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Cryogenic (Cu64.5Al24Mn11.5)99.5Cr0.5 superelastic alloy with broad temperature window of elastocaloric effect
We report giant elastocaloric effect over a broad temperature window from 90 to 420 K in a Cr-doped directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 cryogenic shape memory alloy with ⟨001⟩A preferred orientation. Even at the temperature down to 90 K, the ΔTad values upon loading and unloading can be as large as 6.9 and −5.6 K, respectively. The combination of giant elastocaloric effect and broad temperature range thus yields a pronounced refrigeration capacity of 4.71 J g−1, well beyond those in the cryogenic elastocaloric materials demonstrated before. Moreover, large ΔTad values higher than 7.3 K remain stable for more than 1200 superelastic cycles at liquefied natural gas temperature (∼110 K) with a low degradation rate (5.8 × 10−4 K/cycle), showing great potential for cryogenic elastocaloric cooling applications.
Identifying anyonic topological order in fractional quantum anomalous Hall systems
Recently observed fractional quantum anomalous Hall (FQAH) materials are candidates for topological quantum hardware, but their required anyon states are elusive. We point out dependence on monodromy of the fragile band topology in 2-cohomotopy. An algebro-topological theorem of L. Larmore and E. Thomas, [Math. Scand. 47, 232 (1980)], identifies FQAH anyons over momentum space. Admissible braiding phases involve 2C-th roots of unity, with C the Chern number. This lays the foundation for understanding symmetry-protected topological order in FQAH systems, reducing the problem to computations in equivariant cohomotopy.
A weakness breakdown model of a BOPP film based on blister growth under cyclic pulsed voltage
The investigation of failure mechanisms in thin-film materials has consistently been a critical aspect of ensuring the reliability of energy storage devices. In this study, full-lifecycle pulsed electrical aging tests were conducted on biaxially oriented polypropylene (BOPP) films. Experimental results reveal that the blisters formed on the surface of electrically aged BOPP films are cavity-structured bubbles, which essentially represent a distinct form of “latent electrical weakness” arising from irreversible material degradation under multi-field electro–thermo–mechanical coupling. Furthermore, a physical model and equivalent impedance were established for these bubbles, providing additional evidence that the blisters play a decisive role in the degradation of the breakdown performance of BOPP films.
One-step implementation of a hybrid discrete-variable–continuous-variable phase gate with multiple photonic qubits in circuit QED
Quantum phase gates are of fundamental interest in quantum physics and play an important role in quantum communication and quantum computing. Here, we propose a scheme to implement a hybrid discrete-variable–continuous-variable (DV–CV) phase gate on multiple photonic qubits by utilizing multiple control microwave cavities and a single target microwave cavity, all coupled to a common superconducting qutrit (a three-level quantum system) in circuit quantum electrodynamics (QED). In our scheme, two logic states of the target qubit are encoded via the vacuum state and the coherent state (CV state) of the microwave cavity, while two logic states of the control qubits are encoded through the vacuum and single-photon states (DV states) of the microwave cavity. This hybrid DV–CV phase gate enables target qubit to acquire a phase that depends on the total number of control qubits in non-vacuum states, when the target qubit is in the coherent state. Our protocol is extensible and operationally efficient, involving just one step and the measurement of only one target qubit. In addition, as a practical application, this hybrid DV–CV phase gate can be employed as a quantum voting machine. Our numerical simulation demonstrates that the high-fidelity construction of a hybrid three-qubit DV–CV phase gate is feasible with current circuit QED technology.
Anomalous low-field magnetoresistance in Fe3Ga4 single crystals
Fe3Ga4 possesses a helical spin spiral with a complex competition between ferromagnetic and antiferromagnetic ground states. This competition generates multiple metamagnetic transitions that are governed by both the applied magnetic field and temperature. At intermediate temperatures between T1 (68 K) and T2 (360 K), the ferromagnetically aligned spins transition to an antiferromagnetic spin spiral. In this study, magnetoresistance (MR) measurements are performed on an aligned single crystal and compared to magnetization properties in order to gain insight into the unique alignment of the spins. The high-field MR is positive at low temperatures, indicating cyclotronic behavior, and negative at high temperatures from electron–magnon scattering. Of particular significance is a large anomalous positive MR at low fields, possibly due to emergent spin fluctuations, thus prompting further exploration of this multifaceted material.
Temporal constraints on enhancer usage shape the regulation of limb gene transcription
Abstract Enhancer repertoires orchestrate gene expression during embryonic development, shaping organ structure and function. Individual enhancers can act in overlapping or distinct spatial domains, but their temporal specificity and coordinated action over time remain poorly understood. Here, we identify temporally restricted enhancer repertoires at multiple loci involved in mouse limb development. To capture their dynamic roles, we introduce the regulatory trajectory framework comprising initiation, maintenance, and decommissioning of gene expression. Using a transgenic recorder at the Shox2 locus, we demonstrate that early enhancers initiate transcription, while late enhancers maintain it. Additionally, we found that changes in 3D topology associate with enhancer activities and that loss of enhancer-promoter contacts occurs during decommissioning. Finally, we show that Shox2 regulatory decommissioning can be driven by Hoxd13 , a known antagonist of Shox2 expression. Overall, our work uncovers how temporally restricted enhancers generate complex expression patterns and sheds light on the dynamics of enhancer-promoter interactions.
The heating and cooling of 2D electrons at low temperatures
We present measurements of the cooling length ℓE for hot electrons in a GaAs-based high-mobility two-dimensional electron gas. The thermal measurements are performed on a long 60 μm-wide channel, which is Joule-heated at one end, along which there are three similar hot-electron thermocouples, spaced 30 μm apart. The thermocouples measure an exponentially decaying temperature profile with a characteristic length ℓE, which decreases from 23 to 16 μm as the lattice temperature increases from 1.8 to 5 K. From a simple one-dimensional model of heat diffusion, we measure an inelastic scattering time, which decreases from τi≈360 to 180 ps. The measured τi has a magnitude and temperature dependence consistent with acoustic phonon scattering times. We discuss how the sample design can be varied for further thermal investigations. Knowledge of the temperature profile and its gradient will prove useful in measurements of the thermal conductivity and the Nernst effect.
Parietal alpha frequency shapes own-body perception by modulating the temporal integration of bodily signals
Abstract An influential proposal in the field of cognitive neuroscience suggests that alpha-frequency brain oscillations constrain the temporal sampling of external sensory signals, shaping the temporal binding window (TBW)—the interval during which sensory signals are integrated. However, whether alpha frequency modulates the integration of self-related sensory signals and the perception of the body as one’s own (body ownership) remains unknown. Here, we demonstrate that individual alpha frequency (IAF) from the parietal cortex predicted TBWs and perceptual sensitivities in body ownership and visuotactile simultaneity judgment tasks, with faster frequencies narrowing TBWs and increasing sensitivities, and vice versa. Modulating IAF through brain stimulation altered TBWs and sensitivities, establishing a causal relationship. Computational modeling linked IAF to uncertainty in asynchrony information within the causal inference process. These findings demonstrate that parietal alpha frequency shapes the sense of body ownership by modulating the temporal integration of bodily sensory signals.
Unveiling bonding heterogeneity-driven anharmonicity and ultralow lattice thermal conductivity in NbSe2Br2: A machine learning accelerated discovery
Transition metal chalcogenide halide (TM–Ch–X) compounds with significant heterogeneity in their chemical bonding have immense potential for thermoelectric applications. Their mixed ionic–covalent bonding nature, combined with intrinsic low lattice symmetry, provides a favorable platform for achieving strong lattice anharmonicity and ultralow lattice thermal conductivity. In this work, we developed a temperature-included crystal graph convolutional neural network to accurately predict mode-resolved Grüneisen parameters, a key descriptor of lattice anharmonicity. Using this approach, two-dimensional NbSe2Br2 is identified as a thermoelectric candidate with strong anharmonicity and ultralow lattice thermal conductivity. First-principles results reveal that the strong anharmonic lattice dynamics originate from its weak and heterogeneous chemical bonding, further leading to ultralow lattice thermal conductivity. NbSe2Br2 also exhibits favorable electronic transport behavior, resulting in a maximum ZT of 1.63. Our work provides a theoretical understanding of the origin of low lattice thermal conductivity in TM–Ch–X compounds with bonding heterogeneity and should encourage further exploration of potential thermoelectric materials.
All-fibre-coupled terahertz single-pixel imaging for biomedical applications
Abstract Real-time, non-invasive imaging techniques are essential for advancing biomedical diagnostics and material analysis, yet existing terahertz (THz) systems often suffer from limited speed, bulky designs, and poor adaptability to in situ environments. Addressing these challenges, we present a fully fibre-coupled THz attenuated total internal reflection single-pixel imaging system, offering a compact, flexible, and robust platform for non-destructive spectroscopy and in vivo imaging. This all-fibre architecture enables seamless integration for in situ biomedical applications, including measurements directly on patients. Central to our design is a THz spatial light modulator based on an unpassivated silicon wafer, facilitating high-speed modulation and enabling video-rate imaging with a spatial resolution down to 360 μ m. Despite being in the reflection geometry and using fibre-coupled light, our system achieves an imaging throughput exceeding 30,000 pixels per second for 64-by-64 images - over five-fold higher than the state of the art - representing a substantial improvement in real-time THz imaging capabilities.
Enhanced photocurrent and responsivity of Bi2O2Se nanosheet near-infrared photodetector by <i>in situ</i> surface growth of Te nanowires
The intrinsically weak optical absorption and limited photocarrier separation of atomically thin two-dimensional (2D) materials often limit the photodetector performance. Here, we report an in situ surface growth strategy for preparing a Bi2O2Se/Te heterojunction via a low-temperature chemical vapor deposition method. One-dimensional Te nanowires directly grow on 2D Bi2O2Se nanosheets, forming a clean van der Waals interface and enhancing optical absorption capacity. The Bi2O2Se/Te heterostructure exhibits excellent optoelectronic performance, including an enhanced photocurrent of 1.12 μA, a high responsivity of 50 A/W, and a fast response speed of 32/&gt;168 ms. The enhanced photocurrent and responsivity arise from the efficient electron injection from Te to Bi2O2Se, and hole trapping at the heterointerface. This work demonstrates a non-destructive approach for preparing high-quality heterojunctions and provides an effective pathway for next-generation high-performance near-infrared photodetectors.
Fine-mapping a genome-wide meta-analysis of 98,374 migraine cases identifies 181 sets of candidate causal variants
Abstract Migraine is a highly prevalent neurovascular disorder for which genome-wide association studies (GWAS) have identified over one hundred risk loci, yet the causal variants and genes remain mostly unknown. Here, we meta-analyze three migraine GWAS including 98,374 cases and 869,160 controls and identify 122 independent risk loci of which 35 were new. Fine-mapping of a meta-analysis is challenging because some variants may be missing from some participating studies and accurate linkage disequilibrium (LD) information of the variants is often not available. Here, using the exact in-sample LD, we first investigate which statistics could reliably capture the quality of fine-mapping when only reference LD is available. We observe that the posterior expected number of causal variants best distinguishes between the high- and low-quality results. Next, we perform fine-mapping for 102 autosomal risk regions using FINEMAP. We produce high-quality fine-mapping for 93 regions and define 181 distinct credible sets. Among the high-quality credible sets are 7 variants with very high posterior inclusion probability (PIP > 0.9) and 2 missense variants with PIP > 0.5 (rs6330 in NGF and rs1133400 in INPP5A ). For 35 association signals, we manage to narrow down the set of potential risk variants to at most 5 variants.
Probing cellulose hydrogel dehydration with Brillouin spectroscopy: Insights into mechanical properties
Hydrogels are three-dimensional networks of hydrophilic polymers that retain large amounts of water and can be tailored for medicine, agriculture, electronics, and cosmetics. Their softness and tunable density complicate contact-based mechanical testing. Here, we explore the mechanics of a cellulose-based hydrogel using Brillouin light scattering (BLS) spectroscopy, a non-contact optical probe. We study micro-fibrillated cellulose hydrogels prepared via two drying routes—a dense, ambient-dried film and a foam-like, freeze-dried aerogel—pre-characterized by tensile testing. BLS is then used to extract longitudinal sound velocity and stiffness in three scattering geometries: reflective backscattering 180a and 90r and transmissive 90a. As expected, the structural arrangement imposed by drying (i.e., material density) dominates the stiffness, resulting in a stiffness of 3 GPa for the aerogel and 19 GPa for the hydrogel film. We further track moisture effects by changing the relative humidity (RH) level (40% RH and 75% RH), which leads to a decrease in frequency shift and a broadening of the Brillouin peaks with increasing RH, and a drop in stiffness by factor two. Time-resolved BLS tracks dehydration kinetics: fully wetting the hydrogel film and merely changing RH produce different Brillouin frequency shift dynamics. These results explore BLS as non-contact method for in situ measurement of mechanical properties during conditioning, with further potential applications during processing of technologically relevant soft and polymeric materials.
ERECTA genes and their ligands regulate shoot and inflorescence architecture in maize
Abstract In maize, several yield-related traits are associated with meristem activity, regulated by CLAVATA3/EMBRYO SURROUNDING REGION-related (CLE) peptide signals perceived by CLAVATA(CLV) receptors in the CLAVATA-WUSCHEL (CLV-WUS) pathway. However, additional signaling pathways in maize meristem development remain poorly understood. Here, we identify three receptor-like kinases, ZmERECTA1 (ZmER1), ZmER2 and ZmER1-like (ZmERL), and their ligands, EPIDERMAL PATTERNING FACTOR-like (ZmEPFL), as critical regulators of meristem activity, plant architecture, and ear development. We demonstrate that ZmER receptors act redundantly, with ZmER1 playing a primary role. Zmer1 mutants have compact architecture, enlarged inflorescence meristems (IMs), and increased kernel row numbers (KRNs), while higher-order Zmer mutants display exacerbated phenotypes. We further reveal that ZmER1 specifically binds to five EPFL peptides, which act redundantly in ear development regulation. Furthermore, we find that ZmWUS1 is upregulated in Zmer mutants and mutation in Zmwus1 partially suppress the enlarged IM of Zmer1 mutants. We also generate weak Zmer1 alleles with enhanced yield traits, including reduced leaf angles and increased KRN. These findings offer valuable insights into ER-EPFL signaling in maize meristem development and provide promising genetic targets for breeding high-yield maize varieties through optimized plant and ear architecture.
A low-cost green mixed antisolvent strategy for strain-release and defect-reduction toward efficient perovskite solar cells
Antisolvent engineering is among the most widely used techniques for fabricating high-efficiency perovskite solar cells (PSCs). Recent mixed antisolvent strategies have shown great promise for enhancing the performance of PSCs. These approaches tailor the crystallization kinetics of perovskite films by utilizing solvents with complementary physicochemical properties. In this work, we develop a low-cost and environmentally benign mixed antisolvent system employing ethanol (EtOH) and tert-butanol (TBA). Remarkably, the content of only 5 vol. % TBA in the antisolvent mixture leads to a substantial efficiency improvement, elevating the power conversion efficiency from 21.8% (pure EtOH) to 24.1%, while also significantly enhancing device stability. Further analysis indicates that TBA incorporation effectively mitigates perovskite bulk lattice strain and facilitates pinhole-free grain growth, resulting in enhanced charge carrier mobility and suppressed non-radiative recombination. Our study highlights a simple, cost-effective, and green mixed antisolvent strategy for advancing high-performance PSCs toward practical photovoltaic applications.
Environmental metagenomics enhances detection of circulating viruses from live poultry markets in Cambodia
Abstract Environmental surveillance has emerged as a pivotal strategy for early detection of pathogens that pose a threat to humans. In Asia, live-bird markets (LBMs) are key human-animal interfaces for zoonotic virus transmission. Traditional sampling strategies are time-consuming, expensive and carry significant biosafety risks. Here, we assess the performance of metagenomics on environmental samples (ES) versus traditional poultry swabs for detecting viral pathogens in two Cambodian LBMs between January 2022 and April 2023. ES, including air (n = 35), cage swabs (n = 17), carcass wash water (n = 17) and drinking water (n = 9) are collected alongside oropharyngeal and cloacal swabs from chickens (n = 30) and ducks (n = 29). ES is sensitive in detecting 40 viruses from pathogen families including Orthomyxoviridae and Coronaviridae . Air samples capture the greatest diversity of poultry viruses. Viral contigs from ES show high sequence identity to poultry swab contigs when aligned to the same gene. We show ES outperforms poultry samples in detecting the highly pathogenic influenza A/H5N1, including clades 2.3.4.4b and 2.3.2.1c, which are found in the environment but are missed by poultry swabs. Our findings show metagenomics on ES replicates traditional surveillance, offering broader coverage and improved pathogen detection. This approach could be pivotal for mitigating zoonotic spillover and enhancing pandemic preparedness.
Enhanced conductance linearity in HfS2-based optoelectronic memristors via a defective h-BN interlayer for high-performance neuromorphic visual system
Two-dimensional materials offer potential for developing optoelectronic memristors and neuromorphic visual systems, benefitting from their atomically smooth surfaces and tailorable optoelectronic characteristics. However, the rapid recombination of photogenerated carriers within the two-dimensional materials-based optoelectronic memristors degrades the linearity of conductance updates, impairing the image recognition accuracy of neuromorphic visual systems. This work introduces a defective h-BN interlayer into HfS2-based optoelectronic memristors to improve nonvolatile conductance modulation. The fabricated HfS2/h-BN heterojunction optoelectronic memristor exhibits linear conductance tuning and emulates key synaptic functions, including excitatory postsynaptic current, paired-pulse facilitation, and transition from short-term to long-term plasticity. When used in an artificial neural network for image recognition, the device achieves an accuracy of 94%, higher than the 51% obtained with a pure HfS2 optoelectronic memristor. Mechanism studies reveal that the enhancement arises from efficient trapping and release of photogenerated carriers at the HfS2/h-BN interface. This work reveals that van der Waals heterojunction-interface defects-mediated carrier dynamics enable linear conductance modulation, offering a physical design principle for high-performance neuromorphic vision systems based on two-dimensional materials.
Living sensor display implanted on skin for long-term biomarker monitoring
Giant tunneling electroresistance and multistate data storage in two-dimensional ferroelectric tunnel junctions via polarization–anisotropy coupling
Achieving large tunneling electroresistance (TER) and multistate data storage is crucial for advancing two-dimensional (2D) ferroelectric tunnel junctions (FTJs) toward high-density nonvolatile memories. In this work, we propose a strategy that couples ferroelectric polarization with transport anisotropy to realize multistate data storage in 2D FTJs. As a concrete implementation, we design a van der Waals heterostructure composed of metallic goldene and out-of-plane ferroelectric In2Se3, and construct 2D FTJs based on this heterostructure. Density functional theory combined with nonequilibrium Green's function calculations shows that the interfacial contact in the goldene/In2Se3 heterostructure can be reversibly switched between Schottky and Ohmic types by reversing the ferroelectric polarization, yielding a giant TER ratio of up to 108%. More importantly, the cooperative effect of polarization reversal and transport anisotropy induces four distinct resistance states that can be switched directly without an additional erase step. Our proposal provides a viable pathway for realizing nanoscale 2D FTJs with ultrahigh storage density and simplified multistate memory operation.