8,041 research outputs found

    Rate-Control or Rhythm-Contol: Where do we stand?

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    Atrial fibrillation is the most common sustained rhythm disturbance and its prevalence is increasing worldwide due to the progressive aging of the population. Current guidelines clearly depict the gold standard management of acute symptomatic atrial fibrillation but the best-long term approach for first or recurrent atrial fibrillation is still debated with regard to quality of life, risk of new hospitalizations, and possible disabling complications, such as thromboembolic stroke, major bleeds and death. Some authors propose that regaining sinus rhythm in all cases, thus re-establishing a physiologic cardiac function not requiring a prolonged antithrombotic therapy, avoids the threat of intracranial or extracranial haemorrhages due to Vitamin K antagonists or aspirin. On the contrary, advocates of a rate control approach with an accurate antithrombotic prophylaxis propose that such a strategy may avoid the risk of cardiovascular and non cardiovascular side effects related to antiarrhythmic drugs. This review aims to explore the state of our knowledge in order to summarize evidences and issues that need to be furthermore clarified

    Deamidation at Asparagine and Glutamine As a Major Modification upon Deterioration/Aging of Proteinaceous Binders in MuralPaintings

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    Proteomic strategies are herein proved to be a complementary approach to the well established amino acid composition analysis for the characterization of the aging and deterioration phenomena occurring to proteinaceous materials in works-of-art. Amino acid analyses on several samples demonstrated that proteins in the frescoes from the Camposanto Monumentale in Pisa are deteriorated as revealed by the decrease in Met, Lys, and Tyr content and by the presence in all the samples of amino malonic acid as a result of Ser, Phe, and Cys oxidation. Proteomic analysis identified deamidation at Asn and Gln as a further major event occurred. This work paves the way to the exploitation of proteomic strategies for the investigation of the molecular effects of aging and deterioration in historical objects. Results show that proteomic searches for deamidation by liquid chromatography-tandem mass spectrometry (LC-MS/MS) could constitute a routine analysis for paintings or any artistic and historic objects where proteins are present. Peptides that can be used as molecular markers when casein is present were identified

    Szeg\"o kernel asymptotics and Morse inequalities on CR manifolds

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    We consider an abstract compact orientable Cauchy-Riemann manifold endowed with a Cauchy-Riemann complex line bundle. We assume that the manifold satisfies condition Y(q) everywhere. In this paper we obtain a scaling upper-bound for the Szeg\"o kernel on (0, q)-forms with values in the high tensor powers of the line bundle. This gives after integration weak Morse inequalities, analogues of the holomorphic Morse inequalities of Demailly. By a refined spectral analysis we obtain also strong Morse inequalities which we apply to the embedding of some convex-concave manifolds.Comment: 40 pages, the constants in Theorems 1.1-1.8 have been modified by a multiplicative constant 1/2 ; v.2 is a final updat

    Double Beta Decays into Excited States in 110^{110}Pd and 102^{102}Pd

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    A search for double beta decays of 110^{110}Pd and 102^{102}Pd into excited states of the daughter nuclides has been performed using three ultra-low background gamma-spectrometry measurements in the Felsenkeller laboratory, Germany, the HADES laboratory, Belgium and at the LNGS, Italy. The combined Bayesian analysis of the three measurements sets improved half-life limits for the 2νββ2\nu\beta\beta and 0νββ0\nu\beta\beta decay modes of the 21+2^+_1, 01+0^+_1 and 22+2^+_2 transitions in 110^{110}Pd to 2.910202.9\cdot10^{20} yr, 4.010204.0\cdot10^{20} yr and 3.010203.0\cdot10^{20} yr respectively and in 102^{102}Pd to 7.610187.6\cdot10^{18} yr, 8.810188.8\cdot10^{18} yr and 1.410191.4\cdot10^{19} yr respectively with 90% credibility

    A collimation system for ELI-NP Gamma Beam System - design and simulation of performance

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    The purpose of this study was to evaluate the performance and refine the design of the collimation system for the gamma radiation source (GBS) currently being realised at ELI-NP facility. The gamma beam, produced by inverse Compton scattering, will provide a tunable average energy in the range between 0.2 and 20 MeV, an energy bandwidth 0.5% and a flux of about 108 photons/s. As a result of the inverse Compton interaction, the energy of the emitted radiation is related to the emission angle, it is maximum in the backscattering direction and decreases as the angle increase [1,2]. Therefore, the required energy bandwidth can be obtained only by developing a specific collimation system of the gamma beam, i.e. filtering out the radiation emitted at larger angles. The angular acceptance of the collimation for ELI-NP-GBS must be continuously adjustable in a range from about 700 to 60 μrad, to obtain the required parameters in the entire energy range. The solution identified is a stack of adjustable slits, arranged with a relative rotation around the beam axis to obtain an hole with an approximately circular shape. In this contribution, the final collimation design and its performance evaluated by carrying out a series of detailed Geant4 simulations both of the high-energy and the low-energy beamline are presented

    Esperienze di didattica della fisica in diversi livelli del sistema educativo

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    The growing interest of people in science events, the projects supported by the Italian Ministry of Education, University and Research to foster STEM teaching in different levels of the education system and the introduction of modern physics in some Italian high schools, contributed to the strengthening of interaction between schools, universities and research centers. This interaction realized in dedicated activities characterized by innovative communication and education strategies.This paper presents the events of science dissemination organized in the last years by the University of Ferrara and the National Institute for Nuclear Physics taking into account some case study differentiated by contents, recipients and education strategies.Comment: The article is written in Italia

    Droplets move over viscoelastic substrates by surfing a ridge

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    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a ridge: the initially flat solid surface is deformed into a sharp ridge whose orientation angle depends on the contact line velocity. We measure this angle for water on a silicone gel and develop a theory based on the substrate rheology. We quantitatively recover the dynamic contact angle and provide a mechanism for stick-slip motion when a drop is forced strongly: the contact line depins and slides down the wetting ridge, forming a new one after a transient. We anticipate that our theory will have implications in problems such as self-organization of cell tissues or the design of capillarity-based microrheometers.Comment: 9 pages, 5 figure

    Search for α\alpha decay of 151^{151}Eu to the first excited level of 147^{147}Pm using underground γ\gamma-ray spectrometry

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    The alpha decay of 151^{151}Eu to the first excited level of 147^{147}Pm (Jπ=5/2+J^\pi = 5/2^+, Eexc=91.1E_{exc}=91.1 keV) was searched for at the HADES underground laboratory (500\approx 500 m w.e.). A sample of high purity europium oxide with mass of 303 g and a natural isotopic composition has been measured over 2232.8 h with a high energy resolution ultra-low background n-type semi-planar HPGe detector (40 cm3^3) with sub-micron deadlayer. The new improved half-life limit has been set as T1/23.7×1018T_{1/2} \geq 3.7\times 10^{18} yr at 68% C.L. Possibilities to improve the sensitivity of the experiment, which is already near the theoretical predictions, are discussed. New half-life limit for α\alpha decay of 153^{153}Eu is also set as T1/25.5×1017T_{1/2} \geq 5.5\times 10^{17} yr.Comment: 11 pages, 5 figures, 2 tables, 18 reference
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