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Tailoring arbitrary convex self-bending and low-diffraction elastic waves via deep-subwavelength metasurfaces
Precise control over elastic wave propagation paths, particularly for complex trajectories with preserved beam integrity, remains a significant challenge in various applications. Here, we present a deep-subwavelength elastic metasurface strategy for theoretically tailoring arbitrary convex self-bending elastic waves with remarkably low diffraction over extended distances. Our approach leverages a multi-objective inverse design methodology to optimize deep-subwavelength unit cells, ensuring uniformly high transmission and widely tunable phase shifts. These optimized unit cells are then arranged according to desired phase profiles to sculpt the prescribed curvilinear trajectories. Both numerical simulations and experimental measurements are conducted to validate the exceptional performance of the proposed metasurfaces in shaping complex wavefields. The intensity distribution of the self-bending beams in the vicinity of the mainlobe transversely resembles a squared Airy function while preserving the low-diffraction features along the propagation path within a prescribed range. This unprecedented customization of both the wavefront trajectory and its low-diffraction range opens new avenues for sophisticated elastic wave engineering, promising transformative applications in areas requiring remote, precise energy delivery, enhanced sensing capabilities, and advanced wave-based communication.
Association of urinary diversion type and surgical approach with long-term renal function after radical cystectomy: a nationwide cohort study
Bigger Molecules Enter Smaller Channels of Zeolites via Inward-Coil-Alike Adaptation
Rubidium copper iodide single crystals for deep-ultraviolet detection and imaging
Deep-ultraviolet (DUV) detectors are indispensable for a wide range of applications, including environmental monitoring, flame warning, and intelligent imaging systems. However, the development of DUV-sensitive materials with high performance, excellent stability, and facile fabrication remains challenging. Here, a novel rubidium copper iodide single crystal is synthesized via a facile solution-based approach and systematically studied both experimentally and theoretically. First-principles calculations reveal a wide bandgap and dispersive electronic bands near the band edges, suggesting efficient carrier transport while maintaining intrinsic DUV selectivity. Consequently, photodetectors fabricated from the single crystals exhibit excellent spectral selectivity in the DUV region, achieving a high responsivity of 3.9 A/W and a specific detectivity of 1.36 × 1012 Jones under 235 nm illumination. More importantly, the devices demonstrate remarkable operational robustness, maintaining stable photoresponse under continuous operation, elevated temperatures, and long-term storage conditions. Benefiting from the high performance, wavelength-selective DUV imaging is successfully demonstrated with high image contrast and resolution. This work highlights the potential of the prepared single crystals and detectors for next-generation DUV optoelectronic sensing and imaging technologies.
A global–local hybrid transformer framework for automatic Navarasa facial expression recognition
Discovery of Noninhibitory Macrocyclic Ligands for Protein Tyrosine Phosphatase 1B Using a Function-Based, Iterative Screening Strategy
Dual-tunable polarity reversal of exchange bias in the Fe3GaTe2/O-Fe3GaTe2 heterostructures
The polarity reversal of exchange bias (EB) in two-dimensional (2D) van der Waals magnets remains a significant scientific challenge, yet is highly desirable for advanced spintronic applications. Conventional approaches relying on artificially stacked heterostructures often suffer from weak interfacial coupling and limited tunability. Here, we demonstrate a reversal of the EB polarity in an intrinsically formed Fe3GaTe2/O-Fe3GaTe2 heterostructure achieved through thermal oxidation. This system exhibits a remarkable reversal of the EB polarity with both temperature and magnetic field orientation, alongside robust stability under repeated magnetic cycling. A trilayer magnetic model, comprising a top oxidized layer, an interfacial oxidized region, and a bottom pristine ferromagnetic layer, is proposed to explain the phenomenon, revealing a delicate competition between the Zeeman energy, interlayer exchange, and interfacial coupling. Our work offers a pathway to tune exchange bias in 2D magnets through interface engineering, offering fundamental insights for designing reconfigurable spintronic devices.
Prevalence and associated factors of pre-cancerous cervical lesions among HIV-positive women on ART in Northwest Ethiopia: a retrospective cross-sectional study
Abstract Cervical cancer is a major public health concern in Ethiopia with high mortality rates, especially in women living with HIV/AIDS. While its screening service has been available in Ethiopia since 2009, the updated prevalence of precancerous cervical lesions among HIV-positive women is not well understood. Therefore, this study aimed to determine the prevalence of precancerous cervical lesions and its associated factors among women living with HIV receiving ART in the Northwest Ethiopia. An institution-based retrospective cross-sectional study was conducted from February 28 to April 1, 2024 at the University of Gondar Comprehensive Specialized Hospital. A total of 419 eligible participants were selected by using simple random sampling technique. The data were collected through patient chart review using a pre-tested and structured checklist. The data were entered into Epi-info version 7, cleaned, and analyzed using SPSS version 20. Binary logistic regression model was used to identify factors associated with the outcome variable, and odds ratios with 95% confidence intervals and its corresponding p-values were computed to identify significant variables in the multivariable analysis. In this study, the prevalence of precancerous cervical lesions was found to be 11.5% (95% CI: 8.2–14.7). History of STI (AOR = 3.7, 95% CI: 1.79–7.62), age at first marriage less than 15 years (AOR = 3.02, 95% CI: (1.00-9.24), monthly income below 3000 Ethiopian Birr (AOR = 6.3, 95% CI: 1.20-32.82), and being widowed (AOR = 0.36, 95% CI: 0.13–0.95) were factors significantly associated with the occurrence of precancerous cervical lesions. The present study revealed 11.5% of precancerous cervical lesions among women living with HIV. History of sexually transmitted infections (STIs), early marriage, low income level, and being widowed were significantly associated with the outcome variable. Therefore, targeted interventions such as delaying early marriage and strengthening strategies that promote protection against sexually transmitted infections and poverty are recommended to reduce the burden of the disease in this highly vulnerable population.
Exciton Selectively Coupled to Magnon Dependent on Spin–Lattice Alignment
Alleviating the trade-off between thermal stability and fast switching in Ru-doped Sb3Te phase change films
Phase change memory is a promising candidate for next-generation nonvolatile memory. Improving the amorphous thermal stability of phase-change materials usually comes at the expense of crystallization speed, because suppressing nucleation tends to slow phase transition kinetics. Here, we show that Ru doping in Sb3Te films can significantly enhance thermal stability while preserving fast switching speed. Structural analyses indicate that Ru disrupts the long-range order of the crystalline phase, which improves amorphous stability. Meanwhile, transmission electron microscopy demonstrates that although long-range order is perturbed, the crystal grains largely retain an ordered internal structure with only slight orientational adjustment, minimizing the negative impact on crystal growth. This structural characteristic alleviates the trade-off between thermal stability and crystallization speed, enabling Ru-doped Sb3Te to achieve both improved data retention and rapid switching speed. These findings provide a practical strategy for designing high-performance phase change materials for embedded memory applications.
Dual-fluorescence reporter-based assay for rapid quantitative evaluation of antiviral activity against Venezuelan equine encephalitis virus
Anomalous Solubility-Inverted Behavior of LiPF <sub>6</sub> in Glyme Ether Solvents for High-Voltage Electrochemistry
Bloch oscillations in a semiconductor superlattice shifting from capacitive to conductive responses with electric-field-induced interminiband mixing
We investigate the initial phase of Bloch oscillations in a GaAs-based superlattice designed for fine bias control of interminiband mixing. The type of oscillation current, determined from terahertz emission with the time origin (t=0), is found to shift gradually from damped cos ωBt to damped sin ωBt (ωB/2π: Bloch frequency) as the dc bias electric field is increased. This demonstrates a continuous transition between the capacitive and conductive responses, which have been previously reported in the two regimes where electron wavefunctions are Wannier–Stark localized within a nearly isolated miniband and delocalized by substantial interminiband mixing, respectively.
Resilient fixed-order damping controller for low-frequency inter-area oscillations in power systems under communication failures
Abstract Low-frequency inter-area oscillations (LFOs) pose a critical challenge to small-signal stability, affecting the reliable operation of interconnected power systems. These oscillations can reduce tie-line power transfer capability and weaken overall system performance. This paper proposes, for the first time, a robust fixed low-order two-input single-output (TISO) damping controller based on dual wide-area signals to mitigate the effects of communication failures and time delays on system stability. Inter-area modes can be effectively observed from multiple locations and controlled from a single point, which motivates the use of a wide-area damping controller (WADC). Communication failures and time delays are important challenges in wide-area control, and delays are modeled using the Padé approximation. The controller is designed by optimizing key performance measures, such as the $$H_{\infty }$$ norm, spectral abscissa, and complex stability radius, to improve the robustness and stability of the system under uncertain conditions. The proposed controller improves system resilience by using the two most observable wide-area signals associated with critical inter-area modes. Kundur’s 11-bus system and the IEEE 39-bus test system are used to validate the proposed method. Simulation results show that the controller effectively improves the damping of inter-area oscillations under normal conditions and maintains stable performance even in the presence of communication failures and delays.
A Rhodium-Catalyzed Cyclization of Sulfonimidamides and Sulfondiimidamides: Synthesis and Exploration of Chiral Aromatic Heterocycles
Defect-engineering induced sub-bandgap stimulation in BeZnO for optoelectronic synapse
Optoelectronic synaptic devices offer a promising way to overcome the traditional von Neumann bottleneck, while most studies focused on above-bandgap photons but overlooked sub-bandgap stimulation. In this work, a wide-bandgap Be-doped ZnO (BeZnO) thin film was fabricated to introduce abundant defect levels into the forbidden gap. The BeZnO device exhibits a robust broadband response spanning from the ultraviolet band to the entire visible range, which is essential for an integrated neuromorphic vision system. The key biological synaptic behaviors including excitatory postsynaptic current, paired-pulse facilitation, and the transition from short-term plasticity to long-term plasticity were successfully emulated under optical stimuli by violet, green, and red lights. Furthermore, a VGG-8 convolutional neural network was trained using the below-bandgap stimulated synaptic weights, achieving a high image recognition accuracy of 90.41% on the CIFAR-10 dataset. These results underscore the potential of BeZnO-based optoelectronic synapses for next-generation energy-efficient neuromorphic computing and the broadband artificial visual systems.
The relationship between multidimensional parenting practices and oral health status, oral health behaviours, and dental anxiety in a regional Turkish paediatric population
Phase Engineering of Fe-Polyoxometalate Sub-1 nm Assemblies for High-Efficiency Photoelectrocatalytic Nitrogen Reduction
Mechanically driven piezocatalytic wastewater-to-hydrogen conversion in two-dimensional SnSe nanosheets
Piezocatalysis is an emerging mechano-to-chemistry energy conversion technique that uses mechanically generated positive and negative charges to drive chemical reactions, opening broad opportunities in environmental remediation and energy conversion. However, most reported systems utilize only one type of charge for a single target reaction, leading to inefficient charge use. Here, we demonstrate that two-dimensional SnSe nanosheets can simultaneously use positive charges for pollutant degradation and negative charges for H2 evolution, thereby enabling mechanically driven piezocatalytic wastewater-to-hydrogen conversion. Under ultrasonic excitation at 80 kHz and 120 W, the SnSe nanosheets act as a bifunctional piezocatalyst, achieving a Rhodamine B degradation efficiency of 97.2% and an H2 yield of 1047.3 μmol g−1 within 2 h. The system also shows adaptability to different pollutant concentrations, pH values, pollutant species, and simulated mixed-pollutant wastewater. A flow-type piezocatalytic device further enables continuous H2 production and pollutant degradation beyond conventional batch tests. Mechanistic studies reveal that piezoelectrically generated positive charges promote hydroxyl radical generation for pollutant degradation, while negative charges facilitate H2 evolution through the *H intermediate. This work demonstrates a bifunctional charge utilization strategy for integrating wastewater purification with hydrogen production in a mechanically driven piezocatalytic system.