IMPROVEMENT OF ESR DOSIMETRY FOR THERMAL NEUTRON BEAMS THROUGH THE ADDITION OF GADOLINIUM

In this paper the addition of gadolinium nucleus is proposed as useful tool to enhance the ESR sensitivity of organic compounds to thermal neutrons. The target of this work is the detection of the thermal neutron fluence in a mixed field of photons and neutrons through the ESR technique. The gadolinium nucleus was chosen because it offers a very high capture cross section to thermal neutrons (255000 barns). The nuclear reaction with neutron induces complex inner shell transitions that generate, besides the other particles, also some Auger electrons which release their energy in the neighborhood (only several nanometers) of the reaction place. Two organic compounds were doped with gadolinium: the alanine and the ammonium tartrate. The main result is a greater neutron sensitivity for the dosimeters with gadolinium than for those without gadolinium for both the organic compounds used. Because the use of a dosimeter pair is required to discriminate the two components of the mixed field, we studied the response of each dosimeters pair to the mixed field. Through a blind test we tested the goodness of this dosimetric system and we obtained an estimate of the fluence in the mixed field with maximum uncertainty of 3% using the dosimeters pair of alanine and alanine with gadolinium

Alanine films for EPR dosimetry of low-energy (1-30 keV) X-ray photons

L-alpha-alanine has aroused considerable interest for use in radiation EPR dosimetry and has been formally accepted as a secondary standard for high-dose (kGy) and transfer dosimetry of high-energy photons and electrons. In this work, we extended the investigation of the energy response of alanine EPR films in the low energy range for X-photons (1-30 keV). Electron Paramagnetic Resonance (EPR) measurements were performed on Kodak BioMax alanine films exposed to low-energy X-rays from a Cu-, W- and Mo-targets tube operating at voltages up to 30 kV. Films were chosen because of the low penetration of the soft X-rays used. The response of alanine to low-energy X-rays was characterized experimentally and the relative response (with respect to high energy photons) was found to be between 0.8 and 0.9 for Cu- and W-tube X-rays, and 1.0 for Mo-tube X-rays. The attenuation profiles were investigated and it was found that 1 mm of film material reduces the intensity of the X-ray-beam by about 70%, 50% and 40% for Cu-, W- and Mo-tube X-rays, respectively. Monte Carlo simulations were performed to model the energy release as well as the depth dose profiles for the various radiation beams used. These data are considered relevant for dosimetric applications in low energy beams such the high-gradient treatment fields used in monoenergetic microbeam radiation therapy (MRT) with synchrotron radiation as well as in brachytherapy with low energy sources, for instance Yb-169

Atti del Workshop: Tecniche Speciali e Avanzate di Dosimetria e Radioprotezione

Atti del Workshop organizzato dall'Associazione Italiana di Radioprotezione (AIRP) in collaborazione con l'Università degli Studi di Palermo, dal titolo "Tecniche Speciali e Avanzate in Dosimetria e Radioprotezione" che si svolgerà venerdì 24 Giugno a Palermo presso l'Aula Magna del Dipartimento di Fisica e Chimica, Viale delle Scienze Edificio 18. L'evento rientra tra i 210 Eventi organizzati per i 210 anni dalla fondazione dell'Ateneo palermitano su iniziativa del Magnifico Rettore, Prof. Fabrizio Micari. L’evento prevede la discussione di 4 tematiche in ambito della dosimetria e della radioprotezione in campo sanitario ed ambientale (Dosimetria Clinica, Dosimetria Ambientale, Dosimetria Retrospettiva e Tecniche Dosimetriche avanzate in Radioprotezione) ciascuna delle quali ha una relazione generale ad invito e alcune brevi comunicazioni orali. Le sessioni sono moderate da Dirigenti Fisici medici di due delle più importanti Aziende Ospedaliere Siciliane, Dirigenti dell’Istituto Superiore di Sanità e l’ex Rettore dell’Ateneo e membro del CdA del CNR, il Prof. Roberto Lagalla. Interverranno il magnifico Rettore dell’Università di Palermo, l’Assessore alla Sanità della Regione Sicilia, il Direttore dell’Istituto Zooprofilattico Sperimentale di Sicilia, il Direttore Generale dell’Agenzia per la Protezione dell’Ambiente Sicilia, il Direttore del Dipartimento di Fisica e Chimica, il Direttore di ATeN Center (Advanced Technologies Network), Dirigenti Fisici dell’Istituto Superiore di Sanità e dell’Istituto Europeo Oncologico di Milano. Hanno contribuito alla parte organizzativa e scientifica Dirigenti dell’ARPA Sicilia, Dirigenti dell’ARNAS Civico di Palermo, Docenti dell’Università di Palermo e di Milano, Ricercatori del CNR e Specializzandi UniPa. Questo evento è di grande rilevanza nazionale in termini di divulgazione scientifica vista la presenza dei relatori e moderatori invitati che ne danno lustro e rilevanza. Sarà un'occasione di confronto e di analisi retrospettiva a quarant'anni della giornata di studio “Problemi e prospettive della Fisica Sanitaria nel settore medico” organizzata dalla Prof.ssa Maria Brai

Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation

This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepper and sesame

Irradiation detection of herbal ingredients used in plant food supplements by Electron Spin Resonance on samples pre-treated with alcoholic extraction

This study aimed to verify the applicability of the EN 1787 method for the detection of irradiation in herbal ingredients used in Plant Food Supplements (PFSs). In matrices such as herbs and spices the main limit of the method is the presence of intrinsic radicals responsible for spurious signals leading to complex ESR spectra. To overcome this limit, before ESR measurement a treatment with alcohol has been proposed (Delincée and Soika, 2002; Ahn et al., 2012, 2014). As reported in the literature, this treatment is expected to reduce/eliminate the confounding signals so that the samples may be correctly classified. In this study the efficacy of the pre-treatment was tested on raw herbal ingredients largely used for PFSs, namely Camellia sinensis, Cinnamomum verum, Curcuma longa, Ginkgo biloba, Silybum marianum, Vaccinium myrtillus and Zingiber officinale. Non-irradiated and irradiated (5, 10 kGy) samples were analysed before and after pre-treatment. The results showed a general decrement of signal intensity. In some cases, this was associated with the elimination of some spurious signals, which, however, did not always ensue in an easier interpretation of the ESR spectra. Only for two matrices (Camellia sinensis and Vaccinium myrtillus) was alcoholic extraction crucial for the correct classification of the samples

VALUTAZIONE DELL'EFFETTO DEL TRATTAMENTO CON RADIAZIONI IONIZZANTI SUL CONTENUTO DI MICOTOSSINE NELLA FRUTTA SECCA

Le micotossine sono un gruppo eterogeneo di sostanze chimiche a basso peso molecolare prodotte dal metabolismo secondario di varie specie di funghi tossigeni appartenenti ai generi Aspergillus, Penicillum, Alternaria e Fusarium [1]. Sono molto resistenti al calore e non vengono completamente distrutte durante le normali operazioni di cottura, n\ue9 dai trattamenti fisici, chimici e biologici cui vengono normalmente sottoposte le derrate durante i processi di preparazione degli alimenti. La loro possibile presenza in molti alimenti costituisce oggi un motivo di crescente preoccupazione per la salute dei consumatori poich\ue9 alcune micotossine manifestano caratteristiche di genotossicit\ue0, cancerogenicit\ue0, immunotossicit\ue0, mutagenicit\ue0, nefrotossicit\ue0 e teratogenicit\ue0 [2-4]. Tra i metodi di decontaminazione esistenti ed ampiamente utilizzati, il trattamento degli alimenti con le radiazioni ionizzanti rappresenta un metodo sicuro per ottenere sia una migliore conservazione dei prodotti, sia un controllo delle affezioni alimentari, tramite la riduzione/eliminazione della popolazione patogena [5]. In questo lavoro sono stati valutati gli effetti del processo di irraggiamento con una sorgente di 60Co e dosi comprese tra 0,5 e 3 kGy sul contenuto di micotossine in campioni di frutta secca. In particolare il contenuto di aflatossine G1, G2, B1 e B2, e di ocratossina A (OTA) \ue8 stato valutato, prima e dopo l\u2019irraggiamento, attraverso cromatografia liquida ad alte prestazioni (HPLC) sfruttando le potenzialit\ue0 del rivelatore a fluorescenza. Le analisi HPLC sono precedute da un processo di purificazione del campione che prevede l\u2019utilizzo di colonne di immunoaffinit\ue0 [6-8]. Inoltre sono state valutate le relazioni esistenti tra dose e degradazione delle micotossine

An inter-laboratory comparison to evaluate the suitability of EN 1787 standard to detect irradiation in plant-origin foods with health benefits

This paper reports the results of a study carried out to verify the applicability of the EN 1787 method, which uses the Electron Spin Resonance (ESR) technique for the identification of irradiated plant-origin foods with health benefits. The method was tested on samples of herbal ingredients of Plant Food Supplements (PFSs), nuts and fresh blueberries. Untreated and irradiated samples of Camellia sinensis (leaves) Ginkgo biloba (leaves), Glycine max (seeds), Silybum marianum (fruits), Vaccinium myrtillus (fruits), almonds, hazelnuts, peanuts, pistachios, walnuts and fresh blueberries were analysed. The work includes an inter-laboratory blind test involving five Italian laboratories that perform routine analyses for the official control of irradiated food. A total of 180 untreated and irradiated samples of PFS ingredients, nuts and fresh blueberries were analysed. The analyses on the irradiated samples were replicated even a long time after irradiation (up to two years depending on the matrix) to test the reliability of the method throughout the shelf life of the products. The results were matrix-dependent: all the 5 kGy irradiated nuts and the 1 kGy-irradiated blueberries were correctly classified, whereas herbal ingredients showed complex ESR spectra with spurious signals which often prevented the correct classification of the sample

Why Was the Perception of Human Rights Respect and Care Satisfaction So High in Users of Italian Mental Health Services during the COVID-19 Pandemic?

The aim of this study was to compare users’ and mental health workers’ (MHW) perception of respect of human rights and job/care satisfaction in mental health services in Italy during the COVID-19 pandemic. A sample of users and MHW of Sardinia, Italy, fulfilled the “WellBeing at work and respect for human rights questionnaire” (WWRR). The study included 240 MHW and 200 users. Users showed a higher level of satisfaction of care than MHW of work, and a higher perception of the satisfaction of users and human rights respected for health workers. Both user and MHW responses were about 85% of the maximum score, except for satisfaction with resources. Responses were higher for users, but users and MHW both showed high levels of satisfaction. In previous surveys, MHW of Sardinia showed higher scores in all items of WWRR, except for satisfaction with resources, compared with workers from other health sectors of the same region, and with MHW from other countries. The low score for satisfaction with resources (in users and staff) is consistent with a progressive impoverishment of resources for mental health care in Italy. The study, although confirming the validity of the Italian model, fully oriented towards community, sets off an alarm bell on the risks resulting from the decrease in resources