SynopsisI n order to study structure-tissue reactivity relationships arid ultimately develop a less necrotizing adhesive, this laboratory undertook a study of the synthesis and degradation of the homologous series of a-cyanoacrylate monomers and polymers. A method for synthesizing high purity cyanoacrylates and some of their chemical and physical properties are presented. In vitro kinetics studies under heterogeneous and homogeneous conditions indicate that cyanoacrylate polymers degrade by hydrolytic scission of the polymer chain. The products resulting from such a scission are formaldehyde (positively identified by derivative formation) and ultimately an alkyl cyanoacetate. As the homologous series is ascended, the rate of degradation under neutral conditions decreases. In homogeneous solution, under alkaline conditions, the rate of degradation is considerably higher than under neutral conditions and the rates obtained with the methyl to the butyl derivative are of the same order. A proposed mechanism of degradation is presented. Medical evaluation has indicated that as the homologous series is ascended, the greater the tissue tolerance to the monomers and polymers. The relevance of the results of the in vitro studies to this medical finding is presented.

No abstract

No abstract

No abstract

PurposeIn this paper the aim is to show how the translation of a logical positivist epistemology into neoclassical economics has had profound methodological consequences which over‐determine an inability to predict cusps and their associated crises.Design/methodology/approachBased on a review of epistemological and methodological literature, it is argued that the financial crises of the past 20 years ought to initiate a questioning of the epistemological foundations of the discipline.FindingsAs an alternative, it is suggested that an economics methodology informed by critical realism would increase the probability of a timely prediction of crises.Originality/valueThe paper de‐emphasises falsification as a key criterion for assessing the quality of knowledge, provides more space for non‐quantified reflections on relationships, a thicker model of human agency, a well‐specified model of collective human economic behaviour as well as an endogenous possibility of dramatic change within the economic domain.