Although many anaesthesia machines are equipped with circle rebreathing systems, inhalational anaesthesia remains frequently performed using relatively high fresh-gas flows. The major advantages of rebreathing techniques can be achieved only if the fresh-gas flow is reduced to 1 l.min-1 or less. Although there are potential risks associated with low-flow anaesthesia, modern anaesthesia machines...

this paper proposes a flexible power electronic transformer (fpet) for the application in the micro-grids. the low frequency transformer is usually used at the point of common coupling (pcc) to connect the low voltage grid and utility network to each other. the conventional 50hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. in this pap...

Low-flow, low-gradient aortic stenosis (AS) is a highly challenging condition in terms of diagnosis and therapeutic management. The transvalvular pressure gradient is inversely related to the square of aortic valve area (AVA) and directly related to the square of flow. Hence, a patient with severe AS may nonetheless present with a low gradient if his or her left ventricular (LV) output is reduc...

Correspondence to: Dr John Chambers, Cardiothoracic Centre, St Thomas Hospital, London SE1 7EH, UK; jboydchambers@ aol.com _________________________ A ortic stenosis is thought to have a long, asymptomatic latent phase during which the risk of sudden death is low. In fact symptoms can be revealed by treadmill exercise in a large proportion of apparently asymptomatic patients. Patients may limit...