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

Comparative Study of Human and Automated Screening for Antinuclear Antibodies by Immunofluorescence on HEp-2 Cells

Background: Several automated systems had been developed in order to reduce inter-observer variability in indirect immunofluorescence (IIF) interpretation. We aimed to evaluate the performance of a processing system in antinuclear antibodies (ANA) screening on HEp-2 cells. Patients and Methods: This study included 64 ANA-positive sera and 107 ANA-negative sera that underwent IIF on two commercial kits of HEp-2 cells (BioSystems® and Euroimmun®). IIF results were compared with a novel automated interpretation system, the “CyclopusCADImmuno®” (CAD). Results: All ANA-positive sera images were recognized as positive by CAD (sensitivity = 100%), while 17 (15.9%) of the ANA-negative sera images were interpreted as positive (specificity = 84.1%), =0.799 (SD=0.045). Comparison of IIF pattern determination between human and CAD system revealed on HEp-2 (BioSystems®), a complete concordance in 6 (9.37%) sera, a partial concordance (sharing of at least 1 pattern) in 42 (65.6%) cases and in 16 (25%) sera the pattern interpretation was discordant. Similarly, on HEp-2 (Euroimmun®) the concordance in pattern interpretation was total in 5 (7.8%) sera, partial in 39 (60.9%) and absent in 20 (31.25%). For both tested HEp-2 cells kits agreement was enhanced for the most common patterns, homogenous, fine speckled and coarse speckled. While there was an issue in identification of nucleolar, dots and nuclear membranous patterns by CAD. Conclusion: Assessment of ANA by IIF on HEp-2 cells using the automated interpretation system, the “CyclopusCADImmuno®” is a reliable method for positive/negative differentiation. Continuous integration of IIF images would improve the pattern identification by the CAD

Deep-level defects in n-type GaAsBi alloys grown by molecular beam epitaxy at low temperature and their influence on optical properties

Deep-level defects in n-type GaAs1-x Bi x having 0 ≤ x ≤ 0.023 grown on GaAs by molecular beam epitaxy at substrate temperature of 378 °C have been injvestigated by deep level transient spectroscopy. The optical properties of the layers have been studied by contactless electroreflectance and photoluminescence. We find that incorporating Bi suppresses the formation of GaAs-like electron traps, thus reducing the total trap concentration in dilute GaAsBi layers by over two orders of magnitude compared to GaAs grown under the same conditions. In order to distinguish between Bi- and host-related traps and to identify their possible origin, we used the GaAsBi band gap diagram to correlate their activation energies in samples with different Bi contents. This approach was recently successfully applied for the identification of electron traps in n-type GaAs1-x N x and assumes that the activation energy of electron traps decreases with the Bi (or N)-related downward shift of the conduction band. On the basis of this diagram and under the support of recent theoretical calculations, at least two Bi-related traps were revealed and associated with Bi pair defects, i.e. (VGa+BiGa)(-/2-) and (AsGa+BiGa)(0/1-). In the present work it is shown that these defects also influence the photoluminescence properties of GaAsBi alloys

Computer-Assisted Classification Patterns in Autoimmune Diagnostics: The AIDA Project

Antinuclear antibodies (ANAs) are significant biomarkers in the diagnosis of autoimmune diseases in humans, done by mean of Indirect ImmunoFluorescence (IIF)method, and performed by analyzing patterns and fluorescence intensity. This paper introduces the AIDA Project (autoimmunity: diagnosis assisted by computer) developed in the framework of an Italy-Tunisia cross-border cooperation and its preliminary results. A database of interpreted IIF images is being collected through the exchange of images and double reporting and a Gold Standard database, containing around 1000 double reported images, has been settled. The Gold Standard database is used for optimization of aCAD(Computer AidedDetection) solution and for the assessment of its added value, in order to be applied along with an Immunologist as a second Reader in detection of autoantibodies. This CAD system is able to identify on IIF images the fluorescence intensity and the fluorescence pattern. Preliminary results show that CAD, used as second Reader, appeared to perform better than Junior Immunologists and hence may significantly improve their efficacy; compared with two Junior Immunologists, the CAD system showed higher Intensity Accuracy (85,5% versus 66,0% and 66,0%), higher Patterns Accuracy (79,3% versus 48,0% and 66,2%), and higher Mean Class Accuracy (79,4% versus 56,7% and 64.2%)

Preliminary results of the project A.I.D.A. (Auto Immunity: Diagnosis Assisted by computer)

In this paper, are presented the preliminary results of the A.I.D.A. (Auto Immunity: Diagnosis Assisted by computer) project which is developed in the frame of the cross-border cooperation Italy-Tunisia. According to the main objectives of this project, a database of interpreted Indirect ImmunoFluorescence (IIF) images on HEp 2 cells is being collected thanks to the contribution of Italian and Tunisian experts involved in routine diagnosis of autoimmune diseases. Through exchanging images and double reporting; a Gold Standard database, containing around 1000 double reported IIF images with different patterns including negative tests, has been settled. This Gold Standard database has been used for optimization of a computing solution (CADComputer Aided Detection) and for assessment of its added value in order to be used along with an immunologist as a second reader in detection of auto antibodies for autoimmune disease diagnosis. From the preliminary results obtained, the CAD appeared more powerful than junior immunologists used as second readers and may significantly improve their efficacy

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