Xiamen University

About: Xiamen University is a education organization based out in Amoy, Fujian, China. It is known for research contribution in the topics: Catalysis & Population. The organization has 50472 authors who have published 54480 publications receiving 1058239 citations. The organization is also known as: Amoy University & Xiàmén Dàxué.

Numerical simulation of hot accretion flows ii nature, origin, and properties of outflows and their possible observational applications

Abstract: Hydrodynamical (HD) and magnetohydrodynamical (MHD) numerical simulations of hot accretion flows have indicated that the inflow accretion rate decreases inward. Two models have been proposed to explain this result. In the adiabatic inflow-outflow solution (ADIOS), this is because of the loss of gas in the outflow. In the alternative convection-dominated accretion flow model, it is thought that the flow is convectively unstable and gas is locked in convective eddies. We investigate the nature of the inward decrease of the accretion rate using HD and MHD simulations. We calculate various properties of the inflow and outflow such as temperature and rotational velocity. Systematic and significant differences are found. These results suggest that the inflow and outflow are not simply convective turbulence; instead, systematic inward and outward motion (i.e., real outflow) must exist. We have also analyzed the convective stability of MHD accretion flows and found that they are stable. These results favor the ADIOS scenario. We suggest that the mechanisms of producing outflow in HD and MHD flows are the buoyancy associated with the convection and the centrifugal force associated with the angular momentum transport mediated by the magnetic field, respectively. The latter is similar to the Blandford & Payne mechanism but no large-scale open magnetic field is required. We discuss some possible observational applications, including the Fermi bubble in the Galactic center and winds in active galactic nuclei and black hole X-ray binaries.

Tranilast directly targets NLRP3 to treat inflammasome-driven diseases.

Abstract: The dysregulation of NLRP3 inflammasome can cause uncontrolled inflammation and drive the development of a wide variety of human diseases, but the medications targeting NLRP3 inflammasome are not available in clinic. Here, we show that tranilast (TR), an old anti‐allergic clinical drug, is a direct NLRP3 inhibitor. TR inhibits NLRP3 inflammasome activation in macrophages, but has no effects on AIM2 or NLRC4 inflammasome activation. Mechanismly, TR directly binds to the NACHT domain of NLRP3 and suppresses the assembly of NLRP3 inflammasome by blocking NLRP3 oligomerization. In vivo experiments show that TR has remarkable preventive or therapeutic effects on the mouse models of NLRP3 inflammasome‐related human diseases, including gouty arthritis, cryopyrin‐associated autoinflammatory syndromes, and type 2 diabetes. Furthermore, TR is active ex vivo for synovial fluid mononuclear cells from patients with gout. Thus, our study identifies the old drug TR as a direct NLRP3 inhibitor and provides a potentially practical pharmacological approach for treating NLRP3‐driven diseases.

Photocatalytic transformations of lignocellulosic biomass into chemicals

Abstract: As the largest renewable carbon resource, lignocellulosic biomass has great potential to replace fossil resources for the production of high-value chemicals, in particular organic oxygenates. Catalytic transformations of lignocellulosic biomass using solar energy have attracted much recent attention, because of unique reactive species and reaction patterns induced by photo-excited charge carriers or photo-generated reactive species as well as the mild reaction conditions, which may enable the precise cleavage of target chemical bonds or selective functionalisation of specific functional groups with other functional groups kept intact. Here, we present a critical review on recent advances in the photocatalytic transformation of lignocellulosic biomass with an emphasis on photocatalytic cleavage of C–O and C–C bonds in major components of lignocellulosic biomass, including polysaccharides and lignin, and the photocatalytic valorisation of some key platform molecules. The key issues that control the reaction paths and the reaction mechanism will be discussed to offer insights to guide the design of active and selective photocatalytic systems for biomass valorisation under mild conditions. The challenges and future opportunities in photocatalytic transformations of lignocellulosic biomass are also analysed.