Localized in situ generation of diazonium cations by electrocatalytic formation of a diazotization reagent.

A new one-step electrochemical approach for the localized generation of diazonium cations in the diffusion layer of an electrode by taking advantage of the electrocatalytic properties of the electrode for the formation of the diazotization agent (nitrite) is proposed. Once nitrite anions are formed by electrocatalytic reduction of nitrate, they immediately react with an arylamine to produce the corresponding diazonium cations, which can be electrochemically readily reduced at the electrode surface. By this method, spontaneous modification of the electrode surface can be avoided.

Understanding knowledge transfer in an ergonomics intervention at a poultry processing plant.

This case study reviews the knowledge transfer (KT) process of implementing a knife sharpening and steeling program into a poultry processing plant via a participatory ergonomics intervention. This ergonomics intervention required stakeholder participation at the company level to move a 'train-the-trainer' program, developed in Québec, Canada, into action on the plant's deboning line. Communications and exchanges with key stakeholders, as well as changes in steeling and production behaviours were recorded.

Nitroglycerin reduces myocardial oxygen consumption during exercise despite vascular tolerance.

The long-term benefits of nitroglycerin (NTG) therapy are limited by the development of vascular tolerance and endothelial dysfunction in conductance coronary arteries. We have determined whether nitrate tolerance extends to NTG effects on myocardial O2 consumption (MV(O2)) and the ability of endogenous nitric oxide (NO) to modulate MV(O2) during exercise. In chronically instrumented dogs (n = 8), hemodynamic and MV(O2) responses to treadmill exercise were measured before, during tolerance (3 and 7 days of NTG delivery), and 7 days after NTG withdrawal.

Pathophysiological plasma ET-1 levels antagonize beta-adrenergic dilation of coronary resistance vessels in conscious dogs.

On the basis of in vitro experiments showing that endothelin (ET)-1 interferes with smooth muscle ATP-sensitive K(+) (K(ATP)) channel opening, which is pivotal in beta-adrenergic coronary dilation, we hypothesized that pathophysiological plasma ET-1 levels impair beta-adrenergic dilation of resistance coronary vessels. In conscious instrumented dogs, graded intravenous doses of dobutamine caused the expected inotropic responses. As myocardial O(2) consumption (MVo(2)) increased, the disproportionate rise in coronary sinus (CS) Po(2) indicates that increases in coronary blood flow (CBF) exceeded metabolic requirements, consistent with beta-adrenergic dilation.

Beta-adrenergic receptor blockade impairs NO-dependent dilation of large coronary arteries during exercise.

Shear stress-dependent nitric oxide (NO) formation prevents immoderate vascular constriction. We examined whether shear stress-dependent NO formation limits exercise-induced coronary artery constriction after beta-adrenergic receptor blockade in dogs. Control exercise led to increases (P < 0.

Enhanced contribution of NO to exercise-induced coronary responses after alpha-adrenergic receptor blockade.

We hypothesized that nitric oxide (NO), in addition to beta-adrenergic effects, may contribute to exercise-induced coronary responses after alpha-adrenergic receptor blockade. Data were analyzed as relationships between coronary sinus (CS) O(2) saturation (CS O(2)sat) or coronary blood flow (CBF) and myocardial O(2) consumption (MVO(2)). As MVO(2) increased, CS O(2)sat fell more (P < 0.