RESUMO
The most important radioisotope for use in Nuclear Medicine is (99m)Tc, supplied in the form of a (99)Mo/(99m)Tc generator. After the supply crisis of (99)Mo starting in 2008 the availability of (99)Mo became a worldwide concern. The purpose of this work is to do a brief story of the availability of (99)Mo in the world followed by an overview of the production routes of (99)Mo and the generators technology.
Assuntos
Molibdênio/provisão & distribuição , Aceleradores de Partículas/provisão & distribuição , Geradores de Radionuclídeos/provisão & distribuição , Compostos Radiofarmacêuticos/síntese química , Tecnécio/provisão & distribuição , Tomografia Computadorizada de Emissão de Fóton Único , Reatores Nucleares , Compostos Radiofarmacêuticos/provisão & distribuiçãoRESUMO
Highly polymorphic regions of the circumsporozoite protein (CSP) of Plasmodium falciparum are associated with cellular immune responses. One of these regions, the TH3R polymorfic region of the csp gene codes for known T-cell epitopes. The present study tested the use of SSCP to determine sequence variations of the TH3R regions of four clones of P. falciparum (3D7, HB3, Dd2 and K1) which are known to have different TH3R regions. Single-strand conformation polymorphism (SSCP) technique was performed on amplified products labelled with fluorescent primer (both strands) and electrophoresed in an automated sequencer. Various gel compositions and electrophoresis conditions were tested. Even if some electrophoretogram differences were observed between clones, they could not distinguish between the alleles.
Assuntos
Antígenos de Protozoários/genética , DNA de Protozoário/genética , Epitopos/genética , Plasmodium falciparum/genética , Polimorfismo Conformacional de Fita Simples , Proteínas de Protozoários/genética , Alelos , Animais , Variação Antigênica/genética , Antígenos de Protozoários/imunologia , Eletroforese em Gel de Poliacrilamida , Epitopos/imunologia , Plasmodium falciparum/imunologia , Reação em Cadeia da Polimerase , Proteínas de Protozoários/imunologia , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoRESUMO
The permeation properties of a series of membranes of cellulose esters, presenting a wide range of characteristics, were studied and correlated to the structure of water in the pores, to the polymer hydrophilicity/hydrophobicity, and to the morphology of the surface of the active layer. Asymmetric membranes of cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate were prepared by the phase inversion method and their preferential permeation performance tested. The surface morphology and the structure of the water in the pores of the active layer were studied by atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, respectively. Results show that higher rejection to NaCl and low fluxes are generally associated with smaller clusters of water in the pores. On the other hand, the surface of the membranes presenting smaller clusters of water in the active layer show generally surfaces with lower roughness as measured by AFM.