[Psychiatric comorbidity related to children with attention deficit hyperactivity disorder at schools in Sfax, Tunisia]. / Comorbidité psychiatrique au trouble déficit de l'attention/hyperactivité en population scolaire dans la région de Sfax. Tunisie : étude transversale.

INTRODUCTION: Attention deficit hyperactivity disorder (ADHD) is a prevalent behavioral disorder particularly noticed among school children. It is often associated with other psychological troubles at the origin of an additional difficulty that has to be overcome. OBJECTIVE: Our research's aim was to study the comorbidity of school-aged children diagnosed with ADHD in Sfax, Tunisia. SUBJECTS AND METHODS: A cross-sectional descriptive study was carried out from 1st April 2008 to 1st October 2008. Five hundred and thirteen pupils aged between 6 and 12, from primary arbitrarily chosen schools from Sfax were subjected to this study. Measurements were carried out in two steps: parents and teachers of each child filled in separately Conners questionnaire, then children with a score in subscales inattention, hyperactivity impulsivity higher than 70 were selected for psychiatric interview that was intended to confirm or to invalidate the ADHD diagnosis and the possible comorbid diagnosis. The diagnoses were made according to DSM-IV-TR. RESULTS: We have noticed that 109 pupils exhibited at least one pathological score on the Conners questionnaire. After interviewing these 109 pupils, the results have shown that 51 among them fulfilled criteria of ADHD. Prevalence of ADHD was found to be 9.94 %. About 72.54 % of children with ADHD had one or more comorbid disorder: learning disabilities (23.52 % of cases), anxiety disorder (31.37 % of cases), oppositional defiant disorder in (15.68 % of cases), mood disorder (3.92 % of cases), enuresis (13.72 % of cases) and slight mental retardation (1.95 % of cases). CONCLUSION: We can say that this study has shown that ADHD school children's psychiatric comorbidity is similar to any other previous study.

[Problematic Internet use among teenagers in Sfax, Tunisia]. / Prévalence de l'usage problématique d'Internet chez les adolescents, Sfax, Tunisie.

UNLABELLED: Use of the Internet in Tunisian society and especially among teenagers has increased in recent years. While the use of Internet is primarily intended for research and communication, the Internet has also become an important part of teenager's life. Most people use the Internet in healthy and productive ways. However, some teenagers develop a problematic use of the Internet, which is a condition also known by the term of "Internet addiction". In Tunisia, the literature does not report data on problematic Internet use prevalence among Tunisian teenagers. PURPOSE: The aim of this study was to determine the prevalence of problematic Internet use among teenagers, in the urban area of Sfax. METHODS: This transversal study was carried out between the 15th January and the 15th February 2009. Participants were 600, first to third grade secondary school students, aged 14 to 20. They were recruited from seven secondary schools randomly selected in the urban area in Sfax City. The self-administered Young's 8-item questionnaire was used in this survey. Participants who scored five or more can be considered problematic Internet users. Finally, 587 valid data samples were collected, 263 (44%) males and 324 (56%) females. Eighty-five percent of the participants were in the 15-17 age range. The mean age was 16 years (±1.26). RESULTS: The prevalence of problematic Internet use was 18.05% (total of 587 students). The sex-ratio was 0.75. The problematic Internet use was not correlated with sex. The average time of Internet use per day among problematic Internet users was 4.5hours (±2.84) against 1.02hours (±1.56) among non problematic Internet users (P=0.000). DISCUSSION: In this study, the prevalence of problematic Internet use was higher than that reported in previous studies. Two facts can explain this: first, the use of the only self-administered questionnaire does not distinguish between a simple abuse and a problematic Internet use. A psychiatric examination is essential to support the diagnosis of problematic Internet use. Second, this study was conducted exclusively in an urban area where access to the Internet is easier than in rural areas. This study was not representative of teenagers in Sfax. The gender difference was consistent with the findings of prior research, as was the average time of Internet use per day among problematic Internet users. CONCLUSION: This study shows that problematic Internet use is frequent in our teenage population. A preventive outreach for youths, their families and health professionals is needed to limit the extension of this problem among young people. The existence of misuse of the Internet should not lead to avoiding this media. Reflections on how to moderate the relationship with the Internet are necessary; especially since Internet becomes an essential medium of information and communication. The current lack of Internet education in school curricula is also a shortage to fulfil.

Behavior of aluminum electrodes in electrocoagulation process.

In the present work, electrocoagulation process with aluminum electrodes was investigated. Different operational conditions such as composition of Na(2)SO(4) based solutions, pH and current density were examined in a systematic manner. Their influence on (i) electrode polarization phenomena, (ii) pH evolution during electrolysis and (iii) the amount of Al released (coagulant) was investigated. For this purpose, potentiodynamic tests and electrolyses using different electrochemical cell configurations were conducted. It is mainly found that (i) a minimum Cl(-) concentration of the electrolyte of about 60ppm is required to breakdown the anodic passive film and considerably reduce the cell voltage during electrolysis; (ii) the anodic dissolution efficiency is unit; (iii) the global amount of coagulant (Al(3+)) generated has two origins: electrochemical oxidation of the anode and "chemical" attack of the cathode and (iv) electrolysis with Al electrodes acts as pH neutralization of the electrolytic medium. Taking into account advantage of the pH evolution observed during electrolysis, electrocoagulation tests were performed to treat a synthetic wastewater containing heavy metallic ions (Ni(2+), Cu(2+), Zn(2+)). Removal efficiencies over 98% were reached. Furthermore, our results displayed prominently that an increase of current density notably reduces the treatment duration without inducing a strong increase of the charge loading.

[Tracheal involvement revealing Hodgkin's disease. A case report]. / Atteinte trachéale révélatrice d'une maladie de Hodgkin.

Inaugural tracheobronchitis is a rare but known manifestation of Hodgkin's disease. Clinical signs are often misleading, retarding diagnosis and treatment. We report a case of Hodgkin's disease revealed by wheezing with minimal hemoptysis. Histology of the endoscopic biopsies demonstrated Hodgkin type infiltration of the trachea with mixed cellularity. The patient was given chemotherapy and mediastinal radiotherapy and achieved complete remission.

Effect of Test Parameters on the Friction Behaviour of Anodized Aluminium Alloy.

The tribological behaviour of anodic oxide layer formed on Al5754, used in automotive applications, was investigated against test parameters. The friction coefficient under different normal loads, sliding speeds, and oxide thicknesses was studied using a pin on disc tribometer. Results show that the increase of load and sliding speed increase the friction coefficient. The rise of contact pressure and temperature seems to cause changes in wear mechanism. Glow-discharge optical emission spectroscopy (GDOES) was used to investigate the chemical composition of the oxide layer. Morphology and composition of the wear tracks were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). On the basis of these characterization techniques, a wear mechanism was proposed. The observed mechanical properties can be related to the morphology and the chemical composition of the layer.

Electrochemical removal of Cr(VI) from aqueous media using iron and aluminum as electrode materials: towards a better understanding of the involved phenomena.

In the present work, electrocoagulation process with iron and aluminum electrodes was investigated to deepen the understanding of the mechanism of hexavalent chromium (Cr(VI)) removal. Electrocoagulation treatment efficiency was studied with regards to the abatement of Cr(VI) and the resulting species-namely Cr(III), Fe(II) and/or Fe(III). Unlike iron, aluminum electrodes were found to be unsatisfactory for Cr(VI) removal. To elucidate the removal mechanism of hexavalent chromium, different anode/cathode materials and configurations (Fe/Fe, Pt Ti (platinized titanium)/Fe, Al/Al and Pt Ti/Al) were considered. At nearly neutral pH and considering aluminum electrodes, both electrochemical reduction (Cr(VI) to Cr(III)) at the cathode surface and adsorption on Al(OH)(3) floc mechanisms were responsible for Cr(VI) exhaustion. However, the contribution of the two mechanisms to Cr(VI) removal was not discriminated. On the other hand, in the case of iron electrodes, even though electrochemical reduction may contribute to chromium removal, its influence seemed to be minor since the effect was confined to less than 5% of the removal efficiency. Hence, there was essentially one real root for the reduction of Cr(VI) by electrocoagulation with iron electrodes, and it was proven to be the chemical reduction by Fe(II) anodically generated. Moreover, the resulting Cr(III) was quickly removed from solution, via efficient precipitation as Cr(OH)(3) hydroxides. Besides, the electrodissolved iron remained at low level owing to the precipitation of Fe(OH)(2) and/or Fe(OH)(3). Although chemical reduction by Fe(II) predominantly governed the removal of Cr(VI), acidic pH media was found to promote electrochemical reduction of hexavalent chromium at the cathode and accordingly to enhance Cr(VI) removal efficiency. In contrast, a delay of Cr(III) precipitation and a contamination of the electrolyte by electrodissolved iron were observed under acidic conditions. The effect of supporting electrolyte (Na(2)SO(4) and NaCl) on chromium removal was also studied. No conspicuous disparity in the treatment efficiency was noted under the electrocoagulation conditions used.