18 research outputs found

    Diagnosis of Single- or Multiple-Canal Benign Paroxysmal Positional Vertigo according to the Type of Nystagmus

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    Benign paroxysmal positional vertigo (BPPV) is a common peripheral vestibular disorder encountered in primary care and specialist otolaryngology and neurology clinics. It is associated with a characteristic paroxysmal positional nystagmus, which can be elicited with specific diagnostic positional maneuvers, such as the Dix-Hallpike test and the supine roll test. Current clinical research focused on diagnosing and treating various types of BPPV, according to the semicircular canal involved and according to the implicated pathogenetic mechanism. Cases of multiple-canal BPPV have been specifically investigated because until recently these were resistant to treatment with standard canalith repositioning procedures. Probably, the most significant factor in diagnosis of the type of BPPV is observation of the provoked nystagmus, during the diagnostic positional maneuvers. We describe in detail the various types of nystagmus, according to the canals involved, which are the keypoint to accurate diagnosis

    Dyson Maps and Unitary Evolution for Maxwell Equations in Tensor Dielectric Media

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    A reformulation of Maxwell equations for an inhomogeneous, anisotropic, passive and non-dispersive medium results in a quantum-like Schrodinger equation that admits unitary time evolution. In contrast to other approaches, there is no a-priori introduction of the Riemann-Silberstein-Weber (RSW) vector but the Maxwell equations are considered in their standard fields, with given constitutive relations. From the electromagnetic conservation quantities a pseudo-Hermitian dynamics is found together with a Dyson map that recovers the full Hermicity of the dynamics in an extended Hilbert space that describes the physical notion of unitary evolution. As an example, a uniaxial tensor dielectric medium is considered, with the explicit Dyson map yielding an optimal representation in a set of generalized RSW vectors. In this newly discovered form, a Quantum Computing (QC) implementation for simulation of electromagnetic wave propagation in complex media can be made, with further extension into plasmas.Comment: 19 page

    Study of Allergic Rhinitis in Childhood

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    Allergic rhinitis is common among children and quite often represents a stage of the atopic march. Although sensitization to food and airborne allergens may appear in infancy and early childhood, symptoms of the disease are usually present after age 3. The aim of this study was to determine the most frequent food and indoor and outdoor respiratory allergens involved in allergic rhinitis in children in the region of Piraeus. The study was performed in the outpatient clinic of otolaryngologic allergy of a general hospital. Fifty children (ranged 6–14 ) with symptoms of allergic rhinitis and positive radioallergosorbent test (RAST) for IgE antibodies or skin prick tests were included in the study. Thirty six (72%) of the subjects of the study had intermittent allergic rhinitis. The most common aeroallergens determined were grass pollens and Parietaria, whereas egg and milk were the food allergens identified. The detection of indoor and outdoor allergens in the region of Piraeus, based on skin prick tests and RAST tests, showed high incidence of grasses and food allergens, which is similar to other Mediterranean countries

    Primary Lymphangioma of the Tonsil: A Case Report

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    Benign tumors of the tonsils occur infrequently. Lymphangiomas are rare congenital tumors of the lymphatic system, and tonsillar lymphangioma is an extremely rare occurrence. Its pathogenesis is uncertain, but history, clinical examination, and histological examination should establish the diagnosis. We present a 17-year-old white male with lymphangioma of the right tonsil. The tonsils were excised and biopsy confirmed the diagnosis. Tonsillar lymphangioma is a rare clinical entity, which should be known to the otolaryngologist, in order to diagnose and treat it appropriately and avoid confusion with tonsillar malignancies

    Transiently Evoked Otoacoustic Emissions in Children with Otitis Media with Effusion

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    Introduction. Otitis media with effusion is a common pediatric disease whose diagnosis is based on pneumatic otoscopy, pure-tone audiometry, and tympanometry. The aim of this study was to evaluate transiently evoked otoacoustic emissions in the diagnosis of otitis media with effusion as compared to tympanometry. Patients and Methods. 38 children with bilateral otitis media with effusion were studied. 40 normal children of similar age and sex were used as controls. All subjects underwent pneumatic otoscopy, standard pure-tone audiometry, tympanometry, and transiently evoked otoacoustic emissions. Results. In the group of children with bilateral otitis media, transiently evoked otoacoustic emissions were absent in 51 ears (67%). In the remaining 25 ears (33%) the mean emission amplitude was reduced, as compared to the mean value of the control group. Conclusions. Transiently evoked otoacoustic emissions should be included in the diagnostic workup of otitis media with effusion because it is a fast, reliable, and objective test. Transiently evoked otoacoustic emissions should always be used in conjunction with tympanometry, because a more meaningful interpretation of transiently evoked otoacoustic emissions measures is possible

    Quantum Computing Perspective for Electromagnetic Wave Propagation in Cold Magnetized Plasmas

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    The study of electromagnetic wave propagation in magnetized plasmas is of paramount importance in various fields, including astrophysics, fusion energy, and communication systems. In thermonuclear fusion experiments where transient interaction phenomena between electromagnetic waves and plasma can disrupt the overall confinement, we have to rely on the modern state of the art, computational tools to delve into the physics of wave propagation in plasma. However, even those sophisticated computational methods are facing challenges in terms of memory resources and speed when they are forced to capture all the physical processes that occur in wave-plasma interaction. Simultaneously, the rapidly advancing field of quantum technologies has opened up exciting new frontiers in the computational studies, by promising a minimization on the computational strain. In this paper we examine a theoretical quantum computing re-conceptualization of Maxwell equations inside a cold, inhomogeneous, magnetized plasma that can lead to quantum simulation of electromagnetic wave propagation and scattering from inhomogeneities. By constructing a quantum Schrodinger representation of Maxwell equations in plasma that admit unitary -- energy preserving -- evolution we formulate a unitary product sequence of operators that can form the basis of either a Qubit Lattice Algorithm (QLA) or a pure quantum computing implementation. As an illustration of the power of QLA, a full-wave simulation of wave-packet scattering from different shaped, non-dispersive dielectrics is presented. QLAs when they are fully unitary, they can be directly encoded into a quantum computer, further establishing their versatility and capabilities but more importantly, indicating the impact that quantum computers will have in the computational studies of wave propagation in a fusion plasma.Comment: 13 Pages, 4 Figure

    Qubit Lattice Algorithms based on the Schrodinger-Dirac representation of Maxwell Equations and their Extensions

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    It is well known that Maxwell equations can be expressed in a unitary Schrodinger-Dirac representation for homogeneous media. However, difficulties arise when considering inhomogeneous media. A Dyson map points to a unitary field qubit basis, but the standard qubit lattice algorithm of interleaved unitary collision-stream operators must be augmented by some sparse non-unitary potential operators that recover the derivatives on the refractive indices. The effect of the steepness of these derivatives on two dimensional scattering is examined with simulations showing quite complex wavefronts emitted due to transmissions/reflections within the dielectric objects. Maxwell equations are extended to handle dissipation using Kraus operators. Then, our theoretical algorithms are extended to these open quantum systems. A quantum circuit diagram is presented as well as estimates on the required number of quantum gates for implementation on a quantum computer.Comment: 20 pages, 14 figure

    The effect of MemoVigor 2 on recent-onset idiopathic tinnitus: a randomized double-blind placebo-controlled clinical trial

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    Background: Tinnitus is a common symptom associated with the conscious perception of sound in the absence of a corresponding external or internal sound source, which can severely impact quality of life. Because of the current limited understanding of the precise pathophysiological mechanism of idiopathic tinnitus, no curable treatment has been attained yet. A food supplement trading as MemoVigor 2, which contains a combination of therapeutic ingredients with mainly antioxidant activity, has been used in the treatment of tinnitus. The objective of our study was to evaluate the effectiveness of MemoVigor 2 in the treatment of recent-onset idiopathic tinnitus.Methods: In a prospective single-centre randomized, double-blind, placebo-controlled clinical trial we studied 204 patients with idiopathic tinnitus divided into two groups: 104 patients who received MemoVigor 2 and 100 patients treated with placebo. To evaluate changes in tinnitus we used (1) audiometry/tympanometry; (2) specific measures of tinnitus perception, including tinnitus pitch, loudness at tinnitus pitch, loudness at 1 kHz, minimum masking level, and residual inhibition; (3) questionnaires of tinnitus handicap inventory, mini tinnitus questionnaire and patients’ global impression of change. All patients underwent this test battery at the beginning of the study and in a repeat post-3-month session.Results: All tinnitus measures, including pitch, loudness, minimum masking level and residual inhibition improved significantly in the intervention group. Most of these measures improved in the placebo group too, but in a lesser degree. All questionnaire scores diminished significantly in both groups, but the degree of decrease was greater in the intervention group. The participants’ tinnitus outcome reported after treatment using the patients’ global impression of change score differed significantly between the two groups, with greater improvement observed in the intervention group.Conclusion: We found that the use of MemoVigor 2 improved recent-onset tinnitus, as proved by a set of tests performed for its evaluation, including audiometric measures, specific measures of tinnitus perception and tinnitus questionnaires. Tinnitus in the placebo group improved too, but to a lesser degree.Clinical Trial Registration: isrctn.com, Identifier ISRCTN1602548

    Desmoid tumor of the supraclavicular region: a case report

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    Desmoid tumors are rare, benign fibroblastic tumors that are locally infiltrative and can cause extensive morbidity by destruction of adjacent vital structures. Due to the rarity of these tumors, evidence regarding optimal treatment protocols is drawn from case reports and single-arm series with small patient numbers. We report a case of a patient with a desmoid tumor of the left supraclavicular region that was diagnosed and treated in our department and a review of the current literature

    Qubit Lattice Algorithms Based on the Schrodinger-Dirac Representation of Maxwell Equations and Their Extensions

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    It is well known that Maxwell equations can be expressed in a unitary Schrodinger-Dirac representation for homogeneous media. However, difficulties arise when considering inhomogeneous media. A Dyson map points to a unitary field qubit basis, but the standard qubit lattice algorithm of interleaved unitary collision-stream operators must be augmented by some sparse non-unitary potential operators that recover the derivatives on the refractive indices. The effect of the steepness of these derivatives on two-dimensional scattering is examined with simulations showing quite complex wavefronts emitted due to transmissions/reflections within the dielectric objects. Maxwell equations are extended to handle dissipation using Kraus operators. Then, our theoretical algorithms are extended to these open quantum systems. A quantum circuit diagram is presented as well as estimates on the required number of quantum gates for implementation on a quantum computer
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