271 research outputs found

    Primary tumor sidedness and benefit from FOLFOXIRI plus bevacizumab as initial therapy for metastatic colorectal cancer. Retrospective analysis of the TRIBE trial by GONO

    Get PDF
    Right-sided metastatic colorectal cancer (mCRC) patients have poor prognosis and achieve limited benefit from first-line doublets plus a targeted agent. In this unplanned analysis of the TRIBE study, we investigated the prognostic and predictive impact of primary tumor sidedness in mCRC patients and the differential impact of the intensification of the chemotherapy in subgroups defined according to both primary tumor sidedness and RAS and BRAF mutational status

    Enhanced Eshelby twist on thin wurtzite InP nanowires and measurement of local crystal rotation

    Get PDF
    We have performed a detailed study of the lattice distortions of InP wurtzite nanowires containing an axial screw dislocation. Eshelby predicted that this kind of system should show a crystal rotation due to the dislocation induced torque. We have measured the twisting rate and the dislocation Burgers vector on individual wires, revealing that nanowires with a 10-nm radius have a twist up to 100% larger than estimated from elasticity theory. The strain induced by the deformation has a Mexican-hat-like geometry, which may create a tube-like potential well for carriers

    Visualising highly localised luminescence in GaN/AlN heterostructures in nanowires

    Get PDF
    The optical properties of a stack of GaN/AlN quantum discs (QDiscs) in a GaN nanowire have been studied by spatially resolved cathodoluminescence (CL) at the nanoscale (nanoCL) using a Scanning Transmission Electron Microscope (STEM) operating in spectrum imaging mode. For the electron beam excitation in the QDisc region, the luminescence signal is highly localized with spatial extension as low as 5 nm due to the high band gap difference between GaN and AlN. This allows for the discrimination between the emission of neighbouring QDiscs and for evidencing the presence of lateral inclusions, about 3 nm thick and 20 nm long rods (quantum rods, QRods), grown unintentionally on the nanowire sidewalls. These structures, also observed by STEM dark-field imaging, are proven to be optically active in nanoCL, emitting at similar, but usually shorter, wavelengths with respect to most QDiscs. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

    Integrating modes of policy analysis and strategic management practice : requisite elements and dilemmas

    Get PDF
    There is a need to bring methods to bear on public problems that are inclusive, analytic, and quick. This paper describes the efforts of three pairs of academics working from three different though complementary theoretical foundations and intervention backgrounds (i.e., ways of working) who set out together to meet this challenge. Each of the three pairs had conducted dozens of interventions that had been regarded as successful or very successful by the client groups in dealing with complex policy and strategic problems. One approach focused on leadership issues and stakeholders, another on negotiating competitive strategic intent with attention to stakeholder responses, and the third on analysis of feedback ramifications in developing policies. This paper describes the 10 year longitudinal research project designed to address the above challenge. The important outcomes are reported: the requisite elements of a general integrated approach and the enduring puzzles and tensions that arose from seeking to design a wide-ranging multi-method approach

    Position paper of the Italian Association of Medical Oncology on the impact of COVID-19 on Italian oncology and the path forward: the 2021 Matera statement

    Get PDF
    The coronavirus disease 2019 (COVID-19) pandemic has severely affected cancer care and research by disrupting the prevention and treatment paths as well as the preclinical, clinical, and translational research ecosystem. In Italy, this has been particularly significant given the severity of the pandemic's impact and the intrinsic vulnerabilities of the national health system. However, whilst detrimental, disruption can also be constructive and may stimulate innovation and progress. The Italian Association of Medical Oncology (AIOM) has recognized the impact of COVID-19 on cancer care continuum and research and proposes the '2021 Matera statement' which aims at providing pragmatic guidance for policymakers and health care institutions to mitigate the impact of the global health crisis on Italian oncology and design the recovery plan for the post-pandemic scenario. The interventions are addressed both to the pillars (prevention, diagnosis, treatment, follow-up, health care professionals) and foundations of cancer care (communication and care relationship, system organization, resources, research, networking). The priorities to be implemented can be summarized in the MATERA acronym: Multidisciplinarity; Access to cancer care; Telemedicine and Territoriality; Equity, ethics, education; Research and resources; Alliance between stakeholders and patients

    Nanometer-scale monitoring of the quantum confined stark effect and emission efficiency droop in multiple GaN/AlN quantum disks in nanowires

    Get PDF
    21 pages, 11 figures, published in PRBInternational audienceWe report on a detailed study of the intensity dependent optical properties of individual GaN/AlN Quantum Disks (QDisks) embedded into GaN nanowires (NW). The structural and optical properties of the QDisks were probed by high spatial resolution cathodoluminescence (CL) in a scanning transmission electron microscope (STEM). By exciting the QDisks with a nanometric electron beam at currents spanning over 3 orders of magnitude, strong non-linearities (energy shifts) in the light emission are observed. In particular, we find that the amount of energy shift depends on the emission rate and on the QDisk morphology (size, position along the NW and shell thickness). For thick QDisks (>4nm), the QDisk emission energy is observed to blue-shift with the increase of the emission intensity. This is interpreted as a consequence of the increase of carriers density excited by the incident electron beam inside the QDisks, which screens the internal electric field and thus reduces the quantum confined Stark effect (QCSE) present in these QDisks. For thinner QDisks (<3 nm), the blue-shift is almost absent in agreement with the negligible QCSE at such sizes. For QDisks of intermediate sizes there exists a current threshold above which the energy shifts, marking the transition from unscreened to partially screened QCSE. From the threshold value we estimate the lifetime in the unscreened regime. These observations suggest that, counterintuitively, electrons of high energy can behave ultimately as single electron-hole pair generators. In addition, when we increase the current from 1 pA to 10 pA the light emission efficiency drops by more than one order of magnitude. This reduction of the emission efficiency is a manifestation of the efficiency droop as observed in nitride-based 2D light emitting diodes, a phenomenon tentatively attributed to the Auger effect
    • 

    corecore