23 research outputs found

    Crystallization behaviour of TiO2ZrO2TiO_{2}-ZrO_{2} composite nanoparticles

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    To investigate tumor vascularity by dual source volume perfusion computed tomography (VPCT) in advanced lung adenocarcinoma with positive EGFR-mutant and determine whether any of the VPCT parameters would predict the tumor response to gefitinib.Twelve patients (5 males and 7 females, Median age: 53 years, range: 36 - 69 years) with advanced lung adenocarcinoma received VPCT scan. All patients with positive EGFR-mutant were confirmed by pathological biopsy. After a 6-week therapy of gefitinib, VPCT was repeated and the short-term effect evaluated by the RECIST criteria. The VPCT parameters (blood volume, blood flow and permeability surface) of 12 patients were compared with their differentiation grade and short-term effect.Short-term effects were poor in those cases in whom BF increased after a 6-week of targeted therapy (P = 0.030). BF and PS at pre-therapy were negatively correlated with differentiation grade (r = -0.603, -0.694, P = 0.038, 0.012). There was a negative correlation between the rate of BF decline and differentiation grade (r = -0.686, P = 0.029); a negative correlation existed between the trend of BF and RECIST criteria (r = -0.707, P = 0.010). But there was no significant correlation with differentiation grade (P = 0.059). If the BF decline was considered effective, the dual source VPCT could predict the effect of RECIST criteria. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of VPCT was 100%, 66.7%, 83.3%, 75% and 100% respectively.Dual source VPCT of advanced lung adenocarcinoma can assess effectively tumor vascularity and perfusion changes after the therapy of gefitinib. It is important in evaluating the response of targeted therapy in lung cancer

    The structural and chemical origin of the oxygen redox activity in layered and cation-disordered Li-excess cathode materials

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    Lithium-ion batteries are now reaching the energy density limits set by their electrode materials, requiring new paradigms for Li+ and electron hosting in solid-state electrodes. Reversible oxygen redox in the solid state in particular has the potential to enable high energy density as it can deliver excess capacity beyond the theoretical transition-metal redox-capacity at a high voltage. Nevertheless, the structural and chemical origin of the process is not understood, preventing the rational design of better cathode materials. Here, we demonstrate how very specific local Li-excess environments around oxygen atoms necessarily lead to labile oxygen electrons that can be more easily extracted and participate in the practical capacity of cathodes. The identification of the local structural components that create oxygen redox sets a new direction for the design of high-energy-density cathode materials

    Computational understanding of Li-ion batteries

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    Over the last two decades, computational methods have made tremendous advances, and today many key properties of lithium-ion batteries can be accurately predicted by first principles calculations. For this reason, computations have become a cornerstone of battery-related research by providing insight into fundamental processes that are not otherwise accessible, such as ionic diffusion mechanisms and electronic structure effects, as well as a quantitative comparison with experimental results. The aim of this review is to provide an overview of state-of-the-art ab initio approaches for the modelling of battery materials. We consider techniques for the computation of equilibrium cell voltages, 0-Kelvin and finite-temperature voltage profiles, ionic mobility and thermal and electrolyte stability. The strengths and weaknesses of different electronic structure methods, such as DFT+U and hybrid functionals, are discussed in the context of voltage and phase diagram predictions, and we review the merits of lattice models for the evaluation of finite-temperature thermodynamics and kinetics. With such a complete set of methods at hand, first principles calculations of ordered, crystalline solids, i.e., of most electrode materials and solid electrolytes, have become reliable and quantitative. However, the description of molecular materials and disordered or amorphous phases remains an important challenge. We highlight recent exciting progress in this area, especially regarding the modelling of organic electrolytes and solid-electrolyte interfaces
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