95 research outputs found

    RECYCLING PROCESS OF U3O8 POWDER IN MnO-Al2O3 DOPED LARGE GRAIN UO2 PELLETS

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    The effect of various process variables on the powder properties of recycled U3O8 from MnO-Al2O3 doped large grain UO2 pellets and the effect of those recycled U3O8 powders on the sintered density and grain size of MnO-Al2O3 doped large grain UO2 pellets have been investigated. The evolution of morphology, size, and BET surface area of the recycled U3O8 powders according to the respective variation of the thermo-mechanical treatment variables of oxidation temperature, powder milling, and sequential cyclic heat treatment of oxidation and then reduction was examined. The correlation between the BET surface area of recycled U3O8 powder and the sintered pellet properties of MnO-Al2O3 doped pellets showed that the pellet density and grain size of doped pellets were increased and then saturated by increasing the BET surface area of the recycled U3O8 powder. The density and grain size of the pellets were maximized when the BET surface area of the recycled U3O8 powder was in the vicinity of 3m2/g. Among the process variables applied in this study, the cyclic heat treatment followed by low temperature oxidation was a potential process combination to obtain the sinter-active U3O8 powder

    Automated radiation treatment planning for cervical cancer

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    CITATION: Rhee, D. J. et al. 2020. Automated radiation treatment planning for cervical cancer. Seminars in Radiation Oncology, 30(4):340-347, doi:10.1016/j.semradonc.2020.05.006.The original publication is available at https://www.sciencedirect.comThe radiation treatment-planning process includes contouring, planning, and reviewing the final plan, and each component requires substantial time and effort from multiple experts. Automation of treatment planning can save time and reduce the cost of radiation treatment, and potentially provides more consistent and better quality plans. With the recent breakthroughs in computer hardware and artificial intelligence technology, automation methods for radiation treatment planning have achieved a clinically acceptable level of performance in general. At the same time, the automation process should be developed and evaluated independently for different disease sites and treatment techniques as they are unique from each other. In this article, we will discuss the current status of automated radiation treatment planning for cervical cancer for simple and complex plans and corresponding automated quality assurance methods. Furthermore, we will introduce Radiation Planning Assistant, a web-based system designed to fully automate treatment planning for cervical cancer and other treatment sites.Publisher's versio

    Chlorin e6 Prevents ADP-Induced Platelet Aggregation by Decreasing PI3K-Akt Phosphorylation and Promoting cAMP Production

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    A number of reagents that prevent thrombosis have been developed but were found to have serious side effects. Therefore, we sought to identify complementary and alternative medicinal materials that are safe and have long-term efficacy. In the present studies, we have assessed the ability of chlorine e6 (CE6) to inhibit ADP-induced aggregation of rat platelets and elucidated the underlying mechanism. CE6 inhibited platelet aggregation induced by 10 µM ADP in a concentration-dependent manner and decreased intracellular calcium mobilization and granule secretion (i.e., ATP and serotonin release). Western blotting revealed that CE6 strongly inhibited the phosphorylations of PI3K, Akt, c-Jun N-terminal kinase (JNK), and different mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase 1/2 (ERK1/2) as well as p38-MAPK. Our study also demonstrated that CE6 significantly elevated intracellular cAMP levels and decreased thromboxane A2 formation in a concentration-dependent manner. Furthermore, we determined that CE6 initiated the activation of PKA, an effector of cAMP. Taken together, our findings indicate that CE6 may inhibit ADP-induced platelet activation by elevating cAMP levels and suppressing PI3K/Akt activity. Finally, these results suggest that CE6 could be developed as therapeutic agent that helps prevent thrombosis and ischemia

    Prevalence of foodborne viruses and influenza A virus from poultry processing plants to retailed chickens

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    IntroductionFoodborne viruses are a serious concern in public health. This study investigated the prevalence of eight foodborne viruses norovirus (NoV), adenovirus (AdV), sapovirus (SapoV), astrovirus, hepatitis A virus (HAV), hepatitis E virus (HEV), rotavirus, aichivirus, and influenza A virus (IAV).Material and methodA total of 316 chicken samples were collected from three poultry processing plants to commercial markets (local and online). RT-qPCR- and PCR-positive amplicons obtained from monitoring were confirmed by sequence analysis.ResultsFoodborne viruses and IAV were not found in poultry processing plants. Of the 100 chickens purchased from the local and online markets, 19 (19.0%) AdV and 2 (2.0%) SapoV were detected. NoV, astrovirus, HAV, HEV, rotavirus, aichivirus, and IAV were not detected in the retailed chickens. Phylogenetic analysis identified 18 human AdV-41, one porcine AdV, and two SapoV-GI.1. It was the first case of the discovery of the SapoV gene in chicken. The average contamination level of detected AdV was 2.4 log DNA copies/g, but there were cases where the highest level was 5.35 log DNA copies/g.DiscussionThis study highlights the importance of chicken's contribution to the transmission of AdV with the possibility of annual variability with emerging symptoms. The prevention of AdV contamination in the food chain from slaughterhouses to retail markets should be monitored and controlled in further study

    Serosurveillance for Japanese encephalitis, Akabane, and Aino viruses for Thoroughbred horses in Korea

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    Recent global warming trends may have a significant impact on vector-borne viral diseases, possibly affecting vector population dynamics and disease transmission. This study measured levels of hemagglutination-inhibition (HI) antibodies against Japanese encephalitis virus (JEV) and neutralizing antibodies against Akabane virus (AKAV) and Aino virus (AINV) for Thoroughbred horses in Korea. Blood samples were collected from 989 racehorses in several provinces, between October 2005 and March 2007. Sera were tested using either an HI assay or a virus neutralization test. Approximately half (49.7%; 492/989) of the horses tested were antibody-positive for JEV. The HI titer against JEV was significantly correlated with racehorse age (p < 0.05). Horses with an HI antibody titer of 1:160 or higher accounted for 3.9% of the animals tested, indicating that vectors transmitting arthropod-borne viruses bit relatively few horses. In contrast, 3.8% (19/497) and 19.5% (97/497) of horse sera collected in March 2007 were positive against AKAV and AINV, respectively. The presence of antibodies against AKAV and AINV may indicate the multiplication of AKAV and AINV in these horses

    Customizable landmark-based field aperture design for automated whole-brain radiotherapy treatment planning.

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    PURPOSE: To develop and evaluate an automated whole-brain radiotherapy (WBRT) treatment planning pipeline with a deep learning-based auto-contouring and customizable landmark-based field aperture design. METHODS: The pipeline consisted of the following steps: (1) Auto-contour normal structures on computed tomography scans and digitally reconstructed radiographs using deep learning techniques, (2) locate the landmark structures using the beam's-eye-view, (3) generate field apertures based on eight different landmark rules addressing different clinical purposes and physician preferences. Two parallel approaches for generating field apertures were developed for quality control. The performance of the generated field shapes and dose distributions were compared with the original clinical plans. The clinical acceptability of the plans was assessed by five radiation oncologists from four hospitals. RESULTS: The performance of the generated field apertures was evaluated by the Hausdorff distance (HD) and mean surface distance (MSD) from 182 patients' field apertures used in the clinic. The average HD and MSD for the generated field apertures were 16 ± 7 and 7 ± 3 mm for the first approach, respectively, and 17 ± 7 and 7 ± 3 mm, respectively, for the second approach. The differences regarding HD and MSD between the first and the second approaches were 1 ± 2 and 1 ± 3 mm, respectively. A clinical review of the field aperture design, conducted using 30 patients, achieved a 100% acceptance rate for both the first and second approaches, and the plan review achieved a 100% acceptance rate for the first approach and a 93% acceptance rate for the second approach. The average acceptance rate for meeting lens dosimetric recommendations was 80% (left lens) and 77% (right lens) for the first approach, and 70% (both left and right lenses) for the second approach, compared with 50% (left lens) and 53% (right lens) for the clinical plans. CONCLUSION: This study provided an automated pipeline with two field aperture generation approaches to automatically generate WBRT treatment plans. Both quantitative and qualitative evaluations demonstrated that our novel pipeline was comparable with the original clinical plans

    X-ray Astronomy in the Laboratory with a Miniature Compact Object Produced by Laser-Driven Implosion

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    Laboratory spectroscopy of non-thermal equilibrium plasmas photoionized by intense radiation is a key to understanding compact objects, such as black holes, based on astronomical observations. This paper describes an experiment to study photoionizing plasmas in laboratory under well-defined and genuine conditions. Photoionized plasma is here generated using a 0.5-keV Planckian x-ray source created by means of a laser-driven implosion. The measured x-ray spectrum from the photoionized silicon plasma resembles those observed from the binary stars Cygnus X-3 and Vela X-1 with the Chandra x-ray satellite. This demonstrates that an extreme radiation field was produced in the laboratory, however, the theoretical interpretation of the laboratory spectrum significantly contradicts the generally accepted explanations in x-ray astronomy. This model experiment offers a novel test bed for validation and verification of computational codes used in x-ray astronomy.Comment: 5 pages, 4 figures are included. This is the original submitted version of the manuscript to be published in Nature Physic
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