658 research outputs found

    Full-wave electromagnetic modes and hybridization in nanoparticle dimers

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    The plasmon hybridization theory is based on a quasi-electrostatic approximation of the Maxwell’s equations. It does not take into account magnetic interactions, retardation effects, and radiation losses. Magnetic interactions play a dominant role in the scattering from dielectric nanoparticles. The retardation effects play a fundamental role in the coupling of the modes with the incident radiation and in determining their radiative strength; their exclusion may lead to erroneous predictions of the excited modes and of the scattered power spectra. Radiation losses may lead to a significant broadening of the scattering resonances. We propose a hybridization theory for non-Hermitian composite systems based on the full-Maxwell equations that, overcoming all the limitations of the plasmon hybridization theory, unlocks the description of dielectric dimers. As an example, we decompose the scattered field from silicon and silver dimers, under different excitation conditions and gap-sizes, in terms of dimer modes, pinpointing the hybridizing isolated-sphere modes behind them

    Semileptonic and Rare BB-meson transitions in a QCD relativistic potential model

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    Using a QCD relativistic potential model, previously applied to the calculation of the heavy meson leptonic constants, we evaluate the form factors governing the exclusive decays BρνB\to\rho\ell\nu, BKγB\to K^*\gamma and BK+B\to K^*\ell^+\ell^-. In our approach the heavy meson is described as a QqˉQ\bar q bound state, whose wave function is solution of the relativistic Salpeter equation, with an instantaneous potential displaying Coulombic behaviour at small distances and linear behaviour at large distances. The light vector meson is described by using a vector current interpolating field, according to the Vector Meson Dominance assumption. A Pauli-Villars regularized propagator is assumed for the quarks not constituting the heavy meson. Our procedure allows to avoid the description of the light meson in terms of wave function and constituent quarks, and consequently the problem of boosting the light meson wave function. Assuming as an input the experimental results on BKγB\to K^*\gamma, we evaluate all the form factors describing the Bρ,KB\to \rho, K^* semileptonic and rare transitions. The overall comparison with the data, whenever available, is satisfactory.Comment: Latex, 19 pages, 3 figure

    Francesca Gherardi (1955-2013)

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    Chronic bacterial prostatitis: efficacy of short-lasting antibiotic therapy with prulifloxacin (Unidrox®) in association with saw palmetto extract, lactobacillus sporogens and arbutin (Lactorepens®)

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    Bacterial prostatitis (BP) is a common condition accounting responsible for about 5-10% of all prostatitis cases; chronic bacterial prostatitis (CBP) classified as type II, are less common but is a condition that significantly hampers the quality of life, (QoL) because not only is it a physical condition but also a psychological distress. Commonly patients are treated with antibiotics alone, and in particular fluoroquinolones are suggested by the European Urology guidelines. This approach, although recommended, may not be enough. Thus, a multimodal approach to the prolonged antibiotic therapy may be helpful.210 patients affected by chronic bacterial prostatitis were enrolled in the study. All patients were positive to Meares-Stamey test and symptoms duration was > 3 months. The purpose of the study was to evaluate the efficacy of a long lasting therapy with a fluoroquinolone in association with a nutraceutical supplement (prulifloxacin 600 mg for 21 days and an association of Serenoa repens 320 mg, Lactobacillus Sporogens 200 mg, Arbutin 100 mg for 30 days). Patients were randomized in two groups (A and B) receiving respectively antibiotic alone and an association of antibiotic plus supplement.Biological recurrence at 2 months in Group A was observed in 21 patients (27.6%) and in Group B in 6 patients (7.8%). Uropathogens found at the first follow-up were for the majority Gram - (E. coli and Enterobacter spp.). A statistically significant difference was found at the time of the follow-up between Group A and B in the NIH-CPSI questionnaire score, symptoms evidence and serum PSA.Broad band, short-lasting antibiotic therapy in association with a nutritional supplement (serenoa repens, lactobacillus sporogens and arbutin) show better control and recurrence rate on patients affected by chronic bacterial prostatitits in comparison with antibiotic treatment alone.NCT02130713Date of trial Registration: 30/04/2014

    Mobilità è sviluppo. Strumenti e competenze per il futuro della mobilità

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    Il volume Mobilità è sviluppo è un approfondimento sulle frontiere di sviluppo della mobilità urbana e sulle sue possibili evoluzioni. Il volume intende interrogare il rapporto tra le innovazioni tecnologiche, sociali ed infrastrutturali della mobilità urbana e del loro impatto nel contribuire alla qualità della vita, all’evoluzione di nuove formule di cittadinanza e alle politiche per uno sviluppo territoriale sostenibile. Osservare le comunità di pratiche che innovano il mercato dei servizi e l’organizzazione delle infrastrutture per la mobilità è una questione di particolare rilevanza. Se questi nuovi fattori mettono a disposizione opportunità inedite, sono meno scontate le capacità necessarie per assicurarne l’accesso da parte di tutti i cittadini. Nella nostra visione, osservando queste recenti trasformazioni nel campo della mobilità, occorre fornire un quadro interpretativo sulle competenze, sugli strumenti e sulle regole necessarie a creare promuovere qualità della vita per tutti i cittadini tenendo presente la più ampia cornice dello sviluppo sostenibile (UN, Agenda 2030). I contributi raccolti nel volume vogliono quindi suggerire gli strumenti del futuro della mobilità, descrivendone i percorsi di sviluppo di nuove capacità ed impatti sociali delle pratiche e dei progetti sperimentati, migliorando la qualità della vita dei singoli user e del funzionamento di particolari dinamiche territoriali. A questo scopo, i contributi raccontano di interpretazioni e pratiche emergenti nella mobilità urbana del futuro, proponendo di assumere l’accessibilità (ovvero, muoversi per fare cosa) come prospettiva privilegiata per comprendere e affrontare le questioni della mobilità urbana. In questa prospettiva di capacitazione e sostegno alle opportunità degli individui, i contributi affrontano le sfide e le opportunità poste da nuove infrastrutture e tecnologie (dai dispositivi per la condivisione di informazioni, i veicoli a guida automatica, le infrastrutture leggere)

    In vitro analysis of the fracture resistance of CAD-CAM monolithic zirconia molar crowns with different occlusal thickness

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    Objectives: To compare the fracture resistance and mode of failure of CAD-CAM monolithic zirconia crowns with different occlusal thickness. Material and methods: Forty CAD-CAM monolithic zirconia crowns with different occlusal thickness were randomly distributed into 4 experimental groups: 2.0 mm (group 1), 1.5 mm (group 2), 1.0 mm (group 3) and 0.5 mm (group 4). The restorations were cemented onto human molars with a self-adhesive resin cement. The specimens were loaded until fracture; the fracture resistance and mode of failure were recorded. The data were statistically analyzed with the one-way ANOVA followed by the Fisher's Exact test with Bonferroni's correction (p=0.05). Results: The fracture resistance values of all the specimens exceeded the maximum physiological occlusal loads in molar regions. All the crowns showed cohesive microcracks of the zirconia core; only 1 crown with a thickness of 0.5 mm was interested by a complete fracture. Conclusions: The occlusal thickness of CAD-CAM monolithic zirconia crowns did not influence either the fracture resistance and the mode of failure of the restorations; the occlusal thickness of CAD-CAM monolithic zirconia crowns can be reduced up to a lower bound of 0.5 mm keeping a sufficient strength to withstand occlusal loads; CAD-CAM monolithic zirconia crowns showed sufficient fracture resistance to be used in molar regions, even in a thin configuration (0.5 mm)

    The killer shrimp Dikerogammarus villosus (Sowinsky, 1894) is spreading in Italy.

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