197 research outputs found

    The Multiplicative Inverse Eigenvalue Problem over an Algebraically Closed Field

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    Let MM be a square matrix and let p(t)p(t) be a monic polynomial of degree nn. Let ZZ be a set of n×nn\times n matrices. The multiplicative inverse eigenvalue problem asks for the construction of a matrix in ZZ such that the product matrix MZMZ has characteristic polynomial p(t)p(t). In this paper we provide new necessary and sufficient conditions when ZZ is an affine variety over an algebraically closed field.Comment: 9 Page

    Deep ordinal regression framework for no-reference image quality assessment

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    A bibliometric analysis of myocardial ischemia/reperfusion injury from 2000 to 2023

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    BackgroundMyocardial ischemia/reperfusion injury (MIRI) refers to the more severe damage that occurs in the previously ischemic myocardium after a short-term interruption of myocardial blood supply followed by restoration of blood flow within a certain period of time. MIRI has become a major challenge affecting the therapeutic efficacy of cardiovascular surgery.MethodsA scientific literature search on MIRI-related papers published from 2000 to 2023 in the Web of Science Core Collection database was conducted. VOSviewer was used for bibliometric analysis to understand the scientific development and research hotspots in this field.ResultsA total of 5,595 papers from 81 countries/regions, 3,840 research institutions, and 26,202 authors were included. China published the most papers, but the United States had the most significant influence. Harvard University was the leading research institution, and influential authors included Lefer David J., Hausenloy Derek J., Yellon Derek M., and others. All keywords can be divided into four different directions: risk factors, poor prognosis, mechanisms and cardioprotection.ConclusionResearch on MIRI is flourishing. It is necessary to conduct an in-depth investigation of the interaction between different mechanisms and multi-target therapy will be the focus and hotspot of MIRI research in the future

    SSPNet: Predicting visual saliency shifts

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    When images undergo quality degradation caused by editing, compression or transmission, their saliency tends to shift away from its original position. Saliency shifts indicate visual behaviour change and therefore contain vital information regarding perception of visual content and its distortions. Given a pristine image and its distorted format, we want to be able to detect saliency shifts induced by distortions. The resulting saliency shift map (SSM) can be used to identify the region and degree of visual distraction caused by distortions, and consequently to perceptually optimise image coding or enhancement algorithms. To this end, we first create a largest-of-its-kind eye-tracking database, comprising 60 pristine images and their associated 540 distorted formats viewed by 96 subjects. We then propose a computational model to predict the saliency shift map (SSM), utilising transformers and convolutional neural networks. Experimental results demonstrate that the proposed model is highly effective in detecting distortion-induced saliency shifts in natural images

    Xenotime-type high-entropy (Dy1/7Ho1/7Er1/7Tm1/7Yb1/7Lu1/7Y1/7)PO4: A promising thermal/environmental barrier coating material for SiCf/SiC ceramic matrix composites

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    Rare-earth phosphates (REPO4) are regarded as one of the promising thermal/environmental barrier coating (T/EBC) materials for SiCf/SiC ceramic matrix composites (SiC-CMCs) owing to their excellent resistance to water vapor and CaO–MgO–Al2O3–SiO2 (CMAS). Nevertheless, a relatively high thermal conductivity (κ) of the REPO4 becomes the bottleneck for their practical applications. In this work, novel xenotime-type high-entropy (Dy1/7Ho1/7Er1/7Tm1/7Yb1/7Lu1/7Y1/7)PO4 (HE (7RE1/7)PO4) has been designed and synthesized for the first time to solve this issue. HE (7RE1/7)PO4 with a homogeneous rare-earth element distribution exhibits high thermal stability up to 1750 ℃ and good chemical compatibility with SiO2 up to 1400 ℃. In addition, the thermal expansion coefficient (TEC) of HE (7RE1/7)PO4 (5.96×10−6 ℃−1 from room temperature (RT) to 900 ℃) is close to that of the SiC-CMCs. What is more, the thermal conductivities of HE (7RE1/7)PO4 (from 4.38 W·m−1·K−1 at 100 ℃ to 2.25 W·m−1·K−1 at 1300 ℃) are significantly decreased compared to those of single-component REPO4 with the minimum value ranging from 9.90 to 4.76 W·m−1·K−1. These results suggest that HE (7RE1/7)PO4 has the potential to be applied as the T/EBC materials for the SiC-CMCs in the future

    Effects of the pyrE deletion mutant from Bacillus thuringiensis on gut microbiota and immune response of Spodoptera exigua

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    The gut microbiota is essential for the growth and development of insects, and the intestinal immune system plays a critical role in regulating the homeostasis of intestinal microorganisms and their interactions with pathogenic bacteria. Infection with Bacillus thuringiensis (Bt) can disrupt the gut microbiota of insects, but the regulatory factors governing the interaction between Bt and gut bacteria are not well understood. Uracil secreted by exogenous pathogenic bacteria can activate DUOX-mediated reactive oxygen species (ROS) production, which helps maintain intestinal microbial homeostasis and immune balance. To elucidate the regulatory genes involved in the interaction between Bt and gut microbiota, we investigate the effects of uracil derived from Bt on gut microbiota, and host immunity using a uracil deficient Bt strain (Bt GS57△pyrE) obtained by homologous recombination. We analyze the biological characteristics of the uracil deficient strain and found that the deletion of uracil in Bt GS57 strain changed the diversity of gut bacteria in Spodoptera exigua, as investigated using Illumina HiSeq sequencing. Furthermore, qRT-PCR analysis showed that compared with Bt GS57 (control), the expression of the SeDuox gene and the level of ROS were significantly decreased after feeding with Bt GS57△pyrE. Adding uracil to Bt GS57△pyrE restored the expression level of DUOX and ROS to a higher level. Additionally, we observed that PGRP-SA, attacin, defensin and ceropin genes were significant different in the midgut of S. exigua infected by Bt GS57 and Bt GS57△pyrE, with a trend of increasing first and then decreasing. These results suggest that uracil regulates and activates the DUOX-ROS system, affects the expression of antimicrobial peptide genes, and disturb intestinal microbial homeostasis. We preliminarily speculate that uracil is a key factor in the interaction between Bt and gut microbiota, and these findings provide a theoretical basis for clarifying the interaction between Bt, host, and intestinal microorganisms, as well as for gaining new insights into the insecticidal mechanism of B. thuringiensis in insects

    Effect of arotinolol on chronic heart failure: A systematic review and meta-analysis of randomized controlled trials

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    BackgroundHeart failure is the end stage of all cardiovascular diseases, which brings a heavy burden to the global health network. Arotinolol, as a new type of β Receptor blocker, has a good antihypertensive effect. Many clinical trials have observed the clinical efficacy of arotinolol in the treatment of essential hypertension. However, so far, there has been no systematic evaluation on the efficacy and safety of arotinolol in the treatment of chronic heart failure.ObjectiveThe purpose of this review was to systematically evaluate the clinical efficacy of arotinolol in patients with chronic heart failure.MethodsRandomized controlled trials (RCTs) of arotinolol in the treatment of chronic heart failure were retrieved from seven databases according to the Cochrane manual, including CNKI (China National Knowledge Infrastructure), Wan fang database, VIP database, PubMed, Sinomed, EMBASE, and the Cochrane Library databases. The main outcomes were the effective rate, left ventricular ejection fraction (LVEF), blood pressure, heart rate, cardiac index, stroke volume (SV), brain natriuretic peptide (BNP), hypersensitive C-reactive protein (Hs-CRP), left ventricular end diastolic volume (LVEDV), left ventricular end diastolic diameter (LVEDD), and adverse events (AEs).ResultsA total of 17 trials met the qualification criteria, which included 1,717 patients with heart failure. Most trials had uncertain risks in terms of random sequence generation, allocation hiding, patient loss, and result evaluation. Meta analysis showed that arotinolol significantly improved the treatment efficiency of patients with heart failure (standardized mean difference (SMD) = 4.07, 95% confidence interval (CI) [2.89, 5.72], p = 0.00, I2 = 0), LVEF (SMD = 1.59, 95% CI [0.99, 2.19], p = 0.000 0, I2 = 95.8%), cardiac index (SMD = 0.32, 95% CI [0.11, 0.53], p = 0.03), I2 = 0), SV (SMD = 2.00, 95% CI [1.57, 2.34], p = 0.000, I2 = 64.2%), lower BNP (SMD = −0.804, 95% CI [−0.97, −0.64], p = 0.000, I2 = 94.4%), and LVEDV (SMD = −0.25, 95% CI [−0.45, −0.05], p = 0.015, I2 = 0). There was no statistical significance for blood pressure (SMDsystolic pressure = −0.09, 95% CI [−0.69, 0.51], p = 0.775, I2systolic pressure = 90.2%; SMDdiastolic pressure = −0.16, 95% CI [−0.79, 0.48], P = 0.632, I2diastolic pressure = 91.2%), heart rate (SMD = −0.12, 95% CI [−1.00, 0.75], P = 0.787, I2 = 96.1%), Hs-CRP (SMD = −1.52, 95% CI [−3.43, 0.40], P = 0.121, I2 = 98.3%), and LVEDD (SMD = −0.07, 95% CI [−0.90, 0.76], P = 0.870, I2 = 96.5%).ConclusionArotinolol can safely and effectively improve the effective rate of patients with chronic heart failure, increase LVEF, increase CI and SV, and reduce BNP and LVEDV. However, because of the low overall quality of the included randomized controlled trials, these findings need to be considered carefully. More high-quality randomized controlled trials are needed for further verification, to provide a more scientific basis for the safety and effectiveness of arotinolol in the clinical treatment of heart failure.Systematic review registration[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=371214], identifier [CRD:420223371214]
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