Publications by authors named "A F Lourenco"
Article Synopsis
- Spatial fractionation of proton fields in cancer treatment improves sparing of healthy tissue while ensuring tumor control.
- This study demonstrated the use of the National Physical Laboratory's Primary Standard Proton Calorimeter to measure absorbed dose in a proton beam with a specific configuration.
- Results indicated that uncertainty in absorbed dose measurements was mainly due to positioning accuracy, suggesting that reference dosimetry should focus on measuring Dose-Area Product or using SOBP for more reliable outcomes in spatially fractionated fields.
Article Synopsis
- This study examines how the placement of plane-parallel ionization chambers affects the calculation of specific factors and beam quality correction factors in proton beams.
- Monte Carlo simulations were used to analyze six ionization chamber types with different positioning methods, showing significant differences, especially in areas with steep dose gradients.
- The findings indicate that using the effective point of measurement as recommended by the updated TRS-398 code may introduce systematic errors in the correction factors for these chambers, potentially impacting dosimetry accuracy.
Aims: ZSF1 obese rats harbouring two mutant leptin receptor alleles (Lepr and Lepr) develop metabolic syndrome and heart failure with preserved ejection fraction (HFpEF), making them a widely used animal model in cardiometabolic research. Studies using ZSF1 rats have contributed significantly to the elucidation of pathophysiological mechanisms underlying HFpEF and therapeutic strategies against this multi-organ syndrome. In contrast, hybrid, lean ZSF1 rats (L-ZSF1) do not develop HFpEF and generally serve as controls, disregarding the possibility that the presence of one mutant Lepr allele might affect left ventricular ejection fraction (LVEF), diastolic dysfunction and other relevant HFpEF parameters, such as N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and cardiac inflammation, which could increase during disease manifestation.
View Article and Find Full Text PDFPurpose: To evaluate the efficacy of two third-generation resorbable biomaterials-F18 bioglass and β-tricalcium phosphate (β-TCP)-in promoting new bone formation in post-extraction sockets in rats. β-TCP, a synthetic porous ceramic, is well-established in clinical use, while F18 bioglass, a novel silica based bioglass.
Methods: After extraction of the right upper incisor of 45 rats, the sockets were filled either with F18 or β-TCP, or left to naturally fill with a blood clot in control group.