824 research outputs found

    Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures

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    Obtaining high-quality thin films of 5d transition metal oxides is essential to explore the exotic semimetallic and topological phases predicted to arise from the combination of strong electron correlations and spin-orbit coupling. Here, we show that the transport properties of SrIrO3 thin films, grown by pulsed laser deposition, can be optimized by considering the effect of laser-induced modification of the SrIrO3 target surface. We further demonstrate that bare SrIrO3 thin films are subject to degradation in air and are highly sensitive to lithographic processing. A crystalline SrTiO3 cap layer deposited in-situ is effective in preserving the film quality, allowing us to measure metallic transport behavior in films with thicknesses down to 4 unit cells. In addition, the SrTiO3 encapsulation enables the fabrication of devices such as Hall bars without altering the film properties, allowing precise (magneto)transport measurements on micro- and nanoscale devices.Comment: 5 pages, 3 figure

    Many-body diagrammatic expansion in a Kohn-Sham basis: implications for Time-Dependent Density Functional Theory of excited states

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    We formulate diagrammatic rules for many-body perturbation theory which uses Kohn-Sham (KS) Green's functions as basic propagators. The diagram technique allows to study the properties of the dynamic nonlocal exchange-correlation (xc) kernel fxcf_{xc}. We show that the spatial non-locality of fxcf_{xc} is strongly frequency-dependent. In particular, in extended systems the non-locality range diverges at the excitation energies. This divergency is related to the discontinuity of the xc potential.Comment: 4 RevTeX pages including 3 eps figures, submitted to Phys. Rev. Lett; revised version with new reference

    Kidney Function in Patients With Neuromuscular Disease:Creatinine Versus Cystatin C

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    Background: Accurate measurement of kidney function in patients with neuromuscular disorders is challenging. Cystatin C, a marker not influenced by skeletal muscle degradation, might be of clinical value in these patients.Methods: We consecutively enrolled 39 patients with neuromuscular disorders. We investigated the association of the eGFR, based on plasma creatinine and Cystatin C, with clinical and biochemical variables associated with kidney function, namely age and galectin-3.Results: Creatinine-based eGFR was 242 (±80) and Cystatin C-based eGFR was 110 (±23) mL/min/1.73 m2. Cystatin C-based eGFR was associated with age (β −0.63 p < 0.0001) and galectin-3 levels (β −0.43 p < 0.01), while creatinine-based eGFR was not (β −0.22 p = 0.20; β −0.28 p = 0.10). Sensitivity analyses in Duchenne and Becker patients revealed the same results: Cystatin C-based eGFR was associated with age (β −0.61 p < 0.01) and galectin-3 levels (β −0.43 p = 0.05), while creatinine-based eGFR was not (β −0.32 p = 0.13; β −0.34 p = 0.14).Conclusions: These data indicate that estimation of renal function in patients with neuromuscular disorders cannot reliably be achieved with creatinine, while Cystatin C appears a reasonable alternative. Since a large proportion of patients with neuromuscular disorders develops heart failure, and requires heart failure medication, adequate monitoring of renal function is warranted

    Exchange-correlation kernels for excited states in solids

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    The performance of several common approximations for the exchange-correlation kernel within time-dependent density-functional theory is tested for elementary excitations in the homogeneous electron gas. Although the adiabatic local-density approximation gives a reasonably good account of the plasmon dispersion, systematic errors are pointed out and traced to the neglect of the wavevector dependence. Kernels optimized for atoms are found to perform poorly in extended systems due to an incorrect behavior in the long-wavelength limit, leading to quantitative deviations that significantly exceed the experimental error bars for the plasmon dispersion in the alkali metals.Comment: 7 pages including 5 figures, RevTe

    Heretability and Correlation of Vegetative and Generative Character on Genotypes of Jatropha (Jatropha curcas Linn.)

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    AbstractThis study was aimed to obtain information of heritability predictive value and correlations of vegetative and generative characters on six genotypes of J. curcas. The characters of plant height, leaf number, leaf width, number of primary and secondary branches, number of fruit bunches, number of fruits per plant, seed's and 100 seeds’ dry weight showed high predictive value of heritability. Characters related to positive correlation and high heritability values (leaf width, number of primary branches, number of secondary branches, number of fruit bunches, number of fruits per plant) are able to be used as criteria for selection of J. curcas plant

    ADAR1 Facilitates HIV-1 Replication in Primary CD4+ T Cells.

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    Unlike resting CD4+ T cells, activated CD4+T cells are highly susceptible to infection of human immunodeficiency virus 1 (HIV-1). HIV-1 infects T cells and macrophages without activating the nucleic acid sensors and the anti-viral type I interferon response. Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA editing enzyme that displays antiviral activity against several RNA viruses. Mutations in ADAR1 cause the autoimmune disorder Aicardi-Goutieères syndrome (AGS). This disease is characterized by an inappropriate activation of the interferon-stimulated gene response. Here we show that HIV-1 replication, in ADAR1-deficient CD4+T lymphocytes from AGS patients, is blocked at the level of protein translation. Furthermore, viral protein synthesis block is accompanied by an activation of interferon-stimulated genes. RNA silencing of ADAR1 in Jurkat cells also inhibited HIV-1 protein synthesis. Our data support that HIV-1 requires ADAR1 for efficient replication in human CD4+T cells

    Folate reference interval estimation in the Dutch general population

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    Background: Folate functions as an enzyme co-factor within the one-carbon metabolic pathway, providing key metabolites required for DNA synthesis and methylation. Hence, insufficient intake of folate can negatively affect health. As correct interpretation of folate status is dependent on a well-established reference interval, we set out to perform a new estimation following the restandardization of the Roche folate assay against the international folate standard. Materials and methods: The folate reference interval was estimated using samples obtained from the Dutch population-based Lifelines cohort. The reference interval was estimated using two methods: a nonparametric estimation combined with bootstrap resampling and by fitting the data to a gamma distribution. The lower reference limit was verified in a patient cohort by combined measurement of folate and homocysteine. Results: Dependent on the method used for estimation and in- or exclusion of individuals younger than 21 years of age, the lower reference limit ranged from 6.8 to 7.3 nmol/L and the upper reference limit ranged from 26 to 38.5 nmol/L. Applying a lower reference limit of 7.3 nmol/L resulted in the following percentage of folate deficiencies over a period of 12 months: general practitioner 15.5% (IQR 4.0%), general hospital 12.8% (IQR 5.3%), academic hospital 9.6% (IQR 4.3%). Conclusions: We estimated the folate reference interval in the Dutch general population which is not affected by a folic acid fortification program and verified the obtained lower reference limit by homocysteine measurements. Based on our results, we propose a folate reference interval independent of age of 7.3-38.5 nmol/
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