A novel nitrogen doped hybrid material composed of in situ‐formed graphene natively grown on hierarchical ordered porous carbon is prepared, which successfully combines the advantages of both ...materials, such as high surface area, high mass transfer, and high conductivity. The outstanding structural properties of the resultant material render it an excellent metal‐free catalyst for electrochemical oxygen reduction.
Epstein-Barr virus (EBV), aetiologically linked to nasopharyngeal carcinoma (NPC), is the first human virus found to encode many miRNAs. However, how these viral miRNAs precisely regulate the tumour ...metastasis in NPC remains obscure. Here we report that EBV-miR-BART1 is highly expressed in NPC and closely associated with pathological and advanced clinical stages of NPC. Alteration of EBV-miR-BART1 expression results in an increase in migration and invasion of NPC cells in vitro and causes tumour metastasis in vivo. Mechanistically, EBV-miR-BART1 directly targets the cellular tumour suppressor PTEN. Reduction of PTEN dosage by EBV-miR-BART1 activates PTEN-dependent pathways including PI3K-Akt, FAK-p130(Cas) and Shc-MAPK/ERK1/2 signalling, drives EMT, and consequently increases migration, invasion and metastasis of NPC cells. Reconstitution of PTEN rescues all phenotypes generated by EBV-miR-BART1, highlighting the role of PTEN in EBV-miR-BART-driven metastasis in NPC. Our findings provide new insights into the metastasis of NPC regulated by EBV and advocate for developing clinical intervention strategies against NPC.
A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients ...of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method.
•A method based on second order sliding mode control is proposed for a quadrotor UAV.•The nonlinear coefficients of the defined switching sliding manifolds are further explored via Hurwitz.•Second order sliding mode technique is used to avoid the chattering phenomenon.•The effectiveness and robustness of the proposed control method are demonstrated by the simulations.
Sirt6 has been implicated as a key regulator in aging-related diseases, including osteoarthritis. However, its functional role and molecular mechanism in chondrocyte senescence and osteoarthritis ...pathophysiology remain largely undefined. Here we show that Sirt6 deficiency exaggerates chondrocyte senescence and osteoarthritis progression, whereas intra-articular injection of adenovirus-Sirt6 markedly attenuates surgical destabilization of medial meniscus-induced osteoarthritis. Mechanistically, Sirt6 can directly interact with STAT5 and deacetylate STAT5, thus inhibiting the IL-15/JAK3-induced STAT5 translocation from cytoplasm to nucleus, which inactivates IL-15/JAK3/STAT5 signaling. Mass spectrometry revealed that Sirt6 deacetylated conserved lysine 163 on STAT5. Mutation of lysine 163 to arginine in STAT5 abolished the regulatory effect of Sirt6. In vivo, specific ablation of Sirt6 in chondrocytes exacerbated osteoarthritis. Pharmacological activation of Sirt6 substantially alleviated chondrocyte senescence. Taken together, Sirt6 attenuates chondrocyte senescence by inhibiting IL-15/JAK3/STAT5 signaling. Targeting Sirt6 represents a promising new approach for osteoarthritis.
This review mainly focuses on the major technologies for recycling the LiFePO4 and LiNixCoyMnzO2 cathode materials by hydrometallurgical regeneration and direct regeneration method, and the ...technologies for recycling graphite anode.
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Lithium-ion batteries (LIBs) have been widely applied in portable electronic devices and electric vehicles. With the booming of the respective markets, a huge quantity of spent LIBs that typically use either LiFePO4 or LiNixCoyMnzO2 cathode materials will be produced in the very near future, imposing significant pressure for the development of suitable disposal/recycling technologies, in terms of both environmental protection and resource reclaiming. In this review, we firstly do a comprehensive summary of the-state-of-art technologies to recycle LiNixCoyMnzO2 and LiFePO4-based LIBs, in the aspects of pretreatment, hydrometallurgical recycling, and direct regeneration of the cathode materials. This closed-loop strategy for cycling cathode materials has been regarded as an ideal approach considering its economic benefit and environmental friendliness. Afterward, as for the exhausted anode materials, we focus on the utilization of exhausted anode materials to obtain other functional materials, such as graphene. Finally, the existing challenges in recycling the LiFePO4 and LiNixCoyMnzO2 cathodes and graphite anodes for industrial-scale application are discussed in detail; and the possible strategies for these issues are proposed. We expect this review can provide a roadmap towards better technologies for recycling LIBs, shed light on the future development of novel battery recycling technologies to promote the environmental benignity and economic viability of the battery industry and pave way for the large-scale application of LIBs in industrial fields in the near future.
Non-covalent interactions in the second coordination sphere of metalloenzymes play a significant role in determining activity and selectivity. The importance of these interactions is reflected in the ...increasing number of reports on model complexes with a functional second coordination sphere. These hybrid mimics were developed according to the strategies of modification with functional groups, combination with supramolecular hosts and coupling with polymers, to shed light on the role of non-covalent interactions in metalloenzyme catalysis. This review provides an overview of recent progress in this area. An introduction to native metalloenzymes with an emphasis on the second coordination sphere is also given.
The polypropylene (PP) composites filled with flame retardants (including aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), and zinc borate (ZB)) were prepared, and the composites were ...separately loaded with polyolefin elastomer (POE) and nanometer calcium carbonate (nano-CaCO3). The tensile properties and the fire residue morphology of the specimens after burning for these three groups of composites were measured. The results were shown that the tensile fracture strength and the Young’s modulus increased while the tensile yield strength and the tensile elongation at break (δb) decreased with increasing flame-retardant volume fraction. At the same flame-retardant content, the δb values of the PP/Al(OH)3/Mg(OH)2/ZB/nano-CaCO3/POE composite were the highest in the three groups of composites. The fire residue in the pyrolysis zone of the specimens increased corresponding to the increased flame-retardant volume fraction and with loading the nano-CaCO3 and POE, especially at low-flame-retardant concentration. The reinforcing and the flame-retarded mechanisms of the composites were discussed.
An Fe–N‐decorated hybrid material of carbon nanotubes (CNTs) grown in situ from porous carbon microblocks is designed and constructed. This material successfully combines the desirable merits for ...oxygen reduction reaction (ORR), such as highly active Fe–N species, good conductivity, large pore size, and sufficient surface area. These structural advantages give this low‐priced material an outstanding catalytic performance for ORR closely comparable with Pt/C of the same quantity.
Pseudomonas aeruginosa, a significant opportunistic pathogen, can participate in inter-species communication through signaling by cis-2-unsaturated fatty acids of the diffusible signal factor (DSF) ...family. Sensing these signals leads to altered biofilm formation and increased tolerance to various antibiotics, and requires the histidine kinase PA1396. Here, we show that the membrane-associated sensory input domain of PA1396 has five transmembrane helices, two of which are required for DSF sensing. DSF binding is associated with enhanced auto-phosphorylation of PA1396 incorporated into liposomes. Further, we examined the ability of synthetic DSF analogues to modulate or inhibit PA1396 activity. Several of these analogues block the ability of DSF to trigger auto-phosphorylation and gene expression, whereas others act as inverse agonists reducing biofilm formation and antibiotic tolerance, both in vitro and in murine infection models. These analogues may thus represent lead compounds to develop novel adjuvants improving the efficacy of existing antibiotics.
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