Effective Doses and Organ Doses in the MIRD-5 Phantom Exposed to Monoenergetic 0.1 MeV to 200 MeV Electrons in the LAT Direction

Abstract

Organ doses and effective doses were calculated using the EGS-4 Monte Carlo simulation code and a MIRD-5 mathematical human phantom placed in a vacuum. For broad right and left lateral beams of monoenergetic (0.1-200 MeV) electrons, conversion coefficients from the incident fluence to organ dose, to effective dose, and to effective dose equivalent were obtained. There were no clear differences between the conversion coefficients in the case of left-lateral (LLAT) and right-lateral (RLAT) irradiation. Therefore, when investigating lateral geometries for electron exposure, it is not necessary to evaluate both directions independently. In general, conversion coefficients for lateral irradiation (LAT) were smaller than those for AP and PA. The difference between the AP and PA conversion coefficients and LAT became smaller with increasing incident energy; at 200 MeV the conversion coefficients were almost independent of the irradiation geometry. The agreement between the results of the present study and those of other studies was acceptable within the statistical uncertainties.

Cloning, characterization, and transformation of the phosphoethanolamine N-methyltransferase gene (ZmPEAMT1) in maize (Zea mays L.)

“…PtdCho is not only a structural component; it can also be converted to phosphatidic acid (PA) and free choline (Cho) by phospholipase D (PLD). Importantly, recent studies using plant cell cultures have suggested that PA may also be a signaling molecule that acts as a second messenger in diverse processes during plant development [19,25,26,30]. Therefore, PEAMT is not only the key enzyme in PtdCho biosynthesis, but could also be important for the production of Cho and PA in plants.…”