Cytoprotection is defined as an ability of pharmacologic agents, originally PGs, to prevent gastric and intestinal mucosal injury produced by a variety of ulcerogenic agents (eg, aspirin, indomethacin, bile acids) and by necrotizing agents (eg, boiling water, absolute alcohol, 0.6 mol/L HCl, 0.2 mol/L NaOH).
Definition of systematic error. : an error that is not determined by chance but is introduced by an inaccuracy (as of observation or measurement) inherent in the system.
Two types of errors are defined in order to help organize the contributors to the discrepancy between the final measured value and the accepted or known value: systematic errors and random errors. Systematic errors: These are errors which affect all measurements alike, and which can be traced to an imperfectly made instrument or to the personal technique and bias of the observer.