We propose an effective method to enhance the dynamical robustness of networks of diffusively coupled oscillators experiencing aging transition. By introducing a new control parameter into the normal diffusive coupling, we demonstrate that the dynamical robustness of coupled oscillator networks can be efficiently improved by enhancing the tolerance of dynamic activity in the network to inactivation or deterioration of the individual oscillators. Even a tiny deviation from the normal diffusive coupling greatly strengthens the robustness of networks. Particularly, the strong coupling in our scheme is shown to be in favor of the dynamic activity, which is in sharp contrast to the normal form of diffusive coupling with the tendency to spoil the dynamical robustness. Our proposed approach serves as a rather simple and efficient way to recover dynamic activity in networks of diffusively coupled oscillators that has been lost due to some inactivated or damaged oscillator components.

microRNA-221 (miRNA-221) is upregulated in several malignant tumors and is associated with poor patient prognosis. Therefore, the present study aimed to investigate the role and underlying mechanism of miRNA-221 in doxorubicin (DOX) resistance in osteosarcoma cells. We constructed DOX-resistant Saos-2/DOX cells and treated them with DOX. Cell viability was determined by performing an MTT assay. Cells were transfected with either miRNA-221 mimic or miRNA-221 inhibitor; real-time quantitative reverse transcription PCR was performed to detect the expression of miRNA-221. Flow cytometry and TUNEL staining were used to detect cell apoptosis. The immunofluorescence method was also used to detect cell Stat3 protein expression distribution. In addition, western blotting was used to detect changes in the expression of each protein. We found that miRNA-221 was upregulated in Saos-2/DOX cells. Moreover, the miRNA-221 mimic induced DOX resistance in Saos-2 cells, whereas the miRNA-221 inhibitor enhanced DOX sensitivity in Saos-2/DOX cells. The miRNA-221 mimic upregulated the expression of phosphorylated-Stat3, P-gp, and Bcl-2 proteins in Saos-2 cells and induced the entry of Stat3 into the nucleus, whereas the miRNA-221 inhibitor exerted the opposite effect. Pretreatment with the Stat3 chemical inhibitor, STAT3-IN-3, significantly inhibited the upregulation of P-gp and Bcl-2 protein expression induced by the miRNA-221 mimic in Saos-2 cells; it also caused the Saos-2 cells to overcome DOX resistance induced by the miRNA-221 mimic. Thus, miRNA-221 increased the expression of P-gp and Bcl-2 by activating the Stat3 pathway to promote DOX resistance in osteosarcoma cells, indicating a potential use of miRNA-221 in osteosarcoma treatment.

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This paper considers the state transition of the stochastic Morris-Lecar neuronal model driven by symmetric α-stable Lévy noise. The considered system is bistable: a stable fixed point (resting state) and a stable limit cycle (oscillating state), and there is an unstable limit cycle (borderline state) between them. Small disturbances may cause a transition between the two stable states, thus a deterministic quantity, namely the maximal likely trajectory, is used to analyze the transition phenomena in non-Gaussian stochastic environment. According to the numerical experiment, we find that smaller jumps of the Lévy motion and smaller noise intensity can promote such transition from the sustained oscillating state to the resting state. It also can be seen that larger jumps of the Lévy motion and higher noise intensity are conducive for the transition from the borderline state to the sustained oscillating state. As a comparison, Brownian motion is also taken into account. The results show that whether it is the oscillating state or the borderline state, the system disturbed by Brownian motion will be transferred to the resting state under the selected noise intensity.

Background: This study was a systematic review comparing the clinical outcomes of using the nonirradiated and irradiated allograft for anterior cruciate ligament (ACL) reconstruction. Methods: A comprehensive literature search was conducted using multiple databases, including Medline, Embase, and Cochrane. All databases were searched from the earliest records through August 2019 using the following Boolean operators: irradiated AND nonirradiated AND ACL AND allograft. All prospective and retrospective controlled trials were retrieved that directly compared physical examination and knee function scores and patient-rated outcomes between the nonirradiated and irradiated allograft for ACL reconstruction. Results: Three prospective and 2 retrospective articles were identified by the search, and the findings suggested that the nonirradiated allografts were superior to the irradiated allografts based on improved knee joint functional scores and decreased failure rate, even though there was no significantly difference with respect to overall IKDC, range of motion, vertical jump test, and one-leg hop test. Conclusions: Irradiated allograft should be limited to be used in ACL surgery and further research into new alternative sterilization techniques are needed to avoiding the disease transmission without interference with the biomechanical properties of the grafts.