22 research outputs found

    Salidroside Inhibits HMGB1 Acetylation and Release through Upregulation of SirT1 during Inflammation

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    HMGB1, a highly conserved nonhistone DNA-binding protein, plays an important role in inflammatory diseases. Once released to the extracellular space, HMGB1 acts as a proinflammatory cytokine that triggers inflammatory reaction. Our previous study showed that salidroside exerts anti-inflammatory effect via inhibiting the JAK2-STAT3 signalling pathway. However, whether salidroside inhibits the release of HMGB1 is still unclear. In this study, we aim to study the effects of salidroside on HMGB1 release and then investigate the potential molecular mechanisms. In an experimental rat model of sepsis caused by CLP, salidroside administration significantly attenuated lung injury and reduced the serum HMGB1 level. In RAW264.7 cells, we investigated the effects of salidroside on LPS-induced HMGB1 release and then explored the underlying molecular mechanisms. We found that salidroside significantly inhibited LPS-induced HMGB1 release, and the inhibitory effect was correlated with the HMGB1 acetylation levels. Mechanismly, salidroside inhibits HMGB1 acetylation through the AMPK-SirT1 pathway. In addition, SirT1 overexpression attenuated LPS-induced HMGB1 acetylation and nucleocytoplasmic translocation. Furthermore, in SirT1 shRNA plasmid-transfected cells, salidroside treatment enhanced SirT1 expression and reduced LPS-activated HMGB1 acetylation and nucleocytoplasmic translocation. Collectively, these results demonstrated that salidroside might reduce HMGB1 release through the AMPK-SirT1 signalling pathway and suppress HMGB1 acetylation and nucleocytoplasmic translocation

    Can slide positivity rates predict malaria transmission?

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    Background: Malaria is a significant threat to population health in the border areas of Yunnan Province, China. How to accurately measure malaria transmission is an important issue. This study aimed to examine the role of slide positivity rates (SPR) in malaria transmission in Mengla County, Yunnan Province, China. Methods: Data on annual malaria cases, SPR and socio-economic factors for the period of 1993 to 2008 were obtained from the Center for Disease Control and Prevention (CDC) and the Bureau of Statistics, Mengla, China. Multiple linear regression models were conducted to evaluate the relationship between socio-ecologic factors and malaria incidence. Results: The results show that SPR was significantly positively associated with the malaria incidence rates. The SPR (beta = 1.244, p = 0.000) alone and combination (SPR, beta = 1.326, p < 0.001) with other predictors can explain about 85% and 95% of variation in malaria transmission, respectively. Every 1% increase in SPR corresponded to an increase of 1.76/100,000 in malaria incidence rates. Conclusion: SPR is a strong predictor of malaria transmission, and can be used to improve the planning and implementation of malaria elimination programmes in Mengla and other similar locations. SPR might also be a useful indicator of malaria early warning systems in China

    Does Gender Matter? The Relationship Comparison of Strategic Leadership on Organizational Ambidextrous Behavior between Male and Female CEOs

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    This paper aims to examine the relationship difference of strategic leadership to organizational ambidextrous behavior between male and female CEOs, taking into account the balancing effect and combined effect of explorative and exploitative behaviors. A quantitative analysis is conducted from demographic data and relevant organizational ambidextrous data of male and female CEOs of listed companies from 2016 to 2020. In total, 226 valid male-female CEOs pairs are used to test whether there is a significant difference on gender between strategic leadership and organizational ambidextrous behavior. The findings revealed that female strategic leaders with an ambidextrous advantage do not behave inferior to males. This study clarifies the intrinsic relationship between female strategic leadership and organizational ambidexterity, affirming the ambidextrous synergistic effect of female executives in corporate strategic decision-making. The presentation of women in top management may contribute to a better organizational performance through balancing and combining ambidextrous activities, and this study calls on upholding the cultural values of gender diversity and inclusiveness, and to focus on merits of female leaders

    Does Gender Matter? The Relationship Comparison of Strategic Leadership on Organizational Ambidextrous Behavior between Male and Female CEOs

    No full text
    This paper aims to examine the relationship difference of strategic leadership to organizational ambidextrous behavior between male and female CEOs, taking into account the balancing effect and combined effect of explorative and exploitative behaviors. A quantitative analysis is conducted from demographic data and relevant organizational ambidextrous data of male and female CEOs of listed companies from 2016 to 2020. In total, 226 valid male-female CEOs pairs are used to test whether there is a significant difference on gender between strategic leadership and organizational ambidextrous behavior. The findings revealed that female strategic leaders with an ambidextrous advantage do not behave inferior to males. This study clarifies the intrinsic relationship between female strategic leadership and organizational ambidexterity, affirming the ambidextrous synergistic effect of female executives in corporate strategic decision-making. The presentation of women in top management may contribute to a better organizational performance through balancing and combining ambidextrous activities, and this study calls on upholding the cultural values of gender diversity and inclusiveness, and to focus on merits of female leaders

    Influence of Medium–High Temperature Annealing on Microstructure and Properties of High-Power Laser Melting Deposited Ti-6Al-4V Alloy

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    A high-power laser melting deposition (HP-LMD) device with a maximum output of 5 kW was developed to enhance the production efficiency of fabricating large-scale titanium components. In this study, the medium–high temperature annealing strategy was proposed, wherein the effects of holding temperature and holding time on the residual stress, microstructure evolution, and mechanical properties of the fabricated block were evaluated. The results showed that the residual stress on the surface of the fabricated blocks reduced significantly after annealing treatment. The microstructure of as-deposited Ti-6Al-4V alloy mainly consisted of α’ martensite and basket-weave microstructure, and the aspect ratio of the martensite decreased from 22 to 6 with the increases in annealing temperature and holding time. In addition, the annealing treatments had a favorable benefit on the microhardness and tensile performance of the HP-LMD fabricated Ti-6Al-4V alloy. The optimum annealing treatment was 650 °C/2 h followed by furnace cooling. The tensile samples processed by the optimum annealing treatment exhibited excellent properties with a yield strength of 912 MPa and an elongation of 11.48%, which far exceeded the Chinese aviation standard. In addition, the results of the statistical analysis revealed that the tensile properties of heat-treated samples were superior to as-deposited samples when the aspect ratio of martensite was in the range of 9–14. The fracture mode of both the as-deposited samples and annealed samples was ductile fracture

    Fabrication of Slippery Lubricant-Infused Porous Surface with High Underwater Transparency for the Control of Marine Biofouling

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    Marine optical instruments are bearing serious biofouling problem, which affects the accuracy of data collected. To solve the biofouling problem of marine optical instruments, a novel instance of slippery lubricant-infused porous surface (SLIPS) with high underwater-transparency was designed over glass substrate via infusing lubricant into its porous microstructure fabricated with hydrothermal method. The advantage of SLIPS as antibiofouling strategy to marine optical instruments was proven by comparing its underwater optical and antibiofouling performances with three kinds of samples (hydrophilic glass sample, textured hydrophilic glass sample, and superhydrophobic glass sample). The modification of SLIPS enhances the underwater-transparency of glass sample within the wavelength of 500–800 nm, for the infusion of lubricant with lower refractive index than glass substrate. In contrast with hydrophilic surface, textured hydrophilic surface and superhydrophobic surface, SLIPS can significantly inhibit bacterial and algal settlements, thereby maintaining high underwater-transparency in both dynamic and static seawater. The inhibition of bacterial and algal settlements over SLIPS results from its liquid-like property. The contact angle hysteresis of water over SLIPS increases with immersion time in seawater under different conditions (static, dynamic, and vibration conditions). Both dynamic and vibration conditions accelerate the failure of SLIPS exposed in seawater. This research provides valuable information for solving biofouling problem of marine optical instruments with SLIPS

    Photoinduced Synthesis of Methylated Marine Cyclopeptide Galaxamide Analogs with Isoindolinone as Anticancer Agents

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    The methylation of amino acid residues has played an important role in the biological function of bioactive peptides. In this paper, various methyl-modified and stereostructural-modified marine cyclopeptide galaxamide analogs with isoindolinone were synthesized by a photoinduced single electron transfer cyclization reaction. It was found that the single-methyl substitution was beneficial for the bioactivity of cyclic analogs with isoindolinone fragments, and the influence of methylation on bioactivity is uncertain and is sometimes case-specific. The compound with a single methyl group at Gly5 (compound 8) showed the strongest antiproliferative activity against HepG-2 cells. The tumor cell apoptosis, cell cycle, mitochondrial membrane potential, intracellular Ca2+ concentration and lactate dehydrogenase activity have been studied extensively to evaluate the antitumor potential of compound 8. Western blotting tests showed that compound 8 could decrease the MDM2 level and increase p53 levels efficiently. Careful molecular docking suggested that cyclic peptide 8 could bind firmly with MDM2 oncoprotein, indicating that MDM2 may be a potential drug target of the prepared peptides
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