177 research outputs found

    Protective effects of β-eudesmol against septic liver injury via inhibition of NF-κB signaling

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    Purpose: To investigate the role of β-eudesmol in septic liver injury in mice.Methods: Mice were intraperitoneally injected with 50 or 100 mg/kg β-eudesmol, and then subjected to cecal ligation and puncture for the establishment of a septic model 2 h later. Haematoxylin and eosin staining was used to evaluate histopathological changes in the liver tissues. Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) staining and enzyme-linked immunosorbent assay (ELISA) were employed to determine liver damage, while inflammation and oxidative stress were evaluated by ELISA.Results: Liver tissues of septic mice showed infiltration of inflammatory cells, vacuolar degeneration and obscure nucleus. However, treatment with β-eudesmol ameliorated the histopathological changes (p < 0.01). Moreover, β-eudesmol also reduced hepatocyte apoptosis, and decreased the levels of biomarkers for liver damage. The up-regulation of TNF-α, IL-1β, IL-6 in septic mice were significantly down-regulated by β-eudesmol (p < 0.01), but increased the levels of superoxide dismutase (SOD) and glutathione (GSH) and decreased malondialdehyde (MDA) and myeloperoxidase (MPO) in order to protect the mice against sepsis. In addition, β-eudesmol attenuated the cecal ligation and punctureinduced up-regulation of p-p65 in mice (p < 0.01).Conclusion: β-Eudesmol exerts anti-inflammatory and anti-oxidant effects in septic mice by inactivating NF-κB signaling, and thus may be useful as a potential agent in the management of sepsis

    Displacement mechanism of polymeric surfactant in chemical cold flooding for heavy oil based on microscopic visualization experiments

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     In order to study the microscopic oil displacement mechanism of polymeric surfactant in chemical cold flooding for heavy oil, the indoor microscopic visualization displacement experiments were carried out. The flooding experiment of heavy oil was conducted by using water, osmotic modified oil displacing agent (a kind of polymeric surfactant) and water-in-oil emulsion (obtained by mixing polymeric surfactant and heavy oil) as displacing phases to study the mechanism of polymeric surfactant to enhance oil recovery in heavy oil reservoir. The experimental results show that the polymeric surfactant can increase the viscosity of the water phase, reduce the water-oil mobility ratio, expand the swept area, and there is no obvious fingering phenomenon which occurs during water flooding. The polymeric surfactant has the surfactant characteristics which can reduce the interfacial tension between oil and water to promote the formation of oil droplets with smaller droplet diameter. And the interfacial film composed of polymeric surfactant molecules will be formed on the surface of oil droplets to prevent the coalescence of oil droplets and improve the flow ability of oil phase. The water-in-oil emulsion can be miscible with the oil in heavy oil displacement process, and thus sweeps the areas such as the dead pores which cannot be swept by water and polymeric surfactant flooding, which increases the sweep efficiency to a certain extent.Cited as: Xu, F., Chen, Q., Ma, M., Wang, Y., Yu, F., Li, J. Displacement mechanism of polymeric surfactant in chemical cold flooding for heavy oil based on microscopic visualization experiments. Advances in Geo-Energy Research, 2020, 4(1): 77-85, doi: 10.26804/ager.2020.01.0

    A Dual Stealthy Backdoor: From Both Spatial and Frequency Perspectives

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    Backdoor attacks pose serious security threats to deep neural networks (DNNs). Backdoored models make arbitrarily (targeted) incorrect predictions on inputs embedded with well-designed triggers while behaving normally on clean inputs. Many works have explored the invisibility of backdoor triggers to improve attack stealthiness. However, most of them only consider the invisibility in the spatial domain without explicitly accounting for the generation of invisible triggers in the frequency domain, making the generated poisoned images be easily detected by recent defense methods. To address this issue, in this paper, we propose a DUal stealthy BAckdoor attack method named DUBA, which simultaneously considers the invisibility of triggers in both the spatial and frequency domains, to achieve desirable attack performance, while ensuring strong stealthiness. Specifically, we first use Discrete Wavelet Transform to embed the high-frequency information of the trigger image into the clean image to ensure attack effectiveness. Then, to attain strong stealthiness, we incorporate Fourier Transform and Discrete Cosine Transform to mix the poisoned image and clean image in the frequency domain. Moreover, the proposed DUBA adopts a novel attack strategy, in which the model is trained with weak triggers and attacked with strong triggers to further enhance the attack performance and stealthiness. We extensively evaluate DUBA against popular image classifiers on four datasets. The results demonstrate that it significantly outperforms the state-of-the-art backdoor attacks in terms of the attack success rate and stealthinessComment: 10 pages, 7 figures. Submit to ACM MM 202

    Edge data based trailer inception probabilistic matrix factorization for context-aware movie recommendation

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    The rapid growth of edge data generated by mobile devices and applications deployed at the edge of the network has exacerbated the problem of information overload. As an effective way to alleviate information overload, recommender system can improve the quality of various services by adding application data generated by users on edge devices, such as visual and textual information, on the basis of sparse rating data. The visual information in the movie trailer is a significant part of the movie recommender system. However, due to the complexity of visual information extraction, data sparsity cannot be remarkably alleviated by merely using the rough visual features to improve the rating prediction accuracy. Fortunately, the convolutional neural network can be used to extract the visual features precisely. Therefore, the end-to-end neural image caption (NIC) model can be utilized to obtain the textual information describing the visual features of movie trailers. This paper proposes a trailer inception probabilistic matrix factorization model called Ti-PMF, which combines NIC, recurrent convolutional neural network, and probabilistic matrix factorization models as the rating prediction model. We implement the proposed Ti-PMF model with extensive experiments on three real-world datasets to validate its effectiveness. The experimental results illustrate that the proposed Ti-PMF outperforms the existing ones. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

    Structural and functional characteristics of soil microbial communities in response to different ecological risk levels of heavy metals

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    ObjectiveThe potential ecological risk index (RI) is the most commonly used method to assess heavy metals (HMs) contamination in soils. However, studies have focused on the response of soil microorganisms to different concentrations, whereas little is known about the responses of the microbial community structures and functions to HMs at different RI levels.MethodsHere, we conducted soil microcosms with low (L), medium (M) and high (H) RI levels, depending on the Pb and Cd concentrations, were conducted. The original soil was used as the control (CK). High-throughput sequencing, qPCR, and Biolog plate approaches were applied to investigate the microbial community structures, abundance, diversity, metabolic capacity, functional genes, and community assembly processes.ResultThe abundance and alpha diversity indices for the bacteria at different RI levels were significantly lower than those of the CK. Meanwhile, the abundance and ACE index for the fungi increased significantly with RI levels. Acidobacteria, Basidiomycota and Planctomycetes were enriched as the RI level increased. Keystone taxa and co-occurrence pattern analysis showed that rare taxa play a vital role in the stability and function of the microbial community at different RI levels. Network analysis indicates that not only did the complexity and vulnerability of microbial community decrease as risk levels increased, but that the lowest number of keystone taxa was found at the H level. However, the microbial community showed enhanced intraspecific cooperation to adapt to the HMs stress. The Biolog plate data suggested that the average well color development (AWCD) reduced significantly with RI levels in bacteria, whereas the fungal AWCD was dramatically reduced only at the H level. The functional diversity indices and gene abundance for the microorganisms at the H level were significantly lower than those the CK. In addition, microbial community assembly tended to be more stochastic with an increase in RI levels.ConclusionOur results provide new insight into the ecological impacts of HMs on the soil microbiome at different risk levels, and will aid in future risk assessments for Pb and Cd contamination

    Endoglin promotes cell migration and invasion in endometriosis by regulating EMT

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    Objectives: This study aims to investigate the expression and role of Endoglin (ENG) in endometriosis (EM). Material and methods: In this study, quantitative real-time polymerase chain reaction, western blot and immunohistochemistry were used to examine the expression of ENG in tissues. Cellular experiments were performed to evaluate the effect of ENG on cellular biological function. Western blot was used to examine the expression of epithelial to mesenchymal transition-related proteins. Results: The expression of ENG was significantly higher in the ectopic endometriotic tissues than that in eutopic endometriotic tissues. Knockdown of ENG inhibited cell viability, migration and invasion, and induced cell apoptosis in hEM15A cells. Additionally, silenced ENG caused increased levels of E-cadherin and decreased levels of N-cadherin, vimentin, MMP-2 and MMP-9. Conclusions: These results confirmed that ENG may be involved in the development of endometriosis by promoting EMT process, revealing a new insight into the pathogenesis of endometriosis and contributing to the exploration of molecular therapeutic strategies against endometriosis
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