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.
Many vegetables, especially root vegetables, grow within the soil and collect high concentrations of nitrates. According to the book âNutritional Sciences,â vegetables high in nitrates include lettuce, beets, carrots, green beans, spinach, parsley, cabbage, radishes, celery and collard greens.hoto Credit Marina Lohrbach/iStock/Getty Images. Nitrate is a salt of nitric acid and found naturally in fruits, vegetables and grains. It is also added to cured meats such as salami, bacon and hot dogs as a color preservative and to retard the growth of microorganisms.