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Dysphagia is one of the most common complications of acute ischemic stroke, and prediction of dysphagia is crucial for post-stroke treatment. We aimed to identify predictors of dysphagia and swallowing function recovery following ischemic stroke and to investigate dysphagia-associated lesion location.We prospectively enrolled patients with acute ischemic stroke confirmed on diffusion-weighted imaging. All patients received swallowing evaluation within 48 h after admission. Follow-up oral intake ability was measured on 7 and 30 days after stroke onset. Voxel-based lesion-symptom mapping was performed to determine locations associated with dysphagia.Of 126 patients included in the final analysis, 23 patients (18.3%) were classified as initial dysphagia. The presence of facial palsy (P = 0.008) and larger white matter hyperintensity (WMH) volume (P = 0.003) was associated with initial dysphagia. Initial risk of aspiration assessed by Any2 score (P = 0.001) at baseline was identified as independent predictor for dysphagia at day 7. Patients with higher Any2 score (P 0.001), aphasia (P = 0.013), and larger WMH volume (P = 0.010) were less likely to have a full swallowing function recovery at 1 month. Acute infarcts in right corona radiata and right superior longitudinal fasciculus were correlated with impaired recovery of swallowing ability at 1 month.Initial risk of aspiration was identified as risk factor for short-term and long-term dysphagia. Aphasia and larger WMH volume were revealed to be significant predictors for swallowing function recovery at 1 month. Right corona radiata was identified as an essential brain area for dysphagia.

Relaxor ferroelectrics have been intensely studied for decades based on their unique electromechanical responses which arise from local structural heterogeneity involving polar nanoregions or domains. Here, we report first studies of the ultrafast dynamics and reconfigurability of the polarization in freestanding films of the prototypical relaxor 0.68PbMg

Magnetism in topological materials creates phases exhibiting quantized transport phenomena with potential technological applications. The emergence of such phases relies on strong interaction between localized spins and the topological bands, and the consequent formation of an exchange gap. However, this remains experimentally unquantified in intrinsic magnetic topological materials. Here, this interaction is quantified in MnBi

Numerical simulations and theoretical analyses predict that forearc ophiolites probably record the end of subduction followed by re-initiation. We report here the results of a field study and new geochronological data that enable identification of the Kermanshah forearc basin, SW Iran. This basin is filled with two terrestrial volcaniclastic successions separated by an Upper Cretaceous reef facies limestone. Early Late Cretaceous ocean island basalts, early Eocene incompatible element-enriched mid-ocean ridge basalts/normal-type mid-ocean ridge basalts and late Eocene arc basalts of the basin indicate that Neotethyan subduction ended during the early Late Cretaceous and then re-initiated during the late Eocene. We suggest that the Neotethyan Ocean between the Iranian and Arabian continents consisted of leading and trailing oceanic plates separated by a mid-ocean ridge (MOR). Subduction of the leading plate generated the Jurassic–Early Cretaceous Sanandaj–Sirjan arc, which was ended by MOR–trench collision. The Zagros late Early Cretaceous forearc ophiolites represent the youngest/hottest segments of the leading plate emplaced during the MOR–trench collision. Subsequently, subduction of the MOR generated the forearc basin and basalts with diverse geochemistry. After c. 60 myr, the cooled trailing plate started to subduct, generating the late Eocene arc basalts. This model has significant implications for investigating and understanding other fossil subduction zones elsewhere in the world. Supplementary material: Supplementary material is available at https://doi.org/10.6084/m9.figshare.c.6086586

Recently various topological polar structures have been discovered in oxide thin films. Despite the increasing evidence of their switchability under electrical or mechanical fields, the dynamic property of an isolated one, which is usually required for applications such as data storage, is still absent as they are always formed as arrays in thin films and evolve together due to strong interactions with their neighbors. Here, we show the controlled nucleation and high mobility of isolated three-fold vertices under an applied electric field. At PbTiO3/SrRuO3 interfaces, nanosized three-fold vertices are formed. A two-unit-cell thick SrTiO3 layer provides critical electrical boundary conditions for the formation of three-fold vertices. Utilizing the SrTiO3 layer and in situ TEM electrical testing system, we found isolated three-fold vertices can move a long distance along the interface under electric fields in a controllable and reversible manner. Microstructural evolution details of the nucleation and propagation of isolated three-fold vertices are further revealed by phase-field simulations. This work demonstrates the high mobility of isolated three-fold vertices, shedding light on the extraordinary dynamic properties of isolated topological polar structures.

The tectonic transition from subduction to collision is a fundamental process during orogenesis, yet the magmatic expression of this transition and related deep geodynamic processes remain unclear. This study focuses on a newly identified volcanic belt within the Moyun–Zaduo–Sulu area of the North Qiangtang Block and presents new zircon U-Pb data that indicate that this belt formed during the Middle Triassic (247–241 Ma), a time characterized by a regional transition from subduction to collisional tectonism. The volcanic belt is located to the south of a Permian to Early Triassic arc and is dominated by high-K calc-alkaline and peraluminous rhyolites. These rhyolites have low Mg#, Nb/Ta, and δEu values, contain low contents of Sr, have high Rb/Sr and whole-rock eNd(t) values, and show positive zircon eHf(t) values, all of which suggest that they formed from magmas generated by the dehydration melting of juvenile crustal material. The migration of Middle Triassic volcanism in this region was most likely caused by rollback of the subducting Longmucuo–Shuanghu Tethyan oceanic slab. Combining our new data with previously published results of numerical modeling of subduction–collisional processes and regional data from north-central Tibet yields insights into the magmatic expressions and related deep geodynamics of the transition from oceanic subduction to continental collision. This combination of data also suggests that variations in oxygen fugacity can be used as a proxy for the discrimination of magmatism related to subduction, the transition from subduction to collision, and collisional tectonism.

Strain-mediated magnetoelectric effect can be utilized as an energy-efficient approach for spin manipulation. However, over 90° magnetization rotation is still challenging in un-patterned magnetic films, as the piezo-strain driven by ferroelectric domain switching is generally uniaxial rather than unidirectional, which limits the developments of non-volatile magnetic memory and logic devices. Here we demonstrate the rotation of local magnetization with a large angle of 136° by applying strains with a shear component at a fixed magnetic field of 45 Oe in FeCoSiB/PMN-PT (011) multiferroic heterostructures, revealed by a vector-resolved quantitative magneto-optical Kerr effect (MOKE) microscopy. Phase-field simulations confirm that the approximate 140° rotation of magnetization vectors is a consequence of the shear strain associated with ferroelectric/ferroelastic switching of PMN-PT (011) substrates. The visualization of over 90° magnetization rotation induced by the strain with a shear component paves the way for deterministic magnetization switching that has important implications in the energy-efficient spintronic devices.

Simple strain enhancement Piezoelectric materials are important as sensors and transducers for applications such as ultrasonics. Liu et al. discovered nanopillar regions in a sodium-niobium-oxide film that substantially improve the piezoelectric properties (see the Perspective by Bassiri-Gharb). These nanopillar regions reverse where the cations and anions are located in the crystal structure, with a distinctive boundary in between. This difference in structure results in a strain-sensitive polarity that enhances the piezoelectric properties in a chemically simple material. Science this issue p. 292 ; see also p. 252

Porous tetragonal PbTiO3 nanowires, synthesized through an intermediate pre-perovskite structure, exhibit distinct behaviors from those of the corresponding bulk PbTiO3. Here we investigate the role of nanopores in the ferroelectric, dielectric, and piezoelectric properties of ferroelectric PbTiO3 nanowires employing phase-field simulations. It is found that the presence of pores gives rise to large enhancements in both dielectric constant and piezoelectric coefficient by ~50% and 30%, respectively, compared with those of the bulk PbTiO3. It is shown that the smaller the pore size is, the higher the dielectric and piezoelectric responses of the nanowire are. A charge compensation mechanism is proposed to explain the experimentally measured change of oxygen ions concentration at the pore surfaces. The findings provide in-depth insights into modulation of material properties through nanopores.

While extensive experimental activities have been carried out to study the phase transitions and ferroelectric properties of BaZrxTi1-xO3 solid solutions, the corresponding theoretical understanding is largely lacking due to the unavailability of thermodynamic potentials for this system. In this work, an eighth-order polynomial of thermodynamic potential for BaZrxTi1-xO3 (x≤0.3) solid solutions is established based on the existing potential coefficients of BaTiO3 and theexperimentally measured phase diagram of BaZrxTi1-xO3 solid solutions. It is then employed to predict and understand the domain structures and switching for BaZrxTi1-xO3 (x ≤0.3) single crystals using phase-field simulations. The simulated domain structures and switching are consistent with thermodynamic analysis and available experimental measurements, validating the established thermodynamic potential. It is expected that this thermodynamic potential will find wide applications to studying the phase transitions and ferroelectric properties of BaZrxTi1-xO3 (x ≤0.3) bulk and nanoscale materials.

There has been a surge of interest in applying deep learning (DL) to microstructure generation and materials design. However, existing DL-based methods are generally limited in generating (1) microstructures with high resolution, (2) microstructures with high variability, (3) microstructures with guaranteed periodicity, and (4) highly controllable microstructures. In this study, a DL approach based on a stacked generative adversarial network (StackGAN-v2) is proposed to overcome these shortcomings. The presented modeling approach can reconstruct high-fidelity microstructures of additively manufactured piezoceramics with different resolutions, which are statistically equivalent to original microstructures either experimentally observed or numerically predicted. Advantages of the proposed modeling approach are also illustrated in terms of its capability in controlling the probability density function (PDF) of grain size, grain orientation, and micropore in a large space, which would have significant benefits in exploring the effects of these microstructure features on the piezoelectricity of piezoceramics. In the meantime, periodicity of the microstructures has been successfully introduced in the developed model, which can critically reduce the simulation volume to be considered as a representative volume element (RVE) during computational calculation of piezoelectric properties. Therefore, this DL approach can significantly accelerate the process of designing optimal microstructures when integrating with computational methods (e.g., fast Fourier spectral iterative perturbation (FSIPM)) to achieve desired piezoelectric properties. The proposed DL-based method is generally applicable to optimal design of a variety of periodic microstructures, allowing for maximum explorations of design spaces and fine manipulations of microstructural features.

The dynamics of extended objects such as domain walls, domain bubbles, vortex structures, etc., can be described by their equations of motion associated with their effective mass and spring constant. Here we analytically derive the equations of motion for the polarization dynamics and elastodynamics for the structural responses of ferroelectric polar vortices, and theoretically extract their effective mass, spring constant, and mode frequencies. We demonstrate two subterahertz phonon modes and predicted their frequencies, both consistent with our recent experimental measurements and phase-field simulations. We show that elastic modulation of the energy function and spring constants leads to a condensation of a collective mode upon a second-order structural transition from symmetric to asymmetric vortices at a critical strain, analogous to the ferroelectric soft phonon mode at a ferroelectric transition. The present work offers a theoretical framework for predicting and manipulating the ultrafast collective dynamics of polar nanostructures.

The collective dynamics of topological structures1-6 are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions3,4 have not only deepened our understanding of many-body physics but also offered potential applications in data processing and storage7. Topological structures constructed from electrical polarization, rather than electron spin, have recently been realized in ferroelectric superlattices5,6, and these are promising for ultrafast electric-field control of topological orders. However, little is known about the dynamics underlying the functionality of such complex extended nanostructures. Here, using terahertz-field excitation and femtosecond X-ray diffraction measurements, we observe ultrafast collective polarization dynamics that are unique to polar vortices, with orders-of-magnitude higher frequencies and smaller lateral size than those of experimentally realized magnetic vortices3. A previously unseen tunable mode, hereafter referred to as a vortexon, emerges in the form of transient arrays of nanoscale circular patterns of atomic displacements, which reverse their vorticity on picosecond timescales. Its frequency is considerably reduced (softened) at a critical strain, indicating a condensation (freezing) of structural dynamics. We use first-principles-based atomistic calculations and phase-field modelling to reveal the microscopic atomic arrangements and corroborate the frequencies of the vortex modes. The discovery of subterahertz collective dynamics in polar vortices opens opportunities for electric-field-driven data processing in topological structures with ultrahigh speed and density.

Understanding magnetic domain structures and their responses to electric fields in multiferroic heterostructures is critical to the design of electric-field-driven spintronic devices. High-throughput finite-element and phase-field simulations are performed to probe the piezoelectric strain anisotropy and its relaxation, magnetic domain structures and their responses to applied voltages as function of the in-plane dimensions and thickness of the magnetic Ni nanoislands grown on a Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) membrane. The piezoelectric strain anisotropy is found to increase with the in-plane aspect ratio, but it can be significantly relaxed, as large as >80%, in nanoislands of thickness larger than >15 nm. Magnetic domain diagrams are established to identify the domain structures for Ni nanoislands of different lengths of in-plane major and minor axis, as well as thickness. When a voltage is applied to the multiferroic heterostructure, the single-domain magnetic domain can be switched by the piezoelectric strain, whereas the vortex domain is not switched. However, for a multiferroic heterostructure with a thick nanoisland wherein most of the piezoelectric strain is relaxed, the single-domain magnetic domain shows a weak response to the voltage and cannot be switched. The effect of thickness variation in real magnets on the switching is also discussed. The present results are expected to provide guidance to the understanding and design of multiferroic nanostructures for achieving electric-field-modulated magnetic properties.

Light-rare-earth-based Pr ( Fe 1 - x Si x ) 1.93 alloys ( 0 ⩽ x ⩽ 0.1 ) with pure cubic Laves phase were synthesized by high-pressure annealing method. Si substitution effects on magnetic, electrical and magnetostrictive properties of light-rare-earth-based Pr ( Fe 1 - x Si x ) 1.93 alloys were systematically investigated. It was found that the lattice parameter a and Curie temperature T C of the cubic Laves phase in the alloys increase with the increasing Si content up to x = 0.05 , which might be ascribed to the preferential occupation of Si in the Laves phase interstitial sites. The magnetization at the maximum available field of 15 kOe, σ 15 k , decreases monotonically with the increasing x. A significant increase of 67% in electrical resistivity was observed in Pr ( Fe 0.9 Si 0.1 ) 1.93 alloy at room temperature. The magnetostriction at the field of 3 kOe of Pr ( Fe 0.95 Si 0.05 ) 1.93 is about 542 ppm, which is even larger than the saturation magnetostriction of heavy-rare-earth-based Tb 0.2 Dy 0.22 Ho 0.58 Fe 2 single crystal ( λ s = 530 ppm). The attractive price, lower eddy current loss, together with high magnetostrictive response suggest that the Pr ( Fe 0.95 Si 0.05 ) 1.93 alloy might be a good candidate material for the potential magnetostrictive applications.

Voluminous Jurassic granitoids within the Sanandaj–Sirjan Zone (SSZ) provide insight into the magmatic arc formed in the active margin of Eurasia. Here, we present new in situ zircon U–Pb, whole-rock major and trace element, and Sr–Nd isotopic data for the Gorveh Plutonic Complex (GPC) of the northwestern SSZ in Iran. Six samples from the plutons within the GPC yielded zircon U–Pb ages that range from 151 to 146 Ma. These plutons can be subdivided into two groups based on their geochemistry. Group 1 rocks (the Mobarak Abad diorites and the Gorveh gabbros and diorites) contain relatively high concentrations of the high field strength elements (HFSE; Nb, Ta, Zr, and Ti) and have low Th/Nb (0.20–0.56) and moderate Sm/Yb ratios (1.51–2.32), low (87Sr/86Sr)i values (0.70354–0.70622), and high eNd(t) values (2.3–5.4). These features indicate that the Group 1 rocks formed from magmas derived from a subduction-modified region of the subcontinental lithospheric mantle. The Group 2 plutons (the Bolban Abad granites and the Gorveh quartz monzonites) have A-type granites affinities, including high K2O + Na2O and Zr + Nb + Ce + Y concentrations, and high FeOtot/MgO and 10,000 × Ga/Al ratios. These A-type rocks are enriched in Rb, Th, and K, and depleted in Ba, U, Nb, Ta, Sr, P, and Ti. The Group 2 plutons have different Sr–Nd isotopic compositions to each other, indicating they were derived from different sources and record different igneous processes. The Gorveh quartz monzonites have high (87Sr/86Sr)i ratios (0.70552–0.70617), negative eNd(t) values (−1.1 to −5.4), and extremely low concentrations of MgO (0.32–0.35 wt%), suggesting they were derived from an igneous quartzo-feldspathic crustal source. In comparison, the Bolban Abad granites have positive eNd(t) values and contain high concentrations of SiO2 and low concentrations of MgO, suggesting that they formed from Group 1 magmas that subsequently underwent assimilation and fractional crystallization processes. Combining these new data with the results of previous research, we conclude that this Jurassic magmatism was the result of the formation of a slab window within the subducting Neo-Tethys slab, a process that caused the partial melting of overlying continental lithospheric material.

Domain wall motion in ferroics, similar to dislocation motion in metals, can be tuned by well-concepted microstructural elements. In demanding high-power applications of piezoelectric materials, the domain wall motion is considered as a lossy hysteretic mechanism that should be restricted. Current applications for so-called hard piezoelectrics are abundant and hinge on the use of an acceptor-doping scheme. However, this mechanism features severe limitations due to enhanced mobility of oxygen vacancies at moderate temperatures. By analogy with metal technology, the authors present here a new solution for electroceramics, where precipitates are utilized to pin domain walls and improve piezoelectric properties. Through a sequence of sintering, nucleation, and precipitate growth, intragranular precipitates leading to a fine domain structure are developed as shown by transmission electron microscopy, piezoresponse force microscopy, and phase-field simulation. This structure impedes the domain wall motion as elucidated by electromechanical characterization. As a result, the mechanical quality factor is increased by ≈50% and the hysteresis in electrostrain is suppressed considerably. This is even achieved with slightly increased piezoelectric coefficient and electromechanical coupling factor. This novel process can be smoothly implemented in industrial production processes and is accessible to simple laboratory experimentation for microstructure optimization and implementation in various ferroelectric systems.

By analyzing the text of maker space policy, it is helpful to understand the logic of policy expression and evolution. The co-word analysis method, ROSTCM6.0 and Netdraw systems are used to compare and analyze 81 policy texts with Beijing, Hubei, Sichuan and Jilin as typical representatives. The study found that different regional policy texts have basically the same policy value orientation in terms of service awareness, platform construction, fiscal and taxation policies, etc., while the differentiation level is manifested in incorporating regional resource endowment into the expression of policy texts, thus highlighting advantages and forming social influence. The research conclusion provides empirical evidence for further improving maker space policy.

A joint subduction of the oceanic-continental plates exerts primary controls on the tectonomagmatic activities alongside trench-perpendicular ocean-continental transitional (OCT) belts (i.e., passive continental margin). Such OCT belts with a rheological boundary trigger substantial great crustal density contrast since lateral pressure gradients create where a mature oceanic lithosphere terminate against a thicker continental lithosphere. This study investigates the conjunction between the southernmost segment of the ~1500-km-long, NW–SE-trending Yushu–Yidun Arc Belt and the NE–SW trending Longmen Shan Fault system in southeastern Tibet, to explore the interaction of these two large-scale linear structures. A compilation of geological evidence reveals that an OCT belt previously defined the Longmen Shan Fault, separating the South China Continent from the Garze–Litang Ocean. During the southwestward subduction of the Garze-Litang oceanic lithosphere, this OCT belt which lies on the southeastern edge was reacted with the subduction of the oceanic lithosphere, and subsequently induced slab tearing of its subduction front causing the upwelling of the asthenosphere. This model interprets favorably the intriguing geology of the triangle-shaped Songpan–Garze–Hoh Xil terrane as well as the generation of the Late Triassic enriched mid-ocean ridge basalts or ocean island basalts (EOB) at the southernmost segment of the Yushu–Yidun Arc Belt, where the asthenosphere-sourced mafic lavas are tightly intercalated with normal arc-like igneous rocks in a continental arc.

The ~1500 km, N-NW-trending Yushu-Yidun arc magmatic belt delineate the configuration of the subducted Paleo-tethys oceanic lithosphere in the central-eastern Tibetan Plateau. In its southern termination, not only widespread Late Triassic arc-like rocks but also contemporary minor volume E-MORB/OIB-like basalts (EOB) and porphyry Cu (± Mo ± Au) deposits developed within northern of the southwest extension of the Longmenshan Fault (LF). Above special magmatic-tectonic- metallogenic coupling, combining with the contemporary dextral sliding deformation of the LF and the northeast-southwest striking granitic belt occurred in the northwest of its, is most likely related with the active proto-LF, which is considered as a weakened conservative plate boundary between the subducted Garze-Litang oceanic slab and Yangtze craton. Upwelling of asthenospheric mantle along the subducted conservative boundary experienced decompressive partial melting and formed the parental melts of EOB, which triggered to partial melting of the subducted-slab and the metasomatized mantle-wedge and formed the ore-bearing melts and the arc-like andesites, respectively.

A joint subduction of the oceanic-continental plates exerts primary controls on the tectonomagmatism alongside trench-perpendicular ocean-continental transitional (OCT) belts. Such OCT belts trigger substantial crustal density contrasts since lateral pressure gradients create where a mature oceanic lithosphere terminates against a thicker continental lithosphere. This study investigates the conjunction between the southernmost Yushu–Yidun Arc belt and the Longmen Shan Fault system in northeastern Tibetan Plateau, exploring the interaction of these two large-scale linear structures. Geological evidences compiled reveals that an OCT belt previously defined the Longmen Shan Fault, separating the South China Continent from the Garze–Litang Ocean. This OCT belt lying on the southeastern edge reacted with the subducted Garze–Litang oceanic lithosphere with subsequently tearing of its subduction front causing the upwelling of asthenosphere. This model plausibly interprets the distinctive magmatism in the study region, where the asthenosphere-sourced mafic lavas are tightly intercalated with normal arc-like igneous rocks.