Electrochemical Doping as a Way to Enhance Water Photooxidation on Nanostructured Nickel Titanate and Anatase Electrodes

A number of metal oxides have been proposed as useful materials for the photoelectrochemical (PEC) production of hydrogen from water. However, up to now, an ideal standalone material has not been found. We have investigated the possible use of nickel titanate (NiTiO3) nanorods as a photoanode. Although these electrodes absorb visible light, they show a modest PEC behavior. Interestingly, the photocurrent for water oxidation undergoes a 30-fold enhancement after an optimized reductive electrochemical pretreatment. Here, the induced doping is studied and compared with the corresponding for anatase nanoporous electrodes. The results reveal the key role of the electrolyte pH as well as the size of the electrode building blocks. The photocurrent promotion upon the electrochemical pretreatment can be ascribed to an enhanced charge transport linked to the ability of proton insertion in the crystal structure.We are grateful to the Spanish Ministry of Economy and Competitiveness (MINECO) for financial support through projects PRI-PIBIN-2011-0816, MAT2012-37676 and MAT2015-71727-R (co-financed with FEDER funds by the European Union). S.A. also thanks DST, New Delhi, for the sanction of an India–Spain collaborative research grant (DST/INT/Spain/P-37/11 dt.16th Dec 2011). D.M.-S. acknowledges MINECO for financial support through project MAT2014-59961-C2-2-R, and the Spanish Ministry of Education and Science for the award of an FPI Fellowship (BES-2004-5194)

シェリング哲学の研究 (その1) : 自然哲学から同一哲学への展開

textabstractWhile they account for one-fifth of new cancer cases, rare cancers are difficult to study. A higher than average degree of uncertainty should be accommodated for clinical as well as for population-based decision making. Rules of rational decision making in conditions of uncertainty should be rigorously followed and would need widely informative clinical trials. In principle, any piece of new evidence would need to be exploited in rare cancers. Methodologies to explicitly weigh and combine all the available evidence should be refined, and the Bayesian logic can be instrumental to this end. Likewise, Bayesian-design trials may help optimize the low number of patients liable to be enrolled in clinical studies on rare cancers, as well as adaptive trials in general, with their inherent potential of flexibility when properly applied. While clinical studies are the mainstay to test hypotheses, the potential of electronic patient records should be exploited to generate new hypotheses, to create external controls for future studies (when internal controls are unpractical), to study effectiveness of new treatments in real conditions. Framework study protocols in specific rare cancers to stepwisely test sets of new agents, as from the early post-phase I development stage, should be encouraged. Also the compassionate and the off-label settings should be exploited to generate new evidence, and flexible regulatory innovations such as adaptive licensing could convey new agents early to rare cancer patients, while generating evidence. Though validation of surrogate end points is problematic in rare cancers, the use of an updated notion of tumor response may be of great value in the single patient to optimize the use of therapies, all the more the new ones. Disease-based communities, involving clinicians and patients, should be regularly consulted by regulatory bodies when setting their policies on drug approval and reimbursement in specific rare cancers

Giving Patients’ Preferences a Voice in Medical Treatment Life Cycle : The PREFER Public–Private Project

IMI-PREFE

The influence of support and particle size on the platinum catalysed oxygen reduction reaction

A range of platinum deposits, equivalent thicknesses (?) 0.2–2.5 nm, have been synthesised on carbon and reduced titania (TiOx) supports using physical vapour deposition on (10 × 10) arrays of electrodes. For ? < 1.0 nm, discrete platinum centres are formed and the TiOx supported platinum show two distinct characteristics: (a) a strong positive shift in the potential for the oxidation of monolayers of CO with decreasing loading of Pt leading to an inability to oxidise the CO on the lowest loadings and (b) a strong negative shift in the potential for the reduction of oxygen. Both observations can be understood in terms of an increase in the irreversibility of the Pt/PtO couple at such surfaces. The same trends, although significantly weaker, are seen with the carbon supported platinum, ? < 1.0 nm, and it is suggested that the Pt/PtO couple on carbon shows intermediate kinetics between Pt on TiOx and bulk Pt. These results have significant implications for understanding the mechanism of oxygen reduction on supported Pt catalysts and hence for the search for alternative supports to platinum for ORR electrocatalysts