Elettra-Sincrotrone Trieste S.C.p.A.

Effective bone regeneration requires scaffolds capable of guiding and supporting new mineralized matrix formation. In this study, silk fibroin constructs cultured with human mesenchymal stem cells (hBMSCs) in the presence of either Fetal Bovine Serum (FBS) or Human Platelet Lysate (hPL) are evaluated for their osteogenic potential. A distinctive aspect of this work is the combined use of synchrotron X-ray imaging and a convolutional neural network for high-resolution in situ three-dimensional scaffold osteogenic potential assessment. This approach enables precise evaluation of bone matrix arrangement within the scaffold architecture. Two-dimensional analysis reveals increased mineralization in pores with an average radius of ~115μm, area of ~4.0×104μm2, and eccentricity of ~0.7 in hPL construct. The subsequent three-dimensional analysis extends these findings by quantifying the spatial distribution and connectivity of the mineralized matrix across the scaffold volume. It identifies pores with an equivalent radius between 110 and 120μm, high surface area, and moderate sphericity (0.65-0.75) as optimal not only for mineral deposition but also for uniform 3D matrix propagation. Moreover, unsupervised clustering analysis also identifies optimal geometric interdependencies between pore size, surface area, and sphericity, offering new insights for rational design of high-performance scaffolds. The study demonstrates both the efficacy of silk fibroin scaffolds cultured with hPL in promoting bone regeneration and the relevance of a combined synchrotron imaging-artificial intelligence approach in quantitatively correlating three-dimensional porous geometry with regenerative outcomes.

Topological nodal line semimetal PdSn4 is investigated through high-pressure Raman spectroscopy, corroborated by first principles density functional theory (DFT) calculations. At ambient conditions, the Raman spectrum shows a broad peak structure at around 130 cm−1 together with several weak peaks. DFT calculations within the Ccce orthorhombic structure identify the 12 possible Raman active modes in this system below 140 cm−1, correlating well with the experimental observation. A comparison of the Raman spectra of RSn4 (R = Pd, Pt, and Au) showed a similar broad peak-like structure with slightly differing wavenumbers in agreement with a chemical pressure description of these systems. Indeed, phonon dispersions from DFT studies within the Ccce orthorhombic structure provided similar phonon band structures for both PdSn4 and PtSn4 and demonstrate that the orthorhombic lattice of PdSn4 to be stable at 25 GPa. In this pressure range, DFT as well as experiments showed a regular hardening of the Raman phonon modes. A careful analysis indicates that the pressure dependence of the mode positions has a different rate in the high- and low-pressure regions. This is an indication of a pressure-dependent isostructural phase transition in PdSn4, similar to that observed in PtSn4.

Mechanical ventilation (MV) can induce or exacerbate ventilator-induced lung injury (VILI), particularly in mechanically heterogeneous lungs with pre-existing injury. We investigated VILI in a rat model of bleomycin-induced lung injury and compared it with healthy controls using a combined in-vivo and ex-vivo imaging approach. Previously acquired in-vivo data from four-dimensional (4D) phase-contrast synchrotron micro-computed tomography (microCT) and forced oscillation measurements showed increased lung elastance and reduced local acinar strain in bleomycin-induced injured lungs at baseline and after injurious MV. To identify structural and mechanical correlates, we performed automated three-dimensional (3D) pore analysis and atomic force microscopy (AFM) on formalin-fixed, paraffin-embedded lung tissue, complemented by histology and spatial co-registration. Ex-vivo analysis revealed pronounced airspace enlargement after injurious MV of healthy lungs, whereas this effect was attenuated in fibrotic lungs. AFM demonstrated region-specific mechanical responses, and correlation analyses linked pore geometry and nanoscale stiffness to in-vivo lung mechanics. Spatial analysis further showed colocalization of VILI-associated airspace damage with injured regions. Overall, extracellular matrix remodelling modifies the lung’s mechanical response to injurious MV. This multiscale correlative approach provides mechanistic insight into the interplay between lung injury and VILI and informs ventilation strategies in structurally altered lungs.

The NaFeNb-(PO4)3, NFNP, material has been designed as a candidate anode material for sodium-ion batteries, as in its pristine form it combines the presence of Fe-(III) and Nb-(V)available for possible reduction upon Na insertionallowing for the formal introduction of 3 Na ions at reasonable potentials, and the robust NASICON structure with open channels for Na migration. The NFNP material has been successfully obtained by the solid-state route and fully characterized in terms of structure and transport properties by means of diffraction, XAS, and DFT analysis. Although promising, the electrochemical testing reveals that the initially satisfactory results in terms of capacity and Coulombic efficiencies fade upon cycling. The in-depth operando investigation, with the implementation of in situ XRD and XAS, unveiled a phase transition upon cycling; this involves the formation and accumulation of a low-symmetry secondary phase delivering lower capacity related to the Nb redox couples.

In situ soft X-ray imaging of α-MnO 2 ORR catalysts is advanced by the fabrication of a reliable wet-cell, enabling operando STXM studies under realistic electrochemical conditions.

PERCIVAL, “pixellated energy-resolving CMOS imager versatile and large”, is a 2-megapixel soft X-ray imager developed for use at FELs and modern-day synchrotrons. A combination of capabilities is necessary to meet the scientific needs: a large, uninterrupted imaging area with small pixels, high dynamic range, high frame rate, and soft X-ray suitable entrance window to the sensor. A single PERCIVAL sensor offers over 4 cm × 4 cm uninterrupted imaging area (1408 × 1484 pixels of 27 × 27 μm2). Three auto-adapting gains (per pixel per image) provide the large dynamic range from 13 e- noise to over 3 Me- signal. The sensor is designed for up to 300 Hz frame rate, and can be operated faster in ROI mode.The first generation of the sensor was hampered by severe crosstalk preventing parallel operation of ADC, streamout, and pixel switches and by non-uniformity of baselines over the sensor.A revised “respin” sensor addresses these issues at the root — and good noise performance at higher frame rates as well as a more uniform baseline can now be provided to users.The first generation DAQ system — still based on existing Virtex5 hardware — had limitations that ultimately prevented handling the fast data rates from a Percival running at full speed, or other complexities such as ROI operation. A complete overhaul of the percival-specific DAQ components (FPGA with periphery and firmware) today enables acquisition at envisioned frame rates and in ROI mode.This paper summarizes first laboratory results from the respin sensors in combination with the new DAQ hardware and firmware.

Selective mono-, homo- and heterodinuclear metalation is achieved within a chiral TPMA cage, offering a unified platform to disentangle confinement, nuclearity and second-sphere proton-relay effects in photocatalytic hydrogen evolution.

Ru3Sn7, an intermetallic compound with advanced catalytic properties, exhibits a complex crystal structure and intriguing electronic properties, making it an attractive candidate for investigations under high-pressure (HP). The structural, vibrational and electronic band structure of this compound were investigated at HP up to ∼20 GPa using synchrotron x-ray powder diffraction, micro-Raman, and density functional theory, respectively. Despite the local structural changes implied by a discernible reduction in the compressibility and distinct slope changes in the pressure evolution of the symmetric stretching vibrations of the Ru and Sn atoms around 8 GPa, the cubic structure is found to be stable throughout the pressure range. In support, our calculated phonon dispersion relation confirmed the stability of the cubic phase till the highest pressures. A comprehensive analysis of the Raman spectrum reveals the signatures of the pressure induced sudden strengthening of electron-phonon coupling (EPC) as early as 3 GPa which is backed by a bounce in the phonon and electron density of states (DOS). Electronic structure calculations demonstrate that the metallic nature of Ru3Sn7is preserved in the studied pressure range with a minor redistribution of electronic DOS across the Fermi level (EF). The band structure calculations predict intriguing changes in the electronic structure, revealing the pressure inducedd-phybridization through the high symmetry point of the Brillouin zone which is largely responsible for the observed reduction in the compressibility and enhancement of the EPC in Ru3Sn7.