274 research outputs found
Black-box estimation of expanding parameter for de Sitter universe
We study the black-box parameter estimation of expanding parameters and the
dynamics of Gaussian interferometric power for the de Sitter space. We find
that the state between separated open charts can be employed as probe state for
the black-box quantum metrology. This is nontrivial because the open charts are
causally disconnected and classical information can not be exchanged between
them according to the general relativity. It is shown that the mass of the
scalar field remarkably affects the accuracy of the black-box parameter
estimation in the de Sitter space, which is quite different from the flat space
case where the mass parameter does not influence the precision of estimation.
Quantum discord is found to be a key resource for the estimation of the
expanding parameter when there is no entanglement between the initially
uncorrelated open charts.It is demonstrated that the role of the probe state
between different open charts is quite distinct because curvature effect of the
de sitter space damages quantum resources for the initially correlated probe
states, while it generates quantum resources for the initially uncorrelated
probe states.Comment: 16 pages, 8 figure
A Novel Counterfactual Data Augmentation Method for Aspect-Based Sentiment Analysis
Aspect-based-sentiment-analysis (ABSA) is a fine-grained sentiment evaluation
task, which analyzes the emotional polarity of the evaluation aspects.
Generally, the emotional polarity of an aspect exists in the corresponding
opinion expression, whose diversity has great impact on model's performance. To
mitigate this problem, we propose a novel and simple counterfactual data
augmentation method to generate opinion expressions with reversed sentiment
polarity. In particular, the integrated gradients are calculated to locate and
mask the opinion expression. Then, a prompt combined with the reverse
expression polarity is added to the original text, and a Pre-trained language
model (PLM), T5, is finally was employed to predict the masks. The experimental
results shows the proposed counterfactual data augmentation method performs
better than current augmentation methods on three ABSA datasets, i.e. Laptop,
Restaurant, and MAMS.Comment: Camera-ready for ACML 202
Single Cells Are Spatial Tokens: Transformers for Spatial Transcriptomic Data Imputation
Spatially resolved transcriptomics brings exciting breakthroughs to
single-cell analysis by providing physical locations along with gene
expression. However, as a cost of the extremely high spatial resolution, the
cellular level spatial transcriptomic data suffer significantly from missing
values. While a standard solution is to perform imputation on the missing
values, most existing methods either overlook spatial information or only
incorporate localized spatial context without the ability to capture long-range
spatial information. Using multi-head self-attention mechanisms and positional
encoding, transformer models can readily grasp the relationship between tokens
and encode location information. In this paper, by treating single cells as
spatial tokens, we study how to leverage transformers to facilitate spatial
tanscriptomics imputation. In particular, investigate the following two key
questions: (1) , and (2) . By answering these two questions, we present a transformer-based
imputation framework, SpaFormer, for cellular-level spatial transcriptomic
data. Extensive experiments demonstrate that SpaFormer outperforms existing
state-of-the-art imputation algorithms on three large-scale datasets while
maintaining superior computational efficiency
Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications
Stem cell-based therapies exhibit considerable promise in the treatment of diabetes and its complications. Extensive research has been dedicated to elucidate the characteristics and potential applications of adipose-derived stromal/stem cells (ASCs). Three-dimensional (3D) culture, characterized by rapid advancements, holds promise for efficacious treatment of diabetes and its complications. Notably, 3D cultured ASCs manifest enhanced cellular properties and functions compared to traditional monolayer-culture. In this review, the factors influencing the biological functions of ASCs during culture are summarized. Additionally, the effects of 3D cultured techniques on cellular properties compared to two-dimensional culture is described. Furthermore, the therapeutic potential of 3D cultured ASCs in diabetes and its complications are discussed to provide insights for future research
Genetic diversity and runs of homozygosity analysis of Hetian sheep populations revealed by Illumina Ovine SNP50K BeadChip
Hetian sheep have a long history and a wide distribution. They are renowned for their carpet-grade wool, which makes them a valuable genetic resource in China. The survey revealed that Hetian sheep primarily inhabit three distinct ecological environments: mountains (MTS), mountain–grasslands (MGTS), and grasslands (GTS). To understand the evolutionary relationships and germplasm characteristics of Hetian sheep in these diverse environments, we randomly selected 84 healthy adult ewes from each of these ecological regions. We obtained the Illumina Ovine SNP50K BeadChip by extracting DNA from Hetian sheep ear tissue using the phenol-chloroform method. Afterward, we conducted a population genetic structure and genetic diversity analysis of Hetian sheep using the Illumina Ovine SNP50K Beadchip. Principal component analysis (PCA) and neighbor-joining (NJ) phylogenetic analysis indicated that Hetian sheep in three different ecological environments exhibit distinct genetic distances. Admixture analysis indicated that MGTS and GTS share a common ancestral origins. Additionally, the linkage disequilibrium (LD) analysis indicated that M had the highest decay rate, while MG had the lowest decay rate. Furthermore, we identified the overlapping homozygous genomic regions of Hetian sheep in the three ecological environments through runs of homozygosity (ROH) analysis. We subsequently performed gene annotation and enrichment analysis on these overlapping genomic regions. In the MTS environment, we identified 31 candidate genes associated with high-altitude environmental adaptation. These genes are involved in bone cell generation, differentiation, and the maintenance of bone homeostasis (WNT6, WNT10A, and CHSY1); tooth and tongue development (LEF1, TP63, and PRDM16); and hearing and visual functions (RBP4, ATF6, and JAG1). In the GTS environment, we identified 22 candidate genes related to economic traits, including those associated with reproduction (PLA2G4F, ACVR1, and ADCY2) and growth (CAPN3, YAP1, and FGF9). Research indicates that Hetian sheep can be divided at the genomic level into three subtypes: MTS, MGTS, and GTS. This enhances the genetic diversity of Hetian sheep germplasm resources and provides guidance for the conservation of Hetian sheep breeds. Additionally, we have identified genes related to multiparous traits in MGTS and GTS, offering insights for the selection and breeding of multiparous Hetian sheep
U-Shaped Relationship Between Functional Outcome and Serum Uric Acid in Ischemic Stroke
Background/Aims: We sought to assess a consecutive number of patients with first-ever acute ischemic stroke (AIS), the clinical relevance in regard to functional outcome of the serum uric acid (SUA) measured at admission. Methods: In 2 prospective centers for observational study, serum concentrations of SUA were measured on admission in the serum of 710 consecutive patients with AIS. SUA concentrations were determined by high-performance liquid chromatography. SUA, NIH stroke scale (NIHSS), and conventional risk factors were evaluated to determine their value to predict functional outcome within 3 months. Results: During the follow-up, an unfavorable functional outcome (defined as a mRS score > 2) was found in 219 (30.8%) patients. The unfavorable functional outcome distribution across the SUA quartiles ranged between 12.4% (third quartile) and 50.6% (first quartile). After adjusting for all other significant outcome predictors, SUA concentration remained an independent unfavorable outcome predictor with an adjusted OR of 0.996 (95% CI, 0.993-0.998; P< 0.001). Conclusions: The data show that the U-shaped nature of the exposure-risk relationship was more prominent when the data were assessed in deciles (based on the SUA values). This model predicted the lowest relative risk of unfavorable outcome in the 67th percentile (corresponding to 309 µmol/L). SUA was significantly associated with the risk of poor functional outcomes in Chinese patients with stroke
Preliminary application of improved 3D printed pathological section box to assisting stitching pathological images of bone tumor
Objective·To explore the feasibility of applying improved pathological section boxes based on image post-processing and 3D printing technology to assisting artificial intelligence (AI) in stitching pathological images of bone tumors.Methods·Bone tumor patients who underwent tumor resection surgery between February 2022 and August 2022 were enrolled. Patients and their postoperative tumor specimens were examined by CT and MRI. The skeletal anatomical landmarks of bone tumors were used to register the preoperative CT, and MRI and the postoperative CT images. The personalized pathological slice box was improved and 3D printed to guide the cutting direction of bone tumor specimens. The large pathological slices were grid-like segmented and performed with hematoxylin-eosin staining. After AI stitching the pathological images, the pathological tumor boundaries were compared with the preoperative radiological boundaries.Results·Four patients with bone tumors (2 bone metastatic neoplasm, 1 osteosarcoma, and 1 chondrosarcoma; 3 males and 1 female) were collected to design the pathological section box with an average age of (40.25±25.70) years. The lesions included 3 cases of femur and 1 case of ilium. The mean maximum tumor diameter was (12.10±4.02) cm. The modified 3D printed pathological section box could fit the surface of bone tumor individually,and overcame the problems of difficult cutting or inaccurate cutting location caused by excessive movement of bone tumor specimens in the primary pathological section box. The pathological boundaries could be completely obtained and compared with the preoperative MRI boundaries for colocalization. The outline features of the section boxes could help AI to restore the permutation of pathological fragments, and the image stitching time decreased from the previous seventy hours to one hour while the boundary coincidence rates increased to 90%.Conclusion·The improved pathological section box of 3D printing can accurately assist AI in stitching pathological images, greatly improve the efficiency of pathological image stitching and achieve the colocalization between preoperative MRI and pathological images of bone tumor specimens
A compact core-jet structure in the changing-look Seyfert NGC 2617
The nearby face-on spiral galaxy NGC 2617 underwent an unambiguous
'inside-out' multi-wavelength outburst in Spring 2013, and a dramatic Seyfert
type change probably between 2010 and 2012, with the emergence of broad optical
emission lines. To search for the jet activity associated with this variable
accretion activity, we carried out multi-resolution and multi-wavelength radio
observations. Using the very long baseline interferometric (VLBI) observations
with the European VLBI Network (EVN) at 1.7 and 5.0 GHz, we find that NGC 2617
shows a partially synchrotron self-absorbed compact radio core with a
significant core shift, and an optically thin steep-spectrum jet extending
towards the north up to about two parsecs in projection. We also observed NGC
2617 with the electronic Multi-Element Remotely Linked Interferometer Network
(e-MERLIN) at 1.5 and 5.5 GHz, and revisited the archival data of the Very
Large Array (VLA) and the Very Long Baseline Array (VLBA). The radio core had a
stable flux density of about 1.4 mJy at 5.0 GHz between 2013 June and 2014
January, in agreement with the expectation of a supermassive black hole in the
low accretion rate state. The northern jet component is unlikely to be
associated with the 'inside-out' outburst of 2013. Moreover, we report that
most optically selected changing-look AGN at z<0.83 are sub-mJy radio sources
in the existing VLA surveys at 1.4 GHz, and it is unlikely that they are more
active than normal AGN at radio frequencies.Comment: 10 pages, 7 figures, accepted for publication in MNRA
Bone Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Recovery Following Spinal Cord Injury via Improvement of the Integrity of the Blood-Spinal Cord Barrier
Mesenchymal stem cell (MSC) transplantation has been shown to represent a potential treatment for traumatic spinal cord injury (SCI). However, there are several obstacles that need to be overcome before MSCs can be considered for clinical application, such as failure of MSCs to reach the spinal cord lesion core and possible tumor formation. Recent studies have suggested that MSC treatment is beneficial owing to paracrine-secreted factors. Extracellular vesicles are considered to be some of the most valuable paracrine molecules. However, the therapeutic mechanism of extracellular vesicles on spinal cord injury has not been studied clearly. Therefore, our study investigated the effect of systemic administration of extracellular vesicles on the loss of motor function after SCI and examined the potential mechanisms underlying their effects. Disruption of the blood-spinal cord barrier (BSCB) is a crucial factor that can be detrimental to motor function recovery. Pericytes are an important component of the neurovascular unit, and play a pivotal role in maintaining the structural integrity of the BSCB. Our study demonstrated that administration of bone mesenchymal stem cell-derived extracellular vesicles (BMSC-EV) reduced brain cell death, enhanced neuronal survival and regeneration, and improved motor function compared with the administration of BMSC-EV free culture media (EV-free CM). Besides, the BSCB was attenuated and pericyte coverage was significantly decreased in vivo. Furthermore, we found that exosomes reduced pericyte migration via downregulation of NF-κB p65 signaling, with a consequent decrease in the permeability of the BSCB. In summary, we identified that extracellular vesicles treatment suppressed the migration of pericytes and further improved the integrity of the BSCB via NF-κB p65 signaling in pericytes. Our data suggest that extracellular vesicles may serve as a promising treatment strategy for SCI
Case report: Clinical features of pediatric acute myeloid leukemia presenting with cardiac tamponade: a case series study and literature review
ObjectiveThis study aims to elucidate the clinical features observed in cases of pediatric acute myeloid leukemia (AML) initially presenting with cardiac tamponade and to share treatment experiences.Materials and methodsFive pediatric patients were initially diagnosed with AML accompanied by cardiac myeloid sarcoma (MS). The diagnosis was established by examining our hospital records and reviewing pertinent literature from 1990 to July 2023, accessible through MEDLINE/PubMed. We comprehensively assessed the clinical characteristics and treatment modalities employed for these patients.ResultFive pediatric patients presented with acute symptoms, including shortness of breath, malaise, cough, and fever, leading to their hospitalization. Physical examination revealed irritability, hypoxia, tachypnea, tachycardia, and hypotension. Initial detection utilized chest X-ray or echocardiogram, leading to subsequent diagnoses based on pericardial effusion and/or bone marrow examination. Two patients received chemotherapy at the time of initial diagnosis, one with cytarabine and etoposide, and the other with cytarabine and cladribine. Post-treatment, their bone marrow achieved remission, and over a 2.5-year follow-up, their cardiac function remained favorable. Unfortunately, the remaining three patients succumbed within two weeks after diagnosis, either due to receiving alternative drugs or without undergoing chemotherapy.ConclusionThis is the first and largest case series of pediatric AML patients with cardiac MS, manifesting initially with cardiac tamponade. It highlights the rarity and high mortality associated with this condition. The critical factors for reducing mortality include identifying clinical manifestations, conducting thorough physical examinations, performing echocardiography promptly, initiating early and timely pericardial drainage, and avoiding cardiotoxic chemotherapy medications
- …