scholarly journals Publisher Correction: Recovery of high specific activity molybdenum-99 from accelerator-induced fission on low-enriched uranium for technetium-99m generators

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Alex Brown ◽  
Nathan Johnson ◽  
Artem V. Gelis ◽  
Milan Stika ◽  
Anna G. Servis ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Alex Brown ◽  
Nathan Johnson ◽  
Artem V. Gelis ◽  
Milan Stika ◽  
Anna G. Servis ◽  
...  

AbstractA new process was developed to recover high specific activity (no carrier added) 99Mo from electron-accelerator irradiated U3O8 or uranyl sulfate targets. The process leverages a novel solvent extraction scheme to recover Mo using di(2-ethylhexyl) phosphoric acid following uranium and transuranics removal with tri-n-butyl phosphate. An anion-exchange concentration column step provides a final purification, generating pure 99Mo intended for making 99Mo/99mTc generators. The process was demonstrated with irradiated uranium targets resulting in more than 95% 99Mo recovery and without presence of fission products or actinides in the product.


2001 ◽  
Vol 12 (6) ◽  
pp. 1035-1042 ◽  
Author(s):  
Alessandra Boschi ◽  
Cristina Bolzati ◽  
Elisa Benini ◽  
Erica Malagò ◽  
Licia Uccelli ◽  
...  

2019 ◽  
Vol 19 (3) ◽  
pp. 556 ◽  
Author(s):  
Muhamad Basit Febrian ◽  
Duyeh Setiawan ◽  
Hilda Hidayati

High specific activity is a necessity in the fabrication of 99Mo/99mTc radioisotope generators. Recoil reaction, or the Szilard-Chalmers effect, is a method that could be used as an alternative method for increasing specific activity in radioisotope production in light of tightening regulation of highly enriched uranium (HEU) irradiation. Phthalocyanine compounds are usually used as the target material in recoil reactions for the production of high specific radioisotope activity via the (n,γ) reaction. Molybdenum phthalocyanine (Mo-Pc) could be a promising target material in recoil reactions for producing high specific activity of 99Mo. Mo-Pc was synthesized via solid-state reaction between ammonium heptamolybdate and phthalonitrile in a reflux system at 300 °C for 3 h. This optimum condition was identified after performing several variations of temperature and time of reaction, considering FTIR spectra, the yield of product and melting point of the product. XRD measurement showed that Mo-Pc synthesized at optimum condition was free from MoO2, phthalimide and unreacted molybdenum. Mo-Pc has UV-vis properties of Q-band absorption between 600 and 750 nm when dissolved in tetrahydrofuran, dimethylformamide and trifluoroacetic acid. Splitting at absorption peak in tetrahydrofuran and dimethylformamide solution indicated that protonation had occurred. This split peak did not appear in a trifluoroacetic acid solution. In the preliminary study of irradiation of 1 g Mo-Pc at 3.5x1012 n cm–2 s–1 neutron flux, followed by dissolution in tetrahydrofuran and extraction of Mo-99 into NaOH, we obtained Mo-99 solution with a specific activity of 682.35 mCi/g Mo, this being 254.61 times higher than in the regular MoO3 target.


2019 ◽  
Vol 12 (1) ◽  
pp. 13 ◽  
Author(s):  
Maximilian Klingler ◽  
Christine Rangger ◽  
Dominik Summer ◽  
Piriya Kaeopookum ◽  
Clemens Decristoforo ◽  
...  

The high overexpression of cholecystokinin-2 receptors (CCK2R) in tumors, such as medullary thyroid carcinoma, allows for highly specific diagnostic and therapeutic targeting with radiolabeled peptide probes derived from natural ligands for the receptor. Based on the ideal imaging characteristics, high availability and low cost of technetium-99m (99mTc)-labeled radiopharmaceuticals we have developed two hydrazinonicotinic acid (HYNIC) conjugated minigastrin analogs allowing labeling at high specific activity. The CCK2R targeting peptide conjugates show specific amino acid substitutions in the C-terminal receptor-specific sequence with the aim to increase stability and tumor targeting. The CCK2R affinity and the cell uptake of the new radioligands were analyzed using A431 human epidermoid carcinoma cells stably transfected with human CCK2R and mock transfected cells. Metabolic studies in BALB/c mice revealed a high resistance against enzymatic degradation for both radioligands. Biodistribution studies in tumor-xenografted athymic BALB/c nude mice at 1 h and 4 h p.i. showed that the two 99mTc-labeled compounds showed varying uptake in receptor expressing organs, stomach and pancreas (1.3–10.4% IA/g), as well as kidneys, the main route of excretion (7.8–19.9% IA/g). The tumor uptake in A431-CCK2R xenografts was 24.75 ± 4.38% IA/g for [99mTc]Tc-HYNIC-MGS5 and 42.48 ± 6.99% IA/g for [99mTc]Tc-HYNIC-MGS11 at 4 h p.i., whereas the tumor-to-kidney ratio was comparable (2.6–3.3). On demand availability and potential application for radioguided surgery of a 99mTc-labeled minigastrin analog support the further evaluation of these highly promising new compounds.


1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.


1962 ◽  
Vol 08 (03) ◽  
pp. 425-433 ◽  
Author(s):  
Ewa Marciniak ◽  
Edmond R Cole ◽  
Walter H Seegers

SummarySuitable conditions were found for the generation of autoprothrombin C from purified prothrombin with the use of Russell’s viper venom or trypsin. DEAE chromatographed prothrombin is structurally altered and has never been found to yield autoprothrombin C and also did not yield it when Russell’s viper venom or trypsin were used. Autoprothrombin C is derived from prothrombin with tissue extract thromboplastin, but not in large amounts with the intrinsic clotting factors. With the latter thrombin and autoprothrombin III are the chief activation products. Autoprothrombin III concentrates were prepared from serum and upon activation with 25% sodium citrate solution or with Russell’s viper venom large amounts of autoprothrombin C were obtained, and this was of high specific activity. Theoretically trypsin is not a thrombolytic agent, but on the contrary should lead to intravascular clotting.


2021 ◽  
pp. 1-7
Author(s):  
Michael A. Reichenberger ◽  
Jagoda M. Urban-Klaehn ◽  
Jason V. Brookman ◽  
Joshua L. Peterson-Droogh ◽  
Jorge Navarro ◽  
...  

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