The radiation effects on the mechanical and physical properties of photo-polymerized UDMA resin without filler was investigated by various mechanical tests and spectroscopic measurements. The radiation sources were carbon ion (12C ion) and gamma ray (gamma-ray). With 640 Gy of 12C ion radiation, Vickers hardness increased by about 40%, the degree of abrasion decreased by 30%, and the flexural strength increased by 20%. With the same dose of gamma-ray radiation, only Vickers hardness increased by 19%. The spectra taken by the Fourier Transform Infrared Spectrometer (FT-IR), Raman spectroscopy, and Fluorescence spectrophotometer showed little change in the peak configuration and background intensities. The relative degree of conversion (DC) of carbon double bonds by radiation to the state of non-radiated samples were estimated by FT-IR. Spectroscopic results were indicative for the formation of cross-linking between carbon chains. Cross-linking of carbon molecules induced by radiation might be one of the reasons for the improved mechanical properties of UDMA resin.
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http://dx.doi.org/10.4012/dmj.20.325 | DOI Listing |
J Cereb Blood Flow Metab
January 2025
Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden.
Variations in cerebral blood flow and blood volume interact with intracranial pressure and cerebrospinal fluid dynamics, all of which play a crucial role in brain homeostasis. A key physiological modulator is respiration, but its impact on cerebral blood flow and volume has not been thoroughly investigated. Here we used 4D flow MRI in a population-based sample of 65 participants (mean age = 75 ± 1) to quantify these effects.
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January 2025
Division of Cardiovascular Medicine, Department of Medicine (J.B.H., J.D.B., A.C.D.), Vanderbilt University Medical Center, Nashville, TN.
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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 PDFMol Biol Rep
January 2025
Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
Background: Exposure to ionizing radiation is inevitable due to its extensive use in industrial and medical applications. The search for effective and safe natural therapeutic agents as alternatives to chemical drugs is crucial to mitigate their side effects. This study aimed to evaluate the effects of citicoline as a standalone treatment or in combination with the anti-hepatotoxic drug silymarin in protecting against liver injury caused by γ-radiation in rats.
View Article and Find Full Text PDFNeurosurg Rev
January 2025
Department of Biophysics, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Zabrze, 41-808, Poland.
Atlantoaxial dislocation (AAD) is a serious condition in which the first two cervical vertebrae lose their anatomical position and stability. This may lead to neurological complications, including death. The treatment of AAD remains controversial, and posterior instrumentation with pedicle screw placement is one of the commonly used methods.
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