339 research outputs found

    Experimental evaluation of plasters durability aimed at maintenance planning and scheduling

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    The phase of building management has a strategic importance because of the necessary scheduling of maintenance during executive planning. Moreover, in order to obtain the greatest sustainability of the intervention, a reasonable duration of service life must be balanced with global quality-cost ratio. A contribution towards this objective is given by the reduction in the achievable resources and raw materials consumption through the improvement of the durability requirement of building and its parts. This is true even for the interventions on the existing public building stock, especially if there is lacking of maintenance planning and scheduling. This work, taking cues from a maintenance intervention "at happened breakdown" on an Engineering school building in Palermo, deals with the introduction of process innovations in the management phase, directed towards preventive intervention strategies. Beyond the collection of the informative data, the time behaviour of envelope surfaces is monitored through a viewpoint system. Particular attention has been given to the finishing plaster (rasante) layer and the relative colour, to be evaluated depending on the different technical solutions and exposure to weather conditions. The study, following the methodology of ISO 15686, also foresees accelerated ageing tests on samples of different materials, in order to formulate hypothesis and correlations on the degradation evolution, from a maintenance planning and scheduling viewpoint. The correlations were obtained by taking the colour difference as a representative parameter of the evolution of colour in natural and artificial aging conditions. The results show that the different exposure of surfaces to weathering induces a different decay of surfaces colour, compatible with that induced in the laboratory at different steps of artificial aging

    Innovative siloxane coating formulations: the experimental assessment of the durability of colour

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    The maintenance programming of civil and industrial buildings is a relevant problem, especially in a global situation where natural resources are increasingly limited. Accurately knowing the durability of building products and components, essential for a sustainable use of resources, becomes more and more important after the recent 18 January 2011 resolution of the European Parliament, which introduced the seventh requirement on construction products, specifically regarding the sustainability and therefore the durability of such. This study concerns the evaluation of the durability of some innovative coatings based on acrylic-siloxane resins containing several pigments, used for building external decorative finishing, applied in thin thickness and of different basic components. The parameters investigated are: the surface appearance and the maintenance of the original colour, significant for the aesthetic quality of the architecture. The paper presents the first results of the experimental study on coating materials, produced by Hydrate Ltd, performed according to ISO 15686, aimed at defining the Reference Service Life, by monitoring the behaviour over time of artificially aged samples in the climatic chamber and external exposed samples, as well as the monitoring of a case study

    Effects of choline containing phospholipids on the neurovascular unit: A review

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    The roles of choline and of choline-containing phospholipids (CCPLs) on the maintenance and progress of neurovascular unit (NVU) integrity are analyzed. NVU is composed of neurons, glial and vascular cells ensuring the correct homeostasis of the blood-brain barrier (BBB) and indirectly the function of the central nervous system. The CCPLs phosphatidylcholine (lecithin), cytidine 5'-diphosphocholine (CDP-choline), choline alphoscerate or α-glyceryl-phosphorylcholine (α-GPC) contribute to the modulation of the physiology of the NVU cells. A loss of CCPLs contributes to the development of neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, Parkinson's disease. Our study has characterized the cellular components of the NVU and has reviewed the effect of lecithin, of CDP-choline and α-GPC documented in preclinical studies and in limited clinical trials on these compounds. The interesting results obtained with some CCPLs, in particular with α-GPC, probably would justify reconsideration of the most promising molecules in larger attentively controlled studies. This can also contribute to bett

    Spatial Enablement to Support Environmental, Demographic, Socioeconomics, and Health Data Integration and Analysis for Big Cities: A Case Study With Asthma Hospitalizations in New York City

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    The percentage of the world's population living in urban areas is projected to increase in the next decades. Big cities are heterogeneous environments in which socioeconomic and environmental differences among the neighborhoods are often very pronounced. Each individual, during his/her life, is constantly subject to a mix of exposures that have an effect on their phenotype but are frequently difficult to identify, especially in an urban environment. Studying how the combination of environmental and socioeconomic factors which the population is exposed to influences pathological outcomes can help transforming public health from a reactive to a predictive system. Thanks to the application of state-of-the-art spatially enabled methods, patients can be stratified according to their characteristics and the geographical context they live in, optimizing healthcare processes and the reducing its costs. Some public health studies focusing specifically on urban areas have been conducted, but they usually consider a coarse spatial subdivision, as a consequence of scarce availability of well-integrated data regarding health and environmental exposure at a sufficient level of granularity to enable meaningful statistical analyses. In this paper, we present an application of highly fine-grained spatial resolution methods to New York City data. We investigated the link between asthma hospitalizations and a combination of air pollution and other environmental and socioeconomic factors. We first performed an explorative analysis using spatial clustering methods that shows that asthma is related to numerous factors whose level of influence varies considerably among neighborhoods. We then performed a Geographically Weighted Regression with different covariates and determined which environmental and socioeconomic factors can predict hospitalizations and how they vary throughout the city. These methods showed to be promising both for visualization and analysis of demographic and epidemiological urban dynamics, that can be used to organize targeted intervention and treatment policies to address the single citizens considering the factors he/she is exposed to. We found a link between asthma and several factors such as PM2.5, age, health insurance coverage, race, poverty, obesity, industrial areas, and recycling. This study has been conducted within the PULSE project, funded by the European Commission, briefly presented in this paper

    Immunological pattern alteration in shoe, hide, and leather industry workers exposed to exavalent chromium

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    The aim of this work was to assess the effects of hexavalent chromium [Cr(VI)] on shoe, leather, and hide industry workers, based on the assumption that Cr(VI) can behave as an environmental immunological "stressor." The immunological patterns of 84 male subjects were studied in relation to Cr(VI) hematic and urinary levels. Cr(VI) was measured through atomic absorption. Lymphocyte subsets, mitogen-mediated lymphocyte-proliferation, cytokine levels, and natural killer (NK) cytotoxic activity were also assayed. RESULTS: The urinary levels of the total amount of Cr(VI) were significantly higher in a subgroup of exposed subjects (group B) than in the control or in the lower exposed (group A). In group B, Cr(VI) caused a decrease in the density of glucocorticoid receptors (GR) on peripheral blood mononuclear cells (PBMC) and a increase of IL-6. Cr(VI) did not modify NK-mediated cytotoxicity, the plasmatic levels of inflammatory cytokines and related soluble receptors, and prostaglandin levels, while it tended to increase lymphocyte sensitivity to mitogens and the production of immunomodulant cytokines (IFN-gamma, IL-4, and IL-2). The experimental addition of Cr(VI) to the in vitro lymphocyte culture determined a significant inhibition of phagocytosis percentage, index, and killing percentage. These effects were neutralized by exogenous IFN-gamma. Cr(VI) could represent an environmental immunological stressor whose effects can be evaluated through laboratory surveys. The lymphocyte mitogen-induced proliferation, GR receptor on PBMC, and IL-6 plasma levels may represent a discriminating element between Cr(VI)-induced stress and other kinds of stress

    Rodent Models of Huntington's Disease: An Overview

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    Huntington's disease (HD) is an autosomal-dominant inherited neurological disorder caused by a genetic mutation in the IT15 gene. This neurodegenerative disorder is caused by a polyglutamine repeat expansion mutation in the widely expressed huntingtin (HTT) protein. HD is characterized by the degeneration of basal ganglia neurons and progressive cell death in intrinsic neurons of the striatum, accompanied by dementia and involuntary abnormal choreiform movements. Animal models have been extensively studied and have proven to be extremely valuable for therapeutic target evaluations. They reveal the hallmark of the age-dependent formation of aggregates or inclusions consisting of misfolded proteins. Animal models of HD have provided a therapeutic strategy to treat HD by suppressing mutant HTT (mHTT). Transgenic animal models have significantly increased our understanding of the molecular processes and pathophysiological mechanisms underlying the HD behavioral phenotype. Since effective therapies to cure or interrupt the course of the disease are not yet available, clinical research will have to make use of reliable animal models. This paper reviews the main studies of rodents as HD animal models, highlighting the neurological and behavioral differences between them. The choice of an animal model depends on the specific aspect of the disease to be investigated. Toxin-based models can still be useful, but most experimental hypotheses depend on success in a genetic model, whose choice is determined by the experimental question. There are many animal models showing similar HD symptoms or pathologies. They include chemical-induced HDs and genetic HDs, where cell-free and cell culture, lower organisms (such as yeast, Drosophila, C. elegans, zebrafish), rodents (mice, rats), and non-human primates are involved. These models provide accessible systems to study molecular pathogenesis and test potential treatments. For developing more effective pharmacological treatments, better animal models must be available and used to evaluate the efficacy of drugs
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