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Pichon L.,University Pierre and Marie Curie | Moignard B.,University Pierre and Marie Curie | Lemasson Q.,University Pierre and Marie Curie | Pacheco C.,University Pierre and Marie Curie | And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2014

The New AGLAE external beamline provides analytical data for the understanding of the structure of archaeological and artistic objects, their composition, properties, and changes over time. One of the objectives of this project is to design and set up a new non-invasive acquisition system increasing the quality of the X-ray spectra and reducing the beam current on sensitive materials from work of art. To that end, the surface and the number of PIXE detectors have been increased to implement a cluster of SDD detectors. This can also provide the possibility to accomplish large and/or fast maps on artifacts with a scanning of the beam on the sample. During the mapping, a multi-parameter system saves each event from X-ray, gamma and particle detectors, simultaneously with the X and Y positions of the beam on the sample. To process the data, different softwares have been developed or updated. A first example on a decorated medieval shard highlights the perspectives of the technique. © 2013 Elsevier Ltd. All rights reserved. Source


Mass J.L.,Scientific Research and Analysis Laboratory | Opila R.,University of Delaware | Buckley B.,Barnes Foundation | Cotte M.,European Synchrotron Radiation Facility | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2013

Evidence for the alteration of the yellow paints in Henri Matisse's Le Bonheur de vivre (1905-1906, The Barnes Foundation) has been observed since the 1990s. The changes in this iconic work of Matisse's Fauvist period include lightening, darkening, and flaking of the yellow paints. Handheld X-ray fluorescence (XRF) and multispectral imaging surveys reveal that the degradation is confined to cadmium yellow (CdS) paints. The discoloration of cadmium yellow paints in Impressionist, Post-Impressionist and early modernist work from the 1880s through the 1920s has been ascribed to the photo-oxidative degradation of CdS. Preliminary investigations of the degraded yellow paints in this work involved Cd LIII-edge X-ray Absorption Near Edge Spectroscopy (XANES) at the Stanford Synchrotron Radiation Light Source (SSRL Menlo Park, California) and Scanning Electron Microscopy-energy dispersive X-ray analysis (SEM-EDS) at the Winterthur Museum Scientific Research and Analysis Laboratory. To determine if the visual changes in the paints did in fact indicate photo-oxidative degradation and if different chemistries could be observed for the lightened versus darkened regions, synchrotron radiation-micro Fourier Transform InfraRed (SR-μFTIR) spectroscopy, X-ray Fluorescence (SR-μXRF) mapping and micro X-ray Absorption Near Edge Spectroscopy (μXANES) mapping at the Cd LIII-edge of the altered paint cross-sections were carried out at the European synchrotron radiation facility (ESRF, Grenoble, France) beamline ID-21. The goal is to elucidate the discoloration mechanisms observed in the paint using elemental and speciation mapping. The μXANES mapping and SR-FTIR imaging showed a substantial enrichment of CdCO3 in the off-white surface crust of the faded/discolored CdS paint. This suggests that the CdCO3 is present as an insoluble photodegradation product rather than solely a paint filler or starting reagent. Additionally, oxalates and sulfates were found to be concentrated at the alteration surface. © 2012 Springer-Verlag Berlin Heidelberg. Source


Lebon M.,French Natural History Museum | Zazzo A.,French Natural History Museum | Reiche I.,CNRS Laboratory of Molecular and Structural Archaeology | Reiche I.,Rathgen Research Laboratory
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2014

Bones and teeth are highly hierarchically structured and hererogeneous materials, and post mortem processes can reinforce this heterogeneity. It is therefore important to consider this heterogeneity to better understand diagenetic processes. In this study, ATR-FTIR mapping was applied to several heated and un-heated archaeological samples, and to similar modern references in order to test the potential of this method. ATR-FTIR mapping can provide spatially resolved information on alteration state of mineral and organic matter. This technique allowed to describe the spatial distribution of organic and mineral matter preservation in unheated Palaeolithic bones (Bize-Tournal, France) characterized by a better preservation in the centre of the cortical bone. Spatial variations in the chemical composition of an archaeological heated bone (Abri Pataud, France) compared to a modern reference suggested taphonomical uptake of carbonate in the most external part. This pattern could correspond to a process of re-carbonatation of the calcined mineral matter in the outermost part of the sample due to combustion in a CO2 rich atmosphere. FTIR-ATR is a powerful tool that allows for identifying and characterizing local heterogeneities in bone preservation. This technique open new prospects to reconstruct the taphonomical history of ancient samples. © 2014 Elsevier B.V. Source


Benseny-Cases N.,European Synchrotron Radiation Facility | Benseny-Cases N.,University of Leeds | Klementieva O.,University of Barcelona | Klementieva O.,CIBER ISCIII | And 6 more authors.
Analytical Chemistry | Year: 2014

(Figure Presented) Amyloid peptides are the main component of one of the characteristic pathological hallmarks of Alzheimer's disease (AD): senile plaques. According to the amyloid cascade hypothesis, amyloid peptides may play a central role in the sequence of events that leads to neurodegeneration. However, there are other factors, such as oxidative stress, that may be crucial for the development of the disease. In the present paper, we show that it is possible, by using Fourier tranform infrared (FTIR) microscopy, to co-localize amyloid deposits and lipid peroxidation in tissue slides from patients affected by Alzheimer' s disease. Plaques and lipids can be analyzed in the same sample, making use of the characteristic infrared bands for peptide aggregation and lipid oxidation. The results show that, in samples from patients diagnosed with AD, the plaques and their immediate surroundings are always characterized by the presence of oxidized lipids. As for samples from non-AD individuals, those without amyloid plaques show a lower level of lipid oxidation than AD individuals. However, it is known that plaques can be detected in the brains of some non-AD individuals. Our results show that, in such cases, the lipid in the plaques and their surroundings display oxidation levels that are similar to those of tissues with no plaques. These results point to lipid oxidation as a possible key factor in the path that goes from showing the typical neurophatological hallmarks to suffering from dementia. In this process, the oxidative power of the amyloid peptide, possibly in the form of nonfibrillar aggregates, could play a central role. © 2014 American Chemical Society. Source


Buleon A.,French National Institute for Agricultural Research | Cotte M.,European Synchrotron Radiation Facility | Cotte M.,CNRS Laboratory of Molecular and Structural Archaeology | Putaux J.-L.,French National Center for Scientific Research | And 2 more authors.
Biochimica et Biophysica Acta - General Subjects | Year: 2014

Background Native starch accumulates as granules containing two glucose polymers: amylose and amylopectin. Phosphate (0.2-0.5%) and proteins (0.1-0.7%) are also present in some starches. Phosphate groups play a major role in starch metabolism while granule-bound starch synthase 1 (GBSS1) which represents up to 95% of the proteins bound to the granule is responsible for amylose biosynthesis. Methods Synchrotron micro-X-ray fluorescence (μXRF) was used for the first time for high-resolution mapping of GBSS1 and phosphate groups based on the XRF signal of sulfur (S) and phosphorus (P), respectively. Wild-type starches were studied as well as their related mutants lacking GBSS1 or starch-phosphorylating enzyme. Results Wild-type potato and maize starch exhibited high level of phosphorylation and high content of sulfur respectively when compared to mutant potato starch lacking glucan water dikinase (GWD) and mutant maize starch lacking GBSS1. Phosphate groups are mostly present at the periphery of wild-type potato starch granules, and spread all over the granule in the amylose-free mutant. P and S XRF were also measured within single small starch granules from Arabidopsis or Chlamydomonas not exceeding 3-5 μm in diameter. Conclusions Imaging GBSS1 (by S mapping) in potato starch sections showed that the antisense technique suppresses the expression of GBSS1 during biosynthesis. P mapping confirmed that amylose is mostly present in the center of the granule, which had been suggested before. General significance μXRF is a potentially powerful technique to analyze the minor constituents of starch and understand starch structure/properties or biosynthesis by the use of selected genetic backgrounds. © 2013 Elsevier B.V. Source

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