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The preparation of insoluble stannic molybdate precipitate was radiometrically investigated using Na2MoO4-99Mo solution. For routine preparation of the precipitate, equal volumes of stannic chloride and sodium molybdate solutions (1.08: 1 M/M) were stirred together at 27°C. Stannic molybdate-99Mo precipitates prepared from Na2MoO4-99Mo solutions are a good source for 99mTc-generator. Greater than 60% of the precipitate available 99mTc activity could be eluted in 25 ml of isotonic saline solution. Radionuclidic, radiochemical and chemical analysis of the 99mTc eluted proved to be proper for medical use. On the otherhand, thermal neutron irradiation of inactive stannic molybdate precipitates are not a suitable source for pure 99mTc column-eluates.

Abstract: A study on the labeling of hippuran with no-carrier-added131I assisted by Cu(I) and excess of ascorbic acid is described. The role of ascorbic acid is to prevent the oxidation of Cu(I) to Cu(II) which activates the hydrolysis of o-iodohippuric acid to o-iodobenzoic acid. The use of Cu(I) allows an almost quantitative (97–99%) labeling yield to be obtained within 10–15 minutes at 100°C. The reaction is assumed to take place via the formation of an organocopper complex favoring the exchange reaction between radioiodine and inactive iodine in the hippuran molecule. The activation energy of the reaction was calculated to beE=12.2 kcal/mol.

Abstract: Extraction of Eu3+ from 0.1M aqueous perchlorate medium by thenoyltrifluoroacetone (HTTA) and by mixtures of HTTA and tributylphosphate (TBP), HTTA and triphenylphosphine oxide (TPPO), HTTA and trioctylphosphine oxide (TOPO) and HTTA and triphenylarsine oxide (TPAsO) has been studied at various temperatures allowing for the elucidation of the mechanism of extraction in each case and a comparison between the various bases.

Abstract: The extractability of99Mo-molybdophosphoric acid H3/PMo12O40/ and99mTc-pertechnetic acid /PTcO4/ in 20% (v/v) bis /2-ethylhexyl/ phosphoric acid /HDEHP/ in benzene has been investigated at different concentrations of HCl, HBr and HNO3 acids. The effect of extractant concentration and diluent on the extractability of molybdophosphoric and pertechnetic acids with 20% (v/v) HDEHP in benzene from different concentrations of HCl acid has also been studied.99Mo-molybdo-phosphoric acid was found to be selectively extracted and separated from99mTc-pertechnetic acid with 20% HDEHP in benzene at an acidity of about 0.49M HCl, HBr and HNO3. The extractability of H3/PMo12O40/ from these acids generally follows the decreasing order HBr>HCl>HNO3. The separation factors /Kd molybdophosphoric/Kd pertechnetic/ were found to be 12.9×105 and 7.6×105 for HBr and HCl, respectively. The extractability of pertechnetic acid follows the order HCl>HBrGtHNO3. Benzene is the diluent due to its radiation stability. A new procedure for the separation of99mTc from99Mo was suggested.

Abstract: The present investigation deals with a study of the isotope exchange reaction of iodine between sodium iodide [Na131I] and [4-127I]iodoantipyrine in organic medium, using different iodinating radioiodine reagents of different carrier-iodine concentration. A maximum saturation yield over 90% of pure [4-131I]iodoantipyrine has been obtained by performing the isotope exchange reaction in ethanol at 80°C in 30 min. The same yield has been obtained using the same concentrations by performing the reaction at room temperature (17–20°C) for 3 h. Also the rate of the isotope exchange reaction was found to be carrier-iodine dependent as well as time and temperature dependent. According to these results and reaction conditions, a kit form method was elaborated for the synthesis of [4-131I]iodoantipyrine as well as [4-123I]iodoantipyrine.

The distribution coefficient of some lanthanides such as europium, terbium and thulium was studied using inorganic ion exchangers, zirconium titanium phosphate and zirconium phosphate silicate. The separation studies were carried out from hydrochloric and nitric acid aqueous solutions. From th distribution coefficient data, the monochloride and mononitrate complexes stability constants were calculated.

Abstract: The diffusion coefficients for the two diffusion steps in the133Xe release curves from uranium metal were calculated. There is a linear relation between the logarithm of the diffusion coefficients and the reciprocal of the absolute temperature. The activation energies for the two diffusion processes were calculated. Two equations for the diffusion coefficients were deduced: D(rapid)=2.926·10−3 e−39740/RT cm2/sec D(slow)=2.242·10−7 e−27000/RTcm2/sec The rapid diffusion was attributed to the true diffusion of133Xe gas atoms, while the slow diffusion was attributed to the self-diffusion of the uranium atoms which will lead to the release of133Xe gas.

Abstract: The fractional release of133Xe at different temperatures was studied as a function of time in the presence of an atmosphere of air during post-irradiation annealing of uranium metal. It was found that the relation between the fractional release and t1/2 is irregular. There is an initial step in the annealing curves (at the temperature range of 400–710°C) which decreases by increasing temperature and totally disappears at the high temperature of 800–1000 °C. The other parts of the release curves are typical for133Xe release from uranium metal. The initial step was found to be due to the surface oxidation of uranium metal.

Abstract: Uranium metal samples of large surface to volume ratios were irradiated in the presence of 1 cm3 of air. It was found that 1.708±0.015% of133Xe was released during irradiation. It was proved that this amount of133Xe is due to the decay of133I originally released. The release of133Xe was attributed to the knock-out mechanism.

Potassium zinc hexacyanoferrate, zirconium titanium phosphate (ZTP) and zirconium phosphate silicate (ZPS) ion exchangers were prepared. They were used as cation exchanger to study the uptake of Eu from sulphuric acid solutions. The distribution coefficient data was used to calculate the formation constant of the Europium sulphate complex.

Prior investigations document that proliferative signaling cascades, under some circumstances, initiate apoptosis, although mechanisms that dictate the final outcome are largely unknown. In COS-7 cells, ceramide signals Raf-1 activation through Ras (Zhang, Y., Yao, B., Delikat, S., Bayoumy, S., Lin, X. H., Basu, S., McGinley, M., Chan-Hui, P. Y., Lichenstein, H., and Kolesnick, R. (1997) Cell 89, 63-72), but not apoptosis. However, expression of small amounts of the pro-apoptotic Bcl-2 family member, BAD, conferred ceramide-induced apoptosis onto COS-7 cells. Ceramide signaled apoptosis in BAD-expressing cells by a pathway involving sequentially kinase suppressor of Ras (KSR)/ceramide-activated protein kinase, Ras, c-Raf-1, and MEK1. Downstream, this pathway linked to BAD dephosphorylation at serine 136 by prolonged inactivation of Akt/PKB. Further, mutation of BAD at serine 136 abrogated ceramide signaling of apoptosis. The present study indicates that when ceramide signals through the Ras/Raf cascade, the availability of a single target, BAD, may dictate an apoptotic outcome.

Abstract: Dissolution of a neutron-irradiated uranium target in a medium of 6N HCl containing a few drops of very dilute HNO3 yielded a matrix solution which on running on a silica gel column allowed the complete adsorption of the95Zr−95Nb activity formed in the fission process. The95Zr−95Nb activity is cleanly and totally eluted with 0.5% oxalic acid solution. None of the uranium or the activity of the other fission products was found to be adsorbed on the column.

Abstract: The radioisotope99Mo generated through the fission of neutron-irradiated uranium targets was separated in an extremely radiochemically pure state. The target dissolution mixture was run on a silica gel column whereby the95Zr−95Nb activity, the serious radiocontaminants of99Mo, was adsorbed on the gel. The effluent from the gel column was processed and treated with sodium dihydrogen phosphate. The processed solution was run on an activated alumina column whereby99Mo was adsorbed as phospho-molybdate complex ion, then desorbed from the column as the molybdate ion by eluting with 10% NaOH solution. By recycling the adsorption and desorption steps on alumnia,99Mo was finally obtained totally free from all other radiocontaminants.

Abstract: The distribution of Mo(VI) and the interfering radiocontaminants U(VI), Zr(IV) and Nb(V) have been investigated between chromatographic alumina and aqueous hydrochloric acid solutions of concentrations ranging from 0.5M to 11M. At low acidities (less than 1M HCl) the distribution coefficients increase with the decrease of acid concentration, while in the region of 2–4M they increase with the increase of the acid concentration. Above 4M HCl, the increase inK D continues with the acid concentration for both Zr(IV) and Nb(V), but constant values are reached for U(VI) and Mo(VI).

Two samples of potassium zinc hexacyanoferrate were prepared using two different ratios of the initial materials. The distribution coefficient of Eu3+ on the two samples was determined. The effect of the cation concentration in the aqueous phase on the adsorption of Eu3+ was also studied. The mechanism of the exchange process was described on the light of the data obtained, and the equilibrium constant of the exchange reaction was also calculated.