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We discovered that employing inappropriate calibration curves for activity evaluation resulted in false positive results. Specifically, an artificial efficiency of hydrogen production is exaggerated by up to 2.2-fold if the calibration curves are misused, leading to considerably high false positive results. Our study highlights the importance of utilizing the correct calibration curve to ensure a true performance, and is beneficial for fostering advancements in the development of thermal-assisted photocatalysis.
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To overcome the disadvantages of poor intrinsic conductivity and stability of ZnCo2O4, a ZnCo2O4@MnMoO4 composite as an emerging pseudocapacitor electrode material with high specific capacitance, environmental friendliness, morphological diversity, and unique hierarchical structure was synthesized via a simple two-step hydrothermal method. The research results indicate that the ZnCo2O4@MnMoO4 composite can present a high specific capacity of 1628 F g-1 at a current density of 1 A g-1 and good cycling stability with 69% capacity retention after 10 000 cycles at 10 A g-1. Hybrid supercapacitors (HSCs) assembled with the ZnCo2O4@MnMoO4 cathode and activated carbon anode can deliver an energy density of 48 W h kg-1 at a power density of 695 W kg-1, and their capacity retention reached 61% after 8000 charge-discharge cycles at a current density of 10 A g-1. This could be attributed to the synergistic effect of the specific surface area and electrical conductivity enhanced by compositing ZnCo2O4 with MnMoO4. As a result, the excellent electrochemical properties show that the ZnCo2O4@MnMoO4 composite has strong application potential for high-performance supercapacitors.
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There is a significant unmet need for clinical reflex tests that increase the specificity of prostate-specific antigen blood testing, the longstanding but imperfect tool for prostate cancer diagnosis. Towards this endpoint, we present the results from a discovery study that identifies new prostate-specific antigen reflex markers in a large-scale patient serum cohort using differentiating technologies for deep proteomic interrogation. We detect known prostate cancer blood markers as well as novel candidates. Through bioinformatic pathway enrichment and network analysis, we reveal associations of differentially abundant proteins with cytoskeletal, metabolic, and ribosomal activities, all of which have been previously associated with prostate cancer progression. Additionally, optimized machine learning classifier analysis reveals proteomic signatures capable of detecting the disease prior to biopsy, performing on par with an accepted clinical risk calculator benchmark.
Asunto(s)
Biomarcadores de Tumor , Neoplasias de la Próstata , Proteómica , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/sangre , Biomarcadores de Tumor/sangre , Proteómica/métodos , Espectrometría de Movilidad Iónica/métodos , Antígeno Prostático Específico/sangre , Anciano , Aprendizaje Automático , Persona de Mediana EdadRESUMEN
The unprecedented phenomenon that a charge density wave (CDW) emerges inside the antiferromagnetic (AFM) phase indicates an unusual CDW mechanism associated with magnetism in FeGe. Here, we demonstrate that both the CDW and magnetism of FeGe can be effectively tuned through postgrowth annealing treatments. Instead of the short-range CDW reported earlier, a long-range CDW order is realized below 110 K in single crystals annealed at 320 °C for over 48 h. The CDW and AFM transition temperatures appear to be inversely correlated with each other. The onset of the CDW phase significantly reduces the critical field of the spin-flop transition, whereas the CDW transition remains stable against minor variations in magnetic orders such as annealing-induced magnetic clusters and spin-canting transitions. Single-crystal x-ray diffraction measurements reveal substantial disorder on the Ge1 site, which is characterized by displacement of the Ge1 atom from the Fe_{3}Ge layer along the c axis and can be reversibly modified by the annealing process. The observed annealing-tunable CDW and magnetic orders can be well understood in terms of disorder on the Ge1 site. Our study provides a vital starting point for the exploration of the unconventional CDW mechanism in FeGe and of kagome materials in general.
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Exotic quantum states arise from the interplay of various degrees of freedom such as charge, spin, orbital, and lattice. Recently, a short-ranged charge order (CO) was discovered deep inside the antiferromagnetic phase of Kagome magnet FeGe, exhibiting close relationships with magnetism. Despite extensive investigations, the CO mechanism remains controversial, mainly because the short-ranged behavior hinders precise identification of CO superstructure. Here, combining multiple experimental techniques, we report the observation of a long-ranged CO in high-quality FeGe samples, which is accompanied with a first-order structural transition. With these high-quality samples, the distorted 2 × 2 × 2 CO superstructure is characterized by a strong dimerization along the c-axis of 1/4 of Ge1-sites in Fe3Ge layers, and in response to that, the 2 × 2 in-plane charge modulations are induced. Moreover, we show that the previously reported short-ranged CO might be related to large occupational disorders at Ge1-site, which upsets the equilibrium of the CO state and the ideal 1 × 1 × 1 structure with very close energies, inducing nanoscale coexistence of these two phases. Our study provides important clues for further understanding the CO properties in FeGe and helps to identify the CO mechanism.
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GeSe, an analogue of SnSe, shows promise in exhibiting exceptional thermoelectric performance in the Pnma phase. The constraints on its dopability, however, pose challenges in attaining optimal carrier concentrations and improving ZT values. This study demonstrates a crystal structure evolution strategy for achieving highly doped samples and promising ZTs in GeSe via LiBiTe2 alloying. A rhombohedral phase (R3m) can be stabilized in the GeSe-LiBiTe2 system, further evolving into a cubic (Fm3Ì m) phase with a rising temperature. The band structures of GeSe-LiBiTe2 in the rhombohedral and cubic phases feature a similar multiple-valley energy-converged valence band of L and Σ bands. The observed high carrier concentration (â¼1020 cm-3) reflects the effective convergence of these bands, enabling a high density-of-states effective mass and an enhanced power factor. Moreover, a very low lattice thermal conductivity of 0.6-0.5 W m-1 K-1 from 300 to 723 K is achieved in 0.9GeSe-0.1LiBiTe2, approaching the amorphous limit value. This remarkably low lattice thermal conductivity is related to phonon scattering from point defects, planar vacancies, and ferroelectric instability-induced low-energy Einstein oscillators. Finally, a maximum ZT value of 1.1 to 1.3 at 723 K is obtained, with a high average ZT value of over 0.8 (400-723 K) in 0.9GeSe-0.1LiBiTe2 samples. This study establishes a viable route for tailoring crystal structures to significantly improve the performance of GeSe-related compounds.
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The existence of fractionally quantized topological corner charge serves as a key indicator for two-dimensional (2D) second-order topological insulators (SOTIs), yet it has not been experimentally observed in realistic materials. Here, based on effective model analysis and symmetry arguments, we propose a strategy for achieving SOTI phases with in-gap corner states in 2D systems with antiferromagnetic (AFM) order. We discover that the band topology originates from the interplay between intrinsic spin-orbital coupling and interlayer AFM exchange interactions. Using first-principles calculations, we show that the 2D AFM SOTI phase can be realized in (MnBi2Te4)(Bi2Te3)m films. Moreover, we demonstrate that the SOTI states are linked to rotation topological invariants under 3-fold rotation symmetry C3, resulting in fractionally quantized corner charge, i.e., n3|e| (mod e). Due to the great achievements in (MnBi2Te4)(Bi2Te3)m systems, our results providing reliable material candidates for experimentally accessible AFM SOTIs should draw intense attention.
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Being a major obstacle, Ag2Te has always been restricted in p-type AgSbTe2-based materials to improve their thermoelectric performance. This work reveals a stabilized AgSbTe2 through Sn/Ge alloying as synthesized by melting, annealing, and hot press. Interestingly, addition of Sn/Ge in AgSbTe2 extended the solubility limit up to â¼30% and hence suppressed Ag2Te in Ag(1-x)SnxSb(1-y)GeyTe2 compounds and led to enhanced electrical transport. Moreover, electrical and thermal transport properties of AgSbTe2 have been greatly affected by the phase transition of Ag2Te near 425 K. However, high-entropy Ag0.85Sn0.15Sb0.85Ge0.15Te2 compound results in a stabilized rock-salt structure and presents a high power factor of â¼10.8 µW cm-1 K-2 at 757 K. Besides, density functional theory reveals that available multivalence bands in Sn/Ge-doped AgSbTe2 lead to reduction in energy offsets. Meanwhile, a variety of defects appear in the Ag0.85Sn0.15Sb0.85Ge0.15Te2 sample due to entropy change, and thus lattice thermal conductivity decreases. Ultimately, a high figure of merit of â¼1.5 is attained at 757 K. This work demonstrates a roadmap for other group IV-VI materials so that the high-entropy approach may inhibit the impurity phases with extended solubility limit and result in high thermoelectric performance.
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Single atom catalyst (SAC) is one of the most efficient and versatile catalysts with well-defined active sites. However, its facile and large-scale preparation, the prerequisite of industrial applications, has been very challenging. This dilemma originates from the Gibbs-Thomson effect, which renders it rather difficult to achieve high single atom loading (< 3 mol%). Further, most synthesizing procedures are quite complex, resulting in significant mass loss and thus low yields. Herein, a novel metal coordination route is developed to address these issues simultaneously, which is realized owing to the rapid complexation between ligands (e.g., biuret) and metal ions in aqueous solutions and subsequent in situ polymerization of the formed complexes to yield SACs. The whole preparation process involves only one heating step operated in air without any special protecting atmospheres, showing general applicability for diverse transition metals. Take Cu SAC for an example, a record yield of up to 3.565 kg in one pot and an ultrahigh metal loading 16.03 mol% on carbon nitride (Cu/CN) are approached. The as-prepared SACs are demonstrated to possess high activity, outstanding selectivity, and robust cyclicity for CO2 photoreduction to HCOOH. This research explores a robust route toward cost-effective, massive production of SACs for potential industrial applications.
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Non-centrosymmetric topological material has attracted intense attention due to its superior characteristics as compared with the centrosymmetric one, although probing the local quantum geometry in non-centrosymmetric topological material remains challenging. The non-linear Hall (NLH) effect provides an ideal tool to investigate the local quantum geometry. Here, we report a non-centrosymmetric topological phase in ZrTe5, probed by using the NLH effect. The angle-resolved and temperature-dependent NLH measurement reveals the inversion and ab-plane mirror symmetries breaking at <30 K, consistently with our theoretical calculation. Our findings identify a new non-centrosymmetric phase of ZrTe5 and provide a platform to probe and control local quantum geometry via crystal symmetries.
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Recently, metal sulfides have begun to receive attention as potential cost-effective materials for thermoelectric applications beyond optoelectronic and photovoltaic devices. Herein, based on a comparative analysis of the structural and transport properties of 2D PbSnS2 and 1D PbSnS3, we demonstrate that the intrinsic effects that govern the low lattice thermal conductivity (κL) of these sulfides originate from the combination of the low dimensionality of their crystal structures with the stereochemical activity of the lone-pair electrons of cations. The presence of weak bonds in these materials, responsible for phonon scattering, results in inherently low κL of 1.0 W/m K in 1D PbSnS3 and 0.6 W/m K in 2D PbSnS2 at room temperature. However, the nature of the thermal transport is quite distinct. 1D PbSnS3 exhibits a higher thermal conductivity with a crystalline-like peak at low temperatures, while 2D PbSnS2 demonstrates glassy thermal conductivity in the entire temperature range investigated. First-principles density functional theory calculations reveal that the presence of antibonding states below the Fermi level, especially in PbSnS2, contributes to the very low κL. In addition, the calculated phonon dispersions exhibit very soft acoustic phonon branches that give rise to soft lattices and very low speeds of sounds.
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Rechargeable magnesium batteries (RMBs) have garnered significant attention due to their potential to provide high energy density, utilize earth-abundant raw materials, and employ metal anode safely. Currently, the lack of applicable cathode materials has become one of the bottleneck issues for fully exploiting the technological advantages of RMBs. Recent studies on Mg cathodes reveal divergent storage performance depending on the electrolyte formulation, posing interfacial issues as a previously overlooked challenge. This minireview begins with an introduction of representative cathode-electrolyte interfacial phenomena in RMBs, elaborating on the unique solvation behavior of Mg2+, which lays the foundation for interfacial chemistries. It is followed by presenting recently developed strategies targeting the promotion of Mg2+ desolvation in the electrolyte and alternative cointercalation approaches to circumvent the desolvation step. In addition, efforts to enhance the cathode-electrolyte compatibility via electrolyte development and interfacial engineering are highlighted. Based on the abovementioned discussions, this minireview finally puts forward perspectives and challenges on the establishment of a stable interface and fast interfacial chemistry for RMBs.
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Hydrogen production via the photocatalytic water splitting reaction on semiconductors presents a promising avenue to directly achieve solar energy conversion and storage. Bismuth-based semiconductors with layered structures, a hierarchical arrangement of components stacked in the form of two-dimensional extended layers where the atoms within each layer are typically strongly bonded, while the interactions between the layers are relatively weak, have emerged as an important series of photocatalyst candidates. In this review, we focus on the new emerging layered bismuth-based semiconductors with structures in Sillén, Aurivillius, Sillén-Aurivillius and bismuth chromate systems primarily employed in the photocatalytic water splitting reaction. From a crystal structure-oriented view, we delve into discussions on how the component and unit of a crystal structure influence the intrinsic properties, including light absorption and photogenerated charge transfer and separation, of materials as well as the corresponding photocatalytic performance of the water splitting reaction. The strategies for modulating the ferroelectricity and surface modification of these layered bismuth-based semiconductors are also involved. We also discuss the limitations of these materials accompanied by a forward-looking perspective, and we hope to provide some insights from the view of rational material design and engineering for the fabrication of high-efficiency photocatalytic water splitting systems.
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The development of an electrochemical energy storage system with exceptional performance is an important way to address the energy crisis and environmental pollution of the modem world. In this study, an NiCo2O4@MnS composite with a unique hierarchical structure has been successfully synthesized on an NF substrate using the hydrothermal-electrodeposition method. The results indicate that NiCo2O4@MnS possesses superior specific capacitance and excellent cycling stability. At a current density of 2 A g-1, its specific capacitance can reach 2100 F g-1, while the capacitance retention is still 76% after 10 000 cycles at 10 A g-1. Moreover, when the current density is 1 A g-1, the assembled NiCo2O4@MnS//AC device can deliver a specific capacitance of 203 F g-1, and the energy density is up to 55 W h kg-1 at a power density of 697 W kg-1. These outstanding electrochemical properties of NiCo2O4@MnS can be ascribed to the increase in ion diffusion, specific surface area and electronic conductivity due to its unique hierarchical structure and introduction of MnS.
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The development of advanced multi-functional electrocatalysts and their industrial operation on paired electrocatalysis systems presents a promising avenue for the gradual penetration of renewable energy into practical production. Herein, a self-supported conductive network of silverene nanobelts (Ag-ene NBs) was delicately assembled (Ag-NB-NWs), in which ultralong and few-atom-layer Ag-ene NBs with a high edge-to-facet ratio were interconnected, serving as "superreactors" for electron transfer and mass transport during the reaction. Such superstructures as electrocatalysts delivered an unparalleled performance toward the CO2-to-CO conversion with exclusively high faradaic efficiency (FE) and partial current densities of up to 1 A cm-2. Remarkably, the membrane electrode assembly (MEA) cell with Ag-NB-NWs as the cathode was capable of ultrastable and continuous operation for over 240 h at 0.4 A with â¼100% selectivity. More importantly, by further using Ag-NB-NWs as a bifunctional electrocatalyst, a record-low voltage overall CO2 electrolysis system coupling cathodic CO2 reduction with anodic formaldehyde oxidation in MEA cell was performed to achieve concurrent feed gas generation and formate production, substantially improving electrochemical techno-economic feasibility.
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Copper-rich sulfides are very promising for energy conversion applications due to their environmental compatibility, cost effectiveness, and earth abundance. Based on a comparative analysis of the structural and transport properties of Cu3BiS3 with those of tetrahedrite (Cu12Sb4S13) and other Cu-rich sulfides, we highlight the role of the cationic coordination types and networks on the electrical and thermal properties. By precession-assisted 3D electron diffraction analysis, we find very high anisotropic thermal vibration of copper attributed to its 3-fold coordination, with an anisotropic atomic displacement parameter up to 0.09 Å2. Density functional theory calculations reveal that these Cu atoms are weakly bonded and give rise to low-energy Einstein-like vibrational modes that strongly scatter heat-carrying acoustic phonons, leading to ultralow thermal conductivity. Importantly, we demonstrate that the 3-fold coordination of copper in Cu3BiS3 and in other copper-rich sulfides constituted of interconnected CuS3 networks causes a hole blockade. This phenomenon hinders the possibility of optimizing the carrier concentration and electronic properties through mixed valency Cu+/Cu2+, differently from tetrahedrite and most other copper-rich chalcogenides, where the main interconnected Cu-S network is built of CuS4 tetrahedra. The comparison with various copper-rich sulfides demonstrates that seeking for frameworks characterized by the coexistence of tetrahedral and 3-fold coordinated copper is very attractive for the discovery of efficient thermoelectric copper-rich sulfides. Considering that lattice vibrations and carrier concentration are key factors for engineering transport phenomena (electronic, phonon, ionic, etc.) in copper-rich chalcogenides for various types of applications, our findings improve the guidelines for the design of materials enabling sustainable energy solutions with wide-ranging applications.
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Magnesium ion batteries (MIBs) are expected to be the promising candidates in the post-lithium-ion era with high safety, low cost and almost dendrite-free nature. However, the sluggish diffusion kinetics and strong solvation capability of the strongly polarized Mg2+ are seriously limiting the specific capacity and lifespan of MIBs. In this work, catalytic desolvation is introduced into MIBs for the first time by modifying vanadium pentoxide (V2O5) with molybdenum disulfide quantum dots (MQDs), and it is demonstrated via density function theory (DFT) calculations that MQDs can effectively lower the desolvation energy barrier of Mg2+, and therefore catalyze the dissociation of Mg2+-1,2-Dimethoxyethane (Mg2+-DME) bonds and release free electrolyte cations, finally contributing to a fast diffusion kinetics within the cathode. Meanwhile, the local interlayer expansion can also increase the layer spacing of V2O5 and speed up the magnesiation/demagnesiation kinetics. Benefiting from the structural configuration, MIBs exhibit superb reversible capacity (≈300 mAh g-1 at 50 mA g-1) and unparalleled cycling stability (15 000 cycles at 2 A g-1 with a capacity of ≈70 mAh g-1). This approach based on catalytic reactions to regulate the desolvation behavior of the whole interface provides a new idea and reference for the development of high-performance MIBs.
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A NiB binary catalyst with a unique mulberry-like nanoparticle morphology has been prepared by one-step electrodeposition. The NiB-0.2 catalyst exhibits excellent catalytic activity, selectivity, and stability for the borohydride oxidation reaction. Moreover, a direct borohydride fuel cell using the NiB-0.2 catalyst anode can deliver a peak power density of 453 mW cm-2 and open-circuit voltage of 1.96 V at 343 K. The improved performances are due to the introduction of B. This study may inspire the development of efficient noble-metal-free anode catalysts for DBFCs.
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Confronting the challenge of climate change necessitates innovative approaches for the reduction of CO2 emissions. Metal-support interaction has been widely demonstrated to enable greatly improved performances in thermal-catalytic, photocatalytic and electrocatalytic CO2 reduction. However, its applicability and specifically its role in the emerging piezo-electrocatalytic CO2 reduction are unknown, severely hampering the utilizations of piezo-electrocatalysis in CO2 conversion. Herein, by adopting Au particles supported on ZnO (Au/ZnO) as a paradigm, it is found that the metal-support interaction can remarkably improve the separation and transfer of piezo-carriers and enhance CO2 adsorption. As a result, Au/ZnO demonstrates a substantially boosted activity for piezo-electrocatalytic CO2 reduction and the optimal sample exhibits a 37.3% increase in CO yield compared to the pristine ZnO. The integration of metal-support interactions opens a new avenue to the design of advanced piezo-electrocatalysts for CO2 reduction.