167 research outputs found

    Feasibility evaluation and critical factor analysis for subway scheduling

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    In strategic subway scheduling stage, the conflict sometimes comes from different requirements of the subway operator. This study aims to investigate the significant factors concerning strategic subway scheduling problem and to develop an automatic procedure of feasibility analysis in subway scheduling. To this end, accurate simulation of train movement (via a simulator, named HAMLET) is applied first by considering the line geography, train performances, actual speed restrictions, etc. The critical elements of subway scheduling and their correlations are then studied and a bound structure of the critical factors is established. The feasibility of primary plan requirements is analysed with the restrictions of the bound structure. Infeasible aspects and possible adjustments are shortly discussed. Finally, the subsequent applications including schedule generation and optimization according to various objectives are indicated as well

    Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination

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    Electrokinetic effects are those that take place by application of an electric field to porous materials, with the zeta potential as the key parameter. Specifically, in the case of contaminated construction materials, the generation of an electroosmotic flux, with the corresponding dragging due to water transport, is a crucial mechanism to succeed in the treatment of decontamination. Therefore, it is of great interest trying to optimize the treatment by the addition of specific electrolytes enhancing the electrokinetic phenomena. Most of the data of zeta potential found in literature for construction materials are based in micro-electrophoresis measurements, which are quite far of the real conditions of application of the remediation treatments. In this paper, electrophoretic and electroosmotic experiments, with monolithic and powdered material respectively, have been carried out for mortar, brick and granite clean and contaminated with Cs, Sr, Co, Cd, Cu and Pb. The electrolytes tested have been distilled water (DW), Na2–EDTA, oxalic acid, acetic acid and citric acid. The zeta potential values have been determined through the two different techniques and the results compared and critically analysed

    Metodología para la intervención en elementos históricos: el caso de la espadaña del convento de Nuestra Señora de la Consolación (Alcalá de Henares-Madrid-España)

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    The purpose of this paper is the study of damage detected in the belfry of the convent of “Nuestra Señora de la Consolación”, Alcalá de Henares, as well as the materials analysis to establish both the current state of the structure as the nature and extent of the deterioration of the original materials. For a good detection of defects in the structure were the application of a methodology of previous studies in historical buildings, in which were used, among other techniques, the element Thermographic Analysis, to then proceed to the experimental determination of the emissivities of the different inspected materials. The use of supplementary techniques of analysis as porosimetry of mercury, x-ray diffraction, electron microscopy of scanning and thermogravimetry, as well as mechanical characterization of materials, has made it possible to delve into the characteristics of the Union mortar and employed; evaluate comprehensively current degradation status and facilitating the rehabilitation.El objeto del presente trabajo es el estudio de daños detectados en la espadaña del Convento de Nuestra Señora de la Consolación, Alcalá de Henares, así como el análisis de los materiales para establecer, tanto el estado actual de la estructura, como la naturaleza y grado de deterioro de los materiales originales. Para ello se aplicó una metodología de estudios previos en edificaciones históricas, en la que se utilizaron, entre otras técnicas, el análisis termográfico del elemento, para posteriormente proceder a la determinación experimental de las emisividades de los diferentes materiales inspeccionados. El uso de técnicas complementarias de caracterización y análisis como porosimetría de intrusión de mercurio, difracción de rayos X, microscopía electrónica de barrido y termogravimetría, así como la caracterización mecánica de los materiales, ha permitido ahondar en las características del mortero de unión y las piezas de fábrica; evaluando completamente el estado actual y facilitando su rehabilitación

    A new lower limb portable exoskeleton for gait assistance in neurological patients: a proof of concept study

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    Background: Few portable exoskeletons following the assist-as-needed concept have been developed for patients with neurological disorders. Thus, the main objectives of this proof-of-concept study were 1) to explore the safety and feasibility of an exoskeleton for gait rehabilitation in stroke and multiple sclerosis patients, 2) to test different algorithms for gait assistance and measure the resulting gait changes and 3) to evaluate the user's perception of the device. Methods: A cross-sectional study was conducted. Five patients were recruited (4 patients with stroke and 1 with multiple sclerosis). A robotic, one-degree-of-freedom, portable lower limb exoskeleton known as the Marsi Active Knee (MAK) was designed. Three control modes (the Zero Force Control mode, Mode 1 and Mode 3) were implemented. Spatiotemporal gait parameters were measured by the 10-m walking test (10MWT), the Gait Assessment and Intervention Tool (G.A.I.T.) and Tinetti Performance Oriented Mobility Assessment (gait subscale) before and after the trials. A modified QUEST 2.0 questionnaire was administered to determine each participant's opinion about the exoskeleton. The data acquired by the MAK sensors were normalized to a gait cycle, and adverse effects were recorded. Results: The MAK exoskeleton was used successfully without any adverse effects. Better outcomes were obtained in the 10MWT and G.A.I.T. when Mode 3 was applied compared with not wearing the device at all. In 2 participants, Mode 3 worsened the results. Additionally, Mode 3 seemed to improve the 10MWT and G.A.I.T. outcomes to a greater extent than Mode 1. The overall score for the user perception of the device was 2.8 ± 0.4 95% CI. Conclusions: The MAK exoskeleton seems to afford positive preliminary results regarding safety, feasibility, and user acceptance. The efficacy of the MAK should be studied in future studies, and more advanced improvements in safety must be implemented.G. Puyuelo-Quintana has received financial support by the “Doctorado Industrial” grant of Ministerio de Ciencia, Innovación y Universidades de España (reference DI-16- 08731). A. Plaza-Flores and E. Garces-Castellote have received financial support by the “Doctorado Industrial” grant of Comunidad de Madrid (reference IND2017/TIC-7698 and IND2018/TIC-9618, respectively).Peer reviewe

    Changes in plasma fatty acid composition are associated with improvements in obesity and related metabolic disorders: A therapeutic approach to overweight adolescents

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    Background & aims: In recent years, obesity has reached alarming levels among children and adolescents. The study of plasma fatty acid (FA) composition, as a reflection of diet, and its associations with other parameters, that are closely linked to obesity and the cardiometabolic profile, may be useful for setting nutritional goals for obesity treatment and prevention. This study explored the relationship between plasma FA levels and body fat and cardiometabolic risk markers, in overweight adolescents. Methods: A multidisciplinary weight loss program was followed by 127 overweight and obese adolescents aged 12-17 years old. Plasma FA composition, anthropometric indicators of adiposity and biochemical parameters were analyzed at baseline, two months (the end of the intensive intervention phase) and six months (the end of the extensive phase). Results: While saturated fatty acid (SFA) and n-6 polyunsaturated fatty acid (PUFA) levels decreased significantly during the intervention, monounsaturated fatty acid (MUFA) and n-3 PUFA showed the opposite trend. The decrease in SFA C14:0 was associated with a reduction in total and LDL cholesterol, apolipoprotein B and insulin. The increase in MUFAs, especially C18:1n-9, was related to a reduction in weight, fat mass, fat mass index and glucose. Regarding PUFAs, changes in the n-3 series were not associated with any of the parameters studied, whereas the reduction in n-6 PUFA5 was directly related to weight, fat mass, total and HDL cholesterol, apolipoprotein Al, glucose and insulin, and inversely associated with diastolic blood pressure. The adolescents with greater weight loss presented significant changes in MUFAs, n-6 PUFA5 and C14:0. Conclusions: Modifications in plasma FA composition were associated with adiposity reduction and cardiometabolic profile improvement in an anti-obesity program aimed at adolescents. The changes observed in FA composition were related to the success of the treatment, since the individuals most affected by these variations were those who presented the greatest weight loss

    Relation between plasma antioxidant vitamin levels, adiposity and cardio-metabolic profile in adolescents: Effects of a multidisciplinary obesity programme

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    Background & aims In vivo and in vitro evidence suggests that antioxidant vitamins and carotenoids may be key factors in the treatment and prevention of obesity and obesity-associated disorders. Hence, the objective of the present study was to determine the relationship between plasma lipid-soluble antioxidant vitamin and carotenoid levels and adiposity and cardio-metabolic risk markers in overweight and obese adolescents participating in a multidisciplinary weight loss programme. Methods A therapeutic programme was conducted with 103 adolescents aged 12–17 years old and diagnosed with overweight or obesity. Plasma concentrations of a-tocopherol, retinol, ß-carotene and lycopene, anthropometric indicators of general and central adiposity, blood pressure and biochemical parameters were analysed at baseline and at 2 and 6 months of treatment. Results Lipid-corrected retinol (P < 0.05), ß-carotene (P = 0.001) and a-tocopherol (P < 0.001) plasma levels increased significantly, whereas lipid-corrected lycopene levels remained unaltered during the treatment. Anthropometric indicators of adiposity (P < 0.001), blood pressure (P < 0.01) and biochemical parameters (P < 0.05) decreased significantly, whereas fat free mass increased significantly (P < 0.001). These clinical and biochemical improvements were related to changes in plasma lipid-corrected antioxidant vitamin and carotenoid levels. The adolescents who experienced the greatest weight loss also showed the largest decrease in anthropometric indicators of adiposity and biochemical parameters and the highest increase in fat free mass. Weight loss in these adolescents was related to an increase in plasma levels of lipid-corrected a-tocopherol (P = 0.001), ß-carotene (P = 0.034) and lycopene (P = 0.019). Conclusions Plasma lipid-soluble antioxidant vitamin and carotenoid levels are associated with reduced adiposity, greater weight loss and an improved cardio-metabolic profile in overweight and obese adolescents

    Adrenomedullin as a potential biomarker involved in patients with hereditary hemorrhagic telangiectasia

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    Background: Adrenomedullin (AM) is a vasoactive peptide mostly secreted by endothelial cells with an important role in preserving endothelial integrity. The relationship between AM and hereditary hemorrhagic telangiectasia (HHT) is unknown. We aimed to compare the serum levels and tissue expression of AM between HHT patients and controls. Methods: Serum AM levels were measured by radioimmunoassay and compared between control and HHT groups. AM levels were also compared among HHT subgroups according to clinical characteristics. The single nucleotide polymorphism (SNP) rs4910118 was assessed by restriction analysis and sequencing. AM immunohistochemistry was performed on biopsies of cutaneous telangiectasia from eight HHT patients and on the healthy skin from five patients in the control group. Results: Forty-five HHT patients and 50 healthy controls were included, mean age (SD) was 50.7 (14.9) years and 46.4 (9.9) years (p = 0.102), respectively. HHT patients were mostly female (60% vs 38%, p = 0.032). Median [Q1-Q3] serum AM levels were 68.3 [58.1-80.6] pg/mL in the HHT group and 47.7 [43.2-53.8] pg/mL in controls (p<0.001), with an optimal AM cut-off according to Youden's J statistic of 55.32 pg/mL (J:0.729). Serum AM levels were similar in the HHT subgroups. No patient with HHT had the SNP rs4910118. AM immunoreactivity was found with high intensity in the abnormal blood vessels of HHT biopsies
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