2,008 research outputs found

    Ultra-strong Adhesion of Graphene Membranes

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    As mechanical structures enter the nanoscale regime, the influence of van der Waals forces increases. Graphene is attractive for nanomechanical systems because its Young's modulus and strength are both intrinsically high, but the mechanical behavior of graphene is also strongly influenced by the van der Waals force. For example, this force clamps graphene samples to substrates, and also holds together the individual graphene sheets in multilayer samples. Here we use a pressurized blister test to directly measure the adhesion energy of graphene sheets with a silicon oxide substrate. We find an adhesion energy of 0.45 \pm 0.02 J/m2 for monolayer graphene and 0.31 \pm 0.03 J/m2 for samples containing 2-5 graphene sheets. These values are larger than the adhesion energies measured in typical micromechanical structures and are comparable to solid/liquid adhesion energies. We attribute this to the extreme flexibility of graphene, which allows it to conform to the topography of even the smoothest substrates, thus making its interaction with the substrate more liquid-like than solid-like.Comment: to appear in Nature Nanotechnolog

    Die Europäisierung der öffentlichen Aufgaben

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    Die zunehmende Europäisierung der öffentlichen Aufgaben ist einer der wichtigsten Trends im Wandel der Staatstätigkeit in der Bundesrepublik Deutschland und in anderen Mitgliedstaaten der Europäischen Union. In diesem Essay werden die Stufen der Europäisierung der Staatstätigkeit nachgezeichnet, in Weiterführung von Lindberg/Scheingold (1970) und Schmitter (1996) quantifiziert und hinsichtlich ihrer Kosten und ihres Nutzen erörtert. Inhalt: Stufen der Europäisierung der öffentlichen Aufgaben Der Europäisierungsgrad der öffentlichen Aufgaben von 1950 bis zum Ende des 20. Jahrhunderts Vom Nutzen und von den Kosten der Europäisierung der öffentlichen Angelegenheiten Verzeichnis der zitierten Literatu

    Capability and dependency in the Newcastle 85+ cohort study. Projections of future care needs

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    <p>Abstract</p> <p>Background</p> <p>Little is known of the capabilities of the oldest old, the fastest growing age group in the population. We aimed to estimate capability and dependency in a cohort of 85 year olds and to project future demand for care.</p> <p>Methods</p> <p>Structured interviews at age 85 with 841 people born in 1921 and living in Newcastle and North Tyneside, UK who were permanently registered with participating general practices. Measures of capability included were self-reported activities of daily living (ADL), timed up and go test (TUG), standardised mini-mental state examination (SMMSE), and assessment of urinary continence in order to classify interval-need dependency. To project future demand for care the proportion needing 24-hour care was applied to the 2008 England and Wales population projections of those aged 80 years and over by gender.</p> <p>Results</p> <p>Of participants, 62% (522/841) were women, 77% (651/841) lived in standard housing, 13% (106/841) in sheltered housing and 10% (84/841) in a care home. Overall, 20% (165/841) reported no difficulty with any of the ADLs. Men were more capable in performing ADLs and more independent than women. TUG validated self-reported ADLs. When classified by 'interval of need' 41% (332/810) were independent, 39% (317/810) required help less often than daily, 12% (94/810) required help at regular times of the day and 8% (67/810) required 24-hour care. Of care-home residents, 94% (77/82) required daily help or 24-hour care. Future need for 24-hour care for people aged 80 years or over in England and Wales is projected to increase by 82% from 2010 to 2030 with a demand for 630,000 care-home places by 2030.</p> <p>Conclusions</p> <p>This analysis highlights the diversity of capability and levels of dependency in this cohort. A remarkably high proportion remain independent, particularly men. However a significant proportion of this population require 24-hour care at home or in care homes. Projections for the next 20 years suggest substantial increases in the number requiring 24-hour care due to population ageing and a proportionate increase in demand for care-home places unless innovative health and social care interventions are found.</p

    A Statistical Method for Reassociating Human Tali and Calcanei from a Commingled Context.

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    In a commingled context, assessing that a talus and a calcaneus correspond to the same individual could become a primary step for accurately sorting human remains. For this purpose, the lengths and widths of the trochlea, posterior calcaneal articular surface, and posterior talar articular surface were measured in 197 individuals (105 males, 92 females) from the Athens Collection. A total of 12 highly accurate equations for reassociating tali and calcanei were developed, using simple and multiple linear regression analysis and they were found to be suitable for sorting commingled human remains. Bilateral asymmetry and sex did not have an effect on the accuracy of the method

    All Optical Implementation of Multi-Spin Entanglement in a Semiconductor Quantum Well

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    We use ultrafast optical pulses and coherent techniques to create spin entangled states of non-interacting electrons bound to donors (at least three) and at least two Mn2+ ions in a CdTe quantum well. Our method, relying on the exchange interaction between localized excitons and paramagnetic impurities, can in principle be applied to entangle a large number of spins.Comment: 17 pages, 3 figure

    Screening for coping style increases the power of gene expression studies

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    Background: Individuals of many vertebrate species show different stress coping styles and these have a striking influence on how gene expression shifts in response to a variety of challenges. Principal Findings: This is clearly illustrated by a study in which common carp displaying behavioural predictors of different coping styles (characterised by a proactive, adrenaline-based or a reactive, cortisol-based response) were subjected to inflammatory challenge and specific gene transcripts measured in individual brains. Proactive and reactive fish differed in baseline gene expression and also showed diametrically opposite responses to the challenge for 80% of the genes investigated. Significance: Incorporating coping style as an explanatory variable can account for some the unexplained variation that is common in gene expression studies, can uncover important effects that would otherwise have passed unnoticed and greatly enhances the interpretive value of gene expression data

    A Pair of Dopamine Neurons Target the D1-Like Dopamine Receptor DopR in the Central Complex to Promote Ethanol-Stimulated Locomotion in Drosophila

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    Dopamine is a mediator of the stimulant properties of drugs of abuse, including ethanol, in mammals and in the fruit fly Drosophila. The neural substrates for the stimulant actions of ethanol in flies are not known. We show that a subset of dopamine neurons and their targets, through the action of the D1-like dopamine receptor DopR, promote locomotor activation in response to acute ethanol exposure. A bilateral pair of dopaminergic neurons in the fly brain mediates the enhanced locomotor activity induced by ethanol exposure, and promotes locomotion when directly activated. These neurons project to the central complex ellipsoid body, a structure implicated in regulating motor behaviors. Ellipsoid body neurons are required for ethanol-induced locomotor activity and they express DopR. Elimination of DopR blunts the locomotor activating effects of ethanol, and this behavior can be restored by selective expression of DopR in the ellipsoid body. These data tie the activity of defined dopamine neurons to D1-like DopR-expressing neurons to form a neural circuit that governs acute responding to ethanol

    An empirical approach towards the efficient and optimal production of influenza-neutralizing ovine polyclonal antibodies demonstrates that the novel adjuvant CoVaccine HT(TM) is functionally superior to Freund's adjuvant

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    Passive immunotherapies utilising polyclonal antibodies could have a valuable role in preventing and treating infectious diseases such as influenza, particularly in pandemic situations but also in immunocompromised populations such as the elderly, the chronically immunosuppressed, pregnant women, infants and those with chronic diseases. The aim of this study was to optimise current methods used to generate ovine polyclonal antibodies. Polyclonal antibodies to baculovirus-expressed recombinant influenza haemagglutinin from A/Puerto Rico/8/1934 H1N1 (PR8) were elicited in sheep using various immunisation regimens designed to investigate the priming immunisation route, adjuvant formulation, sheep age, and antigen dose, and to empirically ascertain which combination maximised antibody output. The novel adjuvant CoVaccine HT™ was compared to Freund’s adjuvant which is currently the adjuvant of choice for commercial production of ovine polyclonal Fab therapies. CoVaccine HT™ induced significantly higher titres of functional ovine anti-haemagglutinin IgG than Freund’s adjuvant but with fewer side effects, including reduced site reactions. Polyclonal hyperimmune sheep sera effectively neutralised influenza virus in vitro and, when given before or after influenza virus challenge, prevented the death of infected mice. Neither the age of the sheep nor the route of antigen administration appeared to influence antibody titre. Moreover, reducing the administrated dose of haemagglutinin antigen minimally affected antibody titre. Together, these results suggest a cost effective way of producing high and sustained yields of functional ovine polyclonal antibodies specifically for the prevention and treatment of globally significant diseases.Natalie E. Stevens, Cara K. Fraser, Mohammed Alsharifi, Michael P. Brown, Kerrilyn R. Diener, John D. Haybal
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