Radio-Optically- and Thermally Stimulated Luminescence of Zn(BO2)2:Tb3+ exposed to Ionizing Radiation

The optical absorption of zinc tetraborate at different concentrations of the terbium impurity (0, 0.5, 1, 2, 4, 8 mol%) was analyzed. The radioluminescence (RL) emission spectra was obtained after beta irradiation of a 90Sr/90Y source. The RL spectrum showed the characteristics bands of Tb3+ with two main emissions at 489 nm and 546 nm which corresponding to the5D4→7F6 and 5D4→7F5 transitions respectively in this ion. The OSL and TL characteristics have been analyzed. The stimulation blue light (497 nm) of a diode laser at 500 mA was used to bleach the thermoluminescent (TL) signals obtained with 5Gy of 60Co source. The two main glow peaks (79 and 161 °C) are sensitives under 497 nm stimulation, and they were shifted to higher temperature values and faded their TL intensities. Similar behavior of TL glow curves before and after OSL stimulation with blue light was observed when the samples were exposed to 30 Gy gamma dose of 137Cs irradiator. The OSL signal response was linear with the dose range of 1-10 Gy and increased their response up to 200 Gy gamma dose. The OSL shows a bleaching sensitive shallow traps and diminishing the intensity of the TL glow curves remaining a complex traps distribution. The RL, TL and OSL properties were investigated in Zn(BO2)2:Tb3+ phosphor

Management and outcomes of patients with left atrial appendage thrombus prior to percutaneous closure.

Left atrial appendage (LAA) thrombus has heretofore been considered a contraindication to percutaneous LAA closure (LAAC). Data regarding its management are very limited. The aim of this study was to analyse the medical and invasive treatment of patients referred for LAAC in the presence of LAA thrombus. This multicentre observational registry included 126 consecutive patients referred for LAAC with LAA thrombus on preprocedural imaging. Treatment strategies included intensification of antithrombotic therapy (IAT) or direct LAAC. The primary and secondary endpoints were a composite of bleeding, stroke and death at 18 months, and procedural success, respectively. IAT was the preferred strategy in 57.9% of patients, with total thrombus resolution observed in 60.3% and 75.3% after initial and subsequent IAT, respectively. Bleeding complications and stroke during IAT occurred in 9.6% and 2.9%, respectively, compared with 3.8% bleeding and no embolic events in the direct LAAC group before the procedure. Procedural success was 90.5% (96.2% vs 86.3% in direct LAAC and IAT group, respectively, p=0.072), without cases of in-hospital thromboembolic complications. The primary endpoint occurred in 29.3% and device-related thrombosis was found in 12.8%, without significant difference according to treatment strategy. Bleeding complications at 18 months occurred in 22.5% vs 10.5% in the IAT and direct LAAC group, respectively (p=0.102). In the presence of LAA thrombus, IAT was the initial management strategy in half of our cohort, with initial thrombus resolution in 60% of these, but with a relatively high bleeding rate (~10%). Direct LAAC was feasible, with high procedural success and absence of periprocedural embolic complications. However, a high rate of device-related thrombosis was detected during follow-up

Caracterización de nanofibras de TiO2 y TiO2:R.E. fabricadas por la técnica de electrospinning

En este trabajo se fabricaron nanofibras de TiO2 y TiO2 dopadas con iones de Europio y Terbio por electrospinning. Las muestras se calcinaron a diferentes temperaturas y se caracterizaron por TG, SEM, DRX, FTIR, y EDS. Las fibras fueron nanométricas y cristalinas

Estudio de las propiedades estructurales y luminiscentes de películas de TiO2 impurificadas con Eu3+ sintetizadas por la técnica de rocío pirolítico ultrasónico

En este trabajo se reportan los cambios estructurales y luminiscentes al variar la temperatura de sustrato (Ts) y el porcentaje de impurificarte en películas de TiO2. Los resultados muestran que es posible obtener películas con buenas propiedades

Crecimiento de películas delgadas de TiO2 impurificadas con tierras raras por la técnica de rocío pirolítico asistida por campo eléctrico

En este trabajo se reportan los cambios estructurales y luminiscentes que se presentan al variar la temperatura de depósito (Td) y los porcentajes de material impurificarte o activador en películas delgadas de TiO2. Los resultados demuestran que mediante la técnica de rocío pirolítico (SP) es posible obtener películas delgadas con buenas propiedades estructurales y luminiscentes

Películas delgadas de TiO2 impurificadas con Eu3+ por rocío pirolítico ultrasónico

En este trabajo se reportan los cambios estructurales y luminiscentes presentes al variar la temperatura de sustrato (Ts) y porcentajes de material impurificarte en películas delgadas de TiO2. Los resultados revelan que mediante la técnica de rocío pirolítico (SP) es posible obtener buenas propiedades estructurales y luminiscentes

Caracterización de Zirconia para Dosimetría de Electrones de alta energía en Radioterapia

En este trabajo se presentan los resultados de estudiar las características morfológicas, estructurales y dosimétricas. El material fue obtenido mediante el método hidrotérmico para preparar polvos de ZrO2, a partir de Oxicloruro de Circonio. Las características fueron realizadas utilizando técnicas de caracterización tales como DRX, EDS y SEM. Así mismo se prepararon pastillas de 5mm de diámetro por 1mm de espesor para su fácil manejo y la caracterización termolumiscente (TL). Mediante una serie de pruebas definiremos si el material es apto para su uso en radioterapia como dosímetro de electrones de alta energía