108 research outputs found

    Neutron density distribution and neutron skin thickness of 208^{208}Pb

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    We present and discuss numerical predictions for the neutron density distribution of 208^{208}Pb using various non-relativistic and relativistic mean-field models for the nuclear structure. Our results are compared with the very recent pion photoproduction data from Mainz. The parity-violating asymmetry parameter for elastic electron scattering at the kinematics of the PREX experiment at JLab and the neutron skin thickness are compared with the available data. We consider also the dependence between the neutron skin and the parameters of the expansion of the symmetry energy.Comment: 9 pages, 6 figures, latest MAMI data use

    Elastic and quasi-elastic electron scattering off nuclei with neutron excess

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    We present theoretical predictions for electron scattering on oxygen and calcium isotopic chains. The calculations are done within the framework of the distorted-wave Born approximation and the proton and neutron density distributions are evaluated adopting a relativistic Dirac-Hartree model. We present results for the elastic and quasi-elastic cross sections and for the parity-violating asymmetry. As a first step, the results of the models are tested in comparison with some of the data available for elastic and quasi-elastic scattering on 16O and 40Ca nuclei. Then, the evolution of some nuclear properties is investigated as a function of the neutron number. We also present a comparison with the parity-violating asymmetry parameter obtained by the PREX Collaboration on 208Pb and give a prediction for the future experiment CREX on 48Ca.Comment: 37 pages, 17 figures. version accepted for publication in the Physical Review C. arXiv admin note: text overlap with arXiv:0809.4124 by other author

    A Population Survey in Italy Based on the ICF Classification: Recognizing Persons with Severe Disability

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    Aim of this paper is to describe functioning of subjects with “severe disability” collected with a protocol based on the International Classification of Functioning, Disability, and Health. It included sections on body functions and structures (BF and BS), activities and participation (A&P), and environmental factors (EF). In A&P, performance without personal support (WPS) was added to standard capacity and performance. Persons with severe disability were those reporting a number of very severe/complete problems in BF or in A&P-capacity superior to mean + 1SD. Correlations between BF and A&P and differences between capacity, performance-WPS, and performance were assessed with Spearman's coefficient. Out of 1051, 200 subjects were considered as severely disabled. Mild to moderate correlations between BF and A&P were reported (between 0.148 and 0.394 when the full range of impairments/limitations was taken into account; between 0.198 and 0.285 when only the severe impairments/limitations were taken into account); performance-WPS was less similar to performance than to capacity. Our approach enabled identifying subjects with “severe disability” and separating the effect of personal support from that of devices, policies, and service provision

    Organosilicon phantom for photoacoustic imaging

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    Photoacoustic imaging is an emerging technique. Although commercially available photoacoustic imaging systems currently exist, the technology is still in its infancy. Therefore, the design of stable phantoms is essential to achieve semiquantitative evaluation of the performance of a photoacoustic system and can help optimize the properties of contrast agents. We designed and developed a polydimethylsiloxane (PDMS) phantom with exceptionally fine geometry; the phantom was tested using photoacoustic experiments loaded with the standard indocyanine green dye and compared to an agar phantom pattern through polyethylene glycol-gold nanorods. The linearity of the photoacoustic signal with the nanoparticle number was assessed. The signal-to-noise ratio and contrast were employed as image quality parameters, and enhancements of up to 50 and up to 300%, respectively, were measured with the PDMS phantom with respect to the agar one. A tissue-mimicking (TM)-PDMS was prepared by adding TiO2 and India ink; photoacoustic tests were performed in order to compare the signal generated by the TM-PDMS and the biological tissue. The PDMS phantom can become a particularly promising tool in the field of photoacoustics for the evaluation of the performance of a PA system and as a model of the structure of vascularized soft tissues. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE

    Incidenza della sclerosi multipla in Toscana: uno studio basato su dati amministrativi

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    INTRODUZIONE L’Italia è un’area ad elevato rischio di sclerosi multipla (SM) con una prevalenza stimata di 110.000 casi e un’incidenza di 3.400 casi annui [1]. Gli ultimi dati pubblicati sulla prevalenza sono 149 casi su 100.000 a Genova nel 2007 [2], 140 casi a Padova nel 2009 [3] e 210 nella parte meridionale della Sardegna nel 2007 [4]. Per quanto riguarda l’incidenza, i dati più recenti sono 5,5 casi su 100.000 a Padova nel periodo 2000-09 [3], 6,6 a Genova nel 1998-2007 [2], e 9,7 in Sardegna nel 2003-07 [4]. Dallo scorso anno è stato attivato in Italia un registro nazionale di SM il quale rappresenterà, nel prossimo futuro, un valido strumento per lo studio dell’epidemiologia di questa malattia. Anche in Toscana è presente, dal 2006, un registro regionale della SM ma, al momento, non è rappresentativo dell’intera popolazione di pazienti. Una possibile alternativa per studiare l’epidemiologia è attraverso i dati amministrativi. Questi, infatti, coprono l’intera popolazione residente e vengono raccolti di routine in un modo standardizzato ai fini della gestione del servizio sanitario. In un precedente lavoro, abbiamo creato e validato un algoritmo di cattura dei casi prevalenti basato su fonti amministrative [5]. La prevalenza, calcolata al 2011, è risultata pari a 188 casi per 100.000 [5]. Anche altre Regioni hanno utilizzato i dati amministrativi per stimare la prevalenza della SM, come il Lazio con 131 casi su 100.000 nel 2011 [6], la Puglia con 183 casi nel 2012, il Veneto con 170-180 casi nel 2015, la Sicilia con 110 casi nel 2010 e la Sardegna con 360 casi nel 2016 [1]. OBIETTIVI Calcolare l’incidenza della SM in Toscana utilizzando dati amministrativi. METODI Per il calcolo dell’incidenza abbiamo creato il seguente algoritmo: ospedalizzazione in reparto per acuti e con diagnosi primaria di SM, esenzione attiva per SM, e prescrizione di farmaci specifici. I casi incidenti sono stati identificati come quei casi catturati dall’algoritmo non tracciati in precedenza nei flussi amministrativi, e la data della prima traccia è stata considerata quale data di diagnosi della SM. Da questa coorte di soggetti abbiamo selezionato i pazienti con un’età ≤ 55 anni, residenti in Toscana al momento della diagnosi e presenti in anagrafe da almeno 10 anni (o nati in Toscana se età <10). Abbiamo calcolato i tassi grezzi e standardizzati e gli intervalli di confidenza (IC) al 95% per gli anni 2011-2015. RISULTATI Abbiamo identificato, dal 2011 al 2015, 1.056 nuovi casi in Toscana con un’incidenza che varia da 5,04 nel 2011 a 6,02 casi su 100.000 nel 2015 (Tabella 1). Nelle donne l’incidenza è circa due volte più alta rispetto agli uomini con un range che va da 6,48 nel 2011 a 7,96 su 100.000 nel 2015 nelle donne, e da 3,49 nel 2011 a 3,93 nel 2015 negli uomini (Tabella 2). Prendendo in considerazione l’ultimo anno di analisi (2015), abbiamo inoltre osservato delle differenze per ASL di residenza al momento della diagnosi, con aree in cui il tasso di incidenza è inferiore alla media regionale, come Grosseto (4,58), Pisa (4,33 casi/100.000), Siena (3,30), Lucca (3,07) e Viareggio (3,06), e aree in cui l’incidenza è più elevata rispetto alla media, come Empoli (7,99), Livorno (8,80) e Arezzo (9,78)

    Increasing prevalence of multiple sclerosis in Tuscany: a study based on validated administrative data

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    AIMS Italy is a high-risk area for Multiple Sclerosis (MS) with a prevalence of around 140/105 (2009) with the exception of Sardinia, with about 224 cases/105 (2009). Nowadays, in Italy, prevalence is absolutely higher than the above estimates. Indeed, prevalence is rising due to annual incidence that is higher than annual mortality. In Tuscany a population MS register has been founded but, to date, it’s not yet completed. To monitor disease epidemiology, comorbidities and care pathways, but also to describe the disease burden and to plan its prevention, treatment and management strategies and resource allocation, population-based studies are preferable. Administrative data offer a unique opportunity for population-based prevalence study of chronic diseases such as MS. Our aim is to update the prevalence of MS in Tuscany and to demonstrate its progressive increment. METHODS The prevalence was calculated using a case-finding algorithm based on administrative data: hospitalization, specific MS drug dispensing, disease-specific exemptions from patient copayment, home and residential long-term care and inhabitant registry. To test algorithm sensitivity, we used a true-positive reference cohort of 302 MS patients from the Tuscan MS register. To test algorithm specificity, we used a general population cohort of 2,644,094 individuals who were presumably not affected by MS (who had never effectuated either cranial or spinal cord CT scan or MRI and had never received a neurological outpatient visit within the NHS). We calculated prevalence on three consecutive years (2011, 2012, 2013). RESULTS At prevalence date (31 December), we identified 6,890 cases in 2011, 7,057 in 2012 and 7,330 in 2013 with a rate of 187.9, 191.1 and 195.4/105, respectively. The female:male ratio slightly increased from 2.0 in 2011 to 2.1 in 2012-2013. The sensitivity of algorithm was 98% and its specificity was 99.99%. DISCUSSION We found a progressive increment of prevalence that confirmed our hypothesis of increasing prevalence. Although our validity study demonstrated a high level of sensibility, we could miss some patients, especially individuals with a severe MS, who did not access the healthcare system and who did not use the DMDs included in our algorithm. CONCLUSIONS We confirmed that Tuscany is a high-risk area for MS and that the prevalence is increasing over time. Despite some limitations, we also demonstrated that our algorithm can accurately identify patients and this cohort is suitable to monitor care pathways. Our future aim is to create an integrated dataset with administrative and clinical data from MS register

    Biochemical Alterations in Semen of Varicocele Patients: A Review of the Literature

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    Oxidative stress is a mechanism underlying different kinds of infertility in human males. However, different results can be observed in relation to the method used for its evaluation. Varicocele patients show a number of biochemical abnormalities, including an altered distribution of coenzyme Q between seminal plasma and sperm cells and also an apparent defect in the utilization of antioxidants. Moreover, an influence of systemic hormones on seminal antioxidant system was observed too. Finally, the effects of surgical treatment on oxidativestress indexes and the possible usefulness of some medical therapies, like coenzyme Q supplementation, are discussed. In conclusion, published data show a role of oxidative stress in varicocele-related male infertility, but at present we do not know the precise molecular mechanisms underlying these phenomena

    Nanotopography Induced Human Bone Marrow Mesangiogenic Progenitor Cells (MPCs) to Mesenchymal Stromal Cells (MSCs) Transition

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    Mesangiogenic progenitor cells (MPCs) are a very peculiar population of cells present in the human adult bone marrow, only recently discovered and characterized. Owing to their differentiation potential, MPCs can be considered progenitors for mesenchymal stromal cells (MSCs), and for this reason they potentially represent a promising cell population to apply for skeletal tissue regeneration applications. Here, we evaluate the effects of surface nanotopography on MPCs, considering the possibility that this specific physical stimulus alone can trigger MPC differentiation toward the mesenchymal lineage. In particular, we exploit nanogratings to deliver a mechanical, directional stimulus by contact interaction to promote cell morphological polarization and stretching. Following this interaction, we study the MPC-MSC transition by i. analyzing the change in cell morphotype by immunostaining of the key cell-adhesion structures and confocal fluorescence microscopy, and ii. quantifying the expression of cell-phenotype characterizing markers by flow cytometry. We demonstrate that the MPC mesengenic differentiation can be induced by the solely interaction with the NGs, in absence of any other external, chemical stimulus. This aspect is of particular interest in the case of multipotent progenitors as MPCs that, retaining both mesengenic and angiogenic potential, possess a high clinical appeal
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