Nicotine: From Discovery to Biological Effects.

Nicotine, the primary psychoactive agent in tobacco leaves, has led to the widespread use of tobacco, with over one billion smokers globally. This article provides a historical overview of tobacco and discusses tobacco dependence, as well as the biological effects induced by nicotine on mammalian cells. Nicotine induces various biological effects, such as neoangiogenesis, cell division, and proliferation, and it affects neural and non-neural cells through specific pathways downstream of nicotinic receptors (nAChRs).

Procedural errors in air traffic control: effects of traffic density, expertise, and automation.

Introduction: Air traffic management requires operators to frequently shift between multiple tasks and/or goals with different levels of accomplishment. Procedural errors can occur when a controller accomplishes one of the tasks before the entire operation has been completed. The present study had two goals: first, to verify the occurrence of post-completion errors in air traffic control (ATC) tasks; and second, to assess effects on performance of medium term conflict detection (MTCD) tools.

Cardiopulmonary support during electrophysiological procedures for ventricular tachycardias not haemodynamically tolerated.

The objectives of this study were to evaluate the efficacy of percutaneous cardiopulmonary support (CPS) for circulatory assistance during electrophysiological endocavitary procedures for ventricular tachycardia (VT) in high-risk patients. From January to June 1999, eight patients with VT not haemodynamically tolerated, underwent an electrophysiological mapping and ablation while supported with percutaneous CPS in the cardiac surgery service of the University of Milan. The CPS system allowed for the maintenance of an arterial pressure of 60-70 mmHg during the tachycardia episodes.

Treadmill exercise during adenosine infusion is safe, results in fewer adverse reactions, and improves myocardial perfusion image quality.

Background: Combining low-level treadmill exercise with adenosine infusion may result in fewer bradyarrhythmic complications by increasing sympathetic tone and may improve myocardial perfusion image quality by decreasing background activity.

Methods: Patients referred for outpatient pharmacologic stress myocardial perfusion imaging performed simultaneous treadmill exercise (mean 2.2 metabolic equivalents) throughout 6-minute adenosine infusion (adenosine-exercise n = 507).