Browse Articles

Redox‐Pathway Reconstruction in Carbonate Electrolyte to Achieve Durable Na─S Battery

ABSTRACT The practical performance of room‐temperature sodium–sulfur (RT Na─S) batteries in low‐solubility carbonate electrolytes is fundamentally constrained by slow “solid‐solid” sulfur conversion, causing incomplete redox reactions and rapid capacity fading. Herein, we propose a catalytic strategy via “confinement‐pyrolysis” that restructures this static reaction into a dynamic “solid‐liquid‐solid” pathway. By employing a hierarchical porous framework with atomically dispersed metal sites, the conversion kinetics of sodium polysulfides (NaPSs) are dramatically accelerated. This reconstruction enables continuous liquid‐phase intermediates and circumvents the high diffusion barriers of solid‐state reactions, as confirmed by density functional theory (DFT) calculations. By simulating long‐term cycling through controlled Na 2 S deposition, we employed local dipole moment change ( Δμ ) tracking to reveal the exceptional electronic structure stability and effective lowering of key energy barriers during long‐term cycling. As a result, the Fe‐N‐C/S cathode exhibits outstanding electrochemical performance, delivering a reversible capacity of 799 mAh g −1 at 1 Ag −1 with a capacity decay rate of 0.075% per cycle, and exhibiting an ultralow capacity decay rate of 0.024% per cycle over 2000 cycles at 2 Ag −1 . This work elucidates that redox‐pathway reconstruction is a pivotal strategy to overcome the inherent kinetic limitations of the conventional mode in carbonate‐based Na─S batteries.

Investigation of the interfacial bond behavior of steel pipe pile and bottom-sealing concrete under realistic cofferdam construction conditions

Natural Sunlight IR‐Driven Highly Efficient Synthesis of Acetaldehyde From Bioethanol Over Cu/Fe ₂ O ₃

ABSTRACT Using renewable biomass to synthesize valuable chemicals can reduce fossil fuel dependence and achieve carbon neutrality. Here, for the first time an infrared light‐driven catalyst, Cu/Fe 2 O 3 , was designed to convert bioethanol to valuable acetaldehyde, accompanied by green hydrogen as a by‐product, under both indoor IR light and natural sunlight. It achieves an initial acetaldehyde yield of 237 mmol g −1 h −1 under indoor IR irradiation and 205 mmol g −1 h −1 under real sunlight, with exceptional selectivity (97.7%) and nearly stoichiometric H 2 byproduct production. Notably, the turnover number and initial turnover frequency surpass those of IR‐driven systems by at least one order of magnitude and perform competitively with leading energy‐intensive UV–vis‐driven and thermocatalytic ethanol conversion processes operated up to 573 K. This high performance is attributed to: i) the construction of an efficient IR photons‐to‐phonons energy conversion channel within the ps timescale to drive localized thermocatalysis; and ii) the synergistic effect on the in situ formed of Cu/Fe 2 O 3 interface, where Fe 3+ sites promote dissociative ethanol adsorption, and Cu 0 sites facilitates C─H bond cleavage.

Exploring an AI-driven agentic framework for insider threat detection in secure software development organizations: A survey-based approach

Single‐Atom C‐to‐N Editing Unlocks Bright NIR‐II J‐Aggregates for Imaging Lymphatic Metastasis

ABSTRACT The development of near‐infrared II (NIR‐II) J‐aggregates is hindered by a lack of rational design guidelines. Here we show that single‐atom C‐to‐N skeletal editing in hemicyanine dyes precisely regulates intramolecular charge distribution and intermolecular packing, thereby allowing efficient formation of bright NIR‐II J‐aggregates. Systematic acceptor engineering reveals clear structure‐assembly‐property relationships governing J‐aggregate formation and fluorescence brightness. The optimized dye HZOE9 forms stable J‐aggregates with emission beyond 1000 nm and a quantum yield surpassing most reported cyanine‐based NIR‐II fluorophores. Mechanistic studies further elucidate that phenolic hydroxyl modification can tune J‐aggregation and NIR‐II emission, highlighting its key role in modulating supramolecular excitonic coupling. Encapsulation into biocompatible nanoparticles enables high‐resolution lymphatic imaging, real‐time metastasis visualization, fluorescence‐guided surgery, and therapeutic monitoring in vivo. This work establishes a single‐atom skeletal editing strategy for developing hemicyanine‐based NIR‐II fluorophores and provides a conceptual framework for the future development of activatable NIR‐II fluorophores via controllable supramolecular assembly.

AST_UNet: attention swin transformer U-net-based dental panoramic caries segmentation for early diagnosis

Visible‐Light‐Induced Carbon–Hydrogen Phosphonylation of Conjugated Polymers via Electron Donor–Acceptor Complex Activation

ABSTRACT Electron donor–acceptor (EDA) complexation has emerged as a sustainable strategy for visible‐light‐driven reactions. Although numerous EDA‐based transformations have been applied to small aromatic molecules, conjugated polymers (CPs) have not yet been explored as substrates for EDA‐mediated functionalization. Polymer‐based EDA complexes comprise extended π‐conjugation systems that reduce exciton‐binding energy and facilitate red‐shifted absorption, thereby enabling efficient visible‐light harvesting. These characteristics are expected to intrinsically promote photoinduced functionalization. Here, we demonstrate the photochemical phosphonylation of poly(9,9‐dioctylfluorene) (PFO) induced via the visible‐light activation of its EDA complex. Compared with a monomeric model compound, the reaction of PFO proceeded more efficiently, indicating that CPs are promising substrates for EDA‐excitation‐initiated photochemical transformations. Phosphonylation predominantly proceeded at the 4‐position of the fluorene units, thereby preserving the effective π‐conjugation length of the polymer backbone. Furthermore, density functional theory calculations revealed that the greater stability of the intermediate species and the lower excitation energy required for 4‐position substitution favored that pathway over 3‐position substitution. This study establishes a new platform for integrating CPs into EDA‐mediated photochemical reactions, offering a facile and sustainable route for the synthesis of versatile functional polymer materials.

Body mass index variance scales with the population mean according to Taylor’s Power Law in 236 survey samples from 68 countries

Abstract First proposed in 1961, Taylor’s Power Law relates variance (S 2 ) and mean (m), expressed as S 2  = am b . While this relationship holds in ecology and other fields, it has seen less application in population health. Here, using Taylor’s Power Law, we assess the relationship between variance and mean body mass index across populations in low- and middle-income countries. We extracted adult body mass index data from 236 nationally representative, population-based samples of women aged 20–49 years and men aged 18 years and older, collected between 1994 and 2019 (n = 2,594,211 women, n = 455,479 men). We used log–log linear regression to estimate the scaling exponent (b) and intercept parameters. In women, Taylor’s Power Law showed a strong fit (b = 4.0, R 2  = 0.72, n = 202 surveys), compared to b = 3.9 and R 2  = 0.46 in men (n = 34 surveys). Across survey periods, intercepts increased, while scaling exponents remained stable or declined in some subpopulations, suggesting rising baseline variability in body mass index alongside a slowing of variance growth with continued mean increases. The strength of Taylor’s Power Law relationship varied by social and spatial context, including age, residence, socioeconomic status, and survey period. This approach may offer a useful framework for describing and monitoring population-level variability in body mass index.

Axial N Disrupt <i>d</i> –π Conjugation of Asymmetric Fe─Cu Dual‐Atom Enhances CO ₂ Electroreduction

ABSTRACT Precise spin‐polarization modulation of electronic structures in dual single‐atomic sites (DSAS) is critical yet challenging for boosting electrocatalytic CO 2 reduction reaction (CO 2 RR). Here, we report a Fe 3 d ‐orbital spin‐polarization regulation strategy through constructing an axial N‐bridge bond and adjacent Cu–N 4 on hollow bilayer Fe–Cu dual single‐atom catalysts (HFeCu–N–C DSACs). Experimental and theoretical evidence demonstrate that the axial N‐bridge bond disrupts the D 4h symmetry of the Fe–N 4 active center, resulting in the rearrangement of Fe 3 d electrons and thereby breaking the surface d –π conjugate structure (Fe–N–C). Meanwhile, the Jahn‐Teller effect of the adjacent Cu–N 4 sites is inferred to potentially regulate the spin state of Fe sites, which facilitates the transition from low‐spin ( ↓↑ , ↓↑ , ↑ , _, _) to high‐spin ( ↑ , ↑ , ↑ , ↑ , ↑ ). Therefore, the increased population of unpaired electrons on d xz , and d yz orbitals is pivotal for stabilizing the π * orbitals of CO 2 and activating CO 2 , thus enhancing the intrinsic reaction activity of HFeCu–N–C DSACs. The as‐made HFeCu–N–C DSACs present a superior faraday efficiency (FE) of a highly selective CO product, 99.32% @ −0.5 V (vs. RHE), and long‐term durability. This work provides a new strategy for tuning the electronic spin state of DSACs to boost CO 2 RR electrocatalytic performance.

Metals and metalloids in frequently consumed fish species from Koka and Aba Samuel Reservoirs in central Ethiopia

Abstract The deposition of Metals and metalloids in freshwater has direct impacts on the ecosystem’s health. Consequently, the objective of the present study was to determine the levels of metals and metalloids in the organs of freshwater fish species from Lake Koka and Aba Samuel Reservoir in Ethiopia in February and August 2023. The analysis was performed using an ICP-OES after the hot plate digestion. Statistical analyses indicated that the metal levels in fish organs differed significantly ( p  &lt; 0.05). The mean build-up trend of these elements in the organs of fish was liver &gt; gill &gt; muscle. There exists a substantial difference in the accumulation of Metals and metalloids in muscle and liver ( p  &lt; 0.05). The trace metal accumulation pattern for fish types was C. carpio &gt; C. gariepinus &gt; O. niloticus . Seasonal variation of the trace metal concentrations in fish organs indicated elevated concentrations in the dry season. The findings demonstrate that metals and metalloids accumulate in fish from Lake Koka and Aba Samuel Reservoir, with Pb exceeding permissible limits in some samples. Although health risk assessment indicated generally acceptable non-carcinogenic and carcinogenic risks, elevated Pb levels and widespread metal occurrence warrant continuous monitoring and management to protect ecosystem and public health.

From Berzelius to Hyperspace: Previously Unrecognized Network of Reactivity in Textbook Brominations

ABSTRACT Chemical reactions are traditionally depicted as linear equations optimized toward a single product, with other outcomes treated as minor side products. However, advances in reaction automation now allow systematic exploration of reaction “hyperspaces”—that is, multidimensional landscapes of conditions—showing that even archetypal transformations can yield previously unrecognized dominant products. Using the Robowski robotic platform with low‐cost NMR detection, we scanned nearly 1000 conditions for the bromination of 1,1‐diphenylethylene (DPE) and benzylideneacetone (BDA). These maps revealed new major products, condition‐dependent switchovers between addition and substitution pathways, and novel substitution patterns with potential for derivatization into biologically active scaffolds. In turn, correlations and anticorrelations in product distributions across the hyperspace facilitated reconstruction of mechanistic networks connecting different outcomes. Together, our findings show that even foundational reactions, long considered mechanistically complete, harbor hidden complexity and behave as dynamic, switchable networks embedded in conditions’ space.

Synthesis of facile polystyrene/pol(N-methylaniline)/CuO composite for methyl orange uptake

Abstract Polystyrene (PS) was modified by grafting with poly(N-methylaniline) (PNMANI) and assembling on CuO nanoparticles to be a good adsorbent to methyl orange (MO). Dye-contaminated wastewater remains a critical environmental concern, requiring efficient and economically viable treatment strategies. Herein, polystyrene/poly(N-methylaniline) (PS/PNMANI) and polystyrene/ poly(N-methylaniline)/ CuO (PS/PNMANI/CuO) composite which not prepared before, were synthesized and characterized for MO uptake from aqueous media. Both structural and surface properties were analyzed using SEM, XRD, FTIR, BET, and TGA analyses. Batch adsorption experiments demonstrated that PS/PNMANI and PS/PNMANI/CuO composite achieved a maximum uptake efficiency of 95, 100% at pH 7 with an equilibrium time of 60 min using 0.10 and 0.25 g of composite respectively. The adsorption kinetics obey the pseudo-second-order model (R² = 0.997), while equilibrium data indicated mixed adsorption behavior with a maximum adsorption capacity (Qmax) of 43.29 mg/g for PS/PNMANI/CuO and 7.17 mg/g for PS/PNMANI. BET analysis revealed that the surface area of PS/PNMANI is 33.91 m²/g and 42.28 m²/g for PS/PNMANI/CuO, confirming that CuO incorporation enhanced surface characteristics and removal efficacy of graft. The improved adsorption performance is attributed to increased surface activity, synergistic polymer–CuO interactions, and porous morphology facilitating dye diffusion.

J‐Aggregated Macrocyclic Photocatalysts Enable Nitric Oxide (NO)‐Enhanced Near‐Infrared Photocatalytic Tumor Therapy

ABSTRACT Photocatalytic therapy (PCT) has emerged as a promising strategy for tumor therapy by disrupting mitochondrial redox homeostasis through NADH/NAD + oxidation. However, its broader application is limited by insufficient light penetration, rapid catalyst deactivation under biological conditions, and insufficient catalytic pathways under hypoxia. Here, we develop a near‐infrared (NIR)‐activated photocatalytic platform based on a donor–acceptor conjugated macrocyclic photocatalyst that enables coupled NADH oxidation and nitric oxide (NO) release. The photocatalyst self‐assembles into J‐aggregates within micellar nanostructures, enabling efficient photocatalytic NADH oxidation under 808 nm light irradiation. Simultaneous encapsulation of an N ‐nitrosamine‐based NO donor offers an oxygen‐independent electron acceptor, sustaining the photocatalytic cycle under hypoxia and enabling controlled NO release. Mechanistically, photocatalytic NADH depletion suppresses electron flux through the mitochondrial respiratory chain, while NO further impairs mitochondrial respiration, synergistically aggravating mitochondrial dysfunction and amplifying PCT efficacy. Moreover, this bioenergetic collapse downregulates heat shock protein (HSP)‐mediated stress responses, thereby sensitizing tumor cells to mild photothermal therapy (mPTT) mediated by the same J‐aggregated photocatalyst. This NO‐amplified PCT–mPTT strategy not only induces potent tumor ablation but also remodels the immunosuppressive tumor microenvironment, effectively inhibiting both primary and distant tumor growth in vivo.

Hemostatic agent use and symptomatic anastomotic leakage in colorectal cancer patients with postoperative abdominal bleeding: a hypothesis-generating study

Abstract The association between postoperative abdominal bleeding (POAB) and anastomotic leakage (AL) after colorectal cancer surgery remains unclear, and whether hemostatic therapy would increase AL risk in POAB patients is understudied. We retrospectively analyzed 9651 patients who underwent colorectal resection with anastomosis (2010–2023). Logistic regression models were used to assess the association between POAB and symptomatic AL. In the POAB subgroup, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff for hemostatic agent duration in predicting AL. Symptomatic AL occurred in 348 patients (3.6%). Multivariate analysis showed that POAB (OR 4.311, 95% CI 2.272–8.181; P  &lt; 0.001) and tumor location (OR 3.410, 95% CI 2.669–4.358; P  &lt; 0.001) were significantly associated with an increased risk of symptomatic AL. POAB occurred in 75 patients (0.78%), of whom 12 developed symptomatic AL. ROC analysis determined 6 days as the optimal hemostatic agent duration cutoff for predicting AL(AUC 0.729, 95% CI: 0.551–0.881; sensitivity 66.7%, specificity 77.8%), and univariate analysis showed that hemostatic agent use for ≥ 6 days was significantly associated with symptomatic AL ( P  = 0.004). This hypothesis-generating study suggests that POAB was associated with increased risk of symptomatic AL after colorectal cancer surgery and prolonged hemostatic agent use (≥ 6 days) appears to further exacerbate this risk.

Remote Desaturation of Unprotected Amines and C─H Amination of Alkanes by Polarity‐Matched N‐Radical Cations

ABSTRACT A CuCl‐catalyzed strategy enables practical, selective, and efficient δ desaturation of unprotected amines. These bifunctional molecules allow rapid conversion of simple amines to privileged heterocycles in medicine. The key radical relay mechanism is an interrupted Hofmann–Löffler–Freytag (HLF) reaction, which may now be carried out without protecting groups. Based on ‘radical polarity matching’ analysis, we show here that N‐radical cations are ideal intermediates for facilitating efficient and selective 1,5‐H‐atom transfer (HAT) of unprotected amines. Mechanistic probes illustrate the scope, rate, selectivity, and utility of these distal amino alkenes. Computational studies compare the importance of kinetic (radical polarity) over thermodynamic (bond strength) factors in predicting HAT reactivity. Extension to an intermolecular variant allows the direct, desaturative C─H amination of alkanes in a net triple C─H functionalization.

Real-time HIL validation of a lyapunov-guaranteed optimal FOPID controller for quadrotor UAV trajectory tracking

Abstract This paper presents the real-time Hardware-in-the-Loop (HIL) validation of a robust 6-Degree-of-Freedom (6-DoF) Fractional-Order Proportional-Integral-Derivative (FOPID) control architecture, optimally tuned via the Artificial Gorilla Troops Optimizer (GTOA), for quadrotor Unmanned Aerial Vehicle (UAV) trajectory tracking. First, a comprehensive kinematic and dynamic model is developed, and the control architecture is designed by decoupling the UAV into fully-actuated and under-actuated subsystems through a cascaded inner-outer loop strategy. The global asymptotic stability is mathematically established via Lyapunov theory, and a dynamic Lyapunov penalty mechanism is further integrated into the GTOA objective function to enforce this stability condition across all candidate solutions throughout the optimization process. Subsequently, GTOA is applied to obtain the optimal gains that minimize the Integral of Time-Weighted Absolute Error (ITAE). Real-time HIL experiments are conducted on an industrial OPAL-RT OP4510 real-time target simulator, where the proposed GTOA-FOPID is evaluated against the African Vultures Optimization Algorithm (AVOA)-FOPID, alongside the baseline Particle Swarm Optimization (PSO)-tuned fractional-order and integer-order PID controllers. This comparative study evaluates the proposed architecture from two independent perspectives. First, the fractional-order operators are assessed against a PSO-tuned integer-order PID controller, isolating the contribution of the fractional calculus extension. Second, the GTOA is evaluated against AVOA and PSO, representing a modern metaheuristic and a standard baseline, respectively, across the identical FOPID architecture, isolating the contribution of the optimization strategy. Experimental results demonstrate the superiority of the fractional operators over the traditional integer-order PID controller. Furthermore, the proposed GTOA-FOPID achieves superior transient performance, precise trajectory tracking, and enhanced robustness under realistic hardware constraints and computational delays.

A Highly General Potential‐Gating Strategy for Electrocatalytic Upcycling of Waste Polyester Plastics

ABSTRACT Electrocatalytic upcycling of waste polyester plastics driven by renewable electricity offers a sustainable route for resource utilization, yet its practical implementation is hampered by the poor selectivity control stemming from the inherent complex monomer of polyesters. Herein, we propose a potential‐gating principle for the selectivity‐controllable upcycling of α,ω‐diols and hydroxy acids—the most pivotal monomers of polyester—and design a potential‐gated PVP‐Pd‐Ni(OH) 2 ‐CV/NF catalyst. This catalyst enables precise manipulation of product distribution simply by switching the applied potential without the need for catalyst replacement, while demonstrating broad applicability to seven polyesters. Moreover, the composite catalyst exhibits a sevenfold activity enhancement over the Pd/NF benchmark. Mechanistic investigations reveal that the adsorption behavior of hydroxy acid intermediates is the key selectivity‐determining step. Sequential electrolysis of real post‐consumer polyester hydrolysates over four stages for 198 h retains high target product selectivity (84%–98%), thus showcasing a general and sustainable route for plastic waste recycling.

Experimental analysis of nanofiber embedding and layer thickness on fracture toughness in fiber–epoxy laminates

In Situ Tracking of Radical Evolution in a Conjugated Covalent Organic Framework for Reversible Sodium Storage

ABSTRACT Covalent organic frameworks (COFs) have emerged as promising platforms for sodium‐ion storage owing to their tunable redox‐active sites and ordered porous architectures. However, the role of radical intermediates in their electrochemical processes remains elusive due to the lack of direct experimental evidence. Herein, we report a highly crystalline β‐ketoenamine‐linked COF (BT‐COF‐AA) that delivers exceptional rate capability and ultralong cycling stability over 10 000 cycles at 5 A g − 1 . More importantly, in situ electron paramagnetic resonance (EPR) spectroscopy provides time‐resolved and direct observation of transient radical intermediates, enabling the elucidation of a sequential sodium‐ion storage mechanism. Specifically, Na + ions initially coordinate with nitrogen sites in benzothiadiazole units, triggering localized electron transfer and the formation of stabilized radicals. Subsequent sodiation occurs at carbonyl oxygen sites, generating ketyl radicals accompanied by dynamic electron delocalization across the conjugated framework. This reversible radical evolution establishes a framework‐coupled redox pathway that underpins the outstanding electrochemical performance. Combined experimental and theoretical results reveal a radical‐mediated charge storage mechanism and provide fundamental insights for the rational design of high‐performance organic electrode materials.

Vortex-induced resistive state in Nb-Pb-Nb heterostructure

Abstract We investigate the current-driven resistive state of two-dimensional Pb–Nb core–shell superconductors within the time-dependent Ginzburg–Landau framework, focusing on how proximity induced inhomogeneity and self field effects govern vortex–antivortex (v-av) dynamics and superconducting fragmentation. The system consists of a type-I Pb core surrounded by a type-II Nb shell coupled through a smooth proximity interface, which produces a spatially nonuniform reduced temperature $$T/T_c(\textbf{r})$$ and redistributes both the order parameter and the transport current. By increasing the applied current, we identify a sequence of distinct dynamical regimes. At low currents, dissipation originates from edge-assisted v-av nucleation in the Nb shell, while the Pb core remains a robust superconducting backbone. As the current increases, v-av clusters grow and coalesce inside the Nb layer, progressively suppressing its superconductivity and fragmenting the proximity-coupled network. This process leads to the emergence of isolated Pb superconducting islands that are weakly connected by highly dissipative Nb channels and sustain intermittent phase-slip dynamics. At still higher currents, the Nb shell becomes strongly degraded and transport is governed by edge-driven bursts of v-av activity surrounding the Pb islands, producing a highly nonlinear resistive response. For comparison, we analyze a homogeneous Pb film under the same conditions. Although Pb is a type-I superconductor, the transport self-field induces an intermediate resistive state characterized by a fixed array of superconducting islands embedded in normal regions near the edges. Remarkably, in the high-current limit, the Pb–Nb heterostructure evolves toward a similar island topology, indicating that proximity coupling becomes progressively weaker and self-field effects dominate the spatial organization of superconductivity. Our results establish a mesoscopic framework in which proximity effects, transport self-fields, and vortex dynamics jointly govern dissipative states in hybrid superconducting heterostructures.