13 research outputs found

    Third-order intrinsic anomalous Hall effect with generalized semiclassical theory

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    The linear intrinsic anomalous Hall effect (IAHE) and second-order IAHE have been intensively investigated in time-reversal broken systems. However, as one of the important members of the nonlinear Hall family, the investigation of third-order IAHE remains absent due to the lack of an appropriate theoretical approach, although the third-order extrinsic AHE has been studied within the framework of first- and second-order semiclassical theory. Herein, we generalize the semiclassical theory for Bloch electrons under the uniform electric field up to the third-order using wavepacket method and based on which we predict that the third-order IAHE can also occur in time-reversal broken systems. Same as the second-order IAHE, we find the band geometric quantity, the second-order field-dependent Berry curvature arising from the second-order field-induced positional shift, plays a pivotal role to observe this effect. Moreover, with symmetry analysis, we find that the third-order IAHE, as the leading contribution, is supported by 15 time-reversal broken 3D magnetic point groups (MPGs), corresponding to a wide class of antiferromagnetic (AFM) materials. Guided by the symmetry arguments, a two-band model is chosen to demonstrate the generalized theory. Furthermore, the generalized third-order semiclassical theory depends only on the properties of Bloch bands, implying that it can also be employed to explore the IAHE in realistic AFM materials, by combining with first-principles calculations.Comment: 1 figur

    Topiramate inhibits the proliferation of bladder cancer cells via PI3K/AKTR signaling pathway

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    Purpose: To explore new treatment options for bladder cancer (BC) based on topiramate (TPM).Methods: The MTT assay and flow cytometry were used to determine the effect of topiramate on partial growth-related malignant phenotype of BC cells. Expression levels of apoptosis-related biomarkers and signaling pathway-related factors were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. In vivo experiments were conducted to investigate the role of TPM on tumor growth in mice with bladder cancer.Results: The MTT results showed that topiramate blocked the growth of BC cells (p < 0.05). Growth inhibition was positively correlated with TPM concentration. Flow cytometry results revealed that bladder cancer cell apoptosis rose with increase in TPM concentration, while the mRNAs of apoptosisassociated factors Bcl-2 and Mcl-1 were down-regulated in a concentration-based manner by TPM (p < 0.05). Western blot assay indicated that Bax and Caspase-3 proteins were up-regulated, and the higher the concentration of TPM, the more significant the protein expression levels (p < 0.05).Conclusion: Topiramate (TPM) slows down the rate of growth of BC cells and accelerates their rate of apoptosis through the regulation of P13K/AKT/mTOR signaling pathway. Thus, the compound has potentials for development as an anti-bladder cancer agent

    A Joint Training Dual-MRC Framework for Aspect Based Sentiment Analysis

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    Aspect based sentiment analysis (ABSA) involves three fundamental subtasks: aspect term extraction, opinion term extraction, and aspect-level sentiment classification. Early works only focused on solving one of these subtasks individually. Some recent work focused on solving a combination of two subtasks, e.g., extracting aspect terms along with sentiment polarities or extracting the aspect and opinion terms pair-wisely. More recently, the triple extraction task has been proposed, i.e., extracting the (aspect term, opinion term, sentiment polarity) triples from a sentence. However, previous approaches fail to solve all subtasks in a unified end-to-end framework. In this paper, we propose a complete solution for ABSA. We construct two machine reading comprehension (MRC) problems, and solve all subtasks by joint training two BERT-MRC models with parameters sharing. We conduct experiments on these subtasks and results on several benchmark datasets demonstrate the effectiveness of our proposed framework, which significantly outperforms existing state-of-the-art methods

    Leaching process and kinetics of manganese in low-grade manganese ore

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    Manganese was extracted from leaching low-grade manganese ore in sulfuric acid medium. The effects of granule diameter, leaching time, liquid/solid ratio (V/W) and the concentration of sulfuric acid were investigated through orthogonal and single factor experiments. The experimental results showed that the optimal leaching conditions are, size of 0.054 mm, 120 minutes of reaction time, 3 (V/W) of liquid/solid ratio and 30% of the concentration of sulfuric acid (g/g). Under those conditions, the leaching efficiency is 96.73%. The kinetics of the leaching process is in accordance with the characteristics of fractal reaction

    Effect of R119G Mutation on Human P5CR1 Dynamic Property and Enzymatic Activity

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    Pyrroline-5-carboxylate reductase (P5CR1) is a universal housekeeping enzyme that catalyzes the reduction of Δ1-pyrroline-5-carboxylate (P5C) to proline with concomitant oxidation of NAD(P)H to NAD(P)+. The enzymatic cycle between P5C and proline is important for function in amino acid metabolism, apoptosis, and intracellular redox potential balance in mitochondria. Autosomal recessive cutis laxa (ARCL) results from a mutation in P5CR1 encoded by PYCR1. Specifically, the R119G mutation is reported to be linked to ARCL although it has not yet been characterized. We synthesized R119G P5CR1 and compared it to WT P5CR1. Foldx prediction of WT and R119G mutant P5CR1 protein stability suggests that the R119G mutation could significantly reduce protein stability. We also performed enzymatic activity assays to determine how the mutation impacts P5CR1 enzymatic function. The results of these experiments show that mutagenesis of R119 to G decreases P5CR1 catalytic efficiency for 3,4-dehydro-L-proline relative to WT. Mutagenesis and kinetic studies reveal that the activity of the mutant decreases as temperature increases from 5°C to 37°C, with almost no activity at 37°C, indicating that this mutation impairs P5CR1 function in vivo. Conversely, WT P5CR1 retains its activity after incubation at 37°C and has essentially no remaining activity at 75°C. Taken together, our experimental results indicate the R119G mutation could be an involving pathomechanism for ARCL
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