93 research outputs found
Spin Hall effect in the kagome lattice with Rashba spin-orbit interaction
We study the spin Hall effect in the kagom\'{e} lattice with Rashba
spin-orbit coupling. The conserved spin Hall conductance (see
text) and its two components, i.e., the conventional term
and the spin-torque-dipole term , are numerically
calculated, which show a series of plateaus as a function of the electron Fermi
energy . A consistent two-band analysis, as well as a Berry-phase
interpretation, is also given. We show that these plateaus are a consequence of
the various Fermi-surface topologies when tuning . In particular,
we predict that compared to the case with the Fermi surface encircling the
point in the Brillouin zone, the amplitude of the spin Hall
conductance with the Fermi surface encircling the points is twice
enhanced, which makes it highly meaningful in the future to systematically
carry out studies of the -valley spintronics.Comment: 7 pages, 3 figures. Phys. Rev. B (in press
Unified Image and Video Saliency Modeling
Visual saliency modeling for images and videos is treated as two independent
tasks in recent computer vision literature. While image saliency modeling is a
well-studied problem and progress on benchmarks like SALICON and MIT300 is
slowing, video saliency models have shown rapid gains on the recent DHF1K
benchmark. Here, we take a step back and ask: Can image and video saliency
modeling be approached via a unified model, with mutual benefit? We identify
different sources of domain shift between image and video saliency data and
between different video saliency datasets as a key challenge for effective
joint modelling. To address this we propose four novel domain adaptation
techniques - Domain-Adaptive Priors, Domain-Adaptive Fusion, Domain-Adaptive
Smoothing and Bypass-RNN - in addition to an improved formulation of learned
Gaussian priors. We integrate these techniques into a simple and lightweight
encoder-RNN-decoder-style network, UNISAL, and train it jointly with image and
video saliency data. We evaluate our method on the video saliency datasets
DHF1K, Hollywood-2 and UCF-Sports, and the image saliency datasets SALICON and
MIT300. With one set of parameters, UNISAL achieves state-of-the-art
performance on all video saliency datasets and is on par with the
state-of-the-art for image saliency datasets, despite faster runtime and a 5 to
20-fold smaller model size compared to all competing deep methods. We provide
retrospective analyses and ablation studies which confirm the importance of the
domain shift modeling. The code is available at
https://github.com/rdroste/unisalComment: Presented at the European Conference on Computer Vision (ECCV) 2020.
R. Droste and J. Jiao contributed equally to this work. v3: Updated Fig. 5a)
and added new MTI300 benchmark results to supp. materia
Highly exposed {001} facets of titanium dioxide modified with reduced graphene oxide for dopamine sensing
Titanium dioxide (TiO2) with highly exposed {001} facets was synthesized through a facile solvo-thermal method and its surface was decorated by using reduced graphene oxide (rGO) sheets. The morphology and chemical composition of the prepared rGO/TiO2 {001} nanocomposite were examined by using suitable characterization techniques. The rGO/TiO2 {001} nanocomposite was used to modify glassy carbon electrode (GCE), which showed higher electrocatalytic activity towards the oxidation of dopamine (DA) and ascorbic acid (AA), when compared to unmodified GCE. The differential pulse voltammetric studies revealed good sensitivity and selectivity nature of the rGO/TiO2 {001} nanocomposite modified GCE for the detection of DA in the presence of AA. The modified GCE exhibited a low electrochemical detection limit of 6 μM over the linear range of 2–60 μM. Overall, this work provides a simple platform for the development of GCE modified with rGO/TiO2 {001} nanocomposite with highly exposed {001} facets for potential electrochemical sensing applications
Novel Sulfated Polysaccharides Disrupt Cathelicidins, Inhibit RAGE and Reduce Cutaneous Inflammation in a Mouse Model of Rosacea
Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37.We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37.Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases
Modelling the regulation of telomere length: the effects of telomerase and G-quadruplex stabilising drugs
Telomeres are guanine-rich sequences at the end of chromosomes which shorten during each replication event and trigger cell cycle arrest and/or controlled death (apoptosis) when reaching a threshold length. The enzyme telomerase replenishes the ends of telomeres and thus prolongs the life span of cells, but also causes cellular immortalisation in human cancer. G-quadruplex (G4) stabilising drugs are a potential anticancer treatment which work by changing the molecular structure of telomeres to inhibit the activity of telomerase. We investigate the dynamics of telomere length in different conformational states, namely t-loops, G-quadruplex structures and those being elongated by telomerase. By formulating deterministic differential equation models we study the effects of various levels of both telomerase and concentrations of a G4-stabilising drug on the distribution of telomere lengths, and analyse how these effects evolve over large numbers of cell generations. As well as calculating numerical solutions, we use quasicontinuum methods to approximate the behaviour of the system over time, and predict the shape of the telomere length distribution. We find those telomerase and G4-concentrations where telomere length maintenance is successfully regulated. Excessively high levels of telomerase lead to continuous telomere lengthening, whereas large concentrations of the drug lead to progressive telomere erosion. Furthermore, our models predict a positively skewed distribution of telomere lengths, that is, telomeres accumulate over lengths shorter than the mean telomere length at equilibrium. Our model results for telomere length distributions of telomerase-positive cells in drug-free assays are in good agreement with the limited amount of experimental data available
Development and Applications of Fluorogen/Light-Up RNA Aptamer Pairs for RNA Detection and More.
The central role of RNA in living systems made it highly desirable to have noninvasive and sensitive technologies allowing for imaging the synthesis and the location of these molecules in living cells. This need motivated the development of small pro-fluorescent molecules called "fluorogens" that become fluorescent upon binding to genetically encodable RNAs called "light-up aptamers." Yet, the development of these fluorogen/light-up RNA pairs is a long and thorough process starting with the careful design of the fluorogen and pursued by the selection of a specific and efficient synthetic aptamer. This chapter summarizes the main design and the selection strategies used up to now prior to introducing the main pairs. Then, the vast application potential of these molecules for live-cell RNA imaging and other applications is presented and discussed.journal article2020importe
Investigating the influences of redox buffer compositions on the amyloid fibrillogenesis of hen egg-white lysozyme
Effect of glutathione redox system on lysozyme refolding in size exclusion chromatography
Stability of hen egg white lysozyme during denaturation is enhanced by pretreatment with supercritical carbon dioxide
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