Biomedical subjects

Gianaurelio Cuniberti

Publications and source records attributed to Gianaurelio Cuniberti.

4 recordsLinked to original sources

PubMed2006

Contact dependence of carrier injection in carbon nanotubes: an ab initio study.

We combine ab initio density functional theory with transport calculations to provide a microscopic basis for distinguishing between good and poor metal contacts to nanotubes. Comparing Ti and Pd as examples of different contact metals, we trace back the observed superiority of Pd to the nature of the metal-nanotube hybridization. Based on large scale Landauer transport calculations, we suggest that the optimum metal-nanotube contact combines a weak hybridization with a large contact length between the metal and the nanotube.

Journal Article↗

PubMed2005

The puzzle of contrast inversion in DNA STM imaging.

DNA has been at the center of an imaging effort since the invention of the scanning tunneling microscope (STM). In some of the STM imaging reports the molecules appeared with negative contrast, i.e., "submerged" under the metal background and darker. We demonstrate the phenomenon of contrast inversion in DNA STM imaging by controlled and spontaneous contrast inversions and by the dependence of the DNA apparent height with respect to the surface on the imaging bias voltage. Using these characterizations, we formulate a model explaining the above phenomenon by resonant tunneling through virtual states in the vacuum between the STM tip and the DNA molecule.

DNA↗

PubMed2005

Filament depolymerization by motor molecules.

Motor proteins that specifically interact with the ends of cytoskeletal filaments can induce filament depolymerization. A phenomenological description of this process is presented. We show that under certain conditions motors dynamically accumulate at the filament ends. We compare simulations of two microscopic models to the phenomenological description. The depolymerization rate can exhibit maxima and dynamic instabilities as a function of the bulk motor density for processive depolymerization. We discuss our results in relation to experimental studies of Kin-13 family motor proteins.

Models, Biological↗

PubMed2002

Molecular wire-nanotube interfacial effects on electron transport.

We discuss the conductance of a molecular bridge between mesoscopic electrodes supporting low-dimensional transport and bearing an internal structure. As an example for such nanoelectrodes we assume semi-infinite (carbon) nanotubes. In the Landauer scattering matrix approach, we show that the conductance of this hybrid is very sensitive to the geometry of the contact, unlike the usual behavior in the presence of bulk electrodes.

Carbon↗