Nuclear and Radiation Safety Center

Heavy metals can be enriched in living organisms and seriously endanger human health and the ecological environment, which has evolved into a significant global environmental problem. Based on summarizing the spatial distribution of heavy metals in the environment, this review introduces heavy metal detection technologies such as inductively coupled plasma mass spectrometry/atomic emission spectrometry, atomic absorption spectrometry, atomic fluorescence spectrometry, and laser-induced breakdown spectrometry. It summarizes their respective advantages, characteristics, and applicability. Besides, atmospheric pressure discharge plasma as a potential heavy metal detection technology is also introduced and discussed in this review. The current research mainly focuses on improving the analytical performance and optimizing the practical application. Furthermore, this review not only summarizes the advantages of atmospheric pressure discharge plasma in the field of element analysis but also summarizes the principal scientific and technical problems to be solved urgently.

UNLABELLED: In this study, 27 patients less than 18 yr old with pulmonary metastases from well-differentiated thyroid carcinoma were evaluated to determine their response to (131)I therapy. METHODS: Of 121 children and adolescents treated with (131)I between 1963 and 1996, 27 patients had pulmonary metastases associated with nodal disease. Treatment response from (131)I was measured by three parameters: chest radiograph, scintigraphic images and serum thyroglobulin levels. Total activity of (131)I administered ranged from 4.6 GBq (125 mCi) to 38.7 GBq (1.05 Ci). Four patients were given one treatment, 8 were given two treatments, 4 were given three treatments and 11 were given more than three treatments. Radiation doses to the lungs were estimated in 14 patients using the MIRD methodology. The minimum duration of follow-up was 6 mo. RESULTS: At the time of initial presentation, diagnostic (131)I studies revealed bilateral radioiodine uptake in the lungs in 19 (70.4%) patients, whereas 12 (44.4%) patients had abnormal chest radiographs. One patient was lost to follow-up and was excluded from the study. Of the 26 patients studied, complete ablation of pulmonary metastases was observed in 8 (30.8%), partial ablation in 17 (65.4%) and there was no response to treatment in 1 (3.8%). Dosimetric parameters such as radioiodine uptake as a percentage of therapeutic activity, effective half-life and radiation dose delivered to the lungs were evaluated with each therapy. There was a progressive decline in each of these parameters with successive therapies. No correlation was observed between the radiation dose delivered and the response of pulmonary metastases to therapy. The number of therapies and amount of radioiodine administered had no influence on the ablation response. Of the 26 patients, 13 had a follow-up duration of less than 5 yr, 7 had 5-10 yr and 6 had more than 10 yr. One patient developed new metastases after 7 yr of diagnosis and treatment. One patient died of the disease after 4 yr. All surviving patients were asymptomatic and leading normal lives. CONCLUSION: Complete response of pulmonary metastases after (131)I therapy is difficult to achieve. A partial response with reduction of metastatic disease is possible and, in general, the patients had a good quality of life with no further disease progression and a low mortality rate.

Piezoelectric effect was first used for disinfection. In this process, hydrothermally synthesized nano/micrometer tetragonal-BaTiO3 was selected as the piezo-catalyst which was stressed by ultrasound to generate piezoelectric potential. It was found that the inactivation number of the nano/micrometer tetragonal BaTiO3 exposure or sonication alone within 180 min was 0.30 log and 0.70 log for E. coli in deionized water, respectively, while addition of 2 g tetragonal-BaTiO3 with piezo-activity in the ultrasound system resulted in a 2.72 log inactivation without the input of any additional energy, only by original ultrasound. The latter was 2.72 folds as great as the sum of the two former inactivation numbers. However, addition of cubic-BaTiO3 without piezo-activity only led to a 1.02 log inactivation. And moreover, in the process of serious physical damage and chemical oxidation of cells, substantial leakages of intracellular materials were observed. These great differences not only clearly indicated that the combination of sonication and piezocatalysis possessed a great inactivation potential but also suggested that there was a significant synergistic inactivation effect between piezocatalytic oxidation and sono-mechanical destruction.

. The modified cotton fiber could separate oil/water mixtures efficiently through a flowing system. After 10 cycles, the as-prepared cotton was still highly hydrophobic with a 6-times greater adsorption than raw cotton. By a simple modification, a low-cost, high-adsorption and environmentally friendly modified cotton could be prepared that can be considered a promising alternative to organic synthetic fibers to clean up oil spills.

Optimized lightweight, compact and high temperature sustaining shielding materials for neutron and gamma radiation were developed by genetic algorithms (GA) combined with the Monte Carlo N-Particle (MCNP) code. A series of samples were designed according to the method. Deep penetration tests by the MCNP code were completed. The results show that the designed samples have more advantages related to the radiation shielding effects in comparison with PB202 and KRAFTON-XP3, especially the Cakes with multi-layers structures of the Fe-interlayer-Pb have excellent performance. Taking into account the ratios designed of components among elements in the material, the manufacturing process of polymer with nano-TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> was studied experimentally by differential scanning calorimetry (DSC). Several samples have been tested. The attenuation experiments on the samples were carried out using tandem electrostatic accelerator neutron source, spontaneous fission neutron source of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">252</sup> Cf and gamma-rays source of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co. The experimental results verify the correctness of optimal design and craft. The Cakes are quite suitable for applications in the practices of nuclear science and technology.

A novel bayberry tannin immobilized BSA–BT-NS adsorbent with excellent adsorption capacity and high selectivity for UO₂²⁺.

Stimulus-responsive materials have great potential in advanced controllable oil/water separation applications. Here, a novel, cost-effective, and green approach is developed to produce a pH-responsive smart fabric with switchable wettability. The approach first involves grafting polydopamine (PDA) and cystamine dihydrochloride (cystamine) on a fabric surface to obtain thiol-functionalized fabric (Fabric-SH). Hydrophobic stearyl methacrylate (SMA) and pH-responsive undecylenic acid are then decorated on the Fabric-SH surface through efficient and green photoinduced thiol–ene click coupling chemistry. The obtained fabric exhibits rapidly switchable wettability between superhydrophobicity and superhydrophilicity depending on the contacting liquid pH value and can be applied in controllable separation of various mixtures of water and oil with high efficiency up to 99%. More importantly, the as-prepared fabric is able to realize the separation of oil/water/oil ternary mixtures and can self-clean and repel oil fouling during the separation process. Its superhydrophobicity is robust, showing no significant change after a 500 cycle peeling test. This novel and cost-effective smart cotton fabric exhibits significant potential in satisfying different separation purposes under complicated conditions.

Thrombosis is a leading cause of death and the development of effective and safe therapeutic agents for thrombotic diseases has been proven challenging. In this study, taking advantage of the transparency of larval zebrafish, we developed a larval zebrafish thrombosis model for drug screening and efficacy assessment. Zebrafish at 2 dpf (days post fertilization) were treated with phenylhydrazine (PHZ) and a testing drug for 24 h. Tested drugs were administered into the zebrafish either by direct soaking or circulation microinjection. Antithrombotic efficacy was quantitatively evaluated based on our previously patented technology characterized as an image analysis of the heart red blood cells stained with O-dianisidine staining. Zebrafish at 2 dpf treated with PHZ at a concentration of 1.5 μM for a time period of 24 h were determined as the optimum conditions for the zebrafish thrombosis model development. Induced thrombosis in zebrafish was visually confirmed under a dissecting stereomicroscope and quantified by the image assay. All 6 human antithrombotic drugs (aspirin, clopidogrel, diltiazem hydrochloride injection, xuanshuantong injection, salvianolate injection, and astragalus injection) showed significant preventive and therapeutic effects on zebrafish thrombosis (p < 0.05, p < 0.01, & p < 0.001) in this zebrafish thrombosis model. The larval zebrafish thrombosis model developed and validated in this study could be used for in vivo thrombosis studies and for rapid screening and efficacy assessment of antithrombotic drugs.

Ca–Mg–Al-LDH/nZVI nanocomposites showed excellent U(<sc>vi</sc>) removal performance from aqueous solutions through the coordination of reduction and adsorption reactions.

Controllably breaking the activity–selectivity trade-offs in the electrocatalytic oxygen reduction reaction to produce H 2 O 2 has long been a challenge in renewable energy technologies. Herein, by assigning the activity and selectivity requirements to two independent single-atom sites, we deliberately engineered a Co–Zn DAC for promising H 2 O 2 electrosynthesis, from which the Co sites provided the activity response for oxygen reduction, and the Zn sites regulated the reaction selectivity toward the 2e – pathway. Through multidimensional in situ characterizations, a potential-dependent switching function of the Zn sites was revealed, which made the increase in H 2 O 2 production at various reaction stages controllable. As a result, efficient H 2 O 2 selectivity switching from 11.1% in the single Co atom catalyst to 94.8% in the Co–Zn DAC was realized, with a prominent turnover frequency of 2.7 s –1 among the reported H 2 O 2 -producing catalysts. Notably, a similar effect was also observed in M–Zn DACs (M = Pt, Ru, or Ni), which demonstrated the universal switcher role of the Zn sites. The real-time catalytic site behavior insights gained through this integrated experimental and theoretical study are envisioned to be valuable not only for the ORR but also for other energy catalysis reactions involving activity–selectivity trade-off issues.

A simple fabrication program of graphene oxide (GO) membranes was developed in this work. The GO membranes exhibit ultrahigh water permeances together with high multivalent ion rejection rates.

Exploring the migration behaviors of selenium in granite is critical for the safe disposal of radioactive waste. The matrix diffusion and sorption of 75 Se(IV) (analogue for 79 Se) in granite were systematically studied to set reliable parameters in this work. Through-diffusion and batch sorption experiments were conduct with four types of Beishan granite. The magnitudes of the obtained apparent diffusion coefficient ( D a ) values are of the following order: monzogranite > granodiorite-2 > granodiorite-1, which is opposite to the sequence of the K d values obtained from both the diffusion model and batch sorption experiments. The EPMA results of the granitic flakes showed that there was no obvious enrichment of Se(IV) on quartz, microcline and albite. Only biotite showed a weak affinity for Se(IV). Macroscopic sorption behaviors of Se(IV) on the four types of granite were identical with the sequence of the granitic biotite contents. Quantitative fitting results were also provided. XPS and XANES spectroscopy data revealed that bidentate inner-sphere complexes were formed between Se(IV) and Fe(III). Our results indicate that biotite can be representative of the Se(IV) sorption in complex mineral assemblages such as granite, and the biotite contents are critically important to evaluate Se(IV) transport in granite.

PURPOSE: Identification of early radiation response genes (ERG) in human lymphocytes after gamma-irradiation by using the whole-human-genome DNA-microarrays and the evaluation of their possible role in rapid radiation biodosimetry by applying real-time quantitative polymerase chain reaction (RT-qPCR) methodology for validation in a small group of human individuals. MATERIALS AND METHODS: Whole blood from a healthy human donor was exposed at 37 degrees C to 137Cs gamma-radiations (absorbed dose: 1-4 Gy). Fifteen minutes following irradiation the lymphocytes were isolated from the blood (for 2 h at 20 degrees C) and their gene expression was investigated using the DNA-microarrays. Subsequently, 14 genes were selected and validated using the TaqMan probes based upon the RT-qPCR assay within a group of 6 human donors. RESULTS: A dose-related relative change in quantitative gene expression using the DNA-microarray assay was demonstrated in 24 of 102 genes. Up-regulation of expression was observed in 15 genes: CD69 (CD69 molecule), CDKN1A (cyclin-dependent kinase inhibitor 1A), EGR1 (early growth response 1), EGR4 (early growth response 4), FLJ35725 (chromosome 4 ORF 23), hCG2041177 (hCG - human Celera Genome), hCG1643466.2, IFN-gamma (interferon-gamma), ISG20L (interferon stimulated exonuclease gene 20 kDa - like 1), c-JUN (jun oncogene), MDM2 (mouse double minute 2), MUC5B (mucine), PLK2 (polo-like kinase 2), RND1 (rho-family GTPase 1) and TNFSF9 (tumour necrosis factor superfamily member 9). Down-regulation of expression was found in the remaining nine genes: GRIK3 (glutamate receptor ionotropic kainate 3), hCG1985174, hCG1998530, hCG2038519, OCLN (occludin), RPL10A (ribosomal protein L10a), SERHL2 (serine hydrolase-like 2), SGK3 (serum/glucocorticoid regulated kinase 3) and STARD13 (START domain containing 13). CONCLUSION: A significant correlation between absorbed radiation dose and change in relative gene expression was particularly evident for EGR1, EGR4, IFN-gamma, c-JUN and TNFSF9 (p < or = 0.05). Results warrant the further investigation of these ERG as potential biodosimetric markers.

This manuscript presents a facile paradigm for controllably developing planar-type defect-engineered metal–organic frameworks (DEMOFs) by systematically doping reductive defect linker vanillin (VAN) during the synthesis of HKUST-1.

Zeolite A with commercial quality and high removal efficiency for Sr 2+ was hydrothermally synthesized from lithium slag after mild and facile activation.

Machine learning (ML) has been extensively employed in the field of ecotoxicological research, with a notable application in predicting ecotoxicity. Typically, researchers employ chemical substance property data, environmental exposure data, and species information to predict the potential toxicity of pollutants through specific ML models and algorithms. <a>(1)</a> However, it is difficult to gather systematic collected toxicological data as they are costly and time-consuming to generate, while endless combinations of pollutant species with exposure media properties can be made. This leads to unbalanced experimental data, which often results in data sets with varying quality that are unsuitable for modeling. In fact, many modeling studies in this field lack a solid database. <a>(2)</a> In the process of applying ML for toxicity prediction, limited data and sparse learnable features are common challenges. When the available data cannot meet the requirements for model construction, this situation is termed a “small data” problem. This issue can be understood from two perspectives. First, the sample size fails to meet the minimum data requirements for ML modeling; for instance, previous studies suggested such a minimum threshold as 100 samples. <a>(3,4)</a> Second, the sample size fails to satisfy the specific needs of the modeling task. For example, when the ratio of the number of samples to the number of features is too low, the model is prone to overfitting. In such cases, even thousands of samples may still be considered small data for models with hundreds of features. In our previous literature review, most studies that achieve favorable predictions maintain a sample data-to-features ratio above 20. <a>(5,6)</a> Hence, we suggest that a ratio below 20 should be considered a sign of a small data scenario. Such limited data sets not only curtail the predictive performance of ML models but also diminish the representativeness and persuasiveness of the models. Acknowledging the difficulty of the acquisition of reliable toxicity data, there is an urgent need to develop a specific ML-based modeling process for small data samples, with the aim of improving data utilization and improving the predictive performance of models. A rapid and large-scale prediction of the ecotoxicity of chemicals and/or nanomaterials is crucial for reducing the time and cost of risk assessment, as well as minimizing animal experiments and selecting optimal testing strategies. This is also considered as a key direction in 21st century toxicology. Therefore, we believe that small data ML (SDML) methods are especially valuable when the available research data set is inadequate for applying conventional ML models. The outcomes of SDML models can also identify data gaps and help refine the plan for conducting supplementary ecotoxicity tests, thereby optimizing the allocation of limited resources. In this Viewpoint, we discuss the implementation principles, modeling processes, and challenges of SDML methods and elucidate the application of SDML methods in ecotoxicology for advancing science and technology.

In order to investigate the application of 3D base-seismic isolation system in nuclear power plants (NPPs), comprehensive analysis of constitution and design theory for 3-dimensional combined isolation bearing (3D-CIB) was presented and derived. Four different vertical stiffness of 3D-CIB was designed to isolate the nuclear island (NI) building. This paper aimed at investigating the isolation effectiveness of 3D-CIB through modal analysis and dynamic time-history analysis. Numerical results in terms of dynamic response of 3D-CIB, relative displacement response, acceleration and floor response spectra (FRS) of the superstructure were compared to validate the reliability of 3D-CIB in mitigating seismic response. The results showed that 3D-CIB can significantly attenuate the horizontal acceleration response, and a fair amount of the vertical acceleration response reduction of the upper structure was still observed. 3D-CIB plays a significant role in reducing the horizontal and vertical FRS, the vertical FRS basically do not vary with the floor height. The smaller the vertical stiffness of 3D-CIB is, the better the vertical isolation effectiveness is, whereas, it will increase the displacement and the rocking effect of superstructure. Although the advantage of 3D-CIB is that the vertical stiffness can be flexibly adjusted, it should be designed by properly accounting for the balance between the isolation effectiveness and displacement control including rocking effect. The results of this study can provide the technical basis and guidance for the application of 3D-CIB to engineering structure.

Ultrathin NiCr-LDH nanosheet arrays were prepared by hydrothermal method. It has been revealed that reduced solid–liquid interfacial tension and exposed NiO_6−x active centers enable fast formation of *OOH intermediates for efficient water oxidation.

Although lymphomas of the testicle anecdotally may be confined to that organ, in general they represent a part of the disease which is distributed widely in other parts of the body. A review of the literature and of our nine cases indicates that of those presenting initially in the testicle, the first recurrence is often in a visceral organ or in a noncontiguous lymph node region. Frequent involvement of Waldeyer's ring, the paranasal sinuses, and contralateral testicle makes this disease worthy of further study.

OH. At this condition, the PAO obtained presented the highest adsorption capability for U(vi) under experimental conditions. These results provide pivotal information on the transformation of PAO-based materials during the amidoximation process.