The hyperthermophilic archaeon Pyrococcus furiosus expresses five aldehyde oxidoreductase (AOR) enzymes, all containing a tungsto-bispterin cofactor. The growth of this organism is fully dependent on the presence of tungsten in the growth medium. Previous studies have suggested that molybdenum is not incorporated in the active site of these enzymes. Application of the radioisotope (99)Mo in met...

In this research, a new technetium-99m generator has been developed with addition of Cerium oxide to alumina column.  The adsorption behaviors of 99Mo in the form of molybdate and 99mTc in the form of pertechnetate on CeO2/Al2O3 was investigated and showed that the adsorption capacity of molybdate on this generator is higher than usual generator using Al2O3. Ceric ions were selected as an addit...

When Escherichia coli was grown in the presence of tungstate, inactive forms of two molybdoenzymes, nitrate reductase and formate dehydrogenase, accumulated and were converted to their active forms upon incubation of cell suspensions with molybdate and chloramphenicol. The conversion to the active enzymes did not occur in cell extracts. When incubated with [(99)Mo]molybdate and chloramphenicol,...

Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of pro...

The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like M...

We have reviewed quality control testing of dose calibrators and have analyzed the potential for error. The uncertainty in half-lives of reference sources can lead to inaccurate assessment of the accuracy and constancy in dose calibrator performance. Molybdenum-99 contamination of '"Tc used as a reference source can appear as a nonlinear response of the dose calibrator. The useful life of a ref...