534 research outputs found

    Effect of nematic order on the low-energy spin fluctuations in detwinned BaFe1.935_{1.935}Ni0.065_{0.065}As2_2

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    The origin of nematic order remains one of the major debates in iron-based superconductors. In theories based on spin nematicity, one major prediction is that the spin-spin correlation length at (0,Ï€\pi) should decrease with decreasing temperature below the structural transition temperature TsT_s. Here we report inelastic neutron scattering studies on the low-energy spin fluctuations in BaFe1.935_{1.935}Ni0.065_{0.065}As2_2 under uniaxial pressure. Both intensity and spin-spin correlation start to show anisotropic behavior at high temperature, while the reduction of the spin-spin correlation length at (0,Ï€\pi) happens just below TsT_s, suggesting strong effect of nematic order on low-energy spin fluctuations. Our results favor the idea that treats the spin degree of freedom as the driving force of the electronic nematic order.Comment: 5 pages, 4 figure

    DEM simulation and experimental study on the screening process of elliptical vibration mechanical systems

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    For an elliptical vibration system, the vibration parameters seriously affect conveying speed and sieving efficiency of the materials. In addition, considering the lack of studies about the elliptical vibration machine, we applied the discrete element method to simulate and analyze the elliptical vibration screening process in this paper. A vibration screening model is particularly based on the purpose of our research to fundamentally demonstrate the novel relationships among the conveying speed, sieving efficiency and vibration parameters of the materials. And the sieving experiment of typical materials is additionally carried out on the same simulation system. This paper analyzes the influence rule of vibration parameters on conveying speed and sieving efficiency of the materials during the elliptical vibration screening process by virtue of comprehensively comparing the results of experimental study coupled with simulation research. Consequently, we can throw up the optimal vibration screening parameters to guarantee high sieving efficiency and large throughput of the screening machine at the same time. The screening test carried out in this paper lays the experimental foundation for the study of the mechanism of elliptical vibration screening machine and the study of materials screening characteristics by combining the conclusions of DEM simulation analysis of lots of materials. It provides not only a basis for selecting the vibration parameters of the actual working process of the screening machine, but also data support based on the experiment and simulation for the study of the sieving mechanism of elliptical vibration systems. For screening mechanism, this is a significant progress which will affect future design and manufacture of elliptical vibration machines. Furthermore, the conclusions drawn from this research can help us study and explain better the screening process of other vibration machinery

    Exploring the Compositional Generalization in Context Dependent Text-to-SQL Parsing

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    In the context-dependent Text-to-SQL task, the generated SQL statements are refined iteratively based on the user input utterance from each interaction. The input text from each interaction can be viewed as component modifications to the previous SQL statements, which could be further extracted as the modification patterns. Since these modification patterns could also be combined with other SQL statements, the models are supposed to have the compositional generalization to these novel combinations. This work is the first exploration of compositional generalization in context-dependent Text-to-SQL scenarios. To facilitate related studies, we constructed two challenging benchmarks named \textsc{CoSQL-CG} and \textsc{SParC-CG} by recombining the modification patterns and existing SQL statements. The following experiments show that all current models struggle on our proposed benchmarks. Furthermore, we found that better aligning the previous SQL statements with the input utterance could give models better compositional generalization ability. Based on these observations, we propose a method named \texttt{p-align} to improve the compositional generalization of Text-to-SQL models. Further experiments validate the effectiveness of our method. Source code and data are available.Comment: Accepted to ACL 2023 (Findings), Long Paper, 11 page

    Cold atmospheric plasma for selectively ablating metastatic breast cancer cells

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    Traditional breast cancer treatments such as surgery and radiotherapy contain many inherent limitations with regards to incomplete and nonselective tumor ablation. Cold atomospheric plasma (CAP) is an ionized gas where the ion temperature is close to room temperature. It contains electrons, charged particles, radicals, various excited molecules, UV photons and transient electric fields. These various compositional elements have the potential to either enhance and promote cellular activity, or disrupt and destroy them. In particular, based on this unique composition, CAP could offer a minimally-invasive surgical approach allowing for specific cancer cell or tumor tissue removal without influencing healthy cells. Thus, the objective of this research is to investigate a novel CAP-based therapy for selectively bone metastatic breast cancer treatment. For this purpose, human metastatic breast cancer (BrCa) cells and bone marrow derived human mesenchymal stem cells (MSCs) were separately treated with CAP, and behavioral changes were evaluated after 1, 3, and 5 days of culture. With different treatment times, different BrCa and MSC cell responses were observed. Our results showed that BrCa cells were more sensitive to these CAP treatments than MSCs under plasma dose conditions tested. It demonstrated that CAP can selectively ablate metastatic BrCa cells in vitro without damaging healthy MSCs at the metastatic bone site. In addition, our study showed that CAP treatment can significantly inhibit the migration and invasion of BrCa cells. The results suggest the great potential of CAP for breast cancer therapy

    Synthesis, characterization, and antifungal evaluation of novel 1,2,3-triazolium-functionalized starch derivative

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    1,2,3-Triazolium-functionalized starch derivative was obtained by straightforward quaternization of the synthesized starch derivative bearing 1,2,3-triazole with benzyl bromide by combining the robust attributes of cuprous-catalyzed azide-alkyne cycloaddition. These novel starch derivatives were characterized by FTIR, UV-vis, H-1 NMR, C-13 NMR, and elemental analysis. Their antifungal activities against Colletotrichum lagenarium, Watermelon fusarium, and Phomopsis asparagi were investigated by hypha measurement in vitro. The fungicidal assessment revealed that compared with starch and starch derivative bearing 1,2,3-triazole with inhibitory indices of below 15% at 1.0 mg/mL, 1,2,3-triazolium-functionalized starch derivative had superior antifungal activity with inhibitory rates of over 60%. Especially, the best inhibitory index of 1,2,3-triazolium-functionalized starch derivative against Colletotrichum lagenarium attained 90% above at 1.0mg/mL. The results obviously showed that quaternization of 1,2,3-triazole with benzyl bromide could effectively enhance antifungal activity of the synthesized starch derivatives. The synthetic strategy described here could be utilized for the development of starch as novel antifungal biomaterial. (C) 2017 Elsevier B.V. All rights reserved

    Financing institutional long-term care for the elderly in China: a policy evaluation of new models

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    A rapid ageing population coupled with changes in family structure has brought about profound implications to social policy in China. Although the past decade has seen a steady increase in public funding to long-term care (LTC), the narrow financing base and vast population have created significant unmet demand, calling for reforms in financing. This paper focuses on the financing of institutional LTC care by examining new models that have emerged from local policy experiments against two policy goals: equity and efficiency. Three emerging models are explored: Social Health Insurance (SHI) in Shanghai, LTC Nursing Insurance (LTCNI) in Qingdao and a means-tested model in Nanjing. A focused systematic narrative review of academic and grey literature is conducted to identify and assess these models, supplemented with qualitative interviews with government officials from relevant departments, care home staff and service users. This paper argues that, although SHI appears to be a convenient solution to fund LTC, this model has led to systematic bias in affordable access among participants of different insurance schemes, and has created a powerful incentive for the over-provision of unnecessary services. The means-tested method has been remarkably constrained by narrow eligibility and insufficiency of funding resources. The LTCNI model is by far the most desirable policy option among the three studied here, but the narrow definition of eligibility has substantively excluded a large proportion of elders in need from access to care, which needs to be addressed in future reforms. This paper proposes three lines of LTC financing reforms for policy-makers: (1) the establishment of a prepaid financing mechanism pooled specifically for LTC costs; (2) the incorporation of more stringent eligibility rules and needs assessment; and (3) reforming the dominant fee-for-service methods in paying LTC service providers

    The Strong Cell-based Hydrogen Peroxide Generation Triggered by Cold Atmospheric Plasma.

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    Hydrogen peroxide (H2O2) is an important signaling molecule in cancer cells. However, the significant secretion of H2O2 by cancer cells have been rarely observed. Cold atmospheric plasma (CAP) is a near room temperature ionized gas composed of neutral particles, charged particles, reactive species, and electrons. Here, we first demonstrated that breast cancer cells and pancreatic adenocarcinoma cells generated micromolar level H2O2 during just 1 min of direct CAP treatment on these cells. The cell-based H2O2 generation is affected by the medium volume, the cell confluence, as well as the discharge voltage. The application of cold atmospheric plasma (CAP) in cancer treatment has been intensively investigated over the past decade. Several cellular responses to CAP treatment have been observed including the consumption of the CAP-originated reactive species, the rise of intracellular reactive oxygen species, the damage on DNA and mitochondria, as well as the activation of apoptotic events. This is a new previously unknown cellular response to CAP, which provides a new prospective to understand the interaction between CAP and cells in vitro and in vivo. The short-lived reactive species in CAP may activate cells in vivo to generate long-lived reactive species such as H2O2, which may trigger immune attack on tumorous tissues via the H2O2-mediated lymphocyte activation

    The Specific Vulnerabilities of Cancer Cells to the Cold Atmospheric Plasma-Stimulated Solutions.

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    Cold atmospheric plasma (CAP), a novel promising anti-cancer modality, has shown its selective anti-cancer capacity on dozens of cancer cell lines in vitro and on subcutaneous xenograft tumors in mice. Over the past five years, the CAP-stimulated solutions (PSS) have also shown their selective anti-cancer effect over different cancers in vitro and in vivo. The solutions used to make PSS include several bio-adaptable solutions, mainly cell culture medium and simple buffered solutions. Both the CAP-stimulated medium (PSM) and the CAP-stimulated buffered solution (PSB) are able to significantly kill cancer cells in vitro. In this study, we systematically compared the anti-cancer effect of PSM and PSB over pancreatic adenocarcinoma cells and glioblastoma cells. We demonstrated that pancreatic cancer cells and glioblastoma cells were specifically vulnerable to PSM and PSB, respectively. The specific response such as the rise of intracellular reactive oxygen species of two cancer cell lines to the H2O2-containing environments might result in the specific vulnerabilities to PSM and PSB. In addition, we demonstrated a basic guideline that the toxicity of PSS on cancer cells could be significantly modulated through controlling the dilutability of solution
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