In this article, a similarity solution of the steady boundary layer flow near the stagnation-point flow on a permeable stretching sheet in a porous medium saturated with a nanofluid and in the presence of internal heat generation/absorption is theoretically studied. The governing partial differential equations with the corresponding boundary conditions are reduced to a set of ordinary differential equations with the appropriate boundary conditions via Lie-group analysis. Copper (Cu) with water as its base fluid has been considered and representative results have been obtained for the nanoparticle volume fraction parameter φ in the range 0 ≤ φ ≤ 0.2 with the Prandtl number of Pr = 6.8 for the water working fluid. Velocity and temperature profiles as well as the skin friction coefficient and the local Nusselt number are determined numerically. The influence of pertinent parameters such as nanofluid volume fraction parameter, the ratio of free stream velocity and stretching velocity parameter, the permeability parameter, suction/blowing parameter, and heat source/sink parameter on the flow and heat transfer characteristics is discussed. Comparisons with published results are also presented. It is shown that the inclusion of a nanoparticle into the base fluid of this problem is capable to change the flow pattern.

Multidrug resistance in cancer is significantly limits the effectiveness of cancer chemotherapy. The main purpose of the present study is to investigate the role of autophagy induced by glucose starvation in apoptosis induction in multidrug resistant human leukemia HL60/ADR cell line. The present data indicates that glucose starvation induced autophagy as determined by the level of LC3 protein (autophagy marker), whereas serum deprivation did not induce autophagy at the same time points. The induction of autophagy by glucose starvation exerted a great effect on apoptosis induction and enhancement. It was found that glucose starvation induced caspase3 cleavage more intensive than serum deprivation. Also, glucose starvation up-regulated the pro-apoptotic BAX and down-regulated the anti-apoptotic BCL-1 proteins representation, but serum deprivation did not affect both protein levels. The lipid mediator, Ceramide was the most candidate key player in autophagy and/or apoptosis induction after glucose starvation. Accordingly, Ceramide level was determined by DGK assay, ceramide level was elevated after glucose starvation and decreased after serum deprivation. Elevation of Ceramide by glucose starvation was found to be due to down-regulation of sphingomyelin synthase and glucosyl ceramide synthase activities and up-regulation of neutral sphingomyelinase activity. The opposite case of these enzyme activities was obtained in serum deprived cells. The current data throw the light on autophagy induced by glucose starvation as a powerful tool for apoptosis induction in multidrug resistance malignancy. Abbreviations: SM; sphingomyelin, Cer; Ceramide, DG; Diethyl Glycerol, SMS; Sphingomyelin Synthase, GCS; Glucosyl ceramide Synthase, GCer; Glucosyl Ceramide, ASMase; Acid Sphingomyelinase, NSMase; Neutral Sphingomyelinase, Glu; Glucose, Ser; Serum, MDR; Multidrug Resistance.

After ligation with transferrin (Tf), transferrin receptor (TfR) is aggregated on cell surface in clathrin coated pits and then internalized into the cell. In the present work, the mechanism of (Tf/TfR) and the role of Ceramide in this mechanism were studied. After Tf/TfR ligation, Ceramide level on plasma membrane outer leaflet was temporarily elevated as clarified by immunocytochemical detection of cell surface Ceramide in human "jurkat" T lymphoma cell line. Ceramide elevation was confirmed by Diacylgelycerol kinase assay for biochemical Ceramide measurement. The fast and brief Cer elevation was the result of acid sphingomyelinase activity, and no detection of neutral sphingomyelinase activity was noticed. Sphingomyelin synthase activity was obviously decreased in the same time frame of Ceramide generation, to maintain the elevated level of Ceramide. Inhibition of Ceramide generation by Imipramine, an acid sphingomyelinase inhibitor, or neutralization of the generated Ceramide by anti-Ceramide mAb lead to miss-internalization of transferrin, instead of being clathrin mediated it becomes, most probably, raft mediated as indicated by altered Tf recycling and cell fractionation studies. Miss-internalization of transferrin leads to abrogation of cell growth and finally apoptotic cell death. Abbreviations: ASMase – Acid Sphingomyelinase; Cer – Ceramide; DGK - Diacylgelycerol kinase; NSMase – Neutral Sphingomyelinase; SM – Sphingomyelin; SMS – Sphingomyelin synthase; Tf – Transferrin; TfR – Transferrin receptor.

A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.

A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.

A simple spraying technique was employed to deposit nickel hydroxide films on glass substrates. Nickel oxide films with different crystallite size were obtained by post annealing of Ni(OH)2 films in air at 523–673 K. The structure, chemical composition, surface morphology and thickness of the as-deposited and annealed films were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallite size was found to increase with increasing the annealing temperature. SEM revealed rather homogeneous films with an average thickness of about 10 m. Optical absorption study in 200 - 900 nm wavelength range reveals high absorption for wavelengths (λ) less than 400 nm in the ultraviolet (UV) and visible range. The UV absorption edge of NiO nanostructured films show shorter wavelength-shift that increases with increasing the crystallite size. NiO films exhibit optical transition by both direct and indirect allowed transitions. Direct and indirect optical energy gaps were calculated and found to decrease from 3.25 to 2.87 eV and 3.84 to 3.62 eV respectively; while the width of the localized states increases from 0.306 to 0.586 eV with decreasing the crystallite size from 23.4 to 5.7 nm. Dispersion spectra, real and imaginary parts of the dielectric constant spectra are examined at high frequencies.