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Uptake, localization and dissolution of barium sulfate nanoparticles in human lung cells explored by the combination of ICP-MS, TEM and NanoSIMS
No full textInternational audienceBackground: Barium sulfate nanoparticles (BaSO4-NPs) are considered to be poorly soluble, chemically inert, and therefore relatively non-toxic. For humans, inhalative exposure represents the most significant route of uptake. Objective and methods: Cellular effects after exposure to BaSO4-NPs for 24 and 72 have been investigated in this study on primary human lung cells. To track the fate of BaSO4-NPs in human lung cells, we used inductively coupled plasma mass spectrometry (ICP-MS) to quantify cellular uptake of NPs, as well as transmission electron microscopy (TEM) and nanoscale secondary ion mass spectrometry (NanoSIMS) to investigate subcellular distribution of NPs through high-resolution elemental imaging. Results and conclusions: We show that BaSO4 nanoparticles have been taken up by normal human bronchial epithelial cells (NHBEC) in a dose-dependent manner. However, no clear time-dependent uptake could be observed. The barium sulfate nanoparticles were visible in vesicles within the cytosol by TEM, which was confirmed by high-resolution NanoSIMS images. Nevertheless, no uptake of the particles into the nucleus was observed in this study. However, it was shown that BaSO4-NPs were partly dissolved, and barium ions were distributed throughout the entire cell. Toxicity of the particles was indicated by a dose- and time-dependent loss of viability in human lung cells
Electronic and magnetic properties of diluted magnetic semiconducting NaY1-xCexSe2alloys
No full textInternational audienceThe electronic and magnetic properties of diluted magnetic semiconductor (DMS) materials of the general formula NaY1-xCexSe2 (0.00 ≤ x ≤ 1.00) are studied using density functional theory (DFT) calculations. Alloys with fractional composition of the two rare earth elements (Y and Ce), which have not yet been synthesized, are predicted to exhibit magnetic transition and potential quantum spin liquid properties. As Ce concentration increases, these alloys transition from non-magnetic (NaYSe2) to antiferromagnetic (AFM), with NaCeSe2 forming magnetic layers of Ce3+ ions in a 2D triangular lattice. This structure suggests the potential for quantum spin liquid behavior. The Néel temperature (TN) of these compounds increases with Ce concentration, reaching 114 K at 100% Ce doping. The direct bandgap of NaCeSe2 (approximately 0.5 eV (PBE-GGA) and 1.3 eV (HSE06)) calculated for both spin-up and spin-down directions suggests that these alloys are suitable for magneto-optical applications, such as spin-polarized light-emitting diodes and spin transistors. The magnetic moment (~ 1 μB) primarily arises from Ce atoms and exhibits robustness with respect to changes in crystallographic parameters. These findings position NaY1-xCexSe2 alloys as promising candidates for both quantum spin liquid exploration and magneto-optical device
Distinction entre un mandat social et un contrat de travail : critères à prendre en compte
No full textInternational audience(Soc. 27 nov. 2024, no 23-10.389, F-B, D. 2024. 2065
Corrigendum to ‘Dispatched microbial community assembly processes driving ecological succession during phytostabilization of mercury-rich tailings’ [Environ. Pollut., 365 (2025) 125376]
No full textInternational audienceThe authors regret that the labels used in Fig. 2 and Fig. 5 in the original article are incorrect. The figures labeled as "Abundant and Rare" in original article should be "Core and Satellite". These errors are caused by replacing the figures during the proof process to increase the resolution. The revised figures did not change the conclusion of this work. The authors would like to apologise for any inconvenience caused
Design and validation of a power divider for multi-channel GNLTL synchronization
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Défense nationale, instabilité gouvernementale : l’éternel retour de l’infantilisme
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Vers une écopoétique marine dans les arts hispaniques contemporains
No full textInternational audienceTaking as a starting point a number of works by Hispanic visual and multimedia artists (Carmela García, Tania Gandiani, Irati Inoriza, Dhara Rivera, Pavel Aquilar...), we consider the development of an epistemology specific to marine ecopoetics in the visual arts, based on the adoption of new procedures or the systematisation and conjunction of objects of study, points of view, sensorialities and artistic and aesthetic procedures already present in the arts.A partir de las obras de algunos artistas visuales y multimedia hispanos (Carmela García, Tania Gandiani, Irati Inoriza, Dhara Rivera, Pavel Aquilar...), se plantea el desarrollo de una epistemología propia de las ecopoéticas marinas en las artes visuales, basada en la adopción de nuevos procedimientos o en la sistematización y conjunción de objetos de estudio, puntos de vista, sensorialidades y procedimientos artísticos y estéticos ya presentes en las artes.A partir de quelques réalisations d’artistes hispaniques visuels et multimédias (Carmela García, Tania Gandiani, Irati Inoriza, Dhara Rivera, Pavel Aquilar…), nous envisageons le développement d’une épistémologie propre aux écopoétiques marines dans les arts visuels, qui reposerait sur l’adoption de nouveaux procédés ou la systématisation et la conjonction d’objets d’étude, de points de vue, de sensorialités et de procédés artistiques et esthétiques déjà présents dans les arts
Resistance-capacitance dynamic model for hydrogen storage in metal hydrides with phase change material as thermal management system
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Evaluation of the antioxidant properties and metabolomic characterisation of Dichapetalum guineense (D.C.) Keay leaf extracts
No full textInternational audienceDichapetalum guineense (DC.) Keay, also known as Dichapetalum madagascariense, is a woody plant native to sub-Saharan Africa, found mainly in West Africa and Madagascar. The plant is widely used in traditional medicine, where it plays a central role in the traditional pharmacopoeia of Togo and Benin due to its many pharmacological properties, particularly in the treatment of malaria and hypertension [1,2]. Research has been carried out to scientifically validate its traditional uses, in particular by isolating and biologically assessing the compounds present in extracts (acetone and petroleum ether) of roots and stems. To date, the main class of compounds identified and isolated from this plant are the dichapetalines (A to H and M), belonging to the phenylpyranotriterpenoid family [3]. The aim of this study was to evaluate these antioxidant properties and to identify the compounds present in the polar extract of the leaves. The antioxidant activity of the extracts was determined using the DPPH radical scavenging test and the ferric reduction method (FRAP) [4]. In addition, analysis of the hydroethanolic extract by UHPLC-MS/MS was used to identify the metabolites present in the extract. The spectral data obtained were processed using MZmine4, then analysed using the SIRIUS and GNPS platforms to construct molecular networks and annotate the various features [5,6]. The hydroethanolic extract demonstrated antioxidant activity with an IC50 of 553.55 ± 5.77 µg/ml. UHPLCMS/MS analysis of the hydroethanolic extract identified several metabolites, with a total of 190 and 135 features detected in positive and negative mode respectively. Around 158 metabolites were annotated. Of these, several metabolites were annotated using the databases used, including alkaloids, amino acids, triterpenoids and phenolic compounds (flavonoids, cinnamic acid derivatives and polyphenols), the latter of which may be correlated with the antioxidant activities of the extracts. In conclusion, D. guineense leaves are a promising source of bioactive compounds, in particular phenolic compounds and flavonoids with antioxidant properties. [1] Gbeassor M et al., J Ethnopharmacol., 1989, 25(1) :115-118. [2] Gbolade A, J Ethnopharmacol., 2012, 144(1) :1-10. [3] Chama MA et al., Toxicon 2021, 193 :28-37. [4] Brukum MF et al., Int J Pharm Pharm Sci ., 2023, 15(9) :18-23. [5] Kai Dührkop et al., Nat Methods, 16, 2019. [6] Wang et al, Nat Biotechnol., 2016, 34, 828‑37