1,138 research outputs found
Consequences of f(R)-theories of gravity on gravitational leptogenesis
f(R)-theories of gravity are reviewed in the framework of the
matter-antimatter asymmetry in the Universe. The asymmetry is generated by the
gravitational coupling of heavy (Majorana) neutrinos with the Ricci scalar
curvature. In order that the mechanism works, a time varying non-zero Ricci
curvature is necessary. The latter is provided by f(R) cosmology, whose
Lagrangian density is of the form {\cal L}(R)\sim f(R). In particular we study
the cases f(R)\sim R+\alpha R^n and f(R)\sim R^{1+\epsilon}.Comment: 14 page
Cosmological evolution of thermal relic particles in gravity
By considering gravity models, the cosmic evolution is modified with
respect to the standard CDM scenario. In particular, the thermal
history of particles results modified. In this paper, we derive the evolution
of relics particles (WIMPs) assuming a reliable cosmological solution
and taking into account observational constraints. The connection to the PAMELA
experiment is also discussed. Results are consistent with constraints coming
from BICEP2 and PLANCK experiments.Comment: 8 pages, 4 figure
Three-dimensional simulations of premixed hydrogen/air flames in microtubes
The dynamics of fuel-lean (equivalence ratio φ = 0.5) premixed hydrogen/air atmospheric pressure flames are investigated in open cylindrical tubes with diameters of d = 1.0 and 1.5 mm using three-dimensional numerical simulations with detailed chemistry and transport. In both cases, the inflow velocity is varied over the range where the flames can be stabilized inside the computational domain. Three axisymmetric combustion modes are observed in the narrow tube: steady mild combustion, oscillatory ignition/extinction and steady flames as the inflow velocity is varied in the range 0.5 ≤ UIN ≤ 500 cm s−1. In the wider tube, richer flame dynamics are observed in the form of steady mild combustion, oscillatory ignition/extinction, steady closed and open axisymmetric flames, steady non-axisymmetric flames and azimuthally spinning flames (0.5 ≤ UIN ≤ 600 cm s−1). Coexistence of the spinning and the axisymmetric modes is obtained over relatively wide ranges of UIN. Axisymmetric simulations are also performed in order to better understand the nature of the observed transitions in the wider tube. Fourier analysis during the transitions from the steady axisymmetric to the three-dimensional spinning mode and to the steady non-axisymmetric modes reveals that the m = 1 azimuthal mode plays a dominant role in the transition
The treatment of hyperinsulinemic hypoglycaemia in adults: an update
Treatment of hyperinsulinemic hypoglycaemia (HH) is challenging due to the rarity of this condition and the difficulty of differential diagnosis. The aim of this article is to give an overview of the recent literature on the management of adult HH
BEYOND WAIST CIRCUMFERENCE IN AN ADULT MALE POPULATION OF SOUTHERN ITALY: IS THERE ANY ROLE FOR SUBSCAPULAR SKINFOLD THICKNESS IN THE RELATIONSHIP BETWEEN INSULIN-LIKE GROWTH FACTOR-1 SYSTEM AND METABOLIC PARAMETERS ?
ABSTRACT
Background: Apart from waist circumference, other adiposity measures, such as subscapular skin fold (SST), arouse growing interest due to their relationship to metabolic complications and cardiovascular risk. The Insulin-like Growth Factor (IGF)-1 system is deregulated in obese subjects in proportion to their degree of visceral adiposity. Aim : To examine the association among IGF-1, IGF-Binding Protein (BP)1 and 3 levels and different measures of adiposity in a sample of adult male population in Southern Italy. Materials and Methods: A complete database for this analysis was available for 229 (age range 50–82 years) participating at 2002-2004 Olivetti Heart Study follow-up. Results: After adjustment for age, IGF-1 was inversely associated with BMI and waist circumference (p<0.05). IGFBP1 was inversely associated with BMI, waist circumference, SST, Homeostasis Model Assessment (HOMA) index, Fat Mass (FM). HOMA index, age and SST significantly predicted the IGFBP1 plasma levels, with 24% of IGFPB-1 variability explained at a linear regression analysis. Conclusions: IGFBP1 inversely correlated to adiposity and HOMA index. Among adiposity indexes, SST was the best predictor of IGFPB-1 levels. The evaluation of some components of the IGFs system, and simple measures of body adiposity, such as SST, may represent a further tool to better evidence phenotype profiles associated to the pathogenetic mechanism of cardiovascular risk factor clustering in male adults
A combined approach to assess the potential coverage of a multicomponent protein-based vaccine
Meningococcal disease caused by Neisseria meningitidis sero- group B is a public health concern even in developed countries. Despite glycoconjugate vaccines against the other invasive sero- groups (A, C, W135, Y) are already available and successfully introduced in many countries, no vaccine is currently in use for prevention of serogroup B meningitis.
A protein based, multicomponent vaccine (4CMenB) has been developed and proposed for prevention of invasive serogroup B meningococcal disease (MenB). This novel vaccine has been tested in clinical trials and shown to be well tolerated and immunogenic, inducing bactericidal antibodies in infants, adolescents and adults. The high level of genetic and antigenic variability observed in MenB clinical isolates, requires a suitable method to assess the ability of the 4CMenB vaccine to cover genetically diverse menig- ococcal strains and to estimate the potential public health impact. To this purpose the Meningococcal Antigen Typing System (MATS) has been developed and recently described. This method provides a quick and reproducible tool to estimate the level of expression and immunoreactivity of each of the vaccine antigens, in any meningococcal isolate, and it is related to the likelihood that the isolate will be killed by sera from immunized subjects.
A multi-laboratory study involving several European countries, demonstrates that the 4CMenB has the potential to protect against a significant proportion of menB strains circulating in Europe.
The full article is free available on www.jpmh.or
Characterisation of Fragaria vesca fruit from Italy following a metabolomics approach through integrated mass spectrometry techniques
The phytochemical content of Fragaria vesca L. (wild strawberry) grown in Campania Region (South Italy) was investigated. Wild and cultivated fruit were collected from different geographic areas and from bothautochthonous and non-autochthonous germplasm. Extracts were submitted to untargeted liquid chromatography coupled to high resolution mass spectrometry (LC–ESI-Orbitrap–MS) for metabolite profiling. 39 different phenolic compounds have been detected and identified in the methanolic extract of spontaneous and cultivated strawberries from different origins. Targeted quantitative analyses of selected known metabolites were performed using UHPLC interfaced to Q-Trap mass spectrometer in Multiple Reaction Monitoring mode. Principal Component Analysis (PCA) was applied to both untargeted and targeted results. PCA was applied to the untargeted profiling data indicating that fruits from locations with different pedoclimatic conditions can be discerned. Results from quantitative analysis indicate that autochthonous strawberries display significantly higher levels of anthocyanins, especially cyanidin 3-O-glucoside, and other phenolic compounds, like gallic acid and procyanidin B1, compared to the one from non-autochthonous germplasm. The targeted and untargeted metabolite profiling approach used in this work is proposed for the assessment of geographical origin of the berries
Esperienza dell'attesa e retoriche del tempo. L’impegno dell’antropologia nel campo sanitario
Autism Spectrum Disorder and Narcolepsy: A Possible Connection That Deserves to Be Investigated.
Narcolepsy in childhood-adolescence is characterized by a high occurrence of
psychiatric comorbidities. The most frequent psychiatric disorders reported in
these patients are attention deficit/hyperactivity disorder, depression, anxiety
disorder, and schizophrenia. However, narcolepsy can be associated also with
introversion, sorrowfulness, feelings of inferiority, impaired affectivity
modulation, emotional lability, irritability, aggressiveness, and poor attention,
that have been pooled by some authors under a definition of "narcoleptic
personality." Some aspects of this "narcoleptic personality," and in particular
introversion, impaired affectivity modulation, irritability, and poor attention,
partially overlap with the clinical features of the individuals with autism
spectrum disorder, considering also those that are not regarded as core autism
symptoms. Till now, in literature the number of cases affected by both narcolepsy
and autism spectrum disorder (seven patients) has been clearly too small to
demonstrate the presence of a pathogenetic link between these two conditions, but
this possible connection has not yet been adequately investigated, despite the
presence of several points in common. The finding of a connection between
narcolepsy and autism spectrum disorder could boost the study of possible
etiopathogenetic mechanisms shared between these two apparently so distant
disorders. Basing on the literature data summarized in this paper, in the
diagnostic work-up of a child with narcolepsy it is essential to evaluate also
the social-communicative behavior using standardized tools in order to detect the
real recurrence of clinical features suggesting an autism spectrum disorder. At
the same time, it appears necessary to screen in the individuals with autism
spectrum disorder for the possible presence of evoking symptoms of narcolepsy
- …
