283 research outputs found
Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values
The aim of this study was to investigate the impact of decay data provided by
the newly developed stochastic atomic relaxation model BrIccEmis on dose point
kernels (DPKs - radial dose distribution around a unit point source) and
S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE)
emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn,
119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based
on the nuclear decay data from the medical internal radiation dose (MIRD)
RADTABS program and the BrIccEmis code, assuming both an isolated-atom and
condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo
(MC) code using event-by-event electron and photon transport. S-values for
concentric spherical cells of various sizes were derived from these DPKS using
appropriate geometric reduction factors. The number of Auger and Coster-Kronig
(CK) electrons and x-ray photons released per nuclear decay (yield) from
MIRD-RADTABS were consistently higher than those calculated using BrIccEmis.
DPKs for the electron spectra from BrIccEmis were considerably different from
MIRD-RADTABS in the first few hundred nanometres from a point source where most
of the Auger electrons are stopped. S-values were, however, not significantly
impacted as the differences in DPKS in the sub-micrometre dimension were
quickly diminished in larger dimensions. Overestimation in the total AE energy
output by MIRD-RADTABS leads to higher predicted energy deposition by AE
emitting radionuclides, especially in the immediate vicinity of the decaying
radionuclides. This should be taken into account when MIRD-RADTABS data are
used to simulate biological damage at nanoscale dimensions.Comment: 27 pages, 4 figures, 3 table
Earlier appearance of the ossification centre of the femoral head in breast fed versus formula fed infants.
Role of neuronal activity and kinesin on tract tracing by manganese-enhanced MRI (MEMRI)
MEMRI offers the exciting possibility of tracing neuronal circuits in living animals by MRI. Here we use the power of mouse genetics and the simplicity of the visual system to test rigorously the parameters affecting Mn^(2+) uptake, transport and trans-synaptic tracing. By measuring electrical response to light before and after injection of Mn^(2+) into the eye, we determine the dose of Mn^(2+) with the least toxicity that can still be imaged by MR at 11.7 T. Using mice with genetic retinal blindness, we discover that electrical activity is not necessary for uptake and transport of Mn^(2+) in the optic nerve but is required for trans-synaptic transmission of this tracer to distal neurons in this pathway. Finally, using a kinesin light chain 1 knockout mouse, we find that conventional kinesin is a participant but not essential to neuronal transport of Mn^(2+) in the optic tract. This work provides a molecular and physiological framework for interpreting data acquired by MEMRI of circuitry in the brain
Diagnostic and prognostic value of three micrornas in environmental asbestiform fibers-associated malignant mesothelioma
Fluoro-edenite (FE) is an asbestiform fiber identified in Biancavilla (Sicily, Italy). Environmental exposure to FE has been associated with a higher incidence of malignant mesothelioma (MM). The present study aimed to validate the predicted diagnostic significance of hsa-miR-323a-3p, hsa-miR-101-3p, and hsa-miR-20b-5p on a subset of MM patients exposed to FE and matched with healthy controls. For this purpose, MM tissues vs. nonmalignant pleura tissues were analyzed through droplet digital PCR (ddPCR) to evaluate differences in the expression levels of the selected miRNAs and their MM diagnostic potential. In addition, further computational analysis has been performed to establish the correlation of these miRNAs with the available online asbestos exposure data and clinic-pathological parameters to verify the potential role of these miRNAs as prognostic tools. ddPCR results showed that the three analyzed miRNAs were significantly down-regulated in MM cases vs. controls. Receiver operating characteristic (ROC) analysis revealed high specificity and sensitivity rates for both hsa-miR-323a-3p and hsa-miR-20b-5p, which thus acquire a diagnostic value for MM. In silico results showed a potential prognostic role of hsa-miR-101-3p due to a significant association of its higher expression and increased overall survival (OS) of MM patients
EXTENDING A MOBILE DEVICE WITH LOW-COST 3D MODELING AND BUILDING-SCALE MAPPING CAPABILITIES, FOR APPLICATION IN ARCHITECTURE AND ARCHAEOLOGY
One of the most challenging problem in architecture is the automated construction of 3D (and 4D) digital models of cultural objects with the aim of implementing open data repositories, scientifically authenticated and responding to well accepted standards of validation, evaluation, preservation, publication, updating and dissemination. The realization of such an ambitious objective requires the adoption of special technological instruments. In this paper we plan to use portable devices (i.e. smartphones, tablets or PDAs eventually extended to wearable ones), extended with a small plug-in, for automatically extracting 3D models of single objects and building-scale mapping of the surrounding environment. At the same time, the device will provide the capability of inserting notes and observations. Where the instrument cannot be directly applied, for example for exploring the top of a complex building, we consider mounting our device, or using equivalent existing equipment, on a drone, in a modular approach for obtaining data de-facto interchangeable. The approach based on the expansion packs has the advantage of anticipating (or even promoting) future extensions of new mobile devices, when the spectrum of possible applications justify the corresponding increased costs. In order to experiment and verify this approach we plan to test it in two specific scenarios of the cultural heritage domain in which such devices seem particularly promising: Strada Nuova in Genoa and Palazzo Ducale in Urbino, both located in Italy
Teens, Tweets, and Tanning Beds: Rethinking the Use of Social Media for Skin Cancer Prevention
The incidence of skin cancer is rising in the U.S., and melanoma, the deadliest form, is increasing disproportionately among young white women. Indoor tanning is a modifiable risk factor for all skin cancers and continues to be used at the highest rates in young white women. Adolescents and young adults report personal appearance-based reasons for using indoor tanning. Previous research has explored the influences on tanning bed use, including individual factors as well as relationships with peers, family, schools, media influences, legislation, and societal beauty norms. Adolescents and young adults also have high rates of social media usage, and research is emerging on how best to utilize these platforms for prevention. Social media has the potential to be a cost-effective way to reach large numbers of young people and target messages at characteristics of specific audiences. Recent prevention efforts have shown that comprehensive prevention campaigns that include technology and social media are promising in reducing rates of indoor tanning among young adults. This review examines the literature on psychosocial influences on indoor tanning among adolescents and young adults, and highlights ways in which technology and social media can be used for prevention efforts
Adattamento precoce dell’impianto cocleare in età pediatrica
L’impianto cocleare costituisce una valida opportunità per fornire l’accesso alla stimolazione uditiva nei casi di ipoacusia severa o profonda di origine cocleare. E’ stato ampiamente dimostrato che l’impianto cocleare è una soluzione sicura ed efficace e che la precocità nell’attivazione è associata a risultati migliori. E’ importante studiare le variabili e gli aspetti che possono interferire con un adattamento precoce e un adeguato accesso al mondo sonoro: caratteristiche del bambino, alleanza terapeutica con la famiglia, aspetti tecnici, medici e organizzativi. Obiettivo di questo lavoro è quello di proporre raccomandazioni utili per gli aspetti organizzativi-pratici relativi alle attivazioni precoci di impianto cocleare, attraverso un particolare modello di analisi SWOT e TOWS
Rendere competente la famiglia nei primi mesi successivi all’identificazione di una ipoacusia del figlio
Nelle più recenti linee guida internazionali sull’intervento precoce in audiologia pediatrica emerge l’importanza del coinvolgimento della famiglia nel percorso diagnostico- riabilitativo del bambino con deficit uditivo permanente. Questa modalità di approccio costituisce una ricchezza per lo sviluppo dei bambini con deficit uditivo. Vi sono ad oggi poche evidenze del panorama italiano rispetto a questo ambito e rimangono aperte perplessità e difficoltà di gestione pratica. L’obiettivo di questo articolo è presentare i risultati di un’analisi strategica che prende in considerazione i punti di forza, i punti di debolezza, le opportunità e i rischi di una presa in carico precoce che renda competente la famiglia. Le iniziali fasi della presa in carico devono fornire alle famiglie di bambini con recente diagnosi di ipoacusia permanente le informazioni e/o il sostegno necessario al fine di indurle a compiere la scelta del dispositivo protesico uditivo più idoneo, entro tre mesi dalla diagnosi audiologica. Nell’ambito del progetto del Ministero della Salute CCM 2013 “Programma regionale di identificazione, intervento e presa in carico precoci per la prevenzione dei disturbi comunicativi nei bambini con deficit uditivo” un gruppo di esperti ha identificato tre principali raccomandazioni utili per migliorare lo sviluppo comunicativo del bambino attraverso il coinvolgimento della famiglia e il rafforzamento dell’alleanza terapeutica. Queste considerazioni costituiranno il punto di partenza per riflessioni e analisi più dettagliate che potranno dare luce a linee guida e indicazioni specifiche su come buone prassi di presa in carico di bambino con deficit uditivo e famiglia possano inserirsi e concretizzarsi nel reale panorama italiano
Cardioprotection of PLGA/gelatine cardiac patches functionalised with adenosine in a large animal model of ischaemia and reperfusion injury: A feasibility study
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