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.
The Indian neem tree has been the subject of many recent pest control studies. Neem oil and neem oil products are approved under USDA organic regulations to be an effective and safe pesticide for use on organically grown fruits and vegetables. Neem is not a pesticide with immediate knock-down results.