158 research outputs found
Electrochemistry and application of a novel monosubstituted squarate electron-transfer mediator in a glucose oxidase-doped poly(phenol) sensor
Electrosynthetic poly(phenol) nanofilms were deposited in situ on platinum electrodes
in the presence and absence of glucose oxidase. The synthesis charges and currents of
the nonconducting polymer films were recorded at various applied potentials for films grown
from 25–100 mM phenol concentrations. Film parameters such as the standard rate constant
for film deposition, film thickness, and surface concentration of the poly(phenol) films were
evaluated from the cyclic and step voltammograms of the polymerization process. A novel
electron-transfer mediator consisting of monosubstituted 4-hydroxycyclobut-3-ene-1,2-dione
(squarate) was used as a mediator for Pt/poly(phenol) nano-film/GOx amperometric glucose
biosensors. Amperometric responses for 3-diphenylamino-4-hydroxycyclobut-3-ene-1,2-
dione (diphenylaminosquarate: E°′ = of +328 mV/Ag-AgCl at pH 7.0)-mediated systems
were measured by both steady-state amperometric and cyclic voltammetry. The sensor sensitivity
was calculated to be 558 nA cm
–2
(µM)
–1
Realistic loophole-free Bell test with atom-photon entanglement
The establishment of nonlocal correlations, obtained through the violation of
a Bell inequality, is not only important from a fundamental point of view, but
constitutes the basis for device-independent quantum information technologies.
Although several nonlocality tests have been performed so far, all of them
suffered from either the locality or the detection loopholes. Recent studies
have suggested that the use of atom-photon entanglement can lead to Bell
inequality violations with moderate transmission and detection efficiencies. In
this paper we propose an experimental setup realizing a simple atom-photon
entangled state that, under realistic experimental parameters available to
date, achieves a significant violation of the Clauser-Horn-Shimony-Holt
inequality. Most importantly, the violation remains when considering typical
detection efficiencies and losses due to required propagation distances.Comment: 21 pages, 5 figures, 3 table, to appear in Nature Com
Teacher Perceptions of Appropriate Norms for Smartphone Use During Class
The increase in smartphone use among U.S. adolescents has become a significant concern. Self-regulating smartphone use is difficult for adolescents, as notifications from social media and entertainment apps provide a sense of instant gratification. Addressing problematic smartphone use has become urgent given that adolescents’ physical and mental health has declined, including increased obesity, anxiety and depression, and smartphone addiction. Learning is also impeded when students continuously shift attention between course content and their smartphones, preventing the brain from engaging in the deep thinking necessary for long-term memory storage, retention, and retrieval. However, it is more common to see smartphones present in the classroom as teachers integrate technology to engage students, trusting them to use their devices responsibly with or without the presence of a school-wide electronic device policy. The purpose of this qualitative study was to explore teachers’ perceptions of appropriate norms for smartphone use in the classroom. Applying the value-focused thinking framework, semistructured, eight open-ended interviews were conducted with high school teachers. Participants shared their experiences with students’ and their own smartphone use during class, revealing discrepancies in beliefs about student versus teacher smartphone use, usefulness of smartphones, picking their battles when enforcing policies, and need for support from administrators, colleagues, and parents. These findings have implications for positive social change as the insights provided can inform school-wide electronic device policies with the potential to enhance student learning otherwise impeded by compulsive classroom smartphone use
Transport Properties of the Quark-Gluon Plasma -- A Lattice QCD Perspective
Transport properties of a thermal medium determine how its conserved charge
densities (for instance the electric charge, energy or momentum) evolve as a
function of time and eventually relax back to their equilibrium values. Here
the transport properties of the quark-gluon plasma are reviewed from a
theoretical perspective. The latter play a key role in the description of
heavy-ion collisions, and are an important ingredient in constraining particle
production processes in the early universe. We place particular emphasis on
lattice QCD calculations of conserved current correlators. These Euclidean
correlators are related by an integral transform to spectral functions, whose
small-frequency form determines the transport properties via Kubo formulae. The
universal hydrodynamic predictions for the small-frequency pole structure of
spectral functions are summarized. The viability of a quasiparticle description
implies the presence of additional characteristic features in the spectral
functions. These features are in stark contrast with the functional form that
is found in strongly coupled plasmas via the gauge/gravity duality. A central
goal is therefore to determine which of these dynamical regimes the quark-gluon
plasma is qualitatively closer to as a function of temperature. We review the
analysis of lattice correlators in relation to transport properties, and
tentatively estimate what computational effort is required to make decisive
progress in this field.Comment: 54 pages, 37 figures, review written for EPJA and APPN; one parag.
added end of section 3.4, and one at the end of section 3.2.2; some Refs.
added, and some other minor change
Review: The increasing importance of carbon nanotubes and nanostructured conducting polymers in biosensors
The growing need for analytical devices requiring smaller sample volumes, decreased power consumption and improved performance have been driving forces behind the rapid growth in nanomaterials research. Due to their dimensions, nanostructured materials display unique properties not traditionally observed in bulk materials. Characteristics such as increased surface area along with enhanced electrical/optical properties make them suitable for numerous applications such as nanoelectronics, photovoltaics and chemical/biological sensing. In this review we examine the potential that exists to use nanostructured materials for biosensor devices. By incorporating nanomaterials, it is possible to achieve enhanced sensitivity, improved response time and smaller size. Here we report some of the success that has been achieved in this area. Many nanoparticle and nanofibre geometries are particularly relevant, but in this paper we specifically focus on organic nanostructures, reviewing conducting polymer nanostructures and carbon nanotubes
Customer emotions in service failure and recovery encounters
Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences
PVC-LOT-004-D-137
This article discusses the role of embodiment in judgment and choice to (a) attain clarity on conceptual and methodological issues by presenting a literature review of prior empirical research on embodiment, (b) gain an integrative view on the topic of embodiment in judgment and choice by proposing somatic marker theory as a unifying conceptual framework for bridging cognition and affect in terms of embodiment, and (c) discuss and clarify ideas and directions for further research on the topic
ADAMTS13 regulation of VWF multimer distribution in severe COVID‐19
Background
Consistent with fulminant endothelial cell activation, elevated plasma von Willebrand factor (VWF) antigen levels have been reported in patients with COVID-19. The multimeric size and function of VWF are normally regulated through A Disintegrin And Metalloprotease with ThrombSpondin Motif type 1 motif, member 13 (ADAMTS-13)--mediated proteolysis.
Objectives
This study investigated the hypothesis that ADAMTS-13 regulation of VWF multimer distribution may be impaired in severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection contributing to the observed microvascular thrombosis.
Patients and Methods
Patients with COVID-19 (n = 23) were recruited from the Beaumont Hospital Intensive Care Unit (ICU) in Dublin. Plasma VWF antigen, multimer distribution, ADAMTS-13 activity, and known inhibitors thereof were assessed.
Results
We observed markedly increased VWF collagen-binding activity in patients with severe COVID-19 compared to controls (median 509.1 versus 94.3 IU/dl). Conversely, plasma ADAMTS-13 activity was significantly reduced (median 68.2 IU/dl). In keeping with an increase in VWF:ADAMTS-13 ratio, abnormalities in VWF multimer distribution were common in patients with COVID-19, with reductions in high molecular weight VWF multimers. Terminal sialylation regulates VWF susceptibility to proteolysis by ADAMTS-13 and other proteases. We observed that both N- and O-linked sialylation were altered in severe COVID-19. Furthermore, plasma levels of the ADAMTS-13 inhibitors interleukin-6, thrombospondin-1, and platelet factor 4 were significantly elevated.
Conclusions
These findings support the hypothesis that SARS-CoV-2 is associated with profound quantitative and qualitative increases in plasma VWF levels, and a multifactorial down-regulation in ADAMTS-13 function. Further studies will be required to determine whether therapeutic interventions to correct ADAMTS-13-VWF multimer dysfunction may be useful in COVID-microvascular thrombosis and angiopathy
An international parentage and identification panel for the domestic cat (Felis catus)
Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite-based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random-bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender-specific markers, amelogenin and zinc-finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random-bred cat populations
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