53 research outputs found

    Composition dependent electrochemical properties of earth-abundant ternary nitride anodes

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    Growing energy storage demands on lithium-ion batteries necessitate exploration of new electrochemical materials as next-generation battery electrode materials. In this work, we investigate the previously unexplored electrochemical properties of earth-abundant and tunable Zn1-xSn1+xN2 (x = -0.4 to x = 0.4) thin films, which show high electrical conductivity and high gravimetric capacity for Li insertion. Enhanced cycling performance is achieved compared to previously published end-members Zn3N2 and Sn3N4, showing decreased irreversible loss and increased total capacity and cycle stability. The average reversible capacity observed is > 1050 mAh/g for all compositions and 1220 mAh/g for Zn-poor (x = 0.2) films. Extremely Zn-rich films (x = -0.4) show improved adhesion; however, Zn-rich films undergo a phase transformation on the first cycle. Zn-poor and stoichiometric films do not exhibit significant phase transformations which often plague nitride materials and show no required overpotential at the 0.5 V plateau. Cation composition x is explored as a mechanism for tuning relevant mechanical and electrochemical properties, such as capacity, overpotential, phase transformation, electrical conductivity, and adhesion. The lithiation/delithiation experiments confirm the reversible electrochemical reactions. Without any binding additives, the as-deposited electrodes delaminate resulting in fast capacity degradation. We demonstrate the mechanical nature of this degradation through decreased electrode thinning, resulting in cells with improved cycling stability due to increased mechanical stability. Combining composition and electrochemical analysis, this work demonstrates for the first time composition dependent electrochemical properties for the ternary Zn1-xSn1+xN2 and proposes earth-abundant ternary nitride anodes for increased reversible capacity and cycling stability

    Optimal Ki67 cut-off for luminal breast cancer prognostic evaluation: a large case series study with a long-term follow-up

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    Although Ki67 index suffers from poor reproducibility, it is one of the most important prognostic markers used by oncologists to select the treatment of estrogen receptor (ER) positive breast cancer patients. In this study, we aim to establish the optimal Ki67 cut-offs for stratifying patient prognosis and to create a comprehensive prognostic index for clinical applications. A mono-institutional cohort of 1.577 human epidermal growth factor receptor 2 negative/ER+ breast cancer patients having complete clinical, histological, and follow-up data was collected. The 14 and 20 % Ki67 cut-offs were correlated to disease-free interval (DFI) and disease-specific survival (DSS). To create a comprehensive prognostic index, we used independent variables selected by uni/multivariate analyses. In terms of DFI and DSS, patients bearing tumors with Ki67 < 14 % proliferation index did not differ from those with Ki67 values between 14 and 20 %. Patients with tumor with Ki67 > 20 % showed the poorest prognosis. Moreover, to tumor size, the number of metastatic lymph nodes and Ki67 > 20 % was given a score value, varying depending on definite cut-offs and used to create a prognostic index, which was applied to the population. Patients with a prognostic index ≥3 were characterized by significant risk of relapse [DFI: Hazard Ratio (HR) = 4.74, p < 0.001] and death (DSS: HR = 5.03, p < 0.001). We confirm that the 20 % Ki67 cut-off is the best to stratify high-risk patients in luminal breast cancers, and we suggest to integrate it with other prognostic factors, to better stratify patients at risk of adverse outcome

    Revisione del genere Acallorneuma Mainardi, 1906 (Coleoptera, Curculionidae, Cryptorhynchinae)

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    Volume: 109Start Page: 433End Page: 46
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