Exploring a Multi-Layer Coupled Network Propagation Model Based on Information Diffusion and Bounded Trust

Objective: To explore the law of opinion dissemination and individual opinion evolution at the micro level, this paper analyzes the influence of variation and oyster on communication from the perspective of network structure.Methods: In this paper, we introduce the concepts of “variation” and “oyster”, build a multi-layer coupled network environment combined with the ISOVR model, and conduct simulation experiments of network information dissemination based on the bounded trust model.Results: The experimental results reveal that the extent and scope of variation’s spread in the network are more dependent on the trust of nodes themselves, and decreasing the trust of nodes significantly reduces the rate and peak value of variation. Changing the silence coefficient of variation does not effectively change the direction of rumor propagation, which indicates that rumor has a strong propagation ability after mutation.Conclusion: The insights of this paper on the dissemination of public opinions include: 1) pay attention to people with high trust levels, such as opinion leaders; 2) clarify the misinformation in time to prevent further spread of rumors

Design, synthesis and anticancer properties of isocombretapyridines as potent colchicine binding site inhibitors

A series of novel isocombretapyridines were designed and synthesized based on a lead compound isocombretastatin A-4 (isoCA-4) by replacing 3,4,5-trimethoxylphenyl with substituent pyridine nucleus. The MTT assay results showed that compound 20a possessed the most potent activities against all tested cell lines with IC50 values at nanomolar concentration ranges. Moreover, 20a inhibited tubulin polymerization at a micromolar level and also displayed potent anti-vascular activity in vitro. Further mechanistic studies were conducted to demonstrate that compound 20a could bind to the colchicine site of tubulin,and disrupte the cell microtubule networks, induce G2/M phase arrest, promote apoptosis and depolarize mitochondria of K562 cells in a dose-dependent manner. Notably, 20a exhibited more potent tumor growth inhibition activity with 68.7% tumor growth inhibition than that of isoCA-4 in H22 allograft mouse model without apparent toxicity. The present results suggested that compound 20a may serve as a promising potent microtubule-destabilizing agent candidate for the development of therapeutics to treat cancer

Bio-inspired Material Design and Optimization

Abstract Natural materials such as bone, tooth, and nacre are nano-composites of proteins and minerals with superior stiffness and toughness. At the most elementary structure level, bio-composites exhibit a generic microstructure consisting of staggered mineral bricks wrapped by soft protein in nanoscale. Why does nature design building blocks of biological materials in this form? Can we reproduce this kind of structure from the structural optimization point of view? We believe that biological materials are designed with simultaneous optimization of stiffness and toughness for maximum structural support and flaw tolerance. With this philosophy, an optimization problem is formulated under the assumption of appropriate material constitutive models and failure criteria. It is shown that, within this optimization framework, the staggered microstructure of biological materials can be successfully reproduced at the nanometer length scale. This study may have at least partially provided an answer to the question whether the nanostructure of biological materials is an optimized structure and what is being optimized. The results suggest that we can draw lessons from the nature in designing nanoscale and hierarchically structured materials. Keywords: Bio-inspired mimetic; Material design; Optimization; Flaw tolerance 1

Frequency-dependent transition in power-law rheological behavior of living cells

Living cells are active viscoelastic materials exhibiting diverse mechanical behaviors at different time scales. However, dynamical rheological characteristics of cells in frequency range spanning many orders of magnitude, especially in high frequencies, remain poorly understood. Here, we show that a self-similar hierarchical model can capture cell's power-law rheological characteristics in different frequency scales. In low-frequency scales, the storage and loss moduli exhibit a weak power-law dependence on frequency with same exponent. In high-frequency scales, the storage modulus becomes a constant, while the loss modulus shows a power-law dependence on frequency with an exponent of 1.0. The transition between low- and high-frequency scales is defined by a transition frequency based on cell's mechanical parameters. The cytoskeletal differences of different cell types or states can be characterized by changes in mechanical parameters in the model. This study provides valuable insights into potentially using mechanics-based markers for cell classification and cancer diagnosis.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversityPublished versionG.-K.X. acknowledges the National Natural Science Foundation of China (grant nos. 12122210 and 12072252), and H.G. acknowledges the research start-up grant (002479-00001) from Nanyang Technological University and the Agency for Science, Technology and Research (A*STAR)

Separation of 1-Butene and 2-Butene Isomers via Nanoporous Graphene: A Molecular Simulation Study

Selective separation of 1-C4H8 and 2-C4H8 isomers is of great importance and a daunting challenge in petrochemical industries because these isomers differ only by the position of the C=C double bond. Here, we proposed that an elliptical nanopore embedded in graphene with a minor diameter of similar to 3.4 A can be a promising candidate to separate 2-C4H8 from 1-C4H8 with ultrahigh selectivity. Inspired by chain structures, we designed a series of elongated pores by connecting several elliptical nanopores in series with one removed benzene ring overlapped. The molecular dynamics studies demonstrated that the elongation design greatly enhances the permeability of 2-C4H8 while maintaining the selectivity of 2-C4H8 over 1-C4H8 to a certain extent. The underlying mechanisms are related to the local size sieving and molecular conformations that the pore prefers. We anticipate our findings can guide the future design of more energyefficient and cost-effective membranes for isomer separation

Elastically isotropic truss-plate-hybrid hierarchical microlattices with enhanced modulus and strength

Bioinspired hierarchical design principles have been employed to create advanced architected materials. Here, a new type of truss-plate-hybrid two-level hierarchical architecture is created, referred to as the ISO-COP hierarchical lattice (isotropic truss at the first level and cubic+octet plate at the second level), in which truss-based unit cells are arranged according to the topology of the plate-based unit cell. Finite element analyses reveal that the ISO-COP hierarchical lattice outperforms the best existing octet-truss hierarchical lattices based on fractal geometries in achieving elastic isotropy and enhanced moduli. According to the designed architecture, ISO-COP and several other comparison hierarchical microlattices are fabricated via projection microstereolithography. In situ compression tests demonstrate that the fabricated ISO-COP microlattices exhibit elastic isotropy and enhanced moduli, as predicted from finite element simulations, and superior strength compared with existing fractal octet-truss hierarchical lattices. Theoretical models are further developed to predict the dependence of modulus and failure modes on two design parameters of the hierarchical lattices, with results in good agreement with those from experiments. This study relates mechanical properties of ISO-COP hierarchical lattices to their architectures at each level of hierarchy and exemplifies a route to harnessing hierarchical design principles to create architected materials with desired mechanical properties.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversitySubmitted/Accepted versionX.L. acknowledges the financial support from the National Natural Science Foundation of China (grant numbers 91963117, 11921002, and 11720101002). H.G. acknowledges a research start-up grant (002479-00001) from the Nanyang Technological University and the Agency for Science, Technology and Research (A*STAR). F.X. acknowledges the financial support from the National Natural Science Foundation of China (grant numbers 12122204 and 11872150)

Interfacial Diffusion of Hydrated Ion on Graphene Surface: A Molecular Simulation Study

Hydration plays an important role in the diffusion and sieving of ions within nanochannels. However, it is hard to quantitatively analyze the contribution of hydration to the diffusion rates due to the complex hydrogen-bond and charge interactions between atoms. Here, we quantitatively investigated the interfacial diffusion rates of a single hydrated ion with different number of water molecules on graphene surface through molecular dynamics simulation. The simulation results show the ballistic diffusion mode by analyzing the mean-square displacement, and the diffusion rates change nonmonotonically with the hydration number. The potential energy profiles with the changing position of the hydrated ion on graphene surface were further analyzed, which shows the dominant factor for interfacial diffusion changing from ion-graphene interaction to water-graphene interaction as the number of water molecules increases. Besides, it was found that the surface hydrophilicity weakened the influence of hydration number on the diffusion rates of hydrated ion. Finally, the diffusion properties of different hydrated ions on graphene surface were investigated, and the hydrated Li+, Na+, and K+ containing three, four, and five water molecules, respectively, show the fastest diffusion rate. This work demonstrates the interfacial diffusion behavior and mechanism of hydrated ions at the molecular level, which can provide valuable guidance in nanosensors, seawater desalination, and other hydrated ion-related fields

Network dynamics of the nonlinear power-law relaxation of cell cortex

Living cells are known to exhibit universal power-law rheological behaviors, but their underlying biomechanical principles are still not fully understood. Here, we present a network dynamics picture to decipher the nonlinear power-law relaxation of cortical cytoskeleton. Under step strains, we present a scaling relation between instantaneous differential stiffness and external stress as a result of chain reorientation. Then, during the relaxation, we show how the scaling law theoretically originates from an exponential form of cortical disorder, with the scaling exponent decreased by the imposed strain or crosslinker density in the nonlinear regime. We attribute this exponent variation to the molecular realignment along the stretch direction or the transition of network structure from in-series to in-parallel modes, both solidifying the network toward our one-dimensional theoretical limit. In addition, the rebinding of crosslinkers is found to be crucial for moderating the relaxation speed under small strains. Together with the disorder nature, we demonstrate that the structural effects of networks provide a unified interpretation for the nonlinear power-law relaxation of cell cortex, and may help to understand cell mechanics from the molecular scale.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversityG.-K.X. acknowledges the National Natural Science Foundation of China (grant nos. 12122210 and 12072252), and H.G. acknowledges a research start-up grant (002479-00001) from Nanyang Technological University and the Agency for Science, Technology and Research (A* STAR)