University of Perugia

About: University of Perugia is a education organization based out in Perugia, Umbria, Italy. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 13365 authors who have published 39516 publications receiving 1265601 citations. The organization is also known as: Universitá degli Studi di Perugia & Universita degli Studi di Perugia.

Identifying adult asthma phenotypes using a clustering approach

Abstract: There is a need to improve asthma characterisation by integrating multiple aspects of the disease. The aim of the present study was to identify distinct asthma phenotypes by applying latent class analysis (LCA), a model-based clustering method, to two large epidemiological studies. Adults with asthma who participated in the follow-up of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA2) (n = 641) and the European Community Respiratory Health Survey (ECRHSII) (n = 1,895) were included. 19 variables covering personal characteristics, asthma symptoms, exacerbations and treatment, age of asthma onset, allergic characteristics, lung function and airway hyperresponsiveness were considered in the LCA. Four asthma phenotypes were distinguished by the LCA in each sample. Two phenotypes were similar in EGEA2 and ECRHSII: active treated allergic childhood-onset asthma and active treated adult-onset asthma. The other two phenotypes were composed of subjects with inactive or mild untreated asthma, who differed by atopy status and age of asthma onset (childhood or adulthood). The phenotypes clearly discriminated populations in terms of quality of life, and blood eosinophil and neutrophil counts. The LCAs revealed four distinct asthma phenotypes in each sample. Considering these more homogeneous phenotypes in future studies may lead to a better identification of risk factors for asthma.

TBAF-catalyzed synthesis of 5-substituted 1H-tetrazoles under solventless conditions.

Abstract: Tetrabutylammonium fluoride (TBAF) is an efficient catalyst in the [3 + 2] cycloaddition reaction of organic nitriles 1 with trimethylsilyl azide (TMSN(3)) in solventless conditions. The corresponding 5-substituted 1H-tetrazoles 2 were obtained under mild conditions and in 80-97% yields.

Investigations on scalable fabrication procedures for self-sensing carbon nanotube cement-matrix composites for SHM applications

Abstract: Electrically conductive cement-based composites doped with carbon nanotubes possess the functional properties of being strain- and damage-sensitive, thus providing a cost-effective solution for monitoring of concrete structures. The weak point of the technology is the dispersion of the nanotubes, typically based on special procedures, such as sonication, that are not suitable for large scale applications. This paper presents a systematic investigation on various procedures for fabricating carbon-nanotube-cement pastes, mortars and concretes. Dispersion of nanotubes in water is achieved using chemical dispersants and different mixing strategies, while quality of nanotubes' dispersion is assessed by measuring the rate of nanotube separation and by SEM inspections. Electrical percolation and strain-sensitivity are investigated in order to assess the quality of the fabricated composites. The results of this research allow to identify a processing procedure that, without sonication, might be potentially effective for fabricating self-sensing cement-based composites in a way that is compatible with large scale deployment. In particular, similarly to what observed in the case of sonicated specimens, the percolation thresholds of mortars and concretes fabricated with the “scalable” procedure are seen to be around 1% w. of MWCNTs content with respect of the weight of cement, while the same percolation threshold is less evident for pastes. Electrical conductivity and gauge factor of the same samples are also similar to those of sonicated composites, whereby conductivity of composite pastes, mortars and concretes assumes values of 5.2E-4, 1.8E-4 and 1.0E-4 (Ωcm)−1, respectively, while gauge factors are equal to 130, 68 and 23, respectively.

Fermi Gamma-ray Space Telescope observations of the gamma-ray outburst from 3C454.3 in November 2010

Abstract: The flat-spectrum radio quasar 3C454.3 underwent an extraordinary 5 day γ -ray outburst in 2010 November when the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E > 100 MeV reached (66 ± 2) × 10−6 photons cm−2 s−1. This is a factor of three higher than its previous maximum flux recorded in 2009 December and 5 times brighter than the Vela pulsar, which is normally the brightest source in the γ -ray sky. The 3 hr peak flux was (85 ± 5)×10−6 photons cm−2 s−1, corresponding to an apparent isotropic luminosity of (2.1 ± 0.2)×1050 erg s−1, the highest ever recorded for a blazar. In this Letter, we investigate the features of this exceptional event in the γ -ray band of the Fermi-LAT. In contrast to previous flares of the same source observed with the Fermi-LAT, clear spectral changes are observed during the flare.