Fissure filling is a treatment that improves the apparent clarity of a gemstone by removing air and replacing it with a substance that has a refractive index similar to the host material. Many different substances may be used to fill fissures: oils, resins, waxes, glass, and various polymers, to name a few.
Cerebral autoregulation is a process in mammals, which aims to maintain adequate and stable cerebral blood flow.hile most systems of the body show some degree of autoregulation, the brain is very sensitive to over-and underperfusion. Cerebral autoregulation plays an important role in maintaining an appropriate blood flow to that region.
Cerebral blood vessels are able to change the flow of blood through them by altering their diameters in a process called autoregulation; they constrict when systemic blood pressure is raised and dilate when it is lowered.oo little blood flow (ischemia) results if blood flow to the brain is below 18 to 20 ml per 100 g per minute, and tissue death occurs if flow dips below 8 to 10 ml per 100 g per minute.