Primary xanthoma of calcaneus bone: Case report

AbstractINTRODUCTIONXanthoma (or xanthofibroma) is a benign proliferative lesion, mostly seen in soft tissue. Xanthoma of bone is very rare benign primary bone tumor, more frequently seen in men and in patients over 20 years of age. Histologically, it is characterized by mononuclear macrophage-like cells, abundant foam cells, and multinucleated giant cells. It is sometimes discovered coincidentally and the most frequent symptom is pain.PRESENTATION OF CASEWe present a 50-year-old healthy male patient with primary xanthoma of the calcaneus, who was treated by curettage and bone cement. He presented with a pathological fracture in a calcaneus bone lesion. Giant cell tumor was suspected on X-ray and MRI. Curettage and bone cementing was done through the posterolateral approach. Lipid profile was normal and histological examination revealed findings consistent with primary xanthoma of calcaneus bone.DISCUSSIONTo avoid an erroneous diagnosis, all material should be examined microscopically, the radiological features of the lesion should be studied properly and lipid profile should be investigated to differentiate between primary and secondary xanthoma. Primary xanthoma may be treated with curettage and bone graft while secondary xanthoma is treated nonsurgically and the skeletal manifestations will disappear with systemic treatment of hyperlipidemia.CONCLUSIONWe present this case to raise the suspicion of this lesion that is rarely described in the literatures. This is the first case of primary xanthoma of calcaneus bone that has been reported in Qatar

Les veines synmétamorphiques de quartz à disthène : témoins d'un métamorphisme associé à l'amincissement post-orogénique (Meseta occidentale, Maroc)

International audienceDes études récentes portant sur la chaîne hercynienne marocaine ont essayé de démontrer par de nombreux arguments d'ordre métamorphique, magmatique et structural qu' à une période de collision succède une évolution induite par le retour vers un équilibre thermique et gravitaire d'une croûte sur-épaissie. Par cette étude nous nous attacherons à mettre en évidence ce caractère généralisé de la tectonique extensive post-collision. Dans le massif hercynien des Rehamna, les veines de quartz à disthène sont encaissées dans des métapélites affectées par un métamorphisme à caractère barrovien, qui atteint les conditions du faciès des amphibolites et, de façon synchrone, la fusion partielle qui a engendré les granitoïdes de la région. De nouvelles observations de terrain appuyées par des travaux de laboratoire ont permis de mettre en évidence les caractères suivants : (i) les veines ou les filons de quartz à disthène sont clairement sécants et donc tardifs par rap-port à la stratification et la foliation régionale S0-1 associée à la première phase tectonothermale qui est synchrone de la collision hercynienne ; donc ces veines quartzitiques à disthène sont liées à une structuration plus récente. (ii) la structure pegmatitique et l'orientation des paragenèses minérales (disthène + quartz + micas blancs +/- tourmaline) dans les veines suggèrent une cristallisation qui correspond à une précipitation de minéraux à partir d'une solution hydrothermale riche en silice dans des ouvertures macroscopiques. (iii) presque toujours les veines discordantes de quartz contenant ce silicate d'alumine sont associées à des zones métamorphiques marquées par une forte activité hydrothermale d'origine magmatique, et de ce fait elles sont considérées comme pénécontemporaines des pegmatites tardi-magmatiques, des veines de tourmalinite et des dykes de greisen minéralisés en béryl, rutile et cassitérite. Dans le cadre régional, le premier apport de cette étude est de susciter une hypothèse : le disthène n'est pas attribué à la pression lithostatique, c'est-à-dire à la profondeur, mais plutôt à la pression de fluide engendrée par une solution hydrothermale en surpression. La présente note s'attache précisément à proposer un processus géodynamique où sont intégrés d'une part les veines ou filons synmétamorphiques de quartz à disthène, et d'autre part, l'amincissement crustal post-orogénique, considéré comme élément structural majeur dont le développement s'est accompagné de plu-sieurs manifestations hydrothermales de grande ampleur, vraisemblablement associées à un magmatisme granitique qui contrôle la distribution de la quasi-totalité des minéralisations dans le massif hercynien des Rehamna. Recent studies on the Moroccan Hercynian Belt have used metamorphic, magmatic and structural evidence to demonstrate that the post-collisional period was driven by return of the thickened crust towards thermal and gravi-tational equilibrium. In this study, we aim to characterize this general post-collisional extensional tectonic event. In the Rehamma Hercynian Massif, quartz-kyanite veins are found in association with amphibolite facies Barrovian metapelites. This metamorphism is synchronous with the partial melting episode which generated granitoids in the same region. Both experimental studies and field observations have led to the following conclusions: (i) quartz-kyanite veins or sills occurred later than the stratification and the regional foliation S0-1, which are associated with the first tectonothermal stage of the Hercynian collision. These veins are therefore contemporaneous with a more recent tectonic event. (ii) In the veins, both the pegmatitic structure and orientation of the paragenetic assemblage (kyanite + quartz + muscovite +/- tourmaline) suggest that the minerals precipitated from silica-rich hydrothermal solutions within macroscopic cracks. (iii) Discordant quartz-kyanite veins are usually found in association with metamorphic zones which have been altered by intense hydrothermal activity of magmatic origin. These kyanite-quartz veins can be viewed as penecontemporaneous with other late-magmatic pegmatites, tourmaline veins and greisen dykes rich in beryl, rutile and cassiterite. In this study, we suggest that kyanite growth was induced by high-pressure hydrothermal fluids rather than by litho-static pressure alone (i.e. depth). We show that both quartz-kyanite veins/sills and post-orogenic crustal thinning can be integrated into a single geodynamic process. Significant hydrothermal events are contemporaneous with post-orogenic crustal thinning and are probably associated with the granitic magmatism which controls the distri-bution of almost all the mineralisation in the Rehamna Hercynian Massif

Utilization of Waste Grooved Razor Shell (GRS) as a Catalyst in Biodiesel Production from Refined and Waste Cooking Oils

Biodiesel is a potential alternative for fossil fuel. However, its large-scale application is held up by the disadvantage of a homogenous process, the scarce availability of raw materials and the production cost, which is higher than for fossil diesel. In this work, biodiesel production was carried out using both refined and used cooking oils. The process was investigated in a batch reactor, in the presence of CaO as a heterogeneous catalyst prepared by the calcination of the natural Waste Grooved Razor Shell (GRS). Characterizations by X-Ray Diffraction (XRD) and Thermal Gravimetric (TG)/Differential Thermal Analysis (DTA) showed that the as-received GRS consists of aragonite, (i.e., CaCO3) as the main component and of water and organic matter in a lower amount. After calcination at 900 °C, CaO was formed as the only crystalline phase. The effects of several experimental parameters in the transesterification reactions were studied, and their impact on the produced biodiesel properties was investigated. The studied variables were the methanol/oil molar ratio, the catalyst weight percentage (with respect to the oil mass), the calcination temperature of the parent GRS and the recycling and regeneration of the catalyst. The physico-chemical and fuel properties, i.e., viscosity, density and acid value of used oils and of the produced biodiesel, were determined by conventional methods (American Society for Testing and Materials (ASTM) methods) and compared with the European standards of biodiesel. The optimal identified conditions were the following: the use of a 15:1 methanol/oil molar ratio and 5 wt% of CaO with respect to the oil mass. After 3 h of reaction at 65 °C, the biodiesel yield was equal to 94% and 99% starting from waste and refined oils, respectively

Investigation of Origanum compactum essential oil for analgesic and anti-inflammatory activities

Origanum compactum Benth. has been widely used in moroccan traditional medicine for various therapeutic treatments. Belonging to the same genus, O. onites was found to have marked analgesic and anti-inflammatory activities. The aim of this work is to evaluate theses pharmacological properties of the essential oil of O. compactum in order to provide a basis for the folkloric use of the plant. Aerial parts of plant were subjected to steam distillation, according to the French Pharmacopoeia. Male OF1 mice and male Wistar rats were used for these studies. The analgesic effect was done using Writhing test in mice and Tail-Flick test in rats. The mechanism investigation was evaluated employing an antagonism assay using naloxone, a specific antagonist of opiate receptors. Anti- inflammatory property has been studied using carrageenin and experimental trauma induced edema in rats. The essential oil of the aerial parts of Origanum compactum was found to exert central analgesic properties. Such a dose-dependent action was obtained against chemical and thermic stimuli, respectively, from the doses of 6.25 and 12.5 mg/kg and it was inhibited by a naloxone pretreatment, a specific morphinic antagonist compound. Significant and dose-dependent anti-inflammatory effects were observed on an acute inflammatory process from the dose of 100 mg/kg

Analytical modelling of arc re-ignition conditions on polluted insulating surfaces

The main propose of this paper is the elaboration of an analytical relationship of arc dry-band re-ignition condition of HVAC polluted insulators. The model is based on the equivalent electrical circuit of polluted insulator and the thermal proprieties of the dry-band arc. The developed model shows that the propagation condition and the re-ignition condition are linked. The application of this model is in a good accordance with the experimental measurements

Relationship between phosphorus fractions of some selected Sudanese soil orders to phosphate availability

A laboratory experiment was conducted to determine the extent and the importance of phosphorus (P) fractions of some agriculturally important Sudanese soils on P availability. The soils were gathered from different locations in Sudan, to represent three different orders: Aridisols (Um Dum soil, North Kordofan state), Alfisols (Hagu soil, Senar state), and Vertisols (Hosh soil, Gezira state). The soil P was fractionated using an authenticated procedure. The results showed that the soils had low total, organic and available P contents. Most of the inorganic soil P was present in the Fe-Al fraction in Um Dum soil (> 50%), and about 40% of this fraction in Hagu soil, but, only 20% in alkaline Hosh soil. The Ca-P fraction constituted > 60% in Hosh soil, about 40% in Hagu soil and 20 % in Um Dum soil. The available P in the top soils studied was positively related to the percent sum of Al+Fe -P of the total P, and was negatively related to the percent Ca-P fraction content of the total P. It has been proposed that the P sorption starts by exchange with singly coordinate Fe or Al- OH clay (OH− edge group) and quickly reorganizes into more stable and less soluble ring forms especially at pH more than 7.0, Alkaline pH more than 8.0 in soil like Hosh, will in presence of Ca, favour with time, the formation of inactive less soluble form like octacalcium phosphates and apatites at expense of the initial Al and Fe-P forms which are less stable at alkaline pH

Comportement en flexion des poutres en matériaux sandwichs

Les matériaux sandwichs résultent généralement de l'association de deux semelles ou peaux de faible épaisseur, constituées de matériaux à haute résistance et haut module et d'une âme beaucoup plus épaisse et de faible densité. Ils ont pour avantages: une grande rigidité, une résistance à la rupture élevée associées à un faible poids par unité de surface. Malgré une activité de recherche et de développement sur ces matériaux, le comportement au cours de l'endommagement reste peu connu. L'objectif de cette étude est l'analyse du comportement en flexion 3-points de différents sandwichs au cours de la fatigue. Ils sont constitués de fibres de verre et de résine époxyde pour les peaux et de mousse PVC de différentes densités pour l'âme. Les essais de fatigue sont menés en contrôle déplacement. La réduction de la rigidité ou cours du cyclage est utilisée pour caractériser l'état d'endommagement des sandwichs. L'observation des faciès de rupture ont permis de relever les différents modes d'endommagement entraînant la rupture de l'éprouvette. Enfin, les durées de vie sont caractérisées par les courbes de Wöhler en utilisant le critère N10, correspondant à une réduction de la rigidité de 10 % par rapport à sa valeur initiale

Investigation of competitive adsorption and desorption of heavy metals from aqueous solution using raw rock: Characterization kinetic, isotherm, and thermodynamic

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Qmax) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals