This article investigated the kinetic studies of thorium adsorption from an aqueous solution with graphene oxide functionalized with aminomethyl phosphonic acid (AMPA) as an adsorbent. First, the AMPA-GO adsorbent was characterized using TEM, XRD, and FTIR methods. Experiments were performed in two batch and continuous modes. In batch mode, adsorption kinetics were studied in different pH (1-4), temperature (298-328 K), initial concentration (50-500 mg L-1), and dosages (0.1-2 g L-1). The results showed that thorium adsorption kinetic follows pseudo-first-order kinetic model and that the adsorption reaction is endothermic. The maximum experimental adsorption capacity of thorium ions was observed 138.84 mg g-1 at a pH of 3, adsorbent dosage of 0.5 g L-1, and a temperature of 328 K. The results showed that AMPA-GO adsorbent can be used seven times with an acceptable change in adsorption capacity. In continuous conditions, the effect of feed flow rate (2-8 mL min-1), initial concentration (50-500 mg L-1), and column bed height (2-8 cm) was investigated. The continuous data was analyzed using the Thomas, Yoon-Nelson, and Bohart-Adams models. The experimental data of the column were well matched with the Thomas, and Yoon-Nelson models. The research results showed that the use of functionalized graphene oxide adsorbents has a great ability to remove thorium from aqueous solutions.

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayası regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayası. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg-1 for 232Th, 4.21 to 13.41 Bq kg-1 for 40K, and 0.42-3.26 Bq kg-1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

This article reports the results of an investigation into the activity concentration of natural radionuclides in raw building materials for underground parking lots, together with the assessment of the radiation hazard for the public related to exposure to ionizing radiations. To this purpose, high-purity germanium (HPGe) γ-ray spectrometry was employed in order to quantify the average specific activity of 226Ra, 232Th, and 40K natural radioisotopes. With the aim to assess any possible radiological health risk for the population, the absorbed γ-dose rate (D), the annual effective dose equivalent outdoor (AEDEout) and indoor (AEDEin), the activity concentration index (I), and the alpha index (Iα) were also estimated, resulting in values that were lower than the maximum recommended ones for humans. Finally, the extent of the correlations existing between the observed radioactivity and radiological parameters and of these parameters with the analyzed samples was quantified through statistical analyses, including Pearson\'s correlation, a principal component analysis (PCA), and a hierarchical cluster analysis (HCA). As a result, three clusters of the investigated samples were recognized based on their chemical composition and mineralogical nature. Noteworthily, this paper covers a certain gap in science since its topic does not appear in literature in this form. Thus, the authors underline the importance of this work to global knowledge in the environmental research and public health fields.

Natural radioactive materials in certain conditions can get to hazardous radiological level. The aim of the present work was to evaluate the natural activity concentration from sampled building materials collected from different locations in Babadogo Estate within Nairobi City County. The analysis done using gamma ray spectrometer, which was put into action for spectral data acquisition and then analysis. The activity concentration levels of 238U, 232Th and 40K for the selected samples of building materials was measured by the use of gamma ray spectrometry method. The analyzed data compared with the standard acceptable values. The activity concentration in 40K varied from 55 ± 3 to 2647 ± 132 Bq kg-1, giving an average (sum of all values divided by 33) value of 831 ± 42 Bq kg-1; 238U varied from 39 ± 2 to 3602 ± 180 Bq kg-1, giving average figures of 378 ± 19 Bq kg-1 and 232Th ranged from 5.000 ± 0.300 to 4213 ± 211 Bq kg-1, giving average figure of 290 ± 15 Bq kg-1. The calculated average figures for activity concentration surpassed the world average values of 420, 33 and 45 Bq kg-1 in 40K, 238U and 232Th, respectively.

Crystalline organic-inorganic hybrids, which exhibit colorimetric responses to ionizing radiation, have recently been recognized as promising alternatives to conventional X-ray dosimeters. However, X-ray-responsive organic-inorganic hybrids are scarce and the strategy to fine-tune their detection sensitivity remains elusive. Herein, an unprecedented mixed-ligand strategy is reported to modulate the X-ray detection efficacy of organic-inorganic hybrids. Deliberately blending the stimuli-responsive terpyridine carboxylate ligand (tpc- ) and the auxiliary pba- group with different ratios gives rise to two OD thorium-bearing clusters (Th-102 and Th-103) and a 1D coordination polymer (Th-104). Notably, distinct X-ray sensitivity is evident as a function of molar ratio of the tpc- ligand, following the trend of Th-102 > Th-103 > Th-104. Moreover, Th-102, which is exclusively built from the tpc- ligands with the highest degree of π-π interactions, exhibits the most sensitive radiochromic and fluorochromic responses toward X-ray with the lowest detection limit of 1.5 mGy. The study anticipates that this mixed-ligand strategy will be a versatile approach to tune the X-ray sensing efficacy of organic-inorganic hybrids.

Single crystals of α-ThBr4, thorium(IV) tetra-bromide, were obtained as a side product from the reaction of CuBr with β-ThBr4 at 753 K. In the crystal structure, the Th atom (site symmetry ..) is surrounded by eight Br atoms in the form of a tetra-gonal-disphenoidal coordination polyhedron. The connectivity of these polyhedra is 3 ∞[ThBr4/2Br4/2]. In comparison with the previous crystal structure refinement [Mason et al. (1974 ▸). J. Less-Common Met. 35, 331-338], the current rerefinement resulted in much higher preciscion of the lattice parameters and the atomic coordinates.

OBJECTIVE: PSMA (prostate-specific membrane antigen) is highly expressed on prostate cancer (PrCa) cells and extensively used as a homing target for PrCa treatment. Most prominently, PSMA-targeting conjugate PSMA-617, carrying a DOTA chelator and labeled with therapeutic radionuclides like beta-emitting lutetium-177 or alpha-emitting actinium-225, has shown clinical activity in PrCa patients. We sought to develop PSMA-targeting small molecule (SMOL) conjugates that show high uptake in PSMA-expressing tumors and fast clearance, and can easily be labeled with the alpha emitter thorium-227 (half-life 18.7 days).
METHODS: A novel linker motif with improved competition against 3H-PSMA-617 on PSMA-expressing LNCaP cells was identified. A 2,3-hydroxypyridinone chelator modified with carboxyl groups (carboxy-HOPO) with increased hydrophilicity and robust labeling with thorium-227 was developed and allowed the synthesis of mono-, di-, tri-, and tetrameric conjugates. The resulting monomeric and multimeric PSMA SMOL-TTCs (targeted thorium conjugate) were evaluated for cellular binding, internalization, and antiproliferative activity. The in vivo antitumor efficacy of the PSMA SMOL-TTCs was determined in ST1273 and KUCaP-1 PrCa models in mice, and their biodistribution was assessed in cynomolgus monkeys, minipigs, and mice.
RESULTS: The monomeric and multimeric PSMA SMOL conjugates were readily labeled with thorium-227 at room temperature and possessed high stability and good binding, internalization, and antiproliferative activity in vitro. In vivo, the monomeric, dimeric, and trimeric PSMA SMOL-TTCs showed fast clearance, potent antitumor efficacy, and high uptake and retention in prostate tumors in mice. No major uptake or retention in other organs was observed beyond kidneys. Low uptake of free thorium-227 into bone confirmed high complex stability in vivo. Salivary gland uptake remained inconclusive as mini pigs were devalidated as a relevant model and imaging controls failed in cynomolgus monkeys.
CONCLUSIONS: Monomeric and multimeric PSMA SMOL-TTCs show high tumor uptake and fast clearance in preclinical models and warrant further therapeutic exploration.

This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world\'s largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.

The utilization of phosphorite deposits as an industrial resource is of paramount importance, and its sustainability largely depends on ensuring safe and responsible practices. This study aims to evaluate the suitability of phosphorite deposits for industrial applications such as the production of phosphoric acid and phosphatic fertilizers. To achieve this goal, the study meticulously examines the geochemical characteristics of the deposits, investigates the distribution of natural Radioactivity within them, and assesses the potential radiological risk associated with their use. The phosphorites are massive and collected from different beds within the Duwi Formation at the Hamadat mining area. They are grain-supported and composed of phosphatic pellets, bioclasts (bones), non-phosphatic minerals, and cement. Geochemically, phosphorites contain high concentrations of P2O5 (23.59-28.36 wt.%) and CaO (40.85-44.35 wt.%), with low amounts of Al2O3 (0.23-0.51 wt.%), TiO2 (0.01-0.03 wt.%), Fe2O3 (1.14-2.28 wt.%), Na2O (0.37-1.19 wt.%), K2O (0.03-0.12 wt.%), and MnO (0.08-0.18 wt.%), suggesting the low contribution of the detrital material during their deposition. Moreover, they belong to contain enhanced U concentration (55-128 ppm). They are also enriched with Sr, Ba, Cr, V, and Zn and depleted in Th, Zr, and Rb, which strongly supports the low detrital input during the formation of the Hamadat phosphorites. The high Radioactivity of the studied phosphorites is probably due to the widespread occurrence of phosphatic components (e.g., apatite) that accommodate U in high concentrations. Gamma spectrometry based on NaI (Tl) crystal 3×3 has been used to measure occurring radionuclides in the phosphorite samples. The results indicate that the radioactive concentrations\' average values of 226Ra, 232Th, and 40K are 184.18±9.19, 125.82±6.29, and 63.82±3.19 Bq Kg-1, respectively. Additionally, evaluations have been made of the radiological hazards. The calculated risk indicators exceeded the recommended national and world averages. The data obtained will serve as a reference for follow-up studies to evaluate the effectiveness of the Radioactivity of phosphatic materials collected from the Hamdat mine area.

There are products available on the online market that are claim to contain unique \'energies\' that can improve health and wellness by eliminating toxins and pains and energising food and drinking water. We investigated these products by alpha and gamma spectrometry, and the analysis showed that they contained a few to hundreds of kilobecquerels per kilogram of naturally occurring radionuclides from the 232Th and 238U series. The committed effective dose for an adult drinking water that had been in contact with these products just once was estimated to 12 nSv. Considering a worst-case scenario for the workers inhaling the radioactive substance, 1 d of work would result in an effective dose of 0.39 mSv. The product descriptions do not mention the radionuclide content, and concerns are raised for the consumers and workers exposed to these products with no knowledge of the radioactive content.