4 research outputs found
Recommended from our members
Surface permeability of particulate porous media
The dispersion process in particulate porous media at low saturation levels takes place over the surface elements of constituent particles and, as we have found previously by comparison with experiments, can be accurately described by super-fast non-linear diffusion partial differential equations. To enhance the predictive power of the mathematical model in practical applications, one requires the knowledge of the effective surface permeability of the particle-in-contact ensemble, which can be directly related with the macroscopic permeability of the particulate media. We have shown previously that permeability of a single particulate element can be accurately determined through the solution of the Laplace-Beltrami Dirichlet boundary-value problem. Here, we demonstrate how that methodology can be applied to study permeability of a randomly packed ensemble of interconnected particles. Using surface finite element techniques we examine numerical solutions to the Laplace-Beltrami problem set in the multiply-connected domains of interconnected particles. We are able to directly estimate tortuosity effects of the surface flows in the particle ensemble setting
18F-labelling innovations and their potential for clinical application
An impressive variety of new methodologies for the preparation of 18F-labelled tracers and ligands has appeared over the last decade. Most strategies of the newly developed radiofluorination methods predominantly aim at products of high molar activity by ‘late-stage’ labelling of small (hetero)aromatic molecules and the use of transition metals. This is accompanied by the improvement of technical procedures, like preparation of reactive [18F]fluoride and automated syntheses. The newly introduced procedures reflect a high innovative level and creativity in radio(pharmaceutical) chemistry at present, which are based on modern chemical methods and deep mechanistic insights. Taking also automation and quality control into consideration, major recently developed radiofluorination methods, most of those still under development, are compiled here in view of their potential for clinical PET imaging and thus the ability to advance molecular imaging