14 research outputs found

    Stabilization computation for a kind of uncertain switched systems using non-fragile sliding mode observer method

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    A non-fragile sliding mode control problem will be investigated in this article. The problem focuses on a kind of uncertain switched singular time-delay systems in which the state is not available. First, according to the designed non-fragile observer, we will construct an integral-type sliding surface, in which the estimated unmeasured state is used. Second, we synthesize a sliding mode controller. The reachability of the specified sliding surface could be proved by this sliding mode controller in a finite time. Moreover, linear matrix inequality conditions will be developed to check the exponential admissibility of the sliding mode dynamics. After that, the gain matrices designed will be given along with it. Finally, some numerical result will be provided, and the result can be used to prove the effectiveness of the method

    Inequalities in the Access to Health Services Among Older Migrants: Evidence From the China Migrant Dynamic Monitoring Survey

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    Objectives: To identify differences in healthcare use between older migrant workers (OMWs) and older migrants (OMs) and explore associated factors and paths of healthcare use.Methods: The data came from the 2015 China Migrant Dynamic Monitoring Survey (CMDMS). CMDMS used a multi-stage stratified probability proportionate to size method as the sampling technique and conducted a desk review. The samples include OMWs, OMs for caring offspring (N = 4,439), and OMs for receiving care from family (N = 4,184). We built logistic regression and path analysis models to analyze the data.Results: Social health insurance (SHI) in current place of residence is associated with less expenditure among all subgroups. OMWs and OMs for receiving care from family with SHI in current place of residence are more likely to use healthcare.Conclusion: OMWs are particularly vulnerable in healthcare use and socioeconomic status. Having SHI registered in current place of residence helps decrease expenditure among OMs. We urge policymakers to consider a united health financing scheme across OMWs and other urban employees and streamline policies for migrants to enroll in SHI in current place of residence

    Constructing prediction models for excessive daytime sleepiness by nomogram and machine learning: A large Chinese multicenter cohort study

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    ObjectiveAlthough risk factors for excessive daytime sleepiness (EDS) have been reported, there are still few cohort-based predictive models for EDS in Parkinson’s disease (PD). This 1-year longitudinal study aimed to develop a predictive model of EDS in patients with PD using a nomogram and machine learning (ML).Materials and methodsA total of 995 patients with PD without EDS were included, and clinical data during the baseline period were recorded, which included basic information as well as motor and non-motor symptoms. One year later, the presence of EDS in this population was re-evaluated. First, the baseline characteristics of patients with PD with or without EDS were analyzed. Furthermore, a Cox proportional risk regression model and XGBoost ML were used to construct a prediction model of EDS in PD.ResultsAt the 1-year follow-up, EDS occurred in 260 of 995 patients with PD (26.13%). Baseline features analysis showed that EDS correlated significantly with age, age of onset (AOO), hypertension, freezing of gait (FOG). In the Cox proportional risk regression model, we included high body mass index (BMI), late AOO, low motor score on the 39-item Parkinson’s Disease Questionnaire (PDQ-39), low orientation score on the Mini-Mental State Examination (MMSE), and absence of FOG. Kaplan–Meier survival curves showed that the survival prognosis of patients with PD in the high-risk group was significantly worse than that in the low-risk group. XGBoost demonstrated that BMI, AOO, PDQ-39 motor score, MMSE orientation score, and FOG contributed to the model to different degrees, in decreasing order of importance, and the overall accuracy of the model was 71.86% after testing.ConclusionIn this study, we showed that risk factors for EDS in patients with PD include high BMI, late AOO, a low motor score of PDQ-39, low orientation score of MMSE, and lack of FOG, and their importance decreased in turn. Our model can predict EDS in PD with relative effectivity and accuracy

    Numerical simulation of the leakage and diffusion of CO2 in CCS transportation pipelines

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    This paper aims to develop a CFD model to calculate the leakage and unsteady atmospheric diffusion of CO2 from the transport pipelines in Carbon Capture and Storage (CCS) system. The influences of wind profiles, wind speeds, atmospheric stabilities and ground surface roughness on the diffusion of CO2 are numerically investigated. Under different wind profiles, the mass fractions of CO2 in the horizontal and vertical directions are different. As the wind speed increases, the time to reach the stability of CO2 diffusion and the mass fraction of CO2 in the vertical direction both decrease. The strong atmospheric instability is not useful for the diffusion of CO2 in the horizontal direction. The tougher ground surface is advantageous to the formation of the vertical turbulent fluctuation. However, the horizontal diffusion of CO2 is blocked and the time to achieve the diffusion stability increases

    Structures and Anti-Inflammatory Evaluation of Phenylpropanoid Derivatives from the Aerial Parts of <i>Dioscorea polystachya</i>

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    Seven undescribed phenylpropanoid constituents, including three new bibenzyl derivatives (1–3) along with four new benzofuran stilbene derivatives (4–7), were isolated from the aerial parts of Dioscorea polystachya. The structures of these compounds were elucidated using a combination of spectroscopic analyses, including UV, IR, HRESIMS, 1D, and 2D NMR. Further, all the compounds were evaluated on the anti-inflammatory activity for their inhibition of nitric oxide (NO) production by RAW 264.7 macrophages cells, and some of them (1–3 and 6) displayed inhibitory activity with IC50 values in the range of 9.3–32.3 μM. Moreover, compound 3 decreased the expression of iNOS in Western blot analysis, suggesting compound 3 is mediated via the suppression of an LPS-induced NF-κB inflammasome pathway

    Vibration Analysis of Bilayered Graphene Sheets for Building Materials in Thermal Environments Based on the Element-Free Method

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    Graphene sheets are widely applied due to their unique and highly valuable properties, such as energy conservation materials in buildings. In this paper, we investigate the vibration behavior of double layer graphene sheets (DLGSs) in thermal environments which helps probe into the mechanism of energy conservation of graphene sheets in building materials. The nonlocal elastic theory and classical plate theory (CLPT) are used to derive the governing equations. The element-free method is employed to analyze the vibration behaviors of DLGSs embedded in an elastic medium. The accuracy of the solutions in this study is demonstrated by comparison with published results in the literature. Furthermore, a number of numerical results are presented to investigate the effects of various parameters (boundary conditions, nonlocal parameter, aspect ratio, side length, elastic foundation parameter, and temperature) on the frequency of DLGSs

    Association of socioeconomic status with glycated haemoglobin level and risk factors for diabetic retinopathy: a cross-sectional study in Sichuan, western China

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    Objective Diabetes affects 1 in 10 adults in China. Diabetic retinopathy (DR) is a diabetes-related complication that, if untreated, impairs vision and causes blindness. Evidence on DR diagnosis and risk factors is limited. This study aimed to add evidence from socioeconomic factors.Design A cross-sectional survey of people with diabetes conducted in 2019 was analysed by using logistic regression to evaluate the association of socioeconomic factors with the glycated haemoglobin (HbA1c) level and DR.Setting Five counties/districts of western China (Sichuan) were included.Participants Registered participants with diabetes aged from 18 to 75 years were selected, and at last 2179 participants were included in the analysis.Results In this cohort, 37.13% (adjusted value 36.52%), 19.78% (adjusted value 19.59%) and 17.37% of participants had HbA1c&lt;7.0%, DR (24.96% of those in the high-HbA1c group) and non-proliferative DR, respectively. Participants with higher social health insurance coverage (urban employee insurance (UEI)), higher income and urban residents tended to have glycaemic control (HbA1c) compared with their counterparts (OR: 1.48, 1.08 and 1.39, respectively). Participants with UEI or higher income had a lower risk of DR (OR: 0.71 and 0.88, respectively); higher education was associated with a 53%–69% decreased risk of DR.Conclusion This study shows disparities in the effect of socioeconomic factors on glycaemic (HbA1c) management and DR diagnosis among people with diabetes in Sichuan. Lower socioeconomic (especially non-UEI) status conferred a higher risk of high HbA1c and DR. The insights from this study indicate the need for national programmes to implement community-level measures to facilitate access to better HbA1c management and early detection of DR in patients with lower socioeconomic status and diabetes.Trial registration number Chinese Clinical Trial Registry (ChiCTR1800014432)

    Genetic characterization of a Salmonella enterica serovar Typhimurium isolated from an infant with concurrent resistance to ceftriaxone, ciprofloxacin and azithromycin

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    ABSTRACT: Objectives: To investigate the resistance mechanism of a Salmonella Typhimurium (S. Typhimurium) isolated from a faecal sample of an infant, which exhibited concurrent resistance to ceftriaxone, ciprofloxacin and azithromycin. Methods: Antimicrobial susceptibility testing was performed by broth microdilution in two kinds of drug-sensitive plates. Antimicrobial resistance (AMR) genes were identified by whole genome sequencing and bioinformatics analysis. Genotyping of the strain was performed by multilocus sequence typing (MLST). Plasmid DNA was sequenced and analysed using plasmid bioinformatics tools. Results: The SH11G993 strain was resistant to 28 antibiotics and carried 54 AMR genes. MLST results showed that the strain belonged to a rare genotype. The plasmid profile and plasmid sequencing showed that the strain carried two resistance plasmids. The pSH11G993-1 carried 14 AMR genes (especially co-harboured blaCMY-2, mphA and ermB) and a variety of insertion sequences, belonging to the IncC. The pSH11G993-2 carried 3 AMR genes and 9 virulence genes, belonging to the IncFIB-FII, forming a novel resistance and virulence co-harbouring plasmid. Conclusions: Our findings highlight that continuously monitor the changes in antibiotic resistance patterns and research on the resistance mechanisms in potential human pathogens are imperative
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