44 research outputs found

    Efficient non-collinear antiferromagnetic state switching induced by orbital Hall effect in chromium

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    Recently orbital Hall current has attracted attention as an alternative method to switch the magnetization of ferromagnets. Here we present our findings on electrical switching of antiferromagnetic state in Mn3Sn/Cr, where despite the much smaller spin Hall angle of Cr, the switching current density is comparable to heavy metal based heterostructures. On the other hand, the inverse process, i.e., spin-to-charge conversion in Cr-based heterostructures is much less efficient than the Pt-based equivalents, as manifested in the almost one order of magnitude smaller terahertz emission intensity and spin current induced magnetoresistance in Cr-based structures. These results in combination with the slow decay of terahertz emission against Cr thickness (diffusion length of ~11 nm) suggest that the observed magnetic switching can be attributed to orbital current generation in Cr, followed by efficient conversion to spin current. Our work demonstrates the potential of light metals like Cr as an efficient orbital/spin current source for antiferromagnetic spintronics.Comment: 19 pages, 4 figure

    Bandgap engineering of zigzag graphene nanoribbons by manipulating edge states via defective boundaries

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    One of severe limits of graphene nanoribbons (GNRs) in future applications is that zigzag GNRs (ZGNRs) are gapless, so cannot be used in field effect transistors (FETs). In this paper, using tight-binding approach and first principles method, we derived and proved a general edge (boundary) condition for the opening of a significant bandgap in ZGNRs with defective edge structures. The proposed semiconducting GNRs have some interesting properties including the one that they can be embedded and integrated in a large piece of graphene without the need of completely cutting them out. We also demonstrated a new type of high-performance all-ZGNR FET

    Influence of isoniazid on T lymphocytes, cytokines, and macrophages in rats

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    T lymphocytes, cytokines, and macrophages play important roles in the clearance of Mycobacterium tuberculosis (Mtb) by the immune system. This study aimed to investigate the effects of isoniazid on the functions of both innate and adaptive immune cells. Healthy rats were randomly divided into experimental and control groups. Each group was randomly divided into three subgroups and named according to the duration of drug feeding, 1, 3, and 3 months followed by drug withdrawal for 1 month. The experimental groups were fed with isoniazid (12 mg/mL) and the control groups with normal saline. The percentage of CD4+ and CD8+ T lymphocytes, level of interleukin (IL)-12 and interferon (IFN)-γ, and function of macrophages were determined at these three time points. Isoniazid significantly increased the percentage of CD4+ T lymphocytes and the CD4+/CD8+ T lymphocyte cell ratio (P < 0.05). It transiently (<1 month) enhanced the functions of rat macrophages significantly (P < 0.05). In summary, isoniazid could increase the percentage of CD4+ T lymphocytes, CD4+/CD8+ T lymphocyte cell ratio, and enhance macrophage function in healthy rats

    Impact of dyslipidemia on the severity of symptomatic lumbar spine degeneration: A retrospective clinical study

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    BackgroundLumbar intervertebral disc degeneration (IVDD) is an important cause of low back pain or sciatica, and metabolic factors play an important role. However, little is known about the relationship of dyslipidemia to the risk of intervertebral disc degeneration (IVDD). This study aimed to assess the impact of serum lipid levels on the severity of lumbar disc degeneration and to investigate its association with endplate inflammation.MethodsWe conducted a case retrospective study in which a total of 302 hospitalized Chinese patients were recruited, of whom 188 (112 males and 76 females; mean age: 51.66 years) were without underlying disease, while the remaining 114 patients (51 males and 63 females; mean age: 62.75 years) had underlying diseases. We examined fasting serum lipid levels for total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Magnetic resonance imaging (MRI) was used to determine endplate inflammation. Pfirrmann grading and Weishaupt grading were used to evaluate the severity of intervertebral disc degeneration and facet joint degeneration, respectively.ResultsThere was no difference in age, gender, and general BMI between the two groups (P > 0.05), but there were significantly high levels in TC, LDL-C, and LDL-C/HDL-C (P = 0.04, P = 0.013, P = 0.01, respectively). TG and HDL-C showed no significant difference (P = 0.064, P = 0.336, respectively). The multivariate logistic regression model showed that age was a risk factor for the occurrence of endplate inflammation. In the group without underlying diseases, age, but not other indicators, was a risk factor for the occurrence of endplate inflammation (P < 0.01), In the group with underlying diseases, none of the patient indicators was directly related to the occurrence of endplate inflammation (P > 0.05). A nonlinear machine learning model was used to measure the contribution of each factor to the disease outcome and to analyze the effect between the top three contributing factors and the outcome variables. In patients without underlying diseases, the top three factors contributing to the severity grading of intervertebral disc degeneration were age (32.9%), high-density lipoproteins (20.7%), and triglycerides (11.8%). For the severity grading of facet joint degeneration, the top three contributing factors were age (27.7%), high-density lipoproteins (19.4%), and triglycerides (14.6%). For patients with underlying diseases, the top three factors contributing to intervertebral disc degeneration were age (25.4%), BMI (15.3%), and low-density lipoprotein/high-density lipoprotein ratio (13.9%). In terms of degree classification for facet joint degeneration, the top three contributing factors were age (17.5%), BMI (17.2%), and total cholesterol (16.7%).ConclusionThis study shows that age, high-density lipoprotein, and triglycerides affect the degree of degeneration in patients with symptomatic lumbar degeneration without underlying diseases. Age and BMI are two major factors affecting the severity of degeneration in patients with underlying diseases, and dyslipidemia is a secondary factor. However, there is no clear association between dyslipidemia and the occurrence of endplate inflammation in either group

    Financial networks with socially responsible investing

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    In this paper, we develop a framework for the modeling, analysis, and computation of solutions to multitiered financial network problems with socially responsible investment in which both the sources of financial funds as well as the intermediaries are multicriteria decision-makers. We assume that these decision-makers seek not only to maximize their net revenues but also minimize risk with the risk being penalized by a variable weight. Furthermore, we assume that the intermediaries are socially responsible companies, who want to maximize their social responsibility levels. We make explicit the behavior of the various decision-makers, including the consumers at the demand markets for the financial products. We derive the optimality conditions, and demonstrate that the governing equilibrium conditions of the financial network economy can be formulated as a finite-dimensional variational inequality problem. Qualitative properties of the equilibrium financial flow and price pattern are provided. A numerical example is used to illustrate the model

    Approximate weakly efficient solutions of set-valued vector equilibrium problems

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    Abstract In this paper, we introduce a new kind of approximate weakly efficient solutions to the set-valued vector equilibrium problems with constraints in locally convex Hausdorff topological vector spaces; then we discuss a relationship between the weakly efficient solutions and approximate weakly efficient solutions. Under the assumption of near cone-subconvexlikeness, by using the separation theorem for convex sets we establish Kuhn–Tucker-type and Lagrange-type optimality conditions for set-valued vector equilibrium problems, respectively
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