Latest ArticlesThe extraction complexes of uranyl(Ⅵ) in HNO3 to a hydroxyl-functionalized ionic liquid (IL) phase, HOEtmimNTf2 bearing CMPO, were investigated. Three possibly successive extraction complexes, UO2L2+ (L = CMPO), UO2L22+ and UO2L32+, were detected based on variable U/L ratios. Uranyl(Ⅵ) prefers to be extracted as complex UO2L32+, combining with the ions from HOEtmimNTf2 to construct a solid material through self-assembly. The thermodynamics of complexes, UO2L2+ (j = 1-3), were studied by spectrophotometry and microcalorimetry. All the formation reactions are principally driven by entropy, although a small part of the driving force of complexes UO2L22+ and UO2L32+ comes from enthalpy. Based on the thermodynamic properties for complex UO2L32+, we provide a possible coordination mode in HOEtmimNTf2: the first CMPO molecule coordinates with UO22+ in a bidentate fashion while the others do in a monodentate fashion. The results offer a thermodynamic insight into the formation behaviors of the uranyl(Ⅵ)/CMPO complexes involving the special IL HOEtmimNTf2, which is of significance to advance the novel IL extraction strategy.
Internal contamination of actinides has led to significant health hazards to the public and workers in the context of nuclear power plant accidents, uranium ore mining, and reprocessing of the used fuel. An effective sequestering agent that is able to remove accidentally incorporated actinides in vivo with low toxicity is always in urgent need. The molecular decorporation ligands have been the most widely researched agents for the past few decades, while preliminary studies of functionalized nanoparticles have shown their clear advantages in metal binding selectivity, toxicity, and oxidative stress alleviation. Herein, the state-of-the-art of those two types of decorporation agents is presented with special attention being paid on the correlation between the solution and solid-state chemistry of those agents with actinides and the corresponding decorporation efficacies.
A relatively new branch of science - nuclear forensics, aiming at providing the nature, origin, history and possible trafficking route of seized nuclear materials/devices, has been established and rapidly developed over decades to screen illicit nuclear activities. This highly interdisciplinary science is built upon a foundation of analytical chemistry, radiochemistry, nuclear physics, material sciences, geology, and other scientific disciplines, within which radiochemical methodologies and radioanalytical techniques play a key role. The present review provides a brief overview about the crucial aspects of nuclear forensics, including basic content, procedure, concerned elements, common separation, analytical method, and so on. The state of the art and recent progresses of nuclear forensics by research communities in China are reviewed, while selected examples and practical applications are emphasized. The challenges associated with this new area and on-going developments are highlighted and discussed.
During the chemical weathering of the uranium mill tailings, released uranium could be immobilized by the newly formed secondary minerals such as oxyhydroxides. A deeper understanding of the interaction between uranium and common oxyhydroxides under environmental conditions is necessary. In this work, uranium sorption behaviors on Al-, Mn- and Fe-oxyhydroxide minerals (boehmite, manganite, goethite, and lepidocrocite) were investigated by batch experiments. Results showed that the uranium sorption on Al-oxyhydroxide behaved significantly differently from the other three minerals. The sorption edge of the Mn- and Fe-oxyhydroxides located around pH 5, while the sorption edge of boehmite shifted about 1.5 pH unit to near neutral. The sorption isotherms of uranium on manganite, goethite and lepidocrocite at pH 5.0 could be well fitted by the Langmuir model. Instead of surface complexation, sorption on boehmite happened mainly by uranium-bearing carbonates and hydroxides precipitation as illustrated by the characterization results. Both carbonate and phosphate strongly affected the uranium sorption behavior. The removal efficiency of uranium by boehmite exceeded 98% after three sorption-desorption cycles, indicating it may be a potential material for uranium removal and recovery.
Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver, but early diagnosis and effective treatment are still difficult. With the development of radionuclide applications in medicine, nuclear medicine is playing an increasingly important role in the diagnosis and treatment of HCC. Radionuclide-based positron emission tomography-computed tomography and single-photon emission computed tomography-computed tomography molecular imaging are indispensable for assessing progression, staging, differentiation, preoperative planning, postoperative prediction, and evaluation of HCC in clinical applications. Moreover, radionuclide-based endoradiotherapy provides an objective therapeutic strategy for patients with unresectable advanced HCC. This review highlights the application and development of radionuclides in the diagnosis and treatment of HCC. More efforts are warranted for the development of advanced radionuclides to make significant contributions in the treatment of HCC.
With the rapid development of the nuclear industry, more-stringent requirements are proposed for high-level radioactive waste liquid treatment and the enrichment of isotope products. High-pressure ion exchange chromatography has been widely accepted for the fine separation of elements and nuclides due to its advantages, such as high efficiency, environmental friendliness, ease of operation, and feasibility for large-scale industrial applications. Here, we summarized the evolution of high-pressure ion exchange chromatography and the relevant research progress in ion exchange equilibrium and related separation technology. The prospects for application of high-pressure ion exchange chromatography to rare earth elements, actinide elements and isotope separation were discussed. High-pressure ion exchange chromatography represents a promising strategy for the extraction of rare earth elements and actinide elements from high-level radioactive waste liquid, as well as being an effective method for the automated production of high purity isotope products with great environmental benefits.
A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) measurement. 75Se(Ⅳ) and 75Se(Ⅵ) were prepared and used as tracers during the experiments. The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure. The parameters which affect the uptake of Se(Ⅳ) and Se(Ⅵ) on Dowex1 × 8 resin was optimized and the procedure for Se(Ⅳ) and Se(Ⅵ) separation was proposed. Both Se(Ⅳ) and Se(Ⅵ) are retained on the column in natural or alkaline solution with high distribution coefficient. The successive gradient elution of pre-concentrated species of selenium with HNO3 solution allows to differentiate between them. Se(Ⅳ) and Se(Ⅵ) finally were eluted with 0.05 mol/L HNO3 and 5.0 mol/L HNO3, respectively. The proposed method has been successfully verified using the certified reference materials (CRMs) of real water samples, and spiked recoveries for real samples were 98%-104% with 5% relative standard deviations (RSDs). The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.
Radionuclide imaging is now the premier imaging method in clinical practice for its high sensitivity and tomographic capability. Current clinically available radio imaging methods mostly use positron-emission tomography (PET) and single-photon emission computed tomography (SPECT) to detect anatomic abnormalities that conventional imaging techniques typically have challenges for visualizing. Contrast agents are indispensable for radionuclide imaging, and the radionuclide is always attached to a suitable vector that achieves targeted delivery. Nowadays, peptides have attracted increasing interest in targeting vectors of contrast agents, mainly due to their high specificity for target receptors at nanomolar concentrations and low toxicity. Radiolabeled peptide probes as kinds of PET/SPECT tracers had become essential tools for clinical radionuclide diagnosis. This review mainly summarizes radiolabeled peptide probes for bioimaging, including fundamental concepts of radiolabeled peptide probe design, some typical peptide analogs radiocontrast agents for PET, SPECT, and the combination imaging.
In this work, we proposed a new U(Ⅵ) removal strategy combining adsorption and photocatalytic reduction by the PMo12/UiO-66 heterojunctions. The PMo12 has been encapsulated in the cavities of UiO-66 by a one-step hydrothermal method, and the PMo12/UiO-66 exhibited high adsorption capacity and photocatalytic activity. The maximal theoretical sorption capacity of U(Ⅵ) on 15% PMo12/UiO-66 reached 225.36 mg/g and the photoreduction rate of 15% PMo12/UiO-66 is about thirty times as much as UiO-66. Under the light irradiation, the photogenerated electrons rapidly transport from UiO-66 to PMo12, and the photo-generated electrons could efficiently reduce the pre-enriched U(Ⅵ) to U(Ⅳ). This work provides new insights into remediation of the radioactive environment.
As one of the most common cancers in the world, hepatocellular carcinoma (HCC) has become a major threat to human health. Radioembolization is a first-line option for the treatment of HCC, especially when other conventional treatments fail or there exist some relative contraindications. Herein, we developed a facile and efficient method for preparing 177Lu-microspheres potentially useful for precise radioembolization therapy of HCC. The radiolabeling efficiency of 177Lu-microspheres was as high as 96.8% ± 0.5%, and the radiolabeling process did not alter the morphology of the mother microspheres. The SPECT/CT studies enabled by the unique emissions of 177Lu suggested that almost no 177Lu ion loaded by the microspheres was released over more than 32 d in vivo, which led to remarkable inhibition effect on the growth of HepG2 tumors subcutaneously transplanted in mice. The current approach may thus offer promising 177Lu-microspheres for clinical radioembolization of HCC.