226 RA IN HUMAN EMBRYONIC TISSUE, RELATIONSHIP OF ACTIVITY TO THE STAGE OF PREGNANCY,  MEASUREMENT OF NATURAL 226 RA OCCURRENCE IN THE HUMAN PLACENTA.
D000818:Animals; D001842:Bone and Bones; D005260:Female; D005333:Fetus; D006801:Humans; D008431:Maternal-Fetal Exchange; D010920:Placenta; D011200:Poultry; D011247:Pregnancy; D011883:Radium; D011886:Radon; D012106:Research
D011886:Radon; D011883:Radium
BONE AND BONES; EXPERIMENTAL LAB STUDY; FETUS; MATERNAL-FETAL EXCHANGE; PLACENTA; POULTRY; PREGNANCY; RADIUM; RADON