72 research outputs found

    SEISMIC RELIABILITY-BASED DESIGN OF STRUCTURES EQUIPPED WITH DFPS

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    This work deals with seismic reliability-based design (SRBD) for softening and hardening structures equipped with double friction pendulum system (DFPS) isolators. The isolated system is represented by means of an equivalent 3dof model having a softening/hardening post-yield slope for the superstructure and velocity-dependent rules for the two surfaces of the DFP devices. The yielding characteristics of the superstructures are defined in compli-ance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming ordinary characteristics. Considering several natural seismic records and the relevant random varia-bles, incremental dynamic analyses are carried out for assessing the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability-based design (SRBD) curves for these systems are proposed

    Seismic reliability-based design of softening structures equipped with double sliding devices

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    This study deals with seismic reliability-based design (SRBD) relationships in terms of beha-vior factors and displacement demands for softening structures equipped with double friction pendulum system (DFPS) bearings. An equivalent 3dof system having a softening post-yield slope is adopted to describe the superstructure behavior, whereas velocity-dependent laws are assumed to model the responses of the two surfaces of the DFPS. The yielding characte-ristics of the superstructures are defined for increasing behavior factors in compliance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming a lifetime of 50 years. Considering several natural seismic records and building properties under the hypothesis of modelling the friction coefficients of the two surfaces of the DFPS as random variables, in-cremental dynamic analyses are performed to evaluate the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability is assessed and seismic reliability-based design (SRBD) curves for the two surfaces of the double sliding devices are described

    Exploring Protein Interactions on a Minimal Type II Polyketide Synthase Using a Yeast Two-Hybrid System

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    Interactions between proteins that form the ’minimal’ type II polyketide synthase in the doxorubicin producing biosynthetic pathway from Streptomyces peucetius were investigated using a yeast two-hybrid system (Y2H). Proteins that function as the so called ’chain length factor’ (DpsB) and putative transacylase (DpsD) were found to interact with the ketosynthase subunit (DpsA), which can also interact with itself. On the basis of these results we propose a head-to-tail homodimeric structure, which is consistent with previously published in vivo mutagenesis studies. No interactions were found between the acyl-carrier protein (DpsG) and any of the other constituents of the complex, however, transient interactions, not detectable using the Y2H system, cannot be discounted and warrant further investigation

    Exploring Protein Interactions on a Minimal Type II Polyketide Synthase Using a Yeast Two-Hybrid System

    Get PDF
    Interactions between proteins that form the ’minimal’ type II polyketide synthase in the doxorubicin producing biosynthetic pathway from Streptomyces peucetius were investigated using a yeast two-hybrid system (Y2H). Proteins that function as the so called ’chain length factor’ (DpsB) and putative transacylase (DpsD) were found to interact with the ketosynthase subunit (DpsA), which can also interact with itself. On the basis of these results we propose a head-to-tail homodimeric structure, which is consistent with previously published in vivo mutagenesis studies. No interactions were found between the acyl-carrier protein (DpsG) and any of the other constituents of the complex, however, transient interactions, not detectable using the Y2H system, cannot be discounted and warrant further investigation

    P-RANSAC: An Integrity Monitoring Approach for GNSS Signal Degraded Scenario

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    Satellite navigation is critical in signal-degraded environments where signals are corrupted and GNSS systems do not guarantee an accurate and continuous positioning. In particular measurements in urban scenario are strongly affected by gross errors, degrading navigation solution; hence a quality check on the measurements, defined as RAIM, is important. Classical RAIM techniques work properly in case of single outlier but have to be modified to take into account the simultaneous presence of multiple outliers. This work is focused on the implementation of random sample consensus (RANSAC) algorithm, developed for computer vision tasks, in the GNSS context. This method is capable of detecting multiple satellite failures; it calculates position solutions based on subsets of four satellites and compares them with the pseudoranges of all the satellites not contributing to the solution. In this work, a modification to the original RANSAC method is proposed and an analysis of its performance is conducted, processing data collected in a static test

    Seismic reliability-based design of hardening structures equipped with double sliding devices

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    This study deals with seismic reliability-based design (SRBD) relationships in terms of beha-vior factors and displacement demands for hardening structures equipped with double fric-tion pendulum system (DFPS) bearings. An equivalent 3dof system having a hardening post-yield slope is adopted to describe the superstructure behavior, whereas velocity-dependent laws are assumed to model the responses of the two surfaces of the DFPS. The yielding cha-racteristics of the superstructures are defined for increasing behavior factors in compliance with the seismic hazard of L’Aquila site (Italy) and with NTC18 assuming a lifetime of 50 years. Considering several natural seismic records and building properties under the hypo-thesis of modelling the friction coefficients of the two surfaces of the DFPS as random variables, incremental dynamic analyses are performed to evaluate the seismic fragility and the seismic reliability of these systems. Finally, seismic reliability is evaluated and seismic relia-bility-based design (SRBD) curves for the two surfaces of the double sliding devices are de-scribed

    Physical activity and sport performance: adiponectin in relation to different physio-pathological status

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    Adiponectin (Acrp30), and in particular its High Molecular Weight (HMW) oligomers, contributes to enhance insulin sensitivity and to reduce inflammation levels. Physical exercise improves body’s biochemical balance and metabolism resulting effective in the prevention and therapy of metabolic diseases. Whether improvement of metabolic features mediated by physical exercise is associated with changes in Acrp30 serum composition is not yet clarified. In the present study, we investigated total Acrp30 expression and its oligomeric status in two different metabolic status: professional Water Polo (WP) Players and adult patients affected by Cystic Fibrosis (CF) that performed regular physical exercise. CF is an inherited metabolic disease characterized by alterations in lipid and glucidic metabolism. Our results demonstrated significant elevated BMI, AST and LDH levels and, conversely, significantly lower concentrations of total cholesterol and VLD were present in WP players. No significant difference was found in total Acrp30 and/or HMW oligomers. Interestingly, in WP players, a direct relationship between total Acrp30 and monocytes as well as an inverse relationship between total Acrp30 and AST levels were found. ACDC molecular screening revealed previously described SNPs. In CF patients, physical exercise has significant effects on lipid and glycemic metabolism. Indeed, patients that performed exercise are characterized by significant decrease of either VLDL, cholesterol and triglycerides, border-line significant decrease of either total cholesterol/HDL and non-HDL cholesterol/HDL ratio and by trend decrease of total, LDL and non-HDL cholesterol, although not significant. It’s to highlight that physical exercise significantly reduces glycemia and HOMA-IR and increases serum albumin. However, physical exercise does not modify Acrp30 concentrations that, on the other hand, result significantly higher in all CF patients compared to controls. In conclusion, even if peripheral muscle abnormalities and respiratory factors limit exercise in patients with CF, our study indicated that physical activity has beneficial effects on lipid and glycemic metabolism in these patients not associated with Acrp30

    Role of DNA repair machinery and p53 in the testicular germ cell cancer: a review

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    Notwithstanding the peculiar sensitivity to cisplatin-based treatment, resulting in a very high percentage of cures even in advanced stages of the disease, still we do not know the biological mechanisms that make Testicular Germ Cell Tumor (TGCT) "unique" in the oncology scene. p53 and MDM2 seem to play a pivotal role, according to several in vitro observations, but no correlation has been found between their mutational or expression status in tissue samples and patients clinical outcome. Furthermore, other players seem to be on stage: DNA Damage Repair Machinery (DDR) , especially Homologous Recombination (HR) proteins, above all Ataxia Telangiectasia Mutated (ATM), cooperates with p53 in response to DNA damage, activating apoptotic cascade and contributing to cell "fate". Homologous Recombination deficiency has been assumed to be a Germ Cell Tumor characteristic underlying platinum-sensitivity, whereby Poly(ADP-ribose) polymerase (PARP), an enzyme involved in HR DNA repair, is an intriguing target: PARP inhibitors have already entered in clinical practice of other malignancies and trials are recruiting TGCT patients in order to validate their role in this disease. This paper aims to summarize evidence, trying to outline an overview of DDR implications not only in TGCT curability, but also in resistance to chemotherapy
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