Improving charge separation across a hybrid oxide/polymer interface by Cs doping of the metal oxide

The process of photoinduced charge carrier separation in hybrid optoelectronics remains only partially understood, with the mechanism behind creation and dissociation of bound charge pairs (BCPs) being open questions. To investigate these processes, we employ the model hybrid ZnO/P3HT system and show that Cs doping of ZnO results in a decrease in the density of gap states at the metal oxide surface and in turn, a reduction in the yield of BCPs. This provides direct experimental evidence for a previously proposed model of BCP creation by electron trapping at the metal oxide surface states. Furthermore, Cs doping is found to substantially increase open circuit voltage in these devices without the negative effects on short circuit current that were observed in studies with other dopants. This offers new possibilities for hybrid photovoltaic devices with increased power conversion efficiencies and provides valuable insights on the charge separation processes in hybrid organic-inorganic photovoltaics.We kindly thank Prof. Annemarie Pucci and Prof. Uwe Bunz for providing access to the AFM and the device fabrication facilities, respectively. A. A. B. is a Royal Society University Research Fellow. P. E. H. and Y. V. thank the Excellence Initiative for funding.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/admi.20150061

Calcineurin signaling promotes Takotsubo syndrome

Acknowledgements We thank P. Nawroth (Department of Endocrinology, University Hospital Heidelberg, Germany) for the opportunity to conduct RIA (corticosterone), HPLC (catecholamines) and automated Cobas (hs-TnT) analysis in his laboratory. S. Martinache (Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, Germany), J. Krebs-Haupenthal, S. Harrack and M. Oestringer (all affiliated with the Institute of Experimental Cardiology, Medical Faculty, Heidelberg University, Germany) provided excellent technical assistance. This work was supported by grants from the Deutsche Forschungsgemeinschaft (BA 2258/9-1 and the CRC 1550, INST 35/1699-1) and the Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK; German Centre for Cardiovascular Research), from the BMBF (German Ministry of Education and Research) to J.B., from the German Cardiac Society (DGK) to B.B., I.B. and M.S., and from the German Heart Foundation (DHS) to M.A. C.D. and N.F. were also supported by the CRC 1550 and DZHK. The funders had no role in study design, data collection and analysis, the decision to publish or preparation of the manuscript.Peer reviewedPublisher PD

Evolution Mechanics and Perspectives on Food Web Ecology

The question how hierarchically modularised structures arise from simpler ones is of central importance when desiring to understand our world. To that end, I present the Evolution Mechanics framework which aims to find a concise description of the mechanisms by which evolutionary systems unfold into hierarchically organised modules. While inspired by the evolution of biological life, Evolution Mechanics is abstracted from it and takes a more general perspective, providing a consistent language to address the fundamental processes giving rise to the complexity we observe all around and within us. In a second part, I study the evolution and behaviour of ecological interaction networks. Using an evolutionary food web model, I investigate the structures that arise within it, its response to local and global perturbations, and its capacity to be resilient against these perturbations. These studies not only illustrate aspects of Evolution Mechanics, but stress the importance of taking into account evolutionary processes when aiming to understand these systems

Investigation of thermal management options for robots

This thesis research studies the thermal challenges of robots and evaluates the potential thermal management options. In this regard, it aims to develop and analyze various thermal management options for robotic systems. Ten different thermal management options are investigated theoretically in this thesis, such as forced air/liquid systems, heat pipes, thermal interface materials, thermoelectric generators, phase change materials, thermal insulating materials, etc. Three different thermal insulating materials (namely stone wool, fiberglass, and extruded polyurethane) and an air heating/cooling thermal management system are tested at both high and low temperatures. At 40⁰C, the energy efficiencies for the utilization of these thermal insulating materials are obtained 47.34% for the stone wool, 48.09% for the fiberglass, and 32% for the extruded polyurethane. At the same temperature, the exergy efficiencies for the utilization of these thermal insulating materials are 23.66% for the stone wool, 18.19% for the fiberglass, and 20.73% for the extruded polyurethane. At the -25⁰C, the energy efficiencies are 49.91% for the stone wool, 48.24% for the fiberglass, and 31.31% for the extruded polyurethane, while the exergy efficiencies for the stone wool, fiberglass, and extruded polyurethane are 17.25%, 21%, and 21.12%, respectively. On the other hand, the energy efficiency of the air cooling system is obtained 37.58% at 40⁰C, while the exergy efficiency is 5.89%. Finally, at -25⁰C, the energy efficiency of the air heating thermal management system is 27.32%, and its exergy efficiency becomes 3.60%, respectively.University of Ontario Institute of Technolog

Calcineurin signaling promotes Takotsubo cardiomyopathy

Abstract Aims: Takotsubo cardiomyopathy (TTC) presents an acute heart failure (AHF) syndrome that mimics the symptoms of acute myocardial infarction and is often preceded by an episode of emotional and/or physical stress. There is no specific treatment available, and evidence is based mostly on retrospective data. Here, we show that a high-dose of epinephrine (EPI) recapitulates numerous features of human TTC in mice, enabling genetic KO studies. By gene set enrichment network analysis and studies involving myocardial KO of the endogenous calcineurin inhibitor calcium-calmodulin-dependent kinase II (CaMKII), we identify cyclosporine A (CSA) as a novel potential therapy for TTC.Methods and results: high-dose EPI caused reversible AHF with significant ST-segment changes and high-sensitive Troponin T (hs-TnT) elevation. Male mice displayed markedly elevated hs-TnT and mortality when compared to females, mimicking the clinical syndrome. Left ventricular (LV) catecholamines revealed a distinct pattern of blunted norepinephrine as opposed to elevated EPI in male vs. female mice. Gene set enrichment analysis of LV RNA-sequencing after EPI revealed calcineurin-dependent pro-inflammatory gene networks to be significantly enriched, particularly in male hearts. Cardiac-specific deletion of CaMKII caused exacerbated AHF and myocardial damage, that was attenuated by CSA. In human peripheral blood mononuclear cells from TTC patients, expression of the calcineurin reporter regulator of calcineurin 1 isoform 4 (rcan1-4) was significantly increased compared to age- and gender matched controls, indicating human relevance of this pathway.Conclusion: Combining TTC disease modeling and mouse genetics identified calcineurin inhibition as a novel specific therapeutic concept to treat human TTC.</jats:p