Publications

Giant physical responses were discovered, in numerous systems, when two phases coexist; for example, near a phase transition. An intermetallic FeRh system undergoes a first-order antiferromagnetic to ferromagnetic transition above room temperature and shows two-phase coexistence near the transition. We have investigated the effect of an electric field to FeRh/PMN-PT heterostructures and report 8% change in the electrical resistivity of FeRh films. Such a 'giant' electroresistance (GER) response is striking in metallic systems, in which external electric fields are screened, and thus only weakly influence the carrier concentrations and mobilities. We show that our FeRh films comprise coexisting ferromagnetic and antiferromagnetic phases with different resistivities and the origin of the GER effect is the strain-mediated change in their relative proportions. Finally, the observed behaviour is reminiscent of colossal magnetoresistance in perovskite manganites and illustrates the role of mixed-phase coexistence in achieving large changes in physical properties with low-energy external perturbation.

<p>Supplementary Table 3. The Adjusted Associations of Scaled Body Composition Measurements (Per SD Increase) with Reduced RDI and Relative Changes (%) in the Number of Moderate and Severe Adverse Events</p>

Self-complexation of triblock copolymers based on undeca- and heptadecathiophene cores attached to generation three Fréchet-type poly(benzyl ether) dendrons in solution at low temperature leads to the formation of relatively small but well-defined supramolecular assemblies. The formation of these aggregates is associated with a strong thermochromic effect. Upon cooling dilute solutions, minor concentration-independent changes in the optical absorption due to intrachain planarization precede significant concentration-dependent thermochromic changes that are shown to originate from intermolecular p-p stacking interactions. The structurally well-defined nature of the substrates enables the determination of distinct temperature regimes for both intra- and intermolecular thermochromic changes. Furthermore, combining thermodynamic expressions for both the concentration and temperature dependence of aggregation allows a quantitative analysis of the self-assembly phenomenon. The results show that the supramolecular aggregates are relatively small, yet well-defined involving from 5 to 6 molecules in an average aggregate. The apparent size limitation of the aggregates is ascribed to steric constraints imparted by the dendritic wedges. Relatively high exothermicities accompany the aggregation process, increasing with conjugation length from -73.0 kJ/mol with the undecathiophene triblock (G3-T11-G3) to -85.8 kJ/mol for the heptadecathiophene analogue (G3-T17-G3), suggesting that p-p stacking is the driving force for complexation

<p>Understanding the coordination of ecosystem functions across biomes and climate is still a major challenge that hampers our ability to properly predict biosphere response to climate change. Theories such as the leaf economics spectrum and the least cost investment strategy postulate that plants optimize the rate of investment in transpiration, photosynthetic capacity, and nitrogen (N) allocation dependent on the ratio of their costs to gain given their resources and environment.</p><p>In this contribution we test whether theories about functional traits coordination at leaf and organs level are emerging at ecosystem scale. We further investigate the existence of a global spectrum of ecosystem functional properties, and analyze how state of the art terrestrial biosphere models reproduce the spectrum.</p><p>To do so we used data of CO<sub>2</sub>, water and energy exchange for 164 sites (1237 site years) from the FLUXNET LaThuile and FLUXNET 2015 datasets with at least 3 years of data. For 61 sites, we were able to compile site information on canopy-scale measurements of foliar N concentration, maximum leaf area index , and stand age, from the literature.</p><p>We find evidence that a global spectrum of ecosystem functional properties exist, and that most of the variability (66.2%) is captured by three dimensions. The first dimension represents ecosystem productivity; the second the water availability gradient, and climate limitations to productivity; the third dimension reflects ecosystem respiration potential and carbon-use efficiency and is related to aridity and stand age and disturbance regimes. The first two dimensions of the spectrum are well captured by ecosystem models, while the third dimension is poorly reproduced. This might be related to the spin up of the models (steady-state condition) or to an incomplete representation of processes related to age that might limit the ability of models to accurately predict the dynamic carbon, water and nutrient cycling in ecosystems in disturbed areas.</p><p>Finally, we show across ecosystems globally that leaf level theories can be in some cases translated to the ecosystem scale. As a main example we found an inverse relationship between photosynthetic N and water use efficiency as postulated by the least cost investment theory across FLUXNET sites. However, this is possible only when the contribution of vegetation is properly accounted for, and evaporation from soil and wet surfaces is removed from the analysis. This highlights that emerging biological patterns at ecosystem scale might be masked by other factors related to physical rather than biological responses.</p>

Growing global energy demands and climate change motivate the development of new renewable energy technologies. In this context, water splitting using sustainable energy sources has emerged as an attractive process for carbon-neutral fuel cycles. A key scientific challenge to achieving this overall goal is the invention of new catalysts for the reductive and oxidative conversions of water to hydrogen and oxygen, respectively. This review article will highlight progress in molecular electrochemical approaches for catalytic reduction of protons to hydrogen, focusing on complexes of earth-abundant metals that can function in pure aqueous or mixed aqueous-organic media. The use of water as a reaction medium has dual benefits of maintaining high substrate concentration as well as minimizing the environmental impact from organic additives and by-products.

Purpose – Recognition of the importance and difficulty of engaging physicians in organisational change has sparked an explosion of literature. The social identity approach, by considering engagement in terms of underlying group identifications and intergroup dynamics, may provide a framework for choosing among the plethora of proposed engagement techniques. This paper seeks to address this issue. Design/methodology/approach – The authors examined how four disparate organisations engaged physicians in change. Qualitative methods included interviews (109 managers and physicians), observation, and document review. Findings – Beyond a universal focus on relationship-building, sites differed radically in their preferred strategies. Each emphasised or downplayed professional and/or organisational identity as befit the existing level of inter-group closeness between physicians and managers: an independent practice association sought to enhance members' identity as independent physicians; a hospital, engaging community physicians suspicious of integration, stressed collaboration among separate, equal partners; a developing integrated-delivery system promoted alignment among diverse groups by balancing “systemness” with subgroup uniqueness; a medical group established a strong common identity among employed physicians, but practised pragmatic co-operation with its affiliates. Research limitations/implications – The authors cannot confirm the accuracy of managers' perceptions of the inter-group context or the efficacy of particular strategies. Nonetheless, the findings suggested the fruitfulness of social identity thinking in approaching physician engagement. Practical implications – Attention to inter-group dynamics may help organisations engage physicians more effectively. Originality/value – This study illuminates and explains variation in the way different organisations engage physicians, and offers a theoretical basis for selecting engagement strategies.

Natural gas (Methane) is currently the primary source of catalytic hydrogen production, accounting for three quarters of the annual global dedicated hydrogen production (about 70 M tons). Steam–methane reforming (SMR) is the currently used industrial process for hydrogen production. However, the SMR process suffers with insufficient catalytic activity, low long-term stability, and excessive energy input, mostly due to the handling of large amount of CO2 coproduced. With the demand for anticipated hydrogen production to reach 122.5 M tons in 2024, novel and upgraded catalytic processes are desired for more effective utilization of precious natural resources. In this review, we summarized the major descriptors of catalyst and reaction engineering of the SMR process and compared the SMR process with its derivative technologies, such as dry reforming with CO2 (DRM), partial oxidation with O2, autothermal reforming with H2O and O2. Finally, we discussed the new progresses of methane conversion: direct decomposition to hydrogen and solid carbon and selective oxidation in mild conditions to hydrogen containing liquid organics (i.e., methanol, formic acid, and acetic acid), which serve as alternative hydrogen carriers. We hope this review will help to achieve a whole picture of catalytic hydrogen production from methane.