•Quantitative estimation of beta + emitters production rates with the GEANT4 simulation toolkit at 55, 65, 120 and 220 MeV.•Comparison of the 55 MeV simulated production rates to data from Dendooven ...et al.•Comparison of the simulated β+ activity profiles to those extracted from experimental data.•Study of 12N which, from the work of Dendooven et al., is known to be the main isotope for in-beam PET.
The purpose of this work is to evaluate the precision with which the GEANT4 toolkit simulates the production of β+ emitters relevant for in-beam and real-time PET in proton therapy.
An important evolution in proton therapy is the implementation of in-beam and real-time verification of the range of protons by measuring the correlation between the activity of β+ and dose deposition.
For that purpose, it is important that the simulation of the various β+ emitters be sufficiently realistic, in particular for the 12N short-lived emitter that is required for efficient in-beam and real-time monitoring.
The GEANT4 toolkit was used to simulate positron emitter production for a proton beam of 55 MeV in a cubic PMMA target and results are compared to experimental data.
The three β+ emitters with the highest production rates in the experimental data (11C, 15O and 12N) are also those with the highest production rate in the simulation. Production rates differ by 8% to 174%. For the 12N isotope, the β+ spatial distribution in the simulation shows major deviations from the data. The effect of the long range (of the order of 20 mm) of the β+ originating from 12N is also shown and discussed.
At first order, the GEANT4 simulation of the β+ activity presents significant deviations from the data. The need for precise cross-section measurements versus energy below 30 MeV is of first priority in order to evaluate the feasibility of in-beam and real-time PET.
Aspergilose sistêmica em um cavalo - relato de caso Busato, E.M.; Meirelles, J.R.S.; Castro, M.L. ...
Arquivo brasileiro de medicina veterinária e zootecnia,
01/2020, Letnik:
72, Številka:
1
Journal Article
Recenzirano
Odprti dostop
RESUMO O presente trabalho relata o caso de aspergilose sistêmica em um cavalo da raça Quarto de Milha. O animal apresentava quadro de emagrecimento progressivo e alopecia. Os parâmetros avaliados ...durante o exame clínico encontravam-se de acordo com os valores normais para a espécie. No hemograma verificou-se leucocitose por neutrofilia, sem desvio à esquerda, proteínas plasmáticas totais elevadas e aumento do fibrinogênio, indicando um processo inflamatório acompanhado de desidratação. Os exames bioquímicos séricos demonstraram aumento no valor da ureia. Apesar dos exames realizados e da terapia instituída com antibióticos de amplo espectro e suporte nutricional, após 51 dias de internamento o quadro clínico evoluiu para caquexia e decúbito permanente do paciente, o qual foi submetido à eutanásia seguida de necropsia. Com base nos achados nos exames necroscópico e histopatológico, diagnosticou-se infecção sistêmica por Aspergillus sp., acometendo pulmões, fígado, rins, peritônio parietal e encéfalo. Dentre os fatores predisponentes à relatada infecção fúngica sistêmica, destaca-se o status imunológico debilitado do paciente, possivelmente proporcionado por tratamentos prolongados com antibióticos e anti-inflamatórios esteroidais. O presente trabalho relata o primeiro caso descrito de arpergilose sistêmica no Brasil. O diagnóstico definitivo só foi possível após necropsia e histopatologia, visto que os sinais clínicos inespecíficos não foram determinantes para o diagnóstico em vida.
ABSTRACT This paper reports the case of systemic aspergillosis on a Quarter Horse. The animal had progressive weight loss and alopecia. The parameters evaluated during the clinical examination were in agreement with the normal values for the species. The hemogram showed neutrophilic leukocytosis, without left-sided, elevated total plasma proteins and an increase in fibrinogen, indicating an inflammatory process accompanied by dehydration. Serum biochemical tests showed an increase in the value of urea. Despite the performed tests and established therapy with broad spectrum antibiotics and nutritional support, after 51 days of hospitalization the clinical condition evolved into cachexia and permanent decubitus of the patient which underwent to euthanasia and necropsy. From the findings of necropsy and histopathology, systemic infection was diagnosed by Aspergillus sp., affecting the lungs, liver, kidneys, parietal peritoneum and encephalon. Among the factors predisposing to the reported systemic fungal infection, the patient's weakened immune status is highlighted, possibly due to prolonged antibiotic and steroidal anti-inflammatory treatments. This paper reports the first case described of systemic aspergillosis in Brazil. Definitive diagnosis was only possible after necropsy and histopathology, since nonspecific clinical signs were not determinant for the diagnosis in life.
We report on measurements of the neutron spin asymmetries A{sub 1,2}{sup n} and polarized structure functions g{sub 1,2}{sup n} at three kinematics in the deep inelastic region, with x=0.33, 0.47, ...and 0.60 and Q{sup 2}=2.7, 3.5, and 4.8 (GeV/c){sup 2}, respectively. These measurements were performed using a 5.7 GeV longitudinally polarized electron beam and a polarized {sup 3}He target. The results for A{sub 1}{sup n} and g{sub 1}{sup n} at x=0.33 are consistent with previous world data and, at the two higher-x points, have improved the precision of the world data by about an order of magnitude. The new A{sub 1}{sup n} data show a zero crossing around x=0.47 and the value at x=0.60 is significantly positive. These results agree with a next-to-leading-order QCD analysis of previous world data. The trend of data at high x agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (PQCD) assuming hadron helicity conservation. Results for A{sub 2}{sup n} and g{sub 2}{sup n} have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment d{sub 2}{sup n} was evaluated and the new result has improved the precision of this quantity by about a factor of 2. When combined with the world proton data, polarized quark distribution functions were extracted from the new g{sub 1}{sup n}/F{sub 1}{sup n} values based on the quark-parton model. While results for {delta}u/u agree well with predictions from various models, results for {delta}d/d disagree with the leading-order PQCD prediction when hadron helicity conservation is imposed.
Sondagem da pelve renal guiada por cistoscopia em éguas Strugava, L.; Dornbusch, L.P.T.C.; Silva-Meirelles, J.R. ...
Arquivo brasileiro de medicina veterinária e zootecnia,
10/2018, Letnik:
70, Številka:
5
Journal Article
Recenzirano
Odprti dostop
RESUMO O objetivo deste trabalho foi padronizar a técnica de acesso à pelve renal por meio de sondagem ureteral guiada por cistoscopia em éguas. Foram utilizados oito animais, de raças variadas, com ...peso médio de 439kg. As éguas foram sedadas e mantidas em tronco de contenção para a realização da cistoscopia com endoscópio flexível. Após identificação do óstio ureteral esquerdo, uma sonda de polietileno foi introduzida em seu lume, até a pelve renal. A localização da sonda no rim foi confirmada por meio de ultrassonografia transcutânea. Foram coletados 3mL de urina, de forma asséptica, para citologia e cultura bacteriana. Todas as amostras obtiveram resultados negativos na cultura e análise do sedimento urinário. Nenhum dos animais apresentou quaisquer complicações após a sondagem. Este estudo demonstrou que a coleta de urina diretamente da pelve renal em éguas, com auxílio da cistoscopia na realização da sondagem ureteral, consiste em um procedimento viável e seguro.
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