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1.
Sci Rep ; 13(1): 9624, 2023 Jun 27.
Article in English | MEDLINE | ID: mdl-37369747

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.

2.
Sci Rep ; 12(1): 9668, 2022 06 11.
Article in English | MEDLINE | ID: mdl-35690597

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.


Subject(s)
Microscopy , Synchrotrons , Imaging, Three-Dimensional , Light , Microscopy/methods , Tomography, X-Ray Computed/methods , X-Rays
3.
Front Cell Dev Biol ; 9: 800455, 2021.
Article in English | MEDLINE | ID: mdl-34950666

ABSTRACT

The locomotor system is highly bilateral at the macroscopic level. Homochirality of biological molecules is fully compatible with the bilateral body. However, whether and how single-handed cells contribute to the bilateral locomotor system is obscure. Here, exploiting the small number of cells in the swimming tadpole larva of the ascidian Ciona, we analyzed morphology of the tail at cellular and subcellular scales. Quantitative phase-contrast X-ray tomographic microscopy revealed a high-density midline structure ventral to the notochord in the tail. Muscle cell nuclei on each side of the notochord were roughly bilaterally aligned. However, fluorescence microscopy detected left-right asymmetry of myofibril inclination relative to the longitudinal axis of the tail. Zernike phase-contrast X-ray tomographic microscopy revealed the presence of left-handed helices of myofibrils in muscle cells on both sides. Therefore, the locomotor system of ascidian larvae harbors symmetry-breaking left-handed helical cells, while maintaining bilaterally symmetrical cell alignment. These results suggest that bilateral animals can override cellular homochirality to generate the bilateral locomotor systems at the supracellular scale.

4.
Rev Sci Instrum ; 92(4): 043702, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-34243370

ABSTRACT

Time-resolved x-ray phase tomography using a Talbot interferometer and white synchrotron radiation can provide a three-dimensional movie for visualizing the structural change of materials consisting of light elements. In this study, time-resolved x-ray stroboscopic phase tomography using a Talbot interferometer is demonstrated for a vibrating object under 24 Hz compression-stretch fatigue loading. Moiré patterns are recorded by synchronizing drivers for a shutter, grating displacement, and sample rotation with an x-ray camera with a 200 µs exposure, and phase tomograms are reconstructed at specific motion phases of the vibration. The measurement lasts for a few minutes and the δ value changes before breaking, which is considered due to plastic deformation of soft materials under external vibration are depicted three-dimensionally.

5.
J Synchrotron Radiat ; 28(Pt 3): 732-740, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33949982

ABSTRACT

Owing to the development of X-ray focusing optics during the past decades, synchrotron-based X-ray microscopy techniques allow the study of specimens with unprecedented spatial resolution, down to 10 nm, using soft and medium X-ray photon energies, though at the expense of the field of view (FOV). One of the approaches to increase the FOV to square millimetres is raster-scanning of the specimen using a single nanoprobe; however, this results in a long data acquisition time. This work employs an array of inclined biconcave parabolic refractive multi-lenses (RMLs), fabricated by deep X-ray lithography and electroplating to generate a large number of long X-ray foci. Since the FOV is limited by the pattern height if a single RML is used by impinging X-rays parallel to the substrate, many RMLs at regular intervals in the orthogonal direction were fabricated by tilted exposure. By inclining the substrate correspondingly to the tilted exposure, 378000 X-ray line foci were generated with a length in the centimetre range and constant intervals in the sub-micrometre range. The capability of this new X-ray focusing device was first confirmed using ray-tracing simulations and then using synchrotron radiation at BL20B2 of SPring-8, Japan. Taking account of the fact that the refractive lens is effective for focusing high-energy X-rays, the experiment was performed with 35 keV X-rays. Next, by scanning a specimen through the line foci, this device was used to perform large FOV pixel super-resolution scanning transmission hard X-ray microscopy (PSR-STHXM) with a 780 ± 40 nm spatial resolution within an FOV of 1.64 cm × 1.64 cm (limited by the detector area) and a total scanning time of 4 min. Biomedical implant abutments fabricated via selective laser melting using Ti-6Al-4V medical alloy were measured by PSR-STHXM, suggesting its unique potential for studying extended and thick specimens. Although the super-resolution function was realized in one dimension in this study, it can be expanded to two dimensions by aligning a pair of presented devices orthogonally.

6.
J Bone Miner Res ; 36(8): 1535-1547, 2021 08.
Article in English | MEDLINE | ID: mdl-33905562

ABSTRACT

Auditory ossicles in the middle ear and bony labyrinth of the inner ear are highly mineralized in adult mammals. Cellular mechanisms underlying formation of dense bone during development are unknown. Here, we found that osteoblast-like cells synthesizing highly mineralized hearing-related bones produce both type I and type II collagens as the bone matrix, while conventional osteoblasts and chondrocytes primarily produce type I and type II collagens, respectively. Furthermore, these osteoblast-like cells were not labeled in a "conventional osteoblast"-specific green fluorescent protein (GFP) mouse line. Type II collagen-producing osteoblast-like cells were not chondrocytes as they express osteocalcin, localize along alizarin-labeled osteoid, and form osteocyte lacunae and canaliculi, as do conventional osteoblasts. Auditory ossicles and the bony labyrinth exhibit not only higher bone matrix mineralization but also a higher degree of apatite orientation than do long bones. Therefore, we conclude that these type II collagen-producing hypermineralizing osteoblasts (termed here auditory osteoblasts) represent a new osteoblast subtype. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).


Subject(s)
Bone and Bones , Osteoblasts , Animals , Calcification, Physiologic , Hearing , Mice , Osteocalcin
7.
Opt Express ; 28(11): 16363-16384, 2020 May 25.
Article in English | MEDLINE | ID: mdl-32549461

ABSTRACT

In conventional grating-based X-ray interferometry, it is necessary to repeatedly translate one of the gratings with high accuracy in regular submicron steps and to ensure a constant dose delivery during each step. However, stepping errors and dose fluctuations inevitably occur due to mechanical inaccuracies and/or thermal drift of the interferometer during the stepping process. As a result of these stepping errors and dose fluctuations, the standard reconstruction procedure without considering them causes artifacts in the images as stripes of specific frequencies. In this report, we propose an improved reconstruction method to process phase stepping data with stepping errors and dose fluctuations. The approach can be used to estimate the stepping errors and dose fluctuations, and reconstruct virtually artifact-free images. Based on numerical simulations and experimental data including stepping errors and dose fluctuations, we demonstrate that the proposed method is more effective to other previously reported approaches.

8.
Sci Rep ; 9(1): 7404, 2019 May 22.
Article in English | MEDLINE | ID: mdl-31118428

ABSTRACT

Four-dimensional phase computed tomography (4D phase CT) by an X-ray Talbot interferometer (XTI) with white synchrotron radiation has ever been demonstrated at a temporal resolution of about 1 s for soft-matter samples. However, the radiation damage to samples caused by white synchrotron radiation occasionally hampers our understanding of the sample dynamical properties. Based on the fact that XTI functions with X-rays of a bandwidth up to ca. 10% with performance comparable to that by monochromatic X-rays, filtering white synchrotron radiation to generate a 'pink-beam' of a 10% bandwidth is effective to reduce radiation damage without degrading the image quality and temporal resolution. We have therefore developed pink-beam 4D phase CT at SPring-8, Japan by installing a multilayer mirror with a 10% bandwidth and a 25 keV central photon energy. XTI optimal at this photon energy was built downstream, and a CMOS-based X-ray detector was used to achieve fast image acquisitions with an exposure time of 1 ms (or 0.5 ms) per moiré image. The resultant temporal resolution of pink-beam 4D phase CT was 2 s (1 s). We applied the pink-beam 4D phase CT to in-situ observation of polypropylene, poly(methyl methacrylate), and polycarbonate under infrared laser irradiation (1064 nm). The dynamics of melting, bubbling, and ashing were successfully visualized in 3D movies without problematic radiation damage by synchrotron radiation.

9.
Rev Sci Instrum ; 88(8): 086110, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28863654

ABSTRACT

The intensity distribution in phase space of an X-ray synchrotron radiation beamline was measured using a pinhole camera method, in order to verify astigmatism compensation by a Fresnel zone plate focusing optical system. The beamline is equipped with a silicon double crystal monochromator. The beam size and divergence at an arbitrary distance were estimated. It was found that the virtual source point was largely different between the vertical and horizontal directions, which is probably caused by thermal distortion of the monochromator crystal. The result is consistent with our astigmatism compensation by inclining a Fresnel zone plate.

10.
J Synchrotron Radiat ; 21(Pt 2): 446-8, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24562567

ABSTRACT

The experimental procedure for obtaining the point spread function (PSF) of a focusing beam generated using an X-ray multilayer zone plate (MZP) with a narrow annular aperture has been developed. It was possible to reconstruct the PSF by applying the tomographic process to the measured dataset consisting of line spread functions (LSFs) in every radial direction on the focal plane. The LSFs were measured by a knife-edge scanning method of detecting scattered intensity. In the experimental work, quasi-monochromatic undulator radiation with a first harmonic energy of 20 keV was directly focused without a monochromator by the MZP, and the PSF was measured using this procedure. As a result, a near diffraction-limited focused beam size of 46 nm full width at half-maximum was obtained.

11.
Microscopy (Oxf) ; 62(3): 353-61, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23220770

ABSTRACT

The cotyledon of legume seeds is a storage organ that provides nutrients for seed germination and seedling growth. The spatial and temporal control of the degradation processes within cotyledons has not been elucidated. Calcium oxalate (CaOx) crystals, a common calcium deposit in plants, have often been reported to be present in legume seeds. In this study, micro-computed tomography (micro-CT) was employed at the SPring-8 facility to examine the three-dimensional distribution of crystals inside cotyledons during seed maturation and germination of Lotus miyakojimae (previously Lotus japonicus accession Miyakojima MG-20). Using this technique, we could detect the outline of the embryo, void spaces in seeds and the cotyledon venation pattern. We found several sites that strongly inhibited X-ray transmission within the cotyledons. Light and polarizing microscopy confirmed that these areas corresponded to CaOx crystals. Three-dimensional observations of dry seeds indicated that the CaOx crystals in the L. miyakojimae cotyledons were distributed along lateral veins; however, their distribution was limited to the abaxial side of the procambium. The CaOx crystals appeared at stage II (seed-filling stage) of seed development, and their number increased in dry seeds. The number of crystals in cotyledons was high during germination, suggesting that CaOx crystals are not degraded for their calcium supply. Evidence for the conservation of CaOx crystals in cotyledons during the L. miyakojimae germination process was also supported by the biochemical measurement of oxalic acid levels.


Subject(s)
Calcium Oxalate/analysis , Cotyledon/metabolism , Seeds/metabolism , Calcium Oxalate/chemistry , Cotyledon/cytology , Germination/physiology , Lotus/embryology , Lotus/growth & development , Lotus/metabolism , Seeds/growth & development , X-Ray Microtomography
12.
Rev Sci Instrum ; 83(1): 013705, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22299960

ABSTRACT

A circular multilayer zone plate (MZP) was fabricated and its focusing performance was evaluated using 20-keV x-rays. MoSi(2) and Si layers were alternately deposited by DC magnetron sputtering on a wire core; all the interfaces satisfied the Fresnel zone condition. The measured line spread function was converted to a point spread function by tomographic reconstruction. The results suggest that the MZP has the potential to realize the diffraction-limited resolving power, which is calculated to be 35 nm using the diffraction integral. Furthermore, scanning transmission microscopy using the MZP could resolve a 50-nm line-and-space pattern.

13.
Rev Sci Instrum ; 81(7): 073702, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20687726

ABSTRACT

A new method is proposed for nanoscale hard x-ray measurements. This method uses a reflection on a heavy-metal wire that functions as a single slit with a nanoscale aperture for a parallel x-ray beam. This "nanoslit" can be used to perform high-spatial-resolution measurements of the intensity distribution of a wavefront that diverges from an aperture. In experiments, Fresnel fringes generated by a rectangular aperture were measured using a 300-microm-diameter platinum wire as the nanoslit. In these experiments, the finest fringes with a period of 26 nm could be successfully resolved.

14.
J Synchrotron Radiat ; 9(Pt 3): 128-31, 2002 May 01.
Article in English | MEDLINE | ID: mdl-11972365

ABSTRACT

The first result is presented of an X-ray fluorescence microscope with a Wolter mirror in combination with a CCD camera used as an energy-resolved two-dimensional detector in photon-counting mode. Two-dimensional elemental maps of metallic wires, such as Fe, Co, Ni and Cu, and inclusions of a synthesized diamond could be obtained with an energy resolution of 350 eV.

15.
J Synchrotron Radiat ; 9(Pt 3): 179-81, 2002 May 01.
Article in English | MEDLINE | ID: mdl-11972375

ABSTRACT

A Zernike-type phase-contrast X-ray microscope with a zone plate and a phase plate was constructed at the Photon Factory BL3C2. Parallel monochromatic X-rays of 8.97 keV were incident on a specimen and a direct beam transmitted through the specimen was focused on the back focal plane of the zone plate, where an aluminium phase plate was placed. Tantalum line patterns as fine as 0.3 microm could be imaged. Phase-contrast images of polypropylene wires and polystyrene latex beads were obtained, which showed better contrast than that of their bright field images.

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