24 research outputs found
Highly Efficient Nanostructured Bi2WO6 Thin Film Electrodes for Photoelectrochemical and Environment Remediation
This is the final version. Available on open access from MDPI via the DOI in this recordNanostructured Bi2WO6 thin film electrodes with enhanced solar energy conversion and photocatalytic properties have been fabricated using Aerosol-Assisted Chemical Vapor Deposition (AACVD). By conveniently controlling the deposition process parameters, Bi2WO6 electrodes were fabricated with nanoplates and hierarchical buckyball-shaped microsphere structures morphology. A detailed study has been conducted to correlate the structure and morphology with the photoelectrochemical (PEC) and photocatalytic dye degradation performance. The PEC investigations revealed that the hierarchical buckyball-shaped microsphere structured Bi2WO6 electrodes have shown the photocurrent density of 220 ÎĽAcm-2 while nanoplates have a photocurrent density of 170 ÎĽAcm-2 at 0.23 V (vs. Ag/AgCl/3M KCl) under AM1.5 illumination. The PEC characterization of Bi2WO6 electrodes also reveals that the photocurrent density and photocurrent onset potential is strongly dependent on the orientation and morphology, hence the deposition parameters. Similarly, the methylene blue (MB) and rhodamine B (RhB) photodegradation performance of Bi2WO6 electrodes also show a strong correlation with morphology. This finding provides an appropriate route to engineer the energetic and interfacial properties of Bi2WO6 electrode to enhance solar energy conversion and the photocatalytic performance of semiconductor materials.Engineering and Physical Sciences Research Council (EPSRC)UK-India Education and Research Initiative (UKIERI
Idiopathic Membranous Nephropathy Preceding the Onset of Rheumatoid Arthritis: a Case Report
Introduction: Membranous nephropathy (MN) in the context of rheumatoid arthritis (RA), is often an iatrogenic complication due to the nephrotoxic effects of antirheumatic drugs. Rare cases of non-iatrogenic association between these two diseases were reported in the literature.Case report: A 30-year-old female patient presented in September 2005 with nephrotic syndrome. Renal biopsy showed features consistent with MN. Search for etiology was negative, particularly lupus serology which remained negative throughout the course of her illness. Accordingly, she was diagnosed as a case of idiopathic MN. Initially, she was treated with angiotensin converting enzyme inhibitors and angiotensin receptor blockers which maintained her protein excretion below nephrotic range for two years. Her nephrotic syndrome then relapsed and was treated with steroids and chlorambucil, according to the Ponticelli protocol. A few months later, she presented with early morning joint stiffness, polyarthritis involving the small joints of the hands, and strongly positive rheumatoid factor, fulfilling the diagnostic criteria of rheumatoid arthritis (RA). Her serum creatinine remained normal and a second renal biopsy revealed the same features of MN. Her RA was treated with pulsed methylprednisolone followed by oral steroids and methotrexate resulting in remission of the joints disease and the nephrotic syndrome. Remission was maintained for the last two years up to the time of this report.Conclusion: We hereby report a case of secondary membranous nephropathy that preceded the onset of rheumatoid arthritis by three years.Keywords: Auto-immunity; Membranous nephropathy; Rheumatoid arthriti
Les complications chirurgicales de la transplantation rénale à partir du donneur vivant: expérience du CHU Ibn Sina de Rabat
Introduction: La transplantation rénale (TR) est actuellement considérée comme un traitement de choix de l’insuffisance rénale chronique terminale (IRCT). Ses résultats se sont améliorés au cours des dernières années. Cependant, les complications chirurgicales demeurent graves car elles touchent un rein unique et surviennent sur un terrain fragilisé par l’insuffisance rénale et l’immunosuppression. L’objectif de ce travail est d’évaluer la fréquence des complications chirurgicales lors de l’activité de TR au CHU Ibn Sina de Rabat, et de dégager les facteurs ayant influé l’apparition de ces complications. Méthodes : Étude rétrospective des patients transplantés rénaux à partir de donneurs vivants apparentés (DVA)
de Juin 1999 à Décembre 2008 dans notre centre hospitalo-universitaire. Nous avons recensé les caractéristiques propres au receveur, au prélèvement, au donneur ainsi qu’au greffon. Les complications chirurgicales ont été colligées ainsi que leur prise en charge et évolution.
Résultats: Soixante sept dossiers ont été analysés avec un suivi moyen de 55 +/- 28 mois. 38 complications chirurgicales ont été recensées : sténose des artères rénales (38,7%), lymphocèle (21%), hématome (12,7%), thrombose vasculaire (7,8%), reflux vésico-urétéral (4,8%), rupture du greffon (3,2%), calcul (1 cas), éventration (1 cas), L’analyse statistique de notre série n’a pas mis en évidence de facteurs de
risque significatifs semblant influer sur l’incidence des complications chirurgicales. Conclusion: La morbidité liée aux complications chirurgicales de la TR reste élevée nécessitant un diagnostic et un traitement adéquat afin d’éviter les répercussions sur la survie des patients et des greffons
Association myélome multiple – maladie de Kaposi: à propos d’un cas
L'association Kaposi–myélome multiple est extrêmement rare. Nous rapportons, le cas d'un patient âgé de 76 ans suivi dans notre formation pour un myélome à immunoglobuline A kappa stade III-B selon Durie et Salmon. Ceci a été associé à des lésions cutanées dont la biopsie cutanée était en faveur d’une maladie de Kaposi. La sérologie de l’herpès virus humain de type 8 (HHV8) est revenue positive. Une radiothérapie sur les lésions était refusée par le patient. L'évolution était marquée par une altération de l'état général. Le patient ayant refusé la radiothérapie et toute prise en charge thérapeutique est décédée deux mois plus tard. Nous rapportons, à notre connaissance, le 18ème cas mondial de maladie de Kaposi associée à un Kahler chez un patient HHV8 positif. C'est une association exceptionnelle rendant probable le rôle pathogénique de HHV8 dans le développement du myélome
Preparation of iron molybdate catalysts for methanol to formaldehyde oxidation based on ammonium molybdoferrate(II) precursor
It was demonstrated that iron molybdate catalysts for methanol oxidation can be prepared
using Fe(II) as a precursor instead of Fe(III). This would allow for reduction of acidity of
preparation solutions as well as elimination of Fe(III) oxide impurities which are detrimental for
the process selectivity. The system containing Fe(II) and Mo(VI) species in aqueous solution was
investigated using UV–Vis spectroscopy. It was demonstrated that three types of chemical reactions
occur in the Fe(II)–Mo(VI) system: (i) formation of complexes between Fe(II) and molybdate(VI)
ions, (ii) inner sphere oxidation of coordinated Fe(II) by Mo(VI) and (iii) decomposition of the
Fe–Mo complexes to form scarcely soluble Fe(III) molybdate, Mo(VI) hydrous trioxide and
molybdenum blue. Solid molybdoferrate(II) prepared by interaction of Fe(II) and Mo(VI) in
solution was characterized by EDXA, TGA, DTA and XRD and a scheme of its thermal evolution
proposed. The iron molybdate catalyst prepared from Fe(II) precursor was tested in methanol-toformaldehyde
oxidation in a continuous flow fixed-bed reactor to show similar activity and
selectivity to the conventional catalyst prepared with the use of Fe(III)
Peroxide-based route for the synthesis of zinc titanate powder
In this work the thermodynamical solubility diagrams of zinc and titanium hydroxides
were reviewed in order to determine the conditions for maximum degree of phase composition
homogenization of precipitates. Experimental investigation of dependency of titanium peroxohydroxide
solubility on solution acidity has been carried out and coprecipitation of zinc ions has been
studied. It was concluded that precipitation by constant addition of mixed salts and base solutions
into the mother liquor with constant acidity of pH 8.5 allows maximizing homogenization of
precipitate composition. Thermal treatment process of mixed zinc and titanium hydroxides
coprecipitated with hydrogen peroxide was studied using thermogravimetric analysis, differential
thermal analysis and X-ray diffraction methods. It was found that precipitates of co-precipitated
mixtures of zinc and titanium hydroxides contained impurities of salts precursors of the Zn
(NO3)2 and TiOCl2 at a level of 1%. The experimental data demonstrate the influence of hydrogen
peroxide on crystal growth rate of the zinc titanate during thermal treatment. The temperature
ranges and kinetic parameters of hydroxide mixture dehydration, decomposition of the titanium
peroxohydroxide and precursor impurities were determined
Mixed cryoglobulinemia-associated Sjögren's syndrome leading to spontaneous rupture of the kidney: a case report
Intissar Haddiya,1 Hakim Hamzaoui,1 Zitouna Alhamany,2 Fatime-zohra Berkchi,1 Hakima Rhou,1 Loubna Benamar,1 Naima Ouzeddoun,1 Rabea Bayahia1 1Department of Nephrology-Dialysis-Renal Transplantation, Ibn Sina University Hospital, Rabat, Morocco; 2Department of Pathology, Rabat Children's Hospital, Ibn Sina University Hospital, Rabat, Morocco Background: Spontaneous rupture of the kidney is uncommon and is mainly caused by renal tumors. Only a few cases are caused by vasculitis. We report here the first case of spontaneous rupture of kidney resulting from mixed cryoglobulinemia. Case presentation: A 44-year-old man presented with sudden onset of fever, acute pulmonary edema, left flank abdominal pain unassociated with trauma, and rapidly progressive renal failure requiring dialysis. Computed tomography of the abdomen revealed a large perirenal hematoma of the left kidney. During conservative surgery, the patient underwent renal biopsy that showed renal vasculitis and membranoproliferative glomerulonephritis with intracapillary microthrombi. Tests were positive for mixed cryoglobulinemia caused by Sjögren's syndrome. The patient was better after immunosuppressive therapy, with the disappearance of clinical symptoms and the recovery of baseline renal function. Conclusion: We report on this case and discuss a possible link between spontaneous rupture of kidney and mixed cryoglobulinemia-associated Sjögren's syndrome. Keywords: mixed cryoglobulinemia, Sjögren's syndrome, spontaneous rupture of kidney, renal hematoma, Wünderlich syndrom