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Electrostatic discharge (ESD) is a subclass of electrical overstress and may cause immediate device failure, permanent parameter shifts and latent damage causing increased degradation rate. It has at least one of three components, localized heat generation, high current density and high electric field gradient; prolonged presence of currents of ...
A charged device model (CDM) test is used to define the ESD a device can withstand when the device itself has an electrostatic charge and discharges due to metal contact. This discharge type is the most common type of ESD in electronic devices and causes most of the ESD damages in their manufacturing.
ESD is treated as a small, localized phenomenon, although technically a lightning flash is a very large ESD event. ESD can also be man-made, as in the shock received from a Van de Graaff generator. An ESD event can damage electronic circuitry by injecting a high-voltage pulse, besides giving people an unpleasant shock.
Electrostatic discharge: An ESD may cause immediate failure of the semiconductor junction, a permanent shift of its parameters, or latent damage causing increased rate of degradation. LEDs and lasers grown on sapphire substrate (see silicon on sapphire) are more susceptible to ESD damage.
Brain ischemia has been linked to a variety of diseases or abnormalities. Individuals with sickle cell anemia, compressed blood vessels, ventricular tachycardia, plaque buildup in the arteries, blood clots, extremely low blood pressure as a result of heart attack, and congenital heart defects have a higher predisposition to brain ischemia in comparison to the average population.
Toxic encephalopathy is a neurologic disorder caused by exposure to neurotoxic organic solvents such as toluene, following exposure to heavy metals such as manganese, as a side effect of melarsoprol treatment for African trypanosomiasis, adverse effects to prescription drugs, or exposure to extreme concentrations of any natural toxin such as cyanotoxins found in shellfish or freshwater ...
In PRES secondary to other causes, the blood vessel damage has been attributed to other mechanisms. The "cytotoxic" theory suggests that it is direct cell damage by toxins (usually medications) that precipitates the edema. The "immunogenic" theory suggests a role for the immune system (specifically T cells).
This causes glutamate concentration to be several times higher in the blood than in the brain; in turn, the body must act to maintain equilibrium between the two concentrations by pumping the glutamate out of the bloodstream and into the neurons of the brain.