Exploring the difference in the mechanics of vascular smooth muscle cells from wild-type and apolipoprotein-E knockout mice.

Atherosclerosis-related cardiovascular diseases are a leading cause of mortality worldwide. Vascular smooth muscle cells (VSMCs) comprise the medial layer of the arterial wall and undergo phenotypic switching during atherosclerosis to a synthetic phenotype capable of proliferation and migration. The surrounding environment undergoes alterations in extracellular matrix (ECM) stiffness and composition and an increase in cholesterol content.

Membrane cholesterol and substrate stiffness co-ordinate to induce the remodelling of the cytoskeleton and the alteration in the biomechanics of vascular smooth muscle cells.

Aims: Cholesterol not only deposits in foam cells at the atherosclerotic plaque, but also plays an important role as a regulator of cell migration in atherogenesis. In addition, the progression of atherosclerosis leads to arterial wall stiffening, and thus altering the micromechanical environment of vascular smooth muscle cells (VSMCs) in vivo. Our studies aim to test the hypothesis that membrane cholesterol and substrate stiffness co-ordinate to regulate VSMCs biomechanics, and thus potentially regulate VSMCs migration and atherosclerotic plaque formation.

Is regadenoson an appropriate stressor for MPI in patients with left bundle branch block or pacemakers?

Background: Patients with LBBB or ventricular pacemaker undergoing MPI are at risk for false positive MPI results in the setting of an elevated heart rate (HR) with exercise or dobutamine stress. The areas of increased apparent ischemia are typically the LAD and septal territories.

Methods: In a subanalysis of the ADVANCE MPI 1 and 2 studies, perfusion on an initial adenosine and a second MPI study with regadenoson or adenosine was compared by visual and quantitative analysis.

Conductive atomic force microscope nanopatterning of hydrogen-passivated silicon in inert organic solvents.

Ambient liquid phase atomic force microscope (AFM) techniques for nanopatterning organic molecules on silicon through direct Si-C bonds rely on reactions that are in direct competition with spurious oxidation. We study the effectiveness of an inert hydrophobic organic solvent at suppressing oxidation of hydrogen-passivated silicon under ambient conditions. Nanometer scale features were fabricated on an H:Si(111) substrate using a conductive AFM in hexadecane.

Application of scanning probe microscopy to the characterization and fabrication of hybrid nanomaterials.

Scanning probe microscopy (SPM) is a widely used experimental technique for characterizing and fabricating nanostructures on surfaces. In particular, due to its ability to spatially map variations in materials properties with nanometer spatial resolution, SPM is particularly well suited to probe the subcomponents and interfaces of hybrid nanomaterials, i.e.

X-ray studies of self-assembled organic monolayers grown on hydrogen-terminated Si(111).

The structure of self-assembled monolayers (SAMs) of undecylenic acid methyl ester (SAM-1) and undec-10-enoic acid 2-bromo-ethyl ester (SAM-2) grown on hydrogen-passivated Si(111) were studied by X-ray reflectivity (XRR), X-ray standing waves (XSW), X-ray fluorescence (XRF), atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). The two different SAMs were grown by immersion of H-Si(111) substrates into the two different concentrated esters. UV irradiation during immersion was used to create Si dangling bond sites that act as initiators of the surface free-radical addition process that leads to film growth.