5 research outputs found

    The PLATO TOU optical design: description, properties, and nominal performances

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    The ESA M size mission PLATO (PLAnetary Transits and Oscillation of stars) is planned to be launched in the 2026, with the aim of discover exoplanets that will be characterized with unprecedented precision. The optical elements of PLATO are 26 small telescopes, the TOUs (Telescope Optical Units), that using partially overlapping Fields of View will permit instantaneous sky coverage larger than 2100 square degrees. Each TOU has an aperture of 120 mm diameter assured by an internal stop, and it is composed by 6 lenses, the frontal one having an aspherical surface and the last acting as field flattener. The mechanical structure is realized mainly in AlBeMet. We here describe the optical design, summarizing several optical properties (materials, coatings, etc.), and report on nominal performances of the TOU system

    Linea Guida SIOT-- Prevenzione delle infezioni in chirurgia ortopedica

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    La prevenzione delle infezioni del sito chirurgico (ISC) costituisce una priorità nell’ambito degli obiettivi del Sistema Sanitario Nazionale. Le conseguenze negative che le infezioni postoperatorie comportano (morbilità, durata dell’ospedalizzazione, mortalità) rappresentano eventi particolarmente gravi sia per il singolo paziente sia per la collettività, in considerazione delle risorse assistenziali necessarie per trattarle. In un contesto sanitario globale nel quale si è affermata la medicina basata sulle prove di efficacia, cioè la evidence-based medicine (EBM), tutti gli interventi medici vanno riconsiderati alla luce di quanto desumibile dalla letteratura valutata secondo rigorosi criteri metodologici, a maggior ragione quando le prove sono disponibili e unanimemente condivise. L’obiettivo di questo documento è passare in rassegna le evidenze scientifiche desunte da Linee Guida (LG) accreditate e recenti riguardo le varie metodiche di prevenzione delle infezioni, al fine di stabilire quelle che presentano prove affidabili a sostegno e che meritano di essere condivise, implementate e che in definitiva rappresentano un indicatore della qualità dell’assistenza che siamo in grado di fornire ai nostri pazienti. La SIOT, al termine di un percorso complesso che ha coinvolto collaboratori di diverse specialità e ambiti professionali, ha prodotto la presente LG quale strumento valido e aggiornato per gestire al meglio la prevenzione delle ISC perioperatorie

    Osteosarcoma Development and Stem Cell Differentiation

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    Osteosarcoma is the most common nonhematologic malignancy of bone in children and adults. The peak incidence occurs in the second decade of life, with a smaller peak after age 50. Osteosarcoma typically arises around the growth plate of long bones. Most osteosarcoma tumors are of high grade and tend to develop pulmonary metastases. Despite clinical improvements, patients with metastatic or recurrent diseases have a poor prognosis. Here, we reviewed the current understanding of human osteosarcoma, with an emphasis on potential links between defective osteogenic differentiation and bone tumorigenesis. Existing data indicate osteosarcoma tumors display a broad range of genetic and molecular alterations, including the gains, losses, or arrangements of chromosomal regions, inactivation of tumor suppressor genes, and the deregulation of major signaling pathways. However, except for p53 and/or RB mutations, most alterations are not constantly detected in the majority of osteosarcoma tumors. With a rapid expansion of our knowledge about stem cell biology, emerging evidence suggests osteosarcoma should be regarded as a differentiation disease caused by genetic and epigenetic changes that interrupt osteoblast differentiation from mesenchymal stem cells. Understanding the molecular pathogenesis of human osteosarcoma could ultimately lead to the development of diagnostic and prognostic markers, as well as targeted therapeutics for osteosarcoma patients
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