequent divergence from stress concentrations. In this work, we circumvent these inherent FEM limitations by combining FEM simulations with deep learning. Instead of directly simulating the entire part, a large parametric study of overhang bar geometries under various loading conditions is performed to generate a synthetic dataset of 10 5 data points. This dataset is used to train a deep learning model capable of predicting the sintering distortion risk of printed parts. A key originality of this approach lies in using elastic FEM simulations as descriptors of the mechanical solicitation of the part, combined with the sintering work as a thermal process descriptor. This hybrid methodology is highly efficient: a simple elastic FEM calculation of a 3D part, coupled with a forward prediction by the trained neural network (few seconds) can accurately determine whether a part will withstand sintering or if additional supports are required.