50 research outputs found

    Effects of Material Parameters on Stress Distribution in Casing-cement -formation (CCF) Multilayer Composite System

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    This work focus on the stress distribution of the casing-cement -formation (CCF) multilayer composite system, which is a borehole system with multiple casings and cement sheathes. Most of the previous relevant studies are based on the traditional CCF system with the single casing and cement sheath, but these results are not adaptive to the CCF system multiple composite system. In this paper, the FEM numerical model of CCF multilayer composite system was constructed. Numerical simulations were calculated and compared with the system which consists of the single casing and cement sheath. Results show that the multilayer composite system possesses better performance. On this basis, the sensitivity analysis of main influence mechanical parameters such as in-situ stress, the elastic of cement sheathes and the elastic of formation are conducted. The cement sheath on the inside, namely cement sheath-1, is sensitive to its elastic modulus; meanwhile, the cement sheath on the outside, namely cement sheath-2, is not so sensitive to the elastic modulus of cement sheath-1. Cement sheath-1 and cement sheath-2 are all sensitive to the elastic modulus of cement sheath-2, and the mises stress of them has opposite trend to the elastic modulus of cement sheath-2. The proper values of elastic modulus of cement sheath-1 and cement sheath-2 are 5GPa and 5GPa to 30GPa, respectively. Under the in-situ stress ratio σh / σH = 0.7, the maximum mises stress of cement sheath-1 and cement sheath-2 increase as the increase of σh, and they are nearly equal when σh=15GPa. This research can be helpful for the design and analysis of CCF multilayer composite system

    Effective Few-Shot Named Entity Linking by Meta-Learning

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    Entity linking aims to link ambiguous mentions to their corresponding entities in a knowledge base, which is significant and fundamental for various downstream applications, e.g., knowledge base completion, question answering, and information extraction. While great efforts have been devoted to this task, most of these studies follow the assumption that large-scale labeled data is available. However, when the labeled data is insufficient for specific domains due to labor-intensive annotation work, the performance of existing algorithms will suffer an intolerable decline. In this paper, we endeavor to solve the problem of few-shot entity linking, which only requires a minimal amount of in-domain labeled data and is more practical in real situations. Specifically, we firstly propose a novel weak supervision strategy to generate non-trivial synthetic entity-mention pairs based on mention rewriting. Since the quality of the synthetic data has a critical impact on effective model training, we further design a meta-learning mechanism to assign different weights to each synthetic entity-mention pair automatically. Through this way, we can profoundly exploit rich and precious semantic information to derive a well-trained entity linking model under the few-shot setting. The experiments on real-world datasets show that the proposed method can extensively improve the state-of-the-art few-shot entity linking model and achieve impressive performance when only a small amount of labeled data is available. Moreover, we also demonstrate the outstanding ability of the model's transferability.Comment: 14 pages, 4 figures. Accepted at IEEE ICDE 202

    Can LLMs like GPT-4 outperform traditional AI tools in dementia diagnosis? Maybe, but not today

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    Recent investigations show that large language models (LLMs), specifically GPT-4, not only have remarkable capabilities in common Natural Language Processing (NLP) tasks but also exhibit human-level performance on various professional and academic benchmarks. However, whether GPT-4 can be directly used in practical applications and replace traditional artificial intelligence (AI) tools in specialized domains requires further experimental validation. In this paper, we explore the potential of LLMs such as GPT-4 to outperform traditional AI tools in dementia diagnosis. Comprehensive comparisons between GPT-4 and traditional AI tools are conducted to examine their diagnostic accuracy in a clinical setting. Experimental results on two real clinical datasets show that, although LLMs like GPT-4 demonstrate potential for future advancements in dementia diagnosis, they currently do not surpass the performance of traditional AI tools. The interpretability and faithfulness of GPT-4 are also evaluated by comparison with real doctors. We discuss the limitations of GPT-4 in its current state and propose future research directions to enhance GPT-4 in dementia diagnosis.Comment: 16 pages, 6 figure

    The Efficacy of Adalimumab as an Initial Treatment in Patients with Behçet’s Retinal Vasculitis

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    Background: No study has evaluated the effectiveness of Adalimumab (ADA) as first-line in treatment-naïve patients with retinal vasculitis due to Behçet’s Uveitis (BU).Objective: To compare the efficacy of ADA plus conventional therapy and conventional therapy alone as initial treatments in naïve BU patients characterized by retinal vasculitis.Methods: Medical records of BU patients characterized by retinal vasculitis treated with conventional therapy (CT, refers to glucocorticoid and immunosuppressive agents) alone or ADA plus conventional therapy with at least 6 months of follow-up between February 2015 and June 2020 were analyzed. Only patients who were first diagnosed with BU without previous systemic treatment were reviewed. The retinal vasculitis score based on fluorescein angiography (FA), best-corrected visual acuity, glucocorticoid-sparing effect, the number of relapses and ocular complications were evaluated.Results: A total of 45 patients (87 eyes) were included. Twenty-four patients (55.33%) in the CT group were treated with conventional therapy and 21 patients (46.67%) in the ADA group were treated with ADA plus conventional therapy. The inflammatory parameters improved in both groups. FA scores showed significantly greater improvement in ADA group than CT group (p < 0.001). The median number of relapses was significantly lower, and the duration of remission was longer in ADA group than CT group (p < 0.001). At the last visit, a significantly better BCVA improvement (p = 0.024), better inflammation control (anterior chamber inflammation p = 0.017 and vitritis p < 0.001) and lower daily glucocorticoid dosage (p = 0.005) were identified in patients received ADA therapy. In CT group, 1 patient suffered hepatitis B and tuberculosis, 1 had growth retardation, 1 patient had with osteoporosis, then followed by other mild AEs (mostly respiratory upper tract infections); while in ADA group, 1 patient experienced a mild pneumonia (n = 1) while milder AEs were represented mostly by respiratory upper tract infections followed by gastrointestinal discomfort.Conclusion: ADA plus conventional therapy achieved superiority over conventional therapy as initial treatment in naïve BU patients with retinal vasculitis

    Study on rheological, adsorption and hydration properties of cement slurries incorporated with EPEG-based polycarboxylate superplasticizers

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    A series of polycarboxylate superplasticizers (PCEs) with different side-chain densities, main chain polymerization degrees, and side-chain lengths were designed and synthesized using a novel highly active ethylene glycol mono vinyl ether polyethylene glycol as the ether monomer. The influence of polycarboxylate ether on the rheological properties, interface adsorption, and hydration characteristics in cement paste was investigated through characterization of charge density, rheological properties, adsorption behavior, and hydration heat. The results indicate that the adsorption process of PCE on cement particles is spontaneous physical adsorption, and the hydration kinetics fitting reveals that the geometric crystal growth exponent n is in the range of 1–2, with needle-like and lamellar hydration products formed. With a decrease in side-chain density, the broadening of molecular weight distribution and the increase of charge density accelerate the flow of slurry, reduces saturation adsorption, and delays cement hydration. A decrease in main chain polymerization degree results in a downward trend in molecular weight and charge density, leading to larger molecular conformations, reduced slurry flow, decreased saturation adsorption, and delayed cement hydration. As the side-chain length of PCE (molecular weight) increases, the charge density decreases, and the molecular conformation exhibits a compact structure with reduced slurry flow, decreased saturation adsorption, and delayed cement hydration. In cases of low side-chain density, short side chains, and low molecular weight, enhanced adsorption capacity and faster adsorption rates are observed, resulting in the lower viscosity and a delay in the cement hydration process

    Natural Coevolution of Tumor and Immunoenvironment in Glioblastoma.

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    Isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) has a dismal prognosis. A better understanding of tumor evolution holds the key to developing more effective treatment. Here we study GBM\u27s natural evolutionary trajectory by using rare multifocal samples. We sequenced 61,062 single cells from eight multifocal IDH wild-type primary GBMs and defined a natural evolution signature (NES) of the tumor. We show that the NES significantly associates with the activation of transcription factors that regulate brain development, including MYBL2 and FOSL2. Hypoxia is involved in inducing NES transition potentially via activation of the HIF1A-FOSL2 axis. High-NES tumor cells could recruit and polarize bone marrow-derived macrophages through activation of the FOSL2-ANXA1-FPR1/3 axis. These polarized macrophages can efficiently suppress T-cell activity and accelerate NES transition in tumor cells. Moreover, the polarized macrophages could upregulate CCL2 to induce tumor cell migration. SIGNIFICANCE: GBM progression could be induced by hypoxia via the HIF1A-FOSL2 axis. Tumor-derived ANXA1 is associated with recruitment and polarization of bone marrow-derived macrophages to suppress the immunoenvironment. The polarized macrophages promote tumor cell NES transition and migration. This article is highlighted in the In This Issue feature, p. 2711

    Study on the Seismic Behavior of a Steel Plate–Concrete Composite Shear Wall with a Fishplate Connection

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    The steel plate–concrete composite shear wall (SPCSW), having been widely applied to several super high-rise buildings, is currently regarded as a new type of lateral load-resisting structure. The SPCSW design does not consider the connection to the surrounding structure, normally envisaged as a buttweld connection, while the fishplate lap connection tends to be applied in construction. To explore the fishplate lap connection to achieve the performance standard of SPCSW, in this paper, an SPCSW with a fishplate connection is modeled using ABAQUS to investigate the hysteretic behavior under constant axial force and horizontal cyclic loads. Through the hysteresis curve and a load–displacement skeleton curve, the effects of fishplate thickness and lap length on its hysteretic behavior are studied. The results show that increasing the fishplate thickness contributes to a slight increase in the bearing capacity and energy dissipation and has little influence on stiffness degradation. When the fishplate thickness is more than half the steel plate thickness, the strength and energy dissipation of an SPCSW with a fishplate connection can reach the level of an SPCSW without a fishplate connection. The bearing capacity and stiffness of the SPCSW increase with the increase in lap length. When the lap length is greater than 50 mm, the strength, stiffness and energy dissipation capacity of an SPCSW with a fishplate connection are superior to those without fishplate connections. Finally, engineering suggestions on fishplate connections are put forward

    Study on the Seismic Behavior of a Steel Plate–Concrete Composite Shear Wall with a Fishplate Connection

    Full text link
    The steel plate–concrete composite shear wall (SPCSW), having been widely applied to several super high-rise buildings, is currently regarded as a new type of lateral load-resisting structure. The SPCSW design does not consider the connection to the surrounding structure, normally envisaged as a buttweld connection, while the fishplate lap connection tends to be applied in construction. To explore the fishplate lap connection to achieve the performance standard of SPCSW, in this paper, an SPCSW with a fishplate connection is modeled using ABAQUS to investigate the hysteretic behavior under constant axial force and horizontal cyclic loads. Through the hysteresis curve and a load–displacement skeleton curve, the effects of fishplate thickness and lap length on its hysteretic behavior are studied. The results show that increasing the fishplate thickness contributes to a slight increase in the bearing capacity and energy dissipation and has little influence on stiffness degradation. When the fishplate thickness is more than half the steel plate thickness, the strength and energy dissipation of an SPCSW with a fishplate connection can reach the level of an SPCSW without a fishplate connection. The bearing capacity and stiffness of the SPCSW increase with the increase in lap length. When the lap length is greater than 50 mm, the strength, stiffness and energy dissipation capacity of an SPCSW with a fishplate connection are superior to those without fishplate connections. Finally, engineering suggestions on fishplate connections are put forward
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