Ellipsometric and Rutherford Back scattering Spectrometry studies of SiO(X)N(Y) films elaborated by plasma-enhanced chemical vapour deposition technique.

Silicon oxynitride (SiO(X)N(Y)) thin films were deposited by plasma-enhanced chemical vapour deposition technique (PECVD) from silane (SiH4), nitrous oxide (N2O), ammonia (NH3) and nitrogen (N2) mixture. Spectroscopic ellipsometry (SE), in the range of wavelengths 450-900 nm, was used to define the film thickness and therefore the deposition rate, as well as the refractive index as a function of the N2O gaseous flow. While considering the (Si3N4, SiO2, H2 or void) heterogeneous mixture, Maxwell Garnett (MG) theory allows to fit the SE measurements and to define the volume fraction of the different phases. Finally, Rutherford Backscattering Spectrometry (RBS) results showed that x = O/Si ratio increases gradually with increasing the N2O flow, allowing the correlation of the SiO(X)N(Y) films main parameters.

Human serum albumin conformational changes as induced by tenoxicam and modified by simultaneous diazepam binding.

The binding of tenoxicam to human serum albumin has been shown by affinity chromatography proton titration and equilibrium dialysis to be dependent on the neutral to basic conformational change of the protein. The influence of diazepam on the interaction was also investigated using the same techniques, suggesting that diazepam increases the association of tenoxicam to albumin. Affinity chromatography revealed that the reciprocal effect also occurs. Displacement studies indicated that diazepam causes a significant increase in the affinity of tenoxicam to its main binding site, albumin site I, which is different from the diazepam site (site II). Tenoxicam seemed to cause an allosteric change in the conformation of the protein during its own binding, as did warfarin. The mechanism of this effect was a pH-dependent conformational change of albumin induced by electrostatic forces within the protein. Diazepam induced a distant accommodation of the protein, an effect accompanied by an enhanced inhibition of the release of protons from albumin.

[The occurrence of the parasite Collyriclum faba (Bremser in Schmalz, 1831) in wild birds in Switzerland]. / Zum Vorkommen des Parasiten Collyriclum faba (Bremser in Schmalz, 1831) bei Wildvögeln in der Schweiz.

The infection of our indigenous wild birds by the parasite Collyriclum faba represents a rare event. The adult trematodes reside in the subcutaneous tissue of the host, where prominent cysts can be found. In summer 1988, two cases were diagnosed, in a house sparrow (Passer domesticus) and in a goldcrest (Regulus regulus), which led us to a description of this unusual parasitic disease, whose cycle still remains unknown, and to a review of the prior known appearances in Switzerland. In the time between 1960 and 1989, a total of 2070 wild birds were examined in our Institute. In only four cases could an infection with C. faba be demonstrated. All of the affected birds belonged to the order of the Passeriformes. The occurrence rate of infestation among all wild birds was of 0.2%, and of 0.6% within the order of the Passeriformes. On the basis of this infection rate in our samples, we conclude that the rate of C. faba infections in wild birds of Switzerland is extremely low.