In the case of a radiological emergency it is of utmost importance that we can rapidly quantify theradionuclide content of a person or population to ensure that the right precautions or treatmentsare taken. In this project we investigate how well the Palmer geometry works to quantify the Cs-137 content of a test population. The aim is to find if this geometry could replace the currentmeasuring geometry. To begin with, we investigate the full energy peak efficiencies in the Palmer geometry formeasurements of whole body content of radioactive nuclides using Detective-X, a spectrometricgamma radiation detector produced by ORTEC. First, we perform an empirical efficiency cali-bration based on measurements with the phantom IRINA using both Cs-137 and Eu-152 to cover arange of energies. We employ two configurations of the IRINA phantom to represent the bodyof the average woman and man in Sweden. The detector is directed towards the abdomen of the phantom, which is in a crouched seated position, to emulate the Palmer geometry. Additionally, we construct a detector model in Monte-Carlo N-particle transport code (MCNP).To validate this model we calibrate the detector with a Cs-137 point source at various angles of in-cidence to determine its angular dependence, performing the measurements along two axes ofrotation. We find that the efficiency in the final MCNP model agree well with the empiricalcalibration. The detector model is then used alongside the MCNP models of two IRINA configurations to compare the simulated and empirical calibrations. We observe that the detector model agree well with our empirical calibrations. Finally, we measure the whole body content of Cs-137 in a group of residents around Umeå,Sweden. In these measurements, the Palmer geometry is employed, where the test person sitswith the detector in their lap, having the top cap against their stomach, and crouches over it. These measurement are compared to those taken in a low background setup (mobile whole body counter), where the test person lays down on their back in a lead cradle and have their legs and head above their chest and abdomen. We find that the signal in the Palmer geometry has a higherbackground level, preventing detection of low activities. Additionally, the Palmer setup tends to underestimate the activity compared to the current setup. More test subjects with higher activity is needed to test the setup, as the current data is not sufficient for definite conclusions. In conclusion, the simulation model is sufficient for future simulations of the Palmer geometry. The tests of the Palmer geometry are not sufficient to sufficiently prove if the geometry will be a good method to determine the whole body content of radionuclides. To test it further a larger test population with a higher activity is needed. The calibrations should also be done with other configurations of IRINA and activity distribution to better emulate an adult human.

INTRODUÇÃO: Obesidade é, hoje, considerada uma pandemia, com cerca de 500 milhões de obesos no mundo, com cerca de 2,8 milhões de mortes por ano. A cirurgia de bypass gástrico é um importante tratamento para obesidade, porém, não é isenta de riscos. O dispositivo temporário de exclusão duodeno jejunal - DTED (EndoBarrier Gastrointestinal Liner® GIDynamics, Inc. Lexington, MA), apresenta-se como uma nova forma de tratamento endoscópico da obesidade. Apesar dos bons resultados, os mecanismos de ação do DTED ainda não foram estudados, podendo as alterações humorais e do esvaziamento gástrico promovidas, ser os principais responsáveis pelos resultados obtidos. OBJETIVO: Estudar as alterações promovidas pelo DTED no esvaziamento gástrico, e a relação destas alterações com os resultados clínicos de perda de peso e controle do diabetes tipo 2. MÉTODOS: Vinte e cinco obesos e com diabetes tipo 2, que fizeram uso do DTED por período mínimo de 16 semanas e máximo de 24 semanas, realizaram teste de esvaziamento gástrico cintilográfico, antes, durante a 16ª semana de uso e após 4 semanas de retirada do DTED. Foram obtidas medidas de peso e hemoglobina glicada. As médias e desvio-padrão de retenção gástricas foram obtidas e comparadas entre os três exames realizados, e, após, comparados entre os pacientes que obtiveram e os que não obtiveram melhora no parâmetro clínico selecionado (perda de peso maior que 10%, e hemoglobina glicada menor que 7%). Também se avaliou subjetivamente a sensação de saciedade e quantidade de alimento ingerido durante a 16ª semana de uso do dispositivo. RESULTADOS: Quando avaliadas médias de retenção, nota-se que, na 16ª semana de uso, há maior retenção para a primeira, segunda e quarta horas quando comparados ao baseline (1ª h 74 ± 16,3 % p=0,001, 2ª h 45 ± 25% p < 0,001; 4ª 15 ± 15,8% p < 0,001). Não há diferença estatística entre as retenções na 16ª semanas entre os pacientes que atingiram e os que não atingiram o controle do diabetes (p=0,73), entre os que perderam mais de 10% de peso e os que não perderam (p=0,275). Durante a 16ª semana de uso, 23 pacientes (92%) referiram maior sensação de saciedade precoce e maior saciação, e todos referiram comer em menor volume de em relação ao período prévio à colocação do dispositivo. CONCLUSÕES: O DTED causa lentificação no esvaziamento gástrico, reversível após sua retirada, porém esta alteração no esvaziamento gástrico, mesmo sendo sintomática, com aumento de saciedade e saciação, e com diminuição do volume de alimento ingerido, não tem relação com a perda de peso e melhora do diabetes / INTRODUCTION: Obesity is now considered a pandemic, with about 500 million obese worldwide, with about 2.8 million deaths per year. The gastric bypass surgery is an important treatment for obesity, however, not without risks. The temporary duodenal jejunal exclusion device - DTED (EndoBarrier ® Gastrointestinal Liner GIDynamics, Inc. Lexington, MA), presents itself as a new form of endoscopic treatment of obesity. Despite the good results, the mechanisms of action of DTED have not been studied, and the humoral changes and changes in gastric emptying promoted by the device maybe are the main mechanisms of action of the device. OBJECTIVE: To study the changes introduced by DTED in gastric emptying, and the relationship of these changes with clinical outcomes of weight loss and control of type 2 diabetes. METHODS: Twenty five obese patients with type 2 diabetes who used the DTED for a minimum of 16 weeks and maximum 24 weeks underwent a scintigraphic gastric emptying test, before, during the 16th week of treatment and after 4 weeks of withdrawal the DTED. Measurements of weight, glycated hemoglobin were obtained. The mean and standard deviation of gastric retention were obtained and compared between the three tests, and after, compared between patients who were and those who showed no improvement in selected clinical parameters (weight loss greater than 10%, and lower glycated hemoglobin 7%). Also, a subjective evaluation of the feeling of satiety and amount of food ingested during the 16 weeks of device use was done. RESULTS: When evaluated average retention , we note that in the 16th week of use there is greater retention for the first, second and fourth hour compared to baseline (1st h 74 ± 16.3 % p = 0.001, 2nd h 45 ± 25 % p < 0.001 4th 15.8 ± 15 %, p < 0.001). There is no statistical difference among patients who achieved and those who have not reached the control of diabetes (p = 0.73) or among those who lost more than 10 % by weight and not lost (p = . 0.275) during the 16th week of treatment , 23 patients (92%) reported greater sense of early satiety and satiation greater, and all reported eating less volume of food in relation to the period prior to devide placement. CONCLUSIONS: The DTED cause delay in gastric emptying, reversible after withdrawal, though this change in gastric emptying, even being symptomatic with increased satiety and satiation , decreasing the volume of food ingested , has no relation to weight loss and improved diabetes

INTRODUÇÃO: Obesidade é, hoje, considerada uma pandemia, com cerca de 500 milhões de obesos no mundo, com cerca de 2,8 milhões de mortes por ano. A cirurgia de bypass gástrico é um importante tratamento para obesidade, porém, não é isenta de riscos. O dispositivo temporário de exclusão duodeno jejunal - DTED (EndoBarrier Gastrointestinal Liner® GIDynamics, Inc. Lexington, MA), apresenta-se como uma nova forma de tratamento endoscópico da obesidade. Apesar dos bons resultados, os mecanismos de ação do DTED ainda não foram estudados, podendo as alterações humorais e do esvaziamento gástrico promovidas, ser os principais responsáveis pelos resultados obtidos. OBJETIVO: Estudar as alterações promovidas pelo DTED no esvaziamento gástrico, e a relação destas alterações com os resultados clínicos de perda de peso e controle do diabetes tipo 2. MÉTODOS: Vinte e cinco obesos e com diabetes tipo 2, que fizeram uso do DTED por período mínimo de 16 semanas e máximo de 24 semanas, realizaram teste de esvaziamento gástrico cintilográfico, antes, durante a 16ª semana de uso e após 4 semanas de retirada do DTED. Foram obtidas medidas de peso e hemoglobina glicada. As médias e desvio-padrão de retenção gástricas foram obtidas e comparadas entre os três exames realizados, e, após, comparados entre os pacientes que obtiveram e os que não obtiveram melhora no parâmetro clínico selecionado (perda de peso maior que 10%, e hemoglobina glicada menor que 7%). Também se avaliou subjetivamente a sensação de saciedade e quantidade de alimento ingerido durante a 16ª semana de uso do dispositivo. RESULTADOS: Quando avaliadas médias de retenção, nota-se que, na 16ª semana de uso, há maior retenção para a primeira, segunda e quarta horas quando comparados ao baseline (1ª h 74 ± 16,3 % p=0,001, 2ª h 45 ± 25% p < 0,001; 4ª 15 ± 15,8% p < 0,001). Não há diferença estatística entre as retenções na 16ª semanas entre os pacientes que atingiram e os que não atingiram o controle do diabetes (p=0,73), entre os que perderam mais de 10% de peso e os que não perderam (p=0,275). Durante a 16ª semana de uso, 23 pacientes (92%) referiram maior sensação de saciedade precoce e maior saciação, e todos referiram comer em menor volume de em relação ao período prévio à colocação do dispositivo. CONCLUSÕES: O DTED causa lentificação no esvaziamento gástrico, reversível após sua retirada, porém esta alteração no esvaziamento gástrico, mesmo sendo sintomática, com aumento de saciedade e saciação, e com diminuição do volume de alimento ingerido, não tem relação com a perda de peso e melhora do diabetes / INTRODUCTION: Obesity is now considered a pandemic, with about 500 million obese worldwide, with about 2.8 million deaths per year. The gastric bypass surgery is an important treatment for obesity, however, not without risks. The temporary duodenal jejunal exclusion device - DTED (EndoBarrier ® Gastrointestinal Liner GIDynamics, Inc. Lexington, MA), presents itself as a new form of endoscopic treatment of obesity. Despite the good results, the mechanisms of action of DTED have not been studied, and the humoral changes and changes in gastric emptying promoted by the device maybe are the main mechanisms of action of the device. OBJECTIVE: To study the changes introduced by DTED in gastric emptying, and the relationship of these changes with clinical outcomes of weight loss and control of type 2 diabetes. METHODS: Twenty five obese patients with type 2 diabetes who used the DTED for a minimum of 16 weeks and maximum 24 weeks underwent a scintigraphic gastric emptying test, before, during the 16th week of treatment and after 4 weeks of withdrawal the DTED. Measurements of weight, glycated hemoglobin were obtained. The mean and standard deviation of gastric retention were obtained and compared between the three tests, and after, compared between patients who were and those who showed no improvement in selected clinical parameters (weight loss greater than 10%, and lower glycated hemoglobin 7%). Also, a subjective evaluation of the feeling of satiety and amount of food ingested during the 16 weeks of device use was done. RESULTS: When evaluated average retention , we note that in the 16th week of use there is greater retention for the first, second and fourth hour compared to baseline (1st h 74 ± 16.3 % p = 0.001, 2nd h 45 ± 25 % p < 0.001 4th 15.8 ± 15 %, p < 0.001). There is no statistical difference among patients who achieved and those who have not reached the control of diabetes (p = 0.73) or among those who lost more than 10 % by weight and not lost (p = . 0.275) during the 16th week of treatment , 23 patients (92%) reported greater sense of early satiety and satiation greater, and all reported eating less volume of food in relation to the period prior to devide placement. CONCLUSIONS: The DTED cause delay in gastric emptying, reversible after withdrawal, though this change in gastric emptying, even being symptomatic with increased satiety and satiation , decreasing the volume of food ingested , has no relation to weight loss and improved diabetes

No description available.

Le RAFT-RGD radiomarqué avec un émetteur β- comme nouvel agent de radiothérapie interne vectorisée. L'intégrine αvβ3 est fortement impliquée en oncogenèse à travers son rôle dans la néoangiogenèse tumorale, dans la prolifération et la survie des cellules cancéreuses et dans le processus métastatique. L'intégrine αvβ3 est exprimée faiblement dans la plupart des tissus. Par contre, elle est fortement exprimée par les cellules endothéliales activées lors de l'angiogenèse et par les cellules de nombreux types de cancers invasifs. Ces caractéristiques font de l'intégrine αvβ3 une excellente cible pour l'imagerie et la thérapie de ces tumeurs. Le RAFT-RGD (Regioselectively Addressable Functionalized Template-(cyclo-[RGDfK])4) est un derivé polypeptidique constitué de quatre peptides cyclo-RGD (spécifiques de l'intégrine αvβ3) fixés sur un groupe porteur RAFT. Le RAFT-RGD cible spécifiquement l'intégrine αvβ3 in vitro et in vivo et permet la détection par imagerie nucléaire ou par fluorescence de tumeurs exprimant αvβ3 sur des modèles précliniques. Le RAFT-RGD un excellent vecteur potentiel pour cibler les tumeurs exprimant αvβ3 et pour y délivrer des traitements, que ce soit des molécules de chimiothérapie ou des radionucléides de thérapie. Cette étude est la première à évaluer le potentiel thérapeutique du RAFT-RGD radiomarqué avec un émetteur β- sur un modèle de souris Nude porteuses de tumeurs exprimant l'intégrine αvβ3. Une injection de 37 MBq de 90Y-RAFT-RGD ou de 177Lu-RAFT-RGD permet de ralentir significativement la croissance de tumeurs exprimant l'intégrine αvβ3 par rapport aux souris contrôles non traitées ou traitées avec la même activité de la molécule de contrôle non spécifique de la cible, le RAFT-RAD. En comparaison, une injection de 30 MBq de 90Y-RAFT-RGD ne permet pas de ralentir la croissance de tumeurs n'exprimant pas l'intégrine αvβ3. Le RAFT-RGD présente un bon potentiel pour le traitement de tumeurs exprimant l'intégrine αvβ3 lorsqu'il est radiomarqué avec des émetteurs β-. Mots clés : intégrine αvβ3, RAFT-RGD, ciblage tumoral, radiothérapie interne vectorisée. / Β- emitters radiolabeled RAFT-RGD as new agents for internal targeted radiotherapy. The αvβ3 integrin is known to play an important role in tumor-induced angiogenesis, tumor proliferation, survival and metastasis. Because of its overexpression on neoendothelial cells such as those present in growing tumors, as well as on tumor cells of various origins, αvβ3 integrin is an attractive molecular target for diagnosis and therapy of the rapidly growing and metastatic tumors. A tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets integrin αvβ3 in vitro and in vivo. RAFT-RGD has been used for tumor imaging and drug targeting. This study is the first to evaluate the therapeutic potential of the β- emitters radiolabeled tetrameric RGD peptide RAFT-RGD in a Nude mouse model of αvβ3-expressing tumors. An injection of 37 MBq of 90Y-RAFT-RGD or 177Lu-RAFT-RGD in mice with αvβ3-positive tumors caused a significant growth delay as compared with mice treated with 37 MBq of 90Y-RAFT-RAD or 177Lu-RAFT-RAD or untreated mice. In comparison, an injection of 30 MBq of 90Y-RAFT-RGD had no efficacy for the treatment of αvβ3-negative tumors. 90Y-RAFT-RGD and 177Lu-RAFT-RGD are potent αvβ3-expressing tumor targeting agents for internal targeted radiotherapy. Keys words : integrin αvβ3, RAFT-RGD, tumour targeting, internal targeted radiotherapy.

La radiothérapie interne vectorisée (RIV) permet une irradiation systémique la plus élective possible des lésions métastatiques de cancers. Nous rapportons une étude de phase I avec première injection à l’homme mise en place au Centre Léon Bérard pour le traitement de patients porteurs de métastases de synovialosarcomes. Sur un schéma théranostique, une étape d’imagerie et de dosimétrie était réalisée afin d’étudier la biodistribution du radiopharmaceutique diagnostique (RPD) compagnon du radiopharmaceutique thérapeutique (RPT). En cas de biodistribution favorable (fixation tumorale supérieure aux organes sains environnant) permettant d’envisager la RIV avec un effet tumoricide tout en limitant les effets secondaires de l’irradiation de tissus sains, les patients recevaient le RPT. Au total 20 patients ont été inclus. Dix d’entre eux étaient éligibles à la phase thérapeutique : 2 n’ont pas pu être traités du fait d’une progression de la maladie et 8 ont été traités, incluant 1 patiente ayant pu recevoir une 2ème injection de RPT du fait d’une stabilisation de la maladie. Les effets secondaires ont été principalement hématologiques. Les réponses au traitement ont été des stabilisations transitoires. Face à ces résultats modestes, nous avons réalisé une étude dosimétrique plus approfondie pour mieux les comprendre. Nous discuterons des voies possibles pour optimiser ce traitement en s’appuyant notamment sur les études de RIV ayant montré de réels bénéfices pour les patients / Vectorized Radionuclide Therapy allows a more elective systemic irradiation of metastatic cancer lesions. We are reporting a first in human phase I study set up at the Léon Bérard Cancer Centre for the treatment of patients with synovialosarcoma metastases. Following a theranostic scheme, an imaging and dosimetry step was performed to study the biodistribution of the diagnostic radiopharmaceutical (DRP) companion of the therapeutic radiopharmaceutical (TRP). In case of favorable biodistribution (tumor uptake greater that surrounding healthy organs tracer uptake) allowing IVR to be considered with a tumoricidal effect while limiting the side effects of irradiated healthy tissues, patients received the TRP. A total of 20 patients were included. Ten of them were eligible for the therapeutic phase: 2 could not be treated due to disease progression and 8 were treated, including 1 patient who received a 2nd injection after disease stabilization. The side effects were mainly hematological. Treatment responses were transient stabilizations. In response to these modest results, we conducted a more in-depth dosimetric study to better understand them. We will discuss possible ways to optimize this treatment, based in particular on RIV studies that have shown real benefits for patients

INTRODUÇÃO: O câncer infantil é a primeira causa de morte em crianças, nos países desenvolvidos. Nos últimos 40 anos, graças ao desenvolvimento da Oncopediatria e de drogas como as antraciclinas (ATC), a taxa de cura tem atingido até 80%. Isto repercutiu em significativo aumento da sobrevida e, consequentemente, nos efeitos deletérios da quimioterapia com ATC, como a cardiotoxicidade. A fim de estudar os efeitos tardios da quimioterapia com ATC sobre o sistema nervoso cardíaco simpático (SNS), foi realizado estudo de cintilografia com 123I-mIBG (meta-iodobenzilguanedina ligado ao iodo123) e comparado com dose dos ATCs e fração de ejeção do ventrículo esquerdo (FEVE), através da ventriculografia radioisotópica (VR). As variáveis analisadas pela cintilografia com 123I-mIBG foram a relação coração/mediastino (C/M) e a taxa de clareamento (TC) que sinalizam o funcionamento neuronal cardíaco. MÉTODOS: realizado estudo transversal de pacientes assintomáticos submetidos à quimioterapia com ATC na infância e adolescência, com período de 2 a 21 anos, após o término do tratamento, e com ecocardiograma (ECO) normal. Dos 118 pacientes participantes recrutados, 27 foram excluídos (motivos: radioterapia torácica, desistência e uso de cardioprotetores). Os dados clínicos e patológicos dos 91 pacientes participantes foram coletados dos prontuários ou através de anamnese. Simultaneamente foi estudado um grupo controle (40 voluntários), e, com as avaliações de imagens com 123I-mIBG e VR, foi preenchida uma ficha de coleta padronizada previamente elaborada e digitada em banco de dados no Software IBM® SPSS® Statistics 20.0.1 for Windows, para posterior análise. Os achados dos pacientes foram analisados e comparados aos do grupo controle. RESULTADOS: Neste grupo, a média de acúmulo da 123I-mIBG - 3,5h, avaliada pela relação C/M, foi de 2,23 com IC [95%] (2,17-2,29). A média da TC foi de 10,27% com IC [95%] (7,52-13,03). Para ambas as informações, os valores apresentaram-se dentro da normalidade. Ao se comparar com o grupo controle (40 voluntários, 28 homens e 14 mulheres, idade: 3 a 36 anos), onde a relação C/M foi de 2,26 com IC [95%] (2,18-2,34) e a média da TC foi de 9,64% com IC [95%] (5,76-13,52), não houve diferença significativa. Ressalte-se que 6,6% do total de pacientes, apesar de não alterarem significativamente a média do grupo na análise estatística, apresentaram relação C/M <1,9 (valor considerado cut off). Em relação à variável FEVE da VR, houve uma diferença de -3,68, onde o p valor foi < 0,01 e o IC (-5,99; -1,37), sendo a FEVE do grupo de pacientes menor que a FEVE do grupo controle. CONCLUSÃO: Os valores da relação C/M e TC, encontrados com a cintilografia cardíaca com 123I-mIBG no grupo de pacientes, não mostraram diferença significativa com o grupo controle. No entanto, 6,6% dos pacientes submetidos ao tratamento com ATC apresentaram alterações neuronais cardíacas (relação C/M), abaixo do valor mínimo. Além disso, a média da FEVE foi menor, apesar de ainda encontrar-se com valores absolutos dentro da normalidade. Tais achados podem ser um indício de alterações clínicas relevantes no futuro / INTRODUCTION: Child cancer is the first cause of children\'s death in developed countries. In the last 40 years, thanks to the development of the pediatric oncology and drugs like the Anthracyclines (ATC), cure rate has reached up to 80%. This reflected a significant improvement in survival and as a consequence the deleterious effects from chemotherapy, like cardiotoxicity, has emerged. In order to study the later effects of the chemotherapy with ATC on the sympathetic nervous system (SNS) cardiac 123I-mIBG (123Imetaiodobenzylguanidine) scintigraphy was performed and compared to the left ventricle ejection fraction (LVEF), through radionuclide ventriculography (RV). The variables analized by the 123I-mIBG scintigraphy were the heart/mediastinum ratio (H/M) and the washout rate (WR). METHODS: This is a transversal study of asymptomatic patients undergoing ATC chemotherapy in childhood and adolescence, ages varying from 2 to 21 years after the end of the treatment and normal echocardiogram (ECO). From the 118 recruted participant subjects, 27 were excluded ( thoracic radiotherapy, abandonment and use of cardioprotectors). The clinical and pathological data from the 91 patients were collected from medical records or clinical history. A control group of 40 healthy volunteers(28 male, 14 females; ages varying from 3 to 36) was studied simultaneously and evaluated as well with 123I-mIBG and RV. All data collected were stored in a databank for later analysis, patients findings versus control group. RESULTS: In the patient group the average H/M ratio from the late 123I-mIBG image was 2,23 with CI [95%] (2,17-2,29), and average WR was 10,27% with CI [95%] (7,52-13,03). The control group had the H/M ratio of 2,26 with CI [95%] (2,18-2,34) and the WR rate of 9,64% with CI [95%] (5,76-13,52). The comparison between groups was not significant. However, it has to be highlighted that 6,6% of all the patients had abnormal H/M values which were below the cutoff considered of <1,9. On the other hand, when comparing the mean LVEF, there was a difference of -3,68 with p < 0,01 and CI (-5,99; -1,37), being the LVEF in the patient group lower than the control. CONCLUSION: Although there was no significance in the intergroup comparison for H/M and WR, there was a small proportion of patients who presented neuronal cardiac alterations (H/M ratio) below the minimum value. Besides that, the LVEF average was lower, despite still having absolute values within the normality. Such findings can be an indication of the clinical alterations as relevant in the future

A quantificação da atividade de radionuclídeos emissores de raios gama em amostras medidas por espectrometria gama com detectores HPGe depende da análise dos fotopicos presentes no espectro, especialmente da determinação exata das suas áreas líquidas. Tal análise é geralmente realizada com o auxílio de ferramentas de software proprietário. Este trabalho apresenta uma metodologia, descrição de algoritmos e um aplicativo de código aberto, denominado OpenGamma, para a busca e análise de fotopicos a fim de se obter seus parâmetros relevantes e as atividades dos radionuclídeos na amostra. A implementação computacional é distribuída sob licença aberta para o código principal e com o uso de pacotes de software aberto para o projeto da interface e para bibliotecas matemáticas. O procedimento para a busca de picos é realizado em três etapas. Primeiramente, executa-se uma pesquisa preliminar com o método da segunda diferença, que consiste na geração de um espectro derivado para a busca de picos candidatos. Na segunda etapa, calculam-se as larguras experimentais dos picos, dos quais escolhem-se aqueles bem formados e isolados para a obtenção da função de ajuste da largura vs. canal, por meio do método de Levenberg-Marquardt para ajustes não-lineares. Por fim, regiões do espectro com picos agrupados são delimitadas e novo ajuste não-linear é aplicado a cada região para a obtenção dos termos da linha de base e dos fotopicos. A partir destes termos, são calculadas as áreas líquidas dos picos. Para a determinação da atividade, curvas de calibração de eficiência previamente obtidas, bem como dados de transições gama dos radionuclídeos, são incorporadas ao código e aplicadas. O código foi escrito em linguagem C++ e a interface foi desenvolvida com a ferramenta Qt. Para as funções matemáticas e procedimentos de ajuste, foi usada a biblioteca científica GNU (GSL). A validação de código foi feita por meio da análise de: 1) espectros sintéticos de teste da AIEA, especialmente desenhados para a avaliação de desempenho de software; 2) espectros obtidos com amostras de exercícios de intercomparação e 3) espectros da rotina de trabalho do Laboratório de Radiometria Ambiental (LRA) do IPEN e analisados com o aplicativo comercial InterWinner. Os resultados obtidos são consistentes com os valores de referência e com aqueles obtidos pelo aplicativo citado, sugerindo que o código OpenGamma pode ser utilizado com segurança na espectrometria de raios gama de uso geral. / Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. For the activity determination, previously obtained efficiency calibration curves, as well as nuclides gamma-ray data, are incorporated in the code and applied. The code was developed in C++ language and the interface was developed with Qt GUI software toolkit. GNU scientific library, GSL, was employed to perform fitting procedures as needed. Validation of code was done by analyzing: 1) synthetic test spectra from IAEA, especially designed for software performance evaluation; 2) spectra obtained from samples of intercomparison exercises and 3) spectra from routine activities of the Environmental Radiometric Laboratory (LRA) at IPEN and analyzed with the commercial software package InterWinner. Results obtained are consistent with the reference values and with those obtained by the aforementioned package. The results suggest that the OpenGamma code could be safely used in general-purpose gamma-ray spectrometry.

A quantificação da atividade de radionuclídeos emissores de raios gama em amostras medidas por espectrometria gama com detectores HPGe depende da análise dos fotopicos presentes no espectro, especialmente da determinação exata das suas áreas líquidas. Tal análise é geralmente realizada com o auxílio de ferramentas de software proprietário. Este trabalho apresenta uma metodologia, descrição de algoritmos e um aplicativo de código aberto, denominado OpenGamma, para a busca e análise de fotopicos a fim de se obter seus parâmetros relevantes e as atividades dos radionuclídeos na amostra. A implementação computacional é distribuída sob licença aberta para o código principal e com o uso de pacotes de software aberto para o projeto da interface e para bibliotecas matemáticas. O procedimento para a busca de picos é realizado em três etapas. Primeiramente, executa-se uma pesquisa preliminar com o método da segunda diferença, que consiste na geração de um espectro derivado para a busca de picos candidatos. Na segunda etapa, calculam-se as larguras experimentais dos picos, dos quais escolhem-se aqueles bem formados e isolados para a obtenção da função de ajuste da largura vs. canal, por meio do método de Levenberg-Marquardt para ajustes não-lineares. Por fim, regiões do espectro com picos agrupados são delimitadas e novo ajuste não-linear é aplicado a cada região para a obtenção dos termos da linha de base e dos fotopicos. A partir destes termos, são calculadas as áreas líquidas dos picos. Para a determinação da atividade, curvas de calibração de eficiência previamente obtidas, bem como dados de transições gama dos radionuclídeos, são incorporadas ao código e aplicadas. O código foi escrito em linguagem C++ e a interface foi desenvolvida com a ferramenta Qt. Para as funções matemáticas e procedimentos de ajuste, foi usada a biblioteca científica GNU (GSL). A validação de código foi feita por meio da análise de: 1) espectros sintéticos de teste da AIEA, especialmente desenhados para a avaliação de desempenho de software; 2) espectros obtidos com amostras de exercícios de intercomparação e 3) espectros da rotina de trabalho do Laboratório de Radiometria Ambiental (LRA) do IPEN e analisados com o aplicativo comercial InterWinner. Os resultados obtidos são consistentes com os valores de referência e com aqueles obtidos pelo aplicativo citado, sugerindo que o código OpenGamma pode ser utilizado com segurança na espectrometria de raios gama de uso geral. / Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. For the activity determination, previously obtained efficiency calibration curves, as well as nuclides gamma-ray data, are incorporated in the code and applied. The code was developed in C++ language and the interface was developed with Qt GUI software toolkit. GNU scientific library, GSL, was employed to perform fitting procedures as needed. Validation of code was done by analyzing: 1) synthetic test spectra from IAEA, especially designed for software performance evaluation; 2) spectra obtained from samples of intercomparison exercises and 3) spectra from routine activities of the Environmental Radiometric Laboratory (LRA) at IPEN and analyzed with the commercial software package InterWinner. Results obtained are consistent with the reference values and with those obtained by the aforementioned package. The results suggest that the OpenGamma code could be safely used in general-purpose gamma-ray spectrometry.

The spread of surface coal mining has resulted in loss of forests in the Appalachian region. The Forestry Reclamation Approach (FRA) was developed to provide guidance for restoring forests on reclaimed mined land. This study hypothesizes that the FRA will result in larger magnitude of sediment accumulation rates in reclaimed mine sites compared to those reclaimed using grassland reclamation. Three sediment cores and six trenches were sampled within four reclaimed mined and three previously logged sites in eastern Kentucky. Samples were processed for radionuclides, grain-size, stable isotopes (δ13C), and POC. LIDAR data were used to identify valley fills, while historical aerial photography was used to identify changes in vegetative cover from 1994 to 2016. Radionuclide dating was used to determine sediment accumulation rates over the previous 100 years. Results from logged sites are inconclusive. δ13C data for all sites fall within the range expected for forested landscapes (C3), and do not show any transitions from grassland to forests. POC data indicates that inventories and fluxes were the same for mined and logged sites. Sediment accumulation rates for reclaimed mined lands show elevated values after the implementation of the FRA, compared to grassland reclamation, thus supporting the hypothesis for previously mined sites.