A near-field scanning optical microscope was used to image the photocurrent induced by local illumination along the length of a metal-semiconductor-metal ͑MSM͒ photodetector made from an individual CdS nanowire. Nanowire MSM photodetectors exhibited photocurrents ϳ10 5 larger than the dark current ͑Ͻ2 pA͒ under uniform monochromatic illumination; under local illumination, the photoresponse was localized to the near-contact regions. Analysis of the spatial variation and bias dependence of the local photocurrent allowed the mechanisms of photocarrier transport and collection to be identified, highlighting the importance of near-field scanning photocurrent microscopy to elucidating the operating principles of nanowire devices.

We report a simple procedure that can generate free-standing mesoscale metallic pyramids composed of one or more materials and having nanoscale tips (radii of curvature of less than 2 nm). Mesoscale holes (100-300 nm) in a chromium film are used as an etch mask to fabricate pyramidal pits and then as a deposition mask to form the metallic pyramids. We have fabricated two- and three-layered pyramids with control over their materials and chemical functionality.

A flexible and parallel procedure to generate large-area, free-standing films of subwavelength hole arrays has been demonstrated. This method is materials-general, and multilayered films of different materials were constructed. The optical quality of these films was tested using a near-field scanning optical microscope, which revealed the formation of surface plasmon standing wave patterns that were consistent with numerical simulations. Because the properties of the holes and the film materials can be easily tailored, new types of plasmonic and photonic devices can be envisioned and tested.

In the setting of high salt intake, aldosterone stimulates fibrosis in the heart, great vessels, and kidney of rats. We used uninephrectomized rats treated with angiotensin II and placed on a high salt diet to exaggerate renal fibrosis. We then tested whether mineralocorticoid receptor blockade by spironolactone or aldosterone synthase inhibition by FAD286 have similar effects on end-organ damage and gene expression. Individually, both drugs prevented the hypertensive response to uninephrectomy and high salt intake but not when angiotensin II was administered. Following 4 weeks of treatment with FAD286, plasma aldosterone was reduced, whereas spironolactone increased aldosterone at 8 weeks of treatment. Angiotensin II and high salt treatment caused albuminuria, azotemia, renovascular hypertrophy, glomerular injury, increased plasminogen activator inhibitor-1 (PAI-1), and osteopontin mRNA expression, as well as tubulointerstitial fibrosis in the kidney. Both drugs prevented these renal effects and attenuated cardiac and aortic medial hypertrophy while reducing osteopontin and transforming growth factor-β mRNA expression in the aorta. The two drugs also reduced cardiac interstitial fibrosis but had no effect on that of the perivascular region. Although spironolactone enhanced angiotensin II and salt-stimulated PAI-1 mRNA expression in aorta and heart, spironolactone and FAD286 prevented renal PAI-1 mRNA protein expression. Our study shows that mineralocorticoid receptor antagonism and aldosterone synthase inhibition similarly decrease hypertrophy and interstitial fibrosis of the kidney and heart caused by angiotensin II and high salt.