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The aim of this study was to evaluate the biomechanical properties and ultrastructure of the bone response of partly laser-modified Ti6Al4V implants compared with turned, machined implants after 8 weeks in rabbit. The surface analyses performed with interference microscopy and electron microscopy showed increased surface topography with micro- and nano-sized surface features as well as increased oxide thickness of the modified surface. The biomechanical testing demonstrated a 270% increase in torque value for the surface modified implants compared with the control implants. Histological evaluation of ground sections of specimens subjected to biomechanical testing revealed ongoing bone formation and remodeling. A histological feature exclusively observed at the laser-modified surface was the presence of fracture in the mineralized bone rather than at the interface between the bone and implant. Transmission electron microscopy (TEM) was performed on Focused Ion Beam (FIB) prepared samples of the intact bone-implant interface, demonstrating a direct contact between nanocrystalline hydroxyapatite and the oxide of the laser-modified implant surface. In conclusion, laser-modified titanium alloy implants have significantly stronger bone anchorage compared with machined implants and show no adverse tissue reactions.

Many non-diagnostic radiological examinations were performed and a routine second-look is warranted. The results suggest that attempts at revascularization procedures for acute mesenteric ischaemia may improve the outcome.

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Large batches of more than 18 g of cobalt ferrite nanoparticles (Co x Fe 3-x O 4 , x being close to 1) have been prepared by the "chemie douce approach" using aqueous solutions of metal salts at 90 °C mixed with solutions of hydroxide ions under air atmosphere. By suitable choice of the metal ion to hydroxide ion ratio, it was possible to prepare nanoparticles with the stoichiometric composition (CoFe 2 O 4 ). The composition and the density of the nanoparticles could be controlled by varying the metal ion to hydroxide ion molar ratio in the reactor. Adjusting the initial concentration ratios of the reactants prior to the mixing allowed the variation of the average size of the nanoparticles. The repeatability of the average particle diameter of the synthesis was typically 5 nm and average particle sizes could be controlled between 50 and 80 nm determined by nitrogen adsorption measurements (consistent with the number size average 35-60 nm obtained by transmission electron microscopy studies). Aging of the suspensions resulted in a narrowing of the initial broad unimodal distribution. The narrowing of the size distribution was associated with the phase transformation of δ-FeOOH platelets to spinel phase. The spinel nanoparticles had different morphologies: cubic, spherical, and occasionally irregular. Nanoparticles with the stoichiometric composition were a mixture of cubical and spherical shapes. Nanoparticles with less than the stoichiometric cobalt content had an irregular morphology, whereas nanoparticles with greater than the stoichiometric concentration of cobalt were predominantly spherical.