•The Mn element existence have significantly impact on the grain refinement on the as-extruded Mg-2.0Zn-1.5Mn magnesium alloy.•The Mn element acted as both microscale and nanoscale second phase ...exhibits best grain refinement.•Dynamic precipitates hinder the grain boundary migration and the micron scale second phase has a good PSN effect.•An idea model of the Mn element existence for grain refinement is put forward.
The role of Mn existence types on microstructure and mechanical properties of extruded Mg-2.0Zn-1.5Mn magnesium alloy is investigated. Four different Mn existence types in Mg-2.0Zn-1.5Mn magnesium alloy are obtained by different heat treatment. The four types include: (1) solid solution Mn atoms, (2) nanoscale α-Mn phase, (3) solid solution atoms + micron scale α-Mn phase, (4) micron scale α-Mn phase + nanoscale α-Mn phase, respectively. The result shows pre-existed nanoscale α-Mn particles present good pinning effect for refining grains. The micron scale α-Mn phase activates the particle stimulated nucleation (PSN) mechanism. The combination of micron scale α-Mn phase + nanoscale α-Mn phase state presents the best grain refining effect with an average grain size of 1.3 µm. The mechanical properties are significantly enhanced, the tensile yield strength, tensile strength and fracture elongation are 267 MPa, 305 MPa, 28.6%, respectively. Based on the results, four basic rules for preparing fine grained Mn-containing Mg alloys are proposed and an ideal pre-extrusion state of Mn-containing alloy is obtained: namely, direct extrusion in the as-cast-aging state. Besides has great potential for grain refinement, this state also can be regulated by the coordination of PSN effect and pinning effect in Mn-containing Mg alloy.
Bacterial infections have become major threats to public health all over the world. With the emergence of antibiotic resistance, it is urgent to develop novel antimicrobial materials to efficiently ...overcome drug resistance with high bactericidal activity. In this work, UiO‐66‐NH‐CO‐MoS2 nanocomposites (UNMS NCs) are constructed through the amidation reaction. The UNMS NCs are positively charged which is beneficial for capturing and restricting bacteria. Significantly, UNMS NCs possess a synergistic bactericidal efficiency based on near‐infrared irradiation (808 nm) regulated combination of photothermal, photodynamic, and peroxidase‐like enzymatic activities. Both the photodynamic property and nanozymatic activity of UNMS NCs can lead to the generation of reactive oxygen species. The UNMS NCs show high catalytic activity in a wide pH range and exhibit excellent antibacterial ability against ampicillin‐resistant Escherichia coli and methicillin‐resistant Staphylococcus aureus with negligible cytotoxicity. Interestingly, due to the 808 nm irradiation‐induced hyperthermia in the presence of UNMS NCs, the glutathione oxidation process can be accelerated, resulting in bacterial death more easily. Mice wound models are established to further manifest that UNMS NCs can promote wound healing with good biosafety in living systems.
In this work, a kind of novel positively charged UiO‐66‐NH‐CO‐MoS2 nanocomposite (UNMS NC) is fabricated through the amidation reaction. UNMS NCs possess a synergistic mechanism based on photothermal and photodynamic modulated POD‐mimic enzymatic activities to eliminate both MRSA and AREC in vitro. Animal experiments further manifest that UNMS NCs can promote wound healing with negligible toxicity.
Remote sensing image classification plays a crucial role in the field of remote sensing interpretation. With the exponential growth of multi-source remote sensing data, accurately extracting target ...features and comprehending target attributes from complex images significantly impacts classification accuracy. To address these challenges, we propose a Canny edge-enhanced multi-level attention feature fusion network (CAF) for remote sensing image classification. The original image is specifically inputted into a convolutional network for the extraction of global features, while increasing the depth of the convolutional layer facilitates feature extraction at various levels. Additionally, to emphasize detailed target features, we employ the Canny operator for edge information extraction and utilize a convolution layer to capture deep edge features. Finally, by leveraging the Attentional Feature Fusion (AFF) network, we fuse global and detailed features to obtain more discriminative representations for scene classification tasks. The performance of our proposed method (CAF) is evaluated through experiments conducted across three openly accessible datasets for classifying scenes in remote sensing images: NWPU-RESISC45, UCM, and MSTAR. The experimental findings indicate that our approach based on incorporating edge detail information outperforms methods relying solely on global feature-based classifications.
An 8-week feeding trial was undertaken to evaluate supplemental effects of AviPlus® (AP), a blend of organic acids citric acid, 25%; sorbic acid, 16.7% and essential oils thymol, 1.7%; vanillin, ...1.0%, on growth, gut microbiota, innate immunity and disease resistance of Pacific white shrimp (Litopenaeus vannamei) against Vibrio parahaemolyticus. A basal experimental diet was formulated and supplemented with 0, 0.3, 0.6, 0.9 and 1.2 g kg−1 AP to produce five test diets (Con, AP0.3, AP0.6, AP0.9 and AP1.2). Each diet was fed to triplicate groups of shrimp (0.2 ± 0.01 g, mean ± SE) to apparent satiation three times daily. Growth performance and survival rate were not significantly influenced by AP supplementation (P > 0.05). Significantly (P < 0.05) higher serum total protein was found in groups fed ≥ 0.6 g kg−1 AP compared to control. Serum alkaline phosphatase and phenoloxidase activities were significantly increased in AP0.9 and AP1.2 groups. Also, the group received AP0.6 diet showed significantly higher glutathione peroxidase activity than control. Expression of gut pro-inflammatory genes including TNF-α, LITAF and RAB6A were down-regulated by AP administration. Gut microbiota analysis showed the significant enhancement of the operational taxonomic unit (OTU) diversity and richness indices by AP application. AP supplementation led to increased abundance of Firmicutes and a reduction in abundance of Proteobacteria. Also, dietary inclusion of 1.2 g kg−1 AP led to a significant increase in the abundance of Lactobacillus in shrimp gut. The group offered AP0.3 diet showed significantly higher disease resistance than control group. Furthermore, AP application significantly enhanced relative expression of immune related genes including lysozyme, penaeidin and catalase at 48 h post challenge. In conclusion, these findings show that the tested organic acids and essential oils mixture beneficially affects intestinal microflora and improves immune response and disease resistance of L. vannamei.
•A blend of organic acids and essential oils (AP) was tested in shrimp feed.•AP application improved serum phenoloxidase and glutathione peroxidase activities.•AP enhanced abundance of Lactobacillus and reduced pathogenic bacteria in shrimp gut.•Dietary supplementation of 0.3% AP significantly improved shrimp disease resistance.•AP application enhanced expression of immune related genes at 48 h post challenge.
In this article, a shared‐control system with skill‐based share weight allocation is proposed for a robot‐assisted minimally invasive surgery (MIS) procedure. A convolution neural network (CNN) is ...trained for online skill assessment, and the result is used to generate the share weights of robot autonomy and the user remote control. The control system can ensure synchronization of the two commands from the surgeon and robot autonomy and combine them to determine the motion of the surgical instrument. In this work, a contour‐tracking task is handled by the suggested shared controller to simulate a surgical cutting operation. Experimental results on a lab‐built robotic platform are presented to show the effectiveness of the proposed method. Multiple contour‐tracking experiments have been tested to compare the tracking performances of pure manual remote control and the proposed shared‐control method. Experimental results show that the shared controller achieved 34.5% improvement in tracking accuracy in comparison with pure manual control.
Arguably almost all developments in modern credibility theory have been based on Bühlmann's fundamental Bayes approach to credibility. Despite its simple and widespread applicability, Bühlmann's ...approach leads to a linear Bayesian credibility estimator that is not robust and sensitive to heavy-tailed excess claims and may not accurately approximate a non-linear Bayesian credibility estimator. Since it is based on the sample mean, the linear credibility estimator cannot even be calculated when neither the sample mean nor the individual-level claim data are available. We present a mathematically rigorous extension of Bühlmann credibility theory and propose a general method based on an optimally weighted linear combination of multiple credibility estimators. Our approach allows various linear and nonlinear estimators with potentially different desirable properties such as robustness and efficiency to be incorporated in a dependence framework. We show that the best weights are optimal not only for finite samples but also converge to the asymptotic optimal weights. Furthermore, we introduce some finite-sample weights based on the leading terms of our asymptotic solution. These weights show remarkable performance compared with the optimal finite-sample weights while they are still relatively easy to compute for certain estimators. We perform Monte Carlo simulations to demonstrate the optimal performance in finite samples. We analyze a real-world insurance claims dataset to further illustrate the usefulness and the prediction accuracy of our proposed method.
This study aimed to explore the protective effects of Angelica sinensis polysaccharide (ASP) on rat chondrocyte injury induced by hydrogen peroxide (H2O2). Rat chondrocytes were cultured and treated ...with different concentrations of ASP alone or in combination with H2O2, and they were measured with cell viability, apoptosis, release of inflammatory cytokines, such as interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α), activity of superoxide dismutase (SOD), and catalase (CAT), and levels of malondialdehyde (MDA) production, respectively. In addition, quantitative real-time reverse transcription polymerase chain reaction was used to estimate the relative expression levels of osteoarthritis (OA)-associated genes, such as collagen type II (Col2a1), aggrecan, SOX9, matrix metalloproteinase (MMP)-1, -3, and -9, as well as tissue inhibitor of matrix metalloproteinase (TIMP)-1, respectively. Results indicated that ASP protected chondrocytes from H2O2-induced oxidative stress and subsequent cell injury through its antioxidant, antiapoptotic and anti-inflammatory effects in vitro. Our study suggests that ASP could become a therapeutic supplementation for the treatment of OA.
NFT market have developed into an annual sales scale of nearly $60 billion. After the crazy blockchain investment myth, how can the rational trading market grasp consumer demand? As the main platform ...of marketing for 21st century, social media is widely used by both traditional artists and NFT creator. When artworks are combined with NFT in social media marketing, how do they affect the willingness to purchase digital collectibles? In the hot era of GPT, how will artificial intelligence-generated content (AIGC) affect people's purchasing behavior? This article measures the impact on consumer purchasing willingness from the activity level of social media accounts (number of posts), creator attributes (human vs. artificial intelligence), published content (diversity, content tendency), etc. Through experiments, this article verifies that consumers' demand for uniqueness will positively affect the willingness to purchase digital collectibles and payment prices; artificial intelligence generated content(AIGC) wil
Cardiac fibrosis remains an unresolved problem in heart disease. Its etiology is directly caused by the activation and proliferation of cardiac fibroblasts (CFs). However, there is limited ...information regarding the biological role of cardiac fibroblasts in cardiac fibrosis. Herein, we screened out a gene, IGFBP3, whose expression significantly increased in TGF-β1-stimulated human primary CFs by mining RNA-Seq data for differential and WGCNA. We verified the IGFBP3's expression in transverse aortic constriction (TAC) surgery, isoproterenol (ISO)-induced cardiac fibrosis models, and TGFβ1-stimulated mouse primary CFs. We also found that the knockdown of IGFBP3 could inhibit the migration and proliferation ability of CFs. Furthermore, we found that aberrant N6-methyladenosine(m6A) mRNA modifications in the animal model and activated CFs may regulate the expression of IGFBP3 in developing cardiac fibrosis. Silencing METTL3 could downregulate the expression of IGFBP3 and inhibit the activation of CFs and the degree of cardiac fibrosis both in vitro and in vivo. Indeed, we also verified the expression of METTL3 and IGFBP3 in the atrial tissues of patients with atrial fibrillation (AF). Thus, METTL3 may regulate IGFBP3's expression and CFs activation via RNA epigenetic modifications, laying the foundation for a specific and novel therapeutic target in cardiac fibrosis.
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DNA methylation is one of the most important epigenetic modifications of eukaryotic genomes and is believed to play integral roles in diverse biological processes. Although DNA methylation has been ...well studied in mammals, data are limited in invertebrates, particularly Mollusca. The Pacific oyster Crassostrea gigas is an emerging genetic model for functional analysis of DNA methylation in Mollusca. Recent studies have shown that there is a positive association between methylation status and gene expression in C. gigas; however, whether this association exists at the exon level remains to be determined.
In this study, we characterized the genome-wide methylation pattern across two different tissues of C. gigas and found that methylated genes are expressed in more tissues and development stages than unmethylated genes. Furthermore, we found that different types of exons had different methylation levels, with the lowest methylation levels in the first exons, followed by the last exons, and the internal exons. We found that the exons included in the gene transcript contained significantly higher DNA methylation levels than skipped exons. We observed that the DNA methylation levels increased slowly after the start sites and end sites of exons seperately, and then decreased quickly towards the middle sites of exons. We also found that methylated exons were significantly longer than unmethylated exons.
This study constitutes the first genome-wide analysis to show an association between exon-level DNA methylation and mRNA expression in the oyster. Our findings suggest that exon-level DNA methylation may play a role in the construction of alternative splicing by positively influencing exon inclusion during transcription.
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