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Ostrich eggshells are excellent examples of avian biomineralization. Interest in these eggshells is focused on their potential as a food source, example of a biomaterial for medical and industrial applications, and the use of fossil remains for paleoenvironmental reconstructions. Due to this interest, there is some information about aspects of eggshell biomineralization, but it is scattered in different publications and is limited in scope about mineralogy-crystallography and/or composition. Here, we re-examine the biomineralization of the Struthio eggshells focusing on the structure, from macro- to nano-scales, crystallography, and composition of mineral and organic phases. Our results show that there is a very tight biomineralization control, from well-defined structures at nanoscale to precise crystallographic orientation of calcite crystals, in the formation of a biomineral that is unparalleled in other avian eggshells. Overall, this finding would explain the thickness and excellent mechanical properties of ostrich eggshells.

An improved understanding of an ovary’s structures is highly desirable to support advances in folliculogenesis knowledge and reproductive medicine, with particular attention to fertility preservation options for prepubertal girls with malignant tumors. Although currently the golden standard for structural analysis is provided by combining histological sections, staining, and visible 2D microscopic inspection, synchrotron radiation phase-contrast microtomography is becoming a new challenge for three-dimensional studies at micrometric resolution. To this aim, the proper use of contrast agents can improve the visualization of internal structures in ovary tissues, which normally present a low radiopacity. In this study, we report a comparison of four staining protocols, based on iodine or tungsten containing agents, applied to bovine ovarian tissues fixed in Bouin’s solution. The microtomography (microCT) analyses at two synchrotron facilities under different set-ups were performed at different energies in order to maximize the image contrast. While tungsten-based agents allow large structures to be well identified, Iodine ones better highlight smaller features, especially when acquired above the K-edge energy of the specific metal. Further scans performed at lower energy where the setup was optimized for overall quality and sensitivity from phase-contrast still provided highly resolved visualization of follicular and intrafollicular structures at different maturation stages, independent of the staining protocol. The analyses were complemented by X-ray Fluorescence mapping on 2D sections, showing that the tungsten-based agent has a higher penetration in this type of tissues.

The main advantage of wavelength-dispersive spectrometers applied in X-ray study is their high energy resolution. The design and construction of spectrometer, usually dedicated to the specific experimental systems, for example synchrotron based setups, need information about the characteristics of the main elements of the spectrometer such as X-ray optics elements, crystals and detectors. Such information can be obtained using Monte-Carlo simulations. In this paper, the Monte-Carlo simulations of X-ray tracing in parallel-beam wavelength-dispersive spectrometer (PBWDS), equipped with polycapillary optics, are presented and discussed. The study concentrates on the description of the polycapillary model, simulations of the properties of X-ray polycapillary optics and, finally, on the simulations of X-ray track in the spectrometer designed and installed at the ID21 beamline at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). The results of simulations were compared with experimental data obtained for different registered X-ray energies and spectrometer crystals, showing good agreement. The obtained results showed that the X-ray transmission in the tested polycapillary optics is at the level of 15%, while the divergence of the outgoing beam changes from 8 mrad to 3 mrad with an increase of photon energy from 2 keV to 10 keV. The spectrometer provides an energy resolution of 5 eV and 33 eV in the energy range of 1.4 keV - 6.5 keV. The developed simulation program can be successfully used for the construction of spectrometers dedicated to the different experimental conditions. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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; 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.

As the prospect of human beings exposed to new nanomaterials increases, there are growing concerns about the foetal exposure and effects of such nanomaterials during pregnancy. Among others, due to their ample usage, it becomes urgent to address the vulnerability of the human placental barrier to carbon nanotubes (CNTs). Recently, by applying a combination of advanced synchrotron-based X-ray microscopy and X-ray fluorescence (XRF) techniques, we demonstrated that raw single-walled CNTs (SWCNTs) may cause an asbestos-like iron-related toxicity in mesothelial (MeT5A) cells. This work shows the results obtained with the same approach and experimental conditions in human choriocarcinoma (BeWo) cells as a placental model. XRF microscopy in mild and soft X-ray regimes was used to map the distribution of P, S, Ca, and Fe in exposed and control cells, whereas absorption and phase-contrast imaging (soft X-ray microscopy) provided simultaneous morphological information. The findings show that exposure to SWCNTs affects cell viability and causes a small increase in intracellular iron content, further confirmed by the stimulation of the ferritin protein. It is interesting to note that the iron changes are negligible when highly purified SWCNTs are used. In all tested conditions, including exposure to iron sulfate, the iron accumulation or ferritin increase was much lower in BeWo cells than in MeT5A ones, suggesting a different iron metabolism and possibly a lower vulnerability of the placental barrier to iron-rich nanomaterials.

New scientific frontiers in biomedicine, materials science, and nanotechnology make increasing use of characterization methods at the mesoscopic and nanometer scale. These studies of heterogeneous ...

Mollusc shells are complex organomineral structures, the arrangement and composition depending on the species. Most studies are dedicated to shells composed of an aragonite nacreous and a calcite prismatic layer, so the nacreous prismatic model based on Pinctada and Atrina–Pinna. Here, we studied the micro‐ and nanostructure, the mineralogy and composition of a nacroprismatic bivalve species: Unio pictorum. The prismatic layer of Unio is aragonite, and the inner structure of the prismatic units strongly differs from those of the calcitic layers. The shape of the prisms varies depending on their growth stage. The first layers of nacre are similar to those of gastropods (columnar nacre), then evolve towards the typical bivalve arrangement (sheet nacre). Na, Sr, Mg, P and S are present in both prisms and nacre. The organic prismatic envelopes are rich in sulphur amino acids, whereas organic sulphate is present within the prisms and the nacreous tablets. P is present as phosphate, probably a mixture of organic and mineral complex. Chemical distribution maps confirm the absence of an organic membrane between the nacre and the prisms. The comparison of the structure, mineralogy and composition of Unio pictorum and different species show the diversity of nacroprismatic shells, and that these features are taxonomically dependent.

Very little is known about the distribution of metal ions at the subcellular level. However, those chemical elements have essential regulatory functions and their disturbed homeostasis is involved in various diseases. State-of-the-art synchrotron X-ray fluorescence nanoprobes provide the required sensitivity and spatial resolution to elucidate the two-dimensional (2D) and three-dimensional (3D) distribution and concentration of metals inside entire cells at the organelle level. This opens new exciting scientific fields of investigation on the role of metals in the physiopathology of the cell. The cellular preparation is a key and often complex procedure, particularly for basic analysis. Although X-ray fluorescence techniques are now widespread and various preparation methods have been used, very few studies have investigated the preservation of the elemental content of cells at best, and no stepwise detailed protocol for the cryopreparation of adherent cells for X-ray fluorescence nanoprobes has been released so far. This is a description of a protocol that provides the stepwise cellular preparation for fast cryofixation to enable synchrotron X-ray fluorescence nano-analysis of cells in a frozen hydrated state when a cryogenic environment and transfer is available. In case nano-analysis has to be performed at room temperature, an additional procedure for freeze-drying the cryofixed adherent cellular preparation is provided. The proposed protocols have been successfully used in previous works, most recently in studying the 2D and 3D intracellular distribution of an organometallic compound in breast cancer cells.

Plant-microbe interactions can be utilized in bio-based processes such as bioremediation and biofortification, either to remove hazardous radionuclides and heavy metals from the soil, or to increase the accumulation of desired elements into crops to improve their quality. Optimizing such elegant plant-microbe interactions requires detailed understanding of the chemical element compositions of fresh plant tissues at cellular organelle resolution. However, such analyses remain challenging because conventional methods lack the required spatial resolution, contrast or sensitivity. Using a novel combination of nanoscaleresolution 3D cryogenic synchrotron-light ptychography, holotomography and fluorescence tomography, we show how soil bacteria interact with Arabidopsis thaliana and promote the uptake of various metals. Co-cultivation with Pseudomonas sp. strain T5-6-I alters root anatomy and increases levels of selenium (Se), iron (Fe) and other micronutrients in roots. Our approach highlights the interaction of plants and microbes in bioremediation and biofortification on the subcellular level.

Significance Silver nanowires are a type of novel fiber that are likely to have wide application in consumer electronics but that can also carry risk for cell internalization and toxicity. Here, we show that silver nanowire toxicity can be greatly diminished by reducing nanowire diameter without affecting device performance. X-ray microscopy and supporting studies revealed that endolysosome membranes can mechanically crumple thin silver nanowires, the likely mechanism for diminishing toxicity., Fibrous particles interact with cells and organisms in complex ways that can lead to cellular dysfunction, cell death, inflammation, and disease. The development of conductive transparent networks (CTNs) composed of metallic silver nanowires (AgNWs) for flexible touchscreen displays raises new possibilities for the intimate contact between novel fibers and human skin. Here, we report that a material property, nanowire-bending stiffness that is a function of diameter, controls the cytotoxicity of AgNWs to nonimmune cells from humans, mice, and fish without deterioration of critical CTN performance parameters: electrical conductivity and optical transparency. Both 30- and 90-nm-diameter AgNWs are readily internalized by cells, but thinner NWs are mechanically crumpled by the forces imposed during or after endocytosis, while thicker nanowires puncture the enclosing membrane and release silver ions and lysosomal contents to the cytoplasm, thereby initiating oxidative stress. This finding extends the fiber pathology paradigm and will enable the manufacture of safer products incorporating AgNWs.

Here, we show results on X-ray absorption near edge structure spectroscopy in both transmission and X-ray fluorescence full-field mode (FF-XANES) at the calcium K-edge on human bone tissue in healthy and diseased conditions and for different tissue maturation stages. We observe that the dominating spectral differences originating from different tissue regions, which are well pronounced in the white line and postedge structures are associated with polarization effects. These polarization effects dominate the spectral variance and must be well understood and modeled before analyzing the very subtle spectral variations related to the bone tissue variations itself. However, these modulations in the fine structure of the spectra can potentially be of high interest to quantify orientations of the apatite crystals in highly structured tissue matrices such as bone. Due to the extremely short wavelengths of X-rays, FF-XANES overcomes the limited spatial resolution of other optical and spectroscopic techniques exploiting visible light. Since the field of view in FF-XANES is rather large the acquisition times for analyzing the same region are short compared to, for example, X-ray diffraction techniques. Our results on the angular absorption dependence were verified by both site-matched polarized Raman spectroscopy, which has been shown to be sensitive to the orientation of bone building blocks and by mathematical simulations of the angular absorbance dependence. As an outlook we further demonstrate the polarization based assessment of calcium-containing crystal orientation and specification of calcium in a beta-tricalcium phosphate (β-Ca3(PO4)2 scaffold implanted into ovine bone. Regarding the use of XANES to assess chemical properties of Ca in human bone tissue our data suggest that neither the anatomical site (tibia vs jaw) nor pathology (healthy vs necrotic jaw bone tissue) affected the averaged spectral shape of the XANES spectra.

International audience; X-ray ptychography is a coherent diffraction imaging technique with a high resolving power and excellent quantitative capabilities. Although very popular in synchrotron facilities nowadays, its implementation with X-ray energies above 15 keV is very rare due to the challenges imposed by the high energies. Here, the implementation of high-energy X-ray ptychography at 17 and 33.6 keV is demonstrated and solutions to overcome the important challenges are provided. Among the particular aspects addressed are the use of an efficient high-energy detector, a long synchrotron beamline for the high degree of spatial coherence, a beam with 1% monochromaticity providing high flux, and efficient multilayer coated Kirkpatrick-Baez X-ray optics to shape the beam. The constraints imposed by the large energy bandwidth are carefully analyzed, as well as the requirements to sample correctly the high-energy diffraction patterns with small speckle size. In this context, optimized scanning trajectories allow the total acquisition time to be reduced by up to 35%. The paper explores these innovative solutions at the ID16A nano-imaging beamline by ptychographic imaging of a 200 nm-thick gold lithography sample.

International audience; Manganese (Mn) is an essential metal that can be neurotoxic when elevated exposition occurs leading to parkinsonian-like syndromes. Mutations in the Slc30a10 gene have been identified in new forms of familial parkinsonism. SLC30A10 is a cell surface protein involved in the efflux of Mn and protects the cell against Mn toxicity. Disease-causing mutations block the efflux activity of SLC30A10, resulting in Mn accumulation. Determining the intracellular localization of Mn when disease-causing SLC30A10 mutants are expressed is essential to elucidate the mechanisms of Mn neurotoxicity. Here, using organelle fluorescence microscopy and synchrotron X-ray fluorescence (SXRF) imaging, we found that Mn accumulates in the Golgi apparatus of human cells transfected with the disease-causing SLC30A10-Δ105–107 mutant under physiological conditions and after exposure to Mn. In cells expressing the wild-type SLC30A10 protein, cellular Mn content was low after all exposure conditions, confirming efficient Mn efflux. In nontransfected cells that do not express endogenous SLC30A10 and in mock transfected cells, Mn was located in the Golgi apparatus, similarly to its distribution in cells expressing the mutant protein, confirming deficient Mn efflux. The newly developed SXRF cryogenic nanoimaging (

Gadolinium deposition in tissue is linked to nephrogenic systemic fibrosis (NSF): a rare disorder occurring in patients with severe chronic kidney disease and associated with administration of Gd-based contrast agents (GBCAs) for Magnetic Resonance Imaging (MRI). It is suggested that the GBCAs prolonged permanence in blood in these patients may result in a Gd precipitation in peripheral or central organs, where it initiates a fibrotic process. In this study we investigated new sites of retention/precipitation of Gd in a mouse model of renal disease (5/6 nephrectomy) receiving two doses (closely after each other) of a linear GBCA. Two commercial GBCAs (Omniscan® and Magnevist®) were administered at doses slightly higher than those used in clinical practice (0.7 mmol/kg body weight, each). The animals were sacrificed one month after the last administration and the explanted organs (kidney, liver, femur, dorsal skin, teeth) were analysed by X-ray fluorescence (XRF) at two synchrotron facilities. The XRF analysis with a millimetre-sized beam at the SYRMEP beamline (Elettra, Italy) produced no detectable levels of Gd in the examined tissues, with the notable exception of the incisors of the nephrectomised mice. The XRF analyses at sub-micron resolution performed at ID21 (ESRF, France) allowed to clearly localize Gd in the periodontal ligaments of teeth both from Omniscan® and Magnevist® treated nephrectomised mice. The latter results were further confirmed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The study prompts that prolonged permanence of GBCAs in blood may result in Gd retention in this particular muscular tissue, opening possibilities for diagnostic applications at this level when investigating Gd-related toxicities.

Avian eggshells are composed of several layers made of organic compounds and a mineral phase (calcite), and the general structure is basically the same in all species. A comparison of the structure, crystallography, and chemical composition shows that despite an overall similarity, each species has its own structure, crystallinity, and composition. Eggshells are a perfect example of the crystallographic versus biological concept of the formation and growth mechanisms of calcareous biominerals: the spherulitic-columnar structure is described as "a typical case of competitive crystal growth", but it is also said that the eggshell matrix components regulate eggshell mineralization. Electron back scattered diffraction (EBSD) analyses show that the crystallinity differs between different species. Nevertheless, the three layers are composed of rounded granules, and neither facets nor angles are visible. In-situ analyses show the heterogeneous distribution of chemical elements throughout the thickness of single eggshell. The presence of organic matrices other than the outer and inner membranes in eggshells is confirmed by thermograms and infrared spectrometry, and the differences in quality and quantity depend on the species. Thus, as in other biocrystals, crystal growth competition is not enough to explain these differences, and there is a strong biological control of the eggshell secretion.

Atomic layer deposition (ALD) is a scalable deposition technique known for producing uniform, conformal films of a wide range of compounds on nearly any substrate material. These traits make it an ideal deposition method for producing films to replace the National Institute of Standards and Technology (NIST) standards and create Standard Reference Materials (SRMs) on a wide range of relevant two-dimensional and three-dimensional substrates. The use of SRM from NIST for quantitative analysis of chemical composition using synchrotron based x-ray fluorescence (SR-XRF) and scanning transmission x-ray microscopy (STXM) is common. Such standards, however, can suffer from inhomogeneity in chemical composition and thickness and often require further calculations, based on sample mounting and detector geometry, to obtain quantitative results. These inhomogeneities negatively impact the reproducibility of the measurements and the quantitative measure itself. Utilizing Rutherford backscattering, x-ray reflectivity, quartz crystal microbalance, STXM, and SR-XRF, the authors show that ALD is capable of producing high quality standards that are homogenous over scales ranging from nanometers to 100s of micrometers.Atomic layer deposition (ALD) is a scalable deposition technique known for producing uniform, conformal films of a wide range of compounds on nearly any substrate material. These traits make it an ideal deposition method for producing films to replace the National Institute of Standards and Technology (NIST) standards and create Standard Reference Materials (SRMs) on a wide range of relevant two-dimensional and three-dimensional substrates. The use of SRM from NIST for quantitative analysis of chemical composition using synchrotron based x-ray fluorescence (SR-XRF) and scanning transmission x-ray microscopy (STXM) is common. Such standards, however, can suffer from inhomogeneity in chemical composition and thickness and often require further calculations, based on sample mounting and detector geometry, to obtain quantitative results. These inhomogeneities negatively impact the reproducibility of the measurements and the quantitative measure itself. Utilizing Rutherford backscattering, x-ray reflectivity, ...

Carbon nanotubes (CNTs) are promising products in industry and medicine, but there are several human health concerns since their fibrous structure resembles asbestos. The presence of transition metals, mainly iron, in the fibres seems also implicated in the pathogenetic mechanisms. To unravel the role of iron at mesothelial level, we compared the chemical changes induced in MeT-5A cells by the exposure to asbestos (crocidolite) or CNTs at different content of iron impurities (raw-SWCNTs, purified- and highly purified-SWCNTs). We applied synchrotron-based X-Ray Fluorescence (XRF) microscopy and soft X-ray imaging (absorption and phase contrast images) to monitor chemical and morphological changes of the exposed cells. In parallel, we performed a ferritin assay. X-ray microscopy imaging and XRF well localize the crocidolite fibres interacting with cells, as well as the damage-related morphological changes. Differently, CNTs presence could be only partially evinced by low energy XRF through carbon distribution and sometimes iron co-localisation. Compared to controls, the cells treated with raw-SWCNTs and crocidolite fibres showed a severe alteration of iron distribution and content, with concomitant stimulation of ferritin production. Interestingly, highly purified nanotubes did not altered iron metabolism. The data provide new insights for possible CNTs effects at mesothelial/pleural level in humans.

Ca:LaNbO4 (LNC) constitutes the last real breakthrough in high-temperature proton conductors, with better chemical and mechanical stability with respect to cerate and zirconate perovskites. However, the low amount of bivalent dopant that can be hosted in the LaNbO4 matrix poses a limit to the proton concentration in the electrolyte. Using synchrotron X-ray microspectroscopy, we investigated the compatibility of annealed LNC/LSM electrolyte/cathode bilayers for proton-conducting SOFCs. The element maps are complemented by microEXAFS and microXANES, giving information on the fate of different cations after diffusion. The X-ray microspectroscopy approach described here is applied for the first time to the study of materials for energy, and it is proposed as a useful structural tool, complementary to electrochemical characterization, for the investigation of the compatibility between materials for SOFCs. We demonstrate that an impressive calcium drift towards the LSM cathode takes place: the dopant is depleted throughout a region of LNC several micrometers wide, causing a decrease of charge carriers in the electrolyte and eventually impairing its conductivity. This poses a significant challenge for evaluating electrolyte/electrode couples in proton-conducting SOFCs based on LNC.

Research question Does synchrotron X-ray fluorescence (XRF) provide novel chemical information for the evaluation of human ovarian tissue cryopreservation protocols? Design Tissues from five patients undergoing laparoscopic surgery for benign gynaecological conditions were fixed for microscopic analysis either immediately or after cryopreservation. After fixation, fresh and slowly frozen samples were selected by light microscopy and transmission electron microscopy, and subsequently analysed with synchrotron XRF microscopy at different incident energies. Results The distributions of elements detected at 7.3 keV (S, P, K, Cl, Fe, and Os) and 1.5 keV (Na and Mg) were related to the changes revealed by light microscopy and transmission electron microscopy analyses. The light elements showed highly informative findings. The S distribution was found to be an indicator of extracellular component changes in the stromal tissues of the freeze–stored samples, further revealed by the transmission electron microscopy analyses. Low-quality follicles, frequent in the freeze–thawed tissues, showed a high Na level in the ooplasm. On the contrary, good-quality follicles were detected by a homogeneous Cl distribution. The occurrence of vacuolated follicles increased after cryopreservation, and the XRF analyses showed that the vacuolar structures contained mainly Cl and Na. Conclusions The study demonstrates that elemental imaging techniques, particularly revealing the distribution of light elements, could be useful in establishing new cryopreservation protocols.

International audience; Large-size diamond detectors have been produced and tested with the aim of achieving reliable & efficient sensors for particle tracking or medical applications. Poly-and single-crystal CVD diamond samples were submitted to various ionizing particles. Their metallization was performed by using Distributed MicroWave Plasmas, a process developed by LPSC. Their detection performance was investigated using α and β radioactive sources, 95 MeV/u carbon beams from GANIL (Caen France) and short-bunched 8.5 keV photons from ESRF. This study is part of the ANR project MONODIAM-HE and of the CLaRyS collaboration for the on-line dose monitoring of hadrontherapy. The goal here is to provide large-area detectors with a high detection efficiency for carbon or proton beams, yielding time and position measurement at count rates greater than 100 MHz. A time resolution ranging from 20 ps up to 40 ps and an energy resolution varying from 7 % up to 10% were measured. It allowed us to conclude that poly-crystal CVD diamond detectors are good candidates for this application.

International audience; Due to the growing commercial applications of manufactured nanoparticles (NPs), toxicological studies on NPs, especially during the critical window of development, are of major importance. The aim of the study was to assess the impact of respiratory exposure to metallic and metal oxide NPs during pregnancy on lung development of the offspring and to determine the key parameters involved in lung alterations. Pregnant mice were exposed to weekly doses of 100 mu g (total dose 300 mu g) of titanium dioxide (TiO2), cerium oxide (CeO2), silver (Ag) NPs or saline solution by nonsurgical intratracheal instillation. The offspring lungs were analyzed at different stages of lung development: fetal stage (gestational day 17.5), pulmonary alveolarization (post-delivery day 14.5) and lung maturity (post-delivery day 49.5). Regardless of the type of NP, maternal exposure during gestation induced long-lasting impairment of lung development of the offspring. This effect was accompanied by: i) decreased placental efficiency together with the presence of NPs in placenta, ii) no increase of inflammatory mediators present in amniotic fluid, placenta or offspring lungs and iii) decreased pulmonary expression of vascular endothelial growth factor-alpha (VEGF-alpha) and matrix metalloproteinase 9 (MMP-9) at the fetal stage, and fibroblast growth factor-18 (FGF-18) at the alveolarization stage. Respiratory exposure to metallic NPs during pregnancy induces stereotyped impairment of lung development with a lasting effect in adult mice, independently of the chemical nature of the NP.

Quantitative nano-imaging of metal traces in a solid is a recent capability arising from the construction of hard X-ray nanoprobes dedicated to X-ray Fluorescence (XRF) imaging on upgraded third generation synchrotrons. Micrometer sample preparation valid for trace analysis is a fundamental part of the required developments to capitalize on the reduced Minimum Detection Limits. Practical guidelines lead us to propose a customized use of Focused Ion Beams (FIB) backed by state of the art Monte Carlo XRF modeling to initiate preparations of new samples and certified standards. The usefulness of these developments is illustrated by the first detection of Ni traces (4.57E+07 ± 3.2E+06 (7.1%) at μm −3 ) in a 3.35 Ga old microstructure of putative microbial origin from Barberton (South Africa). A list of feasibility checks provides a way of getting below 5 ppm MDLs for acquisition-times of 10 s with an analytical precision better than 10%.

International audience; The ID16A beamline at ESRF offers unique capabilities for X-ray nano-imaging, and currently produces the worlds brightest high energy diffraction-limited nanofocus. Such a nanoprobe was designed for quantitative characterization of the morphology and the elemental composition of specimens at both room and cryogenic temperatures. Billions of photons per second can be delivered in a diffraction-limited focus spot size down to 13 nm. Coherent X-ray imaging techniques, as magnified holographic-tomography and ptychographic-tomography, are implemented as well as X-ray fluorescence nanoscopy. We will show the latest developments in coherent and spectroscopic X-ray nanoimaging implemented at the ID16A beamline.

International audience; The ID21 beamline (European Synchrotron Radiation facility, France) is a multi micro-analytical platform combining X-ray and infrared micro-probes, for characterization of elements, species, molecular groups and crystalline structures in complex materials. Applications are mainly in the fields of cultural heritage, life science, environmental and earth sciences, materials sciences. Here, we first present the status of instruments: (i) the scanning micro-spectroscopy end-station, operating from 2.0 to 9.2 keV, under vacuum and offering cryo conditions, for the acquisition of 2D micro X-ray fluorescence (μXRF) maps, single point micro X-ray Absorption Near Edge Structure (μXANES) spectra and speciation maps with sub-micrometric resolution; (ii) the XANES full-field end-station, operating in the same vacuum and energy conditions, for the acquisition of hyper-spectral radiographs of thin concentrated samples, resulting in speciation maps with micrometric resolution and millimetric field of view; (iii) the scanning micro-X-ray diffraction (μXRD)/μXRF end-station, operating at 8.5 keV, in air, for the acquisition of 2D crystalline phase maps, with micrometric resolution; and (iv) the scanning infrared microscope, operating in the mid-infrared range for the acquisition of molecular maps and some structural maps with micrometric resolution. Recent hardware and software developments are presented, as well as new protocols for improved sample preparation of thin sections. Secondly, a review of recent applications for the study of cultural heritage is presented, illustrated by various examples: determination of the origin of the color in blue Chinese porcelains and in brown Sèvres porcelains; detection of lead in ink on Herculaneum papyri; identification and degradation of modeling materials used by Auguste Rodin and of chrome yellow pigments used by Vincent van Gogh. Cryo capabilities are illustrated by the analysis of plants exposed to chromate solutions. These examples show the variety of materials analyzed, of questions tackled, and particularly the multiple advantages of the ID21 analytical platform for the analysis of ancient and artistic materials.

cited By 0; International audience; Aquatic fungi can be used to evaluate the functioning of natural ecosystems. Heliscus lugdunensis is an early colonizer of allochthone leafs. Since this aquatic hyphomycete is able to develop in metal contaminated habitats and tolerates cadmium, it appears to be a good candidate to investigate adaptation to metal pollution. This study aimed at examining the sequestration of Cd in the hyphae of H. lugdunensis, and particularly the role of the tip cells. For that, H. lugdunensis growth was evaluated under various Cd concentrations, and a combination of synchrotron micro X‐ray fluorescence and X‐ray absorption near edge structure spectroscopy was carried out to determine the compartments of Cd accumulation and the Cd chemical species, respectively. Results showed that the hyphal tip cells were depleted in Cd, and that the metal was stored in older cells. Cd was mainly associated with sulfur ligands and to a lesser extent bound to phosphates and carboxyl/hydroxyl groups from cell wall and/or organic acids. Finally, the aquatic fungus was able to maintain the tip cell as a functional system, thus allowing the colonization of contaminated environments.

Manganese-enhanced magnetic resonance imaging (MEMRI) is a powerful tool for in vivo tract tracing or functional imag- ing of the central nervous system. However Mn 21 may be toxic at high levels. In this study, we addressed the impact of Mn 21 on mouse hippo- campal neurons (HN) and neuron-like N2a cells in culture, using several approaches. Both HN and N2a cells not exposed to exogenous MnCl2 were shown by synchrotron X-ray fluorescence to contain 5 mg/g Mn. Concentrations of Mn 21 leading to 50% lethality (LC50) after 24 h of incubation were much higher for N2a cells (863 mM) than for HN (90 mM). The distribution of Mn 21 in both cell types exposed to Mn 21 concentrations below LC50 was perinuclear whereas that in cells exposed to concentrations above LC50 was more diffuse, suggesting an overloading of cell storage/detoxification capacity. In addition, Mn 21 had a cell-type and dose-dependent impact on the total amount of intra- cellular P, Ca, Fe and Zn measured by synchrotron X-ray fluorescence. For HN neurons, immunofluorescence studies revealed that concentra- tions of Mn 21 below LC50 shortened neuritic length and decreased mitochondria velocity after 24 h of incubation. Similar concentrations of Mn 21 also facilitated the opening of the mitochondrial permeability transition pore in isolated mitochondria from rat brains. The sensitivity of primary HN to Mn 21 demonstrated here supports their use as a rele- vant model to study Mn 21 -induced neurotoxicity. V C 2014 Wiley

Total reflection X-ray fluorescence (TXRF) and grazing emission X-ray fluorescence (GEXRF) are surface sensitive techniques and can be used for detailed surface studies of different materials, including ultra-low concentration contamination or the lateral and depth distributions of elements. The calibration procedure typically used involves placing a micro-droplet ( ∼ μ l ) of the standard solution onto a silicon wafer (or quartz backing). After evaporation of the solvent, the residual amount of elements is used as a reference standard. Knowledge of the distribution of residue material on the substrate surface is crucial for precise quantification. In the present work the investigation of the lateral distribution of elements in the multielemental calibrating samples, containing the 23 most commonly studied elements, by using the synchrotron radiation based micro X-ray fluorescence is presented. The goal of this project was the study of a uniformity of the elemental distributions and determination of the residual elements morphology depending on the temperature of the drying process. The X-ray images were compared with optical and SEM images. Paper presents in details the experimental setup, sample preparation procedures, measurements and results. In the analysis of the X-ray images of the sample dried in high temperature the censoring approach was applied improving the quality of statistical analysis. The information on the elements distribution in the calibrating samples can be useful for developing more accurate calibration procedures applied in quantitative analysis of surface sensitive TXRF and GEXRF techniques.

Asbestos bodies are the histological hallmarks of asbestos exposure. Both conventional and advanced techniques are used to evaluate abundance and composition in histological samples. We previously reported the possibility of using synchrotron X-ray fluorescence microscopy (XFM) for analyzing the chemical composition of asbestos bodies directly in lung tissue samples. Here we applied a high-performance synchrotron X-ray fluorescence (XRF) set-up that could allow new protocols for fast monitoring of the occurrence of asbestos bodies in large histological sections, improving investigation of the related chemical changes. A combination of synchrotron X-ray transmission and fluorescence microscopy techniques at different energies at three distinct synchrotrons was used to characterize asbestos in paraffinated lung tissues. The fast chemical imaging of the XFM beamline (Australian Synchrotron) demonstrates that asbestos bodies can be rapidly and efficiently identified as co-localization of high calcium and iron, the most abundant elements of these formations inside tissues (Fe up to 10% w/w; Ca up to 1%). By following iron presence, we were also able to hint at small asbestos fibers in pleural spaces. XRF at lower energy and at higher spatial resolution was afterwards performed to better define small fibers. These analyses may predispose for future protocols to be set with laboratory instruments.

The crayfish Cherax quadricarinatus stores calcium ions, easily mobilizable after molting, for calcifying parts of the new exoskeleton. They are chiefly stored as amorphous calcium carbonate (ACC) during each premolt in a pair of gastroliths synthesized in the stomach wall. How calcium carbonate is stabilized in the amorphous state in such a biocomposite remains speculative. The knowledge of the microstructure at the nanometer level obtained by field emission scanning electron microscopy and atomic force microscopy combined with scanning electron microscopy energy-dispersive X-ray spectroscopy, micro-Raman and X-ray absorption near edge structure spectroscopy gave relevant information on the elaboration of such an ACC-stabilized biomineral. We observed nanogranules distributed along chitin-protein fibers and the aggregation of granules in thin layers. AFM confirmed the nanolevel structure, showing granules probably surrounded by an organic layer and also revealing a second level of aggregation as described for other crystalline biominerals. Raman analyses showed the presence of ACC, amorphous calcium phosphate, and calcite. Elemental analyses confirmed the presence of elements like Fe, Na, Mg, P, and S. P and S are heterogeneously distributed. P is present in both the mineral and organic phases of gastroliths. S seems present as sulfate (probably as sulfated sugars), sulfonate, sulfite, and sulfoxide groups and, in a lesser extent, as sulfur-containing amino acids.

We present here the latest results from tests performed at the ESRF ID17 and ID21 beamlines for the characterization of novel beam monitors for Microbeam Radiation Therapy (MRT), which is currently being implemented at ID17. MRT aims at treating solid tumors by exploiting an array of evenly spaced microbeams, having an energy spectrum distributed between 27 and 600 keV and peaking at 100 keV. Given the high instantaneous dose delivered (up to 20 kGy/s), the position and the intensity of the microbeams has to be precisely and instantly monitored. For this purpose, we developed dedicated silicon microstrip beam monitors. We have successfully characterized them, both with a microbeam array at ID17, and a submicron scanning beam at ID21. We present here the latest results obtained in recent tests along with an outlook on future developments.

Among the new emerging cancer therapies, Microbeam Radiation Therapy (MRT) is currently showing very promising results in terms of limiting or decreasing tumor growth while keeping the damage to healthy tissue to a minimum. The MRT is able to deliver unprecedented dose rates of up to 20 kGy/s, posing important questions in terms of treatment planning and patient safety during treatment. For this reason, a beam monitoring system must be built, in which a detector acquires the microbeam array profile in real-time. In case of anomalies detection, the detector signals the beam-line to close the shutter as an emergency safety measure. Many sensors technologies for beam monitoring are currently being considered and silicon strip detectors seem to be very promising candidates. In this study the characterisation in full MRT conditions of a novel silicon strip detector is reported explaining strengths and weaknesses of the devices. Modifications to the sensor layout are also suggested in this study.

We recently developed the synthesis of ultrasmall gadolinium-based nanoparticles (GBN), (hydrodynamic diameter i.e. 15 ppb of gadolinium) for an important increase of the therapeutic effect of irradiation. Such a promising and unexpected result is assigned to a suited distribution of GBN within the tumor, as revealed by the X-ray fluorescence (XRF) maps.

cited By 7; International audience; In this paper, we develop a methodological approach combining macro-X-ray fluorescence and synchrotron radiation-based techniques (μXRF, full-field XANES and μXRD) to determine the composition and microstructure of underglaze decors of Qinghua porcelains (Ming dynasty). Various transition metal elements (Fe, Mn, Co) are present in the blue decoration of these ceramics and the approach proposed allows for establishing the feature of each. Thus it shows that Fe ions are distributed homogeneously over the whole glaze without any significant difference in blue and white parts. They do not play a significant role in the color. In contrast, Co ions exhibit a heterogeneous distribution with CoAl2O4 particles close to the body/glaze interphase. These particles play a key role in the blue color and, the hue variations seem in greater part to link to their density and repartition. Co dispersed in the glassy matrix is also bivalent and mainly in tetragonal coordination, leading also to a blue color. Mn ion distribution is similar to the one of Co but without presenting local high concentrations associated to Mn based particles. Mn affects the darkness of the color and for the sample without CoAl2O4 particle; it is the main color contribution. The presence of CoAl2O4 crystals was confirmed by μXRD, which revealed, in addition, a variation of cell parameters certainly linking to a Co partial substitution.

International audience; During premolt, crayfish develop deposits of calcium ions, called gastroliths, in their stomach wall. The stored calcium is used for the calcification of parts of the skeleton regularly renewed for allowing growth. Structural and molecular analyses of gastroliths have been primarily performed on three crayfish species, Orconectes virilis, Procambarus clarkii, and more recently, Cherax quadricarinatus. We have performed high-resolution analyses of gastroliths from the native noble crayfish, Astacus astacus, focusing on the microstructure, the mineralogical and elemental composition and distribution in a comparative perspective. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) observations showed a classical layered microstructure composed of 200-nm diameter granules aligned along fibers. These granules are themselves composed of agglomerated nanogranules of 50 nm-mean diameters. Denser regions of bigger fused granules are also present. Micro-Raman spectroscopy show that if A. astacus gastroliths, similarly to the other analyzed gastroliths, are mainly composed of amorphous calcium carbonate (ACC), they are also rich in amorphous calcium phosphate (ACP). The presence of a carotenoid pigment is also observed in A. astacus gastrolith contrary to C. quadricarinatus. Energy-dispersive X-ray spectroscopy (EDX) analyses demonstrate the presence of minor elements such as Mg, Sr, Si and P. The distribution of this last element is particularly heterogeneous. X-ray absorption near edge structure spectroscopy (XANES) reveals an alternation of layers more or less rich in phosphorus evidenced in the mineral phase as well as in the organic matrix in different molecular forms. Putative functions of the different P-comprising molecules are discussed.

Mollusc shells are composed of two or three layers. The main layers are well-studied, but the structural and chemical changes at their boundaries are usually neglected. A microstructural, mineralogical, and biochemical study of the boundary between the inner crossed lamellar and outer prismatic layers of the shell of Concholepas concholepas showed that this boundary is not an abrupt transition. Localized structural and chemical analyses showed that patches of the inner aragonitic crossed lamellar layer persist within the outer calcitic prismatic layer. Moreover, a thin aragonitic layer with a fibrous structure is visible between the two main layers. A three-step biomineralization process is proposed that involves changes in the chemical and biochemical composition of the last growth increments of the calcite prisms. The changes in the secretory process in the mantle cells responsible for the shell layer succession are irregular and discontinuous.

Summary 1. Spatially resolved X-ray fluorescence (XRF) spectroscopy with synchrotron radiation is a technique that allows imaging and quantification of chemical elements in biological specimens with high sensitivity. In the present study, we applied XRF techniques at a macro and micro level to carry out drug distribution studies on ex vivo models to confirm the hepatobiliary disposition of the Gd-based magnetic resonance imaging contrast agent B22956/1. 2. Gd presence was selectively quantified allowing the determination of the time dependent disappearance of the drug from blood and its hepatic accumulation in mice after administration. Elemental mapping highlighted the drug distribution differences between healthy and diseased livers. XRF microanalyses showed that in CCl4-induced hepatitis, B22956/1 has greatly reduced hepatic accumulation, shown as a 20-fold reduction of Gd presence. Furthermore, a significant increase of Fe presence was found in steatotic compared with healthy livers, in line with the disease features. 3. The present results show that XRF might be useful in preclinical pharmacological studies with drugs containing exogenous elements. Furthermore, quantitative and high-sensitivity elemental mapping allows simultaneous detection of chemical variation, showing pathological conditions. This approach was useful in suggesting reduced B22956/1 accumulation in steatotic livers, thus opening possible new diagnostic perspectives for this drug.

The effect of the concentration of cobalt ferrite (CoFe 2 O 4 ) nanoparticles (NPs) on their intracellular location and distribution has been explored by synchrotron radiation X-ray and fluorescence microscopy (SR-XRF) monitoring the evolution of NPs elemental composition as well. In cells exposed to low concentrations of CoFe 2 O 4 NPs, the NPs preferentially segregate in the perinuclear region preserving their initial chemical content. At concentrations exceeding 500 μM the XRF spectra indicate the presence of Co and Fe also in the nuclear region, accompanied by sensible changes in the cellular morphology. The increase of the Co/Fe ratio measured in the nuclear compartment indicates that above certain concentrations the CoFe 2 O 4 NPs intracellular distribution could be accompanied by biodegradation resulting in Co accumulation in the nucleus.

A series of physical characterization methods (UV fluorescence microscopy, X-ray microdiffraction, backscattered electron imaging and X-ray absorption spectroscopy) were applied to Polynesian pearls collected after different cultivation periods, varying from three weeks to eighteen months. Through this rigorous time-based sampling, 120 pearls produced by 20 different donor oysters were compared. Results show that the structure of the pearl layer can be understood as a sequence of distinct secretion processes whose progressive occurrence through time may lead to variously arranged and sometimes aberrant mineralized structures. By making comparisons with the structure and growth mode of the Pinctada margaritifera shell, this study shows that the currently accepted theory that views the pearl-bed as a "reversed shell" cannot account for the diversity of the microstructural patterns and mineralogical properties observed in the pearl layers. From a practical and economic view point, it appears that development of these pre-nacreous materials superposed onto a perfectly round-shaped nucleus is the main cause of shape irregularities in pearls and the consequent decrease in their value.

The efficiencies of several Fresnel zone plates, that were fabricated using a direct-write method with high-energy electrons, were measured over a wide range of photon energies., The fabrication and characterization of Fresnel zone plates (FZPs) for hard X-ray microscopy applications are reported. High-quality 500 nm- and 1 µm-thick Au FZPs with outermost zone widths down to 50 nm and 70 nm, respectively, and with diameters up to 600 µm were fabricated. The diffraction efficiencies of the fabricated FZPs were measured for a wide range of X-ray energies (2.8–13.2 keV) showing excellent values up to 65–75% of the theoretical values, reflecting the good quality of the FZPs. Spatially resolved diffraction efficiency measurements indicate the uniformity of the FZPs and a defect-free structure.

X-ray fluorescence (XRF) is rapidly becoming one of the tools of choice in tracing the presence of both endogenous and exogenous chemical elements in biological samples. The sub-micron spatial resolution routinely obtainable at multi-keV energies at third generation light sources, combined with the high brilliance of the photon beam, allows mapping the presence of biologically relevant elements at sub-cell resolution by means of their fluorescent signature. The fluorescent signal also lends itself for a semi-quantitative analysis of the elements composing the specimen. In this work we employed synchrotron-based XRF to analyze two lines of cultured Chang cells. One of them was treated with a Gd-containing magnetic resonance imaging (MRI) contrast agents (CA), and the other was left untreated for control purposes. The experiments highlighted a peri-nuclear distribution of Gd inside the cells, as well as a distinct variation in the distribution and concentration of several elements (P, S, Cl, K, Ca and Fe), with respect to the control line.

Many clinical circumstances impose the necessity of collection and prolonged storage of gametes and/or ovarian tissue in order to preserve the reproduction potential of subjects. This is particularly appropriate in the case of young women and pre-pubertal girls undergoing chemotherapeutic treatments. The success of later assisted fertilization will depend on the suitable cooling protocols minimizing cryo-damages and preserving their biological function. The freeze-thaw processes of cryopreservation may induce, in fact, morphological and structural damages of oocytes and tissue mainly due to the formation of intracellular ice and to the toxicity of cryoprotectant. The most used cryo-protocol is the slow freezing procedure, but recently many authors have proposed vitrification as an alternative, because of its simplicity. The damage extent and the quality of follicles after cryopreservation are usually evaluated morphologically by conventional histological procedures, light and electron microscopy. Our laboratory, to further improve the evaluation and to better investigate damages, is adopting a combination of Synchrotron soft X-ray Microscopy (at TwinMic – Elettra) and XRF at different incident energies (at TwinMic – Elettra and ID21 – ESRF). X-ray techniques were performed on histological sections at micro and sub-micron resolution. Phase contrast and absorption images revealed changes in the compactness of the tissues, as well as cellular abnormalities revealed at sub-micrometric resolution. The distributions of the elements detected at 7.3 and 1.5 keV were compared and particularly Cl resulted to be indicative of follicle integrity. The results demonstrate the utility and the potential of X-ray microscopy and fluorescence in this research field.

To test whether synchrotron-based spectromicroscopy can be used to identify spatial patterns of sulfur (S) and iron (Fe) speciation as well as relationships between the speciation of S and Fe in soil colloids or aggregates at the micrometre and sub-micrometre level, an anoxically prepared dissected soil aggregate (size approximately 1 mm(3)) was analyzed by micro-XANES at the K-edges of S (2472 eV) and Fe (7112 eV). The experiment included (i) elemental mapping at the S K-edge (S, Si, Al) and the Fe K-edge (Fe, Si), (ii) acquisition of 300 microm x 300 microm images of the region of interest with X-ray energies of 2474 eV (addressing reduced organic and inorganic S), 2483 eV (total S), 7121 eV (divalent Fe) and 7200 eV (total Fe), as well as (iii) acquisition of S and Fe micro-XANES spectra at two different positions, where image analysis suggested the dominance of reduced and oxidized S and Fe, respectively. Image analysis revealed a heterogeneous distribution of total Si, S and Fe as well as of different S and Fe species in the aggregate. Microregions which were either enriched in reduced or in oxidized S and Fe could be identified. A microregion with a large contribution of oxidized S (sulfate, sulfonate) to total S contained exclusively Fe(III) oxyhydroxides (probably ferrihydrite) as S-bearing phase, whereas another microregion with a large contribution of reduced organic S (thiol, organic disulfide) to total S contained a small amount of Fe(II)-bearing silicate in addition to the dominating Fe(III) oxyhydroxides. Our results show that combined S and Fe micro-XANES is a powerful tool for studying microscale spatial patterns of S and Fe speciation as well as microscale relationships between the speciation of S and Fe in soil aggregates.

International audience; The MoniDiam project is part of the French national collaboration CLaRyS (Contrôle en Ligne de l'hAdronthérapie par RaYonnements Secondaires) for on-line monitoring of hadron therapy. It relies on the imaging of nuclear reaction products that is related to the ion range. The goal here is to provide large area beam detectors with a high detection efficiency for carbon or proton beams giving time and position measurement at 100 MHz count rates (beam tagging hodoscope). High radiation hardness and intrinsic electronic properties make diamonds reliable and very fast detectors with a good signal to noise ratio. Commercial Chemical Vapor Deposited (CVD) poly-crystalline, heteroepitaxial and monocrystalline diamonds were studied. Their applicability as a particle detector was investigated using α and β radioactive sources, 95 MeV/u carbon ion beams at GANIL and 8.5 keV X-ray photon bunches from ESRF. This facility offers the unique capability of providing a focused (~1 µm) beam in bunches of 100 ps duration, with an almost uniform energy deposition in the irradiated detector volume, therefore mimicking the interaction of single ions. A signal rise time resolution ranging from 20 to 90 ps rms and an energy resolution of 7 to 9% were measured using diamonds with aluminum disk shaped surface metallization. This enabled us to conclude that polycrystalline CVD diamond detectors are good candidates for our beam tagging hodoscope development. Recently, double-side stripped metallized diamonds were tested using the XBIC (X Rays Beam Induced Current) setup of the ID21 beamline at ESRF which permits us to evaluate the capability of diamond to be used as position sensitive detector. The final detector will consist in a mosaic arrangement of double-side stripped diamond sensors read out by a dedicated fast-integrated electronics of several hundreds of channels. Index Terms— Synthetic diamond detectors, on-line monitoring of hadron therapy, charge collection efficiency, time resolution, integrated fast read out electronics