48 research outputs found

    The biocalcarenite stone of Agrigento (Italy): Preliminary investigations of compatible nanolime treatments

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    Nanolime is a promising consolidant for the conservation of most historic structures thanks to its high compatibility with carbonate-based substrates. Nanolime can recover the superficial cohesion of deteriorated surfaces thanks to its potential to complete the carbonation process, recreating a thin network of new cementing calcium carbonate. In this paper, the nanolime was produced by an innovative, time and energy-saving and scalable method, and its efficacy was tested preliminarily on biocalcarenite stones from Agrigento. The stones characterization as well as the treatment effectiveness, in terms of protection against water and superficial consolidation, was investigated by several techniques such as X-ray fluorescence, X-ray diffraction, scotch tape test, water absorption by capillarity, mercury intrusion porosimetry, drilling resistance measurement system and colorimeter. Investigations showed that nanolime could guarantee a complete transformation in pure calcite together with a superficial consolidation and a reduction in water absorption

    Sperm culture and bacterial susceptibility to antibiotics in a large andrological population: prevalence and impact on seminal parameters

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    Background The aim of this study was to evaluate (i) the prevalence of subjects with a positive sperm culture (SC) for bacteria in subjects with or without genitourinary tract inflammation (GTI); (ii) the actual distribution of the species analysed, according to Gram stain; (iii) the impact on sperm parameters; and (iv) the actual bacterial susceptibility to antibiotics.Methods A total of 930 subjects (18-55) years, were retrospectively studied. All the patients underwent SC and in the case of positive tests (CFU> 10(6)), a microbiological susceptibility analysis. The subjects studied were subdivided into group A (n =452), with subjective signs of GTI; group B (n=478), male partners of infertile couples; and group C, 30 healthy normospermic subjects. In group B and in the control group, a semen analysis was performed.Results Overall, the prevalence of positive SC was 21.5% (200/930). The prevalence of positive SC in group A (113/200; 56.5%) was significantly higher vs. group B (87/200; 43.5%; p =0.01) and control group (1/30; 3.3%; p =0.0001). In subjects with GTI, the prevalence of asthenozoospermic (96/285; 33.7%) and oligo-asthenozoospermic (98/285; 34.4%) was significantly higher vs. normospermic, oligo-astheno-teratozoospermic, oligozoospermic and azoospermic subjects (22/285 (7.7%), 48/285 (16.8%), 15/285 (5.3%) and 6/285 (2.1%), respectively; p= 0.001). Finally, Enterococcus faecalis (Grampositive) and Escherichia coli (Gram-negative) showed the highest prevalence of antibiotic resistance.Conclusions The prevalence of positive SC is higher in GTI subjects; however, the SC could also be positive in subjects without GTI. Commonly used antibiotics have an increasing risk of being useless for the treatment of bacterial infections. Finally, the diagnosis of GTIs is important also for male fertility

    Would You Prescribe Mobile Health Apps for Heart Failure Self-care? An Integrated Review of Commercially Available Mobile Technology for Heart Failure Patients

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    Treatment of chronic diseases, such as heart failure, requires complex protocols based on early diagnosis; self-monitoring of symptoms, vital signs and physical activity; regular medication intake; and education of patients and caregivers about relevant aspects of the disease. Smartphones and mobile health applications could be very helpful in improving the efficacy of such protocols, but several barriers make it difficult to fully exploit their technological potential and produce clear clinical evidence of their effectiveness. App suppliers do not help users distinguish between useless/dangerous apps and valid solutions. The latter are few and often characterised by rapid obsolescence, lack of interactivity and lack of authoritative information. Systematic reviews can help physicians and researchers find and assess the 'best candidate solutions' in a repeatable manner and pave the way for well-grounded and fruitful discussion on their clinical effectiveness. To this purpose, the authors assess 10 apps for heart failure self-care using the Intercontinental Marketing Statistics score and other criteria, discuss the clinical effectiveness of existing solutions and identify barriers to their use in practice and drivers for change

    A bright megaelectronvolt emission line in Îł\gamma-ray burst GRB 221009A

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    The highly variable and energetic pulsed emission of a long gamma-ray burst (GRB) is thought to originate from local, rapid dissipation of kinetic or magnetic energy within an ultra-relativistic jet launched by a newborn compact object, formed during the collapse of a massive star. The spectra of GRB pulses are best modelled by power-law segments, indicating the dominance of non-thermal radiation processes. Spectral lines in the X-ray and soft Îł\gamma-ray regime for the afterglow have been searched for intensively, but never confirmed. No line features ever been identified in the high energy prompt emission. Here we report the discovery of a highly significant (>6σ> 6 \sigma) narrow emission feature at around 1010 MeV in the brightest ever GRB 221009A. By modelling its profile with a Gaussian, we find a roughly constant width σ∌1\sigma \sim 1 MeV and temporal evolution both in energy (∌12\sim 12 MeV to ∌6\sim 6 MeV) and luminosity (∌1050\sim 10^{50} erg/s to ∌2×1049\sim 2 \times 10^{49} erg/s) over 80 seconds. We interpret this feature as a blue-shifted annihilation line of relatively cold (kBTâ‰Șmec2k_\mathrm{B}T\ll m_\mathrm{e}c^2) electron-positron pairs, which could have formed within the jet region where the brightest pulses of the GRB were produced. A detailed understanding of the conditions that can give rise to such a feature could shed light on the so far poorly understood GRB jet properties and energy dissipation mechanism.Comment: Submitte

    New Materials and Technologies for Durability and Conservation of Building Heritage

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    The increase in concrete structures’ durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials. This work focuses on building heritage and it highlights the most recent findings for the conservation and restoration of reinforced concrete structures and masonry buildings

    A CMOS Charge Sensitive Amplifier with sub-electron equivalent noise charge

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    We present a CMOS Charge Sensitive Amplifier (CSA) specifically designed for low capacitance pixel or silicon drift detectors for high resolution X-ray spectrometry. The intrinsic noise of the CSA has been measured at different operating temperatures with a triangular shaping with peaking time from 0.8 Όs to 102 Όs. At room temperature, the intrinsic Equivalent Noise Charge (ENC) shows a minimum of 1.18 e- r.m.s. and at -30°C a minimum ENC of 0.89 e- r.m.s. has been measured, corresponding to a line width of 7.8 eV FWHM for a Silicon detector

    New Sustainable, Scalable and One-Step Synthesis of Iron Oxide Nanoparticles by Ion Exchange Process

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    This work introduces an innovative, sustainable, and scalable synthesis of iron oxides nanoparticles (NPs) in aqueous suspension. The method, based on ion exchange process, consists of a one-step procedure, time and energy saving, operating in water and at room temperature, by cheap and renewable reagents. The influence of both oxidation state of the initial reagent and reaction atmosphere is considered. Three kinds of iron nanostructured compounds are obtained (2-lines ferrihydrite; layered-structure iron oxyhydroxide Ύ-FeOOH; and cubic magnetite), in turn used as precursors to obtain hematite and maghemite NPs. All the produced NPs are characterized by a high purity, small particles dimensions (from 2 to 50 nm), and high specific surface area values up to 420 m2/g, with yields of production >90%. In particular, among the most common iron oxide NPs, we obtained cubic magnetite NPs at room temperature, characterized by particle dimensions of about 6 nm and a surface area of 170 m2/g. We also obtained hematite NPs at very low temperature conditions (that is 2 h at 200 °C), characterized by particles dimensions of about 5 nm with a surface area value of 200 m2/g. The obtained results underline the strength of the synthetic method to provide a new, sustainable, tunable, and scalable high-quality production

    VEGA: A low-power front-end ASIC for large area multi-linear X-ray silicon drift detectors: Design and experimental characterization

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    We present the design and the first experimental characterization of VEGA, an Application Specific Integrated Circuit (ASIC) designed to read out large area monolithic linear Silicon Drift Detectors (SDD’s). VEGA consists of an analog and a digital/mixed-signal section to accomplish all the functionalities and specifications required for high resolution X-ray spectroscopy in the energy range between 500 eV and 50 keV. The analog section includes a charge sensitive preamplifier, a shaper with 3-bit digitally selectable shaping times from 1.6 ”s to 6.6 ”s and a peak stretcher/sample-and-hold stage. The digital/mixed-signal section includes an amplitude discriminator with coarse and fine threshold level setting, a peak discriminator and a logic circuit to fulfill pile-up rejection, signal sampling, trigger generation, channel reset and the preamplifier and discriminators disabling functionalities. A Serial Peripherical Interface (SPI) is integrated in VEGA for loading and storing all configuration parameters in an internal register within few microseconds. The VEGA ASIC has been designed and manufactured in 0.35 ”m CMOS mixed-signal technology in single and 32 channel versions with dimensions of 200 ”m×500 ”m per channel. A minimum intrinsic Equivalent Noise Charge (ENC) of 12 electrons r.m.s. at 3.6 ”s peaking time and room temperature is measured and the linearity error is between −0.9% and +0.6% in the whole input energy range. The total power consumption is 481 ”W and 420 ”W per channel for the single and 32 channels version, respectively. A comparison with other ASICs for X-ray SDD’s shows that VEGA has a suitable low noise and offers high functionality as ADC-ready signal processing but at a power consumption that is a factor of four lower than other similar existing ASICs
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