167 research outputs found

    Memory Performance Characterization of SPEC CPU2006 Benchmarks Using TSIM

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    AbstractThis paper uses TSIM, a cycle accurate architecture simulator, to characterize the memory performance of SPEC CPU2006 Benchmarks under CMP platform. The experiment covers 54 workloads with different input sets, and collects statistical information of instruction mixture and cache behaviors. By detecting the cyclical changes of MPKI, this paper clearly shows the memory performance phases of some SPEC CPU2006 programs. These performance data and analysis results can not only help program developers and architects understand the memory performance caused by system architecture better, but also guide them in software and system optimization

    Development of a novel detection technology for drug resistance mutation sites of Mycobacterium tuberculosis using Luminex liquid chip technology

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    Purpose: To develop a novel detection technology for drug-resistance mutation sites of Mycobacterium tuberculosis (MTB) using a Luminex liquid chip.Methods: Using polymerase chain reaction (PCR) amplification and hybridization analysis, MTB infection and drug-resistant mutation sites of the first-line and second-line anti-MTB drugs were simultaneously identified. A novel detection method was applied to analyze the wild-type standard strains of MTB and 33 clinical samples, and the results were compared with Sanger sequencing results for PCR products.Results: It was revealed that the sensitivity (100 %) and specificity (100 %) of the novel detection method for 31 samples were satisfactory, and all mutation sites were correctly detected. Compared with traditional PCR and culture-based drug sensitivity test, the novel detection method increased the speed of identification of drug-resistant TB, reduced clinicians' workload, and decreased treatment cost. Among 31 samples, 12.90 % were resistant to isoniazid (4/31), 35.48 % to rifampicin (11/31), and 12.90 % to ofloxacin (p < 0.05). Furthermore, 2 (6.45 %) samples were resistant to both isoniazid and rifampicin, 2 (6.45 %) samples to both rifampicin and ofloxacin, and 1 (3.22 %) sample to both isoniazid and ofloxacin, and 1 (3.22%) sample to all the three drugs (p < 0.05).Conclusion: Development and wide application of this novel detection method will facilitate the treatment of MTB, thus reducing the spread of drug-resistant MTB, and improving the prevention and treatment of MTB

    1,4-Bis(imidazol-1-yl)benzene–terephthalic acid (1/1)

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    In the title compound, C12H10N4·C8H6O4, 1,4-bis­(imidazol-1-yl)benzene and terephthalic acid mol­ecules are joined via strong O—H⋯N hydrogen bonds to form infinite zigzag chains. Both mol­ecules are located on crystallographic inversion centers. The O—H⋯N hydrogen-bonded chains are assembled into two-dimensional layers through weak C—H⋯O and strong π–π stacking inter­actions [centroid–centroid distance = 3.818 (2) Å], leading to the formation of a three-dimensional supra­molecular structure

    Skyrmion-Bubble Bundles in an X-type Sr2Co2Fe28O46 Hexaferrite above Room Temperature

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    Magnetic skyrmions are spin swirls that possess topological nontriviality and are considered particle-like entities. They are distinguished by an integer topological charge Q. The presence of skyrmion bundles provides an opportunity to explore the range of values for Q, which is crucial for the advancement of topological spintronic devices with multi-Q properties. In this study, we present a new material candidate, Sr2Co2Fe28O46 hexaferrite of the X-type, which hosts small dipolar skyrmions at room temperature and above. By exploiting reversed magnetic fields from metastable skyrmion bubbles at zero fields, we can incorporate skyrmion-bubble bundles with different interior skyrmion/bubble numbers, topological charges, and morphologies at room temperature. Our experimental findings are consistently supported by micromagnetic simulations. Our results highlight the versatility of topological spin textures in centrosymmetric uniaxial magnets, thereby paving the way for the development of room-temperature topological spintronic devices with multi-Q characteristics.Comment: https://doi.org/10.1002/adma.20230611

    Deterministic generation of skyrmions and antiskyrmions by electric current

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    Magnetic skyrmions are nanoscale spin whirlpools that promise breakthroughs in future spintronic applications. Controlled generation of magnetic skyrmions by electric current is crucial for this purpose. While previous studies have demonstrated this operation, the topological charge of the generated skyrmions is determined by the direction of the external magnetic fields, thus is fixed. Here, we report the current-induced skyrmions creation in a chiral magnet FeGe nanostructure by using the \emph{in-situ} Lorentz transmission electron microscopy. We show that magnetic skyrmions or antiskyrmions can be both transferred from the magnetic helical ground state simply by controlling the direction of the current flow at zero magnetic field. The force analysis and symmetry consideration, backed up by micromagnetic simulations, well explain the experimental results, where magnetic skyrmions or antiskyrmions are created due to the edge instability of the helical state in the presence of spin transfer torque. The on-demand generation of skyrmions and control of their topology by electric current without the need of magnetic field will enable novel purely electric-controlled skyrmion devices.Comment: 5 pages and 4 figure

    Observation of Hybrid Magnetic Skyrmion Bubbles in Fe3Sn2 Nanodisks

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    It is well known that there are two types of magnetic bubbles in uniaxial magnets. Here, using Lorentz-transimission electronic microscopy magnetic imaging, we report the direct experimental observation of 3D type-III hybrid bubbles, which comprise N\'eel-twisted skyrmion bubbles with topological charge Q = -1 in near-surface layers and type-II bubbles with Q = 0 in interior layers, in Fe3Sn2 nanodisks. Using the tilted magnetic field, we further show the controlled topological magnetic transformations of three types of bubbles in a confined ferromagnetic nanodisk. Our observations are well reproduced using micromagnetic simulations based on measured magnetic parameters. Our results advance fundamental classification and understanding of magnetic bubbles, which could propel the applications of three-dimensional magnetism.Comment: https://doi.org/10.1103/PhysRevB.107.17442

    Current-Controlled Skyrmion Number in Confined Ferromagnetic Nanostripes

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    Skyrmions are vortex-like localized magnetic structures that possess an integer-valued topological index known as the skyrmion number or topological charge. Skyrmion number determines the topology-related emergent magnetism, which is highly desirable for advanced storage and computing devices. In order to achieve device functions, it is necessary to manipulate the skyrmion number in confined nanostructured geometries using electrical methods. Here, we report the reliable current-controlled operations for manipulating the skyrmion number through reversible topological transformations between skyrmion chains and stripe domains in confined Fe3Sn2 nanostripes. The results of micromagnetic simulations are successful in numerically reproducing our experiments and explaining them through the combined effect of current-induced Joule heating and magnetic hysteresis. These findings hold the potential to advance the development of topological spintronic devices.Comment: https://doi.org/10.1002/adfm.20230404

    Application of extracorporeal membrane oxygenation to adults with cardiogenic shock and cardiac arrest in hospital

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    Objective·To assess the effect of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment on the mortality rate of patients suffering from cardiogenic shock and cardiac arrest in hospital.Methods·A total of 19 patients with cardiogenic shock or cardiac arrest who were treated with VA-ECMO treatment in Suzhou Kowloon Hospital, Shanghai Jiao Tong University School of Medicine from September 2017 to March 2022 were included in the retrospective study. Patients were divided into extracorporeal cardiopulmonary resuscitation (ECPR) group (n=9) and VA-ECMO for cardiogenic shock (E-CS) group (n=10) according to whether cardiac arrest had occurred. The general demographic data, clinical data, Sequential Organ Failure Assessment (SOFA) scores, postoperative complications and prognostic indicators of the two groups of patients were collected. Univariate and multivariate Cox proportional hazard regression analyses were used to evaluate the correlation between each covariate and hospital mortality.Results·Among the included patients, there were 15 males (78.9%), with an average age of 46.5 (34.5, 61.6) years. The incidence of postoperative complications was as follows: bleeding (47.4%), AKI (36.8%), infection (31.6%), limb ischemia (15.8%) and cerebrovascular accident (5.3%). The duration of VA-ECMO was 4.0 (2.0, 6.8) days, and the intensive care duration was 11.5 (5.8, 26.2) days; the ECMO withdrawal success rate was 63.2%, and the hospital mortality was 63.2%. The results of univariate Cox proportional hazard regression analysis showed that AKI (prior to VA-ECMO initiation), postoperative complications of infection and limb ischemia were correlated with the hospital mortality of patients (all P<0.05). The results of multivariate Cox proportional hazard regression analysis showed that AKI (prior to VA-ECMO initiation), postoperative complications of infection and limb ischemia were also independent risk factors for the hospital mortality of patients (all P<0.05).Conclusion·For patients with cardiogenic shock and cardiac arrest treated with VA-ECMO, AKI (prior to VA-ECMO initiation), postoperative infection and limb ischemia are independently associated with higher hospital mortality
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