Photorefractive incoherent-to-coherent optical converter

Photorefractive materials have been extensively used in recent years as real-time recording media for optical holography.(^1,2) One prospective application of real-time holography is in the area of optical information processing; for example, the correlation between two mutually incoherent images has recently been demonstrated in real time in a four-wave mixing geometry. (^3) Often, however, the information to be processed exists only in incoherent form. High performance spatial light modulators(^4) are thus necessary in many optical information processing systems to convert incoherent images to coherent replicas for subsequent processing. We report in this Communication the successful demonstration of real-time incoherent-to-coherent images transduction through the use of holographic recording in photorefractive crystals. Several possible configurations and experimental results are presented

Perinatal-lethal Gaucher disease presenting as hydrops fetalis

Perinatal-lethal Gaucher disease is very rare and is considered a variant of type 2 Gaucher disease that occurs in the neonatal period. The most distinct features of perinatal-lethal Gaucher disease are non-immune hydrops fetalis. Less common signs of the disease are hepatosplenomegaly, ichthyosis and arthrogryposis. We report a case of Gaucher's disease (type 2) diagnosed in a newborn who presented with Hydrops Fetalis

Properties of Cd1-xZnx Te crystals grown by High Pressure Bridgman (HPB)

In this paper we present results of a modelling of the current-voltage characteristics of metal/ultra-thin oxide/semiconductor structures with negatively biased metal gate (V<0), when the oxide thickness varies from 45Å to 80Å. We analyze the theoretical influence of the temperature and Schottky effect on the Fowler-Nordheim (FN) conduction. The results obtained show that these influences depend on the electric field in the oxide and on the potential barrier at the metal/oxide interface. At the ambient temperature, the influence on this potential barrier is lower than 1.5%. However, it can reach 45% on the pre-exponential coefficient of the FN current. It is therefore necessary to consider in the FN classical conduction expression a correction term that takes account the temperature and Schottky effects. These results are validated experimentally by modelling the current-voltage characteristics of the realized structures at high field.In this paper we present results of a modelling of the current-voltage characteristics of metal/ultra-thin oxide/semiconductor structures with negatively biased metal gate (V<0), when the oxide thickness varies from 45Å to 80Å. We analyze the theoretical influence of the temperature and Schottky effect on the Fowler-Nordheim (FN) conduction. The results obtained show that these influences depend on the electric field in the oxide and on the potential barrier at the metal/oxide interface. At the ambient temperature, the influence on this potential barrier is lower than 1.5%. However, it can reach 45% on the pre-exponential coefficient of the FN current. It is therefore necessary to consider in the FN classical conduction expression a correction term that takes account the temperature and Schottky effects. These results are validated experimentally by modelling the current-voltage characteristics of the realized structures at high field

Kyste Amygdaloïde Oropharynge A Propos D\'un Cas

Le kyste amygdaloïde est une tumeur kystique latéro-cervicale haute rare, issue de la 2ème fente branchiale. Il représente 2% des tumeurs latéro-cervicales du cou, et 6,1à 85,2% des anomalies de la deuxième fente. La forme oropharyngée est très rare. Nous rapportons une observation d\'un kyste amygdaloïde oropharyngé, chez une femme de 56 ans. Aucune symptomatologie particulière n\'a été notée. L\'examen clinique a révélé une tuméfaction de la loge amygdalienne droite, refoulant le pilier antérieur. La TDM a objectivé un processus expansif nécrosé de l\'amygdale palatine droite comblant l\'espace parapharyngé droit, en contact avec la base de la langue et le muscle ptérygoïdien médial homolatéral. Une résection complète et sans rupture du kyste a été pratiquée par voie transorale, le geste a été complété par une amygdalectomie droite. L\'histologie a confirmé le diagnostic par la co-existence d\'un revêtement épithélial et d\'une infiltration de tissu lymphoïde. Le recul est de 6 mois sans récidiveSecond branchial cleft cysts are the most common type of branchial abnormalities and usually found high in the neck. Oropharyngeal presence of branchial cleft cyst is very rare. We report a case of oropharyngeal branchial cleft cyst in 56 years women, wich had any specific symptom. Radiologic examination (TDM) revealed an expansive mass of the palatin tonsil. It was removed completely with right palatin tonsil. Cyst had a squamous epithelium-lined wall with lymphoid aggregation in histopathologic study, which was chareacteristic finding of branchial cleft cyst. There was no evidence of recurrence for 6 months for follow-up. We review reported oropharyngeal or nasopharyngeal presentation of these cases in literature and embryologic explanation. Keywords: Oropharyngeal, branchial, cysts Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 49-5

L’acupuncture : comme alternative dans la prise en charge de la paralysie faciale peripherique idiopathique : experience tunisienne

La paralysie faciale périphérique idiopathique ou à frigoré (PfPi) est la plus fréquente des paralysies faciales. Elle pose un problème thérapeutique malgré la diversité des traitements proposés. L’acupuncture est une des alternatives proposées parmi cet arsenal thérapeutique. Le but de ce travail est d’évaluer l’apport de l’acupuncture dans le traitement de la PfPi et de dégager les différents facteurs pronostiques pouvant influencer la récupération de la fonction faciale. Notre étude a regroupé 40 patients porteurs de PfPi recrutés aux services d’ORL de l’hôpital régional de Jendouba et de l’hôpital de Charles Nicolle sur une période de 14 mois et pris en charge aux centres d’acupuncture à l’hôpital Mongi Slim et à l’hôpital régional de Jendouba. Tous les patients ont été traités, auparavant, selon le concept de la médecine occidentale, et n’ont été adressés qu’après échec du traitement médical conventionnel. L’évaluation de notre travail est basée sur deux tests : le testing musculaire de freyss et le grading de House et Brackman. L’étude statistique s’est basée sur le logiciel « SPSS ». Les résultats de cette étude montrent que le traitement par acupuncture trouve son indication lorsque le traitement médical conventionnel a échoué, même après un long délai de consultation.Mots-clés : paralysie faciale périphérique, acupuncture, traitement.The Bell’s palsy is the most common peripheral facial paralysis. it poses a therapeutic problem despite the diversity of treatments. Acupuncture is an alternative among the proposed therapeutic arsenal. The purpose of this study was to evaluate the contribution of acupuncture in the treatment of facial paralysis and to identify different prognostic factors that may influence the recovery of facial function. Our study included 40 patients with Bell’s palsy recruited in the services of ENT in Jendouba hospital and Charles Nicolle hospital over a period of 14 months and supported in centers of acupuncture in Mongi Slim hospital and Jendouba hospital. All patients were previously under the concept of medical treatment, and were sent after failure of this treatment. The evaluation of our work is based on two tests: muscle testing of freyss and grading of House and Brackman. The study is based on statistical software "SPSS". The results of this study show that treatment with acupuncture is indicated in Bell’s palsy when conventional medical treatment has failed and even after a long period of consultation.Keywords: facial palsy, acupuncture, treatment

Dacryocystostomies par voieendonasale:indications et technique chirurgicale

Introduction : La dacryocystorhinostomie consiste à dériver le contenu du sac lacrymal directement vers la lumière de la fosse nasale correspondante en réalisant une large ouverture dans la paroi osseuse et muqueuse du sac, court-circuitant ainsi le canal lacrymonasal obturé. nous nous proposons, à travers cette étude rétrospective, de discuter les aspects techniques chirurgicaux de la dacryocystostomie par voie endonasale et de revoir les indications opératoires.Mots-clefs : dacryocystite ; dacryocystorhinostomie ; chirurgie endonasaleThe purpose of dacryocystorhinostomy is to derive the content of the lacrimal sac directly into the light of the corresponding nasal cavity by making a large opening in the bony wall and sac mucosa, by passing the blocked nasolacrimal duct. We intend, through this retrospective study, discuss the technical aspects of surgical dacryocystostomy by endonasal and review the indications for surgery.Keywords : dacryocystitis; dacryocystorhinostomy; endonasal surgery

Exact solution of the Bragg-diffraction problem in sillenites

A method for the exact solution of the Bragg-difrraction problem for a photorefractive grating in sillenite crystals based on Pauli matrices is proposed. For the two main optical configurations explicit analytical expressions are found for the diffraction efficiency and the polarization of the scattered wave. The exact solution is applied to a detailed analysis of a number of particular cases. For the known limiting cases there is agreement with the published results

Hematome Retropharynge Spontane : Apropos D\'un Cas

L\'hématome retro-pharyngé est une affection rare souvent d\'origine traumatique. La survenue d\'un HRP de façon spontané est exceptionnelle. Le but de notre travail est de rapporter à travers une observation les manifestations cliniques, les différentes hypothèses étiopathogéniques ainsi que les modalités thérapeutiques des HRP. Notre patiente âgée de 40 ans a consulté en urgence pour une ecchymose cervicale apparue spontanément. Les différentes investigations se sont révélées non concluantes. Sous surveillance, l\'évolution a été spontanément favorable.Spontaneous Retropharyngeal Haematoma (SRH) is a rare affection witch occur without traumatism. We report a case of 40\'s old year woman who present a SRH and discuss ethiopathogeny, clinic\'s and therapeutic\'s involvement Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 33-3