3,612 research outputs found
Evaluation "Angels and Demons" (WP-116)
One way to generate the money needed for sustainable innovation is by consumer choosing freely for sustainable products. This way, consumer choice pays for the innovative production method. This requires consumer willingness to buy these products. Willingness to buy is however not so easily measured as the intentions to buy may only partially predict actual purchase behaviour. There is a gap between what consumer say they want, and what they do in practice. For the specific case of sustainable production, consumers often say they are very positive about sustainable products (angelic opinion), yet in their daily behaviour they frequently tend to choose convenient and cheap products (demonic behaviour)
Onset and Recurrence of Depression as Predictors of Cardiovascular Prognosis in Depressed Acute Coronary Syndrome Patients:A Systematic Review
Background: Depression after acute coronary syndrome (ACS) is associated with worse cardiac outcomes. This systematic review evaluated whether depressed ACS patients are at differential risk depending on the recurrence and timing of onset of depressive episodes. Methods: MEDLINE, EMBASE and PsycINFO were searched from inception to 11 April 2009. Additionally, reference lists and recent tables of contents of 34 selected journals were manually searched. Eligible studies evaluated cardiovascular outcomes for subgroups of ACS patients with depression or depressive symptoms according to recurrence or onset. Results: Six studies were included that reported outcomes for subgroups of ACS patients with first-ever versus recurrent depression. Four of these reported also outcomes for post-ACS onset versus pre-ACS onset depression, and incident versus nonincident depression. Worse outcomes (odds ratio >1.4) were reported for ACS patients with first-ever depression in 3 of 6 studies (1 study p <0.05), for patients with post-ACS onset depression in 3 of 4 studies (1 study p <0.05, but better outcomes in one study) and for patients with incident depression in 2 of 4 studies (no studies p <0.05). Conclusions: Although it is still suggested that ACS patients with first and new-onset depression are at particularly increased risk of worse prognosis, the inconsistent results from the studies included in this systematic review show that there is no consistent evidence to support such statements. Copyright (C) 2011 S. Karger AG, Basel</p
A virtual engine laboratory for teaching powertrain engineering
A virtual engine laboratory application for use in automotive engineering education is proposed to allow the practical teaching of powertrain calibration. The laboratory software is built as a flexible Matlab tool that can easily be transferred for applications in other disciplines and promotes the link between teaching and research
High temporal-resolution scanning transmission electron microscopy using sparse-serpentine scan pathways
Scanning transmission electron microscopy (STEM) provides structural analysis with sub-angstrom resolution. But the pixel-by-pixel scanning process is a limiting factor in acquiring high-speed data. Different strategies have been implemented to increase scanning speeds while at the same time minimizing beam damage via optimizing the scanning strategy. Here, we achieve the highest possible scanning speed by eliminating the image acquisition dead time induced by the beam flyback time combined with reducing the amount of scanning pixels via sparse imaging. A calibration procedure was developed to compensate for the hysteresis of the magnetic scan coils. A combination of sparse and serpentine scanning routines was tested for a crystalline thin film, gold nanoparticles, and in an in-situ liquid phase STEM experiment. Frame rates of 92, 23 and 5.8 s-1 were achieved for images of a width of 128, 256, and 512 pixels, respectively. The methods described here can be applied to single-particle tracking and analysis of radiation sensitive materials
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Electron microscopy of nanoparticle superlattice formation at a solid-liquid interface in nonpolar liquids
Nanoparticle superlattice films form at the solid-liquid interface and are important for mesoscale materials, but are notoriously difficult to analyze before they are fully dried. Here, the early stages of nanoparticle assembly were studied at solid-liquid interfaces using liquid-phase electron microscopy. Oleylamine-stabilized gold nanoparticles spontaneously formed thin layers on a silicon nitride (SiN) membrane window of the liquid enclosure. Dense packings of hexagonal symmetry were obtained for the first monolayer independent of the nonpolar solvent type. The second layer, however, exhibited geometries ranging from dense packing in a hexagonal honeycomb structure to quasi-crystalline particle arrangements depending on the dielectric constant of the liquid. The complex structures formed by the weaker interactions in the second particle layer were preserved, while the surface remained immersed in liquid. Fine-tuning the properties of the involved materials can thus be used to control the three-dimensional geometry of a superlattice including quasi-crystals
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Mathematical modeling of drug-induced receptor internalization in the HER2-positive SKBR3 breast cancer cell-line
About 20% of breast cancer tumors over-express the HER2 receptor. Trastuzumab, an approved drug to treat this type of breast cancer, is a monoclonal antibody directly binding at the HER2 receptor and ultimately inhibiting cancer cell growth. The goal of our study was to understand the early impact of trastuzumab on HER2 internalization and recycling in the HER2-overexpressing breast cancer cell line SKBR3. To this end, fluorescence microscopy, monitoring the amount of HER2 expression in the plasma membrane, was combined with mathematical modeling to derive the flux of HER2 receptors from and to the membrane. We constructed a dynamic multi-compartment model based on ordinary differential equations. To account for cancer cell heterogeneity, a first, dynamic model was expanded to a second model including two distinct cell phenotypes, with implications for different conformational states of HER2, i.e. monomeric or homodimeric. Our mathematical model shows that the hypothesis of fast constitutive HER2 recycling back to the plasma membrane does not match the experimental data. It conclusively describes the experimental observation that trastuzumab induces sustained receptor internalization in cells with membrane ruffles. It is also concluded that for rare, non-ruffled (flat) cells, HER2 internalization occurs three orders of magnitude slower than for the bulk, ruffled cell population. © 2019, The Author(s)
Structural and magnetic properties of Fe/ZnSe(001) interfaces
We have performed first principles electronic structure calculations to
investigate the structural and magnetic properties of Fe/ZnSe(001) interfaces.
Calculations involving full geometry optimizations have been carried out for a
broad range of thickness of Fe layers(0.5 monolayer to 10 monolayers) on top of
a ZnSe(001) substrate. Both Zn and Se terminated interfaces have been explored.
Total energy calculations show that Se segregates at the surface which is in
agreement with recent experiments.
For both Zn and Se terminations, the interface Fe magnetic moments are higher
than the bulk bcc Fe moment.
We have also investigated the effect of adding Fe atoms on top of a
reconstructed ZnSe surface to explore the role of reconstruction of
semiconductor surfaces in determining properties of metal-semiconductor
interfaces. Fe breaks the Se dimer bond formed for a Se-rich (2x1)
reconstructed surface. Finally, we looked at the reverse growth i.e. growth of
Zn and Se atoms on a bcc Fe(001) substrate to investigate the properties of the
second interface of a magnetotunnel junction. The results are in good agreement
with the theoretical and experimental results, wherever available.Comment: 7 pages, 8 figures, accepted for publication in PR
Hierarchy of Dirac, Pauli and Klein-Gordon conserved operators in Taub-NUT background
The algebra of conserved observables of the SO(4,1) gauge-invariant theory of
the Dirac fermions in the external field of the Kaluza-Klein monopole is
investigated. It is shown that the Dirac conserved operators have physical
parts associated with Pauli operators that are also conserved in the sense of
the Klein-Gordon theory. In this way one gets simpler methods of analyzing the
properties of the conserved Dirac operators and their main algebraic structures
including the representations of dynamical algebras governing the Dirac quantum
modes.Comment: 16 pages, latex, no figure
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