Fresnel zone plates are core optical elements for transmission X-ray microscopy, with their structural characteristics critically determining imaging quality. However, previous studies have predominantly focused on enhancing spatial resolution and diffraction efficiency, leaving the quantitative relationship between zone plate structural parameters and imaging quality underexplored. This study introduced imaging contrast as a central evaluation metric to systematically examine the effects of duty cycle, zone height, and stiffeners on imaging quality. The results demonstrate that deviations in duty cycle exert the most pronounced influence on imaging contrast, as non-uniformity introduces additional aberrations that significantly degrade contrast, thereby emerging as the dominant factor limiting imaging quality. In comparison, variations in zone height uniformity and stiffeners primarily affect diffraction efficiency, having only a minor impact on contrast. This study establishes the intrinsic link between structural parameters of zone plates and imaging contrast, providing a theoretical foundation for structural optimization and fabrication control, and offering a pathway toward enhanced X-ray microscopy performance.

The combination of near-native, three-dimensional (3D) cryo-soft X-ray tomography (cryo-SXT) with transcriptomics establishes a multiscale platform to link organelle-level structural remodeling to dose-dependent gene expression changes from contaminant exposure. Applying this platform to AgNPs-induced hormesis in Chlamydomonas reinhardtii, we directly correlate organelle remodeling, such as alterations in lipid droplets and starch-associated structures, with transcriptional reprogramming of energy metabolism pathways across exposure gradients. This approach reveals how molecular regulation translates into structural adaptation under hormetic versus toxic conditions. Comparison with silver ions (Ag+) controls indicates that the observed biphasic effects are largely attributable to dissolved Ag+. At low dose (25 μg/L), AgNPs trigger hormetic adaptation, as evidenced by starch sheath thickening and lipid droplets (LDs) shrinkage, driven by upregulation of starch synthesis genes and suppression of triacylglycerol synthesis. Conversely, high-dose (300 μg/L) exposure induces cytotoxicity, wherein triacylglycerol synthesis is promoted and stress-associated metabolic reallocation occurs, accompanied by LDs expansion, starch granule enlargement, pyrenoid shrinkage, and starch sheath thinning. Furthermore, under high-dose stress, intracellular carbon pools are diverted toward starch biosynthesis, resulting in a compositional shift toward highly branched amylopectin. Intriguingly, LDs and starch sheath display biphasic dose-dependent structural changes, identifying them as sensitive biomarkers of cellular state. By quantitatively linking transcriptional reprogramming with organelle remodeling, this study establishes a correlative imaging-omics platform that enables direct association between molecular regulation and structural phenotypes in organisms exposed to nanoparticles.

Vacuum electron beam welded (VEBW) joints of 6061-T6 aluminum alloy are critical for its structural integrity at cryogenic temperatures (~20 K) for the cryogenic moderator system (CMS), yet deformation mechanisms under such extreme conditions remain unclear. In this study, 6061-T6 butt joints were fabricated by VEBW. Tensile tests at 20 K, microhardness tests, and multi-scale analyses were conducted to investigate microstructural evolution, cryogenic mechanical properties, and failure mechanisms. It is found that VEBW joints showed significant inhomogeneity. The weld zone (WZ) was the softest region (~55 Hv) due to dissolution of nano-scale β″ precipitates and formation of a coarse cast microstructure. In contrast, the base metal (BM) shows the higher yield strength (368 ± 4.9 MPa) and tensile strength (442 ± 8.8 MPa) due to nanoscale β″ precipitates pinning dislocations. At 20 K, BM deformation relies on dislocation slip and nanoscale precipitate strengthening for high strength and work hardening, whereas WZ deformation involves easy dislocation movement, multiplication, interaction with acicular α/β phases, and formation of dislocation walls and cellular structures. Cryogenic tensile tests show plastic strain concentrated in WZ and HAZ, but uniform deformation in BM. Fracture failure occurred in the over-aged heat affected zone (HAZ) with brittle cleavage, not in the WZ, making HAZ the weak link. These findings clarify the deformation mechanism and failure origins of critical joining positions, which can offer key insights for optimizing the cryogenic structural design of CSNS-II moderators, and valuable reference for alloy welded structures in other cryogenic engineering applications (such as aerospace and superconducting fields).

The beam-shaping condenser (BSC) has become a key optical component in X-ray microscopy, providing a wide field of view with stable and uniform illumination. However, alternating bright and dark fringes often appear at the focal spot, compromising illumination uniformity. To elucidate the formation mechanism of these diffraction fringes, this study conducted theoretical analyses and numerical simulations. Based on this, a defocused illumination approach was developed to alter the focal positions and spatial relative phases of the sub-gratings, thereby enhancing illumination uniformity. The influence of defocused illumination on fringe patterns and intensity distribution was systematically investigated. To validate this approach, a BSC with a Fresnel number of 20 and a 60 µm × 60 µm field of view was fabricated and tested at the soft X-ray imaging beamline of the Hefei Light Source. Experimental results demonstrate that the device achieves uniform top-hat illumination across the full field, effectively suppressing diffraction-induced artifacts. This work offers an efficient and practical approach for achieving wide-field uniform illumination in X-ray microscopy.

Ptychography is a scanning coherent diffraction imaging technique that enables quantitative imaging with diffraction-limited resolution. By exploiting energy-dependent contrast, spectroscopic ptychography further enables quantitative chemical imaging and has become an important imaging modality. However, conventional approaches require dense ptychographic scans at each photon energy, leading to tedious data acquisition and an increased risk of sample drift and radiation damage. Here, we propose a cross-energy structural consistency constraint (CSCC) algorithm for spectroscopic ptychography that exploits intrinsically energy-invariant regions within the specimen as additional real-space constraints. By automatically identifying spectrally insensitive structures, the method establishes a link between reconstructions acquired at different energies, markedly reducing the need for dense scanning while maintaining high imaging fidelity. Synchrotron experiments demonstrate that high-quality spectroscopic imaging over the same field of view can be achieved using only one quarter of the conventional data and hence radiation dose, thereby significantly accelerating data acquisition. This algorithm provides a practical and scalable strategy for fast and dose-efficient quantitative spectroscopic ptychographic microscopy.

The quality of neutron gratings critically determines the performance of neutron grating interferometers. However, conventional gadolinium-particle filling methods face significant challenges in the fabrication of small-period, high-aspect-ratio neutron absorption gratings. This study proposes a microfluidic particle filling method based on an all-aqueous process for the fabrication of high-aspect-ratio neutron absorption gratings. Liquid-phase pressurization combined with the all-aqueous process effectively addresses particle transport obstruction within high-aspect-ratio grating trenches, thus enhancing the particle filling ratio. The adaptive particle filling mechanism adaptively redistributes the flow rate of particle suspension in response to flow impedance differences caused by variations in geometric parameters and filling conditions in microchannels. This process progressively minimizes impedance differences, enabling uniform particle filling. The effects of pressure, particle suspension flow velocity, and concentration on particle filling were investigated, and the particle filling ratio and uniformity were evaluated using x-ray absorption imaging. Neutron absorption gratings with a period of 4 mu m were successfully fabricated, demonstrating the applicability of this method to small-period, high-aspect-ratio gratings. This work offers a novel and effective strategy to address the challenges associated with fabricating neutron absorption gratings with small periods and high aspect ratios.

Bionano robots have been recognized as a tumor-selective and effective platform for therapeutic outcomes as they synergize the merits of living organisms and nanoparticles. Here, we construct a self-mineralized system (denoted as SO@FeS) by employing the facultative anaerobic bacterium Shewanella oneidensis MR-1 to biosynthesize FeS NPs for effective cancer therapy with dual cell death pathways. Biogenic FeS NPs are embedded into the cell surface with inherent photothermal conversion ability and low crystallinity and tend to simultaneously release Fe2+ and hydrogen sulfide (H2S) in an acidic environment. As a result, the obtained SO@FeS hybrid can couple the versatility of the nanoparticles with the respiration and tumor-targeting capacities of bacterium, ultimately leading to the collaborative clearance of tumor cells. Specifically, cryo-soft X-ray tomography (cryo-SXT) is a near-native 3D imaging modality that directly displays the trafficking pathway of SO@FeS in cancer cells. More importantly, cryo-SXT captures the 3D maps of SO@FeS-initiated ferroptosis and apoptosis, as evidenced by the remodeling of cytoplasmic organelles. This work offers valuable theoretical insights from the perspective of organelle morphology, links subcellular reorganization and cell death pathways, and facilitates the design of living nanoplatforms that integrate multiple therapies.

Dissimilatory metal-reducing bacteria (DMRB) have the talent to convert mercury ions (Hg2+) into elemental mercury (Hg0). Here, we shed light on the directed biomineralization of Hg2+ into mercury selenide (HgSe), which is a promising environmental sink for Hg with minimal ecological risk. This process displays a controlled subcellular localization, improved efficiency, and redistribution of Hg species through the coordination of three modules, including reinforced respiratory, reconfigured electron flow, and anchored trap in Shewanella oneidensis MR-1, a model DMRB. By supplementing redox substance, we first construct a golden Hg2+ capture system, that is S. oneidensis-Se0 hybrid. Redox substance triggers a transition from intracellular selenite reduction to extracellular biosynthesis of Se0 nanoparticles (NPs), resulting in a notably increased yield of Se0 NPs. Importantly, this hybrid alters the biotransformation fate of Hg2+, enabling the efficient formation of less toxic HgSe nanoparticles and decreasing the percentage of volatile Hg0. Such a biological decontamination process relies on sufficient bioelectron donation, unimpeded electron channels, and highly effective Hg2+ traps, all of which can be initiated, directed, and coordinated by the redox-active compound. The resulting S. oneidensis-Se0 hybrid is feasible to scale up for the depuration of Hg2+ in artificial wastewater by using a membrane bioreactor (MBR). Our work provides an integrated strategy for designing biological capture to immobilize Hg2+, offering fundamental guidance to improve biotechnologies in environmental remediation and resource recovery.

Ptychography is a coherent diffraction imaging technique capable of achieving diffraction-limited resolution. However, irregular random vibration between the beam and the sample induced by system instability can induce incoherent blurring of the diffraction patterns, thereby degrading the quality of the reconstruction. Here, we propose what we believe to be a novel purely algorithmic approach, termed the least-squares vibration inverse solution (LSVS) method, which constructs each ptychographic scan point as an independent pseudo-ptychography process of size N × N . By applying the least-squares inverse solution, the method determines the weights of diffraction patterns at N × N distinct offset positions in the recorded diffraction pattern, effectively mitigating the influence of random vibration in ptychography. Both simulation and experimental results demonstrate the effectiveness of LSVS in handling relative random vibrations, providing a new approach for addressing mechanical vibration issues in the ptychography system.

The fourth-generation synchrotron radiation source, based on diffraction-limited storage rings, achieves unprecedented brightness and coherence by reducing the transverse emittance of the electron beam to approach the diffraction limit of the X-ray. The Hefei Advanced Light Facility (HALF), currently under construction, represents such a next-generation facility. One of its initially built beamlines, the Tender Microscopic Spectroscopy Imaging Beamline, which will offer nanoscale-resolution three-dimensional and spectroscopic X-ray imaging through Ptychography and fullmethodologies, and experimental conditions, offering both potential users and the broader scientific community an overview of its unique capabilities. The beamline is expected to play a pivotal role in advancing research across diverse disciplines, including life sciences, materials science, and energy technology.

Calcium metal batteries with high capacity and low cost are promising alternatives to Li-ion batteries for large-scale energy storage. However, its development is crucially impeded by the irreversible Ca metal anode, which is highly associated with uncontrollable Ca plating/stripping. Here, we report a new riveting strategy to regulate the nucleation and growth of a Ca metal anode in the 3D structure of a carbon nanotube film (CNF) by introducing in situ-formed Na metal mediators. Na metal mediators are found to first deposit in the CNF substrate prior to Ca nucleation and subsequently induce dense and uniform Ca plating due to their thermodynamically favorable kinetics. Therefore, even at a high current density of 10 mA cm-2 and a high capacity of 5 mAh cm-2, it realizes the uniform nucleation and growth of dendrite-free Ca metal. Moreover, an unprecedented cycling life of over 800 cycles is also achieved for Ca metal batteries with a high coulombic efficiency above 98.4%. This work demonstrates the significance of a riveting strategy to enable the superior performance of Ca metal batteries by regulating the plating/stripping behaviors of Ca metal anodes and paves a new way for the development of Ca metal batteries.

Metal ions are indispensable to life, as they can serve as essential enzyme cofactors to drive fundamental biochemical reactions, yet paradoxically, excess is highly toxic. Higher-order cells have evolved functionally distinct organelles that separate and coordinate sophisticated biochemical processes to maintain cellular homeostasis upon metal ion stimuli. Here, we uncover the remodeling of subcellular architecture and organellar interactome in yeast initiated by several metal ion stimulations, relying on near-native three-dimensional imaging, cryo-soft X-ray tomography. The three-dimensional architecture of intact yeast directly shows that iron or manganese triggers a hormesis-like effect that promotes cell proliferation. This process leads to the reorganization of organelles in the preparation for division, characterized by the polar distribution of mitochondria, an increased number of lipid droplets (LDs), volume shrinkage, and the formation of a hollow structure. Additionally, vesicle-like structures that detach from the vacuole are observed. Oppositely, cadmium or mercury causes stress-associated phenotypes, including mitochondrial fragmentation, LD swelling, and autophagosome formation. Notably, the organellar interactome, encompassing the interactions between mitochondria and LDs and those between the nuclear envelope and LDs, is quantified and exhibits alteration with multifaceted features in response to different metal ions. More importantly, the dynamics of organellar architecture render them more sensitive biomarkers than traditional approaches for assessing the cell state. Strikingly, yeast has a powerful depuration capacity to isolate and transform the overaccumulated cadmium in the vacuole, mitochondria, and cytoplasm as a high-value product, quantum dots. This work presents the possibility of discovering fundamental links between organellar morphological characteristics and the cell state.

X-ray Talbot-Lau interferometer, offering multi-contrast for the imaged objects, has shown powerful capacity in imaging biological soft tissues, low density materials, etc. However, the length of the system is constant, which limits its applications. Here, we establish a new X-ray Talbot-Lau interferometer theory to achieve a flexible phase contrast imaging system. This interferometer has a tunable length-scale scattering sensitivity. The experiments show that we can regulate the scattering signal individually. Furthermore, we construct a G2-less phase contrast imaging based on this flexible interferometer to validate the possibility of highly compact X-ray Talbot-Lau interferometer.

Grating-based X-ray phase-contrast imaging enhances the contrast of imaged objects, particularly soft tissues. However, the radiation dose in computed tomography (CT) is generally excessive owing to the complex collection scheme. Sparse-view CT collection reduces the radiation dose, but with reduced resolution and reconstructed artifacts particularly in analytical reconstruction methods. Recently, deep learning has been employed in sparse-view CT reconstruction and achieved state-of-the-art results. Nevertheless, its low generalization performance and requirement for abundant training datasets have hindered the practical application of deep learning in phase-contrast CT. In this study, a CT model was used to generate a substantial number of simulated training datasets, thereby circumventing the need for experimental datasets. By training a network with simulated training datasets, the proposed method achieves high generalization performance in attenuation-based CT and phase-contrast CT, despite the lack of sufficient experimental datasets. In experiments utilizing only half of the CT data, our proposed method obtained an image quality comparable to that of the filtered back-projection algorithm with full-view projection. The proposed method simultaneously addresses two challenges in phase-contrast three-dimensional imaging, namely, the lack of experimental datasets and the high exposure dose, through model-driven deep learning. This method significantly accelerates the practical application of phase-contrast CT.

Understanding the spatial orientation of nanoparticles and the corresponding subcellular architecture events favors uncovering fundamental toxic mechanisms and predicting response pathways of organisms toward environmental stressors. Herein, we map the spatial location of label-free citrate-coated Ag nanoparticles (Cit-AgNPs) and the corresponding subcellular reorganization in microalgae by a noninvasive 3D imaging approach, cryo-soft X-ray tomography (cryo-SXT). Cryo-SXT near-natively displays the 3D maps of Cit-AgNPs presenting in rarely identified sites, namely, extracellular polymeric substances (EPS) and the cytoplasm. By comparative 3D morphological assay, we observe that Cit-AgNPs disrupt the cellular ultrastructural homeostasis, triggering a severe malformation of cytoplasmic organelles with energy-producing and stress-regulating functions. AgNPs exposure causes evident disruption of the chloroplast membrane, significant attenuation of the pyrenoid matrix and starch sheath, extreme swelling of starch granules and lipid droplets, and shrinkage of the nucleolus. In accompaniment, the number and volume occupancy of starch granules are significantly increased. Meanwhile, the spatial topology of starch granules extends from the chloroplast to the cytoplasm with a dispersed distribution. Linking the dynamics of the internal structure and the alteration of physiological properties, we derive a comprehensive cytotoxic and response pathway of microalgae exposed to AgNPs. This work provides a perspective for assessing the toxicity at subcellular scales to achieve label-free nanoparticle-caused ultrastructure remodeling of phytoplankton.

Ptychography is a coherent diffractive imaging method that can achieve diffraction-limited resolution. A fly-scan mode in ptychography can mitigate time costs comparing to traditional step-scan processes. However, expanding fly-scan step size may lead to the failure of traditional phase retrieval algorithm. Here, the method we adopt differs from the multi-mode method that has become popular at X-ray synchrotrons in that it models each diffraction pattern as a sum of shifted object patches, rather than the incoherent sum of a number of modes. This methodology is extended to the standard ePIE algorithm called Multi-object ePIE (Mo-ePIE), and simulation and experimental results demonstrate its effectiveness in handling large step size fly-scan, achieving reconstructions with up to 25 maximum fly-scan pixels. Furthermore, the reintegration with multi-mode probe methods can address potential issues of system decoherence, further enhancing the quality of reconstruction. This algorithm exhibits substantial potential in accelerating ptychography experiments, offering a promising solution for high-speed applications.

The Fresnel zone plate plays a pivotal role in X-ray imaging systems, directly influencing the uniformity of imaging contrast. Achieving uniform imaging contrast imposes stringent requirements on the linewidth and height uniformity of the zone plate. The current mainstream method for zone plate fabrication involves utilizing electron beam lithography in conjunction with electroplating. However, in structures with large aspect ratios, precise deposition of gold to the bottom of the trench through electroplating becomes increasingly challenging to control. In this study, we employed a pulse plating process to enhance the uniformity of the plating height. Detailed investigations were conducted to analyze the effects of pulse current density, pulse duty cycle, and pulse frequency on plating height. Utilizing pulse plating, we successfully fabricated a zone plate with an outermost width of 50 nm and a thickness of approximately 245 nm. Structural analysis showed that the plating height uniformity is improved to better than 5%. The high uniformity imaging pattern was obtained by using the Siemens star test pattern at the soft x-ray imaging station at NSRL. The spatial resolution was down to 50 nm.

The properties of liquid-liquid interfaces are intricately linked to its structure, with a particular focus on the concentration distribution within the interface. To obtain precise information regarding the concentration distribution, we have developed a high-resolution soft X-ray imaging method for liquid-liquid interfaces. This work focused on representative partially miscible systems, analyzing the interfacial concentration distribution profiles of water-alkanols under both steady-state and dynamic processes, and obtaining the diffusion coefficients of different water concentrations in alkanols. Significant disparities in concentration distributions and the concentration-related diffusion coefficients were observed despite comparable diffusion distances within the same system across different states. Meanwhile, it was found that alkanols exhibit adsorption phenomena at the interface. This newfound knowledge serves as a crucial stepping stone toward a deeper understanding of partially miscible systems. Our study opens a way to explore liquid-liquid interface information with high-resolution.

The morphology of lithium deposition plays a crucial factor in determining the performance of lithium metal batteries. In order to understand the lithium plating and stripping process, the in-situ cell suitable for soft X-ray microscopy was designed and fabricated. We investigated the plating modes of mossy lithium and the interactions among surrounding grains. Furthermore, we established correlations between the lithium stripping process and the morphology of lithium grains, and thus summarized four stripping modes. The surface stripping and top stripping allow for complete stripping, while the side stripping and root stripping result in the formation of “dead lithium”. These findings provide valuable insights for reducing the formation of “dead lithium” in lithium metal batteries.

Neutron absorption gratings play a crucial role in neutron phase contrast imaging systems, where the fabrication of large-size and small-period absorption gratings that meet imaging requirements presents a significant challenge. The pressurized particle filling method has been successfully applied to fabricate large-size absorption gratings. Here, we investigated the feasibility of the pressurized particle filling method for fabricating small-period gratings and proposed an optimized pressurized particle filling method. The grating surface was covered with a uniform particle layer and then pressurized, utilizing the adaptive deformation of the particle layer to achieve uniform particle filling. Neutron absorption gratings with an area of 60 × 60 mm2 and periods of 8 and 4 µm were fabricated through this method. The particle filling rate and fabrication efficiency were successfully improved. In addition, the evaluation of the particle filling uniformity method by analyzing the proportion of particles on the grating surface was proposed. The better uniformity of small-period neutron absorption gratings indicated that the optimized pressurized particle filling method can achieve relatively uniform particle filling.