Long-Term Excessive Dietary Phosphate Intake Increases Arterial Blood Pressure, Activates the Renin-Angiotensin-Aldosterone System, and Stimulates Sympathetic Tone in Mice.

Increased dietary phosphate intake has been associated with severity of coronary artery disease, increased carotid intima-media thickness, left ventricular hypertrophy (LVH), and increased cardiovascular mortality and morbidity in individuals with normal renal function as well as in patients suffering from chronic kidney disease. However, the underlying mechanisms are still unclear. To further elucidate the cardiovascular sequelae of long-term elevated phosphate intake, we maintained male C57BL/6 mice on a calcium, phosphate, and lactose-enriched diet (CPD, 2% Ca, 1.25% P, 20% lactose) after weaning them for 14 months and compared them with age-matched male mice fed a normal mouse diet (ND, 1.0% Ca, 0.7% P). Notably, the CPD has a balanced calcium/phosphate ratio, allowing the effects of elevated dietary phosphate intake largely independent of changes in parathyroid hormone (PTH) to be investigated. In agreement with the rationale of this experiment, mice maintained on CPD for 14 months were characterized by unchanged serum PTH but showed elevated concentrations of circulating intact fibroblast growth factor-23 (FGF23) compared with mice on ND. Cardiovascular phenotyping did not provide evidence for LVH, as evidenced by unchanged LV chamber size, normal cardiomyocyte area, lack of fibrosis, and unchanged molecular markers of hypertrophy (Bnp) between the two groups. However, intra-arterial catheterization revealed increases in systolic pressure, mean arterial pressure, and pulse pressure in mice fed the CPD. Interestingly, chronically elevated dietary phosphate intake stimulated the renin-angiotensin-aldosterone system (RAAS) as evidenced by increased urinary aldosterone in animals fed the CPD, relative to the ND controls. Furthermore, the catecholamines epinephrine, norepinephrine, and dopamine as well as the catecholamine metabolites metanephrine. normetanephrine and methoxytyramine as measured by mass spectrometry were elevated in the urine of mice on CPD, relative to mice on the ND. These changes were partially reversed by switching 14-month-old mice on CPD back to ND for 2 weeks. In conclusion, our data suggest that excess dietary phosphate induces a rise in blood pressure independent of secondary hyperparathyroidism, and that this effect may be mediated through activation of the RAAS and stimulation of the sympathetic tone

Implanting Germanium into Graphene

Incorporating heteroatoms into the graphene lattice may be used to tailor its electronic, mechanical and chemical properties, although directly observed substitutions have thus far been limited to incidental Si impurities and P, N and B dopants introduced using low-energy ion implantation. We present here the heaviest impurity to date, namely 74Ge+ ions implanted into monolayer graphene. Although sample contamination remains an issue, atomic resolution scanning transmission electron microscopy imaging and quantitative image simulations show that Ge can either directly substitute single atoms, bonding to three carbon neighbors in a buckled out-of-plane configuration, or occupy an in-plane position in a divacancy. First-principles molecular dynamics provides further atomistic insight into the implantation process, revealing a strong chemical effect that enables implantation below the graphene displacement threshold energy. Our results demonstrate that heavy atoms can be implanted into the graphene lattice, pointing a way toward advanced applications such as single-atom catalysis with graphene as the template.Copyright © 2018 American Chemical Societ

HZDR Multiphase Addon for OpenFOAM

The HZDR Multiphase Addon is a software publication released by Helmholtz-Zentrum Dresden-Rossendorf according to the FAIR principles (Findability, Accessibility, Interoperability, and Reuseability). It contains experimental research work for the open-source CFD software OpenFOAM, released by The OpenFOAM Foundation. The developments are dedicated to the numerical simulation of multiphase flows, in particular to the multi-field two-fluid model (Euler-Euler method). Within the OpenFOAM library the multiphaseEulerFoam framework is used for this type of simulation. The addon contains a modified solver named HZDRmultiphaseEulerFoam with the full support of the HZDR baseline model set for polydisperse bubbly flows. In addition a solver dedicated to a hybrid modelling approach (dispersed and resolved interfaces, Meller, Schlegel and Lucas, 2021) named cipsaMultiphaseEulerFoam is provided with the addon. This solver has an interface to the multiphaseEulerFoam framework and utilizes all available interfacial models of it. General enhancements modified turbulent wall functions of Menter according to Rzehak and Kriebitzsch (2015) dynamic time step adjustment via PID controller HZDRmultiphaseEulerFoam bubble induced turbulence model of Ma et al. (2017) drag model of Ishii and Zuber (1979) without correction for swarm and/or viscous effects wall lubrication model of Hosokawa et al. (2002) additional breakup and coalescence models for class method according to Kusters (1991) and Adachi et al. (1994) degassing boundary condition (fvModel) lift force correlation of Hessenkemper et al. (2021) lift force correlation of Saffman (1965) as extended by Mei (1992). aspect ratio correlation of Ziegenhein and Lucas (2017) real pressure treatment via explicit turbulent normal stress according to Rzehak et al. (2021) GPU-based accelerated computation of coalescence and breakup frequencies for the models of Lehr et al. (2002) (Petelin et al., 2021) configuration files and tutorials for easy setup of baseline cases according to Hänsch et al. (2021) cipsaMultiphaseEulerFoam morphology adaptive modelling framework for predicting dispersed and resolved interfaces based on Eulerian multi-field two-fluid model compact momentum interpolation method according to Cubero et al. (2014), including virtual mass numerical drag according to Strubelj and Tiselj (2011) to describe resolved interfaces in a volume-of-fluid like manner n-phase partial elimination algorithm for momentum equations to resolve strong phase coupling (Meller, Schlegel and Lucas, 2021) free surface turbulence damping (Frederix et al., 2018) for k-ω SST - symmetric and asymmetric - according to Tekavčič et al. (2021) sub-grid scale modelling framework (Meller, Schlegel and Klein, 2021) additional LES models for the unclosed convective sub-grid scale term closure models for sub-grid surface tension term configuration files and tutorials for easy setup of hybrid case

HZDR Multiphase Addon for OpenFOAM

The HZDR multiphase addon contains additional code for the open-source CFD software OpenFOAM, released by The OpenFOAM Foundation. The developments are dedicated to the numerical simulation of multiphase flows, in particular to the multi-field two-fluid model (Euler-Euler method). Within the OpenFOAM library the multiphaseEulerFoam framework is used for this type of simulation. The addon contains a modified solver named HZDRmultiphaseEulerFoam with the full support of the HZDR baseline model set for polydisperse bubbly flows. In addition a solver dedicated to a hybrid modelling approach (dispersed and resolved interfaces, Meller, Schlegel and Lucas, 2021) named cipsaMultiphaseEulerFoam is provided with the addon. This solver has an interface to the multiphaseEulerFoam framework and utilizes all available interfacial models of it. General enhancements modified turbulent wall functions of Menter according to Rzehak and Kriebitzsch (2015) dynamic time step adjustment via PID controller HZDRmultiphaseEulerFoam bubble induced turbulence model of Ma et al. (2017) drag model of Ishii and Zuber (1979) without correction for swarm and/or viscous effects wall lubrication model of Hosokawa et al. (2002) additional breakup and coalescence models for class method according to Kusters (1991) and Adachi et al. (1994) degassing boundary condition (fvModel) lift force correlation of Hessenkemper et al. (2021) lift force correlation of Saffman (1965) as extended by Mei (1992). aspect ratio correlation of Ziegenhein and Lucas (2017) real pressure treatment via explicit turbulent normal stress according to Rzehak et al. (2021) GPU-based accelerated computation of coalescence and breakup frequencies for the models of Lehr et al. (2002) (Petelin et al., 2021) configuration files and tutorials for easy setup of baseline cases according to Hänsch et al. (2021) cipsaMultiphaseEulerFoam morphology adaptive modelling framework for predicting dispersed and resolved interfaces based on Eulerian multi-field two-fluid model compact momentum interpolation method according to Cubero et al. (2014), including virtual mass numerical drag according to Strubelj and Tiselj (2011) to describe resolved interfaces in a volume-of-fluid like manner n-phase partial elimination algorithm for momentum equations to resolve strong phase coupling (Meller, Schlegel and Lucas, 2021) free surface turbulence damping (Frederix et al., 2018) for k-ω SST - symmetric and asymmetric - according to Tekavčič et al. (2021) sub-grid scale modelling framework (Meller, Schlegel and Klein, 2021) additional LES models for the unclosed convective sub-grid scale term closure models for sub-grid surface tension term configuration files and tutorials for easy setup of hybrid case

HZDR Multiphase Addon for OpenFOAM

The HZDR Multiphase Addon is a software publication released by Helmholtz-Zentrum Dresden-Rossendorf according to the FAIR principles (Findability, Accessibility, Interoperability, and Reuseability). It contains experimental research work for the open-source CFD software OpenFOAM, released by The OpenFOAM Foundation. The developments are dedicated to the numerical simulation of multiphase flows, in particular to the multi-field two-fluid model (Euler-Euler method).Highlights of the provided addon are:HZDR Baseline Model: addonMultiphaseEulerFoam solver with full support of the HZDR baseline model set for polydisperse bubbly flows, including configuration files and tutorials for simplified setup of Baseline cases (Hänsch et al., 2021).Population Balance Modelling: A GPU-accelerated population balance method according to Petelin et al. (2021).Morphology-adaptive Multifield Two-fluid Model (MultiMorph): cipsaMultiphaseEulerFoam solver featuring a morphology-adaptive modelling approach (dispersed and resolved interfaces, Meller et al., 2021) with an interface to the multiphaseEulerFoam framework to utilise all available interfacial models, and configuration files and tutorials for easy setup of cases with the MultiMorph Model.more ..

Multiphase Code Repository by HZDR for OpenFOAM Foundation Software

The Multiphase Code Repository by HZDR for OpenFOAM Foundation Software is a software publication released by Helmholtz-Zentrum Dresden-Rossendorf according to the FAIR principles (Findability, Accessibility, Interoperability, and Reuseability). It contains experimental research work for the open-source software released by The OpenFOAM Foundation. The developments are dedicated to the numerical simulation of multiphase flows, in particular to the multi-field two-fluid model (Euler-Euler method).Acknowledgement: OpenFOAM(R) is a registered trade mark of OpenCFD Limited, producer and distributor of the OpenFOAM(R) software via www.openfoam.com. The Multiphase Code Repository by HZDR for OpenFOAM Foundation Software is not compatible with the software released by OpenCFD Limited, but is based on the software released by the OpenFOAM Foundation via www.openfoam.orgHighlights of the Multiphase Code Repository by HZDRHZDR Baseline Model: addonMultiphaseEuler solver with full support of the HZDR baseline model set for polydisperse bubbly flows, including configuration files and tutorials for simplified setup of Baseline cases (Hänsch et al., 2021).Population Balance Modelling: A GPU-accelerated population balance method according to Petelin et al. (2021).Morphology-adaptive Multifield Two-fluid Model (MultiMorph): cipsaMultiphaseEuler solver featuring a morphology-adaptive modelling approach (dispersed and resolved interfaces, Meller et al., 2021) with an interface to the multiphaseEuler framework to utilise all available interfacial models, and configuration files and tutorials for easy setup of cases with the MultiMorph Model.more ..