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Finite-element analysis is used to study the thermal deformation of a multilayer mirror due to the heat load from the undulator beam at a low-emittance synchrotron source, specifically the ESRF-EBS upgrade beamline EBSL-2. The energy bandwidth of the double-multilayer monochromator is larger than that of the relevant undulator harmonic, such that a considerable portion of the heat load is reflected. Consequently, the absorbed power is non-uniformly distributed on the surface. The geometry of the multilayer substrate is optimized to minimize thermally induced slope errors. We distinguish between thermal bending with constant curvature that leads to astigmatic focusing or defocusing and residual slope errors. For the EBSL-2 system with grazing angles θ between 0.2 and 0.4°, meridional and sagittal focal lengths down to 100 m and 2000 m, respectively, are found. Whereas the thermal bending can be tuned by varying the depth of the `smart cut', it is found that the geometry has little effect on the residual slope errors. In both planes they are 0.1–0.25 µrad. In the sagittal direction, however, the effect on the beam is drastically reduced by the `foregiveness factor', sin(θ). Optimization without considering the reflected heat load yields an incorrect depth of the `smart cut'. The resulting meridional curvature in turn leads to parasitic focal lengths of the order of 100 m.

Amyloid plaques are one of the principal hallmarks of Alzheimer's disease and are mainly composed of Aβ amyloid peptides together with other components such as lipids, cations, or glycosaminoglycans. The structure of amyloid peptide's aggregates is related to the peptide toxicity and highly depends on the aggregation conditions and the presence of cofactors. While fibrillary aggregates are nowadays considered nontoxic, oligomeric/granular (nonfibrillary) aggregates have been found to be toxic. In this work we have characterized in situ two different types of amyloid deposits analyzing sections of the cortex of patients in advanced stages of Alzheimer disease. By combining SR-μFTIR for the study of the secondary structure of the peptide and ThS fluorescence as an indicator of fibrillary structures, we found two types of plaques: ThS positive plaques with a clear infrared band at 1630 cm-1 that would correspond to fibrillary plaques and ThS negative plaques showing a mixture of nonfibrillar β-sheet and unordered aggregated structures that would correspond to the nonfibrillary plaques (plaques with increased unordered structure). The analysis of the FTIR spectra has allowed correlation of lipid oxidation with the presence of nonfibrillary plaques. The metal composition of the two types of plaques has been analyzed using SR-nano-XRF and XANES. The results have shown higher accumulation of iron (mainly Fe2+) in fibrillary plaques than in nonfibrillary ones. However, in nonfibrillary plaques Fe3+ has been found to predominate over Fe2+. The identification of different types of aggregated forms and the different composition of metals found in the different types of plaques could be of paramount importance for the understanding of the development of Alzheimer disease.

The increasing number of patents suggests that the use of nanoparticles (NPs) in agriculture will continue to grow in the future. Properties associated with nanosized objects might be desirable, but may pose a threat to the environment since the fate of nanomaterials is poorly understood. Seed treatment is an extensive practice to provide micronutrients and disease protection. This study investigates the effect of Ag2S NPs, Ag0 NPs, and AgNO3 (1, 100, and 1000 mg Ag per L) on the germination of Phaseolus vulgaris seeds and the mechanism of interaction in the seed coat. Ag treatments did not affect the germination rate. On the other hand, the development of seedlings was significantly improved by Ag2S NPs while AgNO3 showed a negative effect compared to the control (water). Silver from different sources was accumulated and biotransformed along the seed coat. Ag from the AgNO3 treatment was found as AgCl and bound to oxygen, and Ag0 NPs underwent oxidative dissolution forming thiolate complexes. On the other hand, Ag2S NPs did not show any detectable chemical changes. Silver distribution and speciation were investigated in the bean testa using μ-XRF and μ-XANES, while the macromolecular composition was assessed by ATR-FTIR. The Ag biotransformation depended on the source. For the FTIR results, it is possible to verify perturbations in the carbohydrate region as well as changes in the protein region. The combination of these results can contribute to building another step in the understanding of how nanoparticles can improve agricultural inputs and benefit food crops.

We simulate the focusing of a partially-coherent X-ray beam emitted by an undulator in a fourth-generation storage ring performing coherent mode decomposition and wave optics propagation. The focus position is shifted, and its size is enlarged when an entrance slit crops the beam. This is the usual case when a slit is used to select the coherent fraction. The pairing of two focusing elements (mirrors, lenses or transfocators) to ensure a fixed focal position is also analyzed. Our results show that the image of a partially coherent source, such an undulator in a low-emittance storage ring, is a non-trivial function of the aperture used to control the coherence fraction., Comment: 4 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:2110.05957

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International audience; Carbon nanotubes (CNTs) and titanium dioxide nanoparticles (TiO2-NPs) are among the most used nanomaterials (NMs). However, their impacts especially on the terrestrial ecosystems and on plants are still controversial. Apart from obvious physico-chemical differences, a possible explanation of these contrasting results could be the wide range of methods used to evaluate the toxicity at different levels of plant physiology. Fourier Transformed InfraRed (FTIR) spectroscopy is a sensitive and widely informative technique that probes the chemical composition of plants. In this study, we investigated the impacts of CNTs and TiO2-NPs (100 and 500 mg.kg-1) on tomato plants after 5, 10, 15 and 20 days of exposure in soil. Using morphological parameters, no toxicity was found except after 15 days of exposure (-57% in height and-62% in foliar area for plants exposed to 100 mg.kg-1 TiO2-NPs, but no impact after CNT exposure) while FTIR revealed effects of the two NMs starting after 5 days of exposure and being maximum after 15 days. After spectral data treatment optimization, FTIR results suggested modifications in leaf cell wall components of plants subjected to both NMs. Microarray polymer profiling confirmed changes in xyloglucan and homogalacturonan levels for plants exposed to TiO2-NPs. In summary, FTIR was an effective screening method to evaluate the impacts of NMs on tomato plants and to identify their implications on the plant cell walls.

Despite the increasing attention given to the impacts of nanoplastics in terrestrial environments, there is limited data about the effects on plants, and the quantitative information on uptake. In the present study, wheat plants grown in hydroponics were exposed to Pd-doped nanoplastics. This allowed us to quantify nanoplastics uptake and translocation to the shoots. Visualization of nanoplastics in roots was performed with synchrotron micro X-ray fluorescence (µXRF). Nanoplastics accumulated on the root epidermis, especially at the root tip and in root maturation zones. A close relationship between plant roots, rhizodeposits and nanoplastics behaviour was shown. Reinforcement of the cell wall in roots was evidenced using Fourier transform infrared spectroscopy (FTIR) and synchrotron-computed microtomography (µCT). Synchrotron-computed nanotomography (nanoCT) evidenced the presence of globular structures but they could not be identified as nanoplastics since they were observed both in the control and treated roots. By utilizing the inorganic tracer in the doped-nanoplastics, this study paves the road for elucidating interactions in more complex systems by using an integrative approach combining classical phytotoxicity markers with advanced nanometrology techniques. ISSN:0304-3894 ISSN:1873-3336

The performance of a liquid-nitrogen-cooled high-heat-load monochromator with a horizontal scattering plane has been analysed, aiming to preserve the high quality of the X-ray beam in the vertical plane for downstream optics. Using finite-element analysis, height profiles of the crystal surface for various heat loads and the corresponding slope errors in the meridional and sagittal planes were calculated. Then the angular distortions of the reflected beam in both meridional and sagittal planes were calculated analytically and also modelled by ray tracing, revealing a good agreement of the two approaches. The results show that with increasing heat load in the crystal the slope errors of the crystal surface reach their smallest values first in the sagittal and then in the meridional plane. For the considered case of interest at a photon energy of 14.412 keV and the Si(111) reflection with a Bragg angle of 7.88°, the angular distortions of the reflected beam in the sagittal plane are an order of magnitude smaller than in the meridional one. Furthermore, they are smaller than the typical angular size of the beam source at the monochromator position. For a high-heat-load monochromator operating in the horizontal scattering plane, the sagittal angular distortions of the reflected beam appear in the vertical plane. Thus, such an instrument perfectly preserves the high quality of the X-ray beam in the vertical plane for downstream optics. Compared with vertical scattering, the throughput of the monochromatic beam with the horizontal scattering plane is reduced by only 3.3% for the new EBS source, instead of 34.3% for the old ESRF-1 machine. This identifies the horizontal-scattering high-heat-load monochromator as a device essentially free of the heat-load effects in the vertical plane and without significant loss in terms of throughput.

Significance Ink, invented in ancient Egypt circa 5,000 y ago, is the established and time-honored medium wherewith humankind commits words to writing. A comprehensive synchrotron-based microanalysis of a considerable corpus of ancient Egyptian papyri from the Roman period, inscribed with red and black inks, reveal a hitherto undetected complex composition of inks. Highlighted by the presence of iron, the red color can be attributed to the use of ocher. Unexpectedly, lead is regularly present in both the red and black inks and is associated to phosphate, sulfate, chloride, and carboxylate ions. The analysis shows that lead was probably used as a drier rather than as a pigment, similar to its usage in 15th century Europe during the development of oil paintings., A hitherto unknown composition is highlighted in the red and black inks preserved on ancient Egyptian papyri from the Roman period (circa 100 to 200 CE). Synchrotron-based macro–X-ray fluorescence (XRF) mapping brings to light the presence of iron (Fe) and lead (Pb) compounds in the majority of the red inks inscribed on 12 papyrus fragments from the Tebtunis temple library. The iron-based compounds in the inks can be assigned to ocher, notably due to the colocalization of Fe with aluminum, and the detection of hematite (Fe2O3) by micro–X-ray diffraction. Using the same techniques together with micro-Fourier transform infrared spectroscopy, Pb is shown to be associated with fatty acid phosphate, sulfate, chloride, and carboxylate ions. Moreover, micro-XRF maps reveal a peculiar distribution and colocalization of Pb, phosphorus (P), and sulfur (S), which are present at the micrometric scale resembling diffused “coffee rings” surrounding the ocher particles imbedded in the red letters, and at the submicrometric scale concentrated in the papyrus cell walls. A similar Pb, P, and S composition was found in three black inks, suggesting that the same lead components were employed in the manufacture of carbon-based inks. Bearing in mind that pigments such as red lead (Pb3O4) and lead white (hydrocerussite [Pb3(CO3)2(OH)2] and/or cerussite [PbCO3]) were not detected, the results presented here suggest that the lead compound in the ink was used as a drier rather than as a pigment. Accordingly, the study calls for a reassessment of the composition of lead-based components in ancient Mediterranean pigments.

Different approaches to simulate a modern X-ray beamline are considered. Several methodologies with increasing complexity are applied to discuss the relevant parameters that quantify the beamline performance. Parameters such as flux, dimensions and intensity distribution of the focused beam, and coherence properties are obtained from simple analytical calculations to sophisticated computer simulations using ray-tracing and wave optics techniques. A latest-generation X-ray nanofocusing beamline for coherent applications (ID16A at the ESRF) has been chosen to study in detail the issues related to highly demagnifying synchrotron sources and exploiting the beam coherence. The performance of the beamline is studied for two storage rings: the old ESRF-1 (emittance 4000 pm) and the new ESRF-EBS (emittance 150 pm). In addition to traditional results in terms of flux and beam sizes, an innovative study on the partial coherence properties based on the propagation of coherent modes is presented. The different algorithms and methodologies are implemented in the software suite OASYS. These are discussed with emphasis placed upon the their benefits and limitations of each.

This study presents measurement results of x-ray production cross sections of L α and L β1,3,4 emitted by four lanthanoid elements (La, Ce, Pr and Nd), after irradiation with K α and K β X rays of the elements Co, Ni, Cu, and Zn (covering energies between 7.01 keV and 8.75 keV). Primary x-rays were induced in turn by the irradiation of thick targets of these elements with a beam of x-rays produced by a tube with an Rh anode, operating at 50 kV and 850 μA. The experimental results are compared with theoretical cross sections predicted using known tabulations of photoelectric cross sections. Dirac-Hartree-Slater (DHS) atomic parameters were used for these calculations. An acceptable match between experiment and both sets of tabulated data is found.

An extended study on an advanced method for the cleaning of carbon contaminations from large optical surfaces using a remote inductively coupled low-pressure RF plasma source (GV10x DownStream Asher) is reported. Technical and scientific features of this scaled up cleaning process are analysed, such as the cleaning efficiency for different carbon allotropes (amorphous and diamond-like carbon) as a function of feedstock gas, RF power (from 30 to 300W), and source-object distances (415 to 840 mm). The underlying physical phenomena for these functional dependences are discussed., The authors would like to acknowledge the help by Guillaume Sauthier (ICN2) for his collaboration during the XPS characterization. We also thank ibss Group Inc. for supplying the GV10x DS Asher systems as well as the DLC samples.

Background Phosphorus (P) deficiency limits crop production worldwide. Crops differ in their ability to acquire and utilise the P available. The aim of this study was to determine root traits (root exudates, root system architecture (RSA), tissue-specific allocation of P, and gene expression in roots) that (a) play a role in P-use efficiency and (b) contribute to large shoot zinc (Zn) concentration in Brassica oleracea. Results Two B. oleracea accessions (var. sabellica C6, a kale, and var. italica F103, a broccoli) were grown in a hydroponic system or in a high-throughput-root phenotyping (HTRP) system where they received Low P (0.025 mM) or High P (0.25 mM) supply for 2 weeks. In hydroponics, root and shoot P and Zn concentrations were measured, root exudates were profiled using both Fourier-Transform-Infrared spectroscopy and gas-chromatography-mass spectrometry and previously published RNAseq data from roots was re-examined. In HTRP experiments, RSA (main and lateral root number and lateral root length) was assessed and the tissue-specific distribution of P was determined using micro-particle-induced-X-ray emission. The C6 accession had greater root and shoot biomass than the F103 accession, but the latter had a larger shoot P concentration than the C6 accession, regardless of the P supply in the hydroponic system. The F103 accession had a larger shoot Zn concentration than the C6 accession in the High P treatment. Although the F103 accession had a larger number of lateral roots, which were also longer than in the C6 accession, the C6 accession released a larger quantity and number of polar compounds than the F103 accession. A larger number of P-responsive genes were found in the Low P treatment in roots of the F103 accession than in roots of the C6 accession. Expression of genes linked with “phosphate starvation” was up-regulated, while those linked with iron homeostasis were down-regulated in the Low P treatment. Conclusions The results illustrate large within-species variability in root acclimatory responses to P supply in the composition of root exudates, RSA and gene expression, but not in P distribution in root cross sections, enabling P sufficiency in the two B. oleracea accessions studied.

Nanosized TiO2 is one of the most produced nanomaterials. Agricultural soils are a major compartment of accumulation of TiO2-NPs after release from consumer products into the sewer system, due to the use of sewage sludge as a soil amendment. TiO2 is naturally present in soils, and distinguishing between anthropogenic and natural TiO2 in soils is thus important to assess the risks associated with the increased use of nano-TiO2. Methods to distinguish these materials in complex matrices such as soils are currently lacking. The purpose of this study was, therefore, to search for characteristic physical and chemical properties of natural and engineered nano-TiO2, based on a combination of bulk, micro and nanofocused X-ray fluorescence and X-ray absorption spectroscopy, transmission electron microscopy, X-ray diffraction and chemical analyses. Digested sewage sludge, agricultural soil and sludge-amended soil were studied by these techniques. The particle size distribution was not a relevant criterion since the sludge and the sludge-amended soil contained a variety of nanometer- and micrometer sized Ti-containing particles. Both the sludge and the soil contained a mixture of rutile and anatase, with a minor proportion of amorphous TiO2. In the sludge, there was no trend relating particle size and Ti mineralogy. The morphology of the TiO2 particles proved to be different in the two matrices, with smooth faceted particles in the sludge and rough irregular ones in the soil. In addition, natural TiO2 particles were included in micro and macroaggregates of the soil and formed intricate assemblages with minerals and organic compounds. In the sludge, TiO2 formed homo and heteroaggregates of simpler structure, richer in organic matter. Thus, the study of the morphology of TiO2 particles and their status in unperturbed mineral–organic assemblages may provide some insights into their origin. The observed differences may attenuate over time, due to the incorporation of the sludge material within the soil structure. We thank the French program LabEx Serenade (ANR-11-LABX-0064) for providing a post doc fellowship and COST ES1205 (ENTER) for funding this project, and EquipEx NanoID (ANR-10-EQPX-0039) for funding equipment needed for the project. ISTerre is also part of Labex OSUG@2020 (ANR10 LABX56). Juan Reyes-Herrera acknowledges the Mexican National Council for Science and Technology (CONACYT) for the funding of his post-doctoral position (CONACYT CVU#177448). We thank the ESRF committee for the provision of beamtime and the staff of ID21, ID16b and BM25 for their assistance during measurements. The HRICP-MS was run by Frederic Candaudap (GET) and Gael Le Roux (EcoLab). We thank Delphine Tisserand, Sarah Bureau and Sylvain Campillo at ISTerre for their technical support, and Fayçal Soufi at Edytem (Chambery, France) for preparing the thin sections. We also thank Brian Sinnet of EAWAG who helped in the sewage sludge production, Hengzhong Zhang for sharing the Ti XANES spectrum of amorphous TiO2, and two anonymous reviewers for their comments and suggestions.

Chronic psychological stress is an important public health issue which generates behavioral changes, anxiety, immunosuppression and oxidative damage. Piracetam is a cognitive enhancer, at cellular level it protects from oxidative stress. The aim of this study was to evaluate the effect of psychological stress and of piracetam on circulating mononuclear cells by analyzing the biochemical spectrome using Synchrotron Radiation Fourier Transform Infrared Microspectroscopy (SR-μFTIR). Rats were exposed for five days to a stressor (cat odor) under oral administration of piracetam (600 mg/kg). SR-μFTIR analysis showed a decrease in bands associated to the lipids region (2852 cm−1, 2923 cm−1 and 2962 cm−1) and an increase absorption of the amide I band (1654 cm−1) under stress conditions. The principal component analysis showed increase oxidation of lipids (decrease of 3010 cm−1, 2923 cm−1 and 2852 cm−1 bands) as well as proteins denaturation (increase of 1610 cm−1 and 1690 cm−1 bands) under stress. Piracetam provided protection to polyunsaturated lipids (p ≤ 0.001) and lipids/proteins ratio (p ≤ 0.001). Behaviorally, this drug diminished fear and anxiety in stressed animals by the plus maze test (p ≤ 0.002). However, this drug induced oxidative stress in mononuclear cells from unstressed animals and altered their behavior.

A new apparatus for the simultaneous application of Particle Induced X-ray Emission (PIXE) and X-Ray Fluorescence (XRF) in the elemental analysis of atmospheric aerosol samples is described. Under normal conditions, both techniques have limitations regarding the atomic number range of analyzed elements, because of their sensitivity. Thus, considering only K X-ray lines, PIXE is more sensitive to light elements (Al to Zn) because of the strong decrease of ionization cross sections by protons for heavier elements. In contrast, XRF based on X-ray tubes works better for elements with atomic numbers above around 26 (Fe) and up to roughly Mo, due to the photoelectric cross sections. Therefore, the device was designed and built in order to have a more uniform response for elemental analysis of atmospheric aerosol samples, using PIXE and XRF simultaneously. An expression for quantitative analysis of thin targets with the new method is obtained, and comparisons with previous analyses of aerosol samples are presented, showing an excellent agreement for selected elements like S, Cl, Ti, V, Fe, Cu, and Zn.

Although the graphitic carbon contamination of synchrotron beamline optics has been an obvious problem for several decades, the basic mechanisms underlying the contamination process as well as the cleaning/remediation strategies are not understood and the corresponding cleaning procedures are still under development. In this study an analysis of remediation strategies all based on in situ low-pressure RF plasma cleaning approaches is reported, including a quantitative determination of the optimum process parameters and their influence on the chemistry as well as the morphology of optical test surfaces. It appears that optimum results are obtained for a specific pressure range as well as for specific combinations of the plasma feedstock gases, the latter depending on the chemical aspects of the optical surfaces to be cleaned.

In spite of the existence of a large quantity of experimental results for X-ray production cross sections by proton beam impact, recent publications emphasize the need for more measurements in several targets and energy ranges. Following these recommendations, this work presents results with some heavy elements (72Hf, 77Ir, and 81Tl) irradiated with protons in the energy interval 0.45 MeV–4.75 MeV. The results are compared with experimental data from previous publications, empirical tables, as well as with predictions of the ECPSSR theory with the United Atom modification, intra-shell coupling corrections, and Multiple Ionization effects. Although there is good coincidence with previous experiments, the agreement among the theories with the experimental data does not allow a definitive conclusion about the best predictions for the measured cross sections.

The performance of a new X-ray spectrometer is presented. The device was designed originally to be employed in environmental sciences, and allows the use of different types of primary radiation sources, such as a radioactive source (241Am) or tubes with anodes of different metals (Rh or W). Among the advantages of this spectrometer are the possibility of exchanging detectors to improve efficiency at different X-ray energy ranges [such as Si (Li), Si-PIN, hyperpure Ge, or CdTe detectors], to attach it to a wavelength dispersive system, and its use in vacuum or atmospheric pressure. Furthermore, it is feasible to modify the geometry so a secondary target may be installed for using polarized X-rays as exciting radiation.

Measurements of K-shell X-ray production cross sections induced by proton beams with energies between 3 MeV and 4 MeV are presented. The studied elements were Ce, Nd, Gd, Dy, and Ho, as thick targets. The measured cross sections are evaluated through comparisons with the ECPSSR model, the eECPSShsR-UA theory, the adiabatic perturbation (also known as direct molecular orbital, or MO) theory, and the empirical fits of Kahoul et al. using a scaling based on the reduced velocity parameter ξ K R in every case. Consideration is given to multiple ionization effects and electron capture contribution to K-shell ionization. It is shown that the experimental results are in good agreement with the theoretical predictions in the whole measured ξ K R range.

K-shell X-ray intensity ratios for selected rare earth elements were measured following irradiation with proton beams having energies between 3 and 4 MeV. Using the X-ray intensity ratios, the radiative vacancy transfer probabilities from the shell K to the L sub-shells were determined. The experimental data were compared to theoretical predictions for X-ray line intensities and radiative vacancy transfer probabilities. The results showed a good agreement between theory and experiment.

The Mexican Particle Accelerator Community (CMAP) was created in 2015 and currently its members participate in different experiments around the world. Using their expertise, they are working in the development of the particle accelerators area in Mexico. This paper provides a summary of the research done by its members and presents the preliminary design of an electron linear particle accelerator (eLINAC). This proposal will be the first accelerator designed and created in Mexico.

In a previous work, the measurement of radiative vacancy transfer probabilities from the K shell to the L sub‐shells were measured, when rare earth elements were irradiated with 3 MeV–4 MeV protons. It was found that those probabilities did not depend on the ion energy and there was a close agreement with theoretical predictions. Therefore, in this work the K‐shell X‐ray intensity ratios for rare‐earth elements have been measured following irradiation with 12C4+ and 16O5+ ion beams, with incident energies between 12 MeV and 15 MeV. From the X‐ray intensity ratios, the radiative vacancy transfer probabilities from the shell K to the L sub‐shells were determined. The experimental data were compared to theoretical predictions, such as the Scofield theoretical predictions for these probabilities. The results showed a good agreement between theory and experiment, and did not show dependence with the ion incident energy.