The 4th international comparison on EPR dosimetry with tooth enamel: Part 1: Report on the results

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 München. 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…

From laboratory to in-situ nuclear magnetic resonance diagnostics: an application to building materials of the greek-roman theatre of Taormina

Prostaglandin production by human polymorphnuclear leucocytes during phagocytosis in vitro.

Human polymorphonuclear leukocytes were found to be able to synthetize and release substantial amounts of PGE2' when stimulated by a phagocytic stimulus such as zymosan particles coated with complement. Hydrocortisone, at a concentration of 10(-5) M, which proved to be effective in other biological systems, failed to inhibit phagocytosis and PG release.

Response of an integrated system, for the study of complex phenomena monitored by gas radon

Methodological Aspects of the Application of the Naka-Rushton Equation to Clinical Electroretinogram

The nonlinear relation between stimulus intensity and response amplitude of the electroretinogram (ERG) scotopic b wave can be described by a curve based on the Naka-Rushton (NR) equation. Up to now, the NR equation has been used to assess the features of the normal and pathological ERG, but the best approach for a correct evaluation of the parameters is still debatable. The parameters are thought to be related to the different conditions of retinal activities. The method is well known in experimental laboratories but is quite unusual at the clinical level. In the present paper the derivative analysis of the NR function is proposed as an easier approach to understand the variations of the N…

FUNCTIONAL CONNECTIVITY MODULATION INDUCED BY TRANSCRANIAL DIRECT CURRENT STIMULATION OF THE MOTOR NETWORK

Background: Brain functions arise from the orchestrated activation and cooperation of networks of regions whose specific relationship varies dynamically across functional states. Resting state functional Magnetic Resonance Imaging (RS-fMRI) analyses focuses on spontaneous low frequency fluctuations (< 0.1 Hz) in the BOLD signal and investigates synchronous activations between regions that are spatially distinct (functional connectivity, FC), occurring in the absence of a task or stimulus. 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 Reson…

Confronto XRF – LIBS per la caratterizzazione chimico-fisiche dei materiali lapidei provenienti dal teatro greco-romano di Taormina

Vengono messe a confronto due tecniche spettroscopiche, la fluorescenza a raggi X (XRF) e la ablazione indotta da laser pulsato (LIBS), al fine di caratterizzare la composizione chimico-fisica di materiali lapidei naturali e non provenienti dal teatro Greco-Romano di Taormina. Entrambe le tecniche permettono un’analisi integrata, offrendo la LIBS la possibilità di ottenere informazioni stratigrafiche. Verranno presentati i risultati di analisi XRF e LIBS effettuate in situ e in laboratorio sui campioni prelevati nel teatro. L’interpretazione quantitativa delle analisi LIBS è stata effettuata mediante una tecnica standarless, ossia che non richiede l’uso di standard e denominata tecnica Cali…

Tecniche di analisi di materiali nei Beni Culturali

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

Cultural heritage vestiges represent complex physical systems, able to interact with the environment through continuous exchanges of heat and fluids (water, air). In this wide context, particular relevance is assumed by transport phenomena and diffusion of pollutant, vehiculated inside the considered structure by water itself. Interaction mechanisms can be considered at various observation scales, depending on the material provenance and on its geometry and location. Involved materials are commonly constituted by porous rocks - more or less altered - belonging to geological sedimentary formations, as limestone, calcarenite and travertine. Their appreciable porosity affects significantly liq…