Stroke, cause mechanisms

New elastic polymeric materials (resistance to higher stroke or air) can be obtained by using physical modification methods, but using this method, two phases (PS and rubber) in the mixture were formed. Small rubber particles spread as a PS layer and, after awhile, the relationship between the layers decreases and rubber particles gather in the upper layer of the materials. This can be the cause of the loss of resistance of the materials. These material disadvantages have stimulated the polymer synthesis to increase the PS resistance to higher physico-mechanical properties, such as higher temperature and stroke for the chemical modification of PS with various functional modifiers. 

Dissection of the internal carotid and vertebral arteries is a common cause of stroke, particularly in young patients. Although many occur due to trauma, it is estimated that over half occur spontaneously. The mechanism of stroke following arterial dissection is either by artery-to-artery embolism, by thrombosis in situ, or by dissection-induced lumenal stenosis with secondary cerebral hypoperfusion and low-flow watershed infarction. Occasionally, dissection may lead to the formation of a pseudoaneurysm as a source of thrombus formation. Vertebrobasilar dissections that extend intracranially have a higher risk of rupture leading to subarachnoid hemorrhage (SAH). ° ... 

Wijdicks EF, Scott JP. Causes and outcome of mechanical ventilation in patients with hemispheric ischemic stroke. Mayo Clin Proc 1997 72(3) 210-213. 

Carotid artery disease is one of the major causes of ischemic stroke. The predominant mechanisms by which it causes stroke are (a) arterial embolism from atherosclerotic plaques (b) hemodynamic changes, leading to watershed infarcts and (c) distal propagation of thrombus originating from acute carotid occlusion. ... 

Heat stroke victims have a blocked sweating mechanism, as stated in the third paragraph. This information is given in the second paragraph If the victim still suffers from the symptoms listed in the first sentence of the paragraph, the victim needs more water and salt to help with the inadequate intake of water and the loss of fluids that caused those symptoms. 

Increasing Oxygen. It was once believed that the cause of Alzheimer s dementia was poor oxygen snpply to the brain. This theory suggested that atherosclerosis, hard plaques of fat and calcium, accumulate in blood vessels and block the arteries that snpply the brain, depriving it of oxygen-rich blood. In fact, atherosclerosis does occnr in the carotid arteries that snpply the brain and is the most common cause of stroke and vascnlar dementia. There is no evidence that this mechanism is involved in the pathology of Alzheimer s disease. 

The subphase under the monolayer was stirred by a Teflon-covered magnetic bar that was moved back and forth over the length of the trough by a motor-driven mechanism. The fastest rate which did not cause disruption of the monolayer was about 4 strokes per minute. 

A limited form of excitotoxicity may be useful as a pruning mechanism for normal maintenance of the dendritic tree (see Fig. 1—23), getting rid of cerebral dead wood like a good gardener however, excitotoxicity to an excess is hypothesized to cause various forms of neurodegeneration, ranging from slow, relentless neurodegenerative conditions such as schizophrenia and Alzheimer s disease to sudden, catastrophic neuronal death such as stroke (Fig. 10—26). 

It is worth noting that in a system which behaves according to the intramolecular mechanism shown in Figure 6.8, each light input causes the occurrence of a forward and back ring movement (i.e. a full cycle) without generation of any waste product. In some way, it can be considered as a four-stroke cyclic linear motor powered by light. 

Transient ischemic attack (TIA) is a clinical syndrome characterized by focal neurological symptoms presumed to be of vascular origin that last less than 24 h. Despite the transient nature of symptoms, the cerebrovascular thread is not over yet following a TIA. The mechanism that has given rise to the transient spell may also cause more severe ischemic syndromes if not properly treated. About 10% of patients with TIA suffer from stroke within the ensuing 3 months, 50% of which occur within the first 2 days (Johnston et al. 2003). Accurate and prompt recognition of ischemia as the cause of neurological symptoms is imperative to prevent subsequent strokes. This is, however, a complicated task... 

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