Those originally employed were based either on the fusion of the PCE to a tumour specific antibody (Antibody-Directed Prodrug Therapy, ADEPT) or on the delivery of the gene encoding the PCE using viral or non-viral vectors (Gene-Directed Enzyme Prodrug Therapy, GDEPT).
Urea is widely used in fertilizers as a source of nitrogen and is an important raw material for the chemical industry. Friedrich WÃ¶hler's discovery in 1828 that urea can be produced from inorganic starting materials was an important conceptual milestone in chemistry.
Green plants produce starch and many staple foods like potatoes, rice, and corn contain large amounts of this organic compound. Starch in vegetables are digested primarily by gastric amylase, an enzyme found in the gastrointestinal tract, and the digested starch is then stored in the cells to be used as energy.enerally, there are two types of vegetables according to their carbohydrate content: the starchy vegetables are those with high carbohydrate content, while the non-starchy vegetables are those with low carbohydrates.