54 research outputs found
Evaluation of the performance and degradation of crystalline silicon-based photovoltaic modules in the Saharan environment
© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The aim of this paper is to present three years of an evaluation of the performance and degradation rate of three different crystalline silicon-based photovoltaic (PV) modules in the Saharan environment. The
PV modules are: mc-Si (multi-crystalline), c_Si (mono-crystalline, back contacted) and HiT (heterojunction with intrinsic thin-layer); they are installed in Saida which is located at the proximity of Algeriaâs Sahara. Two methods were used to calculate the degradation rate; the effective peak power of the PV modules and the temperature corrected performance ratio. It was found that the HIT technology performs worse than the other technologies with the highest degradation rate, ranging from -1.53%/year to -1.92%/year. The mc_Si PV and c_Si PV module technologies present a lower degradation rate than the
HIT technology in the range of -0.74%/year to -0.83%/year and -0.58%/year to -0.79%/year respectively.Peer ReviewedPostprint (author's final draft
Prescription of Proton Pump Inhibitors in Elderly Subjects in Real Life: A Retrospective Study in a Gastroenterology Department
The proton-pump inhibitor (PPI) is an effective and widely used treatment but may cause side effects, especially for the elderly. Materials and methods: this is a cross-sectional study including 45 patients older than 65 years, followed at our outpatient and treated with PPIs for at least a year. The indication for PPI, the results of any endoscopy, and the quality of the tolerance of these molecules is specified by the data folder. During the consultation, we conducted an interrogation to an update of the history and medications to our patients and a type checking of the molecule, the dose, and the quality of the observance. Results: patients were divided into 32 women and 13 men with a mean age of 75 ± 7 years (65â92). The average length of PPI use was 6 ± 4 years (1â16) with a consumption of a double dose for at least 1 year in 28.8% of cases. The prescribed dose was higher than the recommended dose in at least 15.5% of cases. PPIs were well tolerated. One patient had presented a microscopic colitis, revealed by diarrhea regressed after discontinuation of PPIs. Conclusion: PPIs were prescribed in elderly subjects by gastroenterologists, in a university center, with a high dose and long. In our series, this treatment is well tolerated in the elderly
Microorganisms Isolated fromMoroccan Olive-Mill Wastes: Screening of Their Enzymatic Activities for Biotechnological Use
In this study, three samples of olive oil wastes: Olive Rinse Water (OR), Olive Mill Wastewater (OM) and Olive Pomace (OP), which were collected from an olive oil mill located at Fez-Morocco, were analyzed for their microbiota. A total of 81 isolates were obtained and constituted a microbial bank formed of 35 bacteria, 41 yeasts and 5 fungi. The microbial communities have been compared in term of metabolic potential by testing hydrolytic enzymes activities of lipase, protease, amylase, cellulase, pectinase and tannase on agar plate media. The results reveal that among the examined microorganisms, 68 isolates were able to produce at least one of the screened enzymes. The pectinase activity was the predominant one (39.51%), followed by cellulase activity (34.57%) and by lipase activity (27.16%). However, the amylase activity was observed only for 11.11% of the studied isolates, followed by protease activity (9.88%) and by tannase activity 6.17%. Thereby, considering the isolates ability to produce enzymes, they can be considered as potential candidates for industrial and biotechnological applications. Lipases are versatile enzymes that are used widely, itâs why the mostly aim of this work was to isolate new bacterial strains producing high level of lipases with interesting biochemical criteria. Thus, two isolates OR34 and OM2 showed the maximum lipase production under the standard conditions, about 9 U/ml and 11 U/ml, respectively, using pH-stat technique. They were identified as Proteus vulgaris and Serratia marcescens, respectively, via partial 16S rDNA gene sequence analysis
Gastrointestinal stromal tumors: epidemiological, clinical and therapeutic profile in Marrakech University Hospital
Les tumeurs stromales gastro-intestinales ou GIST sont des tumeurs mĂ©senchymateuses rares (1 Ă 3 % des tumeurs malignes gastro-intestinales). Elles font lâobjet de multiples controverses. Nous rapportons une Ă©tude rĂ©trospective portant sur 17 cas de tumeurs stromales gastro-intestinales confirmĂ©es histologiquement et Ă l'immunohistochimie, colligĂ©s au CHU Mohammed VI. LâĂąge moyen des patients Ă©tait de 59 ans (de 29 Ă 80 ans). La symptomatologie rĂ©vĂ©latrice Ă©tait une douleur abdominale dans la majoritĂ© des cas (49 %), une masse abdominale retrouvĂ©e chez 35 % des patients et une hĂ©patomĂ©galie dans 2 cas. Il sâagissait de 6 cas de tumeurs gastriques, 4 cas de tumeurs mĂ©sentĂ©riques, 4 cas de tumeurs jĂ©junales, et 3 cas de tumeurs rectales. Quinze patients ont Ă©tĂ© traitĂ©s par exĂ©rĂšse chirurgicale complĂšte. A lâhistologie, lâexpression du marqueur C KIT Ă Ă©tait prĂ©sente dans 100 % des cas. Dans 13 cas, il sâagissait de tumeurs localisĂ©es, deux patients prĂ©sentaient dâemblĂ©e des tumeurs localement avancĂ©es et deux autres avaient des mĂ©tastases hĂ©patiques au moment du diagnostic. Un traitement mĂ©dicamenteux Ă base d'Imatinib Ă©tait entrepris dans les tumeurs classĂ©es de haut grade de malignitĂ©, dans 6 cas en adjuvant, et dans 2 cas en nĂ©oadjuvant. Sur un recul moyen de 3 ans, la survie moyenne Ă©tait de 88 % Ă 3 ans et on notait 8 cas de rĂ©mission complĂšte, 3 cas de rĂ©mission partielle, 2 cas de rĂ©cidive tumorale et 2 cas de dĂ©cĂšs.Stromal tumors or GIST (gastrointestinal mesenchymal tumors) are rare (1-3% of gastro-intestinal malignancies). They are a subject of controversy. We report a retrospective study of 17 cases of gastrointestinal stromal tumors confirmed histologically and immuno-histochemically, collected at the University Hospital Mohammed VI. The average age of patients was 59 years, (29-80 years). The symptoms were abdominal pain in most cases (49%), abdominal mass found in 35% of our patients and hepatomegaly in 2 cases. There were 6 cases of gastric tumors, 4 cases of mesenteric tumors, 4 cases of jejunal tumors, and 3 cases of rectal tumors. Fifteen patients were treated with complete surgical resection. A histological marker expression C KIT was present in 100% of cases. In 13 cases tumors were localized, 2 patients had locally advanced tumors immediately and 2 others had liver metastases at diagnosis. Medication with Imatinib was initiated in the tumors classified high-grade malignancy in 6 cases in adjuvant and neoadjuvant in 2 cases. On a mean of 3 years, the 3-year survival was 88% and we had 8 cases of complete remission, 3 cases of partial remission, 2 cases of tumor recurrence and 2 deaths
Incidence of Gastric Cancer in Marrakech and Casablanca, Morocco
Gastric cancer is the fifth most common cancer globally with over 70% of new cases occurring in developing countries. In Morocco, oncologists in Marrakech suspected higher frequency of gastric cancer compared to Casablanca, a city 150 kilometers away. This study calculated age-specific, sex-specific, and total incidence rates of gastric cancer in Marrakech and was compared to the Casablanca population-based cancer registry. Using medical records from Center Hospital University Mohammad VI and reports from 4 main private pathology laboratories in Marrakech, we identified 774 patients for the period 2008â2012. Comparison of rates showed higher age-specific incidence in Marrakech in nearly all age groups for both genders. A higher total incidence in Marrakech than in Casablanca was found with rates of 5.50 and 3.23 per 100,000, respectively. Incidence was significantly higher among males in Marrakech than males in Casablanca (7.19 and 3.91 per 100,000, resp.) and females in Marrakech compared to females in Casablanca (3.87 and 2.58 per 100,000, resp.). Future studies should address possible underestimation of gastric cancer in Marrakech, estimate incidence in other regions of Morocco, and investigate possible risk factors to explain the difference in rates
Peroxisomal defects in microglial cells induce a disease-associated microglial signature
Microglial cells ensure essential roles in brain homeostasis. In pathological condition, microglia adopt a common signature, called disease-associated microglial (DAM) signature, characterized by the loss of homeostatic genes and the induction of disease-associated genes. In X-linked adrenoleukodystrophy (X-ALD), the most common peroxisomal disease, microglial defect has been shown to precede myelin degradation and may actively contribute to the neurodegenerative process. We previously established BV-2 microglial cell models bearing mutations in peroxisomal genes that recapitulate some of the hallmarks of the peroxisomal ÎČ-oxidation defects such as very long-chain fatty acid (VLCFA) accumulation. In these cell lines, we used RNA-sequencing and identified large-scale reprogramming for genes involved in lipid metabolism, immune response, cell signaling, lysosome and autophagy, as well as a DAM-like signature. We highlighted cholesterol accumulation in plasma membranes and observed autophagy patterns in the cell mutants. We confirmed the upregulation or downregulation at the protein level for a few selected genes that mostly corroborated our observations and clearly demonstrated increased expression and secretion of DAM proteins in the BV-2 mutant cells. In conclusion, the peroxisomal defects in microglial cells not only impact on VLCFA metabolism but also force microglial cells to adopt a pathological phenotype likely representing a key contributor to the pathogenesis of peroxisomal disorders
Risk Factors for Chronic Mastitis in Morocco and Egypt
Chronic mastitis is a prolonged inflammatory breast disease, and little is known about its etiology. We identified 85 cases and 112 controls from 5 hospitals in Morocco and Egypt. Cases were women with chronic mastitis (including periductal, lobular, granulomatous, lymphocytic, and duct ectasia with mastitis). Controls had benign breast disease, including fibroadenoma, benign phyllodes, and adenosis. Both groups were identified from histopathologically diagnosed patients from 2008 to 2011, frequency-matched on age. Patient interviews elicited demographic, reproductive, breastfeeding, and clinical histories. Cases had higher parity than controls (OR = 1.75, 1.62â1.90) and more reported history of contraception use (OR = 2.73, 2.07â3.61). Cases were less likely to report wearing a bra (OR = 0.56, 0.47â0.67) and less often used both breasts for breastfeeding (OR = 4.40, 3.39â5.72). Chronic mastitis cases were significantly less likely to be employed outside home (OR = 0.71, 0.60â0.84) and more likely to report mice in their households (OR = 1.63, 1.36â1.97). This is the largest case-control study reported to date on risk factors for chronic mastitis. Our study highlights distinct reproductive risk factors for the disease. Future studies should further explore these factors and the possible immunological and susceptibility predisposing conditions
Immune response of BV-2 microglial cells is impacted by peroxisomal beta-oxidation
Microglia are crucial for brain homeostasis, and dysfunction of these cells is a key driver in most neurodegenerative diseases, including peroxisomal leukodystrophies. In X-linked adrenoleukodystrophy (X-ALD), a neuroinflammatory disorder, very long-chain fatty acid (VLCFA) accumulation due to impaired degradation within peroxisomes results in microglial defects, but the underlying mechanisms remain unclear. Using CRISPR/Cas9 gene editing of key genes in peroxisomal VLCFA breakdown (Abcd1, Abcd2, and Acox1), we recently established easily accessible microglial BV-2 cell models to study the impact of dysfunctional peroxisomal ÎČ-oxidation and revealed a disease-associated microglial-like signature in these cell lines. Transcriptomic analysis suggested consequences on the immune response. To clarify how impaired lipid degradation impacts the immune function of microglia, we here used RNA-sequencing and functional assays related to the immune response to compare wild-type and mutant BV-2 cell lines under basal conditions and upon pro-inflammatory lipopolysaccharide (LPS) activation. A majority of genes encoding proinflammatory cytokines, as well as genes involved in phagocytosis, antigen presentation, and co-stimulation of T lymphocytes, were found differentially overexpressed. The transcriptomic alterations were reflected by altered phagocytic capacity, inflammasome activation, increased release of inflammatory cytokines, including TNF, and upregulated response of T lymphocytes primed by mutant BV-2 cells presenting peptides. Together, the present study shows that peroxisomal ÎČ-oxidation defects resulting in lipid alterations, including VLCFA accumulation, directly reprogram the main cellular functions of microglia. The elucidation of this link between lipid metabolism and the immune response of microglia will help to better understand the pathogenesis of peroxisomal leukodystrophies
Energy and environmental performance analysis of grid-connected photovoltaic systems under similar outdoor conditions in the Saharan environment
The aim of this paper is to present a one-year performance analysis of four grid-connected PV systems installed at Ghardaia city in Algeriaâs Sahara. The grid-connected PV systems are based on four different PV module technologies which are: monocrystalline silicon (m-Si), multi-crystalline silicon (mc-Si), cadmium telluride (Cd-Te) and amorphous (a-Si) PV module technologies. The PV systems based on the thin film technologies have their performance ratio better throughout the year when the performance ratio of the mc-Si technology is better in the winter season. The a-Si PV system has its performance ratio about 6.13 % more better than mc-Si and 8.90 % better than m-Si. The AC energy produced with the a-Si PV system is 13.32 % more than what the mc-Si system produces. It was found that the a-Si PV system performs better than the other technologies under the Saharan climate conditions of Ghardaia city. The energy payback time (EPBT) and greenhouse gases (GHG) emissions of the different PV systems were analyzed. The EPBT and GHG emissions per year, vary from a minimum value of 2.8 years to a maximum value of 5.73 years and from 13.24 tons to 32.03 tons of CO2/kWh for CdTe and m-Si respectively. The CdTe PV system performs better in terms of EPBT and GHG emissions compared to the other technologies (m-Si, mc-Si and a-Si) due to its low life cycle energy requirement
- âŠ