Search Results (1,313)

Ozone micro- and nanobubbles have emerged as a promising platform for advanced oxidation processes owing to their distinctive physicochemical characteristics, including exceptional stability, prolonged gas residence time, and highly active gas–liquid interfaces. Compared with conventional ozonation, micro/nanobubble-assisted systems significantly enhance ozone dissolution and utilization efficiency. They achieve this by creating a unique interfacial microenvironment that promotes localized and sustained oxidative reactions. Increasing evidence suggests that ozone oxidation is not dominated solely by homogeneous bulk-phase reactions but is strongly coupled with processes occurring at the bubble/water interface, particularly hydroxyl radical generation and surface-localized oxidation. This review provides an application-oriented overview of ozone micro/nanobubble technology by summarizing representative preparation methods and characterization techniques, elucidating their distinctive interfacial physicochemical properties, and critically examining their performance in oxidative cleaning, microbial inactivation, and complex environmental remediation. Special emphasis is placed on interpreting these phenomena from the perspective of gas–liquid reactions and surface-induced radical generation, with the aim of establishing a unified mechanistic framework that bridges fundamental properties with engineering performance. Finally, current challenges and future research directions for translating ozone micro/nanobubble systems into large-scale and long-term applications are discussed. Full article

A dedicated data acquisition system has been developed and commissioned for the tender-energy spectroscopy beamline BL16U1 at the Shanghai Synchrotron Radiation Facility. The system implements a distributed architecture integrating EPICS-based hardware control with the Bluesky experiment orchestration environment, supporting multiple X-ray absorption spectroscopy modes including transmission, total electron yield, total fluorescence yield, and partial fluorescence yield detection. A key technical feature is the hardware-level synchronization between a multi-channel silicon drift detector and a multichannel scaler, enabling precise timing for fluorescence-XAS measurements. A unified graphical interface based on Control System Studio provides streamlined experiment control and real-time data visualization. System validation using standard reference samples demonstrates successful acquisition of high-quality Cl K-edge XANES spectra in fluorescence mode, high signal-to-noise Co K-edge EXAFS data in transmission mode with extended k-space coverage up to 16 Å⁻¹, and high-sensitivity Ti K-edge fluorescence XAFS on dilute (1–3%) TiO₂ polymorphs. These results confirm the system’s capability for reliable, high-precision spectroscopy across the tender-energy range (2–16 keV), supporting both trace-element analysis and detailed local-structure determination. The fully integrated system is now operational at the beamline, providing a robust platform for advanced X-ray absorption studies in environmental, catalytic, and materials science. Full article

As synchrotron radiation sources (SRSs) expand to cover a broader energy range, the demand for hybrid detectors with improved spatial and energy resolution is increasing. This paper presents the design and characterization of a prototype pixel readout ASIC featuring a small pixel size and low noise, developed for low energy soft X-ray applications. This chip adopts the single photon-counting (SPC) approach and each pixel consists of a front-end amplifier, a discriminator, a charge injection circuitry and a pair of 15-bit counters with associated logic. Fabricated in a 130 nm CMOS process, the chip integrates a 2 × 16 pixel matrix with a 50 µm ×50 µm pixel size. Measurement results indicate the maximum pixel equivalent noise charge (ENC) across the matrix is 20 e⁻rms without sensor attached. The results validate that the chip design has the potential to deliver a low-energy resolution for soft X-ray applications. Full article

High-synchrotron-peaked (HSP) BL Lac objects are extreme particle accelerators whose synchrotron emission peaks at high frequencies, typically in the UV-to-X-ray band (${\nu }_{\mathrm{peak}}>{10}^{15}$ Hz; ${\nu }_{\mathrm{peak}}\ge {10}^{17}$ for EHSPs), implying electron Lorentz factors of order ${10}^5$–${10}^6$. Their relative proximity ($z\lesssim 0.5$), clean radiation environments, and favorable Hillas parameters make them prime candidates for ultra-high-energy cosmic ray (UHECR) acceleration beyond ${10}^{19}$ eV and for neutrino production above 100 TeV. The 2017 association of IceCube-170922A with the flaring blazar TXS 0506+056 provided compelling evidence for blazars as neutrino sources, while an archival neutrino flare from 2014–2015 with no clear electromagnetic counterpart (13 events) revealed additional complexity in the emission mechanism. This review examines HSP physical properties, identifies them through WISE-based infrared selection (the 2WHSP and 3HSP catalogs, ∼2000 sources), and contrasts leptonic synchrotron self-Compton models with hadronic alternatives. We assess the observational evidence linking HSPs to high-energy neutrinos and UHECRs, finding that extreme baryonic loading ($L_p/L_e\sim {10}^3$–${10}^5$) strains energetic budgets, Auger composition measurements favor heavy nuclei over proton-dominated scenarios, and the near-isotropy of UHECR arrival directions is difficult to reconcile with rare beamed sources. Potential resolutions involving magnetic reconnection, structured jets, and duty cycle effects are discussed. Next-generation facilities, including IceCube-Gen2, KM3NeT, CTAO, IXPE, and AugerPrime/TA × 4, will probe key observables to either establish HSP BL Lacs as sources of the highest-energy cosmic particles or redirect the search toward alternative accelerator classes. Full article

The dynamic behavior within the melt pool governs the final quality of components fabricated by laser powder bed fusion (LPBF). To address key technical challenges—rapid keyhole evolution, low absorption contrast from metal vapor, and difficulties in quantifying internal flow fields—this study introduces move contrast X-ray imaging (MCXI), a technique leveraging time-series frequency characteristics. Combined with a multi-scale Horn–Schunck global optical flow method, MCXI enables full-field quantitative extraction of the melt-pool velocity field. Experimental validation across feature points shows a relative deviation of less than 2% compared to independent manual feature-point tracking, confirming consistency with the best available experimental ground truth. Analysis reveals the keyhole tail evolution cycle comprises three distinct dynamic stages: expansion, stratification, and contraction, with its area increasing from 1329 μm² to 6508 μm² before stabilizing. For the first time, pore pinch-off events were quantitatively measured, revealing front and rear wall collision velocities of 7.98 m/s and 8.04 m/s, respectively, consistent with available high-fidelity simulations. Furthermore, analysis of the overall melt-pool momentum field demonstrates a near-equal distribution of positive and negative momentum, providing an internal self-consistency check confirming the absence of systematic directional bias in the extracted velocity field. This study enables quantitative analysis of LPBF melt-pool dynamics, providing a novel tool for process optimization and defect control. Full article

A cell-based screening system for viral protease inhibitors was developed using firefly luciferase fragment complementation and validated on the SARS-CoV-2 3CLpro model. The optimal luciferase variant incorporating the VLQSGF proteolytic site (Luc III) retained 88% of its native activity. A critical requirement for system performance was the use of an extended nsp4–nsp6 fragment of the viral polyprotein rather than the mature protease, underscoring the importance of the native context for 3CLpro activity. The bicistronic construct pCAG-Luc-III-IRES-nsp4-6 enables coordinated expression of the reporter and protease, thereby increasing assay reproducibility. IC₅₀ values obtained in this system for nirmatrelvir and GC376 correlated with live-virus assay data but differed significantly from those of a cell-free FRET assay, reflecting the impact of cellular barriers. This approach combines simplicity, a standard substrate, and high reproducibility, making it promising for high-throughput screening in basic laboratory settings and adaptable to other viral proteases. Full article

Stone coal is an important vanadium-bearing resource and a potential source of rare earth elements (REEs). Previous studies have mainly focused on the bulk occurrence, resource potential, and leaching behavior of V or REEs in stone coal, whereas the microscale spatial relationships between V and REEs and their evolution during leaching remain poorly constrained. In this study, three representative stone coal samples were analyzed by synchrotron radiation micro-X-ray fluorescence (μXRF) to characterize the microscale distributions of V and REEs in raw samples and corresponding leaching residues. Pearson correlation analysis was further used to quantify changes in V–REE spatial relationships during leaching. The results showed that V–REE relationships were generally weak and were modified to different extents after leaching. In the GZ sample, the V–Eu correlation coefficient decreased from 0.63 to 0.34, indicating that the migration of V and REEs was not fully synchronized. The three samples also showed different REE distribution tendencies after leaching: GZ showed partial transfer of REEs to the leachate with residual retention, PX showed mixed behavior with appreciable retention in the residue, whereas PZ retained REEs predominantly in the residue. These results suggest that the integrated utilization of V and REEs in stone coal can be better achieved through a staged recovery route, in which the REE recovery pathway is determined according to their actual distribution between the leachate and the residue after V leaching. This study provides a microscale basis for the comprehensive utilization of coal-related critical metal resources. Full article

Colorectal cancer (CRC) remains a major cause of cancer-related death, and resistance to chemotherapy and radiotherapy continues to limit durable disease control. Ferroptosis, an iron-dependent form of cell death driven by lipid peroxidation, has therefore emerged as a potential therapeutic strategy. However, models focused solely on glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) do not fully explain why CRC cells differ in their sensitivity to ferroptosis. In this review, we examine how ferroptosis in CRC is shaped by iron trafficking and selenium-dependent antioxidant defense. We first discuss the poly(rC)-binding proteins 1 and 2 (PCBP1/2)-nuclear receptor coactivator 4 (NCOA4) axis, which regulates iron storage, trafficking, and ferritinophagy. We then review the AlkB homolog 8 (ALKBH8)-directed selenoprotein network, which supports the detoxification of lipid peroxides and maintenance of redox homeostasis. We next consider how these two systems intersect and how their interplay influences ferroptosis sensitivity. We also discuss why concurrent disruption of iron handling and selenium-dependent defense mechanisms may enhance therapeutic efficacy. Finally, we outline potential clinical applications, including combination strategies and biomarker development. Full article

In this study, a femtosecond laser beam is delivered to metal wire targets to generate suprathermal electron jets reaching energies of several hundreds of keV. During the process, it is observed that the mirror-imaging distribution of the beam focus with respect to the surface of the target displays highly asymmetric features and different dynamic responses. Especially, the exterior focus exhibits an extraordinary polarity reversal of the macroscopic current, while the interior focus behaves ordinarily. The former is attributed to the strong field at the focal point outside the surface, causing the secondary ionization and driving electrons back to the target, thereby reshaping the distribution of these high-energy hot electrons and the morphology of plasma jets. A numerical model is proposed to simulate the experimental observation and interpret the unexpected phenomenon. Furthermore, the particle-in-cell algorithm is also implemented to verify the results and present more details. This study seeks to emphasize the role of focal position in regulating the photoemission process, which may offer a fresh perspective for research in laser–material interactions and dynamics. Full article

Psychrophilic organisms are able to grow at temperatures down to −15 °C, while hyperthermophiles can multiply at temperatures up to 122 °C. What structural changes in extremophile proteins are needed to maintain stable and biochemically active structures under such conditions? Understanding how such extremophiles accomplish this is relevant for human health, biotechnology, and our search for life elsewhere in the universe. The purpose of the current study is to report and compare the structures of four rubredoxins (Rds), the first ever two experimental psychrophile bacteria structures (from Gram-positive Clostridium psychrophilum and Gram-negative Polaromonas glacialis) and two hyperthermophiles from the Gram-negative Thermotoga maritima bacterium and the archaeon Pyrococcus yayanosii, also a piezophile, as part of a program to understand structural variations that support both stability and function under extreme conditions. These structures were obtained using synchrotron radiation X-ray diffraction at 100 K. All four structures had the expected overall rubredoxin fold. Rubredoxin from the only aerobic psychrophilic bacterium Polaromonas glacialis had larger variations in sequence and structure, whereas the other psychrophilic bacterium showed properties closely related to hyperthermophile rubredoxins. Multi-subunit structures showed similar RMSD variability independent from their thermal adaptation status. We propose including functional information in the analysis since temperature optimization may not be the only determinant for a specific protein adaptation. Full article

X-ray free-electron lasers (XFELs) have revolutionized structural biology by enabling “diffraction-before-destruction” and capturing the ultrafast dynamics of life. However, the intrinsic sparsity and noise of XFEL diffraction snapshots, often complicated by multi-lattice overlaps, create a formidable computational bottleneck that limits data utilization and structural fidelity. Here, we present MCDPS-SFX, a robust indexing framework based on a reference-based, whole-pattern matching principle integrated with parallelized iterative refinement. By exhaustively sampling orientation space and progressively rejecting outliers, MCDPS-SFX significantly outperforms legacy algorithms—more than doubling crystal yields in heterogeneous datasets (e.g., 21,807 vs. 8792 for MOSFLM)—and achieves highly competitive yields comparable to state-of-the-art indexers, such as extracting over 90,000 lattices in the lysozyme benchmark. We demonstrate its efficacy on standard benchmarks and technically demanding G-protein-coupled receptor (GPCR) systems, including the rhodopsin–arrestin complex and the glucagon receptor. MCDPS-SFX consistently produces high-quality data statistics, enabling the high-resolution visualization of functionally critical, flexible regions such as phosphorylated receptor tails. Our results provide a powerful tool for enhancing the scientific output of XFEL experiments, offering a robust alternative for maximizing information recovery from weakly diffracting or overlapping crystalline samples. Full article

The transverse beam size is a key parameter for characterizing the performance of synchrotron radiation sources. Accurate measurement of the transverse beam size is crucial for assessing beam quality. In this study, a fiber array-photomultiplier tube (PMT) beam measurement system was developed to enable high-precision sampling of beam profile information for beam-size measurement. Furthermore, a hybrid method integrating nonlinear least squares (NLLS) fitting and Gaussian basis-function fitting was proposed to reconstruct the beam intensity profile from discrete sampling data. Before performing NLLS fitting, a median absolute deviation (MAD)-based threshold filter is employed to remove outliers and suppress random noise, thereby improving the stability and robustness of the parameter estimation. The filtered data are then fitted using NLLS to obtain the reconstructed distribution. To capture potential high-order modal features in the beam profile, a Gaussian basis-function fitting model was also introduced for comparison, and its performance was evaluated under complex intensity distributions. Additionally, the relationship between the full width at half maximum (FWHM) and beam intensity was experimentally verified while accounting for measurement effects in the system. The results demonstrate that the proposed hybrid algorithm improves reconstruction accuracy and robustness, enabling precise recovery of the beam-intensity profile in the fiber-array PMT system. Full article

Background/Objectives: The modern prosthetic foot market is characterized by a pronounced polarization between affordable but low-function devices and high-performance yet costly composite prostheses. The aim of this study was to develop and comprehensively evaluate cost-effective, functional prosthetic feet manufactured by fused deposition modeling (FDM). Methods: An iterative design methodology was employed, combining finite element analysis to optimize the biomechanical response of the device, the incorporation of user-specific requirements and experimental validation. Two TPU 95A-based 3D-printed prosthetic foot designs were designed and developed, and their strength and functional characteristics were assessed numerically under the ISO 22675:2024 normative loading cycle. Bench-top mechanical tests were conducted on the fabricated prototypes. Functional performance was evaluated by a transtibial amputee using an inertial motion capture system to analyze gait kinematics. Results: The results demonstrated that both designs operate predominantly within the elastic range with an adequate safety margin. The pilot feasibility gait assessment indicated feasibility and plausibility within the tested protocol and participant for both prototypes. Conclusions: The developed TPU 95A-based FDM prosthetic feet demonstrated promising structural integrity and functional feasibility, supporting the potential of low-cost additive manufacturing as a viable approach for producing affordable prosthetic feet. Further studies with larger participant cohorts and extended testing are needed to confirm clinical applicability and long-term performance. Full article

Selecting appropriate computational methods for organic crystals becomes particularly challenging for systems containing heavy halogens like bromine, whose complex electronic structures and diverse non-covalent interactions challenge approximate methods. Here we benchmark periodic DFT (PBE-D3BJ), CrystalExplorer (CE17/CE21), DFTB3-D3BJ, and PM7 against experimental stability data for 14 chlorine- and bromine-containing polymorphs across six CSD families. Chlorine systems show method-consistent performance, but bromine introduces large lattice energy variations (>10 kJ/mol) and, in several cases, qualitatively wrong stability rankings. Crucially, low mean absolute errors do not ensure correct thermodynamic ordering, and no semi-empirical method proves universally reliable for bromine. Only PBE-D3BJ achieves perfect experimental agreement. These results position bromine-containing crystals as exceptionally sensitive benchmarks and emphasize internal validation against experiment or reference DFT as essential before large-scale studies—particularly timely as machine-learning potentials emerge. Full article

Soil contamination by heavy metals and organic pollutants presents significant challenges to the global environment and public health. However, a lack of micro-scale understanding of the pollution process hinders efforts to remediate and enhance soil quality. Synchrotron-based X-ray imaging and spectroscopy techniques are powerful tools in revealing complex interactions within heterogeneous soil systems. This review systematically explores recent advances in soil research that deepen our knowledge on the chemical states, spatial distribution, and dynamic interactions of heavy metals and organic contaminants via synchrotron-based techniques (e.g., micro-XRF imaging, FTIR, SR-μCT). It highlights the potential of these methods to characterize composition, aggregate structure, and microbial activity within soil matrices with high spatial and temporal resolution, in situ, and with element-specific analysis. Additionally, a forward-looking perspective outlines key research directions to leverage these advantages and develop more effective and sustainable soil restoration strategies. We hope this work emphasizes the role of synchrotron science in field-scale soil applications and inspires future, mechanism-driven, evidence-based soil remediation efforts. Full article