| 1. |
- Duan, Dongban, et al.
(författare)
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Gadolinium Neutron Capture Reaction-Induced Nucleodynamic Therapy Potentiates Antitumor Immunity
- 2023
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Ingår i: CCS Chemistry. - : Chinese Chemical Society. - 2096-5745. ; 5:11, s. 2589-2602
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Tidskriftsartikel (refereegranskat)abstract
- A nuclear reaction-induced dynamic therapy, denoted as nucleodynamic therapy (NDT), has been invented that triggers immunogenic cell death and successfully treats metastatic tumors due to its unexpected abscopal effect. Gadolinium neutron capture therapy (GdNCT) is binary radiotherapy based on a localized nuclear reaction that produces high-energy radiations (e.g., Auger electrons, γ-rays, etc.) in cancer cells when 157Gd is irradiated with thermal neutrons. Yet, its clinical application has been postponed due to the poor ability of Auger electrons and γ-rays to kill cells. Here, we engineered a 157Gd-porphyrin framework that synergizes GdNCT and dynamic therapy to efficiently produce both •OH and immunogenic 1O2 in cancer cells, thereby provoking a strong antitumor immune response. This study unveils the fact and mechanism that NDT heats tumor immunity. Another unexpected finding is that the Auger electron can be the most effective energy-transfer medium for radiation-induced activation of nanomedicines because its nanoscale trajectory perfectly matches the size of nanomaterials. In mouse tumor models, NDT causes nearly complete regression of both primary and distant tumor grafts. Thus, this 157Gd-porphyrin framework radioenhancer endows GdNCT with the exotic function of triggering dynamic therapy; its application may expand in clinics as a new radiotherapy modality that utilizes GdNCT to provoke whole-body antitumor immune response for treating metastases, which are responsible for 90% of all cancer deaths.
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| 2. |
- Li, Junyi, et al.
(författare)
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Formation and stability of studtite in bicarbonate-containing waters
- 2023
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- Studtite and meta-studtite are the only two uranyl peroxides found in nature. Sparsely soluble studtite has been found in natural uranium deposits, on the surface of spent nuclear fuel in contact with water and on core material from major nuclear accidents such as Chernobyl. The formation of studtite on the surface of nuclear fuel can have an impact on the release of radionuclides to the biosphere. In this work, we have experimentally studied the formation of studtite as function of HCO3- concentration and pH. The results show that studtite can form at pH = 10 in solutions without added HCO3-. At pH <= 7, the precipitate was found to be mainly studtite, while at 8 = pH = 9.8, a mixture of studtite and meta-schoepite was found. Studtite formation from UO22+ and H2O2 was observed at [HCO3-] <= 2 mM and studtite was only found to dissolve at [HCO3-] > 2 mM.
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| 3. |
- Wang, Guangwei, et al.
(författare)
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Co-hydrothermal carbonization of polyvinyl chloride and pyrolysis carbon black for the preparation of clean solid fuels
- 2024
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 361
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Tidskriftsartikel (refereegranskat)abstract
- Large quantities of polyvinyl chloride (PVC) and waste tires generated daily have the disadvantage of high content of harmful elements. They cannot be directly applied to blast furnace ironmaking. In this study, Cl in PVC and Zn in pyrolysis products of waste tires (pyrolysis carbon black, CB) were effectively removed by co-hydrothermal carbonization (co-HTC). The results indicated the dechlorination and dezincification efficiencies of co-HTC were improved by 2.78 % and 64.69 %, respectively, compared to HTC. Compositional analysis shows that the ash content of co-HTC is reduced by at least 7.67 % compared to conventional HTC. The hydrochar produced by co-HTC has an higher heating value (HHV) ranging from 30.67 to 34.13 MJ/kg. Results of physical and chemical characteristics analysis showed increasing the proportion of CB can reduce the C–H and -CHCl- functional groups and improve the carbon orderliness of the hydrochar. Combustion characteristics and kinetic analyses show that the combustibility of hydrochar increases with an increase in the proportion of PVC added to the co-HTC. The thermal stability and activation energy of the hydrochar increase with the addition of CB. Overall, this study has removed major harmful elements from PVC and CB through co-HTC, converting both into high-quality solid fuels that can be utilised in blast furnace ironmaking.
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| 4. |
- El Jamal, Ghada, et al.
(författare)
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H2O2-Induced Oxidative Dissolution of UO2 in Saline Solutions
- 2021
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-1948 .- 1099-0682. ; 2021:40, s. 4175-4182
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Tidskriftsartikel (refereegranskat)abstract
- H2O2 is one of the oxidants responsible for driving the process of radiation-induced dissolution of spent nuclear fuel in geological repositories for spent nuclear fuel. As the groundwater composition will vary depending on geographical location as well as on the age of the repository (in relation to glacial cycles, etc.), it is important to elucidate the impact of different groundwater constituents. While several studies have addressed the impact of HCO3− and halide ions on the radiation chemistry of water in general and radiation-induced oxidative dissolution of spent nuclear fuel in particular, very few studies have addressed the impact of halide ions on the mechanism of the reaction between H2O2 and UO2. In this work, the impact of Cl−, Br− and ClO4− on the mechanism and kinetics of H2O2-induced oxidative dissolution of UO2-powder in aqueous suspensions with and without added HCO3− has been studied experimentally. The experiments reveal both ionic strength effects and specific ion effects on the kinetics of the reactions involved. These are discussed in connection to the results.
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| 5. |
- El Jamal, Ghada, et al.
(författare)
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How inorganic anions in groundwater influence the mechanism of oxidativedissolution of nuclear fuels in geological repositories in case of barrier failure.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- H2O2 has previously been shown to be the main oxidant responsible for driving the process of radiation-induced dissolution of spent nuclear fuel in geological repositories for spent nuclear fuel. As the groundwater composition will vary depending on geographical location as well as on the age of the repository (in relation to glacial cycles, etc.), it is important to elucidate the impact of different groundwater constituents. While several studies have addressed the impact of HCO3- and halide ions on the radiation chemistry of water in general and radiation-induced oxidative dissolution of spent nuclear fuel in particular, very few studies have addressed the impact of halide ions on the mechanism of the reaction between H2O2 and UO2. In this work, the impact of Cl-, Br- and ClO4- on the mechanism and kinetics of H2O2-induced oxidative dissolution of UO2-powder in aqueous suspensions with and without added HCO3- has been studied experimentally. The experiments show that for systems containing 10 mM HCO3- and an initial H2O2-concentration of 0.15 mM, the presence of 1 M Cl-, Br- or ClO4- does not influence the kinetics of the reaction. At higher initial H2O2-concentrations, the presence of 1 M Br- appears to increase the rate of H2O2 consumption as well as the rate of UO22+ release. In solutions without added HCO3-, the presence of 1 M Cl-, Br- or ClO4- has an impact on the overall kinetics of the process at all initial H2O2-concentrations. This is partly attributed to an ionic strength effect enhancing adsorption of UO22+ to UO2 and partly attributed to stabilization of soluble uranyl-peroxo complexes mainly by Cl- and Br-.
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| 6. |
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| 7. |
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| 8. |
- Jiang, Chao, et al.
(författare)
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An interpretable framework of data-driven turbulence modeling using deep neural networks
- 2021
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Ingår i: Physics of fluids. - : AIP Publishing. - 1070-6631 .- 1089-7666. ; 33:5
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Tidskriftsartikel (refereegranskat)abstract
- Reynolds-averaged Navier-Stokes simulations represent a cost-effective option for practical engineering applications, but are facing ever-growing demands for more accurate turbulence models. Recently, emerging machine learning techniques have had a promising impact on turbulence modeling, but are still in their infancy regarding widespread industrial adoption. Toward their extensive uptake, this paper presents a universally interpretable machine learning (UIML) framework for turbulence modeling, which consists of two parallel machine learning-based modules to directly infer the structural and parametric representations of turbulence physics, respectively. At each phase of model development, data reflecting the evolution dynamics of turbulence and domain knowledge representing prior physical considerations are converted into modeling knowledge. The data- and knowledge-driven UIML is investigated with a deep residual network. The following three aspects are demonstrated in detail: (i) a compact input feature parameterizing a new turbulent timescale is introduced to prevent nonunique mappings between conventional input arguments and output Reynolds stress; (ii) a realizability limiter is developed to overcome the under-constrained state of modeled stress; and (iii) fairness and noise-insensitivity constraints are included in the training procedure. Consequently, an invariant, realizable, unbiased, and robust data-driven turbulence model is achieved. The influences of the training dataset size, activation function, and network hyperparameter on the performance are also investigated. The resulting model exhibits good generalization across two- and three-dimensional flows, and captures the effects of the Reynolds number and aspect ratio. Finally, the underlying rationale behind prediction is explored.
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| 9. |
- Li, Junyi, et al.
(författare)
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Exploring the Change in Redox Reactivity of UO2 Induced by Exposure to Oxidants in HCO3– Solution
- 2023
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 62:19, s. 7413-7423
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the possible change in UO2 surface reactivity after exposure to oxidants is of key importance when assessing the impact of spent nuclear fuel dissolution on the safety of a repository for spent nuclear fuel. In this work, we have experimentally studied the change in UO2 reactivity after consecutive exposures to O2 or γ-radiation in aqueous solutions containing 10 mM HCO3-. The experiments show that the reactivity of UO2 toward O2 decreases significantly with time in a single exposure. In consecutive exposures, the reactivity also decreases from exposure to exposure. In γ-radiation exposures, the system reaches a steady state and the rate of uranium dissolution becomes governed by the radiolytic production of oxidants. Changes in surface reactivity can therefore not be observed in the irradiated system. The potential surface modification responsible for the change in UO2 reactivity was studied by XPS and UPS after consecutive exposures to either O2, H2O2, or γ-radiation in 10 mM HCO3- solution. The results show that the surfaces were significantly oxidized to a stoichiometric ratio of O/U of UO2.3 under all the three exposure conditions. XPS results also show that the surfaces were dominated by U(V) with no observed U(VI). The experiments also show that U(V) is slowly removed from the surface when exposed to anoxic aqueous solutions containing 10 mM HCO3-. The UPS results show that the outer ultrathin layer of the surfaces most probably contains a significant amount of U(VI). U(VI) may form upon exposure to air during the rinsing process with water prior to XPS and UPS measurements.
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| 10. |
- Li, Junyi, et al.
(författare)
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Meta-studtite stability in aqueous solutions. Impact of HCO3-, H2O2and ionizing radiation on dissolution and speciation
- 2021
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 50:19, s. 6568-6577
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Tidskriftsartikel (refereegranskat)abstract
- Two uranyl peroxides meta-studtite and studtite exist in nature and can form as alteration phases on the surface of spent nuclear fuel upon water intrusion in a geological repository. Meta-studtite and studtite have very low solubility and could therefore reduce the reactivity of spent nuclear fuel toward radiolytic oxidants. This would inhibit the dissolution of the fuel matrix and thereby also the spreading of radionuclides. It is therefore important to investigate the stability of meta-studtite and studtite under conditions that may influence their stability. In the present work, we have studied the dissolution kinetics of meta-studtite in aqueous solution containing 10 mM HCO3-. In addition, the influence of the added H2O2 and the impact of γ-irradiation on the dissolution kinetics of meta-studtite were studied. The results are compared to previously published data for studtite studied under the same conditions. 13C NMR experiments were performed to identify the species present in aqueous solution (i.e., carbonate containing complexes). The speciation studies are compared to calculations based on published equilibrium constants. In addition to the dissolution experiments, experiments focussing on the stability of H2O2 in aqueous solutions containing UO22+ and HCO3- were conducted. The rationale for this is that H2O2 was consumed relatively fast in some of the dissolution experiments.
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