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We report the temperature evolution of hydrogen bond (HB) chains and rings in Mn 5 [ ( PO 4 ) 2 ( PO 3 (OH)) 2 ] (HOH) 4 to reveal conduction pathways based on difference Fourier maps with neutron- and synchrotron x-ray diffraction data. Localized proton dynamics for the five distinct hydrogen sites were observed and identified in this study. Their temperature evaluation over ten orders of magnitude in time was followed by means of quasielastic neutron scattering, dielectric spectroscopy, and ab initio molecular dynamics. Two out of the five hydrogen sites are geometrically isolated and are not suitable for long-range proton conduction. Nevertheless, the detected dc conductivity points to long-range charge transport at elevated temperatures, which occurs most likely (1) over H4–H4 sites between semihelical HB chains (interchain-exchanges) and (2) by rotations of O1–H1 and site-exchanging H4–O10–O5 groups along each semihelical HB chain (intrachain-exchanges). The latter dynamics freeze into a proton-glass state at low temperatures. Rotational and site-exchanging motions of HOH and OH ligands seem to be facilitated by collective motions of framework polyhedra, which we detected by inelastic neutron scattering. [ABSTRACT FROM AUTHOR]

The work is devoted to the dosimetric studies of a low-intensity beam for the implementation of proton radiography on the proton therapy complex Prometeus. In contrast to therapy, radiography using proton beams requires low particle fluxes, less than 1 × 106 protons/(s cm2). The controlled uniform extraction of beams of such intensity at therapeutic accelerators is a significant challenge, and it requires the development of innovative approaches. This study is part of a series of studies on the Russian medical proton synchrotron for implementing the extraction of low-intensity beams. The paper presents data on the key parameter of the extracted beam—the absorbed dose—when performing radiographic plans with a scanning beam. It also provides a quantitative analysis based on computer simulation of the spatial characteristics of proton images obtained using the extracted beam parameters. [ABSTRACT FROM AUTHOR]

The lattice of the fourth-generation of the SYLA electron storage synchrotron of 6 GeV is scaled using the resources of the National Research Center Kurchatov Institute. Parameters of the storage synchrotron that provide design parameters of electron beams in the accumulator have been calculated. The dynamic aperture, momentum acceptance, and Touschek lifetime of the beams were determined, both in the case of no errors in the adjustment of magnetic structure elements and field values in a closed orbit and in their presence, taking into account losses due to synchrotron radiation and quantum excitation. Kicker magnets have been adapted to provide efficient off-axis injection. [ABSTRACT FROM AUTHOR]

The heavy ion facility for technological applications is developed at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. The booster synchrotron with electron cooling is one of the main parts of the facility. This work presents the beam dynamics simulation with betatron coupling and nonlinearities of the guided magnetic field. The transverse betatron coupling excited by electron cooling solenoid was compensated by the pair of skew quadrupole triplets with antisymmetric supply and located symmetrically relative to the solenoid center. The calculation of the vertical dispersion excited by the magnetic field of toroidal sections of the electron cooler was performed. The accelerator lattice was optimized for minimization of vertical dispersion. Another important factor of the beam dynamics is the tune dependence versus momentum deviation called chromaticity. To correct chromaticity, sextupole magnets are applied. On the other hand, sextupoles excite nonlinear resonances that can lead to significant limitation of the dynamic aperture. The dynamic aperture of the synchrotron was simulated by scanning of horizontal and vertical tunes in conditions of chromaticity and betatron coupling suppression. This method makes it possible to identify dangerous resonances. According to the calculations presented, a scheme with application of six sextupole families are developed. This scheme makes it possible to significantly reduce the influence of most dangerous resonances. The wide area of tunes with a fairly large dynamic aperture for particles with required momentum spread was found in simulations. Selection of the operating point in this particular area makes it possible to reduce the space charge effect on the dynamic aperture. At the chosen operating point, the influence of eddy currents and magnetic fields nonlinearities on the dynamic aperture was investigated. [ABSTRACT FROM AUTHOR]

Photoemission electron microscopy (PEEM) is a powerful technique for surface characterization that provides detailed information on the chemical and structural properties of materials at the nanoscale. In this study, the potential is explored using a machine learning algorithm called self‐organizing map with a relational perspective map (SOM‐RPM) for visualizing and analyzing complex PEEM‐generated datasets. The application of SOM‐RPM is demonstrated using synchrotron‐based X‐ray magnetic circular dichroism (XMCD)‐PEEM data acquired from a pyrrhotite sample. Traditional visualization approaches for XMCD‐PEEM data may not fully capture the complexity of the sample, especially in the case of heterogeneous materials. By applying SOM‐RPM to the XMCD‐PEEM data, a colored topographic map is created that represents the spectral similarities and dissimilarities among the pixels. This approach allows for a more intuitive and easily interpretable representation of the data without the need of data binning or spectral smoothing. The results of the SOM‐RPM analysis are compared to the conventional visualization approach, highlighting the advantages of SOM‐RPM in revealing features that are not readily observable in the conventional method. This study suggests that the SOM‐RPM approach can be used complimentarily for other PEEM‐based measurements, such as core level and valence band X‐ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

The long term broad-band spectral study of Flat Spectrum Radio Quasars during different flux states has the potential to infer the emission mechanisms and the cause of spectral variations. To scrutinize this, we performed a detailed broad-band spectral analysis of 3C 279 using simultaneous Swift - XRT / UVOT and Fermi - LAT observations spanning from 2008 August to 2022 June. We also supplement this with the simultaneous Nu STAR observations of the source. The optical/UV, X-ray, and γ-ray spectra were individually fitted by a power law to study the long term variation in the flux and the spectral indices. A combined spectral fit of simultaneous optical/UV and X-ray spectra was also performed to obtain the transition energy at which the spectral energy distribution is minimum. The correlation analysis suggests that the long term spectral variations of the source are mainly associated with the variations in the low energy index and the break energy of the broken power-law electron distribution which is responsible for the broad-band emission. The flux distribution of the source represents a lognormal variability while the γ-ray flux distribution showed a clear double lognormal behaviour. The spectral index distributions were again normal except for γ-ray which showed a double-Gaussian behaviour. This indicates that the lognormal variability of the source may be associated with the normal variations in the spectral index. The broad-band spectral fit of the source using synchrotron and inverse Compton processes indicates different emission processes are active at optical/UV, X-ray, and γ-ray energies. [ABSTRACT FROM AUTHOR]

We report the direct formation of dicarboxylate-based coordination polymer glasses through thermal dehydration. The rearrangement of the coordination networks caused by dehydration was monitored by in situ powder X-ray diffraction, infrared spectroscopy, and synchrotron X-ray characterizations. The microporosity and mechanical properties of these glasses were investigated. [ABSTRACT FROM AUTHOR]

Advanced ionic conductors are crucial for a large variety of contemporary technologies spanning solid state ion batteries, fuel cells, gas sensors, water desalination, etc. In this work, we report on a new member of KTiOPO4-structured materials, NaGaPO4F, with sodium-ion conductivity. NaGaPO4F has been obtained for the first time via a facile two-step synthesis consisting of a hydrothermal preparation of an ammonia-based precursor, NH4GaPO4F, followed by an ion exchange reaction with NaNO3. Its crystal structure was precisely refined using a combination of synchrotron X-ray powder diffraction and electron diffraction tomography. The material is thermally stable upon 450 °C showing no significant structural transformations or degradation but only a ∼1% cell volume expansion. Na-ion mobility in NaGaPO4F was investigated by a joint experimental and computational approach comprising solid-state nuclear magnetic resonance (NMR) and density functional theory (DFT). DFT and bond-valence site energy (BVSE) calculations reveal 3D diffusion of sodium in the [GaPO4F] framework with migration barriers amounting to 0.22 and 0.44 eV, respectively, while NMR yields 0.3–0.5 eV that, being coupled with a calculated bandgap of ∼4.25 eV, makes NaGaPO4F a promising fast Na-ion conductor. [ABSTRACT FROM AUTHOR]

In this Letter, we report on the concept and analysis of a low-emittance electron storage ring, in which the electron beams undergo an early-stage self-amplified spontaneous emission lasing process on a turn-by-turn basis. The lasing process for each pass through a long undulator in the ring is terminated when the radiated power is still negligible compared to the total synchrotron loss of each circulation, and the electron beams can be maintained in an equilibrium state that supports sustainable lasing. A self-consistent model is derived for evaluation of the properties of the electron beams, and a design with numerical modeling is presented that demonstrates the feasibility of generating short wavelength radiation at the kW power level. [ABSTRACT FROM AUTHOR]

In the present study, porous inorganic polymers were synthetized by alkaline activation of volcanic ash and ' ghiara' paleosoil using Al swarf and Al commercial powder as pore inducing agent. The Alkali Activated Foams (AAFs) were characterized in terms of mineralogy, macro- and microstructure, by synchrotron X-ray diffraction, electron microscopy, infrared spectroscopy, and X-ray computed microtomography. The obtained porous matrices show different microstructures; the size and extent of the pores vary according to the type, size and amount of the foaming agent and to the viscosity of the pastes. Addition of Al swarf to the volcanic ash based slurry generates expansion of the paste, whereas ghiara based one do not expand due to a lower viscosity of the slurry. Moreover, results indicate that the Al addition procedure during the synthesis affects the pore characteristics: Al powder added directly to the volcanic ash-based slurry triggers an incipient pore nucleation, whereas AAFs prepared adding Al powder to the solid mix do not develop an extended pore network. Results of this research show that porosity can be efficiently tailored in volcanic based AAFs by regulating the amount and type of Al. [ABSTRACT FROM AUTHOR]

Background: Diagnostic accuracy of endomyocardial biopsy could improve if clinically safe magnetic resonance (MR)-compatible bioptomes were available. We explored two novel MR-compatible cardiac bioptomes for performance, safety, and clinical viability, employing in vivo minipig trials and phase-contrast synchrotron radiation computed microtomography (SRµCT). Methods: Analysis of ex vivo obtained pig endomyocardial biopsies was performed using phase-contrast SRµCT and conventional two-dimensional histology. The technical performance was evaluated by measuring volume, inner and outer integrities, compression, and histological diagnostic value in 3 sets (6 per set) of biopsies for each experimental bioptome. The bioptomes were tested in vivo in 3 healthy minipigs per bioptome. The clinical feasibility was evaluated by procedural and cutting success as well as histological diagnostic value. Results: The bioptome with the 'grind-grind' design achieved similar values to control in compression (p = 0.822), inner (p = 0.628), and outer (p = 0.507), integrities ex vivo. It showed a better performance in the in vivo real-time MRI setting demonstrating a higher cutting success (91.7%) than the 'grind-anvil' (86.2%) design. In both ex vivo and in vivo evaluations, the 'grind-grind' design displayed sufficient diagnostic value (83% and 95%). The 'grind-anvil' design showed adequate diagnostic value both ex vivo and in vivo (78% and 87.5%) but was not comparable to control according to the three-dimensional (3D) analysis. Conclusion: A novel MR-compatible bioptome was identified as plausible in a clinical setting. Additionally, SRµCT and subsequent 3D structural analysis could be valuable in the label-free investigation of myocardial tissue at a micrometer level. Relevance statement: Implementation of MR-guided biopsy can improve animal studies on structural myocardial changes at any point in an experimental setup. With further improvements in guiding catheters, MR-guided biopsy, using the new bioptome, has a potential to increase quality and diagnostic accuracy in patients both with structural and inflammatory cardiomyopathies. Key points: • Novel MR-compatible bioptomes show promise for a clinical application. • SRµCT enabled detailed analysis of endomyocardial biopsies. • The bioptomes showed adequate in vivo performance without major complications. [ABSTRACT FROM AUTHOR]

The unit-cell parameters and volumes of geikielite (MgTiO3) and ilmenite (FeTiO3) were investigated at high temperatures up to 700 K and ambient pressure, using in-situ angle-dispersive synchrotron X-ray diffraction. No phase transition was detected over the experimental temperature range. Using (Berman in J Petrol 29:445–522, 1988. 10.1093/petrology/29.2.445) equations to fit the temperature-volume data, the volumetric thermal expansion coefficients at ambient conditions (αV0) of MgTiO3 and FeTiO3 were obtained as follows: 2.55 (6) × 10–5 K−1 and 2.82 (10) × 10–5 K−1, respectively. We infer that the larger effective ionic radius of Fe2+(VI) (0.78 Å) than that of Mg2+(VI) (0.72 Å) renders FeTiO3 has a larger volumetric thermal expansivity than MgTiO3. Simultaneously, the refined axial thermal expansion coefficients under ambient conditions are αa0 = 0.74 (3) × 10–5 K−1 and αc0 = 1.08 (5) × 10–5 K−1 for the a-axis and c-axis of MgTiO3, respectively, and αa0 = 0.95 (5) × 10–5 K−1 and αc0 = 0.92 (12) × 10–5 K−1 for the a-axis and c-axis of FeTiO3, respectively. The axial thermal expansivity of MgTiO3 is anisotropic, but that of FeTiO3 is nearly isotropic. We infer that the main reason for the different axial thermal expansivity between MgTiO3 and FeTiO3 is that the thermal expansion mode of the Mg-O bond in MgTiO3 is different from that of the Fe–O bonds in FeTiO3. [ABSTRACT FROM AUTHOR]

The microstructural evolution of a thermoplastic polyurethane (TPU) with low hard segment content has been monitored utilizing in situ real-time synchrotron small angle X-ray scattering (SAXS) and time-domain nuclear magnetic resonance (NMR) measurements. The TPU is composed of 23 wt% of [4,4-methylenediphenyl diisocyanate (MDI)]-[1,4-butanediol (BD)] chain segments, which form hard domains, as [polytetrahydrofuran (PTHF)] forming soft domains. The number and distribution of monomer units in hard blocks is determined by the successive self-nucleation and annealing thermal fractionation technique. In situ SAXS method reveals heating-induced increase in the spacing of hard and soft domains, while time-domain 1H-NMR characterizes the changes in the phase composition and chain dynamics in these domains. A glassy fraction of short MDI-BD chain segments in hard domains passes through Tg above ambient temperature. At higher temperatures, MDI-BD nanocrystals start to melt. Sequence length distribution of MDI-BD chain segments causes a distribution in crystal sizes and wide melting temperature range. The melting is accompanied by the mixing of MDI-BD with PTHF segments in soft domains, and by increase in segmental mobility in these domains. Above 180 °C, the TPU melt is homogeneous on the scale above nanometers according to SAXS data. [ABSTRACT FROM AUTHOR]

The development of a sample environment for in situ x-ray characterization during metal Electron Beam Powder Bed Fusion (PBF-EB), called MiniMelt, is presented. The design considerations, the features of the equipment, and its implementation at the synchrotron facility PETRA III at Deutsches Elektronen-Synchrotron, Hamburg, Germany, are described. The equipment is based on the commercially available Freemelt ONE PBF-EB system but has been customized with a unique process chamber to enable real-time synchrotron measurements during the additive manufacturing process. Furthermore, a new unconfined powder bed design to replicate the conditions of the full-scale PBF-EB process is introduced. The first radiography (15 kHz) and diffraction (1 kHz) measurements of PBF-EB with a hot-work tool steel and a Ni-base superalloy, as well as bulk metal melting with the CMSX-4 alloy, using the sample environment are presented. MiniMelt enables time-resolved investigations of the dynamic phenomena taking place during multi-layer PBF-EB, facilitating process understanding and development of advanced process strategies and materials for PBF-EB. [ABSTRACT FROM AUTHOR]

Rapid compression experiments performed using a dynamic diamond anvil cell (dDAC) offer the opportunity to study compression rate-dependent phenomena, which provide critical knowledge of the phase transition kinetics of materials. However, direct probing of the structure evolution of materials is scarce and so far limited to the synchrotron based x-ray diffraction technique. Here, we present a time-resolved Raman spectroscopy technique to monitor the structural evolutions in a subsecond time resolution. Instead of applying a shutter-based synchronization scheme in previous work, we directly coupled and synchronized the spectrometers with the dDAC, providing sequential Raman data over a broad pressure range. The capability and versatility of this technique are verified by in situ observation of the phase transition processes of three rapid compressed samples. Not only the phase transition pressures but also the transition pathways are reproduced with good accuracy. This approach has the potential to serve as an important complement to x-ray diffraction applied to study the kinetics of phase transitions occurring on time scales of seconds and above. [ABSTRACT FROM AUTHOR]

The utilization of a low-frequency (<200 MHz) RF system in storage facilitates the attainment of ultra-low emittances in synchrotron light sources through on-axis injection. This paper focuses on the development of a low-frequency normal conducting (NC) cavity with higher-order mode (HOM) damping for fourth-generation synchrotron light sources. We propose a novel approach to achieve efficient HOM damping in a NC cavity by optimizing the lowest frequency HOM and implementing a beam-line absorber. Notably, unlike conventional NC cavities, the presence of a large beam tube for the beam-line absorber does not compromise the accelerating performance in a coaxial resonant cavity, enabling effective HOM damping while maintaining a high shunt impedance. Through simulations, the prototype design of a 166.6 MHz HOM-damped cavity demonstrates a fundamental mode impedance of ∼8 MΩ, with longitudinal and transverse HOM impedances below 2.0 and 50 kΩ/m, respectively. [ABSTRACT FROM AUTHOR]

The geochemistry and mineralogy of Mn nodules offer crucial insights into the origins, environmental changes, and distribution of abyssal resources. However, the conventional laboratory X-ray diffractometer, usually employed for semi-quantitative analysis of mineral composition in Mn nodules, often fails to sufficiently detect minor phases due to beam flux limitations and high background signals. In this study, we investigated differences in manganate composition, even when comprising around 1% of the phase fraction, in two manganese nodules (KC-8 and KODOS-10) using high-resolution synchrotron X-ray diffraction. The Mn/Fe ratios of KC-8 and KODOS-10 were 1.32 and 6.24, respectively, indicating that KC-8 and KODOS-10 were predominantly formed in hydrogenetic and diagenetic environments. Both samples contained quartz, vernadite, buserite, and feldspar. Todorokite and illite were exclusively observed in KODOS-10. In KC-8, the phase fractions of vernadite and buserite among manganates ranged from 94(5)%–100(4)% and 6(1)%–0%, respectively. However, in KODOS-10, the fractions of vernadite, buserite, and todorokite ranged from 47(1)%–56(2)%, 33.6(4)%–40.1(3)%, and 10(3)%–16.3(8)%, respectively. [ABSTRACT FROM AUTHOR]

The structure of (R)‐rasagiline mesylate [(R)‐RasH+·Mes−], an active pharmaceutical ingredient used to treat Parkinson's disease, is presented. The structure was determined from laboratory and synchrotron powder diffraction data, refined using the Rietveld method, and validated and optimized using dispersion‐corrected DFT calculations. The unit‐cell parameters obtained in both experiments are in good agreement and the refinement with both datasets converged to good agreement factors. The final parameters obtained from laboratory data were a = 5.4905 (8), b = 6.536 (2), c = 38.953 (3) Å, V = 1398.0 (4) Å3 and from synchrotron powder data were a = 5.487530 (10) Å, b = 6.528939 (12) Å, c = 38.94313 (9) Å, V = 1395.245 (5) Å3 with Z = 4 and space group P212121. Preferred orientation was properly accounted for using the synchrotron radiation data, leading to a March–Dollase parameter of 1.140 (1) instead of the 0.642 (1) value obtained from laboratory data. In the structure, (R)‐RasH+ moieties form layers parallel to the ab plane connected by mesylate ions through N—H...O and C—H...O hydrogen bonds. These layers stack along the c axis and are further connected by C—H...π interactions. Hirshfeld surface analysis and fingerprint plot calculations indicate that the main interactions are: H...H (50.9%), H...C/C...H (27.1%) and H...O/O...H (21.1%). [ABSTRACT FROM AUTHOR]

The standard (Bose–Einstein/Fermi–Dirac, or Maxwell–Boltzmann) distribution from the relativistic ideal gas model is used to study the transverse momentum ( p T ) spectra of identified charged hadrons ( π − , π + , K − , K + , p ¯ , and p) with different rapidities produced in inelastic proton–proton ( p p ) collisions at a Super Proton Synchrotron (SPS). The experimental data measured using the NA61/SHINE Collaboration at the center-of-mass (c.m.) energies s = 6.3 , 7.7, 8.8, 12.3, and 17.3 GeV are fitted well with the distribution. It is shown that the effective temperature ( T e f f or T), kinetic freeze-out temperature ( T 0 ), and initial temperature ( T i ) decrease with the increase in rapidity and increase with the increase in c.m. energy. The kinetic freeze-out volume (V) extracted from the π − , π + , K − , K + , and p ¯ spectra decreases with the rapidity and increase with the c.m. energy. The opposite tendency of V, extracted from the p spectra, is observed to be increasing with the rapidity and decreasing with the c.m. energy due to the effect of leading protons. [ABSTRACT FROM AUTHOR]

To examine the pore structure characteristics of sandy silt in metro tunnel surrounding rock, the pore size distribution patterns and fractal dimension of sandy silt samples were determined through small-angle X-ray scattering (SAXS) experiments. This study also explored the relationship between the internal microscale pore structure of sandy silt and its macroscopic behavior. The results show that spherical pores within sandy silt predominantly exist in the forms of micropores and mesopores, with a concentrated distribution in the pore size range of 20–50 nm. Moreover, for scatterers with shapes like ellipsoids and disks, a smaller ratio of height to diameter or major axis to minor axis corresponds to a narrower range in observed pore diameter distribution, accompanied by a higher volume fraction. Meanwhile, the fractal dimensions for sandy silt samples B-1, B-2, and B-3 were 2.33, 2.33, and 2.38, respectively, aligning with the range of 2–3. The augmentation of fractal dimension corresponds to heightened surface irregularity or roughness, indicating a moderately smooth sandy silt surface. Additionally, the results show that the various deformation and strength characteristics possessed by the soil can be considered as a comprehensive reflection of the adjustment and evolution of its internal microscale pore structure elements. By utilizing the pore size distribution features and fractal dimension of the internal pore structure, a quantitative relationship between the internal pore structure of sandy silt and its macroscopic permeability or mechanical properties can be established. [ABSTRACT FROM AUTHOR]

The rheological properties of fresh concrete are a direct function of the interaction behaviour of the granular inventory of the concrete (i.e., gravel, sand and cement) and especially of the colloidal fractions of cement. Under low shear stresses, agglomeration of colloidal particles is observed, while at high shear stresses, dispersion of these agglomerates occurs. Besides the agglomeration state, the formation of shear banding, zones with concentrated shear flow, is another controlling mechanism of the flow behaviour of cement suspensions. Rheological creep tests in this study are focused on investigating the influence of shear history and hydration process on thixotropy of cement suspension. In this paper, the meaning of the word thixotropy is slightly extended to additionally encompass rheological aging and hydration effects. Selected samples were analyzed by coupling a rheometer to synchrotron X‐ray tomography to gain insight into the shear‐induced microstructural changes during shear start‐up tests. The observations show heterogeneities in the velocity profile in the shear gap and the development of shear banding. [ABSTRACT FROM AUTHOR]

The dynamic charge density of KZnB3O6, which contains edge-sharing BO4 units, has been characterized using laboratory and synchrotron X-ray diffraction techniques. The experimental electron density distribution (EDD) was constructed using the maximum-entropy method (MEM) from single crystal diffraction data obtained at 81 and 298 K. Additionally, MEM-based pattern fitting (MPF) method was employed to refine the synchrotron powder diffraction data obtained at 100 K. Both the room-temperature single crystal diffraction data and the cryogenic synchrotron powder diffraction data reveal an intriguing phenomenon: the edge-shared B2O2 ring exhibits a significant charge density accumulation between the O atoms. Further analysis of high-quality single crystal diffraction data collected at 81 K, with both high resolution and large signal-to-noise ratio, reveals no direct O–O bonding within the B2O2 ring. The experimental EDD of KZnB3O6 obtained aligns with the results obtained from ab-initio calculations. Our work underscores the importance of obtaining high-quality experimental data to accurately determine EDDs. [ABSTRACT FROM AUTHOR]

Mycelia were cultivated from a Thai wild mushroom identified as Ganoderma australe based on polymerase chain reaction (PCR) and morphological analyses. The mycelial extracts were examined for their active ingredients using a liquid chromatography-tandem mass spectrometry (LC‒MS/MS) method. This revealed the presence of lovastatin and tentative compounds including p-coumaric, nicotinamide, gamma-aminobutyric acid, choline, nucleosides, amino acids, and saccharides. The extracts had an inhibitory effect on the activity of HMG-CoA reductase in a concentration-dependent manner. At 2.5 mg/mL, the G. australe extracts did not interfere with the viability of HepG2 spheroids, but their biochemical composition was altered as determined by Fourier-transform infrared (FTIR) spectroscopy. The lipid profile of the spheroids treated with the mycelial extract was distinct from that of the control and the 5 µM lovastatin treatment, corresponding with the production of cholesterol by the spheroids. The mycelia of G. australe increased the percentage of high-density lipoprotein (HDL) production to 71.35 ± 2.74%, compared to the control and lovastatin-treated spheroids (33.26 ± 3.15% and 32.13 ± 3.24%, respectively). This study revealed the superior effect of natural compound mixtures to pure lovastatin, and the potential use of Thailand's wild G. australe as a functional food to prevent or alleviate hypercholesterolemia. [ABSTRACT FROM AUTHOR]

Shear particle acceleration is a promising candidate for the origin of extended high-energy emission in extra-galactic jets. In this paper, we explore the applicability of a shear model to 24 X-ray knots in the large-scale jets of FR II radio galaxies and study the jet properties by modelling the multiwavelength spectral energy distributions (SEDs) in a leptonic framework including synchrotron and inverse Compton–CMB processes. In order to improve spectral modelling, we analyse Fermi -LAT data for five sources and reanalyse archival data of Chandra on 15 knots, exploring the radio to X-ray connection. We show that the X-ray SEDs of these knots can be satisfactorily modelled by synchrotron radiation from a second, shear-accelerated electron population reaching multi-TeV energies. The inferred flow speeds are compatible with large-scale jets being mildly relativistic. We explore two different shear flow profiles (i.e. linearly decreasing and power law) and find that the required spine speeds differ only slightly, supporting the notion that for higher flow speeds the variations in particle spectral indices are less dependent on the presumed velocity profile. The derived magnetic field strengths are in the range of a few to 10 µG and the required power in non-thermal particles is typically well below the Eddington constraint. Finally, the inferred parameters are used to constrain the potential of FR II jets as possible ultra-high-energy cosmic-ray accelerators. [ABSTRACT FROM AUTHOR]

Microbeam radiation therapy (MRT) is a radiotherapy technique combining spatial fractionation of the dose distribution on a micrometric scale, X-rays in the 50-500 keV range and dose rates up to 16 x 10³ Gy s-1. Nowadays, in vivo dosimetry remains a challenge due to the ultra-high radiation fluxes involved and the need for high-spatial-resolution detectors. The aim here was to develop a striped diamond portal detector enabling online microbeam monitoring during synchrotron MRT treatments. The detector, a 550 mm bulk monocrystalline diamond, is an eight-strip device, of height 3 mm, width 178 mm and with 60 mm spaced strips, surrounded by a guard ring. An eight-channel ASIC circuit for charge integration and digitization has been designed and tested. Characterization tests were performed at the ID17 biomedical beamline of the European Synchrotron Radiation Facility (ESRF). The detector measured direct and attenuated microbeams as well as interbeam fluxes with a precision level of 1%. Tests on phantoms (RW3 and anthropomorphic head phantoms) were performed and compared with simulations. Synchrotron radiation measurements were performed on an RW3 phantom for strips facing a microbeam and for strips facing an interbeam area. A 2% difference between experiments and simulations was found. In more complex geometries, a preliminary study showed that the absolute differences between simulated and recorded transmitted beams were within 2%. Obtained results showed the feasibility of performing MRT portal monitoring using a microstriped diamond detector. Online dosimetric measurements are currently ongoing during clinical veterinary trials at ESRF, and the next 153-strip detector prototype, covering the entire irradiation field, is being finalized at our institution. [ABSTRACT FROM AUTHOR]

In situ X-ray scattering measurements of CsPbX3 (X = Cl, Br, I) nanocrystal formation and halide exchange at NSLS-II beamlines were performed in an automated flow reactor. Total scattering measurements were performed at the 28-ID-2 (XPD) beamline and small-angle X-ray scattering at the 16-ID (LiX) beamline. Nanocrystal structural parameters of interest, including size, size distribution and atomic structure, were extracted from modeling the total scattering data. The results highlight the potential of these beamlines and the measurement protocols described in this study for studying dynamic processes of colloidal nanocrystal synthesis in solution with timescales on the order of seconds. [ABSTRACT FROM AUTHOR]

Synchrotron radiation can be used as a light source in X-ray microscopy to acquire a high-resolution image of a microscale object for tomography. However, numerous projections must be captured for a high-quality tomographic image to be reconstructed; thus, image acquisition is time consuming. Such dense imaging is not only expensive and time consuming but also results in the target receiving a large dose of radiation. To resolve these problems, sparse acquisition techniques have been proposed; however, the generated images often have many artefacts and are noisy. In this study, a deep-learning-based approach is proposed for the tomographic reconstruction of sparse-view projections that are acquired with a synchrotron light source; this approach proceeds as follows. A convolutional neural network (CNN) is used to first interpolate sparse X-ray projections and then synthesize a sufficiently large set of images to produce a sinogram. After the sinogram is constructed, a second CNN is used for error correction. In experiments, this method successfully produced high-quality tomography images from sparse-view projections for two data sets comprising Drosophila and mouse tomography images. However, the initial results for the smaller mouse data set were poor; therefore, transfer learning was used to apply the Drosophila model to the mouse data set, greatly improving the quality of the reconstructed sinogram. The method could be used to achieve high-quality tomography while reducing the radiation dose to imaging subjects and the imaging time and cost. [ABSTRACT FROM AUTHOR]

The NA64 experiment is a fixed-target experiment at the CERN Super Proton Synchrotron combining the active beam dump and missing energy techniques to search for rare events with 100–150 GeV electron or muon beams. The article presents the program of the NA64 experiment to explore dark sectors coupled to muons, NA64 . The experiment looks for a light vector boson produced in the bremsstrahlung reaction and coupled to the second and third lepton generations through the current. The existence of this boson could explain the () muon anomaly and Dark Matter. In this paper, the method of the search for this boson, the setup and sensitivity of the experiment are described. The results and future plans are also given. [ABSTRACT FROM AUTHOR]

The performance of batteries and the associated operating areas depend, among other things, on the 3D microstructures of the electrode materials, and thus fundamental research is required in the field of electrode design. A multiscale microstructure‐resolved 3D model is developed that investigates two different LiFePO4 freeze‐casted electrode structures, that is, cellular and lamellar. The microstructure is simulated directly from the X‐ray computed tomography data and the nanostructure is combined with the pseudo‐2D simulation approach, where the morphological parameters and the distribution of the binder, carbon, and LiFePO4 are obtained from ex situ focused ion beam scanning electron microscopy measurements. The discharge performance shows that the lamellar structure exhibits a lower ohmic overvoltage and achieves a higher gravimetric capacity compared to the cellular structure, even though both electrode materials have the same porosity and amount of active material. The simulation reveals that the performance is not only directly influenced by the lithium‐ion transport through the porous structure but also by the current distribution through the active material. Based on these insights, lamellar electrode structures should be considered for next‐generation battery electrodes. The modeling approach can assist in electrode fabrication by identifying defects or suggesting better structural parameters. [ABSTRACT FROM AUTHOR]

Many particle accelerators rely on maintaining low pressures to ensure efficient operation, minimize beam losses, and reduce radiation background. To ensure a beam lifetime of 1-20 hours for the Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME) vacuum system, an ideal average dynamic pressure of 1×10-9 mbar was targeted. This pressure was intended to be maintained while running the accelerator at a current of 400 mA after a cumulative dose of 100 Ah. In this study, a MATLAB code was employed to develop a series of one-dimensional equations that simulate the behavior of the vacuum system within the SESAME storage ring. The proposed model was then compared with the results generated by the VACCALC software and the Particle Monte Carlo (TPMC) MOLFLOW code, establishing a comprehensive assessment framework. The collected data from the model was subsequently compared with the recorded static and dynamic pressure measurements obtained during more than 1000 Ah of beam conditioning at 2.5 GeV. In results, the projected and actual values of dynamic pressures exhibited a satisfactory degree of agreement across the investigated range of beam conditioning doses, with a consistency factor exceeding 2 after a 100 Ah dose. [ABSTRACT FROM AUTHOR]

The Second Gamma-ray Burst Catalogue (2FLGC) was announced by the Fermi Large Area Telescope (Fermi-LAT) Collaboration. It includes 29 bursts with photon energy higher than 10 GeV. Gamma-ray burst (GRB) afterglow observations have been adequately explained by the classic synchrotron forward-shock model, however, photon energies greater than 10 GeV from these transient events are challenging, if not impossible, to characterize using this afterglow model. Recently, the closure relations (CRs) of the synchrotron self-Compton (SSC) forward-shock model evolving in a stellar wind and homogeneous medium was presented to analyse the evolution of the spectral and temporal indexes of those bursts reported in 2FLGC. In this work, we provide the CRs of the same afterglow model, but evolving in an intermediate density profile (∝r−k) with 0 ≤ k ≤ 2.5, taking into account the adiabatic/radiative regime and with/without energy injection for any value of the electron spectral index. The results show that the current model accounts for a considerable subset of GRBs that cannot be interpreted in either stellar-wind or homogeneous afterglow SSC model. The analysis indicates that the best-stratified scenario is most consistent with k = 0.5 for no-energy injection and k = 2.5 for energy injection. [ABSTRACT FROM AUTHOR]

This work unveils the idea that the cariogenic status of the oral cavity (the presence of active caries lesions) can be predicted via a lineshape analysis of the infrared spectral signatures of the secondary structure of proteins in dental biofilms. These spectral signatures that work as natural markers also show strong sensitivity to the application in patients of a so-called modulator—a medicinal agent (a pelleted mineral complex with calcium glycerophosphate). For the first time, according to our knowledge, in terms of deconvolution of the complete spectral profile of the amide I and amide II bands, significant intra- and intergroup differences were determined in the secondary structure of proteins in the dental biofilm of patients with a healthy oral cavity and with a carious pathology. This allowed to conduct a mathematical assessment of the spectral shifts in proteins' secondary structure in connection with the cariogenic situation in the oral cavity and with an external modulation. It was shown that only for the component parallel β-strands in the amide profile of the biofilm, a statistically significant (p < 0.05) change in its percentage weight (composition) was registered in a cariogenic situation (presence of active caries lesions). Note that no significant differences were detected in a normal situation (control) and in the presence of a carious pathology before and after the application of the modulator. The change in the frequency and percentage weight of parallel β-strands in the spectra of dental biofilms proved to be the result of the presence of cariogenic mutans streptococci in the film as well as of the products of their metabolism—glucan polymers. We foresee that the results presented here can inherently provide the basis for the infrared spectral diagnosis of changes (shifts) in the oral microbiome driven by the development of the carious process in the oral cavity as well as for the choice of optimal therapeutic treatments of caries based on microbiome-directed prevention measures. [ABSTRACT FROM AUTHOR]

We have analysed SnO2 with a combination of synchrotron X-ray diffraction and X-ray absorption spectroscopy across a pressure range of 0→82.9 GPa with thermal annealing by a CO2 laser allowing access to all of the known high-density polymorphs of SnO2 , and here report their crystallographic information. The metastability of the post-rutile α - PbO2 and PdF2 structures in SnO2 are investigated by experiment and PW-DFT simulations, revealing a complex energetic landscape and suggesting a significant dependence of the observed phases on the pressure–temperature pathway taken in experiment. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'. [ABSTRACT FROM AUTHOR]

Removing CO2 from crude syngas via physical adsorption is an effective method to yield eligible syngas. However, the bottleneck in trapping ppm‐level CO2 and improving CO purity at higher working temperatures are major challenges. Here we report a thermoresponsive metal–organic framework (1 a‐apz), assembled by rigid Mg2(dobdc) (1 a) and aminopyrazine (apz), which not only affords an ultra‐high CO2 capacity (145.0/197.6 cm3 g−1 (0.01/0.1 bar) at 298 K) but also produces ultra‐pure CO (purity ≥99.99 %) at a practical ambient temperature (TA). Several characterization results, including variable‐temperature tests, in situ high‐resolution synchrotron X‐ray diffraction (HR‐SXRD), and simulations, explicitly unravel that the excellent property is attributed to the induced‐fit‐identification in 1 a‐apz that comprises self‐adaption of apz, multiple binding sites, and complementary electrostatic potential (ESP). Breakthrough tests suggest that 1 a‐apz can remove CO2 from 1/99 CO2/CO mixtures at practical 348 K, yielding 70.5 L kg−1 of CO with ultra‐high purity of ≥99.99 %. The excellent separation performance is also revealed by separating crude syngas that contains quinary mixtures of H2/N2/CH4/CO/CO2 (46/18.3/2.4/32.3/1, v/v/v/v/v). [ABSTRACT FROM AUTHOR]

Background: Electron synchrotrons produce x‐ray beams with dose rates orders of magnitude greater than conventional x‐ray tubes and with beam sizes on the order of a few millimeters. These characteristics put severe challenges on current dosimeters to accurately realize absorbed dose or air kerma. Purpose: This work seeks to investigate the suitability of a novel aluminum‐based calorimeter to determine absorbed dose to water with an uncertainty significantly smaller than currently possible with conventional detectors. A lower uncertainty in the determination of absolute dose rate would impact both therapeutic applications of synchrotron‐produced x‐ray beams and research investigations. Methods: A vacuum‐based calorimeter prototype with an aluminum core was built, matching the beam profile of the 140 keV monochromatic x‐ray beam, produced by the Canadian Light Source Biomedical Imaging and Therapy beamline. The choice of material and overall calorimeter design was optimized using FEM thermal modeling software while Monte Carlo radiation transport simulations were used to model the impact of interactions of the radiation beam with the detector components. Results: Corrections for both the thermal conduction and radiation transport effects were of the order of 3% and the simplicity of the geometry, combined with the monochromatic nature of the incident x‐ray beam, meant that the uncertainty in each correction was ≤0.5%. The calorimeter performance was found to be repeatable over multiple irradiations of 1 Gy at the ± 0.6% level, and no systematic dependence on environmental effects or total dose was observed. Conclusion: The combined standard uncertainty in the determination of absorbed dose to aluminum was estimated to be 0.8%, indicating that absorbed dose to water, the ultimate quantity of interest, could be determined with an uncertainty on the order of 1%. This value is an improvement over current techniques used for synchrotron dosimetry and comparable with the state‐of‐the art for conventional kV x‐ray dosimetry. [ABSTRACT FROM AUTHOR]

The high‐pressure behavior of hafnon has been systematically investigated by combining in situ synchrotron X‐ray diffraction, Raman, high‐resolution transmission electron microscopy (HRTEM) techniques, and theoretical simulations. Hafnon starts phase transition at 26.6 GPa and completes the transition to an irreversible scheelite phase (I41/a$I{4}_{1}/a$, Z = 4, a0 = 4.712 Å, and c0 = 10.378 Å) at ∼45 GPa. The HRTEM observation of an interface between hafnon and scheelite phases allows atomic scale understanding of the transition process with a relationship of (200)h‖(112)s, (002¯)h∥(1¯10)s$(00\overline{2})_{\mathrm{h}}\Vert (\overline{1}10)_{\mathrm{s}}$//, and [010]h∥[1¯1¯1]s$[010]_{\mathrm{h}}\Vert [\overline{1}\;\overline{1}\;1]_{\mathrm{s}}$. Hafnon shows a significantly lower transition pressure (∼12.6 GPa), as calculated from the relative enthalpies, than the measured pressure (∼26 GPa), indicating a kinetically hindered process involved in the transition. A high pressure low symmetry phase in hafnon (I4¯2d$I{\overline{4}}_{2}d$) is identified by the simultaneous appearance of two Raman modes (∼75 and 450 cm−1) at 26.6 GPa and their subsequent simultaneous disappearance at 36.7 GPa. These results are important to understanding the mechanism of the zircon‐scheelite transition for both zircon and hafnon. [ABSTRACT FROM AUTHOR]

The characteristics of the prototype of the scintillation detecting segment of time-of-flight and anticoincidence systems of being developed space-based GAMMA-400 gamma-ray telescope is studied. The amplitude resolution, time resolution and charged particle detection efficiency of the prototype with silicon photomultipliers readout obtained using 250 MeV positron beam of synchrotron C-25P "PAKHRA" of P.N. Lebedev Physical Institute are presented. The comparison of applying both "standard" and "fast" outputs of silicon photomultipliers type ON Semiconductor MICROFC-60035-SMT used in the prototype is featured. [ABSTRACT FROM AUTHOR]

Over the past two decades, serial X‐ray crystallography has enabled the structure determination of a wide range of proteins. With the advent of X‐ray free‐electron lasers (XFELs), ever‐smaller crystals have yielded high‐resolution diffraction and structure determination. A crucial need to continue advancement is the efficient delivery of fragile and micrometre‐sized crystals to the X‐ray beam intersection. This paper presents an improved design of an all‐polymer microfluidic 'chip' for room‐temperature fixed‐target serial crystallography that can be tailored to broadly meet the needs of users at either synchrotron or XFEL light sources. The chips are designed to be customized around different types of crystals and offer users a friendly, quick, convenient, ultra‐low‐cost and robust sample‐delivery platform. Compared with the previous iteration of the chip [Gilbile et al. (2021), Lab Chip, 21, 4831–4845], the new design eliminates cleanroom fabrication. It has a larger imaging area to volume, while maintaining crystal hydration stability for both in situ crystallization or direct crystal slurry loading. Crystals of two model proteins, lysozyme and thaumatin, were used to validate the effectiveness of the design at both synchrotron (lysozyme and thaumatin) and XFEL (lysozyme only) facilities, yielding complete data sets with resolutions of 1.42, 1.48 and 1.70 Å, respectively. Overall, the improved chip design, ease of fabrication and high modifiability create a powerful, all‐around sample‐delivery tool that structural biologists can quickly adopt, especially in cases of limited sample volume and small, fragile crystals. [ABSTRACT FROM AUTHOR]

This paper presents the effect of temperature on the electrical fatigue behavior of barium calcium zirconate titanate (Ba0.85Ca0.15Zr0.1Ti0.9O3) ceramics. Fatigue degradation and its practical applications are a significant problem in piezo/ferroelectric ceramics. Fatigue-induced domain orientations, physical damage or microcracking, and defects were studied using, X-ray diffraction (XRD), synchrotron X-ray absorption spectroscopy (XAS), and scanning electron microscope (SEM) techniques. The remnant polarization (Pr) decreased with the number of fatigue cycles, and the rate at which the decrease occurred was different for different fatigue temperatures. The weak and strong domain wall pinning effects played a major role in the Pr value with respect to the fatigue cycles. The sharp rise of Ec value at 5 × 103 cycles and the abrupt decrease of Ec values after 5 × 104 cycles could be due to the field screening effect and heat recovery of pinned domains. The abrupt decrease of Pr values after 5 × 105 cycles could be due to physical damage near the electrode interface region, and the same physical damage decreased with the increase in fatigue temperature. The near-edge X-ray absorption fine structure (NEXAFS) study was utilized to evaluate the oxygen-related defect concentration. [ABSTRACT FROM AUTHOR]

Five different electron density datasets obtained from conventional and synchrotron single crystal X‐ray diffraction experiments are compared. The general aim of the study is to investigate the quality of data for electron density analysis from current state‐of‐the‐art conventional sources, and to see how the data perform in comparison with high‐quality synchrotron data. A molecular crystal of melamine was selected as the test compound due to its ability to form excellent single crystals, the light atom content, and an advantageous suitability factor of 3.6 for electron density modeling. These features make melamine an optimal system for conventional X‐ray diffractometers since the inherent advantages of synchrotron sources such as short wavelength and high intensity are less critical in this case. Data were obtained at 100 K from new in‐house diffractometers Rigaku Synergy‐S (Mo and Ag source, HyPix100 detector) and Stoe Stadivari (Mo source, EIGER2 1M CdTe detector), and an older Oxford Diffraction Supernova (Mo source, Atlas CCD detector). The synchrotron data were obtained at 25 K from BL02B1 beamline at SPring‐8 in Japan (λ = 0.2480 Å, Pilatus3 X 1M CdTe detector). The five datasets were compared on general quality parameters such as resolution, ⟨I/σ⟩, redundancy and R factors, as well as the more model specific fractal dimension plot and residual density maps. Comparison of the extracted electron densities reveals that all datasets can provide reliable multipole models, which overall convey similar chemical information. However, the new laboratory X‐ray diffractometers with advanced pixel detector technology clearly measure data with significantly less noise and much higher reliability giving densities of higher quality, compared to the older instrument. The synchrotron data have higher resolution and lower measurement temperature, and they allow for finer details to be modeled (e.g. hydrogen κ parameters). [ABSTRACT FROM AUTHOR]

The existence and formation of expanded austenite in ferritic stainless steels remains a subject of debate. This research article aims to provide comprehensive insights into the formation and decomposition of expanded austenite through in situ structure analyses during thermal treatments of ferritic steels. To achieve this objective, we employed the Plasma Immersion Ion Implantation (PIII) technique for nitriding in conjunction with in situ synchrotron X-ray diffraction (ISS-XRD) for microstructural analyses during the thermal treatment of the samples. The PIII was carried out at a low temperature (300–400 °C) to promote the formation of metastable phases. The ISS-XRD analyses were carried out at 450 °C, which is in the working temperature range of the ferritic steel UNS S44400, which has applications, for instance, in the coating of petroleum distillation towers. Nitrogen-expanded ferrite (αN) and nitrogen-expanded austenite (γN) metastable phases were formed by nitriding in the modified layers. The production of the αN or γN phase in a ferritic matrix during nitriding has a direct relationship with the nitrogen concentration attained on the treated surfaces, which depends on the ion fluence imposed during the PIII treatment. During the thermal evolution of crystallographic phase analyses by ISS-XRD, after nitriding, structure evolution occurs mainly by nitrogen diffusion. In the nitrided samples prepared under the highest ion fluences—longer treatment times and frequencies (PIII 300 °C 6 h and PIII 400 °C 3 h) containing a significant amount of γN—a transition from the γN phase to the α and CrN phases and the formation of oxides occurred. [ABSTRACT FROM AUTHOR]

In order to establish quantitative process–structure–property relationships in thermal spray coatings, a robust framework for defining (micro)structural characteristics is needed. We present a quantitative characterization of the three-dimensional morphology of porosity in spray-formed tantalum samples based on high-resolution X-ray micro-computed tomography. Using synchrotron facilities, we acquired dozens of high-resolution scans, enabling a statistically meaningful comparison across multiple samples, different regions within samples, and spray processes. We quantify the spatial distribution, size, and topology of porous inclusions, with a significant focus on variability across samples and different spray processes (plasma and cold sprayed), as well as sensitivity to image segmentation and resolution. Based on a typical segmentation, we report porosities ranging from 0.9 to 1.7 pct for all samples tested, with significant sensitivity due to image segmentation resulting in estimates as low as 0.6 pct and as high as 4.8 pct. For the complex pore space morphology observed in these materials, we argue that a conventional analysis based on identifying individual pores is not well suited, and propose an alternative approach based on morphological metrics with a rich history in porous media literature, such as spatial correlations, local pore thickness, and scale-dependent sub-sampling. Spatial correlations indicate anisotropic splat structures, but only mildly anisotropic pores. Various measures of pore size show a wide distribution of sizes, ranging from sub-micron to 10-micron length scales. Scale-dependent variations in porosity suggest that representative volumes of several hundred microns are required for convergence of morphological metrics, with larger volumes for cold-spray materials. This work provides a robust quantitative basis for describing three-dimensional pore structure in thermal spray coatings. [ABSTRACT FROM AUTHOR]

Solid-state batteries (SSB), characterized by solid-state electrolytes—in particular inorganic ones (ISSE)—are an ideal option for the safe implementation of metallic Li anodes. Even though SSBs with ISSEs have been extensively investigated over the last two decades, they still exhibit a series of technological drawbacks. In fact, mechano-chemical issues, mainly the stability of the electrolyte/anode interface, hinder their widespread application. The present investigation focusses on a thin-film LMO (Lithium-Manganese-Oxide)/LAGP (LiAlGe Phosphate)/Copper, anodeless Lithium-metal battery and explores the morphochemical evolution of the electrode/electrolyte interfaces with synchrotron-based Scanning Photoelectron Microscopy (SPEM) of intact pristine and cycled cells. Chemical images were acquired with submicrometer resolution, to highlight the coupled geometrical and chemical-state changes caused by electrochemical ageing. Geometrical changes of the electrolyte/cathode interface were induced by periodic volume changes, causing de-cohesion of the solid-solid contact, but no chemical-state changes accompany the cathodic damaging mode. Instead, shape changes of the electrolyte/anode region pinpoint the correlation between mechanical damaging with the decomposition of the LAGP ISSE, due to the reduction of Ge, triggered by the contact with elemental Li. The micro-spectroscopic approach adopted in this study enabled the assessment of the highly localized nature of the cathodic and anodic degradation modes in SSB devices and to single out the chemical and mechanical contributions. [ABSTRACT FROM AUTHOR]

The protocol describes step-by-step sample preparation, data acquisition, and segmentation of cellular organelles with soft X-ray tomography. It is designed for microscopes built to perform full-rotation data acquisition on specimens in cylindrical sample holders, such as the XM-2 microscope at the Advanced Light Source, LBNL; however, it might be generalized for similar sample holder designs for both synchrotron and table-top microscopes. For complete details on the use and execution of this profile, please refer to Loconte et al. (2021).

Ideal three-dimensional imaging of complex samples made up of micron-scale structures extending over mm to cm, such as biological tissues, requires both wide field of view and high resolution. For existing optics and detectors used for micro-CT (computed tomography) imaging, sub-micron pixel resolution can only be achieved for fields of view of

X-ray radiolytic labeling uses broadband X-rays for in situ hydroxyl radical labeling to map protein interactions and conformation. High flux density beams are essential to overcome radical scavengers. However, conventional sample delivery environments, such as capillary flow, limit the use of a fully unattenuated focused broadband beam. An alternative is to use a liquid jet, and we have previously demonstrated that use of this form of sample delivery can increase labeling by tenfold at an unfocused X-ray source. Here we report the first use of a liquid jet for automated inline quantitative fluorescence dosage characterization and sample exposure at a high flux density microfocused synchrotron beamline. Our approach enables exposure times in single-digit microseconds while retaining a high level of side-chain labeling. This development significantly boosts the method's overall effectiveness and efficiency, generates high-quality data, and opens up the arena for high throughput and ultrafast time-resolved in situ hydroxyl radical labeling.

Radiotherapy is the current standard of care for more than 50% of all cancer patients. Improvements in radiotherapy (RT) technology have increased tumor targeting and normal tissue sparing. Radiations at ultra-high dose rates required for FLASH-RT effects have sparked interest in potentially providing additional differential therapeutic benefits. We present a new experimental platform that is the first one to deliver petawatt laser-driven proton pulses of 2 MeV energy at 0.2 Hz repetition rate by means of a compact, tunable active plasma lens beamline to biological samples. Cell monolayers grown over a 10 mm diameter field were exposed to clinically relevant proton doses ranging from 7 to 35 Gy at ultra-high instantaneous dose rates of 107 Gy/s. Dose-dependent cell survival measurements of human normal and tumor cells exposed to LD protons showed significantly higher cell survival of normal-cells compared to tumor-cells for total doses of 7 Gy and higher, which was not observed to the same extent for X-ray reference irradiations at clinical dose rates. These findings provide preliminary evidence that compact LD proton sources enable a new and promising platform for investigating the physical, chemical and biological mechanisms underlying the FLASH effect.