Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures

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

A real-space, rela-time method for the dielectric function

We present an algorithm to calculate the linear response of periodic systems in the time-dependent density functional thoery, using a real-space representation of the electron wave functions and calculating the dynamics in real time. The real-space formulation increases the efficiency for calculating the interaction, and the real-time treatment decreases storage requirements and the allows the entire frequency-dependent response to be calculated at once. We give as examples the dielectric functions of a simple metal, lithium, and an elemental insulator, diamond.Comment: 17 pages, Latex, 5 figure

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

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

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

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 $f_{xc}$. We show that the spatial non-locality of $f_{xc}$ 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

Learning object relationships which determine the outcome of actions

Peer reviewedPublisher PD

Cigarette smoking is associated with higher thyroid hormone and lower TSH levels:The PREVEND study

PURPOSE: The extent to which smoking is associated with thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) when taking account of clinical variables including alcohol consumption is unclear. We aimed to determine associations of TSH, FT4, and FT3 levels with current smoking. METHODS: A cross-sectional study was performed in 5766 euthyroid participants (Prevention of Renal and Vascular End-Stage Disease cohort). Current smoking was determined by self-report, categorized as never, former, and current (≤20 and >20 cigarettes per day). Smoke exposure was determined by urinary cotinine. RESULTS: Current smoking of ≤20 and >20 cigarettes per day was associated with lower TSH and higher FT3 levels. FT4 levels were higher in subjects smoking 20 cigarettes per day. In agreement, TSH was inversely, whereas FT4 and FT3 levels were positively associated with urinary cotinine (P 30 g per day conferred higher TSH and lower FT3 levels. CONCLUSIONS: Cigarette smoking is associated with modestly higher FT4 and FT3, and lower TSH levels, partly opposing effects of alcohol consumption

Exchange-correlation kernels for excited states in solids

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

Current-Density Functional Theory of the Response of Solids

The response of an extended periodic system to a homogeneous field (of wave-vector $q=0$) cannot be obtained from a $q=0$ time-dependent density functional theory (TDDFT) calculation, because the Runge-Gross theorem does not apply. Time-dependent {\em current}-density functional theory is needed and demonstrates that one key ingredient missing from TDDFT is the macroscopic current. In the low-frequency limit, in certain cases, density polarization functional theory is recovered and a formally exact expression for the polarization functional is given.Comment: 5 pages, accepted in PR

The relationship of peritubular capillary density with glomerular volume and kidney function in living kidney donors

Background: Peritubular capillary rarefaction plays an important role in the progression of chronic kidney disease. Little is known about the relation between peritubular capillary density, glomerular volume and filtration rate in the healthy kidney. Methods: In this single-center study, we included 69 living kidney donors who donated between 2005 and 2008 and had representative renal biopsies available. In all donors, glomerular filtration rate was measured using 125I-Iothalamate before donation and at five years after donation. Before donation, the increase in glomerular filtration rate after dopamine stimulation was measured. Glomerular volume and peritubular capillary density were determined in biopsies taken at the time of transplantation. Pearson’s correlation coefficient and linear regression were used to assess relations between parameters.Results: Mean donor age was 52 ± 11 years and mean measured glomerular filtration rate was 119 ± 22 mL/min before donation and 82 ± 15 mL/min at five years after donation. While peritubular capillary density (measured by either number of peritubular capillaries/50,000 μm2 or number of peritubular capillaries/tubule) was not associated with measured glomerular filtration rate before or after donation, number of peritubular capillaries/tubule was associated with the increase in measured glomerular filtration rate after dopamine stimulation (St.β = 0.33, p = 0.004), and correlated positively with glomerular volume (R = 0.24, p = 0.047). Glomerular volume was associated with unstimulated measured glomerular filtration rate before donation (St.β = 0.31, p = 0.01) and at five years (St.β = 0.30, p = 0.01) after donation, independent of age.Conclusions: In summary, peritubular capillary density was not related to unstimulated kidney function before or after kidney donation, in contrast to glomerular volume. However, number of peritubular capillaries/tubule correlated with the increase in glomerular filtration rate after dopamine stimulation in healthy kidneys, and with glomerular volume. These findings suggest that peritubular capillary density and glomerular volume differentially affect kidney function in healthy living kidney donors. Graphical abstract: [Figure not available: see fulltext.]</p