Efficient Synthesis and HPLC-Based Characterization for Developing Vanadium-48-Labeled Vanadyl Acetylacetonate as a Novel Cancer Radiotracer for PET Imaging

Bis(acetylacetonato)oxidovanadium(IV) [(VO(acac)2], generally known as vanadyl acetylacetonate, has been shown to be preferentially sequestered in malignant tissue. Vanadium-48 (48V) generated with a compact medical cyclotron has been used to label VO(acac)2 as a potential radiotracer in positron emission tomography (PET) imaging for the detection of cancer, but requires lengthy synthesis. Current literature protocols for the characterization of VO(acac)2 require macroscale quantities of reactants and solvents to identify products by color and to enable crystallization that are not readily adaptable to the needs of radiotracer synthesis. We present an improved method to produce vanadium-48-labeled VO(acac)2, [48V]VO(acac)2, and characterize it using high-performance liquid chromatography (HPLC) with radiation detection in combination with UV detection. The approach is suitable for radiotracer-level quantities of material. These methods are readily applicable for production of [48V]VO(acac)2. Preliminary results of preclinical, small-animal PET studies are presented.

Radiological assessment of urban soil samples in the residents of a central Anatolian volcanic province, Turkey

The concentration of natural and anthropogenic radionuclides, emanation fraction (EF), and mass (χM) and area (χA) exhalation rate of 222Rn in urban soil samples collected from dwelling areas in Nevşehir city located in a region known as the central Anatolian volcanic province of Turkey were determined using gamma-ray spectroscopy. The average activity concentrations of 226Ra, 228Ra, 40K and 137Cs were measured as 60.2 ± 3.8, 50.1 ± 2.8, 631.0 ± 29.7 and 5.5 ± 0.4 Bq/kg, respectively. The average concentration of 222Rn in soil and air was estimated as 27 kBq/m3 and 84 Bq/m3, respectively. The average values of EF, χM and χA were found as 20%, 25.4 μBq/kg⋅s and 20.2 mBq/m2⋅s, respectively. The average values of outdoor absorbed gamma dose rate, external and internal annual effective dose and lifetime cancer risk estimated for radiological assessment were found as 85 nGy/h, 104 µSv/y, 797 µSv/y and 4.1 × 10-4, respectively.

Investigation of the human metabolism and disposition of the prolyl hydrolase inhibitor daprodustat using IV microtracer with Entero-Test bile string

Daprodustat is an oral small molecule hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor (PHI) approved in Japan and the United States for the treatment of anemia associated with chronic kidney disease. This phase 1, nonrandomized, 2-period, crossover study in 6 healthy men characterized and quantified the metabolites generated after a microtracer IV infusion of 50 μg (125 nCi) [14 C]-daprodustat administered concomitantly with a nonradiolabeled therapeutic dose of a 6-mg daprodustat tablet, followed by a single oral solution dose of 25 mg (62.5 μCi) [14 C]-daprodustat. High-performance liquid chromatography (HPLC) coupled with radioactivity detection (TopCount or AMS) and HPLC-tandem mass spectrometry (HPLC-MSn ) were used for quantitative measurement and structural identification of radioactive metabolites in plasma, urine, feces, and bile. Following oral administration of [14 C]-daprodustat, unchanged daprodustat was the principal circulating drug-related component, accounting for 40% of plasma radioactivity. Predominant oxidative metabolites M2, M3, M4, and M13 individually represented 6-8% of the plasma radioactivity and together accounted for the majority of radioactivity in urine and feces (53% in both matrices; 12% and 41% of dose, respectively). Unchanged daprodustat was not detected in urine and was only 0.7% of total radioactivity in feces (<0.5% of dose), with the remainder of the dose accounted for by oxidative metabolites. The radio-metabolic profile of duodenal bile following IV infusion of [14 C]-daprodustat was similar to that observed in feces after oral administration. The data suggested that oral daprodustat was extensively absorbed, cleared exclusively by oxidative metabolism, and eliminated via hepatobiliary (primary) and urinary (secondary) excretion.

Development of an economical method to synthesize O-(2-[18 F]fluoroethyl)-L-tyrosine (18 FFET)

Positron emission tomography (PET) using O-(2-[18 F]fluoroethyl)-L-tyrosine ([18 F]FET) has shown great success in differentiating tumor recurrence from necrosis. In this study, we are reporting the experience of synthesis [18 F]FET by varying the concentration of TET precursor in different chemistry modules. TET precursor (2-10 mg) was used for the synthesis of [18 F]FET in an automated (MX Tracerlab) module (n = 6) and semiautomated (FX2N Tracerlab) module (n = 19). The quality control was performed for all the preparations. For human imaging, 220 ± 50 MBq of [18 F]FET was briefly injected into the patient to acquire PET-MR images. The radiochemical purity was greater than 95% for the final product in both modules. The decay corrected average yield was 10.7 ± 4.7% (10 mg, n = 3) and 8.2 ± 2.6% (2 mg, n = 3) with automated chemistry module and 36.7 ± 7.3% (8-10 mg, n = 12), 26.4 ± 3.1% (5-7 mg, n = 4), and 35.1 ± 3.8% (2-4 mg, n = 3) with semiautomated chemistry modules. The PET imaging showed uptake at the lesion site (SUVmax  = 7.5 ± 2.6) and concordance with the MR image. The [18 F]FET was produced with a higher radiochemical yield with 2.0 mg of the precursor with substantial yield and is suitable for brain tumor imaging.

Radiation risks and information needs of pregnant and lactating women

This a historical review and current information regarding risks and effects of ionizing radiation in the context of human pregnancy and in particular the information needed for pregnant women to understand the type and magnitude of risks placing them in a realistic context. Much of our understanding comes from early animal studies but has been supported by studies of human exposure to medical radiation, radiation accidents and nuclear weapons.

Airborne gamma-ray mapping using fixed-wing vertical take-off and landing (VTOL) uncrewed aerial vehicles

Low-cost uncrewed aerial vehicles (UAVs) are replacing manned aircraft for airborne radiation mapping applications such as nuclear accident response scenarios or surveying ore deposits and mine sites because of their cost-effectiveness and ability to conduct surveys at lower altitude compared to manned counterparts. Both multi-rotor UAVs and fixed-wing UAVs are well established technologies for aerial radiation mapping applications, however, both also have drawbacks: multi-rotor UAVs are very limited in flight time and range, and fixed-wing UAVs usually require facilities for take-off and landing. A compromise solution is introduced in this work, using a fixed-wing vertical take-off and landing (VTOL) UAV that combines the flexibility of a multi-rotor UAV with the range and flight time of a fixed-wing UAV. The first implementation of a VTOL with radiation mapping capabilities is presented, based on a commercial WingtraOne UAV augmented with CsI scintillator and CZT semiconductor gamma spectrometers. The radiation mapping capabilities of the prototype are demonstrated in a case study, mapping the distribution of radionuclides around the South Terras legacy uranium mine in the south of England, United Kingdom, and the results are compared with previous studies using multi-rotor and manned aircraft to survey the same area.

Radioactivity of residues from waste incineration facilities in Finland

Waste incineration in Europe has been increasing in the past few decades as there is a need to reduce the burden on landfills and their associated environmental concerns. While incineration reduces the volume of the waste, the volume of slag and ash is still substantial. To find out potential radiation risks that incineration residues could set to workers or the public, the levels of radioactive elements in these residues were investigated from nine waste incineration plants in Finland. Natural and artificial radionuclides were detected in the residues, but in general the activity concentrations were low. This study shows that the level of Cs-137 in the fly ash from municipal waste incineration follows the pattern of 1986 fallout zones in Finland, although the levels are significantly lower than in ash from bioenergy production from the same areas. Am-241 was also detected in many samples, although the activity concentrations were very low. Based on the findings in this study, the typical ash and slag residues from municipal waste incineration do not need radiation protection measures for workers or the public even in regions that received up to 80 kBq m^-2of Cs-137 fallout in 1986. The further use of these residues need not be restricted due to radioactivity. Hazardous waste incineration residues and other special cases need to be considered separately, depending on the original waste composition.

Uptake of Radionuclides by Bryophytes in the Chornobyl Exclusion Zone

The "Chernobyl nuclear disaster" released huge amounts of radionuclides, which are still detectable in plants and sediments today. Bryophytes (mosses) are primitive land plants lacking roots and protective cuticles and therefore readily accumulate multiple contaminants, including metals and radionuclides. This study quantifies ¹³⁷Cs and ²⁴¹Am in moss samples from the cooling pond of the power plant, the surrounding woodland and the city of Prypiat. Activity concentrations of up to 297 Bq/g (¹³⁷Cs) and 0.43 Bq/g (²⁴¹Am) were found. ¹³⁷Cs contents were significantly higher at the cooling pond, where ²⁴¹Am was not detectable. Distance to the damaged reactor, amount of original fallout, presence of vascular tissue in the stem or taxonomy were of little importance. Mosses seem to absorb radionuclides rather indiscriminately, if available. More than 30 years after the disaster, ¹³⁷Cs was washed out from the very top layer of the soil, where it is no more accessible for rootless mosses but possibly for higher plants. On the other hand, ¹³⁷Cs still remains solved and accessible in the cooling pond. However, ²⁴¹Am remained adsorbed to the topsoil, thus accessible to terrestrial mosses, but precipitated in the sapropel of the cooling pond.

Global Transcriptional Response of Escherichia coli Exposed In Situ to Different Low-Dose Ionizing Radiation Sources

Characterization of biological and chemical responses to ionizing radiation by various organisms is essential for potential applications in bioremediation, alternative modes of detecting nuclear material, and national security. Escherichia coli DH10β is an optimal system to study the microbial response to low-dose ionizing radiation at the transcriptional level because it is a well-characterized model bacterium and its responses to other environmental stressors, including those to higher radiation doses, have been elucidated in prior studies. In this study, RNA sequencing with downstream transcriptomic analysis (RNA-seq) was employed to characterize the global transcriptional response of stationary-phase E. coli subjected to ²³⁹Pu, ³H (tritium), and ⁵⁵Fe, at an approximate absorbed dose rate of 10 mGy day^-1 for 1 day and 15 days. Differential expression analysis identified significant changes in gene expression of E. coli for both short- and long-term exposures. Radionuclide source exposure induced differential expression in E. coli of genes involved in biosynthesis pathways of nuclear envelope components, amino acids, and siderophores, transport systems such as ABC transporters and type II secretion proteins, and initiation of stress response and regulatory systems of temperature stress, the RpoS regulon, and oxidative stress. These findings provide a basic understanding of the relationship between low-dose exposure and biological effect of a model bacterium that is critical for applications in alternative nuclear material detection and bioremediation. IMPORTANCE Escherichia coli strain DH10β, a well-characterized model bacterium, was subjected to short-term (1-day) and long-term (15-day) exposures to three different in situ radiation sources comprised of radionuclides relevant to nuclear activities to induce a measurable and identifiable genetic response. We found E. coli had both common and unique responses to the three exposures studied, suggesting both dose rate- and radionuclide-specific effects. This study is the first to provide insights into the transcriptional response of a microorganism in short- and long-term exposure to continuous low-dose ionizing radiation with multiple in situ radionuclide sources and the first to examine microbial transcriptional response in stationary phase. Moreover, this work provides a basis for the development of biosensors and informing more robust dose-response relationships to support ecological risk assessment.

Mass balance study of [14C]SHR0302, a selective and potent JAK1 inhibitor in humans

SHR0302, a selective JAK1 inhibitor developed by Jiangsu Hengrui Pharmaceutical Co., was intended for the treatment of rheumatoid arthritis. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of SHR0302 in six healthy Chinese male subjects after a single 8 mg (80 µCi) oral dose of [¹⁴C]SHR0302.SHR0302 was absorbed rapidly (T_max = 0.505 h), and the average t_1/2 of the SHR0302-related components in plasma was approximately 9.18 h. After an oral dose was administered, the average cumulative excretion of the radioactive components was 100.56% ± 1.51%, including 60.95% ± 11.62% in urine and 39.61% ± 10.52% in faeces.A total of 16 metabolites were identified. In plasma, the parent drug SHR0302 accounted for 90.42% of the total plasma radioactivity. In urine, SHR161279 was the main metabolite, accounting for 33.61% of the dose, whereas the parent drug SHR0302 only accounted for 5.1% of the dose. In faeces, the parent drug SHR0302 accounted for 23.73% of the dose, and SHR161279 was the significant metabolite, accounting for 5.67% of the dose. In conclusion, SHR0302-related radioactivity was mainly excreted through urine (60.95%) and secondarily through faeces (39.61%).The metabolic reaction of SHR0302 in the human body is mainly through mono-oxidation and glucuronidation. The main metabolic location of SHR0302 in the human body is the pyrrolopyrimidine ring.

Assessment of radiation exposure and public health before and after the operation of Sanmen nuclear power plant

Introduction

Sanmen nuclear power plant (SNPP) operates the first advanced passive (AP1000) nuclear power unit in China.

Methods

To assess the radiological impacts of SNPP operation on the surrounding environment and the public health, annual effective dose (AED) and excess risk (ER) were estimated based on continuous radioactivity monitoring in drinking water and ambient dose before and after its operation during 2014-2021. In addition, the residents' cancer incidence was further analyzed through authorized health data collection.

Results

The results showed that the gross α and gross β radioactivity in all types of drinking water were ranged from 0.008 to 0.017 Bq/L and 0.032 to 0.112 Bq/L, respectively. The cumulative ambient dose in Sanmen county ranged from 0.254 to 0.460 mSv/y, with an average of 0.354 ± 0.075 mSv/y. There is no statistical difference in drinking water radioactivity and ambient dose before and after the operation of SNPP according to Mann-Whitney U test. The Mann-Kendall test also indicates there is neither increasing nor decreasing trend during the period from 2014 to 2021. The age-dependent annual effective doses due to the ingestion of drinking water or exposure to the outdoor ambient environment are lower than the recommended threshold of 0.1 mSv/y. The incidence of cancer (include leukemia and thyroid cancer) in the population around SNPP is slightly higher than that in other areas, while it is still in a stable state characterized by annual percentage changes.

Discussion

The current comprehensive results show that the operation of SNPP has so far no evident radiological impact on the surrounding environment and public health, but continued monitoring is still needed in the future.

Strontium-90 in Baby Teeth as a Basis for Estimating U.S. Cancer Deaths From Nuclear Weapons Fallout

Nuclear weapons testing in the atmosphere during the 1950s and 1960s deposited fallout throughout the world, exposing all humans to food and water before the Limited Test Ban Treaty ended large-scale tests. The largest effort to measure in vivo fallout in humans, performed by Washington University (USA), collected over 300,000 deciduous teeth to document a sustained increase in Strontium-90 (Sr-90) during testing and a sharp decline after the test ban. Sr-90 patterns and trends in teeth were consistent with those of bones and milk. Sr-90 is still detectable in about 100,000 of the teeth, which were never tested. Tooth donors were born during atmospheric testing (1946-1965) and thus exposed to fallout in utero and during infancy/childhood, when exposures pose the greatest health risk. Preliminary analysis of global fallout's health risk in the United States indicates recent cancer mortality in several high-fallout areas exceeded that of states with the lowest fallout, peaking for the cohort born in the early 1960s, when fallout was highest. These findings support subsequent measurement of Sr-90 in deciduous teeth of persons who died of diseases such as cancer, along with controls, a novel approach to assessing fallout hazards.

Characterization of Chimeric Antigen Receptor Modified T Cells Expressing scFv-IL-13Rα2 after Radiolabeling with 89Zirconium Oxine for PET Imaging

Background Chimeric antigen receptor (CAR) T cell therapy is an exciting cell-based cancer immunotherapy. Unfortunately, CAR-T cell therapy is associated with serious toxicities such as cytokine release syndrome (CRS) and neurotoxicity. The mechanism of these serious adverse events (SAEs) and how homing, distribution and retention of CAR-T cells contribute to toxicities is not fully understood. Methods To determine if radiolabelling of CAR-T cells could support positron emission tomography (PET)-based biodistribution studies, we labeled IL-13Rα2 targeting scFv-IL-13Rα2-CAR-T cells (CAR-T cells) with 89 Zirconium-oxine ( 89 Zr-oxine), and characterized and compared their product attributes with non-labeled CAR-T cells. The 89 Zr-oxine labeling conditions were optimized for incubation time, temperature, and use of serum for labeling. In addition, product attributes of radiolabeled CAR-T cells were studied to assess their overall quality including cell viability, proliferation, phenotype markers of T-cell activation and exhaustion, cytolytic activity and release of interferon-γ upon co-culture with IL-13Rα2 expressing glioma cells. Results We observed that radiolabeling of CAR-T cells with 89 Zr-oxine is quick, efficient, and radioactivity is retained in the cells for at least 8 days with minimal loss. Also, viability of radiolabeled CAR-T cells was similar to that of unlabeled cells as determined by TUNEL assay and caspase 3/7 enzyme activity assay. Moreover, there were no significant changes in T cell activation (CD24, CD44, CD69 and IFN-γ) or T cell exhaustion(PD-1, LAG-3 and TIM3) markers expression between radiolabeled and unlabeled CAR-T cells. In chemotaxis assays, migratory capability of radiolabeled CAR-T cells to IL-13Rα2Fc was similar to that of non-labeled cells. Conclusions Importantly, radiolabeling has minimal impact on biological product attributes including potency of CAR-T cells towards IL-13Rα2 positive tumor cells but not IL-13Rα2 negative cells as measured by cytolytic activity and release of IFN-γ. Thus, IL-13Rα2 targeting CAR-T cells radiolabeled with 89 Zr-oxine retain critical product attributes and suggest 89 Zr-oxine radiolabeling of CAR-T cells may facilitate biodistribution and tissue trafficking studies in vivo using PET.

Study of Polonium ((210)Po) Activity Concentration in Fruit Wines Derived from Different Locations in Poland

This study aimed at assessing the activity concentration and the annual effective dose of polonium-210 (210Po) in fruit wines derived from four locations in Poland (Warmian−Masurian, Podlaskie, Lubelskie and Małopolskie voivodeships). The fruit wines differed significantly (p < 0.05) in 210Po activity depending on the production site, with the Małopolskie site having the highest activity (61.4−221.4 mBq/L) and the Podlaskie having the lowest (3.5−97.1 mBq/L). The site differentiation was due to environmental conditions—soil parameters (uranium concentration), precipitations and terrain characteristics, e.g., the proximity of the lakes. The increased activity concentration of 210Po in samples from Małopolska compared with the other sites probably derived from the environment polluted with aqueous wastes and particulate air pollution. The annual effective dose due to the ingestion of fruit wines ranged from 0.112 to 1.214 µSv/year. These levels of exposure are safe according to the WHO criterion (0.1 mSv per year for ingestion) and to the IAEA reference level for public exposure including food (1 mSv per year). Summing up, the data obtained provide information on the activity concentration of 210Po in fruit wines and increase databases on the natural radioactivity of foodstuffs. Future work is needed to examine 210Po activity in samples from all vineyard regions in Poland.

Recent Development on Determination of Low-Level 90Sr in Environmental and Biological Samples: A Review

In the context of the rapid development of the world's nuclear power industry, it is vital to establish reliable and efficient radioanalytical methods to support sound environment and food radioactivity monitoring programs and a cost-effective waste management strategy. As one of the most import fission products generated during human nuclear activities, ⁹⁰Sr has been widely determined based on different analytical techniques for routine radioactivity monitoring, emergency preparedness and radioactive waste management. Herein, we summarize and critically review analytical methods developed over the last few decades for the determination of ⁹⁰Sr in environmental and biological samples. Approaches applied in different steps of the analysis including sample preparation, chemical separation and detection are systematically discussed. The recent development of modern materials for ⁹⁰Sr concentration and advanced instruments for rapid ⁹⁰Sr measurement are also addressed.

Natural Radioactivity and Chemical Evolution on the Early Earth: Prebiotic Chemistry and Oxygenation

It is generally recognized that the evolution of the early Earth was affected by an external energy source: radiation from the early Sun. The hypothesis about the important role of natural radioactivity, as a source of internal energy in the evolution of the early Earth, is considered and substantiated in this work. The decay of the long-lived isotopes ²³²Th, ²³⁸U, ²³⁵U, and ⁴⁰K in the Global Ocean initiated the oxygenation of the hydro- and atmosphere, and the abiogenesis. The content of isotopes in the ocean and the kinetics of their decay, the values of the absorbed dose and dose rate, and the efficiency of sea water radiolysis, as a function of time, were calculated. The ocean served as both a "reservoir" that collected components of the early atmosphere and products of their transformations, and a "converter" in which further chemical reactions of these compounds took place. Radical mechanisms were proposed for the formation of simple amino acids, sugars, and nitrogen bases, i.e., the key structures of all living things, and also for the formation of oxygen. The calculation results confirm the possible important role of natural radioactivity in the evolution of terrestrial matter, and the emergence of life.

Synergistic Effects of Particle Radioactivity (Gross β Activity) and Particulate Matter ≤2.5 μm Aerodynamic Diameter on Cardiovascular Disease Mortality

Background Although the effects of fine particulate matter (particulate matter ≤2.5 μm aerodynamic diameter [PM_2.5]) on cardiovascular disease (CVD) morbidity and mortality are well established, little is known about the CVD health effects of particle radioactivity. In addition, there are still questions about which of the PM_2.5 physical, chemical, or biological properties are mostly responsible for its toxicity. Methods and Results We investigated the association between particle radioactivity, measured as gross β activity from highly resolved spatiotemporal predictions, and mortality for CVD, myocardial infarction, stroke, and all-cause nonaccidental mortality in Massachusetts (2001-2015). Within both difference-in-differences model and generalized linear mixed model frameworks, we fit both single-exposure and 2-exposure models adjusting for PM_2.5 and examined the interaction between PM_2.5 and gross β activity. We found significant associations between gross β activity and PM_2.5 and each mortality cause. Using difference-in-differences and adjusting for PM_2.5, we found the highest associations with myocardial infarction (rate ratio, 1.16 [95% CI, 1.08-1.24]) and stroke (rate ratio, 1.11 [95% CI, 1.04-1.18]) for an interquartile range increase (0.055 millibecquerels per cubic meter) in gross β activity. We found a significant positive interaction between PM_2.5 and gross β activity, with higher associations between PM_2.5 and mortality at a higher level of gross β activity. We also observed that the associations varied across age groups. The results were comparable between the 2 statistical methods also with and without adjusting for PM_2.5. Conclusions This is the first study that, using highly spatiotemporal predictions of gross β-activity, provides evidence that particle radioactivity increases CVD mortality and enhances PM_2.5 CVD mortality. Therefore, particle radioactivity can be an important property of PM_2.5 that must be further investigated. Addressing this important question can lead to cost-effective air-quality regulations.

Etna, Sicily, Southern Italy

In this article, an investigation of the natural radioactivity content of pyroclastic products from Mt. Etna, eastern Sicily, Southern Italy, was carried out. In particular, the assessment of the average activity concentration of the investigated radionuclides, related to the mineralogical phase composition of the analyzed samples, and the radiological health risk for the population, was performed. High Purity Germanium (HPGe) gamma-ray spectrometry was employed in order to quantify the average specific activity of ²²⁶Ra, ²³²Th, and ⁴⁰K natural radioisotopes. The absorbed gamma dose rate (D), the radium equivalent activity (Ra_eq), the hazard indices (H_in and H_ex), the annual effective dose equivalent outdoor (AEDE_out), and the excess lifetime cancer risk (ELCR) were also estimated in order to assess any possible radiological hazard for the population. In our case, they were found to be lower than the maximum recommended values for the population members, thus reasonably excluding radiological hazard effects. Moreover, the identification of the source of the aforementioned naturally occurring radionuclides was attempted by X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS), thereby recognizing the main radioisotope-bearing minerals present in the investigated pyroclastic products. Finally, Pearson correlation, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were performed by processing observed radioactivity and radiological parameters in order to determine their correlation with the sampling locations.

Strategic roadmap to assess forest vulnerability under air pollution and climate change

Although it is an integral part of global change, most of the research addressing the effects of climate change on forests have overlooked the role of environmental pollution. Similarly, most studies investigating the effects of air pollutants on forests have generally neglected the impacts of climate change. We review the current knowledge on combined air pollution and climate change effects on global forest ecosystems and identify several key research priorities as a roadmap for the future. Specifically, we recommend (1) the establishment of much denser array of monitoring sites, particularly in the South Hemisphere; (2) further integration of ground and satellite monitoring; (3) generation of flux-based standards and critical levels taking into account the sensitivity of dominant forest tree species; (4) long-term monitoring of N, S, P cycles and base cations deposition together at global scale; (5) intensification of experimental studies, addressing the combined effects of different abiotic factors on forests by assuring a better representation of taxonomic and functional diversity across the ~73,000 tree species on Earth; (6) more experimental focus on phenomics and genomics; (7) improved knowledge on key processes regulating the dynamics of radionuclides in forest systems; and (8) development of models integrating air pollution and climate change data from long-term monitoring programs.

Human and nonclinical disposition of [14C]bictegravir, a potent integrase strand-transfer inhibitor for the treatment of HIV-1 infection

Bictegravir (BIC) is a potent small-molecule integrase strand-transfer inhibitor (INSTI) and a component of Biktarvy®, a single-tablet combination regimen that is currently approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. The absorption, metabolism, distribution, and elimination (ADME) characteristics of BIC were determined through in vivo nonclinical and clinical studies (IND 121318).[¹⁴C]BIC was rapidly absorbed orally in mice, rats, monkeys and human. The cumulative dose recovery was high in nonclinical species (>80%) and humans (95.3%), with most of the excreted dose recovered in faeces. Quantifiable radioactivity with declining concentration was observed in rat tissues suggesting reversible binding. Unchanged BIC was the most abundant circulating component in all species along with two notable metabolites M20 (a sulphate conjugate of hydroxylated BIC) and M15 (a glucuronide conjugate of BIC). BIC was primarily eliminated by hepatic metabolism followed by excretion of the biotransformed products into faeces. In vitro drug-drug interaction (DDI) studies with M15 and M20 demonstrated that no clinically relevant interactions were expected.Overall, BIC is a novel and potent INSTI with a favourable resistance, PK, and ADME profile that provides important improvements over other currently available INSTIs for the treatment of HIV-1.

Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai

The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (H_ex, H_in), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Ra_eq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core ²³²Th/²³⁸U mass fractions were determined from the obtained values of ²³⁸U, ²³²Th and ⁴⁰K for the examined rocks of Seih-Sidri area. The average ²³⁸U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one's radiological health.

Tandem Mass Spectrometry as an Independent Method for Corroborating Fluorine-18 Radioactivity Measurements in Positron Emission Tomography

Positron emission tomography (PET) uses many tracers labeled with fluorine-18 (t _1/2 = 109.8 min; β⁺ 97%) for quantitative imaging of biochemical and physiological processes in animal and human subjects. In PET methodology, the radioactivity in a dose of an ¹⁸F-labeled tracer to be administered to a living subject is measured with a calibrated ionization chamber. This type of detector measures the radioactivity of a sample relative to those of certified amounts of longer-lived surrogate isotopes that are recommended for detector calibration. No alternative means for corroborating widely varying fluorine-18 radioactivity measurements from calibrated ionization chambers has been available. Here, we describe an independent nonradiometric method for this purpose. In this method, highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) is used to quantify the relative masses of the radioactive isotopologue ([¹⁸F]1) and the accompanying nonradioactive counterpart (carrier 1) in an ¹⁸F-labeled tracer preparation to give the mole ratio of [¹⁸F]1. High-performance liquid chromatography (HPLC) with a mass-calibrated absorbance detection is used alongside to provide a separate measurement of the aggregate mass of all isotopologues. The radioactivity of the radiotracer is then derived in becquerels (Bq) from these two measurements, plus Avogadro's number and the decay constant of fluorine-18. For the chosen example [¹⁸F]LSN3316612, the radioactivity values determined nonradiometrically and with a selected ionization chamber were in fair agreement. In addition, LC-MS/MS alone was found to provide an accurate measure of the half-life of fluorine-18.

Determination, Separation and Application of 137Cs: A Review

In the context of the rapid development of the world's nuclear power industry, it is necessary to establish background data on radionuclides of different samples from different regions, and the premise of obtaining such basic data is to have a series of good sample processing and detection methods. The radiochemical analysis methods of low-level radionuclides ¹³⁷Cs (Cesium) in environmental and biological samples are introduced and reviewed in detail. The latest research progress is reviewed from the five aspects of sample pretreatment, determination, separation, calculation, application of radioactive cesium and the future is proposed.

Chemical, radiological and microbiological characterization of a drinking water source: a case study

This study examined water samples from a local stream in Central Serbia, which was consumed as drinking water. The chemical parameters (chemical oxygen demand, pH, total concentration of dissolved substances and electrical conductivity), the concentration of major, trace, and radioactive elements in the water as well as the content of those from the environment, were examined. In addition, the microbiological quality of the water was inspected. The water samples were acidic (pH from 5.27 to 5.69) and chemical oxygen demand ranged in upper permissible limits (up to 6.25 mg O₂ l^-1 (WR)). The concentrations of major, trace and radioactive elements, including radon, were below maximum contaminant levels. The water contained a higher number of total coliform bacteria than it was allowed (˃10 colony forming units (CFU) in 100 ml of water) as well as enterococci and Escherichia coli. The characterization of the isolated bacteria indicated that two isolates demonstrated proteolytic activity, while full antibiotic resistance was not detected. The isolates showed moderate to strong ability to produce biofilm, while the isolates of E. coli were nonpathogenic. The results indicated that examined water samples were not microbiologically and chemically safe, therefore, the usage of analyzed water was not recommended as a water supply. Further research needs to include more frequent monitoring in order to propose measures for the improvement of the water quality and prevention of health risks for consumers.

Excess Lifetime Cancer Risk Associated with Granite Bearing Radioactive Minerals and Valuable Metals, Monqul Area, North Eastern Desert, Egypt

The present work is concerned with assessing the cancer risk contributed by the studied granite types including valuable metals, such as Cu, Au, and Ba mineralization, as well as radioactive-bearing mineralization, such as monazite and zircon, in south Monqul at Wadi Makhrag El Ebel, north Eastern Desert, Egypt. The mineralization analyses illustrated that copper mineralization containing chrysocolla and tenorite minerals were restricted to the alteration zone, especially (argillic, phyllic, and propylitic) in monzogranite. However, barite veinlets had an ENE–WSW trend, while gold mineralization was confined to quartz veins having NE–SW trends. Monazite and zircon are radioactive-bearing minerals recorded in monzogranite causing high radioactive zones in south Monqul. The radionuclide activity concentrations were detected in the studied monzogranites. The mean values of A_U (103 ± 91 Bq kg⁻¹), A_Th (78 ± 19 Bq kg⁻¹), and A_K (1484 ± 334 Bq kg⁻¹) in the monzogranite samples were higher than the recommended worldwide average. The change in radioactive-transporting minerals found inside granite faults caused the high amounts of radioactivity seen in the samples. Due to the monzogranites being applied in building materials, the radiological hazards were assessed by calculating risk indices such as annual effective dose (AED) and excess lifetime cancer risk (ELCR). The acceptable limit for the ELCR readings was surpassed. As a result, the investigated monzogranite samples are not suitable for use in infrastructure materials.

Phytoremediation of radioactive elements, possibilities and challenges: special focus on agricultural aspects

The radioactive contamination has been reported frequently from agricultural lands and ground water. The main reason behind the radioactive pollution is unprotected mining of radioactive elements, unsafe discard of nuclear industrial waste, military applications, dumping of medically used radioisotopes, globally situated (>400) nuclear power plants and use of phosphate fertilizers in farming. Radionuclides are well known potent carcinogens that may cause the various types of cancers to human and animals due to the long exposure to radioactive contaminated sites. To get rid of from the radioactive pollution there is a need of practically successful and cost effective bioremediation technologies that should able to decontaminate the effected lands and water to benefit the mankind. Microbial and phytoremediation are well studied methods for decreasing or gradually eliminating the radioactive contaminants. In this review, we discussed the different strategies of microbial and phytoremediation of radionuclides and recent advancements, that can play the major role in bioremediation of soil and water.

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay-energy spectrometry using chip-scale sub-Kelvin microcalorimeters and direct realization of mass by gravimetric inkjet dispensing using an electrostatic force balance. In contrast to traditional traceability, which typically relies on chemical separation of single-radionuclide samples, 4π integral counting, and additional spectrometry methods to verify purity, the system described here has both 4π counting efficiency and spectroscopic resolution sufficient to identify multiple radionuclides in the same sample at once. This enables primary standardization of activity concentrations of mixed-radionuclide samples. A major benefit of this capability, beyond metrology, is in assay of environmental and forensics samples, for which the quantification of multiplenuclide samples can be achieved where presently inhibited by interferences. This can be achieved without the need for chemical separations or efficiency tracers, thereby vastly reducing time, radioactive waste, and resulting measurement uncertainty.

Potential for Use of Recycled Cathode Ray Tube Glass in Making Concrete Blocks and Paving Flags

The potential to use waste glass, including cathode ray tube (CRT) glass, for making new products or as an admixture to existing ones is being intensively investigated. This kind of research intensified particularly in the period after CRT TV sets and computer monitors were replaced in the market by the advanced technology of thin film transistor (TFT) and liquid crystal display (LCD) screens. Cathode ray tube glass represents a considerable part of electronic waste (e-waste). E-waste globally increases at a far higher rate than other solid waste materials. There is a possibility to recycle cathode ray tube glass and use it in the construction industry. This paper shows the test results of physical and mechanical properties of blocks and paving flags. The reference specimen was made with quartz sand, while the other product employed a combination of quartz sand and ground panel cathode ray tube glass. The glass was ground to the fraction 0.25/1.00 mm, which corresponds to quartz sand fineness. The following tests were performed: shape and dimensions, resistance to freeze/thaw and de-icing salts, water absorption, splitting tensile strength and tensile strength by bending. Special attention was paid to the tests of Böhme wear resistance, slip resistance of the top surface of CRT products using a pendulum, radioactivity and leaching. The texture of the experimental concrete products was observed by SEM (scanning electron microscopy) and analyzed. The results obtained by experimental testing unequivocally show that CRT glass can successfully be used for making concrete blocks and paving flags.

Radioactivity, Metals Pollution and Mineralogy Assessment of a Beach Stretch from the Ionian Coast of Calabria (Southern Italy)

In the present article, a case study is reported regarding an investigation carried out in order to assess radioactivity concentration, heavy metals pollution and mineralogy of a beach stretch extending from Soverato to Squillace municipalities of the Ionian coast of Calabria, South of Italy, a popular tourist destination, especially in summer. The analysis of radionuclides contents was performed by using a High Purity Germanium (HPGe) gamma-ray detector, in order to quantify the average specific activity of ²²⁶Ra, ²³²Th and ⁴⁰K natural radionuclides and ¹³⁷Cs anthropogenic radioisotope. The absorbed dose rate and the annual effective dose equivalent radiological hazard indices were also estimated. Furthermore, X-ray Fluorescence (XRF) spectrometry measurements were carried out for the quantitative elemental analysis of the sand, in order to investigate any possible chemical pollution by heavy metals. For this aim, different indices such as Enrichment Factor (EF), Geoaccumulation Index (I_geo), Contamination Factor (CF) and Pollution Load Index (PLI) were applied to estimate the level of toxicity imposed on the ecosystem by the detected heavy metals. Finally, in order to identify the crystalline mineral components of the investigated sand samples, X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS) measurements were carried out.

Tissue quantification of radioiodine thyroid uptake in humans by an isotopic imaging technique on slides

BACKGROUND

Thyroid metabolism involves iodine, which allows us to use radioactive iodine for diagnostic and therapy purposes. The efficiency of radioiodine therapy depends on several parameters; the ability of thyroid tissue to uptake radioactive iodine is one of them.

OBJECTIVE

The objective of this work is to quantify the radioactive iodine uptake on thyroid tissue.

METHODS

In this work, we developed a method to quantify the in vivo uptake of iodine-131 on sections of thyroid glands removed by thyroidectomies. We performed an analysis of histological sections of the thyroid tissue by beta imaging. We had the opportunity to quantify the fixed radioactivity and to analyze its distribution in the thyroid gland, thanks to the good spatial resolution available with the type of detector used.

RESULTS

The results gave a high image resolution showing the heterogeneity of iodine-131 fixation by the thyroid tissue. We were able to quantify the tissue radioactivity in mega Becquerel (MBq) per volume unit.

CONCLUSION

This work has shown that the direct quantification of the thyroid tissue uptake is possible using the beta imaging system.

Effects of nitrogen on caesium allocation in rice plants (Oryza sativa)

After the nuclear accident in Fukushima Prefecture, Japan, in 2011, ¹³⁷ Caesium (Cs) contaminated nearby agricultural regions. Studies in these rice fields found that low K and high N fertilizer application enhanced Cs uptake in rice shoots. However, the influence of root and soil physics on these findings, as well as precise nutrient levels, remain to be clarified. We sought to analyse these relationships utilizing hydroponically grown rice plants. The rice plants were subjected to various concentrations of K and N nutrient solutions. We measured Cs allocation within the plants and performed transcript analyses using root tissues. Under low-K conditions, low-N plants accumulated less Cs in shoots and more in roots when compared to control-N conditions, even though overall Cs uptake remained unchanged. Expression analyses of root mRNAs showed that low-N plants accumulated reduced levels of OsAKT1 mRNA, encoding a K transporter. We also found a negative relationship between shoot Cs and K status in control-N but not in low-N conditions. Our results suggest that the application of N shifts Cs from roots into the shoots and that OsAKT1 in root vascular tissues influences Cs allocation. In practice, fine tuning N/K application and targeted breeding of K transporters might mitigate Cs contamination in rice plants.

Assessment of Radioactivity Level in the Terrestrial and Marine Organisms in Yangjiang and Its Adjacent Areas (China)

In order to assess the radioactive level in the terrestrial and marine organisms in Yangjiang and the adjacent areas, ⁹⁰Sr, gross beta and gamma-emitting radionuclides (²³⁸U, ²²⁶Ra, ²²⁸Th, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs, ⁵¹Cr, ⁵⁵Fe, ⁵⁴Mn, ⁵⁸Co, ⁶⁰Co and ⁶⁵Zn) were analyzed from 2011 to 2012. The annual effective doses were estimated in the high natural radioactive background areas in Yangjiang (HBRAYJ). The specific activities of ²³⁸U, ²²⁸Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs in all organisms were <0.05–5.20, 0.30–14.50, 0.11–3.58, 11.1–148.0 and <0.003–0.088 Bq/kg, whilst ⁵¹Cr, ⁵⁵Fe, ⁵⁴Mn, ⁵⁸Co, ⁶⁰Co, ⁶⁵Zn and ^110mAg were below the minimum detectable activity. ⁹⁰Sr and gross beta specific activities were 20.0–143.0 and 0.021–0.316 Bq/kg. Results show that ²²⁸Th was significantly higher than ²³⁸U and ²²⁶Ra of natural U series in organisms due to the rich-Th soils in the HBRAYJ; ²²⁸Th, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr were greatly lower than the limited concentrations in Chinese foods. The internal dose mainly contributes to natural ⁴⁰K, ²²⁶Ra and ²²⁸Th. It is useful to provide some basic data and assess the radiological risk from the HBRAYJ and Yangjiang nuclear power plants in future.

Phosphogypsum and its potential use in Croatia: challenges and opportunities

Phosphogypsum (PG) is a waste by-product (residue) originating from the production of phosphoric acid and phosphate fertilisers. PG contains chemical and radioactive impurities, which is why it is mostly stockpiled in controlled areas. Worldwide, only about 15 % of PG is recycled or reused. Today, policies and business strategies prioritise sustainable development through circular economy, which certainly includes PG. This provides new opportunities for Croatia to manage its PG and make an effort to use it as an additive in different industries, such as agriculture and construction. Due to its chemical and radiological properties, PG can potentially cause problems for the environment and human health. Hence, before using PG, detailed knowledge of potential hazards is necessary to protect people and the environment. The aim of this review is to summarise available data on Croatian PG, compare them with other countries, and to identify knowledge gaps and the lack of data on potential hazardous substances in PG in order to assess the opportunities of using PG in Croatia.

Radiological Risk to Human and Non-Human Biota Due to Radioactivity in Coastal Sand and Marine Sediments, Gulf of Oman

Natural and ¹³⁷Cs radioactivity in coastal marine sediment samples was measured using gamma spectrometry. Samples were collected at 16 locations from four beaches along the coastal area of Muscat City, Gulf of Oman. Radioactivity in beach sand was used to estimate the radiological risk parameters to humans, whereas the radioactivity in marine sediments was used to assess the radiological risk parameters to non-human biota, using the ERICA Tool. The average radioactivity concentrations (Bqkg⁻¹) of ²²⁶Ra, ²³²Th, ⁴⁰K, ²¹⁰Pb and ¹³⁷Cs in sediments (sand) were as follows: 16.2 (16.3), 34.5(27.8), 54.7 (45.6), 46.8 (44.9) and 0.08 (0.10), respectively. In sand samples, the estimated average indoor (Din) and outdoor (Dout) air absorbed dose rates due to natural radioactivity were 49.26 and 27.4 and the total effective dose (AEDTotal; µSvy⁻¹) ranged from 150.2 to 498.9 (average: 275.2). The measured radioactivity resulted in an excess lifetime cancer risk (ELCR) in the range of 58–203 (average: 111) in and an average gonadal dose (AGD; µGy.y⁻¹) ranged from 97.3 to 329.5 (average: 181.1). Total dose rate per marine organism ranged from 0.035 µGy h⁻¹ (in zooplankton) to 0.564 µGy h⁻¹ (in phytoplankton). The results showed marine sediments as an important source of radiation exposure to biota in the aquatic environment. Regular monitoring of radioactivity levels is vital for radiation risk confinement. The results provide an important radiological risk profile parameter to which future radioactivity levels in marine environments can be compared.

Effect of Ursodeoxycholic Acid on the Biodistribution and Excretion of Technetium-99m Radiopharmaceuticals in Rat: A Potential Image Quality Enhancer

PURPOSE

This study aimed to investigate the effect of ursodeoxycholic acid (UDCA) on the biodistribution and excretion of technetium-99m (Tc-99m)-labeled radiopharmaceuticals.

MATERIALS AND METHODS

Tc-99m hydroxy-methylene-diphosphonate (HDP), Tc-99m pertechnetate, and Tc-99m dimercaptosuccinic acid (DMSA) were injected via the tail vein of rats. After 30 min, the control group was administered saline, and the UDCA group was given UDCA orally. Scintigraphy images were acquired after 30 min and 1, 2, 3, and 4 h. Radioactivity and rate of change were compared. Tc-99m mercaptoacetyltriglycine (MAG₃) imaging was also performed.

RESULTS

In image analysis of Tc-99m HDP, radioactivity of the buttock was lower in the UDCA group at 4 h. Rates of change in the buttock were significantly different at 3 h-30 min and 4 h-30 min, and buttock radioactivity in the UDCA group had decreased more. In analysis of Tc-99m pertechnetate, radioactivity of the buttock was higher in the control group. Rates of change in the thyroid gland and buttock were different at 1 h-30 min, 3 h-30 min, and 4 h-30 min, with radioactivity in the UDCA group decreasing more. In the analysis of Tc-99m DMSA, while the radioactivity of the kidneys in the control group showed little decrease at 1 h-30 min, that in the UDCA group increased. In the analysis of Tc-99m MAG₃ images, radioactivity and radioactivity/total body radioactivity (TBA) values for the kidneys were higher in the UDCA group at 2 min. At 5 and 10 min, radioactivity/TBA values for soft tissue in the UDCA group were lower than those in the control group.

CONCLUSION

This study demonstrated that administration of UDCA increases renal excretion and soft tissue clearance of radiopharmaceuticals. This investigation could contribute to the broadening of applications of UDCA.

Radioactivity to Rethink the Earth's Energy Balance

This contribution invites to re-examine the whole matter of radioactivity, reconsidering it from the point of view of a realistic source of energy. State-of-the-art and technical aspects are briefly illustrated in this note that aims to open a discussion on this challenging topic.

The effects of ionizing radiation on domestic dogs: a review of the atomic bomb testing era

Dogs were frequently employed as laboratory subjects during the era of atomic bomb testing (1950–1980), particularly in studies used to generate predictive data regarding the expected effects of accidental human occupational exposure to radiation. The bulk of these studies were only partly reported in the primary literature, despite providing vital information regarding the effects of radiation exposure on a model mammalian species. Herein we review this literature and summarize the biological effects in relation to the isotopes used and the method of radionuclide exposure. Overall, these studies demonstrate the wide range of developmental and physiological effects of exposure to radiation and radionuclides in a mid‐sized mammal.

Measurement of Indoor Thoron Gas Concentrations Using a Radon-Thoron Discriminative Passive Type Monitor: Nationwide Survey in Japan

As part of a nationwide survey of thoron (220Rn) in Japan, the indoor 220Rn gas concentrations in 940 dwellings were measured throughout one year, from 1993 to 1996, using a passive type 222Rn-220Rn discriminative monitor. The monitor was placed in a bedroom or a living room in each house for four successive three-month periods. The mean annual indoor 220Rn concentration was estimated from the four measurements in each house. The arithmetic mean, the median and the geometric mean for indoor 220Rn concentrations in 899 dwellings were 20.1, 9.6 and 10.0 Bq m-3, respectively. The 220Rn concentrations exhibited a log-normal distribution. It was found that the 220Rn concentrations were dependent on the nature of the materials used for wall construction and also on the distance of measurement from the wall. Significant seasonal variations in the 220Rn concentration were not observed. It would seem that the nature of the wall material contributed to the increased indoor 220Rn concentrations.

Radiation-Induced Sarcoma of the Head and Neck Following Radiotherapy for Nasopharyngeal Carcinoma: A Single Institutional Experience and Literature Review

Background and Objective

Radiotherapy (RT) is the primary treatment option for nasopharyngeal carcinoma (NPC), but it is associated with radiation-induced sarcomas (RISs). This study aims to investigate clinicopathological features and head and neck RIS prognosis after NPC RT.

Methods

The medical and radiological records of the NPC patients (n =14,074) referred to Zhejiang Cancer Hospital, Hang Zhou, China between January 1995 and December 2018 were retrospectively reviewed. Among them, 22 patients were determined to have RIS after RT for NPC. The clinicopathological data, diagnosis, treatment, and follow-up results of 22 patients with RIS were analyzed in this retrospective research. All 22 patients underwent surgery as the main treatment. The levels of Overall Survival (OS) were determined through the Log-rank test and Kaplan-Meier method.

Results

Among these patients, 13 were males and nine females with the male/female ratio of 1.44:1. The age during the primary RT of NPC ranged from 25 to 61 years old (median age: 37 years old). Patients' ages ranged from 33 to 73 years old (median age: 52.5 years old) when diagnosed with RIS. The latency period for development of the RIS was between 3 and 36 years (median: 8.5 years) after RT. In this cohort, R0 resection was achieved in 13 cases, R1 resection in five cases, and R2 resection in four cases. During the follow-up period ranged from 2 to 102 months (median 14 months), 15 patients had died of the disease. Kaplan-Meier method showed that the 2-year, 3-year, and the 5-year cumulative OS rate was 50.3, 43.2, and 14.4%, respectively. The median survival time was 34 months. Surgical resection with R0 resection achieves a significantly better prognosis (P = 0.012). Patients under the age of 37 years old at the time of initial RT had a relatively better prognosis (P = 0.035).

Conclusions

Although the incidence of RIS after RT of NPC is generally low, the treatment of RIS is very difficult. The RISs are associated with poor overall prognosis. R0 resection can improve the prognosis thus it should be considered as the primary and optimal choice for the treatment of RIS.

Characteristics of Thoron (220Rn) and Its Progeny in the Indoor Environment

The present paper outlines characteristics of thoron and its progeny in the indoor environment. Since the half-life of thoron (²²⁰Rn) is very short (55.6 s), its behavior is quite different from the isotope radon (²²²Rn, half-life 3.8 days) in the environment. Analyses of radon and lung cancer risk have revealed a clearly positive relationship in epidemiological studies among miners and residents. However, there is no epidemiological evidence for thoron exposure causing lung cancer risk. In contrast to this, a dosimetric approach has been approved in the International Commission on Radiological Protection (ICRP) Publication 137, from which new dose conversion factors for radon and thoron progenies can be obtained. They are given as 16.8 and 107 nSv (Bq m^-3 h)^-1, respectively. It implies that even a small quantity of thoron progeny will induce higher radiation exposure compared to radon. Thus, an interest in thoron exposure is increasing among the relevant scientific communities. As measurement technologies for thoron and its progeny have been developed, they are now readily available. This paper reviews measurement technologies, activity levels, dosimetry and resulting doses. Although thoron has been underestimated in the past, recent findings have revealed that reassessment of risks due to radon exposure may need to take the presence of thoron and its progeny into account.

A Review of the Occurrence of Alpha-Emitting Radionuclides in Wild Mushrooms

Alpha-emitting radioisotopes are the most toxic among all radionuclides. In particular, medium to long-lived isotopes of the heavier metals are of the greatest concern to human health and radiological safety. This review focuses on the most common alpha-emitting radionuclides of natural and anthropogenic origin in wild mushrooms from around the world. Mushrooms bio-accumulate a range of mineral ionic constituents and radioactive elements to different extents, and are therefore considered as suitable bio-indicators of environmental pollution. The available literature indicates that the natural radionuclide 210Po is accumulated at the highest levels (up to 22 kBq/kg dry weight (dw) in wild mushrooms from Finland), while among synthetic nuclides, the highest levels of up to 53.8 Bq/kg dw of 239+240Pu were reported in Ukrainian mushrooms. The capacity to retain the activity of individual nuclides varies between mushrooms, which is of particular interest for edible species that are consumed either locally or, in some cases, also traded on an international scale. The effective radiation dose from the ingestion of this food can reportedly range from 0.033 µSv/kg dw to 26.8 mSv/kg and varies depending on the country. Following pollution events, such consumption may expose consumers to highly radiotoxic decay particles produced by alpha emitters.

The origin of the elements: a century of progress

This review assesses the current state of knowledge of how the elements were produced in the Big Bang, in stellar lives and deaths, and by interactions in interstellar gas. We begin with statements of fact and discuss the evidence that convinced astronomers that the Sun is fusing hydrogen, that low-mass stars produce heavy elements through neutron capture, that massive stars can explode as supernovae and that supernovae of all types produce new elements. Nucleosynthesis in the Big Bang, through cosmic ray spallation, and in exploding white dwarfs is only ranked below the above facts in certainty because the evidence, while overwhelming, is so far circumstantial. Next, we highlight the flaws in our current understanding of the predictions for lithium production in the Big Bang and/or its destruction in stars and for the production of the elements with atomic number [Formula: see text]. While the theory that neutron star mergers produce elements through neutron-capture has powerful circumstantial evidence, we are unconvinced that they produce all of the elements past nickel. Also in dispute is the exact mechanism or mechanisms that cause the white dwarfs to explode. It is difficult to determine the origin of rare isotopes because signatures of their production are weak. We are uncertain about the production sites of some lithium and nitrogen isotopes and proton-rich heavy nuclei. Finally, Betelgeuse is probably not the next star to become a supernovae in the Milky Way, in part because Betelgeuse may collapse directly to a black hole instead. The accumulated evidence in this review shows that we understand the major production sites for the elements, but islands of uncertainty in the periodic table exist. Resolving these uncertainties requires in particular understanding explosive events with compact objects and understanding the nature of the first stars and is therefore primed for new discoveries in the next decades. This article is part of the theme issue 'Mendeleev and the periodic table'.

Changing Emotions About Fukushima Related to the Fukushima Nuclear Power Station Accident-How Rumors Determined People's Attitudes: Social Media Sentiment Analysis

Background

Public interest in radiation rose after the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Station accident was caused by an earthquake off the Pacific coast of Tohoku on March 11, 2011. Various reports on the accident and radiation were spread by the mass media, and people displayed their emotional reactions, which were thought to be related to information about the Fukushima accident, on Twitter, Facebook, and other social networking sites. Fears about radiation were spread as well, leading to harmful rumors about Fukushima and the refusal to test children for radiation. It is believed that identifying the process by which people emotionally responded to this information, and hence became gripped by an increased aversion to Fukushima, might be useful in risk communication when similar disasters and accidents occur in the future. There are few studies surveying how people feel about radiation in Fukushima and other regions in an unbiased form.

Objective

The purpose of this study is to identify how the feelings of local residents toward radiation changed according to Twitter.

Methods

We used approximately 19 million tweets in Japanese containing the words “radiation” (放射線), “radioactivity” (放射能), and “radioactive substances” (放射性物質) that were posted to Twitter over a 1-year period following the Fukushima nuclear accident. We used regional identifiers contained in tweets (ie, nouns, proper nouns, place names, postal codes, and telephone numbers) to categorize them according to their prefecture, and then analyzed the feelings toward those prefectures from the semantic orientation of the words contained in individual tweets (ie, positive impressions or negative impressions).

Results

Tweets about radiation increased soon after the earthquake and then decreased, and feelings about radiation trended positively. We determined that, on average, tweets associating Fukushima Prefecture with radiation show more positive feelings than those about other prefectures, but have trended negatively over time. We also found that as other tweets have trended positively, only bots and retweets about Fukushima Prefecture have trended negatively.

Conclusions

The number of tweets about radiation has decreased overall, and feelings about radiation have trended positively. However, the fact that tweets about Fukushima Prefecture trended negatively, despite decreasing in percentage, suggests that negative feelings toward Fukushima Prefecture have become more extreme. We found that while the bots and retweets that were not about Fukushima Prefecture gradually trended toward positive feelings, the bots and retweets about Fukushima Prefecture trended toward negative feelings.

Mass Balance Study of the Engineered Cationic Antimicrobial Peptide, WLBU2, Following a Single Intravenous Dose of 14C-WLBU2 in Mice

BACKGROUND

To address multidrug resistance, we developed engineered Cationic Antimicrobial Peptides (eCAPs). Lead eCAP WLBU2 displays potent activity against drug-resistant bacteria and effectively treats lethal bacterial infections in mice, reducing bacterial loads to undetectable levels in diverse organs.

OBJECTIVE

To support the development of WLBU2, we conducted a mass balance study.

METHODS

CD1 mice were administered 10, 15, 20 and 30 mg/kg of QDx5 WLBU2 or a single dose of [14C]-WLBU2 at 15 mg/kg IV. Tolerability, tissue distribution and excretion were evaluated with liquid scintillation and HPLC-radiochromatography.

RESULTS

The maximum tolerated dose of WLBU2 is 20 mg/kg IV. We could account for greater than >96% of the radioactivity distributed within mouse tissues at 5 and 15 min. By 24h, only ~40-50% of radioactivity remained in the mice. The greatest % of the dose was present in liver, accounting for ~35% of radioactivity at 5 and 15 min, and ~ 8% of radioactivity remained at 24h. High radioactivity was also present in kidneys, plasma, red blood cells and lungs, while less than 0.2% of radioactivity was present in brain, fat, or skeletal muscle. Urinary and fecal excretion accounted for 12.5 and 2.2% of radioactivity at 24h.

CONCLUSION

WLBU2 distributes widely to mouse tissues and is rapidly cleared with a terminal radioactivity half-life of 22 h, a clearance of 27.4 mL/h/kg, and a distribution volume of 0.94 L/kg. At 2-100 μg-eq/g, the concentrations of 14C-WLBU2 appear high enough in the tissues to account for the inhibition of microbial growth.

Anther-smut fungi from more contaminated sites in Chernobyl show lower infection ability and lower viability following experimental irradiation

The long-term contamination that followed the nuclear disaster at Chernobyl provides a case study for the effects of chronic ionizing radiation on living organisms and on their ability to tolerate or evolve resistance to such radiation. Previously, we studied the fertility and viability of early developmental stages of a castrating plant pathogen, the anther-smut fungus Microbotryum lychnidis-dioicae, isolated from field sites varying over 700-fold in degree of radioactive contamination. Neither the budding rate of haploid spores following meiosis nor the karyotype structure varied with increasing radiation levels at sampling sites. Here, we assessed the ability of the same M. lychnidis-dioicae strains to perform their whole life cycle, up to the production of symptoms in the plants, that is, the development of anthers full of fungal spores; we also assessed their viability under experimental radiation. Fungal strains from more contaminated sites had no lower spore numbers in anthers or viability, but infected host plants less well, indicating lower overall fitness due to radioactivity exposure. These findings improve our understanding of the previous field data, in which the anther-smut disease prevalence on Silene latifolia plants caused by M. lychnidis-dioicae was lower at more contaminated sites. Although the fungus showed relatively high resistance to experimental radiation, we found no evidence that increased resistance to radiation has evolved in populations from contaminated sites. Fungal strains from more contaminated sites even tolerated or repaired damage from a brief acute exposure to γ radiation less well than those from non- or less contaminated sites. Our results more generally concur with previous studies in showing that the fitness of living organisms is affected by radiation after nuclear disasters, but that they do not rapidly evolve higher tolerance.

An overview on the concentration of radioactive elements and physiochemical analysis of soil and water in Iraq

In the last decade, radiation physics brought about a revolution in health science by improving scientific equipment and useful methodologies for measurement. Human beings are affected by ionizing radiations that radiate from radioactive elements. The quantity of radioactive elements is different inside and outside the earth's surface. Soil and water are exigencies of human lives which are contaminated by radioactive elements. These radioactive elements enter into the human body through drinking, eating and breathing. On reaching hazardous limits in the human body, these radioactive elements cause stomach cancer, lung cancer and leukemia. Measurement of radioactive elements in soil and water is helpful in monitoring the health issues caused by exposure to these elements. In Iraq, numerous studies about natural radioactivity, radon concentration and physiochemical parameters have been conducted by different researchers, of which most of the studies were conducted in Barsa, Nasirya, Najaf, Karbala, Baghdad, Balad, Kirkuk, Erbil, Mosul and Dohuk cities. This article aims to review and compile the studies conducted in these cities of Iraq from 2011 to 2019. In most articles, high-purity germanium (HPGe), RAD7 and CR-39 detectors are used for radioactivity and radon measurement. These cities are located in the low-high folded and Mesopotamian zones. From this study, it can be concluded that radon concentration in soil and water was greater in the Mesopotamian and lower in the low-high folded zones. Higher concentrations of natural radioactivity in water and soil were found in the low-high folded zone in Iraq. However, most of the conducted studies show that concentrations of radon and natural radioactivity are above the permissible limits recommended by the International Commission on Radiological Protection (ICRP) and World Health Organization (WHO). The values of physiochemical parameters were found to be greater in the Mesopotamian zone, but overall they are not above the permissible limits.

Theoretical Limit of the Color-Change Sensitivity of a Composite Resin Dosimeter Film Based on Spiropyran/BaFCl : Eu2+/Polystyrene

The theoretical limit of the color-change sensitivity of a composite resin dosimeter film based on 6-nitro BIPS/BaFCl : Eu2+/polystyrene under X-ray exposure has been estimated. Each photophysical and photochemical process occurring inside the composite resin dosimeter was quantitatively determined, and the obtained values were used to estimate the theoretical limit of the color-change sensitivity for the composite resin dosimeter. The values obtained were 70.6 % for the X-ray absorption efficiency, 13 % for the fluorescence quantum yield, 73.5 % for the UV absorption efficiency and 37.6 % for the photochemical quantum yield. Assuming that the figure-of-merit is their product, its value is estimated to be 2.5 %, which contributes to the chromaticity difference and leads to a color-change sensitivity of 100 mGy. The figure-of-merit of a structurally optimized composite dosimeter was estimated to be 1.9 times that of the dosimeter without structural optimization, which showed a sensitivity of 100 mGy. We predicted that the structurally optimized composite resin dosimeter film, which eliminates optical losses due to the structure, will be able to detect X-ray exposure doses on the order of approximately 28 mGy.

A Fluorescence-Based Method to Measure ADP/ATP Exchange of Recombinant Adenine Nucleotide Translocase in Liposomes

Several mitochondrial proteins, such as adenine nucleotide translocase (ANT), aspartate/glutamate carrier, dicarboxylate carrier, and uncoupling proteins 2 and 3, are suggested to have dual transport functions. While the transport of charge (protons and anions) is characterized by an alteration in membrane conductance, investigating substrate transport is challenging. Currently, mainly radioactively labeled substrates are used, which are very expensive and require stringent precautions during their preparation and use. We present and evaluate a fluorescence-based method using Magnesium Green (MgGr^TM), a Mg²⁺-sensitive dye suitable for measurement in liposomes. Given the different binding affinities of Mg²⁺ for ATP and ADP, changes in their concentrations can be detected. We obtained an ADP/ATP exchange rate of 3.49 ± 0.41 mmol/min/g of recombinant ANT1 reconstituted into unilamellar liposomes, which is comparable to values measured in mitochondria and proteoliposomes using a radioactivity assay. ADP/ATP exchange calculated from MgGr^TM fluorescence solely depends on the ANT1 content in liposomes and is inhibited by the ANT-specific inhibitors, bongkrekic acid and carboxyatractyloside. The application of MgGr^TM to investigate ADP/ATP exchange rates contributes to our understanding of ANT function in mitochondria and paves the way for the design of other substrate transport assays.

Interstitial fluid drainage from rat apical area takes place via vessels in the mandibular canal

We sought to investigate the transport route for protein-rich fluid from the apical area towards the draining lymph nodes. The first mandibular molar root canals in 24 female Wistar rats were instrumented and filled with radioactive-labelled human serum albumin. The rats were sacrificed at different intervals beginning after 10 min (time 0) and continuing up to 72 h. Three jaw segments, gingiva around the first molar, blood samples, submandibular and cervical lymph nodes were collected and analyzed for radioactivity. The starting volume of tracer (control) for all experiments was calculated from measurements at time 0. At time 0, radioactivity was only detected in the jaw segments. Within lymph nodes and serum, the tracer was found after 4 h, with the highest amount recorded in serum up to 24 h. Lymphatics were found within the mandibular canal along blood vessels and nerves and exiting via foramen mandibularis, after immunohistochemical staining in four untreated rats. Our results show tracer distribution from the apical area towards the mandibular canal in a posterior direction. The tracer washout rate was low, and the fluid was mainly absorbed into blood vessels. The lymphatics in the mandibular canal may be more important for immune cell transport than for fluid drainage.

INVESTIGATION OF RADIATION BACKGROUND IN THE MICRODISTRICTS OF KROPYVNYTSKYI USING DOSIMETER-RADIOMETER MKS-08-01 Gm «DKS-96» AND WIRELESS SENSORS

OBJECTIVE

Determine the radiation background in the Kropyvnytskyi microdistricts using the dosimeter-radiometer MKS-08-01 Gm «DKS-96» and a wireless sensor (dosimeter), analyze the measured values using the Student's t-test and create radiation background interactive map of Kropyvnytskyi microdistricts.

MATERIALS AND METHODS

Measurement of Kropyvnytskyi radiation background was carried out in two ways: using the dosimeter-radiometer MKS-08-01 Gm «DKS-96» to measure the radiation background in the Kropyvnytskyi microdis- tricts (Zavadivka (sanitary zone and observation zone), Kovalivka, Velyka Balka, Lisoparkova, Raion 5/5, Popova, Miskyi sad); using a wireless sensor (dosimeter) with a monitoring system of the area radiation situation on the basis of Wi-Fi module with a microcontroller (Lisoparkova, Zavadivka (sanitary zone and observation zone), Raion 5/5).

RESULTS AND CONCLUSIONS

Experiment results allowed us to conclude that in some microdistricts of Kropyvnytskyi increased level of radiation pollution. Evaluation of exposure for a human from technological reinforced naturally occurring radioactive sources, particularly from 238U and 222Rn is a key factor that determines the risk of cancerous pathologies in Kirovohrad region. We checked the effectiveness of our wireless sensor (dosimeter) for monitoring the radiation situation in the area. To analyze, interpret and report to the general public the results of our study, we created our own application for smartphones based on the Android operating system.