Dynamic range optimisation of CMOS image sensors dedicated to space applications

Nowadays, CMOS image sensors are widely considered for space applications. Their performances have been significantly enhanced with the use of CIS (CMOS Image Sensor) processes in term of dark current, quantum efficiency and conversion gain. Dynamic Range (DR) remains an important parameter for a lot of applications. Most of the dynamic range limitation of CMOS image sensors comes from the pixel. During work performed in collaboration with EADS Astrium, SUPAERO/CIMI laboratory has studied different ways to improve dynamic range and test structures have been developed to perform analysis and characterisation. A first way to improve dynamic range will be described, consisting in improving the voltage swing at the pixel output. Test vehicles and process modifications made to improve voltage swing will be depicted. We have demonstrated a voltage swing improvement more than 30%. A second way to improve dynamic range is to reduce readout noise A new readout architecture has been developed to perform a correlated double sampling readout. Strong readout noise reduction will be demonstrated by measurements performed on our test vehicle. A third way to improve dynamic range is to control conversion gain value. Indeed, in 3 TMOS pixel structure, dynamic range is related to conversion gain through reset noise which is dependant of photodiode capacitance. Decrease and increase of conversion gain have been performed with different design techniques. A good control of the conversion gain will be demonstrated with variation in the range of 0.05 to 3 of initial conversion gain

Organic components of airborne dust influence the magnitude and kinetics of dendritic cell activation

Bioaerosol exposure in highly contaminated occupational settings is associated with an increased risk of disease. Yet, few determinants allow for accurate prediction of the immunopathogenic potential of complex bioaerosols. Since dendritic cells are instrumental to the initiation of immunopathological reactions, we studied how dendritic cell activation was modified in response to individual agents, combined microbial agents, or air sample eluates from highly contaminated environmental settings. We found that combinations of agents accelerated and enhanced the activation of in vitro-generated murine bone marrow-derived dendritic cell cultures, when compared to individual agents. We also determined that endotoxins are not sufficient to predict the potential of air samples to induce bone marrow-derived dendritic cell activation, especially when endotoxin levels are low. Importantly, bone marrow-derived dendritic cell activation stratified samples from three environmental settings (swine barns, dairy barns, and wastewater treatment plants) according to their air quality status. As a whole, these results support the notion that the interplay between bioaerosol components impacts on their ability to activate dendritic cells and that bone marrow-derived dendritic cell cultures are promising tools to study the immunomodulatory impact of air samples and their components

State of the art and the future of microbiome-based biomarkers:a multidisciplinary Delphi consensus

Although microbiome signatures have been identified in various contexts (ie, pathogenesis of non-communicable diseases and treatment response), qualified microbiome-based biomarkers are currently not in use in clinical practice. The Human Microbiome Action consortium initiated a Delphi survey to establish a consensus on the needs, challenges, and limitations in developing qualified microbiome-based biomarkers. The questionnaire was developed by a scientific committee via literature review and expert interviews. To ensure broad applicability of the results, 307 experts were invited to participate; 114 of them responded to the first round of the survey, 93 of whom completed the second and final round as well. The survey highlighted the experts’ confidence in the potential of microbiome-based biomarkers for several indications or pathologies. The paucity of validated analytical methods appears to be the principal factor hindering the qualification of these biomarkers. The survey also showed that clinical implementation of these biomarkers would only be possible if kitted and validated molecular assays with simple interpretation are developed. This initiative serves as a foundation for designing and implementing public-private collaborative projects to overcome the challenges and promote clinical application of microbiome-based biomarkers.</p

A MAP6-Related Protein Is Present in Protozoa and Is Involved in Flagellum Motility

In vertebrates the microtubule-associated proteins MAP6 and MAP6d1 stabilize cold-resistant microtubules. Cilia and flagella have cold-stable microtubules but MAP6 proteins have not been identified in these organelles. Here, we describe TbSAXO as the first MAP6-related protein to be identified in a protozoan, Trypanosoma brucei. Using a heterologous expression system, we show that TbSAXO is a microtubule stabilizing protein. Furthermore we identify the domains of the protein responsible for microtubule binding and stabilizing and show that they share homologies with the microtubule-stabilizing Mn domains of the MAP6 proteins. We demonstrate, in the flagellated parasite, that TbSAXO is an axonemal protein that plays a role in flagellum motility. Lastly we provide evidence that TbSAXO belongs to a group of MAP6-related proteins (SAXO proteins) present only in ciliated or flagellated organisms ranging from protozoa to mammals. We discuss the potential roles of the SAXO proteins in cilia and flagella function

Activation des cellules dendritiques par des composantes de bioaérosols

Plusieurs environnements de travail sont hautement contaminés par des bioaérosols qui sont souvent associés à l’induction de diverses pathologies respiratoires. Il est donc important de mieux définir l’impact des composantes des bioaérosols sur l’immunité mucosale pulmonaire. La cellule dendritique est à l’interface de l’individu et de son environnement et aurait un rôle dans l’initiation de réponses immunopathologiques induites par les bioaérosols. Le but de ce projet était donc de comparer comment divers agents, combinaisons d’agents, ou des échantillons issus d’environnements hautement contaminés par des bioaérosols modulaient l’activation des cellules dendritiques in vitro. Nos résultats montrent que le degré d’activation des cellules dendritiques dérivées de la moelle osseuse in vitro discriminent un agent fortement immunogène, les endotoxines, d’agents faiblement immunogènes tels les β-D glucanes et les archées Methanosphaera stadtmanae et Methanobrevibacter smithii. Nous montrons également qu’une stimulation combinée de ces agents active de façon additive les cellules dendritiques, confirmant ainsi l’importance d’étudier l’impact des bioaérosols comme un ensemble, et non pas seulement certaines composantes individuellement. De plus, la cinétique d’activation des cellules dendritiques est modulée par la nature de la stimulation, ce qui confirme l’hypothèse d’interaction entre les composantes des bioaérosols sur la réponse immune. Enfin, l’activation des cellules dendritiques permet de stratifier par classe divers environnements de travail, ce qui est corroboré par un modèle d’inflammation pulmonaire in vivo. Ce projet élargit donc notre connaissance des mécanismes sous-jacents à l’induction de réactions immunes pathologiques par les bioaérosols complexesSeveral occupational settings are highly contaminated with bioaerosols, which are often associated with the induction of various respiratory pathologies. It is therefore important to define the impact of the components of bioaerosols on mucosal immunity. Dendritic cells are at the interface of the individual and his environment and play a role in the initiation of immunopathological responses induced by bioaerosols. The purpose of this project was to compare how various agents, agent combinations, or samples from environments highly contaminated with bioaerosols modulated dendritic cell activation in vitro. Our results show that the degree of activation of dendritic cells derived from the bone marrow differentiates between a highly immunogenic agent, endotoxins, from weakly immunogenic agents such as β-D glucans and archaea Methanosphaera stadtmanae and Methanobrevibacter smithii. We also show that combined stimulation of these agents additively activates dendritic cells, thus confirming the importance of studying the impact of bioaerosols as a whole, and not just individual components. In addition, the kinetics of activation of dendritic cells is modulated by the nature of the stimulation, which confirms the hypothesis of interaction between the components of bioaerosols on the immune response. Finally, the activation of dendritic cells stratifies various working environments by class, which is corroborated by an in vivo lung inflammation model. This project therefore broadens our understanding of the mechanisms underlying the induction of immunopathological reactions by complex bioaerosols

Développement d'une technique expérimentale de quantification de traces de polluants dans l'air à l'aide d'une source impulsionnelle femtoseconde

Certains processus d'optique non-linéaire induits par des impulsions femtosecondes permettent la création de sources lumineuses de spectre large de l'ultraviolet à l'infrarouge, que ce soit sous forme de continua ou d'impulsions accordables en longueur d'onde. Nous nous sommes intéressés aux possibilités de quantification decomposés gazeux dans l'air à l'aide de telles sources. L'intêret des sources de spectre large est la possibilité d'une détection multi-polluants, permettant de s'affranchir des effets de recouvrement des spectres d'absorption. Une expérience de détection d'espèces à l'air libre a d'abord été mise au point dans le domaine du visible afin d'examiner le potentiel de ces sources pour la détection de traces de polluants. La forme particulière quaso-gaussienne des impulsions ou la forme irrégulière du continuum a alors conduit à mettre au point une technique spécifique d'extraction de spectre d'absorption afin de déterminer la concentration de chaque espèce. Cette technique de quantification ne nécessite aucune connaissance préalable des paramètres de l'impulsion initiale (enveloppe, intensité). La méthode de quantification a finalement été étendue dans le domaine ultraviolet et appliquée à la détection de traces de dioxyde d'azote. Dans l'ultraviolet, le continuum s'est avéré la source la mieux adaptée à une détection multi-polluants. Un minimum détectable de l'ordre de 18 ppb/m a été obtenu avec cette technique.DUNKERQUE-BU Lettres Sci.Hum. (591832101) / SudocSudocFranceF

Etude du mécanisme d'oxydation des guanidines par les no-synthases. recherche de nouveaux précurseurs de No

PARIS5-BU Saints-Pères (751062109) / SudocSudocFranceF

Enhanced Stability and Bangap Tuning of α-[HC(NH2)2]PbI3 Hybrid Perovskite by Large Cation Integration

Computational investigations were conducted thanks to HPC resources provided by [TGCC/CINES/IDRIS] under the allocation 2018-A0010907682 made by GENCIInternational audienceWe report room-temperature synthesis of lead- and iodide-deficient α-[HC(NH)]PbI perovskites (abbreviated d-α-FAPI, FA = formamidinium), with the general formula (A',FA)[PbI] (with A' = hydroxyethylammonium (HEA) or thioethylammonium (TEA) cations, 0.04 ≤ x ≤ 0.15). These materials retain a 3D character of their perovskite network despite incorporation of large HEA or TEA cations, demonstrating that the Goldschmidt tolerance factor can be bypassed. We found that thin films of (TEA,FA)[PbI] ( x = 0.04 and 0.13) show exceptional α-phase stability under ambient conditions, 1 order of magnitude higher than α-FAPI and α-(Cs,FA)PbI thin films. d-α-FAPI phases are shown to maintain a direct band gap, which increases monotonously for x ranging from 0 up to 0.20, with characteristics of a p-type semiconductor for low concentrations of vacancies ( x ≤ 0.13) and n-type for larger ones. They offer alternatives to reach the methylammonium- and bromine-free stable α-FAPI-type phase and open new avenues in the field of perovskite solar cells, up to band gap tuning desirable for tandem solar cells

Lung stiffness of C57BL/6 versus BALB/c mice

Abstract This study was undertaken to determine whether a smaller lung volume or a stiffer lung tissue accounts for the greater lung elastance of C57BL/6 than BALB/c mice. The mechanical properties of the respiratory system and lung volumes were measured with the flexiVent and compared between male C57BL/6 and BALB/c mice (n = 9). The size of the excised lung was also measured by volume liquid displacement. One lobe was then subjected to sinusoidal strains in vitro to directly assess the mechanical properties of the lung tissue, and another one was used to quantify the content of hydroxyproline. In vivo elastance was markedly greater in C57BL/6 than BALB/c mice based on 5 different readouts. For example, respiratory system elastance was 24.5 ± 1.7 vs. 21.5 ± 2.4 cmH2O/mL in C57BL/6 and BALB/c mice, respectively (p = 0.007). This was not due to a different lung volume measured by displaced liquid volume. On the isolated lobes, both elastance and the hydroxyproline content were significantly greater in C57BL/6 than BALB/c mice. These results suggest that the lung elastance of C57BL/6 mice is greater than BALB/c mice not because of a smaller lung volume but because of a stiffer lung tissue due to a greater content of collagen