Spectroscopic fingerprints of work-function-controlled phthalocyanine charging on metal surfaces

The electronic character of a π-conjugated molecular overlayer on a metal surface can change from semiconducting to metallic, depending on how molecular orbitals arrange with respect to the electrodes Fermi level. Molecular level alignment is thus a key property that strongly influences the performance of organic-based devices. In this work, we report how the electronic level alignment of copper phthalocyanines on metal surfaces can be tailored by controlling the substrate work function. We even show the way to finely tune it for one fixed phthalocyanine-metal combination without the need to intercalate substrate-functionalizing buffer layers. Instead, the work function is trimmed by appropriate design of the phthalocyanines supramolecular environment, such that charge transfer into empty molecular levels can be triggered across the metal-organic interface. These intriguing observations are the outcome of a powerful combination of surface-sensitive electron spectroscopies, which further reveal a number of characteristic spectroscopic fingerprints of a lifted LUMO degeneracy associated with the partial phthalocyanine charging.This work was supported by the Spanish Grant Nos. MAT2010-21156-C03-01, PIB2010US-00652, and the Basque Government Grant No. IT-621-13. We acknowledge funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant No. 226716.Peer Reviewe

Risk-shifting Through Issuer Liability and Corporate Monitoring

This article explores how issuer liability re-allocates fraud risk and how risk allocation may reduce the incidence of fraud. In the US, the apparent absence of individual liability of officeholders and insufficient monitoring by insurers under-mine the potential deterrent effect of securities litigation. The underlying reasons why both mechanisms remain ineffective are collective action problems under the prevailing dispersed ownership structure, which eliminates the incentives to moni-tor set by issuer liability. This article suggests that issuer liability could potentially have a stronger deterrent effect when it shifts risk to individuals or entities holding a larger financial stake. Thus, it would enlist large shareholders in monitoring in much of Europe. The same risk-shifting effect also has implications for the debate about the relationship between securities litigation and creditor interests. Credi-tors’ claims should not be given precedence over claims of defrauded investors (e.g., because of the capital maintenance principle), since bearing some of the fraud risk will more strongly incentivise large creditors, such as banks, to monitor the firm in jurisdictions where corporate debt is relatively concentrated

Prognostic value of dobutamine stress echocardiography in patients with diabetes

OBJECTIVE: The aim of this study was to assess the incremental value of dobutamine stress echocardiography (DSE) for the risk stratification of diabetic patients who are unable to perform an adequate exercise stress test. Exercise capacity is frequently impaired in patients with diabetes. The role of pharmacologic stress echocardiography in the risk stratification of diabetic patients has not been well defined. RESEARCH DESIGN AND METHODS: We studied 396 diabetic patients (mean age 61 +/- 11 years, 252 men [64%]) with limited exercise capacity who underwent DSE for evaluation of known or suspected coronary artery disease (CAD). End points were hard cardiac events (cardiac death and non

Self-assembly of bicomponent molecular monolayers: Adsorption height changes and their consequences

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.Codeposition of two molecular species [copper phtalocyanine (CuPc, donor) and perfluoropentacene (PFP, acceptor)] on noble metal (111) surfaces leads to the self-assembly of an ordered mixed layer with a maximized donor-acceptor contact area. The main driving force behind this arrangement is assumed to be the intermolecular C-Hâ̄F hydrogen-bond interactions. Such interactions would be maximized for a coplanar molecular arrangement. However, precise measurement of molecule-substrate distances in the molecular mixture reveals significantly larger adsorption heights for PFP than for CuPc. Most surprisingly, instead of leveling to increase hydrogen-bond interactions, the height difference is enhanced in the blends as compared to the heights found in single-component CuPc and PFP layers. The increased height of PFP in mixed layers points to an overall reduced interaction with the underlying substrate, and its influence on electronic properties like the interface dipole is investigated through work function measurements. © 2014 American Physical Society.This work was supported by the Spanish Grants No. MAT2010-21156-C03-01 and-C03-03, as well as No. PIB2010US-00652, and by the Basque Government (Grant No. IT-621-13). D. G. O. acknowledges support from the European Union under Grant No. FP7-PEOPLE-2010-IOF-271909. We acknowledge funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant No. 226716.Peer Reviewe

Molecular dynamics simulations of oxide memristors: thermal effects

We have extended our recent molecular-dynamic simulations of memristors to include the effect of thermal inhomogeneities on mobile ionic species appearing during operation of the device. Simulations show a competition between an attractive short-ranged interaction between oxygen vacancies and an enhanced local temperature in creating/destroying the conducting oxygen channels. Such a competition would strongly affect the performance of the memristive devices.Comment: submit/0169777; 6 pages, 4 figure

Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

OBJECTIVE: To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. PATIENTS: 30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men). METHODS: Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with (99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch. RESULTS: Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, kappa = 0.77, p = 0.001 v fundamental imaging). CONCLUSIONS: Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability

Hormone replacement therapy enhances IGF-1 signaling in skeletal muscle by diminishing miR-182 and miR-223 expressions : a study on postmenopausal monozygotic twin pairs

MiRNAs are fine-tuning modifiers of skeletal muscle regulation, but knowledge of their hormonal control is lacking. We used a co-twin case-control study design, that is, monozygotic postmenopausal twin pairs discordant for estrogen-based hormone replacement therapy (HRT) to explore estrogen-dependent skeletal muscle regulation via miRNAs. MiRNA profiles were determined from vastus lateralis muscle of nine healthy 54-62-years-old monozygotic female twin pairs discordant for HRT (median 7 years). MCF-7 cells, human myoblast cultures and mouse muscle experiments were used to confirm estrogen's causal role on the expression of specific miRNAs, their target mRNAs and proteins and finally the activation of related signaling pathway. Of the 230 miRNAs expressed at detectable levels in muscle samples, qPCR confirmed significantly lower miR-182, miR-223 and miR-142-3p expressions in HRT using than in their nonusing co-twins. Insulin/IGF-1 signaling emerged one common pathway targeted by these miRNAs. IGF-1R and FOXO3A mRNA and protein were more abundantly expressed in muscle samples of HRT users than nonusers. In vitro assays confirmed effective targeting of miR-182 and miR-223 on IGF-1R and FOXO3A mRNA as well as a dose-dependent miR-182 and miR-223 down-regulations concomitantly with up-regulation of FOXO3A and IGF-1R expression. Novel finding is the postmenopausal HRT-reduced miRs-182, miR-223 and miR-142-3p expression in female skeletal muscle. The observed miRNA-mediated enhancement of the target genes' IGF-1R and FOXO3A expression as well as the activation of insulin/IGF-1 pathway signaling via phosphorylation of AKT and mTOR is an important mechanism for positive estrogen impact on skeletal muscle of postmenopausal women.Peer reviewe

The integrated action framework of Rete Natura 2000 Basilicata

Basilicata Natura 2000 network consists of 50 Sites of Community Importance (SCI) and 17 Special Protection Zones (SPZs), covering alltogether more than 17% of the regional area. This network, partially overlapping other forms of land protection, represents a valuable environmental, agricultural and cultural heritage, in which the safeguard of natural resources and landscapes has to be coupled with the needs of the local population; especially in relation to development and social welfare. The Natura 2000 project involved a panel of experts belonging to 15 different institutions, to form a steering committee with the following professional and scientific skills: vegetation, landscape, fauna, geology, agriculture, forestry, sea, architecture and planning, territorial analysis and representation. Along the 4 years project, the steering committee designed and coordinated the activities of over 150 professionals, mostly from Basilicata, who carried out field surveys and data analysis aimed at assessing the environmental conditions in the SCI and SPZs, proposing measures and plans, implementing thematic databases. SCI/SPZ management plans, by themselves, may not be sufficient to fulfill the requirements of an effective environmental policy, which has to go along with the awareness of people, citizens and local administrators about the instances of a sustainable policy. For this reason, the activities of surveying and management have been coupled with a communication project that involves all the experts and a relevant part of professionals who participated to the Natura 2000 project. The communication activity implies the use and the creation of several tools (publishing, video, websites, meetings, photo contests, social networks ...) targeted to different groups: policy makers (local, regional, national, European ), organizations, citizens, schools, farmers, small and medium enterprises (www.natura2000basilicata.it). A further goal is to feature the environmental highlights of Basilicata which are linked to a specific and often surprising integration of an ancient human presence with the natural elements, and the role performed by the traditional farming activities in the maintenance of ecosystem dynamics and services (in particular with agriculture). In fact, a good number of Natura 2000 sites can be considered High Nature Value Farmlands (HNVF, sensu E. Andersen, 2003), in which a virtuous relationship was established a long time ago between traditional practices and the environment itself. In this context, it combines the convergence between the activities carried on the Natura 2000 network and the project Agrival (http://utagri.enea.it/projects/agrival), a research project led by ENEA in Val d'Agri, in order to experimentally contribute to the methodology for the identification of the High Nature Value Farmlands and make them cohabit with the other economic activities in the local context. The process started with the project Basilicata Natura 2000 Network is therefore an interesting methodological model that, in coherence with the financial planning of the European Community for the period 2014-2020 (Brussels, 12.12.2011, COMM. 874) puts together projects on environmental issues to boost the meeting of agricultural, environmental, cultural and productive policies, fostered by the EC, and enhancing the implementation of the "Prioritized Actions Frameworks" (PAF), pointed out by the European Commission as the optimal tools for the management of Natura 2000 networks

A two-stage online inertia estimation: Identification of primary frequency control parameters and regression-based inertia tracking

In recent years, power system inertia has significantly decreased and has become more variable due to the massive integration of converter-interfaced renewable energy sources. Real-time awareness of the inertia present in the system is essential for operators to take preventive actions and mitigate potential instability risks. Online inertia tracking methods based on field data have been used to accomplish this task. However, most existing methods are disturbance-based and few have proven effective under normal operating conditions. In addition, some methods require prior knowledge of the primary frequency control dynamics, which are usually unknown, especially in presence of power converters. To overcome these limitations, this paper proposes a two-stage online inertia estimation method. The first stage estimates the primary frequency control parameters. The second stage uses a regression-based approach to track the inertia in real time. A sensitivity analysis of the parameters of the regression model is used to determine the conditions under which the primary frequency control parameters must be updated. The performance of the method is validated using the IEEE 39-bus benchmark network under normal operating conditions and under the occurrence of large disturbances. The algorithm is also tested in the presence of converter-interfaced sources controlled in both grid-following and grid-forming modes. Real-time tests validate the applicability of the method

Display System Interface Using Visually-Evoked Cortical Potentials

A brain-computer interface system includes a video processor for producing a display signal, a temporal controller for producing a plurality of repetitive visual stimulus (RVS) signals with different respective temporal aspects, a display device that receives the display signal and displays a corresponding image on a plurality of different display regions and receives the RVS signals and displays corresponding RVS in respective ones of the display regions, an electroencephalographic (EEG) sensor for sensing a visually-evoked cortical potential (VECP) signal in a user with eyes fixated on a viewed one of the display regions, and a VECP processor for processing the VECP signal to identify the respective temporal aspect of the respective RVS of the viewed display region to estimate the eye fixation location. The RVS are generated independently of the display update/refresh rate and at sufficiently high frequencies to avoid flicker perceptible to the user