Surface properties of phenolic compounds and their influence on the dispersion degree and oxidative stability of olive oil O/W emulsions

The surface and interfacial properties of gallic acid, catechin and quercetin, and their effect on the dispersion degree and the oxidative stability of olive oil oil-in-water (O/W) emulsions prepared using β-lactoglobulin and Tween 20 were studied.Gallic acid showed no effect on the surface properties while catechin was proven to be able to accumulate at the air/water interface, decreasing the surface tension values with increasing its concentration. All the phenolic antioxidants caused a decrease in the interfacial tension at the oil/water interface, even though only catechin and quercetin showed a concentration dependent behaviour.In emulsions, gallic acid did not affect the droplet size of the systems, catechin caused the formation of oil droplets bigger than those of the control, whilst quercetin improved the dispersion state of the emulsions with the increasing of its concentration. Gallic acid, despite its partitioning in the water phase due to its polarity, delayed the formation of both the hydroperoxides and TBARs and limited their accumulation. Catechin did not affect the formation of oxidation products whilst quercetin, among the tested antioxidants, caused the lowest formation of both hydroperoxides and TBARs through 33 days of storage.     

A stability-indicating HPLC method to determine cyproterone acetate in tablet formulations

A simple and accurate liquid chromatographic method was developed to estimate cyproterone acetate (CA) in pharmaceuticals. The drug was chromatographed on a reversed-phase C18 column. Eluents were monitored at a wavelength of 254 nm utilizing a mixture (60:40) of acetonitrile and water. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for linearity, accuracy, precision, and selectivity. Due to its simplicity and accuracy, we believe that the method can be used for routine quality control analysis. No specific sample preparation is required except for the use of a column guard and a suitable prefilter attached to the syringe.     

WTO — a deterministic approach to 4-fermion physics

The program WTO, which is designed for computing cross sections and other relevant observables in the e⁺e⁻ annihilation into four fermions, is described. The various quantities are computed over both a completely inclusive experimental set-up and a realistic one, i.e. with cuts on the final state energies, final state angles, scattering angles and final state invariant masses. Initial state QED corrections are included by means of the structure function approach while final state QCD corrections are applicable in their naive formulation. A gauge restoring mechanism is included according to the Fermion-Loop scheme. The program structure is highly modular and particular care has been devoted to computing efficiency and speed.     

New semiconductor active device: the conductivity-controlled transistor

A new semiconductor 3-terminal device has been realised in which a majority-carrier current, flowing in a N+-N-N+ structure, is controlled by a minority-carrier current supplied by a forward-biased P+-N junction. The properties of this device are presented and discussed in terms of a physical model.     

How to Strip a Model to Its Essential Elements

Econometric models can be considered as a quantified representation of current economic theory. The paper suggests a procedure to check the correspondence between theory and practice. After an introduction about methodological aspects, a model of the Canadian economy is reduced by appropriate aggregation of the variables. Its condensed structure is then analysed, in order to investigate especially some noteworthy economic circuits such as financial flows and investment. The whole approach is strictly qualitative, based exclusively on the causal structure of the model. The results remain therefore consistent with any quantification of the model.     

Na2O-CaO-SiO2 glass-ceramic matrix biocomposites

Na₂O-CaO-SiO₂ glass- and glass-ceramic matrix/Ti particle biocomposites have been prepared by means of two processes: pressureless sintering and hot pressing. Time and temperature sintering conditions were optimised on the basis of the thermal properties of mixed glass and Ti powders, determined by Differential Thermal Analysis, Differential Scanning Calorimetry, Hot Stage Microscopy, Dilatometry. Each sintered sample was characterised by means of X-ray diffraction, Scanning Electron Microscopy, EDS, density measurements, Young's modulus, induced crack propagation by Vickers indentations, three point bending test, K _IC measurements. The in vitro bioactivity was investigated on the sintered composites by soaking them in a simulated body fluid (SBF) with the same ion concentration of the human plasma.     

Penalised regression splines: theory and application to medical research

Generalised additive models (GAMs) allow for flexible functional dependence of a response variable on covariates. The aim of this article is to provide an accessible overview of GAMs based on the penalised likelihood approach with regression splines. In contrast to the classical backfitting, the penalised likelihood framework taken here provides researchers with an efficient computational method for automatic multiple smoothing parameter selection, which can determine the functional form of any relationship from the data. We illustrate through an example how the use of this methodology can help to gain insights into medical research.