The therapeutic action of bone marrow-derived mesenchymal stem cells (BMSCs) in acute kidney injury (AKI) has been reported by several groups. However, recent studies indicated that BMSCs homed to kidney tissues at very low levels after transplantation. The lack of specific homing of exogenously infused cells limited the effective implementation of BMSC-based therapies. In this study, we provided evidence that the administration of BMSCs combined with muscone in rats with gentamicin-induced AKI intravenously, was a feasible strategy to drive BMSCs to damaged tissues and improve the BMSC-based therapeutic effect. The effect of muscone on BMSC bioactivity was analyzed in vitro and in vivo. The results indicated that muscone could promote BMSC migration and proliferation. Some secretory capacity of BMSC still could be improved in some degree. The BMSC-based therapeutic action was ameliorated by promoting the recovery of biochemical variables in urine or blood, as well as the inhibition of cell apoptosis and inflammation. In addition, the up-regulation of CXCR4 and CXCR7 expression in BMSCs could be the possible mechanism of muscone amelioration. Thus, our study indicated that enhancement of BMSCs bioactivities with muscone could increase the BMSC therapeutic potential and further developed a new therapeutic strategy for the treatment of AKI.

No abstract

Summary Low‐frequency oscillations (LFOs) are inherent phenomena of modern interconnected electrical power systems, essentially caused by the continuous exchange of momentum among rotating masses. It is widely recognized that LFOs can be induced by both the occurrence of multiple disturbances and the existence of periodic disturbance sources. LFOs can be classified into negative damped oscillations and forced power oscillations. The former can be suppressed by standard controllers (e.g., power system stabilizers). The latter cannot be eliminated until the disturbance source is removed or isolated. Thus, locating the forced disturbance source promptly and accurately is crucial. In this paper, a traditional energy function, simplified and improved, with a new decomposition way to show the direction of energy flow is proposed. Energy associated with the LFO is decomposed into oscillating component and quasi‐steady component at the aim of analyzing the inducing multiple disturbances. The branch energy is hence decomposed into periodic and aperiodic components. By identifying the direction along which the aperiodic component is propagated and dissipated, the periodic forced disturbance source could be located rapidly and accurately. The proposed energy decomposition method provides a novel idea to judge the direction along which the dissipated energy flows. The effectiveness and feasibility of the proposed method were verified by simulation results obtained on an actual large‐scale interconnected power grid in China. Copyright © 2015 John Wiley & Sons, Ltd.

No abstract

No abstract