242 research outputs found

    The material basis of modern technologies. A case study on rare metals

    Get PDF
    The unique properties of a wide range of Rare Metals (RMs) are crucial to achieve the functionality of modern technologies. By text mining 5,146,615 USPTO patents during the period 1976-2015, this paper systematically studies the technological dependence of new inventions on 13 key RMs, with the aim of exploring the link between critical raw materials and frontier technological innovation. We find that RMs play an increasing role as the material basis for modern technologies: the dependence varies significantly across technological areas and metal types, and it is particularly high for some emerging technologies such as semiconductors, nanotechnology, and green energy technologies. Further, we use a panel of technology-RM pairs over four decades to assess the impact of RM supply on innovation dynamics. The results show that increases in the supply of an RM significantly improve the patent output of technology areas based on it, contributing to the understanding of how innovation dynamics are shaped by the availability of natural resources with technological criticality

    On the width of the equatorial deep jets

    Get PDF
    The equatorial deep jets (EDJ) are a striking feature of the equatorial ocean circulation. In the Atlantic Ocean, the EDJ are associated with a vertical scale of between 300 and 700 m, a time scale of roughly 4.5 years and upward energy propagation to the surface. It has been found that the meridional width of the EDJ is roughly 1.5 times larger than expected based on their vertical scale. Here we use a shallow water model for a high order baroclinic vertical normal mode to argue that mixing of momentum along isopycnals can explain the enhanced width. A lateral eddy viscosity of 300 m2 s−1 10 is found to be sufficient to account for the width implied by observations

    Hodgkin's lymphoma: The pathologist's viewpoint

    Get PDF
    Despite its well known histological and clinical features, Hodgkin's lymphoma (HL) has recently been the object of intense research activity, leading to a better understanding of its phenotype, molecular characteristics, histogenesis, and possible mechanisms of lymphomagenesis. There is complete consensus on the B cell derivation of the tumour in most cases, and on the relevance of Epstein-Barr virus infection and defective cytokinesis in at least a proportion of patients. The REAL/WHO classification recognises a basic distinction between lymphocyte predominance HL (LP-HL) and classic HL (CHL), reflecting the differences in clinical presentation and behaviour, morphology, phenotype, and molecular features. CHL has been classified into four subtypes: lymphocyte rich, nodular sclerosing, with mixed cellularity, and lymphocyte depleted. The borders between CHL and anaplastic large cell lymphoma have become sharper, whereas those between LP-HL and T cell rich B cell lymphoma remain ill defined. Treatments adjusted to the pathobiological characteristics of the tumour in at risk patients have been proposed and are on the way to being applied

    Ebv-driven lymphoproliferative disorders and lymphomas of the gastrointestinal tract: A spectrum of entities with a common denominator (part 2)

    Get PDF
    Epstein–Barr virus (EBV) is a common pathogen infecting people primarily early in life. The virus has the ability to persist throughout a person’s life, usually in B lymphocytes. Conditions of immunodeficiency as well as the introduction of immunosuppressive therapies and the advent of transplant technologies has brought immunodeficiency-associated lymphoproliferative disorders into view, which are often driven by EBV. The group of EBV-associated lymphoproliferative disorders includes different entities, with distinct biological features, ranging from indolent disor-ders, which may even spontaneously regress, to aggressive lymphomas requiring prompt and ade-quate treatment. These disorders are often diagnostically challenging due to their overlapping mor-phology and immunophenotype. Both nodal and extra-nodal sites, including the gastrointestinal tract, may be involved. This review, divided in three parts, summarizes the clinical, pathological, molecular features and treatment strategies of EBV-related lymphoproliferative disorders occurring in the gastrointestinal tract and critically analyzes the major issues in the differential diagnosis. In this part of the review, we discuss plasmablastic lymphoma, extra-cavitary primary effusion lymphoma and Burkitt lymphoma

    Ebv-driven lymphoproliferative disorders and lymphomas of the gastrointestinal tract: A spectrum of entities with a common denominator (part 3)

    Get PDF
    EBV is the first known oncogenic virus involved in the development of several tumors. The majority of the global population are infected with the virus early in life and the virus persists throughout life, in a latent stage, and usually within B lymphocytes. Despite the worldwide diffusion of EBV infection, EBV-associated diseases develop in only in a small subset of individuals often when conditions of immunosuppression disrupt the balance between the infection and host immune system. EBV-driven lymphoid proliferations are either of B-cell or T/NK-cell origin, and range from disorders with an indolent behavior to aggressive lymphomas. In this review, which is divided in three parts, we provide an update of EBV-associated lymphoid disorders developing in the gastrointestinal tract, often representing a challenging diagnostic and therapeutic issue. Our aim is to provide a practical diagnostic approach to clinicians and pathologists who face this complex spectrum of disorders in their daily practice. In this part of the review, the chronic active EBV infection of T-cell and NK-cell type, its systemic form; extranodal NK/T-cell lymphoma, nasal type and post-transplant lymphoproliferative disorders are discussed
    • …
    corecore