0000000000449878
AUTHOR
Riccardo Messina
Fever and dyspnoea in a tracheostomised patient
A 65-year-old man was referred for evaluation of acute onset of fever, productive cough and dyspnoea. He had previously received a diagnosis of laryngeal carcinoma, which had been treated with laryngectomy and bilateral laterocervical lymphadenectomy, followed by chemotherapy. He underwent plastic surgery of the laryngocutaneous fistula, and a positron emission tomography (PET)- computed tomography (CT) examination performed during follow-up showed 18-FDG (2-fluoro-2-deoxyd- glucose) lung uptake in the apical right portion. He had a smoking history and his regular medications included dexamethasone, metoclopramide, omeprazole, furosemide, cholecalciferol and pregabalin. He had a history of …
Dispersive interactions between atoms and nonplanar surfaces
We calculate the dispersive force between a ground state atom and a non planar surface. We present explicit results for a corrugated surface, derived from the scattering approach at first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We discuss in detail the inadequacy of the proximity force approximation, and present a simple but adequate approximation for computing the potentia…
Unitary transfer of entanglement in multipartite two–level systems
Casimir-Polder force density between an atom and a conducting wall
In this paper we calculate the Casimir-Polder force density (force per unit area acting on the elements of the surface) on a metallic plate placed in front of a neutral atom. To obtain the force density we use the quantum operator associated to the electromagnetic stress tensor. We explicitly show that the integral of this force density over the plate reproduces the total force acting on the plate. This result shows that, although the force is obtained as a sum of surface element-atom contributions, the stress-tensor method includes also nonadditive components of Casimir-Polder forces in the evaluation of the force acting on a macroscopic object.
Serum surfactant protein D is a potential biomarker of lung damage in systemic sclerosis
Background: Interstitial lung disease (ILD) complicates the course of systemic sclerosis (SSc) up to two-third of the cases, representing the main cause of death in these patients. Assessment of lung involvement by HRCT and close monitoring of lung function are mandatory. At present no serologic biomarkers are validated for the assessment for lung damage in SSc. The current study was designed to test the hypothesis that the levels of surfactant are altered in SSc compared to healthy controls. To this aim serum levels of SP-A (Surfactant Protein A) and SP-D (Surfactant Protein-D) in serum were assessed. Methods: We enrolled 12 consecutive patients (M/F: 2/10) affected by scleroderma referred…
How to unveil chronic respiratory diseases in clinical practice? A model of alliance between general practitioners and pulmonologists
Abstract Introduction Asthma and COPD are under-diagnosed and undertreated in adult populations, mainly due to the discrepancy between guideline recommendations and clinicians' practices. One of the reasons of this discrepancy is the difficulty encountered in real life in sharing the management of chronic respiratory diseases between general practitioners (GPs) and respiratory physicians. Methods An explorative, population-based investigation was performed to test whether, and to what extent, an active collaboration between GPs and pulmonologists increases the diagnosis and proper treatment of chronic obstructive airway diseases. The "COPD action" involved an in-house intervention by pulmon…
Esercizi di Analisi uno
Serum surfactant protein D and exhaled nitric oxide as biomarkers of early lung damage in systemic sclerosis
Background Interstitial lung disease (ILD) complicates the course of systemic sclerosis (SSc), representing the main cause of death in these patients. The identification of parameters that can predict the early onset and progression of ILD in SSc represents an unmet need in clinical practice. The study was designed to explore whether the surfactant proteins (SP) A and D may be used as noninvasive tools for the early identification of ILD in SSc. Alveolar exhaled nitric oxide (NO) was investigated as a surrogate marker of distal inflammation. Methods Unselected consecutive subjects newly diagnosed with scleroderma and subjects free of respiratory and systemic diseases were recruited. All pat…
Dynamical Casimir-Polder forces
We consider the dynamical (time-dependent) Casimir-Polder force between an atom and a perfectly conducting wall, as well as the dynamical Casimir-Polder force between two atoms in the presence of a boundary condition such as a conducting wall. The dynamical Casimir-Polder forces are obtained from iterative solutions of the Heisenberg equations for the time evolution of the electric and magnetic field operators around one atom in the presence of the conducting wall and related field energy densities, which are valid for any initial state. We consider both the case of an initially bare atomic state and of an initially partially dressed atomic state. The problem of relativistic causality in th…
Casimir-Polder forces, boundary conditions and fluctuations
We review different aspects of the atom-atom and atom-wall Casimir-Polder forces. We first discuss the role of a boundary condition on the interatomic Casimir-Polder potential between two ground-state atoms, and give a physically transparent interpretation of the results in terms of vacuum fluctuations and image atomic dipoles. We then discuss the known atom-wall Casimir-Polder force for ground- and excited-state atoms, using a different method which is also suited for extension to time-dependent situations. Finally, we consider the fluctuation of the Casimir-Polder force between a ground-state atom and a conducting wall, and discuss possible observation of this force fluctuation.
The impact of SARS-COV2 pandemic on the management oF IPF patients: Our narrative experience
Abstract Background The SARS-CoV-2 pandemic has changed the health-care systems around the world in a remarkable way. We describe the strategies adopted to cope with the limitations imposed by the pandemic to the access to health care by patients diagnosed with idiopathic Pulmonary Fibrosis (IPF). Material and methods We conducted a retrospective observational analysis including IPF patients under antifibrotic drugs (nintedanib and pirfenidone) that accessed to the Outpatient clinic of the University of Palermo, Italy. Patients received a phone number and an email address in case of any urgency and a virtual meeting was settled up monthly. Results 40 patients (M/F: 30/10) were followed up, …
Management of suspected COVID-19 patients in a low prevalence region
The spread of the SARS-CoV-2 infection among population has imposed a re-organization of healthcare services, aiming at stratifying patients and dedicating specific areas where patients with suspected COVID-related respiratory disease could receive the necessary health care assistance while waiting for the confirmation of the diagnosis of COVID-19 disease. In this scenario, the pathway defined as a “grey zone” is strongly advocated. We describe the application of rules and pathways in a regional context with low diffusion of the infection among the general population in the attempt to provide the best care to respiratory patients with suspected COVID-19. To date, this process has avoided t…
Inhalation therapy in the next decade
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Dynamical Casimir-Polder force on a partially dressed atom near a conducting wall
We study the time evolution of the Casimir-Polder force acting on a neutral atom in front of a perfectly conducting plate, when the system starts its unitary evolution from a partially dressed state. We solve the Heisenberg equations for both atomic and field quantum operators, exploiting a series expansion with respect to the electric charge and an iterative technique. After discussing the behaviour of the time-dependent force on an initially partially-dressed atom, we analyze a possible experimental scheme to prepare the partially dressed state and the observability of this new dynamical effect.
Fluctuations of the Casimir-Polder force between an atom and a conducting wall
We consider the quantum fluctuations of the Casimir-Polder force between a neutral atom and a perfectly conducting wall in the ground state of the system. In order to obtain the atom-wall force fluctuation we first define an operator directly associated to the force experienced by the atom considered as a polarizable body in an electromagnetic field, and we use a time-averaged force operator in order to avoid ultraviolet divergences appearing in the fluctuation of the force. This time-averaged force operator takes into account that any measurement involves a finite time. We also calculate the Casimir-Polder force fluctuation for an atom between two conducting walls. Experimental observabili…
Time-dependent Maxwell fields and energy densities for an atom in front of a conducting wall
Dynamical Casimir-Polder potentials in non-adiabatic conditions
In this paper we review different aspects of the dynamical Casimir¿Polder potential between a neutral atom and a perfectly conducting plate under nonequilibrium conditions. In order to calculate the time evolution of the atom¿wall Casimir¿Polder potential, we solve the Heisenberg equations describing the dynamics of the coupled system using an iterative technique. Different nonequilibrium initial states are considered, such as bare and partially dressed states. The partially dressed states considered are obtained by a sudden change of a physical parameter of the atom or of its position relative to the conducting plate. Experimental feasibility of detecting the considered dynamical effects i…
Unitary Transfer of Entanglement in Multipartite Two-Level Systems
The dynamics of a system composed by two pairs of dipolarly coupled two-level atoms is exactly studied. We show that the initial entanglement stored in a couple of atoms not directly interacting is fully transferred to the other pair in a periodic way. The observability of this phenomenon in laboratory is briefly discussed both in terms of its temporal scale and of its stability against uncertainties in the geometrical parameters defining the physical system.
Riccati equation-based generalization of Dawson's integral function
A new generalization of Dawson's integral function based on the link between a Riccati nonlinear differential equation and a second-order ordinary differential equation is reported. The MacLaurin expansion of this generalized function is built up and to this end an explicit formula for a generic cofactor of a triangular matrix is deduced.
Time-dependent Maxwell field operators and field energy density for an atom near a conducting wall
We consider the time evolution of the electric and magnetic field operators for a two-level atom, interacting with the electromagnetic field, placed near an infinite perfectly conducting wall. We solve iteratively the Heisenberg equations for the field operators and obtain the electric and magnetic energy density operators around the atom (valid for any initial state). Then we explicitly evaluate them for an initial state with the atom in its bare ground state and the field in the vacuum state. We show that the results can be physically interpreted as the superposition of the fields propagating directly from the atom and the fields reflected on the wall. Relativistic causality in the field …
Interstitial Lung Disease in Elderly Rheumatoid Arthritis Patients
The increase in life expectancy together with better care of rheumatoid arthritis (RA) has led to higher proportions of elderly individuals with RA. This has challenged the treatment of the disease in older aged patients, usually characterized by comorbid conditions and polypharmacy. Overall, the lung involvement in RA is present in up to 80% of patients, depending on the assessment tools used, and interstitial abnormalities are among the most common; when present, interstitial lung disease (ILD) worsens the prognosis of RA, and is the second most common cause of mortality. The aged lung undergoes functional and structural changes termed immunosenescence and inflammaging, which facilitate t…
Casimir-Lifshitz force out of thermal equilibrium between dielectric gratings
We calculate the Casimir-Lifshitz pressure in a system consisting of two different 1D dielectric lamellar gratings having two different temperatures and immersed in an environment having a third temperature. The calculation of the pressure is based on the knowledge of the scattering operators, deduced using the Fourier Modal Method. The behavior of the pressure is characterized in detail as a function of the three temperatures of the system as well as the geometrical parameters of the two gratings. We show that the interplay between non-equilibrium effects and geometrical periodicity offers a rich scenario for the manipulation of the force. In particular, we find regimes where the force can…