Endovascular Treatment of a Migrated Superior Vena Cava Stent in the Right Atrium.

A 42-year-old female with end-stage chronic kidney disease, who was on maintenance hemodialysis for the last 3 years, presented with facial and upper-limb swelling of 2-month duration. A computed tomography (CT) scan confirmed significant stenosis of the superior vena cava (SVC). Following discussion in a multidisciplinary meeting, it was proposed to perform a repeat endovascular intervention to relieve the SVC obstruction and manage the migrated stent.

Current crowding mediated large contact noise in graphene field-effect transistors.

The impact of the intrinsic time-dependent fluctuations in the electrical resistance at the graphene-metal interface or the contact noise, on the performance of graphene field-effect transistors, can be as adverse as the contact resistance itself, but remains largely unexplored. Here we have investigated the contact noise in graphene field-effect transistors of varying device geometry and contact configuration, with carrier mobility ranging from 5,000 to 80,000 cmVs. Our phenomenological model for contact noise because of current crowding in purely two-dimensional conductors confirms that the contacts dominate the measured resistance noise in all graphene field-effect transistors in the two-probe or invasive four-probe configurations, and surprisingly, also in nearly noninvasive four-probe (Hall bar) configuration in the high-mobility devices.