Analyse ergonomique semi-quantitative des contraintes biomécaniques du rachis cervical parmi les opérateurs sur écran dans les établissements universitaires tunisiens

Introduction: évaluer les contraintes biomécaniques associées aux cervicalgies parmi les opérateurs sur écran. Méthodes: étude ergonomique réalisée au prés de 325 opérateurs sur écran dans 25 établissements de l’université du centre tunisien, basée sur une étude anthropométrique du poste du travail sur écran et une analyse semi-quantitative sur des enregistrements vidéo des activités des travailleurs conduits sur une période représentative de 30 minutes. Résultats: la prévalence des cervicalgies évaluée à 72,3%, a concerné une population de travailleurs qui exerçait avec un siège et un plan de travail inadaptés (84,6%) et un écran bas situé par rapport au regard horizontal (81,2%). L’analyse semi-quantitative par enregistrement vidéo du poste de travail a conclu que la nuque était maintenue en flexion franche de plus de 40 degrés sur 69% du temps global du travail. La flexion latérale a été visible sur 50,3% du temps de travail et la rotation droite ou gauche sur 57,4% du temps de travail. Ainsi, Les opérations de prise d’information de l’écran, de regard du clavier et de consultation des documents se sont dégagées comme les plus de contraignantes pour la nuque sur le plan gestuel et postural. Conclusion: nos résultats mettent en évidence l’importance des contraintes biomécaniques associées à la conception du poste de travail sur écran non conforme aux dimensions anthropométriques ergonomiquement recommandées. Ces contraintes sont associées à une prévalence élevée des cervicalgies traduisant la nécessité d’aménagement ergonomique de ces postes de travail pour prévenir ce fléau

Monitoring CO2 migration in an injection well: Evidence from MovECBM

Carbon dioxide (CO2) geological storage relies on safe, long-term injection of large quantities of CO2 in underground porous rocks. Wells, whether they are the conduit of the pumped fluid or are exposed to CO2 in the storage reservoir (observation and old wells) are man-made disturbances to the geological storage complex, and are thus viewed by some as a possible risk factor to the containment of the injected CO 2. Wells are composite structures, with an inner steel pipe separated from the borehole rock wall by a thin cement sheath (∼2 cm) that prevents vertical fluid migration. Both carbon steel and cement react in the presence of CO2, although evidence from production of CO2-rich fluids in the oil and gas industry and from lab experiments suggests that competent, defect-free cement offers an effective barrier to CO2 migration and leaks. However, reactivity of cement and steel may result in CO2 migration pathways degrading over time, thus in the leakage risk increasing during the life of the storage project. The issue then becomes how to best integrate preventive verification of zonal isolation/well integrity in the storage site monitoring plan. An analysis of the order of magnitude of possible CO2 leaks, and of their path to potable aquifers or the atmosphere, is also necessary to optimize the assurance (mitigation) monitoring of the storage site. Evidence gathered during the MovECBM project indicates that migration of small quantities of CO2 happened during injection in a coal seam in Southwest Poland. The evidence, gathered from casing and cement logging as well as soil gas monitoring over a 3-year period, was coupled with laboratory testing and extensive modeling of the chemo-mechanical behavior of cement and steel to determine if CO2 migration might have been responsible of the observed behavior. The three lines of evidence were: the detection of very small CO2 fluxes, coupled with less controversial helium concentration in soil; the occurrence of a thin pathway at the interface between cement and casing; and the change in mechanical properties of cement, suggestive of partial carbonation. Whereas the observations suggest that limited CO2 migration might have happened in the well, they are by no means proof that the migration did happen. Nonetheless, the integration of measurement and modeling yields important lessons for wellbore monitoring. First, it puts a probable ceiling on the order of magnitude of expected leaks from reasonably well-cemented wells at around 100 metric tons per year (less than 0.05% of the injected mass in a well like Sleipner or In Salah). It also suggests that cement may be a very effective leak detector: exposure to CO2 modifies its mechanical properties, which in turn can be detected using cement evaluation logs. Finally, coupling with dispersion modeling suggests the precision and accuracy required from soil gas and atmospheric monitoring, as well as the placement of sampling points; it also suggest that hysteresis, due to the accumulation in CO2 in surface aquifers and to the time required for it to be transported to the survey points, may delay initial detection; the same hysteresis may at the same time prolong the occurrence of CO2 shows long after the leak has stopped. © 2010 Elsevier Ltd. © 2011 Published by Elsevier Ltd

Compositions and methods for well treatment

A self-healing cement for use in wells in which carbon dioxide is injected, stored or extracted, comprises a carbonaceous material. In the event of cement-matrix failure, or bonding failure between the cement/casing interface or the cement/borehole-wall interface, the materia! swells when contacted by carbon dioxide. The swelling seals voids in the cement matrix, or along the bonding interfaces, thereby restoring zonal isolation

Arthritis

Abstract In Langerhans cell histiocytosis pulmonary involvement is often isolated. It is rarely a part of a multifocal form. Tenosynovitis is exceptional. Hand bones involvement is atypical. We report the case of a 75-yearold, non-smoker man, without medical history, who presented with arthritis and fever. Examination found arthritis affecting large and small joints. In biology, there was an inflammatory syndrome. Radiographs of the hands showed erosions of the carpal bones. Doppler ultrasonography of the hands showed active synovitis. Tc99 bone scintigraphy highlighted joint uptake in the hands, knees, spine and right upper jaw. Blood cultures and infectious investigations were negative. Anti-nuclear antibodies and rheumatoid factor were negatives. CT scan showed cystic lung lesions and nodular aspect. Bronchoalveolar lavage fluid revealed positivity of anti-CD1a at 6%. A surgical biopsy showed an infiltrate of eosinophilic cells, positive for CD1a in immunohistochemistry studies. The diagnosis of Langerhans cell histiocytosis was retained

Monitoring CO2 migration in an injection well: evidence from MovECBM

Carbon dioxide (CO2) geological storage relies on safe, long-term injection of large quantities of CO2 in underground porous rocks. Wells, whether they are the conduit of the pumped fluid or are exposed to CO2 in the storage reservoir (observation and old wells) are man-made disturbances to the geological storage complex, and are thus viewed by some as a possible risk factor to the containment of the injected CO2. Evidence gathered during the MovECBM project indicates that migration of small quantities of CO2 happened during injection in a coal seam in Southwest Poland. The evidence, gathered from casing and cement logging as well as soil gas monitoring over a 3-year period, was coupled with laboratory testing and extensive modeling of the chemo-mechanical behavior of cement and steel to determine if CO2 migration might have been responsible of the observed behavior. The three lines of evidence were: the detection of very small CO2 fluxes, coupled with less controversial helium concentration in soil; the occurrence of a thin pathway at the interface between cement and casing; and the change in mechanical properties of cement, suggestive of partial carbonation. Whereas the observations suggest that limited CO2 migration might have happened in the well, they are by no means proof that the migration did happen. Nonetheless, the integration of measurement and modeling yields important lessons for wellbore monitoring. First, it puts a probable ceiling on the order of magnitude of expected leaks from reasonably well-cemented wells at around 100 metric tons per year (less than 0.05% of the injected mass in a well like Sleipner or In Salah). It also suggests that cement may be a very effective leak detector: exposure to CO2 modifies its mechanical properties, which in turn can be detected using cement evaluation logs

Les virus de l'hépatite profitent des pratiques traditionnelles pour augmenter la charge du carcinome hépatocellulaire en Tunisie

International audienceHepatocellular carcinoma (HCC) is a major public health issue in Africa. In Tunisia, hepatitis B virus (HBV) is known to be an important risk factor for HCC in the south of the country, but the role played by hepatitis C virus (HCV) still remains unclear. The aim of the current case-control study was to identify risk factors for HCC development in the northern part of the country. Clinical and biological data including viral hepatitis status (serological and molecular) and non-infectious risk factors from 73 patients with HCC and 70 control subjects without hepatic diseases were collected. The mean age of the patients was 63 ± 10 years, and the ratio of males to females was 1.1. HCC occurred in cirrhotic liver in 72.0% of the cases. HCV infection was the dominant risk factor (64.3% of cases); the presence of HBV was observed in 53.4% of the cases. Occult hepatitis B and C were implicated, respectively, in 30.1% and 9.6% of the cases. HCV genotype 1b was predominant. Patients originating from western Tunisia formed a homogeneous group, characterized by significantly higher rates of tattoos or scarifications (83%) and HCV infection (80%) than those from other parts of the country. Chronic HCV infection is currently the primary risk factor for HCC in Tunisia; HBV infection remains frequent in its overt or occult infection forms. Traditional esthetic practices apparently contribute to increasing the burden of terminal liver diseases in western Tunisia

Design and Rationale of the National Tunisian Registry of Heart Failure (NATURE-HF): Protocol for a Multicenter Registry Study

BackgroundThe frequency of heart failure (HF) in Tunisia is on the rise and has now become a public health concern. This is mainly due to an aging Tunisian population (Tunisia has one of the oldest populations in Africa as well as the highest life expectancy in the continent) and an increase in coronary artery disease and hypertension. However, no extensive data are available on demographic characteristics, prognosis, and quality of care of patients with HF in Tunisia (nor in North Africa). ObjectiveThe aim of this study was to analyze, follow, and evaluate patients with HF in a large nation-wide multicenter trial. MethodsA total of 1700 patients with HF diagnosed by the investigator will be included in the National Tunisian Registry of Heart Failure study (NATURE-HF). Patients must visit the cardiology clinic 1, 3, and 12 months after study inclusion. This follow-up is provided by the investigator. All data are collected via the DACIMA Clinical Suite web interface. ResultsAt the end of the study, we will note the occurrence of cardiovascular death (sudden death, coronary artery disease, refractory HF, stroke), death from any cause (cardiovascular and noncardiovascular), and the occurrence of a rehospitalization episode for an HF relapse during the follow-up period. Based on these data, we will evaluate the demographic characteristics of the study patients, the characteristics of pathological antecedents, and symptomatic and clinical features of HF. In addition, we will report the paraclinical examination findings such as the laboratory standard parameters and brain natriuretic peptides, electrocardiogram or 24-hour Holter monitoring, echocardiography, and coronarography. We will also provide a description of the therapeutic environment and therapeutic changes that occur during the 1-year follow-up of patients, adverse events following medical treatment and intervention during the 3- and 12-month follow-up, the evaluation of left ventricular ejection fraction during the 3- and 12-month follow-up, the overall rate of rehospitalization over the 1-year follow-up for an HF relapse, and the rate of rehospitalization during the first 3 months after inclusion into the study. ConclusionsThe NATURE-HF study will fill a significant gap in the dynamic landscape of HF care and research. It will provide unique and necessary data on the management and outcomes of patients with HF. This study will yield the largest contemporary longitudinal cohort of patients with HF in Tunisia. Trial RegistrationClinicalTrials.gov NCT03262675; https://clinicaltrials.gov/ct2/show/NCT03262675 International Registered Report Identifier (IRRID)DERR1-10.2196/1226