1,649 research outputs found
Sex hormones in allergic conjunctivitis: altered levels of circulating androgens and estrogens in children and adolescents with vernal keratoconjunctivitis
PURPOSE:
Vernal keratoconjunctivitis (VKC) is a chronic allergic disease mainly affecting boys in prepubertal age and usually recovering after puberty. To evaluate a possible role of sex hormones in VKC, serum levels of sex hormones in children and adolescents with VKC were assessed.
METHODS:
12 prepubertal and 7 early pubertal boys with active VKC and 6 male patients with VKC in remission phase at late pubertal age and 48 healthy age and sex-matched subjects were included. Serum concentration of estrone, 17 beta-estradiol, dehydroepiandrosterone-sulfate, total testosterone and free testosterone, dihydrotestosterone (DHT), cortisol, delta-4-androstenedione, follicle-stimulating hormone, luteinizing hormone, and sex-hormones binding globuline (SHBG) were evaluated.
RESULTS:
Serum levels of Estrone were significantly increased in all groups of patients with VKC when compared to healthy controls (P < 0.001). Prepubertal and early pubertal VKC showed a significant decrease in DHT (P = 0.007 and P = 0.028, resp.) and SHBG (P = 0.01 and P = 0.002, resp.) when compared to controls and serum levels of SHBG were increased in late pubertal VKC in remission phase (P = 0.007).
CONCLUSIONS AND RELEVANCE:
VKC patients have different circulating sex hormone levels in different phases of the disease and when compared to nonallergic subjects. These findings suggest a role played by sex hormones in the pathogenesis and/or activity of VKC
Rare diseases of the anterior segment of the eye: update on diagnosis and management
This special issue is focused on the current approaches used to identify and manage rare diseases of the anterior segment
of the eye, which range from congenital to acquired disorders that are caused by ocular or systemic conditions and often
have consequences that extend beyond the anterior segment of the eye
Effect of quasi-bound states on coherent electron transport in twisted nanowires
Quantum transmission spectra of a twisted electron waveguide expose the
coupling between traveling and quasi-bound states. Through a direct numerical
solution of the open-boundary Schr\"odinger equation we single out the effects
of the twist and show how the presence of a localized state leads to a
Breit-Wigner or a Fano resonance in the transmission. We also find that the
energy of quasi-bound states is increased by the twist, in spite of the
constant section area along the waveguide. While the mixing of different
transmission channels is expected to reduce the conductance, the shift of
localized levels into the traveling-states energy range can reduce their
detrimental effects on coherent transport.Comment: 8 pages, 9 color figures, submitte
Existence of the Stark-Wannier quantum resonances
In this paper we prove the existence of the Stark-Wannier quantum resonances
for one-dimensional Schrodinger operators with smooth periodic potential and
small external homogeneous electric field. Such a result extends the existence
result previously obtained in the case of periodic potentials with a finite
number of open gaps.Comment: 30 pages, 1 figur
Ergodicity breaking in strong and network-forming glassy system
The temperature dependence of the non-ergodicity factor of vitreous GeO,
, as deduced from elastic and quasi-elastic neutron scattering
experiments, is analyzed. The data are collected in a wide range of
temperatures from the glassy phase, up to the glass transition temperature, and
well above into the undercooled liquid state. Notwithstanding the investigated
system is classified as prototype of strong glass, it is found that the
temperature- and the -behavior of follow some of the predictions
of Mode Coupling Theory. The experimental data support the hypothesis of the
existence of an ergodic to non-ergodic transition occurring also in network
forming glassy systems
Why Social Enterprises Are Asking to Be Multi-stakeholder and Deliberative: An Explanation around the Costs of Exclusion.
The study of multi-stakeholdership (and multi-stakeholder social enterprises in particular) is only at the start. Entrepreneurial choices which have emerged spontaneously, as well as the first legal frameworks approved in this direction, lack an adequate theoretical support. The debate itself is underdeveloped, as the existing understanding of organisations and their aims resist an inclusive, public interest view of enterprise. Our contribution aims at enriching the thin theoretical reflections on multi-stakeholdership, in a context where they are already established, i.e. that of social and personal services.
The aim is to provide an economic justification on why the governance structure and decision-making praxis of the firm needs to account for multiple stakeholders. In particular with our analysis we want: a) to consider production and the role of firms in the context of the “public interest” which may or may not coincide with the non-profit objective; b) to ground the explanation of firm governance and processes upon the nature of production and the interconnections between demand and supply side; c) to explain that the costs associated with multi-stakeholder governance and deliberation in decision-making can increase internal efficiency and be “productive” since they lower internal costs and utilise resources that otherwise would go astray.
The key insight of this work is that, differently from major interpretations, property costs should be compared with a more comprehensive range of costs, such as the social costs that emerge when the supply of social and personal services is insufficient or when the identification of aims and means is not shared amongst stakeholders. Our model highlights that when social costs derived from exclusion are high, even an enterprise with costly decisional processes, such as the multistakeholder, can be the most efficient solution amongst other possible alternatives
Further evidence of antibunching of two coherent beams of fermions
We describe an experiment confirming the evidence of the antibunching effect
on a beam of non interacting thermal neutrons. The comparison between the
results recorded with a high energy-resolution source of neutrons and those
recorded with a broad energy-resolution source enables us to clarify the role
played by the beam coherence in the occurrence of the antibunching effect.Comment: 4 pages, 3 figure
Design of a Virtual Reality-based Framework for Supporting the Work Reintegration of Wheelchair Users
Accidents at work often lead the involved people to severe impairments, which can seriously compromise their life and their work activities. Various studies have proven that, for disabled people, being employed contributes to a better quality of life, thus it is important to give them the opportunity to continue their profes-sional career. This paper presents a framework aimed at supporting the training and the work-reintegration of people that, after an accident, are forced to use a wheelchair. In the proposed work, the Virtual Reality is the leading technology for allowing the wheelchair users to be trained in simulated environments where, in safe conditions, they become aware of their capabilities, while facing different challenging situations. More-over, the behaviour of the users is tracked during the whole training session for monitoring, processing and assessing, through semantic models, their functional level and the jobs that are still suitable for them
High-Pressure Phase Diagram in the Manganites: a Two-site Model Study
The pressure dependence of the Curie temperature in manganites,
recently studied over a wide pressure range, is not quantitatively accounted
for by the quenching of Jahn-Teller distortions, and suggests the occurrence of
a new pressure-activated localizing processes. We present a theoretical
calculation of based on a two-site double-exchange model with
electron-phonon coupling interaction and direct superexchange between the core spins. We calculate the pressure dependence of and compare
it with the experimental phase diagram. Our results describe the experimental
behavior quite well if a pressure-activated enhancement of the
antiferromagnetic superexchange interaction is assumed
Direct experimental evidence of free fermion antibunching
Fermion antibunching was observed on a beam of free noninteracting neutrons.
A monochromatic beam of thermal neutrons was first split by a graphite single
crystal, then fed to two detectors, displaying a reduced coincidence rate. The
result is a fermionic complement to the Hanbury Brown and Twiss effect for
photons.Comment: 4 pages, 2 figure
- …