Collateral duration

Explosion is burning that takes place sonically, hence, a shock front is produced. The damage mechanisms are physical destruction from the shock wave, collateral damage from falling structures, and human bums. Suffocation and poisoning are not usually associated with an explosion because of its short duration. A chemical explosives such as nitroglycerine, trinitrotoluene, dynamite, and others were discussed in Section 7.2.6. 

Hippocampal slices (400-500 frm) were quickly prepared from male Wistar rats (8- to 9-weeks-old) and maintained in a chamber at 35 °C, where they were continuously perfused with artificial cerebrospinal fluid as described in our previous paper [11]. A bipolar tungsten electrode was placed in the stratum radiatum to stimulate Schaffer collateral and commissural afferents. The evoked potential was extracellularly recorded from the pyramidal cell layer of the CA1 subfield with a glass capillary microelectrode. A single test stimulation (0.05 msec duration) was applied at intervals of 30 sec. Drugs were delivered by perfusion. To induce potentiation of the evoked potentials, tetanic stimulation was applied at the same intensity through the same stimulating electrode as used for the test stimulation. The magnitude of LTP was evaluated by the population spike amplitude 30 min after tetanic stimulation. 

In both groups of ACS, the ECG pattern may be different according to the following factors (a) duration, severity and extension of ischaemia (b) presence of collateral flow (c) variation of coro-... 

The duration (price volatility) of the collateral for example, a T-bill compared to the long bond. 

As mentioned earlier, survival of ischemic penumbra is highly dependent on the efficiency of collateral vasculature to provide adequate CBF in the periphery of the ischemic territory. The viability of the penumbra depends on the degree and the duration of ischemia. In animal stroke models the reduction of CBF in the periphery of the ischemic territory is down to about 20% (Jones et al., 1981). Similar levels of diminished CBF are observed in humans (Bandera et al., 2006). In a healthy brain, CBF is maintained between 60 and 150 mmHg by vasoconstriction or vasodilatation in response to changes of perfusion pressure. However, during ischemia this autoregulation is lost, which makes the penumbra highly dependent on systemic blood pressures. 

Accessible emission level—The magnitude of accessible laser or collateral radiation of a specific wavelength or emission duration at a particular point as measured by appropriate methods and devices of the radiation to which human access is possible in accordance with the definitions of the laser s hazard classification. 

A manometer is inserted into the system between the valve and the resistance to monitor the pressure. This pressure should be 10 20 cmH20 at mid-expiration. Tidal breathing, with a slightly active expiration, is used and lung volume is retained at a raised level by avoiding complete expiration. The forced expiration technique is used to clear the secretions that are mobilized. The duration and frequency of treatment are adapted for each individual. PEP increases the pressure gradient between the open and closed alveoli, thus tending to maintain alveoli patency. It increases the functional residual capacity (FRC). This reduces the resistance in collateral and small airways. 

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