1 Select the Triggers tab, and then select New. 2  Set your time and frequency, and then select OK. 3  Open Windows Defender by clicking the Start button. In the search box, type Defender and then, in the list of results, click Windows Defender.  Click Tools, and then click Options.
â Platelet refractoriness is the inability to get an adequate increase in platelet count after transfusion (Arch Pathol Lab Med 2003;127:409, Haematologica 2005;90:247) â Immune causes: anti-platelet or anti-HLA antibodies after multiple exposures from transfusion, pregnancy or transplantation (Transfusion 2005;45:761)
Refractory Period. The time period from the beginning of the action potential to the return to resting state during which the membrane will not respond normally to additional stimuli. Absolue Refractory Period. Period during which the sodium channels are open or inactivated and no action potential is possible. Relative Refractory Period.