A new reentrant ionization chamber SNC 1008 has been introduced for low dose rate (LDR) and high dose rate (HDR) brachytherapy source calibrations. There is no air density correction requirement for the chamber since it is hermetically sealed. In this study we evaluate its use for HDR as well as LDR source calibrations. The magnitude of the ionization current collected was found to be independent of the sign of the polarizing voltage within +/- 0.5%. The axial response curve of the well chamber reveals a "plateau region" (+/- 0.5% dose variation) of 4.2 cm, which is larger than the published values for other commercially available chambers. Long-term stability of the chamber was evaluated. Short-term response and source positioning reproducibility were tested using both LDR and HDR sources. Ion collection efficiency was found to be high, making the chamber suitable for HDR 192Ir sources.
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http://dx.doi.org/10.1118/1.598242 | DOI Listing |
Physiol Plant
January 2025
Department of Radioecology, Institute for Environmental Sciences, Aomori, Japan.
The use of stored carbon is essential for new organ development in deciduous trees during early spring. However, the contribution of carbon to the development of new organs in early spring of subsequent years is not well understood. Using a C labelling approach, we investigated the reallocation of assimilated carbon into new aboveground organs on apple (Malus domestica) saplings in the following two years.
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January 2025
Department of Environmental Sciences, University of California, Riverside, California 92521, United States.
E-cigarette emissions, which contain a variety of hazardous compounds, contribute significantly to indoor air pollution and raise concerns about secondhand exposure to vaping byproducts. Compared to fresh vape emissions, our understanding of chemically aged products in indoor environments remains incomplete. Terpenes are commonly used as flavoring agents in e-liquids, which have the ability to react with the dominant indoor oxidant ozone (O) to produce reactive oxygenated byproducts and result in new particle formation.
View Article and Find Full Text PDFEur J Dent
January 2025
Hard Tissue Pathology Unit, Graduate School of Oral Medicine, Matsumoto Dental University, Nagano, Japan.
Objectives: Plasma rich in growth factors (PRGF) is presumed to be able to stimulate the regeneration of skin and periodontal tissue. This effect can be attributed to the fact that PRGF contains fewer leukocyte-derived interleukins in comparison to platelet-rich plasma (PRP). However, a comparison of the effects of PRGF and PRP on gingival epithelial cells has not been conducted yet.
View Article and Find Full Text PDFACS Omega
January 2025
State Key Laboratory of Offshore Oil Exploitation, Beijing 100028, China.
Shale barriers negatively impact thermal recovery processes of oil sand or ultraheavy oil, particularly during the rising stage of SAGD, by affecting oil flow, steam chamber evolution, and heat distribution. Existing mathematical models for the rising stage of SAGD often overlook the influence of shale barriers on the evolution of the steam chamber and heat distribution. This study includes experiments to investigate the impact of a single shale barrier above the production well during the rising stage of the SAGD.
View Article and Find Full Text PDFSci Rep
January 2025
Institute and Clinic for Occupational, Social and Environmental Medicine, LMU University Hospital, LMU Munich, Ziemssenstr. 5, 80336, Munich, Germany.
The long-tern implications of stress during university for individuals' mental health are not well understood so far. Hence, we aimed to examine the potential effect of stress while studying at university on depression in later life. We analysed data from two waves of the longitudinal Study on Occupational Allergy Risks.
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