Low-energy X-ray Fluorescence Research Articles

Bone lead variability in bone repository skeletal samples measured with portable x-ray fluorescence

Bone lead serves as a better, more accessible biomarker to many communities experiencing chronic exposure to lead. A new method using low energy x-ray fluorescence in a handheld device (portable XRF) allows us to measure this chronic biomarker in only a few minutes. However, many unknowns remain about this biomarker measured using a new low energy x-ray technique. The low energy of the new method was theorized to measure a slightly different portion of the bone than previous techniques, which could influence measurements at different bone sites and types. We tested how bone measurements varied across five bone sites: mid-tibial shaft, proximal tibia, distal tibia (ankle), ilium, and cranium. We found bone lead measurements are not significantly different between skeletal elements when measured using a portable XRF. On average, bone lead in the repository samples was measured to be 21.6 ± 21.3 μg/g with an XRF detection limit of 2.1 ± 0.5 μg/g. Cumulative lead exposure can be effectively measured using the portable XRF on a variety of bone types, but the tibia should be preferentially measured to compare between studies and individuals.

Impact of Sample Preparation Methods on Single-Cell X-ray Microscopy and Light Elemental Analysis Evaluated by Combined Low Energy X-ray Fluorescence, STXM and AFM.

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. 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. 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. 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.

Elemental changes in heart and coronaries after breast cancer radiotherapy assessed by synchrotron radiation soft X-ray spectromicroscopy

Radiotherapy (RT) plays a pivotal role in the treatment of breast cancer (BC) and various thoracic malignancies. Radiation induced heart disease (RIHD) is one such long term toxicity which can offset the improvement in cancer specific mortality. Long term normal tissue toxicity is becoming a bigger concern, as early diagnosis and the improvement in the treatment of these cancers has led to patients surviving longer. Our research group on Physics applied to biomedical sciences has been investigating the side effects of BC treatment (RT and chemotherapy) for more than ten years. The cardiac regeneration has been studied to better understand the damage that occurs following radiation procedures in the heart tissue after many thoracic cancer treatments. One possible complication is coronary artery disease induced by irradiation after radiotherapy in thoracic area. Studies on the structures of cardiac tissue and the distribution of low atomic weight element can help to understand mechanisms associated with damage to healthy tissue, as these are of fundamental importance to metabolism in biological systems. The present study aimed to elucidate how radiotherapy in the thoracic area causes damage in the coronary artery, and to verify the potential use of losartan in reducing, or even preventing, the side effects of irradiation in this artery. To assess elemental and morphological differences in aortic and coronary samples, the Low Energy X-Ray Fluorescence (LEXRF) technique using Synchrotron Radiation was employed. SR- LEXRF and scanning transmission X-ray microscopy measurements were carried out at the beamline TwinMic at Elettra Sincrotrone Triste, Italy.

Synchrotron radiation soft X-ray microscopy and low energy X-ray fluorescence to reveal elemental changes in spermatozoa treated with photobiomodulation therapy.

Male infertility is a worldwide clinical issue that increases the number of couples resorting to assisted reproductive technologies (ARTs) to achieve pregnancy. Photobiomodulation therapy (PBMT) is a promising technique that can biostimulate cells and tissues and it is currently successfully employed to enhance the sperm motility in vitro. Nevertheless, its use has been so far restricted to the research field. In the present work, we exploited two PBMT protocols at an 800 nm wavelength on sperm derived from infertile individuals, detecting an increase in sperm motility 1 hour after irradiation. Moreover, in order to add new information about the molecular effect of PBMT, the content of some light elements was evaluated using high resolution X-ray fluorescence imaging. Interestingly, an increase in Na content was detected in the irradiated samples, possibly suggesting a role of this element in sperm motility; indeed, a low Na content was previously correlated with a poor sperm quality, low semen volume, and modest fertilization rate. Amplifying the knowledge of PBMT in the ART field will expedite the translational potentiality of the PBMT use in clinical settings.

Elemental distribution in the aortic arch using LEXRF: Side effects of angiotensin receptor blockers as antihypertensive treatment

Hypertension is one of the major public health problems worldwide due to its strong impact on cardiovascular morbidity and mortality. It can cause damage in target organs such as arteries. Previous studies have shown that the blockade of angiotensin II type 1 receptor (AT1) with an angiotensin II receptor blocker (ARB) may reverse vascular pathology independent of blood pressure lowering. Antihypertensive agents such as ARBs have demonstrated some vascular and cardiac benefits. Studies on the distribution of elemental constituents in tissues have a great importance in the study of diseases since chemical imbalance can alter biological functions. The efficiency of ARBs in protecting organs at an elemental level has not been demonstrated in the literature. The aim of this work was to evaluate, at an elemental level, the effects of two ARBs (losartan and olmesartan) in the aortic arch of hypertensive rats. Low-energy X-ray fluorescence technique was used to analyze elemental and morphological differences in aortic samples. In view of the amount of O, Na, Mg and Zn in the aorta of the rats treated with losartan were comparable to the health rats, it can be conclude that losartan is more efficient in protect, at an elemental level, the aortic arch of hypertensive rats.

Impact of microscopic In fluctuations on the optical properties of InxGa1-xN blue light-emitting diodes assessed by low-energy X-ray fluorescence mapping using synchrotron radiation

Among the III-nitride semiconductors, InxGa1-xN is a key material for visible optical devices such as light-emitting diodes (LEDs), laser diodes, and solar cells. Light emission is achieved via electron-hole recombination within the InxGa1-xN layer. When InxGa1-xN-based blue LEDs were first commercialized, the high probability of electron-hole radiative recombination despite the presence of numerous threading dislocations was a mystery. Extensive studies have proposed that carrier localization in nanoscopic potential fluctuations due, for example, to the immiscibility between InN and GaN or random alloy fluctuations is a key mechanism for the high emission efficiency. In actual LED devices, not only nanoscopic potential fluctuations but also microscopic ones exist within the InxGa1-xN quantum well light-emitting layers. Herein we map the synchrotron radiation microbeam X-ray fluorescence of InxGa1-xN blue LEDs at a sub-micron level. To acquire weak signals of In, Ar, which is in the air and has a fluorescent X-ray energy similar to that of In, is evacuated from the sample chamber by He purge. As a result, we successfully visualize the spatial In distribution of InxGa1-xN layer nondestructively and present good agreement with optical properties. Additionally, we demonstrate that unlike nanoscopic fluctuations, microscopic In compositional fluctuations do not necessarily have positive effects on device performance. Appropriately controlling both nanoscopic and microscopic fluctuations at the same time is necessary to achieve supreme device performance.

Zinc incorporation in marine bivalve shells grown in mine-polluted seabed sediments: a case study in the Malfidano mining area (SW Sardinia, Italy).

Zinc incorporation into marine bivalve shells belonging to different genera (Donax, Glycymeris, Lentidium, and Chamelea) grown in mine-polluted seabed sediments (Zn up to 1% w/w) was investigated using x-ray diffraction (XRD), chemical analysis, soft x-ray microscopy combined with low-energy x-ray fluorescence (XRF) mapping, x-ray absorption spectroscopy (XAS), and transmission electron microscopy (TEM). These bivalves grew their shells, producing aragonite as the main biomineral and they were able to incorporate up to 2.0-80mg/kg of Zn, 5.4-60mg/kg of Fe and 0.5-4.5mg/kg of Mn. X-ray absorption near edge structure (XANES) analysis revealed that for all the investigated genera, Zn occurred as independent Zn mineral phases, i.e., it was not incorporated or adsorbed into the aragonitic lattice. Overall, our results indicated that Zn coordination environment depends on the amount of incorporated Zn. Zn phosphate was the most abundant species in Donax and Lentidium genera, whereas, Chamelea shells, characterized by the highest Zn concentrations, showed the prevalence of Zn-cysteine species (up to 56% of total speciation). Other Zn coordination species found in the investigated samples were Zn hydrate carbonate (hydrozincite) and Zn phosphate. On the basis of the coordination environments, it was deduced that bivalves have developed different biogeochemical mechanisms to regulate Zn content and its chemical speciation and that cysteine plays an important role as an active part of detoxification mechanism. This work represents a step forward for understanding bivalve biomineralization and its significance for environmental monitoring and paleoreconstruction.

Elemental distribution in ascending aortic after radiotherapy and chemotherapy by Low Energy X-ray Fluorescence spectroscopy

Breast cancer (BC) is the most frequent cancer and the leading cause of cancer-related mortality in women. The treatment techniques for the BC include chemotherapy (CT) and/or radiotherapy (RT) and can modify elementary the cell matrix by calcificating tissues due to biological and morphological changes. Also, treatments for BC induce cardiotoxicity and it is important to understand the mechanisms involved in order to prevent this late effect in treated breast cancer patients. The high incidence of cardiovascular mortality in breast cancer patients is partially credited to increased intimal and medial calcifications of the aorta. The aim of this work is to investigate the distibution of low atomic number elements such as Magnesium (Mg), due to its importance for the cardiac metabolism; iron (Fe), since BC treatment may be associated with oxidative stress; and Sodium (Na), that is extremely related to the damage of endothelial cells. An optimal technique to observe these changes in aorta tissue is soft X-ray FLuorescence that can provide elemental maps of these important elements. The results performed by Low Energy X-ray Fluorescence LEXRF analyses showed that when the tissue is submitted to treatments with CT and/or RT, some normal structures become disorganized, and consequently the intensity of elemental compounds can be changed. All the experiments were carried out at the TwinMic beamline at Elettra Synchrotron facility using as animal model Wistar rats in order to evaluate the distribution of Na, Mg and Fe in aorta walls of Wistar rats, after BC treatment. Simultaneous acquisition of LEXRF and attenuation coefficient maps suggest that the combined chemotherapy and radiotherapy caused more damage to the aortic tissue as compared to radiation therapy alone. These findings add an in-depth understanding of elemental lack or excess in the tissue and contribute to locate these changes.

Quantification of 2D elemental distribution maps of intermediate-thick biological sections by low energy synchrotron μ-X-ray fluorescence spectrometry

Two fundamental-parameter (FP) based models for quantification of 2D elemental distribution maps of intermediate-thick biological samples by synchrotron low energy μ-X-ray fluorescence spectrometry (SR-μ-XRF) are presented and applied to the elemental analysis in experiments with monochromatic focused photon beam excitation at two low energy X-ray fluorescence beamlines—TwinMic, Elettra Sincrotrone Trieste, Italy, and ID21, ESRF, Grenoble, France. The models assume intermediate-thick biological samples composed of measured elements, the sources of the measurable spectral lines, and by the residual matrix, which affects the measured intensities through absorption. In the first model a fixed residual matrix of the sample is assumed, while in the second model the residual matrix is obtained by the iteration refinement of elemental concentrations and an adjusted residual matrix. The absorption of the incident focused beam in the biological sample at each scanned pixel position, determined from the output of a photodiode or a CCD camera, is applied as a control in the iteration procedure of quantification.

A new large solid angle multi-element silicon drift detector system for low energy X-ray fluorescence spectroscopy

Low-energy X-ray fluorescence (LEXRF) is an essential tool for bio-related research of organic samples, whose composition is dominated by light elements. Working at energies below 2 keV and being able to detect fluorescence photons of lightweight elements such as carbon (277 eV) is still a challenge, since it requires in-vacuum operations to avoid in-air photon absorption. Moreover, the detectors must have a thin entrance window and collect photons at an angle of incidence near 90 degrees to minimize the absorption by the protective coating. Considering the low fluorescence yield of light elements, it is important to cover a substantial part of the solid angle detecting ideally all emitted X-ray fluorescence (XRF) photons. Furthermore, the energy resolution of the detection system should be close to the Fano limit in order to discriminate elements whose XRF emission lines are often very close within the energy spectra. To ensure all these features, a system consisting of four monolithic multi-element silicon drift detectors was developed. The use of four separate detector units allows optimizing the incidence angle on all the sensor elements. The multi-element approach in turn provides a lower leakage current on each anode, which, in combination with ultra-low noise preamplifiers, is necessary to achieve an energy resolution close to the Fano limit. The potential of the new detection system and its applicability for typical LEXRF applications has been proved on the Elettra TwinMic beamline.

Iron-related toxicity of single-walled carbon nanotubes and crocidolite fibres in human mesothelial cells investigated by Synchrotron XRF microscopy

Carbon nanotubes (CNTs) are promising products in industry and medicine, but there are several human health concerns since their fibrous structure resembles asbestos. The presence of transition metals, mainly iron, in the fibres seems also implicated in the pathogenetic mechanisms. To unravel the role of iron at mesothelial level, we compared the chemical changes induced in MeT-5A cells by the exposure to asbestos (crocidolite) or CNTs at different content of iron impurities (raw-SWCNTs, purified- and highly purified-SWCNTs). We applied synchrotron-based X-Ray Fluorescence (XRF) microscopy and soft X-ray imaging (absorption and phase contrast images) to monitor chemical and morphological changes of the exposed cells. In parallel, we performed a ferritin assay. X-ray microscopy imaging and XRF well localize the crocidolite fibres interacting with cells, as well as the damage-related morphological changes. Differently, CNTs presence could be only partially evinced by low energy XRF through carbon distribution and sometimes iron co-localisation. Compared to controls, the cells treated with raw-SWCNTs and crocidolite fibres showed a severe alteration of iron distribution and content, with concomitant stimulation of ferritin production. Interestingly, highly purified nanotubes did not altered iron metabolism. The data provide new insights for possible CNTs effects at mesothelial/pleural level in humans.

Alleviation of Al Toxicity by Si Is Associated with the Formation of Al-Si Complexes in Root Tissues of Sorghum.

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.

Current status of the TwinMic beamline at Elettra: asoft X-ray transmission and emission microscopy station.

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.

A new detector system for low energy X-ray fluorescence coupled with soft X-ray microscopy: First tests and characterization

The last decades have witnessed substantial efforts in the development of several detector technologies for X-ray fluorescence (XRF) applications. In spite of the increasing trend towards performing, cost-effective and reliable XRF systems, detectors for soft X-ray spectroscopy still remain a challenge, requiring further study, engineering and customization in order to yield effective and efficient systems. In this paper we report on the development, first characterization and tests of a novel multielement detector system based on low leakage current silicon drift detectors (SDD) coupled to ultra low noise custom CMOS preamplifiers for synchrotron-based low energy XRF. This new system exhibits the potential for improving the count rate by at least an order of magnitude resulting in ten-fold shorter dwell time at an energy resolution similar to that of single element silicon drift detectors.

Alterations in Low-Z Elements Distribution in Heart Tissue after Treatments to Breast Cancer Using LEXRF Technique

Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for the BC, including chemotherapy and/or radiotherapy, increased the survival rates for this type of cancer. One late complication induced by BC treatment is the cardiotoxicity. This term comprises different cardiotoxic side effects, which include blood pressure alterations, myocardial ischemia, congestive heart failure and other damages. This study aimed to evaluate the cardiac alterations induced by radiotherapy and chemotherapy, simulating a treatment for BC in Wistar rats. It is, therefore, important to understand the mechanisms involved in the cardiotoxicity, in order to prevent women from this late effect, when they undergo BC treatments. The major interests in this work are in Low atomic weight elements as Sodium, because it is strongly related to cardiomyocyte contraction; Magnesium, because it is important in the cardiac metabolism; and Iron, because BC treatment induced cardiotoxicity can be associated to the oxidative stress. Changes that occur in unhealthy tissues in case to cardiovascular damages can be better understood when elemental compounds and structures of healthy tissues are known. Low Energy X-ray Fluorescence (LEXRF) technique was used to obtain elemental maps of low Z-elements providing a semi-quantitative analysis of the tissues evaluated under different conditions. Through the technique LEXRF we obtained elemental and absorption maps. The results showed more damages when associating chemotherapy and radiotherapy in comparison to myocardium healthy. Those images taken together with light microscopy, X-ray absorption and phase contrast images, satisfactorily characterize the cardiac tissue for the first time in the literature, from the structural and morphological points of view. LEXRF was carried out at TwinMic beamline in the ELETTRA Synchrotron Fa-cility, at the beamline TwinMic, in Trieste, Italy.

Coelectrodeposition of Ternary Mn-Oxide/Polypyrrole Composites for ORR Electrocatalysts: A Study Based on Micro-X-ray Absorption Spectroscopy and X-ray Fluorescence Mapping

Low energy X-ray fluorescence (XRF) and soft X-ray absorption (XAS) microspectroscopies at high space-resolution are employed for the investigation of the coelectrodeposition of composites consisting of a polypyrrole(PPy)-matrix and Mn-based ternary dispersoids, that have been proposed as promising electrocatalysts for oxygen-reduction electrodes. Specifically, we studied Mn–Co–Cu/PP, Mn–Co–Mg/PPy and Mn–Ni–Mg/PPy co-electrodeposits. The Mn–Co–Cu system features the best ORR electrocatalytic activity in terms of electron transfer number, onset potential, half-wave potential and current density. XRF maps and micro-XAS spectra yield compositional and chemical state distributions, contributing unique molecular-level information on the pulse-plating processes. Mn, Ni, Co and Mg exhibit a bimodal distribution consisting of mesoscopic aggregates of micrometric globuli, separated by polymer-rich ridges. Within this common qualitative scenario, the individual systems exhibit quantitatively different chemical distribution patterns, resulting from specific electrokinetic and electrosorption properties of the single components. The electrodeposits consist of Mn3+,4+-oxide particles, accompanied by combinations of Co0/Co2+, Ni0/Ni2+ and Cu0,+/Cu2+ resulting from the alternance of cathodic and anodic pulses. The formation of highly electroactive Mn3+,4+ in the as-fabricated material is a specific feature of the ternary systems, deriving from synergistic stabilisation brought about by two types of bivalent dopants as well as by galvanic contact to elemental metal; this result represents a considerable improvement in material quality with respect to previously studied Mn/PPy and Mn-based/PPy binaries.

First results of a novel Silicon Drift Detector array designed for low energy X-ray fluorescence spectroscopy

We developed a trapezoidal shaped matrix with 8 cells of Silicon Drift Detectors (SDD) featuring a very low leakage current (below 180pA/cm2 at 20°C) and a shallow uniformly implanted p+ entrance window that enables sensitivity down to few hundreds of eV. The matrix consists of a completely depleted volume of silicon wafer subdivided into 4 square cells and 4 half-size triangular cells. The energy resolution of a single square cell, readout by the ultra-low noise SIRIO charge sensitive preamplifier, is 158eV FWHM at 5.9keV and 0°C. The total sensitive area of the matrix is 231mm2 and the wafer thickness is 450μm. The detector was developed in the frame of the INFN R&D project ReDSoX in collaboration with FBK, Trento. Its trapezoidal shape was chosen in order to optimize the detection geometry for the experimental requirements of low energy X-ray fluorescence (LEXRF) spectroscopy, aiming at achieving a large detection angle. We plan to exploit the complete detector at the TwinMic spectromicroscopy beamline at the Elettra Synchrotron (Trieste, Italy). The complete system, composed of 4 matrices, increases the solid angle coverage of the isotropic photoemission hemisphere about 4 times over the present detector configuration. We report on the layout of the SDD matrix and of the experimental set-up, as well as the spectroscopic performance measured both in the laboratory and at the experimental beamline.

A novel multi-cell silicon drift detector for Low Energy X-Ray Fluorescence (LEXRF) spectroscopy

The TwinMic spectromicroscope at Elettra is a multipurpose experimental station for full-field and scanning imaging modes and simultaneous acquisition of X-ray fluorescence. The actual LEXRF detection setup consists of eight single-cell Silicon Drift Detectors (SDD) in an annular configuration. Although they provide good performances in terms of both energy resolution and low-energy photon detection efficiency, they cover just about 4% of the whole photoemission solid angle. This is the main limitation of the present detection system, since large part of the emitted photons is lost and consequently a high acquisition time is required. In order to increase the solid angle, a new LEXRF detection system is being developed within a large collaboration of several institutes. The system, composed of 4 trapezoidal multi-cell silicon drift detectors, covers up to 40% of the photoemission hemisphere, so that this geometry provides a 10 times improvement over the present configuration. First measurements in the laboratory and on the TwinMic beamline have been performed in order to characterize a single trapezoidal detector, configured and controlled by means of two multichannel ASICs, which provide preamplification, shaping and peak-stretching, connected to acquisition electronics based on fast ADCs and FPGA and working under vacuum.

Direct mapping of 19F in 19FDG-6P in brain tissue at subcellular resolution using soft X-ray fluorescence

Low energy x-ray fluorescence (LEXRF) detection was optimized for imaging cerebral glucose metabolism by mapping the fluorine LEXRF signal of 19F in 19FDG, trapped as intracellular 19F-deoxyglucose-6-phosphate (19FDG-6P) at 1μm spatial resolution from 3μm thick brain slices. 19FDG metabolism was evaluated in brain structures closely resembling the general cerebral cytoarchitecture following formalin fixation of brain slices and their inclusion in an epon matrix. 2-dimensional distribution maps of 19FDG-6P were placed in a cytoarchitectural and morphological context by simultaneous LEXRF mapping of N and O, and scanning transmission x-ray (STXM) imaging. A disproportionately high uptake and metabolism of glucose was found in neuropil relative to intracellular domains of the cell body of hypothalamic neurons, showing directly that neurons, like glial cells, also metabolize glucose. As 19F-deoxyglucose-6P is structurally identical to 18F-deoxyglucose-6P, LEXRF of subcellular 19F provides a link to in vivo 18FDG PET, forming a novel basis for understanding the physiological mechanisms underlying the 18FDG PET image, and the contribution of neurons and glia to the PET signal.

Life science applications and research potential of the TwinMic spectromicroscopy station at ELETTRA

Since its opening to the users in late 2007, the TwinMic beamline at the Elettra synchrotron has been attracting the interest of a broad life science community. The recent development and implementation of a low energy x-ray fluorescence detection mode have increased the capability and the versatility of the scanning mode of the TwinMic microscope. Now using simultaneously the x-ray transmission and emission detection systems one can perform elemental, absorption and phase contrast imaging that provides complementary chemical and morphological information for the sample under investigation. The recent achievements in the performance of the instrument using combined acquisition modes for characterization of nano and micro-structured biomaterials will be illustrated with selected exemplary results.