Indicators of river system hydromorphological character and dynamics: understanding current conditions and guiding sustainable river management

The work leading to this paper received funding from the EU’s FP7 programme under Grant Agreement No. 282656 (REFORM). The Indicators were developed within the context of REFORM deliverable D2.1, therefore all partners involved in this deliverable contributed to some extent to their discussion and development

Isotopic Probe Illuminates the Role of the Electrode Surface in Proton Coupled Hydride Transfer Electrochemical Reduction of Pyridinium on Pt(111)

A recently proposed mechanism for electrochemical CO2 reduction on Pt (111) catalyzed by aqueous acidic pyridine solutions suggests that the observed redox potential of ca. −600 mV vs. SCE is due to the one-electron reduction of pyridinium through proton coupled electron transfer (PCET) to form H atoms adsorbed on the Pt surface (Hads). The initial pyridinium reduction was probed isotopically via deuterium substitution. A combined experimental and theoretical analysis found equilibrium isotope effects (EIE) due to deuterium substitution at the acidic pyridinium site. A shift in the cathodic cyclic voltammetric half wave potential of −25 mV was observed, consistent with the theoretical prediction of −40 mV based on the recently proposed reaction mechanism where pyridinium is essential to establish a high concentration of Brønsted acid in contact with the substrate CO2 and with the Pt surface. A prefeature in the cyclic voltammogram was examined under isotopic substitution and indicated an Hads intermediate in pyridinium reduction. Theoretical prediction and observation of an EIE supported the assignment of the cathodic wave to the proposed reduction of pyridinium through PCET forming Hads and eventually H2 on the Pt surface

Light-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and Photoelectrodes

Although modern photoelectrochemistry is often traced back to 1972 and the report by Honda and Fujishima 1 that a TiO2 photoanode in an electrochemical cell caused the splitting of water into O2 and H2 when illuminated, the first report of this type of phenomenon dates back to Becquerel’s studies, published in 1839. 2 This makes photoelectrochemistry one of the oldest investigated techniques for the conversion of sunlight into usable energy. Over this time frame, two general types of photoelectrochemical cells have been developed. The first, typified by Honda’s electrochemistry, is focused primarily on the storage of light energy as high energy chemical products. Initially, this was termed “artificial photosynthesis,” and was focused for the most part on splitting water to generate H2 as an environmentally benign fuel. The second type of photoelectrochemical cell utilizes a chemically reversible redox couple that undergoes a redox change of state at the photoelectrode, followed by conversion of the product species back to the reactant at the counter electrode. The net effect of this reaction is a chemically invariant system that generates electricity from light. The initial implementation of the Grätzel cell, which used a 3 reversible I 2/I 3- couple and a dye-sensitized TiO2 photoanode, is an example of this type of system.3 The work under consideration in this paper focuses on the photosynthetic cells and related systems. However, an analysis of these systems, as is more obviously critical to electricity-generating systems, must take into account whether the system is merely catalytic for the reaction of interest or is a system that actually converts light energy into stored chemical energy. Thus, how one parameterizes and evaluates a heterogeneous photoinduced charge transfer process becomes a critical issue that is therefore reviewed in this work

A critical review of the role of Fc gamma receptor polymorphisms in the response to monoclonal antibodies in cancer

<p>Abstract</p> <p>Antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism of action of therapeutic monoclonal antibodies (mAbs) such as cetuximab, rituximab and trastuzumab. Fc gamma receptors (FcgR) on human white blood cells are an integral part of the ADCC pathway. Differential response to therapeutic mAbs has been reported to correlate with specific polymorphisms in two of these genes: <it>FCGR2A</it> (H131R) and <it>FCGR3A</it> (V158F). These polymorphisms are associated with differential affinity of the receptors for mAbs. This review critically examines the current evidence for genotyping the corresponding single nucleotide polymorphisms (SNPs) to predict response to mAbs in patients with cancer.</p