345 research outputs found

    Simulation of the response of a diamond-based radiation detector to ultra-short and intense high-energy electron pulses

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    Single-crystal synthetic diamond sensors have been widely used in radiation dosimetry and beam diagnostics. The foreseen harsh radiation environment in electron-positron colliders at the luminosity frontier requires a thorough investigation of diamond's response to large radiation burst, in particular, to intense high-energy electron pulses. In this article, a two-step numerical simulation approach (Sentaurus~+~LTspice) is proposed to explore this topic. Time response of the diamond detector is simulated via TCAD-Sentaurus while the transmission effect of the electronic circuit is taken into account using LTspice. Good agreement is observed between results of the numerical simulation and preliminary experimental data from detector's exposure to high-energy sub-picosecond electron pulses, on both the amplitude and the shape of the induced signals. This simulation combination is a novel approach to designing and optimising diamond detectors for radiation and beam loss monitoring in particle physics experiments

    Note tassonomiche e biosistematiche su Anthemis aeolica (Asteraceae).

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    Sono riportati i risultati relativi alla caratterizzazione morfologica, distribuzione attuale , ecologia e correlazioni sistematiche della specie endemica Anthemis aeolic

    Skin manifestations after ionizing radiation exposure. a systematic review

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    Morphological and functional skin alterations secondary to the action of ionizing radiation are well documented. In addition to its application in the medical field, ionizing radiation represents a public health problem for diagnostic and therapeutic purposes due to the potential risk of exposure to unexpected events, such as nuclear accidents or malicious acts. With regard to the use of ionizing radiations in the medical field, today, they constitute a fundamental therapeutic method for various neoplastic pathologies. Therefore, the onset of adverse skin events induced by radiation represents a widespread and not negligible problem, affecting 95% of patients undergoing radiotherapy. A systematic literature search was performed from July 2021 up to August 2021 using PubMed, Embase, and Cochrane databases. Articles were screened by title, abstract and full text as needed. A manual search among the references of the included papers was also performed. This systematic review describes the various skin reactions that can arise following exposure to ionizing radiation and which significantly impact the quality of life, especially in cancer patients

    Release of Palladium from Biomechanical Prostheses in Body Fluids Can Induce or Support PD-Specific IFNγ T Cell Responses and the Clinical Setting of a Palladium Hypersensitivity:

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    The increased use of Palladium (Pd) for biomedical applications, which has more than doubled in the last ten years, appears to be associated with an increased frequency of adverse reactions to Pd. The aim of this study is to investigate the relationship between the implant of a biomechanical apparatus containing Pd and the setting of a hypersensitivity to Pd by determining the levels of the metal released in biological fluids, assessing the effects of Pd on peripheral blood mononuclear cell (PBMC) cytokine production and exploring the clinical setting of skin sensitization. Of a total of 3,093 subjects examined in 2006, sensitization to Pd alone or in association with nickel (Ni) was observed in 1.6% and 13.03% of the individuals, respectively. Of these, a group of six subjects positive to Pd and negative to Ni at patch testing were selected on the basis of the oral clinical symptoms in order to measure both the levels of Pd in biological fluids and the degradation of the dental prostheses. Specific Pd measurements were carried out on salivary fluid, urine and serum samples by High Resolution Inductively Coupled Plasma-Mass Spectrometry. In addition, the degradation of the dental prostheses was assessed by both a "leaching test" and an analysis of the micro morphology of orthodontic prostheses. The induction of IFN-γ production by Pd was assessed in PBMC by the ELISpot assay. Skin sensitization to Pd was evaluated by patch testing and clinical examination. Ten healthy subjects were comparatively tested as controls. We found a specific induction of an IFN-γ response by Pd in PBMC collected from all the subjects positive to Pd at patch testing. On the contrary, control subjects did not show any response to Pd as assessed by IFN-γ ELISpot assay or by skin testing. Remarkably, the levels of Pd in all biological samples (saliva, sera, urine) were significantly higher in Pd-sensitized patients than in those collected from controls, reaching the highest concentrations in the urine. The leaching studies gave additional evidence that the dental appliances can release measurable levels of Pd in saliva. Oral clinical symptoms in patients with Pd dental prostheses were associated with measurable levels of Pd in the biological fluids, the induction of Pd-specific IFN-γ responses in PBMC and the clinical evidence of skin sensitization to Pd. These data suggest that dental appliances may represent an active source of Pd in the body, and this, in turn, can favour the clinical setting of a hypersensitivity to this metal

    Vanadium pentoxide induces the secretion of CXCL9 and CXCL10 chemokines in thyroid cells

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    Vanadium is a grey metal, existing in different states of oxidation, whose most common form in commercial products is vanadium pentoxide (V2O5). All vanadium compounds have been considered toxic. A carcinogenic role of vanadium on the thyroid has recently been proposed. However no in vivo or in vitro studies have evaluated thyroid disruption in humans and/or animals after exposure to vanadium. In the present study we evaluate the effect of V2O5on proliferation, and chemokine secretion in normal thyrocytes. Our study demonstrated that V2O5has no effect on thyroid follicular cell viability or proliferation, but it is able to induce the secretion of T-helper (Th)1 chemokines into the thyroid, synergistically increasing the effect of important Th1 cytokines such as interferon (IFN)γ and tumor necrosis factor (TNF)α. Through this process, V2O5promotes the induction and perpetuation of an inflammatory reaction in the thyroid. Further studies are necessary to evaluate thyroid function, and nodules, in subjects occupationally exposed, or living in polluted areas

    CXCL8 and CXCL11 chemokine secretion in dermal fibroblasts is differentially modulated by vanadium pentoxide

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    An increase in skin rashes or atopic dermatitis has been observed in individuals working with vanadium. However, to the best of our knowledge no in vivo or in vitro studies have evaluated the effect of exposure to vanadium in dermal fibroblasts. Cells viability and proliferation were assessed by WST-1 assay, cells were treated with increasing concentrations of V2O5(1, 10 and 100 nM). CXCL8 and CXCL11 concentrations were measured in the supernatants using an ELISA assay. V2O5was not observed as having a significant effect on dermal fibroblast's viability and proliferation. However, it was revealed that V2O5was able to induce the secretion of CXCL8 and CXCL11 chemokines into dermal fibroblasts. V2O5synergistically increased the effect of interferon (IFN)? on CXCL11 secretion. In addition, V2O5synergistically increased the effect of the tumor necrosis factor a on CXCL8 secretion and abolished the inhibitory effect of IFN?. V2O5induction of CXCL8 and CXCL11 chemokines may lead to the appearance and perpetuation of an inflammatory reaction into the dermal tissue. Further studies are required to evaluate dermal integrity and manifestations in subjects occupationally exposed, or living in polluted areas

    Floristic and vegetation changes on a small mediterranean island over the last century

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    A synthetic and updated overview about the vascular flora and vegetation of the Island of Capo Passero (SE‐Sicily) is provided. These data issue from two series of field surveys—the first carried out between 1997 and 2000, and the second between 2005 and 2019 and mostly focused on refining and implementing vegetation data. The current islet’s flora consists of 269 taxa, of which 149 (58%) are annual plants. The Mediterranean species are largely prevailing, 108 (40%) of which have a strictly Mediterranean biogeographical status. The comparison with a species list published in 1919 and updated in 1957 suggest that, despite the overall prevalence of anemochorous taxa, the vertebrate fauna represents an important vector for the plant colonization of the island, while the immigration of myrmechocorous taxa does not compensate the extinction rate. As many as 202 phy-tosociological relevés, 191 of which issue from original recent field surveys, enabled identifying 12 different plant communities. The comparison with a vegetation map published in 1965 suggests a strong reduction in dune habitats (2120 and 2210 according to EU ‘Habitats’ Directive 92/43), as well as a deep disruption in the succession typical of the local psammophilous vegetation series. In order to preserve rare, endangered and protected plant species (such as Aeluropus lagopoides, Cichorium spinosum, Limonium hyblaeum, L. syracusanum, Poterium spinosum, Senecio pygmaeus and Spergularia heldreichii) and to stop the ongoing habitat degradation, urgent and effective conservation measures should be adopted for this tiny, yet precious islet

    Health surveillance for former asbestos exposed worker: a specific programme developed in an Italian region

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    Asbestos-related diseases usually have a long latency since first exposure and this legitimates a health surveillance programme addressed to asbestos workers after the cessation of their occupational exposure. After a brief history of health surveillance initiatives performed in Italy as well as in other countries, we describe a regional programme for former asbestos-exposed workers, focusing on organizational features. A regional group of experts defined its operational and economical aspects. The Regional Council supported the whole programme, making it free of charge for all subjects who fulfil the predefined enrolment criteria (being resident in the region, being younger than 80 years old with cessation of occupational asbestos exposure within the last 30 years). The programme activities are classified in two levels: a first level for a basic health evaluation and a second level for in-depth analyses. In order to guarantee an homogeneous delivery in the whole region, the programme has to be performed by public health services with a quality control of activities. The involvement of specific public health services and the cooperation of social stakeholders are expected to play a major role in overcoming still open critical issues, such as the lack of programme existence awareness and adhesion, the correct stratification of subjects for the follow-up, and the real homogeneous delivery of the health surveillance in whole region

    Induction of Th1 chemokine secretion in dermal fibroblasts by vanadium pentoxide

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    Vanadium is a soft, silvery-grey metal with a number of different oxidation states. The most common commercial form of vanadium is vanadium pentoxide (V2O5). All vanadium compounds are considered toxic. An increase in skin rashes has been observed in certain vanadium workers, including the development of atopic dermatitis. However, to the best of our knowledge, no prior in vivo or in vitro studies have evaluated the effect of vanadium exposure in human dermal fibroblasts. The present study evaluated the effect of V2O5on proliferation and chemokine secretion in dermal fibroblasts. The results revealed that V2O5had no significant effect on the viability or proliferation of fibroblasts, however it was able to induce the secretion of T-helper (Th)1 chemokines from dermal fibroblasts, synergistically increasing the effect of important Th1 cytokines, including interferon-γ and tumor necrosis factor-α. Through these processes, V2O5may lead to the induction and perpetuation of an inflammatory reaction in dermal tissue. The induction and perpetuation of inflammation in the dermis and the variety of involved candidate genes may be at the base of V2O5-induced effects following occupational and environmental exposures. Further studies are necessary to evaluate dermal integrity and manifestations in subjects who are occupationally exposed, or living in polluted areas
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