Subarachnoid and basal cistern navigation through the sacral hiatus with guide wire assistance.

Background: Intraspinal navigation with catheters and fiberscopes has shown feasible results for diagnosis and treatment of intraspinal and intracranial lesions. The most common approach, lumbar puncture, has allowed access to the spinal cord, however, coming with the difficulties of fiberscope damage and decreased torque for guidance. Our objective in this study is to allow an alternate access, the sacral hiatus, with guide wire assistance into the subarachnoid and intracranial structures, while easing the angle of entry and increasing torque.

Long synthetic nanotubes from calix[4]arenes.

We report the synthesis and encapsulation properties of long (up to 5 nm) molecular nanotubes 1-4, which are based on calix[4]arenes and can be filled with multiple nitrosonium (NO(+)) ions upon reaction with NO(2)/N(2)O(4) gases. These are among the largest nanoscale molecular containers prepared to date and can entrap up to five guests. The structure and properties of tubular complexes 1(NO(+))(2)-4(NO(+))(5) were studied by UV/Vis, FTIR, and (1)H NMR spectroscopy in solution, and also by molecular modeling.