Lead-Free Perovskite Thin Films with Tailored Pockels-Kerr Effects for Photonics.

Pockels and Kerr effects are linear and nonlinear electro-optical effects, respectively, used in many applications. The modulation of the refractive index is employed in different photonic circuits. However, the greatest challenge is in photonic elements for quantum computing at room temperature.

Resolving hydrogen atoms at metal-metal hydride interfaces.

Hydrogen as a fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals, causing embrittlement. Understanding fundamental behavior of hydrogen at the atomic scale is key to improve the properties of metal-metal hydride systems.

Investigation of the Switching Mechanism in TiO2-Based RRAM: A Two-Dimensional EDX Approach.

The next generation of nonvolatile memory storage may well be based on resistive switching in metal oxides. TiO2 as transition metal oxide has been widely used as active layer for the fabrication of a variety of multistate memory nanostructure devices. However, progress in their technological development has been inhibited by the lack of a thorough understanding of the underlying switching mechanisms.

An in situ correlative STEM-EDS and HRTEM based nanoscale chemical characterization of solid-liquid interfaces in an aluminium alloy.

The chemistry and the structure of solid-liquid interface in an Al-Si based alloy during high temperature phase transformation were characterized at nanoscale using scanning Transmission Electron Microscopy-EDS and HRTEM. Such studies were until recently limited by large sample drift associated with conventional heating holders. This study was made possible thanks to the modern low-drift MEMS-chip based localized heating technology.

A MEMS-based heating holder for the direct imaging of simultaneous in-situ heating and biasing experiments in scanning/transmission electron microscopes.

The introduction of scanning/transmission electron microscopes (S/TEM) with sub-Angstrom resolution as well as fast and sensitive detection solutions support direct observation of dynamic phenomena in-situ at the atomic scale. Thereby, in-situ specimen holders play a crucial role: accurate control of the applied in-situ stimulus on the nanostructure combined with the overall system stability to assure atomic resolution are paramount for a successful in-situ S/TEM experiment. For those reasons, MEMS-based TEM sample holders are becoming one of the preferred choices, also enabling a high precision in measurements of the in-situ parameter for more reproducible data.

Steroid pretreatment of organ donors to prevent postischemic renal allograft failure: a randomized, controlled trial.

Background: Posttransplantation acute renal failure (ARF) occurs in roughly 25% of recipients of organs from deceased donors. Inflammation in the donor organ is associated with risk for ARF.

Objective: To determine whether administering corticosteroids to deceased organ donors reduces the incidence and duration of ARF in organ recipients more than placebo.

Calcineurin inhibitor-based immunosuppressive therapy, donor age, and long-term outcome after kidney transplantation.

Background: It is unclear whether the choice of maintenance immunosuppression modulates the negative effect of advanced donor age on outcome after renal transplantation.

Methods: All 1829 patients who received their first transplant between 1990 and 2003 at the Vienna Medical Centre and had a functioning graft after 90 days were studied. At this time point, 1587 received calcineurin inhibitors (CNI+), 242 did not (CNI-).

Statin use is associated with prolonged survival of renal transplant recipients.

The efficacy of statins for the prevention of cardiovascular events is well established in the general population but remains unknown in renal transplant recipients. In this study, the association of statin use with patient and graft survival was investigated in a cohort of 2041 first-time recipients of renal allografts between 1990 and 2003. Multivariable Cox regression demonstrated that statin use was independently associated with lower mortality rates.

Markers of cellular senescence in zero hour biopsies predict outcome in renal transplantation.

Although chronological donor age is the most potent predictor of long-term outcome after renal transplantation, it does not incorporate individual differences of the aging-process itself. We therefore hypothesized that an estimate of biological organ age as derived from markers of cellular senescence in zero hour biopsies would be of higher predictive value. Telomere length and mRNA expression levels of the cell cycle inhibitors CDKN2A (p16INK4a) and CDKN1A (p21WAF1) were assessed in pre-implantation biopsies of 54 patients and the association of these and various other clinical parameters with serum creatinine after 1 year was determined.

Bone disease after kidney transplantation.

Post-transplant renal osteopathy (ROP) remains a serious problem, which contributes to substantial long-term morbidity of the graft recipients. Bone loss is most pronounced during the first months after engraftment; concerning bone density development in long-term transplant recipients, controversial data exist. The clinical impact of ROP is a marked increase in fracture rate following kidney transplantation compared with both general population and patients on dialysis treatment.

ACE-inhibitor or AT2-antagonist therapy of renal transplant recipients is associated with an increase in serum potassium concentrations.

Background: Angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II type 1 receptor blockers (ARB) are frequently prescribed to renal transplant recipients with a reduced glomerular filtration rate (GFR). The aim of this study was to investigate the association of ACEI/ARB use and serum potassium levels in renal graft recipients.

Methods: We conducted an open cohort study of 2041 first renal allograft recipients, transplanted at the Medical University of Vienna between 1990 and 2003.

Gene-expression profiles and age of donor kidney biopsies obtained before transplantation distinguish medium term graft function.

Background: Donor factors such as age profoundly influence long-term graft function after cadaveric renal transplantation, but the molecular signature of these aspects in the allograft remains unknown.

Methods: We analyzed the genome-wide gene expression signature of donor kidney biopsies of different ages obtained before transplantation. Subsequent analysis compared expression profiles from allografts with excellent function versus impaired function at 1 yr after engraftment.

Room temperature synthesis of surface-functionalised boron nanoparticles.

Capped boron nanoparticles have been synthesized at room temperature by a simple route that does not involve the use of flammable boranes.

Age and sex are sufficient for predicting fractures occurring within 1 year of hemodialysis treatment.

Background: The incidence of fractures averages 20 per 1000 hemodialysis patient years at risk. This study sought to design and evaluate the utility of a simple prediction rule for fractures in dialysis patients using only standard demographical and biochemical information.

Methods: 1777 prevalent hemodialysis patients of the Austrian dialysis and transplant database who had an evaluation of fractures in 2004 and 2005 were included into analysis.

Effects of bisphosphonates on bone loss in the first year after renal transplantation--a meta-analysis of randomized controlled trials.

Background: Bone loss remains a serious problem after kidney transplantation and is most pronounced during the first months after engraftment. Bisphosphonates are frequently used to treat post-transplant osteodystrophy, but data of large randomized controlled trials (RCTs) are missing.

Methods: We, therefore, conducted this systematic review of the literature, searching electronic databases, reference lists and abstracts from scientific meetings to identify RCTs in all languages.

Electron-irradiation damage in chromium nitrides and chromium oxynitride thin films.

The aim of this work is to monitor changes of the N-K electron energy-loss near-edge structure (ELNES) of chromium nitride layers (CrN) introduced by electron irradiation in a transmission electron microscope (TEM). These changes are different for each sample material and seem to give an indication for a particular composition. The CrN samples (CrN and Cr(0.

Angiotensin-converting enzyme inhibitor or angiotensin II type 1 receptor antagonist therapy is associated with prolonged patient and graft survival after renal transplantation.

Angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II type 1 receptor blockers (ARB) reduce cardiovascular death in the general population, but data for renal transplant recipients remain elusive. Similarly, ACEI/ARB have been shown to reduce proteinuria, but data on graft survival are lacking. Therefore a retrospective open cohort study was conducted of 2031 patients who received their first renal allograft at the Medical University of Vienna between 1990 and 2003 and survived at least 3 mo.

Transcriptional response in the unaffected kidney after contralateral hydronephrosis or nephrectomy.

Background: Unilateral loss of kidney function is followed by compensatory contralateral growth. The early, genome-wide transcriptional response of the untouched kidney to unilateral ureteral obstruction (UUO) or unilateral nephrectomy is unknown.

Methods: Twelve adult male Sprague-Dawley rats were subjected to UUO and twelve rats to unilateral nephrectomy.

Cross-section analysis of organic light-emitting diodes.

The 'lift-out' technique using a focused ion beam microscope was applied to prepare cross-sectional specimens of organic light-emitting diodes for use in transmission electron microscopy. The focused ion beam equally thins the organic/inorganic hybrid devices despite the difference in material hardness of the compounds. This allowed to overcome preparation difficulties of conventional techniques such as ion thinning or ultra-microtomy.

Alterations in gene expression in cadaveric vs. live donor kidneys suggest impaired tubular counterbalance of oxidative stress at implantation.

Recipients of live donor transplant kidneys (LIV) exhibit a significantly longer allograft half-life compared with cadaveric donor organs (CADs). The reasons are incompletely understood. Therefore this study sought to elucidate the genome-wide gene expression profiles in microdissected transplant kidney biopsies obtained from five cadaveric and five matched live donors before transplantation.

Health-related quality of life outcomes after kidney transplantation.

With the improvements in short and long term graft and patient survival after renal transplantation over the last two decades Health-Related Quality of Life (HRQL) is becoming an important additional outcome parameter. Global and disease specific instruments are available to evaluate objective and subjective QOL. Among the most popular global tools is the SF-36, examples of disease specific instruments are the Kidney Transplant Questionnaire (KTQ), the Kidney Disease Questionnaire (KDQ) and the Kidney Disease-Quality of Life (KDQOL).

Genome-wide gene-expression patterns of donor kidney biopsies distinguish primary allograft function.

Roughly 25% of cadaveric, but rarely living donor renal transplant recipients, develop postischemic acute renal failure, which is a main risk factor for reduced long-term allograft survival. An accurate prediction of recipients at risk for ARF is not possible on the basis of donor kidney morphology or donor/recipient demographics. We determined the genome-wide gene-expression pattern using cDNA microarrays in three groups of 36 donor kidney wedge biopsies: living donor kidneys with primary function, cadaveric donor kidneys with primary function and cadaveric donor kidneys with biopsy proven acute renal failure.

Nonsustained effect of short-term bisphosphonate therapy on bone turnover three years after renal transplantation.

Background: We recently showed that two doses of 4 mg of zoledronic acid (ZOL) ameliorated the bone loss and improved bone histology within the first six months after kidney transplantation. The aim of the present study was to evaluate whether this early short-term intervention exhibited a sustained bone-sparing effect.

Methods: A homogenous group of 20 de novo renal transplant recipients were equally randomized to two infusions of 4 mg of ZOL or placebo at two weeks and three months after engraftment.

Impaired tubulointerstitial expression of endothelin-1 and nitric oxide isoforms in donor kidney biopsies with postischemic acute renal failure.

Background: About 30% of cadaveric renal allografts, but almost never living-donor kidneys, develop postischemic acute renal-transplant failure (ARF). We therefore quantified the expression of essential reperfusion regulators in different compartments of cadaveric and living-donor kidney biopsies.

Methods: Specimens were obtained from donor kidneys at the end of the cold ischemia time before implantation and categorized into three groups according to donor source and early posttransplant function.

Flow monitoring: performance characteristics of ultrasound dilution versus color Doppler ultrasound compared with fistulography.

Background: Measurement of access blood flow is the preferred noninvasive screening test for hemodialysis arteriovenous (AV) fistula stenosis. However, performance characteristics of the 2 most frequently used ultrasound techniques compared with fistulography remain elusive.

Methods: We evaluated 59 hemodialysis patients with native forearm AV fistulae who underwent all 3 measurements in a prospective order: the ultrasound dilution technique (UDT), color Doppler ultrasonography (CDUS), and fistulography.