Analysis of artificially degraded DNA using STRs and SNPs--results of a collaborative European (EDNAP) exercise.

Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories was organised under the auspices of EDNAP. Each laboratory was supplied with a SNP multiplex kit (Foren-SNPs) provided by the Forensic Science Service, two mini-STR kits provided by the National Institute of Standards and Technology (NIST) and a set of degraded DNA stains (blood and saliva). Laboratories tested all three multiplex kits, along with their own existing DNA profiling technique, on the same sets of degraded samples. Results were collated and analysed and, in general, mini-STR systems were shown to be the most effective. Accordingly, the EDNAP and ENFSI working groups have recommended that existing STR loci are reengineered to provide smaller amplicons, and the adoption of three new European core loci has been agreed.

Characterization of optical thin films.

Various properties of dielectric thin films are discussed in this paper: refractive index and absorption coefficient, light scattering, structure, microstructure, density, gas sorption, chemical composition, homogeneity, adhesion, hardness and mechanical stress, and environmental influences.

Electron microscopic investigations of cross sections of optical thin films.

In this paper results are given of an electron optical investigation of the cross section of optical single films and multilayers obtained by fracture. Direct observation techniques with scanning microscopy and the surface replica technique with transmission microscopy were used. Scanning microscopy is simple in sample preparation but has relatively low resolution. The highest resolution of microstructural details can be obtained only with the replica technique in the transmission microscope. Photographs of ZnS-, MgF(2)-, ThF(4)-, TiO(2), and SiO(2)-films mainly in the form of multilayers and of a cermet-type sun protection film are shown. Some optical film properties, such as refractive index and light scattering, are strongly influenced by film microstructure.

Refractive indices of TiO(2) films produced by reactive evaporation of various titanium-oxygen phases.

In this paper experiments with reactive evaporation of the starting materials Ti, TiO, Ti(2)O(3), Ti(3)O(5), and TiO(2) to obtain nonabsorbing TiO(2) films are under discussion. For the starting materials TiO and Ti(3)O(5) the dependence of the TiO(2) film refractive index on the substrate temperature, oxygen pressure, and deposition rate was measured. For TiO dispersion curves of the resulting TiO(2) films as a function of the substrate temperature during film formation were determined. The successive evaporation of the different starting materials resulted in the formation of lambda/4 TiO(2) films with different refractive indices. This phenomenon was most obvious during the first evaporation. It disappeared after several evaporations in two groups of TiO2 films with different refractive indices. From the beginning only the starting materials Ti and Ti(3)O(5) resulted in TiO(2) films with constant refractive indices. The first material produced a high, the latter a lower film index. Depending on the number of evaporations performed, both types of TiO(2) films can be obtained with TiO. The films and residues in the crucibles were also subjected to chemical analyses. An attempt was made to explain the optical properties of the resulting TiO(2) films with regard to crystal structure, chemical composition, packing density influenced by the molecular composition of the vapor beam, chemical reaction with the crucible, substrate temperature, O(2) pressure, and deposition rate.

All-oxide broadband antireflection coatings by reactive ion plating deposition.

Coating experiments were made with reactive low-voltage ion plating to achieve the computer designed performance of all-oxide broadband antireflection systems on BK-7 glass. Reasonable accordance between calculated design and coating experiment as well as reliable production have been demonstrated.