Nükleer tıp merkezlerinde kullanılan radyoizotop kalibratörlerinde kalite sağlanması üzerine bir uygulama-lineerite testi An application study(Linearity test)about maintaining quality in radioisotope calibrators which are used in nuclear medicine centers Yazar (Author): Kemal KOÇ

Positron Emission Tomography (PET) is the imaging system used to diagnose an illness. Positrons from a radioactive nucleus are injected into the patient. There are few existing papers on the energy loses of positrons especially with low energy in the biological target. So, in this study, the goal was to investigate how low kinetic energy positrons (20eV-10keV) interact with DNA by using the Monte-Carlo simulation. In the simulation, screened Rutherford scattering Formula where Wentzel screening parameter was used for elastic collisions, algorithm proposed for the electron-matter interactions of re-edited version of positron interaction was used for inelastic collisions. Because positron-matter interaction involves randomness, the simulation was done using the Monte Carlo Method. In this simulation the screened Rutherford scattering formula using Wentzel screening parameters for elastic collisions and the electron-matter interaction model suggested by Liljequist for inelastic collisions were rearranged in order to determine positron interaction. The stopping powers of adenine, guanine, thymine, cytosine compounds and DNA were determined and compared with that of other related results. The results were found to be considerably higher than reported in some other papers.

In this work, it has been shown that it is possible to determine the radiation doses in human blood exposed to internal or external ionizing radiation treatment, both directly and retrospectively. OSL counts from the waste blood of a patient injected with a radiopharmaceutical for diagnostic or treatment purposes and from a blood sample having a laboratory-injected radiation dose were both used for measurements. The dose values obtained the bloods were found as ~0.46 Gy for the 1-5Gy dose range and as ~0.51 Gy for the 0.143-0.858 Gy dose range using the optically stimulated luminescence technique. The blood aliquots from a healthy person were exposed to different external laboratory doses. The dose values corresponding to a 10Gy laboratory dose from the aliquots exposed to external radiation were found as 10.94 ± 3.30 Gy for Disc 3 and 10.79 ± 3.28 Gy for Disc 1. This study shows that the dose received by a person can be measured simply and retrospectively, using only a very small amount of blood. The results may have important ramifications for the medicine and healthcare fields in particular.

The creativity is a process which can be enhanced by education. The creativity process may be evaluated in the most efficient way by following the student studies. The significant point is to look at the events, ideas, rules, behaviors and objects from different perspectives and to experience it in the life itself. The creativity is an important dimension of learning. The creative thinking is vital for acquiring the information and the environments convenient to enhancing the creativity help learners to hold positive attitudes towards learning. In this study, the creativity and creative thinking which are crucial nowadays and assumed to increase its importance in the future are examined in terms of the relationship between “alternative assessment methods” and “performance tasks” which have entered into our education system in recent years.

<p>The sensitivity of detector mainly depends on two parameters as energy resolving power and detection efficiency. In the studies made with radioisotopes, particularly the high detection efficiency allows for conducting high quality medical operations with low radiation doses. While today highly-advanced imaging systems are effectively used in the nuclear medicine studies, the use of some conventional counting systems such as thyroid uptake probe are continued effectively. A NaI(Tl) scintillation counter is used in the thyroid uptake probe for detection of radiation and this detector is one of detector types which is very frequently used in the measurement of gamma rays. In this study, some of parameters leading to the efficiency of thyroid uptake probe was measured by taking its significance mentioned above in consideration. The count rate was calculated based on these results and these count rates were compared with the count rates measured.</p>