Abstract Food-grade titanium dioxide (TiO 2 ) containing a nanoscale particle fraction (TiO 2 -NPs) is approved as a white pigment (E171 in Europe) in common foodstuffs, including confectionary. ...There are growing concerns that daily oral TiO 2 -NP intake is associated with an increased risk of chronic intestinal inflammation and carcinogenesis. In rats orally exposed for one week to E171 at human relevant levels, titanium was detected in the immune cells of Peyer’s patches (PP) as observed with the TiO 2 -NP model NM-105. Dendritic cell frequency increased in PP regardless of the TiO 2 treatment, while regulatory T cells involved in dampening inflammatory responses decreased with E171 only, an effect still observed after 100 days of treatment. In all TiO 2 -treated rats, stimulation of immune cells isolated from PP showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased. E171 or NM-105 for one week did not initiate intestinal inflammation, while a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model. These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO 2 from dietary sources.
Skin reactions are well described complications of tattooing, usually provoked by red inks. Chemical characterizations of these inks are usually based on limited subjects and techniques. This study ...aimed to determine the organic and inorganic composition of inks using X‐ray fluorescence spectroscopy (XRF), X‐ray absorption spectroscopy (XANES) and Raman spectroscopy, in a cohort of patients with cutaneous hypersensitivity reactions to tattoo. A retrospective multicenter study was performed, including 15 patients diagnosed with skin reactions to tattoos. Almost half of these patients developed skin reactions on black inks. XRF identified known allergenic metals – titanium, chromium, manganese, nickel and copper – in almost all cases. XANES spectroscopy distinguished zinc and iron present in ink from these elements in endogenous biomolecules. Raman spectroscopy showed the presence of both reported (azo pigments, quinacridone) and unreported (carbon black, phtalocyanine) putative organic sensitizer compounds, and also defined the phase in which Ti was engaged. To the best of the authors' knowledge, this paper reports the largest cohort of skin hypersensitivity reactions analyzed by multiple complementary techniques. With almost half the patients presenting skin reaction on black tattoo, the study suggests that black modern inks should also be considered to provoke skin reactions, probably because of the common association of carbon black with potential allergenic metals within these inks. Analysis of more skin reactions to tattoos is needed to identify the relevant chemical compounds and help render tattoo ink composition safer.
Using X‐ray fluorescence spectroscopy, X‐ray absorption spectroscopy and Raman spectroscopy, the chemical composition of inks was analyzed in a cohort of patients with cutaneous hypersensitivity reactions to tattoo. Known inorganic allergenic metals (titanium, chromium, manganese, nickel and copper) were identified in almost all cases as well as azo pigments, quinacridone, carbon black and phthalocyanine.
Coleoidea (squids and octopuses) comprise all crown group cephalopods except the Nautilida. Coleoids are characterized by internal shell (endocochleate), ink sac and arm hooks, while nautilids lack ...an ink sac, arm hooks, suckers, and have an external conch (ectocochleate). Differentiating between straight conical conchs (orthocones) of Palaeozoic Coleoidea and other ectocochleates is only possible when rostrum (shell covering the chambered phragmocone) and body chamber are preserved. Here, we provide information on how this internalization might have evolved. We re-examined one of the oldest coleoids,
from the Early Carboniferous of the Bear Gulch Fossil-Lagerstätte (Montana) by synchrotron, various lights and Reflectance Transformation Imaging (RTI). This revealed previously unappreciated anatomical details, on which we base evolutionary scenarios of how the internalization and other evolutionary steps in early coleoid evolution proceeded. We suggest that conch internalization happened rather suddenly including early growth stages while the ink sac evolved slightly later.
Various applications benefit from the use of compounds combining lanthanides and 3d metals because of their fundamental physicochemical properties. To tune compositions for dedicated applications and ...to overcome the criticality of raw materials or geopolitical tension, a better understanding of the binary, ternary and even quaternary systems is needed. The present work focuses on the ternary Mn-Ni-Sm system, which is particularly interesting for energy storage applications as it forms hydrogen absorbing intermetallic compounds. The fruitful combination of standard X-ray diffraction, anomalous X-ray diffraction close to the Mn 3d edge, X-ray absorption near edge structure, electron probe micro-analysis and first-principles calculations provides a better understanding of the physicochemical properties and phase equilibrium of this ternary system. In particular, the atomic substitution of Mn atoms in the Ni sites has been investigated for the stacking AB2/AB5 Sm2MnyNi7-y system. The Mn atoms substitute preferentially in the AB5 sub-units, whereas Sm vacancies are observed in the AB2 sub-units inducing an antagonist variation in cell volume units. In the SmMnyNi12-y system, the preferential localization of Mn atoms has been highlighted in site 8i for the SmMn4Ni8 compound.
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•Experiments and first-principles calculations combination to study Mn-Ni-Sm system.•Localization of Mn atoms through anomalous diffusion under synchrotron radiation.•Linear correlation between Sm sub-occupancy and Mn substitution for Sm2MnyNi7-y stacking alloys.
Anglesite (PbSO
4
) is a lead sulfate that belongs to the barite group and is naturally ubiquitous in the environment. This work describes a simple way to synthesize crystalline lead sulfate by using ...a straightforward hydrothermal procedure. Typically, Pb(NO
3
)
2
and Fe
2
(SO
4
)
3
precursors were mixed and heated at 94 °C for 24 h. The synthesized samples have been characterized by coupling X-Ray diffraction (XRD) to spectroscopic methods (FTIR and micro-Raman), X-ray absorption spectroscopy (XAS), and electronic microscopy (SEM and TEM). In fine, the results about this new well crystalline synthetic anglesite confirm the efficiency and the importance of this cheap protocol and the synthesized phases obtained. Moreover, the environmental stability and bioaccessibility of anglesite have been done to evaluate environmental stability of anglesite under various physico-chemical conditions and sanitary risks. Finally, the paper allows to obtain precise data on a pure phase in order to be able to more easily evaluate and understand the role of anglesite in as-polluted sites and soils.
Fossils, including those that occasionally preserve decay-prone soft tissues, are mostly made of minerals. Accessing their chemical composition provides unique insight into their past biology and/or ...the mechanisms by which they preserve, leading to a series of developments in chemical and elemental imaging. However, the mineral composition of fossils, particularly where soft tissues are preserved, is often only inferred indirectly from elemental data, while X-ray diffraction that specifically provides phase identification received little attention. Here, we show the use of synchrotron radiation to generate not only X-ray fluorescence elemental maps of a fossil, but also mineralogical maps in transmission geometry using a two-dimensional area detector placed behind the fossil. This innovative approach was applied to millimetre-thick cross-sections prepared through three-dimensionally preserved fossils, as well as to compressed fossils. It identifies and maps mineral phases and their distribution at the microscale over centimetre-sized areas, benefitting from the elemental information collected synchronously, and further informs on texture (preferential orientation), crystallite size and local strain. Probing such crystallographic information is instrumental in defining mineralization sequences, reconstructing the fossilization environment and constraining preservation biases. Similarly, this approach could potentially provide new knowledge on other (bio)mineralization processes in environmental sciences. We also illustrate that mineralogical contrasts between fossil tissues and/or the encasing sedimentary matrix can be used to visualize hidden anatomies in fossils.
One of the challenges of all synchrotron facilities is to offer the highest performance detectors for all their specific experiments, in particular for X‐ray diffraction imaging and its high ...throughput data collection. In that context, the DiffAbs beamline, the Detectors and the Design and Engineering groups at Synchrotron SOLEIL, in collaboration with ImXPAD and Cegitek companies, have developed an original and unique detector with a circular shape. This detector is based on the hybrid pixel photon‐counting technology and consists of the specific assembly of 20 hybrid pixel array detector (XPAD) modules. This article aims to demonstrate the main characteristics of the CirPAD (for Circular Pixel Array Detector) and its performance – i.e. excellent pixel quality, flat‐field correction, high‐count‐rate performance, etc. Additionally, the powder X‐ray diffraction pattern of an LaB6 reference sample is presented and refined. The obtained results demonstrate the high quality of the data recorded from the CirPAD, which allows the proposal of its use to all scientific communities interested in performing experiments at the DiffAbs beamline.
The DiffAbs beamline, the Detectors and the Design and Engineering groups at Synchrotron SOLEIL, in collaboration with ImXPAD and Cegitek companies, have developed an original and unique detector with a circular shape. This detector is based on the hybrid pixel photon‐counting technology and consists of the specific assembly of 20 hybrid pixel array detector (XPAD) modules.
High-flux synchrotron techniques allow microspectroscopic analyses of artworks that were not feasible even a few years ago, allowing for a more detailed characterization of their constituent ...materials and a better understanding of their chemistry. However, interaction between high-flux photons and matter at the sub-microscale can generate damages which are not visually detectable. We show here different methodologies allowing to evidence the damages induced by microscopic X-ray absorption near-edge structure spectroscopy analysis (
μ
XANES) at the Fe and Zn K-edges of a painting dating from the turn of the twentieth century containing Prussian blue and zinc white. No significant degradation of the pigments was noticed, in agreement with the excellent condition of the painting. However, synchrotron radiation damages occurred at several levels, from chemical changes of the binder, modification of crystal defects in zinc oxide, to Prussian blue photoreduction. They could be identified by using both the
μ
XANES signal during analysis and with photoluminescence imaging in the deep ultraviolet and visible ranges after analysis. We show that recording accurately damaged areas is a key step to prevent misinterpretation of results during future re-examination of the sample. We conclude by proposing good practices that could help in integrating radiation damage avoidance into the analytical pathway.
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