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Sodium is an essential mineral in the human body that is vital for many body functions. The role of dietary sodium in hypertension and associated diseases has been widely accepted; however, few studies have been conducted on how sodium is stored and metabolized in the human body. This study aimed to evaluate the feasibility of a compact neutron generator-based neutron activation analysis system for the in vivo quantification of sodium in pig models. Two six-week-old male pigs were fed a high and low-concentration sodium diet for 14 days. The in vivo bone sodium was measured with a DD110 neutron generator-based irradiation system. The hind leg of pigs was irradiated for 10 minutes, and the gamma spectrum with 23Na was collected using high efficiency, high purity germanium (HPGe) detector. The in vivo sodium concentration in two male pigs was found to be (788 ±11 ppm) and (785±10 ppm) at the end of the dietary sodium period. There was no significant difference for in vivo bone sodium of low-sodium (pig L) and high-sodium diet pig (pig H) after 14 days of dietary sodium intervention. In contrast, the ex-vivo bone sodium concentrations for pig L (1870±11 ppm) and pig H (2029 ±6 ppm) showed a significant difference in the bone sodium deposition in pig H and pig L as a response to the sodium diet. In conclusion, this experimental study shows that IVNAA technique can be successfully used to quantify bone sodium in response to the dietary interventions.

Hair is used as a biomarker of manganese (Mn) exposure, yet there is limited evidence to support its utility to quantify internal vs external Mn exposure. C57BL/6 J mice and Sprague-Dawley rats were exposed in two blocks of 3 subcutaneous injections every 3 days starting on day 0 or 20. The control group received two blocks of saline (vehicle); Treatment A received the first block as Mn (50 mg/kg MnCl2 tetrahydrate), with the second block as either methylmercury (MeHg at 2.6 or 1.3 mg/kg) for mice or vehicle for rats; and Treatment B received Mn for both blocks. Hair was collected on days 0 and 60 from all treatment groups and Mn quantified by inductively coupled plasma-mass spectrometry (ICP-MS) and total Hg by Direct Mercury Analyzer (DMA). No correlation between internal Mn dose and hair Mn was observed, whereas hair Hg was significantly elevated in MeHg exposed vs non-exposed mice. Whole body Mn content at day 60 was quantified postmortem by neutron activation analysis, which detected significantly elevated Mn for Treatment B in mice and rats. Overall, we find no evidence to support the use of hair as a valid biomarker for internal exposure to Mn at a neurotoxic level.

Potassium is known for its effect on modifiable chronic diseases like hypertension, cardiac disease, diabetes (type-2), and bone health. In this study, a new method, neutron generator based neutron activation analysis (NAA), was utilized to measure potassium (K) in mouse carcasses. A DD110 neutron generator based NAA assembly was used for irradiation.Thirty-two postmortem mice (n= 16 males and 16 females, average weight $$22.02\pm 1.3$$ 22.02 ± 1.3 and $$17.9\pm 1.1$$ 17.9 ± 1.1 g) were employed for this study. Soft-tissue equivalent mouse phantoms were prepared for the calibration. All mice were irradiated for 10 minutes, and the gamma spectrum with 42K was collected using a high efficiency, high purity germanium (HPGe) detector. A lead shielding assembly was designed and developed around the HPGe detector to obtain an improved detection limit. Each mouse sample was irradiated and measured twice to reduce uncertainty. The average potassium concentration was found to be significantly higher in males $$(2846 \pm 525 \upmu g/g)$$ ( 2846 ± 525 μ g / g ) compared to females $$(2116.2 \pm 432 \upmu g/g)$$ ( 2116.2 ± 432 μ g / g ) . We also observed a significant correlation between potassium concentration and the weight of the mice. The detection limit for potassium quantification with the NAA system was 46 ppm. The radiation dose to the mouse was approximately 56 $${ \pm 1.6 }$$ ± 1.6 mSv for 10-min irradiation. In conclusion, this method is suitable for estimating individual potassium concentration in small animals. The direct evaluation of total body potassium in small animals provides a new way to estimate potassium uptake in animal models. This method can be adapted later to quantify potassium in the human hand and small animals in vivo. When used in vivo, it is also expected to be a valuable tool for longitudinal assessment, kinetics, and health outcomes.

Background: Trace and essential elements both play a crucial role in maintaining normal cellular and organ functions in human, while abnormal exposure to some of them is also potentially related to diseases, e.g. manganism. To study the association between elemental intake and health outcomes, accurate assessment of elemental uptake and storage in the human body is essential. Objective: Technology based on neutron activation analysis can be used for in vivo measurement of the trace elements given that the measurement system guarantees a low detection limit with an acceptable dose. This study aims to design and optimize a customized and portable deuterium–deuterium neutron generator-based irradiation assembly for the NAA of trace elements in vivo, using Monte Carlo simulations. Approach: The irradiation assembly includes a moderator, a fast neutron filter, a reflector, and shielding. The human hand phantoms doped with manganese (Mn) and potassium (K) are used to determine the respective elements’ system sensitivity and detection limit. Main results: The calculated detection limit is 0.16 μg Mn per gram dry bone (ppm) for Mn and 17 ppm for K, with an equivalent dose of 36 mSv to the hand for 10 min irradiation. Significance: This more sensitive in vivo neutron activation analysis system will detect trace elements in vivo.

The plastic scintillators are used in different areas of science and technology. One of the use of these scintillator detectors is as beam loss monitors (BLM) for new generation of high intensity heavy ion in superconducting linear accelerators. Operated in pulse counting mode with rather high thresholds and shielded by few centimeters of lead in order to cope with radiofrequency noise and X-ray background emitted by accelerator cavities, they preserve high efficiency for high energy gamma ray and neutrons produced in the nuclear reactions of lost beam particles with accelerator components. Efficiency calculation and calibration of detectors is very important before their practical usage. In the present work, the efficiency of plastic scintillator detectors is simulated using FLUKA for different gamma and neutron sources like, 60Co, 137Cs and 238Pu-Be. The sources are placed at different positions around the detector. Calculated values are compared with the measured values and a reasonable agreement is ob...