[en] We study the correlation between detrended fluctuation analysis (DFA) and the Lempel-Ziv complexity (LZC) in nonlinear time series analysis in this paper. Typical dynamic systems including a logistic map and a Duffing model are investigated. Moreover, the influence of Gaussian random noise on both the DFA and LZC are analyzed. The results show a high correlation between the DFA and LZC, which can quantify the non-stationarity and the nonlinearity of the time series, respectively. With the enhancement of the random component, the exponent a and the normalized complexity index C show increasing trends. In addition, C is found to be more sensitive to the fluctuation in the nonlinear time series than α. Finally, the correlation between the DFA and LZC is applied to the extraction of vibration signals for a reciprocating compressor gas valve, and an effective fault diagnosis result is obtained

[en] We use the controllability limit theory to study impact of correlation between in- and out-degrees (degree correlation) on edge controllability of real networks. Simulation results and analytic calculations show that the degree correlation plays an important role in the edge controllability of real networks, especially dense real networks. The upper and lower controllability limits hold for all kinds of real networks. Any edge controllability in between the limits is achievable by properly adjusting the degree correlation. In addition, we find that the edge dynamics in some real networks with positive degree correlation may be difficult to control, and explain the rationality of this anomaly based on the controllability limit theory. (paper)

[en] Natural halloysite nanotubes (HNTs), with nanotubular structure, are attracting considerable attention in recent years. The hollow tubular structure allows HNTs to play an important role in drug delivery system as drug carriers. However, the wide applications of HNTs in biomedicine have been hampered by the lack of sufficient intracellular researches so far. In this study, we systemically investigated the transport mechanisms of HNTs in A549 living cells. The colocalization and inhibition experiments illustrated FITC-labeled HNTs were readily internalized into cells by both clathrin- and caveolae-dependent endocytosis, and the transport pathway of HNTs is an actin- and microtubule-associated process via Golgi apparatus and lysosome. Meanwhile, the cell cycle assay clarified that HNTs can prompt the intracellular transportation of gemcitabine and enhance the gemcitabine concentration in A549 tumor cells. Such elucidation of intracellular transport pathway of HNTs offers insights into the site-specific delivery and cellular internalization of HNTs, which provide a reasonable guidance for the design of novel drug delivery system.