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International audience; A leucogranite sill in the footwall of the extensional Pilat shear zone (PSZ) Eastern French Massif Central was emplaced and sheared in a short time interval, between 301.8–3.1 and 303.0–1.6 Ma (zircon U–Pb and mica 40 Ar/ 39 Ar ages, respectively). Extension ended at 298.5–1.5 Ma ( 40Ar/ 39 Ar on mica) as shown by a non deformed dike cross cutting the sheared zone. On the hanging wall of the fault, the opening of the St. Etienne Basin filled by coarse clastic sedimentation confirms the existence of a relief south of the PSZ. U-Pb dating of a lithic-rich ignimbrite at the bottom of the basin and of a volcanic layer at the top delivred ages of 310.5–3.4 Ma and 299.3–1.3 Ma, respectively. Close U-Pb and 40 Ar/ 39 Ar ages from syn- to post-tectonic granites indicate very fast cooling (150°C/Myr) and exhumation rate (6 mm/yr) corresponding to the emplacement of granites in the middle crust immediately followed by their fast tectonic exhumation and cooling into the upper crust. The development of the Pilat fault in the thermally softened crust is responsible for the rapid exhumation of the Velay dome, a Metamorphic Core Complex localized in the footwall of the sheared zone. Here we propose that its rapid exhumation was due to localized sub crustal lithospheric mantle dripping. These new data show that there was only one extensional phase in the PSZ coeval with the opening of the St. Etienne coal Basin. Finally, the new chronology obtained in this study is challenging previous ages suggesting 20 Ma activity for the Pilat shear zone.

The ferric iron content in hydrothermally altered ultrabasic rocks and their major minerals, serpentines and Mg-chlorites, is important for establishing the oxidation state budget from oceanic ridges to subduction zones, in carbonaceous chondrites, and for modeling phase equilibria. A compilation of literature Mössbauer spectroscopic data on serpentines and magnesian chlorites from high-pressure ophiolites yields much lower ferric-to-total-iron ratios (Fe3+ / Fetotal) than those obtained on similar samples by X-ray absorption near-edge spectroscopy (XANES), leading to contradictory estimates of the ferric iron budget of subduction zones. New Mössbauer analysis of antigorite and Mg-chlorite samples from suites of high-pressure ophiolitic terrains of various Phanerozoic ages confirms the low and homogeneous values previously obtained by this technique, while lizardite inherited from oceanic hydrothermal alteration is ferric iron rich. We argue that XANES values may be biased by photo-oxidation when samples have a high Mg content, which is the case for serpentines and chlorites from subduction zones. Photo-oxidation is less important in Fe-poor phyllosilicates of the mica and talc families and does not affect the Fe-rich serpentines (greenalite, cronstedtite) of meteorites or Fe-rich terrestrial phyllosilicates. Mössbauer Fe3+ / Fetotal ratios of serpentine confirm the occurrence of a major redox change at the lizardite–antigorite transition near 300–400 ∘C rather than at the dehydration of antigorite at 500–650 ∘C in serpentinites from high-pressure ophiolites.

Graphene has been widely used as a nanofiller in advanced electronic devices and nanocomposite materials to achieve enhanced electronic, mechanical, and barrier properties. Adequate polymers play the role of the composite matrix and can assist in the liquid-phase exfoliation of pristine graphene without any heavy chemical modification and the detriment of the properties of graphene. This stabilization mechanism is generally attributed to the steric forces formed between the polymer-adsorbed adsorbent. However, the key influence of the polymer concentration on the maximum graphene content in the colloidal solutions is still unclear. In this study, three different molar weights of water-soluble polyvinyl alcohol (PVA) were used for graphene dispersion. The influence of the PVA concentration on the graphene dispersion was systematically studied. Based on Flory's theory, we first proposed a model to describe the polymer adsorption process in the graphene/PVA/water ternary system in the "dilute" regime and simulated the adsorption-free energy changes during this transformation. This model is in good agreement with the experimental results and explains the critical polymer concentration

A three-dimensional model enables the development of accurate solutions to have more information about the thickness, texture, and characteristics of small-size samples for education and metrology applications. This project proposes an idea to obtain a complete 3D surface reconstruction using the application of Pollen 3D for the scanning electron microscope (SEM) images with high magnification. The main objective is to have a set of images of the complete 360° rotation of the sample with a robot inside the chamber of the SEM. Simulation SEM images with Blender (open source application) are proposed for results validation.

The incorporation of a luminescent probe into a nano-vector is one of the approaches used to design chemosensors and nanocargos for drug delivery and theranostics. The location of the nano-vector can be followed using fluorescence spectroscopy together with the change of environment that affects the fluorescence properties. The ligand 9-anthracene carboxylate is proposed in this study as a luminescent probe to locate two types of manganese complexes inside three series of porous nanoparticles of different composition: resol-silica, carbon-silica and pure silica. The manganese complexes are a tetranuclear MnIII cluster [MnIII4(μ-O)2(μ-AntCO2)6(bpy)2(ClO4)2] with a butterfly core, and a MnII dinuclear complex [{MnII(bpy)(AntCO2)}2(μ-AntCO2)2(μ-OH2)]. The magnetic measurements indicate that both complexes are present as dinuclear entities when incorporated inside the particles. Both the Mn complexes and the nanoparticles are luminescent. However, when the metal complexes are introduced into the nanoparticles, the luminescent properties of both are altered. The study of the fluorescence of the nanoparticles’ suspensions and of the supernatants shows that MnII compounds seem to be more retained inside the particles than MnIII compounds. The resol-silica nanoparticles with MnII complexes inside is the material that presents the lowest complex leaching in ethanol.

International audience; Here, we present a mesoporous mixed manganese zirconium oxide (MnZr) synthesized by evaporation induced self-assembly (EISA) method involving a block copolymer self-assembly method. The MnZr oxide has been fully characterized by X-ray diffraction, transmission electronic microscopy, analytical electronic tomography, nitrogen adsorption/desorption isotherms, thermogravimetric analysis, X-ray photoelectron spectroscopy and electronic paramagnetic resonance. Electronic tomography analysis reveals that a mesoporous solid solution MnZr was successfully obtained by this way, with a homogeneous dispersion of Mn. X-ray diffraction, X-ray photoelectron spectroscopy, thermal analysis and electronic paramagnetic resonance inform about the manganese oxidation states present (II, III and IV) and their location within the sample.

Objective Approximately 750,000 women worldwide have undergone ESSURE hysteroscopic sterilization since 2002. In 2015, an increase in adverse effects was noted, with gynaecological and systemic symptoms reported. Scanning electron microscopy (SEM) analysis of fallopian tube and uterine horn tissues and implants, after hysterectomy or salpingectomy, revealed the presence of inorganic particles resulting from implant degradation. Study design Ten patients (age 42–53 years) were included in this study. Of these, eight patients had undergone hysterectomy and two patients had undergone salpingectomy. Mean exposure time was 85.5 months (standard deviation 26.8 months, range 34–105 months). Mineralogical analyses were performed on 13 tissue biopsies and four implants by SEM coupled with energy dispersive x-ray spectrometry. Results In five of the 10 patients, tin particles were observed in fallopian tube or uterine horn tissues with inflammatory cell reactions. In the other five cases, iron, chromium, nickel or platinum particles were observed. For implants, major deterioration of the weld zone was observed with either destroyed appearance or the presence of an organic coating containing numerous particles. Discussion and conclusion Analysis of the preclinical studies performed by the manufacturer suggests that degradation of the tin weld plays a major role in these adverse events, with increasing leaching and corrosion between 3 and 6 months for an intratubal insert that si designed to remain in an woman’s body for her entire life. For patients with gynaecological symptoms (e.g. pain, metrorragies) needing explantation, these findings raise the question of a causal relationship between tin particles from implant degradation and the inflammatory tissue response. For patients with systemic symptoms (e.g. blurred vision, headache, asthenia, myalgia), the hypothesis that these symptoms may be related to the formation of organotin (chemical compounds based on tin with hydrocarbon substituents) in the body has yet to be proven. Tin levels in blood have to be measured before and after explantation. To the authors’ knowledge, this is the first study to report significant degradation of the ESSURE implant weld, evidenced by the detection of tin particles in the uterine tissue of patients and comparison of the welding zone between unused and used implants.

In the original publication the author name ''Cristian Leostean'' has been incorrectly displayed as ''Cristian Loestean". The correct name of the author is ''Cristian Leostean".

International audience; The graphene is a material obtained when carbon atoms form large planar molecules. Well organized, large graphene molecules stacked ontop each other convey to graphene particularly interesting properties useful in nuclear industry. Understanding how the organization on the molecular scale influences the mechanical properties of the material is a key element in the material manufacturing process. In this scope, features like local orientation and length have already been largely explored in the literature. This paper brings a new feature evaluating the number of plans stacked ontop each other and the length of this stacking. It allows obtaing other features such as the overall rate of organization or locality and preferential orientation. These informations, synthesized in the form of histograms provides a key information in the processus the material design. Experimental results obtained on images taken by an electronic scanning microscope are presented to illustrate the proposed method.

International audience