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Rekhila G.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,National Veterinary School of Algiers | Trari M.,University of Science and Technology Houari Boumediene
International Journal of Hydrogen Energy | Year: 2013

The spinel type compounds represent a new family of photocatalysts that can be used as photoelectrodes capable to produce hydrogen under visible light. In the current study, the NiFe2O4 spinel, which is prepared by the sol-gel method, is investigated as a possible candidate, and the structure, opto-electronic, electrochemical and photoactive properties are characterized. NiFe2O4 exhibits a p-type semiconductor behaviour with a hole mobility of 1.57 × 10-10 cm2 (V s)-1. The conduction at 300 K is found to take place by electron-hopping mechanism with an activation energy ΔEσ1=0.12ev, and the lowest optical transition is observed at 1.56 eV. The valence band is of cationic character and derives from the Ni-3d orbital (5.23 eV/vacuum). On the other hand, the conduction band, ECB = -1.62 VSCE, is located above the H2O/H2 potential (-0.98 V SCE), which allows for the H2-evolution under illumination. The effects of NiFe2O4 amount, pH level and S2O3 2- concentration are optimized. Under these ideal conditions, the rate of H2 involvement attains 0.68 × 10-3 mL mg-1 min-1 with a quantum efficiency η(H2) = 0.53%. Electrochemical impedance spectroscopy is also used to model the photosystem and an electronic equivalent circuit is proposed. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Helaili N.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,National Veterinary School of Algiers | Bouguelia A.,University of Science and Technology Houari Boumediene | Trari M.,University of Science and Technology Houari Boumediene
Solar Energy | Year: 2010

The p-Cu2O/n-ZnO system is studied for its potential use as a photoactive heterojunction able to highly perform under visible light. The main application deals with the degradation of organic dyes such as Orange II and the effects of Cu2O amount, Orange II concentration and light intensity are investigated. Results show that the kinetics of degradation follows a pseudo-first order and the optimum sensitization effect is obtained using a 70% concentration of Cu2O. The degradation rate reaches its maximum (Rinitial = 22.45 × 10-2 mg l-1 min-1) at 15 mg l-1 of Orange II. The effect of the irradiation intensity is also investigated taking the electrical energy consumption per order of magnitude (EE/O) as a figure of merit. The highest efficiency is obtained at an irradiation intensity of ∼122 × 10-5 kW with kOBS = 14.97 × 10-3 min-1 and EE/O, which corresponds to 12.54 kW h m-3 of energy consumption. This heterojunction allows a ∼25% saving of electrical energy in comparison to the p-Cu2O/n-TiO2 system, demonstrating the important role of the collector. © 2010 Elsevier Ltd. All rights reserved.


Brahimi R.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,University of Science and Technology Houari Boumediene | Bessekhouad Y.,National Veterinary School of Algiers | Nasrallah N.,University of Science and Technology Houari Boumediene | Trari M.,University of Science and Technology Houari Boumediene
Journal of Hazardous Materials | Year: 2012

In this study, 64% of hexavalent chromium Cr(VI) reduction from the initial concentration (10 -4M) is reported under visible light using the (CuAlO 2/CdS) hetero-system. In this new hetero-system, low doped CuAlO 2 delafossite, synthesized by sol-gel works as an electrons reservoir with a wide space charge region (440nm). In this case, the electron transfer to chromate is mediated via the hexagonal CdS variety, whose conduction band level is at -1.08V with respect to the saturated calomel electrode which is more negative than the CrO 4 2-/Cr 3+ level. This high reduction rate is achieved under optimized pH and CuAlO 2 percentage. Moreover, salicylic acid gives the best performance among hole scavengers and CuAlO 2 approaches 100% photostability at pH 7.5. The photo-catalytic process follows a pseudo first order kinetic with a half life of 2h. The reaction products are identified by UV-visible spectrophotometry and linear voltametry at a platinum rotating electrode. The results reveal the presence of Cr 3+ after irradiation. © 2012 .


Ait-Oudhia K.,National Veterinary School of Algiers | Gazanion E.,IRD Montpellier | Vergnes B.,IRD Montpellier | Oury B.,IRD Montpellier | Sereno D.,MIVEGEC UM1 CNRS 5290 IRD 224
Parasitology Research | Year: 2011

Leishmania is the causative agent of various forms of leishmaniasis, a significant cause of morbidity and mortality. The clinical manifestations of the disease range from self-healing cutaneous and mucocutaneous skin ulcers to a fatal visceral form named visceral leishmaniasis or kala-azar. In the absence of any effective vaccine, the only means to treat and control leishmaniasis is affordable medication. The treatment choice is essentially directed by economic considerations; therefore, for a large majority of countries, chemotherapy relies only on the use of cheaper antimonial compounds. The emergence of antimonial therapy failure in India linked to proven parasite resistance has stressed questions about selective factors as well as transmission risk of drug resistance. Unfortunately, in most parts of the world, the frequency of parasite antimony resistance linked to treatment failure is unknown because of a lack of information on Leishmania antimony susceptibility. This information is crucial for addressing the risk of selection and transmission of drug-resistant parasites, particularly in areas where antimony is the only chemotherapeutic alternative. However, the poor knowledge about factors that favor selection of resistant parasites, the multiplicity of the agents that can play a role in the in vivo antileishmanial activity of antimony, and the lack of a standard protocol to diagnose and survey parasite resistance all contribute to insufficient monitoring of antimony resistance. In this review, we discuss on the factors potentially involved in the selection of antimony resistance in the field and discuss on the methods available for its diagnosis. © Springer-Verlag 2011.


Denis S.,IRD Montpellier | Carla M.,New University of Lisbon | Khatima A.-O.,National Veterinary School of Algiers
International Journal for Parasitology: Drugs and Drug Resistance | Year: 2012

Leishmania drug resistance and particularly antimony resistance still continues to emerge in different part of the world. Because visceral and cutaneous leishmaniasis are transmitted in foci with zoonotic or anthroponotic life-cycles, the link between chemotherapeutic resistance and the selection for drug resistance, through drug consumption, cannot be as obvious for all forms of leishmaniasis. The underlying factors that trigger the selection of antimony resistant parasites are poorly studied in regard to environmental aspects. Recently, a correlation between the emergence of antimony unresponsiveness in India and water arsenic contamination has been raised. The presence of some yet unidentified environmental factors driving the selection of antimony resistant Leishmania populations in a zoonotic context of leishmaniasis is also currently questioned. The identification of key molecules involved in the selection of antimony resistance and their importance in the selective process have to be re-evaluated in light of the environment were all the hosts of Leishmania (mammalian and arthropod) evolved. These new insights will help to (i) address the risk of therapeutic failure associated with the emergence of drug-resistance and (ii) propose new therapeutic protocols to aim at reducing the risk of resistance in endemic areas. © 2012.


Daculsi G.,University of Nantes | Daculsi G.,Bordeaux University Hospital Center | Goyenvalle E.,National Veterinary School of Algiers | Cognet R.,National Veterinary School of Algiers | And 2 more authors.
Biomaterials | Year: 2011

The objective of this study was to determine the effect of calcium phosphate mineral content on the bone in-growth at the expense of composite of co-polylactide polymer charged with 2 different ratios of β-TCP granules (10 and 24 w-% of β-TCP). The evaluation was realized in a long term rabbit bone model. After 24, 48 and 76 weeks, the implants were examined by micro CT, scanning electron microscopy (SEM) using backscattered electron (BSE) and light microscopy (polarized and blue light microscopy). No foreign body reaction was detected during the 76 weeks follow-up in any of the test samples. Polymer hydrolysis began at approximately 24 weeks, by 76 weeks, the pure polymer implant had begun to release P(96L/4D)LA particles and show signs of peripheral localized bone resorption. A decrease in the amount of CaP was noticed between 24 and 76 weeks in both 10 wt-% and 24 wt-% β-TCP/P(96L/4D)LA composites. The study showed that the highest bone in-growth was with 24 wt-% β-TCP/P(96L/4D)LA composite. Bone in-growth and mineralization were evident for the composites associated with specific peripheral bone architecture. Fluorescent labelling demonstrated high bone in-growth and remodeling at the interface, while for pure co-polymer no bone remodeling or bone activity was maintained after 48 weeks. The study demonstrated the positive effect of calcium phosphate content into P(96L/4D)LA. This kind of composite is a suitable resorbable osteoconductive matrix, which provides long term stability required for ligament fixation device. © 2011 Elsevier Ltd.


Bensid A.,National Veterinary School of Algiers | Ucar Y.,Cukurova University | Bendeddouche B.,National Veterinary School of Algiers | Ozogul F.,Cukurova University
Food Chemistry | Year: 2014

The effect of ice containing thyme (0.04% w/v), oregano (0.03% w/v) and clove (0.02% w/v) extracts on the quality parameters of anchovy (Engraulis encrasicholus) was assessed through the chemical, sensory and microbiological methods. According to sensory analyses, anchovy stored in ice prepared with each plant extracts had a shelf life of 12 days, while batch stored in traditional ice had a shelf life of 9 days. pH were not significantly affected by the presence of plant extracts in the ice. However, a marked antioxidant effect (P < 0.05) could be detected with fish kept under plant extract icing systems, according to peroxide (PV) and thiobarbituric acid (TBA) values. Moreover, the employment of such icing systems led to lower (P < 0.05) total volatile base-nitrogen (TVB-N) value and free fatty acid (FFA) formation. Thus, TVB-N proved to be a suitable index for the spoilage of anchovies during chilled storage. The employment of such icing systems also led to significantly lower counts of aerobic mesophiles and psychrotrophic bacteria in anchovy muscle with skin, as compared with the traditional ice batch. This work demonstrates that the use of ice with plant extracts for the storage of gutted and beheaded anchovy can be recommended to improve the quality and extend the shelf life. © 2013 Elsevier Ltd. All rights reserved.


da Cruz J.C.M.,Embrapa Goat and Sheep Research Center | Singh D.K.,Winston-Salem State University | Lamara A.,National Veterinary School of Algiers | Chebloune Y.,Joseph Fourier University
Viruses | Year: 2013

Zoonotic events of simian immunodeficiency virus (SIV) from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2), the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections, in addition to the emergence of new strains, challenge every aspect of SRLV control measures for providing efficient tools to prevent the transmission of diseases between wild ungulates and livestock. © 2013 by the authors; licensee MDPI, Basel, Switzerland.


Bouayad L.,National Veterinary School of Algiers | Hamdi T.-M.,National Veterinary School of Algiers
Food Control | Year: 2012

The aim of this study was to establish the occurrence of Listeria spp., especially Listeria monocytogenes in ready to eat RTE food marketed in Algiers (Algeria).A total of 227 samples were collected from different producers and retailers.All samples were analyzed using a conventional cultivation method AFNOR V08-055.Out of 227 samples tested, 21 (9.3%) tested positive for Listeria spp. among them, 6 (2.6%) tested positive for L. monocytogenes. L. innocua was the most common Listeria species found being detected in 11 samples (4.8%), although both Listeria ivanovii and Listeria welshimeri were detected in 3 (1.3%) and 1 (0.4%) food samples respectively.The study of the antimicrobial sensitivity of Listeria monocytogenes strains showed no resistance.The study has enabled us to detect these contaminants in a wide range of RTE foods, to suggest that contamination likely occurs after heat treatment, and to assess the danger represented by this category of food for populations at risk. © 2011 Elsevier Ltd.


Mezali L.,National Veterinary School of Algiers | Hamdi T.M.,National Veterinary School of Algiers
Foodborne Pathogens and Disease | Year: 2012

This study was conducted in order to estimate the proportion of raw meat and processed meat products contaminated by Salmonella in the region of Algiers, Algeria, to identify serovars and to determine the antimicrobial resistance patterns of isolates. Out of the total 314 samples (144 of raw red meat and meat products, 128 of raw poultry meat and poultry products, and 42 of processed meat products) collected from various retail outlets, 61 (19.43%) were tested positive for Salmonella. The most significant occurrences were recorded for the categories of red meat (23.61%, n=34) and poultry (17.97%, n=23). Among the 64 isolates recovered, 21 different serovars were identified and two strains were nontypable. The most prevalent serovars were Salmonella Anatum (14.6%, n=9), Salmonella Altona (12.50%, n=8), Salmonella Corvallis (7.81%, n=5), Salmonella Enteritidis (7.81%, n=5), and Salmonella Typhimurium (7.81%, n=5). Sixty-two Salmonella isolates were tested for their susceptibility to 32 selected antimicrobial agents. Fifty-six (90.32%) isolates were resistant to at least one antimicrobial, of which 20 (32.26%) showed multidrug resistance. Resistance to sulphonamides (87.10%, n=54) was the most common. Resistance rates were lower to nalidixic acid (16.13%, n=10), streptomycin (16.13%, n=10), and tetracycline (12.90%, n=8), while resistance to pefloxacin was estimated at 4.84% (n=3). Fourteen different resistance patterns were observed. The "ACSSuT" pentaresistance pattern was observed in three of the Salmonella Typhimurium strains. The obtained results show that these foodstuffs are a potential source of antimicrobial-resistant Salmonella for human infections. © Copyright 2012, Mary Ann Liebert, Inc.

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