Hysteretic behaviour in a vacuum deposited submonolayer of single ion magnets.

With element-specific X-ray absorption spectroscopy and X-ray magnetic circular dichroism we have investigated submonolayer coverages of TbPc2 and DyPc2 molecules sublimated on highly ordered pyrolytic graphite. We have studied the field dependence of the magnetization of the central lanthanide ion at very low temperatures. Even in zero applied magnetic field we still observe a remanence in the magnetization.

[Dialysis and ultrafiltration therapy in patients with cardio-renal syndrome: recommendations of the working group "heart-kidney" of the German Cardiac Society and the German Society of Nephrology].

Renal failure is common in patients with severe heart failure. This complex pathophysiological interaction has been classified as cardio-renal syndrome. In these patients hydropic decompensation is the main cause of hospitalization.

Electric in-plane polarization in multiferroic CoFe₂O₄/BaTiO₃ nanocomposite tuned by magnetic fields.

Ferrimagnetic CoFe2O4 nanopillars embedded in a ferroelectric BaTiO3 matrix are an example for a two-phase magnetoelectrically coupled system. They operate at room temperature and are free of any resource-critical rare-earth element, which makes them interesting for potential applications. Prior studies succeeded in showing strain-mediated coupling between the two subsystems.

Antiferromagnetic coupling of TbPc2 molecules to ultrathin Ni and Co films.

The magnetic and electronic properties of single-molecule magnets are studied by X-ray absorption spectroscopy and X-ray magnetic circular dichroism. We study the magnetic coupling of ultrathin Co and Ni films that are epitaxially grown onto a Cu(100) substrate, to an in situ deposited submonolayer of TbPc2 molecules. Because of the element specificity of the X-ray absorption spectroscopy we are able to individually determine the field dependence of the magnetization of the Tb ions and the Ni or Co film.

A guideline for atomistic design and understanding of ultrahard nanomagnets.

Magnetic nanoparticles are of immense current interest because of their possible use in biomedical and technological applications. Here we demonstrate that the large magnetic anisotropy of FePt nanoparticles can be significantly modified by surface design. We employ X-ray absorption spectroscopy offering an element-specific approach to magnetocrystalline anisotropy and the orbital magnetism.

Forcing ferromagnetic coupling between rare-earth-metal and 3d ferromagnetic films.

Using density functional calculations, we have studied the magnetic properties of nanocomposites composed of rare-earth-metal elements in contact with 3d transition metals (Fe and Cr). We demonstrate the possibility to obtain huge magnetic moments in such nanocomposites, of order 10mu(B)/rare-earth-metal atom, with a potential to reach the maximum magnetic moment of Fe-Co alloys at the top of the so-called Slater-Pauling curve. A first experimental proof of concept is given by thin-film synthesis of Fe/Gd and Fe/Cr/Gd nanocomposites, in combination with x-ray magnetic circular dichroism.

Endoscopic transluminal insertion of a peritoneal dialysis catheter.

Background: At present there are various more or less invasive surgical and laparoscopic ways to place a catheter suitable for peritoneal dialysis (PD); however, once the catheter is in place, there is no possibility to inspect the peritoneal cavity without de novo laparotomy or laparoscopy.

Patients And Methods: To establish a minimally invasive technique and allowing for maximal options, we used a PD catheter with an extra large inside diameter of 3.5 mm.

Epidemiology of atherosclerotic renal artery stenosis as a mirror of prospective trials.

Diagnosis and treatment of atherosclerotic renal artery stenosis (ARAS) in the elderly is a never-ending challenge for every nephrologist. Kalra et al. report that adjusted hazard ratios for ARAS increased threefold from 1992 to 2004 in 16 million United States Renal Data System participants aged 66 years or older.

Leflunomide therapy for polyomavirus-induced allograft nephropathy: efficient BK virus elimination without increased risk of rejection.

Background: Optimal treatment of polyomavirus-induced allograft nephropathy (PVAN) with immunosuppressive and antiviral therapy is uncertain at present. Reduced immunosuppression is accompanied by increased risk of rejection, and antiviral agents are nephrotoxic. Leflunomide has immunosuppressive and antiviral properties and may be an alternative treatment agent.

Tailoring the nature of magnetic coupling of Fe-porphyrin molecules to ferromagnetic substrates.

We demonstrate that an antiferromagnetic coupling between paramagnetic Fe-porphyrin molecules and ultrathin Co and Ni magnetic films on Cu(100) substrates can be established by an intermediate layer of atomic oxygen. The coupling energies have been determined from the temperature dependence of x-ray magnetic circular dichroism measurements. By density functional theory+U calculations the coupling mechanism is shown to be superexchange between the Fe center of the molecules and Co surface-atoms, mediated by oxygen.

Color Doppler indices of renal allografts depend on vascular stiffness of the transplant recipients.

A resistance index (RI) of 0.8 or higher was shown to be a strong predictor of kidney allograft and patient survival. Uncertainties persist since the intrarenal RI is closely associated with the vascular stiffness of the allograft recipient.

Imaging of renal artery stenosis.

Renal artery stenosis is the cause of progressive ischemic nephropathy and of renovascular hypertension. Due to the invasiveness of arteriography, which is claimed to be the gold standard at the present time, several noninvasive imaging techniques are available. Colour Doppler sonography is cost-effective, but magnetic resonance angiography and computer tomography are more expensive; however, both are potential candidates for the definition of a new gold standard.

Atherosclerotic renal artery stenosis and reconstruction.

Renal artery stenosis is common especially in patients with generalized atherosclerosis. It is frequently associated with difficult-to-treat hypertension and with renal failure. There is an ongoing debate about the appropriate screening and treatment of atherosclerotic renal artery stenosis.

Renal Doppler sonography--update in clinical nephrology.

These days renal Doppler sonography has been established as a diagnostic tool of the daily nephrological work-up. Extra- and intrarenal flow signals are obtained for different indications. The intrarenal resistive index is the best examined parameter in the literature.

Impact of in vivo complement activation and cryoglobulins on graft outcome of HCV-infected renal allograft recipients.

Background: Chronic hepatitis C virus (HCV) infection is closely associated with mixed cryoglobulinemia. Cryoglobulins can activate complement leading to vascular damage. We examined whether cryoglobulinemia and complement turnover is associated with HCV infection in renal transplant recipients and whether this has an adverse effect on graft outcome.

Reduction of hypotensive side effects during online-haemodiafiltration and low temperature haemodialysis.

Background: This study compares the effect of online-haemodiafiltration (o-HDF, post-dilution mode) with conventional haemodialysis (HD) and 'temperature-controlled' HD (Temp-HD) on the haemodynamic stability of hypotension-prone patients.

Methods: Seventeen patients with a history of frequent hypotensive episodes during dialysis sessions were studied, each patient serving as his or her own control. The first 25 HD treatments in comparison with 25 o-HDF sessions were evaluated using identical dialysate temperature.

Urinary tetrahydroaldosterone as a screening method for primary aldosteronism: a comparative study.

Background: The major aldosterone metabolite 3 alpha,5 beta tetrahydroaldosterone reflects up to 45% of the aldosterone secretion. Its 24-h urinary excretion is likely to provide an accurate index of the daily aldosterone production and to be an indicator for primary aldosteronism (PA).

Methods: In a prospective study, the validity of tetrahydroaldosterone as a screening test for PA was evaluated in comparison to serum potassium, plasma aldosterone, plasma renin activity, plasma aldosterone/renin activity ratio (PARR), as well as 24-h urinary aldosterone-18-glucuronide and free aldosterone.

Careful clinical monitoring in comparison to sequential Doppler sonography for the detection of acute rejection in the early phase after renal transplantation.

Acute rejection is the most frequent cause of early graft failure. There is unanimity that Doppler sonography is a helpful method for the detection of complications after kidney transplantation. In the past, the indication for renal biopsy relied mainly on clinical assessment, although this assessment has not been standardised.