1,953 research outputs found
Spontaneous Pattern Formation in a Polariton Condensate
Polariton condensation can be regarded as a self-organization phenomenon,
where phase ordering is established among particles in the system. In such
condensed systems, further ordering can possibly occur in the particle density
distribution, under particular experimental conditions. In this work we report
on spontaneous pattern formation in a polariton condensate under non-resonant
optical pumping. The slightly elliptical ring-shaped excitation laser we employ
is such to force condensation to occur in a single-energy state with periodic
boundary conditions, giving rise to a multi-lobe standing wave patterned state
Spontaneous self-ordered states of vortex-antivortex pairs in a Polariton Condensate
Polariton condensates have proved to be model systems to investigate
topological defects, as they allow for direct and non-destructive imaging of
the condensate complex order parameter. The fundamental topological excitations
of such systems are quantized vortices. In specific configurations, further
ordering can bring the formation of vortex lattices. In this work we
demonstrate the spontaneous formation of ordered vortical states, consisting in
geometrically self-arranged vortex-antivortex pairs. A mean-field generalized
Gross-Pitaevskii model reproduces and supports the physics of the observed
phenomenology
Spin-to-Orbital Angular Momentum Conversion in Semiconductor Microcavities
We experimentally demonstrate a technique for the generation of optical beams
carrying orbital angular momentum using a planar semiconductor microcavity.
Despite being isotropic systems, the transverse electric - transverse magnetic
(TE-TM) polarization splitting featured by semiconductor microcavities allows
for the conversion of the circular polarization of an incoming laser beam into
the orbital angular momentum of the transmitted light field. The process
implies the formation of topological entities, a pair of optical half-vortices,
in the intracavity field
IL-33 ameliorates Alzheimer’s disease-like pathology and cognitive decline
Alzheimer’s disease (AD) is a devastating condition with no known effective treatment. AD is characterized by memory loss as well as impaired locomotor ability, reasoning, and judgment. Emerging evidence suggests that the innate immune response plays a major role in the pathogenesis of AD. In AD, the accumulation of β-amyloid (Aβ) in the brain perturbs physiological functions of the brain, including synaptic and neuronal dysfunction, microglial activation, and neuronal loss. Serum levels of soluble ST2 (sST2), a decoy receptor for interleukin (IL)-33, increase in patients with mild cognitive impairment, suggesting that impaired IL-33/ST2 signaling may contribute to the pathogenesis of AD. Therefore, we investigated the potential therapeutic role of IL-33 in AD, using transgenic mouse models. Here we report that IL-33 administration reverses synaptic plasticity impairment and memory deficits in APP/PS1 mice. IL-33 administration reduces soluble Aβ levels and amyloid plaque deposition by promoting the recruitment and Aβ phagocytic activity of microglia; this is mediated by ST2/p38 signaling activation. Furthermore, IL-33 injection modulates the innate immune response by polarizing microglia/macrophages toward an antiinflammatory phenotype and reducing the expression of proinflammatory genes, including IL-1β, IL-6, and NLRP3, in the cortices of APP/PS1 mice. Collectively, our results demonstrate a potential therapeutic role for IL-33 in AD
X-Net: Brain Stroke Lesion Segmentation Based on Depthwise Separable Convolution and Long-range Dependencies
The morbidity of brain stroke increased rapidly in the past few years. To
help specialists in lesion measurements and treatment planning, automatic
segmentation methods are critically required for clinical practices. Recently,
approaches based on deep learning and methods for contextual information
extraction have served in many image segmentation tasks. However, their
performances are limited due to the insufficient training of a large number of
parameters, which sometimes fail in capturing long-range dependencies. To
address these issues, we propose a depthwise separable convolution based X-Net
that designs a nonlocal operation namely Feature Similarity Module (FSM) to
capture long-range dependencies. The adopted depthwise convolution allows to
reduce the network size, while the developed FSM provides a more effective,
dense contextual information extraction and thus facilitates better
segmentation. The effectiveness of X-Net was evaluated on an open dataset
Anatomical Tracings of Lesions After Stroke (ATLAS) with superior performance
achieved compared to other six state-of-the-art approaches. We make our code
and models available at https://github.com/Andrewsher/X-Net.Comment: MICCAI 201
Genomic and Resistome Analyses of <em>Elizabethkingia anophelis</em> Strain B2D isolated from Dental Plaque of Patient
\ua9 2024, HH Publisher. All rights reserved.In this study, strain B2D isolated from a dental plaque sample of a human patient was studied for its general characteristics, taxonomic identification, genome features, and resistome profile. The bacterium exhibited antibiotic resistance to all beta-lactam antibiotics, nitrofuran, and sulfonamides, with high minimum inhibitory concentrations. It was only sensitive to the fluoroquinolone ciprofloxacin and intermediately susceptible to aminoglycoside tobramycin. A preliminary identification through 16S rRNA gene sequences revealed that it shared the highest sequence identity with Elizabethkingia anophelis subsp. endophytica JM-87T (100%) and Elizabethkingia anophelis subsp. anophelis R26T (99.31%). The draft genome of strain B2D was approximately 3.9 Mbp with 50 contigs and 35.5% GC content. A 16S rRNA gene and core genes-based phylogenetic analyses revealed a close phylogenetic relationship between strain B2D and the other Elizabethkingia type strains. An above species level threshold average nucleotide identity value confirmed its taxonomic identity as Elizabethkingia anophelis. Furthermore, we conducted a resistome analysis of strain B2D and Elizabethkingia type strains, revealing the presence of widespread antibiotic resistance genes, including beta-lactamases and genes associated with cationic antiseptic resistance and glycopeptide resistance. Overall, the multidrug resistant profile of strain B2D as elucidated and confirmed through whole genome analysis indicated its potential as a reservoir of beta-lactamase genes. Moreover, its presence within dental plaque in the human oral cavity prompts speculation regarding its role as an opportunistic pathogen capable of causing infections, particularly in immunocompromised individuals
Probing the Dynamics of Spontaneous Quantum Vortices in Polariton Superfluids
The experimental investigation of spontaneously created vortices is of utmost
importance for the understanding of quantum phase transitions towards a
superfluid phase, especially for two dimensional systems that are expected to
be governed by the Berezinski-Kosterlitz-Thouless physics. By means of time
resolved near-field interferometry we track the path of such vortices, created
at random locations in an exciton-polariton condensate under pulsed
non-resonant excitation, to their final pinning positions imposed by the
stationary disorder. We formulate a theoretical model that successfully
reproduces the experimental observations
Are interventions to increase the uptake of screening for cardiovascular disease risk factors effective? a systematic review and meta-analysis
Background: Cardiovascular disease (CVD) is the leading cause of death globally. However many individuals are unaware of their CVD risk factors. The objective of this systematic review is to determine the effectiveness of existing intervention strategies to increase uptake of CVD risk factors screening. Methods: A systematic search was conducted through Pubmed, CINAHL, EMBASE and Cochrane Central Register of Controlled Trials. Additional articles were located through cross-checking of the references list and bibliography citations of the included studies and previous review papers. We included intervention studies with controlled or baseline comparison groups that were conducted in primary care practices or the community, targeted at adult populations (randomized controlled trials, non-randomized trials with controlled groups and pre- and post-intervention studies). The interventions were targeted either at individuals, communities, health care professionals or the health-care system. The main outcome of interest was the relative risk (RR) of screening up take rates due to the intervention. Results: We included 21 studies in the meta-analysis. The risk of bias for randomization was low to medium in the randomized controlled trials, except for one, and high in the non-randomized trials. Two analyses were performed; optimistic (using the highest effect sizes) and pessimistic (using the lowest effect sizes). Overall, interventions were shown to increase the uptake of screening for CVD risk factors (RR 1.443; 95% CI 1.264 to 1.648 for pessimistic analysis and RR 1.680; 95% CI 1.420 to 1.988 for optimistic analysis). Effective interventions that increased screening participation included: use of physician reminders (RR ranged between 1.392; 95% CI 1.192 to 1.625, and 1.471; 95% CI 1.304 to 1.660), use of dedicated personnel (RR ranged between 1.510; 95% CI 1.014 to 2.247, and 2.536; 95% CI 1.297 to 4.960) and provision of financial incentives for screening (RR 1.462; 95% CI 1.068 to 2.000). Meta-regression analysis showed that the effect of CVD risk factors screening uptake was not associated with study design, types of population or types of interventions. Conclusions: Interventions using physician reminders, using dedicated personnel to deliver screening, and provision of financial incentives were found to be effective in increasing CVD risk factors screening uptake
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