Microstructural and chemical features of impact melts on Ryugu particle surfaces: Records of interplanetary dust hit on asteroid Ryugu.

The Hayabusa2 spacecraft delivered samples of the carbonaceous asteroid Ryugu to Earth. Some of the sample particles show evidence of micrometeoroid impacts, which occurred on the asteroid surface. Among those, particles A0067 and A0094 have flat surfaces on which a large number of microcraters and impact melt splashes are observed.

In situ high-pressure pair distribution function measurement of liquid and glass by using 100 keV pink beam.

Understanding the pressure-induced structural changes in liquids and amorphous materials is fundamental in a wide range of scientific fields. However, experimental investigation of the structure of liquid and amorphous material under in situ high-pressure conditions is still limited due to the experimental difficulties. In particular, the range of the momentum transfer (Q) in the structure factor [S(Q)] measurement under high-pressure conditions has been limited at relatively low Q, which makes it difficult to conduct detailed structural analysis of liquid and amorphous material.

Seeded stimulated X-ray emission at 5.9 keV.

X-ray free-electron lasers (XFELs) provide intense pulses that can generate stimulated X-ray emission, a phenomenon that has been observed and studied in materials ranging from neon to copper. Two schemes have been employed: amplified spontaneous emission (ASE) and seeded stimulated emission (SSE), where a second color XFEL pulse provides the seed. Both phenomena are currently explored for coherent X-ray laser sources and spectroscopy.

Enhanced solid-state phosphorescence of organoplatinum π-systems by ion-pairing assembly.

Anion binding and ion pairing of dipyrrolyldiketone Pt complexes as anion-responsive π-electronic molecules resulted in photophysical modulations, as observed in solid-state phosphorescence properties. Modifications to arylpyridine ligands in the Pt complexes significantly impacted the assembling behaviour and photophysical properties of anion-free and anion-binding (ion-pairing) forms. The Pt complexes, in the presence of guest anions and their countercations, formed various anion-binding modes and ion-pairing assembled structures depending on constituents and forms (solutions and crystals).

Real-time tilting and twisting motions of ligand-bound states of α7 nicotinic acetylcholine receptor.

The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response.

Overlooked Hydrogen Bond in a Blue Copper Protein Uncovered by Neutron and Sub-Ångström Resolution X-ray Crystallography.

Metalloproteins play fundamental roles in organisms and are utilized as starting points for the directed evolution of artificial enzymes. Knowing the strategies of metalloproteins, by which they exquisitely tune their activities, will not only lead to an understanding of biochemical phenomena but also contribute to various applications. The blue copper protein (BCP) has been a renowned model system to understand the biology, chemistry, and physics of metalloproteins.

Unraveling Non-Uniform Strain-Induced Crystallization Near a Crack Tip in Natural Rubber.

Strain-induced crystallization (SIC) in natural rubber (NR) near crack tips significantly enhances crack growth resistance, but understanding the interplay between local strain field and crystallization remains challenging due to confined and heterogeneous characteristics. Using micro-scale digital image correlation (DIC) and scanning wide-angle X-ray diffraction (WAXD, with a narrow 10 µm square beam), this study maps local strain tensor properties and SIC in the vicinity of the crack tip and its peripheral zone (≈3 mm × 1 mm area). The analysis reveals a significant correlation between these properties.

Replicating shear-mediated self-assembly of spider silk through microfluidics.

The development of artificial spider silk with properties similar to native silk has been a challenging task in materials science. In this study, we use a microfluidic device to create continuous fibers based on recombinant MaSp2 spidroin. The strategy incorporates ion-induced liquid-liquid phase separation, pH-driven fibrillation, and shear-dependent induction of β-sheet formation.

Open-[60]fullerenols with water adsorbed both inside and outside.

The water affinity on [60]fullerenols was found to be governed by surface electrostatic potential while water aggregation is initiated by the hydroxy groups attached on the carbon surface. The molecular water adsorption at the internal sphere caused a significnat inhibition of water adsorption at the external carbon surface.

Lateral Heterometal Junction Rectifier Fabricated by Sequential Transmetallation of Coordination Nanosheet.

Heterostructures of two-dimensional materials realise novel and enhanced physical phenomena, making them attractive research targets. Compared to inorganic materials, coordination nanosheets have virtually infinite combinations, leading to tunability of physical properties and are promising candidates for heterostructure fabrication. Although stacking of coordination materials into vertical heterostructures is widely reported, reports of lateral coordination material heterostructures are few.

High-precision finishing method for narrow-groove channel-cut crystal x-ray monochromator using plasma chemical vaporization machining with wire electrode.

A channel-cut crystal monochromator (CCM) is a popular and powerful device for producing monochromatic x-ray beams with extreme angular stability at a nano-radian level. Narrowing the groove width of CCMs has various benefits; for example, it is made possible to design more compact CCMs with an equivalent working energy range and to reduce the optical delay and the amount of beam shift, enhancing compatibility with various experimental techniques. An obstacle to the use of narrow-groove CCMs is the lack of a high-precision finishing method for the inner-wall reflecting surfaces, which imposes the distortion of x-ray wavefronts and spectral purity.

X-ray phase contrast reveals soft tissue and shell growth lines in mollusks.

High-resolution 3D imaging of species with exoskeletons such as shell-bearing mollusks typically involves destructive steps. Nondestructive alternatives are desirable since samples can be rare and valuable, and destructive steps are time-consuming and may distort the tissue. Here, we show for the first time that propagation-based phase-contrast X-ray imaging can significantly increase contrast in mollusks with intact shells.

Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu.

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.

Denary High-Entropy Oxide Nanoparticles Synthesized by a Continuous Supercritical Hydrothermal Flow Process.

High-entropy oxide nanoparticles (HEO NPs) have been intensively studied because of their attractive properties, such as high stability and enhanced catalytic activity. In this work, for the first time, denary HEO NPs were successfully synthesized using a continuous supercritical hydrothermal flow process without calcination. Interestingly, this process allows the formation of HEO NPs on the order of seconds at a relatively lower temperature.

Visualization of the Dynamics of Photoinduced Crawling Motion of 4-(Methylamino)Azobenzene Crystals via Diffracted X-ray Tracking.

The photoinduced crawling motion of crystals is a continuous motion that azobenzene molecular crystals exhibit under light irradiation. Such motion enables object manipulation at the microscale with a simple setup of fixed LED light sources. Transportation of nano-/micromaterials using photoinduced crawling motion has recently been reported.

Ferroic Order for Anisotropic Magnetic Dipole Term in Collinear Antiferromagnets of (t_{2g})^{4} System.

We present the possibility of x-ray magnetic circular dichroism on RuO_{2} with collinear antiferromagnetism (AFM). Given that the crystal symmetry breaks the time reversal symmetry when the antiparallel spin aligns along the [100] direction, the expectation vector of the anisotropic magnetic dipole operator ⟨t⟩ remains uncanceled along the [010] direction. Our Letter reveals that the magnetic dipole (T_{z}) term in the x-ray magnetic circular dichroism is induced by the residual ⟨t⟩.

Siliceous zeolite-derived topology of amorphous silica.

The topology of amorphous materials can be affected by mechanical forces during compression or milling, which can induce material densification. Here, we show that densified amorphous silica (SiO) fabricated by cold compression of siliceous zeolite (SZ) is permanently densified, unlike densified glassy SiO (GS) fabricated by cold compression although the X-ray diffraction data and density of the former are identical to those of the latter. Moreover, the topology of the densified amorphous SiO fabricated from SZ retains that of crystalline SZ, whereas the densified GS relaxes to pristine GS after thermal annealing.

The Blinking of Small-Angle X-ray Scattering Reveals the Degradation Process of Protein Crystals at Microsecond Timescale.

X-ray crystallography has revolutionized our understanding of biological macromolecules by elucidating their three-dimensional structures. However, the use of X-rays in this technique raises concerns about potential damage to the protein crystals, which results in a quality degradation of the diffraction data even at very low temperatures. Since such damage can occur on the micro- to millisecond timescale, a development in its real-time measurement has been expected.

In situ high temperature powder x-ray diffraction technique using a sapphire single-crystal flat cell.

Understanding the behaviors of materials in their operating and manufacturing environments is essential not only in the scientific field, but also in the context of designing industrial materials for target applications. In this study, we developed a high-temperature x-ray diffraction (XRD) system, using a small microscope heating stage at the BL02B2 beamline in SPring-8. Newly designed sample cells composed of sapphire single crystals were employed to perform XRD experiments using powdered samples at high temperatures and under oxidization/reduction gas atmospheres, with a short sample exchange time.

Pressure-induced reversal of Peierls-like distortions elicits the polyamorphic transition in GeTe and GeSe.

While polymorphism is prevalent in crystalline solids, polyamorphism draws increasing interest in various types of amorphous solids. Recent studies suggested that supercooling of liquid phase-change materials (PCMs) induces Peierls-like distortions in their local structures, underlying their liquid-liquid transitions before vitrification. However, the mechanism of how the vitrified phases undergo a possible polyamorphic transition remains elusive.