Antioxidant status of rats' blood and liver affected by sodium selenite and selenium nanoparticles.

Background: Selenium is an essential element; however, at higher doses, it can be toxic. Therefore, alternative nanotechnological solutions are required to overcome toxicological issues, rather than conventional alternatives. Nanoparticles show new and promising properties that may be able to suppress toxicity while maintaining the positive effects of selenium on an organism.

Pectate hydrolases of parsley (Petroselinum crispum) roots.

The presence of various enzyme forms with terminal action pattern on pectate was evaluated in a protein mixture obtained from parsley roots. Enzymes found in the soluble fraction of roots (juice) were purified to homogeneity according to SDS-PAGE, partially separated by preparative isoelectric focusing and characterized. Three forms with pH optima 3.

Electron paramagnetic resonance study of free-radical kinetics in ultraviolet-light cured dimethacrylate copolymers.

A spin-trapping technique and direct kinetic measurements of electron paramagnetic resonance spectra were used to investigate the kinetics of radical production in the cross-linking photo-initiator system based on camphoroquinone and dimethyl-aminoethylmethacrylate in the presence of the corresponding monomer dimethacrylate copolymer mixture, as well as in the pure photo-initiator system. Consequently, in both cases, the kinetics of radical production and decay was measured. From the measured data the formal kinetic parameters of particular radical processes were calculated by the non-linear least-squares regression method.

Exploration of the electrophoretic behaviour of borane cluster anions and of the capability of capillary electrophoresis to separate them chirally.

Mobilities of investigated boron cluster compounds in 3-(N-morpholino)propanesulfonic and phosphate buffers adjusted to pH 7 either with sodium hydroxide or with tris(hydroxymethyl)aminomethane depend on both buffer ions. The zone width and zone asymmetry, which are usually markedly higher than those of organic or common inorganic ions of comparable size, depend on the type of the borane cluster anion. Unusual shapes of zones of two investigated compounds have been found in tris phosphate buffer.

Low NOx burners--prediction of emissions concentration based on design, measurements and modelling.

This paper describes possible ways of prediction of nitrogen oxides formation during combustion of hydrocarbon fuels. Mathematical model based on experimental data acquired from the testing facility has been developed. The model enables to predict--at a high probability measure--the extent of nitrogen oxides emissions.

Clinical application of laser-induced breakdown spectroscopy to the analysis of teeth and dental materials.

Objectives: The luminous plasma generated during laser ablation of dental tissue and dental materials has been analyzed to determine qualitative and quantitative elemental composition.

Background Data: The use of pulsed lasers for controlled material ablation now is frequently suggested as an alternative to mechanical drilling for the removal of caries and in tooth modification. Spectral analysis of the ablated plasma can be exploited to monitor precisely the laser drilling process in vivo and in real time.

The Darwin procedure in optics of layered media and the matrix theory.

The Darwin dynamical theory of diffraction for two beams yields a nonhomogeneous system of linear algebraic equations with a tridiagonal matrix. It is shown that different formulae of the two-beam Darwin theory can be obtained by a uniform view of the basic properties of tridiagonal matrices, their determinants (continuants) and their close relationship to continued fractions and difference equations. Some remarks concerning the relation of the Darwin theory in the three-beam case to tridiagonal block matrices are also presented.

Determination of biogenic amines in cheese by ion exchange chromatography.

A sensitive, fully automated method, yielding reproducible results, was developed for the determination of relevant biogenic amines in cheese. Histamine, tyramine, putrescine, cadaverine, tryptamine, agmatine, spermidine and spermine were separated in the ion exchanger of OSTION LG ANB column of the automatic amino acid analyser Mikrotechna 339 T. Elution was carried out at 60 degrees C using a system of two buffers.

Injection moulded hydroxyapatite ceramics.

The injection moulding of hydroxyapatite (HA) and properties (relative density, shrinkage, microstructure, thermal strength and phase composition) of HA ceramics sintered at temperatures of 1373-1773 K were studied. Particles of oval shape and size of 0.5 microns were most suitable for injection moulding.

Fuzzy bioengineering models.

A classical quantitative (analytical and/or statistical) analysis is not appropriate for some ill-defined and/or very complex bioengineering problems. Therefore, a new form of analysis using fuzzy mathematics has been developed. The fuzzy model can utilize semiqualitative and linguistic data which are to a certain level inconsistent.