491 research outputs found

    Anomalous Nernst effect in compensated ferrimagnetic CoxGd1-x films

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    The anomalous Nernst effect (ANE) is one of the most intriguing thermoelectric phenomena which has attracted growing interest both for its underlying physics and potential applications. Typically, a large ANE response is observed in magnets with pronounced magnetizations or nontrivial Berry curvature. Here, we report a significant ANE signal in compensated ferrimagnetic CoxGd1-x alloy films, which exhibit vanishingly small magnetization. In particular, we found that the polarity of ANE signal is dominated by the magnetization orientation of the transition metal Co sublattices, rather than the net magnetization of CoxGd1-x films. This observation is not expected from the conventional understanding of ANE but is analogous to the anomalous Hall effect in compensated ferrimagnets. We attribute the origin of ANE and its Co-dominant property to the Co-dominant Berry curvature. Our work could trigger a more comprehensive understanding of ANE and may be useful for building energy-harvesting devices by employing ANE in compensated ferrimagnets

    Electric field-induced creation and directional motion of domain walls and skyrmion bubbles

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    Magnetization dynamics driven by an electric field could provide long-term benefits to information technologies because of its ultralow power consumption. Meanwhile, the Dzyaloshinskii-Moriya interaction in interfacially asymmetric multilayers consisting of ferromagnetic and heavy-metal layers can stabilize topological spin textures, such as chiral domain walls, skyrmions, and skyrmion bubbles. These topological spin textures can be controlled by an electric field, and hold promise for building advanced spintronic devices. Here, we present an experimental and numerical study on the electric field-induced creation and directional motion of topological spin textures in magnetic multilayer films and racetracks with thickness gradient and interfacial Dzyaloshinskii-Moriya interaction at room temperature. We find that the electric field-induced directional motion of chiral domain wall is accompanied with the creation of skyrmion bubbles at certain conditions. We also demonstrate that the electric field variation can induce motion of skyrmion bubbles. Our findings may provide opportunities for developing skyrmion-based devices with ultralow power consumption.Comment: 26 pages, 6 figure

    One-stop interventional procedure for bicuspid aortic stenosis in a patient with coexisting aortic coarctation: a case report

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    IntroductionCoarctation of the aorta (CoA) is usually diagnosed and corrected early in life. Most untreated patients with CoA usually die before 50 years of age. Adult patients with concomitant CoA and severe bicuspid aortic stenosis are relatively rare and present complex management challenges without standard guidelines.Case summaryA 63-year-old female patient with uncontrolled hypertension was admitted due to chest pain and dyspnea upon exertion (NYHA grades III). Echocardiogram showed a severely calcified and stenotic bicuspid aortic valve (BAV). A severe stenotic calcified eccentric aortic coarctation 20 mm distal to the left subclavian artery (LSA) was discovered by computed tomography (CT) angiography. Following consultation with the cardiac team and patient willingness, we performed a one-stop interventional procedure to repair both defects. First, a cheatham-platinum (CP) stent was implanted via the right femoral access, immediately distal to the LSA. Due to the markedly twisted and angled descending aortic arch, we chose to perform transcatheter aortic valve replacement (TAVR) via the left common carotid artery. The patient was discharged and followed up for 1 year without symptoms.DiscussionAlthough surgery is still the main treatment for these diseases, it is not suitable for high-risk surgical patient. Transcatheter intervention for patients with severe aortic stenosis complicated with CoA simultaneously is rarely reported. The success of this procedure depends on the patient's vascular condition, the skills of the heart team, and the availability of the technical platform.ConclusionOur case report demonstrates the feasibility and efficacy of a one-stop interventional procedure in an adult patient with concurrent severely calcified BAV and CoA via two different vascular approaches. Transcatheter intervention, in contrast to traditional surgical approaches or two-stop interventional procedures, as a minimally invasive and novel method, offers a wider range of therapeutic methods for such diseases

    Morphology of the medial collateral ligament of the knee

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    <p>Abstract</p> <p>Background</p> <p>Quantitative knowledge on the anatomy of the medial collateral ligament (MCL) is important for treatment of MCL injury and for MCL release during total knee arthroplasty (TKA). The objective of this study was to quantitatively determine the morphology of the MCL of human knees.</p> <p>Methods</p> <p>10 cadaveric human knees were dissected to investigate the MCL anatomy. The specimens were fixed in full extension and this position was maintained during the dissection and morphometric measurements. The outlines of the insertion sites of the superficial MCL (sMCL) and deep MCL (dMCL) were digitized using a 3D digitizing system.</p> <p>Results</p> <p>The insertion areas of the superficial MCL (sMCL) were 348.6 ± 42.8 mm<sup>2 </sup>and 79.7 ± 17.6 mm<sup>2 </sup>on the tibia and femur, respectively. The insertion areas of the deep MCL (dMCL) were 63.6 ± 13.4 mm<sup>2 </sup>and 71.9 ± 14.8 mm<sup>2 </sup>on the tibia and femur, respectively. The distances from the centroids of the tibial and femoral insertions of the sMCL to the tibial and femoral joint line were 62.4 ± 5.5 mm and 31.1 ± 4.6 mm, respectively. The distances from the centroids of dMCL in the tibial insertion and the femoral insertion to the tibial and femoral joint line were 6.5 ± 1.3 mm and 20.5 ± 4.2 mm, respectively. The distal portion of the dMCL (meniscotibial ligament - MTL) was approximately 1.7 times wider than the proximal portion of the dMCL (meniscofemoral ligament - MFL), whereas the MFL was approximately 3 times longer than the MTL.</p> <p>Conclusions</p> <p>The morphologic data on the MCL may provide useful information for improving treatments of MCL-related pathology and performing MCL release during TKA.</p

    Effects of Fat Composition and Crystallization Characteristics on the Quality and Whipping Performance of Cream

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    In order to establish the internal relationship between the composition and crystallization characteristics of fat and the product quality and whipping properties, the fat composition and crystallization characteristics, emulsion quality, whipped product quality and whipping properties of dairy, non-dairy and mixed creams were analyzed in this study. The results showed that the crystal network formed by mixed animal and vegetable fats had a dense structure and high susceptibility to shear-induced partial aggregation, the resulting emulsion had high viscosity and low overrun, while the whipped product had high hardness and moderate conformal capacity. However, the crystallization properties of vegetable fat were opposite to those of mixed animal and vegetable fats, and the susceptibility to shear-induced partial aggregation was low. The vegetable cream emulsion had low viscosity and high overrun, whereas the whipped product has low hardness and the best conformal capacity. Animal fat had the lowest solid fat content, resulting in the weakest crystal network structure; the rate of partial aggregation, viscosity and overrun of the resulting emulsion were the lowest, and the whipped product had the lowest hardness and conformal capacity. Therefore, the product quality and whipping performance can be controlled by regulating the fat composition and crystallization characteristics. This study can provide theoretical guidance for the development of high-quality whipped cream

    Skyrmions in nanorings: a versatile platform for Skyrmionics

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    The dynamical properties of skyrmions can be exploited to build devices with new functionalities. Here, we first investigate a skyrmion-based ring-shaped device by means of micromagnetic simulations and Thiele equation. We subsequently show three applications scenarios: (1) a clock with tunable frequency that is biased with an electrical current having a radial spatial distribution, (2) an alternator, where the skyrmion circular motion driven by an engineered anisotropy gradient is converted into an electrical signal, and (3) an energy harvester, where the skyrmion motion driven by a thermal gradient is converted into an electrical signal, thus providing a heat recovery operation. We also show how to precisely tune the frequency and amplitude of the output electrical signals by varying material parameters, geometrical parameters, number and velocity of skyrmions, and we further prove the correct device functionality under realistic conditions given by room temperature and internal material defects. Our results open a new route for the realization of energy efficient nanoscale clocks, generators, and energy harvesters
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