Barbara Fayard

• PhD
• CEO at NOVITOM

Looting and plough damage to the eighth–fifth centuries BC tumulus of Creney-le-Paradis, France, hinders interpretation of this potentially significant site. Nevertheless, application of novel microtomographic techniques in combination with optical and scanning electron microscopy allows the first detailed examination of 99 textile fragments recove...

The correlations between the electrical behavior and microstructural properties of samples consisting of particle composites fabricated from SiC particles embedded in a silicone matrix, were investigated using X-ray computed tomography. In the voltage field range 200-1000 V/mm, the measured conductivity as a function of SiC volume fraction exhibits...

The development of digital tools exploiting computed tomography (CT) data intelligently, in their entirety and in a simple manner is a major challenge for the full deployment of this technology in industrial production control environment. This work aims at developing a pipeline able to detect material discontinuities in metallic parts, in an autom...

Analyzing data obtained from X-ray CT acquisitions may be challenging due to the presence of image artifacts. In recent years, deep learning has proven to be one of the fastest growing technologies in computer science and has become a confirmed trend in X-ray CT. In this study, we propose using deep learning-based algorithm to reduce noise and ring...

Novi-Sim is an X-ray tomography simulation software that models the attenuation contrast and scattered radiation in laboratory imaging systems, as well as phase contrast in systems with coherent X-ray sources, such as synchrotrons. It simulates multiple X-ray sources, including but not limited to X-ray reflexion and transmission tubes, as well as t...

Archaeological textile remains from Antiquity are rare due to their perishable nature. In certain cases, the conservation of the morphology and / or of chemical signatures can be exquisite. Detailed archaeological information on the social and cultural life of past societies, such as on funerary practices, can then be deduced from their study. In t...

White-matter injury leads to severe functional loss in many neurological diseases. Myelin staining on histological samples is the most common technique to investigate white-matter fibers. However, tissue processing and sectioning may affect the reliability of 3D volumetric assessments. The purpose of this study was to propose an approach that enabl...

This contribution tries to indicate to the clinician what kind of information can be investigated through X-ray fluorescence, what kind of information can be extracted from this spectroscopy and finally how it competes with other tools described in previous publications such as Fourier Transform Infrared or Raman spectroscopy, X-ray Absorption Near...

White-matter injury leads to severe functional loss in many neurological diseases. Myelin staining on histological samples is the most common technique to investigate white-matter fibers. However, tissue processing and sectioning may affect the reliability of 3D volumetric assessments. The purpose of this study was to propose an approach that enabl...

X-ray phase contrast imaging can provide improved or complementary information to traditional attenuation-based X-ray imaging, making the field a vast and rapidly evolving research subject. X-ray Speckle Based Imaging (SBI) is one phase-contrast imaging approach that has shown high potential in providing both high sensitivity and high resolution wh...

X-ray Phase Contrast Imaging (PCI) is an emerging modality whose availability in clinics for mammography and lung imaging is expected to materialize within the coming years. In this study, we evaluate the PCI Computed Tomography (PCI-CT) performances with respect to current conventional imaging modalities in the context of osteo-articular disorders...

This work aims to study the mechanisms of oxygen bubble formation coming from redox reaction of a polyvalent element incorporated in a glass melt. Borosilicate glass composition is selected for its use as a glass matrix for nuclear waste conditioning. Cerium is selected as a polyvalent element as it may be found in nuclear waste. The chosen materia...

Human vocal folds possess outstanding abilities to endure large, reversible deformations and to vibrate up to more than thousand cycles per second. This unique performance mainly results from their complex specific 3D and multiscale structure, which is very difficult to investigate experimentally and still presents challenges using either confocal...

Performance of X-Ray Speckle Tracking Phase Retrieval Algorithms Towards a Dose Improvement - Volume 24 Supplement - Helene Labriet, Emmanuel Brun, Barbara Fayard, Sylvain Bohic, Sébastien Berujon

Objectif Les propriétés vibromécaniques remarquables du pli vocal, mal comprises à ce jour, sont liées à sa structure multicouches et à l’architecture de ses réseaux fibreux [1]. La caractérisation 3D de chaque élément constitutif aux échelles micrométriques est un challenge en microscopie confocale (profondeur de champ limitée), en micro-IRM (réso...

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 e...

High-resolution X-ray microtomography was used to get deeper insight into the underlying mass transport mechanisms controlling drug release from coated pellets. Sugar starter cores were layered with propranolol HCl and subsequently coated with Kollicoat SR, plasticized with 10% TEC. Importantly, synchrotron X-ray computed microtomography (SR-μCT) a...

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 decorati...

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 disease conditions and for different tissue maturation stages. We observe that the dominating spectral differences originating from different tissu...

Nanotechnology is the new industrial revolution of our century. Its development leads to an increasing use of nanoparticles and thus to their dissemination. Their fate in the environment is of great concern and especially their possible transfer in trophic chains might be an issue for food safety. However, so far our knowledge on this topic has bee...

Synchrotron Radiation (SR) - based techniques such as SR-μ Fourier Transform InfraRed (FTIR) spectroscopy, SR-μ X-Ray Fluorescence (XRF), SR-μ X-Ray Absorption Near Edge Spectroscopy (XANES) and SR-μ X-Ray Diffraction (XRD) are increasingly used for the study of cultural heritage materials, as they offer enhanced spatial resolution and chemical sen...

The chemical and physical alterations of cadmium yellow (CdS) paints in Henri Matisse’s The Joy of Life (1905–1906, The Barnes Foundation) have been recognized since 2006, when a survey by portable X-ray fluorescence identified this pigment in all altered regions of the monumental painting. This alteration is visible as fading, discoloration, chalkin...

Background: Although major concerns exist regarding the potential consequences of human exposure to nanoparticles (NP), no human toxicological data is currently available. To address this issue, we took welders, who present various adverse respiratory outcomes, as a model population of occupational exposure to NP.The aim of this study was to evalu...

TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE)...

Environmental context Speleothem chemical records are used to reconstruct environmental change on a broad range of timescales. However, one of the biggest challenges is to link the records contained within speleothems at the sub-annual timescale to changing meteorological conditions. Seasonal infiltration patterns and cave ventilation dynamics are...

Abstract We assessed the biodistribution and in situ speciation of sub-lethal concentrations of citrate-coated silver nanoparticles and dissolved silver within Fundulus heteroclitus embryos. Using a thorough physico-chemical characterization, we studied the role of salinity on both uptake and in situ speciation. The Ag uptake or adsorption on the c...

Roman black gloss ceramics from two different locations and separated by 50–80 years were investigated by X-ray absorption near edge structure analysis in full field hard X-ray transmission microscopes. These spectro-microscopy measurements were complemented by Raman spectroscopy, and X-ray diffraction spot analyses to gain insights into possible d...

Carbon nanotubes (CNT) are a family of materials featuring a large range of length, diameter, numbers of walls and, quite often metallic impurities coming from the catalyst used for their synthesis. They exhibit unique physical properties, which have already led to an extensive development of CNT for numerous applications. Because of this developme...

Curing is generally required to stabilize film coating from aqueous polymer dispersion. This post-coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the coating equipment stands for an attractive industrial application. Recen...

The ID21 Scanning X-ray Microscope (SXM) is optimized for micro-spectroscopy with submicron resolution in the 2 to 9.5 keV energy range. After a brief description of the microscope setup, we present here recent developments, in particular, the latest version of the compact Wavelength Dispersive Spectrometer and the refurbished cryo-stage.

A new X-ray absorption near-edge spectroscopy (XANES) full-field imaging station has been developed, installed and tested on beamline ID21 at the European Synchrotron Radiation Facility (ESRF). The set-up operates in the 2-9 keV energy range and allows for the simultaneous acquisition of up to 4.106 XANES spectra over large sample areas with preser...

Micro-beam x-ray absorption fine structure spectroscopy was used to investigate rutile TiO2 nanoparticles internalized into gastrointestinal cells during their crossing of a gut model barrier. Nanoparticles diluted in culture medium tend to accumulate in cells after 48 h exposure; however, no spectral differences arise between particles in cellular...

Very little is known about the sub-cellular distribution of metal ions in cells. Some metals such as zinc, copper and iron are essential and play an important role in the cell metabolism. Dysfunctions in this delicate housekeeping may be at the origin of major diseases. There is also a prevalent use of metals in a wide range of diagnostic agents an...

Amyloidoses are increasingly recognized as a major public health concern in Western countries. All amyloidoses share common morphological, structural, and tinctorial properties. These consist of staining by specific dyes, a fibrillar aspect in electron microscopy and a typical cross-β folding in x-ray diffraction patterns. Most studies that aim at...

Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium d...

Nanoparticles (NPs) are introduced in a growing number of commercial products, including food and beverage but their effects on gastrointestinal tract are poorly investigated. Here we focused on the translocation of TiO2 NPs through Caco-2 monolayers exposed to anatase and rutile NPs up to 24 h. Internalization was followed by transmission electron...

Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium d...

X-ray fluorescence (XRF) microscopy features unique capabilities which make it well suited for biological investigations. Its high sensitivity together with high spatial resolution and penetration depth provide a unique tool for trace elements analysis in heterogeneous samples. Like most of the X-ray based techniques, radiation damage sets hard lim...

Cadmium (Cd) is a metal of high toxicity for plants. Resolving its distribution and speciation in plants is essential for understanding the mechanisms involved in Cd tolerance, trafficking and accumulation. The model plant Arabidopsis thaliana was exposed to cadmium under controlled conditions. Elemental distributions in the roots and in the leaves...

The incorporation and localisation of 133Cs in a plant cellular model and the metabolic response induced were analysed as a function of external K concentration using a multidisciplinary approach. Sucrose-fed photosynthetic Arabidopsis thaliana suspension cells, grown in a K-containing or K-depleted medium, were submitted to a 1 mM Cs stress. Cell...

Cesium as an alkali element exhibits a chemical reactivity similar to that of potassium, an essential element for plants. It has been suggested that Cs phytotoxicity might be due either to its competition with potassium to enter the plant, resulting in K starvation, or to its intracellular competition with K binding sites in cells. Such elemental i...

This paper describes the opportunities given by the synchrotron radiation techniques regarding the structural characterisation of biological enti-ties. After a short recall on the characteristics of the synchrotron radiation, are described the experimental devices based on fluorescence X, wide angle X-ray scattering and X-ray absorption spectroscopy...

The soluble protein Ure2p from the yeast Saccharomyces cerevisiae assembles in vitro into straight and insoluble protein fibrils, through subtle changes of conformation. Whereas the structure of soluble Ure2p has been revealed by X-ray crystallography, further characterization of the structure of insoluble Ure2p fibrils is needed. We performed X-ra...

This paper describes the opportunities given by the synchrotron radiation techniques regarding the structural characterisation of biological entities. After a short recall on the characteristics of the synchrotron radiation, are described the experimental devices based on fluorescence X, wide angle X-ray scattering and X-ray absorption spectroscopy...

The development of high brilliance high energy X-ray sources coupled with advances in manufacturing technologies of focus-ing optics has led to significant improvements in sub-micrometer probes for spectroscopy, diffraction and imaging applications in the multi-keV 'hard' X-ray range. Both by extrapolation of the experience gained in the soft X-ray...

Hexavalent chromium compounds are known carcinogens for the respiratory tract in humans. The mechanism of cell transformation by hexavalent chromium compounds is not fully understood although a role for intracellular reduction is sought. The aim of this study was to determine the distribution of Cr valence states in human cells after in vitro expos...

Among the 40 beamlines in operation at the European Synchrotron Radiation Facility, three beamlines are fully dedicated to X-ray microscopy and micro-spectroscopy techniques in the multi-keV range. Offering a unique combination of non destructive analytical techniques which aim to satisfy the growing demand from experimental research fields such as...

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To study the frequency of chromosome aberrations induced by soft X-rays. To see if the core ionization of DNA atoms is involved in this end-point as much as it appears to be in cell killing. V79 hamster cells were irradiated by synchrotron radiation photons iso-attenuated in the cell (250, 350, 810eV). The morphological chromosome aberrations detec...

X-ray microscopy microscope installed at the beam line ID21 at European Synchrotron Radiation Facility (ESRF) was used for the elucidation of micro-distribution of vanadium in ascidians. In order to examine chemical states of vanadium in the alive blood cell, a high pressure cryo-fixation technique was applied to fix its chemical states of vanadium...

Hexavalent chromium compounds are established carcinogens but their mechanism of cell transformation has not been elucidated yet. In this study, chromium oxidation state distribution maps in cells exposed to soluble (Na2CrO4), or insoluble (PbCrO4), Cr(VI) compounds have been obtained by use of the ESRF ID-21 X-ray microscope. In addition, the quan...

Transthyretin (TTR) amyloid fibrils are the main component of the amyloid deposits occurring in Familial Amyloidotic Polyneuropathy patients. This is 1 of 20 human proteins leading to protein aggregation disorders such as Alzheimer's and Creutzfeldt-Jakob diseases. The structural details concerning the association of the protein molecules are essen...

Blood cells of ascidians (tunicates) are known to accumulate high levels of vanadium selectively from sea water [1]. It has long been extensively studied how much vanadium is accumulated, which organ participate in the accumulation of vanadium, and what is the route of vanadium accumulation. However, they are not yet revealed completely. Micro-XANE...

The widespread use of chromium in industrial applications such as chemical production of pigments, refractory brick production, tanning, metallurgy, electroplating, and combustion of fuels has lead to human occupational exposure and to its increased introduction into the environment. Hexavalent chromium compounds are established carcinogens but the...

We describe a novel approach for converting the specimens phase information into strong image contrast in the x-ray region, the differential interference contrast x-ray microscopy (X-DIC). In the used setup, X-DIC operation was accomplished by a twin zone plate (TZP), i.e. two zone plates on both sides of the same substrate, laterally shifted by ab...

New information about calcium status in human scalp hair shaft, deduced from X-ray microfluorescence imaging, including its distribution over the hair section, the existence of one or several binding-types and its variation between people, is presented. The existence of two different calcium types is inferred. The first one corresponds to atoms (or...

New information about calcium status in human scalp hair shaft, deduced from X-ray micro-fluorescence imaging, including its distribution over the hair section, the existence of one or several binding-types and its variation between people, is presented. The existence of two different calcium types is inferred. The first one corresponds to atoms (o...

This paper presents some radiobiology experiments which have enlightened physical events initiating essential biological end points and describes some typical models which have been developed over the last forty years. The likely major role played by core ionizations of DNA atoms is revealed.

X-ray imaging in differential interference contrast (DIC) with submicrometer optical resolution was performed by using a twin zone plate (TZP) setup generating focal spots closely spaced within the TZP spatial resolution of 160 nm. Optical path differences introduced by the sample are recorded by a CCD camera in a standard full-field imaging and by...

The large RBE (approximately 7) measured for the killing of Chinese hamster V79 cells by 340 eV ultrasoft X rays, which preferentially ionize the K shell of carbon atoms (Hervé du Penhoat et al., Radiat. Res. 151, 649-658, 1999), was used to investigate the location of sensitive sites for cell inactivation and the physical modes of action of radiat...

In order to assess the lethal efficiency and other biological effects of inner shell ionisations of constituent atoms of DNA ('K' events), experiments were developed at the LURE synchrotron facility using ultrasoft X rays as a probe of K events. The lethal efficiency of ultrasoft X rays above the carbon K threshold was especially investigated using...

Some ascidians (sea squirts) accumulate the transitional metal vanadium in their blood cells at concentrations of up to 350 mM, about 10(7) times its concentration found in seawater. There are approximately 10 different types of blood cell in ascidians. The identity of the true vanadium-containing blood cell (vanadocyte) is controversial and little...

The development of high brilliance X-ray sources coupled with advances in manufacturing technologies of focusing optics has led to significant improvements in submicrometer probes for spectroscopy, diffraction and imaging applications. For instance, X-ray microscopy in the 1-10 keV energy range is better-suited for analyzing trace elements in fluor...

Transthyretin (TTR) amyloidosis results from the self‒association of TTR leading to insoluble deposits that occur at the extra cellular level. Sulphur K‒edge XANES spectroscopy was used to determine the sulphur oxidation state in transtyretin present in amyloid fibrils. These data is discussed in relation to molecular mechanisms involved in amyloid...

Resume : L'hypothese d'un role biologique important des evenements d'ionisation en couche interne ("K") de l'ADN est examinee. En ce qui concerne la mort cellulaire, ce role est confirme par des mesures d'efficacite letale des evenements "K" utilisant les rayons X ultra-mous comme sonde. En outre la mise en evidence d'une correlation entre mort cel...

A direct in-situ visualization of montmorillonite gels at 50 g/L has been obtained for the first time, using silicon fluorescence yield imaging at the ESRF ID21 X-ray microscopy line. An unexpected superstructure formed by alternating clay-rich and clay-poor domains was evidenced with mesoscopic orientational order. The order and size of the orient...

To test a possible specific effect of carbon K-shell ionizations in DNA, survival curves for Chinese hamster V79 cells were measured for X irradiations at energies below and above the carbon K-shell ionization threshold. Specific values of the X-ray energies (250 and 340 eV) were chosen to ensure isoattenuation of the two kinds of radiation within...

In order to understand the underlying mechanisms of heavy ion interactions with biological targets, we have developed a scoring program which enumerates the ionization clusters in nanometrical volumes such as nucleosomes. This cluster model was first suggested by Goodhead et al. to explain the important role of low energy electrons in the cellular...

In order to investigate the molecular consequences of a carbon K photo-ionization located on DNA, dry pBS plasmid samples were irradiated with ultra-soft X-rays at energies below and above the carbon K-threshold (${\rm E}_K=278$ eV). Single- and double-strand breaks (ssb and dsb) were quantified after resolution of the three plasmid forms (supercoi...

The biological action of swift ions decreases for increasing stopping power (LET), and the loss of eciency is particularly high for heavy ions when the LET reaches its maximum value. In one of the models developed in the literature to account for this behavior, the biological action of light ions (and X rays) is attributed to clusters of energy de...

Initial steps of radiation action mechanism on biological targets are still undnown. The strong correlation observed between inactivation cross sections by heavy ions and K-vacancy production cross sections has drawn the attention on this process. Although quite minor in the energy deposition of these particles, the K-ionization process gives rise...

First biological models of radiation action were based on the average energy deposited in the cell nucleus. Later theories have stressed the importance of the energy deposition at the nanometer level. Clusters of ionizations generated by K-electron removal seem to be a highly efficient mechanism for the induction of cell inactivation by heavy ions....

The complexity and heterogeneity of artistic materials make their chemical characterization uneasy. Micro-imaging techniques are commonly applied to attain full 2D descriptions of fragments cross-sections. At the European Synchrotron Radiation Facility (ESRF), Grenoble, France, the ID21 beamline is primarily designed for scanning X-ray microscopy....