An empirical formula for the secondary adsorption phenomena was derived based on the following assumptions: the primary adsorption of potential-determining ion obeys the Freundlich adsorption isotherm and the secondary adsorption of ion in question follows the Freundlich type equation relating to the concentration of that ion in the solution and the amounts of potential-determining ions on the adsorbent. The utility of this equation was judged by a significance test, that is, F-test for data relating to the secondary adsorption of thorium-B on silver halides and thallium (I) iodide. All calculated F-values exceeded the critical values of F for a one-tailed test (P=0.01) . In other words, the secondary adsorption phenomena obeyed well the proposed equation.
X-Ray irradiation-induced paramagnetic radicals in rare earth (Ln) ion-doped glaserite and Ln ion-doped langbeinite were studied by means of ESR technique, aiming at developing the highly sensitive sensor for an ESR dosimetry. The samples were prepared by two kinds of procedures as follows. In one process, the glaserite (K3Na (SO4) 2) matrix or the langbeinite (K2Mg2 (SO4) 3) matrix were synthesized by heating the mixture of K2SO4and Na2SO4or the mixture of K2SO4and MgSO4at 1023 K for 1 hour in He flow. The matrices obtained were mixed well with a fixed amount of Ln2 (S04) 3 (Ln=La, Eu, Gd, Lu) powder and heated at 1023 K for 1 hour in He flow. In the other process, the homogeneous mixture of a fixed amount of K2SO4, Na2SO4and Ln2 (SO4) 3powders or a fixed amount of K2SO4, MgSO4and Ln2 (SO4) 3powders was heated at 1023 K for 2 hours in He flow. The glaserite was more favorable matrix than the langbeinite, because of the ease of the diffusion of rare earth ion into the matrix due to the phase transition of the matrix. A remarkable difference was observed in ESR signal intensity for Ln ion-doped glaserite prepared by a different process, because of the formation of the solid solution between Na2SO4and Ln2 (SO4) 3 prior to the formation of the glaserite in the latter process. The paramagnetic radicals (SO3-) was easily produced by the irradiation of X-ray in the sample doped with the stable trivalent rare earth ion. The Gd ion-doped (0.1 mol%) glaserite faded hardly and was available for the highly sensitive sensor to measure the irradiation dose of X-ray.
The potential of monoclonal antibody 17-1A (MoAb 17-1A) , which binds preferentially to a tumor cell surface glycoprotein moiety, was investigated for the detection and therapy of pancreatic carcinomas. Immunoreactivity of MoAb 17-1A with human pancreatic carcinoma cell line HuP-T4 was confirmed histochemically by the avidin-biotinylated enzyme complex method. The biodistribution of111In-and125I-labeled MoAb 17-1A was examined at 24, 48, and 72 h in nude mice bearing HuP-T4 xenografts. MoAb 17-1A was labeled with125I using the Iodogen method, giving a labeling efficiency of 92.5% and a specific activity of 6.0 MBq/mg. MoAb 17-1A was also labeled with111In using a chelating agent of either diethylene-triaminepentaacetic anhydride (DTPA anhy) or 1- (p-benzyldiazonium) DTPA (DTPA azo) . The labeling efficiencies were 77.6% for DTPA anhy and 82.3% for DTPA azo, and specific activities were 2.9 MBq/mg and 3.0 MBq/mg, respectively. Significant higher tumor uptake was observed at 72 h after I. V. injection of125I-labeled MoAb 17-1A compared with that of125I-labeled nonspecific mouse IgG.125I-Labeled MoAb 17-IA showed a higher localization in the tumor than in any other tissues except the blood and the lung. Furthermore in the experiment of111In-labeled MoAb 17-1A, a much higher accumulation in the tumor and a lower blood level were achieved as compared with those of125I-labeled MoAb 17-1A, resulting in a better tumor to blood ratio. These results suggest that MoAb 17-1A may be applicable to the radioimmunodetection and radioimmunotherapy of pancreatic carcinomas.
A 2π-proportional counter system was designed to determine the surface emission rate of plane sources. The counter shows good plateau characteristics concerning source position and sample thickness and is capable of containing the ISO reference sources. The system is useful as a reference transfer instrument for traceability of calibration sources in radiation protection measurements.