Acute effects of calcineurin inhibitors on kidney allograft microperfusion visualized by contrast-enhanced sonography.

Background: Calcineurin inhibitors induce detrimental vascular remodeling, which may be one cause of chronic allograft failure. Real-time contrast-enhanced sonography (CES) is a relatively new technique in providing quantitative information on microvascular tissue perfusion in kidney allografts in more detail. The purpose of the study was to explore whether acute changes of kidney allograft microperfusion due to the administration of cyclosporine A (CsA) and tacrolimus (Tac) can be evidenced using real-time CES.

STM-induced surface aggregates on metals and oxidized silicon.

We have observed an aggregation of carbon or carbon derivatives on platinum and natively oxidized silicon surfaces during STM measurements in ultra-high vacuum on solvent-cleaned samples previously structured by e-beam lithography. We imaged the aggregated layer with scanning tunneling microscopy (STM) as well as scanning electron microscopy (SEM). The amount of the aggregated material increases with the number of STM scans and with the tunneling voltage.