1,755 research outputs found

    Short-Term Neurodevelopmental Outcome in Term Neonates Treated with Phenobarbital versus Levetiracetam: A Single-Center Experience

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    BACKGROUND: Phenobarbital (PB) has been traditionally used as the first-line treatment for neonatal seizures. More recently, levetiracetam (LEV) has been increasingly used as a promising newer antiepileptic medication for treatment of seizures in neonates. OBJECTIVES: The aim of our study was to compare the effect of PB vs. LEV on short-term neurodevelopmental outcome in infants treated for neonatal seizures. METHOD: This randomized, one-blind prospective study was conducted on term neonates admitted to the Neonatal Intensive Care Unit of S. Bambino Hospital, University Hospital "Policlinico-Vittorio Emanuele," Catania, Italy, from February 2016 to February 2018. Thirty term neonates with seizures were randomized to receive PB or LEV; the Hammersmith Neonatal Neurological Examination (HNNE) was used at baseline (T0) and again one month after the initial treatment (T1). RESULTS: We found a significantly positive HNNE score for the developmental outcomes, specifically tone and posture, in neonates treated with LEV. There was no significant improvement in the HNNE score at T1 in the neonates treated with PB. CONCLUSION: This study suggests a positive effect of levetiracetam on tone and posture in term newborns treated for neonatal seizures. If future randomized-controlled studies also show better efficacy of LEV in the treatment of neonatal seizures, LEV might potentially be considered as the first-line anticonvulsant in this age grou

    INTERACTION OF STRAIN RATE AND NECKING ON THE STRESS-STRAIN RESPONSE OF UNIAXIAL TENSION TESTS BY HOPKINSON BAR

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    Abstract The effect of the necking combined to that of the strain rate is analysed in dynamic split Hopkinson bar (SHTB) tests, by both experiments and finite elements. Experiments from the literature by Noble et al. are considered here together with other tests ran at the University of Catania. Two different characterization procedures are used for modeling the materials, leading to strain and strain rate-dependent flow stress according to the Johnson-Cook model for the Remco Iron by Noble et al., and to an MLR-based calibration for the FeN steel implemented by fortran subroutines, respectively. After satisfactory validation of the finite elements results and of the dynamic hardening models via comparison to the experimental stress-strain, a detailed investigation on the way the necking perturbation of the stress interacts with the strain rate is carried out, expecially investigating how the ratio of the flow stress/true stress evolves with the strain and the strain rate. Special modifications are introduced to the subroutine modeling the strain rate-promoted dynamic amplification of the stress; the related response from finite elements confirms the outcomes of previous papers, unveiling a new feature of the dynamic stress in SHTB tests and providing new information about the suitability and the accuracy of the modern procedures for the dynamic stress-strain characterization

    A new yield criteria including the effect of lode angle and stress triaxiality

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    AbstractAccording to several experiments reported in the literature, the elastoplastic behaviour of metals depends not only on the first stress invariant (triaxiality) for the ductile damage and on the second stress invariant (equivalent von Mises stress) for the yield, but also on the third stress invariant (normalized Lode angle X) which may affect at the same time the yielding and the ductile failure.In this paper a new yield model is presented, where the yield surface depends on the Lode Angle and, eventually, also on the triaxiality ratio.The proposed model is identified by a calibration parameter expressing the degree of nonlinearity of the yield with respect to the Lode angle, and a calibration function expressing the maximum variability of the hardening stress at the two extremities of the Lode angle range, corresponding to the uniaxial and to the pure shear stress states.The proposed model has been tested against several experimental data from the literature on the Titanium alloy Ti6Al4V, including mixed tension-torsion loading which allowed to control the evolution of X and to confine its values into different narrow ranges for better investigating the Lode angle effects on the yield response

    Identification of aroma compounds of Vitis vinifera L. flowers by SPME GC-MS analysis

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    Using a gas chromatographic method (GC-MSanalysis), it was possible to determine the volatile constituent of an odorous flower from Vitis vinifera varieties growing in Sicily. More than 50 compounds were identified and the technique allowed us to determine that sesquiterpenes, as well as monoterpenes such as limonene and cymene, were the principal components. The odour-profiles allowed us to distinguish between variety groups or even single varieties.

    Tensor variational inequalities: Theoretical results, numerical methods and applications to an economic equilibrium model

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    The paper deals with the study of tensor variational inequalities. and some projection methods to solve them. In particular, some properties on the solutions to such an inequality are established and a fixed point theorem is proved. Moreover, some numerical methods are introduced and the convergence analysis of them is investigated. All the theoretical results are applied to analyze a general oligopolistic market equilibrium problem in which each firm produces several commodities and has some production excesses since the equilibrium condition is characterized by means of a tensor variational inequality. A numerical example is also discussed

    Dietary strategy for prevention and management of dyslipidemia: International guidelines

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    Primary prevention of cardiovascular disease should begin with a detailed metabolic study of our patients who must follow a nutritional therapy. Recently, new guidelines ESC/EAS 2011 on the treatment of dyslipidemia have been drawn up, according to which it is possible to arrive at desirable values of cholesterol and triglycerides with a synergy between drug treatment and adequate diet therapy. At this time, Mediterranean diet has been undergoing a radical transformation: there is hyperalimentation of the Mediterranean diet in all its components. The effectiveness of the Mediterranean diet on the reduction of lipids has been demonstrated, and the problem is how to implement this diet in the general population and dyslipidemic patients. Certainly, awareness, education of their nutritional status, suitable food and portions can increase adherence to diet

    static and dynamic response of titanium alloy produced by electron beam melting

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    Abstract The suitability of Titanium alloys for many specialized applications requiring excellent performances at both static and dynamic strain rates, benefits of modern manufacturing technologies like the additive manufacturing, oriented toward the obtainment of complicated component shapes. The EBM methodology for the production of Ti6Al4V components is based on the localized melting of alloy powders by way of guided electron beams scanning the powder volume by successive planar trajectories; for this reason, the whole production process may confer a certain degree of anisotropy to the components. The material behavior of the EBM alloy may be orientation-dependent in terms of stress-strain elastoplastic response as well as in terms of damage sensitivity and ductile fracture under given triaxiality histories. The static and dynamic behavior of a sintered Ti6Al4V alloy is investigated here by way of quasistatic tension-torsion tests and dynamic tensile Hopkinson bar (SHTB) tests. The outcome of the latter experiments, compared to similar tests results from the literature concerning Ti alloy obtained by classical metallurgical techniques, gives some indications about how the technological process may affect the final performance of the material and the component

    Impact of mediterranean diet on chronic non-communicable diseases and longevity

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    The average life expectancy of the world population has increased remarkably in the past 150 years and it is still increasing. A long life is a dream of humans since the beginning of time but also a dream is to live it in good physical and mental condition. Nutrition research has focused on recent decades more on food combination patterns than on individual foods/nutrients due to the possible synergistic/antagonistic effects of the components in a dietary model. Various dietary patterns have been associated with health benefits, but the largest body of evidence in the literature is attributable to the traditional dietary habits and lifestyle followed by populations from the Mediterranean region. After the Seven Countries Study, many prospective observational studies and trials in diverse populations reinforced the beneficial effects associated with a higher adherence to the Mediterranean diet in reference to the prevention/management of age-associated non-communicable diseases, such as cardiovascular and metabolic diseases, neurodegenerative diseases, cancer, depression, respiratory diseases, and fragility fractures. In addition, the Mediterranean diet is ecologically sustainable. Therefore, this immaterial world heritage constitutes a healthy way of eating and living respecting the environment
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