IntroductionVoluntary poisoning with neurotoxic products in order to achieve euphoria is common especially among young people. Neurological complications are quite likely and can be serious and ...irreversible.ObjectivesWe aim to describe the peripheral neuropathies secondary to N-Hexane intoxication in a Tunisian population.MethodsA retrospective descriptive study was carried out in our department of neurology in the NationalInstitute of Neurology of Tunis including patients diagnosed with N-Hexane neuropathy. All patientshad a history of a N-Hexane exposure. The diagnosis was confirmed after excluding other etiologiesthrough appropriate investigations. Clinical and para-clinical data as well as follow-up were assessed.ResultsWe selected 38 patients with a mean age of 22.7 years 14-36. Among them, 37 were glue-sniffer and 1 had a voluntary toxic exposure to paint. An associated cannabis consumption was found in 6 patients. All of them had a low socio-economic background and 17 were unemployed. Time to onset of neurological signs ranged from 5 months to 11 years. The clinical exam showed a quadriparesis (15,7%), a paraparesis (58%), sensory involvement (55,2%) amyotrophy (40%) and abolished tendon reflexes in lower limbs (81,5%). Swallowing disorder and optic neuritis were found in one case. The electroneuromyogram revealed an axono-demyelinating sensory-motor polyneuropathy (PN) in 16 cases and a demyelinating motor PN in 9 cases. Vitamin therapy, motor rehabilitation and psychotherapy sessions have been indicated. Only 6 patients showed slight clinical improvement after withdrawal. The rest of our patients did not quit; 84% of them became bedridden.ConclusionsGlue-sniffer related neuropathy is very common in our country especially in adolescents and young adults with low socio-economic background. The neurological outcome is serious and usually irreversible if exposure is persistent.Disclosure of InterestNone Declared
more than 100 alleles have been described on the alpha 1 antitrypsin gene. Normal variants (PiM1, PiM2 and PiM3) encodes AAT molecules which are different but functional and normally secreted. The ...more frequent risk variants are PiS and PiZ. In this study, an AAT polymorphism analysis in correlation with pulmonary diseases was conducted.
analyses were performed on 96 asthmatics, 67 emphysema cases and 318 control subjects. Alpha 1 antitrypsin phenotypes were studied by quantitative determination of AAT concentration and isoelectrofocusing. Genotyping was performed by RFLP PCR.
PiM1, PiM2, PiM3, PiS and PiZ allelic frequencies were calculated (0.7395, 0.2291, 0.0156, 0.0104, 0.0052 in asthmatics; 0.7547, 0.1716, 0.0298, 0.0298, 0.0149 in emphysema patients and 0.8030, 0.1525, 0.0408, 0.006, 0.0000 in controls, respectively). Results showed an increase in PiM2 allele frequencies in both patients' groups compared to controls. Allelic frequencies difference is significant only with the asthmatic group (p=0,0179). PiS and PiZ deficiency alleles are more prevalent in the emphysema (0.0298, 0.0149) than in the asthmatic subjects (0.0104, 0.0052). Meanwhile, no significant difference in PiS and PiZ allelic frequencies was observed between patients and controls.
PiM2 allele can be considered as genetic risk factor for asthma. PiS and PiZ alleles are very rare in Tunisia in comparison with the European population, leading to a very small contribution in pulmonary diseases pathogenesis in Tunisia.
The study investigated alpha 1 antitrypsin (AAT) gene polymorphism in the Tunisian population. We aimed to analyze the correlation between Pi polymorphism and the risk of developing chronic ...obstructive pulmonary disease (COPD).
We focused our study on two samples originating from the Tunisian centre: 318 healthy controls and 90 patients suffering from COPD. Data analysis was investigated by AAT level quantification, serum isoelectric focusing (IEF) and RFLP-PCR performed with PiS and PiZ allele specific primers.
We calculated PiM1, PiM2, PiM3, PiS and PiZ allele frequencies in patients and controls. The difference in allele frequencies is significant only for the PiM2 allele (
P
=
0.00378). In COPD patients, we note the presence of PiZ allele. This allele mainly observed in European populations, is rare in Subsharian populations and not described in North Africa.
PiZ allele is found in COPD sample and never in Tunisian controls. However, no significant difference in PiZ allele frequency between patients and controls can be concluded. PiM2 allele, which is considered as “normal” variant can be associated with COPD risk.
Notre étude consiste en une investigation du polymorphisme du gène de l’alpha 1 antitrypsine (AAT) dans la population tunisienne en vue de rechercher une éventuelle corrélation entre ce polymorphisme et le risque de développement de bronchopneumopathies chroniques obstructives (BPCO).
Nous avons focalisé notre étude sur deux échantillons originaires du centre tunisien
: 318 donneurs sains et 90 patients atteints de BPCO. L’analyse des données consiste en un dosage de l’AAT, l’isoélectrofocalisation du sérum et l’étude moléculaire par RFLP-PCR utilisant des amorces spécifiques des allèles Pi S et PiZ.
Nous avons calculé les fréquences alléliques de PiM1, PiM2, PiM3, PiS et PiZ chez les malades et les témoins. La différence de ces fréquences alléliques n’est statistiquement significative que pour l’allèle PiM2 qui est plus fréquent chez les malades (
p
=
0,00378). Nous avons noté la présence de l’allèle PiZ dans l’échantillon des malades. Cet allèle, fréquemment observé en Europe, est rare dans les populations subsahariennes et non décrit en Afrique du Nord.
L’allèle PiZ est décrit uniquement chez les patients atteints de BPCO. Cependant, aucune différence significative des fréquences alléliques de l’allèle PiZ entre l’échantillon des patients et celui des témoins ne peut être conclue. L’allèle PiM2 considéré comme variant «
normal
» pourrait être associé au risque de développement de BPCO.
This article investigates the multi-material topology optimization (MMTO) of the three-phase stator of an electrical machine. The density-based optimization framework uses a gradient descent on the ...physical properties of the candidate materials (magnetic polarization and current density). The results indicate that a smoothing procedure is necessary to avoid non-manufacturable designs and promote a broader exploration of solutions. They also highlight a current angle shifting due to the presence of permanent magnets from the beginning of the optimization. The current angle is, therefore, added to the optimization variables to address this issue. An efficient optimization procedure that couples both techniques is proposed to improve the performance of the algorithm. The following hybrid method returns symmetrical results that perform better than the asymmetrical structures obtained with the other techniques applied independently, indicating that the asymmetry represents a local optimum.
This paper presents 3-D finite-element analysis of a new double excitation synchronous machine. It is shown that the machine has true field regulation capability. The principle of operation and ...design aspects of this new machine are presented in the paper. Comparison of 3-D FEA with an experimental study done on a prototype having a different rotor structure is also investigated.
This paper presents a new method to minimize the torque ripple of a 3-phase, 6-slot, and 4-pole mutually coupled switched reluctance motor (MCSRM 6/4). The difference between a MCSRM and a classical ...SRM is their winding configuration. In a MCSRM, the mutual inductances are no longer neglectable when compared to self inductance. On the contrary, due to mutual inductances, the MCSRM can produce higher average torque than a classical SRM. A literature review is firstly performed to identify the source of high torque ripple level of a MCSRM. Then, the method using punching holes in rotor poles to modify the waveforms of flux as well as derivatives of inductances with respect to rotor position (dL/d and dM/d ) is proposed. Using the 2-D finite-element method (FEM), the influence of dimensions of punching hole on the electromagnetic performances (average torque and torque ripple) is analyzed. The two MCSRM are supplied by three-phase sine wave currents, and comparisons in terms of average torque and torque ripple versus RMS current density are also carried out. In order to make sure that the presence of punching holes does not cause mechanical problems, some mechanical studies are performed. Finally, experimental tests are also realized to validate numerical results obtained by 2-D FEM.
This paper presents a 3-D analytical model of an axial flux permanent-magnet synchronous machine, based on formal resolution of Maxwell equations. This method requires much less computation time than ...conventional 3-D finite elements, and is therefore suitable for optimization purposes. In a first part, the mathematical procedure used to compute the machine no-load flux is described in detail. This method is 3-D, and then takes into account the radial edge effects of the machine, as well as the curvature effects by a resolution in cylindrical coordinates. Moreover, the originality of this method lies in the fact that it is totally analytical. The obtained results are verified using 3-D finite elements, and compared with simpler analytical models of axial flux machines, taken from the literature. This work puts in evidence the advantages of the proposed model. In particular, it is shown that the radial edge effects are important for a correct estimation of the no-load flux. On the contrary, the curvature effects are a second-order phenomenon.
We describe a 3-D analytical model based on formal resolution of Maxwell's equations of a permanent-magnet linear actuator, with circular-shaped magnets. We present all details of the 3-D analytical ...calculation for the no-load flux and then compare results obtained by this model to those obtained by 3-D finite-element analysis. The comparisons show a good agreement between the two models and so validate our analytical model. Unlike 3-D finite-element analyses, which are time consuming, the analytical models that we present in this paper are suitable for an optimization process of such a structure.
Les troubles cognitifs (TC) au cours de la sclérose en plaques (SEP) sont fréquents. Plusieurs domaines cognitifs peuvent être touchés. Le diagnostic positif dépend d’un bilan neuropsychologique ...spécifique.
Décrire les troubles cognitifs et déterminer leur prévalence dans notre population SEP. Des corrélations entre l’atteinte cognitive, la durée d’évolution, le score EDSS, l’atrophie cérébrale et les troubles anxiodépressifs vont être aussi déterminées.
C’est une étude transversale analytique incluant les patients hospitalisés au service de neurologie de l’hôpital Sahloul à partir du mois d’octobre 2020, dont le diagnostic de SEP selon critères de McDonald est déjà porté. Les tests utilisés sont : Symbol Digit Modalities Test (SDMT), The Multiple Sclerosis Neuropsychological Questionnaire (MSNQ), Mini-Mental State Examination (MMSE), Hospital Anxiety Depression Scale (HADS), le test des 5 mots et le test de l’horloge. L’étude des IRM des patients a été incluse.
Nous avons recensé 50 patients. La durée moyenne d’évolution de la maladie était de 7,56 ans. Nous avons noté un TC chez 29,6 % des patients. Le domaine le plus touché était la vitesse de traitement d’information (33,3 %). Un trouble anxiodépressif était présent chez 52 % des patients. L’atrophie cérébrale était présente chez 63 % des patients. La présence de TC était associée significativement aux comorbidités anxiodépressives et la durée d’évolution de la maladie (p<0,05).
Les TC concernent 40 à 70 % des patients atteints de SEP. La vitesse de traitement d’information est la fonction la plus touchée. Sa fréquence est 68,8 % selon la littérature. L’âge avancé, la durée d’évolution, la fatigue, la dépression et l’anxiété peuvent contribuer à l’apparition ou l’aggravation des TC. L’atrophie cérébrale est un marqueur sensible et précoce de la présence de TC.
L’apparition des troubles cognitifs chez un patient atteint de SEP représente un tournant majeur quant à sa qualité de vie. Leur détection est primordiale dans la prise en charge.
