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.
There issubstantial evidence that the dependence of tissue oxy-gen on blood flow is responsible for autoregulation inorgans with high oxygen consumption.Both myocardium and brain exhibit a high degree ofautoregulation, and in both organs blood flow is highlydependent on tissue oxygen consumption.lso, when cerebralO 2 consumption is reduced by 50% in pentobarbitalcoma, cerebral blood flow also falls by 50% and auto-regulation is not impaired. 19 Similarly, in the heart,reduction in cardiac function leads to a fall in myocar-dial blood flow but the degree of autoregulation is notimpaired.