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Effects of Microplastics and Nanoplastics on the Kidneys
No full textInternational audiencePlastics are hydrophobic carbon polymers with a half-life of approximately 500 years. The widespread production and environmental accumulation of plastics pose significant toxicity concerns. Humans are routinely exposed to micro- and nanoplastics (MNPs), which can enter rate the bloodstream and reach various organs, including the kidneys. Here, we review research on nephrotoxic effects of plastics and the underlying mechanisms. The results of several studies of kidneys in mammals and kidney cells from humans suggest that MNPs induce renal toxicity. Although the underlying mechanisms remain to be characterized in detail, the current body of evidence suggests that MNPs promote the production of reactive oxygen species and thus trigger local (renal) and systemic inflammatory responses. These processes enhance cytotoxicity and may drive MNP-induced kidney damage. This toxicity results in histopathological changes in renal tissues (including glomerular and tubular damage and fibrosis) and modifications in key biomarkers of renal function (such as the glomerular filtration rate, albuminuria, and the blood urea nitrogen level). Moreover, MNPs have been shown to induce cardiovascular damage, which may contribute to the progression of chronic kidney disease (CKD) - potentially via the activation of aryl hydrocarbon receptors. Notably, the nephrotoxic effects of MNPs appear to be exacerbated by co-exposure to other environmental contaminants and uremic toxins. CKD can impair the kidneys' ability to eliminate MNP. Furthermore, dialyzed patients are substantially exposed to MNPs during dialysis sessions, which potentially compounds their vulnerability. With a view to better understanding the effects of MNPs on renal health and the impact of CKD and dialysis on levels of exposure to plastics, further studies are essential
Long Term Outcomes in Patients With Non-Infectious Mixed Cryoglobulinemic Vasculitis.
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Technological innovations and regional diversity in Western Europe at ca. the MIS 11 threshold: a cladistic approach
No full textInternational audienceThe ca: Marine Isotope Stage (MIS) 11 interglacial is considered to be a threshold for behavioural innovations in Western Europe. Innovations both in technology and subsistence are observed, as well as the appearance of Neanderthal anatomical features. Core technologies and Large Cutting Tools reflect changes in behaviours and innovations, with for instance, the onset and diffusion of the iconic Levallois core technology associated with more complex and standardized debitage. Following the severe glacial event of MIS 12, the lithic assemblages yield evidence of both innovations, but the chronology of their appearance remains unclear. For tracking these innovations and generally characterizing the technological and typological features of this period of time, a large database of the available ca. MIS 11 assemblages (from MIS 12 to MIS 10) has been built including a revision of some of the assemblages. In order to unravel the relationship between sites of this period, we applied a cladistic approach using three-item analysis, considering the assemblages themselves as the object of analysis, with an emphasis on core technology. We show how three-item analysis is an efficient method capable of correctly analysing characters from lithic technologies that appear to be intrinsically hierarchical. Our results suggest that Levallois core technology survived during the glacial event of MIS 12 and diversified during the long interglacial of MIS 11. Our results also show the absence of cultural endemism, which may be linked to significant mingling between northern and southern Europe
Life-stage-specific specialities in the cell atlases of the Clytia hemisphaerica planula and medusa
No full textJellyfish have complex life-cycles, but there has been limited exploration of how this is achieved at the cellular level. We used single-cell transcriptomics to assemble a cell atlas for the planula larva of Clytia hemisphaerica, and compared it to an updated cell atlas for the medusa (jellyfish) stage. The cells of the planula fell into the same broad categories as for the medusa: ectoderm, gastroderm, interstitial cells (i-cells), nematocytes (stinging cells), neurons and secretory cells. Although the planula cells generally showed less diversity than medusae within each category, cells with specialized features unique to their stage could be distinguished by their transcriptional profiles as well as by ultrastructure. Some planula-specific types were identified: aboral secretory cells involved in settlement, and a cell type attributed a role in immunity or post-metamorphic theca production. Distinct transcriptome profiles within different regions of the ciliated planula ectoderm reflected different post-metamorphosis fates of domains along the oral-aboral axis. Inspection of the cell clusters showing significant similarity of marker genes between planula and medusa, and inference of similarity using a statistical model of marker gene presence/absence, revealed correspondences between families of cells from planula and medusa rather than precise cell identities
Influence of Ageing on Mechanical, Thermal, and Physical Properties of Concrete with Recycled Polystyrene Granules
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Simulated parametric study of coherent differential imaging for exoplanet detection with SPHERE
No full textInternational audienceMotivations: Classical high-contrast imaging (ADI, RDI,…) always requires extensive observation time for speckle calibration. We investigate Coherent Differential Imaging (CDI), a powerful alternative that relies on active, user-controlled modulation rather than passive diversity.Method: We implemented the Pair-Wise Probing algorithm within COMPASS simulations to actively modulate optical aberrations in a VLT/SPHERE-like environment.Results: We performed a comprehensive parametric analysis, demonstrated a contrast gain up to a factor of 11 in simulations and identified distinct corrective regimes.Perspective: This work paves the way for CDI as a highly efficient strategy for next-generation instruments like SPHERE+ and the Roman Space Telescope
Compared SIMS and NanoSIMS Analyses of Duplex Oxide Layers Growth After Sequential Oxidation Tests Using Oxygen Isotope Tracers
No full textInternational audienceA precise methodology for determining the growth mode of oxide layers on metallic materials at high temperatures is proposed. The approach combines sequential isotopic oxidation tests (using 16 O and 18 O isotopes) with secondary ion mass spectrometry (SIMS and nanoSIMS) analyses. NanoSIMS provides high-resolution localisation of oxygen diffusion pathways and oxide growth zones. However, its limited accessibility and specialised instrumentation can pose practical constraints. In contrast, dynamic SIMS offers broader accessibility and the ability to directly quantify oxygen isotope ratios across depth profiles. The detection of both conventional atomic (O − ) and diatomic (O 2 − ) oxygen signals in dynamic SIMS analysis proved highly effective in offering insights on oxide growth mode, closely replicating nanoSIMS results. The diatomic signal analysis complements the atomic signal data by improving the understanding of oxidant transport within the oxide layer. The methodology was validated through its application to a Co-10Cr alloy oxidised at 900 °C in O 2, under sequential exposures to 16 O and 18 O isotopes. Both SIMS and nanoSIMS revealed the formation of a duplex oxide layer, consisting of an outer layer formed by outward Co cation diffusion and an inner layer growing by inward oxygen penetration, particularly in the grain-boundary regions of the outer oxide layer. The alloy is proposed to oxidise according to the Available Space Model
Enhancing peripheral scene recognition through spatial frequency training: Behavioral evidence from macular degeneration and healthy aging
No full textInternational audienceMacular degeneration (MD) causes central vision loss and leads to long-term reorganization of visual functions. Central vision loss in MD severely reduces access to high spatial frequencies (HSF) that convey fine visual details, while low spatial frequencies (LSF) remain relatively accessible through peripheral vision and may support compensatory processing. This study investigated whether repeated training in categorizing filtered scenes improves peripheral scene recognition by enhancing spatial frequency processing. Ten MD patients and ten age- and gender-matched controls performed a scene categorization task (indoor vs. outdoor) using LSF or HSF images. Both groups completed a 12-session training protocol: patients performed the task at their preferred retinal location (PRL), and controls fixated with their fovea and viewed stimuli through an individualized artificial scotoma matched to their paired patient. Before training, MD patients showed a marked deficit for HSF scenes compared to controls, and a milder deficit for LSF scenes. After training, patients exhibited a significant improvement in categorizing LSF scenes, and an improvement specifically limited to HSF outdoor scenes, suggesting enhanced use of preserved peripheral information and partial compensation for the HSF deficit. Older controls also showed reduced performance for HSF scenes in peripheral vision, and similarly benefited from training. These results highlight the potential of perceptual training to enhance peripheral visual processing in MD patients, particularly by leveraging coarse visual cues. They support the idea that such protocols may be beneficial not only for visual rehabilitation in MD but also for preserving visual-cognitive functions in normal aging
Spatiotemporal modulation of the magnetic order in FeRh using sub-gigahertz strain waves
No full textInternational audienceWe probe the first-order hysteretic antiferromagnetic (AFM) to ferromagnetic (FM) phase transition of FeRh in a FeRh/Ta/GaAs stack using surface acoustic waves (SAW) of three different frequencies up to 889 MHz. A clear signature of the phase transition is observed in the Rayleigh velocity and attenuation variations across the phase coexistence temperature range. The velocity variation closely follows the thermal hysteresis exhibited by the phase transition when probed with magnetometry, thereby enabling the determination of the FM fraction of FeRh versus temperature in the SAW path. The variation of attenuation is modeled under the assumption of strain-induced modulation of magnetic order via the movement of AFM-FM phase domain walls (PDWs) at the SAW frequency. This movement is driven by the strain-dependent difference between the AFM and FM Gibbs free energies, which originates from volume magnetostriction. The measured attenuation and its dependence upon the temperature and SAW frequency can be explained through a dissipative mechanism associated with the PDW oscillation driven by the strain wave. Finally, we demonstrate the drastic changes in the temperature dependence of SAW attenuation caused by the applied magnetic field within the FM-rich phase coexistence range, which arise from SAW-induced ferromagnetic resonance
A Theoretical Proposal to Localize and Determine the Amount of Methane, Ammonia and Carbon Dioxide in Nano-Cages of Water Clathrate Through the Space Infrared Spectroscopic Observations
No full textInternational audienceThis paper investigates the different relaxation channels of a single symmetric top NH3 and a spherical top CH4 molecule trapped at low temperature in a clathrate hydrate nano-cage in the infrared absorption domain of their vibrational degrees of freedom. The approach utilizes the Born–Oppenheimer approximation and the extended site inclusion model applied to CO2 in a previous work, which was based on pairwise atom–atom effective interaction potentials. The calculations show that trapping the methane or ammonia molecule is energetically more favorable in a type sI clathrate structure than in an sII one, and entropic considerations show that methane can be released much more easily than ammonia from clathrate hydrate nano-cages. In the small (s) and large (l) nano-cages with the sI structure, the CH4 molecule exhibits a more or less perturbed rotational motion, while the NH3 molecule shows a strongly hindered orientational motion that tends to a three-dimension librational motion (oscillation motion) around its orientational equilibrium configuration. The calculated orientational energy level schemes are quite different from those of the molecular free rotation. In the static field inside the cage, degenerate ν3 and ν4 vibrational modes of methane and ammonia molecules are shifted and split. Moreover, for ammonia molecules, the ν1 and ν2 modes are shifted, and the inversion motion is no longer allowed. The non-radiative and radiative relaxation channels of CH4, NH3 and CO2 in clathrate nano-cages are discussed with reference to the matrix isolation spectroscopic results. Upon laser excitation, then, from the energy levels calculated for the different degrees of freedom, NH3 and CO2 are expected to fluoresce, while for CH4, non-radiative relaxation should lead to evaporation at the surface of clathrates. Experimental setups are suggested to localize and study these species underneath ice surfaces on distant planets or planetesimals from mobile detectors such as drones or CubeSats equipped with appropriate laser sources and telescopes with 2D imaging detectors