Adult intradural lipoma with tethered spinal cord syndrome

A 48-year-old woman presented to our imaging department with lumbar sciatica. The patient had a medical history of low back pain and spina bifida. A transverse section lumbar spine CT-scan, obtained with soft-tissue window setting (Fig. A, arrow) showed, a fat-density (45-HU), oblong, posterior intradural supracentimetric lesion, at level of L5-S1. The use of bone window setting revealed a spina bifida at L4-L5-S1 (Fig. B, arrow). Lumbar spine MRI performed shortly afterwards confirmed the presence of a posterior intradural supracentimetric lesion, at level of L5-S1, hyperintense on T1 (Fig. C, arrow) and T2, and hypointetense on T2 Stir weighted imaging (Fig. D, arrow), and showed that the filum terminale was attached to the aforementioned lesion. It also demonstrated that the conus medullaris was in an abdormally low position, set at the spinal level of L3-L4. Intradural spinal lipoma with tethered spinal cord was diagnosed. The patient will benefit from physiotherapy and a surgical option could be envisaged according to the clinical evolution

Supramolecular thermoplastics and thermoplastic elastomer materials with self-healing ability based on oligomeric charged triblock copolymers

Supramolecular polymeric materials constitute a unique class of materials held together by non-covalent interactions. These dynamic supramolecular interactions can provide unique properties such as a strong decrease in viscosity upon relatively mild heating, as well as self-healing ability. In this study we demonstrate the unique mechanical properties of phase-separated electrostatic supramolecular materials based on mixing of low molar mass, oligomeric, ABA-triblock copolyacrylates with oppositely charged outer blocks. In case of well-chosen mixtures and block lengths, the charged blocks are phase separated from the uncharged matrix in a hexagonally packed nanomorphology as observed by transmission electron microscopy. Thermal and mechanical analysis of the material shows that the charged sections have a T-g closely beyond room temperature, whereas the material shows an elastic response at temperatures far above this T-g ascribed to the electrostatic supramolecular interactions. A broad set of materials having systematic variations in triblock copolymer structures was used to provide insights in the mechanical properties and and self-healing ability in correlation with the nanomorphology of the materials

Scanning-transmission electron-microscopy to observe ionic domains in model ionomers

Small domains of high electronic density have been imaged in halato-telechelic ionomers by Scanning Transmission Electron Microscopy (STEM) using the technique of atomic number or Z-contrast. The possibility that these are ionic domains is evaluated and the morphology compared with that derived from recent SAXS experiments

Thermally stimulated currents studies in blends of immiscible telechelic polymers

Thermally stimulated polarized and depolarized currents techniques have been applied to the investigation of the morphology of blends of immiscible telechelic polymers bearing complementary functional groups. From this study,it appears that the introduction of such interacting groups produces a blend which properties are comparable with those of block copolymers. © 1989 Springer-Verlag

Supramolecular Multiblock Polystyrene–Polyisobutylene Copolymers via Ionic Interactions

A supramolecular multiblock copolymer was synthesized by mixing two telechelic oligomers, α,ω-sulfonated polystyrene, HO3S-PS-SO3H, derived from a polymer prepared by RAFT polymerization, and α,ω-amino-polyisobutylene, H2N-PIB-NH2, prepared by cationic polymerization. During solvent casting, proton transfer from the sulfonic acid to the amine formed ionic bonds that produced a multiblock copolymer that formed free-standing flexible films with a modulus of 90 MPa, a yield point at 4% strain and a strain energy density of 15 MJ/m3. Small angle X-ray scattering characterization showed a lamellar morphology, whose domain spacing was consistent with the formation of a multiblock copolymer based on comparison to the chain dimensions. A reversible order–disorder transition occurred between 190 and 210 °C, but the sulfonic acid and amine functional groups were observed to decompose at those elevated temperatures based on companion optical microscopy and spectroscopy measurements. For high nonlinear strains, the dynamic modulus, G′, decreased by nearly an order of magnitude and the loss modulus, G″, decreased by a factor of 1.4, but both recovered to their original values once the strain was reduced to within the linear response region