Luminescence and Structural Characterization of Gd2O2S Scintillators Doped with Tb3+, Ce3+, Pr3+ and F for Imaging Applications

none14siRadiodiagnostic technologies are powerful tools for preventing diseases and monitoring the condition of patients. Medicine and sectors such as industry and research all use this inspection methodology. This field demands innovative and more sophisticated systems and materials for improving resolution and sensitivity, leading to a faster, reliable, and safe diagnosis. In this study, a large characterization of gadolinium oxysulfide (Gd2O2S) scintillator screens for imaging applications has been carried out. Seven scintillator samples were doped with praseodymium (Pr3+), terbium (Tb3+) activators and co-doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F). The sample screens were prepared in the laboratory in the form of high packing density screens, following the methodology used in screen sample preparation in infrared spectroscopy and luminescence. Parameters such as quantum detection efficiency (QDE), energy absorption efficiency (EAE), and absolute luminescence efficiency (ALE) were evaluated. In parallel, a structural characterization was performed, via XRD and SEM analysis, for quality control purposes as well as for correlation with optical properties. Spatial resolution properties were experimentally evaluated via the Modulation Transfer Function. Results were compared with published data about Gd2O2S:Pr,Ce,F screens produced with a standard method of a sedimentation technique. In particular, the ALE rose with the X-ray tube voltage up to 100 kVp, while among the different dopants, Gd2O2S:Pr exhibited the highest ALE value. When comparing screens with different thicknesses, a linear trend for the ALE value was not observed; the highest ALE value was measured for the 0.57 mm thick Gd2O2S:Pr,Ce,F sample, while the best MTF values were found in the thinner Gd2O2S:Pr,Ce,F screen with 0.38 mm thickness.De Martinis, Alessia; Montalto, Luigi; Scalise, Lorenzo; Rinaldi, Daniele; Mengucci, Paolo; Michail, Christos; Fountos, George; Martini, Nicki; Koukou, Vaia; Valais, Ioannis; Bakas, Athanasios; Fountzoula, Christine; Kandarakis, Ioannis; David, StratosDe Martinis, Alessia; Montalto, Luigi; Scalise, Lorenzo; Rinaldi, Daniele; Mengucci, Paolo; Michail, Christos; Fountos, George; Martini, Nicki; Koukou, Vaia; Valais, Ioannis; Bakas, Athanasios; Fountzoula, Christine; Kandarakis, Ioannis; David, Strato

Removal of a severely impacted mandibular third molar minimizing the risks of compromised periodontium, nerve injury, and mandibular fracture.

A technique is presented for severely impacted and dentigerous-cyst-related mandibular third molar removal, avoiding any associated risks. CASE PRESENTATION A healthy patient complained about unpleasant smell and taste in the mouth and unilateral extraoral palpation of a protuberance, at the right corner of the mandible. Restricted field CBCT showed a severely impacted third molar, which penetrated the inferior cortical bone of the mandibular corner and was associated with a dentigerous cyst that had resorbed considerable bone in the region. Surgical exposure of the impacted tooth and cyst marsupialization procedures under local anesthesia were combined with orthodontic extrusion of the impacted tooth to facilitate third molar removal. Treatment resulted in successful bone formation and safe tooth removal. The symptoms gradually improved after the first surgery and were eliminated by 14 months later, when the third molar was removed. Follow-up examination 1 year after removal showed favorable periodontal conditions. CONCLUSION Although it is not normally the first treatment of choice, orthodontically assisted impacted tooth removal is an alternative that can minimize the risk of compromised periodontium or injury to the adjacent tooth and the inferior alveolar nerve, as well as the risk of mandibular fracture, in complicated cases

Optimisation under uncertainty for a bioreactor that produces red blood cells

Recent work developed a novel, biomimetic, cost effective 3D hollow fibre bioreactor for growing healthy red blood cells ex vivo [4]. This bioreactor recapitulates the architectural and functional properties of erythrocyte formation and thereby reduces the need for expensive growth factors by more than an order of magnitude. But the optimal bioreactor design is unclear; we propose global, robust, superstructure optimisation for configuring and operating the bioreactor. We discuss the potential of robust superstructure design not only on this individual bioreactor but also more generally on bioprocess optimisation..