Search results for "ESr"

ALANINE/ESR DOSIMETRY FOR TOTAL BODY IRRADIATION USING AN ANTHROPOMORPHIC PHANTOM

2016

Introduction: Total Body Irradiation (TBI) is a technique widely used in the radiation blood-oncology in the treatment of patients that need bone marrow transplantation or peripheral stem cell transplantation. This technique has some limitations such as the lack of homogeneity of the dose distribution (which may show variations of 20% in the different areas), irradiation of critical organs such as the lungs, the liver, the intestine and the eye-lens which can receive a dose comparable to that nominal and require appropriate shielding and a proper evaluation of the dose absorbed by them. The positive outcome of this type of radiation therapy is strictly related to a precise and accurate meas…

Dosimetry to Electron Spin Resonance (ESR) using organic compounds (alanine and ammonium tartrate) for mixed neutron-gamma fields

2015

Alongside with the development of Neutron Capture Therapy (NCT) and the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the characterization of the beam in order to optimize therapy procedures. Reliable dose measurements should be able to determine the various (neutrons and photonic) components of the mixed beam usually employed for therapy. This paper studies the effect of additives such as Boric and Gadolinium nuclei on the sensitivity of neutron organic (alanine and ammonium tartrate) dosimeters analyzed through Electron Spin Resonance (ESR) technique. These dosimeters were exposed to a mixed (neutron-gamma) field mainly composed of thermal neutro…

Weimar als Argument: Das Republikschutzgesetz in den Debatten um Staats- und Verfassungsschutz in der frühen Bundesrepublik

2022

Elogio de la manifestación

2002

Monte Carlo simulation of the response of ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons

2009

Abstract Monte Carlo numerical calculations of the response of alanine and ammonium tartrate ESR (electron spin resonance) dosimeters exposed to neutron fields with different energy spectra are reported. Results have been obtained for various gadolinium concentrations inside the dosimeters. Furthermore, in order to simulate the in-phantom response we have carried out calculations by varying the depth of the dosimeter. We have found that a large enhancement is obtained for thermal neutrons, because of the very high capture cross section of gadolinium to thermal neutrons. A good enhancement was obtained for epithermal neutrons, whereas the sensitivity improvement in the case of fast neutron i…

Economía criminal y terror

2001

Relation of oxidant stress with endothelial activation in hemodialysis.

2006

Introduction and Aims: Enhanced oxidative stress may be implicated in the pathogenesis of atherosclerosis in hemodialysed patients (HDs). We hypothesized that in hypertensive HDs oxidative stress should be elevated and associated to endothelial activation, and inflammation. Methods:We examined oxidative stress, as measured by 8-ISO-PGF2alpha, endothelial activation by measuring endothelin-1 (ET-1) and adhesion molecules ICAM-1 and VCAM-1, and the biomarker of acute-phase inflammation CRP. In 52 mild HDs and in 50 healthy controls (Cs) we analysed, in the interdialytic day, plasma levels of 8-ISO-PGF2alpha, ET-1, ICAM-1 and VCAM-1, and high sensitivity CRP. Results: The comparison between Cs…

Columnar aerosol properties in a Northeastern Atlantic site (Plymouth, United Kingdom) by means of ground based skyradiometer data during years 2000-…

2012

Between 2000 and 2008, columnar optical and radiative properties were measured at the Plymouth Marine Laboratory (PML), UK (50° 21.95'N, 4° 8.85'W) using an automatic Prede POM01L sun-sky photometer. The database was analyzed for aerosol optical properties using the SKYRAD radiative inversion algorithm and calibrated using the in situ SKYIL calibration method. Retrievals include aerosol optical depth, ångström wavelength exponent, aerosol volume distribution, refractive index and single scattering albedo. The results show that the Plymouth site is characterized by low values of aerosol optical depth with low variability (0.18 ± 0.08 at 500 nm) and a mean annual ångström exponent of 1.03 ± 0…

La crisis que hace temblar al capitalismo

2008

Caratterizzazione dosimetrica della facility a neutroni termici del reattore TRIGA di Pavia: studio della dose da fotoni mediante rivelatori ESR di a…

2014

The optimization of the procedures of Neutron Capture Therapy (NCT) for cancer treatments involves research for beam characterization. One major issue for this therapy is the reliable dosimetric determination of the various (neutronic and photonic) components of the employed beam. In particular, the precise and accurate measurements of the gamma photon component is fundamental for evaluating the risks to healthy tissues hit by the mixed field. Among solid state dosimeters the alanine detectors read by Electron Paramagnetic Resonance (EPR) technique present several advantages such as: tissue equivalence for photon and electron beams, linearity of its dose-response over a wide range, high sta…