Integrated analytical methodologies for the study of corrosion processes in archaeological bronzes

Abstract The investigations on structure and micro-chemical composition of archaeological metal alloys are needed in archaeometry. The aim of this study is devoted both to acquire information about their provenance and production technology, and to improve our understanding about the corrosion processes. In this paper we present the study of the corrosion phenomena of bronze samples, laboratory-made according to binary, ternary and quaternary alloys typical of Roman archaeometallurgical production through an integrated methodology based on the use of non or micro invasive physical techniques. Among the analysed samples, two were artificially aged through burial in the archaeological site of…

Laboratorio a contaminazione controllata per tecniche fisiche applicate ai beni culturali

Phenol compounds as new materials for electron spin resonance dosimetry in radiotherapy

Phenol compounds as new materials for electron spin resonance dosimetry in radiotherapy

Introduction: Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the electron spin resonance (ESR) arouses increasing interest for applications in various therapy procedures. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiationinduced free radicals is proportional to the absorbed dose and this allows for dosimetric measurements through ESR technique which enables to quantitatively determine the radical concentration. In this work we report the ESR investigation of phenol pellets and thin films exposed to various types of radiation beams (clinical photon and el…

XRF and LIBS integrated analysis to identify the chemical composition and the conservation state of photographic and paper materials

Resting state fMRI as a tool to investigate brain functional connectivity

Degradation of stone materials in the archaeological context of the Greek-Roman Theatre in Taormina (Sicily, Italy)

In the present work results on the degradation phenomena of stone materials in the Ancient Theatre of Taormina, one of the most important Greek–Roman monuments of Sicily, are reported. Artificial stone materials in different conservation conditions were investigated. Samples of salt efflorescences from brick walls and degraded setting mortars were taken from the open gallery in “summa cavea”. The chemical, physical and structural characterization was performed by means of X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF), both in situ and ex situ. Results showed that the deterioration of stone materials is due to the aggressive action of the enviro…

SPERIMENTAZIONE DI PRODOTTI NANOSTRUTTURATI IMPERMEABILIZZANTI SU CAMPIONI DI DIVERSE SPECIE LEGNOSE

Application of Electron Spin Resonance technique in neutron dosimetry

Along with the Neutron Capture Therapy (NCT) development and with the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the beam characterization in order to optimize the therapy procedures. Reliable dosimetric measurements should be able to determine the various components (neutronic and photonic) of the mixed beam usually employed for therapy [1]. We have studied the effect of the additive such as gadolinium and 10B-boric acid on the neutron sensitivity of alanine ESR dosimeters exposed to a gamma and mixed (n, gamma) field mainly composed by thermal neutrons. We have chosen both this additive nuclei because of their very high capture cross section t…

Materiali porosi d’interesse per i beni culturali: studio di un reperto lapideo dal teatro antico di Taormina

Diffusion and sensitivity characteristics of a chemically cross-linked PVA-Fricke gel dosimeter

Introduction: Current radiotherapy techniques implement treatment plans based on volumetric distributions of dose with complex shapes and sharp gradients. The agreement between these plans and the dose that is truly delivered is very challenging to verify. Thus, there is the need for a dosimetric system that is truly three dimensional, sensitive to radiation in each point and tissue equivalent. In this framework, great interest is encountered by radio-chromic gel dosimeters. In order to address the limitations of gels based on natural matrices, some investigators have proposed dosimeters based on poly vinyl alcohol (PVA) made by freezing-thawing cycles. Even though these gels have a low dif…

Characterization of the ESR response of alanine dosimeters to low-energy (1-40 keV) X-rays

The aminoacid L-a-alanine has attracted considerable interest for use in radiation ESR dosimetry and has been formally accepted as a secondary standard for high-dose (kGy) and transfer dosimetry . The accuracy of the method is quite high, largely due to the low dependence of the alanine response on various irradiation parameters (photon energies above 100 keV, dose rate, temperature, etc.). Furthermore, this system presents alinear response to dose, fairly high sensitivity, tissue equivalence, absence of fading, small dimensions, ruggedn ess, and non-destructive readout. In this work, we examined the energy dependence of alanine ESR dosimeters in the low energy X-photon energy range between…

A statistical description of the human a-wave ERG component

EXPOSURE OF Gd2O3-ALANINE AND Gd2O3-AMMONIUM TARTRATE ESR DOSIMETERS TO THERMAL NEUTRONS: EXPERIMENTS AND MONTE CARLO SIMULATIONS

Pulsed EPR investigations on radiations dosimeters.

Dosimetria tramite Risonanza Elettronica di Spin (ESR) in Electron Intra-Operative RadioTherapy (IORT): misure di Output Factor e simulazioni Monte Carlo-GEANT4

La Radioterapia IntraOperatoria (IORT) È una modalità di trattamento in cui una singola dose di radiazioni è impartita direttamente al letto tumorale o al tumore durante l'intervento chirurgico, evitando di colpire i tessuti sani circostanti. Nel caso di irraggiamento alla mammella, una singola frazione di 21 Gy impartita al volume neoplastico durante la procedura chirurgica è equivalente ad una dose totale di 60 Gy che solitamente viene somministrata con la radioterapia frazionata. Questo lavoro riporta il confronto tra la risposta ESR di dosimetri di alanina e di camere a ionizzazione Markus per le misurazioni degli Output Factor (OF) di fasci di elettroni prodotti da un acceleratore line…

Time-Frequency behaviour of the a-wave of the human electroretinogram

The electroretinogram is the record of the electrical response of the retina to a light stimulus. The two main components are the a-wave and the b-wave, the former is related to the early photoreceptoral activity. Aim of this paper is to acquire useful information about the time-frequency features of the human a-wave, by means of the wavelet analysis. This represents a proper approach in dealing with nonstationary signals. We have used the Mexican Hat as mother wavelet. The analysis, carried out for four representative values of the luminance, comprehends the frequency dependence of the variance and the skeleton. The results indicate a predominance of low frequency components, their time di…

Phenol compounds as a New Materials for EPR dosimetry in radiation therapy

Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the Electron Paramagnetic Resonance (EPR) arouses increasing interest for applications in various therapy procedures. When a compound is irradiated with ionizing radiations free radicals are produced and their concentration is proportional to the absorbed dose. This allows for dosi-metric measurements through EPR technique which is able to quantitatively de-termine the radical concentration. Our research group has started an investigation of the EPR response of some phenols compounds for possible dosimetric applications. In this work we report the EPR investigation of IRGANOX 1076 …

Tecniche fisiche integrate applicate allo studio di rocce sedimentarie

Environmental Radioactivity and Volcanological Features of Three Islands of the Mediterranean Sea (Pantelleria, Ustica and Vulcano)

Abstract The Mediterranean Sea is an area of great interest for its volcanic activities. This paper presents a comparative study of radiometric and chemical data regarding three volcanic islands located in southern Italy (Pantellena, Ustica, and Vulcano) characterized by different magmatic histories. Measurements of radionulide contents and chemical composition of rock samples belonging to the main lithologies present in the three islands were carried out the observed correlations among radiometric, chemical and mineralogical data reflect the differences in the volcanological genesis and suggest some hypotheses on the magmatic evolution.

Distribuzione di radicali liberi in dosimetri EPR irradiati con radiazioni di diverso LET

In questo lavoro abbiamo analizzato la distribuzione spaziale dei radicali liberi osservati in dosimetri di tartrato di ammonio esposti a vari fasci di radiazione (protoni da 19.3 M e V , fotoni gamma del ^°Co e ioni carbonio da 62 MeV/nucleone). Lo studio è stato effettuato sia tramite Electron Spin Resonance in onda continua che tramite Electron Spin Echo ( E S E ) decay analysis che forniscono informazioni rispettivamente sulla concentrazione macroscopica e microscopica d i radicali liberi. U n a più approfondita indagine della distribuzione d i radicali liberi all'interno dei dosimetri è stata condotta attraverso l a tecnica Doublé Electron-Electron Resonance ( D E E R ) che è i n grado…

Wavelet analysis of the a-wave of the human electroretinographic signal

Dosimetria ESR con alanina per adronterapia per protoni e ioni carbonio

Environmental Metal Pollution Considered as Noise: Effects on the Spatial Distribution of Benthic Foraminifera in two Coastal Marine Areas of Sicily (Southern Italy)

We analyze the spatial distributions of two groups of benthic foraminifera (Adelosina spp. + Quinqueloculina spp. and Elphidium spp.), along Sicilian coast, and their correlation with six different heavy metals, responsible for the pollution. Samples were collected inside the Gulf of Palermo, which has a high level of pollution due to heavy metals, and along the coast of Lampedusa island (Sicily Channel, Southern Mediterranean), which is characterized by unpolluted sea waters. Because of the environmental pollution we find: (i) an anticorrelated spatial behaviour between the two groups of benthic foraminifera analyzed; (ii) an anticorrelated (correlated) spatial behaviour between the first …

Seasonal variation of air kerma rate in Sicily.

Thermoluminescence dosimetry has been used to measure air kerma in 29 sites in Sicily. Four three month measurement campaigns have been carried out in order to assess seasonal variations. Average annual values between 20 and 90 nGy h(-1), after cosmic background subtraction, are reported. Average annual values are strongly dependent on site lithology, and we find that winter data are generally the highest, while spring and autumn rates are generally the lowest with very similar trends in any site. Summer values generally lay in between. Largest seasonal variations are found in sites along the southern coast of the island, probably because of stronger action of winds affecting radon, along w…

Seasonal variation of air kerma in the "Vulcano Porto" area (Aeolian Islands, Italy).

Abstract Air kerma was measured in the “Vulcano Porto” area of the Vulcano Island, belonging to the Aeolian Islands, in the Mediterranean Sea. Measurements were carried out using thermoluminescence dosimeters. The relationship between observed dose values and source lithology has been assessed. Data show a seasonal variation due to weather conditions but also probably related to features of the soils, making the variation more evident.

NDT for the detection and characterization of superficial treatments on stone material from archaeological sites of Merida (Spain)

ESR response of watch glasses to neutron irradiation

Abstract In this paper we report the results of the electron spin resonance (ESR) study of the radiation-induced signal of watch glasses exposed to neutrons. This work extends the series of analyses of the response of watch glasses to various radiation beams which our research group is carrying out for possible applications in retrospective dosimetry. We have considered fluences up to about 3 × 1011 cm−2. We evaluated the signal fading and we found that in the first hours after exposure the signal rapidly decreases. After about 1000 h, it decreases much more slowly. The signal was reduced by about 25% in about 5 months. The radiation induced signal is found to be linearly dependent on neutr…

Spettrofotometria per il monitoraggio degli interventi di restauro: valutazione tramite PCA

La realizzazione di indagini spettrofotometriche per il monitoraggio delle variazioni cromatiche pone la necessità di gestire un elevato numero di dati richiedendo l’utilizzo di analisi statistiche. A tale scopo, la PCA è stata applicata a dati spettrofotometrici relativi a diverse tipologie di superfici (musive, marmoree, etc). Tale metodologia permette di valutare in maniera efficace gli effetti generati a seguito del restau;ro, evidenziando la correlazione tra tutte variabili spettrofotometriche. La distribuzione in cluster dei dati consente di visualizzare la variabile che maggiormente contribuisce allo spostamento cromatico, permettendo il monitoraggio differenziato del comportamento d…

EPR DOSIMETRY INTERCOMPARISON USING SMART PHONE TOUCH SCREEN

This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident.

La spettroscopia ad ablazione laser per analisi stratigrafiche: esempi di applicazioni per lo studio dei beni culturali

La spettroscopia ad ablazione laser (LIBS), a differenza di altre tecniche d'indagine, permette di condurre analisi stratigrafiche anche direttamente sul campione tramite impulsi consecutivi sullo stesso punto. Le attività condotte hanno riguardato l'ottimizzazione dei parametri strumentali (laser energy, delay, exposition time) per verificare la possibilità di ottenere profili di profondità degli elementi chimici costituenti materiali di differente tipologia (bronzi archeologici, lapidei, materiali pittorici, etc.), valutando anche l'influenza delle variabili presenti (spessori, composizione, proprietà del plasma). Tale approccio metodologico, seppur micro-distruttivo, evita la necessità d…

PVA gel dosimeters for radiotherapy applications,

Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità, and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which suffer from limited batch -to-batch …

Anomalous behavior of LiF:Mg,Cu,P (TLD100H) irradiated with electron beams

Abstract Thermoluminescent dosimeters of LiF:Mg,Cu,P (TLD100H) were exposed to 60Co γ -ray, protons, high energy electrons and the glow curves were analyzed. We observed an unusual behavior of the TL response of dosimeters to 7 and 14 MeV electron beam. In fact the relative amplitude between two of the five peaks (2° and 3° peaks) assumes values smaller than the unity for doses up to 5 Gy and values greater than the unity for doses equal to or greater than 10 Gy. A possible explanation of this behavior is given adopting a model of the formation of the peaks 2° and 3° and examining the different ways of energy release in matter for each beam. To perform this analysis we deconvoluted the glow…

Qualitative and quantitative characterization of historical pigments by XRF spectrometry

Gamma activity and geochemical features of building materials: estimation of gamma dose rate and indoor radon levels in Sicily.

A high-purity germanium detector has been used to measure the abundance of radium (Ra), thorium (Th) and potassium (K) in building materials used in Sicilian dwellings. The measurements were performed to evaluate which material was suitable for the construction of an enclosure, which would have a low background emission. The materials examined in this work showed concentrations of 226Ra, 232Th and 40K dramatically variable depending on the lithologies, particularly in the case of blocks, sands and aggregates commonly used in building materials in Sicily. The results are discussed and a criterion is indicated to reduce the radiation dose to humans. Since radon inlet is a major health problem…

ESR response to gamma-rays of alanine pellets containing B(OH)3 or Gd2O3.

ESR response to gamma-irradiation (1-50 Gy) of blends containing alanine and either B(OH)(3) or Gd(2)O(3) is reported. The sensitivity of the alanine--B(OH)(3) blend is comparable to the sensitivity of pure alanine, although its lowest detectable dose, LDD, is smaller ( approximately 1.3 Gy) than that of pure alanine ( approximately 2.9 Gy). Alanine with Gd(2)O(3) is about two times more sensitive than pure alanine, and its LDD is 0.8 Gy. The better sensitivity and LDD are probably due to the high atomic number (Z=64) of gadolinium, which enhances the interaction probability with photons and, consequently, the radical yield. This study suggests that other high-Z atoms may be useful for incr…

An EPR method applied to the recognition of radiation quality.

Nanostructured protective for historical-artistic stone materials: evaluation of effectiveness and persistence by non invasive techniques

Resting state FMRI: A tool to investigate functional connectivity modulation induced by transcranial direct current stimulation of the motor network

Introduction: Resting-state functional connectivity (fcMRI) represents a novel fMRI approach that allows detection of temporal correlations in spontaneous BOLD signal oscillations while subjects rest quietly in the scanner. Under resting conditions the brain is engaged in spontaneous activity that causes a low frequencies (<0.1 Hz) BOLD signal fluctuations. Functional connectivity (FC) can be defined as the synchrony of neural activity among spatially distant regions. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that is known to modulate cortical activity and FC among brain regions, as measured by functional magnetic resonance imaging. This st…

Study of the ESR signal of ammonium tartrate dosimeters exposed to various radiation beams.

ALANINE/EPR DOSIMETRY APPLIED TO THE VALIDATION OF A TOTAL BODY IRRADIATION (TBI) PROTOCOL AND TREATMENT PLANNING DOSE CALCULATION USING A HUMANOID PHANTOM

L’irraggiamento a corpo intero (Total Body Irradiation - TBI) è una tecnica di radioterapia oncologica di largo impiego nella clinica ematoncologica nell’ambito del trattamento di pazienti avviati al trapianto di midollo osseo o al trapianto di cellule staminali periferiche. La TBI da una parte permette di sopprimere il sistema immunitario del ricevente per prevenire il rigetto del midollo del donatore ed eliminare le cellule neoplastiche residue dai trattamenti chemioterapici. In genere, la modalità di somministrazione della TBI prevede irraggiamenti in 3 giorni consecutivi con un bi-frazionamento giornaliero (2 Gy, 2 volte al giorno con intervallo minimo di 6 ore tra le sedute, per 3 gior…

Out-of-phase second harmonic detection as a tool for the determination of relaxation times

Analysis of the human a-wave ERG component

The a-wave is one of the main issues of research in the field of ocular electrophysiology, since it is strictly connected with early photoreceptoral activities. The present study proposes mathematical methods that analyse this component in human subjects, and supports experimental evidence relating to possible correlations among the responses of photoreceptoral units under a light stimulus. The investigation is organized in two parts: the first part concerns the onset and the initial slope, up to the first minimum (about 10-15 ms), the second part deals with the main portion of the wave, up to about 30 ms. In both cases, the a-waves, recorded at various levels of luminance, have been fitted…

Testing and calibration of ESR response of Fricke gel dosimeters in mixed neutron-gamma fields

Advanced techniques in Magnetic Resonance Imaging: characterization of non-gaussian water diffusion using DIFFUSION KURTOSIS IMAGING (DKI)

Diffusion Kurtosis Imaging: prime applicazioni cliniche in ambito neuroradiologico

EPR/ALANINE PELLETS WITH LOW Gd CONTENT FOR NEUTRON DOSIMETRY

This paper reports on results obtained by electron paramagnetic resonance (EPR) measurements and Monte Carlo (MC) simulation on a blend of alanine added with low content of gadolinium oxide (5 % by weight) to improve the sensitivity to thermal neutron without excessively affecting tissue equivalence. The sensitivity is enhanced by this doping procedure of more an order of magnitude. The results are compared with those obtained with the addition of boric acid (50 % by weight) where boron is in its natural isotopic composition in order to produce low-cost EPR dosemeters. The gadolinium addition influences neutron sensitivity more than the boron addition. The presence of additives does not sub…

Radiation quality discrimination by continuous and pulse ESR techniques

The biological damages produced by ionizing radiations in tissues and cells depend on the radiation quality, besides on the dose. The discrimination of the radiation quality, which is related to the linear energy transfer (LET), interests various fields such as radiobiology, astronautic space research, radiotherapy research and accidental dosimetry. In this work we have applied continuous wave ESR (cw-ESR) and pulse ESR techniques to ammonium tartrate samples with the aim of developing procedures able to discriminate radiation quality whose knowledge is fundamental for rabiobiological considerations. We have chosen the ammonium tartrate because it is a promising compound for the measurement…

DOSIMETRIA DI FASCI NEUTRONICI TRAMITE SPETTROSCOPIA DI RISONANZA PARAMAGNETICA ELETTRONICA (EPR)

Non-invasive characterization of archaeological polychrome pottery and metallic artefacts: advantage and limits of XRF in situ analysis

"Historical pigments characterisation by quantitative X-ray fluorescence"

Abstract Most of the historical paints are mainly constituted by inorganic pigments, either pure or mixed, spread on the surfaces using different binding agents. The knowledge of the exact amount of different constituents of the paint, as well as of the mixing and pictorial techniques, is crucial for a careful program of conservation of polychrome works. Moreover, since the availability of these pigments has been changing through the centuries, their identification and chemical characterisation is useful to acquire or deepen information about the artist and his/her work. This information can also be useful for authentication purposes through relative dating because the identification of one…

Temporal trends of heavy metals in sediment core from the gulf of Palermo (Sicily, Italy)

The evaluation of long–term heavy metal concentrations in the Gulf of Palermo was carried out in this study. Measurements of Cr, Cu, Hg, Pb and Zn concentrations were performed by atomic absorption spectrophotometry (AAS) on dated fractions of a sediment core, dated by the 210Pbex method. They are found to cover a time period from 1951 to 2004. The constant sedimentation rate model was used for dating. Specific activities of 137Cs have also been measured in the sediment core sections as a check of the time scale derived by the 210Pbex method. A time-series analysis based on temporal decomposition was used in order to investigate the presence of heavy metal pollution trend. The additive comp…

Functional connectivity modulation induced by transcranial direct current stimulation of the motor network investigated by resting state fMRI

This study is aimed at measuring the variation of functional connectivity between cortical brain regions after tDCS along time. For this purpose we enrolled 20 healthy right-handed subjects.

Foraminiferi bentonici, metalli pesanti e radioattività - ARPAVIEW

Analisi statistica tramite PCA su dati colorimetrici di tessere musive pavimentali

Sensitivity of alanine dosimeters with gadolinium exposed to 6 MV photons at clinical doses.

In this study we analyzed the ESR signal of alanine dosimeters with gadolinium exposed to 6 MV linear accelerator photons. We observed that the addition of gadolinium brings about an improvement in the sensitivity to photons because of its high atomic number. The experimental data indicated that the addition of gadolinium increases the sensitivity of the alanine to 6 MV photons. This enhancement was better observed at high gadolinium concentrations for which the tissue equivalence is heavily reduced. However, information about the irradiation setup and of the radiation beam features allows one to correct for this difference. Monte Carlo simulations were carried out to obtain information on …

Fricke gel, electron spin resonance and thermoluminescence for integration and intercomparison of measurements in NCT dosimetry

Studio del cinabro: integrazione indagini XRF con SR-XRF e SR-XRD

Ad approfondimento ed integrazione dei risultati analitici già presentati, riguardanti la caratterizzazione in situ tramite fluorescenza a raggi X (XRF) dei materiali pittorici presenti su opere marmoree della collezione statuaria della Galleria Regionale di Palazzo Abatellis (Palermo), sono state effettuate ulteriori indagini su un campione di cinabro (HgS) caratterizzato da una colorazione nera. Tali analisi, condotte tramite misure XRF e XRD presso la beam line ID18 dell’European Syncroton Radiation Facility (Grenoble, Francia), hanno fornito informazioni complementari fondamentali per la corretta interpretazione dello stato di conservazione dello strato pittorico studiato.

Degradation study of XVIII century graffiti on the walls of Chiaramonte Palace (Palermo, Italy)

A systematic investigation of the original materials and the degradation phenomena induced by soluble salts on the wall matrix and on the graffiti of the Inquisition jails of Chiaramonte Palace in Palermo (Italy) was carried out. Built in the XIV century, Chiaramonte Palace was used as Inquisition court during the XV–XVI centuries. The ancient graffiti, recently discovered, represent a unique historical witness of the prisoners that lived during that terrible period. In order to study the nature, the amount and the distribution of the salts in the masonry, stone materials sampled at different depth from the wall matrix and saline efflorescences were analysed. Different physical techniques w…

Gilding and pigments of Renaissance marble of Abatellis Palace: non-invasive investigation by XRF spectrometry

Most of the artworks constituting the collection of Renaissance statuary of Abatellis Palace in Palermo (Sicily) show evidence of colour layers and fragments of gold foil that probably once covered the whole marble surface. The restoration of some of these statues has allowed to carry out archaeometric studies about the painting technique and to highlight the original materials and inclusion present on the precious marbles by two famous Italian sculptors of the Renaissance, Francesco Laurana and Antonello Gagini. The measurements have been performed in situ through the integrated use of two non-invasive techniques: visible fluorescence stimulated by ultraviolet light and X-ray fluorescence.…

Correlation between ferrous ammonium sulfate concentration, sensitivity and stability of Fricke gel dosimeters exposed to clinical X-ray beams

Abstract This work describes the characterization of various Fricke-Agarose-Xylenol gels (FXG) dosimeters using NMR relaxometry and MRI analysis. Using X-rays from a clinical linear accelerator (LINAC), the gels were irradiated in the dose range from 0 Gy to 20 Gy. The photon sensitivity of the FXGs was measured in terms of NMR relaxation rates; its dependence on radiation dose was determined as a function of ferrous ammonium sulfate contents (from 0.5 mM to 5 mM). Furthermore, the stability of the NMR signal was monitored over several days after irradiation. These measurements were aided by Magnetic Resonance Imaging (MRI) scans which allowed three-dimensional (3D) dose mapping. In order t…

The response behaviour of LiF:Mg,Cu,P thermoluminescence dosimeters to high-energy electron beams used in radiotherapy

To ensure the effectiveness of radiation-therapy treatments, both in-phantom and in-patient reliable dose measurements are required. Thermoluminescence dosimeters are used commonly for both applications. Among the various available materials, the relatively new LiF:Mg,Cu,P phosphor is a suitable candidate for quality control of in vivo dosimetry in electron-beam therapy. The response behaviour of LiF:Mg,Cu,P chips to 6-21 MeV electron beams used in radiotherapy was studied. Batch homogeneity, dose linearity, sensitivity change after use, dose and dose-rate response, energy dependence and fading characteristics were investigated. The contribution from each factor to the overall uncertainty i…

Improvement of the LET sensitivity in ESR dosimetry for -photons and thermal neutrons through gadolinium addition

Abstract We investigated the ESR response of new materials, alanine and ammonium tartrate to which gadolinium was added. The addition of gadolinium enhances sensitivity for Co 60 γ -photons because of its high atomic number ( Z = 64 ) and an enhancement of sensitivity for thermal neutrons because of its high thermal neutron cross section and high linear energy transfer (LET) secondary particles produced after the reaction with neutrons. In particular, in this paper we analyzed the microwave power saturation properties of dosimeters of alanine and ammonium tartrate with or without gadolinium exposed to different LET beams. The power saturation trends of dosimeters exposed to photons and to t…

Proprietà del segnale ESR di dosimetri a tartarato di ammonio irradiati con radiazioni di diverso LET

Use of alanine EPR dosimeters for discriminating neutron and photon components in the thermal column of Pavia Triga reactor

The main gol of the present work is to investigate the response behaviour of alanine EPR pellets in clinical proton anc carbon ion beams. Proton irradiations were carried out at PSI (Switzerland) using both passive and active scattering modality, whereas, C ions irradiation were performed at GSI (Germany) adopting the raster scanning modality.

Impiego delle radiazioni ionizzanti per il trattamento degli alimenti a scopo conservativo

Wavelet-Based thresholding technique for noise reduction in medical magnetic resonance imaging

Risposta ESR di dosimetri di tartarato di ammonio irradiati con 60Co dopo un processo di stagionatura.

Response charactterization of ammonium tartrate solid state pellets for ESR dosimetry with radiotherapeutic photon and electron beams.

Solid state pellets (1 mm thick) for electron spin resonance (ESR) dosimetry were made using ammonium tartrate as the radiation-sensitive substance. Their behaviour was experimentally investigated as a function of dose with 60Co gamma rays. The calibration function obtained permits measurements of absorbed dose in the 2-50 Gy range, with a combined uncertainty of +/-4%. The lowest detectable dose was about 0.5 Gy. These properties are comparable with or even better than those of ESR dosimeters made from other materials. The time stability of the ESR signal of ammonium tartrate dosimeters at different storage conditions after irradiation was studied. A rather complex behaviour was observed, …

Gel di Fricke: studio della risposta NMR in funzione della concentrazione di ferro ed utilizzo dosimetrico in ambito clinico (3D MRI)

MULTIVARIATE STATISTICAL TOOLS FOR THE RADIOMETRIC FEATURES OF VOLCANIC ISLANDS

The Aeolian Islands represents a Quaternary volcanic arc related to the subduction of the Ionian plate beneath the Calabrian Arc. The geochemical variability of the islands has led to a broad spectrum of magma rocks. Volcanic products from calc-alkaline (CA) to calc-alkaline high in potassium (HKCA) are present throughout the Archipelago, but products belonging to shoshonitic (SHO) and potassium (KS) series characterize the southern portion of Lipari, Vulcano and Stromboli. Tectonics also plays an important role in the process of the islands differentiation. In this work, we want to review and cross-analyze the data on Lipari, Stromboli and Vulcano, collected in measurement and sampling cam…

Microwave Power Saturation of EPR Signal of Modern and Ancient Woods

LIBS analysis for a stratigraphic study on Cultural Heritage material

Improvement of ESR dosimetry for thermal neutron beams through the addition of gadolinium.

In this paper, the addition of gadolinium is proposed as a useful tool to enhance the electron spin resonance (ESR) sensitivity of organic compounds to thermal neutrons. The target of this work is the detection, through the ESR technique, of the thermal neutron fluence in a mixed field of photons and neutrons. Gadolinium was chosen because it has a very high capture cross section to thermal neutrons; its nuclear reaction with thermal neutrons induces complex inner shell transitions that generate, besides other particles, Auger electrons, which in turn release their energy in the neighborhood (only several nanometers) of the place of reaction. Gadolinium was added to two organic molecules: a…

Characterization of Fricke gel dosimeters exposed to gamma rays and neutrons

The use of bioindicators (Posidonia oceanica and benthic foraminifera) to evaluate metal pollution in a complex ecological system: marine coastal environment.

The use of gadolinium for ESR dosimetry

The application of gadolinium to sensitize Electron Spin Resonance (ESR) dosimeters is reviewed. This nucleus is chosen because it has very good features in interacting with ionizing radiations. In particular, it has a very high capture cross section for thermal neutrons which favors the interactions of these particles within the detector; moreover, the charged secondary particles released after neutron interactions (mainly Auger and internal conversion electrons) are able to release their energy close the gadolinium site and, therefore, inside the sensitive volume of the detector. Consequently, the addition of gadolinium inside ESR dosimeters produces a significant enhancement of thermal n…

Water Capillary Absorption in Porous Media in Different Wettability Conditions studied by quantitative MRI and X-ray CT

X-ray computed tomography (CT) and magnetic resonance imaging (MRI) have been successfully applied to study both the capillary properties of several samples of Lecce stone and the performances of treatments used for protection and conservation of historical stone artifacts

PRIN 2007: tecniche innovative per la definizione dello stato di degrado nei metalli

Rilassometria NMR in legni moderni e in legni trattati e non trattati provenienti da una statua lignea del XVI secolo

Analisi integrata tramite XRF e LIBS per lo studio dei materiali pittorici

Lo studio dei materiali pittorici è uno degli obiettivi primari per la caratterizzazione storico- artistica delle opere d’arte poiché fornisce informazioni utili circa i materiali originali e di degrado, la tecnica di esecuzione ed eventuali interventi di restauro pregressi. Tuttavia, la complessità delle indagini archeometriche è legata alla necessità di garantire la salvaguardia del bene culturale che rende essenziale l’uso di tecniche di indagini non o micro invasive. Tra le metodologie d’indagine integrata, l’uso della fluorescenza a raggi X (XRF) e della spettroscopia mediante ablazione laser (LIBS) risponde a tale esigenza e risulta particolarmente utile per la complementarietà delle …

X-ray CT imaging as a scientific tool to study the capillary water absorption in sedimentary rocks used in cultural heritages

This paper proposes the X-Ray CT imaging as appropriate tool for investigating the capillary water absorption in sedimentary rocks. This technique, in fact, provides information useful for deeping the knowledge about of the porosity and the kinetics of the water capillary absorption in porous materials. The possibility to improve in non invasive manner, the understanding of this phenomenon, constitutes a fundamental aspect to take actions in the restoration and conservation of lapideous artifact and monuments from cultural heritages. The investigated sedimentary rocks come from different Sicilian quarries and were used for the building of the Greek temples in the archaeological areas of Agr…

Study of the glow curves of TLD exposed to thermal neutrons.

The glow curves of thermoluminescent dosimeters (TLD600, TLD700 and MCP), exposed to a mixed field of thermal neutrons and gamma photons are analysed. The fluence values of thermal neutrons used, comparable with those used in radiotherapy, allow one to define the reliability of the TLDs, in particular the most sensitive MCP, in this radiation field and to get information on the dose absorbed values. The glow curves obtained have been deconvoluted using general order kinetics and the observed differences for the different LET components have been analysed. In particular, the ratio of the n(0) parameter of two different peaks seems to allow to discriminate the different contributions of neutr…

Neutron dosimetry by means of electron spin resonance (ESR) tecnique

Along with the Neutron Capture Therapy (NCT) development and with the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the beam characterization in order to optimize the therapy procedures. Reliable dosimetric measurements should be able to determine the various components (neutronic and photonic) of the mixed beam usually employed for therapy. We have studied the effect of the additive such as gadolinium and 10B-boric acid on the neutron sensitivity of alanine ESR dosimeters exposed to a gamma and mixed (n, gamma) field mainly composed by thermal neutrons. We have chosen both this additive nuclei because of their very high capture cross section to th…

Computer simulation of the a-wave of the human ERG. Medicon and Health telematics

Sensibilità e stabilità dei dosimetri gel di tipo Fricke esposti ai fotoni nel range clinico in funzione della concentrazione di ferro e degli additivi presenti: 3D MRI per applicazioni dosimetriche

COMPARATIVE EVALUATION OF DATA PREPROCESSING SOFTWARE TOOLS TO INCREASE EFFICIENCY AND ACCURACY IN DIFFUSION KURTOSIS IMAGING

Introduction: Diffusion tensor imaging (DTI) is the most commonly used technique to extract microstructural features from a set of diffusionweighted images. In addition to the metrics obtained with DTI, diffusion kurtosis imaging (DKI) can provide non-Gaussian diffusion measures by means of the kurtosis tensor. DKI has shown to be more sensitive to tissue microstructural changes in both normal and pathological neural tissue. In a clinical setting, however, these benefits are often nullified by numerous acquisition artifacts. The aim of this study was compare two preprocessing software for DTI apply to DKI. Also, the major preprocessing, processing and post-processing procedures applied to D…

Le statue rinascimentali di palazzo Abatellis: caratterizzazione delle dorature e dei pigmenti tramite spettrometria XRF.

TL dose reconstruction in watch glasses exposed to photon, electron and proton beams

Analisi della risposta ESR di vetri di orologi irradiati con vari fasci di radiazioni ionizzanti per dosimetria retrospettiva

NMR di materiali lapidei e di legni archeologici

The gadolinium as a powerful additive for enhancing the neutron sensitivity of ESR dosimeters.

Investigation of applicability of alanine pellets and films for dosimetry of proton clinical beams

Laser-driven proton has recently gained a great interest as an alternative to conventional and more expensive acceleration techniques. These ion beams have desirable qualities such as small source size, high luminosity and small emittance to be used in different physics fields. This is very promising specially for the future perspective of a new concept of hadrontherapy based on laser-based devices could be developed, replacing traditional accelerating machines. ELIMED (Medical Applications at Extreme Light Infrastructure) is a task-force originally born by an idea of ELI-Beams (Prague) and INFN-LNS (Italian Institute for Nuclear Physics of Catania) researchers. ELIMED main goal is to perfo…

Studi preliminari mediante MRR e MRI su legni bagnati d'interesse archeologico

Noise reduction for magnetic resonance imaging by wavelet. An application to the study of the capilary water absorption in sedimentary rocks

Integrated characterization study of building materials in the greek roman theatre of Taormina

Dosimetria a risonanza di spin elettronico (ESR) tramite composti organici (alanina e tartrato di ammonio) per campi misti neutroni-gamma

Distribution of Heavy Metals in Marine Sediments of Palermo Gulf (Sicily, Italy)

Concentrations of Cr, Cu, Hg, Pb and Zn have been measured, by atomic absorption spectrophotometry, in the fine fraction (<63 μm) of surface sediments collected in 30 sites in the Palermo Gulf (Sicily, Italy) in order to assess the levels and the spatial distribution of these elements. Enrichment factors calculated with respect to clean areas have been considered to discriminate between levels due to background or to pollution contributions. The sampling stations, which form a grid inside these areas, are characterized by geographic proximity and by the presence of pollution sources. Ratio matching technique along with hierarchical clustering, minimum spanning tree and principal component a…

A mathematical approach to model diffusion properties of sedimentary rocks relevant to Sicily cultural heritage.

Non-destructive physical measurements for the study of museum environments and characterization of archaeological artifact

Mercury levels in Engraulis encrasicolus and Sardina pilchardus in the Strait of Sicily

EPR dosimetry intercomparison using smart phone touch screen glass

International audience; This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident. There were 13 participants to whom samples were dispatched, and 11 laboratories reported results. The participants received five calibration samples (0, 0.8, 2, 4, and 10 Gy) and four blindly irradiated samples (0, 0.9, 1.3, and 3.3 Gy). Participants were divided into two groups: for group A (formed by three participants), samples came from a homogene…

Qualitative and quantitative thermoluminescence analysis on irradiated oregano

Abstract Thermoluminescence (TL) dosimetry is one of the physical methods used for the identification of irradiated food, suitable for foods from which silicate minerals can be extracted. The aims of the present work were to apply the TL analysis for a qualitative identification of irradiated oregano, and to set up a quantitative procedure to estimate the original treatment dose on the sample. The experimental results show that the TL analysis allows to distinguish irradiated oregano even seven months after the treatment. The additive dose procedure gives a rough estimation of the treatment dose, but can be helpful when the TL ratio method is unsatisfactory.

NUCLEAR MAGNETIC RESONANCE RELAXOMETRY AND IMAGING FOR DOSIMETRY WITH AGAROSE FRICKE GEL

Introduction: Fricke Xylenol Gel (FXG) dosimetric system is based on the radiation induced oxidation of ferrous to ferric ions. In this kind of gels it can occur that ferrous and ferric ions diffuse in the gel matrix. To preserve the spatial distribution of the dose from diffusion, Fricke gels must be undergoing measurement within a few hours of their irradiation. Thus, the spatial integrity of the dose distribution in the Fricke gel is maintained. The oxidation of ferrous ions also causes a reduction of the longitudinal nuclear magnetic relaxation time which can be measured by means of nuclear magnetic resonance (NMR) instrumentation. In this work we performed NMR relaxometry and MR imagin…

I fenoli come nuovi materiali per la dosimetria EPR in campo misto neutroni-gamma

Functional analysis of Normal and CSNB a-wave ERG component

The features of a-wave of the human electroretinogram are one of the more debated problems in electrophysiology since the a-wave reflects the functional integrity of the two photoreceptoral populations (rods and cones). Although different models concerning the contributions of the early photoreceptoral response are available in current literature, a fully comprehensive theory is difficult to formulate because of the large amount of individual photoreceptors. We study the kinetics of the photoreceptoral response through the analysis of the a-wave shape both in healthy and in patients affected by the Congenital Stationary Night Blindness, that interests the rod population only. The physiologi…

FROM LABORATORY TO IN-SITU NUCLEAR MAGNETIC RESONANCE DIAGNOSTICS: AN APPLICATION TO BUILDING MATERIALS OF THE GREEK-ROMAN THEATRE OF TAORMINA

Computer simulation of the a-wave of the human ERG

12C ion beam dose distribution in presence of medium inhomogeneities: comparison between different measurements and simulations with the treatment planning system for particles trip98

Heavy-ions beams offer several advantages compared to other radiation such as low lateral scattering and high biological effectiveness (RBE) in the Bragg peak region, making them particularly attractive for the treatment of radio-resistant tumours localized close to organs at risk [1]. The extension of ion therapy to new clinical cases requires the exploitation of a dedicated treatment planning system (TPS) based on the existing version of TRiP98 [2,3], established TPS for carbon ions. The theoretical models and experimental databases included in TRiP98 are presently mainly based on measurements in water. This approximation can be applied successfully to reproduce many biological tissues wi…

Alanine blends for ESR measurements of thermal neutron fluence in a mixed radiation field

In this paper, the results of a study on the electron spin resonance (ESR) dosimetry to measure thermal neutron fluence in a mixed radiation field (neutron and photons) are presented. The ESR responses of alanine dosemeters with different additives are compared. In particular, the (10)B-acid boric and the Gd-oxide were chosen to enhance the sensitivity of alanine dosemeters to thermal neutrons. Irradiations were carried out inside the thermal column of the TAPIRO reactor of the ENEA center, Casaccia Rome. The main results are a greater neutron sensitivity and a smaller lowest detectable fluence for the dosemeters with gadolinium than for dosemeters of alanine with (10)B, which is well known…

Studi preliminari mediante MRR e MRI su legni bagnati di interesse archeologico

m-XRF applied to sedimentary rocks used in cultural heritages

ESR Spectra o f Normal Human Serum after Treatment with Complement Activating Agents*

Abstract We describe the appearance of a free-radical signal in the ESR spectrum of normal human serum incubated with several complement activating agents. The intensity of this signal is dependent of dose of activating agents, time and temperature. Signals elicited by different complement activators differ in morphology and kinetics. Inhibition by treatment with EDTA and the presence of the signal in activated C 6-deficient rabbit serum suggest that the con-vertase forming steps of complement activation (C2 to 5) could be the source of free-radical containing molecules.

Applicazione della spettroscopia ESR per la ricostruzione della dose in ossa di pollo irradiato a scopo conservativo

Integrated techniques to study sedimentary rocks from Sicily used in Cultural Heritage

Neutron ESR dosimetry through ammonium tartrate with low Gd content.

This paper continues analyses on organic compounds for application in neutron dosimetry performed through electron spin resonance (ESR). Here, the authors present the results obtained by ESR measurements of a blend of ammonium tartrate dosemeters and gadolinium oxide (5 % by weight). The choice of low amount of Gd is due to the need of improving neutron sensitivity while not significantly influencing tissue equivalence. A study of the effect of gadolinium presence on tissue equivalence was carried out. The experiments show that the neutron sensitivity is enhanced by more than an order of magnitude even with this small additive content. Monte Carlo simulations on the increment of energy rele…

Watch glasses exposed to 6 MV photons and 10 MeV electrons analysed by means of ESR technique

Time-frequency analysis of the human photoreceptoral response

Studio della glow curve di TLD irradiati con neutroni termici

CT imaging applied to capillary water absorption in sicilian sedimentary rocks used in cultural heritages

DOSimetria in Situazioni di Emergenza Radiologica (DOSSIER)

REVIEW OF RETROSPECTIVE DOSIMETRY TECHNIQUES FOR EXTERNAL IONISING RADIATION EXPOSURES

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic re…

Analisi Quantitativa su miscele di pigmenti tramite XRF

Datazione mediante la tecnica della TL: Il teatro greco-romano di Taormina

Ori e cromie dei marmi rinascimentali di Palazzo Abatellis: indagine non invasiva tramite spettrometria XRF.

DOSIMETRIA ESR CON ALANINA PER ADRONTERAPIA CON IONI CARBONIO

La sicurezza del paziente sottoposto a trattamenti terapeutici con radiazioni ionizzanti e il buon esito degli ultimi sono strettamente legati all’ottimizzazione delle procedure di esposizione alle radiazioni ionizzanti. In particolare è fondamentale arrecare il danno minore possibile ai tessuti sani che circondano la neoplasia da trattare. Rispetto ai campi di radiazione convenzionali utilizzati in radioterapia (fotoni), le particelle cariche pesanti (protoni e ioni carbonio) offrono diversi vantaggi quali la bassa dispersione laterale, l’alta efficacia biologica (RBE) nella regione del picco di Bragg ed un profilo di dose caratteristico in profondità del tutto differente da quello dei fot…

Environmental risk assesment around archaeological sites in Sicily

Neutron–gamma mixed field measurements by means of MCP–TLD600 dosimeter pair

Abstract In this paper, we compared the TL response of three types of thermoluminescence dosimeters, TLD600 (6LiF:Mg,Ti), TLD700 (7LiF:Mg,Ti) and MCP (LiF:Mg,Cu,P) after exposure to a n–γ mixed field in the fluence range of radiotherapeutic applications. Since a dosimeter pair is required to discriminate the two components of the mixed field, we analyzed the ability of each dosimeter pair to provide the fluence value in the mixed field. At this aim we performed a 60Co–γ calibration and a neutron calibration for all three dosimeter types. Finally, a blind test was performed in order to analyze the accuracy of each dosimeter pair and we found that in this mixed field the fluence value obtaine…

Datazione di materiali lapidei

Dosimetria ESR per la identificazione di frutta secca irradiata e stima della dose

XRF ANALYSES ON MOSAIC TESSERAE OF THE PALATINE CHAPEL OF PALERMO

Energy resolution and throughput of a new real time digital pulse processing system for x-ray and gamma ray semiconductor detectors

New generation spectroscopy systems have advanced towards digital pulse processing (DPP) approaches. DPP systems, based on direct digitizing and processing of detector signals, have recently been favoured over analog pulse processing electronics, ensuring higher flexibility, stability, lower dead time, higher throughput and better spectroscopic performance. In this work, we present the performance of a new real time DPP system for X-ray and gamma ray semiconductor detectors. The system is based on a commercial digitizer equipped with a custom DPP firmware, developed by our group, for on-line pulse shape and height analysis. X-ray and gamma ray spectra measurements with cadmium telluride (Cd…

Electronic paramagnetic resonance power saturation of wooden samples

The deterioration of wood used for artifacts of artistic interest involves the production of different free radicals from the macromolecules of the wooden matrix (cellulose, lignin, and hemicellulose). Among the techniques able to provide information about these free radicals, the contribution of electronic paramagnetic resonance (EPR) can be very valuable. In this paper, the study of EPR signals (with g 2) of both modern and ancient wooden taxa was undertaken in order to analyze some features of the free radicals in natural wood. In particular, we have studied the microwave power saturation behaviors of seasoned wooden samples from ten species, and we have found remarkable differences betw…

DOSE RECOSTRUCTION IN IRRADIATED FOOD CONTAINING HYDROXIAPATITE USING ESR SPECTROMETRY

Discrimination of Radiation Quality Through Second Harmonic Out-of-Phase cw-ESR Detection

The ability to discriminate the quality of ionizing radiation is important because the biological effects produced in tissue strongly depends on both absorbed dose and linear energy transfer (LET) of ionizing particles. Here we present an experimental electron spin resonance (ESR) analysis aimed at discriminating the effective LETs of various radiation beams (e.g., 19.3 MeV protons, 60Co photons and thermal neutrons). The measurement of the intensities of the continuous wave spectrometer signal channel first harmonic in-phase and the second harmonic out-of-phase components are used to distinguish the radiation quality. A computational analysis, was carried out to evaluate the dependence of …

Tecniche spettroscopiche integrate per lo studio di pigmenti storici

Tra le tecniche spettroscopiche per lo studio dei pigmenti storici, la fluorescenza a raggi X (XRF) e la spettroscopia mediante ablazione laser (LIBS) risultano complementari per le informazioni fornite in termini composizionali e di spessori indagati. A differenza dell'analisi XRF, la LIBS permette l'identificazione degli elementi chimici a basso Z e, attraverso impulsi laser consecutivi, consente di ricostruire la stratigrafia caratteristica del campione. Sono state condotte analisi spettroscopiche su frammenti di pitture murali provenienti da diversi siti e su pigmenti in polvere. I risultati hanno permesso di valutare le potenzialità, in campo archeometrico, della tecnica LIBS rispetto …

NMR analysis of pore-size distribution in buildng materials coming from the ancient theatre of Taormina

GAS CHROMATOGRAPHIC/MASS SPECTROMETRIC AND MICROBIOLOGICAL ANALYSISES ON IRRADIATED CHICKEN

Inquinamento da metalli pesanti in ambiente marino in correlazione con la distribuzione dei foraminiferi bentonici

Changes in the morphology of sea urchin embryos exposed during specific stages of development to 50 Hz electric and magnetic fields

Nuclear magnetic resonance relaxometry and imaging for dosimetry with agarose Fricke gel

Validity of NMR pore-size analysis of cultutal heritage ancient building materials containing magnetic impurities

NMR relaxation time distributions, obtained with laboratory and portable devices, are utilized to characterize the pore-size distributions of building materials coming from the Roman remains of the Greek-Roman Theatre of Taormina. To validate the interpretation of relaxation data in terms of pore-size distribution, comparison of results from standard and in situ NMR experiments with results of the mercury intrusion porosimetry (MIP) has been made. Although the pore-size distributions can be obtained by NMR in terms of either longitudinal (T-1) or transverse (T-2) relaxation times distributions, the shorter duration of the T-2 measurement makes it, in principle, preferable, although the dete…

Tecniche tomografiche a raggi X per lo studio dei beni culturali

DATAZIONE MEDIANTE LA TECNICA DELLA TERMOLUMINESCENZA

Study of the response of phenol compounds exposed to gamma photons and neutrons for Electron Spin Resonance dosimetry

Use of 70 MeV proton beam for medical applications at INFN-LNS: CATANA project

The project CATANA (Centro di Adro Terapia ed Applicazioni Nucleari Avanzate) is a collaboration between the INFN-Laboratori Nazionali del Sud (LNS), Physics Department, Ophthalmology Institute and Radiology Institute of the Catania University and CSFNSM Catania. The main goal of CATANA is the study and the application of protontherapy for the treatment of shallow tumors (4 cm max) like uveal melanomas and subfoveal macular degenerations.

Application of the ESR spectrometry to evaluate the original dose in irradiated dried fruit

The identification of irradiated dried fruit can be achieved by means of the electron spin resonance (ESR) spectrometry, as recommended by the European Community, since ionizing radiation induces free radicals in cellulose, a constituent of the shell. The aim of this work was to use the ESR spectrometry also as a quantitative procedure to evaluate the original dose in irradiated dried fruits, using the additive dose method. Little shell pieces, taken from nuts, chestnuts, peanuts and pistachios, were irradiated at “original” dose values in the range 1 to 8 kGy, and the ESR signal intensity was measured. Each specimen was then reirradiated with added doses of 1 kGy, and the ESR signal was me…

Ulteriori valutazioni sull’impiego della Principal Component Analysis su dati colorimetrici di tessere musive pavimentali

Uso della spettroscopia ESR per la valutazione della dose nel pollo irradiato

Risposta TL di dosimetri irradiati con radiazione di diverso LET

DATA ANALYSIS OF ESR SIGNALS OF DOSIMETERS FOR NEUTRON-GAMMA MIXED FIELD WITH GADOLINIUM AS AN ADDITIVE

RISPOSTA ESR DI COMPOSTI ORGANICI PER LA DOSIMETRIA DI NEUTRONI TERMICI

An approach based on wavelet analysis for feature extraction in the electroretinogram

Most biomedical signals are non-stationary. The knowledge of their frequency content and temporal distribution is then useful in a clinical context. The wavelet analysis is appropriate to achieve this task. The present paper uses this method to reveal hidden characteristics and anomalies of the human a-wave, an important component of the electroretinogram since it is a measure of the functional integrity of the photoreceptors. We here analyse the time–frequency features of the a-wave both in normal subjects and in patients affected by Achromatopsia, a pathology disturbing the functionality of the cones. The results indicate the presence of two or three stable frequencies that, in the pathol…

Dose verification with EPR/alanine dosimeters in Helical Tomotherapy Stereotactic Radiosurgery (HT SRS) treatments

Intracranial stereotactic radiosurgery (SRS) is a technique to deliver an ablative radiation dose with an extremely sharp dose gradient to small brain tumors. This tecnique allows to deliver high doses of radiation to the tumor sparing the surrounding healthy tissue. In this study the accuracy of the dose delivered in a SRS session by a non conventional radiotherapy machine, the TomoTherapy Hi-Art System, was investigated using an "end-to-end" test. This is perfome d by means of alanine Electron Paramagnetic Resonance (EPR) pe llets. The response of these dosimeters is compared to that of gafchromic films which are particularly suitable for two-dimensional dose verification providing accura…

Comparative evaluation of data preprocessing software tools to increase efficiency and accuracy in diffusion kurtosis imaging

Heavy metals in the fine fraction of coastal sediments from Gulf of Palermo.

Characterization of Fricke gel dosimeters exposed to clinical photons beams and of MRI dosimetrical applications

A degradation study of XVIII century graffiti on the walls of Chiaramonte Palace (Palermo, Italy)

Dosimetry of Mainz reactors by means of ESR dosimetry with alanine added with gadolinium

Exposure of -alanine and -ammonium tartrate ESR dosimeters to thermal neutrons: Experiments and Monte Carlo simulations

Abstract Electron spin resonance solid state dosimetry with alanine and ammonium tartrate pellets is a valuable tool in both medical and industrial applications when dealing with photon and charged particle beams. Its use in neutron beams is limited by the low nuclear cross section values of atoms in the pellets. Addition of boron (10B) or gadolinium ( Gd 2 O 3 ) , known to have high neutron capture cross sections, has been proposed to improve neutron sensitivity. In this paper we present the results of an experimental study concerning neutron sensitivity vs. gadolinium concentration in dosimeter mixtures, with the aim of optimizing mixture composition and maximizing the electron spin resol…

Benthic foraminifera assemblages in coastal marine ecosystem and relationship with metal distribution. A spatial study along Sicilian coasts.

Watch glasses exposed to 6 MV photons and 10 MeV electrons analysed by means of ESR technique: A preliminary study

Abstract In this work we report a case study of the ESR response of watch glasses exposed to 6 MV photons and to 10 MeV electrons. The choice of watch glasses is justified by the fact that watch glasses are very close to the exposed individual. For both types of radiation beams, the absorbed doses belong to the range between 1 and 20 Gy. The samples have been irradiated in water-equivalent plastic phantom with a linear accelerator used for radiotherapy. After exposure watch glass samples have been cut in small strip-shaped pieces with suitable size to be put into the quartz tube for ESR measurements. The signal induced by radiation (RIS) lies in the g ∼ 2 region and must be discriminated fr…

Studio del degrado indotto da sali solubili su materiali lapidei nelle ex-carceri dello Steri a Palermo

Discrimination of LINAC photon and sunlight contributions in watch glass analyzed by means of thermoluminescence

Abstract The research described in this paper shows how to extract from the glow curves of watch glasses exposed to LINAC photons and sunlight a contribution sensitive to LINAC photons dose. As first step, the dependence of the TL signal due to sunlight on the exposure duration was studied and a signal saturation was observed after about 20 weeks. The comparison of TL signals due to solar light and to LINAC photons highlights a partial overlap of the two signals. Here, two different analysis procedures of glow curves (general order kinetics deconvolution and principal components analysis) are reported to point out components which depend differently on LINAC photon radiation dose. For both …

COMPARATIVE ANALYSIS FOR THE ASSESSMENT OF RESTORATION TREATMENTS ON STONE MATERIAL FROM THE ROMAN THEATER OF MERIDA (SPAIN)

Indagini ESR su legni moderni e antichi.

Datazione mediante la tecnica della Termoluminescenza

Dosimetria EPR con alanina per fasci di protoni per adronterapia

RADICAL DISTRIBUTIONS IN AMMONIUM TARTRATE SINGLE CRYSTALS EXPOSED TO PHOTON AND NEUTRON BEAMS

The radiation therapy carried out by means of heavy charged particles (such as carbon ions) and neutrons is rapidly becoming widespread worldwide. The success of these radiation therapies relies on the high density of energy released by these particles or by secondary particles produced after primary interaction with matter. The biological damages produced by ionising radiations in tissues and cells depend more properly on the energy released per unit pathlength, which is the linear energy transfer and which determines the radiation quality. To improve the therapy effectiveness, it is necessary to grasp the mechanisms of free radical production and distribution after irradiation with these …

Influence of waste water in marine ecosystem: preliminary data on benthic foraminifera assemblages and metal concentration in marine sediments

Studio e calibrazione della risposta ottica ed NMR di dosimetri gel di tipo Fricke (FXG) in campi misti neutroni-gamma per applicazioni cliniche

Organismi unicellulari "spie" dell'inquinamento dell'ambiente marino.

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages

Abstract The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used…

Confronti dosimetrici tra due tecniche radioterapiche a modulazione di intensità nei trattamenti stereotassici polmonari ipofrazionati

La radioterapia stereotassica extra-cranica (Stereotactic Body Radiation Therapy) consente di somministrare una dose ablativa ad un volume bersaglio non encefalico mediante un numero ridotto di frazioni. La riduzione nel numero di frazioni comporta necessariamente un aumento della precisione ed accuratezza in tutte le fasi del trattamento, dalla simulazione CT alla pianificazione ed all’erogazione della dose terapeutica. Dal punto di vista dosimetrico i trattamenti SBRT sono caratterizzati innanzitutto da un elevato grado di conformazione e soprattutto dalla presenza di gradienti di dose particolarmente ripidi necessari per minimizzare la dose ai tessuti sani circostanti ed agli organi a ri…

Datazione di materiali ceramici e lapidei

Dosimetria tramite Risonanza Elettronica di Spin (ESR) in RadioTerapia IntraOperatoria (IORT): misure di Output Factors e simulazioni Monte Carlo-GEANT4

La RadioTerapia IntraOperatoria (IORT) è una modalità di trattamento in cui una singola dose di radiazioni è impartita direttamente al letto tumorale o al tumore durante l'intervento chirurgico, evitando di colpire i tessuti sani circostanti. La fabbricazione di acceleratori lineari mobili per elettroni dedicati alla IORT ha permesso una grande diffusione di questa tecnica radioterapica. Lo scopo di questo lavoro è il confronto tra la risposta di dosimetri di alanina letti tramite Risonanza Elettronica di Spin (ESR) e di camere a ionizzazione Markus per le misurazioni degli Output Factors (OFs) di fasci di elettroni prodotti da un acceleratore lineare utilizzato per la IORT. Gli OFs dei fas…

Gas chromatographic/mass spectrometric and microbiological analyses on irradiated chiken

Ionizing radiation is widely used as treatment technique for food preservation. It involves among others reduction of microbial contamination, disinfestations, sprout inhibition and extension of shelf life of food. However, the commercialization of irradiated food requires the availability of reliable methods to identify irradiated foodstuffs. In this paper, we present results on the application to irradiated chicken of this method, based on the detection, in muscle and skin samples, of the peaks of ions 98 Da and 112 Da, in a ratio approximately 4:1, typical of radiation induced 2-dodecylcyclobutanones (2-DCB). Aim of the work was also to study the time stability of the measured parameters…

ESR response of watch glasses to proton beams

In this paper we have analyzed the electron spin resonance (ESR) signal of watch glasses irradiated with %60 MeV proton beams in the dose range between 1 and 105 Gy. The composition of samples expressed in oxides weight percentages has been obtained carrying out X-ray fluorescence spectrometry (XRF) mea- surements. The ESR signal has been studied in terms of its dependence on microwave power and modulation field in order to choose the optimal recording parameters. The dependence of the radioinduced signal on the exposure dose has been investigated. A numerical procedure aimed at improving the sensitivity in the low dose range has been developed.

APPLICATION OF THE ESR SPECTROMETRY TO EVALUATE THE ORIGINAL DOSE IN IRRADIATED FOOD CONTAINING HYDROXIAPATITE

Comparison between NMR and MIP in characterizing porosity of limestone used in Cultural Heritage,

Limestone with different porosity are used extensively as a sculptural and architectural stone in artistic-architectural field. As it is known, this kind of material is subjected to physico-chemical decay that involves the loss of surface and in-depth cohesion [1]. Consolidation interventions are performed in order to preserve building and decorative surfaces of architectural monuments, to reduce their degradation rate and to improve cohesion and adhesion in the stone [2]. Porosity of stone and pore size distribution are important factors to evaluate the effectiveness of a consolidation treatment and they are normally performed using a single technique such as mercury intrusion porosimetry,…

Alanine/ESR dosimetry for electron Intra-Operative RadioTherapy: output factor measurements and Monte Carlo-GEANT4 simulations for IORT mobile dedicate accelerator

Intra-operative radiation therapy (IORT) is a treatment modality where a single high dose of radiation is delivered directly to the tumor bed or to the exposed tumor during the surgical intervention, while avoiding surrounding dose-limiting structures. Mobile electron linear accelerators dedicated to IORT have been manufactured which have promoted a local large diffusion of this radiotherapy modality. For breast irradiation, a single fraction of 21 Gy delivered on the target volume during the surgical procedure is equivalent to the total dosage (60 Gy) usually delivered during 30 external fractionated radiotherapy at 2Gy/fraction. Alternatively, a single dose of 10 Gy can be administered as…

Pulsed EPR analysis of tooth enamel samples exposed to UV and gamma radiations

Environmental Gamma Radiation Measurements on the Island of Pantelleria

The population exposure to those living on the island of Pantelleria, Italy, was estimated by measuring the natural gamma background. Gamma spectra of natural rocks and measurements of absorbed dose in air were taken. A correlation was found between the mean gamma exposure rate and the mean values of natural radionuclide concentrations in the investigated rocks.

Thermoluminescence response of sodalime glass irradiated with photon and electron beams in the 1-20 Gy range

Abstract The thermoluminescence response of a watch commercial glass was studied after irradiation with photons and electrons, in the range 1–20 Gy, of interest in accidental dosimetry; a linear response was obtained with both beams. This result, together with the satisfactory time stability of the thermoluminescence signal, indicates this glass as a potential material for retrospective dosimetry applications.

DOPED ALANINE ESR DOSIMETERS FOR MEASUREMENTS OF THERMAL NEUTRON FLUENCE IN A MIXED RADIATION FIELD

Verso una diagnostica integrata dei materiali porosi mediante tecniche tradizionali ed NMR: una rete nazionale di laboratori

Fino ad anni recenti la Risonanza Magnetica Nucleare non era stata sostanzialmente impiegata per lo studio di materiali di interesse per i Beni Culturali. Ora le tecniche di Rilassometria NMR per i materiali porosi sono divenute un importante strumento di indagine della struttura dello spazio poroso, delle sua alterazioni, e del contenuto di acqua. Vengono mostrati esempi di integrazione tra le tecniche NMR ed altre tecniche tradizionali.

DOSE RECONSTRUCTION IN IRRADIATED OREGANO BY THERMOLUMINESCENCE DOSIMETRY

Physics, Techniques and Review of Neuroradiological Applications of Diffusion Kurtosis Imaging (DKI)

In recent years many papers about diagnostic applications of diffusion tensor imaging (DTI) have been published. This is because DTI allows to evaluate in vivo and in a non-invasive way the process of diffusion of water molecules in biological tissues. However, the simplified description of the diffusion process assumed in DTI does not permit to completely map the complex underlying cellular components and structures, which hinder and restrict the diffusion of water molecules. These limitations can be partially overcome by means of diffusion kurtosis imaging (DKI). The aim of this paper is the description of the theory of DKI, a new topic of growing interest in radiology. DKI is a higher or…

Cyclic influences on the heavy metal chronology in a Central Mediterranean area (Palermo Gulf, Italy)

PurposeThe evaluation of long-term heavy metal concentrations in the Gulf of Palermo (Italy) has been carried out in order to investigate how changes of pollution levels in the last 50 years can be reflected in marine sediments. Measurements of Cr, Cu, Hg, Pb, and Zn concentrations were performed on dated fractions of a sediment core. Time series analysis has allowed to obtain information on the chronology of the heavy metal pollution of the area and to identify seasonal components and trends.Materials and methodsHeavy metal concentrations in the <63 μm fraction of core sections were obtained by Atomic Absorption Spectrophotometry, after wet sieving, drying, and digestion procedures. Dating…

THE RESEARCH AND DEVELOPMENT ACTIVITY IN ESR DOSIMETRY AT UNIVERSITA' DI PALERMO, ITALY

Sensibilità e stabilità dei dosimetri gel di tipo Fricke esposti ai fotoni nel range clinico in funzione della concentrazione di ferro: 3D MRI ed applicazioni dosimetriche

Phenol compounds as new materials for Electron Spin Resonance (ESR) dosimetry in clinical photon and electron beams

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Spin Resonance (ESR) dosimetry to radiotherapy with different types of radiation beams. ESR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through ESR technique which able to quantitatively determine the radical concentration.The use of alanine as a dosimetric…

Applicazione Integrata di Tecniche Analitiche per la Caratterizzazione di Pigmenti Storici

X-rays Ct imaging techniques applied to survey capillary absorption kinetics of Sicilian sedimentary rocks utilized in cultural heritage.

Solid-liquid nuclear magnetic resonance relaxation and signal amplitude relationships with ranking of seasoned softwoods and hardwoods

In 1H NMR (Nuclear Magnetic Resonance) relaxation measurements for a set of eight hardwood and softwood samples, each Free Induction Decay (FID) is fit by the sum of a “Solid” signal of the form A exp[−c(t/Ts)2] [1−g(t/Ts)2+h(t/Ts)4] plus a “Liquid” signal B exp(−t/T2 FID). Distributions of longitudinal (T1) relaxation times were computed separately for the Solid and Liquid components, giving also the Solid/Liquid 1H ratio α. From measurements on the samples dried, seasoned, and hydrated, the moisture content, (Liquid/Solid weight ratio) was found to be approximately 0.50/α. For each of the “Seasoned” samples (10-13% moisture content) a single T1 peak was found for the Solid and two for the…

Environmental radioactivity at Stromboli (Aeolian Islands)

HPGe gamma spectrometry, thermoluminescence dosimetry, X-ray diffractometry and fluorescence techniques have been used to analyze the natural radionuclides content of soil and rock samples, air kerma and geochemical features on the island of Stromboli, belonging to the Aeolian Islands, in the Mediterranean Sea. The 214Bi, 238Ac, and 40K contents obtained are in agreement with the magmatic evolution of the rock formation, as shown by the correlations between radionuclide and chemical elements abundacies, depending on the various magmatic differentiation mechanisms. Correlations between radiometric, lithological and geochemical data have been assessed in order to obtain some hints on the geoc…

VALUTAZIONE DELL'EFFICACIA E DURABILITÀ DI PROTETTIVI NANOSTRUTTURATI APPLICATI SU CAMPIONI DI MARMO DI CARRARA

An integrated analytical approach can be useful to study the effectiveness of preservation treatment for Carrara marble surfaces, carried out for testing commercial products which are based on nano-structured silica oxides. Variation in hydrophobic properties, porosity distribution, and chemical composition of treated surfaces have been studied. With this aim, contact angle evaluation, NMR, XRF measurements have been used. Changes of above mentioned physical and chemical characteristics have been evaluated before and after aging in saline chamber of the treated and untreated samples. Moreover, the effectiveness of ultrasonic treatment in “safe” removal of the products from treated surfaces …

EFFECTS OF ELECTROMAGNETIC FIELDS ON IFN-GAMMA RELEASE AND CONTENENT FROM HUMAN SUBSETS OF CD4+T CELLS.

Nuclear Magnetic Resonance for Cultural Heritage

Valutazione dello stato di degrado di materiali lapidei in contesti archeologici: “Il Teatro Antico di Taormina”

Characterization of foxing stains in early twentieth century photographic and paper materials

The subject of this present work is a group of nine historical pictures shot in Palermo by the Sicilian photographer E. Interguglielmi in 1912. They are nine matte-collodion prints mounted on the original cardboard supports and all of them show foxing stains affecting the paper surface. In order to characterise the chemical composition of the supports and investigate foxing spots, non-destructive and micro-destructive analysis were carried out. X-rays fluorescence (XRF) analysis was used to characterise the elemental composition of all the mounting boards, allowing a comparison between the foxing spots and non-affected areas. Laser-Induced Breakdown Spectroscopy was used to investigate the …

STUDY OF CAPILLARY ABSORPTION KINETICS BY X-RAY CT IMAGING TECHNIQUES: A SURVEY ON SEDIMENTARY ROCKS OF SICILY

Sedimentary rocks are natural porous materials with a great percent of microscopic interconnected pores: they contain fluids, permitting their movement on macroscopic scale. Generally, these rocks present porosity higher then metamorphic rocks. Under certain points of view, this feature represents an advantage; on the other hand, this can constitute an obstacle for cultural heritage applications, because the porosity grade can lead to a deterioration of the lapideous monument for water capillary absorption. In this paper, CT (Computerized Tomography) image techniques are applied to capillary absorption kinetics in sedimentary rocks utilized for the Greek temples as well as baroc monuments, …

Dating of a sediment core in the Palermo Bay (Sicily, Italy)

An extensive study of sediment cores in the Palermo Bay has been carried during the last two years. Main goal of the research was to study the environmental pollution of the area, using foraminifers as an environmental indicator.

ESR study of proton irradiation response of watch glasses.

PRODOTTI NANOSTRUTTURATI PER LA PROTEZIONE DI SUPERFICI LAPIDEE: VALUTAZIONE DELL’EFFICACIA MEDIANTE TECNICHE FISICHE NON INVASIVE

The use of nanoproducts in the Cultural Heritage (CH) field requires great sensitivity and responsibility and, above all, analytical research and studies evaluating effectively their potential use. In order to evaluate the capability of nanostructured protective in the CH field, limestone materials of historical-artistic interest were treated and then studied. The study focuses on the non-invasive evaluation of samples stone, of interest in the CH field, their surface has been tested with nanostructured products. In particular, samples of limestone of Favara (Sicily) have been studied, before and after artificial aging. The analytical methodology involved X-ray fluorescence measurements, in…

Classificabilità di essenze lignee mediante rilassometria e imaging NMR

Studio della cinetica di assorbimento di fluidi in mezzi porosi tramite Imaging a Risonanza Magnetica Nucleare

In questo lavoro, la tecnica di Imaging a Risonanza magnetica Nucleare (MRI) è stata impiegata per studiare in modo quantitativo, non invasivo, non distruttivo, la cinetica di assorbimento capillare di acqua in campioni di Pietra di Lecce, una biocalcarenite omogenea nella quale il fronte di bagnamento avanza pressoché piatto. MRI permette di misurare in funzione del tempo l’altezza raggiunta dal fronte in qualunque sezione interna del campione. Al fine di studiare l’anisotropia del fenomeno dovuta ad eventuali strati sedimentari, alcuni esperimenti sono stati effettuati variando l’asse principale di assorbimento (ortogonale al piano dove avviene l’assorbimento) attraverso la semplice rotaz…

Misure di rilassamento 1H-NMR per la classificazione di essenze lignee e per lo studio di trattamenti protettivi e consolidanti

Complementarity of the XRF and LIBS analyses in the conservation science: the case studies of the bronze alloys

The present study confirms how the integrated use of non-destructive or micro-destructive spectroscopic techniques are capable to provide a clear response to the investigative needs in the conservation science. In particular, the X-ray fluorescence analysis in association with laser-induced breakdown spectroscopy can be useful for collecting information about chemical composition and elemental stratigraphic distribution of the external layers. The complementarity of these techniques has been tested by analysing bronze samples, made in the laboratory according to binary, ternary and quaternary alloys, typical of Roman archaeometallurgical production and buried for one year. The findings have…

Preliminary data on correlations between aberrant benthic foraminifera and metal concentrations in sediments from Palermo and Termini gulfs (Sicily)

Wavelet analysis of human photoreceptoral response

Feature detection of biomedical signals is crucial for deepening our knowledge of the physiological phenomena giving rise to them. To achieve this aim, even if many analytic approaches have been suggested only few are able to deal with signals whose features are time dependent, and to provide useful clinical information. In this work we use the wavelet analysis to extract peculiarities of the early response of the photoreceptoral human system, known as a-wave ERG-component. The analysis of the a-wave features is important since this component reflects the functional integrity of the two populations of photoreceptors, rods and cones whose activation dynamics are not well known. Moreover, in …

Response of benthic foraminifera to heavy metal contamination in marine sediments (Sicilian coasts, Mediterranean sea)

To examine the suitability of benthic foraminifera and their test deformations as bioindicators of pollution in coastal marine environments, we studied foraminifera and metal concentrations in 72 marine sediment samples, collected from the inner shelf along the Sicilian coast (Gulfs of Palermo and Termini) and on the south-eastern coast of Lampedusa Island. These areas are characterised by different environmental conditions. On the basis of pollution sources and foraminiferal assemblages, we recognised different zones in the Gulf of Palermo. The most polluted zones showed high metal concentrations, and low diversity of benthic foraminifera with species typical of stressed environments. By c…

Effects of gamma-irradiation on trehalose–hydroxyethylcellulose microspheres loaded with vancomycin

Ionizing radiation can be used as a drug sterilization technique, provided that the drug itself is not modified and that no toxic products are produced; moreover, if the irradiated product is a drug delivery system, the drug release characteristics must not be significantly altered by radiation. The aim of this work was to study the effects of sterilization by ionizing radiation on hydroxyethylcellulose/trehalose spherical micromatrices, containing the antibiotic vancomycin. Our experimental results showed that gamma-rays did not alter the chromophore groups of vancomycin (UV measurements), and did not modify the kinetic behavior of drug release from microspheres. Moreover, no significant c…

Nuclear Magnetic Resonance for Cultural Heritage

Abstract Nuclear magnetic resonance (NMR) portable devices are now being used for nondestructive in situ analysis of water content, pore space structure and protective treatment performance in porous media in the field of cultural heritage. It is a standard procedure to invert T 1 and T 2 relaxation data of fully water-saturated samples to get “pore size” distributions, but the use of T 2 requires great caution. It is well known that dephasing effects due to water molecule diffusion in a magnetic field gradient can affect transverse relaxation data, even if the smallest experimentally available half echo time τ is used in Carr–Purcell–Meiboom–Gill experiments. When a portable single-sided N…

NMR relaxometry measurements of Fricke gel dosimeters exposed to neutrons

Fricke infused gel matrices offer several features making them suitable for dosimetric applications; among the set here are tissue equivalence, low cost and ease of preparation. Their nuclear magnetic resonance (NMR) relaxation properties can be used as a radiation detector for the dosimetry of beams used in cancer therapy. In recent years neutron capture therapy has been resumed for the treatment of various types of cancer and it requires three-dimensional mapping of the neutron fields. In this work, we investigated this particular application through NMR relaxometry and MR imaging of Fricke gels exposed to neutrons. We analyzed both the R1 and R2 relaxation rates, which relate to the long…

Analysis of the spatial distribution of free radicals in ammonium tartrate by pulse EPR techniques

Using pulse electron paramagnetic resonance (EPR) on a series of l(+)-ammonium tartrate (AT) dosimeters exposed to radiations with different linear energy transfer (LET), we assessed the ability of pulse EPR spectroscopy to discriminate the quality of various radiation beams such as (60)Co gamma-ray photons, protons and thermal neutrons at various doses by analyzing the local radical distributions produced by the different beams. We performed two types of pulse EPR investigations: two-pulse electron spin echo decay obtained by varying the microwave power, and a double electron-electron resonance (DEER) study. Both methods provide information about the dipolar interactions among the free rad…

Studio della risposta di vetro minerale per dosimetria in emergenza radiologica

Diffusion and sensitivity characteristics of a chemically cross-linked PVA-Fricke gel dosimeter

Comparison of LIBS and micro-XRF measurements on bronze alloys for monitoring plasma effects

The laser-induced breakdown spectroscopy (LIBS) technique is often used as atomic spectroscopic technique for elemental analysis of materials. However, it presents some drawbacks that make an accurate quantitative analysis difficult. Since the plasma properties, such as spatial inhomogeneity and plume stoichiometry strongly depend on the experimental conditions, the measurements are less reproducible. In order to evaluate the measurement fluctuations, we propose to use the more established micro X-Ray fluorescence (μ-XRF) technique for validating LIBS data. In particular, the quantitative data, obtained by varying the laser fluence, the shot numbers and the temporal acquisition parameters, …

TRANS-CRANIAL MRI-GUIDED FOCUSED ULTRASOUND SURGERY (TCMRGFUS): ITALIAN AND WORLD-FIRST EXPERIENCE AT 1.5 TESLA

Introduction: Transcranial magnetic resonance-guided focused ultrasound surgery (tcMRgFUS) is a promising new technology for the noninvasive treatment of various brain disorders. Here, we present our preliminary results achieved with the first Italian installation of a transcranial MRI-guided focused ultrasound surgery (tcMRgFUS) certified system for functional neurosurgery. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. Materials and Methods: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed me…

Continous wave and pulsed EPR analysis of spatial distribution of free radicals in ammonium tartrate samples.

Agarose and PVA Fricke gel dosimeters exposed to clinical photons beams: Nuclear Magnetic Resonance Relaxometry and Imaging

Fricke Xylenol Gel (FXG) dosimetric system is based on the radiation induced oxidation of ferrous (Fe2+) to ferric (Fe3+) ions. The application of Fricke gels for ionizing radiation dosimetry is continuously increasing worldwide due to their many favorable properties. However, one of their shortcomings is that ferrous and ferric ions diffuse in the gel matrix. To maintain the spatial integrity of the dose distribution, Fricke gels must be undergoing measurement within a few hours of their irradiation, so that ferric ions remain close to their point of production. Thus, the spatial integrity of the dose distribution in the Fricke gel is maintained. The gel matrix also contributes to the oxid…

Caratterizzazione ESR di composti fenolici: nuovi materiali per la dosimetria in campo misto neutroni-gamma

Sviluppo di un software per l’analisi di immagini di Diffusion Kurtosis Imaging

L’analisi mediante RM del tensore di diffusione (Diffusion Tensor Imaging, DTI) consente di valutare anche in vivo e con modalità non invasive il processo di diffusione delle molecole d’acqua nei tessuti biologici. La peculiare organizzazione di alcuni tessuti biologici (es: muscoli, sostanza bianca del sistema nervoso centrale e tessuti ad alta cellularità) influenza tale fenomeno rendendolo anisotropo e quindi ben valutabile con tali tecniche di studio. Nonostante i grandi vantaggi di tale tecnica, il DTI è basato su un modello molto semplificato che assume che lo spostamento per diffusione segua un profilo gaussiano il che è molto raro in un ambiente variegato come i tessuti biologic…

Caratterizzazione NMR ed EPR di mattoni del Teatro Antico di Taormina.

Glow curve analysis of TLD-100H irradiated with radiation of different LET: Comparison between two theoretical method

In the present paper we show the result of study on the thermoluminescent signal of LiF:Mg,Cu,P (TLD-100H) after irradiation with beams of different LET (photons, electrons and protons). Through the analysis of the glow curve it is possible to obtain information on the LET of the radiation beam. To perform this analysis we have deconvoluted the glow curves adopting general order kinetic equation for the description of the peak shape. In addition a numerical simulation has been performed to find a connection among the physical parameters of the model (OTOR) and the parameters of the empirical expression used in the analysis of the experimental data (GOK). The methodology indicate that the ki…

Dependence of MRI sensitivity of Fricke gel dosimeters exposed to clinical photons beams on ferrous ammonium sulfate content

Integrated techniques to evaluate the features of sedimentary rocks of archaeological areas of sicily.

Sicily includes a great variety of lithologies, giving a high complexity to the geologic landscape. Their prevalent lithology is sedimentary. It is well known that rocks of sedimentary origin, compared with metamorphic and volcanic deposits, can be relatively soft and hence fairly easy to model. Nevertheless, this workability advantage is a drawback for Cultural Heritage applications. In fact, these materials show a high porosity, with pore-size distributions that lead to deterioration through absorption of water. In this paper, several sedimentary rocks used in historical Cultural Heritage items of Sicily, from "Magna Graecia" to nowadays, are classified for mineralogical features, chemica…

Heavy metals analysis by non invasive techniques for fish food quality control

Confronto XRF-LIBS per la caratterizzazione chimico-fisica di laterizi provenienti dal teatro greco romano di Taormina

Metodologie spettroscopiche integrate per la caratterizzazione dei prodotti di corrosione nei bronzi archeologici

Power saturation of ESR signal in ammonium tartrate exposed to 60Co gamma-ray photons, electrons and protons.

Abstract Marrale, M., Brai, M., Triolo, A., Bartolotta, A. and D'Oca, M. C. Power Saturation of ESR Signal in Ammonium Tartrate Exposed to 60Co γ-Ray Photons, Electrons and Protons. Radiat. Res. 166, 802–809 (2006). In this paper we present an investigation of the electron spin resonance (ESR) line shape of ammonium tartrate (AT) dosimeters exposed to radiation with different linear energy transfer (LET). We exposed our dosimeters to γ-ray photons (60Co), 7 MeV and 14 MeV initial energy electrons, and 19.3 MeV initial energy protons. The differences in the power saturation behavior of ESR spectra of AT irradiated with photons, electrons and protons could be correlated to the effective LET o…

Mosaic floors of roman Villa del Casale: Principal component analysis on spectrophotometric and colorimetric data

Abstract Spectrophotometric and colorimetric data obtained during a measurement campaign aimed at supporting the Roman "Villa del Casale" (Piazza Armerina, Sicily, Italy) conservation activities, are presented. Special attention was paid to the possible variation of the chromatic coordinates, possibly due to the interventions of cleaning, consolidation, and protection. Data have been analyzed by the Principal Component Analysis (PCA) statistical technique, with the attempt to investigate its role in data variability reduction and verify its effectiveness in interpreting the phenomena occurring on the mosaic surface of the Villa, through grouping the observations into homogenous clusters. Ef…

Characterization of alanine EPR detectors response in clinical carbon ion beams

Heavy-ions beams offer several advantages compared to other radiation such as low lateral scattering and high biological effectiveness (RBE) in the Bragg peak region, making them particularly attractive for the treatment of radio-resistant tumors localized close to organs at risk [1]. Although ion beam radiotherapy ultimately requires dose prescription in terms of biological dose or cell survival, absorbed dose is still the quantity mostly used in clinical quality assurance and to dosimetrically characterize the beam. Moreover, the nuclear projectile fragmentation of heavy ions because of inelastic nuclear interactions with medium produces secondary particles with lower Z. The detailed know…

Chemistry, mineralogy and radioactivity inposidonia oceanicameadows from North-Western Sicily

This paper presents measurements of major, minor, metal trace elements and radionuclides in sediments and in Posidonia oceanica samples from north-western Sicily (Italy). The mineralogical and chemical composition of sediments were determined by X-ray diffraction and X-ray fluorescence techniques, respectively. A flame atomic absorption spectrophotometry was used to measure concentrations of Cu, Zn, Cd and Pb in P. oceanica samples and in sediments. Specific activities of selected radionuclides have been determined by high-resolution gamma spectrometry. Standard statistical analysis was used to assess correlations between different elements and different sample types.

Correlation of radioactivity measurements, air kerma rates and geological features of Sicily

Abstract Sicily, the largest Mediterranean island (with an extension of about 25 000 km 2 ), exhibits a very wide variety of lithologies, ranging from sedimentary to metamorphic and volcanic rocks. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) have been applied to air kerma values measured by thermoluminescent dosimetry in several sites and to data of radionuclide concentrations, geochemical and mineralogical features of rocks and soils sampled in 29 sites of Sicily to point out similarities among different lithologies. The study was devoted to find multiple correlations and allow a better classification of Sicilian lithotypes. Samples of rocks and soils have be…

Utilizzo del gadolinio in composti organici per la misura di fluenza di neutroni termici

Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages. A comparison with micro-X-ray fluorescence analysis

Gilding and pigments of Renaissance marble of Abatellis Palace: non-invasive investigation by XRF spectrometry

Most of the artworks constituting the collection of Renaissance statuary of Abatellis Palace in Palermo (Sicily) show evidence of colour layers and fragments of gold foil that probably once covered the whole marble surface. The restoration of some of these statues has allowed to carry out archaeometric studies about the painting technique and to highlight the original materials and inclusion present on the precious marbles by two famous Italian sculptors of the Renaissance, Francesco Laurana and Antonello Gagini. The measurements have been performed in situ through the integrated use of two non-invasive techniques: visible fluorescence stimulated by ultraviolet light and X-ray fluorescence.…

Monte Carlo simulation of the response of ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons

Abstract Monte Carlo numerical calculations of the response of alanine and ammonium tartrate ESR (electron spin resonance) dosimeters exposed to neutron fields with different energy spectra are reported. Results have been obtained for various gadolinium concentrations inside the dosimeters. Furthermore, in order to simulate the in-phantom response we have carried out calculations by varying the depth of the dosimeter. We have found that a large enhancement is obtained for thermal neutrons, because of the very high capture cross section of gadolinium to thermal neutrons. A good enhancement was obtained for epithermal neutrons, whereas the sensitivity improvement in the case of fast neutron i…

Water capillary absorption in porous media in different wettability conditions studied by Quantitative MRI and X-ray CT

X-ray computed tomography (CT) and magnetic resonance imaging (MRI) have been successfully applied to study both the capillary properties of several samples of Lecce stone and the performances of treatments used for protection and conservation of historical stone artifacts. The presence of water inside the sample may be visualized by both MRI and X-ray CT. For the treated samples, the different dynamics of water absorption gives indirectly the efficacy of the polymer in the rock.

Study of the spatial distribution of free radicals in ammonium tartrate dosimeters through pulsed ESR techniques.

Indagini NMR su legni moderni e antichi.

ERG signal analysis using wavelet transform

The wavelet analysis is a powerful tool for analyzing and detecting features of signals characterized by time-dependent statistical properties, as biomedical signals. The identification and the analysis of the components of these signals in the time-frequency domain, give meaningful information about the physiological mechanisms that govern them. This article presents the results of the wavelet analysis applied to the a-wave component of the human electroretinogram. In order to deepen and improve our knowledge about the behavior of the early photoreceptoral response, including the possible activation of interactions and correlations among the photoreceptors, we have detected and identified …

ALANINE/ESR DOSIMETRY FOR TOTAL BODY IRRADIATION USING AN ANTHROPOMORPHIC PHANTOM

Introduction: Total Body Irradiation (TBI) is a technique widely used in the radiation blood-oncology in the treatment of patients that need bone marrow transplantation or peripheral stem cell transplantation. This technique has some limitations such as the lack of homogeneity of the dose distribution (which may show variations of 20% in the different areas), irradiation of critical organs such as the lungs, the liver, the intestine and the eye-lens which can receive a dose comparable to that nominal and require appropriate shielding and a proper evaluation of the dose absorbed by them. The positive outcome of this type of radiation therapy is strictly related to a precise and accurate meas…

Alanine EPR pellets for dosimetry of clinical proton and carbon ion beams

The main gol of the present work is to investigate the response behaviour of alanine EPR pellets in clinical proton anc carbon ion beams. Proton irradiations were carried out at PSI (Switzerland) using both passive and active scattering modality, whereas, C ions irradiation were performed at GSI (Germany) adopting the raster scanning modality.

Nuove metodologie per la valutazione dello stato di inquinamento dell'ambiente marino

A comparison among different techniques for human ERG signals processing and classification

A comparison among different techniques for human ERG signals processing and classification ( Articles not published yet, but available online Article in press About articles in press (opens in a new window) ) Barraco, R.a, Persano Adorno, D.a , Brai, M.a, Tranchina, L.b a Dipartimento di Fisica e Chimica, Università di Palermo and CNISM, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy b Laboratorio di Fisica e Tecnologie Relative - UniNetLab, Università di Palermo, Viale delle Scienze, Ed. 18, I-90128 Palermo, Italy Abstract Feature detection in biomedical signals is crucial for deepening our knowledge about the involved physiological processes. To achieve this aim, many analytic appro…

THE EFFECT OF GADOLINIUM ON THE ESR RESPONSE OF ALANINE AND AMMONIUM TARTRATE EXPOSED TO THERMAL NEUTRONS

Many efforts have been made to develop neutron capture therapy (NCT) for cancer treatment. Among the challenges in using NCT is the characterization of the features of the mixed radiation field and of its components. In this study, we examined the enhancement of the ESR response of pellets of alanine and ammonium tartrate with gadolinium oxide exposed to a thermal neutron beam. In particular, the ESR response of these dosimeters as a function of the gadolinium content inside the dosimeter was analyzed. We found that the addition of gadolinium improves the sensitivity of both alanine and ammonium tartrate. However, the use of gadolinium involves a reduces in or abolishes tissue equivalence b…

TAC applicata allo studio di rocce sedimentarie utilizzate nei Beni Culturali

Dating of a Sediment Core by 210Pbex Method and Pb Pollution Chronology in the Palermo Gulf (Italy)

Within a more general study on marine sediments in the Gulf of Palermo (Sicily, Italy), the 210Pbex dating method (using a model with constant sedimentation rate) has been applied to one sediment core. The main goal of the research was to study the Pb pollution chronology. Dating of the core has allowed evaluating the time evolution of the gulf lead concentrations. Specific activities of 137Cs have also been measured in the sediment core sections as an independent confirmation of the chronology derived by the 210Pbex method. The time scale has then been used to correlate lead concentrations in core sections to estimated lead emissions in air due to gasoline combustion. A good correlation be…

Nanostructured products applications for the conservation of Cultural Heritage samples

Volcanic products of Lipari (Aeolian islands, Italy): Multivariate analysis of petrographic and radiometric data

Abstract A petrographic and radiometric study, along with statistical multivariate analysis of volcanic products of the island of Lipari (Aeolian islands, Italy) was carried out. The volcanological history of Lipari was reconstructed defining two stages (pre- and post-erosive stages) further on subdivided in four volcanic phases, each of which characterized by products with a particular chemical composition and separated by stratigraphic unconformities. The correlations between petrographic features, determined by X-ray fluorescence, and volcanological history of the island highlight a gradual differentiation with younger rocks showing a more acid chemical composition than the older ones. R…

Indagini NMR su legni moderni ed antichi

Qualitative and quantitative characterization of historical pigment mixtures through non-invasive techniques

Tecniche di risonanza di spin elettronico applicate allo studio di campioni lignei

A study of the human rod and cone electroretinogram a-wave component

The study of the electrical response of the retina to a luminous stimulus is one of the main fields of research in ocular electrophysiology. The features of the first component (a-wave) of the retinal response reflect the functional integrity of the two populations of photoreceptors: rods and cones. We fit the a-wave for pathological subjects with functions that account for possible mechanisms governing the kinetics of the photoreceptors. The paper extends a previous analysis, carried out for normal subjects, in which both populations are active, to patients affected by two particular diseases that reduce the working populations to only one. The pathologies investigated are Achromatopsia, a…

Applicazione di tecniche e materiali innovative per la conservazione ed il restauro di materiali lapidei

In-soil radon anomalies as precursors of earthquakes: A case study in the SE slope of Mt. Etna in a period of quite stable weather conditions

In-soil radon concentrations as well as climatic parameters (temperature, atmospheric pressure and relative humidity) were collected in St. Venerina (Eastern Sicily - Italy) from March 19th to May 22nd 2009, close to an active fault system called Timpe Fault System (TFS), which is strictly linked to the geodynamics of Mt. Etna. During the monitoring period no drastic climatic variations were observed and, on the other hand, important seismic events were recorded close to the monitoring site. A seismic swarm composed of 5 earthquakes was observed in the Milo area on March 25th (M-max = 2.7) at just 5.1 km from the site, and on May 13th an earthquake of 3.6 magnitude was recorded in the terri…

Relationship among anthropogenic pollution, benthic foraminifera assemblages and their morphological deformations from marine sediments of the Sicilian coast (Southern Italy)

Analisi NMR su gel di tipo Fricke irradiati con fasci routinari per la radioterapia: stabilità e sensibilità in funzione degli additivi

In questo lavoro sono presentate le misure effettuate tramite rilassometria NMR su campioni costituiti da una matrice gelatinosa drogata con ioni ferrosi comunemente chiamati dosimetri gel di tipo Fricke (FXG). La dosimetria con gel Fricke si basa sulla ossidazione degli ioni ferrosi (Fe2+) in ioni ferrici (Fe3+) all’interno di una matrice gelatinosa a seguito di irraggiamento (Schreiner, 2004). Tale processo è fortemente dipendente dalla dose somministrata (Marrale, 2014a). I dosimetri di Fricke sono tessuto-equivalenti, rispondono ad ogni tipo di radiazione ionizzante ed, assumendo la forma del contenitore in cui avviene la gelificazione, possono essere utilizzati per studiare l’effetto d…

Dosimetria a stato solido a termoluminescenza e a risonanza di spin elettronico

Looking into the architecture of the brain with MRI: quantification of non-Gaussian water diffusion by Diffusion Kurtosis Imaging (DKI)

The aim of this work is the definition of an MRI protocol for Diffusion Kurtosis Imaging (DKI) by using a 1.5T clinical scanner and the development of a software for DKI analysis.

Simulazioni numeriche e test di applicabilità clinica della Diffusion Kurtosis Imaging su tomografi RM da 1.5 Tesla

Preliminary 1H NMR study on archaeological waterlogged wood.

Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological…

ESR response to 60Co-rays of ammonium tartrate pellets using as additive

Abstract This work presents experimental results regarding a new ammonium tartrate blend for ESR dosimetry, with a higher sensitivity and a lower lowest detectable dose (LDD) to Co 60 γ -rays than the recently used pure ammonium tartrate. The blend composed by ammonium tartrate and gadolinium-oxide ( Gd 2 O 3 ) shows a greater sensitivity ( ∼ 2 times) and a smaller LDD than ammonium tartrate. The increased sensitivity was mainly attributed to the great atomic number ( Z = 64 ) of gadolinium, that increases the effective atomic number of the blend; the interaction probability with photons and consequently the radical yield is therefore enhanced. Moreover ammonium tartrate with Gd 2 O 3 has a…

Double Laser LIBS and micro-XRF spectroscopy applied to characterize materials coming from the Greek-Roman theater of Taormina

The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown, in recent years, its great potential for rapid qualitative analysis of materials. The possibility to implement a portable instrument that perform LIBS analysis makes this technique particularly useful for in situ analysis in the field of cultural heritages. The aim of this work is to compare the results, obtained by LIBS measurements with X-Ray Fluorescence (XRF) ones, on calcareous and refractory materials coming from the Greek-Roman theater of Taormina. Calibration curves for LIBS and XRF were obtained by measuring certified reference materials and using them as standards. LIBS measurements we…

Wavelet Analysi of the human electroretinogram

Cinetica di assorbimento dell'acqua trmite NMR imaging per la valutazione della efficacia di trattamenti idrorepellenti

MONTE CARLO SIMULATIONS OF THE RESPONSE OF ESR DOSIMETERS TO NEUTRON BEAMS

Electron Spin Resonance (ESR) spectroscopy is extensively used in gamma photon dosimetry. It relies on the detection of the signal from free radicals (paramagnetic species) produced after sample irradiation. Organic materials, such as alanine and ammonium tartrate, are widely used for dosimeter preparation, thanks to the good photon sensitivity and tissue equivalence of such compounds. However, the low neutron cross section of their nuclei does not make them suitable for neutron dosimetry. Thanks to its very high neutron capture cross section and to the high Linear Energy Transfer of released particles, even small additions of gadolinium will yield large sensitivity enhancements of the dosi…

ESR RESPONSE TO 60 CO-RAYS OF AMMONIUM TARTRATE PELLETS USING GD2O3 AS ADDITIVE.

This work presents experimental results regarding a new ammonium tartrate blend for ESR dosimetry, with a higher sensitivity and a lower lowest detectable dose (LDD) to 60 Co -rays than the recently used pure ammonium tartrate. The blend composed by ammonium tartrate and gadolinium-oxide (Gd2 O3 ) shows a greater sensitivity (∼2 times) and a smaller LDD than ammonium tartrate. The increased sensitivity was mainly attributed to the great atomic number (Z = 64) of gadolinium, that increases the effective atomic number of the blend; the interaction probability with photons and consequently the radical yield is therefore enhanced. Moreover ammonium tartrate with Gd2 O3 has a linear dose respons…

POST-THALAMOTOMY NEUROFUNCTIONAL FINDINGS ON PATIENTS TREATED WITH TRANS-CRANIAL MAGNETIC RESONANCE GUIDED FOCUSED ULTRASOUND SURGERY (TCMRGFUS): PRELIMINARY RESULTS

BACKGROUND AND PURPOSE: We present functional connectivity (FC) changes found in the very first patients treated with the first Italian installation of a trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS) certified system for functional neurosurgery. TcMRgFUS is a promising new technique for non-invasive treatment of neurologic disorders such as Essential Tremor, tremor associated to Parkinson's Disease and Neuropathic Pain. TcMRgFUS is able to focally target and destroy specific regions in the brain through intact skull, by using a high intensity focused ultrasound beam. Resting state functional Magnetic Resonance Imaging (RS-fMRI) analyses focuses on spontaneous low frequency …

Trace metals in “Posidonia oceanica” seagrass from south-eastern Sicily

Heavy-metal concentrations were measured in sediments and tissues of Posidonia oceanica seagrass from south-eastern Sicily (Italy) in order to assess the degree of metal pollution in the coastal area. Seagrasses and sediments were collected at four sites along the south-eastern coast of Sicily. Flame atomic absorption spectrophotometry (FAAS) was used to measure concentrations of Cu, Zn, Cd and Pb. Standard statistical analyses were used to assess significant differences among the levels of the elements measured in different tissues and sediment and spatial distribution. The greatest values of potentially toxic metal concentrations were observed at the station near the industrial sites of A…

Thermoluminescence response of sodalime glass irradiated with proton and neutron beams

In the research field of emergency dosimeters to be used in case of accidental radiation exposure of the population, watch glass has been considered as a possible fortuitous dosimetric material. This paper reports on results obtained by thermoluminescence of glass samples exposed to neutron and proton beams. Thermoluminescent glow curves have been analyzed for each irradiation studying the modifications induced by the irradiation as a function of proton dose or neutron fluence. The glow curve in a specific temperature range has been used as dosimetric parameter. The thermoluminescence response of samples exposed to protons has been found to be linear in the dose range between 2 and 20 Gy an…

Neutron Electron Spin Resonance dosimetry with phenol compounds

INTEGRATED TECHNIQUE TO EVALUATE THE FEATURES OF SEDIMENTARY ROCKS OF ARCHAELOGICAL AREAS OF SICILY

XRF analysis to identify historical photographic processes: The case of some Interguglielmi Jr.’s images from the Palermo Municipal Archive

Abstract In the early period, even though professional photographers worked with similar techniques and products, their artistic and commercial aims determined different choices and led them to follow different, often personal, recipes. For this reason, identification of the techniques through date and name of the photographer or through some visual features like colour, tonality and surface of the image layer, often needs further investigation to be proved. Chemical characterization, carried out in a non or micro destructive way, can be crucial to provide useful information about the original composition, degradation process, realization technique, in obtaining an indirect dating of the ph…

Electron Spin Resonance (ESR) characterization of phenol compounds as new materials for dosimetry in radiotherapy

Among the various dosimetric techniques used for characterizing the radiation beams used in radiation therapy, the electron spin resonance (ESR) arouses increasing interest for applications in various therapy procedures [1]. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the absorbed dos e and this allows for dosimetric measurements through ESR technique which able to quantitatively determine the radical concentration [2]. Our research group has started an investigation of the ESR response of some phenols compounds for possible ESR dosimetric ap plications suitable feature…

Free radical distribution in ESR dosimeters exposed to various LET radiation beams: comparison between experimental data and simulations.

Noise reduction in magnetic resonance images by Wavelet transforms: an application to the study of capillary water absorption in sedimentary rocks

Magnetic resonance imaging (MRI) is a powerful technique to study capillary water absorption kinetics in sedimentary rocks. However, the noise in the images can limit the correct identification and the quantitative measurement of the average height reached by the wetting front inside the porous material where imbibition occurs. Therefore, denoising methods can be applied to improve the image quality for a more accurate analysis, without the disadvantages of longer acquisition times. This study attempts to improve the signal-to-noise ratio of the images acquired by MRI on a sedimentary rock (Pietra di Lecce) using a waveletbased thresholding technique. The idea is to average some slightly di…

The 4th international comparison on EPR dosimetry with tooth enamel

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Munchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated s…

Natural radioactivity in a volcanic island: Ustica, Southern Italy

Abstract Gamma-ray spectrometric measurements were performed on rocks and soils of the island of Ustica (Southern Italy) to quantify the concentrations of the natural radionuclides. The 238U, 232Th, and 40K concentration ranges (15–164, 16–174, and 201–1350 Bq kg−1, respectively) were compared with mineralogical and chemical data obtained by XRD and XRF analyses. The observed levels of the primordial radionuclides corresponded to the magmatological features of the rocks. Soil samples generally showed specific gamma-ray activities not directly correlatable to those measured in the underlying rocks. A survey was also perormed to measure air kerma in outdoor and indoor environments using therm…

The 4th International Comparison of EPR dosimetry with Tooth Enamel: Part 1, Report on the results

Pulsed EPR analysis of tooth enamel samples exposed to UV and gamma-radiations

Abstract The electron paramagnetic resonance (EPR) spectroscopy is widely applied for retrospective dosimetric purposes by means of quantitative detection of radicals in tooth enamel and bone samples. In this work we report a study by cw and pulsed EPR on two samples of human tooth enamel respectively irradiated by UV (254 nm) and γ-exposed. The continuous wave (cw) EPR spectra have shown the usual presence in both samples of two types of CO 2 − radicals, with axial and orthorombic g tensors. We have obtained the electron spin echo detected EPR (ED-EPR) spectra at 80 K of the two samples, and we have shown that they are suitable to mark the difference between the effects produced by the dif…

Posidonia oceanica as a Historical Monitor Device of Lead Concentration in Marine Environment

We show that Posidonia oceanica is able to reliably monitor the variability of environmental lead (Pb). We analyze lead concentration measured in the scales and rhizomes of Posidonia oceanica collected in seven sites along the coasts of the Sicily island and subsequently fractioned them according to a lepidochronological analysis. We measure lead concentration in Posidonia oceanica tissues by using the flame atomic absorption spectrophotometry technique. We compare the measured lead concentration with the estimated lead emission in air due to the gasoline sold and used for combustion in car engines in Sicily. By computation of the Pearson cross-correlation coefficient, we show that lead con…

Preliminary application of thermoluminescence and single aliquot regeneration method for dose reconstruction in soda lime glass

The research described in this paper shows that the use of the single aliquot regeneration (SAR) method for thermoluminescence (TL) measurements applied to soda lime glasses allows to carry out a retrospective dose evaluation. We have followed a fast and efficient sample preparation procedure which permits measurements without powdering and sieving processes. We have analyzed the TL signal of commercial soda lime watch glass irradiated with 6 Mega Volts (MV) LINAC photons, 10 MeV LINAC electrons and 62 MeV protons. After the initial exposure and following TL reading, the samples are successively irradiated with increasing doses of photons. Therefore, for each sample its calibration curve is…

IMPROVEMENT OF SENSITIVITY IN ESR GAMMA-DOSIMETRY BY GADOLINIUM ADDICTION

Application of the ESR spectroscopy to estimate the original dose in irradiated chicken bone

Abstract The paper discusses the results of an investigation aimed to use the ESR spectroscopy as a quantitative procedure to estimate the original dose in irradiated chicken. The time stability of the ESR signal was at first carried out, to obtain a correction factor to be applied to the dose estimated with the added dose method. Our results show that this procedure gives an estimation of the original dose within ±25%.

An EPR method for discriminating radiation beams in ammonium tartrate and tooth enamel

The radiation linear energy transfer (LET), which is the energy released by ionizing radiation per path unit, arouses great scientific interest because the biological damage produced by ionizing radiation in tissues is strictly related to LET. Radiation beams with different LETs will cause different spatial energy distribution and therefore different effects inside matter. In the last twenty years the EPR spectroscopy has become a valuable dosimetric tool. This technique allows absorbed dose measurements through the detection of free radicals produced by ionizing radiation in organic and/or inorganic compounds. In this work we have analyzed the possibility of using the acquisition of two co…

Phenol compounds for Electron Spin Resonance dosimetry of gamma and neutron beams

Ottimizzazione della dosimetria a termoluminescenza per la identificazione di spezie ed erbe aromatiche irradiate

Mural salts characterization of "Penitenziati" mural paintings in Chiaramonte Palace (Palermo)

Dosimetria per fasci di protoni tramite spettroscopia di risonanza paramagnetica elettronica (EPR)

Combined TL and 10B-alanine ESR dosimetry for BNCT

The dosimetric technique described in this paper is based on electron spin resonance (ESR) detectors using an alanine-boric compound acid enriched with 1 0 B, and beryllium oxide thermoluminescent (TL) detectors; with this combined dosimetry, it is possible to discriminate the doses due to thermal neutrons and gamma radiation in a mixed field. Irradiations were carried out inside the thermal column of a TRIGA MARK II water-pool-type research nuclear reactor, also used for Boron Neutron Capture therapy (BNCT) applications, with thermal neutron fluence from 10 9 to 10 1 4 n t h cm - 2 . The ESR dosemeters using the alanine-boron compound indicated ESR signals about 30-fold stronger than those…

ASPETTI OPERATIVI NELLA VALUTAZIONE DELLA DOSE AL CRISTALLINO DEI LAVORATORI NELLE PROCEDURE INTERVENTISTICHE DI EMODINAMICA.

Recenti studi epidemiologici hanno evidenziato una incidenza di complicanze oculari (cataratte), per esposizione alle radiazioni ionizzanti del cristallino, superiore a quanto ritenuto in passato. Nella sua pubblicazione del 21 aprile 2011 dal titolo “Statement on Tissue Reactions”, sugli effetti tissutali deterministici non cancerogeni delle radiazioni ionizzanti, l’ICRP indica per il cristallino una dose soglia di 0,5 Gy e raccomanda, per esposizioni lavorative, il limite annuale di 20 mSv di dose equivalente come media su un periodo di 5 anni, senza che sia mai superato il valore di 50 mSv in ogni singolo anno. Questo valore è di gran lunga inferiore all’attuale limite di legge che è par…

Caratterizzazione di materiali lapidei