Abstract: The exhibit shows that colloidal aggregates (10 to 20 mu) of human serum albumin I131 may be used safely by intravenous injection to perform photoscans of the heart, liver, spleen, stomach, and salivary glands in man. Large particle size suspensions (10 to 50 mu) of the same material are being investigated experimentally in animals for scanning the lungs after intravenous injection and the brain following injection into an internal carotid artery. The advantages of this test material are the relatively low radiation exposure to the target organs and the number of organs that may be examined. Radiation exposure is low because of the rapid turnover in the target organs and removal from the body, mainly by urinary excretion, within 72 hours. The mechanism of liver-spleen localization with this organic colloid is the same as for inorganic colloidal radiogold198, namely, rapid removal from the blood by the phagocytic cells of the liver and spleen. However, in contrast to the inorganic colloid, which remains in the phagocytic cells permanently, albumin is digested by proteolytic enzymes and the I131 abel is set free to re-enter the general circulation. With the thyroid blocked, the I131 is excreted mainly in the urine as free …

First paragraph of report: M. Neumann and H. Sherrard reported the development of a wire spark chamber experiment toward receiving digitized spark information. Since late 1962 our effort has been directed toward a wire-chamber with a core memory, using standard ferrite cores, and toward an on-line operation between spark chamber and computer.

Abstract. An a priori calculation of the radiolysis of oxygen gas in the pressure ; range 10-3 to 100 atm has been made. In the low background region (1- 100 atm) all track effects have been considered. The calculated G(O3) values seem to be in reasonable agreement with experiment if only one excited oxygen molecule is initially formed per ion pair. Effects of pressure, LET and dose rate have been discussed. The radiation-induced chain decomposition of O3 has not been considered.

Abstract. By means of the pulse radiolysis technique a short-lived transient species has been observed in irradiated de-aerated ethanol and methanol, exhibiting an optical absorption throughout the visible and near infra-red. This transient is suggested to be the solvated electron on the basis of the nature of the spectrum, the reactivity with hydrogen ion and with various organic electron acceptors, and the formation of mononegative ions of some of these acceptors. The absolute rate constants have been determined for the reactions of the solvated electron with hydrogen ion, oxygen and benzyl chloride in ethanol and methanol. The diphenylide ion was found to be short-lived in ethanol. The absolute rate constant for the first-order decay of the diphenylide ion has been determined.

Abstract. The rate constants for the reaction of the hydrated electron eaq with a number of solutes and with radicals formed in water radiolysis are reported. Hydrated electrons were formed in the electron pulse irradiated solutions at concentrations in the range from 1 to 10 pM. Their reaction was followed by the decay of the optical absorption of eaq at 5780 A. Generally a 04 psec pulse of 15 MeV electrons was used. In the absence of eaq scavengers, second-order kinetics prevailed owing to the dominance of the reactions,eaq+eaq, eaq+H, and eaq+H202 when OH radical scavengers were present in alkaline solution. An analysis of the decay curves leads to values for keaq+eaq and keaq+H of 0.9~ 1010 and 3 x 1010 M-1 sec-1, respectively. With scavenger present in excess over [eaq], pseudo first-order kinetics were found and rate constants for a number of inorganic and organic compounds are reported. The agreement of these and other rate constants with diffusion-controlled reaction theory is discussed.