Fictions, Conditionals, and Stellar Astrophysics

This article argues in favour of an inferential role for fictions in scientific modelling. The argument proceeds by means of a detailed case study, namely models of the internal structure of stars in stellar astrophysics. The main assumptions in such models are described, and it is argued that they are best understood as useful fictions. The role that conditionals play in these models is explained, and it is argued that fictional assumptions play an important role as either background or antecedent conditions. I then expand on the argument for the compatibility of fictions and scientific realism. I argue that realism and antirealism plausibly offer correspondingly different accounts of the semantics of these fictional conditionals

Molecularly imprinted polymer nanospheres as synthetic affinity receptors obtained by miniemulsion polymerisation

Highly crosslinked polymer nanospheres composed of poly[(methacrylic acid)-co-(ethylene glycol dimethacrylate)] and poly(EGDMA) have been synthesised by miniemulsion polymerisation in presence of a chiral molecular template, L- or D-Boc-phenylalanine anilid. The miniemulsions and the resulting microgels were characterised by surface tension measurements, gravimetric analysis, dynamic light scattering, transmission electron microscopy, 1H and 13C CP-MAS NMR, and Brunauer-Emmett-Teller gas adsorption measurements. The efficiency of the non-covalent molecular imprinting was examined by binding experiments and quantified by UV absorption. The miniemulsions were converted to coagulate-free and stable latexes with a conversion of 98 ± 2% and an apparent hydrodynamic particle diameter of 200 ± 20 nm. Molecular imprinting was most effective when a miniemulsion of molar ratio nMAA/nEGDMA = 0.25:1 was used for the microgel preparation. Enantioselective binding of the templates to the particles was observed. Binding of the L-enantiomer was four times greater in the L-imprinted polymer than in the non-imprinted polymer and 10 times than binding of the D-enantiomer in the L-imprinted microgels. This new method allows for a one-stage preparation of fully synthetic affinity receptors with a defined spherical shape and a high specific surface area due to their nanoscopic dimension