710 research outputs found

    Enhancing cycling durability of Li-ion batteries with hierarchical structured silicon–graphene hybrid anodes

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    Hybrid anode materials consisting of micro-sized silicon (Si) particles interconnected with few-layer graphene (FLG) nanoplatelets and sodium-neutralized poly(acrylic acid) as a binder were evaluated for Li-ion batteries. The hybrid film has demonstrated a reversible discharge capacity of ∼1800 mA h g−1 with a capacity retention of 97% after 200 cycles. The superior electrochemical properties of the hybrid anodes are attributed to a durable, hierarchical conductive network formed between Si particles and the multi-scale carbon additives, with enhanced cohesion by the functional polymer binder. Furthermore, improved solid electrolyte interphase (SEI) stability is achieved from the electrolyte additives, due to the formation of a kinetically stable film on the surface of the Si

    Hospitalisations from one to six years of age: Effects of Gestational Age and Severe Neonatal Morbidity

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    Background: To investigate whether the adverse infant health outcomes associated with early birth and severe neonatal morbidity (SNM) persist beyond the first year of life and impact on paediatric hospitalisations for children up to six years of age. Methods: The study population included all singleton live births, >32 weeks gestation in New South Wales, Australia in 2001-2005, with follow-up to six years of age. Birth data were probabilistically linked to hospitalisation data (n=392,964). The odds of hospitalisation, mean hospital length of stay (LOS) and costs, and cumulative LOS were evaluated by gestational age and SNM using multivariable analyses. Results: A total of 74,341 (18.9%) and 41,404 (10.5%) infants were hospitalized once and more than once, respectively. SNM was associated with increased odds of hospitalisation once (adjusted odds ratio (aOR) 1.16 [95% CI 1.10, 1.22]), and more than once (aOR 1.51 [1.42, 1.60]). Decreasing gestational age was associated with increasing odds of hospitalisation more than once from aOR 1.19 at 37-38 weeks to 1.49 at 33-34 weeks. Average LOS and costs per hospital admission were increased with SNM but not with decreasing gestational age. Cumulative LOS was significantly increased with SNM and decreasing gestational age. Conclusions: Adverse effects of SNM and early birth persist between one and six years of age. Strategies to prevent early birth and reduce SNM, and to increase health monitoring of vulnerable infants throughout childhood may help reduce paediatric hospitalisations.NHMRC, NSW Health Population Health and Health Services Gran

    Prosthetic heart valves in pregnancy, outcomes for women and their babies: A systematic review and meta-analysis

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    Background Historically, pregnancies among women with prosthetic heart valves have been associated with an increased incidence of adverse outcomes. While there have been advances in prosthetic heart valve design, obstetric and medical care, subsequent impact on incidence of adverse outcomes during pregnancy has not been quantified. Objectives To assess the risk of adverse pregnancy outcomes among women with a prosthetic heart valve(s) in the contemporary setting. Search Strategy Electronic literature search of Medline, The Cochrane Library, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and Embase to find recent studies. Selection Criteria Studies of pregnant women with heart valve prostheses including trials, cohort studies and unselected case series. Data Collection and Analysis Absolute risks and 95% confidence intervals for pregnancy outcomes were calculated using either a random effects model or the logit transformation of total events and participants (the latter method when multiple studies had event counts of zero). Main Results Eleven studies capturing 499 pregnancies among women with heart valve prostheses were eligible for inclusion. Pooled maternal mortality rate was 0.8/100 pregnancies (95% CI 0.3-2.1), pregnancy loss rate 32.1/100 pregnancies (95% CI 28.1-36.3) and perinatal mortality rate 4.7/100 births (95% CI 2.7-7.9). Conclusions Women with heart valve prostheses experienced higher rates of adverse outcomes then would be expected in a general obstetric population, however lower than previously reported. Multidisciplinary pre-pregnancy counselling and vigilant cardiac and obstetric surveillance throughout the perinatal period remains warranted for these women and their infantsNHMRC 1001066, NHMRC 1021025, NHMRC 1062262, ARC FT120100069 and Australian Heart Foundatio

    Configuration interaction wave functions: A seniority number approach

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    This work deals with the configuration interaction method when an N-electron Hamiltonian is projected on Slater determinants which are classified according to their seniority number values. We study the spin features of the wave functions and the size of the matrices required to formulate states of any spin symmetry within this treatment. Correlation energies associated with the wave functions arising from the seniority-based configuration interaction procedure are determined for three types of molecular orbital basis: canonical molecular orbitals, natural orbitals, and the orbitals resulting from minimizing the expectation value of the N-electron seniority number operator. The performance of these bases is analyzed by means of numerical results obtained from selected N-electron systems of several spin symmetries. The comparison of the results highlights the efficiency of the molecular orbital basis which minimizes the mean value of the seniority number for a state, yielding energy values closer to those provided by the full configuration interaction procedure.Fil: Alcoba, Diego Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Torre, Alicia. Universidad del Pais Vasco; EspañaFil: Lain, Luis . Universidad del Pais Vasco; EspañaFil: Massaccesi, Gustavo Ernesto. Universidad de Buenos Aires. Ciclo Básico Común; ArgentinaFil: Oña, Ofelia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
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