ABSTRACT
In NCBJ, Poland a new laboratory for BNCT research is being constructed at MARIA reactor. In the first phase it will provide a thermal neutron beam for experiments with cellular samples and small animals. In the next step, a converter will be mounted to provide fast neutron beam. Beam shaping assembly will moderate the beam to epithermal energies allowing for irradiation human phantoms. The laboratory infrastructure as well as radiation shielding of the laboratory are being designed using MCNP6 software.
ABSTRACT
This paper presents the results on radiation shielding of special types of concrete, designed for nuclear reactor containments. The research focused on the study of shielding properties against neutron component of ionizing radiation. For this purpose, two types of ionizing source were used: the isotopic reference neutron field of 239Pu-Be in calibration laboratory and the MARIA Research Reactor.
Subject(s)
Construction Materials/adverse effects , Gamma Rays/adverse effects , Neutrons , Nuclear Reactors , Radiation Protection/instrumentation , Radiometry/instrumentation , Radiometry/methods , Beryllium/analysis , Computer Simulation , Humans , Plutonium/analysis , Radiation Protection/methodsABSTRACT
Recombination chambers are linear energy transfer (LET)-dependent detectors and their applications are closely related to the problem of estimating radiation quality. The operational principle is based on the phenomenon of the initial recombination of ions in gases. Practical usefulness of the chambers is well confirmed by experimental results, however, the correlation of the response with LET is based on an approximated theoretical description of initial recombination of ions in gases. In this work, a precise numerical model of the REM-2 recombination chamber has been prepared, in order to calculate the dose distributions versus LET inside the chamber. The results form a set of data for further validation of recombination methods.
Subject(s)
Gases , Linear Energy Transfer , Models, Theoretical , Radiometry/instrumentation , Radiometry/methods , Computer Simulation , Equipment Design , Ions , Radiation DosageABSTRACT
INTRODUCTION: Identifying factors effecting the quality of nephrolithiasis surgical treatment could improve medical care for patients suffering from kidney stone disease. The objective of the article is to identify factors influencing reintervention rate after surgical treatment of kidney stone disease either by percutaneous nephrolitholapaxy or flexible ureterorenoscopy. METHOD: A retrospective study was conducted on 149 patients who underwent a surgery for a kidney stone disease at the Urological department of F.D. Roosevelt hospital Banská Bystrica from January 2015 till June 2015. The cohort included 60 women at average age of 57 (range 28-91) and 89 men at average age of 58 (range 30-92). Patients were treated by percutaneous litholapaxy (67 cases) and flexible ureterorenoscopy (82 cases, including 72 using dusting technique). Factors with potential influence on probability of repeated intervention during following 12 months have been studied and statistically analyzed. For the statistical analysis we used the generalized linear regression framework (GLM Generalized Linear Model) with the stepwise forward modeling approach. RESULTS: Using the significance level of 5% the statistically significant factors affecting the probability of the re-intervention for ipsilateral kidney stone disease are the stone size (p-value 0.0035) and the postoperative stone free status (p-value 0.0418). Other studied factors as demographical data (age, gender), surgical method (percutaneous nephrolitolapaxy or flexible ureterorenoscopy), stone count, postoperative draining system (nefrostomy or JJ stent) did not have any statistically significant impact. CONCLUSION: Patients could benefit from early diagnosis which could lead to earlier identification of smaller stones. Perfect operative technique with intraoperative achievement of stone free status is important to lower the need of repeated intervention.Key words: kidney stone disease - reintervention residual fragments.
Subject(s)
Kidney Calculi , Lithotripsy , Adult , Aged , Aged, 80 and over , Female , Humans , Kidney Calculi/surgery , Male , Middle Aged , Retrospective Studies , Treatment Outcome , UreteroscopyABSTRACT
In this work we present Polish achievements on the ground of BNCT research. Starting from preliminary built therapeutic stand at MARIA reactor going through designing of unique detectors for in-phantom and in-beam measurements for mixed radiation fields and finally coming to boron carriers synthesizing and examination in cellular and animal models. Now it is planned to restart research on boron compounds in specially designed BIMA line, to set up epithermal neutron irradiation facility for BNCT research and education and to improve recombination detectors for neutron beams characterisation.
Subject(s)
Biomedical Research , Boron Neutron Capture Therapy , Animals , Humans , Models, Animal , Phantoms, Imaging , PolandABSTRACT
A model of a multi-electrode ionisation chamber, with polypropylene electrodes coated with a thin layer of B4C was created within Monte Carlo N-Particle Transport Code (MCNPX) and Fluktuierende Kaskade (FLUKA) codes. The influence of the layer thickness on neutron absorption in B4C and on the neutron spectra in the consecutive intra-electrode gas volumes has been studied using the MCNPX and FLUKA codes. The results will be used for designing the new type of the ionisation chamber.
