| 1. |
- Aneheim, Emma, 1982, et al.
(author)
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Shelf-Life of e-Lysyl-3-(Trimethylstannyl)Benzamide Immunoconjugates, Precursors for At-211 Labeling of Antibodies
- 2015
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In: Cancer Biotherapy and Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1084-9785 .- 1557-8852. ; 30:1, s. 41-45
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Journal article (peer-reviewed)abstract
- Astatine-211 is possibly the most promising radionuclide for targeted alpha-particle therapy when it comes to the treatment of occult disseminated cancer. Preclinical research has proven effective, and patient studies have been initiated based on these results. However, a lack of production capacity and the complex radiochemistry of At-211 are major obstacles for research and prospective clinical applications. In the present study, astatination of immunoconjugates, already prepared well in advance before radiolabeling, was performed to investigate the possibility of formulating a kit-like reagent for the production of At-211 radiopharmaceuticals. The shelf-life of e-lysyl-3-(trimethylstannyl)benzamide immunoconjugates was evaluated, that is, the effect of different storage times on the quality of the immunoconjugates. The quality being referred to is the capacity to maintain a good radiochemical yield and good cell-binding property after labeling with At-211. The stability of the conjugates was found to be pH dependent with high stability at pH >= 7 and less stability at pH <= 5.5. The immunoconjugates (based on trastuzumab) could be kept for more than 3 months in a phosphate buffered saline solution (pH 7.4) at 4 degrees C before labeling, without compromising the quality of the labeled product. The conjugates are also unaffected by storage at -20 degrees C. Conjugates with a good shelf-life compatible with distant shipping as well as improved radiochemistry are important steps to facilitate further clinical progress with At-211.
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| 2. |
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| 3. |
- Albler, F. J., et al.
(author)
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A comparison of two methods of recovering cobalt from a deep eutectic solvent: Implications for battery recycling
- 2017
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 167, s. 806-814
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Journal article (peer-reviewed)abstract
- Progress towards a sustainable industrial process for the recycling of unwanted batteries using a deep eutectic solvent is presented. The effect of lactate anions on the recovery of metals from chloride media by extraction by a lipophilic chloride ionic liquid has been investigated with using solvent extraction experiments with a special emphasis on the behaviour of cobalt and nickel. A new solvent extraction system for the recovery of both cobalt and nickel from acidic (lactic acid) media is presented. The relative impacts of the new extraction system and an aliquat system on both workplace air and the wider environment are compared. The new system was found to pose a smallet threat to both workers and the environment.
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| 4. |
- Ali, Yusuf, et al.
(author)
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Experimental determination of concentration factors of Ni, Ru and Sb in the model diatom Phaeodactylum tricornutum
- 2023
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In: Scientific Reports. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- This paper describes the experimental determination of concentration factors (CF) for nickel, ruthenium and antimony in the model diatom Phaeodactylum tricornutum Bohlin (Bacillariophyceae), which was chosen as a representative of marine phytoplankton. Better determinations of these CF are needed to improve the modelling of marine ecosystems at release points, where radioactive pollutants enter the ecosystem, for more accurate predictions of radiation dose to humans caused by these pollutants. A literature study revealed that the currently implemented values of these CF are based on very scarce data, and a computational sensitivity study showed that the radiation dose caused by radioisotopes of these elements depend strongly on the phytoplankton CF. Nutrient-enriched water samples from Swedish coastal waters were used as a medium for growing of the diatom species P. tricornutum and radioactive isotopes of the studied elements were added to the cultures during the exponential growth phase. The radioactivity in the P. tricornutum and in the culture medium were measured separately and used for determination of CF. Conservative estimates of the CF based on this phytoplankton proxy on the present data are 6400 L/kg for nickel, 20,000 L/kg for ruthenium and 890 L/kg for antimony, with P. tricornutum biomass masses referring to dry weight. The estimates for nickel and ruthenium are similar to previously published values, which underpins the credibility of radiation dose calculations based on these values. The estimate for antimony is uncertain, but also, to our knowledge, represents the first published experimentally based data on this CF.
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| 5. |
- Dubois, Isabelle, 1983, et al.
(author)
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Dependency of BET surface area on particle size for some granitic minerals.
- 2011
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In: Proc. Radiochimica Acta. - : Oldenbourg Wissenschaftsverlag. - 2193-2875. ; 1, s. 75-82, s. 75-82
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Journal article (peer-reviewed)abstract
- In order to assess the geochemical retention properties of rocks, which will be the final barrier for radionuclide transport to the biosphere in the case of a failed deep underground repository for spent nuclear fuel, radionuclide sorption experiments are usually made with crushed material. This raises the issue of extrapolating results obtained from laboratory experiments to the field scale. As sorption is generally related to the surface area of the geological material, it is then important to consider the dependency of the specific surface area on the particle size. In this work, BET surface area determinations of samples of different particle sizes are conducted on two minerals commonly found in granite: labradorite and magnetite. The results show a linear relationship between BET surface area and the inverse of the particle size, up to a certain particle size. Furthermore, results also show that the specific surface area for intact, larger pieces is much smaller than the one predicted by a linear extrapolation of results on crushed material. Therefore, extrapolation of BET area for fine particles to the field situation will lead to an overestimation of the surface area and thereby also the radionuclide sorption, if sorption coefficients are extrapolated as well. Also of importance is that these results show that sorption experiments on crushed material may dominantly reflect properties of new surface, created during the mechanically treatment of the samples.
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| 6. |
- Dubois, Isablle E., et al.
(author)
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Correlation between particle size and surface area for chlorite and K-feldspar
- 2010
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In: Water-Rock Interaction - Proceedings of the 13th International Conference on Water-Rock Interaction, WRI-13. - 9780415604260 ; , s. 717-720, s. 717-720
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Conference paper (peer-reviewed)abstract
- The specific surface area as determined by BET analysis is often used for scaling mineral surface reaction capacities and rates between particles of different sizes as found in nature. Generally, an inverse proportionality between BET area and particle size is assumed, based on geometry. However, macroscopic laboratory studies of mineral surface reactions generally employ crushed material that may have been mechanically disturbed, potentially leading to an artificial increase in the specific surface area, and a change in the apparent surface reactivity. In this study, we determine the BET area for natural K-feldspar and chlorite samples from Sweden as function of particle size in a first step towards relating the surface reactivity for these minerals to grain size.
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| 7. |
- Fachinger, J, et al.
(author)
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Behaviour of spent HTR fuel elements in aquatic phases of repository host rock formations
- 2006
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In: Nuclear Engineering and Design. - 0029-5493. ; 236:5-6, s. 543-554
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Journal article (peer-reviewed)abstract
- One back-end option for spent HTR fuel elements proposed for future HTR fuel cycles in the EC is an open fuel cycle with direct disposal ofconditioned or non-conditioned fuel elements. This option has already been chosen in Germany due to the political decision to terminate the useof HTR technology. First integral leaching investigations at Research Centre Juelich on the behaviour of spent HTR fuel in salt brines, typical ofaccident scenarios in a repository in salt, proved that the main part of the radionuclide inventory cannot be mobilised as long as the coated particlesdo not fail. However, such experiments will not lead to a useful model for performance assessment calculations, because a failure of the coatingsby corrosion will not occur during experimental times of a few years. In order to get a robust and realistic model for the long-term behaviour inaqueous phases of host rock systems, it is necessary to understand the barrier function of the different parts of an HTR fuel element, i.e. the matrixgraphite, the different coating materials, and the fuel kernel.Therefore, our attention is focused on understanding and modelling the barrier performance of the different parts of an HTR fuel element withrespect to their barrier function, and on the development of an overall model for performance assessment. In order to understand this behaviour,it is necessary to start with investigations of unirradiated material, and to proceed with experiments with external gamma irradiation to determinethe effects of oxidising radiolysis species. Further experiments with irradiated material have to be performed to investigate the influence of theirradiation damage, and finally an investigation has to be made of the irradiated material plus additional gamma irradiation. Experimental data arenow available for the diffusive transport of radionuclides in the water-saturated graphite pore system, the corrosion rates of unirradiated graphitewith and without external gamma irradiation and unirradiated and irradiated silicon carbide, and for the dissolution rates of UO2 and (Th,U)O2 fuelkernels with and without external gamma irradiation. All investigations were performed in aquatic phases from salt, granite, and clay host rock.
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| 8. |
- Foreman, Mark, 1973, et al.
(author)
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Activity coefficients in deep eutectic solvents: Implications for the solvent extraction of metals
- 2018
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In: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1369-9261 .- 1144-0546. ; 42:3, s. 2006-2012
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Journal article (peer-reviewed)abstract
- An understanding of the effects of the water content on the solvent extraction of metals from the deep eutetic formed from choline chloride and lactic acid has been obtained. This change can be rationalised as being due to a change in the activity coefficient of chloride in the deep eutetic.
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| 9. |
- Hansson, Niklas, 1992, et al.
(author)
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Influence of groundwater composition on the reductive precipitation of U(VI) on corroding iron foil surfaces
- 2023
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 577
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Journal article (peer-reviewed)abstract
- In order to assess the disposal of spent nuclear fuel in a deep geological nuclear waste repository, the interactions between U(VI) and corroded iron present in the canister material are of importance. It is important to correctly model the fate of the oxidatively dissolved uranium in order to correctly estimate radium releases from the canister in the long term. The release of radionuclides into the environment depends on the dissolution of the UO2 matrix which is dependent on the redox conditions at the fuel surface. The effect of metallic iron on the reduction of U(VI) was studied under anoxic conditions using synthetic groundwaters with different compositions, chosen to investigate the influence of calcium-uranyl-carbonato complexes on the thermodynamics and kinetics of U(VI) reduction on anoxically corroding iron. The corrosion products formed on the iron surface were investigated using SEM-EDS and XPS to identify elemental composition and oxidation states of uranium and iron on the surface. The iron foils efficiently reduced U(VI) to U(IV) causing its significant sorption and precipitation on the iron foil surfaces in the form of U(IV).
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| 10. |
- Holgersson, Stellan, 1964, et al.
(author)
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A literature review on thermodynamic sorption models of radionuclides with some selected granitic minerals
- 2023
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In: Frontiers in Nuclear Engineering. - 2813-3412. ; 2
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Research review (peer-reviewed)abstract
- The literature for radionuclide sorption on four common granitic minerals have been surveyed. Mainly, such studies were modelling using Thermodynamic Sorption Models were investigated. Although the studies give a far from concerted results, they agree on the necessity to model radionuclide uptake by granitic minerals with a combination of ion exchange and surface complexation reactions. For the sheet-silicates biotite and chlorite alkaline and alkaline earth mainly bind by ion exchange but there is also a clear pH effect for this, which shows the importance of protons competing with metal cations for the exchange sites. For multivalent metal cations, surface complexation is the model of choice since the binding to mineral surfaces seems to be strongly dependent on pH and to be little affected by an increase in ion strength. Anion sorption seems to be taking place also by surface complexation, where the sorption mainly takes place at low pH. For the feldspar minerals K-feldspar and plagioclase the sorption is also modelled by the two reaction mechanisms ion exchange and surface complexation. Surface complexation seems to be especially prevalent for the M(III) and M(VI) state, while ion exchange probably dominates M (II) uptake. Although the literature on these minerals is sparse, the studies show that also these minerals have considerable sorption capacity and must be considered if sorption onto granite is to be modelled from single mineral data. What is usually missing from these studies are more systematic variations in pH, ion strength and temperature. Instead, there is a certain overemphasis on the establishment of sorption isotherms.
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