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Cinnamic acid sugar ester derivatives (CASEDs) are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depre...
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Cinnamic acid sugar ester derivatives (CASEDs) are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM), presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds. View Full-Text
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The genus Alnus (Betulaceae) is comprised of more than 40 species. Many species of this genus have a long history of use in folk medicines. Phytochemical investigations have revealed the presence of diarylheptanoids, polyphenols, ...
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The genus Alnus (Betulaceae) is comprised of more than 40 species. Many species of this genus have a long history of use in folk medicines. Phytochemical investigations have revealed the presence of diarylheptanoids, polyphenols, flavonoids, terpenoids, steroids and other compounds. Diarylheptanoids, natural products with a 1,7-diphenylheptane structural skeleton, are the dominant constituents in the genus, whose anticancer effect has been brought into focus. Pure compounds and crude extracts from the genus exhibit a wide spectrum of pharmacological activities both in vitro and in vivo. This paper compiles 273 naturally occurring compounds from the genus Alnus along with their structures and pharmacological activities, as reported in 138 references. View Full-Text
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Elevator safety is closely related to public safety. Overspeed governor is a crucial part of the elevator safety system. Its inspection and calibration involve the measurement of tripping velocity. The frequently-used contact-type...
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Elevator safety is closely related to public safety. Overspeed governor is a crucial part of the elevator safety system. Its inspection and calibration involve the measurement of tripping velocity. The frequently-used contact-type measurement method has risks. This paper proposes a non-contact image-recognizing measurement method by the camera, which includes the processes of rotor centre recognition, feature points matching, and tripping switches recognition. The velocity curve can be obtained by feature points displacement based on the rotor centre. Tripping switches recognition can determine the electrical and mechanical tripping velocities in the speed curve. The experimental results demonstrate that the proposed method has no significant difference from the common contact-type measurement method, while it significantly eliminates the risks of physical damage and improves measurement safety. Moreover, this paper proposes the deduction and calculation of measurement uncertainty decided by camera performance. Due to the enhancement of measuring safety, the proposed method will have further application in the field of elevator inspection. Practical application: The research on tripping velocity measurement for overspeed governor in this paper is principally based on image recognition with the help of a camera. The experiment result indicates that the proposed method is capable of completing the speed measurement for the overspeed governor without contact. The proposed method significantly mitigates the risks of physical damage and improves measurement safety rather than the contact-type measurement method. The proposed non-contact image-recognizing method can substitute for the existing contact-type method and contributes to the inspection, maintenance, and management of elevators, which will have further application prospects.
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A solid oxide fuel cell (SOFC) is a promising energy conversion device with high efficiency and low pollutant emission. The practical application of the conventional SOFCs is limited mainly because of their high operating temperat...
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A solid oxide fuel cell (SOFC) is a promising energy conversion device with high efficiency and low pollutant emission. The practical application of the conventional SOFCs is limited mainly because of their high operating temperature and the inconvenience brought by the H_2 fuel utilization. This work reviews the recent progress on intermediate temperature SOFCs especially with non-hydrogen fuels. Composite electrolyte consisting of a solid oxide ionic conducting phase and a molten carbonate phase exhibits sufficient ionic conductivity in the intermediate temperature range, i.e. 500-800 ℃, and facilitates the simultaneous conduction of H~2, O~2 and CO_3~2 ions. A single cell with the composite electrolyte shows a promising power density, 1700 mW cm~(-1) at 650 ℃ with hydrogen as the fuel. The composite electrolyte has been also employed in a direct carbon fuel cell (DCFC), and the simultaneous conduction of O~2 and CO_3~2 in the electrolyte has been proposed. Recently, perovskite structured materials are found to have good resistance to coke formation as the anode of the direct hydrocarbon solid oxide fuel cell, and several carbon resistant perovskite anodes are employed in all-perovskite structured SOFCs, which exhibit excellent performance with CH_4 and methanol as the fuel.
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Meat is the main source of protein nutrition for humans. However, given the increasing population and environmental pressure, a shortage of meat is expected in the future. The preparation of plant-based (meat) products using exist...
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Meat is the main source of protein nutrition for humans. However, given the increasing population and environmental pressure, a shortage of meat is expected in the future. The preparation of plant-based (meat) products using existing processing methods represents a breakthrough to solve the shortage of traditional animal meat in the future, and texture is a key issue determining whether plant-based (meat) products can replace traditional animal meat. Therefore, this review highlights recent progress in the texture of plant-based (meat) products. First, the texture changes in plant-based (meat) products were reviewed based on components (proteins, starch, lipids, food additives) and processing methods (processing factors, instrumental factors). Then, the current methods used to analyze the texture of plant-based (meat) products were summarized based on sensory evaluation and instrumental analysis (mechanical analysis, spectral analysis, and image analysis). Finally, this review outlined methods to improve the texture quality of plant-based (meat) products and analytical evaluation methods and provided an outlook on future research priorities.
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Arginine has a positive effect on pre-implantation development in pigs. However, the exact mechanism by which arginine promotes embryonic development is undefined. Here, single-cell RNA sequencing technology was applied to porcine...
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Arginine has a positive effect on pre-implantation development in pigs. However, the exact mechanism by which arginine promotes embryonic development is undefined. Here, single-cell RNA sequencing technology was applied to porcine in vivo pre-implantation embryos from the zygote to morula stage, it was found that that the expression of arginine metabolism-related genes clearly changed from the 2-cell stage to the 4-cell stage, when zygotic genome activation (ZGA) occurs in porcine embryos. Further analysis showed that arginine metabolism-related genes are significantly correlated with key ZGA genes. To determine the function of arginine in porcine embryos during ZGA, the in vitro fertilization embryos were cultured in PZM-3 medium (0.12 mM arginine, Control group), a modified PZM-3 medium (0 mM arginine, Block group) and a modified PZM-3 medium supplemented with arginine (0.12 mM arginine, Block + Arg group). The results showed that the 4-cell arrest rate was significantly increased in the Block group compared to the Control group ( P < 0.05). The 4-cell arrest rate in the Block + Arg group was significantly decreased than that in the Block group ( P < 0.05). Meanwhile, the expression of ZGA marker genes and SIRT1 protein in 4-cell embryos was significantly decreased in the Block group compared to the Control group, and their expression was significantly increased in the Block + Arg group. In addition, we observed that the glutathione (GSH), ATP levels, and lipid droplet contents were significantly increased, and the reactive oxygen species (ROS) level was decreased in the Block + Arg group compared to the Block group. Compared with Control group, spermine content in culture medium and the mRNA expression of ornithine decarboxylase1 (ODC1) of embryos in the Block group were significantly decreased ( P < 0.05), and those in the Block + Arg group were significantly increased compared with the Block group ( P < 0.05). Moreover, when difluoromethylornithine (an inhibitor of ODC1) was added to the modified PZM-3 medium supplemented with arginine, the effect of arginine on ZGA was inhibited. In summary, our findings demonstrated that arginine may regulate ZGA under nutrition restriction in porcine embryos by promoting polyamine synthesis.
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Antimicrobial resistance (AMR) is a global, multifaceted crisis that poses significant challenges to the successful eradication of devastating pathogens, particularly methicillin-resistant Staphylococcus aureus (MRSA), a persisten...
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Antimicrobial resistance (AMR) is a global, multifaceted crisis that poses significant challenges to the successful eradication of devastating pathogens, particularly methicillin-resistant Staphylococcus aureus (MRSA), a persistent superbug that causes devastating infections. The scarcity of new antibacterial drugs is obvious, and antivirulence strategies that reduce the pathogenicity of bacteria by weakening their virulence have become the subject of intense investigation. Alpha-hemolysin (Hla), a cytolytic pore-forming toxin, has a pivotal role in S. aureus pathogenesis. Here, we demonstrated that echinatin, a natural compound isolated from licorice, effectively inhibited the hemolytic activity of MRSA at 32?μg/mL. In addition, echinatin did not interfere with bacterial growth and had no significant cytotoxicity at the inhibitory concentration of S. aureus hemolysis. Heptamer formation tightly correlated with Hla-mediated cell invasion, whereas echinatin did not affect deoxycholic acid-induced oligomerization of Hla. Echinatin affected hemolytic activity through indirect binding to Hla as confirmed by the neutralization assay and cellular thermal shift assay (CETSA). Furthermore, qRT–PCR and western blot analyses revealed that echinatin suppressed Hla expression at both the mRNA and protein levels as well as the transcript levels of Agr quorum-sensing system-related genes. Additionally, when echinatin was added to a coculture system of A549 cells and S. aureus, it significantly reduced cell damage. Importantly, echinatin exhibited a significant therapeutic effect in an MRSA-induced mouse pneumonia model. In conclusion, the present findings demonstrated that echinatin significantly inhibits the hemolysin effect and may be a potential candidate compound for combating drug-resistant MRSA infections.
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The dramatic increase of methicillin-resistant Staphylococcus aureus (MRSA) poses a great challenge to the treatment of Staphylococcus aureus ( S. aureus ) infections. Therefore, there is an urgent need to identify novel anti-infe...
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The dramatic increase of methicillin-resistant Staphylococcus aureus (MRSA) poses a great challenge to the treatment of Staphylococcus aureus ( S. aureus ) infections. Therefore, there is an urgent need to identify novel anti-infective agents to attack new targets to overcome antibiotic resistance. Casein hydrolase P (ClpP) is a key virulence factor in S. aureus to maintain cellular homeostasis. We screened from flavonoids and finally determined that quercetin could effectively attenuate the virulence of MRSA. The results of the thermal shift assay showed that quercetin could bind to ClpP and reduce the thermal stability of ClpP, and the K D value between quercetin and ClpP was 197?nM as determined by localized surface plasmon resonance. We found that quercetin exhibited a protective role of a mouse model of MRSA-induced lethal infection in a murine model. Based on the above facts, quercetin, as a ClpP inhibitor, could be further developed as a potential candidate for antivirulence agents to combat S. aureus infections. IMPORTANCE The resistance of Staphylococcus aureus ( S. aureus ) to various antibiotics has increased dramatically, and thus the development of new anti-infective drugs with new targets is urgently needed to combat resistance. Caseinolytic peptidase P (ClpP) is a casein hydrolase that has been shown to regulate a variety of important virulence factors in S. aureus . Here, we found that quercetin, a small-molecule compound from traditional Chinese herbal flavonoids, effectively inhibits ClpP activity. Quercetin attenuates the expression of multiple virulence factors in S. aureus and effectively protects mice from lethal pneumonia caused by MRSA. In conclusion, we determined that quercetin is a ClpP inhibitor and an effective lead compound for the development of a virulence factor-based treatment for S. aureus infection.
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Lead–tin (Pb/Sn) mixed perovskites are considered as promising photovoltaic materials owing to their adjustable bandgap and excellent optoelectronic properties. The low-bandgap perovskite solar cells (PSCs) based on lead–tin mix...
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Lead–tin (Pb/Sn) mixed perovskites are considered as promising photovoltaic materials owing to their adjustable bandgap and excellent optoelectronic properties. The low-bandgap perovskite solar cells (PSCs) based on lead–tin mixed perovskites play a critical role in the overall performance of perovskite-based tandem devices. Nevertheless, the current record efficiencies for Pb/Sn PSCs are mostly reported in devices with p–i–n configuration rather than n–i–p, which restricts the further development of conventional perovskite-based tandem solar cells. Herein, this work systematically investigates the influence of the interlayers on the performance of low-bandgap PSCs by analyzing the energy losses in both n–i–p and p–i–n devices. Quasi-Fermi level splitting (QFLS) analysis of pristine films and films covering charge extraction layers reveals that the electron transport layer/perovskite interface is dominating the VOC losses. A joint experimental–simulative approach quantitatively determines the interface defect density to be more than one order in magnitude larger for the n–i–p architecture. Among the polymeric hole transport layers investigated for n–i–p devices, poly(3-hexylthiophen-2,5-diyl) (P3HT) exhibits the most favorable energy-level alignment to Pb/Sn perovskites. These results clarify the nature of VOC losses in Pb/Sn perovskites and highlight the necessity to develop electron extraction layers with a significantly reduced interface defect density.
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BackgroundExploring the correspondences across multi-view images is the basis of many computer vision tasks. However, most existing methods are limited on accuracy under challenging conditions. In order to learn more robust and ac...
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BackgroundExploring the correspondences across multi-view images is the basis of many computer vision tasks. However, most existing methods are limited on accuracy under challenging conditions. In order to learn more robust and accurate correspondences, we propose the DSD-MatchingNet for local feature matching in this paper. First, we develop a deformable feature extraction module to obtain multi-level feature maps, which harvests contextual information from dynamic receptive fields. The dynamic receptive fields provided by deformable convolution network ensures our method to obtain dense and robust correspondences. Second, we utilize the sparse-to-dense matching with the symmetry of correspondence to implement accurate pixel-level matching, which enables our method to produce more accurate correspondences. Experiments have shown that our proposed DSD-MatchingNet achieves a better performance on image matching benchmark, as well as on visual localization benchmark. Specifically, our method achieves 91.3% mean matching accuracy on HPatches dataset and 99.3% visual localization recalls on Aachen Day-Night dataset.
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