Regional mechanics and energetics of stunned myocardium in vivo

There is still some controversy about the definition of ischemia. a tenn originally derived from ischo hairna (to restrain blood). In this thesis. I would like to follow the defInition of Robert Kloner: "Myocardial ischemia is that state in which blood flow (oxygen and substrate delivery) to the myocardium has been reduced to the point where myocardial metabolism shifts from aerobic to anaerobic and the products of anoxic metabolism accumulate in the tissue. The reduction in blood flow may be absolute, as occurs with a total coronary artery occlusion or relative, as occurs when there is an increase in oxygen demand that outweighs oxygen supply (as in the case of a coronary stenosis in the setting of exercise or rapid pacing)". The reason to choose this definition lies in the fact that an absolute reduction in blood flow is not necessary for ischemia. and that it clearly defInes when blood flow is inadequate. Apart from myocardial stunning, which is defined below. several other ischemic syndromes have been described. In this section I will concisely discuss ischemic preconditioning, myocardial hibernation, and silent ischemia

Introduction to plasma accelerators : the basics

In this article, we concentrate on the basic physics of relativistic plasma wave accelerators. The generation of relativistic plasma waves by intense lasers or electron beams in low-density plasmas is important in the quest for producing ultra-high acceleration gradients for accelerators. A number of methods are being pursued vigorously to achieve ultra-high acceleration gradients using various plasma wave drivers; these include wakefield accelerators driven by photon, electron, and ion beams. We describe the basic equations and show how intense beams can generate a large-amplitude relativistic plasma wave capable of accelerating particles to high energies. We also demonstrate how these same relativistic electron waves can accelerate photons in plasmas

Transverse beam envelope structures in strongly coupled stimulated Brillouin scattering

We use a newly developed code to investigate cross beam energy transfer via Brillouin scattering in the strong coupling limit. The code couples a single fluid model of the plasma to the complete set of Maxwell's equations. The code can describe beam interaction at arbitrary angles. We observe that the formation of a transverse structure on both beams is caused when the pump beam is fully depleted within the width of the beam. We present a simplified envelope model that confirms the results of the simulation. This transverse beam structure formation has implications for short pulse amplification. The results may also be relevant for fast ignition schemes for inertial confinement fusion

Peak intensity measurement of relativistic lasers via nonlinear Thomson scattering

The measurement of peak laser intensities exceeding 10^{20} \text{W/cm^2} is in general a very challenging task. We suggest a simple method to accurately measure such high intensities up to about 10^{23} \text{W/cm^2}, by colliding a beam of ultrarelativistic electrons with the laser pulse. The method exploits the high directionality of the radiation emitted by ultrarelativistic electrons via nonlinear Thomson scattering. Initial electron energies well within the reach of laser wake-field accelerators are required, allowing in principle for an all-optical setup. Accuracies of the order of 10% are theoretically envisaged.Comment: 4 pages, 2 figure