Quantification of scattered photons in addition to unscattered primary particles, under realistic exposure scenario, is best dealt with a parameter called "Buildup factor". The aim of this work is to simulate the transmission buildup factor (BUF) of gamma-ray in the energy range .15-15 MeV for 20 human tissues and organs using the Geant4 (version 10.5) Monte Carlo simulation followed by a geometrical progression (GP) parameterization procedure. Firstly, we verified the accuracy of Geant4 ability to predict the effective transmitted dose according to published data. Also, a comparison of simulated BUF for different geometrical configurations was carried out for some tissues and source energies. Then, we checked out the linear dependency of the K parameter (BUF is function of K) function of mean free path (mfp). Finally, we developed a fitting procedure according to GP method for BUF corresponding to 20 tissues and organs and different mfp (from 1 to 8) for energy range .15-15 MeV. We found a good agreement with previous published data. Proper comprehension of BUF for tissues leads to carefully controlling the energy absorption in the human body. Consequently, provided BUF could be of great interest for estimating safe dose levels in medical imaging and radiation therapy.
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http://dx.doi.org/10.1177/15593258211068621 | DOI Listing |
Phytomedicine
November 2024
Department of Traditional Chinese Medicine and Oncology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China. Electronic address:
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View Article and Find Full Text PDFPolym Chem
December 2024
Polymer Science, Zernike Institute for Advanced Materials, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
Int J Mol Sci
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Department of Chemical and Material Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
Annu Rev Genet
November 2024
Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA; email:
Meiotic drive is the biased transmission of alleles from heterozygotes, contrary to Mendel's laws, and reflects intragenomic conflict rather than organism-level Darwinian selection. Theory has been developed as to how centromeric properties can promote female meiotic drive and how conflict between the X and Y chromosomes in males can promote male meiotic drive. There are empirical data that fit both the centromere drive and sex chromosome drive models.
View Article and Find Full Text PDFPLoS Genet
November 2024
Department of Biological Sciences, Butler University, Indianapolis, Indiana, United States of America.
Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored.
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