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Zirconium mononitride (ZrN), among other nitrides, is of interest as a catalyst in general and especially for the electrochemical nitrogen reduction reaction (NRR). Synthesis of nanoparticulate ZrN is challenging due to the formation of undesired other phases and the need for hazardous precursors or high temperatures. The urea glass method (UGM) was used in this work to synthesise nanoparticulate zirconium nitride. A focused parameter variation of the precursor composition and process conditions lead to an optimised synthesis, greatly improving material purity in regard to minor phase and residual carbon content. The nitride starts to form at a pyrolysis temperature of 900 °C, likely by irreversible decomposition of previously‐formed oxynitride, which forms from amorphous ZrO2 and urea during pyrolysis. An increased pyrolysis temperature improves product purity but slightly lowers nitride purity. Calcium admixture slows the urea decomposition, yielding a more phase‐pure product with less residual carbon at low amounts. A classical carbothermal nitridation (CN) was used in comparison to the UGM to synthesise ZrN. This was successful in synthesising zirconium carbonitride Zr(N, C) without minor phase, but significant carbon remains if added overstoichiometrically. Using less carbon and a longer dwelling time yielded ZrN without significant carbide (ZrC) incorporation or residual carbon, but with some minor ZrO2 phase, proving a promising synthesis route. A limited electrochemical investigation of a synthesised ZrN material was carried out to scope the general material behaviour and to qualitatively derive the potential catalytic activity for the NRR. Higher reductive currents in nitrogen‐saturated electrolyte qualitatively point to NRR activity, but further and more in‐depth examination is required. [ABSTRACT FROM AUTHOR]

Infants born to mothers with phenylketonuria (PKU) may develop congenital abnormalities because of elevated phenylalanine (Phe) levels in the mother during pregnancy. Maintenance of blood Phe levels between 120 and 360 μmol/L reduces risks of birth defects. Sapropterin dihydrochloride helps maintain blood Phe control, but there is limited evidence on its risk–benefit ratio when used during pregnancy. Data from the maternal sub‐registries—KAMPER (NCT01016392) and PKUDOS (NCT00778206; PKU‐MOMs sub‐registry)—were collected to assess the long‐term safety and efficacy of sapropterin in pregnant women in a real‐life setting. Pregnancy and infant outcomes, and the safety of sapropterin were assessed. Final data from 79 pregnancies in 57 women with PKU are reported. Sapropterin dose was fairly constant before and during pregnancy, with blood Phe levels maintained in the recommended target range during the majority (82%) of pregnancies. Most pregnancies were carried to term, and the majority of liveborn infants were reported as 'normal' at birth. Few adverse and serious adverse events were considered related to sapropterin, with these occurring in participants with high blood Phe levels. This report represents the largest population of pregnant women with PKU exposed to sapropterin. Results demonstrate that exposure to sapropterin during pregnancy was well‐tolerated and facilitated maintenance of blood Phe levels within the target range, resulting in normal delivery. This critical real‐world data may facilitate physicians and patients to make informed treatment decisions about using sapropterin in pregnant women with PKU and in women of childbearing age with PKU who are responsive to sapropterin. [ABSTRACT FROM AUTHOR]

Fe‐N‐C catalysts are a promising alternative to replace cost‐intensive Pt‐based catalysts in high temperature polymer electrolyte membrane fuel cell (HT‐PEMFC) electrodes. However, the electrode fabrication needs to be adapted for this new class of catalysts. In this study, gas diffusion electrodes (GDEs) are fabricated using a commercial Fe‐N‐C catalyst and different polytetrafluorethylene (PTFE) binder ratios, varying from 10 to 50 wt % in the catalyst layer (CL). The oxygen reduction reaction performance is investigated under HT‐PEMFC conditions (160 °C, conc. H3PO4 electrolyte) in a half‐cell setup. The acidophilic character of the Fe‐N‐C catalyst leads to intrusion of phosphoric acid electrolyte into the CL. The strength of the acid penetration depends on the PTFE content, which is visible via the contact angles. The 10 wt % PTFE GDE is less capable to withdraw product water and electrolyte and results into the lowest half‐cell performance. Higher PTFE contents counterbalance the acid drag into the CL and impede flooding. The power density at around 130 mA mgCatalyst−2 increases by 34 % from 10 to 50 wt % PTFE. [ABSTRACT FROM AUTHOR]

For renewable hydrogen production, polymer electrolyte membrane water electrolysis is the most promising technology. However, the technology is not yet competitive with conventional hydrogen production in terms of cost. The impact of cost reduction options on CAPEX and OPEX is investigated. Depending on the hours of operation, the main cost factor is the production and manufacturing of components or the price of electricity. Clearly a tremendous need to implement low‐cost electrolysis cells on a large scale to bring green hydrogen production costs to a level 1–3 € kg−1 hydrogen. [ABSTRACT FROM AUTHOR]

Platinum on graphitized low surface area carbon (Pt/C) is coated with a silicon oxide thin film and is employed as anode catalyst to manipulate the tolerance of proton exchange membrane fuel cells toward carbon monoxide and hydrogen sulfide contamination. The SiO2 coating, prepared by successive hydrolysis of 3‐aminopropyl‐triethoxisilane and tetraethoxysilane, forms clusters in proximity to Pt in sizes comparable to the catalyst particles, leaving most of the carbon surfaces free. The performance with and without CO is investigated in situ at relative humidities (RH) of 100%, 70%, and 40%. When operated with neat hydrogen, SiO2‐Pt/C shows marginally better performance owing to an improved protonic conduction due to the water retaining hydrophilic SiO2. Upon operation with CO‐contaminated fuel, the SiO2‐Pt/C performs worse than that of Pt/C particularly at high RH. CO stripping measurements reveal an increase in CO oxidation potential for the SiO2‐Pt/C, suggesting an increased CO coverage and consequently higher anode overpotentials during operation with CO‐contaminated fuel. Upon operation with H2S in the fuel, the SiO2 coating extends the lifetime until the cell voltage broke down, which is attributed to the enhanced water retention due to SiO2 and the solubility of sulfuric species. [ABSTRACT FROM AUTHOR]

Assessing novel electrocatalysts for the electrochemical ammonia synthesis (EAS) requires reliable quantitative trace analysis of electrochemically produced ammonia to infer activity and selectivity. This study concerns the development of an ion chromatography (IC) method for quantitative trace analysis of ammonium in 0.1 M sulfuric acid electrolyte, which is applied to EAS gas‐diffusion electrode (GDE) experiments with commercial chromium nitride as electrocatalyst. The developed IC method is highly sensitive, versatile, and reliable, achieving a limit of quantification (LOQ) of 6 μg l−1 (6 ppbmol) ammonium. The impacts of the sample matrix, dilution, and neutralization, as well as contamination, on the quantitative analysis by IC are analyzed. Experimental constraints result in an effective LOQ including dilution of 60 μg l−1 for the determination of ammonium in 0.1 M sulfuric acid electrolyte, owing to necessary sample dilution. The practical guide presented herein is intended to be very relevant for the field of EAS as a guideline and applicable to a broad range of catalyst systems and ion chromatography devices. [ABSTRACT FROM AUTHOR]

Porous gas‐diffusion electrodes (GDEs) are widely used in electrochemical applications where a gaseous reactant is converted to a target product. Important applications for silver‐based GDEs are the chlor‐alkali and the CO2 electrolysis processes in which silver catalyzes the oxygen‐ or carbon dioxide reduction reaction. The wetting of the porous GDEs is of utmost importance for the achieved performance of the electrode: a completely dry electrode will result in low current densities due to the reduced active surface area while on the other hand, a completely flooded electrode will deteriorate the access of the gaseous reactant. Therefore, we investigated silver‐based GDEs for the oxygen reduction reaction with different amounts of the hydrophobic agent polytetrafluoroethylene (PTFE) and analyzed the potential‐induced wetting behavior (electrowetting). The electrolyte breakthrough was recorded by a digital microscope and subsequently evaluated via imaging analysis of the observed breached electrolyte droplets. In order to characterize the wetting state during transition to the steady‐state, we applied electrochemical impedance spectroscopy measurements and retrieved the double‐layer capacitance. Our results indicate that a higher overvoltage facilitates the breakthrough of electrolytes through the gas‐diffusion electrode. Surprisingly, a faster breakthrough of electrolyte was observed for electrodes with higher PTFE content. Porometry measurements revealed that the GDE with low PTFE content has a monomodal pore size distribution, whereas electrodes with higher PTFE amount exhibit a bimodal pore size distribution. In GDEs with monomodal pore size distribution the time in which the double layer capacitance is leveling off correlates with the breakthrough time of the electrolyte. In summary, we emphasize that the wetting of GDEs is a complex interplay of the applied potential, electrode composition, and resulting porous structure which requires further advanced measurements and analysis considering the parameters affecting the wetting behavior as a whole. [ABSTRACT FROM AUTHOR]

The chemical industry must become carbon neutral by 2050, meaning that process‐, energy‐, and product‐related CO2 emissions from fossil sources are completely suppressed. This goal can only be reached by using renewable energy, secondary raw materials, or CO2 as a carbon source. The latter can be done indirectly through the bioeconomy or directly by utilizing CO2 from air or biogenic sources (integrated biorefinery). Until 2030, CO2 waste from fossil‐based processes can be utilized to curb fossil CO2 emissions and reach the turning point of global fossil CO2 emissions. A technology mix consisting of recycling technologies, white biotechnology, and carbon capture and utilization (CCU) technologies is needed to achieve the goal of carbon neutrality. In this context, CHEMampere contributes to the goal of carbon neutrality with electricity‐based CCU technologies producing green chemicals from CO2, N2, O2, and H2O in a decentralized manner. This is an alternative to the e‐Refinery concept, which needs huge capacities of water electrolysis for a centralized CO2 conversion with green hydrogen, whose demand is expected to rise dramatically due to the decarbonization of the energy sector, which would cause a conflict of use between chemistry and energy. Here, CHEMampere's core reactor technologies, that is, electrolyzers, plasma reactors, and ohmic resistance heating of catalysts, are described, and their technical maturity is evaluated for the CHEMampere platform chemicals NH3, NOx, O3, H2O2, H2, CO, and CxHyOz products such as formic acid or methanol. Downstream processing of these chemicals is also addressed by CHEMampere, but it is not discussed here. [ABSTRACT FROM AUTHOR]

Knowing the phase evolution behavior of battery materials is important for optimizing the operating conditions and understanding the aging behavior of the material. Phase changes of state‐of‐the‐art battery materials at room temperature are well understood, but the influence of temperature on the phase evolution is barely investigated. In this study, operando X‐ray diffraction (XRD) is applied for the observation of phase changes of graphite during cycling at different temperatures. The phase evolution is altered at lower temperatures (0 °C) compared to room temperature due to slower kinetics and diffusion rates even at low current rates of C/20. Differences in phase evolution between charge and discharge are more pronounced at 0 °C compared to higher temperatures. During delithiation at 43 °C, the formation of stage 2L is more distinct than at 25 °C whereas at 0 °C, no stage 2L formation is observed. However, at 0 °C, several phases co‐exist, supporting the theory of the shrinking annuli mechanism for phase evolution during (de‐)lithiation of graphite. [ABSTRACT FROM AUTHOR]

The performance of rechargeable magnesium batteries is strongly dependent on the choice of electrolyte. The desolvation of multivalent cations usually goes along with high energy barriers, which can have a crucial impact on the plating reaction. This can lead to significantly higher overpotentials for magnesium deposition compared to magnesium dissolution. In this work we combine experimental measurements with DFT calculations and continuum modelling to analyze Mg deposition in various solvents. Jointly, these methods provide a better understanding of the electrode reactions and especially the magnesium deposition mechanism. Thereby, a kinetic model for electrochemical reactions at metal electrodes is developed, which explicitly couples desolvation to electron transfer and, furthermore, qualitatively takes into account effects of the electrochemical double layer. The influence of different solvents on the battery performance is studied for the state‐of‐the‐art magnesium tetrakis(hexafluoroisopropyloxy)borate electrolyte salt. It becomes apparent that not necessarily a whole solvent molecule must be stripped from the solvated magnesium cation before the first reduction step can take place. For Mg reduction it seems to be sufficient to have one coordination site available, so that the magnesium cation is able to get closer to the electrode surface. Thereby, the initial desolvation of the magnesium cation determines the deposition reaction for mono‐, tri‐ and tetraglyme, whereas the influence of the desolvation on the plating reaction is minor for diglyme and tetrahydrofuran. Overall, we can give a clear recommendation for diglyme to be applied as solvent in magnesium electrolytes. [ABSTRACT FROM AUTHOR]

Ni‐doped chromite anodes were integrated into electrolyte‐supported cells (ESC) with 5×5 cm2 size and investigated in fuel cell mode with H2/H2O fuel gas. Both a stoichiometric and a nominally A‐site deficient chromite anode material showed promising performance at 860 °C approaching the ones of state‐of‐the‐art Ni/Gd‐doped ceria (CGO) anodes. While the difference in polarization resistance was small, an increased ohmic resistance of the perovskite anodes was observed, which is related to their limited electronic conductivity. Increasing the chromite electrode thickness was shown to enhance performance and stability considerably. Degradation increased with current density, suggesting its dependency on the electrode potential, and could be reversed by redox cycling. Sulfur poisoning with 20 ppm hydrogen sulfide led to rapid voltage drops for the chromite anodes. It is discussed that Ni nanoparticle exsolution facilitates hydrogen dissociation to the extent that it is not rate‐limiting at the investigated temperature unless an insufficiently thick electrode thickness is employed or sulfur impurities are present in the feed gas. [ABSTRACT FROM AUTHOR]

Tin foil and SnOx/C gas‐diffusions electrodes (GDEs) were investigated via electrochemical impedance spectroscopy (EIS) to extract the differential double‐layer capacitance (Cdl) as a measure of the wetted surface area. Time‐dependent Cdl values revealed an immediate stationary wetting for tin foil electrodes while a distinct increase of Cdl – which becomes stationary with time – was observed for GDEs. The time‐dependent wetting behavior of the GDEs was substantiated by physical post‐mortem characterization. Since the wetted surface area determines the number of reachable active sites the performance of GDEs should be normalized to the wetted surface area for evaluation of reactivity. [ABSTRACT FROM AUTHOR]

Water electrolysis is the key to a decarbonized energy system, as it enables the conversion and storage of renewably generated intermittent electricity in the form of hydrogen. However, reliability challenges arising from titanium‐based porous transport layers (PTLs) have hitherto restricted the deployment of next‐generation water‐splitting devices. Here, it is shown for the first time how PTLs can be adapted so that their interface remains well protected and resistant to corrosion across ≈4000 h under real electrolysis conditions. It is also demonstrated that the malfunctioning of unprotected PTLs is a result triggered by additional fatal degradation mechanisms over the anodic catalyst layer beyond the impacts expected from iridium oxide stability. Now, superior durability and efficiency in water electrolyzers can be achieved over extended periods of operation with less‐expensive PTLs with proper protection, which can be explained by the detailed reconstruction of the interface between the different elements, materials, layers, and components presented in this work. [ABSTRACT FROM AUTHOR]

In this study three identically constructed ten‐layer stacks with electrolyte supported cells were tested in exothermic steam and co‐electrolysis mode at elevated pressures of 1.4 and 8 bar. Investigations during constant‐current operation at a current density of –0.5 A cm−2 and a reactant conversion of 70% over 1,000–2,000 h were carried out. The inlet gas composition for steam electrolysis was 90/10 (H2O/H2) and 63.7/31.3/3.3/1.7 (H2O/CO2/H2/CO) for co‐electrolysis operation. All stacks showed highly similar resistances at the beginning of the tests indicating a high level of accuracy and repeatability during manufacturing. The stack operated in steam electrolysis mode at 1.4 bar showed comparably low degradation of 8 mV kh−1 cell−1, whereas the stack operated at 8 bar showed an approximately four times higher degradation. The third stack was operated in co‐electrolysis mode at 1.4 and 8 bar and showed noticeably higher degradation rates than during steam electrolysis mode. The predominant increase of the ohmic resistance during operation was identified to be mainly responsible for the observed degradation of all three stacks, whereas the increase of the polarization resistances played a subordinate role. Within the post‐test analysis, noticeably high nickel depletion was observed for the stack operated at the highest pressure in steam electrolysis mode. Furthermore, partial delamination of electrodes was observed. The degradation is discussed with relation to phenomena and experimental parameters during operation. [ABSTRACT FROM AUTHOR]

The chances of improving the properties of biocomposites lie in the efficient combination of processing and compositional parameters. Achieving required properties for a specified application will involve a systematic process design. In this study, we focus on achieving improvement in properties of the bio‐acrylic resin/wood fiber composites via a rational design of process and parameters. We aim to identify processing parameters where the wood fibers participate in the chemical reaction giving rise to a robust composite structure and consequently improved properties. First, processing variables were streamlined to arrive at an efficient, easy, and less expensive processing route. Thereafter, fiber treatment, length, aspect ratio, and weight fraction were correlated to optimize the structural properties. Composites were prepared with varying fiber weight fraction (35–60 wt %) and fiber aspect ratio (2–13.7) using raw wood fibers (RWFs) and raw cellulose fibers (RCFs) from commercial sources. Generally, it was noted that with appropriate choice of treatment and size of fillers, the curing reaction can be enhanced leading to improvement in properties. Results show that flexural strength increases with decrease in fiber aspect ratio for both treated and untreated fibers. Maximum tensile strength (96 MPa) was obtained with 45 wt % filler content and filler aspect ratio of 13.7 for untreated fibers. When compared at the same weight fraction and average fiber length, RCF composites possess about 40% improvement in flexural strength over that of RWFs. The best compromise between processing and properties of the finished ecocomposite varies with fiber aspect ratio, treatment, and weight fraction of the fillers. The study provides an insight for the development of high‐performance green composites for extended applications such as underbody panels, wheel wells, and underhood components. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48719. [ABSTRACT FROM AUTHOR]

Abstract: The major difference for the durability of the materials in PEM fuel cells and PEM electrolyzers is the exposure to humidified gases and to liquid water, respectively. Aquivion and Nafion ionomer was investigated at surfaces of membranes and cross‐sections of electrodes by material‐sensitive atomic force microscopy. The dimensional behavior of electrodes and membranes in a membrane‐electrode assembly cross section was studied as a function of combined humidity and temperature changes. The observed opposite effects of ionomer dimensional changes in membrane and catalytic layers are important for understanding mechanical stress factors and degradation. For the lamellar polymer phase at moderate humidity, a linear swelling behavior and the enclosure of multiples of 0.8 nm‐thick water layers was observed. Submersed in water, 3 nm‐thick enclosed water layers were found. At the water‐immersed Aquivion membrane derived from alcoholic dispersion larger 30–50 nm sized water‐rich areas were found. In contrast, for membranes derived from water‐based dispersion the water‐rich phase was smaller with 11 nm. The thickness of the ultrathin ionomer layers in the electrode was investigated as a function of humidity and temperature. A linear swelling was found for humidity changes whereas nonlinear behavior with 100% expansion and hysteresis was seen for temperature cycles. [ABSTRACT FROM AUTHOR]

Abstract: The paper focuses on the investigation of durability and performance of a low temperature polymer electrolyte membrane fuel cell (PEMFC) stack as a function of Pt loading in automotive test conditions. Major motivations are problems related to the need to reduce the amount of Pt in membrane electrode assemblies (MEAs) in order to make PEMFC more competitive. The particular challenge is to maintain sufficiently high performance and long‐term durability. The study shows that for cathode Pt loadings below 0.2 mg cm−2 and for current densities exceeding 1 A cm−2 a sudden drop of performance is observed. The same threshold value is found for the increase of irreversible voltage losses which lead to an intense reduction of PEMFC durability for cathodic loadings below 0.2 mg cm−2. Another durability issue at cathodic Pt loadings < 0.4 mg cm−2 is the acceleration of reversible degradation, which leads to a strong voltage drop during continues fuel cell operation (i.e., without a recovery interruption). [ABSTRACT FROM AUTHOR]

Isothermal cold starts of polymer electrolyte fuel cells were performed at sub-zero temperatures and analyzed by means of neutron radiography in order to unravel the relation between the preconditioning of the cell and the cold start capability. It was found out that the initial humidification state of the membrane (determined by its resistance) has a clear correlation with the duration of the initial phase of the cold start, but not with the total duration of startup until cell failure. In the experimental setup the impact of realistic and commercial sealing solutions was taken into account by adding an edge channel. The impact of water accumulations in this region on the cold start capability was assessed. Liquid water located in the outer perimeter of a cell could be directly verified to freeze during cell cool down by a novel dual spectrum neutron radiography method. The amount of water accumulated in the outer cell perimeter showed some correlation with the total duration of the cold start. It was found out that residual water located in the edge channel can initiate freezing of a substantial part of the active area nearby. [ABSTRACT FROM AUTHOR]

The focus of this study is the measurement and understanding of the sulfur poisoning phenomena of Ni/gadolinium-doped ceria (CGO) based solid oxide fuel cells (SOFC). Cells with Ni/CGO10 and NiCu5/CGO40 anodes were characterized by using impedance spectroscopy at different temperatures and H2/H2O fuel ratios. The short-term sulfur poisoning behavior was investigated systematically at temperatures of 800-950 °C, current densities of 0-0.75 A cm−2, and H2S concentrations of 1-20 ppm. A sulfur poisoning mitigation effect was observed at high current loads and temperatures. The poisoning behavior was reversible for short exposure times. It was observed that the sulfur-affected processes exhibited significantly different relaxation times that depend on the Gd content in the CGO phase. Moreover, it was demonstrated that the capacitance of Ni/CGO10 anodes is strongly dependent on the temperature and gas-phase composition, which reflects a changing Ce3+/Ce4+ ratio. [ABSTRACT FROM AUTHOR]

In July 2011, in a zoological garden in Rome, Italy, malignant catarrhal fever ( MCF), a fatal, systemic disease of Artiodactyla, was suspected on the basis of neurological signs and gross lesions observed in a banteng, the first animal to die of this infection. An MCF type-specific PCR with subsequent sequencing of the PCR amplicon confirmed the aetiological agent as ovine herpesvirus-2 (Ov HV-2). Biological samples were collected from the dead animals for gross, histological, bacteriological, virological and serological examinations. An epidemiological investigation was conducted to identify the source of the outbreak, as further deaths due to Ov HV-2 still occurred after the removal of the acknowledged reservoirs, domestic sheep and goats. For this purpose, samples from other susceptible species and reservoir hosts were collected for virological and serological analysis. In conjunction, a retrospective sero-investigation was conducted on sera collected between 1999 and 2010 from some of the species involved in the present episode. In total, 11 animals belonging to four different species (banteng, Himalayan tahr, Nile lechwe and sika deer) died between July 2011 and October 2012. The severe gross and histological lesions were consistent with the disease, namely haemorrhages and congestion of several organs as well as lymphoid cell infiltrates and vasculitis of varying severity. The virological tests confirmed that all animals had died of sheep-associated MCF. The investigation indicated that the Ov HV-2 infection could have been due to the arrival of sheep in the petting zoo, with cases commencing after first lambing and subsequent shedding of virus. This was also supported by the serological retrospective study that indicated limited previous MCF virus circulation. Further MCF cases that occurred even after the removal of the domestic sheep and goats were attributed to the mouflon. This episode confirms the importance of biosecurity measures in zoos, which house MCF susceptible species, especially those endangered. [ABSTRACT FROM AUTHOR]

In this study it is theoretically analyzed how flue gas recirculation at the hydrogen electrode of solid oxide cells (SOC) systems effects fuel utilization and carbon formation. Interdepence between cell fuel utilization, system fuel utilization and gas recirculation is investigated numerically. Tendency towards carbon deposits is evaluated via thermodynamic equilibrium calculations. It is quantified which gas recirculation rates are necessary to achieve high values of system fuel utilization even if the cell fuel utilization is kept at a moderate level. Furthermore, tendency towards carbon deposition strongly depends on temperature, pressure and feed gas composition and can be reduced by adequate recirculation rates. The presented results can be used for the configuration of gas recirculation in SOC systems. [ABSTRACT FROM AUTHOR]

Background Transjugular intrahepatic portosystemic shunt (TIPSS) cause haemodynamic changes in patients with cirrhosis, yet little is known about long-term cardiopulmonary outcomes. Aim To evaluate the long-term cardiopulmonary outcome after TIPSS. Methods We evaluated cardiopulmonary parameters including echocardiography during long-term follow-up after TIPSS. Results at 1-5 years after TIPSS were compared to those of cirrhotic controls. Pulmonary hypertension ( PH) diagnoses rates were included. Endothelin 1, thromboxane B2 and serotonin were measured. Results We found significant differences 1-5 years after TIPSS compared to pre-implantation values: median left atrial diameter ( LAD) increased from 37 mm [interquartile range ( IQR): 33-43] to 40 mm ( IQR: 37-47, P = 0.001), left ventricular end-diastolic diameter ( LV- EDD) increased from 45 mm (range: 41-49) to 48 mm ( IQR: 45-52, P < 0.001), pulmonary artery systolic pressure ( PASP) increased from 25 mmHg ( IQR: 22-33) to 30 mmHg ( IQR: 25-36, P = 0.038). Comparing results 1-5 years post-implantation to the comparison cohort revealed significantly higher ( P < 0.05) LAD, LV- EDD and PASP values in TIPSS patients. PH prevalence was higher in the shunt group (4.43%) compared to controls (0.91%, P = 0.150). Thromboxane B2 levels correlated with PASP in the TIPSS cohort ( P = 0.033). There was no transhepatic gradient observed for the vasoactive substances analysed. Conclusions TIPSS placement is accompanied by long-term cardiovascular changes, including cardiac volume overload, and is associated with an increased rate of pulmonary hypertension. The need for regular cardiac follow-up after TIPSS requires further evaluation. [ABSTRACT FROM AUTHOR]

Treatment preferences of groups (e.g., clinical centers) have often been proposed as instruments to control for unmeasured confounding-by-indication in instrumental variable (IV) analyses. However, formal evaluations of these group-preference-based instruments are lacking. Unique challenges include the following: (i) correlations between outcomes within groups; (ii) the multi-value nature of the instruments; (iii) unmeasured confounding occurring between and within groups. We introduce the framework of between-group and within-group confounding to assess assumptions required for the group-preference-based IV analyses. Our work illustrates that, when unmeasured confounding effects exist only within groups but not between groups, preference-based IVs can satisfy assumptions required for valid instruments. We then derive a closed-form expression of asymptotic bias of the two-stage generalized ordinary least squares estimator when the IVs are valid. Simulations demonstrate that the asymptotic bias formula approximates bias in finite samples quite well, particularly when the number of groups is moderate to large. The bias formula shows that when the cluster size is finite, the IV estimator is asymptotically biased; only when both the number of groups and cluster size go to infinity, the bias disappears. However, the IV estimator remains advantageous in reducing bias from confounding-by-indication. The bias assessment provides practical guidance for preference-based IV analyses. To increase their performance, one should adjust for as many measured confounders as possible, consider groups that have the most random variation in treatment assignment and increase cluster size. To minimize the likelihood for these IVs to be invalid, one should minimize unmeasured between-group confounding. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background Alkaline phosphatase ( ALP) is an important serum marker in primary sclerosing cholangitis ( PSC). Patients with obstruction of the large bile ducts due to dominant strictures ( DS) are a special, clinically important phenotype. Aim To determine the impact of ALP reduction on liver transplantation-free survival in PSC patients with DS. Methods Prospective cohort study in 215 PSC patients. We performed subgroup analysis for patients without DS (no DS, n = 84), DS at first presentation ( DS early, n = 72) and development of DS during the course of the study ( DS late, n = 59). We evaluated two scores of ALP reduction. ALP reduction 1 was defined as ALP normalisation, 50% reduction compared with baseline values, or reduction below 1.5 times of upper limit of normal ( ULN) within 6 months. ALP reduction 2 was defined as ALP reduction below 1.5 times of ULN within 12 months. Results Of the patients, 59.5% reached an ALP reduction 1 and 56.7% according to ALP reduction 2. Achievement of each score was associated with longer transplantation-free survival in all three groups ( ALP reduction 1: no DS P = 0.001; DS early P < 0.001; DS late P = 0.022; ALP reduction 2: no DS P = 0.014; DS early P = 0.001; DS late P = 0.002). Cox-regression analysis revealed each score as an independent predictor for improved transplantation-free survival ( ALP reduction 1 and 2 P < 0.001 each). We further analysed previously published scores of ALP improvement in PSC showing also improved survival in patients with ALP normalisation or a reduction below 1.5 times of ULN ( P = 0.003, P = 0.001, respectively), whereas the score determined by 40% reduction did not show significant differences in survival ( P = 0.55). Conclusions Reduction in alkaline phosphatase values within the first year is associated with improved transplantation-free survival in patients with primary sclerosing cholangitis independent of the presence of dominant strictures. Alkaline phosphatase might be an adequate surrogate marker for outcome assessment in clinical studies both for patients with and without dominant strictures. [ABSTRACT FROM AUTHOR]

Guidelines have recommended single pool Kt/ V > 1.2 as the minimum dose for chronic hemodialysis ( HD) patients on thrice weekly HD. The Dialysis Outcomes and Practice Patterns Study ( DOPPS) has shown that 'low Kt/ V' (<1.2) is more prevalent in Japan than many other countries, though survival is longer in Japan. We examined trends in low Kt/ V, dialysis practices associated with low Kt/ V, and associations between Kt/ V and mortality overall and by gender in Japanese dialysis patients. We analyzed 5784 HD patients from Japan DOPPS (1999-2011), restricted to patients dialyzing for >1 year and receiving thrice weekly dialysis. Logistic regression models estimated the relationships of patient characteristics with Kt/ V. Logistic models also were used to estimate the proportion of low Kt/ V cases attributable to various treatment practices. Multivariable Cox regression was used to estimate the associations of low Kt/ V, blood flow rate ( BFR), and treatment time ( TT), with all-cause mortality. From 1999 to 2009, the prevalence of low Kt/ V declined in men (37-27%) and women (15-10%). BFR <200 mL/min, TT <240 minutes, and dialyzate flow rate ( DFR) < 500 mL/min were common (35, 13, and 19% of patients, respectively) and strongly associated with low Kt/ V. Fifteen percent of low Kt/ V cases were attributable to BFR <200 and 13% to TT <240, compared to only 3% for DFR <500. Lower Kt/ V was associated with elevated mortality, more so among women (hazard ratio [ HR] = 1.13 per 0.1 lower Kt/ V, 95% CI: 1.07-1.20) than among men ( HR = 1.06 per 0.1 lower Kt/ V, 95% CI: 1.00-1.12). The relatively large proportion of low Kt/ V cases in Japanese facilities may potentially be reduced 30% by increasing BFR to 200 mL/min and TT to 4 hours thrice weekly in HD patients. Associations of low Kt/ V with elevated mortality suggest that modification of these practices may further improve survival for Japanese HD patients. [ABSTRACT FROM AUTHOR]

Background A recent genome-wide association study identified the FUT2 secretor status and genotype defined by the single-nucleotide polymorphism rs601338 as potential genetic risk factor in primary sclerosing cholangitis ( PSC), which significantly influences biliary bacterial composition. Aim To determine the impact of the rs601338- FUT2 genotype on frequency of biliary infections, development of dominant stenosis and liver-transplantation-free survival in patients with PSC. Methods Cohort study of 215 patients with PSC treated at our tertiary care centre with respect to their rs601338- FUT2 genotype. Results of endoscopic retrograde cholangiography and bile culture were analysed; 639 biliary samples were obtained, cultured and subjected to microbial analysis. Clinical and laboratory data were analysed using chart reviews. Results For the rs601338- FUT2 genotype, 69 patients (32.1%) were found to be wildtype ( GG), 97 (45.1%) patients were heterozygous ( AG) and 49 patients (22.8%) were homozygous-mutated ( AA). In addition to alterations in the bacterial pattern, especially in heterozygous carriers, patients with mutated alleles had a marked increase in the frequency of biliary Candida infections ( P = 0.025). Further, patients with mutated alleles showed an increased frequency of episodes of cholangitis ( P = 0.0025), development of dominant stenosis ( P < 0.002) and a reduced actuarial transplantation-free survival ( P = 0.044). Levels of biliary Ca19-9 were significantly elevated in the homozygous-mutated patients. Conclusions The rs601338- FUT2 genotype is strongly associated with episodes of cholangitis, fungobilia and the incidence of dominant stenosis, which are three clinical hallmarks of PSC; FUT2 is thus an important genetic risk factor for host-microbial diversity and disease progression in PSC. [ABSTRACT FROM AUTHOR]

This paper presents a multi-scale model of a solid oxide fuel cell (SOFC) stack consisting of five anode-supported cells. A two-dimensional isothermal elementary kinetic model is used to calculate the performance of single cells. Several of these models are thermally coupled to form the stack model. Simulations can be carried out at steady-state as well as dynamic operation. The model is validated over a wide range of operating conditions including variation of temperature, gas composition (both on anode and cathode side), and pressure. Validation is carried out using polarization curves and impedance spectra. The model is then used to explain the pressure-induced performance increase measured at constant fuel utilization of 40%. Results show that activation and concentration overpotentials are reduced with increasing pressure. [ABSTRACT FROM AUTHOR]

To increase the long term stability and performance of solid oxide fuel cell (SOFC) materials, it is important to understand the main degradation processes in their functional layers. In this work, the interface between electrolyte and anode material was investigated by in situ X-ray diffraction (XRD) stress and phase analysis. It has been found that the determining process for the initial degradation of SOFC is the reduction of the anode material with hydrogen. During this process a tensile strength of 600-700 MPa is measured. These stresses are induced in the electrolyte material and produce crack networks. The reduction from nickel oxide to pure nickel was monitored by in situ phase analysis. This reaction induces tensile stress at the interface between electrolyte and anode. The stress produced in the electrolyte material was also confirmed by the observation of crack networks detected using scanning electron microscopy (SEM). Finally, the reducing process was optimized using different process gases, decreasing the destructive tensile stress level. [ABSTRACT FROM AUTHOR]

Borck G, Rainshtein L, Hellman-Aharony S, Volk AE, Friedrich K, Taub E, Magal N, Kanaan M, Kubisch C, Shohat M, Basel-Vanagaite L. High frequency of autosomal-recessive DFNB59 hearing loss in an isolated Arab population in Israel. Autosomal-recessive non-syndromic hearing impairment (DFNB) is usually of prelingual onset with a moderate to profound degree of hearing loss. More than 70 DFNB loci have been mapped and ∼40 causative genes have been identified. Non-syndromic hearing impairment caused by mutations of DFNB59 (encoding pejvakin) has been described in a couple of families in which affected individuals presented with either auditory neuropathy or hearing loss of cochlear origin. We have identified and clinically evaluated three consanguineous families of Israeli Arab origin with prelingual non-syndromic hearing impairment and absent otoacoustic emissions in a total of eight affected individuals. All the families originate from the same village and bear the same family name. We have identified a c.406C>T (p.R136X) nonsense mutation in the DFNB59 gene in affected individuals from these families. Among the inhabitants of the village, we found an exceptionally high carrier frequency of ∼1 in 12 individuals (7/85; 8.2%). The high prevalence of hearing impairment can be explained by a founder effect and the high consanguinity rate among the inhabitants of this village. [ABSTRACT FROM AUTHOR]

Abstract: Treatment with tetrahydrobiopterin (BH4), the natural cofactor of phenylalanine hydroxylase (PAH), can reduce blood phenylalanine (Phe) levels in patients with BH4‐responsive phenylketonuria (PKU). A number of studies has reported on the short‐term BH4 treatment of patients with PKU, but long‐term data are lacking. Here, we describe the effects of long‐term treatment with BH4 on 16 patients, who showed a >28% reduction in blood Phe following testing for BH4 overload. The mean dose of BH4 was 16 mg/kg body weight (range 5–36 mg/kg body weight). The mean treatment duration was 56 months (range 24–110 months). Of 16 patients, 14 achieved long‐term Phe control with BH4 treatment, with a mean blood Phe concentration of 321 ± 236 µmol/l. The mean decrease from baseline in blood Phe levels in these 14 patients was 54.6%. Of the seven patients who required continued dietary restriction, Phe intake increased from 200–300 mg/day to 800–1000 mg/day. Factors that may cause fluctuation of Phe levels in BH4‐treated patients include patients' PAH genotype, Phe intake, changes in protein catabolism or anabolism, and periods of illness or infection. [ABSTRACT FROM AUTHOR]

We performed molecular, enzyme, and metabolic studies in 50 patients with D-2-hydroxyglutaric aciduria ( D-2-HGA) who accumulated D-2-hydroxyglutarate ( D-2-HG) in physiological fluids. Presumed pathogenic mutations were detected in 24 of 50 patients in the D-2-hydroxyglutarate dehydrogenase ( D2HGDH) gene, which encodes D-2-hydroxyglutarate dehydrogenase ( D-2-HGDH). Enzyme assay of D-2-HGDH confirmed that all patients with mutations had impaired enzyme activity, whereas patients with D-2-HGA whose enzyme activity was normal did not have mutations. Significantly lower D-2-HG concentrations in body fluids were observed in mutation-positive D-2-HGA patients than in mutation-negative patients. These results imply that multiple genetic loci may be associated with hyperexcretion of D-2-HG. Accordingly, we suggest a new classification: D-2-HGA Type I associates with D-2-HGDH deficiency, whereas idiopathic D-2-HGA manifests with normal D-2-HGDH activity and higher D-2-HG levels in body fluids compared with Type I patients. It remains possible that several classifications for idiopathic D-2-HGA patients with diverse genetic loci will be revealed in future studies. Hum Mutat 31:1-5, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The article discusses the findings of a study which investigated the structural profile of pultruded poly(ethyleneterephthalate) (PET)/ low-density polyethylene (LDPE)- bristles by evaluating various processing parameter including temperature, and pulling speed. The experiment was conducted by researchers from University of Sofia, Bulgaria, the Technical University of Kaiserslautern, Germany, and King Saud University, Saudi Arabia. Results showed the similarity of pultruded profiles for microfibrillar-reinforced composites (MFC) and PET-LDPE blends.

Background IL-13 promotes acute allergic asthma and is discussed to play a role in late asthmatic features such as fibrotic processes and airway remodelling. The contributions of IL-13-mediated mechanisms to subepithelial events related to fibrosis are not yet settled. Objective We investigated the impact of IL-13 on lung epithelial cells as apoptotic effector and on lung fibroblasts as inducer of pro-fibrotic gene expression. Methods Using the two lung epithelial cell lines A549 and BEAS-2B as well as primary lung epithelial cells, we investigated the capability of IL-13 to induce apoptosis by both flow-cytometry and ELISA. The ability of IL-13 to increase the expression of pro-fibrotic genes and to exert influence on the expression of its own receptor was investigated by real-time quantitative PCR measurement of mRNAs encoding collagen I, collagen III, basic fibroblast growth factor (bFGF), α-smooth muscle actin (α-SMA) and the IL-13 receptor α1 (IL-13Rα1) chain in human primary lung fibroblasts. The specificity of IL-13-mediated cellular responses was confirmed by means of an inhibitory monoclonal antibody directed to the IL-13 receptor. Results IL-13 induces apoptosis in lung epithelial cell lines as well as in primary lung epithelial cells. Furthermore, IL-13 increases the expression of mRNA for α-SMA and collagen III, but not for bFGF in human primary lung fibroblasts. The susceptibility of lung fibroblasts to IL-13-induced up-regulation of pro-fibrotic genes is associated with the regulation of IL-13 receptor expression. IL-13-dependent fibrosis-associated effects could be inhibited by antibody-mediated blockade of the IL-13Rα1 subunit. Conclusion Our findings indicate a function of IL-13 as a mediator in fibrotic processes leading to loss of functional airway tissue in asthma. They also highlight the therapeutic potential of specifically targeting the interaction between IL-13 and its receptor. [ABSTRACT FROM AUTHOR]

The term “reverse epidemiology” has been proposed to address the apparent different relationship between numerous risk factors and outcomes among dialysis patients: thus, obesity, hypertension, high cholesterol, and elevated creatinine all appear to be associated with decreased risk. Since this is contrary to the general findings in otherwise healthy populations, some kind of “reversal” has been suggested, that would be contrary to classical epidemiology. The authors describe several faults to this conception. The rules of epidemiology have not been reversed in dialysis patients. In fact, the complexity of the population implies a greater need for attention to the distinction between association and causation and the importance of confounding and bias. In particular existing subclinical and clinical disease which is very common among dialysis patients can change associations so drastically that they are dominated by different causal pathways than those seen in the general population. For example, lower cholesterol is a better marker of poor health than of a healthy diet and thus is associated with different outcomes. To the extent the term reverse epidemiology implies either epidemiology or biology is different in dialysis patients it can be misleading and detrimental. The differences between risk factors in end-stage renal disease (ESRD) and other individuals are surely important, but can themselves be the basis of excellent epidemiology, applied with the classic rules developed for this discipline with the goal of uncovering causal association and hypotheses to be tested in clinical trials. [ABSTRACT FROM AUTHOR]

Abnormalities in mineral metabolism have been linked to mortality in hemodialysis (HD) patients. We postulated that these abnormalities would have a particularly large deleterious impact on deaths due to cardiovascular causes in Japan. This study describes the recent status of abnormal mineral metabolism, significant predictors, and potential consequences in the Dialysis Outcomes and Practice Patterns Study (DOPPS), Phases 1 and 2, in Japan. Major predictor variables were patient demographics, comorbidities, and laboratory markers of mineral metabolism such as albumin-adjusted serum calcium (calciumAlb), phosphorus, and intact PTH (iPTH). In a cross section of 3973 Japanese HD patients in DOPPS I and II, a large faction had laboratory values outside of the recommended Kidney Disease Outcomes Quality Initiative (K/DOQI) guideline range for serum concentrations of phosphorus (51% of patients above upper target range), calciumAlb (43.7% above), calcium-phosphorus (Ca × P) product (41.1% above), and iPTH (18.6% above). All-cause mortality was significantly and independently associated with calciumAlb (relative risk [RR]=1.22 per 1 mg/dL, p=0.0005) and iPTH (RR=1.04 per 100 pg/mL, p=0.04). Cardiovascular mortality was significantly associated with calciumAlb (RR=1.28, p=0.02), phosphorus (RR=1.13 per 1 mg/dL, p=0.008), Ca × P product (RR=1.07 per 2 mg2/dL2, p=0.002), and PTH (RR=1.08, p=0.0001). This study expands our understanding of the relationship between altered mineral metabolism and mortality outcomes, showing slightly stronger associations with cardiovascular causes than observed for all-cause mortality. These findings have important therapeutic implications for Japanese HD patients. [ABSTRACT FROM AUTHOR]