20 research outputs found
Measurement of interaction forces between crossed quartz glass rods in presence of adsorbed macromolecules
Combustion simulation and emission control in natural gas fuelled combustor of gas turbine
A new method for detecting interactions between macroscopic bodies: Forces between fused silica plates bearing adsorbed polystyrene layers in cyclohexane
Determination of the coagulation kinetics in silica hydrosols by photon correlation spectroscopy
Hyperthermia and paraquat-induced G1 arrest in the yeastSaccharomyces cerevisiae is independent of the RAD9 gene
Artifact level produced by different femoral head prostheses in CT imaging: diamond coated silicon nitride as total hip replacement material
Commercial femoral head prostheses (cobalt–chromium alloy, yttria partially stabilized zirconia (Y-PSZ) and alumina) and new silicon nitride ceramic ones (nanocrystalline diamond coated and uncoated) were compared in terms of artifact level production by computed tomography (CT). Pelvis examination by CT allows the correct diagnosis of some pathologies (e.g. prostate and colon cancer) and the evaluation of the prosthesis-bone interface in post-operative joint surgery. Artifact quantification is rarely seen in literature despite having a great potential to grade biomaterials according to their imaging properties. Materials’ characteristics (density and effective atomic number), size and geometry of the prostheses can cause more or less artifact. A quantification procedure based on the calculation of four statistical parameters for the Hounsfield pixel values (mean, standard deviation, mean squared error and worst case error) is presented. CT sequential and helical scanning modes were performed. Results prove the artifact reproducibility and indicate that the cobalt–chromium and Y-PSZ are the most artifact-inducing materials, while alumina and silicon nitride (diamond coated and uncoated) ceramic ones present a low level of artifact. Considering the excellent biocompatibility and biotribological behaviour reported in earlier works, combined with the high medical imaging quality here assessed, diamond coated silicon nitride ceramics are arising as new materials for joint replacement