Low-level gamma-ray spectrometry, particularly in underground laboratories, is used to measure radioactivity in diverse close geometries, often placing samples directly on the detector which favours strong cascade summing effects. Monte-Carlo modelling of the efficiency is extended to cascade summing effects from complete decay sequences including positron emitting radionuclides. The effect of geometrical uncertainties on the overall uncertainty is presented. The results reinforce the need for radiography of the detector and inclusion of the detector shielding in the model.
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http://dx.doi.org/10.1016/j.apradiso.2006.02.038 | DOI Listing |
Phys Med Biol
January 2025
Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, Republic of Korea.
. This study aims to enhance positron emission tomography (PET) imaging systems by developing a continuous depth-of-interaction (DOI) measurement technique using a single-ended readout. Our primary focus is on reducing the number of readout channels in the scintillation detectors while maintaining accurate DOI estimations, using a high-pass filter-based signal multiplexing technique combined with artificial neural networks (ANNs).
View Article and Find Full Text PDFJ Acquir Immune Defic Syndr
July 2024
Indiana University Fairbanks School of Public Health, Indianapolis, IN.
Background: The HIV care cascade is a framework to examine effectiveness of HIV programs and progress toward global targets to end the epidemic but has been conceptualized as a unidirectional process that ignores cyclical care patterns. We present a dynamic cascade that accounts for patient "churn" and apply novel analytic techniques to readily available clinical data to robustly estimate program outcomes and efficiently assess progress toward global targets.
Methods: Data were assessed for 35,649 people living with HIV and receiving care at 78 clinics in East Africa between 2014 and 2020.
Med Phys
July 2024
Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California, USA.
Background: 3D neural network dose predictions are useful for automating brachytherapy (BT) treatment planning for cervical cancer. Cervical BT can be delivered with numerous applicators, which necessitates developing models that generalize to multiple applicator types. The variability and scarcity of data for any given applicator type poses challenges for deep learning.
View Article and Find Full Text PDFVavilovskii Zhurnal Genet Selektsii
December 2023
Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Science, Novosibirsk, Russia Novosibirsk State University, Novosibirsk, Russia Kurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia.
The plant cell wall represents the outer compartment of the plant cell, which provides a physical barrier and triggers signaling cascades under the influence of biotic and abiotic stressors. Drought is a factor that negatively affects both plant growth and development. Cell wall proteins (CWP) play an important role in the plant response to water deficit.
View Article and Find Full Text PDFData Brief
October 2023
Gonzaga University Computer Science Department, Gonzaga University, 502 E Boone Ave Spokane, WA 99258, USA.
We present a social network dataset based on interactions between members of the 117 United States Congress between Feb. 9, 2022, and June 9, 2022. The dataset takes the form of a directed, weighted network in which the edge weights are empirically obtained "probabilities of influence" between all pairs of Congresspeople.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!