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An analysis of sintered uranium dioxide has been conducted using a hyperspectral camera sensitive to short-wave infrared wavelengths in the range 949–2472 nm. Three groups of sintered UO 2 nuclear fuel pellets were prepared and analysed, with stable sub-group surrogates introduced at the preparation stage to emulate the presence of fission product elements. Results show a clear, consistent, and reproducible spectral response across the pellet groups for pure UO 2 . Furthermore, the addition of fission product elements is observed to affect the shortwave infrared response, causing an overall flattening of the spectra. We have shown that this spectral change is correlated significantly with the presence of lanthanides in the fuel matrix. This result could have important potential in post-irradiation examination for quantifying nuclear fuel burn-up and radiotoxicity at discharge, as the hyperspectral imaging setup allows multiple (> 20) samples to be analysed in a single image, captured in under 30 s.

Photodynamic therapy (PDT) is a light triggered therapy by producing reactive oxygen species (ROS), but traditional PDT may suffer from the real‐time illumination that reduces the compliance of treatment and cause phototoxicity. A supramolecular photoactive G‐quartet based material is reported, which is self‐assembled from guanosine (G) and 4‐formylphenylboronic acid/1,8‐diaminooctane, with incorporation of riboflavin as a photocatalyst to the G4 nanowire, for post‐irradiation photodynamic antibacterial therapy. The G4‐materials, which exhibit hydrogel‐like properties, provide a scaffold for loading riboflavin, and the reductant guanosine for the riboflavin for phototriggered production of the therapeutic H2O2. The photocatalytic activity shows great tolerance against room temperature storage and heating/cooling treatments. The riboflavin‐loaded G4 hydrogels, after photo‐irradiation, are capable of killing gram‐positive bacteria (e.g., Staphylococcus aureus), gram‐negative bacteria (e.g., Escherichia coli), and multidrug resistant bacteria (methicillin‐resistant Staphylococcus aureus) with sterilization ratio over 99.999%. The post‐irradiated hydrogels also exhibit great antibacterial activity in the infected wound of the rats, revealing the potential of this novel concept in the light therapy. A post‐irradiation photodynamic therapy is presented that has no requirement for confinement of the patients to the illumination source. Supramolecular riboflavin‐loaded G4‐hydrogels are triggered by blue light to catalytically generate H2O2, which is then subjected to the infected wound for killing bacteria.

Cranial irradiation for the treatment of brain cancer elicits progressive and severe cognitive dysfunction that is associated with significant neuropathology. Radiation injury in the CNS has been linked to persistent microglial activation, and we find upregulation of pro-inflammatory genes even 6 weeks after irradiation. We hypothesize that depletion of microglia in the irradiated brain would have a neuroprotective effect. Adult mice received acute head only irradiation (9 Gy) and were administered a dietary inhibitor (PLX5622) of colony stimulating factor-1 receptor (CSF1R) to deplete microglia post-irradiation. Cohorts of mice maintained on a normal and PLX5662 diet were analyzed for cognitive changes using a battery of behavioral tasks 4–6 weeks later. PLX5622 treatment caused a rapid and near complete elimination of microglia in the brain within 3 days of treatment. Irradiation of animals given a normal diet caused characteristic behavioral deficits designed to test medial pre-frontal cortex (mPFC) and hippocampal learning and memory and caused increased microglial activation. Animals receiving the PLX5622 diet exhibited no radiation-induced cognitive deficits, and exhibited near complete loss of IBA-1 and CD68 positive microglia in the mPFC and hippocampus. Our data demonstrate that elimination of microglia through CSF1R inhibition can ameliorate radiation-induced cognitive deficits in mice.

In the past decade, patients with nasopharyngeal cancer (NPC) have been deemed candidates for proton radiotherapy, due to the large and comprehensive target volumes and the necessity for the retention of the surrounding healthy tissues. In this study, we aimed to compare the incidence and severity of post-irradiation sinusitis by detecting sinus mucosa diseases (SMDs) via the magnetic resonance imaging (MRI) of patients with NPC after intensity-modulated proton therapy (IMPT) and volume-modulated arc therapy (VMAT). A total of 53 patients in the IMPT group and 54 patients in the VMAT group were enrolled in this study. There were significantly lower endoscopic scores and Lund–Mackay staging scores determined from MRI scans in the IMPT group during different follow-up periods. For the most vulnerable sinuses, the incidence and severity of SMD were the highest during the third post-radiotherapy month in both groups. These decreased steadily, and there was no significant increase in the incidence and severity of SMD during the second post-radiotherapy year in the IMPT group. Our data show that NPC patients with IMPT have a significantly lower incidence and decreased severity of SMD than those with VMAT. A better and faster recovery of sinonasal function after radiotherapy in the IMPT group was also observed.

Concrete has been widely utilized as a radiation shielding material due to its properties and structural integrity. This study aims to evaluate the efficiency of ordinary concrete versus barite concrete as radiation shielding materials, focusing on the physical aspects and changes in crystal size lattice parameters after neutron irradiation. Specifically, the research investigates the shielding effectiveness of these materials across different grades (M15, M25, M35, and M45) against gamma-ray sources Cobalt-60 and Caesium-137. The methodology involves measuring the linear attenuation coefficient (μ), half value layer (HVL), tenth value layer (TVL), and mean free path (MFP). Additionally, X-ray diffraction (XRD) was employed to assess crystallite size and lattice parameter changes post-irradiation for neutron irradiation. Results indicate that incorporating barite as an aggregate significantly enhances the density and crystallite macroscopic properties of the concrete. Irradiation with Cobalt-60 and Cesium 137 revealed that ordinary concrete has a lower linear attenuation (μ) ranging from 0.172 to 0.195 cm −1 , with consistent mass attenuation across all grades at 0.81 cm 2 /g. XRD analysis demonstrated a rightward shift in the SiO₂ and BaSO₄ peaks post-irradiation, signifying crystalline expansion. In terms of lattice parameters, the d-value showed a notable decrease of 0.10 after 48 h of irradiation in grade 25, while the most significant increase of 0.02 occurred after 24 h of irradiation in grades 15 and 45. In conclusion, barite concrete proves to be more effective for radiation shielding in nuclear facilities, whereas ordinary concrete is suitable for medical shielding, or facilities exposed to lower radiation doses.

We investigated and evaluated post-irradiation survival in cyclooxygenase-2-deficient (COX-2 KO) mice. Thirty-day survival following exposure of COX-2 KO mice to a lethal dose of 8.5 Gy of γ-rays was observed to be statistically significantly lower in both males and females, as well as when the sexes were merged, in comparisons with their wild-type counterparts. These findings were related to the previous observations concerning the detrimental influence of the COX-2 genetic disruption on hematopoiesis in sublethally irradiated mice. Deteriorated post-irradiation survival of COX-2 KO mice confirmed the previously anticipated conclusion regarding negative influence of the anti-inflammatory action of COX-2 deficiency under the conditions of exposure of the animals to ionizing radiation.

Fuel rods containing a mixed uranium–plutonium nitride (MNUP) fuel were subjected to irradiation in BOR-60 and BN-600 reactors to assess their performance and potential use in BREST-OD-300 and BN-1200M reactors. Post-irradiation examinations revealed that their deformation behavior differs from that of fuel rods with oxide fuel. Nitride fuel rods demonstrated increased axial elongation and cladding ovalization under identical irradiation conditions within the same assembly. Elongation and ovalization studies were carried out for 12 fuel rods with cold-worked ChS68-ID cladding, 38 rods with cold-worked EK164-ID cladding, and 69 rods with EP823-Sh cladding. The fuel rods were irradiated in 17 experimental fuel assemblies, covering a range of maximum fuel burnup from 3.1–9.1% heavy atoms and displacement damage from 26–108 displacements per atom (dpa). The experimental data suggest that axial elongation is predominantly attributable to axial forces that emerge from thermomechanical interactions between the fuel and cladding. These interactions are attributed to the random displacement of pellets and/or their fragments from an axisymmetric position.

Tristructural isotopic (TRISO) fuel is a promising next-generation fuel form for advanced nuclear reactors. TRISO fuel consists of sub-millimeter diameter uranium-bearing fuel kernels encapsulated in multiple layers of carbon and ceramic materials. As part of the assessment of TRISO fuels, post irradiation examination (PIE) is performed to provide information on changes in microstructure, mechanical properties, and potential degradation. X-ray computed tomography (XCT) is a nondestructive technique that collects a series of two-dimensional radiographs as a function of sample rotation and mathematically reconstructs them into a three-dimensional dataset that provides volumetric information on the sample’s internal features. This work focuses on PIE of irradiated TRISO fuels using XCT with a focus on examining the impact of highly radioactive fuels on the images generated with the instrument’s CsI detector. Despite examining samples with over 2.00 Sv/hr on contact, techniques such as frame-averaging as well as a lack of interaction of high-energy gamma-rays with the detector ensure there is no noticeable impact on the quality of the CT images due to detector noise.

U-10Zr Metal fuel is a promising nuclear fuel candidate for next-generation sodium-cooled fast spectrum reactors. Since the Experimental Breeder Reactor-II in the late 1960s, researchers accumulated a considerable amount of experience and knowledge on fuel performance at the engineering scale. However, a mechanistic understanding of fuel microstructure evolution and property degradation during in-reactor irradiation is still missing due to a lack of appropriate tools for rapid fuel microstructure assessment and property prediction based on post irradiation examination. This paper proposed a machine learning enabled workflow, coupled with domain knowledge and large dataset collected from advanced post-irradiation examination microscopies, to provide rapid and quantified assessments of the microstructure in two reactor irradiated prototypical annular metal fuels. Specifically, this paper revealed the distribution of Zr-bearing secondary phases and constitutional redistribution across different radial locations. Additionally, the ratios of seven different microstructures at various locations along the temperature gradient were quantified. Moreover, the distributions of fission gas pores on two types of U-10Zr annular fuels were quantitatively compared.

Exosomes are promising disease diagnostic markers and drug delivery vehicles, although their use in practice is limited by insufficient homogeneous quantities that can be produced. We reveal that exposing cells to high frequency acoustic irradiation stimulates their generation without detriment to cell viability by exploiting their innate membrane repair mechanism, wherein the enhanced recruitment of calcium ions from the extracellular milieu into the cells triggers an ESCRT pathway known to orchestrate exosomal production. Given the high post-irradiation cell viabilities (≈95%), we are able to recycle the cells through iterative irradiation and post-excitation incubation steps, which facilitate high throughput production of a homogeneous population of exosomes—a particular challenge for translating exosome therapy into clinical practice. In particular, we show that approximately eight- to ten-fold enrichment in the number of exosomes produced can be achieved with just 7 cycles over 280 mins, equivalent to a yield of around 1.7–2.1-fold/h. Ambattu et al. report that high frequency acoustic stimulation of mammalian cancer cells promotes exosome generation without affecting cell viability. Acoustic stimulation increases calcium ion influx which triggers an ESCRT pathway related to exosome production. This method may allow for large-scale exosome production with potential clinical applications.