Confocal laser scanning microscopy and super-resolution microscopy provide high-contrast and high-resolution fluorescent imaging, which has great potential to increase the diagnostic yield of endomyocardial biopsy (EMB). EMB is currently the gold standard for identification of cardiac allograft rejection, myocarditis, and infiltrative and storage diseases. However, standard analysis is dominated by low-contrast bright-field light and electron microscopy (EM); this lack of contrast makes quantification of pathological features difficult. For example, assessment of cardiac allograft rejection relies on subjective grading of H&E histology, which may lead to diagnostic variability between pathologists. This issue could be solved by utilising the high contrast provided by fluorescence methods such as confocal to quantitatively assess the degree of lymphocytic infiltrate. For infiltrative diseases such as amyloidosis, the nanometre resolution provided by EM can be diagnostic in identifying disease-causing fibrils. The recent advent of super-resolution imaging, particularly direct stochastic optical reconstruction microscopy (dSTORM), provides high-contrast imaging at resolution approaching that of EM. Moreover, dSTORM utilises conventional fluorescence dyes allowing for the same structures to be routinely imaged at the cellular scale and then at the nanoscale. The key benefit of these technologies is that the high contrast facilitates quantitative digital analysis and thereby provides a means to robustly assess critical pathological features. Ultimately, this technology has the ability to provide greater accuracy and precision to EMB assessment, which could result in better outcomes for patients.

Magnetization reversal and magnetoresistance behavior of perpendicularly magnetized [Co/Pd]4/Au/[Co/Pd]2 nanowires J. Appl. Phys. 112, 073902 (2012) Magnetization reversal in multisegmented nanowires: Parallel and serial reversal modes Appl. Phys. Lett. 101, 122412 (2012) Electric field-induced magnetization reversal in a perpendicular-anisotropy CoFeB-MgO magnetic tunnel junction Appl. Phys. Lett. 101, 122403 (2012) The magnetic Y-branch nanojunction: Domain-wall structure and magneto-resistance Appl.We systematically studied the effect of exchange bias (EB) on the magnetization reversal behavior in lithographic IrMn/Fe rings and their unbiased Fe counterparts, with the thickness of the Fe layer, t Fe , varying from 10 to 80 nm. For unbiased and exchange biased rings, an evolution in the shape of the hysteresis loop from single-step to double-step is observed as t Fe increases. However, for EB rings, this transition happens at larger thickness, which is attributed to the uniaxial anisotropy induced by exchange bias in the Fe layer. The strength of the magnetic anisotropy induced by exchange bias is investigated by fitting the angular dependence of the exchange bias field H eb at different Fe thickness.

The evolution of magnetic switching mechanism is investigated for micron-scale polycrystalline Fe ring arrays with Fe layer thickness, t Fe , varying between 10 nm and 50 nm. Single-step and doublestep switching are observed for the 10 nm and 50 nm rings, with the 30 nm sample showing a transient behavior. As thickness increases, the first-step switching field, H c1 , increases, while the second-step switching field, H c2 , and remanent magnetization, M r decreases. Magnetic force microscopy imaging and micromagnetic simulations reveal that in the reversal process, H c1 and H c2 correspond to the switching fields of two distinct halves of the ring. The relative separation between these two fields decides the switching behavior of the ring. V