2,989 research outputs found

    Oscillations above the barrier in the fusion of 28Si + 28Si

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    Fusion cross sections of 28Si + 28Si have been measured in a range above the barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y+repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters

    Higher in-hospital mortality during weekend admission for acute coronary syndrome: a large-scale cross-sectional Italian study

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    AIMS: An increased mortality risk during weekend hospital admission has been consistently observed. In the present study, we evaluated whether the current improvement in management of acute coronary syndromes (ACS) has reduced this phenomenon. METHODS AND RESULTS: We extracted data from the Italian National Healthcare System Databank of 80\u200a391 ACS admissions in the region of Lombardia between 2010 and 2014. ICD-9 codes were used to assess the diagnosis. We performed a multiple logistic regression analysis to compare the mortality rates between weekend and weekday admissions.Mean age of the study population was 67.6 years; 30.1% of patients were women. ST segment elevation myocardial infarction (STEMI) accounts for 42.2% of admissions. The total in-hospital mortality was 3.05% and was positively predicted by weekend admission [odds ratio (OR) 1.13, P\u200a=\u200a0.006], age and female sex. The weekend effect on mortality was only significant for STEMI (OR 1.11, P\u200a=\u200a0.04) in comparison to non-STEMI (NSTEMI) or unstable angina.The trend of the risk of death was found to be negatively correlated with age: the risk of death was significantly higher in all age clusters younger than 75 (OR 1.22, P\u200a<\u200a0.01) and even greater in the very young subgroup under 45 years of age (OR 2.09, P\u200a=\u200a0.03). CONCLUSION: Our data indicate that increased mortality risk is still present during weekend admissions. This phenomenon is particularly evident in younger patients and in individuals admitted for STEMI

    Temporal Rainbow Scattering at Boundary-Induced Time Interfaces

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    Since the dawn of modern optics and electromagnetics, optical prism is one of the most fascinating optical elements for refracting light. Exploiting its frequency dispersive behaviour, a prism is able to refract different frequencies in different directions, realizing polychromatic light rainbows. Recently, thanks to their engineerable electromagnetic response, metamaterials have been exploited for achieving novel refractive scattering processes, going beyond the classical prism effects. In this Manuscript, we report on a novel rainbow-like scattering process taking place at the interface of a boundary-induced temporal metamaterial realized by instantaneously opening the boundary conditions of a parallel plate waveguide. Changing abruptly the conductivity of one of the two metallic plates, we demonstrate that an equivalent temporal interface between two different media is realized, and the monochromatic wave propagating into the waveguide gets scattered into a polychromatic rainbow in free-space. We derive the relationships between the waveguide mode and the raising rainbow in terms of scattered amplitude and frequencies as a function of the elevation angle with respect to the waveguide axis. We apply the underlying physics to control the temporal rainbow by imposing a principal direction of scattering by design. Full-wave numerical simulations are performed for computing the rainbow temporal scattering and verifying the design guidelines for achieving controlled temporal rainbow scattering.Comment: 14 pages, 3 figures, Appendi

    Effects of daily gain in pre- and postpubertal replacement dairy heifers on body condition score, body size, metabolic profile, and future milk production.

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    Two trials were conducted to evaluate the effect of moderate (0.7 kg) and accelerated (0.9 kg) average daily gain before (trial 1) and after (trial 2) puberty on body condition, metabolic profile, and first lactation milk production of Italian Holstein-Friesian heifers. There were 20 heifers in trial 1 and 22 in trial 2. Trials started when heifers averaged 150 and 300 kg of body weight in trial 1 and 2, respectively, and lasted 7 mo (experimental period). Across diet groups, half of the heifers were mated at first estrus after 370 kg and the other half after 420 kg of body weight gain. Actual average daily gains were 0.667 and 0.775 kg in trial 1 and 0.748 and 0.824 kg in trial 2 for moderate and accelerated experimental groups, respectively. Diets for high average daily gain did not affect body condition during growing phase in trial 1, whereas it did in trial 2. High average daily gain increased plasma glucose in trial 1 and plasma urea concentration in trial 2. Rearing diet did not affect milk production and milk protein percent; age in both trials. High average daily gain decreased milk fat percentage in trial 2. Early calving negatively influenced milk production in both trials and milk fat percentage in trial 1. Early calving heifers showed higher protein percentage than those with late calving only in trial 1

    Time stability of asymmetric Fabry-Perot modulator based analog lightwave links

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    Lightwave links for analog signal transfer are being developed and evaluated for application in high-density interconnects. The reflective links are based on compact electro-optic intensity modulators connected by ribbons of single-mode fibres to remotely located transceivers (lasers and photoreceivers) and read-out electronics. For long-term characterization, four Asymmetric Fabry-Perot Modulator (AFPM) prototypes were continuously operated and monitored over a period of eight monthes. The collected data allow evaluation of the system time stability and simulation of the possible recalibration procedures. The recalibration requirements to achieve the desirable accuracy and reliability are inferred statistically

    Multibeam scanning antenna system based on beamforming metasurface for fast 5G NR initial access

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    Fifth-generation (and beyond) networks are characterized by ever more demanding requirements in terms of speed, bandwidth, and number of servable users. Fast and reliable access to the main network is mandatory, requiring technologies and procedures that ensure high performing cell search and initial access (IA). Existing phased array antennas (PAAs) are limited by the single beam scanning approach and complex feeding systems. In this paper, a beamforming metasurface that shifts the field manipulation from an electric level to an electromagnetic one is proposed for speeding up the IA procedure with respect to a traditional system using PAAs. The main advantage is given by the simultaneous transmission of multiple signals in different directions. The numerical results demonstrate that a much faster IA with similar success probability can be reached. Our system provides high gain, parallel computation, and scalability for larger systems, becoming a relevant candidate in the new radio and smart electromagnetic environment context

    Iron entry route in horse spleen apoferritin Involvement of the three-fold channels as probed by selective reaction of cysteine-126 with the spin label 4-maleimido-tempo

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    AbstractApoferritin has been selectively labeled with a maleimide nitroxide derivative at Cys-126, located in the hydrophilic 3-fold channels. Titration of this derivative with Fe(II), which gives rise to the initial Fe(III)-apoferritin complex, produces, at low metal-to-protein ratios, a decrease of the intensity of the label EPR signal due to the occurrence of a magnetic dipolar interaction. A label-metal distance ranging between 8–12 Å can be estimated from titrations performed with VO(IV), which is known to bind in the 3-fold channels, and likewise produces a decrease in the label EPR signal. The present findings indicate that iron binds in the hydrophilic channels in its higher oxidation slate and that these channels represent the metal entry route at least at low metal-to-protein ratios
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