Free-wall rupture

Complications of MI include cardiogenic shock, heart failure, valvular dysfunction, various arrhythmias, pericarditis, stroke secondary to left ventricular (LV) thrombus embolization, venous thromboembolism, and LV free-wall rupture. 

Cardiovascular Reports suggest an apparent association between corticosteroid use and left ventricular free wall rupture after a recent Ml. 

Free-wall rupture is the most frequent and may be acute, followed by sudden death secondary to electromechanical dissociation, or subacute with recurrent chest pain and haemorrhage within the pericardial sac, with or without cardiac tampon-... 

Figueras J, Curos A, Cortadellas J, Sans M, Soler-Soler J. Relevance of electrocardiographic findings, heart failure, and infarct site in assessing risk and timing of left ventricular free wall rupture during acute myocardial infarction. Am J Cardiol 1995 76 543. 

Zidar N, Jeruc J, Balazic J, Stajer D. Neutrophils in human myocardial infarction with rupture of the free wall. Cardiovasc Pathol 2005 14 247-250. 

The most important mechanical complications of ACS evolving to MI occur in transmural infarctions, usually Q-wave infarction. They consist in cardiac rupture, which may occur in the free wall, the interventricular septum or the papillary muscles and the ventricular aneurisms. 

Poly(ethylene oxide) forms a water-insoluble association complex with poly(acrylic add). This is the basis of microencapsulation of nonaqueous printing inks. Dry, free-flowing powders obtained by this process can be used to produce carbonless carbon papers (see Microencapsulation in Chapter 5). When pressure is applied to the paper coated with the microencapsulated ink, the capsule wall ruptures and the ink is released. 

Different factors contribute to the mechanical properties of plant tissue cell turgor, which is one of the most important ones, cell bonding force through middle lamella, cell wall resistance to compression or tensile forces, density of cell packaging, which defines the free spaces with gas or liquid, and some factors, also common to other products, such as sample size and shape, temperature, and strain rate (Vincent, 1994). Depending on the sample properties (mainly turgor and resistance of middle lamella), two failure modes have been described (Pitt, 1992) cell debonding and cell rupture. 

Oxidative chain reactions of organic compounds are current targets of theoretical and experimental study. The kinetic theory of collisions has influenced research on liquid-phase oxidation. This has led to determining rate constants for chain initiation, branching, extension, and rupture and to establishing the influence of solvent, vessel wall, and other factors in the mechanism of individual reactions. Research on liquid-phase oxidation has led to studies on free radical mechanisms and the role of peroxides in their formation. 

A recent resurgence of interest in AEP has occurred because it is regarded as green processing with little environmental impact. Most of the current work is focused on using enzymes to enhance oil and protein extraction in AEP (Rosenthal et al., 1996, 1998, 2001). Critical steps in improving oil extraction are those operations used to rupture cell walls and release the oil so that it can be recovered as an emulsified cream, or even more preferably, as free oil. Enzymes are helpful in such separations, and interest in enzyme-assisted AEP is increasing as enzyme costs decline. 

The results obtained to date have led to the conclusion that microwave radiation causes no degradation of the extracted compounds, unless an excessively high temperature arises in the vessel. However, a specific effect of microwaves on plant material has been found. Microwaves interact selectively with the free water molecules present in the gland and vascular systems, leading to rapid heating and temperature increase, followed by rupture of the walls and release of the essential oils into the solvent. Similar mechanisms are suspected in soils and sediments, where strong, localized heating should lead to an increase in pressure and subsequent destruction of the matrix macrostmcture. 

The most common problem associated with the use of gas cylinders is the problem of leaks. The cylinder can develop leaks at any of four points, assuming that no gross rupture of the cylinder wall itself has occurred the valve threads, valve safety device threads, the valve stem, and the valve outlet. Repairs of leaks in the first two of these would require repairs done at high pressure and are not to be attempted in most laboratory facilities. It may be possible that some adjustments are incorporated into the design of the cylinder to allow stopping leaks in the latter two areas. In either case, it is best to contact the manufacturer for advice before attempting any repair. Forced freeing of a frozen or corroded valve should not be attempted. 

Medical researchers are interested in retarding ice crystal growth in organs destined for transplantation. Temperatures that halt or retard deterioration in the organs may also cause intercellular fluids to freeze, a process that tears the tissues and ruptures cell walls. If the fish antifreeze or related substances could be modified to keep human organs free from ice crystals at, say, 10°C, the viability of potential transplant organs might be extended. 

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