125 research outputs found

    Catalytic Potential of Post-Transition Metal Doped Graphene-Based Single-Atom Catalysts for the CO2 Electroreduction Reaction

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    Catalysts are required to ensure electrochemical reduction of CO2 to fuels proceeds at industrially acceptable rates and yields. As such, highly active and selective catalysts must be developed. Herein, a density functional theory study of p-block element and noble metal doped graphene-based single-atom catalysts in two defect sites for the electrochemical reduction of CO2 to CO and HCOOH is systematically undertaken. It is found that on all of the systems considered, the thermodynamic product is HCOOH. Pb/C3, Pb/N4 and Sn/C3 are identified as having the lowest overpotential for HCOOH production while Al/C3, Al/N4, Au/C3 and Ga/C3 are identified as having the potential to form higher order products due to the strength of binding of adsorbed HCOOH

    Non-destructive depth reconstruction of Al-Al2_2Cu layer structure with nanometer resolution using extreme ultraviolet coherence tomography

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    Non-destructive cross-sectional characterization of materials systems with a resolution in the nanometer range and the ability to allow for time-resolved in-situ studies is of great importance in material science. Here, we present such a measurements method, extreme ultraviolet coherence tomography (XCT). The method is non-destructive during sample preparation as well as during the measurement, which is distinguished by a negligible thermal load as compared to electron microscopy methods. Laser-generated radiation in the extreme ultraviolet (XUV) and soft x-ray range is used for characterization. The measurement principle is interferometric and the signal evaluation is performed via an iterative Fourier analysis. The method is demonstrated on the metallic material system Al-Al2_2Cu and compared to electron and atomic force microscopy measurements. We also present advanced reconstruction methods for XCT which even allow for the determination of the roughness of outer and inner interfaces.Comment: First two authors contributed equally to this work and are ordered alphabetically. 14 page

    A Beautiful Thing: A Service Learning Partnership Develops

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    This roundtable presents multiple perspectives on a multi-year partnership between an urban school and its university neighbor. Building and nurturing a thriving mutually beneficial partnership between an urban Pre-K-8 school and its neighboring university is, as the principal of Cesar Batalla School often says, “a beautiful thing.” Cesar Batalla, serving 800 students and families from a multilingual, multiethnic community in a low-income neighborhood, is located a stone’s throw from a mid-sized suburban, private university that attracts undergraduate and graduate students with little personal firsthand experience with racial, ethnic and linguistic diversity, or of poverty and its challenges. “Geographical neighbors, yet worlds apart” would aptly describe the university school juxtaposition before we embarked upon our partnership. Transforming a coincidental proximity into a deep partnership has been a journey of many discoveries

    Preserving π-conjugation in covalently functionalized carbon nanotubes for ptoelectronic applications

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    Covalent functionalization tailors carbon nanotubes for a wide range of applications in varying environments. Its strength and stability of attachment come at the price of degrading the carbon nanotubes sp2 network and destroying the tubes electronic and optoelectronic features. Here we present a non- destructive, covalent, gram-scale functionalization of single-walled carbon nanotubes by a new [2+1] cycloaddition. The reaction rebuilds the extended π-network, thereby retaining the outstanding quantum optoelectronic properties of carbon nanotubes, including bright light emission at high degree of functionalization (1 group per 25 carbon atoms). The conjugation method described here opens the way for advanced tailoring nanotubes as demonstrated for light-triggered reversible doping through photochromic molecular switches and nanoplasmonic gold-nanotube hybrids with enhanced infrared light emission

    Population pharmacokinetics of ciprofloxacin in neonates and young infants less than 3 months age

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    Ciprofloxacin is used in neonates with suspected or documented Gram-negative serious infections. Currently, its use is off-label partly because of lack of pharmacokinetic studies. Within the FP7 EU project TINN (Treat Infection in NeoNates), our aim was to evaluate the population pharmacokinetics of ciprofloxacin in neonates and young infants \u3c3 months of age and define the appropriate dose in order to optimize ciprofloxacin treatment in this vulnerable population. Blood samples were collected from neonates treated with ciprofloxacin and concentrations were quantified by high-pressure liquid chromatography-mass spectrometry. Population pharmacokinetic analysis was performed using NONMEM software. The data from 60 newborn infants (postmenstrual age [PMA] range, 24.9 to 47.9 weeks) were available for population pharmacokinetic analysis. A two-compartment model with first-order elimination showed the best fit with the data. A covariate analysis identified that gestational age, postnatal age, current weight, serum creatinine concentration, and use of inotropes had a significant impact on ciprofloxacin pharmacokinetics. Monte Carlo simulation demonstrated that 90% of hypothetical newborns with a PMA of \u3c34 weeks treated with 7.5 mg/kg twice daily and 84% of newborns with a PMA ≥34 weeks and young infants receiving 12.5 mg/kg twice daily would reach the AUC/MIC target of 125, using the standard EUCAST MIC susceptibility breakpoint of 0.5 mg/liter. The associated risks of overdose for the proposed dosing regimen were \u3c8%. The population pharmacokinetics of ciprofloxacin was evaluated in neonates and young infants \u3c3 months old, and a dosing regimen was established based on simulation

    from a better etiological understanding, through valid diagnosis, to more effective health care

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    Background Autism Spectrum Disorder (ASD) is a severe, lifelong neurodevelopmental disorder with early onset that places a heavy burden on affected individuals and their families. Due to the need for highly specialized health, educational and vocational services, ASD is a cost- intensive disorder, and strain on health care systems increases with increasing age of the affected individual. Methods The ASD-Net will study Germany’s largest cohort of patients with ASD over the lifespan. By combining methodological expertise from all levels of clinical research, the ASD-Net will follow a translational approach necessary to identify neurobiological pathways of different phenotypes and their appropriate identification and treatment. The work of the ASD-Net will be organized into three clusters concentrating on diagnostics, therapy and health economics. In the diagnostic cluster, data from a large, well-characterized sample (N = 2568) will be analyzed to improve the efficiency of diagnostic procedures. Pattern classification methods (machine learning) will be used to identify algorithms for screening purposes. In a second step, the developed algorithm will be tested in an independent sample. In the therapy cluster, we will unravel how an ASD-specific social skills training with concomitant oxytocin administration can modulate behavior through neurobiological pathways. For the first time, we will characterize long-term effects of a social skills training combined with oxytocin treatment on behavioral and neurobiological phenotypes. Also acute effects of oxytocin will be investigated to delineate general and specific effects of additional oxytocin treatment in order to develop biologically plausible models for symptoms and successful therapeutic interventions in ASD. Finally, in the health economics cluster, we will assess service utilization and ASD-related costs in order to identify potential needs and cost savings specifically tailored to Germany. The ASD-Net has been established as part of the German Research Network for Mental Disorders, funded by the BMBF (German Federal Ministry of Education and Research). Discussion The highly integrated structure of the ASD-Net guarantees sustained collaboration of clinicians and researchers to alleviate individual distress, harm, and social disability of patients with ASD and reduce costs to the German health care system. Trial registration Both clinical trials of the ASD- Net are registered in the German Clinical Trials Register: DRKS00008952 (registered on August 4, 2015) and DRKS00010053 (registered on April 8, 2016)

    Functional Connectivity Analyses in Imaging Genetics: Considerations on Methods and Data Interpretation

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    Functional magnetic resonance imaging (fMRI) can be combined with genotype assessment to identify brain systems that mediate genetic vulnerability to mental disorders (“imaging genetics”). A data analysis approach that is widely applied is “functional connectivity”. In this approach, the temporal correlation between the fMRI signal from a pre-defined brain region (the so-called “seed point”) and other brain voxels is determined. In this technical note, we show how the choice of freely selectable data analysis parameters strongly influences the assessment of the genetic modulation of connectivity features. In our data analysis we exemplarily focus on three methodological parameters: (i) seed voxel selection, (ii) noise reduction algorithms, and (iii) use of additional second level covariates. Our results show that even small variations in the implementation of a functional connectivity analysis can have an impact on the connectivity pattern that is as strong as the potential modulation by genetic allele variants. Some effects of genetic variation can only be found for one specific implementation of the connectivity analysis. A reoccurring difficulty in the field of psychiatric genetics is the non-replication of initially promising findings, partly caused by the small effects of single genes. The replication of imaging genetic results is therefore crucial for the long-term assessment of genetic effects on neural connectivity parameters. For a meaningful comparison of imaging genetics studies however, it is therefore necessary to provide more details on specific methodological parameters (e.g., seed voxel distribution) and to give information how robust effects are across the choice of methodological parameters

    Discrepancies between dimensions of interoception in autism: implications for emotion and anxiety

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    Emotions and affective feelings are influenced by one's internal state of bodily arousal via interoception. Autism Spectrum Conditions (ASC) are associated with difficulties in recognising others' emotions, and in regulating own emotions. We tested the hypothesis that, in people with ASC, such affective differences may arise from abnormalities in interoceptive processing. We demonstrated that individuals with ASC have reduced interoceptive accuracy (quantified using heartbeat detection tests) and exaggerated interoceptive sensibility (subjective sensitivity to internal sensations on self-report questionnaires), reflecting an impaired ability to objectively detect bodily signals alongside an over-inflated subjective perception of bodily sensations. The divergence of these two interoceptive axes can be computed as a trait prediction error. This error correlated with deficits in emotion sensitivity and occurrence of anxiety symptoms. Our results indicate an origin of emotion deficits and affective symptoms in ASC at the interface between body and mind, specifically in expectancy-driven interpretation of interoceptive information
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