The excitation functions were measured for the nuclear reactions of127I (p, xn) 123, 125, 127Xe. The maximum cross sections in the corresponding excitation functions were found to be 370 mb (at 54 MeV), 900 mb (at 29 MeV) and 280 mb (at 12 MeV), respectively. From the yield curves, thick target yields of123Xe and125Xe were estimated to be 5.2 GBq (140 mCi) /μA h in sodium iodide, irradiated by 60 Me V protons. The relationship among irradiation time, waiting time to generate123I from123Xe and outlet beam energy were discussed for the effective production of highly pure123I The yield of123I was calculated to be 0.52 GBq (14 mCi) /μA h in sodium iodide at optimum waiting time. For the practical production, an aqueous solution of 60% sodium iodide (10 mm thick) was irradiated at 3.2-4.1μA for 5-6 hours by 60 Me V protons under a flow of 30 ml/min helium gas which swept away123Xe generated in the target solution. 5.6-7.0 GBq (150 -190 mCi) of123I was obtained at the yield of 0.27±0.03 GBq (7.2±0.9 mCi) /μA h with 0.22±0.07% of125I contamination. The yield of1231 increased 1.6 times, using a solution of NaI (25%) +I2 (50%) +H2O (25%) .
Optically active cyphenothrins, α-cyano-3 phenoxybenzyl (1R) -cis- and (1R) -trans-chrysan-themates, were labelled with14C at the vinyl position for use in metabolic studies. The key intermediates, (1R) -cis- and (1R) -trans-chrysanthemic- (propenyl-2-14C) acids (9a and 9b), were synthesized stereospecifically by applying the Wittig reaction of14C-labelled phosphorane (6) with optically active formyl esters (7a and 7b) .
Recent plausibility of generator produced62Cu, a positron emitter is attracting the interest of those working in the development of bifunctional radiopharmaceuticals (BR) . In our development of bifunctional radiopharmaceuticals containing a neutral dithiosemicarbazone (DTS) metal chelate, tertiary (p-DPA-DTS) and quaternary (p-TPA-DTS) amino DTS derivatives were synthesized. As for the basic understanding of their divalent metal (Cu2+, Ni2+, Zn2+) complex formation and stability, spectophotometrical studies were carried out, comparatively with KTS. Upon assessment of preferential behavior of Cu chelate, the radiolabeled64Cu-DTS derivative chelates were tested in mice, and potential use with62Cu in positron nuclear medicine is discussed.
123I Produced by124Te (p, 2n) 123I reaction is contaminated with124I (<5%) and126I (<0.3%) . High energy photons from these mixed radioiodine compromise seriously image quality due to scattered photons and to septal penetration in the collimator. Four collimators of LEAP (for low energy all purpose), LEHR (for low energy high resolution), MESI (for medium energy made by Siemens) and MENU (for medium energy made by nuclear technology) mounted on a rotating gamma camera (Siemens, ZLC-7500), were examined in order to select a suitable collimator for123I SPECT (singel photon emission computed tomography) imaging. Sensitivities were measured with a plane source (5×5×0.5 cm) at the collimator face and distances from 2 to 30 cm in air. And, spatial resolutions in FWHM (full width at half maximum) and FWTM (full width at tenth maximum) were determined from line spread functions with planar and SPECT imaging. From the comparison of collimator performances with99mTe and123I, both collimators for low energy were not useful for123I imaging. In other two collimators for medium energy, however, apparently the effect of septal penetration by the higher energy photons were also recognized, MENU with high geometrical resolution was more suitable for123I SPECT imaging compared with MESI. And, it is important to perform the SPECT imaging with radius as short as possible.
Adsorption of Fe (III) on XAD-7 from LiCl, NaCl, KCl, RbCl, CsCl, CaCl2and AlCl3solutions was studied. Fe (III) was quantitatively adsorbed on XAD-7 in high chloride concentrations above 6 M. As an application of such adsorption behavior of Fe (III), determination of trace iron usually present as an impurity in reagent grade metal chlorides was examined. After adsorbing Fe (III) from high chloride concentrations on XAD-7, neutron activation was carried out on the resin. Iron amounts of 0.3 ppm, 1.6 ppm and 1.3 ppm were obtained with LiCl, CaCl2⋅2H2Oand AlCl3⋅6H2O, respectively.
A new method has been developed for imaging the thyroid gland by the use of201Tl radioactive implant induced X-ray emission (RIXE) . The thyroid phantom was made from two cylindrical tubes embedded in plastic neck phantom. Each tube consisted of stable iodine and201Tl radioactive source in 10 ml water solution. Some photopeaks in the energy range from 20 to 200 keV were scanned along a horizontal axis by the collimated Ge detector with high energy resolution. The distribution on the horizontal axis was obtained for the generated I Ka-ray and some primary201Tl radiations. The201Tl RIXE scanning can provide information about the distribution of iodine with201Tl as well as201Tl distribution in the thyroid gland. The effectiveness of the201Tl RIXE technique as a thyroid scanning method is discussed.