214 research outputs found
New Constraints on the Variable Equation of State Parameter from X-Ray Gas Mass Fractions and SNe Ia
Recent measurements are suggesting that we live in a flat Universe and that
its present accelerating stage is driven by a dark energy component whose
equation of state may evolve in time. Assuming two different parameterizations
for the function , we constrain their free parameters from a joint
analysis involving measurements from X-Ray luminosity of galaxy clusters and
SNe type Ia data.Comment: paper, 6 pages, 1 figure Accepted by Int. Journal of Modern Physics D
(IJPMD
Perturbative approach to the structure of rapidly rotating neutron stars
We construct models of rotating stars using the perturbative approach
introduced by J. Hartle in 1967, and a set of equations of state proposed to
model hadronic interactions in the inner core of neutron stars. We integrate
the equations of stellar structure to third order in the angular velocity and
show, comparing our results to those obtained with fully non linear codes, to
what extent third order corrections are needed to accurately reproduce the
moment of inertia of a star which rotates at rates comparable to that of the
fastest isolated pulsars.Comment: 17 pages, 5 figures, minor changes to match version accepted by Phys.
Rev.
Stochastic backgrounds of gravitational waves from extragalactic sources
Astrophysical sources emit gravitational waves in a large variety of
processes occurred since the beginning of star and galaxy formation. These
waves permeate our high redshift Universe, and form a background which is the
result of the superposition of different components, each associated to a
specific astrophysical process. Each component has different spectral
properties and features that it is important to investigate in view of a
possible, future detection. In this contribution, we will review recent
theoretical predictions for backgrounds produced by extragalactic sources and
discuss their detectability with current and future gravitational wave
observatories.Comment: 10 pages, 9 figures, proceedings of the GWDAW 10 Conference,
submitted to Class. & Quantum Gra
Optimization of a Monobromobimane (MBB) Derivatization and RP-HPLC-FLD Detection Method for Sulfur Species Measurement in Human Serum after Sulfur Inhalation Treatment
(1) Background: Hydrogen sulfide (H2S) is a widely recognized gasotransmitter, with key roles in physiological and pathological processes. The accurate quantification of H2S and reactive sulfur species (RSS) may hold important implications for the diagnosis and prognosis of diseases. However, H2S species quantification in biological matrices is still a challenge. Among the sulfide detection methods, monobromobimane (MBB) derivatization coupled with reversed phase high-performance liquid chromatography (RP-HPLC) is one of the most reported. However, it is characterized by a complex preparation and time-consuming process, which may alter the actual H2S level; moreover, a quantitative validation has still not been described. (2) Methods: We developed and validated an improved analytical protocol for the MBB RP-HPLC method. MBB concentration, temperature and sample handling were optimized, and the calibration method was validated using leave-one-out cross-validation and tested in a clinical setting. (3) Results: The method shows high sensitivity and allows the quantification of H2S species, with a limit of detection of 0.5 mu M. Finally, it can be successfully applied in measurements of H2S levels in the serum of patients subjected to inhalation with vapors rich in H2S. (4) Conclusions: These data demonstrate that the proposed method is precise and reliable for measuring H2S species in biological matrices and can be used to provide key insights into the etiopathogenesis of several diseases and sulfur-based treatments. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
The use of protic ionic liquids with cathodes for sodium-ion batteries
Herein, we report for the first time the use of a protic ionic liquid as a component of a new Na-ion battery electrolyte. The protic ionic liquid has been tested in combination with two different types of sodium-ion cathode materials, polyanionic Na3V2(PO4)3 and layered Na0.67Mn0.89Mg0.11O2, in order to reveal its impact on the electrode material electrochemical performance. The results evidence that this novel electrolyte performs very well in combination with a polyanionic electrode material, while it shows poor performance with a layered oxide material
The SKA Dish SPF and LMC Interaction Design: Interfaces, Simulation, Testing and Integration
The Square Kilometre Array (SKA) project is responsible for developing the SKA Observatory, the world's largest radio telescope ever built: eventually two arrays of radio antennas - SKA1-Mid and SKA1-Low - will be installed in the South Africa's Karoo region and Western Australia's Murchison Shire respectively, each covering a different range of radio frequencies. In particular, the SKA1-Mid array will comprise of 133 15m diameter dish antennas observing in the 350 MHz-14 GHz range, each locally managed by a Local Monitoring and Control (LMC) system and remotely orchestrated by the SKA Telescope Manager (TM) system. All control system functionality run on the Tango Controls platform. The Dish Single Pixel Feed (SPF) work element will design the combination of feed elements, orthomode transducers (OMTs), and low noise amplifiers (LNAs) that receive the astronomical radio signals. Some SPFs have cryogenically cooled chambers to obtain the sensitivity requirements. This paper gives a status update of the SKA Dish SPF and LMC interaction design, focusing on SPF, LMC simulators and engineering/operational user interfaces, prototypes being developed and technological choices
Medicinali equivalenti in Italia: le ragioni della diffidenza di medici e farmacisti = Equivalent medicinal products in Italy: the reasons for the prudence of physicians and pharmacists
Despite the regulatory framework favourable to the use of equivalent medicines in Italy, it remains below the European average. Although the causes are not fully clarified, several factors can concur to the patient reluctance to take generic medicines. In this context, the influence of health professionals (e.g., physicians, pharmacists) could play an important role. The aim of this work is to investigate the reasons behind the reticence of doctors and pharmacists to prescribe/ recommend equivalent medicines by means of a survey sent to 308 health professionals. The results confirmed a lack of confidence in 43% of the interviewees. Based on such results, another survey was conducted on the same sub-group of health professionals to better identify the causes of their reluctance. Among the main causes of distrust towards equivalent medicines remains the erroneous belief that the quality, safety and efficacy profile is not comparable with the originator. Physicians and pharmacists were particularly sceptics towards the equivalent drugs of the therapeutic classes most frequently used to treat chronic diseases (e.g., hypertension, arrhythmias, cardiopathies, diabetes mellitus). Such results highlighted that there is room for improving the preparation of the health professionals towards a better patient education about equivalent medicines. On the other side, the results highlighted the caution of both physicians and pharmacists with respect to uncontrolled switching of medicines and their propensity to promote a linear therapeutic choice so that the patient takes the same medicine throughout the therapy
Correlation between pathological findings and bacteriological culture on paratuberculous cattle.
ABSTRACT - Paratuberculosis (PTB) is a chronic enteritis determined by Mycobacterium avium subsp. paratuberculosis (Map) that affects ruminants. Three crossbred dairy cattle with clinical PTB were necropsied; tissue samples were collected and processed for histopathology and culture. Intestinal lesions were characterized in three levels of severity (mild, moderate and severe) by gross examination. Gross examination, microscopy and tissue culture were analyzed and compared. Mean tissue culture sensitivity was 66.6%. Map was recovered from 42.8% of intestinal mild lesions, 55.5% of intestinal moderate lesions, and 100% of severe intestine lesions. The results indicate a significant correlation between the level of lesions severity and the isolation of Map
Probing the high-redshift universe with SPICA: Toward the epoch of reionisation and beyond
With the recent discovery of a dozen dusty star-forming galaxies and around 30 quasars at z > 5 that are hyper-luminous in the infrared (μ LIR > 1013 L⊙, where μ is a lensing magnification factor), the possibility has opened up for SPICA, the proposed ESA M5 mid-/far-infrared mission, to extend its spectroscopic studies toward the epoch of reionisation and beyond. In this paper, we examine the feasibility and scientific potential of such observations with SPICA’s far-infrared spectrometer SAFARI, which will probe a spectral range (35–230 μm) that will be unexplored by ALMA and JWST. Our simulations show that SAFARI is capable of delivering good-quality spectra for hyper-luminous infrared galaxies at z = 5 − 10, allowing us to sample spectral features in the rest-frame mid-infrared and to investigate a host of key scientific issues, such as the relative importance of star formation versus AGN, the hardness of the radiation field, the level of chemical enrichment, and the properties of the molecular gas. From a broader perspective, SAFARI offers the potential to open up a new frontier in the study of the early Universe, providing access to uniquely powerful spectral features for probing first-generation objects, such as the key cooling lines of low-metallicity or metal-free forming galaxies (fine-structure and H2 lines) and emission features of solid compounds freshly synthesised by Population III supernovae. Ultimately, SAFARI’s ability to explore the high-redshift Universe will be determined by the availability of sufficiently bright targets (whether intrinsically luminous or gravitationally lensed). With its launch expected around 2030, SPICA is ideally positioned to take full advantage of upcoming wide-field surveys such as LSST, SKA, Euclid, and WFIRST, which are likely to provide extraordinary targets for SAFARI
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