Search results for "ionizing"
showing 10 items of 149 documents
Watch glasses exposed to 6 MV photons and 10 MeV electrons analysed by means of ESR technique: A preliminary study
2011
Abstract In this work we report a case study of the ESR response of watch glasses exposed to 6 MV photons and to 10 MeV electrons. The choice of watch glasses is justified by the fact that watch glasses are very close to the exposed individual. For both types of radiation beams, the absorbed doses belong to the range between 1 and 20 Gy. The samples have been irradiated in water-equivalent plastic phantom with a linear accelerator used for radiotherapy. After exposure watch glass samples have been cut in small strip-shaped pieces with suitable size to be put into the quartz tube for ESR measurements. The signal induced by radiation (RIS) lies in the g ∼ 2 region and must be discriminated fr…
The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy
2014
International audience; A new efficient type of gadolinium-based theranostic agent (AGuIX) has recently been developed for magnetic resonance imaging (MRI)-guided radiotherapy. These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Due to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, while a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, these particles present no evidence of toxicity, in the absence of irradiation with up to 10 times the planned dose f…
Caveolin-1, breast cancer and ionizing radiation
2015
Breast cancer (BC) recovery has increased in recent years thanks to efforts of Omics-based research in this field. However, despite the important results obtained, BC remains a complex multifactorial pathology that is difficult to treat appropriately. Caveolin-1 (CAV1), the basic constituent protein of specialized plasma membrane invaginations called caveolae, is emerging as a potential therapeutic biomarker in BC. This factor may modulate BC response to chemotherapy and radiation therapy. In addition, recent reports describe the key role of CAV1 during cell response to oxidative stress. The aim of the present review was to describe the biological roles of CAV1 in BC considering its contras…
Protecting sensitive patient groups from imaging using ionizing radiation: effects during pregnancy, in fetal life and childhood
2019
The frequency of imaging examinations requiring radiation exposure in children (especially CT) is rapidly increasing. This paper reviews the current evidence in radiation protection in pediatric imaging, focusing on the recent knowledge of the biological risk related to low doses exposure. Even if there are no strictly defined limits for patient radiation exposure, it is recommended to try to keep doses as low as reasonably achievable (the ALARA principle). To achieve ALARA, several techniques to reduce the radiation dose in radiation-sensitive patients groups are reviewed. The most recent recommendations that provide guidance regarding imaging of pregnant women are also summarized, and the…
Lack of correlation between apoptosis and DNA single-strand breaks in X-irradiated human peripheral blood mononuclear cells in the course of ageing
1998
The dependence on age of both the basal and the X-radiation-induced levels of apoptosis was examined in human peripheral blood mononuclear cells (PBMC). In the same samples, the base value and the extent of induced DNA single-strand breaks were determined, using a sensitive and fast microplate assay. PBMC were isolated from blood of donors of various age groups (20-30, 40-60 and > 70 years of age) and X-irradiated ex vivo using a 6 MV linear accelerator to give a total exposure of 4 Gy. The mean basal levels of apoptosis in PBMC from donors in the 40-60 year age group and the > 70 year age group were found to be only slightly higher (by 20-10%) compared to that of the 20-30 year age group, …
Rare-earth doped silica optical fibres for ionizing radiation detection
2016
Scintillating silica optical fibre sensors have shown interesting results for ionizing radiation monitoring and therefore can be useful for dosimetry applications in medical field. In fact, they enable a remote, punctual and real-time dose assessment (Mones et al., 2008). In addition, the high radiation hardness that characterizes silica optical fibers, makes these systems promising for radiation detection in high energy physics experiments (Chiodini et al., 2014). This work aims to review the recent progresses in the development and characterization of rare-earth doped silica fibres. The radioluminescent and dosimetric properties of Ce, Eu, Yb and Pr-doped silica matrices are described and…
DOES STILL EXIST A CORRELATION BETWEEN X-RAYS OCCUPATIONAL EXPOSURE AND BENIGN NODULAR THYROID DISEASE?
2019
Objective: The prevalence of benign nodular thyroid disease in the general population is high, as shown by various studies, and the diagnosis is eased by the improved diagnostic capacity of the instruments used. The aim of the present study is the evaluation of occupational exposure to ionizing radiation as a possible significant risk factor in the determinism of this pathology. Method: A cross-sectional observational study in “A category” X-ray exposed workers (doctors, nurses, technicians) of the University Hospital of Palermo, compared with a sample of the general population, was carried out from June 2016 to June 2017. We evaluated data obtained from the Personal Health Records, includi…
Radiation Hardness Assurance Through System-Level Testing: Risk Acceptance, Facility Requirements, Test Methodology, and Data Exploitation
2021
International audience; Functional verification schemes at a level different from component-level testing are emerging as a cost-effective tool for those space systems for which the risk associated with a lower level of assurance can be accepted. Despite the promising potential, system-level radiation testing can be applied to the functional verification of systems under restricted intrinsic boundaries. Most of them are related to the use of hadrons as opposed to heavy ions. Hadrons are preferred for the irradiation of any bulky system, in general, because of their deeper penetration capabilities. General guidelines about the test preparation and procedure for a high-level radiation test ar…
Interventistica eco-guidata per l’articolazione d’anca
2013
Lo scopo di questo lavoro è di rivedere le principali applicazioni della interventistica eco-guidata d’anca, descrivendone le indicazioni e la metodologia. L’ecografia è una metodica considerata sicura per i pazienti, in quanto non è stato dimostrato un possibile danno dovuto all’energia trasmessa dagli ultrasuoni ai tessuti del paziente, contrariamente alle metodiche che fanno uso di radiazioni ionizzanti, come la radiografia convenzionale e la tomografia computerizzata. Inoltre, l’ecografia risulta rapida ed efficace nel guidare l’ago verso la sede voluta evitando di intercettare strutture vascolari e/o nervose, consentendo quindi una maggiore sicurezza, rispetto alle tecniche interventis…
Ionizing radiation-induced E-selectin gene expression and tumor cell adhesion is inhibited by lovastatin and all-trans retinoic acid
2004
E-selectin mediated tumor cell adhesion plays an important role in metastasis. Here we show that ionizing radiation (IR) induces E-selectin gene and protein expression in human endothelial cells at therapeutically relevant dose level. E-selectin expression is accompanied by an increase in the adhesion of human colon carcinoma cells to primary human umbilical vein endothelial cells (HUVEC). The HMG-CoA reductase inhibitor lovastatin impairs IR-stimulated E-selectin expression as analyzed at the level of the protein, mRNA and promoter. Inactivation of Rho GTPases either by use of Clostridium difficile toxin A or by co-expression of dominant-negative Rho blocked IR-induced E-selectin gene indu…