The first quantitative rating system of the antioxidant capacity of beauty creams via the Briggs-Rauscher reaction: a crucial step towards evidence-based cosmetics

Oxidative damage is the primary cause of skin aging. Skin care products are numerous and overwhelming, yet there is certain similarity among different formulations. Moisturizers are ubiquitous and the presence of particular added ingredients supports specific marketing claims. The antioxidant effects of botanical polyphenols possess tremendous marketing appeal, because oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the skin ability to neutralize them. The concept of evidence-based cosmetics lacks a widely accepted method to estimate the antioxidant capacity of the beauty cream. This was the motive force of the present study: for the first time we put forth a quantitative rating system of skin care products. The overall antioxidant power of 75 widely used and advertised beauty creams was comparatively measured via the oscillating Briggs-Rauscher (BR) reaction. Many dermocosmetic products confirmed their ability to ensure protection against free radicals, even if differences among various creams are striking and often not correlated with the their price. The method we developed is simple and cheap and it can allow dermatologists and consumers to compare and choose effectively; on the other hand, producers can used this method to select the most active antioxidant cosmetic agent to optimise the product performance.     

A Parallel Shallow Water Finite Element Solver for the Venice Lagoon

The aim of this paper is to investigate the concurrent implementation on Multiple Instruction, Multiple Data (MIMD) distributed memory multiprocessors of a shallow water finite element model built to simulate the tidal motion in the Venice lagoon. A recursive technique is used to partition the meshed computational domain into subdomains of (almost) equal number of elements, a requisite for balance the workload on parallel computers.     

Initial results utilizing optical pumping with a laser to produce spin-polarized hydrogen

Spin-polarized hydrogen was produced by laser optical pumping of rubidium and subsequent spin exchange with hydrogen atoms created by an rf discharge. Initial experiments produced approximately 10¹⁴ hydrogen atoms with a polarization of about 64%. Utilization of a suitable wall coating will allow significant improvement in these results.     

Linear boundary value problems for systems of ordinary differential equations on non compact intervals

Sunto In guesta nota si esaminano la completa continuità e il rango dell'operatore integrale associate al sistema x – A(t)x=f(t, x Tx=r al variare del tipo di stabilità della parte lineare.     

Optical heterodyne measurement of small shift differences between two stimulated Brillouin lines

The beats between two stimulated Brillouin scattering beams issued either from one single crystal or from two differently oriented crystals were observed and this allowed the shift differences to be measured in the range 60 MHz to 1 GHz.     

Extended thermodynamic approach to ion interaction chromatography: a thorough comparison with the electrostatic approach,and further quantitative validation

Based on a simple, chromatography-based analogy, a quantitatively exact explanation for the strong additional band broadening induced by the presence of the side-walls in flow channels with a large aspect-ratio rectangular cross-section is given and validated for two different flow types: pressure-driven and shear-driven flow.     

The dipole approach in the lon-interaction chromatography of zwitterions— Use of a potential approximation to obtain a simplified retention equation

Summary In ion-interaction chromatography (IIC) the zwitterionic analyte is believed to interact with the stationary phase potential as a result of its electrical dipole, and to compete with the ion-interaction reagent (IIR) for available inner layer sites. The most reliable set of literature data relating to the retention behavior of zwitterions in IIC has been used for successful testing of a high surface-potential approximation which enables the fitting of retention data without detailed information about the physical and chemical properties of the mobile phase. This approach can explain quantitatively, very simply, the retention behavior of zwitterions in IIC.