Effects of hydration on molecular junction transport

The study of charge transport through increasingly complex small molecules will benefit from a detailed understanding of how contaminants from the environment affect molecular conduction. This should provide a clearer picture of the electronic characteristics of molecules by eliminating interference from adsorbed species. Here we use magnetically assembled microsphere junctions incorporating thiol monolayers to provide insight into changing electron transport characteristics resulting from exposure to air. Using this technique, current-voltage analysis and inelastic electron tunnelling spectroscopy (IETS) demonstrate that the primary interaction affecting molecular conduction is rapid hydration at the gold-sulphur contacts. We use IETS to present evidence for changing mechanisms of charge transport as a result of this interaction. The detrimental effects on molecular conduction discussed here are important for understanding electron transport through gold-thiol molecular junctions once exposed to atmospheric conditions

The renal system

The chapter reviews the alterations that occur in the body during the stress of acute exercise, including the decrease in renal blood flow, glomerular filtration rate, excretion of water and sodium/chloride, the release of renin-angiotensin and norepinephrine, increase in the excretion of proteins and other macromolecules, and changes in metabolic functions. Exercise alters renal hemodynamics, excretory function, and hormone release. Many of these changes can affect exercise performance. Renal function during exercise is usually not considered to be essential or critical in terms of limiting or determining exercise capacity. It is extremely difficult to assess the renal system during exercise. Changes in cardiovascular and thermoregulatory function with aging, point toward the alterations in kidney function with age. The problem of exercise or exercise and dehydration induce acute renal failure, which remains an issue. The role of the kidneys as an endocrine organ, not only for the release of renin-angiotensin but also norepinephrine, has profound implications, explaining the effects of chronic exercise on certain disease states. © 2003 American Physiological Society Published by Elsevier Ltd All rights reserved.SCOPUS: ch.binfo:eu-repo/semantics/publishe