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Proton NMR has been used to reveal the effect of adding L1CF3SO3 on both the structure and dynamics of poly(ethylene oxide) melts. A range of molecular weights from unentangled to entangled chains was examined at different salt concentrations. The transverse relaxation was interpreted using recent theoretical models due to Brereton. Short chains were shown to undergo Rouse dynamics with salt merely altering the local monomer friction coefficient and not influencing the structure of the melt. From the higher molecular weight chains it was possible to measure the entanglement density, which was shown to be independent of salt concentration. The main conclusion of this paper is that the salt only affects the viscosity experienced by the chain without forming cross-links.

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We have developed a simple technique for demonstrating the sagittal profile of each rotated level of a scoliotic spine and used it to determine the patterns of lordosis and kyphosis in each of six clinical types of idiopathic scoliosis. The currently accepted classification of scoliosis is inaccurate and a modification is proposed. The three main types of scoliosis were shown to have sagittal profiles distinctly different from each other and from normal. Single structural curves had short lordotic sections at their apices, limited above and below by kyphosis. Double curves showed longer lordotic sections limited only by one area of kyphosis. Lordosis throughout the thoracic and lumbar spine was associated with triple curve patterns. The biomechanical effects of the abnormal sagittal profiles provide a simple explanation for the genesis and progression of the different types of scoliosis, and the recognition of the pattern of the sagittal abnormalities permits treatment to be designed on a sound anatomical basis for individual cases.