198 research outputs found

    Deploy Energy-efficient Technologies in the Restoration of a Traditional Building in the Historical Center of Catania (Italy)☆

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    Abstract The policy about energy efficiency of buildings, including minimum energy requirements and energy performance certificate (EPC), have to be also applied to existing buildings in the case of energy retrofit. In this paper, the possible strategies that can be used to reduce the energy needs of traditional massive buildings, that are widespread in the old town of the Mediterranean cities, have been investigated. To this aim, this study evaluates the energy consumption of a massive building placed in Catania city, called "La Casa del Portuale", which was recently refurbished with the aim to host two local administrative centers. The energy needs of this building was evaluated through computer simulation both in the heating and cooling period, on a yearly basis. The activities research were developed analyzing different refurbishment solutions suitable to improve the thermal performance of most traditional buildings without adversely affecting their fabric and character. Therefore, the feasibility comparison has been performed between the examined refurbishment solutions. The results of the proposed research, considering the diffusion of this typology of buildings, could be assumed as reference to a significant portion of the traditional real estate

    Age-related influence of hypothyroidism on caveolins and nitric oxide modulation

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    Introduction: Hypothyroidism and age impact on cardiac and renal nitricoxide (NO) production. Caveolins, which are negativemodulators of NO synthase (NOS) activity, are affected byboth factors. Objectives: The aim of this study was to evaluate caveolin (CAV) participationin the modulation of renal and cardiac NOS activityin adult hypothyroid animals. Methods: Euthyroid and hypothyroid [methimazole 0.02% (v/v) in thedrinking water during 28 days] male Sprague-Dawley ratswere used. Animals were sacrificed to remove the heart andkidneys. Results: Right atrial NOS activity decreased with age and hypothyroidism.Caveolin-1 expression increased with age andhypothyroidism. Conversely, left ventricular NOS activityincreased with aging and hypothyroidism and the expressionof both CAV isoforms decreased in adult and hypothyroidgroups. In the renal medulla, hypothyroidism reducedNOS activity in young and raised it in adult animals andCAV-1 expression decreased with age and in hypothyroidyoung animals. Caveolin-3 protein levels decreased in adulthypothyroid animals. Conclusions: Hypothyroidism impacts on NOS activity and on that ofits modulators, caveolins, in the cardiovascular and renalsystems. Hypothyroidism enhances the effects of aging inboth systems.Fil: Detomaso, Florencia M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Braga, Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Rodríguez, Lourdes. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Arreche, Noelia Daniela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Sarati, Lorena Ivonne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Balaszczuk, Ana María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Fellet, Andrea L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentin

    Radar observation and recontruction of Cosmos 1408 fragmentation

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    The population of objects in space has increased dramatically over recent decades. Space debris now represents the majority of objects in space resulting from inactive satellites, breakups, collisions and fragmentations. It has become a concern for institutions all over the world and, as such, it has led to the fostering of several programmes to counter the issues. Among these, the use of ground-based sensors for Space Surveillance Tracking (SST) activities and services and tools for analysing fragmentations play a crucial role. This work presents the activities carried out by Politecnico di Milano, Italian Space Agency and Italian National Institute of Astrophysics in this framework, using data from SST networks and the observation measurements from Bistatic Radar for LEo Survey (BIRALES), an Italian bistatic radar belonging to the EUropean Space Surveillance and Tracking (EUSST), which contributed most to the monitoring of the cloud of fragments. Exploiting Two-Line Elements (TLEs) of observed fragments, a reverse engineering approach is used to reconstruct a fragmentation in orbit through the use of the software suite PUZZLE developed at Politecnico di Milano. The analyses focus on studying the fragmentation of the Cosmos 1408 satellite, which occurred on November 15th 2021 following an Anti-SATellite (ASAT) missile test. More than 1000 trackable pieces and millions of smaller debris (estimated from numerical analysis) were produced by this event, increasing the population of inactive objects around the Earth, and threatening nearby orbiting objects. First, the processing method adopted from BIRALES in observing Cosmos debris is presented and discussed and a critical analysis about the derivable information is conducted. Then, these data and those from SST network observations are used to identify the epoch and the location of the fragmentation. In this procedure, the software toolkit PUZZLE, developed by Politecnico di Milano within a project funded by the Italian Space Agency and extended through the European Research Council, is used

    Deep generative modeling for single-cell transcriptomics.

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    Single-cell transcriptome measurements can reveal unexplored biological diversity, but they suffer from technical noise and bias that must be modeled to account for the resulting uncertainty in downstream analyses. Here we introduce single-cell variational inference (scVI), a ready-to-use scalable framework for the probabilistic representation and analysis of gene expression in single cells ( https://github.com/YosefLab/scVI ). scVI uses stochastic optimization and deep neural networks to aggregate information across similar cells and genes and to approximate the distributions that underlie observed expression values, while accounting for batch effects and limited sensitivity. We used scVI for a range of fundamental analysis tasks including batch correction, visualization, clustering, and differential expression, and achieved high accuracy for each task

    Tetraethyl orthosilicate and acrylic acid forming robust carboxylic functionalities on plastic surfaces for biodiagnostics

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    Surface functionalisation and effects related to non-specific binding of the detection molecules are the key aspects to be considered for fluorescence-linked bioassays. Here, we present a deposition of polymeric structures with carboxylic acid functionalities by plasma enhanced chemical vapour deposition. We report on characterisation and some unique properties of the film formed as a result of sequential, plasma assisted fragmentation and deposition from vapours of acrylic acid (AA) and tetraethyl orthosilicate (TEOS). TEOS serves as an adhesion layer to the plastic substrate and also as a network building layer for further cross-linking with AA, the sequential plasma deposition resulting in a film of composition graded from inside to outside. The presence of silanols (Si-OH) can facilitate large uptake of water molecules and cause significant hydration of the layer, which in combination with high total negative charge lowers the non-specific binding of biomolecules. Furthermore, the specific combination of TEOS and AA significantly increased the proportion of carboxyl groups in the layer, above that found from deposition of AA alone. The availability and reactivity of the carboxyl functionalities for covalent attachment of specific bioreceptor molecules was confirmed by a total internal reflection ellipsometry technique in a reaction with amino terminated ssDNA. The combination of low non-specific binding and high specific binding amount gave a high signal/noise ratio. Ageing studies of the film showed long-term stability over 50 d. Carboxylic acid coatings have been deposited by PECVD onto cyclic olefin polymer substrates from an acrylic acid monomer. Carboxy properties are enhanced through the addition of TEOS as a base layer to the substrate, results are compared to coatings without this adhesion layer. A thorough analysis of the deposited surface and a comprehensive characterisation of the surface is investigated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    The critical role of the operating conditions on the Fenton oxidation of 2-chlorophenol: assessment of PCDD/Fs formation

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    This work assesses the influence of the operating conditions H2O2dose (20 or 100% of the stoichiometric amount), temperature (20 or 70◦C), and the presence of chloride in the oxidation medium in the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during Fenton treatment of aqueous samples of 2-chlorophenol, 2-CP, one of the strongest precursor of PCDD/Fs. After 4 h of oxidation in the experiments carried out with 20% H2O2chlorinated phenoxyphenols and biphenyls, which are intermediates in PCDD/Fs formation, as well as PCDD/Fs were observed, resulting in concentrations11 times higher than in the untreated sample. Additionally, when NaCl was also present in the reaction medium, PCDD/Fs were formed at higher extent, with a total concentration 74.4 times higher than in the untreated 2-CP solution. Results depicted a preferential formation of PCDFs over PCDDs, with dominance of lower chlorinated PCDD/Fs (tetra and penta-PCDD/Fs). Besides, the formation of the most toxic PCDD/Fs congeners (2,3,7,8-PCDD/Fs) was not favored under the operating conditions used in this work.Financial support from the projects CTQ2011-25262, CTQ2008-05545 and CTQ2008-00690 (Ministerio de Economía y Competitividad – MINECO (SPAIN) and Fondo Europeo de Desarrollo Regional – FEDER) is gratefully acknowledged

    Pyrite-induced hydroxyl radical formation and its effect on nucleic acids

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    BACKGROUND: Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested. RESULTS: Using a combination of electron spin resonance (ESR) spin-trapping techniques and scavenging reactions involving nucleic acids, the formation of hydroxyl radicals in pyrite/aqueous suspensions is demonstrated. The addition of EDTA to pyrite slurries inhibits the hydrogen peroxide-to-hydroxyl radical conversion, but does not inhibit the formation of hydrogen peroxide. Given the stability of EDTA chelation with both ferrous and ferric iron, this suggests that the addition of the EDTA prevents the transformation by chelation of dissolved iron species. CONCLUSION: While the exact mechanism or mechanisms of the hydrogen peroxide-to-hydroxyl radical conversion cannot be resolved on the basis of the experiments reported in this study, it is clear that the pyrite surface promotes the reaction. The formation of hydroxyl radicals is significant because they react nearly instantaneously with most organic molecules. This suggests that the presence of pyrite in natural, engineered, or physiological aqueous systems may induce the transformation of a wide range of organic molecules. This finding has implications for the role pyrite may play in aquatic environments and raises the question whether inhalation of pyrite dust contributes to the development of lung diseases
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