Latest ArticlesRadionuclide 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.
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.
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.
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.
The radionuclide (RN) migration study is not only helpful to understand environmental behavior of RNs, but also can establish the basis for the safety assessment of geological disposal of high-level radioactive waste (HLW). In the context of China's HLW disposal, this review briefly summaries the progress of China's RN migration studies over the past decade regarding three aspects, RN sorption, RN transport and radioactive colloid. Domestic studies from other disciplines (such as geology and environmental science) are also included in this review because they can provide references for the RN migration study. Overall, China has achieved clear progress in RN migration study over the past decade, although large-scaled field experiments are lacked and a gap still exists comparing with the international advanced level. Finally, several suggestions are proposed for future RN migration research in China.
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.
Separation and recovery of U(Ⅵ) and Th(Ⅳ) from rare earth minerals is a very challenging work in rare earth industrial production. In the present study, a homemade membrane emulsification circulation (MEC) extractor was used to separate U(Ⅵ) and Th(Ⅳ) from rare earth elements by using Cyphos IL 104 as an extractant. Batch experiments were carried out using a constant temperature oscillator to investigate the extraction parameters of the single element and the results indicated that Cyphos IL 104 could reach the extraction equilibrium within 30 min for all the three elements, i.e., U(Ⅵ), Th(Ⅳ), and Eu(Ⅲ). Besides, the MEC extractor possessed a strong phase separation ability. The extraction efficiencies of U(Ⅵ), Th(Ⅳ), La(Ⅲ), Eu(Ⅲ) and Yb (Ⅲ) increased with the increase of pH. La(Ⅲ), Eu(Ⅲ) and Yb(Ⅲ) were hardly extracted when pH ≤ 1.50, which was beneficial for effectively separating U(Ⅵ) and Th(Ⅳ) from La(Ⅲ), Eu(Ⅲ) and Yb(Ⅲ). In the multi-stages stripping experiments, when the stripping stage number was 3, the effective separation could be achieved by using HCl and H2SO4, since the stripping efficiency reached 80.0% and 100.0% for Th(Ⅳ) and U(Ⅵ), respectively. Slope method and FT-IR spectra showed that Cyphos IL 104 reacted with U(Ⅵ) and Th(Ⅳ) by chelation mechanism. The extraction of multi-elements indicated that U(Ⅵ) and Th(Ⅳ) could be well separated from the solution which contains all rare earth elements, and the extraction efficiencies of U(Ⅵ) and Th(Ⅳ) both were close to 100.0%. Based on the above experimental results, a flowchart for efficient separation of U(Ⅵ) and Th(Ⅳ) from rare earth elements was proposed.
Separation of the minor actinides (Am and Cm) from lanthanides in high-level liquid wastes (HLLW) is one of the most challenging chemical separation tasks known owing to their chemical similarities and is highly significant in nuclear fuel reprocessing plants because it could practically lead to sustainable nuclear energy by closing the nuclear fuel cycle. The solid phase extraction is proposed to be a possible strategy but all reported sorbent materials severely suffer from limited stability and/or efficiency caused by the harsh conditions of high acidity coupled with intense irradiation. Herein, a phenanthroline-based polymeric organic framework (PhenTAPB-POF) was designed and tested for the separation of trivalent americium from lanthanides for the first time. Due to its fully conjugated structure, PhenTAPB-POF exhibits previously unachieved stability under the combined extreme conditions of strong acids and high irradiation field. The americium partitioning experiment indicates that PhenTAPB-POF possesses an ultrahigh adsorption selectivity towards Am(Ⅲ) over lanthanides (e.g., SFAm(Ⅲ)/Eu(Ⅲ) = 3326) in highly acidic simulated HLLW and relatively fast adsorption kinetics in both static and dynamic experiments. Am(Ⅲ) can be almost quantitatively eluted from the PhenTAPB-POF packed-column using a concentrated nitric acid elution. The high stability and superior separation performance endow PhenTAPB-POF with the promising alternative for separating minor actinides over lanthanides from highly acidic HLLW streams.
In this work, a technique was proposed to prepare UO2 from UO3 by the two processes of fluorination reaction of UO3 with NH4HF2 and electrochemical reduction of UO22+ for the recycle uranium. The feasibility of fluorination reaction was firstly confirmed using thermodynamic calculation; then, the products were analyzed using XRD, Raman and fluorescence to be UO2F2. The fluorination mechanism was inferred to be UO3(s) + NH4HF2 → (NH4)3UO2F5→ NH4(UO2)2F5 → UO2F2. The redox behavior of UO22+ on W electrode was investigated by cyclic voltammetry and square wave voltammetry, which indicated that UO22+ was reduced to UO2 via a two-step single electron transfer with diffusion-controlled. The diffusion coefficient of UO22+ was calculated to be 6.22 × 10−5 cm2/s. The disproportionation reaction of UO22+ was observed, and the relationship between the disproportionation reaction and scan rate was discussed. Moreover, the electrochemical fabrication of UO2 was conducted by electrolysis at −0.8 V, and the product was analyzed by XRD, SEM and EDS to be UO2. ICP-AES results showed that the extraction efficiency of UO2 could reach 98.53%.
A process for actinide(Ⅲ) and lanthanum(Ⅲ) extraction separation from high-level liquid waste (HLLW) was proposed, with N,N,N',N'-tetraoctyl diglycolamide (TODGA) as the extractant, tri-n‑butyl phosphate (TBP) as the phase modifier and 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl]pyridine (PyTri-Diol or PTD) as hydrophilic stripping agent. This 'hot test' was successfully carried out, achieving 99.92% removal of americium-241 (241Am) with a separation factor SF(Eu/Am) of 3.8 × 103 in the actinide(Ⅲ) product solution. The results show that bisamide podand extractants can effectively realize the extraction and separation of actinide(Ⅲ) and lanthanum(Ⅲ) from Chinese commercial HLLW and thus have a bright practical application potential for the treatment of commercial HLLW.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
