Effect of MHD on Nanofluid flow, Heat and Mass Transfer over a Stretching Surface Embedded in a Porous Medium

The steady, laminar, mixed convection, boundary layer flow of an incompressible nanofluid past over a semi-infinite stretching surface in a nanofluid –saturated porous medium with the effects of magnetic field and chemical reaction is studied. The governing boundary layer equations (obtained with the Boussinesq approximation) are transformed into a system of nonlinear ordinary differential equations by using similarity transformation. The effects of various physical parameters are analyzed and discussed in graphical and tabular form. Comparison with published results is presented and we found an excellent agreement with it. Mainly, it found firstly, that an increase in magnetic parameter M decreases both the local Nusselt number and local Sherwood number. Secondly, a great order of the chemical reaction increases the Nusselt and Sherwood numbers

Phenotypic and molecular detection of biofilm formation in staphylococcus aureus Isolated from Different Sources in Algeria

Staphylococcus aureus is an opportunistic bacterium causing a wide variety of diseases. Biofilm formation of Staphylococcus aureusis of primary public and animal health concern. The purposes of the present study were to investigate the ability of Staphylococcus aureus isolated from animals, humans, and food samples to form biofilms and to screen for the presence of biofilm-associated and regulatory genes. In total, 55 Staphylococcus aureusisolated from sheep mastitis cases (n=28), humans (n = 19), and from food matrices (n = 8) were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The ability of Staphylococcus aureus for slime production and biofilm formation was determined quantitatively. A DNA microarray examination was performed to detect adhesion genes (icaACD and biofilm-associated protein gene (bap)), genes encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), regulatory genes (accessory gene regulator (agr) and staphylococcal accessory regulator (sarA)), and the staphylococcal cassette chromosome mec elements (SCCmec). Out of 55 Staphylococcus aureus isolates, 39 (71.0%) and 23 (41.8%) were producing slime and biofilm, respectively. All Staphylococcus aureus strains isolated from food showed biofilm formation ability. 52.6% of the Staphylococcus aureus strains isolated from sheep with mastitis, and 17.9% of isolates from humans, were able to form a biofilm. Microarray analysis typed the Staphylococcus aureus into 15 clonal complexes. Among all Staphylococcus aureus isolates, four of the human isolates (21.1%) harbored the mecA gene (SCCmec type IV) typed into 2 clonal complexes (CC22-MRSA-IV and CC80-MRSA-IV) and were considered as methicillin-resistant, while two of them were slime-producing. None of the isolates from sheep with mastitis harbored the cna gene which is associated with biofilm production. The fnbB gene was found in 100%, 60% and 40% of biofilm-producing Staphylococcus aureus isolated from food, humans, and sheep with mastitis, respectively. Three agr groups were present and agr group III was predominant with 43.6%, followed by agr group I (38.2%), and agr group II (18.2%). This study revealed the capacity of Staphylococcus aureus isolates to form biofilms and highlighted the genetic background displayed by Staphylococcus aureus isolates from different sources in Algeria

Physico-Chemical Characteristics and antioxidant Activity of Phenolic Compounds and oil of Citrus aurantium Seeds from Northwest Algeria

Sour orange (Citrus aurantium) is a tree of the family of Rutaceae. It is cultivated today in many parts of the world; the fruit, leaves, twigs and flowers have numerous applications in food and perfumery. Citrus aurantium used in this study originate from Tlemcen in North East of Algeria.Our study focused firstly on the physicochemical analysis of seed oil of sour orange namely the determination of indices, fatty acids, vitamin E and polyphenols.Secondly we evaluated total phenols, flavonoids, condensed tannins of Citrus aurantium seeds and their antioxidant activity of using in vitro methods: ferric reducing antioxidant power (FRAP) assay and β-carotene bleaching test.The seeds oil contents is 38.21%, their fatty major acids were palmitic (26.85 %) and linoleic acid (38.29%). The physicochemical analysis of oil showed index values of density, acid value, ester value, saponification value and refractive index estimated respectively: 0926; 1.212, 190.39, 191.52, 1467.The quantitative estimation of Citrus aurantium seeds showed that content of polyphenol is 2.12 mg GA /g DW which the predominant part is represented by tannins (0.3 mg CE /g DW) followed by the flavonoids (0.076 mg CE /g DW). Our results demonstrate that all extracts have antioxidant capacity. Among these extracts, the ethyl acetate fraction of flavonoids showed the highest value of antioxidant activities for seed which might constitute an important source of natural antioxidants

Physico-Chemical Characteristics and antioxidant Activity of Phenolic Compounds and oil of Citrus aurantium Seeds from Northwest Algeria

Sour orange (Citrus aurantium) is a tree of the family of Rutaceae. It is cultivated today in many parts of the world; the fruit, leaves, twigs and flowers have numerous applications in food and perfumery. Citrus aurantium used in this study originate from Tlemcen in North East of Algeria.Our study focused firstly on the physicochemical analysis of seed oil of sour orange namely the determination of indices, fatty acids, vitamin E and polyphenols.Secondly we evaluated total phenols, flavonoids, condensed tannins of Citrus aurantium seeds and their antioxidant activity of using in vitro methods: ferric reducing antioxidant power (FRAP) assay and β-carotene bleaching test.The seeds oil contents is 38.21%, their fatty major acids were palmitic (26.85 %) and linoleic acid (38.29%). The physicochemical analysis of oil showed index values of density, acid value, ester value, saponification value and refractive index estimated respectively: 0926; 1.212, 190.39, 191.52, 1467.The quantitative estimation of Citrus aurantium seeds showed that content of polyphenol is 2.12 mg GA /g DW which the predominant part is represented by tannins (0.3 mg CE /g DW) followed by the flavonoids (0.076 mg CE /g DW). Our results demonstrate that all extracts have antioxidant capacity. Among these extracts, the ethyl acetate fraction of flavonoids showed the highest value of antioxidant activities for seed which might constitute an important source of natural antioxidants