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International audience; Mighei-type carbonaceous chondrites (CM) figure among the most primitive objects in the solar system. Yet, they all have experienced various degrees of aqueous alteration having modified their insoluble organic matter (IOM), in a sequence that remains to be accurately constrained. Here, we exposed the IOM of Paris, the least altered CM available, to hydrothermal conditions at 150 °C for 49 days and compared the experimental residue to the IOM of two altered CMs likely originating from the same parent body as Paris, namely Aguas Zarcas and Mukundpura. The experimental residue shows a chemical and isotopic composition similar to those of Aguas Zarcas and Mukundpura IOMs, confirming that these CMs can be seen as altered counterparts of Paris. The abundance of organic radicals also increases significantly during the experiment. Isotopic hotspots do not seem to have been lost during the experiment, suggesting that the hotspots generally observed within the CM IOMs may date back from pre-accretion era. Of note, the Raman signature of the residue differs from that of the CM IOMs, highlighting the need for further experiments better mimicking asteroidal-like conditions.

International audience; The Loire River is the longest river in France, where the building of bridges and their long-term maintenance have never been easy tasks, because of strong currents and frequent floods. At a distance of 500 km from its source, between La Charité-sur-Loire and La Chapelle-Montlinard, the remains of a medieval bridge were recently discovered. A multidisciplinary approach is used to reconstruct the long history of building maintenance and re-building of these bridges, which occurred several times, over eight centuries, after their destruction by natural causes or human activity. For this purpose, the study of archival literature (texts and maps) was combined with underwater archaeology, dendrochronology, building archaeology, and geomorphological landscape analyses. Although this is an ongoing research project, sufficient data have been collected to allow the presentation of a preliminary series of results.Haut de page; La Loire constitue un obstacle à franchir impérativement si l’on veut garantir la circulation pérenne des biens et des personnes à l’échelle du territoire et de son réseau de voies terrestres. Fleuve dit « sauvage », ayant la réputation de malmener les ponts, il a cependant conservé les vestiges de certains de ces ouvrages qui constituent des aménagements marquants dans le paysage fluvial. Entre La Charité-sur-Loire et La Chapelle-Montlinard, les prospections archéologiques, l’étude des archives et l’analyse du bâti ancien permettent de restituer, sur huit siècles, différentes étapes de construction et de destruction de ponts.

Journal of analytical atomic spectrometry 37(1), 114 - 129 (2022). doi:10.1039/D1JA00271F, Redox processes activated by environmental factors have been identified as the main cause of the chromatic alterations of a number of artists' pigments, including the yellow pigment orpiment (As$_2$S$_3$). Although a general comprehension of the mechanisms has been provided through characterization of degradation compounds of As$_2$S$_3$, experimental evidences to prove how other paint components and how different environmental agents influence the formation pathways of specific secondary compounds are still lacking. Thus, it becomes fundamental to develop a methodological strategy which enable achieving a discrimination among the causes affecting the chemical stability of more heterogenous As$_2$S$_3$-based paints and defining the mechanism through which the alteration establishes and evolves, with the ultimate goal of optimizing the preventive conservation measures of unique masterpieces. In this paper, we propose a comprehensive multi-material and multi-method approach based on the combination of synchrotron radiation X-ray micro-analytical techniques (i.e., X-ray diffraction, X-ray fluorescence and X-ray absorption near edge structure spectroscopy at S K-/Ag L$_3$-/As K-edges) and vibrational micro-spectroscopy methods to unveil the causes and mechanism of darkening of ���fake-gilded��� decorations in tempera paintings, originally consisting of an unusual mixture of A$_2$S$_3$ and metallic silver (Ag$^0$). Such degradation process is a not yet understood phenomenon threatening a series of Old Master paintings, including those by the Italian painters Cimabue and Pietro Lorenzetti. The high specificity, sensitivity and lateral resolution of the employed analytical methods allowed providing first-time evidence for the presence of black acanthite ($��$-Ag$_2$S), mimetite [Pb$_5$(AsO$_4$)$_3$Cl] and syngenite [K$_2$Ca(SO$_4$)$_2$��H$_2$O] as degradation products of the ���fake-gilded��� decorations in the Maest�� by Cimabue (Church of Santa Maria dei Servi, Bologna, Italy). Furthermore, the study of the painting combined with that of tempera paint mock-ups permitted to explore and define the environmental agents and internal factors causing the darkening, by proving that: (i) Ag$^0$ and moisture are key-factors for triggering the transformation of As$_2$S$_3$ to $��$-Ag$_2$S and As-oxides; (ii) S$^2$--ions arising from the degradation of A$_2$S$_3$ are the main responsible for the formation of $��$-Ag$_2$S; (iii) light exposure strengthens the tendency of the paint components towards alteration. Based on our findings, we finally propose a degradation mechanism of As$_2$S$_3$/Ag$^0$-based tempera paints., Published by ChemSoc, Cambridge

International audience; From the 15 th century onwards, painters began to treat their oils with lead compounds before grinding them with pigments. Such a treatment induces the partial hydrolysis of the oil triglycerides and the formation of lead soaps, which significantly modify the rheological properties of the oil paint. Organization at the supramolecular scale is thus expected to explain these macroscopic changes. Synchrotron Rheo-SAXS (Small Angle X-Ray Scattering) measurements were carried out on leadtreated oils, with different lead contents. We can now propose a full picture of the relationship between structure and rheological properties of historical saponified oils. At rest, lead soaps in oil are organized as lamellar phases with a characteristic period of 50 Å. Under shear, the loss of viscoelastic properties can be linked to the modification of this organization. Continuous shear resulted in a preferential and reversible orientation of the lamellar domains which increased with the concentration of lead soaps. The parallel orientation predominates over the entire shear range (0-1000 s-1). Conversely, oscillatory shear coiled the lamellae into cylinders that oriented themselves vertically in the rheometer cell. This is the first report of such a vertical cylindrical structure obtained under shear from lamellae.

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Three anthraquinone-based chromophores (9,10-anthraquinone, alizarin, purpurin) are compared from the point of view of their experimental and computed NMR and UV-visible light absorption spectra. Using an hybrid (explicit/implicit) solvent model, each proton chemical shift can be reproduced with an error less than 7\%, even when such protons are engaged in inter-molecular hydrogen bonds with the solvent or when the analyzed sample contains a significant amount of impurities, for instance 9,10-anthraquinone in purpurin. All the steady-state UV-visible absorption spectra feature a significant vibrational progression in the first absorption band. The shape of the corresponding computed spectra, including vibronic couplings obtained with the Adiabatic Hessian approach and the Franck-Condon and Hertzberg-Teller approximation of the transition dipole, are in excellent agreement with the experimental one. The importance and the nature of the vibronic couplings are different for the three molecules, even if they only differ by the number of hydroxyl groups.

International audience; The two paintings Infant Bacchanals (Museo Nazionale d’Arte Antica, Palazzo Barberini, Rome, Italy) executed by Nicolas Poussin (Les Andelys, 1594–Rome, 1665) in around 1626 are thought to have been painted “a guazzo”, which means either with a glue or with an egg binding medium. To date, this has never been confirmed through analysis. Dual-beam time-of-flight secondary ion mass spectrometry (TOF-SIMS), using a bismuth cluster liquid metal ion gun and an argon gas cluster ion beam, allows the mapping of organic and inorganic matter on paintings cross sections, with the possibility to acquire submicrometer-resolution mass spectrometry images of the sample, together with high mass resolution using a delayed extraction of secondary ions. The surfaces of cross sections from both paintings were prepared beforehand either by polishing or by microtome cutting and then cleaned with the gas cluster ion beam directly inside the vacuum chamber of the instrument. The nature of the binders in the two paintings was investigated by TOF-SIMS analyses. By considering the uneven physical properties of the heterogeneous analyzed surfaces, several high-resolution images were recorded with different instrument settings. The detection of lipids seems to point toward an oil-containing medium, rather than a glue-binding medium. An emulsion made of oil and glue is another hypothesis to be explored to better understand the artist’s working methods in his early career.

International audience; The most ancient fossil record contains fundamentally important information on both the diversity and disparity of ancient life. Yet this ancient record is not that easy to decode, due to difficulties mainly pertaining to the impact of the geological history. Thus, the convergence of multiple lines of evidence is seen as necessary to build a robust demonstration of the biogenicity of putative traces of life. Yet, we experimentally show here that abiotic organic cell-like microstructures meeting all the criteria of biogenicity may form in cherts under classical conditions of diagenesis. These organic biomorphs produced from a mixture of RNA and quartz in water exposed to temperature and pressure conditions (200°C, ∼15 bars) exhibit morphological, chemical and isotopic signatures typical of organic microfossils. The results of this study exemplify the pitfalls that Archean palaeontologists may encounter when searching for traces of life in ancient rocks.

Le programme collectif de recherches intitulé « La céramique médiévale et moderne (12e - 17e siècles) en Bourgogne : production, consommation, diffusion » a entamé ses travaux en 2018, pour une programmation sur quatre années, jusqu’en 2021. Il a pour objectifs de détecter les sites de fabrication potière médiévaux et moderne en Bourgogne, d’en caractériser la production et d’évaluer leur diffusion sur les sites d’habitat.Le nombre de chercheurs associés au programme, rattaché à l’UMR ARTEHIS (Dijon), varie légèrement d’année en année mais tourne en moyenne autour d’une douzaine (11 en 2018, 13 en 2019, 14 en 2020 et 2021). Ils sont issus de diverses institutions (Inrap, Etat, privé, UMR, bénévole, université...) et, comme dans tout PCR, la mesure de leurengagement est très inégale.De 2018 à 2021, l’activité s’est principalement concentrée sur l’élaboration des outils, avec en particulier le répertoire des formes selon la méthodologie élaborée par le collectif « Informations sur la CEramique Médiévale et Moderne » (Iceramm) désormais accessible sur le site internet, ainsi que la bibliographie normalisée sous Zotero.Un SIG a également être élaboré dont la structure commence à être convenablement nourrie. Les inventaires et la détections des sites de productions (prospections géophysiques) ont été ciblés sur différents secteurs géographiques de la région, en particulier l’autunois, (productions grises micacées), le dijonnais (productions rouge-orangée et pâtes grises coquillées) ainsi que dans le sénonais et le charollais. Des études typo-chronologiques ont pu être conduites sur le mobilier d’ateliers à Auxerre (Yonne) ainsi qu’à Tracy-sur-Loire (Nièvre) au sud de la Puisaye. Ces études sont accompagnées de campagnes d’analyses archéométriques effectuées en partenariat avec le laboratoire du Craham (université de Caen). Une expérimentation de datations archéomagnétiques sur tessons est également lancée avec le LAMS.Après une année 2020 difficile en raison de la crise sanitaire, les actions du PCR ont été un peu plus intenses en 2021. Les travaux ont notamment été conduits sur l’axe de la céramique grise coquillée dans le cadre du master recherche d’Alix Badel (université de Dijon) permettant d’en cibler les zones de production et de diffusion. L’intégration de plusieurs flux de données au SIG (carte archéologique, dépouillements de M. Maerten sur la Saône-et-Loire et d’A. Badel sur les corpus de grise-coquillées) a permis une augmentation de 60 à 70% du nombre d’ateliers référencés dans patriarche pour l’aire bourguignonne.La reprise d’anciennes collections conservées au musée de Saint-Amand-en- Puisaye issues de la fouille d’ateliers de proto-grès et de grès a permis d’en dresser l’inventaire et nourrir les répertoires. Sur Tracy-sur-Loire, les analyses archéomagnétiques menées ont montré une forte disparité de réponse entre les deux groupes échantillonnés. Il est nécessaire de refaire un échantillonnage partiel (four 1) sur des tessons plus gros afin de clore convenablement l’étude.Parallèlement au PCR mais avec les mêmes acteurs, deux importantes actions de diffusion ont pu être organisée. En premier lieu, une exposition intitulée : [Passé] à table accompagnée d’un catalogue a pu être montée au musée archéologique de Dijon (mai-novembre 2021). En second lieu, les recherches ont pu être présentées lors des journées Iceramm, organisées à Dijon en novembre 2021. Les actions entamées nécessitent d’être poursuivies et c’est pourquoi une nouvelle période de trois ans est sollicitée pour le PCR. L’année 2022 sera mise à profit pour aboutir une publication, bilan d’étape des travaux de l’équipe. Les travaux du PCR sont financés entièrement par la DRAC, complétés par une dotation de 17 jours PAS accordée par l’Inrap. D’autres jours recherches sont aussi accordés aux chercheurs d’autres institutions.

Ion signal detection at the true (unperturbed) cyclotron frequency instead of the conventional reduced cyclotron frequency has remained a formidable challenge since the inception of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Recently, routine FT-ICR MS at the true cyclotron frequency has become a reality with the implementation of ICR cells with narrow aperture detection electrodes (NADEL). Here, we describe the development and implementation of the next generation of these cells, namely, a 2xNADEL ICR cell, which comprises four flat detect and four ∼45° cylindrical excite electrodes, enabling independent ion excitation and quadrupolar ion detection. The performance of the 2xNADEL ICR cell was evaluated on two commercial FT-ICR MS platforms, 10 T LTQ FT from Thermo Scientific and 9.4 T SolariX XR from Bruker Daltonics. The cells provided accurate mass measurements in the analyses of singly and multiply charged peptides (root-mean-square, RMS, mass error Δm/m of 90 ppb), proteins (Δm/m = 200 ppb), and petroleum fractions (Δm/m < 200 ppb). Due to the reduced influence of measured frequency on the space charge and external (trapping) electric fields, the 2xNADEL ICR cells exhibited stable performance in a wide range of trapping potentials (1-20 V). Similarly, in a 13 h rat brain MALDI imaging experiment, the RMS mass error did not exceed 600 ppb even for low signal-to-noise ratio analyte peaks. Notably, the same set of calibration constants was applicable to Fourier spectra in all pixels, reducing the need for recalibration at the individual pixel level. Overall, these results support further experimental development and fundamentals investigation of this promising technology.

International audience; Scanning macro-XRF, XRF point measurements and hyperspectral reflectance imaging in the visible and near-infrared range were combined to characterize the pigments of a Tibetan painting. The complementary use of the different investigation techniques allowed us to (i) clearly identify the pigments used by the artist, (ii) strengthen the few data present in historical and contemporary sources and (iii) provide data necessary for any accurate conservation treatment of the painting. The proposed methodology allows an in-depth characterization of the materials used in thangkas, with the identification of all the pigments used by Tibetan artists, as shown by the analyses of reference samples. In the present study traditional pigments, commonly cited in historical sources, were identified such as vermilion, minium, orpiment and azurite, but also more unusual compounds such as brochantite and antlerite (in blue/green areas). Elemental distribution images confirmed that some parts of the thangka were restored, without taking into account the original pigments or the original design. Underlying annotations and a carbon black under-drawing were highlighted by the application of near-infrared hyperspectral imaging technique, which proved to be particularly useful for the study of such paintings.

International audience; In this article we present a first assessment of recent results of chemical analysis of the decor of the Font-de Gaume cave. These data were obtained during four field missions between 2013 and 2017. Slightly more than two hundred representations are divided between animal art and signs (tectiforms), in proportions of about two thirds to one third. Most represented is the bison, hence the name "Bison Cave". The figures were made with different techniques. We find polychrome paintings, drawings and engravings. The state of conservation of the cave is a reflection of its great fragility. The walls are very heterogeneous, which represents a real analytical challenge for the chemical analysis of figures since the analyzes must be lim-ited to non-invasive approaches without contact. Thus, we carried out around two hundred analyzes by portable X-ray fluorescence to characterize the coloring matters. These analyzes were carried out in order to obtain new elements of answer as for the chemical composition of the coloring matter used and the techniques of realization of these works of the Upper Paleolithic. Here we present the approach used, focusing particularly on the processing of the measurements carried out. These first evaluations of the data made it possible to identify dif-ferent coloring materials used in the Font-de-Gaume cave. The approach developed has thus shown its potential, when applying on a larger number of figures and by integrating additional information. In the long term this enables improving knowledge of these works and their suc-cessive realization in the case of superimposed figures which seems very important, in the absence of a direct dating of the parietal works of Font-de-Gaume.; Dans cet article est présenté un premier bilan des résultats récents d’analyse chimiques du décor de la grotte de Font-de Gaume. Ces données ont été obtenues lors de quatre missions de terrain entre 2013 et 2017. Un peu plus de deux cents représentations se répartissent entre un art animalier et des signes (tectiformes), dans des proportions d’environ deux tiers un tiers. L'animal le plus représenté est le bison, d'où le nom la "Caverne des bisons". Les figures ont été réalisées avec différentes techniques. On retrouve la peinture polychrome, le dessin et les gravures. L’état de conservation de la grotte étant le reflet de sa grande fragilité, les parois sont très hétérogènes, ce qui représente un réel défi analytique pour l’analyse chimique des figures dans la mesure où les analyses doivent se limiter à des approches non invasives sans contact. Ainsi, nous avons réalisé environ deux cents analyses par fluorescence X portable pour caractériser les matières colorantes. Ces analyses ont été effectuées dans le but d'obte-nir de nouveaux éléments de réponse quant à la composition chimique de la matière colo-rante utilisée et les techniques de réalisation de ces œuvres du Paléolithique supérieur. Nous présentons ici l'approche utilisée en se focalisant particulièrement sur les traitements des me-sures effectuées. Ces premières évaluations des données ont permis d'identifier différentes matières colorantes utilisées dans la grotte de Font-de Gaume. L'approche développée a ainsi montré son potentiel, lorsqu'elle sera utilisée sur un plus grand nombre de figures et en inté-grant d’autres informations complémentaires. Elle devrait permettre à terme d’améliorer la connaissance de ces œuvres et de leur réalisation successive dans le cas de superpositions des figures ce qui parait très important, en l’absence d’une datation directe des œuvres parié-tales de Font-de-Gaume.

International audience; Alizarin (Az) lake is a typical example of madder lake pigments that are widely used in cultural heritages. Previous work focused on the complex formation in solution, theoretical models, and crystallized stoichiometric structures (Az/Al3+ = 1:1 or 2:1). However, the classical recipe for preparing madder lake demonstrated that the dosage of the dye was much less than Al3+. Aiming to interpret the structure of a non-stoichiometric Az lake pigment, Az lakes of non-stoichiometric complexes (Az/Al3+ = 1:5 to 1:200) were prepared and characterized. The influences of the dye concentration, pH, and basic reagents on the structures and chromatic properties were studied by attenuated total reflection Fourier transform infrared spectroscopy, nuclear magnetic resonance, and CIE 1976 color space. In order to interpret the interaction between Az molecules and inorganic substrate, Az was deposited on a thin Al2Ox film prepared by the physical vapor deposition method. Polarization modulation infrared reflection absorption spectroscopy was employed to characterize the chemical reactivity and degradation of the Az–Al2Ox film complex. Az derivatives interacted with Al2Ox film like lakes. Al3+ was coordinated with the 1,2-dihydroxyl (catechol) group, instead of the 1-hydroxy-9-keto group. Exposure under UV light resulted in the degradation of the Az–Al2Ox film complex by oxidizing catechol groups to carbonyl. This study presented a new insight into the structure and degradation of Az lake.

International audience; The integration of functional thin film materials with adapted properties is essential for the development of new paradigms in information technology. Among them, complex oxides with perovskite structures have huge potential based on the particularly large diversity of physical properties. Here we demonstrate the possibility of transferring perovskite oxide materials like SrTiO 3 onto silicon substrate using an environmentally friendly process at nanoscale, by means of a water-soluble perovskite sacrificial layer: SrVO 3. Based on in situ monitoring atomic force microscopy and photoemission studies, we reveal that dissolution is initiated from a strontium rich phase at the extreme surface of SrVO 3. The transferred nanothick SrTiO 3 layer on silicon presents an effective morphology and monocrystalline quality, providing a proof of concept for the integration and development of an all perovskite oxide electronics or "oxitronics" onto any Si-based substrates.

The objective of the PhD was to evaluate the potential of TOF-SIMS imaging, particularly 3D, to reliably study chemical composition in stratigraphic sections of ancient paintings. TOF-SIMS imaging can simultaneously map organic and inorganic materials at the micrometer scale, providing answers to questions about ancient paintings, such as elucidating the nature of the binders and pigments in the various layers, or studying the chemical transformations of ingredients through the action of time and interactions. The construction of a database of TOF-SIMS mass spectra for reference materials in parallel with the study of several samples of old paintings, has allowed to identify which reliable chemical information can be associated with the use several centuries ago of a given ingredient according to a certain painting technique. The references and the parameters of the analyses were adapted according to the observations made on the cross sections. The identification of drying oils and egg yolk was considered. Different surface preparations and secondary ion extraction parameters were compared to optimise the detection of surface-formed ionic species and obtain more representative chemical information. The conditions under which argon aggregate sputtering can be used were defined. A preliminary analysis of the contribution of TOF-SIMS imaging to the understanding of the structure of dried drying oils has provided results that will be continued in the future.; L'objectif de la thèse était d'évaluer le potentiel de l'imagerie TOF-SIMS, notamment 3D, pour étudier la composition chimique de façon fiable sur des coupes stratigraphiques de peintures anciennes. L’imagerie TOF-SIMS peut cartographier simultanément les matières organiques et inorganiques à l’échelle micrométrique, répondant à des questions sur les tableaux anciens, comme l’élucidation de la nature des liants et pigments des différentes couches, ou l’étude des transformations chimiques des ingrédients par l’action du temps et des interactions. La construction d'une base de donnée de spectres de masse TOF-SIMS pour les matériaux de références en parallèle de l'étude de plusieurs échantillons de peintures anciennes, a permis d'identifier quelles informations chimiques fiables peuvent être associées à l'usage il y a plusieurs siècles d'un ingrédient donné selon une certaine technique picturale. Les références et les paramètres d’analyses ont été adaptés en fonction des observations menées sur les coupes stratigraphiques. Une réflexion a été menée pour chercher à identifier les huiles siccatives et le jaune d’œuf. Différentes préparations de la surface et paramètres d’extraction des ions secondaires ont été comparés pour optimiser la détection des espèces ioniques formées en surface et obtenir une information chimique plus représentative. Les conditions dans lesquelles la pulvérisation d’agrégats d’argon peut être utilisées ont été définies. Une analyse préliminaire sur l’apport de l’imagerie TOF-SIMS dans la compréhension de la structure des huiles siccatives séchées a apporté des résultats qui sont voués à être continués dans le futurs.

International audience

Les fouilles ont eu lieu en 2016-2017 sur une surface de près de 9 hectares. Elles faisaient suite au diagnostic de 2007 (RO : T. Capararro, Inrap) et à une première fouille réalisée en 2010 sur une surface de 1,5 hectares (RO : G. Bruley-Chabot, Inrap). Hormis quelques éléments épars du Paléolithique Moyen au Néolithique, les premières traces d'occupation remontent à l'âge du Bronze final (quelques fosses et un enclos circulaire de plus de 330 m2 ). Le Hallstatt et La Tène A sont représentés par un faible nombre de structure. Une importante nécropole date de La Tène B2-C1. Elle regroupe 42 inhumations et une probable crémation. Si les ossements sont pour la plupart très mal conservés, le mobilier funéraire est particulièrement abondant, avec notamment de multiples éléments d'armement. Quelques silos de grand gabarit sont attribuables à La Tène D. Vers le milieu du Ier siècle ap. J.-C., une exploitation agricole prend place au centre du site. Organisée dans et autour d'un système d'enclos quadrangulaires, elle comporte pour tout bâti conservé une cave et un petit lambeau de mur (fouillés en 2010), quelques trous de poteau (sans restitution possible de plans de bâtiments), quelques structures de combustion, des fosses et un ensemble de six petits celliers non maçonnés. Le site est toujours habité au Bas-Empire. Un véritable village se développe sur la quasi-intégralité de l'emprise du site au tout début de la période mérovingienne (fin Ve -début VIe s.). Celui-ci est constitué d'un ensemble assez rigoureux de parcelles reliées entre elles par des chemins. Dans ces parcelles prennent place de très nombreux fonds de cabane, des fours domestiques et des bâtiments sur poteaux, ainsi que deux puits à eau (autour de 10 m de profondeur). À partir du VIIIe s., le village commence à se contracter vers les axes de communication principaux et des aires d'ensilage sous-terrain se développent (le site comptant au total plus de 900 silos). Ces deux tendances s'accentuent dans les siècles suivants, jusqu'à l'abandon du village à partir de la première moitié du XIe s. Quelques inhumations sont installées à proximité des structures d'habitat et de production mais l'importante nécropole découverte lors de l'opération de diagnostic n'était pas concernée par les opérations de fouille. Il faut noter l'existence d'une étrange structure funéraire datée fin VIIIe -IXe s. : dans un silo, un immature a fait l'objet d'une crémation in situ, puis a été recouvert par le cadavre (non brûlé) d'un autre immature (peut-être mutilé, mais en tous les cas, jeté sans ménagement dans la structure), et par le crâne d'un adulte. Des esquilles osseuses suggèrent la crémation d'au moins quatre autres individus dans cette structure. Le mobilier archéologique, ainsi que les écofacts (ossements animaux et restes carpologiques) sont très abondants et documentent les activités et les productions au sein du village. Ils témoignent plutôt d'une vie laborieuse tournée vers la céréaliculture et les travaux agricoles, avec un niveau social général probablement modeste. Quelques éléments, notamment l'importance du porc (abattu jeune) pour la dernière phase d'occupation, plaident néanmoins pour l'existence d'individus relativement aisés. Plusieurs siècles après l'abandon du village (et probablement le déplacement de la population vers l'actuel centre-bourg de Bonneuil-en-France), vers les XVe -XVIe s., la partie basse du site est exploitée pour l'extraction de calcaire. Les derniers vestiges archéologiques correspondent à des aménagements aéroportuaires datant de la Seconde Guerre mondiale.

International audience; Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) imaging is a surface analysis technique that identifies and spatially resolves the chemical composition of a sample with a lateral resolution of less than 1 µm. Depth analyses can also be performed over thicknesses of several microns. In the case of a painting cross-section for example, TOF-SIMS can identify the organic composition, by detecting molecular ions and fragments of binders, as well as the mineral composition of most of the pigments. Importantly, the technique is almost not destructive and is therefore increasingly used in cultural heritage research such as the analysis of painting samples, especially old paintings. In this review, state-of-the-art of TOF-SIMS analysis methods will be described with a particular focus on tuning the instruments for the analysis of painting cross-sections, and with several examples from the literature showing the added value of this technique when studying cultural heritage samples.

International audience; At the end of the 1st c. AD, seven privileged burials, two of which are in mausoleums, were excavated in a private area located 150 m southwest of a villa in Atrebato-Nervian territory. The monumental aspect of the vaults of these graves, the selection and abundance of artefact deposits and the distinctiveness of some of the objects provide remarkable evidence of activities linked to cosmetic and therapeutic care.; À la fin du Ier s. apr. J.-C., sept tombes privilégiées, dont deux signalées par des mausolées, ont été creusées dans un espace privatif situé à moins de 150 m au sud-ouest d’une villa entre Arras/Nemetacum et Cambrai/Camaracum. Le caractère exceptionnel de ces chambres souterraines tient à la monumentalité des caveaux, au choix et à l’abondance des dépôts, mais aussi à l’originalité de certains objets disposés dans quelques tombes, qui attestent d’activités liées aux soins cosmétiques et thérapeutiques.

International audience; Cultivated pearls frequently exhibit morphological irregularities making obvious that mineral deposition was irregularly distributed onto nucleus surface. Taking advantage of experimental cultivations with short durations (from 10 days to few months), these irregular deposits predating occurrence of the nacre were investigated in Polynesian pearls by biochemical characterizations and a series of physical methods. Diversity in the resulting data suggests that various in‐depth alterations of the biomineralization mechanism may have occurred during the grafting process, leading to diversity in the biochemical pathways to nacreous deposition. This allows a precise discussion of current views about pearl formation. The “reversed shell theory” is formally disproved through point to point comparison with development of the shell growing edge. Similarity of pearl formation with “regeneration” or “shell repair” is also discussed, emphasizing the differences between these concepts.

International audience; Over the past couple of years, imaging mass spectrometry (IMS) has arisen as a powerful tool to answer research questions in the biomedical field. Imaging mass spectrometry allows for label-free chemical imaging by providing full molecular information. The IMS technique best positioned for cell and tissue analysis is time-of-flight secondary ion mass spectrometry (ToF-SIMS) because it has the best spatial resolution of all the molecular IMS techniques and can detect many biochemical species and especially lipids with high sensitivity. Because one must rely on the mass and isotopic pattern of an ion in combination with positive correlations with lower mass fragments to help identify its structure, one major problem during ToF-SIMS experiments is the ambiguity when assigning a molecule to a certain mass peak. The solution are instruments with tandem MS capabilities as was already the case for many MALDI-ToF instruments more than a decade ago. It's been a few years since instruments with this capability were introduced and a number of interesting publications have been produced highlighting the advantages in biological SIMS work. Here, we present a protocol describing how tandem MS can be used to elucidate the structure of unknown or ambiguous mass peaks in biological tissue samples observed during ToF-SIMS imaging based on our experiences.

International audience; Egg-tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico-chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg-tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment.

International audience; Seven new archeointensity data are obtained through the analysis of groups of pottery and kiln fragments from ceramic workshops unearthed in France, precisely dated from the High Middle Ages. The measurements are carried out using the Triaxe magnetometer, following a dedicated experimental protocol that takes into account the effects of anisotropy and cooling rate (CR) on thermoremanent magnetization acquisition. The new data are consistent with the evolution of intensity variations described by our previous data obtained in France and Northern Italy, which display between the 5th and 10th c. a pronounced camel-back shape. In particular, they provide supporting evidence of an intensity minimum that occurred around the transition between the 7th and 8th century. These data, combined with a selection of previously published results within a 700 km radius of Beaune and re-examined based on CR correction, formed the basis of new regional mean intensity variation curves based on two independent modeling approaches. The first algorithm developed by Thébault and Gallet (2010) based on bootstrapping and now irregularly spaced knots according to the data distribution gives rather smooth intensity variations, while the second approach proposed by Livermore et al (2018) based on a transdimensional Bayesian technique shows more abrupt variations with sometimes stronger amplitudes. We explore the dating potential of these two variations curves, which have an unprecedented resolution, by studying two medieval pottery workshops. Six fragment groups (three per workshop) are analyzed using the Triaxe protocol, providing mean archeointensity values for each of the two sites. Two different procedures are used for their dating, either by comparing the intensity value to be dated with the reference intensity variation curves obtained from the two modeling techniques or by analyzing the marginal posterior probability distribution of the age values derived from the method of Livermore et al (2018). For France, the two techniques yield very similar results. The archeointensity dating results combined with archeological arguments and radiocarbon data, make it possible to better constrain the age of the end of activity of the two workshops. Archeointensity investigation of displaced materials thus appears as an effective means to obtain original chronological constraints on the age of their production, paving the way for a wide range of complementary research on Medieval pottery.

International audience; Archaeomagnetic data are fundamental for our understanding of the evolution of Earth's magnetic field on centennial to millennial timescales. From the earliest studies of the Thelliers, Aitken, Nagata and others in the 1950s and 1960s, archaeomagnetic data have been vital for extending our knowledge of the field to times prior to observational measurements. Today, many thousands of archaeomagnetic data allow us to explore the geomagnetic field in more detail than ever before. Both regional time series of archaeomagnetic data and the inclusion of archaeomagnetic data in time-varying global spherical harmonic field models have revealed a range of newly discovered field behaviour. More sophisticated approaches to developing regional curves and global models have allowed us to resolve the field in certain regions more robustly and with greater resolution than previously possible. In this review we give an overview of the widely used global archaeomagnetic database GEOMAGIA50, discuss the methods used to obtain archaeomagnetic data, their challenges, and explore progress over the past twenty years in developing regional secular variation curves and global spherical harmonic models of the archaeomagnetic field. We end the review by covering what we see as the “grand challenges” in archaeomagnetism, including which regions of the world should be focussed on with regards to data acquisition.

International audience; Hyperspectral reflectance imaging in the short-wave infrared range (SWIR, “extended NIR”, ca. 1000 to 2500 nm) has proven to provide enhanced characterization of paint materials. However, the interpretation of the results remains challenging due to the intrinsic complexity of the SWIR spectra, presenting both broad and narrow absorption features with possible overlaps. To cope with the high dimensionality and spectral complexity of such datasets acquired in the SWIR domain, one data treatment approach is tested, inspired by innovative development in the cultural heritage field: the use of a pigment spectral database (extracted from model and historical samples) combined with a deep neural network (DNN). This approach allows for multi-label pigment classification within each pixel of the data cube. Conventional Spectral Angle Mapping and DNN results obtained on both pigment reference samples and a Buddhist painting (thangka) are discussed.

International audience; This paper examines the production technology of Egyptian blue, an ancient artificial pigment, through the investigation of an unsuccessfully produced pellet derived from the Hellenistic production site of Kos (Dodecanese, Greece). This heterogeneous material was investigated by a combination of laboratory and synchrotron radiation-based (SR) techniques: scanning electron microscopy coupled with energy-dispersive Xray spectrometry, micro-Raman spectroscopy, high-resolution SR micro-X-ray fluorescence spectroscopy, and SR micro-X-ray absorption near-edge structure spectroscopy (XANES), at the ID21 beamline of the European Synchrotron Radiation Facility. Principal component analysis of a large dataset of 171 micro-XANES spectra acquired on the archaeological samples and on a series of reference copper compounds emphasizes high variations of XANES features due to different speciation and also orientation effects, as demonstrated by the simulated XANES spectra. The results indicate that, rather than inadequate firing temperatures that could have led to the reddish cuprite (Cu 2 O), unsuccessful production may occur due to the use of inappropriate starting materials, which contain an unusually high iron content. The contextual interpretation underlines the intertwined relationship between the production of Egyptian blue and metallurgy.

International audience; The fading of organic dyes is a serious challenge for conservation of art works. Inspired by the ancient Maya blue pigment, a hybrid pigment of halloysite (Hal) and alizarin (AZ) was prepared by adsorption in aqueous solution. In addition, a layer of polyorganosilane (POS) is used to cover the surface of the hybrid pigment to enhance the chemical resistance and photostability. The hybrid pigments were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and thermal analysis. The adsorption behavior of AZ onto Hal was investigated and optimized. AZ-Hal hybrid pigment was prepared at pH = 9. Chemical stability was checked by 1 mol/L HCl, 1 mol/L NaOH and ethanol attack. Photostability was evaluated by exposing the pigment to visible light for 360 h, which is equal to more than 28 years in a common museum. AZ molecules were adsorbed on the external and/or internal surface via physical adsorption and hydrogen bonds. The presence of POS in the hybrid pigment influences positively the chemical and light resistance. This may be due to the protective layer that isolates sensitive dyes and oxidising agents.

International audience; The increasing demands for oil and gas and associated difficult drilling operations require oil-based drilling fluids that possess excellent rheological properties and thermal stability. The objective of the present work was to investigate the rheological properties and thermal stability of organo-montmorillonite (OMnt) modified with various surfactants and under various loading levels in oil-based drilling fluids, as revealed by the interaction between organic surfactants and montmorillonite. The influence of the structural arrangement of surfactants on the thermal stability of organo-montmorillonite (OMnt) in oil-based drilling fluids was also addressed. OMnt samples were prepared in aqueous solution using surfactants possessing either a single long alkyl chain two long alkyl chains. OMnt samples were characterized by X-ray diffraction, high-resolution transmission electron microscopy, thermal analysis, and X-ray photoelectron spectroscopy. Organic surfactants interacted with montmorillonite by electrostatic attraction. The arrangements of organic surfactants depended on the number of long alkyl chains and the geometrical shape of organic cations. In addition to the thermal stability of surfactants, intermolecular interaction also improved the thermal stability of OMnt/oil fluids. A tight paraffin-type bilayer arrangement contributed to the excellent rheological properties and thermal stability of OMnt/oil fluids. The deterioration of rheological properties of OMnt/oil fluids at temperatures up to 200°C was due mainly to the release of interlayer surfactants into the oil.

Ancient bone proteins provide a plethora of information regarding the identity, period, and diet/environment of animal species through proteomic analysis, radiocarbon dating and isotopic analysis respectively. However, each technique imposes specific constraints for bone protein extraction. Despite the sample preciousness and heterogeneity, these analyses are not routinely performed on the same aliquot. Protocol for radiocarbon dating are the most restrictive in terms of sample preparation and their effects have seldom been evaluated at the molecular level. Here, several extraction protocols were tested using modern and archaeological bones. Molecular characterization of the extracts was performed using electrophoresis and proteomics. Protocol-induced biases in peptide sequences and their effect on species identification were evaluated using database searching and partial de novo sequencing. This work shows that extraction protocols corresponding to mild bone decalcification conditions and using ultrafiltration are the most suitable for species identification.

La spectrométrie de masse est une technique versatile permettant l’identification et la caractérisation structurale des espèces chimiques. L’imagerie par spectrométrie de masse va permettre d’ajouter une nouvelle dimension avec un accès direct à la visualisation de la distribution spatiale de ces mêmes espèces chimiques. Cette stratégie d’imagerie a connu un rapide essor avec toujours plus d’enjeux analytiques qui sont au cœur de ce chapitre. Celui-ci s’adresse aussi bien à des débutants qu’à des chercheurs initiés, et a pour vocation de vous décrire et illustrer l’ensemble des technologies utilisées dans le domaine de l’imagerie par spectrométrie de masse. Cet état de l’art se veut être une introduction pédagogue à l’imagerie par spectrométrie de masse afin de se familiariser avec cette stratégie analytique et ses bonnes pratiques. Pour tirer pleinement parti de cette formidable approche, des sujets généraux seront abordés de la préparation des échantillons au traitement des données, en passant par les dernières avancées méthodologiques et technologiques propres à chaque instrument.

A prehistoric conch shell converted into a musical instrument makes its first sounds in 18,000 years., Anthropologists and ethnomusicologists assert that there is no society without song, and more specifically, there is no ritual or celebration without accompanying sound. The production of sounds in social contexts is very ancient. Here, we report on the study of a seashell from the decorated cave of Marsoulas and demonstrate that the Magdalenian occupants of this site transformed this shell into a wind instrument. It is one of the very rare examples, if not the only one for the Paleolithic period, of a musical instrument fashioned from a large shell, and the first conch shell of this use thus far discovered. We already know that prehistoric people transformed many shells into portable ornaments and that they thus attributed substantial corporal symbolism to them. This seashell horn, with its unique sonority, both deep and strong with an enduring reverberation, sheds light on a musical dimension until now unknown in the context of Upper Paleolithic societies.

Many studies have recently explored a new class of reversible photoswitching compounds named Donor–Acceptor Stenhouse Adducts (DASAs). Upon light irradiation, these systems evolve from a coloured open-chain to a colourless closed-ring form, while the thermal back-reaction occurs at room temperature. In order to fulfill the requirements for different applications, new molecules with specific properties need to be designed. For instance, shifting the activation wavelength towards the red part of the visible spectrum is of relevance to biological applications. By using accurate computational calculations, we have designed new DASAs and predicted some of their photophysical properties. Starting from well-studied donor and acceptor parts, we have shown that small chemical modifications can lead to substantial changes in both photophysical and photoswitching properties of the resulting DASAs. Furthermore, we have also analysed how these substitutions impact the electronic structure of the systems. Finally, some pertinent candidates have been successfully synthesized and their photoswitching properties have been characterized experimentally., New photoswitch Donor–Acceptor Stenhouse Adducts (DASAs) have been synthesized thanks to accurate computational chemistry predictions. They possess good properties, notably red light activation.

Since the mid-19th century, direct measurements of both intensity and directions of the Earth's magnetic field have been available, allowing an accurate determination of its spatio-temporal variations. Prior to this time, between ∼1600 and 1840, only direct directional measurements are available. Therefore, the construction of global field models over this period requires either a specific treatment of the axial dipole field component or the use of archeomagnetic intensity data. In this study, we use a regional approach based on the construction of an archeointensity variation curve in Central Asia. We analyze baked clay brick fragments sampled in Bukhara (Uzbekistan), dated between the end of the 16th century and the beginning of the 19th century. This city is of particular interest for archeomagnetism due to the well-preserved old buildings accurately dated by documentary archives. A series of archeointensity results is obtained using the Triaxe experimental protocol, which shows a decreasing trend in intensity from ∼1600 to ∼1750, with intensities during the 18th century lower than expected from global geomagnetic field models. These new data appear consistent with other Triaxe data previously obtained in western Europe and western Russia, when transferred to Bukhara using the field geometry of the gufm1 model. Together, these data are used to recalibrate the axial dipole moment evolution provided by this model. The resulting evolution appears non-linear, with a clear relative minimum in the magnitude of the axial dipole during the late 18th century. We illustrate the fact that at present this evolution can neither be satisfactorily confirmed nor refuted by other datasets available in western Eurasia (as well as at a wider spatial scale), mainly due to the significant dispersion of the data. Our interpretation relies on the accuracy of the field geometry of the gufm1 model, which appears less reliable prior to ∼1750. Nevertheless, the minimum proposed in the 18th century seems to be a true feature of axial dipole behavior.

International audience; From the literature research review of studies that involved the physicochemical characterization of rock art paintings in Argentina and Chile, we evaluate the impact of this analytic approach in our understanding of these visual and material practices in the southern region of South America. We identify the techniques, protocols and sample preparation, the information obtained, and archaeological questions addressed with these analyses. Consequently, we propose the need for a microarchaeological approach. We stress the materiality and particularities of the rock art practice, as an action performed over continuously altered walls, which forms complex microstratigraphies. Moreover, we highlight the benefits of obtaining comparable results with the use of paintings on different supports and contexts to hold an Archaeology of Color that allows studying not only the meaning, but also understand the exploitation, production, and consumption of color, being the painted rock art one form of the final stage of a complex sequence related to color materials.

The material evidence for the wax finish on ancient marble statues, known as ganosis, is scarce and controversial, although Greek and Latin sources describe the recipes and cultural value of this treatment. The surface treatment of a colossal Roman head from the Roman theatre of Dougga (Tunisia), dated to the end of the second century CE, is studied by a multi-analytical protocol (video-microscope, cross section, and time-of-flight secondary ion mass spectrometry of one sample). The results of this physico-chemical analysis and the comparison with ancient recipes, prove the use of ganosis on a Roman statue and explore, for the first time, the application of the recipes described in ancient sources. This result shows the potential of the Time-of-Flight Secondary Ion Mass Spectrometry analysis, detecting at the same time organic and inorganic materials and their stratigraphy, to study the ancient recipes.

International audience; Hypothesis: The objective is to elucidate the multiscale dynamics of water within natural mixtures of minerals, green earth pigments that are mainly composed of phyllosilicates containing large amount of iron. In particular, the interaction of water with the different kinds of surfaces has to be probed. One issue is to examine the influence of surface type, basal or edge, on the dispersion quality.Experiment: The study was carried out using 1H variable field NMR relaxometry on various green earth pigment dispersions and concentrations. To analyse the data, a new analytical model was developed for natural phyllosilicates containing large amount of paramagnetic centres.Finding: The proposed theoretical framework is able to fit the experimental data for various samples using few parameters. It allows to determining water diffusion and residence times in complex phyllosilicate dispersions. Furthermore, it makes it possible to differentiate the contribution of the basal and edge surfaces and their respective surface area in interaction with water. Moreover, NMR relaxation profile reveals to be highly sensitive to the structural aspect of the phyllosilicates and to the accessibility of water to iron, hence allowing to discriminate clearly between two very similar phyllosilicates (glauconite and celadonite) that are difficult to distinguish by standard structural methods.

International audience; Two polychrome sculptures from the late Middle Age were investigated by means of non-invasive techniques with the aim of characterizing sophisticated relief decoration named "applied brocade". Here, we have used portable instrumentation solely in order to perform X-ray powder diffraction and fluorescence measurements at the surface of the sculptures. The results show a reliable localisation and identification of the different materials making up an applied brocade: a filler material, a tin-based foil and a gilding, even in the case of a largely overpainted sculpture. More particularly, a direct identification of the organic material used for the filler as natural beeswax is proposed. Differences between the two investigated artworks have also been identified: (i) in the structure of the calcium sulphate preparation layers (one or double layer of gesso) (ii) in the presence or absence of a priming paint layer under decors (iii) in the choice of the material used to make the gilding: pure gold or probable zwischgold. The characterization of the degradation of this type of decorations was also assessed, namely romarchite (SnO) and cassiterite (SnO 2) were identified and their relative proportion estimated.

International audience; ThomX is a new generation Compact Compton Source. It is currently commissioned by and at the IJCLab (Laboratoire de physique des 2 infinis - Irène Joliot-Curie (UMR9012)) at Orsay. The first beam is expected at the begining of 2021. The aim of ThomX is to demonstrate the characteristics of an intense and Compact (lab-size) X-ray source based on Compton Scattering. The performances are mostly driven by the laser optical system which is above the state of the art of stored laser power. Proof of principle of various X-ray techniques will be performed thanks to the versatile ThomX beamline. Firstly, this article presents the machine description. Secondly, the issues and limits of the laser system are discussed. Then, the ThomX beamline is described and the machine status conclude the ThomX presentation. Finally, the expected performances for the next years and the possible experiments that can be made with this new machine are detailed.

This research aims to contribute to the study and characterization of the pigments used by the French painter Étienne Dinet at the dawn of the 20th century. Our approach draws on painting manuals written by the artist (Les fléaux de la peinture), in which he shows his search for materials to be used in painting. Based on these writings, a database of scientific photographs and reflectance spectra (visible and near infrared) was created to determine the pigments used in his paintings. Seven paintings were then studied. Scientific imaging enabled us to characterize the painter’s palette, especially when we had the opportunity to combine several analytical techniques producing complementary data. We have thus shown the value of using a set of non-invasive imaging techniques simultaneously for pigment characterization: no pictorial material is required and the low amount of light radiation during measurements does not affect its conservation. Technical photography can provide a lot of information about the state of preservation of a painting and allows us to detect restoration interventions done over time. It also allows us to make hypotheses about the painter’s palette. To confirm these hypotheses, analyses such as X-ray fluorescence and hyperspectral imaging, which provide more accurate information and more direct interpretation, are required.; Au cours de cette recherche, nous avons contribué à l’étude et à la caractérisation des pigments utilisés par le peintre français Étienne Dinet à l’aube du XXe siècle. Notre approche a consisté à nous appuyer sur les manuels de peinture écrits par le peintre (Les fléaux de la peinture) dans lesquels il expose sa recherche des matériaux à utiliser en peinture. En nous basant sur ces écrits, nous avons créé une base de données de photographies scientifiques et de spectres de réflectance (visible et proche infrarouge) pour pouvoir déterminer les pigments employés dans ses tableaux. Sept tableaux ont ensuite étudié. L’imagerie scientifique nous a permis de caractériser la palette du peintre, en particulier lorsque nous avons eu la possibilité d’associer plusieurs techniques d’analyse produisant des données complémentaires. Nous avons ainsi montré l’intérêt d’employer simultanément un ensemble de techniques non invasives d’imagerie pour la caractérisation des pigments : aucun prélèvement de matière picturale n’est nécessaire et la faible quantité de lumière irradiant l’œuvre durant les mesures n’affecte pas sa conservation. La photographie technique peut fournir de nombreuses informations sur l’état de conservation d’une peinture et nous permet de détecter les interventions de restaurations effectuées au cours du temps. Elle nous permet aussi de formuler des hypothèses sur la palette du peintre. Pour confirmer ces hypothèses, il est nécessaire d’effectuer des analyses comme la fluorescence des rayons X et l’imagerie hyperspectrale, qui fournissent des informations plus précises et dont l’interprétation est plus certaine.

The data presented here are related to the research paper entitled “Green Earth pigments dispersions: water dynamics at the interfaces”. The nuclear magnetic resonance (NMR) relaxometry data are provided for various aqueous Green Earth (GE) pigments dispersions with volume fraction spanning approximately from 0.1 to 0.5. For two of them (Cyprus GE and Bohemian GE), the NMR relaxation profiles from 10 kHz to 30 MHz (1H frequency) is given for several temperatures spanning from 293 to 318K. In addition, the X-ray diffraction pattern is provided for France GE (Kremer pigments) for the identification of the main mineral component. The nitrogen gas isotherms are provided for Cyprus GE and Bohemian GE.

International audience; In this article we present a first assessment of recent results of chemical analysis of the decor of the Font-de Gaume cave. These data were obtained during four field missions between 2013 and 2017. Slightly more than two hundred representations are divided between animal art and signs (tectiforms), in proportions of about two thirds to one third. Most represented is the bison, hence the name "Bison Cave". The figures were made with different techniques. We find polychrome paintings, drawings and engravings. The state of conservation of the cave is a reflection of its great fragility. The walls are very heterogeneous, which represents a real analytical challenge for the chemical analysis of figures since the analyzes must be lim-ited to non-invasive approaches without contact. Thus, we carried out around two hundred analyzes by portable X-ray fluorescence to characterize the coloring matters. These analyzes were carried out in order to obtain new elements of answer as for the chemical composition of the coloring matter used and the techniques of realization of these works of the Upper Paleolithic. Here we present the approach used, focusing particularly on the processing of the measurements carried out. These first evaluations of the data made it possible to identify dif-ferent coloring materials used in the Font-de-Gaume cave. The approach developed has thus shown its potential, when applying on a larger number of figures and by integrating additional information. In the long term this enables improving knowledge of these works and their suc-cessive realization in the case of superimposed figures which seems very important, in the absence of a direct dating of the parietal works of Font-de-Gaume.; Dans cet article est présenté un premier bilan des résultats récents d’analyse chimiques du décor de la grotte de Font-de Gaume. Ces données ont été obtenues lors de quatre missions de terrain entre 2013 et 2017. Un peu plus de deux cents représentations se répartissent entre un art animalier et des signes (tectiformes), dans des proportions d’environ deux tiers un tiers. L'animal le plus représenté est le bison, d'où le nom la "Caverne des bisons". Les figures ont été réalisées avec différentes techniques. On retrouve la peinture polychrome, le dessin et les gravures. L’état de conservation de la grotte étant le reflet de sa grande fragilité, les parois sont très hétérogènes, ce qui représente un réel défi analytique pour l’analyse chimique des figures dans la mesure où les analyses doivent se limiter à des approches non invasives sans contact. Ainsi, nous avons réalisé environ deux cents analyses par fluorescence X portable pour caractériser les matières colorantes. Ces analyses ont été effectuées dans le but d'obte-nir de nouveaux éléments de réponse quant à la composition chimique de la matière colo-rante utilisée et les techniques de réalisation de ces œuvres du Paléolithique supérieur. Nous présentons ici l'approche utilisée en se focalisant particulièrement sur les traitements des me-sures effectuées. Ces premières évaluations des données ont permis d'identifier différentes matières colorantes utilisées dans la grotte de Font-de Gaume. L'approche développée a ainsi montré son potentiel, lorsqu'elle sera utilisée sur un plus grand nombre de figures et en inté-grant d’autres informations complémentaires. Elle devrait permettre à terme d’améliorer la connaissance de ces œuvres et de leur réalisation successive dans le cas de superpositions des figures ce qui parait très important, en l’absence d’une datation directe des œuvres parié-tales de Font-de-Gaume.

International audience; Pulmonary arterial hypertension (PAH) is a rare and deadly disease affecting roughly 15–60 people per million in Europe with a poorly understood pathology. There are currently no diagnostic tools for early detection nor does a curative treatment exist. The lipid composition of arteries in lung tissue samples from human PAH and control patients were investigated using matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) combined with time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging. Using random forests as an IMS data analysis technique, it was possible to identify the ion at m/z 885.6 as a marker of PAH in human lung tissue. The m/z 885.6 ion intensity was shown to be significantly higher around diseased arteries and was confirmed to be a diacylglycerophosphoinositol PI(C18:0/C20:4) via MS/MS using a novel hybrid SIMS instrument. The discovery of a potential biomarker opens up new research avenues which may finally lead to a better understanding of the PAH pathology and highlights the vital role IMS can play in modern biomedical research.

International audience; Lead white was a white pigment extensively used in paintings from Antiquity until the beginning of the 20th century. It is composed of hydrocerussite (Pb3(CO3)2(OH)2) and cerussite (PbCO3). Historical recipes report metallic lead, vinegar and horse manure as ingredients to produce the two lead carbonates. The incorporation of organic CO2 carrying 14C representative of the time of manufacture of lead white allows radiocarbon dating of this pigment. One possible protocol for lead white paint preparation for dating is based on the extraction of carbon from lead carbonates by thermal decomposition. Since lead white paints are mixed with a binder and other pigments, a thermogravimetric study was implemented to study CO2 extraction from each component. The measurements were carried out on samples of modern paints prepared with lead white (lead carbonate), Meudon white (calcium carbonate) and linseed oil. The results show that it is possible to separate the carbon of interest (carrying the 14C signature: lead white and linseed oil) from the dead carbon coming from geological carbonates (containing no radiocarbon: Meudon white) by heating the paint sample at 400 °C. This study provides a better understanding of the thermal behavior of these three paint constituents and confirms the validity of the thermal protocol for the preparation of lead white paints for radiocarbon dating.

International audience; The quality of natural and cultured pearls depends on the size, shape and properties of the surface. The inner structure of the pearl is not known, and not taken into account. Indeed, it is assumed that the cultured pearl is a nucleus covered by a thin organic layer, a thin prismatic layer and a thick nacreous layer. The examination of spherical and pear shape samples resulting from the grafting of the black lip pearl oyster (Pinctada margaritifera) shows that this assumption is, in most cases, erroneous. Optical, electron and atomic force microscopic observations, infrared and Raman analyses, as well as micro X-ray fluorescence and micro X-ray absorption near-edge spectroscopy data show that the inner structure of a pearl does not depend on its shape. Both circle or pear shape and spherical pearls show a large variability of the inner structures and composition. There are no two identical samples. Moreover, the arrangement is irregular within a single pearl, and some structures (aragonitic pseudo-prisms) do not exist in the shell.

International audience; Diclofenac sodium (DS) is an emergent pollutant, and among the methods investigated for its removal, adsorption is the most widely utilized technique. Hydroxyapatite and chitosan are biomaterials often used for adsorption. However, both biomaterials are limited due to their low chemical stability in an acidic medium; furthermore, pure hydroxyapatite interacts poorly with diclofenac. In this work, hydroxyapatite was organofunctionalized with 3-aminopropyltrimethoxysilane and further used to obtain amino hydroxyapatite /chitosan hybrids by crosslinking with glutaraldehyde at pH 3, 4, 5, and 6. X-ray diffraction patterns indicated the preservation of the hydroxyapatite phase under all pH conditions. Based on the control reaction of the amino hydroxyapatite with glutaraldehyde and its further reduction in sodium borohydride, the formation of CN moieties was highlighted as the main interaction mechanism between the aldehyde and amino groups. Therefore, crosslinking with glutaraldehyde was evaluated by infrared, Raman spectroscopy, and 13C NMR techniques; the results suggested contributions of imine formation and hydrogen bonding. The hybrid obtained at pH 3 exhibited an enhanced adsorption capacity of 125 mg g−1 at 15 min. The synergy between amino hydroxyapatite and chitosan crosslinked by glutaraldehyde was demonstrated.

International audience; The search for the most ancient traces of life on Earth has always been fraught with controversies because of the inevitable degradation undergone by fossilized biomolecules. Laboratory experiments may provide unique clues to achieve a better mechanistic understanding of the key processes involving (biogenic or abiotic) organic carbon during a geological history. The Earth atmosphere has changed over geological times, from a CO 2-rich atmosphere during the Hadean and Archean to the O 2-rich atmosphere of the present day, with a direct impact on the nature of the gas phase trapped within the sediment porosity. Yet, the influence of the nature of this gas phase on fossilization processes has almost never been investigated. Here, we conducted a series of fossilization experiments using an emblematic biomolecule (i.e. RNA) and clay minerals at 200°C for 7 days in closed systems in equilibrium with two different gas phases (e.g. CO 2 versus N 2 /O 2). The multiscale characterization of experimental residues using a suite of advanced microscopy and spectroscopy techniques showed that the final organomineral assemblages strongly depend on the nature of the gas phase. In addition to the nature of the mineral phases, results showed that the nature of the gas phase impacts the chemistry of the residual N-rich organic compounds trapped within the interlayer spaces of Mg-smectites (e.g. mainly aliphatic-rich under CO 2 vs dominated by heterocycles under N 2 /O 2). Altogether, the present study demonstrates the necessity to take into account the nature of the gas phase composition when experimentally simulating fossilization processes aiming at better constraining which biosignatures may be preserved in ancient rocks. Finally, the experimental results reported here may serve to identify the potential biosignatures that should be searched for on other planetary bodies.

Johannes Vermeer (1632–1675) is known for his brilliant blue colours, and his frequent use of the costly natural ultramarine. This paper reveals new findings about ultramarine in the headscarf ofGirl with a Pearl Earring(c. 1665, Mauritshuis). The painting was examined using a range of micro- and macroscale techniques as part of theGirl in the Spotlightresearch project (2018). Analysis of micro-samples mounted as cross-sections using SEM–EDX and FTIR-ATR showed that Vermeer used high-quality ultramarine in the blue headscarf, based on the relative abundance of bright blue particles of lazurite. Analysis with synchrotron sulphur K-edge XANES suggested that the ultramarine pigment was prepared—at least in part—from a heat-treated lapis lazuli rock. The entire painting was imaged using MS-IRR, MA-XRF, RIS, and digital microscopy to reveal the distribution of materials of the headscarf, and to give more insight into Vermeer’s painting process. The shadow part of the headscarf has a remarkably patchy appearance, due to paint degradation that is probably related to the large amounts of chalk Vermeer mixed in the ultramarine paint in this area. The question was raised as to whether extra chalk was added deliberately to the paint to adjust the handling properties or opacity, or whether the chalk was the substrate of a—now faded—yellow lake. Schematic paint reconstructions were made to investigate the effect of the addition of chalk or yellow lake on the paint properties. The analyses and reconstructions led to the hypothesis that the blue headscarf originally contained a wider range of different blue colour shades: an opaque light blue for the left (lit) zone, a slightly brighter opaque blue for the middle zone, and a deep dark blue-green glaze with alternating blue-green glazing brushstrokes for the shadow zone—now largely compromised by paint degradation.

International audience; At the end of the 1st c. AD, seven privileged burials, two of which are in mausoleums, were excavated in a private area located 150 m southwest of a villa in Atrebato-Nervian territory. The monumental aspect of the vaults of these graves, the selection and abundance of artefact deposits and the distinctiveness of some of the objects provide remarkable evidence of activities linked to cosmetic and therapeutic care.; À la fin du Ier s. apr. J.-C., sept tombes privilégiées, dont deux signalées par des mausolées, ont été creusées dans un espace privatif situé à moins de 150 m au sud-ouest d’une villa entre Arras/Nemetacum et Cambrai/Camaracum. Le caractère exceptionnel de ces chambres souterraines tient à la monumentalité des caveaux, au choix et à l’abondance des dépôts, mais aussi à l’originalité de certains objets disposés dans quelques tombes, qui attestent d’activités liées aux soins cosmétiques et thérapeutiques.