Copper is equipped with excellent electrical and thermal properties. However, its poor mechanical properties and poor high-temperature stability prevent its extensive used in structural materials. ...Therefore, establishing an effective strengthening method that enables copper to increase its strength and high-temperature tolerance can promote wide-ranging copper applications. An effective method is the addition of ceramic particles as a reinforcement phase to improve the mechanical properties of copper. The preparation processes of several ceramic particles reinforced copper-based composites are discussed in this paper, including three powder metallurgy processes as mechanical alloying, internal oxidation, and wet chemistry, as well as friction stir processing, reactive spray deposition, and liquidus in situ reaction. The effects of each process on the mechanical properties of copper-matrix composites are introduced.
•Preparation of copper-matrix composites reinforced by the second phase is reviewed.•Mechanical alloying has the characteristics of simple process and low production cost.•Ti, La, and so on in CMCs is of great significance for improving the stability and strength of copper.•Friction stir process is mainly used to modify copper surface.
With the rapid development of nanotechnology, nanoparticles have been widely used in many applications such as phototherapy, cell imaging, and drug/gene delivery. A better understanding of how ...nanoparticles interact with bio‐system (especially cells) is of great importance for their potential biomedical applications. In this review, the current status and perspective of theoretical and computational investigations is presented on the nanoparticle‐biomembrane interactions in cellular delivery. In particular, the determining parameters (including the properties of nanoparticles, cell membranes and environments) that govern the cellular uptake of nanoparticles (direct penetration and endocytosis) are discussed. Further, some special attention is paid to their interactions beyond the translocation of nanoparticles across membranes (e.g., nanoparticles escaping from endosome and entering into nucleus). Finally, a summary is given, and the challenging problems of this field in the future are identified.
Nanoparticles have recently been widely used as drug delivery carriers. This review summarizes the recent progresses on the theoretical and computational investigations of nanoparticle‐biomembrane interactions in cellular delivery. The factors that govern cellular uptake of nanoparticles are discussed in detail, and their interactions in intracellular trafficking are also illustrated. Finally, the challenging problems of this field in the future are given.
Cancer cells often acquire capabilities to evade cell death induced by current chemotherapeutic treatment approaches. Caspase-8, a central initiator of death receptor-mediated apoptosis, for example, ...is frequently inactivated in human cancers via multiple mechanisms such as mutation. Here, we show an approach to overcome cell death resistance in
-deficient colorectal cancer (CRC) by induction of necroptosis. In both a hereditary and a xenograft mouse model of
-deficient CRC, second mitochondria-derived activator of caspase (SMAC) mimetic treatment induced massive cell death and led to regression of tumors. We further demonstrate that receptor-interacting protein kinase 3 (RIP3), which is highly expressed in mouse models of CRC and in a subset of human CRC cell lines, is the deciding factor of cancer cell susceptibility to SMAC mimetic-induced necroptosis. Thus, our data implicate that it may be worthwhile to selectively evaluate the efficacy of SMAC mimetic treatment in CRC patients with
deficiency in clinical trials for the development of more effective personalized therapy.
Control over the protein corona of nanomaterials allows them to function better. Here, by taking graphene/gold as examples, we comprehensively assessed the association of surface properties with the ...protein corona. As revealed by in vitro measurements and computations, the interaction between graphene/gold and HSA/IgE was inversely correlated with the hydroxyl group availability, whereas the interaction between that and ApoE was comparatively less relevant. Molecular simulations revealed that the number and the distribution of surface hydroxyl groups could regulate the manner in which nanomaterials interact with proteins. Moreover, we validated that ApoE pre-adsorption before injection enhances the blood circulation of nanomaterials relative to their pristine and IgE-coated counterparts. This benefit can be attributed to the invulnerability of the complementary system provided by ApoE, whose encasement does not increase cytotoxicity. Overall, this study offers a robust yet simple way to create protein corona enriched in dysopsonins to realize better delivery efficacy.
Understanding how nanoparticles with different shapes interact with cell membranes is important in drug and gene delivery, but this interaction remains poorly studied. Using computer simulations, we ...investigate the physical translocation processes of nanoparticles with different shapes (for example, spheres, ellipsoids, rods, discs and pushpin-like particles) and volumes across a lipid bilayer. We find that the shape anisotropy and initial orientation of the particle are crucial to the nature of the interaction between the particle and lipid bilayer. The penetrating capability of a nanoparticle across a lipid bilayer is determined by the contact area between the particle and lipid bilayer, and the local curvature of the particle at the contact point. Particle volume affects translocation indirectly, and particle rotation can complicate the penetration process. Our results provide a practical guide to geometry considerations when designing nanoscale cargo carriers.
This article reports our study on the issue of finite-time adaptive fuzzy tracking control for a class of uncertain nonlinear systems with the prescribed performance. A novel finite-time prescribed ...performance control approach, in which fuzzy systems are employed to approximate completely unknown nonlinear functions, is proposed by incorporating the technique of prescribed performance control with the method of command filtered design. Based on the finite-time stability theory, all the signals of the closed-loop system can be bounded and the output tracking error can converge to a prescribed small region within a finite-time by the proposed scheme; meanwhile, the problem of complexity explosion can be avoided. The effectiveness of the presented method is verified by two examples.
Carbon materials are frequently used to improve the cycle and rate performance of VS4 as anode material for lithium ion batteries. However, the interfacial interaction between VS4 and carbon has not ...been elucidated clearly. Various VS4@C composites are prepared and the interface between VS4 and porous carbon is investigated by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and first‐principles calculations. The interfacial structure between VS4 and carbon and the mechanism of flower‐like VS4 growth on carbon substrate are revealed clearly. The results indicate that C−V bonds and C−O−V bonds are formed when oxygen functional groups are introduced into the porous carbon, and the C−V bonds and C−O−V bonds accelerate the electron transport and enhance structural stability of the VS4@C composite. Deriving from the unique structure and robust interfacial interaction, the electrochemical performances of VS4@C composite are much better than that of pure VS4. Moreover, through the study of lithium storage mechanism of VS4 anode, it is found that there is an irreversible amorphization change of the original VS4 in the first cycle, and that during the following electrochemical process, the main storage behavior of lithium ions derives from the insertion−extraction reactions in the amorphous VS4 with the reaction between V4+ and V3+.
Carbon materials are frequently used to improve the cycle and rate performances of VS4 as anode material for lithium ion batteries. However, the interface between VS4 and carbon is unclear. It is demonstrated that the robust “skeletons” of vanadium−carbon and vanadium−oxygen−carbon between VS4 and carbon material are the origin of this synergistic effect.
It is a great challenge for nanomedicine to develop novel dendrimers with maximum therapeutic potential and minimum side-effects for drug and gene delivery. As delivery vectors, dendrimers must ...overcome lots of barriers before delivering the bio-agents to the target in the cell. Extensive experimental investigations have been carried out to elucidate the physical and chemical properties of dendrimers and explore their behaviors when interacting with biomolecules, such as gene materials, proteins, and lipid membranes. As a supplement of the experimental techniques, it has been proved that computer simulations could facilitate the progress in understanding the delivery process of bioactive molecules. The structures of dendrimers in dilute solutions have been intensively investigated by monomer-resolved simulations, coarse-grained simulations, and atom-resolved simulations. Atomistic simulations have manifested that the hydrophobic interactions, hydrogen-bond interactions, and electrostatic attraction play critical roles in the formation of dendrimer-drug complexes. Multiscale simulations and statistical field theories have uncovered some physical mechanisms involved in the dendrimer-based gene delivery systems. This review will focus on the current status and perspective of theoretical and computational contributions in this field in recent years. (275 references).
The occurrence and transmission of chirality is a fascinating characteristic of nature. However, the intermolecular transmission efficiency of circularly polarized luminescence (CPL) remains ...challenging due to poor through‐space energy transfer. We report a unique CPL transmission from inducing the achiral acceptor to emit CPL within a specific liquid crystal (LC)‐based intermolecular system through a circularly polarized fluorescence resonance energy transfer (C‐FRET), wherein the luminescent cholesteric LC is employed as the chirality donor, and rationally designed achiral long‐wavelength aggregation‐induced emission (AIE) fluorophore acts as the well‐assembled acceptor. In contrast to photon‐release‐and‐absorption, the chirality transmission channel of C‐FRET is highly dependent upon the energy resonance in the highly intrinsic chiral assembly of cholesteric LC, as verified by deliberately separating the achiral acceptor from the chiral donor to keep it far beyond the resonance distance. This C‐FRET mode provides a de novo strategy concept for high‐level information processing for applications such as high‐density data storage, combinatorial logic calculation, and multilevel data encryption and decryption.
Circularly polarized luminescence (CPL) transmission is a critical challenge in chiroptical research but there are two questions on CPL transmission. How to transfer CPL within intermolecular systems? And can achiral emitters emit CPL? We find the CPL transmission is critically dependent on the resonance transfer, which was attributed to unique circularly polarized fluorescence resonance energy transfer (C‐FRET).
Viral infections trigger host innate immune responses, characterized by the production of type-I interferons (IFN) including IFNβ. IFNβ induces cellular antiviral defense mechanisms and thereby ...contributes to pathogen clearance. Accumulating evidence suggests that mitochondria constitute a crucial platform for the induction of antiviral immunity. Here we demonstrate that the mitochondrial protein phosphoglycerate mutase family member 5 (PGAM5) is important for the antiviral cellular response. Following challenge of HeLa cells with the dsRNA-analog poly(I:C), PGAM5 oligomers and high levels of PGAM5 were found in mitochondrial aggregates. Using immunoprecipitation, a direct interaction of PGAM5 with the mitochondrial antiviral-signaling protein (MAVS) was demonstrated. In addition, PGAM5 deficient cells showed diminished expression of IFNβ and IFNβ target genes as compared to WT cells. Moreover, PGAM5 deficient mouse embryonic fibroblasts (MEFs) exhibited decreased phosphorylation levels of IRF3 and TBK1 when challenged with poly(I:C) intracellularly. Finally, PGAM5 deficient MEFs, upon infection with vesicular stomatitis virus (VSV), revealed diminished IFNβ expression and increased VSV replication. Collectively, our study highlights PGAM5 as an important regulator for IFNβ production mediated via the TBK1/IRF3 signaling pathway in response to viral infection.
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