OBJECTIVES To evaluate the influence of thickness on the optical properties of two enamel shade composites, one with a high refractive index and one traditional. METHODS A medium value enamel shade was selected from the resin composites Enamel Plus HRi (UE2) and Enamel Plus HFO (GE2). Enamel Plus HRi is a high refractive index composite. Samples were fabricated in five different thicknesses: ...

STATEMENT OF PROBLEM Surface-finishing protocols have a mechanical impact on ceramic surfaces that could eventually affect surface topography and light scattering. An optimum protocol is needed to avoid damaging the optical properties of ceramics. PURPOSE The purpose of this study was to determine the effects of different surface-finishing protocols on the surface roughness, color change, and...

Objective: To evaluate the hydrothermal aging effect on the translucency of partially stabilized tetragonal zirconia with yttria (Y-TZP) used as monolithic or fully milled zirconia and of core type. Methods: Twenty disc-shaped specimens (1 and 10 mm) for each type of monolithic and core Y-TZP materials were milled and sintered according to the manufacturer's instruction. The final specimens wer...

INTRODUCTION To evaluate the performance of first trimester nuchal translucency scan screening among pregnant women in Nigeria. METHODS A prospective observational and questionnaire based study involving 510 pregnant women between 11(+0) and 13(+6) weeks. Routine counselling and nuchal translucency measurement was conducted using the FMF, London guidelines. Chorionic villous sampling was done...

A fundamental problem in processing sequences of images is the computation of optic ow, an approximation of the motion eld which is the projection of velocities of 3-d surface points onto the imaging plane of a visual sensor. A wide variety of algorithms for computing optical ow has been reported in the literature. However, it is not until recently that multiple motion paradigms were seriously ...

In this work we study the effects of delayed feedback on vocal fold dynamics. To perform this study, we work with a vocal fold model that is made as simple as possible while retaining the spectral content characteristic of human vocal production. Our results indicate that, even with the simplest explanation for vocal fold oscillation, delayed feedback due to reflected sound in the vocal tract c...

Purpose: the aim of this study was to evaluate color masking ability three dental ceramics with different translucencies. Materials and methods: Fifty-four discs were made from ceramic materials (High translucency zirconia, low IPS E.max CAD translucent Vita Suprinity). Shade A2. They divided into equal groups (n=18). Each group subdivided subgroups (n=6) according composite substrate shade (A4...

First-trimester sonographic assessment of the risk of chromosomal abnormalities is routinely performed throughout the world, primarily by measuring fetal nuchal translucency thickness between 11-13 weeks' gestation, combined with assessment of serum markers. The development of high-frequency transvaginal transducers has led to improved ultrasound resolution and better visualization of fetal ana...

Professor Wald and his team (Wald et al., 2004) have remodelled the already modelled SURUSS data (Wald et al., 2003a) to claim, firstly, that their results are now similar to those of the multicentre study co-ordinated by the Fetal Medicine Foundation (Snijders et al., 1998), and, secondly, that the gestation of choice for nuchal translucency (NT) measurement is 10 weeks. The latest modelling e...

AIM To evaluate the prevalence of increased nuchal translucency (NT) in multiple pregnancies and its relation to fetal karyotype and pregnancy outcome. METHODS We measured fetal nuchal translucency (NT) in 6,338 women pregnant from 10+3 to 13+6 weeks by ultrasound and evaluated the prevalence of NT=95th centile in 115 multiple pregnancies, including 100 pairs of twins (70 dichorionic and 30 m...