143 research outputs found

    Speed of sound measurements in deuterium oxide (D 2 O) at temperatures between (276.97 and 363.15) K and at pressures up to 210 MPa

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    partially_open3embargoed_20211119Lago Simona, Giuliano Albo Paolo Alberto, Cavuoto GiuseppeLago, Simona; GIULIANO ALBO, PAOLO ALBERTO; Cavuoto, Giusepp

    Speed of sound measurements in deuterium oxide (D2O) at temperatures between (276.97 and 363.15) K and at pressures up to 210 MPa

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    This paper presents speed of sound measurements in heavy water (deuterium oxide, ) along six isotherms between 276.97 K and 363.15 K for pressures up to 210 MPa using a double pulse-echo method. The experimental apparatus was validated measuring the speed of sound in ordinary water at ambient pressure and at temperatures between 295.5 K and 363.15 K with results found in agreement with values calculated from the reference equation of state for water by Wagner and Pruß within 0.005%. The relative combined expanded uncertainty of our speed of sound measurements, at a confidence level of 95%, is estimated to be less than 0.03% for pressures up to 10 MPa and in the order of 0.05% for pressures up to 210 MPa in the whole investigated temperature range. The speed of sound results have been compared with values calculated from the reference equation for heavy water the IAPS84 Formulation by Hill et al. (1982), and with the prediction of the newly developed equation of state for heavy water by Herrig et al. (2018). The relative deviations of these comparison were found to be consistent with the reference equations within their combined uncertainty. The results presented here were also compared with the most recent data by Wegge et al. and found to be in agreement within 0.05%

    High-Pressure Speed of Sound Measurements of trans-1-Chloro-3,3,3-trifluoropropene (R1233zd(E)) in Liquid Region for Temperature from (273.15 to 353.15) K

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    This paper presents speed of sound measurements of liquid trans-1-chloro-3,3,3-trifluoropropene (R1233zd­(E)) along six isotherms over the temperature range from (273.15 to 353.15) K for pressures up to 35 MPa by means of the double pulse–echo method. The expanded uncertainty of the speed of sound measurements at a confidence level of 95% is 0.1%. The experimental results were compared with predictions from the state-of-the-art Fundamental Helmholtz Energy equation of state [Mondéjar, M.E.; McLinden, M.O.; Lemmon, E.W., Thermodynamic Properties of trans-1-Chloro-3,3,3-trifluoropropene (R1233zd­(E)): Vapor Pressure, (p,ρ,T) Behavior, and Speed of Sound Measurements, and Equation of State. J. Chem. Eng. Data, 2015, 60, 2477–2489]

    Temperature Increase Dependence on Ultrasound Attenuation Coefficient in Innovative Tissue-mimicking Materials

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    Although high intensity focused ultrasound beams (HIFU) have found rapid agreement in clinical environment as a tool for non invasive surgical ablation and controlled destruction of cancer cells, some aspects related to the interaction of ultrasonic waves with tissues, such as the conversion of acoustic energy into heat, are not thoroughly understood. In this work, innovative tissue- mimicking materials (TMMs), based on Agar and zinc acetate, have been used to conduct investigations in order to determine a relation between the sample attenuation coefficient and its temperature increase measured in the focus region when exposed to an HIFU beam. An empirical relation has been deduced establishing useful basis for further processes of validations of numerical models to be adopted for customizing therapeutic treatments

    Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water

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    partially_open6The Boltzmann constant k has been determined from a measurement of the speed of sound in helium gas in a quasi-spherical resonator (volume 0.5 l) maintained at a temperature close to the triple point of water (273.16 K). The acoustic velocity c is deduced from measured acoustic resonance frequencies and the dimensions of the quasi-sphere, the latter being obtained via simultaneous microwave resonance. Values of c are extrapolated to the zero pressure limit of ideal gas behaviour. We find J⋅K−1, a result consistent with previous measurements in our group and elsewhere. The value for k, which has a relative standard uncertainty of 1.02 ppm, lies 0.02 ppm below that of the CODATA 2010 adjustment.mixedPitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P APitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P

    Vitamin D binding protein isoforms and apolipoprotein E in cerebrospinal fluid as prognostic biomarkers of multiple sclerosis

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    Multiple sclerosis (MS) is a multifactorial autoimmune disease of the central nervous system with a heterogeneous and unpredictable course. To date there are no prognostic biomarkers even if they would be extremely useful for early patient intervention with personalized therapies. In this context, the analysis of inter-individual differences in cerebrospinal fluid (CSF) proteome may lead to the discovery of biological markers that are able to distinguish the various clinical forms at diagnosis.To this aim, a two dimensional electrophoresis (2-DE) study was carried out on individual CSF samples from 24 untreated women who underwent lumbar puncture (LP) for suspected MS. The patients were clinically monitored for 5 years and then classified according to the degree of disease aggressiveness and the disease-modifying therapies prescribed during follow up.The hierarchical cluster analysis of 2-DE dataset revealed three protein spots which were identified by means of mass spectrometry as Apolipoprotein E (ApoE) and two isoforms of vitamin D binding protein (DBP). These three protein spots enabled us to subdivide the patients into subgroups correlated with clinical classification (MS aggressive forms identification: 80%). In particular, we observed an opposite trend of values for the two protein spots corresponding to different DBP isoforms suggesting a role of a post-translational modification rather than the total protein content in patient categorization.These findings proved to be very interesting and innovative and may be developed as new candidate prognostic biomarkers of MS aggressiveness, if confirmed

    The IMERAPlus Joint Research Project For Determinations Of The Boltzmann Constant

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    Abstract. To provide new determinations of the Boltzmann constant, k, which has been asked for by the International Committee for Weights and Measures concerning preparative steps towards new definitions of the kilogram, the ampere, the kelvin and the mole, an iMERAPlus joint research project has coordinated the European activities in this field. In this major European research project the Boltzmann constant has been determined by various methods to support the new definition of the kelvin. The final results of the project are reviewed in this paper. Determinations of the Boltzmann constant k were achieved within the project by all three envisaged methods: acoustic gas thermometry, Doppler broadening technique, and dielectric constant gas thermometry. The results were exploited by the interdisciplinary Committee on Data for Science and Technology (CODATA) in their 2010 adjustment of recommended values for fundamental constants. As a result, the CODATA group recommended a value for k with a relative standard uncertainty about a factor of two smaller than the previous u(k)/k of 1.7×10 −6

    Is Blue Dye Indicated for Sentinel Lymph Node Biopsy in Breast Cancer Patients With a Positive Lymphoscintigram?

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    The use of isosulfan blue dye in sentinel node biopsy for breast cancer has been questioned because of its risk of allergic reaction. We hypothesized that blue dye could be safely omitted in the subgroup of patients who have evidence of successful sentinel node localization by lymphoscintigraphy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41406/1/10434_2005_Article_6556.pd

    Incidence of poisonings in domestic carnivores in Italy

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