Assessment of the sensitivity of DQF/ZQF H NMR of DO for studying modified nafion membranes at 20 °C and 80 °C.

Double and zero quantum filtered (ZQF/DQF) H NMR spectroscopy was used to study DO in five different Nafion membranes, N117, N115, NR212, XL, and HP, in order to assess the effectiveness of the technique for monitoring differences in thickness, membrane reinforcement, and the addition of chemical stabilizers. Experiments were also carried out at 20 and 80 °C to understand if the ZQF/DQF technique could detect changes in the water environments and exchange dynamics as a function of temperature. For two of the membranes, significant decreases in the 1/T relaxation rates were observed at 80 °C.

Complications of outpatient transbrachial intraarterial digital subtraction angiography. Work in progress.

To assess the safety of nonselective intraarterial digital subtraction angiography (DSA) performed from a brachial artery approach, the complications of 660 consecutive examinations, most of which (greater than 95%) were performed on outpatients, were studied. Contrast material injections into the aorta were made through a 4-F multiple side-hole pigtail catheter inserted percutaneously from the brachial artery. Two brachial artery complications severe enough to require surgery occurred (one hematoma and one arterial laceration/thrombosis), for a rate of 0.