Search results for "RADIATION"

Annual effective dose and excess life time cancer risk assessment from tobacco plants

2019

Cigarette smoking is one of the pathways that might cause radiation exposure due to the presence of radioactive elements in tobacco leaves used in the manufacture of cigarettes. From the health point of view, the knowledge of radioactivity content of the various radionuclides in tobacco leaves and their derivative products is important to assess the radiological effects associated with tobacco smoking for smokers. In this work, naturally occurring radionuclides 226Ra, 232Th and 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometry. Results show that the average concentrations of 226Ra, 232Th and 40K vary from 4.30 ± 0.2 to 11.85 ± 0.7 (average 8.17), 1.35 ± 0.1 to 16.…

Environmental radioactivity at Stromboli (Aeolian Islands)

2002

HPGe gamma spectrometry, thermoluminescence dosimetry, X-ray diffractometry and fluorescence techniques have been used to analyze the natural radionuclides content of soil and rock samples, air kerma and geochemical features on the island of Stromboli, belonging to the Aeolian Islands, in the Mediterranean Sea. The 214Bi, 238Ac, and 40K contents obtained are in agreement with the magmatic evolution of the rock formation, as shown by the correlations between radionuclide and chemical elements abundacies, depending on the various magmatic differentiation mechanisms. Correlations between radiometric, lithological and geochemical data have been assessed in order to obtain some hints on the geoc…

Natural radioactivity in a volcanic island: Ustica, Southern Italy

1997

Abstract Gamma-ray spectrometric measurements were performed on rocks and soils of the island of Ustica (Southern Italy) to quantify the concentrations of the natural radionuclides. The 238U, 232Th, and 40K concentration ranges (15–164, 16–174, and 201–1350 Bq kg−1, respectively) were compared with mineralogical and chemical data obtained by XRD and XRF analyses. The observed levels of the primordial radionuclides corresponded to the magmatological features of the rocks. Soil samples generally showed specific gamma-ray activities not directly correlatable to those measured in the underlying rocks. A survey was also perormed to measure air kerma in outdoor and indoor environments using therm…

Correlation of radioactivity measurements, air kerma rates and geological features of Sicily

2006

Abstract Sicily, the largest Mediterranean island (with an extension of about 25 000 km 2 ), exhibits a very wide variety of lithologies, ranging from sedimentary to metamorphic and volcanic rocks. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) have been applied to air kerma values measured by thermoluminescent dosimetry in several sites and to data of radionuclide concentrations, geochemical and mineralogical features of rocks and soils sampled in 29 sites of Sicily to point out similarities among different lithologies. The study was devoted to find multiple correlations and allow a better classification of Sicilian lithotypes. Samples of rocks and soils have be…

2017

In the context of radiopharmacy and molecular imaging, the concept of theranostics entails a therapy-accompanying diagnosis with the aim of a patient-specific treatment. Using the adequate diagnostic radiopharmaceutical, the disease and the state of the disease are verified for an individual patient. The other way around, it verifies that the radiopharmaceutical in hand represents a target-specific and selective molecule: the “best one” for that individual patient. Transforming diagnostic imaging into quantitative dosimetric information, the optimum radioactivity (expressed in maximum radiation dose to the target tissue and tolerable dose to healthy organs) of the adequate radiotherapeutica…

Patients perception of ionising radiation risks in CT ionising exposure. Does dose bill works?

2015

Communicating to patients the magnitude of risk related to ionizing radiation exposure is problematic because of the uncertainty in estimates derived principally from epidemiological studies of large populations [1-6]. Euratom directive 59/2013 requires that dose bill will be part of the radiological report in European Countries [7]. However, how a risk is framed has a profound effect on risk perception. To date, no previous studies evaluated which could be the best way to make patient friendly dose bill. Our aim was to evaluate patients' perception of radiation exposure related to routine CT and their understanding after dose bill.

Cumulative radiation CT dose in young traumatic patients: a single centre 5 years retrospective review

2014

The Effect of Nicotinamide on Microcirculatory Function, Tissue Oxygenation and Bioenergetic Status in Rat Tumors

1994

The failure of many attempts to improve tumor oxygenation - and thus the outcome of standard radiotherapy - may be due to the fact that the occurrence of hypoxia in tumors is not solely a result of diffusion-limited “chronic” hypoxia but is also due to temporary flow cessations in microregional tumor perfusion which have been shown to occur in tumor tissue1. As a result, attempts have more recently been made to reduce hypoxia in tumors through the reduction of tumor perfusion fluctuations. The benzamide analog nicotinamide is an agent which has recently received attention in this respect. It has been reported to be an effective, tumor-specific radiosensitizer in several tumor models, an eff…

A fully automatic approach for multimodal PET and MR image segmentation in gamma knife treatment planning

2017

The aim of this study is to combine Biological Target Volume (BTV) segmentation and Gross Target Volume (GTV) segmentation in stereotactic neurosurgery.Our goal is to enhance Clinical Target Volume (CTV) definition, including metabolic and morphologic information, for treatment planning and patient follow-up.We propose a fully automatic approach for multimodal PET and MR image segmentation. This method is based on the Random Walker (RW) and Fuzzy C-Means clustering (FCM) algorithms. A total of 19 brain metastatic tumors, undergone stereotactic neuro-radiosurgery, were retrospectively analyzed. A framework for the evaluation of multimodal PET/MRI segmentation is presented, considering volume…

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…