Comparison of methods for the synthesis of silver nanoparticles stabilized in a solid polymethacrylate matrix.

Silver nanoparticles were synthesized inside the small plates of transparent polymer medium by reduction of silver cations. The difference in morphology and sizes of nanoparticles synthesized by chemical, photochemical and thermal reduction was revealed, which depends both on the component ratio of the mixture and on the reduction time for the specific component ratio The polymethacrylate matrix itself acts as the stabilizing agent. A colorimetric sensor based on polymethacrylate matrix and silver nanoparticles was developed for the detection of hydrogen peroxide.

A novel impedimetric sensor based on N-acetyl-L-cysteine for the determination of hydroxyl radicals in cell cultures in vitro.

We report a novel impedimetric sensor based on a graphite electrode impregnated with polyethylene and paraffin under vacuum (IGE) modified with electrochemically deposited gold and a self-assembled monolayer of N-acetyl-L-cysteine (NAC/Au/IGE) for selective and sensitive determination of extracellular hydroxyl radicals (OH) generated by living cells. The application of a sulphur-containing molecule oxidized by OH predicts the high selectivity of the sensor, and the utilization of the non-faradaic impedance spectroscopy for recording an analytical response makes it possible to achieve superior sensitivity with a detection limit of 0.01 nM and a linear dynamic range of 0.

Adsorptive stripping voltammetric determination of carbofuran in food using novel type of modified carbon-based electrode with grafted layers of nickel.

A voltammetric determination of carbofuran (CBF) was developed using a novel type of carbon-containing electrode (CCE) modified with carbon ink (CI) and a chromatographic sorbent (CS) based of chromaton (Ch), polyethylene glycol and nickel acetylacetonate with grafted layers of nickel (NiCS, stands for Ni modified CS) further denoted as CI/NiCS/CCE. The surface morphology of this modified electrode was investigated by scanning electron microscopy (SEM) and by electrochemical impedance spectroscopy (EIS). CBF which is not electrochemically oxidizable was first hydrolyzed in alkaline medium to give anodically active phenolic analogue CBFP.

Endothelial Cell Behavior and Nitric Oxide Production on a-C:H:SiO-Coated Ti-6Al-4V Substrate.

This paper focuses on the surface modification of the Ti-6Al-4V alloy substrate via a-C:H:SiO coating deposition. Research results concern the a-C:H:SiO coating structure, investigated using transmission electron microscopy and in vitro endothelization to study the coating. Based on the analysis of the atomic radial distribution function, a model is proposed for the atomic short-range order structure of the a-C:H:SiO coating, and chemical bonds (C-O, C-C, Si-C, Si-O, and Si-Si) are identified.

Dynamical and thermodynamical approaches to open quantum systems.

The non-Markovian dynamics of open quantum systems is studied from two different points of view. The first one coincides with the traditional tracing out of the environmental degrees of freedom, presented in classical textbooks on open quantum systems. The second one is an approximation of the exact density operator with the knowledge of only several dynamical variables in the spirit of non-equilibrium thermodynamics.