Targeting murine heart and brain: visualisation conditions for multi-pinhole SPECT with 99mTc- and 123I-labelled probes

The study serves to optimise conditions for multi-pinhole SPECT small animal imaging of (123)I- and (99m)Tc-labelled radiopharmaceuticals with different distributions in murine heart and brain and to investigate detection and dose range thresholds for verification of differences in tracer uptake.A Triad 88/Trionix system with three 6-pinhole collimators was used for investigation of dose requirements for imaging of the dopamine D(2) receptor ligand [(123)I]IBZM and the cerebral perfusion tracer [(99m)Tc]HMPAO (1.2-0.4 MBq/g body weight) in healthy mice. The fatty acid [(123)I]IPPA (0.94 +/- 0.05 MBq/g body weight) and the perfusion tracer [(99m)Tc]sestamibi (3.8 +/- 0.45 MBq/g body weight) were applied to cardiomyopathic mice overexpressing the prostaglandin EP(3) receptor.In vivo imaging and in vitro data revealed 45 kBq total cerebral uptake and 201 kBq cardiac uptake as thresholds for visualisation of striatal [(123)I]IBZM and of cardiac [(99m)Tc]sestamibi using 100 and 150 s acquisition time, respectively. Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake. The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight.Multi-pinhole SPECT enables detection of alterations of the cerebral uptake of (123)I- and (99m)Tc-labelled tracers in an appropriate dose range in murine models targeting physiological processes in brain and heart. The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers

Mechanistic and adsorption equilibrium studies of dibenzothiophene-rich-diesel on MnO2-loaded-activated carbon: Surface characterization

In this work, the preparation and characterization of MnO2-modified-activated carbon for selective removal of organosulfur compounds including dibenzothiophene were outlined. The deposited particles of the modifier were entrapped within the micropores and the resulting adsorbent was efficient to desulfurize in diesel with rich-sulfur (7055 mgS kg1). Removal of organosulfur compounds was positively correlated with the deposited MnO2 and the best efficiency was observed at surface loading 30.6%Mn. The comprehensive characterization tests indicated drastic changes in the physicochemical properties of the modified adsorbents. The main findings were: (a) particles of -MnO2 were accumulated within the microspores and (b) less acidic surface compared to activated carbon was created in all modifications. Scanning electron microscope pictures indicated the filling of the pores by particles of MnO2. The mechanisms of S-compounds removal by the modified adsorbent were elucidated with the aid of Infrared spectral analysis. Adsorption isotherms of dibenzothiophene were measured and the data were presented by different models. Dubinin-Radushkevich model confirmed that adsorption of dibenzothiophene was exothermic and both Jovanovi and Langmuir models indicated the homogeneity of the modified surface. Jovanovi? model gave the best prediction of the maximum adsorption capacity. Combustion qualities of deeply desulfurized diesel were found within the regulated limits.Scopu