339 research outputs found

    Uncertainty Quantification of an ORC turbine blade under a low quantile constrain

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    Typical energy sources for ORC power systems, such as waste heat recovery or biomass, geothermal, and solar energy, typically feature variable heat load and turbine-inlet thermodynamic conditions. In this context, advanced uncertainty quantification and robust optimization methodologies are nowadays available and could be used during the ORC turbine design process in order to account for multiple uncertainties. This study presents a preliminary ANOVA and Uncertainty Quantification analysis, prior to apply robust shape optimization approach to ORC turbine blades, to overcome the limitation of a deterministic optimization that neglects the effect of uncertainties of operating conditions or design variables. The analysis is performed by applying a two-dimensional inviscid computational fluid dynamic model to a typical supersonic turbine cascade for ORC applications. The working fluid is siloxane MDM, which in the conditions of interest exhibits relevant non-ideal effects, here modeled by using of a Peng-Robinson-Stryjek-Vera equation of state

    Antiplasmodial activity of p-substituted benzyl thiazinoquinone derivatives and their potential against parasitic infections

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    Malaria is a life-threatening disease and, what is more, the resistance to available antimalarial drugs is a recurring problem. The resistance of Plasmodium falciparum malaria parasites to previous generations of medicines has undermined malaria control efforts and reversed gains in child survival. This paper describes a continuation of our ongoing efforts to investigate the effects against Plasmodium falciparum strains and human microvascular endothelial cells (HMEC-1) of a series of methoxy p-benzyl-substituted thiazinoquinones designed starting from a pointed antimalarial lead candidate. The data obtained from the newly tested compounds expanded the structure-activity relationships (SARs) of the thiazinoquinone scaffold, indicating that antiplasmodial activity is not affected by the inductive effect but rather by the resonance effect of the introduced group at the para position of the benzyl substituent. Indeed, the current survey was based on the evaluation of antiparasitic usefulness as well as the selectivity on mammalian cells of the tested p-benzyl-substituted thiazinoquinones, upgrading the knowledge about the active thiazinoquinone scaffold

    In vitro study: binding of 99mTc-DPD to synthetic amyloid fibrils

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    Abstract This paper is an report of the investigation of the in vitro binding of 99mTc-DPD for synthetic amyloid fibrils used for the diagnosis of cardiac amyloidosis (CA), as compared with the use of 99mTc-HMDP and 99mTc-PPI. It also includes an inquiry into the role played by Ca2+ ions and serum proteins on binding to amyloid like materials, as well as the saturability and specificity of DPD for fibrils versus amorphous precipitates (AP). In the work, synthetic insulin fibrils (SIF) and AP were characterized by Congo red staining and TEM imaging. An equal amount of three radiopharmaceuticals were then added to fibrils in Ca2+ (0-4.2 mmol/L) or human serum (HS) adjoined samples and radiopharmaceutical uptake was assessed. To test the saturability of amyloid binding sites, a displacement assays with cold DPD was performed, while adding 50-1500 nmol of 99mTc-DPD to SIF or AP, saturation binding tests were subsequently carried out for evaluating its specificity for amyloid. Herein, synthetic fibrils and AP showed conformational differences at TEM and polarized microscopy analysis. In our study, 99mTc-DPD fibrils uptake was seen to be the highest and increased with calcium ions concentration. What is more, serum proteins reduced the bound fraction to the amyloid deposits of about 15%, and the Kd values of 90 nM and 114 nM relative to SIF and AP, respectively, did not significantly differ. We saw that 99mTc-DPD is the best seeker for amyloid fibrils in cardiac amyloidosis, and that Ca2+ concentration positively influenced DPD fibrils binding. Furthermore, the radioactivity bound to the serum protein clear up the idea of nuclide exchanging dynamic balance between amyloid and circulating proteins. Moreover, non-labeled DPD did not exert a competition for 99mTc-DPD binding sites, and, finally, DPD cannot be defined a radiopharmaceutical specific for amyloid deposits

    Investigating the antiparasitic potential of the marine sesquiterpene avarone, its reduced form avarol, and the novel semisynthetic thiazinoquinone analogue thiazoavarone

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    The chemical analysis of the sponge Dysidea avara afforded the known sesquiterpene quinone avarone, along with its reduced form avarol. To further explore the role of the thiazinoquinone scaffold as an antiplasmodial, antileishmanial and antischistosomal agent, we converted the quinone avarone into the thiazinoquinone derivative thiazoavarone. The semisynthetic compound, as well as the natural metabolites avarone and avarol, were pharmacologically investigated in order to assess their antiparasitic properties against sexual and asexual stages of Plasmodium falciparum, larval and adult developmental stages of Schistosomamansoni (eggs included), and also against promastigotes and amastigotes of Leishmania infantum and Leishmania tropica. Furthermore, in depth computational studies including density functional theory (DFT) calculations were performed. A toxic semiquinone radical species which can be produced starting both from quinone- and hydroquinone-based compounds could mediate the anti-parasitic effects of the tested compounds

    Dynamical decoherence in a cavity with a large number of two-level atoms

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    We consider a large number of two-level atoms interacting with the mode of a cavity in the rotating-wave approximation (Tavis-Cummings model). We apply the Holstein-Primakoff transformation to study the model in the limit of the number of two-level atoms, all in their ground state, becoming very large. The unitary evolution that we obtain in this approximation is applied to a macroscopic superposition state showing that, when the coherent states forming the superposition are enough distant, then the state collapses on a single coherent state describing a classical radiation mode. This appear as a true dynamical effect that could be observed in experiments with cavities.Comment: 9 pages, no figures. This submission substitutes paper quant-ph/0212148 that was withdrawn. Version accepted for publication in Journal of Physics B: Atomic, Molecular & Optical Physic

    EFFECT OF WIND LOADS ON NON REGULARLY SHAPED HIGH-RISE BUILDINGS

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    Wind loads have historically been recognized as one of the most important issue in high-rise buildings analysis and design. In particular, in regions of low seismic intensity, a high-rise building lateral design is controlled by wind loads. In wind analysis, Computational Fluid Dynamics (CFD) and/or wind tunnel testing are required to calculate the external pressures acting on a building. In this paper, two case studies are presented to show how the wind loads are calculated and applied in design. The first case study is based on the CFD results for the New Marina Casablanca Tower in Casablanca, Morocco. The second case study considers the results from the wind tunnel test studies conducted for the Al- Hamra tower, in Kuwait City, Kuwait. The New Marina Casablanca tower is a 167m tall concrete building, with a unique twisting shape generated from the relative rotation of two adjacent floors. Sloped columns are introduced in the perimeter to follow the tower outer geometry and to support the concrete slabs spanning between the central core and the perimeter frame. The effects of wind loads on the twisted geometry has been studied in details since the pressure coefficients are not easily identified for such a complex form. In addition, the effect of the wind loads on the structure presented unique challenges that required innovative structural solutions. The Al-Hamra tower is a 412m tall concrete building with a sculpted twisting form which optimizes the views to the Arabian Gulf while minimizing the solar heat gain. The complex form is realized using sloped walls and vertical columns on the perimeter and a central concrete core. The unique shape of the tower presented several design challenges related to the wind loads on the structure. This paper will discuss the unique challenges and solutions associated with wind loads effect on buildings of unique form

    Nuove tecniche di prospezione archeologica mediante strumenti multifrequenza

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    EnIn this work we present some results obtained in a measurement survey performed with a stepped frequency Ground Penetrating Radar (GPR). The GPR and the survey at hand have been conceived for archaeological purposes.The stepped frequency GPR has been developed by the Italian Research Consortium CO.RI.S.T.A. in the framework of the ARCHEO project, founded by Italian M.U.R.S.T. The system can work within a large bandwidth and both in ungated and gated mode. It is equipped with a positioning system able to move the transmitting and receiving antennas of the GPR independently on each other and to place them automatically and in a precise fashion. The GPR has been tested first in laboratory of CO.RI.S.T.A., then in a controlled site, and finally in the real archaeological site of Cales, near Capua (Southern Italy), preventively and appositely studied by a team of archaeologists. The final results obtained in the field have been coherent with a previous prospecting performed at Cales and have individuated some new further buried targets, whose nature is still unknown at the moment

    Time makes histone H3 modifications drift in mouse liver

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    To detect the epigenetic drift of time passing, we determined the genome-wide distributions of mono- and tri-methylated lysine 4 and acetylated and tri-methylated lysine 27 of histone H3 in the livers of healthy 3, 6 and 12 months old C57BL/6 mice. The comparison of different age profiles of histone H3 marks revealed global redistribution of histone H3 modifications with time, in particular in intergenic regions and near transcription start sites, as well as altered correlation between the profiles of different histone modifications. Moreover, feeding mice with caloric restriction diet, a treatment known to retard aging, reduced the extent of changes occurring during the first year of life in these genomic regions

    Genetic predictors of response to treatment of chronic hepatitis C virus infection in patients from southern Italy

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    Various clinical and genetic factors affect response to antiviral treatment of chronic hepatitis C virus (HCV) infection. The IL28B single-nucleotide polymorphism (SNP) rs12979860 is associated with a sustained viral response (SVR), and the suppressor cytokine signaling 3 (SOCS3) gene is over-expressed in HCV-1b non-responders. The aim of this study was to look for correlations between genetic, clinical and viral factors implicated in response to antiviral treatment in chronic HCV infection. We evaluated 190 controls and 148 HCV-infected patients (102 HCV-1 and 46 HCV-2). Demographic, metabolic and histological features related to antiviral treatment were recorded. Univariate and multivariate analyses were used to identify correlations between the genetic and non-genetic features examined and response to antiviral treatment. IL28B expression was higher in CC SNPs versus other alleles in controls (P=0.01) and this difference was associated with viral infection (HCV vs controls P=0.006), particularly in HCV-2 patients (P=0.003). SOCS3 and IL28B expression was correlated with controls (P=0.011), whereas there was an inverse correlation between the expression of the two genes in HCV patients and HCV-1b non-responders (P=0.014 and P=0.03, respectively). Multivariate analysis showed that the only independent SVR predictive factor was rapid virological response. The frequency of IL28B rs12979860 SNP alleles in controls (C allele=71.1% and T allele= 28.9%) was comparable to that of the HCV population (C allele=66.6% and T allele=33.4%). Rapid virological response seems to be the only significant independent predictor of an SVR to antiviral treatment. The inverse correlation between SOCS3 and IL28B expression in genotype 1b non-responders suggests that SOCS3 may affect IL28B expression thereby influencing response to antiviral therapy
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