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Targeted alpha therapy (TαT) represents an emerging and cutting-edge treatment option for patients dealing with highly challenging metastatic cancer diseases. Critically, the limited supply of alpha-particle-emitting radionuclides, so-called alpha in vivo nanogenerators, hampers wider utilization of TαT in clinical settings. This could effectively be circumvented by alternative production routes, including straightforward purification and reformulation strategies. Radionuclide generators offering great potential in simple and robust elution strategies can be provided that still adhere to high radioisotopic, radionuclidic, and radiochemical purity criteria. This study takes a first step towards novel separation strategies by providing additional sources of alpha in vivo nanogenerators for TαT through experiments with various metal surrogates. With different systems, 232Th/natBa was used as a radionuclide generator analogue to 227Th/223Ra, and 232Th/natBa/natLa was used as a triplet analogue to 229Th/225Ra/225Ac. Three selective resins (UTEVA, TEVA, DGA-N) were evaluated for the 232Th/natBa system. Two perturbations of the best-performing resin were further evaluated using a larger diameter column and 1 week of equilibration. For the 232Th/natBa/natLa separation system, a combined column with two selective resins (TK200, TK101) was employed and evaluated. The results thus obtained pave the way for alternative separation strategies in radioactive proof-of-concept validation in the near future. [ABSTRACT FROM AUTHOR]

Targeted alpha therapy (TαT) represents an emerging and cutting-edge treatment option for patients dealing with highly challenging metastatic cancer diseases. Critically, the limited supply of alpha-particle-emitting radionuclides, so-called alpha in vivo nanogenerators, hampers wider utilization of TαT in clinical settings. This could effectively be circumvented by alternative production routes, including straightforward purification and reformulation strategies. Radionuclide generators offering great potential in simple and robust elution strategies can be provided that still adhere to high radioisotopic, radionuclidic, and radiochemical purity criteria. This study takes a first step towards novel separation strategies by providing additional sources of alpha in vivo nanogenerators for TαT through experiments with various metal surrogates. With different systems, 232Th/natBa was used as a radionuclide generator analogue to 227Th/223Ra, and 232Th/natBa/natLa was used as a triplet analogue to 229Th/225Ra/225Ac. Three selective resins (UTEVA, TEVA, DGA-N) were evaluated for the 232Th/natBa system. Two perturbations of the best-performing resin were further evaluated using a larger diameter column and 1 week of equilibration. For the 232Th/natBa/natLa separation system, a combined column with two selective resins (TK200, TK101) was employed and evaluated. The results thus obtained pave the way for alternative separation strategies in radioactive proof-of-concept validation in the near future.

This work aims at addressing whether a catastrophic failure of an entry, descent, and landing event of a Multimission Radioisotope Thermoelectric Generator-based lander could embed the heat sources into the martian subsurface and create a local environment that (1) would temporarily satisfy the conditions for a martian Special Region and (2) could establish a transport mechanism through which introduced terrestrial organisms could be mobilized to naturally occurring Special Regions elsewhere on Mars. Two models were run, a primary model by researchers at the Lawrence Berkeley National Laboratory and a secondary model by researchers at the Jet Propulsion Laboratory, both of which were based on selected starting conditions for various surface composition cases that establish the worst-case scenario, including geological data collected by the Mars Science Laboratory at Gale Crater. The summary outputs of both modeling efforts showed similar results: that the introduction of the modeled heat source could temporarily create the conditions established for a Special Region, but that there would be no transport mechanism by which an introduced terrestrial microbe, even if it was active during the temporarily induced Special Region conditions, could be transported to a naturally occurring Special Region of Mars.

• Tin dioxide can be used as a stationary phase to separate Ti and Sc. • A radionuclide generator system for 44Ti/44Sc was developed using tin dioxide. • Radiochemically pure 44Sc can be repeatedly collected from the generator system. • Demonstrated a robust 44Ti/44Sc generator without decreasing performance overtime. Towards application of 44Sc for diagnostic nuclear medicine, a 44Ti/44Sc generator based on an inorganic resin has been evaluated. Unlike other radionuclide generators used for medical applications, the long-term retention of the parent 44Ti is vital due to its long half life. Herein, tin dioxide (SnO 2), a robust inorganic-based resin, has been synthesized and used as the stationary phase for a 44Ti/44Sc generator. The sorption behavior of 44Ti/44Sc was tested on SnO 2 with varying acids, concentrations, and times. Preliminary batch study results showed >88 % 44Ti retention to the resin at lower acid concentrations (0.05 M HNO 3 and 0.05 M HCl). A pilot generator was evaluated for a year, demonstrating 85.3 ± 2.8 % 44Sc elution yields and 0.71 ± 0.14 % 44Ti breakthrough in 5 M HNO 3. Based on capacity studies, a 7.4 MBq (200 µCi) upscaled generator system was constructed for further evaluation of the SnO 2 resin stability and the efficacy of the eluted 44Sc for radiolabeling. 44Sc could be regularly eluted from this generator in 5 M HNO 3 with an overall average radiochemical yield 84.7 ± 9.5 %. Post-elution processing of the 44Sc with DGA-normal resin removed all 44Ti present and allowed for high 44Sc-DOTA labeling yields of 94.2 ± 0.5 %. Overall, SnO 2 has been shown to be a viable material for a 44Ti/44Sc generator. [ABSTRACT FROM AUTHOR]

Noninvasive in vivo imaging of androgen receptor (AR) levels with positron emission tomography (PET) is becoming the primary tool in prostate cancer detection and staging. Of the potential (18)F-labeled PET tracers, (18)F-FDHT has clinically shown to be of highest diagnostic value. We demonstrate the first automated synthesis of (18)F-FDHT by adapting the conventional manual synthesis onto the fully-automated ELIXYS radiosynthesizer. Clinically-relevant amounts of (18)F-FDHT were synthesized on ELIXYS in 90 min with decay-corrected radiochemical yield of 29±5% (n=7). The specific activity was 4.6 Ci/µmol (170 GBq/µmol) at end of formulation with a starting activity of 1.0 Ci (37 GBq). The formulated (18)F-FDHT yielded sufficient activity for multiple patient doses and passed all quality control tests required for routine clinical use.

Background: Radioligand therapy using alpha emitters has gained more and more prominence in the last decade. Despite continued efforts to identify new appropriate radionuclides, the combination of 225 Ac/ 213 Bi remains among the most promising. Bismuth-213 has been employed in clinical trials in combination with appropriate vectors to treat patients with various forms of cancer, such as leukaemia, bladder cancer, neuroendocrine tumours, melanomas, gliomas, or lymphomas. However, the half-life of 213 Bi (T ½  = 46 min) implies that its availability for clinical use is limited to hospitals possessing a 225 Ac/ 213 Bi radionuclide generator, which is still predominantly scarce. We investigated a new Ac/Bi generator system based on using the composite sorbent α-ZrP-PAN (zirconium(IV) phosphate as active component and polyacrylonitrile as matrix). The developed 225 Ac/ 213 Bi generator was subjected to long-term testing after its development. The elution profile was determined and the elution yield, the contamination of the eluate with the parent 225 Ac and the contamination of the eluate with the column material were monitored over time., Results: The high activity (75 MBq of parent 225 Ac) generator with a length of 75 mm and a diameter of 4 mm containing the composite sorbent α-ZrP-PAN with a particle size of 0.8 to 1.0 mm as the stationary phase, eluted with a mixture of 10 mM DTPA in 5 mM nitric acid, provided 213 Bi with yields ranging from 77 % to 96 % in 2.8 mL of eluate, with parent 225 Ac contamination in the order of 10 -3  %, up to twenty days of use., Conclusion: All the results of the monitored parameters indicate that the composite sorbent α-ZrP-PAN based separation system for the elution of 213 Bi is a very promising and functional solution., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Radionuclide generator systems can routinely provide radionuclides on demand such as 68Ga produced by a 68Ge/68Ga generator without the availability of an on-site accelerator or a research reactor. Thus, in this work nano-SnO2 was used to develop a new 68Ge/68Ga generator which was evaluated over a period of 17 months and 305 elution cycles. The elution yield was 91.1 ± 1.8% in the first 7 mL (1 M HCl as eluent) when the generator was new and then it decreased with time and use to 73.8 ± 1.9%. Around 80% of the elutable 68Ga activity was obtained in 1 mL and the 68Ge content in the eluate did not exceed 1 × 10–4% over the investigation period when it was eluted regularly. The described generator provided adequate results for radiolabelling of DOTA-TOC with direct use of eluate. In addition, [68Ga]Ga-DOTA-TOC was tested satisfactorily for in vivo tumor detection by microPET/CT imaging in a lung cancer mouse model. [ABSTRACT FROM AUTHOR]

The expression of storm events in the geological record is poorly understood; therefore, stratigraphic investigations of known events are needed. The 1953 North Sea storm surge was the largest natural disaster for countries bordering the southern North Sea during the twentieth century. We characterize the spatial distribution of a sand deposit from the 1953 storm surge in a salt marsh at Holkham, Norfolk (UK). Radionuclide measurements, core scanning X-ray fluorescence (Itrax), and particle size analyses, were used to date and characterise the deposit. The deposit occurs at the onset of detectable 137 Cs - coeval with the first testing of nuclear weapons in the early 1950s. The sand layer is derived from material eroded from beach and dunes on the seaward side of the salt marsh. After the depositional event, accumulation of finer-grained silt and clay materials resumed. This work has important implications for understanding the responses of salt marshes to powerful storms and provides a near-modern analogue of storm surge events for calibration of extreme wave events in the geological record. [ABSTRACT FROM AUTHOR]

Determining rates and modes of shore platform development and the age of associated elements are among the greatest challenges facing rock coast researchers today. These coasts generally lack dateable deposits but cosmogenic nuclide analysis (CNA) can be applied directly to bare rock surfaces to estimate erosion rates or the time that a surface has been exposed over millennial timescales. Therefore this technique has the potential to revolutionize current theories on rock coast evolution and modes of development. Because environmental and geomorphological factors affect rates of nuclide accumulation and retention, however, the results of CNA analysis are dependent on the validity of the theoretical models that have to be employed according to the particular application. Among the important assumptions that may be made are those concerned with shading, tidal immersion, beach sediment covers, and other factors that influence rates of nuclide accumulation, and with possible spatial and temporal patterns in shore platform erosion, primarily by wave-generated backwearing and weathering-induced downwearing, that reduce nuclide concentrations. Our lack of understanding of the factors that control these variables, and in particular shore platform erosion, which is the subject of this review, has important implications for modelling rock coast evolution, assessing the possible contribution of inheritance, and dating, especially by CNA, the occurrence of important, formative events. [ABSTRACT FROM AUTHOR]

In this paper, we present novel methods for automated pulse shape discrimination. The classifiers are trained using simple radionuclide sources and do not require ground truth labeling. We test their performance using labels derived from time of flight experiments and present the results in terms of energy-dependent Receiver Operating Characteristic (ROC) curves. In addition, we also train and test standard pulse shape discrimination methods on the same data for comparison. We find multiple methods that can yield similar false neutron and true neutron rates at 24 keVee as tail-to-total or Gatti’s optimal linear filter yield at 54 keVee . [ABSTRACT FROM AUTHOR]

Mass transport in compacted clays is predominantly by diffusion, making them preferred candidates for barriers to radionuclide transport in future repositories for nuclear waste. Diffusivity of species depends on a number of factors: (1) the physical and chemical properties of the clay, such as the geometry and topology of the pore space and the functional groups on the surface; (2) the environmental system, e.g. pH, ionic strength, temperature and organic matter; (3) the nature of species, e.g. charges, sizes and their interactions. Existing models do not consider these characteristics integrally in diffusion simulations and analysis. In this work, a developed pore network model is used to study the diffusion behaviour of Cl − with different ionic strengths. The network is constructed based on experimental pore space information and mineral compositions, and captures the anisotropy and heterogeneity of clays. Opalinus clay is selected for testing the model. The effects of pore size distribution, porosity, cation exchange capacity and surface area on the transport behaviour of anions with different ionic strength are analysed. This improves the understanding of the effects of different factors on the species transport in Opalinus clay. The ionic strength of the pore water is varied between 0.01 and 5 M to evaluate its effect on the diffusion of Cl − in clays. It is shown that the model predictions are in good agreement with measured experimental data of Opalinus clay. The agreement demonstrated, both qualitatively and quantitatively, suggests that the proposed approach for integrating known effects on diffusivity is reliable and efficient. [ABSTRACT FROM AUTHOR]

Pharmaceutical grade DOTATOC kits compliant with all the quality control criteria were formulated and radiolabeled with 68 Ga in high yields. Comparison with module-based 68 Ga-DOTATOC established product equivalency. Clinical utility was evaluated in patients with histopathologically confirmed well-differentiated neuroendocrine tumors. Kit-based preparation of 68 Ga-DOTATOC could identify sites of primary and metastatic disease. PET/CT images of patients conformed to the established criteria for somatostatin imaging agents and clinical expectations. Results of this study emphasize the potential of kit-based 68 Ga-DOTATOC for PET imaging of neuroendocrine tumors. [ABSTRACT FROM AUTHOR]

To assess the impact of an accidental or chronic radionuclide release in form of aerosol particles in the atmosphere, it is important to study their dry deposition in a rural environment. For particles of less than 1 µm, there is a lack of experimental data in this regard, leading to uncertainty in terms of the results of models, which can reach up to two orders of magnitude (Petroff Mailliat, Amielh, & Anselmet, 2008). Moreover, there is no in situ deposition velocity measurement data available for particles that are smaller than 10 nm. The objective of this study is to measure and analyse the dry deposition velocity for aerosol particles with a particle size of between 2.5 nm and 1.2 µm, with particular focus on the particle size range of 2.5–14 nm. To this end, an in situ experimental method based on eddy correlation was used. This method uses an Electrical Low Pressure Impactor (ELPI, DEKATI) for particles of between 7 nm and 1.2 µm and an original method that entails coupling two condensation particle counters (CPC 3788 and 3786, TSI). Seven experimental campaigns were conducted between 2007 and 2015, during which the dry deposition velocities ( Vd in m.s −1 ) were obtained for atmospheric aerosol particles of size between 2.5 nm and 1.2 µm in size, above different natural surfaces (maize, grassland, bare soil and forest). The findings highlight the influence of the following parameters: friction velocity of the wind, surface sensible heat flux and atmospheric stability (quantified by the length of Monin-Obukhov). Comparing the findings for each natural surface revealed it can reasonably be assumed that the influence of each natural surface on deposition is mainly explained in the data provided by friction velocity ( u* m.s −1 ). The other parameters related to the natural surface, such as the Leaf Area Index (LAI) or vegetation cover properties (adherence, micro roughness), have a second order impact on all the findings. [ABSTRACT FROM AUTHOR]

The characterization of radionuclide diffusion behavior is necessary for performance assessment of granite as a geological barrier for high-level radioactive waste disposal. Rutherford backscattering spectrometry (RBS), a novel nuclear ion-beam technique, was selected in this study because it is suitable for analyzing the concentration gradients of heavy elements in a well-defined matrix and allows measuring diffusion coefficients on a micrometer scale. In this study Cs was selected to represent Cs-135 (a key radionuclide in high-level waste) diffusion in granite. The Cs energy spectrum and concentration deep profile were analyzed and the diffusion coefficient of Cs in granite for three different locations were determined, which were 2.06 × 10 −19 m 2 s −1 , 3.58 × 10 −19 m 2 s −1 , and 7.19 × 10 −19 m 2 s −1 -19m2 s–19m2 s −1 , respectively, which were of a similiar order of magnitude. Results from other studies are also compared and discussed in this paper. [ABSTRACT FROM AUTHOR]

A chemical separation technique for removing interfering gamma-ray radionuclides by combined precipitation of Nb pentoxide and anion exchange was proposed, thereby allowing detection of trace 94 Nb in low-level radwastes. The detection limit for 94 Nb was improved by a factor of 10–10 3 , and the scaling factor ( 94 Nb/ 60 Co) of the radwastes was estimated to be less than 10 −5 . This technique can be used for low-level radwaste classification and power reactor decommissioning. [ABSTRACT FROM AUTHOR]

The present article reports the synthesis and characterization of mesoporous tin oxide (MTO) nanoparticles by a solid-state mechanochemical route. The synthesized material was used as an advanced sorbent material for 68Ge/68Ga radionuclide generator technology. Gallium-68 (t½ = 68 min) obtained from the 68Ge/68Ga generator is an important diagnostic radioisotope which holds tremendous potential in the non-invasive monitoring of various diseases, including cancer, using positron emission tomography (PET). The crystallite size of the MTO nanoparticles was in the range of 6–12 nm with a large surface area of 265 ± 16 m2 g−1, while the mean pore radius was found to be 2.1 ± 0.6 nm. Determination of the zeta-potential of the MTO nanoparticles dispersed in solutions at different pH values aided in understanding the sorption and separation mechanisms, which were based on the surface charge developed on the nanosorbent. The sorption capacity observed under column-flow conditions was 85 ± 5 mg Ge per g of nanosorbent. A clinical-scale 68Ge/68Ga generator (740 MBq) was developed using this nanosorbent. Gallium-68 could be regularly eluted from this generator over a prolonged period of 1 year with ＞70% elution yield and met all the requirements for clinical use. The suitability of 68Ga obtained from it was evaluated in preclinical settings by the preparation of a 68Ga-labeled peptide containing the arginine-glycine-aspartic acid (RGD) motif. To the best of our knowledge, this is the first report on the synthesis of MTO nanoparticles by a mechanochemical route which could be effectively utilized for the routine preparation of clinical-scale 68Ge/68Ga generators. The promising results obtained in this study would facilitate greater implementation of mechanochemistry for the synthesis of nanosorbents for radionuclide generator technology since this method is simple, economical and convenient. [ABSTRACT FROM AUTHOR]

A conceptual design is presented for a low complexity, heritage-based flyby mission to Io, Jupiter’s innermost Galilean satellite and the most volcanically active body in the Solar System. The design addresses the 2011 Decadal Survey’s recommendation for a New Frontiers class mission to Io and is based upon the result of the June 2012 NASA-JPL Planetary Science Summer School. A science payload is proposed to investigate the link between the structure of Io’s interior, its volcanic activity, its surface composition, and its tectonics. A study of Io’s atmospheric processes and Io’s role in the Jovian magnetosphere is also planned. The instrument suite includes a visible/near-IR imager, a magnetic field and plasma suite, a dust analyzer, and a gimbaled high gain antenna to perform radio science. Payload activity and spacecraft operations would be powered by three Advanced Stirling Radioisotope Generators (ASRG). The primary mission includes 10 flybys with close-encounter altitudes as low as 100 km. The mission risks are mitigated by ensuring that relevant components are radiation tolerant and by using redundancy and flight-proven parts in the design. The spacecraft would be launched on an Atlas V rocket with a delta- v of 1.3 km/s. Three gravity assists (Venus, Earth, Earth) would be used to reach the Jupiter system in a 6-year cruise. The resulting concept demonstrates the rich scientific return of a flyby mission to Io. [ABSTRACT FROM AUTHOR]

An instrumental model of a neuron based on a phase-locked loop with a bandpass filter in the control loop is proposed. The main constructive elements of the system are described. The existence of different dynamic modes that are qualitatively similar to the spiking and bursting neuron dynamics has been experimentally demonstrated. [ABSTRACT FROM AUTHOR]

This paper presents a calculator to facilitate assessments of ingestion doses from Aboriginal bush foods. The calculator combines information on traditional diet and land use with radionuclide concentration ratios and ingestion dose coefficients to estimate doses. The calculator was applied to the planned remediation of Ranger uranium mine to derive a set of scaling factors between radionuclide activity concentrations in environmental media and ingestion dose from bush foods. The scaling factors can be used to estimate doses from bush foods once the post-remediation radiological conditions of the mine and surrounding environment are known. [ABSTRACT FROM AUTHOR]

At the preliminary stage of mass spectrometry (MS) technology development, it was mainly applied to determine the nuclear industry related inorganic isotope abundance. With the rapid development of nuclear industry, MS has been employed to analyze the impurities in nuclear fuel and nuclear materials, burnup of nuclear fuels, and nuclides from high-temperature gas-cooled reactor (HTGR). The study mainly discussed the basic principles, application, and the research method’s advantages and disadvantages of inorganic mass spectrometry applied to analysis of tritium from HTGR, trace amounts of plutonium and neptunium and 14C in its spent fuel. The application and R&D status of gas isotope mass spectrometer (GIMS), inductively coupled plasma mass spectrometer (ICP-MS), laser resonance ionization mass spectrometry (LRIMS), and accelerator mass spectrometer (AMS) at domestic and abroad were introduced, and problems of the instruments, application and development tendency were pointed out. The low resolution GIMS has the disadvantages of strict conditions, limited scope of application, and complex error during the analysis of hydrogen isotopes, while the high resolution GIMS is overcome the disadvantages of low resolution GIMS, and able to realize the rapid and accurate analysis with low determinative error. However, high resolution GIMS is embargoed due to the special military applications, and need to independently develop it by China. The disadvantages of ICP-MS such as poor anti-interference performance, low resolution, analyze by destroy the simple, and severe inhibition effects for space charge leads its low accuracy, which limit the application in nuclear field. Although there are prominent advantages for LRIMS, it still has poor reproducibility of laser source as one of laser MS, and need further research. China is developing rapidly in import and independent R&D of AMS, but there are many problems in the spent fuel and other nuclear industry related application and R&D field, such as low sensitivity and limited determination of special or several nuclides. The main application of AMS with gas ion source is determination of 14C, and the sensitivity reaches to 10-16. Until now, the R&D of gas ion source for AMS hasn’t be reported in China. This study discussed future developing direction of relevant mass spectrometry and outlined the potential solutions. In order to improve the efficiency of MS application on HTGR research, it is urgent to develop the easy operating intelligent instruments with small volume and simple structure. [ABSTRACT FROM AUTHOR]

Although a wide range of separation techniques are used for preparation of radionuclide generators, the low pressure column chromatography technique has dominated the field significantly. In this technique, the adsorbent remains at the ‘heart’ of the system holding the parent radionuclide and this represents the cornerstone for its success. Although this strategy constitutes a successful paradigm for the preparation of radionuclide generators, the limited capacity of conventional adsorbents restricts their applicability for preparation of high activity generators while using low specific activity parent radionuclides. In this direction, the scope of using nanostructured materials in radionuclide generators represents an active area of research. This review is a comprehensive account of the latest research and development activities on the use of nanomaterial-based adsorbents in the development of radionuclide generators. It conveys the importance of nanomaterial-based-adsorbents, which can change the paradigm of radionuclide generator technology and stimulate further interest in the scientific community towards this field. [ABSTRACT FROM PUBLISHER]

Background: PET/CT imaging of glucagon-like peptide receptor 1 has recently filled a gap in reliably diagnosing insulinoma through non-invasive means. 68 Ga-labelled derivatives of exendin-4 show high sensitivity as well as sufficient serum stability to enable routine clinical application. Here, we provide data for automated production of [ 68 Ga][Nle 14 ,Lys 40 (Ahx-DOTA-Ga)NH 2 ]exendin-4 ([ 68 Ga]Ga-DOTA-exendin-4) on a cassette based synthesis module (Modular-Lab PharmTracer, Eckert & Ziegler) using commercially available cassettes in combination with an approved 68 Ge/ 68 Ga generator (GalliaPharm, Eckert & Ziegler). This setup ensured high reproducibility as well as low radiation burden for the production team. Quality control including determination of radiochemical purity was performed by RP-HPLC using a water/0.1 % TFA/acetonitrile gradient on a C18 column. A modified TLC system with ammonium acetate & methanol as mobile phase and a novel limit test for determination of polysorbate 80 content in the final formulation are also described in this study., Main Findings: Reliable yields as well as high molar activity for patient use were only achieved using a fractionated elution approach. Batch data showed radiochemical purity of >93 % as determined by RP-HPLC and TLC as well as good stability over 2 h post production. Testing for polysorbate 80 confirmed a concentration <1 mg/mL in the final product solution. Specifications for routine production were established based on existing Pharmacopeia monographs for other radiopharmaceuticals and were validated with 5 master batches., Conclusion: The described synthesis method enables reproducible, automated in-house production of [ 68 Ga]Ga-DOTA-exendin-4 for routine clinical application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Scandium-44 g (half-life 3.97 h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, 18 F, due to its favorable decay parameters. One source of 44g Sc is the long-lived parent nuclide 44 Ti (half-life 60.0 a). A 44 Ti/ 44g Sc generator would have the ability to provide radionuclidically pure 44g Sc on a daily basis. The production of 44 Ti via the 45 Sc(p,2n) reaction requires high proton beam currents and long irradiation times. Recovery and purification of no-carrier added (nca) 44 Ti from scandium metal targets involves complex separation chemistry. In this study, separation systems based on solid phase extraction chromatography were investigated, including branched diglycolamide (BDGA) resin and hydroxamate based ZR resin. Results indicate that ZR resin in HCl media represents an effective 44 Ti/ 44g Sc separation system. [ABSTRACT FROM AUTHOR]

In vivo radionuclide generators make complex combinations of physical and chemical properties available for medical diagnostics and therapy. Perhaps the best-known in vivo generator is 212Pb/212Bi, which takes advantage of the extended half-life of 212Pb to execute a targeted delivery of the therapeutic short-lived α-emitter 212Bi. Often, as in the case of 81Rb/81Kr, chemical changes resulting from the transmutation of the parent are relied upon for diagnostic value. In other instances such as with extended alpha decay chains, chemical changes may lead to unwanted consequences. This article reviews some common and not-so-common in vivo generators with the purpose of understanding their value in medicine and medical research. This is currently relevant in light of a recent push for alpha emitters in targeted therapies, which often come with extended decay chains. [ABSTRACT FROM AUTHOR]

The present article reports the synthesis and characterization of mesoporous tin oxide (MTO) nanoparticles by a solid-state mechanochemical route. The synthesized material was used as an advanced sorbent material for 68Ge/68Ga radionuclide generator technology. Gallium-68 (t½ = 68 min) obtained from the 68Ge/68Ga generator is an important diagnostic radioisotope which holds tremendous potential in the non-invasive monitoring of various diseases, including cancer, using positron emission tomography (PET). The crystallite size of the MTO nanoparticles was in the range of 6–12 nm with a large surface area of 265 ± 16 m2 g−1, while the mean pore radius was found to be 2.1 ± 0.6 nm. Determination of the zeta-potential of the MTO nanoparticles dispersed in solutions at different pH values aided in understanding the sorption and separation mechanisms, which were based on the surface charge developed on the nanosorbent. The sorption capacity observed under column-flow conditions was 85 ± 5 mg Ge per g of nanosorbent. A clinical-scale 68Ge/68Ga generator (740 MBq) was developed using this nanosorbent. Gallium-68 could be regularly eluted from this generator over a prolonged period of 1 year with ＞70% elution yield and met all the requirements for clinical use. The suitability of 68Ga obtained from it was evaluated in preclinical settings by the preparation of a 68Ga-labeled peptide containing the arginine-glycine-aspartic acid (RGD) motif. To the best of our knowledge, this is the first report on the synthesis of MTO nanoparticles by a mechanochemical route which could be effectively utilized for the routine preparation of clinical-scale 68Ge/68Ga generators. The promising results obtained in this study would facilitate greater implementation of mechanochemistry for the synthesis of nanosorbents for radionuclide generator technology since this method is simple, economical and convenient. [ABSTRACT FROM AUTHOR]

Several hydroxamate-based resins were synthesized and tested for use in 44 Ti/ 44 Sc generator systems in small scale experiments (740 kBq 44 Ti). The most promising resin was tested further in larger scale generator studies (37 MBq). This resin displayed impressive retention of 44 Ti over several elutions, and high quantities of 44 Sc were obtained in small volumes of dilute HCl eluents. Initial radiolabeling experiments were conducted and demonstrated the possibility of direct radiolabeling of the generator produced 44 Sc with DOTA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

In recent years, there has been an increased interest in 44 Ti/ 44 Sc generators as an onsite source of 44 Sc for medical applications without needing a proximal cyclotron. The relatively short half-life (3.97 hours) and high positron branching ratio (94.3%) of 44 Sc make it a viable candidate for positron emission tomography (PET) imaging. This review discusses current 44 Ti/ 44 Sc generator designs, focusing on their chemistry, drawbacks, post-elution processing, and relevant preclinical studies of the 44 Sc for potential PET radiopharmaceuticals., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The basic model of radionuclide content of Cs-137 in the cascade Didorivsky ponds was constructed. The cascade monitoring data were obtained. Base model extrapolation was made up on the base of the observed data and accurate model of the cascade was obtained. Model extrapolation resulted in conclusions concerning accumulation of Cs-137 radionuclide in the cascade of Didorivsky ponds for 50 years. [ABSTRACT FROM AUTHOR]

The calculation of the spent-fuel composition is the baseline problem of the analysis of the nuclear and radiological safety of objects with spent fuel assemblies. The use of fission product libraries formed on the basis of evaluated nuclear data with an enlarged number of energy points is especially important for high-precision calculations of the nuclide composition of fuel irradiated in a fast spectrum. The results of an analysis of the nuclide composition of mixed oxide and uranium-plutonium-zirconium metal fuel with burnup ~10% h.a. in a fast spectrum, which were obtained in high-precision calculations based on data from different fission product yield libraries, are presented. [ABSTRACT FROM AUTHOR]

Different routes can be used to produce the PET isotope 68Ga by proton reactions on different targets. The experimental excitation functions for the reactions 68Zn( p, n) and 72Ge( p, nα) were collected from previous studies and compared with each other, for each reaction, in order to get the most trusted data. Some data were excluded because they gave either too high or too low cross section values. The others were averaged together to give a kind of trusted data set for the production of this important radioisotope. The production of the radionuclide 68Ge, used in the generator 68Ge/68Ga, through proton reactions was also discussed in the same manner. Model calculations of excitation functions of the above mentioned reactions were performed, using both TALYS-1.4 and EMPIRE-3.1 codes, and the results were compared with the averaged experimental data. Some statistical parameters were introduced to control the quality of the overlapping between experimental data and model calculations. The integrated yields for the different reactions leading to 68Ga were estimated. The various routes were discussed on the basis of the given results. [ABSTRACT FROM AUTHOR]