Experiments with RADFET dosimeter in electron-beams irradiation and numerical computation of the physical shielding factor

MOSFET electronic components are already the subject of several decades of research in various fields of dosimetry and radiation protection. Special interest appeared when these components are started to be used as dosimeters in radiotherapy with electron beams. However, if one looks much more serious in the wider scientific research horizon, all the results obtained in experiments with precisely defined energies of incident electrons can be used in other disciplines which consider the impacts spectra of cosmic radiation on electronic devices, which is especially importance for cosmic science and space research instrumentation. In this paper, one of the objectives was to examine the electrical characteristics specially designed ESAPMOS RADFET dosimeters in the experiments that were conducted on a linear accelerator installations. RADFET components are bombarded electron beams energy of 6 MeV and 8 MeV, and then are followed by changes in threshold voltage shift mean values depending on the change of absorbed dose is referred to as D(cGy) was determined in water. Conclusions performance RADFET components are more than encouraging in terms of further research to improve the linearity of the energy dependence as widely energy electrons. In the second part of the test complex structure of packaging components RADFET focus is placed on the determination of the energy deposited in layers that are of interest for the analysis of microscopic processes related to the recombination of radiation-induced electron-hole pairs. Transport incident electrons through all the layers of structure RADFET component type ESAPMOS was carried out numerical simulations of the Monte Carlo method using the software package FOTELP-2K12. On this occasion, were taken into account all the physical processes of interaction of electrons with materials given structure. When he conquered the numerical application of mathematical and physical model for determining the value of the absorbed energy as the energy deposited per unit mass in a given layers with different materials, it could be accessed defining physical shielding factor (PSF) for a given structure RADFET components. Physical shielding factor (PSF) is defined as the ratio of absorbed dose values, which in fact means that it is equal to the energy deposited when the RADFET is shielded with protection, and the RADFET without lid. When we know the energy dependence factor for PSF of RADFET with and without armour, can be carried out and the analysis of whether and to what extent the energy required compensating the electronic components. Monte Carlo simulations were performed for the transport of incident electrons from 4 MeV, 6 MeV, 8 MeV and 12 MeV. It can be concluded that the different energy of incident electrons there is a significant influence of material Kovar on the absorbed energy in SiO2 and Si layers structure RADFET, in cases where Kovar used among other things as physical protection.Third International Conference on Radiation and Applications in Various Fields of Research, RAD 2015, June 8-12, 2015, Budva, Montenegr

Primary pericardial mesothelioma presenting as constrictive pericarditis

Primary pericardial mesothelioma is an extremely rare and lethal cardiac tumor. We report an autopsy case of a primary pericardial mesothelioma in a 52-year-old man. He developed dyspnea, cough, low-grade fever and night sweats approximately 3 months before last admission. Initially, he was evaluated at a hospital in another city, without a firm diagnosis. Due to progressive symptoms and the development of lower-extremity edema, he presented at our hospital in September 2005. The physical examination at admission demonstrated signs of pericardial tamponade. Chest radiography revealed marked enlargement of the cardiac silhouette. Specimens of bloody pericardial fluid were positive for pericardial mesothelioma by cytologic examination. The general condition of the patient worsened very rapidly and he was transferred to the intensive care unit where he later died. Postmortem examination confirmed primary pericardial mesothelioma of the mixed/biphasic type with lymphatic metastasis in the right lung. By using immunohistochemical analysis for specific markers of mesothelioma and for differentiation of the mesothelioma from the lung adenocarcinoma, definitive diagnosis was established: primary pericardial mesothelioma

CHRONIC INTRAVENOUS HEROIN ABUSE AND HEPATIC AMYLOIDOSIS

A few data on systemic amyloidosis in heroin abusers as well as the development of liver amyloidosis, as its important target, are the reasons for this examination. The liver amyloidosis was found in 22,5 % of autopsies and it was very often associated with liver alcoholicdisease. Amyloid deposits were found in the walls of arteries and arterioles, as well as inside portal and lobular connective tissue frame. The role of macrophage-derived enzymes and cytokines,together with a genetically determined strucural abnormality in the SAA molecule in the genesis of systemic amyloidosis, was discussed

CAUSES OF DEATH IN CHILDREN AND ADOLESCENTS ACCORDING TO THE MATERIAL OF THE INSTITUTE OF FORENSIC MEDICINE IN NIŠ FOR THE PERIOD 2003-2012

This paper examines the causes of death in children and adolescents for a ten-year period (2003-2012) according to data from the autopsy records of the Institute of Forensic Medicine in Niš. The causes of death (natural or violent) were analyzed in relation to sex, age, season, and environment (rural and urban areas), socio-economic and living conditions, and the number of children in the family. The results obtained were statistically analyzed, plotted and discussed in relation to data from the literature available. Regarding the autopsy cases of children and adolescents (194), 106 (54.63%) were the cases of violent causes of death and 87 were the cases (44.84%) of natural causes of death, while in one case the cause of death could not be determined due to late-stage decomposition alterations of the corpse. The most common natural causes of death were asphyxia, immaturity of the fetus and acute pneumonia. Most common causes of violent death were contusion of the brain, destruction of the brain and brainstem, polytrauma, and bleeding

Ultrastructural Changes in the Liver of Intravenous Heroin Addicts

The ultrastructural research has a decisive role in gathering the knowledge on the liver’s response to the influence of some drugs. The aim of the study was to perform an ultrastructurai analysis of the liver in chronic intravenous heroin addicts. The study involved the autopsy conducted on 40 bodies of intravenous heroin addicts and 10 control autopsies. The liver tissue was fixed in glutaraldehyde and moulded with epon for investigation purposes of ultrastructural changes. The analysis was performed using the method of transmission electron microscopy. In the group of intravenous heroin addicts, the liver autopsy samples showed degenerative vesicular and fat changes, chronic active and persistent hepatitis, cirrhosis, reduction in the amount of glycogen in hepatocytes, as well as the Kupffer cell’s dominant hypertrophy. Various changes occur in organelles, plasma membrane of hepatocytes and biliary channels as well as in the nucleus. The most important ultrastructural findings include: hyperplasia and hypertrophy of the smooth endoplasmic reticulum, which is histologically proven vesicular degeneration of hepatocyte occurring as a result of the increased synthesis of enzymes of smooth endoplasmic reticulum due to chronic intravenous heroin intake, and the presence of continuous basal membrane followed by transformation of the sinusoids into capillaries (in the cases of chronic active hepatitis and cirrhosis) which leads to a disorder of microcirculation and further progress of cirrhosis

Ultrastructural Changes in the Liver of Intravenous Heroin Addicts

The ultrastructural research has a decisive role in gathering the knowledge on the liver’s response to the influence of some drugs. The aim of the study was to perform an ultrastructurai analysis of the liver in chronic intravenous heroin addicts. The study involved the autopsy conducted on 40 bodies of intravenous heroin addicts and 10 control autopsies. The liver tissue was fixed in glutaraldehyde and moulded with epon for investigation purposes of ultrastructural changes. The analysis was performed using the method of transmission electron microscopy. In the group of intravenous heroin addicts, the liver autopsy samples showed degenerative vesicular and fat changes, chronic active and persistent hepatitis, cirrhosis, reduction in the amount of glycogen in hepatocytes, as well as the Kupffer cell’s dominant hypertrophy. Various changes occur in organelles, plasma membrane of hepatocytes and biliary channels as well as in the nucleus. The most important ultrastructural findings include: hyperplasia and hypertrophy of the smooth endoplasmic reticulum, which is histologically proven vesicular degeneration of hepatocyte occurring as a result of the increased synthesis of enzymes of smooth endoplasmic reticulum due to chronic intravenous heroin intake, and the presence of continuous basal membrane followed by transformation of the sinusoids into capillaries (in the cases of chronic active hepatitis and cirrhosis) which leads to a disorder of microcirculation and further progress of cirrhosis