Inom nuklearmedicin exponeras personal dagligen för joniserande strålning. Det kan vara både i form av en öppen strålkälla vid uppdrag av radiofarmaka och vid bildtagning där personalen hjälper och ger stöd till patienten som blivit injicerad. Vid uppdrag av radiofarmaka används strålskydd i form av sprutskydd och distansverktyg medan blyförkläde används vid kontakt med patienter. Dessa skydd är till för att minska skador som kan uppstå vid exponering. Den svenska strålsäkerhetsmyndigheten (SSM) har föreskrivit dosgränser som inte får överskridas för att minska risken för skador. Teknetium-99m (99mTc) är den vanligaste radionukliden inom den nuklearmedicinska verksamheten. Syftet med denna studie var att kartlägga strålningsexponeringen för personal som jobbar med 99mTc och på så sätt visa behovet av olika typer av strålskydd för att reducera stråldosen. I denna studie utfördes fingerdosmätningar vid uppdrag av 99mTc med hjälp av termoluminiscenta dosimetrar som placerades på de tre mest utsatta fingrarna, digitus I-III, bilateralt. Mätningarna genomfördes vid uppdrag utan strålskydd, med en pincett och med fullt strålskydd (sprutskydd samt två pincetter). Studien innefattar även stråldosmätningar med och utan blyförkläde för myokardscintigrafi, skelettscintigrafi och lungscintigrafi. Dessa mätningar utfördes med en direktavläsande personal electronic dosimeter (PED) där den effektiva dosen registrerades. Resultaten för fingerdosmätningarna visar en signifikant skillnad i stråldos beroende på om och vilket strålskydd som används. Högst dos fick de som drog upp helt utan strålskydd och vänster långfinger fick den högsta ekvivalenta dosen. För stråldosmätningarna med och utan blyförkläde utfördes ett Mann-Whitney U-test som visade ett p-värde på <0,05 vilket tyder på att det finns en statistisk signifikant skillnad. Högst effektiv dos uppmättes vid lungscintigrafi för personal som inte använde blyförkläde. / Personnel working with radiopharmaceuticals in the nuclear medicine department are exposed to radiation on the daily basis. The source of radiation can both be open as in the withdrawal procedure and external as when the patient has been injected and ready for imaging. There are different types of radiation protection depending on which task that is performed. Syringe shielding and distance tools are used during the withdrawal and lead aprons are used when positioning the patient under the camera. The Swedish radiation safety authority (SSM) prescribe dose limits to reduce any risk of injury connected to radiation. These limits must not be exceeded. Technetium-99m (99mTc) is the most common radiopharmaceutical in the nuclear medicine department. The purpose of this study was to study the radiation exposure to personnel working with 99mTc and evaluate the need for radiation protection to reduce the radiation dose. This study includes measurement of the equivalent dose to the three most exposed fingers, digitus I-III bilateral, during the withdrawal of 99mTc. Thermoluminiscent dosimeters was used to detect radiation and was placed on top of the finger. The measurements were performed without radiation shielding, with only one tweezer as distance tool and with full radiation shielding (syringe shielding and two tweezers as distance tools). It also includes measurement of the effective dose during myocardial scintigraphy, bone scan and lung scintigraphy with or without lead apron. For these measurements a personal electronic dosimeter was used to detect radiation. The result of the finger doses showed a significant difference in radiation dose depending on which protection was used. The highest dose was recovered from not using any protection at all and the highest equivalent dose was obtained by left middle finger. For the measurement regarding the effective dose with or without lead apron a Mann-Whitney U-test was performed and showed a p-value of <0,05 which indicates a statistical significant difference. The highest effective dose was recovered from lung scintigraphy when the personnel was not wearing a lead apron.

The practice in the department of nuclear medicine requires the involvement of radiation protection with care of patients and occupational safety of radiation workers. Nuclear medicine involves the handling of radioactive substances that may cause external or internal irradiation of workers. The amount of the dose depends on the type of radionuclide, the amount of energy, the work performed by the worker within the department. Patients or staff may be exposed to the external or internal irradiation. The topic of this thesis is the analysis of the current state of radiation protection in the department of nuclear medicine according to the new legislation. The part of the work is the evaluation of monitoring of workers and patients. The research results of the average annual effective dose of total body irradiation at radiation workers ranged from 1.35 to 1.73 mSv, monthly ranged from 0.1? 0.65 mSv. The average annual equivalent dose of Hp (0,07) ranged from 1.15 to 117.68 mSw. The lowest monthly Hp (0.07) was 0.07 mSw and the highest one was 19.92 mSw. At SSK-treated patients the doses applied were 4% lower than diagnostic reference level and the dose at DSSL-treated patients was 22% less than DRU. In conclusion, it was found that the values from personal dosimeters were below the limit and in the case of finger dosimeters in two cases the values were above the examination level. The values of other workers were below the monitoring level during the monitored period. The applied doses of radiopharmaceuticals were less in the observed group of patients than the established diagnostic reference level. On the basis of the presented results it can be stated that radiation protection is in the Department of Nuclear Medicine of Znojmo Hospital f.o, secured in accordance with the applicable legislation.

The ability to extrapolate nutritional intervention data from experimental rodent models to humans requires standardization of dietary design. The inability to translate the level of nutrients from animal models to humans has contributed to contradictory findings between species. It is hypothesized that dietary linoleic acid (LA) promotes chronic and acute diseases by enriching tissues with arachidonic acid (AA), its downstream metabolite. However, levels of LA in rodent diets are notoriously erratic making interspecies comparisons unreliable. Therefore, the ability to extrapolate the biological effects of dietary LA from experimental rodents to humans necessitates an allometric scaling model that is rooted within a human equivalent context. To determine the physiological effect of dietary LA on tissue AA, a mathematical model for extrapolating nutrients based on energy was designed to mimic human equivalent doses. C57BL/6J mice were divided into 9 groups fed a background diet equivalent to that of the US diet (including LA, ALA, AA, EPA, DHA) with supplemental doses of LA (up to 2.3x) or AA (up to 5x). Changes in the phospholipid fatty acid compositions were monitored in plasma and erythrocytes and compared to data from humans supplemented with equivalent doses of LA or AA. Increasing dietary LA had little effect on tissue AA, while supplementing diets with AA significantly increased tissue AA levels, recapitulating results from human trials. Thus, interspecies comparisons for dietary LA between rodents and humans can be achieved when rodents are provided human equivalent doses based on differences in metabolic activity as defined by energy consumption.

Darbe nagrinėjamas lygiavertės dozės galios (LDG) laukų struktūros virš mažų teritorijų nustatymas optimalios interpoliacijos metodu, lygiavertės dozės galios laukų struktūros pokyčiai nuo meteorologinių sąlygų. Baltijos jūros priekrantėje prie Juodkrantės atlikti LDG matavimai prie žemės paviršiaus ir vieno metro aukštyje virš jos. Matavimai atlikti 2008 m. liepos 2, 7, 10 ir 12 dienomis 63 taškuose (2,00,2) km teritorijoje esant šiaurės, pietų, rytų ir vakarų vėjo kryptims. Vidutinių dydžių ekstremalios reikšmės buvo 50 nSv/h ir 130 nSv/h. LDG laukų struktūrai nustatyti ir įvertinti buvo panaudotas optimalios interpoliacijos metodas trim atvejams – kai tyrimų teritorijoje atlikta 63, 33 ir 18 matavimų. Gautos identiškos LDG laukų struktūros. Rasta, kad naudojant tik 18 matavimo rezultatų modelyje gaunamas patenkinamas eksperimentinių ir teorinių rezultatų sutapimas, t.y. skirtumas tarp išmatuotų ir sumodeliuotų rezultatų neviršija 20  paklaidos. Nustatyta, kad esant šiaurės, pietų ir vakarų vėjo kryptims, padidėjus vėjo greičiui vidutiniškai 3 kartus, LDG sumažėja apie 8 nSv/h. Esant rytų vėjui, padidėjus vėjo greičiui 3 kartus, LDG padidėja 7 nSv/h. Darbą sudaro 3 dalys: įvadas, darbo metodai ir priemonės, išvados, literatūra. Darbo apimtis – 58 p. teksto be priedų, 46 iliustr., 1 lent., 36 bibliografiniai šaltiniai. Atskirai pridedami darbo priedai ir publikacija, parengta spaudai. / In this work equivalent dose rate (EDR) field structures under small area was estimated by applying optimal interpolation method and EDR fields structure differences was depended on meteorological conditions. EDR measurements were made to the ground surface and one meter above it beside Juodkrante near Baltic seaside. Measurements carried out in 2008 July 2, 7, 10 and 12 days, in 63 points (2.0 x 0.2) km area then was the north, south, east and west wind direction. Extreme values of the average was 50 nSv/h ir 130 nSv/h. To determine EDR fields structure was used the optimal interpolation method in three cases – then in research area conducted 63, 33 and 18 measurements. Received identical EDR fields structure. Found that the use of only 18 measurements in the model obtained satisfactory experimental and theoretical results coincide, i.e., the difference between measured and model results in less than 20  errors. Found that, in the north, south and west wind direction, wind speed increased by an average of 3 times, EDR decreases about 8 nSv/h. In the east wind, the wind speed increased by 3 times, EDR increased 7 nSv/h / h. Structure: introduction, methods and tools of work, conclusions and suggestions, references. Thesis consist of: 58 p. text without appendixes, 46 pictures, 1 tables, 36 bibliographical entries. Appendixes and publication included.

This research deals with equivalent dose rate (EDR) in the ground level air caused by gamma radiation. Weighting factor for gamma radiation is equal one, so EDR in the ground air is identical absorbed ionic radiation dose. Highways A6 Kaunas-Zarasai and A11 Panevėžys-Šiauliai-Palanga were investigated. In this research the main parameters determining the level of equivalent dose rate in the ground air by the Lithuanian highways have been defined and analyzed. The objective of this research is to measure EDR in the ground air by the Lithuanian highways and compare to adequate average regional and with reference to modulation values evaluate variation reasons. In the expeditions EDR in the ground air was measured in winter and in summer. Samples of soil and asphalt were examined with gamma spectrometer and analyze presented. There was determined the dependence of EDR in the ground air from soil composition, floral or snow cover and distance to the asphalt cover. Cosmic radiation impact on EDR formation is equal to all locations. Natural origin radionuclides in soil gamma radiation have the main influence to EDR formation in the ground air. Modeling program VISIPLAN was used to define impact of radionuclides radiation in asphalt cover to EDR formation in the roadside zone. Modeling program InterRAS was used to define EDR in the ground air formation from gamma radiation of radionuclide in soil.

Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2017-11-22T16:27:19Z No. of bitstreams: 0 / Made available in DSpace on 2017-11-22T16:27:19Z (GMT). No. of bitstreams: 0 / Este trabalho consiste no desenvolvimento de um detector composto por um calorímetro com núcleo de água para dosimetria de feixes de 60Co e 137Cs com média intensidade. Além do calorímetro, foi também dimensionada a instrumentação, a metodologia de calibração e a medição de temperatura. O trabalho foi dividido em 4 etapas distintas: escolha do melhor projeto como base para desenvolvimento do calorímetro, dimensionamento de parâmetros e ajuste fino do projeto, construção e calibração. Durante o desenvolvimento deste trabalho foi construída uma Unidade de Tratamento de Água que permite a produção da água que o calorímetro emprega. Em seguida foi construído o calorímetro em sí com os conceitos das etapas anteriores. O equipamento foi testado tanto nas instalações da GMR quanto no CTR do IPEN, obtendo taxas de dose na água com fontes de 137Cs e 60Co com diversas atividades (3,3 TBq, 15,54 TBq e 7 TBq) e em algumas distâncias. Foram obtidas taxas de dose que variavam de 2 mGy/s até 15 mGy/s, dependendo do tipo de fonte e SDD escolhida. O projeto contou com simulações de códigos como MCNP5 e FLUENT 14 e foram essenciais na construção do equipamento. O objetivo deste trabalho foi aprimorar a infraestrutura do LCI, desenvolvendo um detector que deverá aumentar a gama dos serviços prestados pelo LCI com um tipo de medição dosimétrica ainda inexistente no país. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP