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Heat treatment in an oxygen-rich environment to suppress deep-level traps in Cu2ZnSnS4 solar cell with 11.51% certified efficiency
No full textInternational audienceSulfide kesterite Cu2ZnSnS4 (CZTS) is a competitive photovoltaic material, especially for multijunction solar cells. However, the device power conversion efficiency has remained stagnant for years. Deep-level defects, such as sulfur vacancies (VS), cause serious non-radiative recombination of charge carriers. Here we propose a passivation strategy for VS through the heat treatment of the CdS/CZTS heterojunction in an oxygen-rich environment. In this process, VS are occupied by oxygen atoms, suppressing VS defects. In addition, the diffusion of Cd ions to the CZTS absorber layer, and the formation of positive Na-O and Sn-O complexes can passivate related defects. These effects led to a reduced charge recombination and favourable band alignment. We demonstrate a certified efficiency of 11.51% for air-solution-processed CZTS solar cells (bandgap of 1.5 eV) without any extrinsic cation alloying. The study offers insights into defect passivation and performance improvement mechanism of kesterite solar cells
Influence of Ball Reception on Visual Tracking Performance of Soccer Players in a Virtual Reality Multiple-Player-Tracking Task
No full textInternational audienceVisual tracking tasks are commonly used in laboratory settings to investigate the relationship between team sports expertise and the ability to dynamically allocate attention to multiple moving targets
Evaluation of a deep learning segmentation tool to help detect spinal cord lesions from combined T2 and STIR acquisitions in people with multiple sclerosis
No full textInternational audienceObjective: To develop a deep learning (DL) model for the detection of spinal cord (SC) multiple sclerosis (MS) lesions from both sagittal T2 and short tau inversion recovery (STIR) sequences and to investigate whether such a model could improve the performance of clinicians in detecting SC lesions.Materials and methods: A DL tool was developed based on SC sagittal T2 and STIR acquisitions from the imaging database of the French MS registry (OFSEP), including retrospective data from 40 different scanners. A multi-reader study based on retrospective data was performed between December 2023 and June 2024 to compare the performance of 20 clinicians in interpreting upper and lower SC acquisitions with and without the use of the tool. A ground truth was established by three experts. Sensitivity, precision, and inter-reader variability were evaluated.Results: We included 50 patients (39 females, median age: 41 years [range: 15-67]) with SC MRI acquired between February 2017 and December 2022. When reading with the tool, the clinicians' mean sensitivity to detect SC lesions improved (from 74.3% [95% CI = 67.8-80.6%] to 79.2% [95% CI: 73.5-85.0%]; p < 0.0001), with no evidence of difference in the mean precision: (69.0% [95% CI: 62.8-75.2%] vs 70.1% [95% CI: 64.3-75.9%]; p = 0.08). Inter-reader variability in lesion detection was slightly improved with the tool (Light's kappa = 0.55 vs 0.60), but without statistical difference (p = 0.056).Conclusion: The use of an automatic tool can help clinicians detect SC lesions in pwMS by increasing their sensitivity.Key points: Question No tool to help detect MS SC lesions is used in clinical practice despite their frequency and prognostic value. Findings This DL-based tool led to improvement in clinicians' sensitivity in detecting SC lesions from both sagittal T2 and STIR sequences, without decreasing precision. Clinical relevance Our study indicated the potential of a DL-based tool to assist clinicians in the challenging task of detecting SC lesions in people with MS on a combination of sequences commonly acquired in clinical practice
Halogen-regulating synthesis of a novel semiconductor hybrid material [(CH3)3N(CH2)3Br]2ZnBr4 with high-temperature phase transition
No full textInternational audienceThe continuous progress in the synthesis and characterization of materials in the vast family of hybrid organic-inorganic metal halide perovskites have been pushed by their exceptional properties mainly in optoelectronic applications. Here, we have used specific reagents to design and synthesize a low dimensional semiconductor material, [Br(CH 2 ) 3 N(CH 3 ) 3 ] 2 ZnBr 4 using slow evaporation method which is crystalized in a monoclinic system with a P2/c space group with cell parameters of a = 23.572 ( 3) Å, b = 9.4987 (10) Å, c = 15.8731 (16) Å, b = 91.440 (4)1 and Z = 6 at room temperature. The crystal structure of [Br(CH 2 ) 3 -N(CH 3 ) 3 ] 2 ZnBr 4 was determined to be zero-dimensional (0D). In this structure, the inorganic [ZnBr 4 ] 2À anions are completely isolated from each other. These anionic groups are separated by [Br(CH 2 ) 3 N(CH 3 ) 3 ] + cations. The UV-visible absorption spectrum of the polycrystalline sample estimates the band gap, which was found to be approximately 3.36 eV. Differential scanning calorimetric analysis exhibits one irreversible phase transition at 358 K. The XRD as function of the temperature confirms this transition by the change of the symmetry of this material. The temperature-dependent Raman scattering study analyzed in detail the full width at half-maximum (FWHM) of internal modes of the anions and cations which are connected by intermolecular C-HÁ Á ÁBr hydrogen bonds and an intramolecular C-HÁ Á ÁBr interaction. The change of energy activation confirms the phase transition. The electrical properties further validate the transition mechanism through the observed change in energy activation using the variation of the conductivity versus temperature
Side-channel attack hardware detection module added to RISC-V core
No full textInternational audienceProcessor performance optimizations such as Out-of-Order or speculative execution are known to be exploitedby attackers for malicious purposes. Numerous side-channel attacks have been developed over decades andmore recently transient attacks are considered as serious threats. As a countermeasure, previous works offereddetection methods monitoring hardware performance counters (HPC). In this work we propose to take advantageof dynamic instructions insertion to monitor HPCs and detect side-channel attacks. This approach offersflexibility as it allows to dynamically adapt the events monitored by HPCs to the state of the system. We presentour light-weight hardware micro-decoding unit used to insert monitoring instructions in the execution flow of aRISC-V core and detect side-channel attacks
Étude de la perception et de la manipulation d'objets virtuels en réalité augmentée à l'aide de dispositifs haptiques portables
No full textWearable haptic devices provide tactile sensations in a compact form. They have been little used in augmented reality (AR), where virtual content is integrated into real world perception. In this thesis, we investigate their use to enhance direct hand interaction with virtual and augmented objects in AR. First, we investigate how visual rendering affects the perception of vibrotactile texture augmentations of real surfaces directly touched by the finger. To this end, we propose a system for rendering visuo-haptic texture augmentations using an AR headset and a wearable vibrotactile device. Next, we evaluate how the perceived roughness of virtual textures differs when touched via a virtual hand vs. one's own hand, and in AR vs. virtual reality (VR). We then investigate the realism and coherence of combining visual and haptic texture augmentations in AR. Second, we investigate how visuo-haptic feedback as a hand augmentation improves the direct manipulation of virtual objects with the hand in AR, in terms of performance and usability. We study the effect of six visual feedback of the virtual hand as augmentation of the real hand. We then evaluate two vibrotactile contact techniques, provided at four different positions on the real hand and compare them to two visual hand augmentations.Les dispositifs haptiques portables procurent des sensations tactiles tout en restant compacts. Ils ont été peu utilisés en réalité augmentée (RA), où le contenu virtuel est intégré à la perception du monde réel. Dans cette thèse, nous étudions leur utilisation pour améliorer les interactions de la main avec des objets virtuels et augmentés en RA. Nous commençons par étudier l'impact du rendu visuel sur la perception des textures vibrotactiles virtuelles qui augmentent des surfaces réelles touchées directement par le doigt. Nous proposons un système d’augmentation de textures visuo-haptiques à l'aide d'un casque de RA et d'un dispositif vibrotactile portable. Nous évaluons ensuite comment la rugosité perçue des textures augmentées diffère lorsqu'elles sont touchées via une main virtuelle, en réalité virtuelle (RV) et en RA, ou par sa propre main. Nous étudions alors le réalisme et la cohérence de la combinaison des textures augmentées visuelles et haptiques en RA. Nous étudions ensuite comment des retours sensoriels visuo-haptiques augmentant la main améliorent les performances et l’expérience utilisateur lors de la manipulation d'objets virtuels en RA. Nous commençons par étudier l'effet de six retours visuels de la main virtuelle comme augmentation de la main réelle. Nous évaluons ensuite deux techniques de contact vibrotactile à quatre endroits différents sur la main et nous les comparons à deux augmentations visuelles de la main
Abstract 6494: Genetically characterized canine tumoral cell lines are relevant models to test the efficacy of new targeted therapies: Example of anti-MDM2 targeted therapy
No full textInternational audienceGenetic characterization of cell lines is essential for understanding and predicting sensitivity to anti-tumoral targeted therapies. This study develops a panel of genetically characterized tumoral cell lines to test novel and repositioned anti-tumor therapies, focusing on canine mucosal melanoma (MM) and histiocytic sarcoma (HS) models. We established a diverse panel of MM and HS canine cell lines, leveraging the strong genetic and clinical similarities between canine and human cancers. Using long-read sequencing (Nanopore) technology, we performed comprehensive genetic characterization, identifying single nucleotide variants, structural variations, and copy number alterations. RNA sequencing complemented our genomic analysis by assessing gene expression profiles and potential fusion transcripts. Our methodology involved several key steps:1. Cell line establishment from tumor samples2. Comprehensive genetic profiling3. In vitro drug sensitivity screening4. In vivo validation through mouse xenograft modelsAs a proof of concept, we evaluated Idasanutlin, an MDM2 inhibitor, across our developed cell lines. Our findings demonstrated a clear correlation between TP53 status and drug sensitivity: cell lines with wild-type TP53 were sensitive to the drug, while those with mutated TP53 showed resistance. This result underscores the potential of genetic profiling to guide treatment decisions. The unique value of our approach lies in its ability to:· Identify biomarkers of drug response· Elucidate resistance mechanisms · Discover treatment-responsive subgroups based on genetic profile in previously untreated cancer· Inform the potential of new or repositioned targeted therapiesCanine cancer models offer distinct advantages, including:· Higher incidence of rare cancers in specific breeds· Genetic predispositions from selective breeding· Closer genetic and clinical similarity to human cancersOur cell line panel provides a systematic approach to validate therapeutic strategies tailored to specific genetic contexts. By integrating genomic, transcriptomic, and drug sensitivity data, we create a powerful research tool for both veterinary and human oncology. The research demonstrates the potential of comparative oncology in advancing cancer treatment. Our genetically characterized cell lines offer a comprehensive platform for drug screening and biomarker discovery, ultimately aiming to improve patient care and survival rates for challenging cancers. This work represents a significant step towards more personalized and precise cancer therapies, bridging the gap between preclinical research and clinical application
Cluster Analysis of Palliative Care Patients’ Trajectories in Primary Care: Hospitalization Yes, but Home and Nursing Home Care Above All
No full textInternational audienceBackground: Understanding the environment in which patients live at the end of their lives is essential to improving palliative care for these patients and their families. Objectives: We aimed to explore the different living places and trajectories of palliative care patients in the last three months of life in primary care and to identify patient characteristics associated with these trajectories. Methods: This retrospective national study was carried out among a population of adult patients who died a non-sudden death. The trajectories were modeled and classified using sequence analysis, optimal matching, and hierarchical ascendant clustering. Univariate and multivariate multinomial logistic regression compared patient characteristics associated with these trajectories. The focus was on primary care. Patients had to have spent at least one day at home or in a nursing home in the last three months before their death. The research took place between November 2020 and November 2021 in mainland France. Results: Three hundred adult patients were included in the study. Cluster analysis revealed three main trajectories during the last three months of life: \"staying at home\" (57%), \"staying in a nursing home\" (29%), and \"moving from home to hospital\" (14%). Dementia and having children limited hospitalization. Not having an informal caregiver and having dementia were associated with staying in a nursing home. Conclusions: Palliative care patients' living situations and transitions can be tracked using primary care practice data. This study highlights the unique needs of palliative care in home and nursing home settings. Additionally, factors such as dementia and family dynamics play a significant role in determining where patients live, which can help inform clinical practices and research strategies in palliative care
Magnac-Laval, Saint-Léger-Magnazeix, Les Gorceix, La Châtre (87), rapport de diagnostic archéologique
No full textInnovative Antibacterial Air Filters Impregnated with Photocatalytic MgFe2O4 Nanoparticles for Improved Microbiological Air Quality
No full textInternational audienceOver time, nanoparticles’ chemistry has shown exceptional ability to solve a wide range of problems in various fields, including the control of microbiological air quality in buildings. Herein, magnesium ferrite (MgFe2O4) was synthesized using coprecipitation, then characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), Transmission Electron Microscopy (TEM) and photoelectron spectroscopy (XPS). MgFe2O4 nanoparticles were then assessed for their ability to inhibit Escherichia coli ATCC 8739 growth and airborne bacterial viability in a laboratory atmosphere through a direct air filtration system. The material showed strong inhibitory activity against E. coli by eliminating practically all viable cells in the tested suspensions after 1 h contact time in the presence of light. Finally, the prepared air filtration setup revealed that passing air bacteria through non-woven fabric filters impregnated with MgFe2O4 effectively eliminates them. Thus, only 1 colony-forming unit (CFU) was obtained from 36 L of filtered air, while a control filter (without MgFe2O4) allowed the passage of 2.6 × 105 CFU to the liquid medium. The obtained results initiate potential applications of MgFe2O4 nanoparticles in controlling microbiological indoor air quality (IAQ), especially in healthcare facilities where microbial resistance to antibiotics is the most notable, individuals are the most exposed, and contamination risks are the highest