143 research outputs found
Women with TSC : Relationship between Clinical, Lung Function and Radiological Features in a Genotyped Population Investigated for Lymphangioleiomyomatosis
The advent of pharmacological therapies for lymphangioleiomyomatosis (LAM) has made early diagnosis important in women with tuberous sclerosis complex (TSC), although the lifelong cumulative radiation exposure caused by chest computer tomography (CT) should not be underestimated. We retrospectively investigated, in a cohort of TSC outpatients of San Paolo Hospital (Milan, Italy) 1) the role of pulmonary function tests (PFTs) for LAM diagnosis, 2) the association between LAM and other features of TSC (e.g. demography, extrapulmonary manifestations, genetic mutations, etc.), and 3) the characteristics of patients with multifocal micronodular pneumocyte hyperplasia (MMPH). Eighty-six women underwent chest CT scan; pulmonary involvement was found in 66 patients (77%; 49% LAM with or without MMPH, and 28% MMPH alone). LAM patients were older, with a higher rate of pneumothorax, presented more frequently with renal and hepatic angiomyolipomas, and tended to have a TSC2 mutation profile. PFTs, assessed in 64% of women unaffected by cognitive impairments, revealed a lower lung diffusion capacity in LAM patients. In multivariate analysis, age, but not PFTs, resulted independently associated with LAM diagnosis. Patients with MMPH alone did not show specific clinical, functional or genetic features. A mild respiratory impairment was most common in LAM-TSC patients: In conclusions, PFTs, even if indicated to assess impairment in lung function, are feasible in a limited number of patients, and are not significantly useful for LAM diagnosis in women with TSC
Reaction rate for carbon burning in massive stars
Carbon burning is a critical phase for nucleosynthesis in massive stars. The conditions for igniting this burning stage, and the subsequent isotope composition of the resulting ashes, depend strongly on the reaction rate for C12+C12 fusion at very low energies. Results for the cross sections for this reaction are influenced by various backgrounds encountered in measurements at such energies. In this paper, we report on a new measurement of C12+C12 fusion cross sections where these backgrounds have been minimized. It is found that the astrophysical S factor exhibits a maximum around Ecm=3.5-4.0 MeV, which leads to a reduction of the previously predicted astrophysical reaction rate
Fusion measurements of 12C+12C at energies of astrophysical interest
The cross section of the 12C+12C fusion reaction at low energies is of paramount importance for models of stellar nucleosynthesis in different astrophysical scenarios, such as Type Ia supernovae and Xray superbursts, where this reaction is a primary route for the production of heavier elements. In a series of experiments performed at Argonne National Laboratory, using Gammasphere and an array of Silicon detectors, measurements of the fusion cross section of 12C+12C were successfully carried out with the γ and charged-particle coincidence technique in the center-of-mass energy range of 3-5 MeV. These were the first background-free fusion cross section measurements for 12C+12C at energies of astrophysical interest. Our results are consistent with previous measurements in the high-energy region; however, our lowest energy measurement indicates a fusion cross section slightly lower than those obtained with other techniques
Influência de diferentes meios de cultura sobre o crescimento de Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae) para conservação in vitro
Produtividade da soja correlacionada com a porosidade e a densidade de um Latossolo Vermelho do cerrado brasileiro
Caracterização das exigências nutricionais de mudas de Pfaffia glomerata em Argissolo Vermelho distrófico arênico pela técnica do nutriente faltante
Strategy of specification of management areas: rice grain yield as related to soil fertility
Spatially heterogeneous ages in glassy dynamics
We construct a framework for the study of fluctuations in the nonequilibrium
relaxation of glassy systems with and without quenched disorder. We study two
types of two-time local correlators with the aim of characterizing the
heterogeneous evolution: in one case we average the local correlators over
histories of the thermal noise, in the other case we simply coarse-grain the
local correlators. We explain why the former describe the fingerprint of
quenched disorder when it exists, while the latter are linked to noise-induced
mesoscopic fluctuations. We predict constraints on the pdfs of the fluctuations
of the coarse-grained quantities. We show that locally defined correlations and
responses are connected by a generalized local out-of-equilibrium
fluctuation-dissipation relation. We argue that large-size heterogeneities in
the age of the system survive in the long-time limit. The invariance of the
theory under reparametrizations of time underlies these results. We relate the
pdfs of local coarse-grained quantities and the theory of dynamic random
manifolds. We define a two-time dependent correlation length from the spatial
decay of the fluctuations in the two-time local functions. We present numerical
tests performed on disordered spin models in finite and infinite dimensions.
Finally, we explain how these ideas can be applied to the analysis of the
dynamics of other glassy systems that can be either spin models without
disorder or atomic and molecular glassy systems.Comment: 47 pages, 60 Fig
SND@LHC: The Scattering and Neutrino Detector at the LHC
SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the pseudo-rapidity region of . The experiment is located 480 m downstream of the ATLAS interaction point, in the TI18 tunnel. The detector is composed of a hybrid system based on an 830 kg target made of tungsten plates, interleaved with emulsion and electronic trackers, also acting as an electromagnetic calorimeter, and followed by a hadronic calorimeter and a muon identification system. The detector is able to distinguish interactions of all three neutrino flavours, which allows probing the physics of heavy flavour production at the LHC in the very forward region. This region is of particular interest for future circular colliders and for very high energy astrophysical neutrino experiments. The detector is also able to search for the scattering of Feebly Interacting Particles. In its first phase, the detector will operate throughout LHC Run 3 and collect a total of 250
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