Disinfection is essential for inactivating pathogens and preventing waterborne diseases. However, there is concern that bacteria might form highly toxic nitrogenous disinfection byproducts (N-DBPs) during chlorine-based disinfection. This study investigated the formation of haloacetonitriles (HANs) and halonitromethanes (HNMs) from Pseudomonas aeruginosa (P. aeruginosa) during UV265-LED/chlorine disinfection. Results indicated that dichloroacetonitrile (DCAN, accounting for 84.82%-91.40%), chloronitromethane (CNM), and trichloronitromethane (TCNM) were formed from P. aeruginosa. UV-vis and excitation-emission matrix (EEM) fluorescence spectroscopy analyses revealed that P. aeruginosa rapidly released bacterial organic matter during UV265-LED/chlorine disinfection. Among these, tryptophan-like and fulvic acid-like compounds exhibited high reactivity with disinfectants. Furthermore, the effects of disinfection operating parameters and coexisting ions on the formation of these N-DBPs were evaluated. Based on the detected potential precursors and transformation products, it was proposed that bacterial organic matter might be degraded into small-molecule nitrogenous organic compounds, which were subsequently converted into DCAN, CNM, and TCNM. Finally, the presence of P. aeruginosa was demonstrated to enhance the formation and toxicity of DCAN and HNMs during real water disinfection. This study provided deeper insight into the formation of N-DBPs from bacteria, offering a theoretical basis for the better use of UV265-LED/chlorine disinfection processes.

The brain is the most complex organ in the human body. For over a century, the classical Golgi staining method has been a cornerstone in neuroanatomy, but its low efficiency and uneven staining in large samples have limited its utility for systematic neural network analysis. This long-standing challenge persisted without a satisfactory solution—until we embarked on a daring exploration inspired by cross-disciplinary curiosity.

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.

Traditional thermodynamic models of natural gas hydrate formation posit that nucleation occurs only under high-pressure and low-temperature conditions. These thermodynamic models overlook liquid-solid interfacial adsorption of gas molecules, which creates high-density surface nanobubbles in gas-liquid-solid systems, leading to significant local gas enrichment even at low pressures. This study reveals a unique nucleation pathway for methane hydrate from the three-phase contact lines of the surface methane nanobubbles under atmospheric pressure and 277.15 K. High-resolution atomic force microscopy shows hydrate crystals growing radially from nanobubbles on highly oriented pyrolytic graphite, while Raman spectroscopy confirms that the crystal is structure H (sH). This phenomenon is attributed to the high local methane concentration in the environment surrounding surface nanobubbles and a reduced nucleation energy barrier at the contact line. Our findings redefine the spatial and thermodynamic boundaries of hydrate stability, suggesting that hydrates can occur as widespread nanoscale deposits within natural reservoirs, which raises concerns about their susceptibility to releasing methane under global warming.

The cellular membrane serves as the primary interface for sensing environmental cues, yet how it decodes the concentration-dependent toxicity of essential metal ions like copper remains a fundamental question. Here, we unveil a bimodal molecular switching mechanism by which Cu²⁺ reorganizes anionic lipid membranes, suggesting that the cell membrane could act as a sensor for copper concentration. Using an integrative biophysical approach on phosphatidylcholine/phosphatidylglycerol membranes, we demonstrate that at low concentrations, Cu²⁺ binds individually to anionic lipids, reorienting headgroups and priming the membrane for separation (Stage I). Crucially, beyond a critical threshold, adjacent membrane-bound Cu²⁺ ions form metal-metal bonds, creating rigid [PG-Cu-Cu-PG] bridges that act as molecular clamps (Stage II). This cooperative bridging event forcefully squeezes lipids together, driving extensive phase separation and the formation of Cu-rich domains with markedly enhanced thermodynamic stability. We provide evidence through atomic force microscopy, X-ray scattering, and calorimetry, complemented by the spectroscopic signature of ESR-silent Cu-Cu pairs. This bimodal switch model provides a physicochemical basis for copper's dual biological identity, with direct implications for understanding its antimicrobial mechanism and its potential role in neurotoxicity. Our findings establish a new paradigm for how transition metal coordination chemistry can programmatically control membrane architecture.

The formation of two-dimensional protein crystallites on solid surfaces is crucial in both natural biological processes and bottom-up nanofabrication. However, direct molecular-level insight into the dynamic evolution of epitaxial interfaces has remained challenging. Here, using in situ atomic force microscopy, we reveal the two-dimensional crystallization dynamics of streptavidin on muscovite mica with single-molecule resolution. We directly imaged the initial formation of multiple orientation domains during the crystallization process, a direct consequence of epitaxial matching to the three-fold symmetry of the mica lattice. This metastable poly-domain structure then evolves into a single-oriented crystallite through two coexisting classical ripening pathways, i. e. Ostwald ripening and Smoluchowski-type coalescence. The dominance of a single domain orientation arises from a competitive selection process during ripening, in which the initially largest domain ultimately consumes the neighboring domains of other orientations. Our work establishes a paradigm of domain coarsening in biomolecular epitaxy, providing a solid foundation for the rational design of functional bio-nano interfaces.

Nanobubbles (NBs) exhibit unique physicochemical properties with significant promise for biomedical applications. Current strategies rely on ex situ preparation of NBs-containing media followed by introducing them into organisms, which imposes limitations including special storage requirements, reduced NB concentration, and limited in vivo targeting. In principle, in situ NBs generation offers a more efficient approach to harnessing their functional properties. Here, we investigated whether NBs could be generated in situ within cells and evaluated preliminarily their biological effects. Intracellular O2-NBs in a cell model were generated via a compression-decompression method and directly visualized by synchrotron-based scanning transmission X-ray microscopy (STXM) in a cryogenic mode. The effects of NBs on cell viability, proliferation, and overall cellular oxidative activity were explored, which indicates that the composition and the gas-liquid interface of NBs can affect cell metabolism. These findings provide a unique strategy for modulating the cellular microenvironment to achieve biological effects and potential therapeutic outcomes through NB generation by purely physical means.

Reactive bromine species (RBS) play a critical role in global halogen cycling and atmospheric oxidative processes, yet their temporal dynamics and formation mechanisms in marine environments are not fully understood. Here, we report the first continuous observation of diel variations of RBS in coastal surface seawater using a newly developed osmotic pump-based sampler coupled with in situ derivatization. Hour-resolved time-series monitoring was conducted at a subtropical coastal wetland during summer and winter, revealing pronounced diel patterns characterized by strong daytime enhancement and nighttime depletion of RBS, closely tracking solar irradiance. Peak RBS concentrations occurred around midday, reaching up to 32.6 nmol/L in summer and 24.0 nmol/L in winter. Concurrent measurements of Fe(II) and H2O2, together with on-site perturbation experiments and laboratory simulated photo-Fenton reaction, demonstrate that photo-Fenton reactions are the dominant pathway driving RBS formation in coastal surface seawater. The presence of dissolved organic matter (DOM) significantly enhances photo-Fenton efficiency through ligand-to-metal charge transfer-mediated Fe(III) photoreduction and Fe(II) regeneration, amplifying RBS production by approximately 5.6-fold. In contrast, DOM photosensitization alone generated negligible RBS under comparable conditions. These results reveal sunlight-driven photo-Fenton, coupled with DOM-mediated iron cycling, is a major contributor to RBS dynamics in coastal environments. This study advances our understanding of diel bromine activation in coastal waters and highlights the importance of sunlight-driven photo-Fenton chemistry in marine halogen cycling.

Abnormal accumulation of reactive oxygen species (ROS) induces oxidative stress, a central pathological factor in many human diseases. Traditionally, antioxidants are suggested to relieve oxidative stress in the body; however, their efficacy is limited by poor stability in vivo and inadequate tissue targeting in clinical practice. Therefore, there is a great need for an effective, safe, biocompatible, and environmentally friendly antioxidant strategy to reduce damage caused by oxidative stress. Previous work has demonstrated that nanobubbles (NBs) can regulate hydroxyl radical (•OH)-mediated redox reactions. However, it remains unclear whether NBs can exert similar regulatory control on singlet oxygen (1O2), and the molecular mechanisms that control this interaction need to be elucidated. In this work, we employed photodynamic reactions to generate 1O2 and systematically investigated the effects of NBs of different particle sizes and different encapsulated gas compositions (N2 or O2) on 1O2-mediated oxidation of selective fluorescent probes. Our findings indicate that ultrasmall NBs exhibit remarkable antioxidant activity across all test systems and that even NBs prepared with O2, a gas that typically enhances ROS-driven oxidation, inhibit 1O2-mediated substrate oxidation. These insights establish a basic framework for the rational design of NB-based antioxidant platforms, which hold significant promise for applications in biomedical antioxidant therapy, material protection, and food preservation.

The efficient detoxification of arsenite (As(III)) in anoxic waters remains a critical challenge. This study investigates the role of hydrogen nanobubbles (HNBs), spontaneously generated during the reaction of nanoscale zero-valent iron (nZVI) with water, in modulating the reactive interfaces of nZVI and enhancing the sequestration of toxic arsenic (As). The presence of HNBs significantly promotes the removal kinetics and capacity of As(III) by nZVI under anoxic aqueous conditions. Mechanistic studies, employing X-ray photoelectron spectroscopy and synchrotron radiation X-ray absorption near-edge structure analysis, reveal that HNBs facilitate the transformation of adsorbed As(III) into less toxic As(0) and As(V) within the iron oxide shell of nZVI. The inherent reducibility of HNBs was confirmed through reactions with 3,3',5,5'-tetramethylbenzidine (TMB, a substrate prone to oxidation) and levofloxacin (LEV, a photosensitizer), as well as by the direct detection of hydrogen radicals (•H) in the system. Furthermore, defects and fractures in the nZVI oxide shell are found to facilitate the interfacial transfer of atomic hydrogen radicals and hydroxyl radicals, thereby mediating the redox reactions of As(III) at the gas-liquid-solid triple interface. This work not only elucidates the mechanism behind the HNB-enhanced reactivity of nZVI but also presents a novel and efficient strategy for the sustainable remediation of water contaminated with heavy metal(loid)s.

The three-dimensional x-ray absorption near edge structure (3D XANES) imaging technique can analyze the 3D morphology and chemistry at the nanoscale. High-quality conventional 3D XANES imaging requires sufficient full-view projections across every near-edge energy point, prolonging the imaging time. This limits the method's application in dynamic process monitoring (e.g., in situ electrochemical reactions and phase transitions). This study presents a novel workflow to accelerate 3D XANES imaging based on sparse sampling and deep learning. Sparse-view sampling strategies can significantly reduce acquisition time, while the STC-UNet deep learning algorithm can correct sampling artifacts and preserve precision in quantitative elemental chemical analysis. The proposed approach was applied to LiNi0.8Co0.1Mn0.1O2 (NCM811) battery cathode particles to analyze 3D chemical state mapping of nickel. The results demonstrate a tenfold reduction in data acquisition time compared to conventional protocols while maintaining equivalent image quality and quantitative analytical accuracy, thereby enabling potential for operando 3D chemical imaging.

A liquid-nitrogen-cooled cryogenic gas target system has been developed and installed for radioactive ion beam (RIB) production at the Radioactive Ion Beam Line in Lanzhou (RIBLL). Light-element gases (H_2, D_2, and ^4He) filled in the target cell were cooled to cryogenic temperatures, with the gas-cell outlet temperature typically monitored at 82–86 K during beam irradiation and operating pressures up to 1000 mbar. The system was used to produce ^7Be, ^16N, and ^15O RIBs via the ^1H(^7Li, ^7Be)n, ^2H(^15N, ^16N)p, and ^1H(^15N, ^15O)n inverse kinematics reactions, yielding purities of 85%, 99%, and 95%, with intensities of 1.02×10^6, 2.7×10^5, and 1.0×10^5 pps, respectively. A ^93mMo isomer beam was also produced via the ^4He(^94Zr, 5n)^93mMo reaction, achieving an intensity of 5.38×10^3 pps and a purity of 20% (which can be further improved to ∼50% with offline time-of-flight gating). By delivering a broader range of high-intensity secondary RIBs, this setup establishes a robust platform at RIBLL for low- and medium-energy nuclear astrophysics and reaction studies.

Bacterial contamination of aquatic environments occurs globally, posing challenges to safe water supply. UV-LED (265 nm)/chlorine is an attractive disinfection method, but the formation of disinfection byproducts (DBPs) is a concern. Note that bacteria pose a risk of forming DBPs during chlorine-based disinfection. This study investigated the formation risk and mechanisms of haloacetonitriles (HANs) and halonitromethanes (HNMs) from Escherichia coli (E. coli, a key microbiological indicator of water quality) during UV-LED (265 nm)/chlorine disinfection. Results showed that E. coli can form dichloroacetonitrile (DCAN), chloronitromethane (CNM), and trichloronitromethane (TCNM) during disinfection. After 10 min of reaction, the concentration of total DBPs in UV-LED (265 nm)/chlorine disinfection was 66.26% higher than that in chlorination. Additionally, bacterial organic matter released by E. coli during UV-LED (265 nm)/chlorine disinfection contributed to DCAN, CNM, and TCNM formation. Based on the detected precursors and intermediates, possible formation mechanisms of DCAN and HNMs derived from E. coli were proposed. Finally, real water disinfection experiments indicated that the presence of E. coli could increase the formation and toxicity of DCAN and HNMs. This study can deepen the understanding of DCAN and HNMs formation from bacteria, which will assist water managers in controlling DBPs formation during UV-LED (265 nm)/chlorine disinfection.

B. cereus and nitrophenols simultaneously exist in aquatic systems and can produce chlorinated disinfection byproducts (Cl-DBPs) with high toxicity in chlorinated waters. Nevertheless, it has not been reported that B. cereus coexisted with nitrophenols can influence Cl-DBPs formation. Herein, it is the first time investigate the effects of B. cereus coexisted with nitrophenols on chlorinated halonitromethanes (Cl-HNMs), dichloroacetonitrile (DCAN), and trichloromethane (TCM) formation in the sequential UV-chlorine disinfection process. The coexistence of nitrophenols with a low concentration of B. cereus enhanced Cl-DBPs formation but nitrophenols coexisted with a high concentration of B. cereus dramatically inhibited that. Meanwhile, increasing UV fluence, chlorine dose, and nitrophenol concentration in a certain range increased Cl-DBPs formation, and alkaline pH inhibited Cl-HNMs and DCAN formation but favored TCM formation. Besides nitrophenols, the organic matter (e. g., metabolites, soluble microbial byproducts, and intracellular organic matter) produced from B. cereus cells was degraded into small molecules, which could serve as precursors for Cl-DBPs formation. Likewise, nitrophenols could be degraded through the B. cereus pathway and generate Cl-DBPs. Finally, the Cl-DBPs yields and toxicity in different water samples followed the order of real waters > simulated waters in most cases. This study offers a new and deeper understanding of the effects of B. cereus and nitrophenols on Cl-DBPs formation during chlorine- based disinfection and provides experimental references for the sequential UV-chlorine disinfection process application.

Redox homeostasis is essential for the proper functioning of biological systems, and its disruption by excessive reactive oxygen species (ROS) underlies the pathogenesis of numerous diseases. Gas-liquid interfaces, owing to their unique physicochemical characteristics, can enrich ROS and thereby modulate oxidative reactions. Nanobubbles (NBs), with nanoscale gas domains suspended in aqueous solutions, present a high surface-to-volume ratio, offering abundant interfacial area with potential for ROS regulation. Though lots of evidences suggest that the NBs do play important antioxidative or prooxidative effects, the mechanisms by which NBs influence redox chemistry remain elusive. Herein, we evaluated the oxidative response of the model molecule glutathione (GSH) and a GSH-derived amphiphilic copolymer (ECGFF) to ROS in the presence of NBs of varying sizes. Our study reveals a striking size and substrate-specific redox modulation: normal-sized NBs (∼100-400 nm) suppressed oxidation of hydrophilic GSH but promoted oxidation of hydrophobic ECGFF; In contrast, ultra-small NBs (<50 nm) exerted antioxidative effects on both substrates. These results suggest that the interplay between NBs size, interfacial radical accumulation, and substrate hydrophobicity governs redox behavior at the gas-liquid interface. The insight of this mechanism not only advances our understanding of NBs-mediated redox processes but also offers a foundation for the rational design of NBs-based antioxidant strategies across diverse fields, including biomedicine, materials science, chemical engineering, and food technology.

Achieving detailed neuronal structural information in large-volume brain tissue has been a longstanding challenge in human brain imaging. A key obstacle arises from the trade-off between staining efficiency and tissue autolysis. Traditional Golgi staining, typically conducted at room temperature or 37 °C to optimize staining efficiency, leads to rapid autolysis of brain tissue, resulting in the loss of fine structural details. Here, a near-freezing temperature (NFT) staining strategy in post-mortem frozen (PMF) human brain samples are presented, using a mercury chloride-based method under ice-water bath conditions. In contrast to the 37 °C Golgi staining, this NFT-based method significantly reduces tissue autolysis, preserving fine neuronal structures. Notably, neuronal counts in the same field of view increased by 5.5-fold, and dendritic spine density increases by 22-fold. Using this approach, uniform staining of millimeter-thick is achieved, centimeter-scale human brain slices and integrated it with synchrotron-based X-ray microscopy to perform micrometer resolution 3D reconstructions of the cerebellum and frontal lobe. This novel technique offers a powerful tool for the fine-structural imaging of large-volume brain tissue, providing new insights into the intricate organization of neural networks.

One primary challenge in whole-brain imaging technology is to achieve high-resolution visualization of neuronal connectivity at large scales. Although the Golgi method allows for labeling random neurons in their entirety, visualizing individual dendritic trees, and tracing long-distance axonal projections, the lengthy processing time poses a limitation, as staining a mouse whole-brain sample of ∼500 mm3 takes over two weeks. Here, we developed a high-pressure-assisted Golgi-Cox (HP Golgi-Cox) method that reduced the staining time for mouse whole-brain neurons from 16 to 4 days. We demonstrated its applicability in zebrafish, mice, and rats, and further achieved rapid staining of hippocampal neurons in an intact pig brain, which is challenging with the classical Golgi-Cox method. By combining the HP Golgi-Cox method with synchrotron-based X-ray microscopy, we achieved high-resolution imaging of whole-brain neurons in mice. This HP Golgi-Cox method enables rapid and high-resolution neuronal imaging in large model organisms, showcasing its broad applicability for diverse applications.

The generation and stabilization of nanobubbles (NBs) are crucial concerns, considering their great potential for applications in various fields. Nonetheless, research on the stabilization of bulk nanobubbles (BNBs) generation across various systems under ultrasonic irradiation is relatively few. For example, how dissolved gases and different conditions affect the evolution of BNBs in the acoustic field remains unclear. Therefore, this study focused on generating and stabilizing BNBs over time under various conditions including ultrasonic frequency, power, and dissolved gases in both open and closed systems. First, for a given solution, the concentration of BNBs would increase with higher ultrasonic power and lower ultrasonic frequency. Furthermore, a considerably elevated concentration of BNBs was obtained in closed systems relative to open systems, which may be attributed to a closed system providing a more stable environment for nucleation growth, thus facilitating the generation and stabilization of BNBs. More surprisingly, by changing dissolved gas saturation, we found that in gas-saturated water, the concentration of BNBs becomes higher than in the other two saturations: supersaturated and undersaturated water. A detailed study also found that the concentration of formed BNBs differs based on the positions of vessel, and more BNBs will be formed at the bottom or upper side of the vessel, indicating bubbles easily nucleate near the vessel wall and at the gas-liquid interface. This study provides essential insights into the principles of the generation and stabilization of NBs under ultrasonic fields, potentially expanding application ranges and improving the efficiency of ultrasonic irradiation.

Due to increasing public awareness of environmental concerns and stricter cleaning process requirements, traditional cleaning technologies characterized by high pollution, excessive energy consumption, and substantial damage are insufficient to meet contemporary demands. There is an urgent need for efficient, low-damage, and environmentally friendly cleaning technologies. In recent years, the rapid advancement of micro-nano bubbles (MNBs), which exhibit unique physicochemical properties, have emerged as a promising solution for green cleaning applications. This review begins with an overview of the benefits of MNBs in cleaning processes, followed by an in-depth analysis of the factors influencing their cleaning effectiveness as well as the possible mechanisms involved. Additionally, the producing and application of MNBs across various cleaning scenarios are summarized. Finally, prospects for their development are discussed. Research and advancements in MNB preparation technologies are expected to boost their applicability and commercialization in a greater variety of cleaning contexts in the future.

Oxygen nanobubbles (ONBs) have attracted significant attention due to their unique physicochemical properties and potential applications in biomedical, environmental, and energy-related fields. Efficient production of ONBs is the key to further promote their application challenges yet still remains a challenge. In this work, we systematically compared the performance on the stable generation of ONBs between two distinct methods: the conventional electrolysis and a combined sonication-electrolysis approach with a well-designed electrolysis device with separate cathode and anode chambers. Our results demonstrated that electrolysis alone could produce ONBs with a concentration of 2.6 × 107 particles mL-1 and an X50 (the median indicating that particle sizes below this value accounted for 50% of the total number of particles) size of about 80 nm. In contrast, the synergistic integration of ultrasound and electrolysis significantly improved the yield, achieving a higher concentration of 9.6 × 107 particles mL-1, albeit with a slightly larger X50 size of about 115 nm. This work provides a feasible strategy for precisely controlling the size and concentration of ONBs, which is critical for their scalable preparation and further applications.