432 research outputs found
Primary Carcinoid Tumor of the Skull Base: Case Report and Review of the Literature
We present an unusual case of primary intracranial carcinoid tumor of the skull base centered at the level of the foramen jugulare, which was proven with surgical biopsy and later with Somatostatin receptor nuclear medicine scan. We present the salient magnetic resonance imaging features of this rare tumor, describe their characteristic nuclear medicine findings, and briefly review the literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79329/1/j.1552-6569.2008.00317.x.pd
Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface
The oxide heterostructure LaAlO3/SrTiO3 supports a two-dimensional electron
liquid with a variety of competing phases including magnetism,
superconductivity and weak antilocalization due to Rashba spin-orbit coupling.
Further confinement of this 2D electron liquid to the quasi-one-dimensional
regime can provide insight into the underlying physics of this system and
reveal new behavior. Here we describe magnetotransport experiments on narrow
LaAlO3/SrTiO3 structures created by a conductive atomic force microscope
lithography technique. Four-terminal local transport measurements on
~10-nm-wide Hall bar structures yield longitudinal resistances that are
comparable to the resistance quantum h/e2 and independent of the channel
length. Large nonlocal resistances (as large as 10^4 ohms) are observed in some
but not all structures with separations between current and voltage that are
large compared to the 2D mean-free path. The nonlocal transport is strongly
suppressed by the onset of superconductivity below ~200 mK. The origin of these
anomalous transport signatures is not understood, but may arise from coherent
transport defined by strong spin-orbit coupling and/or magnetic interactions
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