Photoluminescence and thermoluminescence dosimetry properties of Ag/Y co-doped ZnO nanophosphor for radiation measurements.

This work explores the thermoluminescence (TL) and photoluminescence (PL) properties of Ag/Y co-doped zinc oxide (ZnO) nanophosphor. The proposed dosimeter was prepared by the coprecipitation method and sintered at temperatures from 400°C to 1000°C in an air atmosphere. Raman spectroscopy was studied to investigate the structural features of this composition. The new proposed dosimeter revealed two peaks at 150°C and 175°C with a small shoulder at high temperature (225°C). The PL spectrum showed strong green emissions between 500 to 550 nm. The Raman spectrum showed many bands related to the interaction between ZnO, silver (Ag), and yttrium oxide (Y2 O3 ). The rising sintering temperature enhanced the TL glow curve intensity. The Ag/Y co-doped ZnO nanophosphor showed an excellent linearity index within a dose from 1 to 4 Gy. The minimum detectable dose (MDD) of the Ag/Y co-doped ZnO nanopowder (pellets) equaled 0.518 mGy. The main TL properties were achieved in this work as follows: thermal fading (37% after 45 days at 1 and 4 Gy), optical fading (53% after 1 h and 68% after 6 h by exposure to sunlight), effective atomic number (27.6), and energy response (flat behavior from 0.1 to 1.3 MeV). Finally, the proposed material shows promising results nominated to be used for radiation measurements.

National Early Warning Score (NEWS) as Prognostic Triage Tool for Septic Patients.

PURPOSE: We assessed the National Early Warning Score (NEWS) in emergency triage for predicting sepsis-related outcomes. METHODS: A retrospective chart review of all cases enrolled in the sepsis management protocol for a one-year duration. The protocol utilized the NEWS as a screening tool for sepsis in the triage area. Primary outcomes of interest were hyperlactatemia, admission to ICU and intrahospital mortality. Sensitivity, specificity, and area under the curve (AUC) were calculated for a given NEWS. RESULTS: A total of 444 patients were reviewed from July 2018 to June 2019, with a mean age of 58.7 years. A NEWS ≥5 was more than 88% sensitive in predicting hyperlactatemia, ICU admission, and/or mortality. Specificity, on the other hand, was as low as 12%. The AUC for the NEWS was 0.667 for predicting hyperlactatemia and 0.602 for predicting ICU admission or mortality. CONCLUSION: The NEWS was a sensitive screening tool for predicting sepsis-related outcomes. However, it was not specific, and further studies are recommended to assess the integration of other factors to improve specificity.