RESUMO
In this work we compare the kVp estimate between CDTN multipurpose instrument, UnforsXI and Radcal 4075 meters under different combinations of voltage and filtration. The non-invasively measurements made using x-ray diagnostic and interventional radiology devices show similar tendencies to increase the kVp estimate when aluminum filters are placed in the path of the x-ray beam. The results reveal that the kVp estimate made by the CDTN multipurpose instrument is always satisfactory for highly filtered beam intensities.
RESUMO
In a 17-kb genomic fragment of Trypanosoma cruzi chromosome XX, we identified three tandemly linked genes coding for CX(2)CX(4)HX(4)C zinc finger proteins. We also showed that similar genes are present in T. brucei and Leishmania major, sharing three monophyletic groups among these trypanosomatids. In T. cruzi, TcZFP8 corresponds to a novel gene coding for a protein containing eight zinc finger motifs. Molecular cloning of this gene and heterologous expression as a fusion with a His-tag were performed in Escherichia coli. The purified recombinant protein was used to produce antibody in rabbits. Using Western blot analysis, we observed the presence of this protein in all three forms of the parasite: amastigote, trypomastigote and epimastigote. An analysis of cytoplasmic and nuclear cell extracts showed that this protein is present in nuclear extracts, and indirect immunofluorescence microscopy confirmed the nuclear localization of TcZFP8. Homologues of TcZFP8 in T. brucei are apparently absent, while one candidate in L. major was identified.
Assuntos
Núcleo Celular/metabolismo , Código Genético/genética , Proteínas de Protozoários/genética , Trypanosoma cruzi/genética , Dedos de Zinco/genética , Animais , Sequência de Bases , Western Blotting , Clonagem Molecular , DNA de Protozoário/genética , DNA de Protozoário/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Microscopia de Fluorescência , Dados de Sequência Molecular , Proteínas de Protozoários/metabolismo , RNA de Protozoário/genética , RNA de Protozoário/metabolismo , Coelhos , Trypanosoma cruzi/metabolismoRESUMO
In a 17-kb genomic fragment of Trypanosoma cruzi chromosome XX, we identified three tandemly linked genes coding for CX2CX4HX4C zinc finger proteins. We also showed that similar genes are present in T. brucei and Leishmania major, sharing three monophyletic groups among these trypanosomatids. In T. cruzi, TcZFP8 corresponds to a novel gene coding for a protein containing eight zinc finger motifs. Molecular cloning of this gene and heterologous expression as a fusion with a His-tag were performed in Escherichia coli. The purified recombinant protein was used to produce antibody in rabbits. Using Western blot analysis, we observed the presence of this protein in all three forms of the parasite: amastigote, trypomastigote and epimastigote. An analysis of cytoplasmic and nuclear cell extracts showed that this protein is present in nuclear extracts, and indirect immunofluorescence microscopy confirmed the nuclear localization of TcZFP8. Homologues of TcZFP8 in T. brucei are apparently absent, while one candidate in L. major was identified.
Assuntos
Animais , Coelhos , Núcleo Celular/metabolismo , Código Genético/genética , Proteínas de Protozoários/genética , Trypanosoma cruzi/genética , Dedos de Zinco/genética , Sequência de Bases , Western Blotting , Clonagem Molecular , DNA de Protozoário/genética , DNA de Protozoário/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Microscopia de Fluorescência , Dados de Sequência Molecular , Proteínas de Protozoários/metabolismo , RNA de Protozoário/genética , RNA de Protozoário/metabolismo , Trypanosoma cruzi/metabolismoRESUMO
This investigation has been performed to test the feasibility of using K2YF5:Tb3+ crystals as thermoluminescence dosemeters (TLD). K2YF5 single crystals doped with 0.2, 10.0 and 50.0 at.% of trivalent optically active Tb3+ ions as well as K2TbF5 and undoped K2YF5 crystals have been synthesized under hydrothermal conditions. Polished crystal platelets with thickness of about 1 mm have been irradiated with X and gamma rays in order to study thermoluminescent (TL) sensitivity as well as dose and energy response in terms of the Tb3+ concentration in K2YF5. Within this concentration series, K2YF5 crystals doped with 10.0 at.% Tb3+ have been found to have maximum TL response due to a broad asymmetric TL glow peak at 269 degrees C with good linearity of dose response and reproducibility of dose measurements. After deconvolution, the main dosimetric peak has been revealed to be composed of two individual peaks, both with linear TL response behaviour, centered at 210 and 269 degrees C. As it has been proved, the linear TL signal coefficient for K2Y0.9Tb0.1F5 is almost 10 times greater than that for commercial TLD-100 (LiF:Mg,Ti), irradiated with a 137Cs gamma radiation source at the same conditions. The reported results indicate that K2YF5 crystals doped with Tb3+ have potential as promising materials for radiation dosemeters.
