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Institution

University of Udine

EducationUdine, Italy
About: University of Udine is a education organization based out in Udine, Italy. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 6745 authors who have published 20530 publications receiving 669088 citations. The organization is also known as: Università degli Studi di Udine & Universita degli Studi di Udine.


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Journal ArticleDOI
TL;DR: In this paper, the authors examine the behavior of a dilute dispersion of heavy particles in a vertical channel flow, using pseudo-spectral direct numerical simulation to calculate the turbulent flow eld at a shear Reynolds number Re = 150, and Lagrangian tracking to describe the dynamics of particles.
Abstract: Particle transfer in the wall region of turbulent boundary layers is dominated by the coherent structures which control the turbulence regeneration cycle. Coherent structures bring particles toward and away from the wall and favour particle segregation in the viscous region, giving rise to non-uniform particle distribution proles which peak close to the wall. The object of this work is to understand the reasons for higher particle concentration in the wall region by examining turbulent transfer of heavy particles to and away from the wall in connection with the coherent structures of the boundary layer. We will examine the behaviour of a dilute dispersion of heavy particles { flyashes in air { in a vertical channel flow, using pseudo-spectral direct numerical simulation to calculate the turbulent flow eld at a shear Reynolds number Re = 150, and Lagrangian tracking to describe the dynamics of particles. Drag force, gravity and Saman lift are used in the equation of motion for the particles, which are assumed to have no influence on the flow eld. Particle interaction with the wall is fully elastic. As reported in several previous investigations, we found that particles are transferred by sweeps { Q2 type events { in the wall region, where they preferentially accumulate in the low-speed streak environments, whereas ejections { Q4 type events { transfer particles from the wall region to the outer flow. We quantify the eciency of the instantaneous realizations of the Reynolds stresses events in transferring different size particles to the wall and away from the wall, respectively. Our ndings conrm that sweeps and ejections are ecient transfer mechanisms for particles. In particular, we nd that only those sweep and ejection events with substantial spatial coherence are eective in transferring particles. However, the eciency of the transfer mechanisms is conditioned by the presence of particles to be transferred. In the case of ejections, particles are more rarely available since, when in the viscous wall layer, they are concentrated under the low-speed streaks. Even though the low-speed streaks are ejection-like environments, particles remain trapped for a long time. This phenomenon, which causes accumulation of particles in the near-wall region, can be interpreted in terms of overall fluxes toward and away from the wall by the theory of turbophoresis. This theory, proposed initially by Caporaloni et al. (1975) and re-examined later by Reeks (1983), can help to explain the existence of net particle fluxes toward the wall as a manifestation of the skewness in the velocity distribution of the particles (Reeks 1983). To understand the local and instantaneous mechanisms which give rise to the phenomenon of turbophoresis, we focus on the near-wall region of the turbulent boundary layer. We examine the role of the rear-end of a quasistreamwise vortex very near to the wall in preventing particles in the proximity of the wall from being re-entrained by the pumping action of the large, farther from the wall, forward-end of a following quasi-streamwise vortex. We examine several mechanisms

432 citations

Journal ArticleDOI
TL;DR: FMRI results suggest that the activity of cortical nociceptive networks may be directly influenced by cognitive factors, and provide evidence for top-down mechanisms, triggered by anticipation, modulating cortical systems involved in sensory and affective components of pain even in the absence of actual noxious input.
Abstract: Anticipation of pain is a complex state that may influence the perception of subsequent noxious stimuli. We used functional magnetic resonance imaging (fMRI) to study changes of activity of cortical nociceptive networks in healthy volunteers while they expected the somatosensory stimulation of one foot, which might be painful (subcutaneous injection of ascorbic acid) or not. Subjects had no previous experience of the noxious stimulus. Mean fMRI signal intensity increased over baseline values during anticipation and during actual stimulation in the putative foot representation area of the contralateral primary somatosensory cortex (SI). Mean fMRI signals decreased during anticipation in other portions of the contralateral and ipsilateral SI, as well as in the anteroventral cingulate cortex. The activity of cortical clusters whose signal time courses showed positive or negative correlations with the individual psychophysical pain intensity curve was also significantly affected during the waiting period. Positively correlated clusters were found in the contralateral SI and bilaterally in the anterior cingulate, anterior insula, and medial prefrontal cortex. Negatively correlated clusters were found in the anteroventral cingulate bilaterally. In all of these areas, changes during anticipation were of the same sign as those observed during pain but less intense ( approximately 30-40% as large as peak changes during actual noxious stimulation). These results provide evidence for top-down mechanisms, triggered by anticipation, modulating cortical systems involved in sensory and affective components of pain even in the absence of actual noxious input and suggest that the activity of cortical nociceptive networks may be directly influenced by cognitive factors.

431 citations

Journal ArticleDOI
TL;DR: New recommendations have been made regarding the following: boundaries between levels I and II and between levels III/IV and VI; terminology of the superior mediastinal nodes; and the method of submitting surgical specimens for pathologic analysis.
Abstract: Objective To update the guidelines for neck dissection terminology, as previously recommended by the American Head and Neck Society. Participants Committee for Neck Dissection Classification, American Head and Neck Society; representation from the Committee for Head and Neck Surgery and Oncology, American Academy of Otolaryngology–Head and Neck Surgery (T.A.D.). Evidence Review of current literature on neck dissection classification. Consensus Process Semiannual face-to-face meetings of the Committee for Neck Dissection Terminology and e-mail correspondence. Conclusions Standardization of terminology for neck dissection is important for communication among clinicians and researchers. New recommendations have been made regarding the following: boundaries between levels I and II and between levels III/IV and VI; terminology of the superior mediastinal nodes; and the method of submitting surgical specimens for pathologic analysis.

430 citations

Journal ArticleDOI
TL;DR: It is shown that coded microsatellite data produced in different laboratories with different protocols and conditions can be compared, and that it is suitable for the identification and SSR allele characterization of cultivars.
Abstract: In order to investigate the comparability of microsatellite profiles obtained in different laboratories, ten partners in seven countries analyzed 46 grape cultivars at six loci (VVMD5, VVMD7, VVMD27, VVS2, VrZAG62, and VrZAG79) No effort was made to standardize equipment or protocols Although some partners obtained very similar results, in other cases different absolute allele sizes and, sometimes, different relative allele sizes were obtained A strategy for data comparison by means of reference to the alleles detected in well-known cultivars was proposed For each marker, each allele was designated by a code based on the name of the reference cultivar carrying that allele Thirty-three cultivars, representing from 13 to 23 alleles per marker, were chosen as references After the raw data obtained by the different partners were coded, more than 97% of the data were in agreement Minor discrepancies were attributed to errors, suboptimal amplification and visualization, and misscoring of heterozygous versus homozygous allele pairs We have shown that coded microsatellite data produced in different laboratories with different protocols and conditions can be compared, and that it is suitable for the identification and SSR allele characterization of cultivars It is proposed that the six markers employed here, already widely used, be adopted as a minimal standard marker set for future grapevine cultivar analyses, and that additional cultivars be characterized by means of the coded reference alleles presented here The complete database is available at http://wwwgenresde/eccdb/vitis/ Cuttings of the 33 reference cultivars are available on request from the Institut National de la Recherche Agronomique Vassal collection (didiervares@ensaminrafr)

427 citations

Journal ArticleDOI
TL;DR: The presence of nitrotyrosine in the plasma of diabetic patients indicates that peroxynitrite is generated in diabetes, suggesting a possible involvement of peroxlynitrite in the development of diabetic complications.
Abstract: Aims/hypothesis. Oxidative stress plays an important role in diabetic vascular complications. It has been shown that an imbalance in the ratio of nitric oxide: superoxide anion, because of a prevalence of superoxide anion, leads to an alteration in vascular reactivity. In this condition peroxynitrite production, resulting from the reaction between nitric oxide and superoxide, could increase. Peroxynitrite is responsible for nitration of tyrosine residues in proteins. Therefore, the presence of nitrotyrosine in plasma proteins is considered indirect evidence of peroxynitrite production. The aim of this study was to demonstrate the presence of nitrotyrosine in the plasma of patients with Type II (non-insulin-dependent) diabetes mellitus and to correlate its concentrations with the plasma concentrations of glucose and antioxidant defenses. Methods. A total of 40 Type II diabetic patients and 35 healthy subjects were enrolled, and glycaemia, plasma nitrotyrosine, total antioxidant parameter and glycated haemoglobin were measured. Nitrotyrosine was detected by ELISA with a detection limit of 10 nmol/l. Results. Nitrotyrosine was found in the plasma of all diabetic patients (means ± SD = 0.251 ± 0.141 μmol/l), whereas it was not detectable in the plasma of healthy control subjects. Nitrotyrosine plasma values were correlated with plasma glucose concentrations (r = 0.38, p < 0.02) but not with total antioxidant parameter or glycated haemoglobin. Total antioxidant parameter was reduced in diabetic patients (p < 0.01). Conclusions. The presence of nitrotyrosine in the plasma of diabetic patients indicates that peroxynitrite is generated in diabetes, suggesting a possible involvement of peroxynitrite in the development of diabetic complications. [Diabetologia (2001) 44: 834–838]

426 citations


Authors

Showing all 6857 results

NameH-indexPapersCitations
M.-Marsel Mesulam15055890772
Francesco Longo14274589859
Georges Aad135112188811
Bobby Samir Acharya1331121100545
G. Della Ricca133159892678
Marina Cobal132107885437
Fernando Barreiro130108283413
Saverio D'Auria129114283684
Jean-Francois Grivaz128132297758
Evgeny Starchenko12886475913
Muhammad Alhroob12788071982
Michele Pinamonti12684669328
Reisaburo Tanaka12696769849
Kerim Suruliz12679569456
Kate Shaw12584170087
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202350
2022142
20211,338
20201,388
20191,223
20181,102