1,534 research outputs found
The Lamb-Bateman integral equation and the fractional derivatives
The Lamb-Bateman integral equation was introduced to study the solitary wave
diffraction and its solution was written in terms of an integral transform. We
prove that it is essentially the Abel integral equation and its solution can be
obtained using the formalism of fractional calculus.Comment: 3 pages; revised version (misprints corrected, acknowledgements
added
Progress towards Bell-type polarization experiment with thermal neutrons
Experimental tests of Bell-type inequalities distinguishing between quantum
mechanics and local realistic theories remain of considerable interest if
performed on massive particles, for which no conclusive result has yet been
obtained. Only two-particle experiments may specifically test the concept of
spatial nonlocality in quantum theory, whereas single-particle experiments may
generally test the concept of quantum noncontextuality. Here we have performed
the first Bell-type experiment with a beam of thermal-neutron pairs in the
singlet state of spin, as originally suggested by J. S. Bell. These
measurements confirm the quantum-theoretical predictions, in agreement with the
results of the well-known polarization experiments carried out on optical
photons years ago
Hysteresis effects in Bose-Einstein condensates
Here, we consider damped two-components Bose-Einstein condensates with
many-body interactions. We show that, when the external trapping potential has
a double-well shape and when the nonlinear coupling factors are modulated in
time, hysteresis effects may appear under some circumstances. Such hysteresis
phenomena are a result of the joint contribution between the appearance of
saddle node bifurcations and damping effect.Comment: 10 pages, 2 figure
Effect of recombinant human nerve growth factor eye drops in patients with dry eye: a phase IIa, open label, multiple-dose study
Background: Dry eye disease (DED) affects more than 14% of the elderly population causing decrease of quality of life, high costs and vision impairment. Current treatments for DED aim at lubricating and controlling inflammation of the ocular surface. Development of novel therapies targeting different pathogenic mechanisms is sought-after. The aim of this study is to evaluate safety and efficacy of recombinant human nerve growth factor (rhNGF) eye drops in patients with DED. Methods: Forty consecutive patients with moderate to severe DED were included in a phase IIa, prospective, open label, multiple-dose, clinical trial to receive rhNGF eye drops at 20 μg/mL (Group 1: G1) or at 4 μg/mL (Group 2: G2) concentrations, two times a day in both eyes for 28 days (NCT02101281). The primary outcomes measures were treatment-emerged adverse events (AE), Symptoms Assessment in Dry Eye (SANDE) scale, ocular surface staining and Schirmer test. Results: Of 40 included patients, 39 completed the trial. Both tested rhNGF eye drop concentrations were safe and well tolerated. Twenty-nine patients experienced at least one AE (14 in G1 and 15 in G2), of which 11 had at least 1 related AE (8 in G1 and 3 in G2). Both frequency and severity of DED symptoms and ocular surface damage showed significant improvement in both groups, while tear function improved only in G1. Conclusions: The data of this study indicate that rhNGF eye drops in both doses is safe and effective in improving symptoms and signs of DED. Randomised clinical trials are ongoing to confirm the therapeutic benefit of rhNGF in DED. Trial registration number: NCT02101281
Pressure-tuning of the electron-phonon coupling: the insulator to metal transition in manganites
A comprehensive understanding of the physical origin of the unique magnetic
and transport properties of A_(1-x)A'^xMnO_3 manganites (A = trivalent
rare-earth and A' = divalent alkali-earth metal) is still far from being
achieved. The complexity of these systems arises from the interplay among
several competing interactions of comparable strength. Recently the
electron-phonon coupling, triggered by a Jahn-Teller distortion of the MnO_6
octahedra, has been recognised to play an essential role in the insulator to
metal transition and in the closely related colossal magneto-resistance. The
pressure tuning of the octahedral distortion gives a unique possibility to
separate the basic interactions and, at least in principle, to follow the
progressive transformation of a manganite from an intermediate towards a weak
electron-phonon coupling regime. Using a diamond anvil cell, temperature and
pressure-dependent infrared absorption spectra of La_(0.75)Ca_(0.25)MnO_3 have
been collected and, from the spectral weight analysis, the pressure dependence
of the insulator to metal transition temperature T_IM has been determined for
the first time up to 11.2 GPa. The T_IM(P) curve we proposed to model the
present data revealed a universality character in accounting for the whole
class of intermediate coupling compounds. This property can be exploited to
distinguish the intermediate from the weak coupling compounds pointing out the
fundamental differences between the two coupling regimes.Comment: 8 pages, 4 figure
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
A paraoxonase gene polymorphism, PON 1 (55), as an independent risk factor for increased carotid intima-media tickness in middle-aged women.
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
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