153 research outputs found

    Structure of diethyl‐phosphonic acid anchoring group affects the charge‐separated state on an iridium(III) complex functionalized NiO surface

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    Abstract Cyclometalated Iridium(III) complexes, i. e . [Ir(C N) 2 (dppz)][PF 6 ], bearing either two or four ‐CH 2 PO(OH) 2 anchoring groups ( IrP 2 dppz or IrP 4 dppz ) are explored as photosensitizers for p‐type dye sensitized solar cell (DSSC). The synthetic route is described and the iridium(III) complexes are characterized with respect to their electrochemical and photophysical properties. The modified anchoring ligand geometry exploited in this work not only alters the electronic nature of the complex (that is by destabilizing the LUMO energetically) but more importantly improves the grafting ability of the complex towards the NiO surface. The photoinduced long‐lived charge separated state (CSS) at the NiO|IrP x dppz interface is of a different nature comparing the two complexes. For IrP 2 dppz and IrP 4 dppz the electron density of the CSS dominantly resides on the dppz and the C N ligand, respectively. The stability of the CSS can be correlated to the solar cell performance in NiO‐based p‐DSSCs, which yield conversion efficiencies which are among the highest in the class of iridium(III) complexes developed for p‐DSSCs

    Clustering of galaxies around GRB sight-lines

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    There is evidence of an overdensity of strong intervening MgII absorption line systems distributed along the lines of sight towards GRB afterglows relative to quasar sight-lines. If this excess is real, one should also expect an overdensity of field galaxies around GRB sight-lines, as strong MgII tends to trace these sources. In this work, we test this expectation by calculating the two point angular correlation function of galaxies within 120â€Čâ€Č^{\prime\prime} (∌470 h71−1 Kpc\sim470~h_{71}^{-1}~\mathrm{Kpc} at ⟹z⟩∌0.4\langle z\rangle \sim0.4) of GRB afterglows. We compare the Gamma-ray burst Optical and Near-infrared Detector (GROND) GRB afterglow sample -- one of the largest and most homogeneous samples of GRB fields -- with galaxies and AGN found in the COSMOS-30 photometric catalog. We find no significant signal of anomalous clustering of galaxies at an estimated median redshift of z∌0.3z\sim0.3 around GRB sight-lines, down to KAB<19.3K_{\mathrm{AB}}<19.3. This result is contrary to the expectations from the MgII excess derived from GRB afterglow spectroscopy, although many confirmed galaxy counterparts to MgII absorbers may be too faint to detect in our sample -- especially those at z>1z>1. We note that the addition of higher sensitivity Spitzer IRAC or HST WFC3 data for even a subset of our sample would increase this survey's depth by several orders of magnitude, simultaneously increasing statistics and enabling the investigation of a much larger redshift space.}Comment: 10 pages, 6 figures. A&A accepte

    Using peer education to improve diabetes management and outcomes in a low-income setting: A randomized controlled trial

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    Background: Diabetes is an important health burden in Indonesia. However, diabetes management and treatment remain poor, with most people with diabetes in Indonesia not achieving the recommended blood glucose levels. Peer education may have particular potential in low-income settings in complementing diabetes care without being a large additional strain on the health system. Methods/design: This cluster randomized controlled trial aims to identify the effect of the implementation of peer education for patients with type 2 diabetes on diabetes-related outcomes in Aceh, Indonesia, which will complement the diabetes treatment provided at primary-care health posts (puskesmas). Altogether, 29 puskesmas were recruited in Banda Aceh and Aceh Besar, each of which was randomly assigned to either the control or the intervention group. Then, 534 people with diabetes were identified and recruited through their respective puskesmas. The intervention consists of up to two peer education groups per puskesmas, which are led by previously trained people with diabetes. Peer education sessions are held every month for 18 months, with follow-up data being collected 9 and 18 months after the first peer education session. The main objective is to improve diabetes management and the health behavior of participants receiving peer education to reduce their average blood glucose levels as measured by glycated hemoglobin (HbA1c) levels. Secondary outcomes are the effects of peer education on lipid levels, waist circumference, blood pressure, quality of life, treatment adherence, diabetes knowledge, physical activity, and dietary diversity. Data sources for the measurement of outcomes include patient and health facility surveys and biomarker measurements. An economic evaluation will be conducted to assess the cost-effectiveness of the intervention. Discussion: This trial will contribute to the evidence on the effectiveness and cost-effectiveness of peer education in improving diabetes management in a low-income setting in Indonesia and in other comparable contexts

    Associations between oxytocin and vasopressin concentrations, traumatic event exposure and posttraumatic stress disorder symptoms: group comparisons, correlations, and courses during an internet-based cognitive-behavioural treatment

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    Background: Posttraumatic stress disorder (PTSD) is characterized by impairments in extinction learning and social behaviour, which are targeted by trauma-focused cognitive behavioural treatment (TF-CBT). The biological underpinnings of TF-CBT can be better understood by adding biomarkers to the clinical evaluation of interventions. Due to their involvement in social functioning and fear processing, oxytocin and arginine vasopressin might be informative biomarkers for TF-CBT, but to date, this has never been tested. Objective: To differentiate the impact of traumatic event exposure and PTSD symptoms on blood oxytocin and vasopressin concentrations. Further, to describe courses of PTSD symptoms, oxytocin and vasopressin during an internet-based TF-CBT and explore interactions between these parameters. Method: We compared oxytocin and vasopressin between three groups of active and former male service members of the German Armed Forces (n = 100): PTSD patients (n = 39), deployed healthy controls who experienced a deployment-related traumatic event (n = 33) and non-deployed healthy controls who never experienced a traumatic event (n = 28). PTSD patients underwent a 5-week internet-based TF-CBT. We correlated PTSD symptoms with oxytocin and vasopressin before treatment onset. Further, we analysed courses of PTSD symptoms, oxytocin and vasopressin from pre- to post-treatment and 3 months follow-up, as well as interactions between the three parameters. Results: Oxytocin and vasopressin did not differ between the groups and were unrelated to PTSD symptoms. PTSD symptoms were highly stable over time, whereas the endocrine parameters were not, and they also did not change in mean. Oxytocin and vasopressin were not associated with PTSD symptoms longitudinally. Conclusions: Mainly due to their insufficient intraindividual stability, single measurements of endogenous oxytocin and vasopressin concentrations are not informative biomarkers for TF-CBT. We discuss how the stability of these biomarkers might be increased and how they could be better related to the specific impairments targeted by TF-CBT

    Model-Based Engineering fĂŒr die Automatisierung von ValidierungsaktivitĂ€ten am Beispiel Fahrerassistenzsysteme

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    Dieser Beitrag untersucht Potenziale des Einsatzes von MBE-AnsÀtzen bei der Validierung von Fahrerassistenzsystemen. Ziel ist die Untersuchung der Machbarkeit des Aufbaus einer Validierungsumgebung zur Automatisierung von Tests im Rahmen der kontinuierlichen Validierung von Fahrerassistenzsystemen. [... aus der Einleitung

    Time resolved in-situ multi-contrast X-ray imaging of melting in metals

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    In this work, the application of a time resolved multi-contrast beam tracking technique to the investigation of the melting and solidification process in metals is presented. The use of such a technique allows retrieval of three contrast channels, transmission, refraction and dark-field, with millisecond time resolution. We investigated different melting conditions to characterize, at a proof-of-concept level, the features visible in each of the contrast channels. We found that the phase contrast channel provides a superior visibility of the density variations, allowing the liquid metal pool to be clearly distinguished. Refraction and dark-field were found to highlight surface roughness formed during solidification. This work demonstrates that the availability of the additional contrast channels provided by multi-contrast X-ray imaging delivers additional information, also when imaging high atomic number specimens with a significant absorption

    Gesellschaftliche Akzeptanzfragen bei der Umsetzung von Wasserstofftechnologien

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    Die Bundesrepublik Deutschland hat sich zum Ziel gesetzt, bis 2045 klimaneutral zu werden. Das kann nur funktionieren, wenn fossile Rohstoffe durch erneuerbare Energien ersetzt werden - insbesondere in den Bereichen Industrie und Verkehr. Ein wesentlicher Baustein in diesem Transformationsprozess ist die Errichtung einer Wasserstoffwirtschaft, innerhalb derer Strom aus erneuerbaren Energien in grĂŒnen Wasserstoff umgewandelt und dieser als EnergietrĂ€ger vor allem in den Bereichen Industrie und Verkehr angewendet wird
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