Browsing by Author "Sun, M."
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Item Open Access Characterization of sleep spindles using higher order statistics and spectra(IEEE, 2000-08) Akgül, T.; Sun, M.; Sclabassi, R. J.; Çetin, A. EnisThis work characterizes the dynamics of sleep spindles, observed in electroencephalogram (EEG) recorded from humans during sleep, using both time and frequency domain methods which depend on higher order statistics and spectra. The time domain method combines the use of second- and third-order correlations to reveal information on the stationarity of periodic spindle rhythms to detect transitions between multiple activities. The frequency domain method, based on normalized spectrum and bispectrum, describes frequency interactions associated with nonlinearities occuring in the observed EEG.Item Open Access Efficient production and enhanced tumor delivery of engineered extracellular vesicles(Elsevier Ltd, 2016) Watson, D. C.; Bayik D.; Srivatsan, A.; Bergamaschi, C.; Valentin, A.; Niu, G.; Bear, J.; Monninger, M.; Sun, M.; Morales-Kastresana, A.; Jones, J. C.; Felber, B. K.; Chen, X.; Gurse,l I.; Pavlakis, G. N.Extracellular vesicles (EV), including exosomes and microvesicles, are nano-sized intercellular communication vehicles that participate in a multitude of physiological processes. Due to their biological properties, they are also promising candidates for the systemic delivery of therapeutic compounds, such as cytokines, chemotherapeutic drugs, siRNAs and viral vectors. However, low EV production yield and rapid clearance of administered EV by liver macrophages limit their potential use as therapeutic vehicles. We have used a hollow-fiber bioreactor for the efficient production of bioactive EV bearing the heterodimeric cytokine complex Interleukin-15:Interleukin-15 receptor alpha. Bioreactor culture yielded ∼40-fold more EV per mL conditioned medium, as compared to conventional cell culture. Biophysical analysis and comparative proteomics suggested a more diverse population of EV in the bioreactor preparations, while serum protein contaminants were detectable only in conventional culture EV preparations. We also identified the Scavenger Receptor Class A family (SR-A) as a novel monocyte/macrophage uptake receptor for EV. In vivo blockade of SR-A with dextran sulfate dramatically decreased EV liver clearance in mice, while enhancing tumor accumulation. These findings facilitate development of EV therapeutic methods. © 2016Item Embargo Top executives’ great famine experience and stock price crash risk(Elsevier Inc., 2021-10-09) Cui, X.; Sun, M.; Şensoy, Ahmet; Wang, P.; Wang, Y.Using Chinese stock market data, we examine the impact of top executives’ great famine experience on stock price crash risk. We provide insights on the consequences of early-life disaster experience and the underlying mechanisms through which top executives’ famine experience affects crash risk. Evidence shows that, firms led by top executives who experienced the great famine in early-life have lower stock price crash risk. In addition, these firms have higher information transparency and lower information risk, which ultimately reduce the future stock price crash risk. And the effect varies with top executives’ growth stage, firm characteristics, and external monitoring.