77 research outputs found

    Efectos de la radiación y comportamiento de los iones ligeros en cerámicas para la envoltura regeneradora de fusión.

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    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 05-09-201

    D-depth profiling in as-implanted and annealed Li-based breeder blanket ceramics

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    In future power plants (i.e. DEMO), the nuclear fusion of hydrogen isotopes will be used for energy production. The behaviour of hydrogen isotopes in lithium-enriched ceramics for breeder blankets (BBs) is one of the most important items to be understood. In this paper we present the chemical, microstructural and morphological features of Li4SiO4, Li2TiO3 and a third ceramic candidate with a higher Li:Si proportion (3:1), implanted with D at an energy of 100 keV and at room temperature at a fluence of 1 × 1017 cm−2. The D depth-profile in as-implanted and annealed ceramics (at T ⩽ 200 °C) was characterised by Resonance Nuclear Reaction Analysis (RNRA). The RNRA data indicate that the total amount of D is retained at room temperature, while annealing at 100 °C promotes D release and annealing at T ⩾ 150 °C drives D to completely desorb from all the studied ceramics. D release will be discussed as a function of the microstructurural and morphological features of each material

    Thermal diffusion profile by NRA of Deuterium implanted in solid breeder blanket materials

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    This paper studies the relationship between aging, physical changes and the results of non-destructive testing of plywood. 176 pieces of plywood were tested to analyze their actual and estimated density using non-destructive methods (screw withdrawal force and ultrasound wave velocity) during a laboratory aging test. From the results of statistical analysis it can be concluded that there is a strong relationship between the non-destructive measurements carried out, and the decline in the physical properties of the panels due to aging. The authors propose several models to estimate board density. The best results are obtained with ultrasound. A reliable prediction of the degree of deterioration (aging) of board is presented. Breeder blanket materials have to produce tritium from lithium while fulfilling several strict conditions. In particular, when dealing with materials to be applied in fusion reactors, one of the key questions is the study of light ions retention, which can be produced by transmutation reactions and/or introduced by interaction with the plasma. In ceramic breeders the understanding of the hydrogen isotopes behaviour and specially the diffusion of tritium to the surface is crucial. Moreover the evolution of the microstructure during irradiation with energetic ions, neutrons and electrons is complex because of the interaction of a high number of processes

    DEMNUni: cross-correlating the nonlinear ISWRS effect with CMB-lensing and galaxies in the presence of massive neutrinos

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    We present a novel analytical approach to study the cross-correlations between the Integrated Sachs Wolfe--Rees Sciama (ISWRS) effects and large-scale structure tracers in the presence of massive neutrinos. Our method has been validated against large N-body simulations with a massive neutrino particle component, namely the DEMNUni suite. We investigate the impact of different neutrino masses on the cross-correlations between ISWRS and both Cosmic Microwave Background (CMB) lensing and galaxies. We show that the position of the sign inversion due to nonlinear effects is strongly related to the neutrino mass. While such nonlinear cross-correlation signals may not be able alone to constrain the neutrino mass, our approach paves the way for future studies to detect the amplitude of these cross-spectra on small scales, and to explore the combined impact of dark energy and neutrino mass from future galaxy surveys and CMB experiments.Comment: 31 pages , 15 fig

    A new case of de novo 6q24.2-q25.2 deletion on paternal chromosome 6 with growth hormone deficiency: A twelve-year follow-up and literature review

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    BACKGROUND: Deletions on the distal portion of the long arm of chromosome 6 are relatively uncommon, and only a small number occurs in the paternal copy, causing growth abnormalities. As a result, extensive clinical descriptions are lacking. CASE PRESENTATION: We describe a male of Italian descent born at 35 weeks by elective caesarean delivery presenting hypoplastic left colon, bilateral inguinal hernia, dysplastic tricuspid and pulmonary valves, premature ventricular contractions, recurrent otitis media, poor feeding, gastro-oesophageal reflux, bilateral pseudopapilledema, and astigmatism. He also showed particular facial dysmorphisms and postnatal growth failure. Early psychomotor development was mildly delayed. At 3.75 years, he was evaluated for severe short stature (−2.98 SD) and delayed bone age. He showed an insulin-like growth factor 1 concentration (IGF-1) in the low-normal range. Growth hormone stimulation tests showed a low response to clonidine and insulin. Magnetic resonance imaging showed hypophyseal hypoplasia. Genetic evaluation by Single Nucleotide Polymorphism arrays showed a de novo 6q24.2-q25.2 deletion on paternal chromosome 6. CONCLUSION: We confirm that this is a new congenital malformation syndrome associated with a deletion of 6q24.2-q25.2 on paternal chromosome 6. We suggest evaluating the growth hormone axis in children with 6q24.2-q25.2 deletions and growth failure

    Caracterización de especies ligeras en cerámicas de Li

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    Desarrollar cerámicas de Li con propiedades adecuadas para ser utilizadas en el manto reproductor de reactores de fusión. Estudiar el comportamiento de especies ligeras, en particular D, en cerámicas de Li en función de: Composición, Microestructura, Temperatura

    In the wake of the ongoing mass mortality events: Co-occurrence of Mycobacterium, Haplosporidium and other pathogens in Pinna nobilis collected in Italy and Spain (Mediterranean Sea)

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    Following the Mass Mortality Events (MMEs) of the pen shell P. nobilis in Campania region and Sicily, a survey of moribund P. nobilis specimens was also conducted in other Italian regions (Campania, Tuscany, Sardinia, and Apulia) and Spain (Catalunya). Histopathological and molecular examination of 27 specimens of P. nobils revealed different types of pathogens associated with tissue lesions, morbidity and mortality. Presence of Mycobacterium, Vibrio species, Haplosporidium pinnae and Perkinsus sp. were detected, differently distributed into the areas. The Mycobacterium sp., previously reported in Campania and Sicily samples, was observed in all the analyzed areas and individuals, associated to systemic inflammatory lesions. In Spain, H. pinnae was observed in 36% of cases, always associated to the Mycobacterium sp. Molecular study using hsp65 genes and Internal Transcriber Spacer ITS support that a new species of Mycobacteria is infecting P. nobilis, close to M. triplex and belonging to the group of M. simiae complex with M. sherrisi. Presence of Perkinsus spp. resembling P. mediterraneus was observed in 2 out of 13 Italian individuals whose presence should be addressed as potential risk for shellfish aquaculture of the area. Vibrio spp. were also detected in some case. The preliminary results of this study suggest that Mycobacterium sp., Vibrio spp., H. pinnae and Perkinsus sp. cooperate to disease pathogenesis, being Mycobacterium and Haplosporidium most of the time involved. Vigilant inspection of those areas where MME is now starting, along with continuous systematic surveys, are crucial to define the spatiotemporal progress of mortality and the role of every single pathogen in the disease outcome.info:eu-repo/semantics/publishedVersio

    JLB: a flexible and effective device in critical patients. Review of clinical cases

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    JLB catheter (Deltamed Inc) is an alternative way to manage difficult venous access; it is placed under US-guidance in large bore veins, with an easy-sterile approach. Internal jugular vein (IJV) is the first choice for cannulation, followed by subclavian or deep upper-arm veins. The catheter is available in different lengths and gauges, it allows high flow rates and can be left in place up to 30 days. From June 2015 to March 2017, JLB has been positioned in 409 patients: in 354 as primary access in IJV, brachial or subclavian vein; in 55 cases JLB became an introducing line for the Seldinger guidewire and further CVC positioning. All clinical cases were reviewed selecting those with greater clinical relevance. We report 8 cases in which JLB resulted determinant for the patient treatment: a 16 years old obese girl born with perinatal distress, a 78 years old obese woman with hemorrhagic shock caused by gastrointestinal bleeding, a 40 years old man with severe hypokalemia, a 30 years old man with severe sepsis, a 40 years old man with Becker’s muscular dystrophy and severe sepsis, a 40 years old man with multiple myeloma who had to carry out cycles of chemotherapy, a 76 years old man with CMV pancolitis and myelofibrosis who needed parenteral nutrition, antiviral therapy and frequent blood and platelets transfusion. Moreover, it has been useful in elderly patients who needed to carry out palliative care for seniority or cancer lasting up to 30 days . In our experience the JLB catheter is safe, easy to place, quick and cost –effective. It is a valid solution either in unstable patients requiring an immediate access in emergency and stable patients with difficult venous access, in which invasive devices can be considered an over-treatment

    Effect of systemic therapies or best supportive care after disease progression to both nivolumab and cabozantinib in metastatic renal cell carcinoma: The Meet‐Uro 19BEYOND study

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    Background Nivolumab and cabozantinib are currently approved agents in metastatic renal cell carcinoma (mRCC) but there are no data available for patients progressing to both treatments. The aim of this study was to compare active therapeutic options and best supportive care (BSC) after progression to nivolumab and cabozantinib in mRCC. Methods In this retrospective study, we selected 50 patients from eight Italian centers. The primary endpoint of the study was the overall survival (OS) of patients on active treatment versus BSC. Secondary endpoints were the progression-free survival (PFS) and objective response rate (ORR). The efficacy of active therapy was also investigated. Results After progression to both nivolumab and cabozantinib, 57.1% of patients were given active treatment (mainly everolimus and sorafenib) while 42.9% received BSC. The median OS was 13 months (95% CI: 4-NR) in actively treated patients and 3 months (95% CI: 2–4) in BSC patients (p = 0.001). Patients treated with sorafenib had better disease control than those treated with everolimus (stable disease: 71.4% vs. 16.7%, progression disease: 14.3% vs. 58.3%; p = 0.03), with no significant differences in PFS (5 and 3 months, 95% CI: 1–6 vs. 2–5; p = 0.6) and OS (12 and 4 months, 95% CI: 3-NR vs. 2-NR; p = 0.2). Conclusion After treatment with both nivolumab and cabozantinib, the choice of a safe active systemic therapy offered better outcomes than BSC
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