Fluorine-based color centers in diamond.

We report on the creation and characterization of the luminescence properties of high-purity diamond substrates upon F ion implantation and subsequent thermal annealing. Their room-temperature photoluminescence emission consists of a weak emission line at 558 nm and of intense bands in the 600-750 nm spectral range. Characterization at liquid He temperature reveals the presence of a structured set of lines in the 600-670 nm spectral range. We discuss the dependence of the emission properties of F-related optical centers on different experimental parameters such as the operating temperature and the excitation wavelength. The correlation of the emission intensity with F implantation fluence, and the exclusive observation of the afore-mentioned spectral features in F-implanted and annealed samples provides a strong indication that the observed emission features are related to a stable F-containing defective complex in the diamond lattice.

[Assessment of coronary revascularization with 99mTC-sestamibi SPECT. Quantitative analysis of segmentary perfusion]. / Evaluación de la revascularización coronaria con 99m Tc-sestamibi SPECT. Análisis cuantitativo de perfusión segmentaria.

UNLABELLED: We analyzed the change in myocardial perfusion recovery after revascularization using Dipyridamole-99mTc-Sestamibi SPECT in 37 patients (mean age 59 years old; 33 males), all of whom had wall motion abnormalities and 84% who had myocardial infarction. The perfusion defects were evaluated before the revascularization and at 64 days of the angioplasty in 18 cases and of the coronary artery bypass graft (CABG) in 19 and were compared with a normal Dipyridamole database. The bullseye parameters were: decrease in severity, size and ischemia area of the defect and worsening of the defect. It was found that the defects decreased in an average of 31. 4% for extension and 35,8% for severity (with no significant differences between the 2 techniques); the ischemia was reduced in 75.7%. No new defects appeared although some presented a slight worsening. The net change in reduction was 26% for extension and 29% for severity. CONCLUSION: In patients with a high prevalence of myocardial infarction, revascularization obtained a moderate decrease in the perfusion defects and a significant ischemia decrease.