Increased Readiness for Water Splitting: NiO-Induced Weakening of Bonds in Water Molecules as Possible Cause of Ultra-Low Oxygen Evolution Potential.

The development of non-precious metal-based electrodes that actively and stably support the oxygen evolution reaction (OER) in water electrolysis systems remains a challenge, especially at low pH levels. The recently published study has conclusively shown that the addition of haematite to H2SO4 is a highly effective method of significantly reducing oxygen evolution overpotential and extending anode life. The far superior result is achieved by concentrating oxygen evolution centres on the oxide particles rather than on the electrode. However, unsatisfactory Faradaic efficiencies of the OER and hydrogen evolution reaction (HER) parts as well as the required high haematite load impede applicability and upscaling of this process. Here it is shown that the same performance is achieved with three times less metal oxide powder if NiO/H2SO4 suspensions are used along with stainless steel anodes. The reason for the enormous improvement in OER performance by adding NiO to the electrolyte is the weakening of the intramolecular O─H bond in the water molecules, which is under the direct influence of the nickel oxide suspended in the electrolyte. The manipulation of bonds in water molecules to increase the tendency of the water to split is a ground-breaking development, as shown in this first example.

Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments.

Replacing fossil fuels with energy sources and carriers that are sustainable, environmentally benign, and affordable is amongst the most pressing challenges for future socio-economic development. To that goal, hydrogen is presumed to be the most promising energy carrier. Electrocatalytic water splitting, if driven by green electricity, would provide hydrogen with minimal CO2 footprint. The viability of water electrolysis still hinges on the availability of durable earth-abundant electrocatalyst materials and the overall process efficiency. This review spans from the fundamentals of electrocatalytically initiated water splitting to the very latest scientific findings from university and institutional research, also covering specifications and special features of the current industrial processes and those processes currently being tested in large-scale applications. Recently developed strategies are described for the optimisation and discovery of active and durable materials for electrodes that ever-increasingly harness first-principles calculations and machine learning. In addition, a technoeconomic analysis of water electrolysis is included that allows an assessment of the extent to which a large-scale implementation of water splitting can help to combat climate change. This review article is intended to cross-pollinate and strengthen efforts from fundamental understanding to technical implementation and to improve the 'junctions' between the field's physical chemists, materials scientists and engineers, as well as stimulate much-needed exchange among these groups on challenges encountered in the different domains.

From Bad Electrochemical Practices to an Environmental and Waste Reducing Approach for the Generation of Active Hydrogen Evolving Electrodes.

The electrodeposition of noble metals using corresponding dissolved metal salts represents an interesting process for the improvement of the electrocatalytic hydrogen evolution reaction (HER) properties of less active substrate materials. The fact that only a small fraction of the dissolved noble metals reaches the substrate represents a serious obstacle to this common procedure. We therefore chose a different path. It was found that the HER activity of Ni42 alloy drastically increased (η=140 mV at j=10 mA cm-2 ; pH 1) when a platinum counter electrode was used during polarization experiments in acid. This improvement was caused by a platinum transfer from the platinum anode to the steel cathode, a process which occurred simultaneously to the hydrogen evolution. The negligible accumulation of Pt (26 µg) in the electrolyte turns this straight-forward transfer procedure into a highly cost-effective, environmentally friendly, and waste reducing approach for the generation of cheap, stable and effective HER electrodes.

Refining the impact of TCF7L2 gene variants on type 2 diabetes and adaptive evolution.

We recently described an association between risk of type 2diabetes and variants in the transcription factor 7-like 2 gene (TCF7L2; formerly TCF4), with a population attributable risk (PAR) of 17%-28% in three populations of European ancestry. Here, we refine the definition of the TCF7L2 type 2diabetes risk variant, HapB(T2D), to the ancestral T allele of a SNP, rs7903146, through replication in West African and Danish type 2 diabetes case-control studies and an expanded Icelandic study. We also identify another variant of the same gene, HapA, that shows evidence of positive selection in East Asian, European and West African populations. Notably, HapA shows a suggestive association with body mass index and altered concentrations of the hunger-satiety hormones ghrelin and leptin in males, indicating that the selective advantage of HapA may have been mediated through effects on energy metabolism.

Ultrafine sanding paper: a simple tool for creating small particles.

A top-down approach, i.e., creating small particles by mechanical force starting from bulk materials, probably presents the most logical approach to particle size reduction and, therefore, top-down techniques are among the first to achieve small particles. A new solvent-free, amazingly simple approach is reported, suitable to achieve nanoparticles and sub-micro particles.

Making medical decisions in dependence of genetic background: estimation of the utility of DNA testing in clinical, pharmaco-epidemiological or genetic studies.

An index measuring the utility of testing a DNA marker before deciding between two alternative treatments is proposed which can be estimated from pharmaco-epidemiological case-control or cohort studies. In the case-control design, external estimates of the prevalence of the disease and of the frequency of the genetic risk variant are required for estimating the utility index. Formulas for point and interval estimates are derived. Empirical coverage probabilities of the confidence intervals were estimated under different scenarios of disease prevalence, prevalence of drug use, and population frequency of the genetic variant. To illustrate our method, we re-analyse pharmaco-epidemiological case-control data on oral contraceptive intake and venous thrombosis in carriers and non-carriers of the factor V Leiden mutation. We also re-analyse cross-sectional data from the Framingham study on a gene-diet interaction between an APOA2 polymorphism and high saturated fat intake on obesity. We conclude that the utility index may be helpful to evaluate and appraise the potential clinical and public health relevance of gene-environment interaction effects detected in genomic and candidate gene association studies and may be a valuable decision support for designing prospective studies on the clinical utility.

Biomarker driven population enrichment for adaptive oncology trials with time to event endpoints.

The development of molecularly targeted therapies for certain types of cancers has led to the consideration of population enrichment designs that explicitly factor in the possibility that the experimental compound might differentially benefit different biomarker subgroups. In such designs, enrollment would initially be open to a broad patient population with the option to restrict future enrollment, following an interim analysis, to only those biomarker subgroups that appeared to be benefiting from the experimental therapy. While this strategy could greatly improve the chances of success for the trial, it poses several statistical and logistical design challenges. Because late-stage oncology trials are typically event driven, one faces a complex trade-off between power, sample size, number of events, and study duration. This trade-off is further compounded by the importance of maintaining statistical independence of the data before and after the interim analysis and of optimizing the timing of the interim analysis. This paper presents statistical methodology that ensures strong control of type 1 error for such population enrichment designs, based on generalizations of the conditional error rate approach. The special difficulties encountered with time-to-event endpoints are addressed by our methods. The crucial role of simulation for guiding the choice of design parameters is emphasized. Although motivated by oncology, the methods are applicable as well to population enrichment designs in other therapeutic areas.

Novel common copy number variation for early onset extreme obesity on chromosome 11q11 identified by a genome-wide analysis.

Heritability of obesity is substantial and recent meta-analyses of genome-wide association studies (GWASs) have been successful in detecting several robustly associated genomic regions for obesity using single-nucleotide polymorphisms (SNPs). However, taken together, the SNPs explain only a small proportion of the overall heritability. Copy number variations (CNVs) might contribute to the 'missing heritability'. We searched genome-wide for association between common CNVs and early-onset extreme obesity. Four hundred and twenty-four case-parents obesity trios and an independent sample of 453 extremely obese children and adolescents and 435 normal-weight and lean adult controls were genotyped by the Affymetrix Genome-Wide Human SNP Array 6.0. We detected 20 common copy number variable regions (CNVRs) which were associated with obesity. The most promising CNVRs were followed-up in an independent sample of 365 obesity trios, confirming the association for two candidate CNVRs. We identified a common CNVR exclusively covering the three olfactory receptor genes OR4P4, OR4S2 and OR4C6 to be associated with obesity (combined P-value = 0.015 in a total of 789 families; odds ratio for the obesity effect allele = 1.19; 95% confidence interval = 1.016-1.394). We also replicated two common deletions (near NEGR1 and at chromosome 10q11.22) that have previously been reported to be associated with body weight. Additionally, we support a rare CNV on chromosome 16 that has recently been reported by two independent groups. However, rare CNVs had not been the focus of our study. We conclude that common CNVs are unlikely to contribute substantially to the genetic basis of early-onset extreme obesity.

PERMORY-MPI: a program for high-speed parallel permutation testing in genome-wide association studies.

UNLABELLED: PERMORY is software for accelerated permutation testing of genome-wide association studies (GWAS). We have parallelized PERMORY using the Message-Passing Interface resulting in a nearly linear speedup. Furthermore, we added accelerated analysis of GWAS using quantitative phenotypes, and an accurate estimation of the effective number of independent tests. AVAILABILITY AND IMPLEMENTATION: Free download from http://permory.org.

Two new Loci for body-weight regulation identified in a joint analysis of genome-wide association studies for early-onset extreme obesity in French and german study groups.

Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85x10(-8) in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84x10(-7)), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at approximately 1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults.

The Readiness of Water Molecules to Split into Hydrogen + Oxygen: A Proposed New Aspect of Water Splitting.

The potential of the anode, at which the evolution of oxygen begins, is a key parameter that describes how well water is split in water electrolyzers. Research efforts related to electrocatalytically initiated water splitting that aim at reducing the oxygen evolution reaction (OER) overpotential to date focus on the optimization of materials used to produce the electrodes. Descriptors for the readiness of the H2 O molecule itself to break down into its components have not been considered in water electrolysis experiments so far. In a simple set of experiments, it is found that adding dioxane to aqueous solutions leads to a substantial blueshift of the frequency of the OH stretch vibration which is a sign of an increased strength of the OH bond (intramolecular bonding). This phenomenon coincides with a significant increase in the OER onset potential as derived from cyclic voltammetry experiments. Thus, the OH stretch frequency can be an ideal indicator for the readiness of water molecules to be split in its cleavage products. This is thought to be first example of a study into the relationship between structural features of water as derived from Fourier transform infrared (FTIR) spectroscopic studies and key results derived from water electrolysis experiments.

Loss of a FYN-regulated differentiation and growth arrest pathway in advanced stage neuroblastoma.

Tumor stage, age of patient, and amplification of MYCN predict disease outcome in neuroblastoma. To gain insight into the underlying molecular pathways, we have obtained expression profiles from 94 primary neuroblastoma specimens. Advanced tumor stages show a characteristic expression profile that includes downregulation of multiple genes involved in signal transduction through Fyn and the actin cytoskeleton. High expression of Fyn and high Fyn kinase activity are restricted to low-stage tumors. In culture, expression of active Fyn kinase induces differentiation and growth arrest of neuroblastoma cells. Expression of Fyn predicts long-term survival independently of MYCN amplification. Amplification of MYCN correlates with deregulation of a distinct set of genes, many of which are target genes of Myc. Our data demonstrate a causal role for Fyn kinase in the genesis of neuroblastoma.

PERMORY: an LD-exploiting permutation test algorithm for powerful genome-wide association testing.

MOTIVATION: In genome-wide association studies (GWAS) examining hundreds of thousands of genetic markers, the potentially high number of false positive findings requires statistical correction for multiple testing. Permutation tests are considered the gold standard for multiple testing correction in GWAS, because they simultaneously provide unbiased type I error control and high power. At the same time, they demand heavy computational effort, especially with large-scale datasets of modern GWAS. In recent years, the computational problem has been circumvented by using approximations to permutation tests, which, however, may be biased. RESULTS: We have tackled the original computational problem of permutation testing in GWAS and herein present a permutation test algorithm one or more orders of magnitude faster than existing implementations, which enables efficient permutation testing on a genome-wide scale. Our algorithm does not rely on any kind of approximation and hence produces unbiased results identical to a standard permutation test. A noteworthy feature of our algorithm is a particularly effective performance when analyzing high-density marker sets. AVAILABILITY: Freely available on the web at http://www.permory.org.

Upconverting nanoparticles.

Upconversion (UC) refers to nonlinear optical processes in which the sequential absorption of two or more photons leads to the emission of light at shorter wavelength than the excitation wavelength (anti-Stokes type emission). In contrast to other emission processes based on multiphoton absorption, upconversion can be efficiently excited even at low excitation densities. The most efficient UC mechanisms are present in solid-state materials doped with rare-earth ions. The development of nanocrystal research has evoked increasing interest in the development of synthesis routes which allow the synthesis of highly efficient, small UC particles with narrow size distribution able to form transparent solutions in a wide range of solvents. Meanwhile, high-quality UC nanocrystals can be routinely synthesized and their solubility, particle size, crystallographic phase, optical properties and shape can be controlled. In recent years, these particles have been discussed as promising alternatives to organic fluorophosphors and quantum dots in the field of medical imaging.

Optimal multistage designs--a general framework for efficient genome-wide association studies.

Genome-wide association studies (GWAS) have become increasingly affordable but they are still costly. Therefore, cost saving 2-stage designs were proposed in the literature. The restriction to 2 stages, however, seems artificial and does not exploit the full potential of the underlying methods. We extend the 2-stage approach to the general framework of any number of stages. Based on the theory of group sequential methods, we derive optimal multistage designs. With current genotyping cost structures, our results suggest that up to 4 stages are sufficient in order to get feasible and efficient designs. Furthermore, we consider the problem of choosing the optimal number of stages depending on the costs of the statistical interim analysis at each stage and provide guidelines for planning the number of stages in practice. In particular, we found that in the majority of cases both 3-stage designs and 4-stage designs are more efficient than 2-stage designs. Although prices for marker panels are showing a continuing downward trend, we still recommend implementing and using optimal multistage designs in practice. In addition to the immediate benefit, it will be necessary to acquire know-how regarding the application of multistage designs in order to be able to adapt the general framework of multistage designs to upcoming technologies in the area of GWAS.

Mutation screen and association studies for the fatty acid amide hydrolase (FAAH) gene and early onset and adult obesity.

BACKGROUND: The orexigenic effects of cannabinoids are limited by activation of the endocannabinoid degrading enzyme fatty acid amide hydrolase (FAAH). The aim of this study was to analyse whether FAAH alleles are associated with early and late onset obesity. METHODS: We initially assessed association of five single nucleotide polymorphisms (SNPs) in FAAH with early onset extreme obesity in up to 521 German obese children and both parents. SNPs with nominal p-values 0.05). CONCLUSIONS: As we observed some evidence for an association of the FAAH variants rs2295632 rs324420 with early onset but not adult obesity, we conclude that the FAAH variants analyzed here at least do not seem to play a major role in the etiology of obesity within our samples.

Familiality and molecular genetics of attention networks in ADHD.

Indices from a more elementary neuropsychological level might be useful in the search for genes for complex psychiatric disorders, such as ADHD. In this study we investigated systematically whether attentional performance as measured with the Attention Network Test (ANT) is suited for the identification of endophenotypes of ADHD. Attentional performance in affected sib pairs with ADHD (n = 181) was compared to unaffected control siblings (n = 121). Intrafamilial correlation patterns were calculated. In addition, linkage and association analyses were conducted between quantitative scores of attentional functions and dopamine receptor D4 (DRD4) and dopamine transporter (DAT1 or SLC6A3) gene variants. Only the executive attention network was significantly impaired in subjects with ADHD compared to controls (P < 0.05) and showed evidence for familiality in both affected and unaffected families. Linkage analyses revealed the highest LOD score for a severity score based on DSM-IV inattentive symptoms in the DAT1 chromosomal region (LOD score 2.6 at 15 cM). However, a SNP (rs6350) at the DAT1 locus showed a tendency for association with both alerting performance (P = 0.02) and executive attention (P = 0.01) although it did not survive alpha adjustment for multiple testing. No evidence was found for association of any of the investigated phenotypes with the VNTR in the DRD4. Thus, our data suggest that the quantitative behavioral ratings of inattentive symptoms might be more useful when searching for new genes associated with ADHD, however, among the ANT measures the executive attention network seems to be best suited for further endophenotype analyses.

Optimal robust two-stage designs for genome-wide association studies.

Optimal robust two-stage designs for genome-wide association studies are proposed using the maximum of the recessive, additive and dominant linear trend test statistics. These designs combine cost-saving two-stage genotyping with robustness against misspecification of the genetic model and are much more efficient than designs based on a single model specific test statistic in detecting multiple loci with different modes of inheritance. For given power of 90%, typical cost savings of 34% can be realised by increasing the total sample size by about 13% but genotyping only about half of the sample for the full marker set in the first stage and carrying forward about 0.06% of the markers to the second stage analysis. We also present robust two-stage designs providing optimal allocation of a limited budget for pre-existing samples. If a sample is available which would yield a power of 90% when fully genotyped, genotyping only half of the sample due to a limited budget will typically cause a loss of power of more than 55%. Using an optimal two-stage approach in the same sample under the same budget restrictions will limit the loss of power to less than 10%. In general, the optimal proportion of markers to be followed up in the second stage strongly depends on the cost ratio for chips and individual genotyping, while the design parameters of the optimal designs (total sample size, first stage proportion, first and second stage significance limit) do not much depend on the genetic model assumptions.

A randomized trial of deep-brain stimulation for Parkinson's disease.

BACKGROUND: Neurostimulation of the subthalamic nucleus reduces levodopa-related motor complications in advanced Parkinson's disease. We compared this treatment plus medication with medical management. METHODS: In this randomized-pairs trial, we enrolled 156 patients with advanced Parkinson's disease and severe motor symptoms. The primary end points were the changes from baseline to six months in the quality of life, as assessed by the Parkinson's Disease Questionnaire (PDQ-39), and the severity of symptoms without medication, according to the Unified Parkinson's Disease Rating Scale, part III (UPDRS-III). RESULTS: Pairwise comparisons showed that neurostimulation, as compared with medication alone, caused greater improvements from baseline to six months in the PDQ-39 (50 of 78 pairs, P=0.02) and the UPDRS-III (55 of 78, P<0.001), with mean improvements of 9.5 and 19.6 points, respectively. Neurostimulation resulted in improvements of 24 to 38 percent in the PDQ-39 subscales for mobility, activities of daily living, emotional well-being, stigma, and bodily discomfort. Serious adverse events were more common with neurostimulation than with medication alone (13 percent vs. 4 percent, P<0.04) and included a fatal intracerebral hemorrhage. The overall frequency of adverse events was higher in the medication group (64 percent vs. 50 percent, P=0.08). CONCLUSIONS: In this six-month study of patients under 75 years of age with severe motor complications of Parkinson's disease, neurostimulation of the subthalamic nucleus was more effective than medical management alone. (ClinicalTrials.gov number, NCT00196911 [ClinicalTrials.gov].).