3,626 research outputs found

    Realization of superconducting quantum devices based on tunnel Josephson junctions by micro and nanofabrication techniques

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    This PhD Thesis is focused on the realization of superconducting quantum devices based on overdamped Nb/Al-AlOx/Nb SNIS (Superconductor - Normal metal - Insulator - Superconductor) tunneling Josephson junctions, interesting for several application fields (voltage metrology, digital electronics, radiation sensors, nanoSQUID, etc.). The challenges faced by quantum electronics and metrology are directing the new generations of devices towards smaller dimensions and higher levels of integration. Taking into account this requirement, the fabrication of SNIS-based devices has been addressed on downscaling the junction dimensions form the micro to the nanoscale. In particular, the effective area of junctions has been reduced exploiting three different lithographic techniques: the optical lithography to realize SNISs for a micrometer resolution, the Electron Beam Lithography (EBL) at the subµm and, finally, the Focused Ion Beam (FIB) sculpting method to achieve nanometer sizes. Specifically, prototypes have been realized exploiting the thin film technology, to guarantee a good control of electrical parameters of junctions, a higher reproducibility of their current-voltage I-V characteristics, and an accurate dimension control. Reliable and simpler fabrication processes have been implemented and validated, and the device downscaling was pursued without affecting the fundamental properties of SNIS junctions such as the non hysteretic I-V response and the skill on generating quantised voltage steps under radiofrequency irradiation. This work has thereby led to the definition and validation of a new generation of devices and processes down to the nanometer scale, and these approaches represent precious experiences of nanofabrication valuable for new research activities and projects

    Integrating Safety-I and Safety-II Approaches in Near Miss Management: A Critical Analysis

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    Safety-II is a recently theorized approach, considering safety as the ability of a system to reach a positive outcome under variable conditions: analyzing “what goes right” can help to understand the dynamics of the analyzed system and improve its inherent safety level. On the contrary, a more traditional perspective, defined as Safety-I, aims at analyzing “what goes wrong”, thereby relating the safety level of a system to the number of adverse events that occurred. This study explores the potentialities of integrating these two approaches in near-miss management. Through a Safety-I approach, near-miss events are analyzed to identify the root causes generating the event chain, in order to delete them and prevent future accidents. Applying a Safety-II approach, the analysis can include elements that contributed to limiting the consequences and blocking the event chain, revealing the resilience level of the systems. This study presents a critical analysis of the two approaches and proposes a practical framework to integrate them into near-miss management systems. A test case shows the potential benefits of this integration. This work provides a tool to support the implementation of Safety-II on the operative level while suggesting a new perspective for near-miss management

    Localization of antimicrobial peptides in the tunic of Ciona intestinalis ( Ascidiacea, Tunicata) and their involvement in local inflammatory-like reactions

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    Tunicates comprising a wide variety of different species synthesize antimicrobial peptides as important effector molecules of the innate immune system. Recently, two putative gene families coding for antimicrobial peptides were identified in the expressed sequence tag database of the tunicate Ciona intestinalis. Two synthetic peptides representing the cationic core region of one member of each of the families displayed potent antibacterial and antifungal activities. Moreover, the natural peptides were demonstrated to be synthesized and stored in distinct hemocyte types. Here, we investigated the presence of these natural peptides, namely Ci-MAM-A and Ci-PAP-A, in the tunic of C. intestinalis considering that the ascidian tunic is a body surface barrier exposed to constant microbial assault. Furthermore, as the tunic may represent a major route of entry for pathogen invasion after its damage we monitored the location of these peptides upon a local inflammatory-like reaction induced by injection of foreign cells. Using immunocytochemistry and electron microscopy both peptides were localized to the tunic and were massively present in granulocytes of inflamed tissue. Conclusively, antimicrobial peptides may constitute a chemical barrier within the tunic of urochordates

    A Relevância da Avaliação Institucional na UNIVALI

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    A Universidade do Vale do Itajaí - UNIVALI, ao longo de sua história, vem privilegiando a Avaliação Institucional como instrumento de gestão e de autoconhecimento em busca da excelência. Sua proposta de Avaliação Institucional foi anunciada no documento base do projeto da Universidade, em 1993, e, desde então, vem ampliando e aperfeiçoando seus métodos de trabalho. A UNIVALI tem como meta, em seu Projeto Institucional, o rigor com a qualidade de ensino e, para isso, está consciente da necessidade de um processo de avaliação permanente e criterioso. O tema avaliação institucional ocupa posição relevante na formulação e implementação das políticas públicas de educação, por indicar possibilidades de integração de diferentes perspectivas no planejamento das instituições de ensino. As modalidades de avaliação descritas foram: auto-avaliação dos cursos da graduação; desempenho docente, discente e da organização didático-pedagógica e infra-estrutura, perfil socioeconômico discente; avaliação do curso pelo egresso; avaliação dos colégios de aplicação; dos cursos de pós-graduação lato sensu e stricto sensu; e avaliação dos estágios supervisionados. É a comunidade que indica o mérito e a relevância do que a universidade produz, e o Programa de Avaliação Institucional, integrado às demais modalidades de Avaliações Externas, deve investir em uma linguagem comum na divulgação de resultados, que permita, não simplesmente uma classificação de cursos, pessoas ou unidades de ensino, mas o estabelecimento de diagnósticos que possam sinalizar necessárias mudanças no processo interno da Universidade

    a combined treatment with myo inositol and monacolin k improve the androgen and lipid profiles of insulin resistant pcos patients

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    Objective: We sought to assess and compare the effects of myo-inositol combined with monacolin k (Group A) versus inositol only (Group B) and metformin (Group C), on the clinical, hormonal, metabolic and lipid profiles of insulin-resistant PCOS patients. Study design: 60 insulin resistant PCOS patients were randomly assigned into three groups. All groups were treated for 6 months with either myo-inositol and monacolin k, inositol only or metformin. Patients clinical, hormonal and metabolic profiles were compared between all groups, and within each group, prior and following the aforementioned treatment. Results: All treatment arms improved patients' clinical, hormonal and metabolic profiles, with a tendency toward better results in patients using the combination of myo-inositol and monacolin k. Conclusion: The combined treatment with the natural products: monacolin K and myo-inositol represents a valid and well tolerated alternative to the common medical therapy, improving the PCOS related symptoms, with minimal side effects

    Conceptual design of offshore platform supply vessel based on hybrid diesel generator-fuel cell power plant

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    Nowadays increasing fuel prices and upcoming pollutant emission regulations are becoming a growing concern for the shipping industry worldwide. While fuel prices will keep rising in future years, the new International Convention for the Prevention of Pollution from Ships (MARPOL) and Sulphur Emissions Control Areas (SECA) regulations will forbid ships to use heavy fuel oils at certain situations. To fulfil with these regulations, the next step in the marine shipping business will comprise the use of cleaner fuels on board as well as developing new propulsion concept. In this work a new conceptual marine propulsion system is developed, based on the integration of diesel generators with fuel cells in a 2850 metric tonne of deadweight platform supply vessel. The efficiency of the two 250 kW methanol-fed Solid Oxide Fuel Cell (SOFC) system installed on board combined with the hydro dynamically optimized design of the hull of the ship will allow the ship to successfully operate at certain modes of operation while notably reduce the pollutant emissions to the atmosphere. Besides the cogeneration heat obtained from the fuel cell system will be used to answer different heating needs on board the vesse

    Role of the mTOR pathway in normal and tumoral adrenal cells

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    The mammalian target of rapamycin (mTOR) is a kinase of the phosphoinositide 3-kinase (PI3Ks)/protein kinase B (PKB or AKT) signaling pathway, which is one of the most important intracellular mediators of the activity of growth factors receptors, including vascular endothelial growth factor (VEGF) and insulin-like growth factors (IGFs). Dysregulation of the mTOR pathway has been found in many human tumors. Therefore, the mTOR pathway is considered as a target for antineoplastic therapy in several malignancies. Presently, the role and functions of mTOR and its signaling pathway in the normal and pathological adrenal gland has not been clarified yet. However, many growth factors and growth factor receptors, which are considered to play a role in the pathogenesis of adrenal tumors, can at least in part exert their effects through the activation of PI3K/AKT/mTOR pathway. Dysregulation of AKT has been reported in adrenocortical carcinomas and adrenomedullary tumors, named pheochromocytomas. Adrenocortical carcinomas and malignant pheochromocytomas are aggressive tumors with poor prognosis and scant treatment options. Therefore, new treatment options are warranted for these malignancies. On the basis of the current knowledge, mTOR could play a role in the pathogenesis of both adrenocortical carcinomas and pheochromocytomas. Moreover, mTOR inhibitors, interfering with the activation of several mitogenic and angiogenic factors, could be considered as a novel treatment opportunity for the management of malignant adrenal tumors

    Exosome-mediated crosstalk between chronic myelogenous leukemia cells and human bone marrow stromal cells triggers an interleukin 8-dependent survival of leukemia cells

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    Chronic myelogenous leukemia (CML) is a myeloproliferative disorder characterized by the Bcr–Abl oncoprotein with constitutive tyrosine kinase activity. Exosomes are nanovesicles released by cancer cells that are involved in cell-to-cell communication thus potentially affecting cancer progression. It is well known that bone marrow stromal microenvironment contributes to disease progression through the establishment of a bi-directional crosstalk with cancer cells. Our hypothesis is that exosomes could have a functional role in this crosstalk. Interleukin-8 (IL 8) is a proinflammatory chemokine that activates multiple signalling pathways downstream of two receptors (CXCR1 and CXCR2). We demonstrated that exosomes released from CML cells stimulate bone marrow stromal cells to produce IL 8 that, in turn, is able to modulate both in vitro and in vivo the leukemia cell malignant phenotype
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