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Abstract In grating-based X-ray Talbot interferometry, the wave nature of X-ray radiation is exploited to generate phase contrast images of objects that do not generate sufficient contrast in conventional X-ray imaging relying on X-ray absorption. The phase sensitivity of this interferometric technique is proportional to the interferometer length and inversely proportional to the period of gratings. However, the limited spatial coherency of X-rays limits the maximum interferometer length, and the ability to obtain smaller-period gratings is limited by the manufacturing process. Here, we propose a new optical configuration that employs a combination of a converging parabolic micro-lens array and a diverging micro-lens array, instead of a binary phase grating. Without changing the grating period or the interferometer length, the phase signal is enhanced because the beam deflection by a sample is amplified through the array of converging-diverging micro-lens pairs. We demonstrate that the differential phase signal detected by our proposed set-up is twice that of a Talbot interferometer, using the same binary absorption grating, and with the same overall inter-grating distance.

Synchrotron radiation X-ray computed tomography (CT) provides information about the three-dimensional electron density inside a sample with a high spatial resolution. Recently, the need to examine the internal structure of materials composed of light elements, such as water and carbon fibers in resins, has increased. Small density differences in these systems give low X-ray contrast; segmentation methods suited for this type of problem are necessary. Machine learning is typically used to analyze CT data, and a large amount of training data is required to train a machine learning model. Conversely, transfer learning, which uses existing learning models, can develop a learning model using only a small amount of training data. In this study, the synchrotron radiation X-ray CT images of an epoxy resin containing water have been analyzed using transfer learning as the validation of a method for analyzing low-contrast CT data with high accuracy. Circular domain structures in the resin have been observed using the X-ray CT method, and statistical information about these structures has been successfully obtained by transfer learning-based analysis. Here, transfer learning is performed using twelve slices within an X-ray CT 3D image, demonstrating that low-contrast synchrotron CT data can be segmented with a small amount of training data.

Abstract Microscopy by Achromatic X-rays With Emission of Laminar Light (MAXWELL) is a new X-ray/visible technique with attractive characteristics including isotropic resolution in all directions, large-volume imaging and high throughput. An ultrathin, laminar X-ray beam produced by a Wolter type I mirror irradiates the sample stimulating the emission of visible light by scintillating nanoparticles, captured by an optical system. Three-dimensional (3D) images are obtained by scanning the specimen with respect to the laminar beam. We implemented and tested the technique with a high-brightness undulator at SPring-8, demonstrating its validity for a variety of specimens. This work was performed under the Synchrotrons for Neuroscience—an Asia–Pacific Strategic Enterprise (SYNAPSE) collaboration.

Neutron imaging based on a compact Talbot–Lau interferometer was demonstrated using the RIKEN accelerator-driven compact neutron source (RANS). A compact Talbot–Lau interferometer consisting of gadolinium absorption gratings and a silicon phase grating was constructed and connected to the RANS. Because of pulsed thermal neutrons from the RANS and a position-sensitive detector equipped with time-of-flight (TOF) analysis, moiré interference patterns generated using the interferometer were extracted at a TOF range around the design wavelength (2.37 Å) optimal for the interferometer. Differential phase and scattering images of the metal rod samples were obtained through phase-stepping measurements with the interferometer. This demonstrates the feasibility of neutron phase imaging using a compact neutron facility and the potential for flexible and unique applications for nondestructive evaluation.

Developing long bones alter their shape while maintaining uniform cortical thickness via coordinated activity of bone)forming osteoblasts and bone-resorbing osteoclasts at periosteal and endosteal surfaces, a process we designate trans-pairing. Two types of trans-pairing shift cortical bone in opposite orientations: peri-forming trans-pairing (peri-t-p) increases bone marrow space and endo-forming trans-pairing (endo-t-p) decreases it, via paired activity of bone resorption and formation across the cortex. Here, we focused on endo-t-p in growing bones. Analysis of endo-t-p activity in the cortex of mouse fibulae revealed osteoclasts under the periosteum compressed by muscles, and expression of RANKL in periosteal cells of the cambium layer. Furthermore, mature osteoblasts were localized on the endosteum, while preosteoblasts were at the periosteum and within cortical canals. X-ray tomographic microscopy revealed the presence of cortical canals more closely associated with endo- than with peri-t-p. Sciatic nerve transection followed by muscle atrophy and unloading induced circumferential endo-t-p with concomitant spread of cortical canals. Such canals likely supply the endosteum with preosteoblasts from the periosteum under endo-t-p, allowing bone shape to change in response to mechanical stress or nerve injury. [ABSTRACT FROM AUTHOR]