Primary hydatid cyst of the gallbladder: an unusual localization diagnosed by Magnetic Resonance Imaging (MRI)

Hydatid disease is endemic in Tunisia and has been considered as one of the most common surgical pathology. Several localizations have been described, but hydatidosis of the liver is the most frequent clinical entity. Primary hydatid cyst of the gallbladder is very rare. We report in this observation a new case of primary hydatid cyst of the gallbladder diagnosed by Magnetic Resonance Imaging (MRI).Pan African Medical Journal 2013; 14:1

Sulfide influence on metal behavior in a polluted southern Mediterranean lagoon: implications for management

International audienc

Highly improved optical properties of silicon nanowires by deposition of Poly[2-methoxy-5-(2 '-ethylhexyloxy)-1,4-phenylene vinylene] polymer

International audienceThis paper reports on the effect of the Poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) deposition on the chemical composition and the optical properties of silicon nanowires (SiNWs). The SiNWs were obtained by a single-step Ag-assisted chemical etching method, and then coated by MEH-PPV polymer using the electroless dipping method. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Fourier Trans-formed Infra-Red (FTIR) spectroscopy were used to probe the deposition of the polymer on the SiNWs surface and its chemical interaction with them. The optical properties of the elaborated samples were investigated by pho-toluminescence (PL) spectroscopy. The PL spectra show that the PL emission range of the nanowires is practically the same as that of the MEH-PPV. We also get an enhancement of five orders of the integrated PL intensity of MEH-PPV/SiNWs sample compared to that of untreated SiNWs sample. The PL intensity enhancement is attributed to the luminescent centers of MEH-PPV molecules as well as the passivation of silicon nanowires surface. Interchain and intrachain transitions in the polymeric layer as well as the carriers transfer between SiNWs and MEH-PPV are the main sources of the multiband PL spectra

Structural investigations and calorimetric dissolution of manganese phosphate glasses

Two series of manganese phosphate glasses (50x/2)Na2O-xMnO-(50 − x/2)P2O5 and (50 − x)Na2O-xMnO-50P2O5 (0 ≤ x ≤ 33 mol%), were prepared and investigated by means of density measurements, molar volume evolutions, FTIR and Raman spectroscopy, differential scanning calorimetry and calorimetric dissolution. In both series, density and glass transition temperature increase with composition. For the first series of glasses (3 ≤ O/P ≤ 3.49), spectroscopic analysis indicates that the addition of MnO content induces an evolution of structural units from Q2 to Q1 tetrahedral sites indicating the depolymerization of phosphate chains. By introducing MnO oxide into the second glass series (O/P = 3), Psingle bondOsingle bondP linkages are disrupted, suggesting a structural changes in the vitreous network. Calorimetric dissolution of both series of glasses in 4.5% weight of H3PO4 solution shows that the dissolution phenomenon is endothermic for the low MnO content and becomes exothermic as MnO concentration increases. This behavior may be correlated to the structural modification resulted from the depolymerization of the infinite metaphosphate chains

Structural and thermochemical study of Na2O-ZnO-P2O5 glasses

Glasses of the (50 − x/2)Na2O-xZnO-(50 − x/2)P2O5(3 ≤ O/P ≤ 3.49) and (50 − x)Na2O-xZnO-50P2O5 (O/P = 3) (0 ≤ x ≤ 33 mol%) compositions were prepared using the conventional melt quenching technique. The increase of density and glass transition temperature in both series is related to the reticulation of phosphate chains. For the first series of glasses, Fourier-transformed infrared (FTIR), Raman and 31P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy revealed the decrease of Q2 tetrahedral sites and the increase of phosphate dimers (Q1), indicating the shortening of phosphate chains. For the second series, FTIR and Raman spectroscopy show only the presence of Q2 tetrahedral sites. Dissolution of these series in 4.5% weight of H3PO4 solution has been followed calorimetrically and showed that the dissolution of the first series is endothermic for the low ZnO content and becomes exothermic when x rises. This behavior is correlated to the structural modification. For the second series, the dissolution phenomenon is endothermic confirming the presence of the same structure over the whole composition range

Structural and thermochemical properties of sodium magnesium phosphate glasses

Ternary phosphate based glasses with the general formula (50−x/2)Na2O–xMgO–(50−x/2)P2O5 (0 ⩽ x ⩽ 42.8 mol%), where the O/P ratio was varied from 3 to 3.75, have been prepared using a conventional melt quenching technique. Samples were investigated by means of density measurements, Fourier-transformed infrared (FTIR), Raman and 31P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies, differential scanning calorimetry (DSC), inductively coupled plasma atomic emission spectroscopy (ICP/AES) analysis and calorimetric dissolution.The depolymerization of metaphosphate chains are described by the decrease of Q2 tetrahedral sites allowing the formation of pyrophosphate groups (Q1) revealed by spectroscopic investigations. As a result, the increase of density and glass transition temperature when x rises. Calorimetric study shows that the dissolution phenomenon is endothermic for a lower MgO content and becomes exothermic when magnesium oxide is gradually incorporated, suggesting the disruption of phosphate chains with increasing O/P ratio