1,615 research outputs found

    Comparison of stroke volume measurement between non-invasive bioreactance and esophageal Doppler in patients undergoing major abdominal-pelvic surgery

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    PURPOSE: Bioreactance is a non-invasive technology for measuring stroke volume (SV) in the operating room and critical care setting. We evaluated how the NICOM® bioreactance device performed against the CardioQ® esophageal Doppler monitor in patients undergoing major abdominal–pelvic surgery, focusing on the effect of different hemodynamic interventions. METHODS: SVNICOM and SVODM were simultaneously measured intraoperatively, including before and after interventions including fluid challenge, vasopressor boluses, peritoneal gas insufflation/removal, and Trendelenburg/reverse Trendelenburg patient positioning. RESULTS: A total of 768 values were collected from 21 patients. Pre- and post-intervention measures were recorded on 155 occasions. Bland–Altman analysis revealed a bias of 8.6 ml and poor precision with wide limits of agreement (54 and −37 ml) and a percentage error of 50.6%. No improvement in precision was detected after taking into account repeated measurements for each patient (bias: 8 ml; limits of agreement: 74 and −59 ml). Concordance between changes in SVNICOM and SVODM before and after interventions was also poor: 78.7% (all measures), 82.4% (after vasopressor administration), and 74.3% (after fluid challenge). Using Doppler SV as the reference technique, the area under the receiver operating characteristic curve assessing the ability of the NICOM device to predict fluid responsiveness was 0.81 (0.7–0.9). CONCLUSIONS: In patients undergoing major abdomino-pelvic surgery, SV values obtained by NICOM showed neither clinically or statistically acceptable agreement with those obtained by esophageal Doppler. Although, in the setting of this study, bioreactance technology cannot reliably replace esophageal Doppler monitoring, its accuracy for predicting fluid responsiveness was higher, up to approximately 80%

    Depth profile investigations of surface modifications of limestone artifacts by laser-induced breakdown spectroscopy.

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    Made available in DSpace on 2017-11-01T23:23:05Z (GMT). No. of bitstreams: 1 PROCI17Depthprofileinvestigations....pdf: 1977315 bytes, checksum: f46ba065d28554ead651738267cea5a4 (MD5) Previous issue date: 2017-10-30bitstream/item/165807/1/PROCI-17-Depth-profile-investigations....pd

    Polarization Asymmetry In The Photodisintegration Of The Deuteron

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    The reaction ²(γ,p)n has been studied using a monochromatic and polarized gamma ray beam at energies E(γ)=19.8, 29.0, 38.6, and 60.8 MeV. The beam of an intensity ∼4×10⁵ γ/sec was obtained by Compton back scattering of mode-locked laser light off electron bunches in the Adone storage ring. Photoneutron yields were measured at nine neutron angles thetan≃15, 30, 45, 60, 90, 120, 135, 150, and 165 deg in the center of mass (c.m.) for E(γ)=19.8, 29.0, and 38.6 MeV, and at thetan≃30, 60, 90, 120, and 150 deg c.m. for E(γ)=60.8 MeV. The polarization independent component Iₒ(theta) of the differential cross section and the polarization dependent component PI₁(theta) were deduced and the angular distribution of the azimuthal asymmetry factor Σ(theta)=I₁(theta)/Iₒ(theta) was obtained. An extensive comparison with theory has been carried out and the inclusion of corrections due to meson exchange currents and to Δ-isobar configurations have been shown to be mandatory at energies E(γ)≳40 MeV. Theoretical and experimental implications of intermediate energy deuteron photo- disintegration studies are discussed in some detail

    Is there a common origin for the WMAP low multipole and for the ellipticity in BOOMERanG CMB maps?

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    We have measured the ellipticity of several degree scale anisotropies in the BOOMERanG maps of the Cosmic Microwave Background (CMB) at 150 GHz. The average ellipticity is around 2.6-2.7. The biases of the estimator of the ellipticity and for the noise are small in this case. Large spot elongation had been detected also for COBE-DMR maps. If this effect is due to geodesic mixing, it would indicate a non precisely zero curvature of the Universe which is among the discussed reasons of the WMAP low multipole anomaly. Both effects are related to the diameter of the Universe: the geodesics mixing through hyperbolic geometry, low multipoles through boundary conditions.This common reason can also be related with the origin of the the cosmological constant: the modes of vacuum fluctuations conditioned by the boundary conditions lead to a value of the cosmological constant being in remarkable agreement with the supernovae observations.Comment: Added: two co-authors and a comment on the possible relation of the discussed CMB properties with the origin of the observed value of the cosmological constan

    WMAP confirming the ellipticity in BOOMERanG and COBE CMB maps

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    The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The effect has been found for spots up to several degrees in size, where the biases of the ellipticity estimator and of the noise are small. To check the effect, now we have studied, with the same algorithm and in the same sky region, the WMAP maps. We find ellipticity of the same average value also in WMAP maps, despite of the different sensitivity of the two experiments to low multipoles. Large spot elongations had been detected also for the COBE-DMR maps. If this effect is due to geodesic mixing and hence due to non precisely zero curvature of the hyperbolic Universe, it can be linked to the origin of WMAP low multipoles anomaly.Comment: More explanations and two references adde

    Il Fibroblast Growth Factor-23 (FGF-23)

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    Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico

    Development of an algorithm for assessing canopy volumes with terrestrial LiDAR to implement precision spraying in vineyards

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    Received: February 13th, 2021 ; Accepted: November 28th, 2021 ; Published: December 3rd, 2021 ; Correspondence: [email protected] spraying is one of the techniques for the reduction of pesticides use and it can help achieve the new European Green Deal standards. The aim of such technique is to apply the right amount of pesticides according to the target characteristics. The precision spraying implementation requires target volume assessment, which can be carried out by LiDAR sensors. Such technique requires complex and time-consuming procedures of canopy characteristics computing through post-processing points cloud reconstruction. The present work aimed to develop and test an algorithm through the use of a tractor-coupled with terrestrial LiDAR and GNSS technology in order to simplify the process. With the aim to evaluate the algorithm the LiDAR-based volume was correlated with two manual measurements of canopy volume (Tree Row Volume and Point Net Cloud). The results showed good correlations between manual and LiDAR measures both for total canopy volumes (R 2 = 0.67 and 0.56) and for partial canopy volume (R 2 = 0.74). In conclusion, although the LiDAR-based algorithm works in automatic mode, the canopy volumes approximation seems acceptable to estimate the canopy volumes, with the advantages of a swifter procedure and less laborious post-processing computations

    Congested traffic equilibria and degenerate anisotropic PDEs

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    Congested traffic problems on very dense networks lead, at the limit, to minimization problems posed on measures on curves as shown in Baillon and Carlier (Netw. Heterogenous Media 7: 219--241, 2012). Here, we go one step further by showing that these problems can be reformulated in terms of the minimization of an integral functional over a set of vector fields with prescribed divergence. We prove a Sobolev regularity result for their minimizers despite the fact that the Euler-Lagrange equation of the dual is highly degenerate and anisotropic. This somehow extends the analysis of Brasco et al. (J. Math. Pures Appl. 93: 652--671, 2010) to the anisotropic case
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