Freeze-drying and irradiation are common process used by tissue banks to preserve and sterilize bone allografts. Freeze dried irradiated bone is known to be more brittle. Whether bone brittleness is due to irradiation alone, temperature during irradiation or to a synergetic effect of the freeze-drying-irradiation process was not yet assessed. Using a left-right femoral head symmetry model, 822 compression tests were performed to assess the influence of sequences of a 25 kGy irradiation with and without freeze-drying compared to the unprocessed counterpart. Irradiation of frozen bone did not cause any significant reduction in ultimate strength, stiffness and work to failure. The addition of the freeze-drying process before or after irradiation resulted in a mean drop of 35 and 31% in ultimate strength, 14 and 37% in stiffness and 46 and 37% in work to failure. Unlike irradiation at room temperature, irradiation under dry ice of solvent-detergent treated bone seemed to have no detrimental effect on mechanical properties of cancellous bone. Freeze-drying bone without irradiation had no influence on mechanical parameters, but the addition of irradiation to the freeze-drying step or the reverse sequence showed a detrimental effect and supports the idea of a negative synergetic effect of both procedures. These findings may have important implications for bone banking.
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http://dx.doi.org/10.1007/s10561-010-9209-1 | DOI Listing |
JCO Glob Oncol
January 2025
Uganda Cancer Institute, Department of Radiotherapy, Kampala, Uganda.
The evolution of radiation therapy in Uganda has been a journey marked by significant milestones and persistent challenges. Since the inception of radiotherapy services in 1988-1989, there has been a concerted effort to enhance cancer treatment services. The early years were characterized by foundational developments, such as the installation of the first teletherapy units, low-dose-rate brachytherapy units, and conventional simulators, and the recognition of radiation oncologists and medical physicist professionals laid the groundwork for radiotherapy treatment modalities.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Radiation Physics, Zhejiang Key Laboratory of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang, China.
Accurate and efficient automatic segmentation is essential for various clinical tasks such as radiotherapy treatment planning. However, atlas-based segmentation still faces challenges due to the lack of representative atlas dataset and the computational limitations of deformation algorithms. In this work, we have proposed an atlas selection procedure (subset atlas grouping approach, MAS-SAGA) which utilized both image similarity and volume features for selecting the best-fitting atlases for contour propagation.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Radiation Oncology, Chulabhorn Hospital, Chulabhorn Royal Academy, Bangkok, Thailand.
Radiotherapy is the main treatment for patients with head and neck cancer (HNC) and is associated with an increased risk of ischemic cerebrovascular events (ICVE). The purpose of this cross-sectional study was to determine the incidence of ICVE and carotid artery stenosis (CAS) in patients with HNC who receive radiotherapy and the risk factors for CAS. We enrolled 907 patients with HNC who underwent radiotherapy between February 2011 and June 2022 and obtained information on their clinical and tumor characteristics and their treatment from the clinical records.
View Article and Find Full Text PDFJ Am Soc Nephrol
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Selzman Institute for Kidney Health, Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
Background: Arteriovenous (AV) fistulas are the preferred access for dialysis but have a high incidence of failure. This study aims to understand the crosstalk between skeletal muscle catabolism and AV fistula maturation failure.
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Nano Converg
January 2025
Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeolabuk-do, 56212, Republic of Korea.
Metal-oxide thin-film semiconductors have been highlighted as next-generation space semiconductors owing to their excellent radiation hardness based on their dimensional advantages of very low thickness and insensitivity to crystal structure. However, thin-film transistors (TFTs) do not exhibit intrinsic radiation hardness owing to the chemical reactions at the interface exposed to ambient air. In this study, significantly enhanced radiation hardness of AlO-passivated ZnO TFTs against high-energy protons with energies of up to 100 MeV is obtained owing to the passivation layer blocking interactions with external reactants, thereby maintaining the chemical stability of the thin-film semiconductor.
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