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A series of PET studies using phantoms is presented to characterize the imaging and quantitative performance of the positron-emitting iodine isotope 124I. Measurements were performed on the 2D-PET scanner GE 4096+ as well as on the Siemens PET scanner HR+ operated in both 2D and 3D modes. No specific correction was applied for the γ-rays emitted together with the positrons. As compared to 18F, in studies with 124I there is a small loss of image resolution and contrast, and an increase in background. The quantitative results varied between different scanners and various acquisition as well as reconstruction modes, with an average relative difference of −6±13% (mean±SD) in respect of the phantom radioactivity as measured with γ-ray spectroscopy. We conclude that quantitation of a radiopharmaceutical labelled with 124I is feasible and may be improved by the development of specific corrections. [Copyright &y& Elsevier]

Nuclear reaction cross sections for the formation of 72 As and 71 As in proton-induced reactions on enriched 72 Ge targets were measured up to 45 MeV utilizing three different cyclotrons at the Forschungszentrum Jülich. The stacked-thin sample activation technique in combination with high-resolution γ-ray spectrometry was used. The major γ-ray peaks of 72 As and 71 As formed via the 72 Ge(p,n) 72 As and 72 Ge(p,2n) 71 As reactions, respectively, were analyzed. The incident proton energy and flux on a foil were determined using several monitor reactions. Based on integrated counts, irradiation data and the nuclear decay data, the reaction cross sections were measured. All data describe the first measurements. Theoretical nuclear model calculations were then carried out by using the codes TALYS 1.96, EMPIRE 3.2 and ALICE-IPPE. A very good agreement between the measured data and calculated values was found. The new data enabled us to calculate the thick target yields and estimate the radionuclidic impurities for a given energy range. Over the optimum energy range Ep = 14 → 7 MeV, the calculated thick target yield of 72 As amounts to 272 MBq/μAh with no 71 As impurity at all. The 72 Ge(p,n) 72 As reaction on the enriched 72 Ge is thus very suitable for clinical scale production of 72 As at a medical cyclotron., (© 2024. The Author(s).)

This work reports the production cross-section data for seventy-one radionuclides produced by 0.3 GeV-1.7 GeV protons impinging on thin tantalum targets. For that purpose, activation experiments were performed using the COSY synchrotron at FZ Jülich utilizing the stacked-foils technique and γ-ray spectrometry with high-purity germanium detectors. The Al-27(p,x)Na-24 reaction has been used as monitor reaction. All experimental data have been systematically compared with the existing literature. The excitation functions of Te-116, I-123, Dy-153 and Er-158 are reported for the first time., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This work presents the production cross-sections of Ce, Tb and Dy radionuclides produced by 300 MeV to 1.7 GeV proton-induced spallation reactions in thin tantalum targets as well as the related Thick Target production Yield (TTY) values and ratios. The motivation is to optimise the production of terbium radionuclides for medical applications and to find out at which energy the purity of the collection by mass separation would be highest. For that purpose, activation experiments were performed using the COSY synchrotron at FZ Jülich utilising the stacked-foils technique and γ spectrometry with high-purity germanium detectors. The Al-27(p,x)Na-24 reaction has been used as monitor reaction. All experimental data have been systematically compared with the existing literature., Competing Interests: RF-C was employed by AdAcAp during his PhD thesis under the MEDICIS-promed agreement, when the experiments presented in this work have been conducted. The research has been perform within the framework of the MEDICIS-promed Horizon 2020 Marie Sklodowska-Curie Innovative Training Network. OF, RG, BN, BS, IS, and SS were employed by Forschungszentrum Julich GmbH when the experiments presented in this work have been conducted. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Duchemin, Cocolios, Dockx, Farooq-Smith, Felden, Formento-Cavaier, Gebel, Köster, Neumaier, Scholten, Spahn, Spellerberg, Stamati, Stegemann and Verhoeven.)

Two experiments are reported which addressed the flexibility of visuo-motor processing by manipulating the availability of visual information while executing a discrete aiming movement. The flexibility of visuo-motor processing was tested by unexpectedly changing the proportion of the movement trajectory that visual feedback was present. Visual feedback was manipulated for a short (0.30), medium (0.60) or long (0.90) proportion of the trajectory within a block of trials. Each of these three proportions of vision occlusion (Experiment 1) or visual disclusion (Experiment 2) during the initial trajectory was examined. Within a visual condition, one of the three visual feedback proportions occurred with a high probability (p = 0.72), whereas the remaining two proportions each occurred with a low probability (p = 0.14). The results clearly indicated that spatial accuracy was determined by the actual vision period, independent of its probability of occurrence. The data are consistent with a model of continuous on-line control of movement execution.