Quantitation of Oxidative Stress Gene Expression in MCF-7 Human Cell Lines Treated with Water-Dispersible CuO Nanoparticles

The objective of this study was to assess the cytotoxicity of water-dispersible CuO nanoparticles by quantifying the reactive oxygen species (ROS)-related genes (glutathione S-transferase (GST) and catalase) using real-time polymerase chain reaction (RT-PCR). Monodisperse CuO nanoparticles of 14 nm in size were used. Cytotoxicity of CuO nanoparticles was evaluated under in vitro condition at different concentrations (10, 50, and 100 μg/ml) and incubation times (12, 24, and 48 h) with human cancer cell lines (breast cancer epithelial cells). The genetic level cytotoxic screening produced consistent results showing that GST and catalase ROS gene expression was maximized in 24 h incubation at 100 μg/ml concentration of CuO nanoparticles. However, the cytotoxicity of water-dispersible CuO nanoparticle was not significant compared with control experiments, demonstrating its high potential in the application of nanomedicines for a diagnostic and therapeutic tool.     

Assembly-enhanced triplet-triplet annihilation upconversion in the aggregation formed by Schiff-base Pt(Ⅱ) complex grafting-permethyl-β-CD and 9,10-diphenylanthracence dimer

Water-soluble triplet sensitizer with permethyl-β-cyclodextrin(PMCD) grafting on a Schiff-base Pt(Ⅱ)complex(Pt-2),in which PMCD unit serves as a host for binding the acceptors and the Schiff-base Pt(Ⅱ)complex serves as a triplet sensitizer,was synthesized to investigate the effect of supramolecular complexation and assembly on the triplet-triplet annihilation upconversion emission in water.9,10-Diphenylanthracence(DPA) carboxylate(A-1) and its dimer(A-2) in which two DPA carboxylate were covalently linked with an alkyl chain were synthesized as triplet acceptors which also play a role of guest molecules for PMCD.A-1 and A-2 showed high affinity with PMCD,and A-2 can readily aggregate in water and form micron sized assemblies due to the hydrophobic effect and π-π stacking of anthracene core in A-2.The efficiency of TTA-UC was demonstrated to be enhanced by a synergistic effect of host-guest complexation of Pt-2 with A-2 and the self-aggregation of the acceptor A-2,which facilitated the energy transfer and energy fusion among donor and acceptor.     

Carbon Nanotubes/Heteroatom‐Doped Carbon Core–Sheath Nanostructures as Highly Active,Metal‐Free Oxygen Reduction Electrocatalysts for Alkaline Fuel Cells

A facile, scalable route to new nanocomposites that are based on carbon nanotubes/heteroatom‐doped carbon (CNT/HDC) core–sheath nanostructures is reported. These nanostructures were prepared by the adsorption of heteroatom‐containing ionic liquids on the walls of CNTs, followed by carbonization. The design of the CNT/HDC composite allows for combining the electrical conductivity of the CNTs with the catalytic activity of the heteroatom‐containing HDC sheath layers. The CNT/HDC nanostructures are highly active electrocatalysts for the oxygen reduction reaction and displayed one of the best performances among heteroatom‐doped nanocarbon catalysts in terms of half‐wave potential and kinetic current density. The four‐electron selectivity and the exchange current density of the CNT/HDC nanostructures are comparable with those of a Pt/C catalyst, and the CNT/HDC composites were superior to Pt/C in terms of long‐term durability and poison tolerance. Furthermore, an alkaline fuel cell that employs a CNT/HDC nanostructure as the cathode catalyst shows very high current and power densities, which sheds light on the practical applicability of these new nanocomposites.     

X-ray Photoelectron Spectroscopy of Imidazolium-Based Zwitterions: The Intramolecular Charge-Transfer Effect

Russian Journal of Physical Chemistry A - We investigate the imidazolium-based zwitterions, 1-butyl-3-methylimidazolium-2-pentafluorophosphate, together with 1-butyl-3-methylimidazolium...     

A novel adaptive spectrum reservation strategy in CRNs and its performance optimization

Spectrum reservation strategy is an effective technology for conserving communication resources in Cognitive Radio Networks. In order to better adapt to changes of the system load, we present an adaptive control approach to determine the reservation ratio of the licensed spectrum for secondary users and propose a novel adaptive spectrum reservation strategy. We then establish a three-dimensional discrete time Markov Chain model to capture the stochastic behavior of users. By using a method similar to that of the matrix geometric solution, we obtain the steady-state probability distribution for the system model, and derive the formulas for some required performance measures of two types of users. Numerical experiments and simulation experiments indicate that the system performance is sensitive to system parameters like the adaptive control factor and the admission threshold. Finally, we construct a system cost function to balance different performance measures, and present an intelligent searching algorithm to optimize the system parameters with the global minimum system cost.     

Non-equilibrium and stochasticity influence the activation process of the yeast DNA damage pathway

正Living cells are open systems that exist far away from a state of thermodynamical equilibrium.They utilize the high-grade chemical energy provided by food to produce ATP and release ADP and Pi together with heat dissipation.Living cells exist in a non-equilibrium steady state(NESS),they replicate themselves and respond to various environmental changes via