152 research outputs found
Response to Comment on "Pairing and Phase Separation in a Polarized Fermi Gas"
Zwierlein and Ketterle rely on subjective arguments and fail to recognize
important differences in physical parameters between our experiment and theirs.
We stand by the conclusions of our original report
Deformation of a Trapped Fermi Gas with Unequal Spin Populations
The real-space densities of a polarized strongly-interacting two-component
Fermi gas of Li atoms reveal two low temperature regimes, both with a
fully-paired core. At the lowest temperatures, the unpolarized core deforms
with increasing polarization. Sharp boundaries between the core and the excess
unpaired atoms are consistent with a phase separation driven by a first-order
phase transition. In contrast, at higher temperatures the core does not deform
but remains unpolarized up to a critical polarization. The boundaries are not
sharp in this case, indicating a partially-polarized shell between the core and
the unpaired atoms. The temperature dependence is consistent with a tricritical
point in the phase diagram.Comment: Accepted for publication in Physical Review Letter
Spatial Behavior of a Coupled System of Wave-Plate Type
The spatial behavior of a coupled system of wave-plate type is studied. We get the alternative results of Phragmén-Lindelöf type in terms of an area measure of the amplitude in question based on a first-order differential inequality. We also get the spatial decay estimates based on a second-order differential inequality
Metastability in Spin-Polarized Fermi Gases
We study the role of particle transport and evaporation on the phase
separation of an ultracold, spin-polarized atomic Fermi gas. We show that the
previously observed deformation of the superfluid paired core is a result of
evaporative depolarization of the superfluid due to a combination of enhanced
evaporation at the center of the trap and the inhibition of spin transport at
the normal-superfluid phase boundary. These factors contribute to a
nonequilibrium jump in the chemical potentials at the phase boundary. Once
formed, the deformed state is highly metastable, persisting for times of up to
2 s.Comment: 4 pages, 6 figure
Pairing and Phase Separation in a Polarized Fermi Gas
We report the observation of a pairing in a number polarized two-component
gas of atomic fermions. Beyond a critical polarization, the gas separates into
a superfluid paired core surrounded by a shell of normal unpaired fermions. The
critical polarization diminishes with decreasing attractive interaction. We
also measure the parameter \beta = 0.54 (5) describing the universal energy of
a strongly interacting Fermi gas, and find good agreement with most recent
theory. These results are relevant to predictions of exotic new phases of quark
matter and of strongly magnetized superconductors
Type-II Ising Pairing in Few-Layer Stanene
Spin-orbit coupling has proven indispensable in realizing topological
materials and more recently Ising pairing in two-dimensional superconductors.
This pairing mechanism relies on inversion symmetry breaking and sustains
anomalously large in-plane polarizing magnetic fields whose upper limit is
expected to diverge at low temperatures, although experimental demonstration of
this has remained elusive due to the required fields. In this work, the
recently discovered superconductor few-layer stanene, i.e. epitaxially strained
-Sn, is shown to exhibit a new type of Ising pairing between carriers
residing in bands with different orbital indices near the -point. The
bands are split as a result of spin-orbit locking without the participation of
inversion symmetry breaking. The in-plane upper critical field is strongly
enhanced at ultra-low temperature and reveals the sought for upturn
Exploring OCR Capabilities of GPT-4V(ision) : A Quantitative and In-depth Evaluation
This paper presents a comprehensive evaluation of the Optical Character
Recognition (OCR) capabilities of the recently released GPT-4V(ision), a Large
Multimodal Model (LMM). We assess the model's performance across a range of OCR
tasks, including scene text recognition, handwritten text recognition,
handwritten mathematical expression recognition, table structure recognition,
and information extraction from visually-rich document. The evaluation reveals
that GPT-4V performs well in recognizing and understanding Latin contents, but
struggles with multilingual scenarios and complex tasks. Specifically, it
showed limitations when dealing with non-Latin languages and complex tasks such
as handwriting mathematical expression recognition, table structure
recognition, and end-to-end semantic entity recognition and pair extraction
from document image. Based on these observations, we affirm the necessity and
continued research value of specialized OCR models. In general, despite its
versatility in handling diverse OCR tasks, GPT-4V does not outperform existing
state-of-the-art OCR models. How to fully utilize pre-trained general-purpose
LMMs such as GPT-4V for OCR downstream tasks remains an open problem. The study
offers a critical reference for future research in OCR with LMMs. Evaluation
pipeline and results are available at
https://github.com/SCUT-DLVCLab/GPT-4V_OCR
Astrocytic p75NTR expression provoked by ischemic stroke exacerbates the blood-brain barrier disruption
The disruption of the blood–brain barrier (BBB) plays a critical role in the pathology of
ischemic stroke. p75 neurotrophin receptor (p75NTR) contributes to the disruption of
the blood-retinal barrier in retinal ischemia. However, whether p75NTR influences the
BBB permeability after acute cerebral ischemia remains unknown. The present study
investigated the role and underlying mechanism of p75NTR on BBB integrity in an
ischemic stroke mouse model, middle cerebral artery occlusion (MCAO). After 24 h of
MCAO, astrocytes and endothelial cells in the infarct-affected brain area up-regulated
p75NTR. Genetic p75NTR knockdown (p75NTR+/ ) or pharmacological inhibition of
p75NTR using LM11A-31, a selective inhibitor of p75NTR, both attenuated brain damage and BBB leakage in MCAO mice. Astrocyte-specific conditional knockdown of
p75NTR mediated with an adeno-associated virus significantly ameliorated BBB disruption and brain tissue damage, as well as the neurological functions after stroke. Further
molecular biological examinations indicated that astrocytic p75NTR activated NF-κB
and HIF-1α signals, which upregulated the expression of MMP-9 and vascular endothelial growth factor (VEGF), subsequently leading to tight junction degradation after
ischemia. As a result, increased leukocyte infiltration and microglia activation exacerbated brain injury after stroke. Overall, our results provide novel insight into the role of
astrocytic p75NTR in BBB disruption after acute cerebral ischemia. The p75NTR may
therefore be a potential therapeutic target for the treatment of ischemic stroke
Cdc42-Interacting Protein-4 Promotes TGF-Β1-Induced Epithelial-Mesenchymal Transition and Extracellular Matrix Deposition in Renal Proximal Tubular Epithelial Cells
Cdc42-interacting protein-4 (CIP4) is an F-BAR (Fer/CIP4 and Bin, amphiphysin, Rvs) family member that regulates membrane deformation and endocytosis, playing a key role in extracellular matrix (ECM) deposition and invasion of cancer cells. These processes are analogous to those observed during the initial epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. The role of CIP4 in renal tubular EMT and renal tubulointerstitial fibrosis was investigated over the course of the current study, demonstrating that the expression of CIP4 increased in the tubular epithelia of 5/6-nephrectomized rats and TGF-β1 treated HK-2 cells. Endogenous CIP4 evidenced punctate localization throughout the cytosol, with elevated levels observed in the perinuclear region of HK-2 cells. Subsequent to TGF-β1 treatment, CIP4 expression increased, forming clusters at the cell periphery that gradually redistributed into the cytoplasm. Simultaneously, EMT induction in cells was confirmed by the prevalence of morphological changes, loss of E-cadherin, increase in α-SMA expression, and secretion of fibronectin. Overexpression of CIP4 promoted characteristics similar to those commonly observed in EMT, and small interfering RNA (siRNA) molecules capable of CIP4 knockdown were used to demonstrate reversed EMT. Cumulatively, results of the current study suggest that CIP4 promotes TGF-β1-induced EMT in tubular epithelial cells. Through this mechanism, CIP4 is capable of inducing ECM deposition and exacerbating progressive fibrosis in chronic renal failure
CDDSA: Contrastive Domain Disentanglement and Style Augmentation for Generalizable Medical Image Segmentation
Generalization to previously unseen images with potential domain shifts and
different styles is essential for clinically applicable medical image
segmentation, and the ability to disentangle domain-specific and
domain-invariant features is key for achieving Domain Generalization (DG).
However, existing DG methods can hardly achieve effective disentanglement to
get high generalizability. To deal with this problem, we propose an efficient
Contrastive Domain Disentanglement and Style Augmentation (CDDSA) framework for
generalizable medical image segmentation. First, a disentangle network is
proposed to decompose an image into a domain-invariant anatomical
representation and a domain-specific style code, where the former is sent to a
segmentation model that is not affected by the domain shift, and the
disentangle network is regularized by a decoder that combines the anatomical
and style codes to reconstruct the input image. Second, to achieve better
disentanglement, a contrastive loss is proposed to encourage the style codes
from the same domain and different domains to be compact and divergent,
respectively. Thirdly, to further improve generalizability, we propose a style
augmentation method based on the disentanglement representation to synthesize
images in various unseen styles with shared anatomical structures. Our method
was validated on a public multi-site fundus image dataset for optic cup and
disc segmentation and an in-house multi-site Nasopharyngeal Carcinoma Magnetic
Resonance Image (NPC-MRI) dataset for nasopharynx Gross Tumor Volume (GTVnx)
segmentation. Experimental results showed that the proposed CDDSA achieved
remarkable generalizability across different domains, and it outperformed
several state-of-the-art methods in domain-generalizable segmentation.Comment: 14 pages, 8 figure
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