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Notes: Polarized Raman spectra of pelargonic acid (PA), CH3–(CH2)7–CO2H, at liquid–solid interfaces were recorded, using the excitation of the surface plasmon of silver. In this device, the exciting electric field decreases exponentially (or quasi-exponentially) into the sample. Therefore, the molecules in the vicinity of the solid surface are preferentially illuminated. This study was performed on two types of systems: 1°—One interface: a drop of PA is deposited on a solid surface [silver, silica, cetyltrimethylammonium bromide (CTAB), or Langmuir–Blodgett (LB) layers of barium stearate]; 2°—two interfaces: liquid ultrathin films of PA are placed between silica or barium stearate LB layers; the thickness of the film (250 to 5 nm) being measured by an interferential method. The shape of the 2800–3000 cm−1 band, which is very sensitive to the chain conformation, was studied. Since in the convenient polarization, the spectra of the drops were different from the spectrum of the isotropic liquid (classical cell), we can assume that the PA molecules have an anisotropic distribution in the vicinity of a solid surface and that the molecules are, therefore, more or less uniaxially oriented.The orientation is dependent on the nature and the smoothness of the solid surface, as is the distance over which the orientation spreads. (1°) If the distance of orientation is short relative to the penetration depth ((approximately-equal-to)100 nm) of the exciting wave, most of the illuminated molecules belong to an isotropic distribution: there is, therefore, little difference between the spectra of the drop and of the isotropic liquid, but, as in the ultrathin films only the oriented molecules are illuminated, spectra of films and liquid are very different. (2°) If the orientation distance is long (PA on barium stearate LB layers), the greater part of the illuminated molecules are oriented: the spectrum of the drop is therefore very different from the spectrum of the bulk (isotropic liquid); and the spectra of ultrathin films are similar to the spectrum of the drop. The differences observed in the band shapes are due to an increasing intensity of the peaks assigned to the symmetric vibrations of the CH2 and CH3 groups. These modifications can be explained by the comparison of the calculated scattering activities of uniaxially oriented molecules and random ones. The causes of the orientation and conformation change of the hydrocarbon chain have been discussed.

Notes: The self-consistent WCA method is generally regarded as more accurate than the WCA method at high densities, which may seem surprising in view of the orders of approximation expected. It is shown in this note that, in fact, the relative ranking of the two methods depends on the representation chosen for the indirect correlation function of the reference hard-sphere fluid.

Notes: Abstract: Commercially available and affinity-purified bu-tyrylcholinesterases isolated from human serum were examined for their esterasic activity and their ability to hydrolyze various neuropeptides, including neurotensin, substance P, and leucine-enkephalin. The three pools that displayed the lowest esterasic activities were shown to hydrolyze neurotensin with the same HPLC degradative pattern. By contrast, noticeable qualitative and quantitative discrepancies were observed when hydrolyses of substance P and leucineenkephalin by these three butyrylcholinesterase pools were studied. The pool that exhibited the highest esterasic activity appeared to be homogeneously constituted by 90- and 180-kDa protein bands by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and was totally unable to hydrolyze these three neuropeptides. This suggested that the three other butyrylcholinesterase preparations could be contaminated by exogenous peptidases. This was confirmed by means of three distinct monoclonal antibodies directed toward human serum butyrylcholinesterase. The three IgG-purified fractions precipitated the esterasic activity, whereas they failed to precipitate the neuropeptide-hydrolyzing activities whatever the substrate examined. Altogether, these results demonstrate that peptidases associated with butyrylcholinesterase are contaminating enzymes that cannot be considered as intrinsic activities of this enzyme.

Notes: A preoccupation with aesthetics and a real desire for social development has brought about an increase in the demand for safe, effective depigmenting products among African and Asian populations.For many years now, we have used an experimental model which uses the black mouse CS BL/6/JICO.As a result of developing needs and the necessity to check the results obtained from animals on humans, we have had to change the methodology in order to take into account the specific characteristics of human skin.After a summary of the protocol used on the mouse, here you will find a description of the technical changes which had to be made in order to carry out the study on humans.The results of a comparative test between the two models are given. This was carried out with a cosmetic preparation containing 2% hydroquinone introduced via a vector that facilitates its absorption.The depigmentation observed in the animal model was not found significant in humans.Taking into consideration the large number of differences between individuals, and in order to demonstrate a significant result on humans, it would be necessary to use a larger experimental group, treated for a longer period than that normally used with animals.

Notes: Previous studies have shown significant differences between the moisturizing effects and skin tolerances of virgin and refined vegetable oils when incorporated in cosmetic emulsions. They have also shown significantly greater and longer lasting moisturizing potential for a cosmetic emulsion containing virgin vegetable oils when compared with refined oils in the same emulsion. Results were obtained with sweet almond and hazelnut oils. Hazelnut oil has now been analysed to show the effect of refining. The phospholipid content of the oil decreased from 286 ppm in virgin oil to traces in refined oil.These oils were added at 10% to a cosmetic emulsion applied twice a day for 28 days to the skin of 56 volunteers and the changes in moisturizing effect measured by means of the capacitance method (corneometer CM 240 Khazaka). Measurements were made under conditions of controlled temperature and humidity on the first day of application and repeated after 21 and 28 days of treatment. A significant increase in the moisturizing effect of the emulsion containing virgin hazelnut oil was found and this was itself significantly greater than the emulsion containing refined oil. Both emulsions had a greater moisturizing effect when compared with the control emulsion and the untreated skin.Phospholipids were isolated by dialysis from virgin oil and added to the refined oil (234 ppm). The moisturizing effect obtained with the emulsion containing the enriched refined oil was shown to be the same as that obtained with the virgin oil emulsion.