In situ beam reduction of Pu(IV) and Bk(IV) as a route to trivalent transuranic coordination complexes with hydroxypyridinone chelators.

The solution-state interactions of plutonium and berkelium with the octadentate chelator 3,4,3-LI(1,2-HOPO) (343-HOPO) were investigated and characterized by X-ray absorption spectroscopy, which revealed in situ reductive decomposition of the tetravalent species of both actinide metals to yield Pu(III) and Bk(III) coordination complexes. X-ray absorption near-edge structure (XANES) measurements were the first indication of in situ synchrotron redox chemistry as the Pu threshold and white-line position energies for Pu-343-HOPO were in good agreement with known diagnostic Pu(III) species, whereas Bk-343-HOPO results were found to mirror the XANES behavior of Bk(III)-DTPA. Extended X-ray absorption fine structure results revealed An-OHOPO bond distances of 2.498 (5) and 2.415 (2) Šfor Pu and Bk, respectively, which match well with bond distances obtained for trivalent actinides and 343-HOPO via density functional theory calculations. Pu(III)- and Bk(III)-343-HOPO data also provide initial insight into actinide periodicity as they can be compared with previous results with Am(III)-, Cm(III)-, Cf(III)-, and Es(III)-343-HOPO, which indicate there is likely an increase in 5f covalency and heterogeneity across the actinide series.

[Absorption of 249Bk from the gastrointestinal tract of rats]. / Vsasyvanie 249Bk iz zheludochno-kishechnogo trakta krys.

In experiments with albino mongrel female rats a study was made of the absorption of 249Bk from the gastrointestinal tract after a single per os administration. The bulk of 249Bk (96 per cent) administered either intravenously or per os was mainly deposited in the skeleton and liver. The value of 249Bk absorption from the gastrointestinal tract by days 4 and 8 following administration was 0.05 per cent.

[Berkelium-249 metabolism in the body of animals]. / Obmen berkliia-249 v organizme zhivotnykh.

A study was made of the kinetics of metabolism and distribution of 249Bk within the albino rat body. After the intraperitoneal administration of 249Bk nitrate, the radionuclide circulated with blood for a long time and was deposited mainly in the skeleton (up to 39.8% of the quantity administered) and liver (18.4%). The radionuclide concentrations in the adrenal glands, liver, spleen, kidneys and osseous tissue were 7.3, 3.2, 1.3, 1.1, and 1.2%, respectively, of the quantity administered per 1 g of fresh tissue. 249Bk was mainly excreted in urea. During 30 days of observation 18.2% and 10.4%, of the quantity administered, were excreted in urea and feces, respectively.

[The blastomogenic effect of 249Bk in rats]. / Blastomogennyi éffekt 249Bk u krys.

It is shown that 249Bk nitrate injected intraperitoneally in a wide range of doses to albino mongrel female rats is preferentially accumulated in the bony tissue (39.8%) and liver (18.4%). Incorporation of 249Bk to rats results in development of osteosarcomas, neoplasms of hemopoietic and lymphoid tissues, mammary tumours, thyroid and pituitary glands.

Fast neutron yields and spectra from targets of varying atomic number bombarded with deuterons from 16 to 50 MeV.

Neutron production from targets of Be, C, Mo, Cu, Ta and Au bombarded with deuterons of 16, 33 and 50 MeV has been studied at the isochronous cyclotron at Louvain-la-Neuve. Neutron spectra were measured by the time of flight method. The yields of neutrons and gamma rays were also measured, and the greatest ratio of neutrons to gamma rays in the forward direction was found to occur with 50 MeV deuterons on a Be target. The angular distribution of neutrons from Be was measured at 16, 33 and 50 MeV, and neutron spectra were measured as function of angle with 50 MeV deuterons on Be.