Target manufacturing by Spark Plasma Sintering for efficient 89Zr production.

Zirconium-89 (89Zr) is an emerging radionuclide for positron emission tomography (PET), with nuclear properties suitable for imaging slow biological processes in cellular targets. The 89Y(p,n)89Zr nuclear reaction is commonly exploited as the main production route with medical cyclotrons accelerating low-energy (< 20 MeV) and low-current (< 100 µA) proton beams. Usually, natural yttrium solid targets manufactured by different methods, including yttrium electrodeposition, yttrium sputtering, compressed yttrium powders, and foils, were employed. In this study, the Spark Plasma Sintering (SPS) technique has been investigated, for the first time, to manufacture yttrium solid targets for an efficient 89Zr radionuclide yield. The natural yttrium disc was bonded to a niobium backing plate using a commercial SPS apparatus and a prototype machine assembled at the University of Pavia. The resulting targets were irradiated in a TR19 cyclotron with a 12 MeV proton beam at 50 µA. A dedicated dissolution module, obtained from a commercial system, was used to develop an automated process for the purification and recovery of the produced 89Zr radionuclide. The production yield and recovery efficiency were measured and compared to 89Zr produced by irradiating standard yttrium foils. SPS manufactured targets withstand an average heat power density of approximately 650 W∙cm-2 for continuous irradiation up to 5 h without visible damage. A saturation yield of 14.12 ± 0.38 MBq/µAh was measured. The results showed that the obtained 89Zr production yield and quality were comparable to similar data obtained using standard yttrium foil targets. In conclusion, the present work demonstrates that the SPS technique might be a suitable technical manufacturing solution aimed at high-yield 89Zr radioisotope production.

[Epidemiology of malignant hyperthermia in Piedmont and Valle d'Acosta. A study conducted with 2 different methods]. / Epidemiologia dell'ipertermia maligna in Piemonte e Valle d'Aosta. Studio condotto con due differenti metodiche.

The Authors report on the results of two researchers about malignant hyperthermia (MH) carried out in Piemont and Valle D'Aosta using two different methods. The former, based on a form sent to 492 anaesthesists got 22.7 per cent answers. They indicated 4 cases of MH during the years between 1982 and 1986, out of 213,444 narcoses with an average rate of 1:71,000. The latter was canned and by questioning directly the head physicians of anaesthesia and reanimation wards about the occurrence of MH in Piemont and Valle D'Aosta in the years between 1984 and 1988. According to this research, there were 5 cases out of 891,729 narcoses (that is 1:178,346).