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The time-evolution of dynamics as well as microstructure and mechanical response of phosphate-based geopolymers was probed using x-ray photon correlation spectroscopy and rheological tests. The analyzed relaxation processes in the freshly prepared geopolymer mixes evidenced a q-independent mode of the autocorrelation function, ascribed to density fluctuations of the already established molecular network, undergoing reconfiguration without significant mass transport. Upon curing, the detected motions are localized and depict a system evolving toward structural arrest dominated by slower hyperdiffusive dynamics, characterized by a compressed exponential regime, pointing to a structural relaxation process subjected to internal stresses, in a context of marked dynamical and structural heterogeneity. The system ages through a "densification" process producing declining small angle scattered intensity, as two finely intermixed gel-like reaction products, namely, one hydrated aluminophosphate and one hydrated silica, form a percolated network possessing surface fractal scaling of progressively shorter average correlation length. In this scenario, the nominal Al/P molar ratio of the mix, being an index of network-forming ability, is positively correlated with the dynamic viscosity and the overall kinetics, whereas the contrary occurs for the fraction of water. [ABSTRACT FROM AUTHOR]

We exhaustively investigate the temporal correlations between the ultrahigh-frequency (of the order of 1–6 GHz), very high-frequency (of the order of 10–100 MHz), and x-ray (photons with energies from 5 keV to 1 MeV) emissions together with the optical emissions in the near-infrared (within 700–1100 nm) and near-ultraviolet (within 300–400 nm) wavelength regions. The emissions are produced by a laboratory atmospheric discharge developing in an 55 cm air gap at voltages up to 1 MV. When registering various electromagnetic emissions, the discharge current and voltage are measured, as well as nanosecond imaging of the discharge evolution in its own glow is performed. The spatiotemporal localization of the discharge regions associated with the x-ray generation is carried out by employing the group of fast scintillation detectors, and the evolution of plasma structures during the x-ray generation is traced. A chronological map is constructed providing an in-depth understanding of the temporal character and correlations of various electromagnetic emissions. The map allows one to analyze fast ionization processes occurring in the gas-discharge medium and triggering the generation of the corresponding emissions. The generation mechanisms of the considered emissions in an extended high-voltage discharge are discussed. The findings can be helpful in revealing the sources of various electromagnetic emissions accompanying the formation of laboratory and atmospheric discharges. [ABSTRACT FROM AUTHOR]

The temporal, spectral, and angular characteristics of the x-ray emissions (photons with energies within 5–1000 keV) are exhaustively investigated during the discharge formation at voltages up to 1 MV in approximately 55 cm air gaps. The temporal correlations between the x-ray emissions and discharge voltage and current waveforms are established. The evolution of the discharge plasma structures developing in the time periods of the x-ray generation is traced with a nanosecond resolution. Based on statistical data, theoretical analysis, and estimates the regularities in the x-ray emission characteristics are revealed together with their relationship with the ionization processes occurring in the gas-discharge medium. On the basis of the obtained experimental data, the probable x-ray generation mechanisms are discussed. The findings can provide a deeper understanding of the physics behind the sources of hard x rays arising during the development of laboratory and atmospheric discharges. [ABSTRACT FROM AUTHOR]

Zinc tungstate is a semiconductor known for its favorable photocatalytic, photoluminescence, and scintillation properties, coupled with its relatively low cost, reduced toxicity, and high stability in biological and catalytic environments. In particular, zinc tungstate evinces scintillation properties, namely the ability to emit visible light upon absorption of energetic radiation such as x rays, which has led to applications not only as radiation detectors but also for biomedical applications involving the delivery of optical light to deep tissue, such as photodynamic therapy and optogenetics. Here, we report on the synthesis of zinc tungstate nanorods generated via an optimized but facile method, which allows for synthetic control over the aspect ratio of the as-synthesized anisotropic motifs via rational variation of the solution pH. We investigate the effect of aspect ratio on their resulting photoluminescent and radioluminescent properties. We further demonstrate the potential of these zinc tungstate nanorods for biomedical applications, such as photodynamic therapy for cancer treatment, by analyzing their toxicological profile within cell lines and neurons. [ABSTRACT FROM AUTHOR]

The design and optimization of laser-Compton x-ray systems based on compact distributed charge accelerator structures can enable micron-scale imaging of disease and the concomitant production of beams of Very High Energy Electrons (VHEEs) capable of producing FLASH-relevant dose rates. The physics of laser-Compton x-ray scattering ensures that the scattered x-rays follow exactly the trajectory of the incident electrons, thus providing a route to image-guided, VHEE FLASH radiotherapy. The keys to a compact architecture capable of producing both laser-Compton x-rays and VHEEs are the use of X-band RF accelerator structures which have been demonstrated to operate with over 100 MeV/m acceleration gradients. The operation of these structures in a distributed charge mode in which each radiofrequency (RF) cycle of the drive RF pulse is filled with a low-charge, high-brightness electron bunch is enabled by the illumination of a high-brightness photogun with a train of UV laser pulses synchronized to the frequency of the underlying accelerator system. The UV pulse trains are created by a patented pulse synthesis approach which utilizes the RF clock of the accelerator to phase and amplitude modulate a narrow band continuous wave (CW) seed laser. In this way it is possible to produce up to 10 μA of average beam current from the accelerator. Such high current from a compact accelerator enables production of sufficient x-rays via laser-Compton scattering for clinical imaging and does so from a machine of "clinical" footprint. At the same time, the production of 1000 or greater individual micro-bunches per RF pulse enables > 10 nC of charge to be produced in a macrobunch of < 100 ns. The design, construction, and test of the 100-MeV class prototype system in Irvine, CA is also presented.

The ability to visualize x-ray and neutron emission from fusion plasmas in 3D is critical to understand the origin of the complex shapes of the plasmas in experiments. Unfortunately, this remains challenging in experiments that study a fusion concept known as Magnetized Liner Inertial Fusion (MagLIF) due to a small number of available diagnostic views. Here, we present a basis function-expansion approach to reconstruct MagLIF stagnation plasmas from a sparse set of x-ray emission images. A set of natural basis functions is "learned" from training volumes containing quasi-helical structures whose projections are qualitatively similar to those observed in experimental images. Tests on several known volumes demonstrate that the learned basis outperforms both a cylindrical harmonic basis and a simple voxel basis with additional regularization, according to several metrics. Two-view reconstructions with the learned basis can estimate emission volumes to within 11% and those with three views recover morphology to a high degree of accuracy. The technique is applied to experimental data, producing the first 3D reconstruction of a MagLIF stagnation column from multiple views, providing additional indications of liner instabilities imprinting onto the emitting plasma. [ABSTRACT FROM AUTHOR]

The structure and mechanism of the water-oxidation chemistry that occurs in photosystem II have been subjects of great interest. The advent of X-ray free electron lasers allowed the determination of structures of the stable intermediate states and of steps in the transitions between these intermediate states, bringing a new perspective to this field. The room-temperature structures collected as the photosynthetic water oxidation reaction proceeds in real time have provided important novel insights into the structural changes and the mechanism of the water oxidation reaction. The time-resolved measurements have also given us a view of how this reaction-which involves multielectron, multiproton processes-is facilitated by the interaction of the ligands and the protein residues in the oxygen-evolving complex. These structures have also provided a picture of the dynamics occurring in the channels within photosystem II that are involved in the transport of the substrate water to the catalytic center and protons to the bulk.

Molecular chirality has long been monitored in the frequency domain in the ultraviolet, visible, and infrared regimes. Recently developed time-domain approaches can detect time-dependent chiral dynamics by enhancing intrinsically weak chiral signals. Even-order nonlinear signals in chiral molecules have gained attention thanks to their existence in the electric dipole approximation, without relying on the weaker higher-order multipole interactions. We illustrate the optimization of temporal polarization pulse-shaping in various frequency ranges (infrared/optical and optical/X ray) to enhance chiral nonlinear signals. These signals can be recast as an overlap integral of matter and field pseudoscalars which contain the relevant chiral information. Simulations are carried out for second- and fourth-order nonlinear spectroscopies in L-tryptophan.

The α-hydroxyethyl radical (CH3·CHOH, 2A) is a key intermediate in ethanol biochemistry, combustion, atmospheric chemistry, radiation chemistry, and astrochemistry. Experimental data on the vibrational spectrum of this radical are crucially important for reliable detection and understanding of the chemical dynamics of this species. This study represents the first detailed experimental report on the infrared absorption bands of the α-hydroxyethyl radical complemented by ab initio computations. The radical was generated in solid para-H2 and Xe matrices via the reactions of hydrogen atoms with matrix-isolated ethanol molecules and radiolysis of isolated ethanol molecules with x rays. The absorption bands with maxima at 3654.6, 3052.1, 1425.7, 1247.9, 1195.6 (1177.4), and 1048.4 cm−1, observed in para-H2 matrices appearing upon the H· atom reaction, were attributed to the OHstr, α-CHstr, CCstr, COstr + CCObend, COstr, and CCstr + CCObend vibrational modes of the CH3·CHOH radical, respectively. The absorption bands with the positions slightly red-shifted from those observed in para-H2 were detected in both the irradiated and post-irradiation annealed Xe matrices containing C2H5OH. The results of the experiments with the isotopically substituted ethanol molecules (CH3CD2OH and CD3CD2OH) and the quantum-chemical computations at the UCCSD(T)/L2a_3 level support the assignment. The photolysis with ultraviolet light (240–300 nm) results in the decay of the α-hydroxyethyl radical, yielding acetaldehyde and its isomer, vinyl alcohol. A comparison of the experimental and theoretical results suggests that the radical adopts the thermodynamically more stable anti-conformation in both matrices. [ABSTRACT FROM AUTHOR]

In this study, we observed natural methane (CH4) hydrate sediments, which are a type of unconventional natural gas resources, using x-ray computed tomography (CT). Because CH4 hydrates are formed by hydrogen bonding of water molecules with CH4, material decomposition becomes challenging when CH4 hydrates coexist with liquid or solid water in natural sediments. Tri-contrast (absorption, refraction, and scattering) imaging was performed via diffraction enhanced x-ray CT optics using monochromatic synchrotron x rays. The quantitative characterization of the contrast changes successfully enabled the decomposition of CH4 hydrates coexisting with frozen seawater (ice) in natural sediments obtained from the Okhotsk Sea. This study reveals complementary structural information about the microtexture and spatial relation among CH4 hydrates, ice, and pores by utilizing the distinct physical properties of x rays when passing through the materials. These results highlight the exceptional capabilities of high-resolution multicontrast x-ray tomography in materials science and geoscience applications. [ABSTRACT FROM AUTHOR]

Oblique shock wave–interface interactions of gases and liquids have been extensively studied in shock tubes using optical methods to measure equation-of-state (EOS) parameters. However, this is difficult with solids due to their opaqueness to visible light. X ray phase contrast imaging (XPCI) has the penetrative strength to probe solids while still being sensitive to mass density and enhancing the visibility of material boundaries. We investigate the accuracy and repeatability of measuring the mean value of the average mass density (areal density divided by thickness) over region S (B S) and flow deflection angle (θ) from XPCI images of a sample. To that end, a Hough transform-based method for measuring θ is developed. To measure B S , the XPCI image intensity probability density function (PDF) is modeled accounting for the spatial distribution of x ray energy, scintillator response, and pulse-to-pulse variation in the x ray intensity. In addition, a Monte Carlo-based algorithm for computing the B S PDF is developed. Both methods are validated on an impact-generated oblique shock wave interacting at a solid polymer-to-polymer interface. This is accomplished through a comparison to hydrodynamic simulations using well-established EOS. Under the modeling framework for the XPCI image intensity, B S is computed with an accuracy of < 0.1 % and precision of 3%–5%, while θ has an uncertainty of 0.2 ° , respectively. This shows that the XPCI-based model that is developed here could be an invaluable tool for high-fidelity testing of hydrodynamic models in shock polar configurations. [ABSTRACT FROM AUTHOR]

Millimeter-thick methylammonium lead tribromide (MAPbBr3) single crystal x-ray detectors have recently raised attention due to their high x-ray attenuation efficiency and good charge transport properties. However, an intriguing feature of the photocurrent response of MAPbBr3 detectors has been largely overlooked in the literature. After biasing, transient sensitivity is measured under x rays at short-circuit (bias = 0 V), thus revealing a large remnant electric field that builds up under bias. Here, we exploit the x-ray sensitivity of MAPbBr3 detectors at zero-bias in order to probe the internal built-in field, as well as to investigate the charge transport properties of the perovskite material. Our model derived from the Hecht equation is able to fully rationalize the response of the detectors both at short-circuit and under moderate applied bias. Moreover, we provide a method for the estimation of the internal electric field, and for the sum of the electrons and holes mobility–lifetime products μ e τ e + μ h τ h. This general method could extend to any perovskite-based x-ray detector exhibiting transient sensitivity at zero-bias. [ABSTRACT FROM AUTHOR]

Macromolecular crystallography generally requires the recovery of missing phase information from diffraction data to reconstruct an electron-density map of the crystallized molecule. Most recent structures have been solved using molecular replacement as a phasing method, requiring an a priori structure that is closely related to the target protein to serve as a search model; when no such search model exists, molecular replacement is not possible. New advances in computational machine-learning methods, however, have resulted in major advances in protein structure predictions from sequence information. Methods that generate predicted structural models of sufficient accuracy provide a powerful approach to molecular replacement. Taking advantage of these advances, AlphaFold predictions were applied to enable structure determination of a bacterial protein of unknown function (UniProtKB Q63NT7, NCBI locus BPSS0212) based on diffraction data that had evaded phasing attempts using MIR and anomalous scattering methods. Using both X-ray and micro-electron (microED) diffraction data, it was possible to solve the structure of the main fragment of the protein using a predicted model of that domain as a starting point. The use of predicted structural models importantly expands the promise of electron diffraction, where structure determination relies critically on molecular replacement.

Vitrification is a promising approach for ice-free cryopreservation of biological material, but progress is hindered by the limited set of experimental tools for studying processes in the interior of the vitrified matter. Isochoric cryopreservation chambers are often metallic, and their opacity prevents direct visual observation. In this study, we introduce photon counting X-ray computed tomography (CT) to compare the effects of rigid isochoric and unconfined isobaric conditions on vitrification and ice formation during cooling of two aqueous solutions: 50 wt% DMSO and a coral vitrification solution, CVS1. Previous studies have only compared vitrification in isochoric systems with isobaric systems that have an exposed air-liquid interface. We use a movable piston to replicate the surface and thermal boundary conditions of the isochoric system yet maintain isobaric conditions. When controlling for the boundary conditions we find that similar ice and vapor volume fractions form during cooling in isochoric and isobaric conditions. Interestingly, we observe distinct ice and vapor cavity morphology in the isochoric systems, possibly due to vapor outgassing or cavitation as rapid cooling causes the pressure to drop in the confined systems. These observations highlight the array of thermal-fluid processes that occur during vitrification in confined aqueous systems and motivate the further application of imaging techniques such as photon counting X-ray CT in fundamental studies of vitrification.

We present the results of a new X-ray to near-IR photometric and spectroscopic monitoring of the changing look active galactic nucleus NGC 2617 carried out from March 2022 to March 2024. We found significant variability at all wavelengths and in the intensities and profiles of the broad Balmer lines. Reverberation mapping was carried out for three observing seasons during 2021–2024. We obtained time delays of |$\sim$| 4 d for the response of the H  |${\beta }$| line to optical continuum variations. The X-ray variations correlate well with the UV and optical, with a few days lag for longer wavelengths. The K band lagged the B band by |$\sim$| 15 d during the last three seasons, which is significantly shorter than the delays reported previously by the 2016 and 2017–2019 campaigns. Near-IR variability arises from two different emission regions: the outer part of the accretion disc and a more distant dust component. The |$HK$| -band variability is governed primarily by dust. The H  |${\beta }$| /H  |${\alpha }$| ratio variations (for broad components only) correlate with the X-ray and UV fluxes. The spectral type changed from type 1.8 to type 1.9 during 2023 October–2024 January and then a more rapid change to type 1.5 occurred in 2024 February. We interpret these changes as a combination of two factors: changes in the accretion rate as a dominant cause but also the sublimation or recovery of dust along the line of sight. [ABSTRACT FROM AUTHOR]

Thanks to the rapid follow-up observations by the Swift X-Ray Telescope (XRT), a good part of gamma-ray bursts' (GRBs) high-latitude emission have been observed in the X-ray band. Some even show a dropdown decay after this period, which strongly indicates the edge of the jet is corresponding to the breaking time. This study constrains the jet opening angles of GRBs by analyzing the very steep decay phase in the early X-ray afterglow. Using data from Swift/XRT, we identified GRBs with significant breaks in their light curves and applied a broken power-law model to describe the decay phases. Assuming a spherical and isotropic emitting surface, we set constraints on the radiation radius (R γ ) to estimate jet opening angles (θ jet) from the breaking time. Our results indicate that jet opening angles can be constrained, although they are sensitive to the assumed radiation radius. This approach provides yet another method for estimating GRB jet opening angles. [ABSTRACT FROM AUTHOR]

We present the X-ray crystal structure of a complex between a G-clamp and an internal loop motif of pre-mir-125a, selected from high affinity RNAs identified in a large-scale RNA-binding profile. This X-ray crystal structure reveals that the G-clamp interacts with three distinct guanine bases, forming robust bonds through hydrogen bonding and stacking interactions. [ABSTRACT FROM AUTHOR]

We combine X-ray data from the X-ray Multi-Mirror Mission 12th data release (4XMM DR12) and the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) Final Equatorial-Depth Survey (eFEDS) early data release catalogues with the Galaxy and Mass Assembly spectroscopic galaxy survey to form a sample of 526 local (⁠|$0.05\le z \le 0.3$|⁠), moderately luminous active galactic nuclei (AGNs; |$L_{\rm X} \ge 10^{42}$| erg s-1). We compare the distribution of AGN hosts with that of the general galaxy population, finding no evidence of AGNs being preferentially hosted within over/underdense environments at a 7-Mpc scale. Next, we compare the distances to nearest-neighbour galaxies and find that AGN host galaxies are separated from their neighbours by the same distance as galaxies in a matched non-AGN sample. Finally, we consider mid-IR colour, provided by the All-WISE survey, the |$L_{\rm X}/L_{6\, \mu \mathrm{m}}$| ratio, and X-ray hardness as tracers of AGN obscuration, to explore whether there is a change in the galaxy environment for obscured AGNs. We find no evidence of increasing AGN obscuration with decreasing separation in close galaxy pairs. We conclude that close galaxy–galaxy interactions may not be sufficiently disruptive to cause any observable increase in AGN activity. [ABSTRACT FROM AUTHOR]

NHC-[60]fullereborane (NHC-BH2-C60H) has been synthesized, isolated in pure form, and characterized. The reaction of C60 with NHC–borane produced NHC-BH2-C60H as the first air-stable and separatable fullerene–borane compound. The formation of a N-heterocyclic carbene stabilized this borane complex of C60, and the structure of the complex was unambiguously determined throughsingle-crystal X-ray analysis. This fullerene–borane complex exhibited remarkable stability and promising electrochemical properties. [ABSTRACT FROM AUTHOR]

Background: Although the Neer and AO/OTA classifications have been widely accepted, observer reliability studies of these two classifications have questioned their reliability and reproducibility to date. We developed an entirely new classification, the Mitsuzawa classification, for dislocated and displaced proximal humeral fractures and tested all three classifications for their intra- and interobserver reliability. Methods: Two experienced shoulder surgeons and two orthopedic residents independently evaluated the Xray (xR) values of 100 proximal humeral fractures (PHFs). The inclusion criteria for PHFs were (1) fracture-dislocation of the glenohumeral joint, (2) severely displaced fracture that required arthroplasty, such as hemi-arthroplasty or reverse shoulder arthroplasty, and (3) age > 18 years. Four reviewers classified all 100 fractures according to the Neer, AO/OTA, and Mitsuzawa classifications on two occasions. The intraobserver reliability was calculated using a Cohen κ statistic, while the interobserver reliability was calculated using a Fleiss κ statistic. Results: The average intraobserver agreements for the Neer, AO/OTA, and Mitsuzawa classifications were 0.57 (moderate), 0.67 (substantial), and 0.77 (substantial), respectively. The average interobserver agreements for the Neer, AO/OTA, and Mitsuzawa classifications were 0.49 (moderate), 0.56 (moderate), and 0.73 (substantial), respectively. The most common fracture type in each classification was an anterior dislocated fracture with a greater tuberosity fragment, which corresponded to A3a (57 cases) in the Mitsuzawa classification. Conclusions: The Mitsuzawa classification of PHF incorporates different perspectives regarding glenohumeral compatibility, assessment before and after shoulder dislocation reduction, and the degree of displacement of the proximal stump of the humeral shaft. Compared with the Neer and AO/OTA classifications, our new classification system adopted a user-friendly flowchart format and provided satisfactory intra- and interobserver reliability. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and Gaia DR3 using an X-ray + optical color–color diagram (the "X-ray Main Sequence"). This tool identifies all CV subtypes, including magnetic and low-accretion rate systems, in contrast to most previous surveys. We find 23 CVs, 3 of which are AM CVns, out to 150 pc in the Western Galactic Hemisphere. Our 150 pc sample is spectroscopically verified and complete down to L X = 1.3 × 1029 erg s−1 in the 0.2–2.3 keV band, and we also present CV candidates out to 300 pc and 1000 pc. We discovered two previously unknown systems in our 150 pc sample: the third nearest AM CVn and a magnetic period bouncer. We find the mean L X of CVs to be 〈 L X〉 ≈ 4.6 × 1030 erg s−1, in contrast to previous surveys which yielded 〈 L X〉 ∼ 1031−1032 erg s−1. We construct X-ray luminosity functions that, for the first time, flatten out at L X ∼ 1030 erg s−1. We infer average number, mass, and luminosity densities of ρ N,CV = (3.7 ± 0.7) × 10−6pc−3, ρ M = (5.0 ± 1.0) × 1 0 − 5 M ⊙ − 1 , and ρ L X = (2.3 ± 0.4) × 1 0 26 erg s − 1 M ⊙ − 1 , respectively, in the solar neighborhood. Our uniform selection method also allows us to place meaningful estimates on the space density of AM CVns, ρ N,AM CVn = (5.5 ± 3.7) × 10−7 pc−3. Magnetic CVs and period bouncers make up 35% and 25% of our sample, respectively. This work, through a novel discovery technique, shows that the observed number densities of CVs and AM CVns, as well as the fraction of period bouncers, are still in tension with population synthesis estimates. [ABSTRACT FROM AUTHOR]

Numerous constrained optimization methods have been suggested to reduce the X-ray dose in computerized tomography. These approaches focus on minimizing a regularizing function, which gauges the deviation from prior knowledge about the imaged object. These approaches focus on minimizing a regularizing function that assesses the lack of consistency of about the object that is being imaged using some prior knowledge. This minimization is conducted under the condition of maintaining a predetermined level of consistency with the detected X-ray attenuation. Total variation (TV) is a frequently explored regularizing function. TV minimization techniques exhibit excellent denoising performance for simple images, yet they lead to the loss of texture information when employed on more complex images. Given that medical imaging frequently involves textured images, utilizing TV may not be advantageous in such scenarios. Alternative studies propose incorporating multi-scale geometric transforms into the regularization function. One recent preference in this regard is the adoption of the shearlets transform. This work presents a proof-of-concept that showcases the application of the discrete shearlets transform as a sparsifying transform in the computed tomography reconstruction solver. Specifically, the regularization term utilized is the l1-norm of the shearlets coefficients. In this work, the algorithm's iterative computation incorporates an operation on the shearlets coefficients. Particularly, the soft-thresholding operator is used with the parameter adaptively chosen. To improve its relevance for biomedical imaging, we propose a desired sparsity level of the thresholding parameter value obtained from a biological object. The effectiveness of the proposed method is assessed using two different types of data: data from chest dataset generated by MATLAB and real data collected from X-ray tomographic measurements of an axial slice of a ladybug. [ABSTRACT FROM AUTHOR]

Detection and teeth segmentation from X-rays, aiding healthcare professionals in accurately determining the shape and growth trends of teeth. However, small dataset sizes due to patient privacy, high noise, and blurred boundaries between periodontal tissue and teeth pose challenges to the models' transportability and generalizability, making them prone to overfitting. To address these issues, we propose a novel model, named Grouped Attention and Cross-Layer Fusion Network (GCNet). GCNet effectively handles numerous noise points and significant individual differences in the data, achieving stable and precise segmentation on small-scale datasets. The model comprises two core modules: Grouped Global Attention (GGA) modules and Cross-Layer Fusion (CLF) modules. The GGA modules capture and group texture and contour features, while the CLF modules combine these features with deep semantic information to improve prediction. Experimental results on the Children's Dental Panoramic Radiographs dataset show that our model outperformed existing models such as GT-U-Net and Teeth U-Net, with a Dice coefficient of 0.9338, sensitivity of 0.9426, and specificity of 0.9821. The GCNet model also demonstrates clearer segmentation boundaries compared to other models. [ABSTRACT FROM AUTHOR]

We investigate the role of the simba feedback model on the structure of the intragroup medium (IGrM) in the new hyenas suite of cutting-edge cosmological zoom-in simulations. Using 34 high-resolution zooms of haloes spanning from |$10^{13}-10^{14}$| |${\rm M_\odot}$| at |$z=0.286$|⁠ , we follow haloes for 700 Myr, over several major active galactic nuclei (AGNs) jet feedback events. We use the moxha package to generate mock Chandra X-ray observations, as well as predictive mocks for the upcoming LEM mission, identifying many feedback-generated features such as cavities, shock-fronts, and hot-spots, closely mimicking real observations. Our sample comprises 105 snapshots with identified cavities, 50 with single bubbles, and 55 with two, and spans three orders of magnitude in observed cavity enthalpies, from |$10^{41}-10^{44}$| erg s−1. Comparing semimajor axis length, midpoint radius, and eccentricity to a matched sample of observations, we find good agreement in cavity dimensions with real catalogues. We estimate cavity power from our mock maps following observational procedures, showing that this is typically more than enough to offset halo cooling, particularly in low-mass haloes, where we match the observed excess in energy relative to cooling. Bubble enthalpy as measured with the usual midpoint pressure typically exceeds the energy released by the most recent jet event, hinting that the mechanical work is done predominantly at a lower pressure against the IGrM. We demonstrate for the first time that X-ray cavities are observable in a modern large-scale simulation suite and discuss the use of realistic cavity mock observations as new halo-scale constraints on feedback models in cosmological simulations. [ABSTRACT FROM AUTHOR]

Transitional millisecond pulsars (tMSPs) are neutron star systems that alternate between a rotation-powered radio millisecond pulsar state and an accretion disc-dominated low-mass X-ray binary (LMXB)-like state on multi-year time-scales. During the LMXB-like state, the X-ray emission from tMSPs switches between 'low' and 'high' X-ray brightness modes on a time-scale of seconds to minutes (or longer), while the radio emission shows variability on time-scales of roughly minutes. Coordinated Very Large Array (VLA) and Chandra observations of the nearby tMSP PSR J1023+0038 uncovered a clear anticorrelation between radio and X-ray luminosities such that the radio emission consistently peaks during the X-ray low modes. In addition, there are sometimes also radio/X-ray flares that show no obvious correlation. In this paper, we present simultaneous radio and X-ray observations of a promising tMSP candidate system, 3FGL J1544.6 |$-$| 1125, which shows optical, |$\gamma$| -ray, and X-ray phenomena similar to PSR J1023+0038, but which is challenging to study because of its greater distance. Using simultaneous VLA and Chandra observations, we find that the radio and X-ray emission are consistent with being anticorrelated in a manner similar to PSR J1023+0038. We discuss how our results help in understanding the origin of bright radio emission from tMSPs. The greater sensitivity of upcoming telescopes such as the Square Kilometre Array will be crucial for studying the correlated radio/X-ray phenomena of tMSP systems. [ABSTRACT FROM AUTHOR]

Purpose: There is paucity of guidelines with inadequate data available about the extent and prevention of bone and joint disease in beta-thalassemic patients in Indian population. This study aims to determine bone and joint involvement in beta-thalassemic patients. It evaluates serum biochemical parameters of bone formation and resorption and correlates with the symptomatology in these patients. The study also determines their daily physical activity and find a correlation if any with bone mineral density. Methods: The study was carried out on 40 regularly transfused beta thalassemic patients between 5 and 18 years of age under regular follow-up at our centre from June 2012 to June 2014. All patients were interviewed as per a well-structured proforma for symptoms relating to bone and joint disease as described by the patient/parents in past 1 year and physical activity by QAPACE questionnaire. Venous blood samples were drawn under aseptic conditions and used for estimation of biochemical parameters (calcium, phosphorus, alkaline phosphatase, vitamin D, parathyroid hormone and serum ferritin). Enrolled subjects were scanned for bone mineral density (BMD) at femur neck, trochanter and Ward's angle using dual-energy X-ray absorptiometry. Results: A total of 40 patients were enrolled in the study (Male:Female = 80:20). Half the patients (n = 20) had symptoms pertaining to bone and joint disease. The most common symptom was leg pain (42.50%), followed by backache (22.50%). Asymptomatic patients had greater mean serum vitamin D as compared to the symptomatic patients (22.2 vs 15.08 ng/ml) (p = 0.225). Five patients were detected to have osteopenia, all above 10 years of age. The mean BMD in symptomatic patients at femur neck, trochanter and ward's angle was 0.781, 0.639 and 0.735 g/cm2, respectively, as compared to 0.754, 0.635 and 0.722 g/cm2 in asymptomatic patients. The difference was not statistically significant. Patients with low BMD had lower mean pre-transfusion Hb (< 9 g/dl) (p = 0.01). Eighty percent of osteopenic patients had sedentary lifestyle as compared to 44% of patients with normal BMD. Bone mineral density did not have any correlation with vitamin D levels, serum ferritin and type of chelation therapy. Conclusion: Pre-transfusion hemoglobin of more than 9 gm/dL has a protective role in maintaining good bone health and bone mineral density. Engaging thalassemia patients in physical activity has a positive effect on bone mineral density. Low vitamin D levels contribute to symptoms of bone and joint involvement in thalassemia and the same needs to be determined and supplemented. [ABSTRACT FROM AUTHOR]

The high-precision phase estimation of X-ray pulsar signals is crucial for X-ray pulsar navigation. This paper introduces a novel feature modeling method named Two-Dimensional Profile Map (2D-PM), which enhances the time-domain information of the period axis using the epoch folding algorithm. Compared to traditional profiles, the newly proposed 2D-PM model exhibits richer information content, and greater robustness in terms of folding period precision. Furthermore, a new time-series neural network structure, inspired by groundbreaking advancements in the field of Natural Language Processing (NLP), is developed using the TensorFlow framework. This structure is designed to learn the proposed features and achieve precise phase estimation. The paper also outlines training schemes and debugging strategies for hyperparameters. To test the method, sample sets were created using simulated data and Rossi X-ray Timing Explorer (RXTE) observational data. These samples are specifically designed to enhance feature consistency and the generalization capability of the network. The effectiveness of the proposed method is demonstrated through a comparative analysis with traditional cross-correlation algorithms. The results confirm a high degree of alignment between the network outputs and the feature model, highlighting the significant potential of the proposed method for application in X-ray pulsar navigation. [ABSTRACT FROM AUTHOR]

In this paper, we study and compare the optical and X-ray counterparts of subparsec supermassive black hole binaries (SMBHBs). With that aim, we simulated the profiles of optical spectral lines emitted from the broad line region (BLR) as well as X-ray spectral lines emitted from the relativistic accretion disks around both black holes and compared them with each other. The obtained results showed that SMBHBs could cause a specific, but different variability of the lines from the optical part and Fe K α line, leaving potentially detectable imprints in their profiles. Since these imprints depend on the orbital phase of the system, they could be used for reconstructing the Keplerian orbits of the components in the observed SMBHBs. Moreover, such signatures in the optical and X-ray line profiles of the observed SMBHBs could be used as a tool for the detection of these objects as well as for studying their properties. [ABSTRACT FROM AUTHOR]

Background: The exploration of Chat generative pre-training transformer's (GPT's) applications in medicine is gaining momentum, with artificial intelligence, particularly ChatGPT, showing promise in enhancing orthopedic care. ChatGPT can assist clinicians by providing relevant information based on patient symptoms, medical history, and radiological findings, aiding in differential diagnosis, and suggesting appropriate imaging modalities. This study focuses on evaluating the effectiveness of ChatGPT-4 in diagnosing and managing common orthopedic fractures. Methods: This study involved inputting a diverse set of fracture images into the ChatGPT-4 model. The process commenced by prompting ChatGPT with four questions: "What does the radiograph show?" The second prompt instructed ChatGPT with the actual diagnosis, followed by inquiries on how a clinician should manage the condition and potential complications. All generated responses underwent grading by two authors (musculoskeletal radiologist and orthopedic trainee), utilizing a 5-point Likert scale. Intraclass correlation coefficient (ICC) analysis measurements were performed to assess inter-rater reliability. Descriptive statistical analysis was then employed to provide a comprehensive summary of the study's findings. Results: ChatGPT demonstrated limitations in identifying diagnoses based on inputted X-ray images. However, it excelled in providing comprehensive information about fracture management and potential complications. There was excellent interobserver reliability with a kappa of 0.9. Conclusion: Our study underscores the utility of ChatGPT as a valuable tool for aiding in the management of common fractures, offering a comprehensive overview of diagnosis, management, and potential complications. The findings highlight its potential role as a supplementary resource in orthopedic practice. [ABSTRACT FROM AUTHOR]

Rheumatic disorders in children include inflammatory arthritis, inflammatory bone disorders such as chronic nonbacterial osteomyelitis (CNO), connective tissue disorders, and vasculitides (juvenile dermatomyositis, scleroderma). The diagnosis in these children is based on a combination of history, clinical examination, and laboratory investigations. Radiographs play an important role in children with arthritis, who have atypical presentation or for assessment of disease-related damage and differentiation from mimics. Further, radiographs also have an ancillary role in the assessment of musculoskeletal disorders such as dermatomyositis and hemophilia. This review seeks to present a detailed analysis of the specific indications and advantages of radiographs in the situations. Further, a structured reporting format for assessment of radiographs in pediatric rheumatic disorders has also been presented for the reader's reference. [ABSTRACT FROM AUTHOR]

Objective: Although SLAP-5 lesions are associated with recurrent dislocations, their causes and pathomechanisms have not been fully elucidated. This study aimed to investigate the association between SLAP-5 lesions and scapular morphology in traumatic anterior shoulder instability (ASI). We hypothesized that there may be a relationship between SLAP-5 lesions and scapular morphology in traumatic ASI patients. Materials and methods: The study included 74 patients with isolated Bankart lesions and 69 with SLAP-5 lesions who underwent arthroscopic labral repair for ASI. Critical shoulder angle (CSA) was measured on the roentgenograms, while glenoid inclination (GI) and glenoid version (GV) were measured on magnetic resonance imaging (MRI) by two observers in two separate sessions blinded to each other. Both groups were compared in terms of CSA, GI, and GV. Results: The mean ages of Bankart and SLAP-5 patients were 28.4±9.1 and 27.9±7.7 (P=0.89), respectively; their mean CSA values were 33.1°±2.6° and 28.2°±2.4°, respectively (P<0.001). The ROC analysis's cut-off value was 30.5°, with 75.0% sensitivity and 76.7% specificity (AUC = 0.830). SLAP-5 lesions were more common on the dominant side than isolated Bankart lesions (P=0.021), but no difference was found between the groups in terms of GI and GV (P=0.334, P=0.081, respectively). Conclusions: In ASI, low CSA values appeared to be related to SLAP-5 lesions, and the cut-off value of CSA for SLAP lesion formation was 30.5° with 75.0% sensitivity and 76.7% specificity. Scapula morphology may be related to the SLAP-5 lesions, and CSA can be used as an additional parameter in provocative diagnostic tests and medical imaging techniques for the detection of SLAP lesions accompanying Bankart lesions. Level of Evidence: III retrospective case-control study [ABSTRACT FROM AUTHOR]

Understanding the spatial coherence of synchrotron x-ray sources is crucial for both source characterization and coherent experimental techniques. Here, we present a method to probe the two-dimensional spatial complex coherence factor (CCF) of divergent x-ray beams without prerequisite source information. Phases of the divergent beams are obtained by the transport-of-intensity equation, which is indispensable for the retrieval of the CCF from the diffraction intensity of a Poisson-disk binary phase mask. Our method has been validated through simulations and is expected to be widely used in measuring coherence for fourth-generation synchrotron x-ray sources. [ABSTRACT FROM AUTHOR]

Enaminones are important synthetic intermediates for the construction of diverse heterocyclic scaffolds owing to their push-pull electronic structures. A series of novel (Z)-1-(3,5-bis(trifluoromethyl)phenyl)-3-(aryl/alkyl)prop-2-en-1-ones (5, 6) and (Z)-3-(aryl/alkylamino)-1-(4-(trifluoromethyl)phenyl)prop-2-en-1-ones (9, 10) were synthesized with (E)-1-(3,5-bis(trifluoromethyl)phenyl)-3-(dimethylamino)prop-2-en-1-one (2) & (E)-3-(dimethylamino)-1-(4-(trifluoromethyl)phenyl) prop-2-en-1-one (8) as starting materials. The structures of the fluorinated enaminones were established with the help of spectral and analytical data. X-ray crystallographic study for a model compound (6a) gave a vivid image showing the existence of the product in Z-form unlike the corresponding intermediate that exists in E-form. [ABSTRACT FROM AUTHOR]

How effective is an e-learning program based on international clinical guidelines in promoting beliefs more aligned with the current evidence for the management of low back pain among physiotherapists? Randomised controlled trial with concealed allocation and intention-to-treat analysis. 106 physiotherapists who treat patients with low back pain. The experimental group received access to an e-learning program, based on recommendations of clinical practice guidelines for the management of low back pain, over a 6-week period. The program consisted of six units, totalling 15 hours, and was offered in a self-instructional and self-paced format. The control group was instructed to continue their activities as usual. The primary outcome was beliefs about low back pain measured using the Modified Back Beliefs Questionnaire (MBBQ, –50 worst to 50 best). Secondary outcomes included the Back Pain Attitudes Questionnaire (Back-PAQ, –20 worst to 20 best) and agreement with two statements (1: X-rays or scans are necessary to get the best medical care for low back pain; 2: Everyone with low back pain should have spine imaging). Participants were evaluated at baseline and 6 weeks. Out of 53 participants allocated to the e-learning program, two completed only the first unit and one did not complete any units, resulting in an overall adherence rate of 94%. Compared with control, the e-learning program improved the MBBQ (MD 8 points, 95% CI 5 to 10) and the Back-PAQ score (MD 3.1 points, 95% CI 1.8 to 4.3). For the imaging beliefs statements, the e-learning program was able to increase the proportion of participants with beliefs aligned with the current evidence (statement 1: RD 38%, 95% CI 21 to 52; statement 2: RD 17%, 95% CI 7 to 29) compared with the control group. The e-learning program based on recommendations of clinical practice guidelines for the management of low back pain improved physiotherapists' beliefs about the management of low back pain. NCT05661968. [ABSTRACT FROM AUTHOR]

Although multiple studies suggest that ionizing radiation can induce bystander effects (radiation-induced bystander effect, RIBE) in cultured cell lines, it is still unclear whether RIBE is evolutionarily conserved in invertebrates. In this study, we investigated the frequency of cell death of unirradiated starfish (Patiria pectinifera) oocytes co-cultured with oocytes irradiated with X rays (0, 2 and 4 Gy). We observed increased frequencies of cell death determined by morphological abnormality and TUNEL-positive cells in unirradiated oocytes co-cultured with oocytes irradiated with 2 Gy or 4 Gy oocytes. In addition, the seawater cultured with 4 Gy irradiated oocytes induced cell death in unirradiated oocytes, and TUNEL-positive cells were observed. Our results suggest that RIBE is evolutionarily conserved in starfish. [ABSTRACT FROM AUTHOR]

A weight-bearing lateral radiograph (WBLR) of the foot is a gold standard for diagnosing adult-acquired flatfoot deformity. However, it is difficult to measure the major axis of bones in WBLR without using auxiliary lines. Herein, we develop semantic segmentation with a deep learning model (DLm) on the WBLR of the foot for enhanced diagnosis of pes planus and pes cavus. We used 300 consecutive WBLRs from young Korean males. The semantic segmentation model was developed based on U2-Net. An expert orthopedic surgeon manually labeled ground truths. We used 200 radiographs for training, 100 for internal validation, and two external datasets for external validation. The model was trained using a hybrid loss function, combining Dice Loss and boundary-based loss, to enhance both overall segmentation accuracy and precise delineation of boundary regions between pes planus and pes cavus. Angle measurement errors with minimum moment of inertia (MMI) and ellipsoidal fitting (EF) based on the segmentation results were evaluated. The DLm exhibited better results than human observers. For internal validation, the absolute angle errors of the DLm using MMI and EF were 0.92 ± 1.32° and 1.34 ± 2.07°, respectively. In external validation, these errors were 1.17 ± 1.60° and 1.60 ± 2.42° for AMC's dataset, and 1.23 ± 1.39° and 1.68 ± 1.98° for the LERA dataset, respectively. The DLm showed higher overall diagnostic accuracy than human observers in identifying flatfoot angles, regardless of the measurement methods. The absolute angle errors and diagnostic accuracy of the developed DLm are superior to those of the three human observers. Furthermore, when comparing the angle measurement methods within the DLm, the MMI method proves to be more accurate than EF. Finally, the proposed deep learning model, particularly with the implementation of the U2-Net demonstrates enhanced boundary segmentation and achieves sufficient external validation results, affirming its applicability in the real clinical setting. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective chart review. Objectives: Lumbar interbody fusion (LIF) can be achieved with various techniques. Evidence supporting the long-term clinical advantages of one technique over another are inconclusive. The purpose of this study was to (1) determine the changes in sagittal parameters in the preoperative, intraoperative, and post-operative phase, (2) evaluate the radiographic maintenance of these parameters over time, and (3) compare the demographics and patient reported outcomes of patients undergoing various LIF techniques. Methods: We performed a retrospective chart review of patients with degenerative spine disease undergoing single level anterior (ALIF), lateral (LLIF), posterior (PLIF), or transforaminal (TLIF) lumbar interbody fusion. Data collected included patient demographics and diagnosis at time of surgery. Upright lumbar radiographs taken pre-operatively, intra-operatively, and post-operatively were measured for lumbar lordosis (LL), segmental lordosis (SL), posterior disc height (PDH), and foraminal height (FH). Results: 194 patients in a single center were included. PDH and FH increased intra-operatively following ALIF (P <.0001), PLIF (P <.0001), LLIF (P <.0001), and TLIF (P <.0001). SL also increased intra-operatively for ALIF (P =.002) and LLIF (P =.0007). Compared to intra-operative radiographs, PDH and FH decreased at latest post-operative phase for ALIF (P <.03), LLIF (P <.003), TLIF (P <.001), and PLIF (P <.005). SL decreased for ALIF (P =.0008), and TLIF (P =.02). LL did not change postoperatively across techniques. Patient reported outcomes improved post-surgically and disability index decreased, but neither differed between techniques. Conclusion: LIF, regardless of technique, was shown to provide significant radiographic changes in PDH and FH. Techniques utilizing larger intervertebral cage sizes (ALIF/LLIF) improved SL. Single level LIF did not affect overall LL. No single technique displayed superior radiographic robustness over time. [ABSTRACT FROM AUTHOR]

Many conditions, such as pulmonary edema, bleeding, atelectasis or collapse, lung cancer, and shadow formation after radiotherapy or surgical changes, cause Lung Opacity. An unsupervised cross-domain Lung Opacity detection method is proposed to help surgeons quickly locate Lung Opacity without additional manual annotations. This study proposes a novel method based on adversarial learning to detect Lung Opacity on chest X-rays. Focal loss, GIoU loss, and WBF (weighted boxes fusion) were used in training. We conducted extensive experiments on Chest X-rays from RSNA (Radiological Society of North America) and Vingroup Big Data Institute to verify the performance of cross-domain detection. The results indicate that our method has superior performance. The AP reached 34.30% and 36.55%, while the AR10 reached 74.11% and 75.91% in two cross-domain detection tasks. The visualization results show that the randomly selected samples were more accurately detected for Lung Opacity after applying our method. Compared with other excellent detection frameworks, our method achieved competitive results without additional annotations, making it suitable for assisting in Lung Opacity detection. [ABSTRACT FROM AUTHOR]

Objective: This study aims to introduce a two-stage surgical procedure, namely oblique lateral interbody fusion (OLIF), for spinal disorders treatment. Furthermore, clinical outcomes and imaging results are analyzed between OLIF with posterior fixation and posterior lumbar interbody fusion (PLIF) with fixation for lumbosacral curve-driven degenerative lumbar scoliosis (DLS). Methods: 146 patients with type 2 DLS who underwent OLIF or PLIF between January 2019 and November 2023 were included. Spinal and pelvic parameters were measured using X-ray imaging before and after surgery. Clinical symptoms were assessed using Oswestry Disability Index (ODI) and visual analog scale (VAS). Operation time, intraoperative blood loss, surgical fixation segments, drainage tube indwelling time, and drainage volume were recorded. Results: 70 patients underwent OLIF and 76 underwent PLIF. Preoperative and postoperative clinical symptoms remain the same (p > 0.05). OLIF group exhibited significantly less intraoperative blood loss, fewer fixation segments, shorter drainage tube retention time, and reduced drainage volume (p < 0.01). Additionally, improvements in coronal parameters, including coronal balance distance, were more pronounced in OLIF group with less potential postoperative coronal imbalance (p < 0.05). Conclusion: For type 2 DLS, two-stage surgery of OLIF with posterior fixation represents a more efficient surgical approach, reducing surgical fusion segments, causing less trauma and bleeding, and effectively avoiding postoperative coronal plane decompensation than traditional posterior surgery. [ABSTRACT FROM AUTHOR]

The total ionizing dose (TID) effect on MOSFETs, which use the Bipolar-CMOS-DMOS (BCD) technology, is investigated under different gate biases utilizing X-rays. The threshold voltage, maximum transconductance and subthreshold swing of the device before and after irradiation were obtained. The results indicate that the TID effect is significantly influenced by gate bias. For NMOSFET, the maximum threshold voltage shift occurs at a positive gate bias of 3 V. For PMOSFET, the minimum threshold voltage shift occurs at a negative gate bias of −3 V. The mechanism was revealed to be the result of the combined effects of initial recombination, hole capture, and electron tunneling processes. However, the case of PMOSFET differs from NMOSFET due to the disappearance of electron tunneling and the change in the direction of hole movement under negative gate bias. [ABSTRACT FROM AUTHOR]

We present the results of the optical monitoring of 18 southern blazars in the V and R Johnson–Cousins bands. Our main objective is to study the variations in the optical flux and their relationship with the colour and spectral variabilities. The optical observations were acquired with the 2.15 m 'Jorge Sahade' telescope, CASLEO, Argentina. The whole campaign comprised from 2014 April to 2019 September. In addition, X-ray data were taken from the Chandra X-ray Observatory and the Swift /XRT databases, and |$\gamma$| -ray data were taken from the Fermi -Large Area Telescope 3FGL catalogue. From the total of 18 blazars, we found variability in each one of the time-scales considered for 6 blazars (PKS 0208–512, PKS 1116–46, PKS 1440–389, PKS 1510–089, PKS 2005–489, and PKS 2155–304). In particular, from the colour–magnitude and the multiwavelength analysis, we found that PKS 1510-089 (flat-spectrum radio quasar) is undergoing an activity phase. For the case of PKS 2005–489 (BL Lac), this blazar is in a quiescent state, in which it has been for more than a decade, and it is compatible with its bluer-when-brighter moderate tendency, possibly due to the presence of shocks within the jet. [ABSTRACT FROM AUTHOR]

The design and optimization of laser-Compton x-ray systems based on compact distributed charge accelerator structures can enable micron-scale imaging of disease and the concomitant production of beams of Very High Energy Electrons (VHEEs) capable of producing FLASH-relevant dose rates (∼ 10 Gy in less than 100 ns). The physics of laser-Compton x-ray scattering ensures that the x-rays produced by this process follow exactly the trajectory of the electrons from which the x-rays were produced, thus providing a route to not only compact VHEE radiotherapy but also image-guided, VHEE FLASH radiotherapy. This manuscript will review the compact accelerator architecture considerations that simultaneously optimize the production of laser-Compton x-rays from the collision of energetic laser pulses with high energy electrons and the production of high-bunch-charge VHEEs. The primary keys to this optimization are use of X-band RF accelerator structures which have been demonstrated to operate with over 100 MeV/m acceleration gradients. The operation of these structures in a distributed charge mode in which each radiofrequency (RF) cycle of the drive RF pulse is filled with a low-charge, high-brightness electron bunch is enabled by the illumination of a high-brightness photogun with a train of UV laser pulses synchronized to the frequency of the underlying accelerator system. The UV pulse trains are created by a patented pulse synthesis approach which utilizes the RF clock of the accelerator to phase and amplitude modulate a narrow band continuous wave (CW) seed laser. In this way it is possible to produce up to 10 µA of average beam current from the accelerator. Such high current from a compact accelerator enables production of sufficient x rays via laser-Compton scattering for clinical imaging and does so from a machine of "clinical" footprint. At the same time, the production of 1,000 or greater individual micro-bunches per RF pulse enables > 10 nC of charge to be produced in a macrobunch of < 100 ns. The design, construction, and test of the 100-MeV class prototype system in Irvine, CA is also presented. [ABSTRACT FROM AUTHOR]

Objective: To examine the effects of Jintiange on enhancing the healing of osteoporotic fractures in aged rats. Methods: An osteoporotic fracture model of femur was established using 70 SD rats (aged > 12 months), which were randomly numbered and divided into an experimental group and a control group, each with an equal sample size (n = 35). The experimental group received Jintiange capsule ingredients via intragastric administration, while the control group received an equal volume of saline via the same method. X-ray examinations were conducted at the 4th and 12th weeks to evaluate fracture healing in the rats. After 12 weeks, micro-CT scanning was employed to assess the microstructure of the healthy femurs, and the parameters of the experimental and control groups were compared. Results: After 4 weeks, the mean fracture healing scores were 0.78 ± 0.43 in the experimental group and 0.56 ± 0.51 in the control group. After 12 weeks, the mean scores were 1.50 ± 0.71 in the experimental group and 0.96 ± 0.68 in the control group. The scores in the experimental group were higher than those in the control group (P < 0.05). Micro-CT examination of the femurs showed an improvement trend in bone microarchitecture in the experimental group, indicated by increased bone volume fraction (BV/TV), trabecular number (Tb. N), and trabecular thickness (Tb. Th). However, these improvements were not statistically significant. A negative correlation with statistical significance was observed between trabecular separation (Tb. Sp) and fracture healing scores. Conclusions : Jintiange may promote osteoporotic fracture healing in aged rats by enhancing bone microstructure. [ABSTRACT FROM AUTHOR]