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This study examined the distributions of radon and its parent radionuclides 226Ra and 238U in groundwater samples from the Singhbhum region, Jharkhand, India. Radon showed a heterogeneous spatial distribution pattern, with a lognormal distribution. A good correlation between radon bubbler-Lucas cells and liquid scintillation counting techniques was observed for radon monitoring. 222Rn and 226Ra were negatively correlated with pH, suggesting the mobilization of radionuclides at low pH. Uranium was positively correlated with common ions (e.g., Ca, Mg, and SO42−). The activity ratios among the radionuclides indicated disequilibrium, with 222Rn origin controlled by parent radionuclide activity in bedrock. The 226Ra and 238U concentrations in groundwater were lower than the limits recommended by the WHO. [ABSTRACT FROM AUTHOR]

Radon-222 concentrations in drinking water samples, collected from four sites, with known concentrations, located in Troine, Hoffelt and Hachiville (Luxembourg) and Sainte Adèle source (Belgium) have been found about 111.2, 90.4, 86.0, and 83.7 Bq l−1 respectively. The samples have been analysed by six laboratories using gamma-ray spectrometry, emanometry and liquid scintillation counting. The performance of the participating laboratories and their measurements were evaluated with respect to the consensus value using statistical tests. The obtained results indicate that all measurement system used as well as methods to measure radon-222 in water are good and comply to the European directive. [ABSTRACT FROM AUTHOR]

In this study tritium exposure was assessed through urine samples analysis by the determination of tritium concentration and effective dose of selected 25 laboratory radiation workers in non-nuclear power plant (non-NPP) facility and 15 people of general public in Jakarta. The samples were mixed with activated charcoal, filtered, and distilled before analysis using liquid scintillation counter. It is revealed that the concentration of tritium levels in urine varied substantially depending not only on the job category but also their water intake, metabolism, and environment. These findings are important as reference data for evaluating the radiological impact on the population from future tritium contamination in Indonesia. [ABSTRACT FROM AUTHOR]

With the aim of assessing the radiological impact on public health from water consumption, tritium and gross α-β radioactivity levels were determined in tap and bottled drinking water consumed in Singapore using ultra-low level liquid scintillation counting. Tritium and gross α activities were < MDA values, while gross β activity levels varied between 0.228 and 0.258 Bq/L in tap water samples. For bottled drinking water, the activity concentrations of tritium, gross α and gross β ranged from < MDA–1.59 Bq/L, < MDA–0.437 Bq/L and < MDA–1.33 Bq/L respectively. The annual total effective doses were also estimated for both children and adults due to intake of radionuclides from consumption of tap and bottled water. Our results showed that consumption of tap and bottled water presents insignificant radiological risk to the Singapore population. [ABSTRACT FROM AUTHOR]

In this study, a method for selective separation of 63Ni and 55Fe with simultaneous wash-out of 60Co was developed. Purification of 63Ni and 55Fe was carried out using a chelating ion-exchange resin Chelex 100. The elaborated procedure was applied for aqueous and stainless steel matrices. Average recoveries were around 80% for both isotopes, confirmed by ICP-MS and LSC measurements. 60Co, interfering with the isotopes spectra in the same energy range, was washed-out from the system prior to 63Ni and 55Fe separation. The most important advantages over existing methods are short separation time (c.a. 8 h), application of a single chromatographic column and overall simplicity. [ABSTRACT FROM AUTHOR]

The growing concern over micropollutants in aquatic ecosystems motivates the development of electrochemical membrane reactors (EMRs) as a sustainable water treatment solution. Nevertheless, the intricate interplay among adsorption/desorption, electrochemical reactions, and byproduct formation within EMR complicates the understanding of their mechanisms. Herein, the degradation of micropollutants using an EMR equipped with carbon nanotube membrane are investigated, employing isotope-labeled steroid hormone micropollutant. The integration of high-performance liquid chromatography with a flow scintillator analyzer and liquid scintillation counting techniques allows to differentiate hormone removal by concurrent adsorption and degradation. Pre-adsorption of hormone is found not to limit its subsequent degradation, attributed to the rapid adsorption kinetics and effective mass transfer of EMR. This analytical approach facilitates determining the limiting factors affecting the hormone degradation under variable conditions. Increasing the voltage from 0.6 to 1.2 V causes the degradation dynamics to transition from being controlled by electron transfer rates to an adsorption-rate-limited regime. These findings unravels some underlying mechanisms of EMR, providing valuable insights for designing electrochemical strategies for micropollutant control. Pervasive micropollutants in aquatic environments pose significant threats to global water supply safety. Here, authors achieved permeate concentrations below the detection limit (2.5 ng/L) using a CNT-based electrochemical membrane, with the contributions of adsorption and degradation distinguished. [ABSTRACT FROM AUTHOR]

Studying groundwater renewal time is a valuable tool to deepen the comprehension of sustainable groundwater resources specific to arid regions. Tritium is a radioactive isotope of hydrogen often used as an environmental tracer to study groundwater renewal time. The present work reports groundwater renewal times by the environmental tracer tritium to understand sustainable water resources in arid regions. First, groundwater samples were collected from wells in northeastern arid regions of Saudi Arabia. Then, an electrolysis process was employed to significantly increase the tritium level from twenty-five to thirty times the original concentration. Subsequently, the enriched water was analyzed using a liquid scintillation counter under optimized measurement conditions to determine the tritium concentration precisely. Two internationally recognized tritium laboratories conducted independent assessments to validate the estimated tritium levels. The verified tritium concentration was then used to estimate the groundwater renewal time using the Morgenstern and Pimenta curves. The results suggest that most of the monitored wells in the surveyed areas are more than a century old. Conversely, a few monitoring wells exhibit renewal times of several hundred years and may be considered nonrenewable water sources. These studies help to understand the geochemical characteristics of arid regions to ensure the sustainable management and protection of groundwater resources. [ABSTRACT FROM AUTHOR]

Yttrium-90 (90Y) microsphere radioembolization is a promising internal therapy for treatment of hepatic tumors. Development of a precise method for measuring the activity of 90Y in blood samples is needed to facilitate preclinical safety assessment of drugs. This paper presents the development of a triple-to-double coincidence ratio (TDCR) Cherenkov counting method for quantifying blood 90Y activity. The impact of heating temperature and the quantities of nitric acid and H2O2 on wet oxidation of blood were studied for rapid sample preparation. Elevated heating temperatures and the addition of concentrated nitric acid expedited blood decolorization and effectively suppressed chemiluminescence interference. The addition of H2O2 also accelerated blood decomposition while mitigating sample color quenching. The digested samples were counted using a Hidex 300SL liquid scintillation counter for 5 minutes, and a minimum detectable activity of 0.31 kBq/L was achieved with the region of interest (ROI) analysis window set at 80–300 channels. The method was validated using whole blood samples spiked with varying activities of 90Y in the range of 3.37–51.15 kBq/L. [ABSTRACT FROM AUTHOR]

Carbon-14 and tritium are important radionuclides to be present in gaseous effluents of some nuclear power plants types. Tritium being usually included in gaseous effluents bearing carbon-14, the influence of its presence in the analyzes to be done must carefully be taken into account. When Liquid Scintillation Counting method is used, this influence can't be completely eliminated by selecting different channels only for measuring carbon-14. In this paper, experimental verification of the influence of tritium on the carbon-14 measurements also miscibility of samples, detection efficiency and measurement precision were studied. [ABSTRACT FROM AUTHOR]

The Centers for Disease Control and Prevention (CDC) Radiation Laboratory's primary mission is to provide laboratory support for an effective and efficient response to public health radiological emergencies. The laboratory has developed methods for several radiological threat agents, including Iridium-192 (Ir-192). Ir-192 can be analyzed via its gamma energy through analytical methods such as High Purity Germanium (HPGe) and its beta energy through Liquid Scintillation Counting (LSC). In this work, we present and compare HPGe and LSC rapid response methods for Ir-192 quantification. Both methods show the reasonable results and can be used in emergency situations. [ABSTRACT FROM AUTHOR]

The liquid scintillation counting based triple to double coincidence ratio (TDCR) method is a widely employed, direct activity determination technique to standardize pure beta emitters. An "FPGA-based standalone, portable TDCR system" is developed for absolute activity measurement of pure beta-emitting radionuclides. The system has a local 7″ touchscreen display to provide an intuitive GUI for operating the standalone instrument. The portable system will boost the capabilities of users in the field by providing a reference measurement method of radionuclide metrology. In nuclear medicine, the portable system will enable them to calibrate short-lived radionuclides within the dose-administering facility and avoid transporting radioactive sources to standardizing laboratories. The system's performance is evaluated by comparing the activity determination results of 14C, 204Tl and 147Pm radionuclides with the ones from the CIEMAT/NIST method. The comparison shows that the activity measurement results from the system are closely aligned with those obtained using the CIEMAT/NIST method within the uncertainty limits. In this paper, the system's performance evaluation is presented. [ABSTRACT FROM AUTHOR]

A cost-effective method for uranium measurements in soil, utilizing a Liquid Scintillation Counter with an extraction system and alpha/beta discrimination, has been developed. The study explores the method's applicability and validity in assessing uranium levels in soil and yellowcake samples. The scintillation cocktail achieves high capacity, ensuring 100% counting efficiency and a 98.6% extractive yield, with a 0.929 mg/g detection limit. Validation involves estimating uranium concentrations in certified reference materials and ore samples from different Jordanian locations. The results are comparable to measurements obtained through gamma spectroscopy, ICP-MS, and alpha spectroscopy techniques. [ABSTRACT FROM AUTHOR]

The aim of this study was to test two potential tritium determination methods (with and without electrolysis enrichment) suitable for low-level measurements. Both methodologies were applied to water samples from the Baltic Sea and ten Polish rivers providing new data on tritium activity concentration. Optimization steps carried out to the standard method lowered minimum detectable activity concentration (MDC) from 3.1 to 1.8 Bq L–1 (at 95% confidence level) enabling to apply it to environmental water samples. However, electrolytic enrichment method of MDC of 0.20 Bq L–1 provided more accurate results for tritium activity concentration in surface waters. [ABSTRACT FROM AUTHOR]

In this work the distribution coefficients (D) of polonium between 0.1 mol dm−3 TOPO/toluene; TOPO/cyclohexane; TBP/toluene and TBP/cyclohexane and aqueous solutions of inorganic acids (HCl, HNO3, H2SO4 and H3PO4) were determinated. The molarities of inorganic acids were between 0.5 and 12.0 mol dm−3. The activity of extracted Po-209 was measured by means of liquid scintillation counting. The best result was obtained for TOPO/toluene and 2 mol dm−3 H2SO4 system (D = 62 ± 9). The most stable conditions of extraction were found for TOPO/toluene-HCl system. [ABSTRACT FROM AUTHOR]

Among natural radionuclides, 226Ra and 228Ra intake can contribute considerably to radiological dose. Liquid scintillation counting offers a reliable and sensitive method for measurement in environmental (water) and biological (urine) matrices. While the determination of 226Ra in water is quite simple, its determination in urine requires a suitable radiochemical procedure. In both cases an indirect measurement of daughter 222Rn (with 218Po and 214Po) in secular equilibrium allows to determine 226Ra activity. Moreover, in presence of anthropogenic radionuclides, a sequential separation of 228Ra and 90Sr in water has been developed, isolating daughters 228Ac and 90Y in secular equilibrium in the same vial. [ABSTRACT FROM AUTHOR]

Environmental radiochemistry is a key pillar of the education of nuclear engineering students and young professionals. Teaching the fundamentals of this multidisciplinary field is best performed also through well-designed hands-on experiments. A simple and fast radiochemical procedure has been developed to determine uranium in tap water by liquid scintillation counting. The proposed method provides reliable and repeatable results, with accuracy and precision within 5%. It can be proficiently executed by undergraduate students, who have appreciated the engagement and got acquainted with standard analysis protocols, from sample collection and manipulation to radiometric measure and data analysis. [ABSTRACT FROM AUTHOR]

The inflammatory corpuscle recombinant absents in melanoma 2 (AIM2) and cholesterol efflux protein ATP binding cassette transporter A1(ABCA1) have been reported to play opposing roles in atherosclerosis (AS) plaques. However, the relationship between AIM2 and ABCA1 remains unclear. In this study, we explored the potential connection between AIM2 and ABCA1 in the modulation of AS by bioinformatic analysis combined with in vitro experiments. The GEO database was used to obtain AS transcriptional profiling data; screen differentially expressed genes (DEGs) and construct a weighted gene co-expression network analysis (WGCNA) to obtain AS-related modules. Phorbol myristate acetate (PMA) was used to induce macrophage modelling in THP-1 cells, and ox-LDL was used to induce macrophage foam cell formation. The experiment was divided into Negative Control (NC) group, Model Control (MC) group, AIM2 overexpression + ox-LDL (OE AIM2 + ox-LDL) group, and AIM2 short hairpin RNA + ox-LDL (sh AIM2 + ox-LDL) group. The intracellular cholesterol efflux rate was detected by scintillation counting; high-performance liquid chromatography (HPLC) was used to detect intracellular cholesterol levels; apoptosis levels were detected by TUNEL kit; levels of inflammatory markers (IL-1β, IL-18, ROS, and GSH) were detected by ELISA kits; and levels of AIM2 and ABCA1 proteins were detected by Western blot. Bioinformatic analysis revealed that the turquoise module correlated most strongly with AS, and AIM2 and ABCA1 were co-expressed in the turquoise module with a trend towards negative correlation. In vitro experiments demonstrated that AIM2 inhibited macrophage cholesterol efflux, resulting in increased intracellular cholesterol levels and foam cell formation. Moreover, AIM2 had a synergistic effect with ox-LDL, exacerbating macrophage oxidative stress and inflammatory response. Silencing AIM2 ameliorated the above conditions. Furthermore, the protein expression levels of AIM2 and ABCA1 were consistent with the bioinformatic analysis, showing a negative correlation. AIM2 inhibits ABCA1 expression, causing abnormal cholesterol metabolism in macrophages and ultimately leading to foam cell formation. Inhibiting AIM2 may reverse this process. Overall, our study suggests that AIM2 is a reliable anti-inflammatory therapeutic target for AS. Inhibiting AIM2 expression may reduce foam cell formation and, consequently, inhibit the progression of AS plaques. [ABSTRACT FROM AUTHOR]

Cannabidiol is a major component of cannabis but without known psychoactive properties. A wide range of properties have been attributed to it, such as anti-inflammatory, analgesic, anti-cancer, anti-seizure and anxiolytic. However, being a fairly new compound in its purified form, little is known about cannabidiol brain entry, especially during development. Sprague Dawley rats at four developmental ages: embryonic day E19, postnatal day P4 and P12 and non-pregnant adult females were administered intraperitoneal cannabidiol at 10 mg/kg with [3H] labelled cannabidiol. To investigate the extent of placental transfer, the drug was injected intravenously into E19 pregnant dams. Levels of [3H]-cannabidiol in blood plasma, cerebrospinal fluid and brain were estimated by liquid scintillation counting. Plasma protein binding of cannabidiol was identified by polyacrylamide gel electrophoresis and its bound and unbound fractions measured by ultrafiltration. Using available RNA-sequencing datasets of E19 rat brain, choroid plexus and placenta, as well as P5 and adult brain and choroid plexus, expression of 13 main cannabidiol receptors was analysed. Results showed that cannabidiol rapidly entered both the developing and adult brains. Entry into CSF was more limited. Its transfer across the placenta was substantially restricted as only about 50% of maternal blood plasma cannabidiol concentration was detected in fetal plasma. Albumin was the main, but not exclusive, cannabidiol binding protein at all ages. Several transcripts for cannabidiol receptors were expressed in age- and tissue-specific manner indicating that cannabidiol may have different functional effects in the fetal compared to adult brain. [ABSTRACT FROM AUTHOR]

Presently several beta emitting radionuclides are in use as brachytherapy sources, due to their inherent advantages of short-range radiation dose delivery compared to their gamma emitting counterparts. 90Y is one of the well-known hard beta-emitting radioisotopes for the therapeutic application of radioactivity. Among various other modalities, 90Y resin microsphere as a brachytherapy source has its application for liver cancer. In the present study, 90Y was recovered from 235,238U,239Pu(nfast,f)90Sr(β−)90Y using Sr selective crown ether followed by quick purification using the Ion Chromatography technique. The purified 90Y was labelled in strong cation exchange resin to form 90Y resin microsphere. Various quality control parameters, e.g., water solubility, chemical, radionuclidic purity, and half-life, were verified using Gamma spectrometry, Cerenkov, and Liquid Scintillation Counting techniques. The obtained half-life was 64.05 h, which is in excellent agreement with the literature and is indirect evidence of the very high radionuclidic purity of the sample. A rapid method for the synthesis of 90Y resin microsphere brachytherapy source is being reported for the first time after its recovery from irradiated fast reactor fuel dissolver solution. After the separation of 90Sr along with trace level impurities inside the hot cell, simultaneous purification of parent 90Sr and daughter 90Y using single-stage Ion Chromatography step takes 15–25 min only in comparison to 24 h or more time using multistage conventional Ion exchange chromatography column, which saves the separation time and in turn, increase the yield of 90Y per separation campaign. [ABSTRACT FROM AUTHOR]

Liquid Scintillation Counting (LSC) gross alpha/beta screening is a valuable tool for providing rapid laboratory response for the analysis of human clinical urine samples during a large-scale radiation incident event. Verification of method performance, as required for clinical laboratory testing, is accomplished by the evaluation of routine, periodic measurements of radioactive spiked samples for quality control, performance testing, and accuracy checks. Radionuclide stability of alpha and beta emitters in urine for LSC analysis is an important consideration. The purpose of this work is to demonstrate optimal preparations and storage conditions of samples used for method verification. [ABSTRACT FROM AUTHOR]

A purification method is developed to determine 90Sr in radioactive waste. A separation based on Sr-resin® with a pretreatment using TRU-resin® provides satisfactory Sr recovery yields before the 90Sr measurement by liquid scintillation counting (LSC) regardless the analyzed samples with low or high activity level. The selectivity of the procedure is checked by measuring the 90Y ingrowth after different days of separation without waiting for secular equilibrium. In order to obtain a REACH compliant method without scintillation cocktails, a plastic scintillation resin selective for Sr is implemented on the basis of the developed protocol. The optimized method is applied successfully to representative nuclear waste including samples with high Pu content (effluents, concretes and sludges). [ABSTRACT FROM AUTHOR]

Background and Objective: Lenacapavir (LEN) is a novel, first-in-class, multistage, selective inhibitor of human immunodeficiency virus type 1 (HIV-1) capsid function recently approved for the treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection. The purpose of this multicohort study was to evaluate the pharmacokinetics, metabolism, excretion, safety, and tolerability of LEN following a single intravenous (IV) infusion of 10 mg LEN or 20 mg [14C]LEN in healthy participants. Methods: Twenty-one healthy adult participants were enrolled into the study and received either a single IV dose of 10 mg LEN (n = 8 active, n = 3 placebo; cohort 1) or a single IV dose of 20 mg [14C]LEN containing 200 µCi (n = 10; cohort 2). Blood, urine, and feces samples (when applicable) were collected after dosing, and radioactivity (cohort 2) was assessed using liquid scintillation counting in both plasma and excreta. LEN in plasma was quantified by liquid chromatography (LC) tandem mass spectroscopy (MS/MS) method bioanalysis. Metabolite profiling in plasma and excreta were performed using LC-fraction collect (FC)-high-resolution MS and LC-FC-accelerator mass spectrometry in plasma. Results: Between the 10 mg and 20 mg doses of LEN, the observed plasma exposure of LEN doubled, while the elimination half-life was similar. Following administration of 20 mg [14C]LEN (200 µCi), the mean cumulative recovery of [14C] radioactivity was 75.9% and 0.24% from feces and urine, respectively. The mean whole [14C] blood-to-plasma concentration ratio was 0.5–0.7, which showed a low distribution of LEN to red blood cells. Intact LEN was the predominant circulating species in plasma (representing 68.8% of circulating radioactivity), and no single metabolite contributed to > 10% of total radioactivity exposure through 1176 h postdose. Similarly, intact LEN was the most abundant component (32.9% of administered dose; 75.9% of recovered dose) measured in feces, with metabolites accounting for trace amounts. These results suggest metabolism of LEN is not a primary pathway of elimination. Of the metabolites observed in the feces, the three most abundant metabolites were direct phase 2 conjugates (glucuronide, hexose, and pentose conjugates), with additional metabolites formed to a lesser extent via other pathways. The administered LEN IV doses were generally safe and well-tolerated across participants in this study. Conclusions: The results of this mass balance study indicated that LEN was majorly eliminated as intact LEN via the feces. The renal pathway played a minor role in LEN elimination (0.24%). In addition, no major circulating metabolites in plasma or feces were found, indicating minimal metabolism of LEN. [ABSTRACT FROM AUTHOR]

This study was conducted to confirm the Cs-137 and Sr-90 adsorption properties of illite. In the experimental method, illite was added to Cs-137 and Sr-90 solutions and stirred. And Following the completion of the adsorption reaction, the solid/liquid phase was separated using a centrifuge, and the adsorption rate was calculated by measuring the radioactivity concentration of the separated liquid phase using a gamma nuclide analyzer, Liquid Scintillation Count (LSC). As a result of the experiment, after reacting for 30 min, 94% of Cs-137 was adsorbed. And 84.26% of Sr-90 was adsorbed. [ABSTRACT FROM AUTHOR]

This article discusses tritium concentrations in monthly precipitation in part of the Difficult-to-Return Zone in Namie Town during 2012–2021. The tritium concentrations, which were measured with a low background liquid scintillation counter after carrying out an enrichment procedure, fluctuated seasonally from 0.10 ± 0.02 to 0.85 ± 0.02 Bq L−1. This range of concentrations is concluded to not be unusual based on comparisons with the concentrations at other sites and estimates of the past range of the concentrations. Moreover, no significant variations in observed tritium concentrations were observed due to decommissioning work at the Fukushima Dai-ichi Nuclear Power Plant. These results contribute to understanding the background level of tritium concentration in precipitation before the oceanic discharge of treated water from the Fukushima plant. In addition, this article evaluates the amount of tritium supplied to the ocean by terrestrial rainwater pouring into the Pacific Ocean via Ukedo River, which flows through Namie Town; this information will contribute to the discussion on the impact of the oceanic discharge of treated water. [ABSTRACT FROM AUTHOR]

As a part of radiation emergency response, a rapid method for estimation of gross-α and gross-β activities in urine samples using liquid scintillation counting technique was standardized and validated using spiked urine samples. Effect of various storage conditions such as temperature, storage time and use of preservatives on estimation of gross-α and gross-β activities was investigated systematically. Measurement results revealed that urine samples either should be stored at lower temperatures (≤ 5 °C) or should be acidified with 1% v/v HCl for quantification of gross-α and gross-β activities with bias ≤ 10%. [ABSTRACT FROM AUTHOR]

This article presents two newly developed radiochemical procedures for the destructive analysis of niobium plates irradiated in the core of water-water energetic nuclear reactor (WWER), as well as determination of the specific activity of the generated during the irradiation metastable isotope 93mNb. The procedures were developed and tested using standard samples containing 93mNb and 94Nb. Measurements were made by low energy gamma spectrometry (LEGS) and liquid scintillation counting (LSC) and the obtained data were verified by interlaboratory comparison. All the results were compared with the calculated ones to confirm and evaluate the accuracy and superiority of the two measurement methods. [ABSTRACT FROM AUTHOR]

Background and Objective: Trofinetide is the first drug to be approved for the treatment of Rett syndrome, a neurodevelopmental disorder. The purpose of the study is to fully characterize the metabolic and excretion profiles of trofinetide in humans. Methods: This Phase 1, open-label, single-dose trial conducted in healthy male adults was designed to characterize the pharmacokinetics of trofinetide (absorption, metabolism, and excretion), mass balance of [14C]-trofinetide, and safety profile of trofinetide following administration of an oral 12-g dose administered as a mixture of trofinetide and [14C]-trofinetide. Blood, urine, and fecal samples were collected at prespecified timepoints. The pharmacokinetics of trofinetide were assessed in blood and urine samples using high-performance liquid chromatography (HPLC) with tandem mass spectrometric detection. Bioanalysis of radioactivity was conducted in blood, plasma, urine, and fecal samples using liquid scintillation counting. Metabolite profiling was conducted in blood, plasma, urine, and fecal samples using HPLC with liquid scintillation counting of chromatographic fractions. Safety and tolerability, including treatment-emergent adverse events (TEAEs), were assessed. Results: Blood concentration-time profiles of trofinetide and total radioactivity were almost superimposable up to ~12 h after dosing. Urine concentration-time profiles of trofinetide and total radioactivity were similar. Trofinetide was rapidly absorbed into the circulation with an initial rapid decline (half-life [t½] alpha ~2.6 h), followed by a relatively slow terminal elimination phase (t½ beta ~20 h). The blood-to-plasma total radioactivity ratios were 0.529–0.592, indicating a lack of affinity for the cellular portion of blood. Renal excretion accounted for 83.8% of the administered radiochemical dose; 15.1% was recovered in feces. Urine and fecal recovery of radioactivity accounted for 99% of the administered dose at 168 h after dosing. Parent [14C]-trofinetide was the major radiolabeled entity in blood and plasma (88.4% and 93.1% in area under the concentration–time curves from 0 to 12 h [AUC0–12] in pooled blood and plasma samples, respectively) and the major entity excreted in urine (91.5% in 0–48-h pooled urine samples) and in feces (52.7% in 0–192-h pooled fecal samples). Only small levels of metabolites were present. In blood and plasma, only two minor metabolites were identified (each metabolite ≤ 2.24% of the AUC0–12 pool). These two metabolites were also observed in urine and fecal samples (≤ 2.41% of dose). In feces, one additional metabolite (0.84% of dose) was identified. Two mild TEAEs were reported in two participants and were not considered related to trofinetide. There were no clinically meaningful changes in individual laboratory parameters, vital signs, physical findings, or electrocardiogram results. Conclusions: Metabolic and excretion profiles confirm that trofinetide undergoes minimal hepatic or intestinal metabolism and is primarily excreted unchanged in the urine. Trofinetide containing radiolabeled [14C]-trofinetide was well tolerated. Plain Language Summary: Trofinetide is the first approved treatment for Rett syndrome, a rare genetic condition that affects brain development. Study aims were to look at how a single oral dose of trofinetide is absorbed into the bloodstream, to see whether trofinetide's chemical structure is changed once in the body, and to see how trofinetide and any metabolites (chemically altered trofinetide) are removed from the body. Safety and tolerability of trofinetide were also assessed. Eight healthy adult men took a single oral 12-g dose administered as a mixture of 14C-radiolabeled and nonlabeled trofinetide. Researchers collected blood, urine, and stool samples at regular intervals for up to 10 days postdose to measure levels of trofinetide and its metabolites. Trofinetide was rapidly absorbed (time to maximum concentration was 2 h postdose) and was primarily present in the blood as the unaltered compound. Concentrations decreased rapidly during the first 24 h postdose and more slowly thereafter. Most of the dose was recovered in urine with a lower amount in stool samples (83.8% and 15.1% of the radiochemical dose, respectively). Total recovery in urine and stool samples was 99%, primarily as the chemically unaltered compound. Only low levels of three trofinetide metabolites were detected. Two metabolites were found in blood, urine, and stool samples, while one metabolite was found in stool samples only. Two mild treatment-emergent adverse events, considered to be unrelated to trofinetide, were reported. In summary, trofinetide is rapidly absorbed, minimally metabolized, and mainly removed from the body in the urine as the unchanged drug. [ABSTRACT FROM AUTHOR]

Radon (222Rn) is radium's immediate radioactive decay product (226Ra) in the uranium decay series. Radon is classified as a group 1 carcinogen due to its hazard to human health, and the evaluation of radon concentrations has become essential. Therefore, an advanced method was applied to a liquid scintillation counter (Hidex 300SL) to measure the radon concentration in groundwater. The estimated radon concentration was between 0.1 and 3.20 Bq/L, with an average of 0.96 Bq/L and with a standard deviation of 0.82 Bq/L. The estimated radon concentrations are in the safe range recommended by the United States Environmental Protection Agency (USEPA) and European Atomic Energy Community (EAEC). However, the values are far below the safe range set by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCARE), European Commission (EC), and World Health Organization (WHO) standards. Nevertheless, the estimated radon concentration by this advanced application ensured no risk of radon exposure from the groundwater of the tested area. [ABSTRACT FROM AUTHOR]

The present study is an attempt to assess the radiogenic quality of groundwater on the basis of gross α, gross β and tritium (3H or H-3) activities in the Bakreswar-Tantloi geothermal region of Chotanagpur Plateau, West Bengal and Jharkhand, India. The aforesaid parameters in groundwater samples were measured using liquid scintillation counting triple to double coincidence ratio (LSC-TDCR) technique. Groundwater samples collected from Bakreswar-Tantloi geothermal region show gross α activities from below the minimum detectable activity (BMDA) to 0.5 ± 0.05 Bq/L, gross β activities from BMDA to 0.2 ± 0.01 Bq/L and H-3 activities from BMDA to 63.42 Bq/L. The average gross α, gross β and H-3 activities are also within the permissible limits prescribed by the World Health Organization (WHO). Though the annual effective doses in some samples were higher than the reference dose level of 0.1 mSv, the overall result suggests that the groundwater in the Bakreswar-Tantloi geothermal region is radiologically safe considering the radionuclides covered in this study. [ABSTRACT FROM AUTHOR]

Strontium-90 emits beta-particles and decays into yttrium-90. At this time, the beta-particles released affect a human body, and liquid scintillation counting is used to detect such beta-particles. In general, cocktail method that mixes samples and liquid scintillators is used in conventional liquid scintillator counters. In the cocktail method, the degree of miscibility or solubility between samples and scintillators, precipitation phenomena, etc. reduce the reproducibility of the experiment. A new method for measuring beta-particles after separating samples and scintillators from each other is presented. In addition, several experiments are conducted to investigate the efficiency and tendency of the new method. [ABSTRACT FROM AUTHOR]

Intrinsic 40 K radioactive backgrounds from impurities of natural K in liquid scintillation cocktails have previously been demonstrated to limit their use in ultra-sensitive applications. This work explores two methodologies in parallel for the reduction of 40 K backgrounds in the cocktails, and lays the groundwork for use in ultra-sensitive applications. In one method, alternative low-K liquid scintillation matrix constituents were identified and in the other, a simple purification method for single components and finished cocktails was developed. Both methods were verified via ICP-MS analysis. Liquid scintillation counting of selected purified cocktails demonstrated background reduction, improved stability, and enhanced performance. The best performing purified cocktail was also counted on a custom-built ultra-low background liquid scintillation counter, with results below the detector background. [ABSTRACT FROM AUTHOR]

Rapid detection and quantification of gross alpha/beta-emitting radionuclides by liquid scintillation counting (LSC) is vital in guiding response to a nuclear or radiological incidents. Liquid scintillation counters use signal pulse shape to discriminate alpha and beta events in samples but require precise optimization to minimize the spillover, or misclassification, of those events. In this study, samples at varying activity levels were analyzed by LSC to determine the effect of activity level, emitter type, and sample matrix on spillover. Analysis proved a matrix effect and a direct correlation of activity level on spillover percentage for both alpha and beta emitting-nuclides. [ABSTRACT FROM AUTHOR]

These levels include an activity-based prescription with patient-averaged dosimetry, an activity-based prescription with patient-specific dosimetry and, a dosimetry-based prescription and post-therapy dosimetry verification. In those documents, time of medical physicists for an outpatient therapy of thyrotoxicosis with [ SP 131 sp I]I-NaI, an in-patient therapy of differentiated thyroid carcinoma with [ SP 131 sp I]I-NaI and for a complex therapy, such as therapies with [ SP 131 sp I]I-mIBG, SP 177 sp Lu or SP 90 sp Y, are reported. It was concluded that in the UK, most medical physics groups are well equipped to provide a simple form of dosimetry service, but in most cases refrain to perform dosimetry routinely by "lack of clinical evidence and practice" and that more complex dosimetry will require additional staffing. Whole-body dosimetry using a portable radiation detector in the treatment of neuroblastoma wi... In treatments of neuroblastoma with [ SP 131 sp I]I-mIBG, patients often spend several days in the treatment room for radiation-protection purposes [[29]]. [Extracted from the article]

In the present work, an ion exchange-based radionuclides removal method for the treatment of radioactive laboratory organic liquid waste was developed. The removal of radionuclides was accomplished with the combined action of an in-house developed chelating type polystyrene based weakly acidic cation exchange resin and oxalic acid complexant. The efficacy of the method was investigated based on the results of gamma spectrometry, liquid scintillation counting and alpha spectrometry. The radioactive organic liquid waste treatment was demonstrated finally through column mode of separation method for nearly 1 Litre of the waste. [ABSTRACT FROM AUTHOR]

In this study, gross alpha and gross beta activities in 14 bottled mineral waters in Morocco were measured by Liquid Scintillation Counting following the standard method ISO 11704:2018. Method verification was carried out using standard approaches to confirm the performance parameters of the method, being used routinely in our laboratory. Gross alpha and gross beta activities lie between minimum < DL (below detection limit) and maximum 0.211 ± 0.015 and 0.151 ± 0.008 Bq L− 1 respectively. No significant correlation was found between activities and total dissolved salts (TDS) contents, ranging from 141 to 2078 mg L− 1. [ABSTRACT FROM AUTHOR]

This study presented the determination and distribution of 210Pb in plants using Liquid Scintillation Counting. The analysis method of 210Pb in plants has been improved by optimizing the pulse shape analysis setup,constructing quenched correction curves, as well as consideration of the counting from both 210Pb and its progeny 210Bi. This method was used to test for the determination of 210Pb in samples of three species collected from two sites around a uranium mining facility. [ABSTRACT FROM AUTHOR]

A sensitive method for determination of low-level tritium in seawater samples was established by enrichment of tritium from large volume of seawater using electrolysis and ultra-low level liquid scintillation counting measurement. A constant and optimal overall measurement efficiency of tritium was obtained by controlling the electrolysis conditions and optimizing the measurement parameters. A detection limit of this method of 0.45 TU for tritium was achieved using 700 mL seawater samples, which enables to determine tritium in most of seawater except for some deep seawater. The developed method has been applied for determination of tritium in the East China Sea. [ABSTRACT FROM AUTHOR]

In this study, tritium levels in some water sources frequently used by the public in the Bursa province were investigated using Liquid Scintillation Counter. The minimum detectable activity concentration (MDA) for the employed method was established at 1.31 Bq/L. The mean tritium concentration for the 21 samples was calculated as 2.05 ± 0.47 Bq/L (17.36 ± 3.98 TU). Additionally, the annual effective dose rates and lifetime cancer risk values associated with the consumption of the studied water samples were calculated. The results show that consumption of these water samples does not pose a health risk to individuals in terms of tritium radioisotope. [ABSTRACT FROM AUTHOR]

A rapid radiochemical separation method was developed for the assessment of uranium in urine using indigenously synthesised amidoximated crosslinked polyacrylonitrile (ACPAN) adsorbent. The synthesised adsorbent exhibited a high uranium adsorption capacity for urine samples conditioned at pH 2. The reusability of the ACPAN adsorbent was demonstrated by its stable adsorption capacity for ultra-trace levels of uranium over multiple cycles. The standardized method complied ANSI 13.30 radio bioassay performance criteria, validating the suitability of this novel technique for precise determination of uranium in urine. The method developed is rapid, sensitive, and can be applied for emergency bioassay of uranium in urine. [ABSTRACT FROM AUTHOR]

Purpose: SHC014748M is a potent, novel selective PI3Kδ isoform inhibitor and is proposed for the treatment of non-Hodgkin lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma. This study investigated the pharmacokinetics, mass balance, metabolism and excretion of SHC014748M in Chinese male subjects following a single oral dose of 150 mg (100 μCi) [14C] SHC014748M. Methods: Six healthy Chinese male subjects administrated an oral suspension of 150 mg (100 μCi) [14C] SHC014748M and the samples of blood, urine and feces were collected for measuring. Liquid chromatography–tandem mass spectrometry and liquid scintillation counter were utilized to obtain mass balance and the pharmacokinetic data. Results: The median Tmax for [14C]-radioactivity was 1.6 ± 0.5 h after the oral administration of [14C] SHC014748M and the mean Cmax was 3863 ± 354 ng Eq./mL in plasma, while the mean Cmax, t1/2 values and AUC0–∞ values for total radioactivity in whole blood were 2466 ± 518 ng Eq./mL, 32.2 ± 30.5 h and 66,236 ± 44,232 h * ng Eq./mL, respectively. Fecal excretion was proposed as the predominant elimination route, accounting for a mean of 90.68 ± 11.38% of the administered dose, whereas the mean urine excretion was 6.00 ± 1.48% within 336 h post-dose. The proposed major metabolic pathway of [14C] SHC014748M in the human body were as follows: (I) monooxidation, (II) glucuronide acid conjugation, and (III) monoxide–hydrogenation. Conclusions: SHC014748M was absorbed, metabolized and excreted with unchanged SHC014748M as its main circulating component in plasma following oral administration. In addition, it was speculated that fecal excretion was the principal excretion pathway; meanwhile, monohydroxy, glucuronide conjugation, oxygen, and hydrogenation were the major clearance pathways of SHC014748M through urine and/or feces. Trial registration: The trial registration number: CTR20202505. [ABSTRACT FROM AUTHOR]

This study was the first to determine the effectiveness of radon concentration measurement in water using the degassing method as a screening method based on the liquid scintillation counter method. The degassing method used two radon monitors (AlphaGUARD and RAD7) and two monitor-attached degassing devices (AquaKIT and RAD H2O). These were effective screening methods based on the WHO guideline value of 100 Bq L−1. The screening values confirmed that a combination of the AlphaGUARD and AquaKIT was preferred. The results are useful for radon measurement for exposure control in drinking water and environmental in-situ field measurement. [ABSTRACT FROM AUTHOR]

Recently developed direct LSC method for the biogenic fraction determination in biodiesel samples was evaluated. Intercomparison samples had the unknown composition of biomaterials/fossil fuels and a broad range of quench levels. Reliable results were obtained with the direct two-step LSC method for the samples with a quench level of roughly 50 channels above the SQP(E) limit of the method's applicability. The Internal Standard method for the detection efficiency determination provided better accuracy, additionally lowering the SQP(E) limit of the method's applicability. The adapted two-step method's calibration via Internal Standard technique was tested on samples with sunflower seed biocomponent. [ABSTRACT FROM AUTHOR]

Introduction: Mefuparib (CVL218) is a novel second-generation poly-ADP-ribose polymerase (PARP) inhibitor for cancer treatment. CVL218 can easily enter the brain. However, the transport mechanism by which CVL218 crosses the blood–brain barrier (BBB) is unknown. Methods: (1) [14C] CVL218 metabolism in rats was traced by a liquid scintillation counter and oxidative combustion. (2) Metabolic profiles and metabolites were identified by UHPLC-β-RAM/UHPLC-Fraction Collector and UHPLC-Q Exactive Plus MS. (3) The partition coefficient Kp,uu,brain value was simulated by two strategies. One strategy was using ACD and GastroPlus Software based on the results of intravenous administration pharmacokinetics and plasma protein-binding studies. The reliability was confirmed by comparison with another strategy (brain/plasma distribution study). Results: (1) Rapid drug elimination was observed 24 h after intragastric administration. The total cumulative excretion in urine and feces within 168 h accounted for 97.15% of the dose. The cumulative radioactive dose recovery in bile was 41.87% within 72 h. The drug-related substances were extensively distributed to the tissues within 48 h. (2) M8 was the major metabolite in plasma, urine, feces and bile. (3) CVL218 exhibited high brain protein-binding rate (88.16%). The Kp,uu,brain value (8.42) simulated by the simple software strategy was similar to that of the brain/plasma distribution study (7.01). Conclusions: CVL218 is a fast-metabolizing drug and is mainly excreted in feces. The B/P ratio prediction and observation data for CVL218 were consistent. Furthermore, the Kp,uu,brain value indicated that penetration through the BBB might be mediated by uptake transporters. [ABSTRACT FROM AUTHOR]

The long-lived fission product 151Sm (T1/2 ≈ 90 y) present in archived dissolved Trinity nuclear test debris samples was analyzed using liquid scintillation counting and the results were compared to the expected values based upon historical analysis results. The measured 151Sm activities were found to agree with the expected values within experimental error. This demonstration validates the use of this technique in situations where the sample is too old for traditional shorter half-life radioactive fission product signatures such as 99Mo (T1/2 = 2.75 d), 97Zr (T1/2 = 16.7 h), 147Nd (T1/2 = 10.98 d), and 153Sm (T1/2 = 46.3 h), or too dilute for determining fissions through stable isotope ratio measurements. [ABSTRACT FROM AUTHOR]

Dissolved fission product samples were analyzed using advanced radio-emission spectroscopy techniques using a proof-of-concept instrument. Reduction factors of 2–7 in the minimum detectable activity relative to traditional gamma counting were observed for trace fission products and actinides. A gamma-gamma coincidence detector was combined with a custom liquid scintillation counter to evaluate the benefits of alpha and beta coincident and anti-coincident analysis. The improvements observed in the detection sensitivity of fission products and actinides achieved by combining time-correlated radiation signatures is of value to applications such as nuclear physics, environmental monitoring, reactor releases, and nuclear forensics. [ABSTRACT FROM AUTHOR]

The performance of LSC cocktails in ultra-sensitive applications was evaluated. Backgrounds from radioactive contaminations in commercially available and in-house developed liquid scintillation cocktails were measured and compared to the predicted background levels of the ultra-low background liquid scintillation counter. Through the ICP-MS assay of the cocktails and their constituents, potassium impurities in the surfactant component were identified as a significant source of background, potentially limiting the use of LSC counting in ultra-sensitive applications. This work lays the groundwork for future research towards ultrapure LSC cocktails for ultrasensitive LSC counting. [ABSTRACT FROM AUTHOR]

It was concluded from two European wide proficiency tests that the gross alpha/beta methods used for drinking water analysis have fundamental pitfalls regardless of the specific gross-counting methods. The majority of gross-counting methods suffer from serious trueness and repeatability issues. To replace inaccurate gross activity measurements an alternative rapid radionuclide specific screening procedure for water analysis is proposed. This procedure considers liquid scintillation counting, alpha-particle- and gamma-ray spectrometry. The proposed procedure is more robust and can achieve lower uncertainties than gross-counting methods. Furthermore, qualitative and quantitative analytical data can be obtained with turnaround times comparable to the gross-counting methods. [ABSTRACT FROM AUTHOR]

In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine liquid scintillation counting measurements. The NPE are added in the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)—list of amendments to Annex XIV, as chemicals which can't be used anymore (Commission Regulation (EU) 2017/999). Nine NPE-free cocktails were bought from different producers and investigated with respect to the homogeneity, background level and influence on counting efficiency for different radionuclides. Several sample matrices were considered for direct measurement of 3H and 14C. Based on this study we could select the best cocktail which fulfills our requirements for routine analyses. [ABSTRACT FROM AUTHOR]

Determination of fraction of biogenic component in liquid fuels by a direct radiocarbon measurement in liquid scintillation counter (direct-LSC method) has been validated by participation in the international intercomparison exercise. All the results for samples with the standard quench parameter SQP(E) value above ≈ 650 were accepted. Highly quenched sample of used edible oil was diluted with the 14C-free petroleum ether to optimize the region of applicability. It was established that quantitative results were obtained for SQP(E) values above 700, while in the SQP(E) region between 700 and 600 only the qualitative results of fbio can be taken. [ABSTRACT FROM AUTHOR]

This work shows a study of the effect of the non-uniformity of photocathode response on the energy resolution of plastic scintillators optimized for pulse-shape discrimination. The studies were performed with Hamamatsu R7600U-200 and R9779 photomultiplier tubes. The pulse-height and pulse-shape spectra were obtained for a small piece of radon-222 loaded plastic scintillator positioned at different places on the photocathode. We show that alpha spectra can be approximated well with a normal distribution if the non-uniformity of the photon response of the photocathode is minimized. In the cases when the non-uniformity cannot be minimized, we propose an analytical function which describes the shape of the alpha peaks well under a variety of conditions. A possible effect of the non-uniformity of the photocathode response on the primary activity measurements by liquid scintillation counting is highlighted. [ABSTRACT FROM AUTHOR]