94 research outputs found

    Effect of heat and mass transfer and rotation on peristaltic flow through a porous medium with compliant walls

    Get PDF
    Purpose: The purpose of this paper is to investigate the peristaltic flow of an incompressible Newtonian fluid in a channel with compliant walls. The effects of rotation and heat and mass transfer are also taken into account. The governing equations of two dimensional fluid have been simplified under long wavelength and low Reynolds number approximation. An exact solutions is presented for the stream function, temperature, concentration field, velocity and heat transfer coefficient. Design/methodology/approach: The effect of the concentration distribution, heat and mass transfer and rotation on the wave frame are analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of rotation and heat and mass transfer. Findings: The results indicate that the effect of the permeability and rotation are very pronounced in the phenomena. Originality/value: The objective of the present analysis is to analyze the effects of rotation, heat and mass transfer and compliant walls on the peristaltic flow of a viscous fluid

    Anti-inflammatory Activity of the Plant Cannabis sativa (L) Petrolium Ether Extract in Albino Rats

    Get PDF
    In this study the plant Cannabis sativa seeds petroleum oil extract was investigated for anti- inflammatory activity on albino rats. The inflammation was firstly obtained by using carrageenan suspension 0.1 ml of 10% saline injected at the sub – plantar region of the left limb for inducing a local acute oedema. A decreased in oedema size was reported after 24 hours for the rats pretreated with carrageenan30 minutes before injection with suspension( 4.56, 0.59 and 0.93 for control, 1ml/kg per day and 0.5ml/kg per day groups given C. sativa seed extracts respectively.), compared to Indomethacin standard antiinflammatory drug which reported a decrease in oedema size diameter to 0.55mm, which indicated an increase inhibition percentages were reported for the different pretreated groups 0.00, 87.03, 79.56 and 87.91 including the comparative Indomethacin treated groups of rats respectively. On the other hand, the post-treated groups of rats (given C. sativa oil extract after 30 minutes of injection of suspension) showed a similar results for maximum concentration 1 ml/day of C. sativa oil extract in comparison to the standard drug. Hence, such results recommend the prospect focus for the preventive medication use of the extract. The study also highlights no significant changes for serum and protein of the blood taken from rats of the experiments. Although there were significant decrease in lymphocyte and neutrophil, but the changes were not significant. Indomethacin was given to the rats used for a comparative drug (10mg/kg). Moreover, the drug indomethacin used as a comparative parameter showed similar results in comparison to the extract, hence wise the reported results may be recommended for use as anti-inflammatory agent and should be explored more to formulate drug on basis of its activity

    ASSESSMENT OF TOTAL PHENOLIC, FLAVONOID CONTENT, ANTIOXIDANT POTENTIAL AND HPLC PROFILE OF THREE MORINGA SPECIES LEAF EXTRACTS

    Get PDF
    In the current investigation, three selected Moringa species (M. stenopetala, M. peregrina and M. oleifera) grown at Orman Botanical Garden, Giza, Egypt were tested to quantify spectrometrically, the total phenolic compounds according to Folin–Ciocalteu's assay and flavonoids content to assess their corresponding effect on their antioxidative activity. Different leaf extracts (hexane, ethyl acetate and ethanol 70%) of the three studied species were prepared. The obtained results revealed that M. peregrina gave the best extract yield for the leaves extracted by the different solvents. Regarding the total phenolic compounds, data exposed ethanol 70% extract of M. peregrina leaves as the highest value among other species (11.66 g GAE/100 g extract), while it was for hexane extract that showed the highest value among other species in flavonoids content (7.21 g QE/100 g extract). Antioxidant activity of leaf extracts was evaluated by means of 2,2-dyphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid (ABTS) scavenging assays. Data exhibited M. peregrina as the highest species to afford free radical scavenging activity with DPPH and ABTS assays in all concentrations of all extracts especially, 1000 μg/ml of ethanol (70%) with 97.00 and 92.67% inhibition, respectively. Moreover, HPLC with UV detection was employed for the identification and quantification of the phenolic compounds and flavonoid content, present in leaf methanolic extracts of the studied species. HPLC assay identified 25 phenolic compounds and 11 flavonoids in the leaves. It was noticed that M. stenopetala leaves emerged the highest values in most of the phenolic compounds and flavonoids. Eventually, it can be concluded that Moringa leaves showed their certain nutritional value and therefore had the potential as source of natural antioxidants. In addition, their regular consumption in diet could provide health benefits to humans by their protection role against oxidative stress

    Magnetic resonance imaging of head and neck vascular anomalies: pearls and pitfalls

    Get PDF
    Purpose: The aim of this study was to describe typical MRI features of the head and neck vascular anomalies and the possible diagnostic pitfalls.Patients and methods: Patients with extracranial vascular anomalies of the head and neck, who underwent MRI examinations between January 2013 and January 2016, were included in the study. Precontrast and postcontrast T1-WI,T2-WI, with and without fat saturation were acquired. When indicated, a noncontrast MR angiography was performed. Dynamic postcontrast MRI techniques were available in six children.Results: The study included 33 patients (age ranged from 10 to 20 years, mean: 49 months). MRI confirmed the clinical diagnosis in equivocal cases, and provided proper determination of lesion extension and/or associated intracranial anomalies. The study included 10 cases of vascular tumors (hemangioma), whereas the remaining 23 cases had the diagnosis of vascular malformations (one patient with arteriovenous malformation, one with capillary malformation, seven with venous, nine with macrocystic lymphatic, and five with microcystic lymphatic malformations).Conclusion: Vascular anomalies in the head and neck are mostly diagnosed on clinical basis; however, when the history is uncertain or the diagnosis is equivocal, a well-tailored MR examination can be a single valuable diagnostic tool providing structural and functional information.Keywords: children, head and neck, hemangioma, lymphatic malformation, magnetic resonance angiography, venous malformatio

    Inflation and late time acceleration in braneworld cosmological models with varying brane tension

    Get PDF
    Braneworld models with variable brane tension λ\lambda introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic interpretation of the varying brane tension models, by showing that the field equations with variable λ\lambda can be interpreted as describing matter creation in a cosmological framework. The particle creation rate is determined by the variation rate of the brane tension, as well as by the brane-bulk energy-matter transfer rate. We investigate the effect of a variable brane tension on the cosmological evolution of the Universe, in the framework of a particular model in which the brane tension is an exponentially dependent function of the scale factor. The resulting cosmology shows the presence of an initial inflationary expansion, followed by a decelerating phase, and by a smooth transition towards a late accelerated de Sitter type expansion. The varying brane tension is also responsible for the generation of the matter in the Universe (reheating period). The physical constraints on the model parameters, resulted from the observational cosmological data, are also investigated.Comment: 25 pages, 8 figures, accepted for publication in European Physical Journal

    In Vitro and In Silico Antioxidant Efficiency of Bio-Potent Secondary Metabolites From Different Taxa of Black Seed-Producing Plants and Their Derived Mycoendophytes

    Get PDF
    Oxidative stress is involved in the pathophysiology of multiple health complications, and it has become a major focus in targeted research fields. As known, black seeds are rich sources of bio-active compounds and widely used to promote human health due to their excellent medicinal and pharmaceutical properties. The present study investigated the antioxidant potency of various black seeds from plants and their derived mycoendophytes, and determined the total phenolic and flavonoid contents in different extracts, followed by characterization of major constituents by HPLC analysis. Finally, in silico docking determined their binding affinities to target myeloperoxidase enzymes. Ten dominant mycoendophytes were isolated from different black seed plants. Three isolates were then selected based on high antiradical potency and further identified by ITS ribosomal gene sequencing. Those isolated were Aspergillus niger TU 62, Chaetomium madrasense AUMC14830, and Rhizopus oryzae AUMC14823. Nigella sativa seeds and their corresponding endophyte A. niger had the highest content of phenolics in their n-butanol extracts (28.50 and 24.43 mg/g), flavonoids (15.02 and 11.45 mg/g), and antioxidant activities (90.48 and 81.48%), respectively, followed by Dodonaea viscosa and Portulaca oleracea along with their mycoendophytic R. oryzae and C. madrasense. Significant positive correlations were found between total phenolics, flavonoids, and the antioxidant activities of different tested extracts. The n-butanol extracts of both black seeds and their derived mycoendophytes showed reasonable IC50 values (0.81–1.44 mg/ml) compared to the control with significant correlations among their phytochemical contents. Overall, seventeen standard phenolics and flavonoids were used, and the compounds were detected in different degrees of existence and concentration in the examined extracts through HPLC analysis. Moreover, the investigation of the molecular simulation results of detected compounds against the myeloperoxidase enzyme revealed that, as a targeted antioxidant, rutin possessed a high affinity (−15.3184 kcal/mol) as an inhibitor. Taken together, the black seeds and their derived mycoendophytes are promising bio-prospects for the broad industrial sector of antioxidants with several valuable potential pharmaceutical and nutritional applications

    Reheating the Universe in Braneworld Cosmological Models with bulk-brane energy transfer

    Full text link
    The emergence of the cosmological composition (the reheating era) after the inflationary period is analyzed in the framework of the braneworld models, in which our Universe is a three-brane embedded in a five-dimensional bulk, by assuming the possibility of the brane-bulk energy exchange. The inflaton field is assumed to decay into normal matter only, while the dark matter is injected into the brane from the bulk. To describe the reheating process we adopt a phenomenological approach, by describing the decay of the inflaton field by a friction term proportional to the energy density of the field. After the radiation dominated epoch the model reduces to the standard four dimensional cosmological model. The modified field equations are analyzed analytically and numerically in both the extra-dimensions dominate reheating phase (when the quadratic terms in energy density dominate the dynamics), and in the general case. The evolution profiles of the matter, of the scalar field and of the scale factor of the universe are obtained for different values of the parameters of the model, and of the equations of state of the normal and dark matter, respectively. The equation describing the time evolution of the ratio of the energy density of the dark and of the normal matter is also obtained. The ratio depends on the rate of the energy flow between the bulk and the brane. The observational constraint of an approximately constant ratio of the dark and of the baryonic matter requires that the dark matter must be non-relativistic (cold). The model predicts a reheating temperature of the order of 3×1063\times 10^6 GeV, a brane tension of the order of 102510^{25} GeV4^4, and the obtained composition of the universe is consistent with the observational data.Comment: 29 pages, 9 figures, accepted for publication in JCA
    corecore