Search

Advances in physics have been significantly driven by state‐of‐the‐art technology, and in photonics and X‐ray science this calls for the ability to manipulate the characteristics of optical beams. Orbital angular momentum (OAM) beams hold substantial promise in various domains such as ultra‐high‐capacity optical communication, rotating body detection, optical tweezers, laser processing, super‐resolution imaging etc. Hence, the advancement of OAM beam‐generation technology and the enhancement of its technical proficiency and characterization capabilities are of paramount importance. These endeavours will not only facilitate the use of OAM beams in the aforementioned sectors but also extend the scope of applications in diverse fields related to OAM beams. At the FERMI Free‐Electron Laser (Trieste, Italy), OAM beams are generated either by tailoring the emission process on the undulator side or, in most cases, by coupling a spiral zone plate (SZP) in tandem with the refocusing Kirkpatrick–Baez active optic system (KAOS). To provide a robust and reproducible workflow to users, a Hartmann wavefront sensor (WFS) is used for both optics tuning and beam characterization. KAOS is capable of delivering both tightly focused and broad spots, with independent control over vertical and horizontal magnification. This study explores a novel non‐conventional 'near collimation' operational mode aimed at generating beams with OAM that employs the use of a lithographically manufactured SZP to achieve this goal. The article evaluates the mirror's performance through Hartmann wavefront sensing, offers a discussion of data analysis methodologies, and provides a quantitative analysis of these results with ptychographic reconstructions. [ABSTRACT FROM AUTHOR]

Multimodal imaging and spectroscopy like concurrent scanning transmission X-ray microscopy (STXM) and X-ray fluorescence (XRF) are highly desirable as they allow retrieving complementary information. This paper reports on the design, development, integration and field testing of a novel in situ atomic force microscopy (AFM) instrument for operation under high vacuum in a synchrotron soft X-ray microscopy STXM–XRF end-station. A combination of μXRF and AFM is demonstrated for the first time in the soft X-ray regime, with an outlook for the full XRF–STXM–AFM combination. [ABSTRACT FROM AUTHOR]

Scanning microscopies and spectroscopies like X-ray Fluorescence (XRF), Scanning Transmission X-ray Microscopy (STXM), and Ptychography are of very high scientific importance as they can be employed in several research fields. Methodology and technology advances aim at analysing larger samples at better resolutions, improved sensitivities and higher acquisition speeds. The frontiers of those advances are in detectors, radiation sources, motors, but also in acquisition and analysis software together with general methodology improvements. We have recently introduced and fully implemented an intelligent scanning methodology based on compressive sensing, on a soft X-ray microscopy beamline. This demonstrated sparse low energy XRF scanning of dynamically chosen regions of interest in combination with STXM, yielding spectroimaging data in the megapixel-range and in shorter timeframes than were previously not feasible. This research has been further developed and has been applied to scientific applications in biology. The developments are mostly in the dynamic triggering decisional mechanism in order to incorporate modern Machine Learning (ML) but also in the suitable integration of the method in the control system, making it available for other beamlines and imaging techniques. On the applications front, the method was previously successfully used on different samples, from lung and ovarian human tissues to plant root sections. This manuscript introduces the latest methodology advances and demonstrates their applications in life and environmental sciences. Lastly, it highlights the auxiliary development of a mobile application, designed to assist the user in the selection of specific regions of interest in an easy way. [ABSTRACT FROM AUTHOR]

X‐ray fluorescence (XRF) spectroscopy is a widely used technique in microscopy, spanning from biology to cultural heritage applications. Its purpose is to characterize qualitatively and quantitatively, the presence of elemental species in a sample. This is accomplished through fitting the acquired data to a Gaussian model, identifying which XRF lines and associated elements are present. As a result, 2D images of cumulative count‐rate maps associated with each element are produced. This procedure is not trivial to apply efficiently in a workflow, as it requires the user to be able to set a series of parameters (e.g., beam energy, background subtraction, etc.) on top of selecting XRF lines under investigation. Furthermore, users should easily and swiftly be able to change setup parameters and evaluate the effects on the results. In the present work, we introduce a web‐based application that allows users to load the XRF data, setup a fit and inspect the results interactively within a simple graphical user interface (GUI) that enables easily going back and forth from setup to result inspection. In particular, it is possible to quickly view the count‐rate maps and curve fitting simultaneously, on any single pixel spectra present in the images. The web‐application can be accessed locally by a web‐browser, but runs remotely on a cloud, freeing from the need of installing any software and will be made publicly available in the near future. At present, it has been designed to work on both conventional and sparse XRF data such as Compressive Sensing, in an embarrassingly parallel manner. [ABSTRACT FROM AUTHOR]

Computational techniques allow breaking the limits of traditional imaging methods, such as time restrictions, resolution, and optics flaws. While simple computational methods can be enough for highly controlled microscope setups or just for previews, an increased level of complexity is instead required for advanced setups, acquisition modalities or where uncertainty is high; the need for complex computational methods clashes with rapid design and execution. In all these cases, Automatic Differentiation, one of the subtopics of Artificial Intelligence, may offer a functional solution, but only if a GPU implementation is available. In this paper, we show how a framework built to solve just one optimisation problem can be employed for many different X-ray imaging inverse problems. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Although X-ray fluorescence microscopy is becoming a widely used technique for single-cell analysis, sample preparation for this microscopy remains one of the main challenges in obtaining optimal conditions for the measurements in the X-ray regime. The information available to researchers on sample treatment is inadequate and unclear, sometimes leading to wasted time and jeopardizing the experiment's success. Many cell fixation methods have been described, but none of them have been systematically tested and declared the most suitable for synchrotron X-ray microscopy. Methods: The HEC-1-A endometrial cells, human spermatozoa, and human embryonic kidney (HEK-293) cells were fixed with organic solvents and cross-linking methods: 70% ethanol, 3.7%, and 2% paraformaldehyde; in addition, HEK-293 cells were subjected to methanol/ C3H6O treatment and cryofixation. Fixation methods were compared by coupling low-energy X-ray fluorescence with scanning transmission X-ray microscopy and atomic force microscopy. Results: Organic solvents lead to greater dehydration of cells, which has the most significant effect on the distribution and depletion of diffusion elements. Paraformaldehyde provides robust and reproducible data. Finally, the cryofixed cells provide the best morphology and element content results. Conclusion: Although cryofixation seems to be the most appropriate method as it allows for keeping cells closer to physiological conditions, it has some technical limitations. Paraformaldehyde, when used at the average concentration of 3.7%, is also an excellent alternative for X-ray microscopy. [ABSTRACT FROM AUTHOR]

In this work, we propose the software library PyPore3D, an open source solution for data processing of large 3D/4D tomographic data sets. PyPore3D is based on the Pore3D core library, developed thanks to the collaboration between Elettra Sincrotrone (Trieste) and the University of Trieste (Italy). The Pore3D core library is built with a distinction between the User Interface and the backend filtering, segmentation, morphological processing, skeletonisation and analysis functions. The current Pore3D version relies on the closed source IDL framework to call the backend functions and enables simple scripting procedures for streamlined data processing. PyPore3D addresses this limitation by proposing a full open source solution which provides Python wrappers to the the Pore3D C library functions. The PyPore3D library allows the users to fully use the Pore3D Core Library as an open source solution under Python and Jupyter Notebooks PyPore3D is both getting rid of all the intrinsic limitations of licensed platforms (e.g., closed source and export restrictions) and adding, when needed, the flexibility of being able to integrate scientific libraries available for Python (SciPy, TensorFlow, etc.). [ABSTRACT FROM AUTHOR]

X-ray ptychography is an advanced computational microscopy technique, which is delivering exceptionally detailed quantitative imaging of biological and nanotechnology specimens, which can be used for high-precision X-ray measurements. However, coarse parametrisation in propagation distance, position errors and partial coherence frequently threaten the experimental viability. In this work, we formally introduce these actors, solving the whole reconstruction as an optimisation problem. A modern deep learning framework was used to autonomously correct the setup incoherences, thus improving the quality of a ptychography reconstruction. Automatic procedures are indeed crucial to reduce the time for a reliable analysis, which has a significant impact on all the fields that use this kind of microscopy. We implemented our algorithm in our software framework, SciComPty, releasing it as open-source. We tested our system on both synthetic datasets, as well as on real data acquired at the TwinMic beamline of the Elettra synchrotron facility. [ABSTRACT FROM AUTHOR]

Soft X-ray microscopy coupled with low energy X-ray fluorescence is a powerful tool for investigating complex biological systems like cells and tissues. Due to certain characteristics of X-ray sources, sample stage motors, and detectors, the examination of large areas at high resolutions is very time consuming, often confining the analysis only to a restricted number of pre-selected representative regions. Here we propose and demonstrate a compressive sensing method that provides an alternative approach for overcoming such limitations and can be applied to different kinds of samples and other microscopy and analytical techniques. [ABSTRACT FROM AUTHOR]

Synchrotron X-ray µ- and nano-probes are increasingly affirming their relevance in cultural heritage applications, especially in material characterization of tiny and complex micro-samples which are typical from archaeological and artistic artifacts. For such purposes, synchrotron radiation facilities are tailoring and optimizing beamlines and set-ups for CH, taking also advantages from the challenges offered by the third-generation radiation sources. In ancient ceramics studies, relevant information for the identification of production centers and manufacture technology can be obtained in a non-invasive and non-destructive way at the micro-sample level by combining different SR based methods. However, the selection of appropriate beamlines, techniques and set-ups are critical for the success of the experiments. Fine and varnished wares (e.g., Attic and western-Greek colonial products) are an excellent case study for exploring challenges offered by synchrotron X-ray microprobes optimized to collect microchemical and phase-distribution maps. The determination of provenance and/or technological tracers is relevant in correctly classifying productions, often based only on ceramic paste, gloss macroscopic features or style. In addition, when these vessels are preserved in Museums as masterpieces or intact pieces the application of non-invasive approach at the micro sample is strictly required. Well-designed synchrotron µXRF and µXANES mapping experiments are able providing relevant clues for discriminating workshops and exploring technological aspects, which are fundamental in answering the current archaeological questions on varnished Greek or western-Greek colonial products. [ABSTRACT FROM AUTHOR]

Featured Application: Cryo-nano tomography of biological samples with no landmarks in view. The high resolution of synchrotron cryo-nano tomography can be easily undermined by setup instabilities and sample stage deficiencies such as runout or backlash. At the cost of limiting the sample visibility, especially in the case of bio-specimens, high contrast nano-beads are often added to the solution to provide a set of landmarks for a manual alignment. However, the spatial distribution of these reference points within the sample is difficult to control, resulting in many datasets without a sufficient amount of such critical features for tracking. Fast automatic methods based on tomography consistency are thus desirable, especially for biological samples, where regular, high contrast features can be scarce. Current off-the-shelf implementations of such classes of algorithms are slow if used on a real-world high-resolution dataset. In this paper, we present a fast implementation of a consistency-based alignment algorithm especially tailored to a multi-GPU system. Our implementation is released as open-source. [ABSTRACT FROM AUTHOR]

Progress in nanotechnology calls for material probing techniques of high sensitivity and resolution. Such techniques are also used for high-impact studies of nanoscale materials in medicine and biology. Soft X-ray microscopy has been successfully used for investigating complex biological processes occurring at micrometric and sub-micrometric length scales and is one of the most powerful tools in medicine and the life sciences. Here, we present the capabilities of the TwinMic soft X-ray microscopy end-station at the Elettra synchrotron in the context of medical and biological imaging, while we also describe novel uses and developments. [ABSTRACT FROM AUTHOR]

Hydrophobic treatment is one of the most important interventions usually carried out for the conservation of stone artefacts and monuments. The study here reported aims to answer a general question about how two polymers confer different protective performance. Two fluorinated-based polymer formulates applied on samples of Cusa's stone confer a different level of water repellence and water vapour permeability. The observed protection action is here explained on the basis of chemico-physical interactions. The distribution of the polymer in the pore network was investigated using scanning electron microscopy and X-ray microscopy. The interactions between the stone substrate and the protective agents were investigated by means of solid state NMR spectroscopy. The ss-NMR findings reveal no significant changes in the chemical neighbourhood of the observed nuclei of each protective agent when applied onto the stone surface and provide information on the changes in the organization and dynamics of the studied systems, as well as on the mobility of polymer chains. This allowed us to explain the different macroscopic behaviours provided by each protective agent to the stone substrate. [ABSTRACT FROM AUTHOR]

Zn–air batteries are very promising devices for energy storage at high energy density due to their intrinsic safety, environmental friendliness, and low cost, but still, there are key issues to be solved to get to the industrial scale. One of the unsolved problems is the poor cyclability of batteries based on aqueous solvents that urges to consider nonaqueous solvents. Among different possible options are deep eutectic solvents, which are cost‐effective and technologically relatively easy to implement. The present investigation reports for the first time an operando scanning soft X‐ray microscope analysis of the Zn behaviour in a choline–chloride/urea deep eutectic solvents electrolyte during the cathodic and anodic phase formation processes taking place in battery charge and discharge, providing a platform for in‐depth space–time dependent investigations of the chemistry of crystallites evolving during potential cycling. These operando measurements have been enabled by the construction of a novel wet cell, improving the design and filling protocol of earlier generation cells developed by authors. High‐resolution soft X‐ray microscope images were acquired in two modes: (a) dynamic mode at a fixed beam energy, allowing to follow morphology evolution under electrochemical control and (b) static mode for selected morphologies representative of characteristic Zn growth and dissolution steps. [ABSTRACT FROM AUTHOR]

The possibility of fast X‐ray fluorescence (XRF) imaging using on‐the‐fly acquisition is very attractive due to its high acquisition speed. The underlying assumption is that there must be a meaningful flux of XRF emitted photons collected by the detectors. On‐the‐fly XRF has already been demonstrated at mid‐to‐high X‐ray energies, both for laboratory and synchrotron‐based instruments. In this manuscript, we report on the capability of DANTE digital pulse processor (DPP) in the soft X‐ray regime. DANTE is a novel compact and low‐power DPP with high energy resolution and high count rate. This work presents preliminary measurements performed at the TwinMic beamline at Elettra synchrotron (Trieste, Italy) addressing the feasibility of on‐the‐fly low energy XRF imaging. [ABSTRACT FROM AUTHOR]

Silicon is reported to reduce the toxic effects of Al on root elongation but the in planta mechanism by which this occurs remains unclear. Using seedlings of soybean (Glycine max) and sorghum (Sorghum bicolor), we examined the effect of up to 2 mM Si on root elongation rate (RER) in Al-toxic nutrient solutions. Synchrotron-based low energy X-ray fluorescence (LEXRF) was then used for the in situ examination of the distribution of Al and Si within cross-sections cut from the apical tissues of sorghum roots. The addition of Si potentially increased RER in Al-toxic solutions, with RER being up to ca. 0.3 mm h-1 (14%) higher for soybean and ca. 0.2 mm h-1 (17%) higher for sorghum relative to solutions without added Si. This improvement in RER could not be attributed to a change in Al-chemistry of the bulk nutrient solution, nor was it due to a change in the concentration of Al within the apical (0–10 mm) root tissues. Using LEXRF to examine sorghum, it was demonstrated that in roots exposed to both Al and Si, much of the Al was co-located with Si in the mucigel and outer apoplast. These observations suggest that Si reduces the toxicity of Al in planta through formation of Al–Si complexes in mucigel and outer cellular tissues, thereby decreasing the binding of Al to the cell wall where it is known to inhibit wall loosening as required for cell elongation. [ABSTRACT FROM AUTHOR]

In spite of the constant technological improvements in the field of detector development, X-ray fluorescence (XRF) in the soft X-ray regime remains a challenge. The low intrinsic fluorescence yield for energies below 2 keV indeed renders the applicability of low-energy XRF still difficult. Here, we report on a new multi-element multi-tile detection system currently under development, designed to be integrated into a soft X-ray microscopy end station. The system will be installed at the TwinMic beamline of Elettra synchrotron (Trieste, Italy) in order to increase the detected count rate by up to an order of magnitude. The new architecture is very versatile and can be adapted to any XRF experimental setup. Even though the first results of the previous version of such a multi-element system were encouraging, several issues still needed to be addressed. The system described here represents a further step in the detector evolution. It is based on four trapezoidal-shaped monolithic silicon drift detector tiles (matrices) with six hexagonal elements each equipped with a custom ultra-low noise application-specific integrated circuit readout. The whole signal processing chain has been improved leading to an overall increase in performances, namely, in terms of energy resolution and acquisition rates. The design and development of this new detection system will be described, and recent results obtained at the TwinMic beamline at Elettra will be presented. Future perspectives and improvements will also be discussed. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In wheat (Triticum aestivum), it is commonly assumed that Al is detoxified by the release of organic anions into the rhizosphere, but it is also possible that detoxification occurs within the apoplast and symplast of the root itself. Using Al-resistant (ET8) and Al-sensitive (ES8) near-isogenic lines of wheat, we utilized traditional and synchrotronbased approaches to provide in situ analyses of the distribution and speciation of Al within root tissues. Some Al appeared to be complexed external to the root, in agreement with the common assumption. However, root apical tissues of ET8 accumulated four to six times more Al than ES8 when exposed to Al concentrations that reduce root elongation rate by 50% (3.5 mM Al for ES8 and 50 mM for ET8). Furthermore, in situ analyses of ET8 root tissues indicated the likely presence of Al-malate and other forms of Al, predominantly within the apoplast. To our knowledge, this is the first time that X-ray absorption near edge structure analyses have been used to examine the speciation of Al within plant tissues. The information obtained in the present study is important in developing an understanding of the underlying physiological mode of action for improved root growth in systems with elevated soluble Al. [ABSTRACT FROM AUTHOR]

Nanotoxicology and nanomedicine investigations often require the probing of nano-objects such as fibres and particles in biological samples and cells, whilst internalization and intracellular destiny are the main issues for in vitro cellular studies. Various high resolution microscopy techniques are well suited for providing this highly sought-after information. However, sample preparation, nanomaterial composition and sectioning challenges make it often difficult to establish whether the fibres or particles have been internalized or they are simply overlaying or underlying the biological matter. In this paper we suggest a novel suitable combination of two different microscopic techniques to reveal in intact cells the uptake of asbestos fibres by mesothelial cells. After exposure to asbestos fibres and fixation, cells were first analysed under the AFM instrument and then imaged under the TwinMic soft X-ray microscope at Elettra Sincrotrone. The suggested approach combines standard soft X-ray microscopy imaging and AFM microscopy, with a common non-invasive sample preparation protocol which drastically reduces the experimental uncertainty and provides a quick and definitive answer to the nanoparticle cellular and tissue uptake. [ABSTRACT FROM AUTHOR]

An important computational operation in a set of spectra is that of aligning them to a reference spectrum. In X-ray fluorescence, this is referred to as energy calibration and may be necessary for fitting low-count acquisitions. It may be useful for multi-element detector systems. Typically, this is carried out in a linear manner, and sometimes requires user feedback. Automated methods exist but are often focused on specific type of data. We propose a new automated method that is based on a nonlinear approach and is specialised for X-ray fluorescence data. The initial application in two different multi-element detector systems in the TwinMic beamline (Elettra - Sincrotrone Trieste) yielded promising results. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Understanding the lateral variations in the elemental and chemical state of constituents induced by electrochemical reactions at nanoscales is crucial for the advancement of electrochemical materials science. This requires in situ studies to provide observables that contribute to both modeling beyond the phenomenological level and exactly transducing the functionally relevant quantities. A range of X-ray coherent diffraction imaging (CDI) approaches have recently been proposed for imaging beyond the diffraction limit with potentially dramatic improvements in time resolution with chemical sensitivity. In this paper, we report a selection of ptychography results obtained in situ during the electrodeposition of a metal-polymer nanocomposite. Our selection includes dynamic imaging during electrochemically driven growth complemented with absorption and phase spectroscopy with high lateral resolution. We demonstrate the onset of morphological instability feature formation and correlate the chemical state of Mn with the local growth rate controlled by the current density distribution resulting from morphological evolution. [ABSTRACT FROM AUTHOR]

The current status of the TwinMic beamline at Elettra synchrotron light source, that hosts the European twin X-ray microscopy station, is reported. The X-ray source, provided by a short hybrid undulator with source size and divergence intermediate between bending magnets and conventional undulators, is energy-tailored using a collimated plane-grating monochromator. The TwinMic spectromicroscopy experimental station combines scanning and full-field imaging in a single instrument, with contrast modes such as absorption, differential phase, interference and darkfield. The implementation of coherent diffractive imaging modalities and ptychography is ongoing. Typically, scanning transmission X-ray microscopy images are simultaneously collected in transmission and differential phase contrast and can be complemented by chemical and elemental analysis using across-absorption-edge imaging, X-ray absorption near-edge structure or low-energy X-ray fluorescence. The lateral resolutions depend on the particular imaging and contrast mode chosen. The TwinMic range of applications covers diverse research fields such as biology, biochemistry, medicine, pharmacology, environment, geochemistry, food, agriculture and materials science. They will be illustrated in the paper with representative results. [ABSTRACT FROM AUTHOR]

X-ray computed tomography (CT) experiments performed at synchrotron radiation facilities require adequate computing and storage resources due to the large amount of acquired and reconstructed data produced. To satisfy the heterogeneous needs of beamline users, flexible solutions are also required. Moreover, the growing demand of quantitative image analysis impose an easy integration between the CT reconstruction process and the subsequent feature extraction step. This paper presents some of the software solutions adopted by the SYRMEP beamline of the Italian synchrotron radiation facility Elettra. By using the enhanced version of the reconstruction software here presented as well as data reduction and data analysis tools, beamline users can easily implement an integrated and comprehensive approach to the digital image processing and image analysis required by a tomography-oriented scientific workflow. [ABSTRACT FROM AUTHOR]

This paper reports the development and application of a novel thin-layer electrochemical microcell for in situ soft x-ray fluorescence and absorption microspectroscopy. The microcell, fabricated using ultraviolet lithography, is an improved version of concepts previously developed in our group, featuring a wide optical window that allows the extension of the range of accessible in situ microspectroscopy and imaging methods, including those requiring small emission take-off angles. The threeelectrode design implemented in the cell enables optimal electrochemical control. The first in situ experiment employing this new cell explores the electrochemical growth of a novel Mn-Co/polypyrrole composite that is a prospective electrocatalyst for Pt replacement in air cathodes. Morphological, compositional, and chemical-state distributions of Mn and Co codeposited with polypyrrole are subsequently performed in situ as a function of time and position, yielding otherwise unachievable information regarding the electrodeposition process. [ABSTRACT FROM AUTHOR]

The corrosion control of WC-Co type hardmetals is steadily gaining momentum for novel crucial applications in the Oil & Gas and food industries. The corrosion rate of the Co-based binder, and the extent to which coupling to WC speeds it up, are strongly influenced by alloying. In this paper, we investigate the impact of Cr on the corrosion-product film formation of Co- and Co Ni based hardmetal binders in acidic, neutral and alkaline aqueous solutions. We centred our study on the role of Cr in driving the distribution of oxidized Co and Ni at the micrometre scale, thanks to synchrotron-based soft-X ray microspectroscopy. We have investigated morphochemical distributions for the following grades: Co 96 Cr 4 , Co 48 Ni 48 Cr 4 , Co 50 Cr 50. Chemical-state mapping has been complemented by electrochemical measurements and metallographic observations. Amounts of Cr and Ni of ca. 50% notably increase the corrosion resistance in all ambients, with a stronger beneficial effect of the former element. 4% addition of Cr results in slight positive effects, with the exception of the Co Ni system in alkaline ambient, that, together with Co 50 Cr 50 , outperforms the other grades. In all investigated alloy-ambient combinations, a continuous oxidized metal film grows, onto which micrometric island form of shape and dimensions that depend on the specific grade and aggressive conditions. Quantitative descriptors of chemical-state maps and their theoretical interpretation in terms of electrochemical phase-formation by oxy-hydroxide precipitation, allow to correlate the island patterns with the degree of pseudopassivation. Unlabelled Image • Role of Cr in corrosion resistance of Co- and Co-Ni-based hardmetal model binders. • Corrosion of Co Cr based grades studied in aerated aqueous solutions in pH range 1–10. • Soft-X ray microspectroscopy yields chemical-state maps of pseudopassivation films. • Pseudopassivation layers form oxidized metal patterns, depending on attack conditions. • Corrosion resistance correlates with morphochemical details of oxide film patterns. [ABSTRACT FROM AUTHOR]

Human exposure to asbestos can cause a wide variety of lung diseases that are still a current major health concern, even if asbestos has been banned in many countries. It has been shown in many studies that asbestos fibers, ingested by alveolar macrophages, disrupt lung iron homeostasis by sequestering iron. Calcium can also be deposited on the fibers. The pathways along which iron and above all calcium interact with fibers are still unknown. Our aim was that of investigating if the iron accumulation induced by the inhaled asbestos fibers also involves calcium ions accumulation. Lung sections of asbestos-exposed mice were analyzed using an extremely sensitive procedure available at the synchrotron facilities, that provides morphological and chemical information based on X-ray fluorescence microspectroscopy (μ-XRF). In this study we show that (1) where conventional histochemical procedures revealed only weak deposits of iron and calcium, μ-XRF analysis is able to detect significant deposits of both iron and calcium on the inhaled asbestos fibers; (2) the extent of the deposition of these ions is proportionally directly related and (3) iron and calcium deposition on inhaled asbestos fibers is concomitant with the appearance of inflammatory and hyperplastic reactions. [ABSTRACT FROM AUTHOR]