The Effects of Ibuprofen Cytoxic Dose on caspase-3, -8 and -9 Activity level in cervical cancer (Hela) cells

BACKGROUND AND OBJECTIVE: Studies have shown that ibuprofen can have an anti-cancer effect on cervical cells, although the mechanism of this effect is not well known in cellular and molecular terms. Accordingly, the aim of this study was to investigate the effect of cytotoxic concentration of ibuprofen on the activity of caspases -3, -8 and -9 in cervical cancer (Hela) cells. METHODS: In this experimental-laboratory study, Hela cells were prepared from Pasteur Institute cell Bank and were divided into the control group and groups exposed to 0.01, 0.1, 1 and 10 mg/ml of Ibuprofen. Viability of cells was measured by MTT assay. The activity level of caspases-3, -8 and -9 was assessed by colorimetric method. The data were statistically analyzed using ANOVA. FINDINGS: The viability decreased significantly in cervical cancer cells exposed to 0.1 (76%), 1(64%) and 10(15%) mg/ml of ibuprofen compared to control group (100%)(p<0.05, p<0.001 and p<0.001 respectively). The caspases-3، -8 and -9 activity level increased significantly in cervical cancer cells exposed to IC50 dose of ibuprofen compared with control group (p<0.001, p<0.001 and p<0.01 respectively). CONCLUSION: The results of present study showed that ibuprofen is able to reduce the viability of cervical cancer cells in a dose-dependent pathway, and this pathway is induced by activating of caspases-3, -8 and -9

Modeling and Simulation of Interfacial Turbulent Flows

Majority of the fluid flows in nature and industries are turbulent flows. Due to their complexity, modeling and simulation of turbulent flows are still among the top research topics in the field of fluid mechanics. The objective of this work is to consider the turbulence effects at the interface. The presence of interface affects the turbulence structures and they become anisotropic near the interface. In this work, the main objective is to consider the fluctuations of the interface topology and their effects on the volume fraction and the surface tension force at the interface. These effects are important under some circumstances especially when the shape of the interface changes rapidly and abruptly. The surface tension forces and the volume fraction-velocity fluctuation correlation have also important impact on the interface topology and its complicated features such as coalescence and breakup. Different new models are presented and the impacts of those parameters on the flow at the interface are presented in this work. In developing the models for mean velocity-volume fraction fluctuations the inhomogeneity of the flow at the interface is taken into account. Both Reynolds Averaged Navier-Stokes Equations and the Large Eddy Simulation Techniques were used to simulate turbulent interfacial flows and implement the novel models introduced in this work. The Kelvin-Helmholtz instability, two-dimensional and three dimensional jets, and water/oil phase separation were simulated numerically and the results were compared with corresponding valid data and the accuracy of the models was examined

Report of two parasitoid wasps on Helicoverpa armigera (Lep.: Noctuidae) from Iran

In a two-year study on natural enemies of tomato fruit worm, Helicoverpa armigera (Hubner) (Lep.: Noctuidae) in Golestan province, two parasitoid wasps belonging to the family Ichneumonidae were identified, which are newly recorded from Iran: 1. Hyposoter didymator (Thunberg), which was collected in 8 July 2003, in Seyed-Miran, 9 Km west of Gorgan, and 2. Ctenichneumon panzeri (Wesmael), which was collected in 20 July 2003 at Gorgan Agricultural Research Station. These two species were identified by Dr K. Horstmann, Universitaet Wuerzburg, Germany and Dr E. Diller, Zoologische Staatssammlung Munchen, Germany, respectively

Optical Properties of Periodically and Aperiodically Nanostructured p-n Junctions

Recently, semiconductor nanograting layers have been introduced and their optical properties have been studied. Spectroscopic ellipsometry has shown that nanograting significantly modifies the dielectric function of c-Si layers. Photoluminescence spectroscopy reveals the emergence of an emission band with a remarkable peak structure. It has been observed that nanograting also alters the electronic and magnetic properties. In this study, we investigate the quantum efficiency and spectral response of Si p-n junctions fabricated using subwavelength grating layers and aperiodically nanostructured layers

Investigation of Interfacial Charge Separation at PbS QDs/ (001) TiO2 Nanosheets Heterojunction Solar Cell

In the recent years, the heterojunction solar cells based on quantum dots (QDs) have attracted attention due to strong light absorbing characteristics and the size effect on the bandgap tuning. This paper reports on the kinetics of interfacial charge separation of PbS QDs/(001) TiO2 nanosheets heterojunction solar cells. PbS QDs are deposited using a bifunctional linker molecule on two different TiO2 films, i.e., TiO2 nanosheets (with 001 dominant exposed facet) and TiO2 nanoparticles (with 101 dominant exposed facet). Upon bandgap excitation, electrons are transferred from the PbS QDs conduction band to the lower lying conduction band of TiO2. Based on the ultrafast pump-probe laser spectroscopy technique, the kinetics of charge separation is scrutinized at the PbS/TiO2 interface. The interfacial charge separation at PbS/TiO2 nanosheets films made of (001) dominant exposed facets is five times faster than that on (101) dominant exposed facets TiO2 nanoparticles. The quantum yields for charge injection are higher for the (001) TiO2 nanosheets than the (101) TiO2 nanoparticles due to enhanced interfacial interaction with (001) surface compared to the (101) nanoparticles. The superior interfacial charge separation at PbS/(001) nanosheets respect to PbS/(101) nanoparticles is consistent with the higher photocurrent and enhanced power conversion efficiency in the PbS QDs/(001) TiO2 heterojunction solar cell. The use of (001) TiO2 nanosheets can be a better alternative to conventional mesoporous TiO2 films in QD heterojunction solar cells and perovskites-based heterojunction solar cells

Ultrafast charge separation dynamics in opaque, operational dye-sensitized solar cells revealed by femtosecond diffuse reflectance spectroscopy

Efficient dye-sensitized solar cells are based on highly diffusive mesoscopic layers that render these devices opaque and unsuitable for ultrafast transient absorption spectroscopy measurements in transmission mode. We developed a novel sub-200 femtosecond time-resolved diffuse reflectance spectroscopy scheme combined with potentiostatic control to study various solar cells in fully operational condition. We studied performance optimized devices based on liquid redox electrolytes and opaque TiO2 films, as well as other morphologies, such as TiO2 fibers and nanotubes. Charge injection from the Z907 dye in all TiO2 morphologies was observed to take place in the sub-200 fs time scale. The kinetics of electron-hole back recombination has features in the picosecond to nanosecond time scale. This observation is significantly different from what was reported in the literature where the electron-hole back recombination for transparent films of small particles is generally accepted to occur on a longer time scale of microseconds. The kinetics of the ultrafast electron injection remained unchanged for voltages between +500 mV and –690 mV, where the injection yield eventually drops steeply. The primary charge separation in Y123 organic dye based devices was clearly slower occurring in two picoseconds and no kinetic component on the shorter femtosecond time scale was recorded

Enhanced Electron Collection Efficiency in Dye-Sensitized Solar Cells Based on Nanostructured TiO2 Hollow Fibers

Nanostructured TiO2 hollow fibers have been prepared using natural cellulose fibers as a template. This cheap and easily processed material was used to produce highly porous photoanodes incorporated in dye-sensitized solar cells and exhibited remarkably enhanced electron transport properties compared to mesoscopic films made of spherical nanoparticles. Photoinjected electron lifetime, in particular, was multiplied by 3-4 in the fiber morphology, while the electron transport rate within the fibrous photoanaode was doubled. A nearly quantitative absorbed photon-to-electrical current conversion yield exceeding 95% was achieved upon excitation at 550 nm and a photovoltaic power conversion efficiency of 7.2% reached under simulated AM 1.5 (100 mW cm(-2)) solar illumination

Stability of hypermassive neutron stars with realistic rotation and entropy profiles

Binary neutron star mergers produce massive, hot, rapidly differentially rotating neutron star remnants; electromagnetic and gravitational wave signals associated with the subsequent evolution depend on the stability of these remnants. Stability of relativistic stars has previously been studied for uniform rotation and for a class of differential rotation with monotonic angular velocity profiles. Stability of those equilibria to axisymmetric perturbations was found to respect a turning point criterion: along a constant angular momentum sequence, the onset of unstable stars is found at maximum density less than but close to the density of maximum mass. In this paper, we test this turning point criterion for non-monotonic angular velocity profiles and non-isentropic entropy profiles, both chosen to more realistically model post-merger equilibria. Stability is assessed by evolving perturbed equilibria in 2D using the Spectral Einstein Code. We present tests of the code's new capability for axisymmetric metric evolution. We confirm the turning point theorem and determine the region of our rotation law parameter space that provides highest maximum mass for a given angular momentum.Comment: 12 pages, 9 figure

Photoinduced interfacial electron transfer and lateral charge transport in molecular donor–acceptor photovoltaic systems

Nanostructured liquid|solid and solid|solid bulk heterojunctions designed for the conversion of solar energy offer ideal models for the investigation of light-induced ET dynamics at surfaces. Despite significant study of processes leading to charge generation in third-generation solar cells, a conclusive picture of the photophysics of these photovoltaic converters is still missing. More specifically searched is the link between the molecular structure of the interface and the kinetics of surface photoredox reactions. Fundamental scientific issues in this field are addressed by the research project undertaken in the frame of the NCCR-MUST endeavor, an outline of which is given here