248 research outputs found
Probing dynamics of dark energy with latest observations
We examine the validity of the CDM model, and probe for the dynamics
of dark energy using latest astronomical observations. Using the
diagnosis, we find that different kinds of observational data are in tension
within the CDM framework. We then allow for dynamics of dark energy
and investigate the constraint on dark energy parameters. We find that for two
different kinds of parametrisations of the equation of state parameter , a
combination of current data mildly favours an evolving , although the
significance is not sufficient for it to be supported by the Bayesian evidence.
A forecast of the DESI survey shows that the dynamics of dark energy could be
detected at confidence level, and will be decisively supported by the
Bayesian evidence, if the best fit model of derived from current data is
the true model.Comment: 4.5 pages, 3 figures, 1 table; references adde
Dynamic Snake Convolution based on Topological Geometric Constraints for Tubular Structure Segmentation
Accurate segmentation of topological tubular structures, such as blood
vessels and roads, is crucial in various fields, ensuring accuracy and
efficiency in downstream tasks. However, many factors complicate the task,
including thin local structures and variable global morphologies. In this work,
we note the specificity of tubular structures and use this knowledge to guide
our DSCNet to simultaneously enhance perception in three stages: feature
extraction, feature fusion, and loss constraint. First, we propose a dynamic
snake convolution to accurately capture the features of tubular structures by
adaptively focusing on slender and tortuous local structures. Subsequently, we
propose a multi-view feature fusion strategy to complement the attention to
features from multiple perspectives during feature fusion, ensuring the
retention of important information from different global morphologies. Finally,
a continuity constraint loss function, based on persistent homology, is
proposed to constrain the topological continuity of the segmentation better.
Experiments on 2D and 3D datasets show that our DSCNet provides better accuracy
and continuity on the tubular structure segmentation task compared with several
methods. Our codes will be publicly available.Comment: Accepted by ICCV 202
RNA-destabilizing Factor Tristetraprolin Negatively Regulates NF-kappa B Signaling
Tristetraprolin (TTP) is a CCCH zinc finger-containing protein that destabilizes mRNA by binding to an AU-rich element. Mice deficient in TTP develop a severe inflammatory syndrome mainly because of overproduction of tumor necrosis factor alpha. We report here that TTP also negatively regulates NF-kappa B signaling at the transcriptional corepressor level, by which it may repress inflammatory gene transcription. TTP expression inhibited NF-kappa B-dependent transcription. However, overexpression of TTP did not affect reporter mRNA stability. Instead, TTP functioned as a corepressor of p65/NF-kappa B. In support of this concept, we found that TTP physically interacted with the p65 subunit of NF-kappa B and was also associated with HDAC1, -3, and -7 in vivo. Treatment with histone deacetylase inhibitors or small interfering RNA induced HDAC1 or HDAC3 knockdown completely or partly abolished the inhibitory activity of TTP on NF-kappa B reporter activation. Consistently, chromatin immuno-precipitation showed decreased recruitment of HDAC1 and increased recruitment of CREB-binding protein on the Mcp-1 promoter in TTP(-/-) cells compared with wild-type cells. Moreover, overexpression of TTP blocked CREB-binding protein-induced acetylation of p65/NF-kappa B. Taken together, these data suggest that TTP may also function in vivo as a modulator in suppressing the transcriptional activity of NF-kappa B
Cryopreservation in Ophthalmology
Amniotic membranes (AMs) and corneas are critical materials in ocular surface reconstruction. AM has specific structures (e.g., basement and two types of cells with stemness characteristics: amniotic epithelial cells and amniotic mesenchymal cells), which contribute to its attractive physical and biological properties that make it fundamental to clinical application. The corneal endothelial cell is a vital part of the cornea, which can influence postoperative vision directly. However, widespread use of fresh AM and cornea has been limited due to their short use span and safety concerns. To overcome these concerns, different preservation methods have been introduced. Cryopreservation is distinguished from many preservation methods for its attractive advantages of prolonged use span, optimally retained tissue structure, and minimized infection risk. This review will focus on recent advances of cryopreserved AM and cornea, including different cryopreservation methods and their indications in ophthalmology
5-HydrÂoxy-1-(3-hydrÂoxy-2-naphthoÂyl)-3,5-dimethyl-2-pyrazoline
In the title molÂecule, C16H16N2O3, intraÂmolecular O—H⋯O hydrogen bonds influence the molÂecular conformation. InterÂmolecular O—H⋯O hydrogen bonds [O⋯O = 2.922 (2) Å] link the molÂecules into centrosymmetric dimers. Weak interÂmolecular C—H⋯O interÂactions assemble these dimers into layers parallel to the bc plane
Controllability results of neutral Caputo fractional functional differential equations
In this paper, using the properties of the phase space on infinite delay, generalized Gronwall inequality and fixed point theorems, the existence and controllability results of neutral fractional functional differential equations with multi-term Caputo fractional derivatives were obtained under Lipschitz and non-Lipschitz conditions
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