236 research outputs found

    The “Mandolesi Pavilion”: an information model for a process of integrating multidisciplinary knowledge

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    The Mining Engineering Pavilion was designed by Enrico Mandolesi in 1962. It represents an icon heralding the transition from masonry to reinforced concrete and the use of “new” materials. Its recovery may become an important starting point for integrating all scientific levels, from the construction history, which reconstructs the history of the project and that of the building site, up to the most sophisticated energy diagnoses that include the definition of an integrated information system on the building, to be used in cutting-edge style with the BIM approach or even with experimentation in a first-step evolution towards a cognitive building

    The building information modeling for the retrofitting of existing buildings. A case study in the University of Cagliari.

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    Italy's very consistent buildings stock has become the major field for real estate investments and for the related projects and actions. The urge of working on built environment is however facing some crucial issues. The first is the lack of documentation on the construction history and on the real constructive layout of existing buildings (in terms of components, installations, plants, etc.). The second is the poor activity in surveying their current status, with reference to use (energy behaviour, real consumptions, etc.) and maintenance (conservation status, previous maintenance works, compliance with current regulations, etc.). These obstacles cause a deep inefficiency in the planning, programming and controlling of requalification and/or refunctionalisation works. Starting from these assumptions, this paper shows the findings of a research shared by the Politecnico of Milan and the Department of Civil and Environmental Engineering and Architecture of the University of Cagliari. It is aimed at testing the use of building information modeling (BIM) to structure the necessary knowledge to evaluate intervention scenarios. The research is focused on the Mandolesi Pavilion of the University of Cagliari, designed by Enrico Mandolesi. It is a highly stimulating architectural object because it incorporates values that require a conservative approach, but at the same time, like most contemporary buildings, it was designed and built for innovation and not for “long duration”. The work has actually led to the realization of a BIM model of the case study. It represents the first prefiguration of an approach that develops from construction history and continues with advanced diagnostics on the statical and energy performances of the building. The model formalizes knowledge and information on a significant building, aimed at its management. It allows also the setting of intervention scenarios that can be evaluated with real-time simulations of cost, time and ROI

    Evaluation of growth potential and growth dynamics of Listeria monocytogenes on ready-to-eat fresh fruit

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    The consumption of fresh or RTE fruits is increasing every year and Listeria monocytogenes has been identified on raw or minimally processed fruits. A food product can become contaminated with L. monocytogenes anywhere along the pathway of food production during planting, harvesting, packaging, distribution and serving. The aim of this work was to assess the microbiological risks associated with consumption of ready-to-eat fruit such as melon, pineapple, coconut and fruit salad. The presence of Escherichia coli, Salmonella spp. and L. monocytogenes was also evaluated. Microbiological challenge tests were carried out for the evaluation of the L. monocytogenes growth potential in RTE fruit stored at 4 and 8°C. E. coli counts resulted under the detection limit of 10 CFU g-1, Salmonella and L. monocytogenes were not detected (absence in 25g). The growth potential values in coconut and melon (δ>0.5) showed the growth capacity of Listeria at the temperatures considered. A low initial load, also derived from good hygiene practices, and correct storage temperatures are essential to reduce bacterial growth in RTE fruit. The challenge test showed how each type of RTE fruit has a different commercial life based on its specific growth potential and that food should be stored at temperatures not higher than 4°C for a short period

    Terrestrial Laser Scanner and Close Range Photogrammetry point clouds accuracy assessment for the structure deformations monitoring

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    In this paper we show the results of several tests carried out using methods and instrumentation typical of an architectural survey, along with a set of metrological instrumentation, on a Reinforced Concrete (RC) beam subjected to increasing loads. The goal was to assess the accuracy in the displacements estimated by a medium quality terrestrial laser scanner (TLS) Focus 3d from Faro Technologies, and the low-cost digital camera Canon PowerShot S110 used in a Close Range Photogrammetry (CRP) survey. The software used for scan-data and point clouds processing was Reconstructor JRC Software v. 3.1.0, maintained by Gexcel Ltd, while the images processing was performed with the software Photoscan from Agisoft, which implements Structure from Motion (SfM) approach. Two processing strategies were used in the point clouds comparison: mesh2mesh and modelling the beam behavior fitting the contours of the beam with second order polynomials. Comparisons between the TLS and CRP techniques and the metrological equipment used in parallel highlighted the limits and potentialities of the two geomatic techniques used. It has been shown that modeling the behavior of the beam leads to significantly better results than using the mesh2mesh comparison. For the CRP the increase in accuracy was in the order of 40%, while for the TLS of 50%

    Binge-like administration of alcohol mixed to energy drinks to male adolescent rats severely impacts on mesocortical dopaminergic function in adulthood: A behavioral, neurochemical and electrophysiological study

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    A growing body of evidence indicates that the practice of consuming alcohol mixed with energy drinks (ED) (AMED) in a binge drinking pattern is significantly diffusing among the adolescent population. This behavior, aimed at increasing the intake of alcohol, raises serious concerns about its long-term effects. Epidemiological studies suggest that AMED consumption might increase vulnerability to alcohol abuse and have a gating effect on the use of illicit drugs. The medial prefrontal cortex (mPFC) is involved in the modulation of the reinforcing effects of alcohol and of impulsive behavior and plays a key role in the development of addiction. In our study, we used a binge-like protocol of administration of alcohol, ED, or AMED in male adolescent rats, to mimic the binge-like intake behavior observed in humans, in order to evaluate whether these treatments could differentially affect the function of mesocortical dopaminergic neurons in adulthood. We did so by measuring: i) physiological sensorimotor gating; ii) voluntary alcohol consumption and dopamine transmission before, during, and after presentation of alcohol; iii) electrophysiological activity of VTA dopaminergic neurons and their sensitivity to a challenge with alcohol. Our results indicate that exposure to alcohol, ED, or AMED during adolescence induces differential adaptive changes in the function of mesocortical dopaminergic neurons and, in particular, that AMED exposure decreases their sensitivity to external stimuli, possibly laying the foundation for the altered behaviors observed in adulthood

    Repurposing the Antibacterial Activity of the Drug Teniposide Against Gram‐Positive Bacteria

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    Drug repurposing is sparking considerable interest due to reduced costs and development times. The current study details the screening of teniposide, an antitumor drug, for its antibacterial activity against both Gram-positive and Gram-negative strains, with a focus on Staphylococcus epidermidis (S. epidermidis), the primary causative agent of nosocomial and transplant-related infections. The cytotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and hemolysis assays on immortalized human keratinocyte (HaCaT) cells and human erythrocytes. After 20 h of treatment, the recorded concentrations causing 50% cytotoxicity (CC50) and hemolysis (HC50) were 33.63 and 121.55 μg/mL, respectively. The antibacterial screening employed disk diffusion, the broth microdilution method, LIVE/DEAD staining, and a time-killing test. The drug induced a growth inhibitory area in the 22–25 mm range for all Gram-positive strains. The minimum concentration that inhibited 90% of bacteria (MIC90) was 6.25 μg/mL against Staphylococcus aureus and S. epidermidis and 12.5 μg/mL versus Enterococcus faecalis, exhibiting bactericidal action. Treatment resulted in S. epidermidis cell morphology deformities and damage to the cell membrane, observed by scanning electron microscopy (SEM). Mechanism analysis revealed alterations in the selective permeability of the cell membrane, observed under the fluorescence microscope by the absorption of propidium iodide (PI). The synergistic effect of teniposide in combination with fosfomycin and gentamicin was documented by disk diffusion and checkboard assay, recording a fractional inhibitory concentration index (FICI) of 0.28 and 0.37, respectively. The drug’s action on S. epidermidis biofilm biomass was investigated using crystal violet (CV) and MTT. Teniposide affected biofilm viability in a dose-dependent manner, inducing, at a concentration of 3.12 μg/mL, a matrix inhibition of about 42% and 61%, with a sessile metabolic activity of 54% and 24% recorded after 2 and 24 h, respectively. Overall, this study suggests the potential repurposing of the anticancer drug teniposide as a therapeutic agent to counteract S. epidermidis infections

    Single-step green synthesis and characterization of gold-conjugated polyphenol nanoparticles with antioxidant and biological activities

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    Background: Gold nanoparticles (GNPs) are likely to provide an attractive platform for combining a variety of biophysicochemical properties into a unified nanodevice with great therapeutic potential. In this study we investigated the capabilities of three different natural polyphenols, epigallocatechin-3-gallate (EGCG), resveratrol (RSV), and fisetin (FS), to allow synergistic chemical reduction of gold salts to GNPs and stabilization in a single-step green process. Moreover, antioxidant properties of the nanosystems, as well as preliminary antiproliferative activity and apoptotic process investigation of model EGCG-GNPs on stable clones of neuroblastoma SH-SY5Y cells expressing CFP-DEVD-YFP reporter, were examined. Methods: The GNPs were characterized by physicochemical techniques, polyphenol content, and in vitro stability. The antioxidant activity of the GNPs was also determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS) radical-scavenging assays. Stable clones of neuronal SH-SY5Y-CFP-DEVD-YFP were generated and characterized, and cell viability after treatment with EGCG-GNPs was assessed after 72 hours through a 3(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Activation of the apoptotic pathways was also investigated by Western blot analysis. Results: With a diameter in the size range of 10–25 nm, the obtained nanoparticles (NPs) were found to contain 2.71%, 3.23%, and 5.47% of EGCG, RSV, and FS, respectively. Nanoprototypes exhibited remarkable in vitro stability in various media, suggesting that NP surface coating with phytochemicals prevents aggregation in different simulated physiological conditions. The scavenging activities for DPPH and ABTS were highly correlated with EGCG, RSV, and FS content. Moreover, high correlation coefficients between the ABTS and DPPH values were found for the prepared nanosystems. EGCG-GNPs induce a dose-dependent reduction on SH-SY5Y-CFP-DEVD-YFP cell viability that is likely to involve the activation of the apoptotic pathways, similarly to free EGCG, as suggested by the processing of the CFP-DEVD-YFP reporter. Conclusion: These results prompted us to propose the ecofriendly synthesized EGCG-, RSV-, and FS-based nanogold conjugates as suitable carriers for bioactive polyphenols to be used for the treatment of disorders associated with oxidative stress, including neurodegenerative disorders, cardiovascular disease, and cancer.</br

    2-arilbenzimidazoli come potenziali agenti antivirali e antitumorali

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    I derivati benzimidazolici trovano impiego in numerose patologie. Tra gli esempi di più estesa applicazione si ricordano i farmaci antielmintici per il loro meccanismo d’inibizione mitotica. Recentemente sono stati oggetto di valutazione anche come farmaci antivirali. Gli esempi riportati rappresentano la struttura di composti che mimano i nucleosidi purinici, nei quali la base è stata sostituita con il nucleo benzimidazolico
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