2,850 research outputs found
Antitumor effect and mechanism of action of polysaccharides extracted from Polygonum perfoliatum L whole plant in human lung carcinoma A549 cell line
Purpose: To optimize the extraction conditions of polysaccharides from Polygonum perfoliatum L. (PSDP) and to evaluate their anti-tumor activities on A549 cell line.Methods: Extraction of PSDP was optimized using Box-Behnken design (BBD). Three factors of response surface methodology (RSM) including extraction time, ratio of water to raw material and number of extractions were employed to optimize the yield of PSDP. The cytotoxic effect of PSDP on human lung carcinoma A549 cell line was evaluated in vivo, while its effects on expressions of caspase- 3, caspase-9, Bcl-2 and Bax were determined by western blot assay.Result: BBD was significant and applicable to PSDP extraction. Based on the contour plots, response surface plots and variance analysis, it predicted that the optimum conditions for PSDP extraction were: 1.58 h (extraction time); 30.18 mL/g (ratio of water to raw material); and 2.02 (number of extractions). PSDP had significant inhibitory effect on the growth of A549 cells in a concentration- and timedependent manner (p < 0.05). After treatment with PSDP, caspase-3, caspase-9 and Bax were significantly up-regulated (p < 0.05), whereas Bcl-2 was down-regulated, all concentration-dependently.Conclusion: RSM analysis is an appropriate method to optimize PSDP extraction. The results also indicate that PSDP has significant anti-tumor effect against A549 cells, most likely via inducing mitochondria-mediated apoptosis.Keywords: Polygonum perfoliatum, Polysaccharides, Anti-tumor effect, Human lung carcinoma, Mitochondria-mediated apoptosi
Effects of behavioral response and vaccination policy on epidemic spreading - an approach based on evolutionary-game dynamics
date of Acceptance: 23/06/2014 This work was supported by the National Natural Science Foundation of China (Grant Nos. 11331009, 11135001, 11105025). Y.-C.L. was supported by AFOSR under Grant No. FA9550-10-1-0083.Peer reviewedPublisher PD
Entanglement criterion via general symmetric informationally complete measurements
We study the quantum separability problem by using general symmetric
informationally complete measurements and present a separability criterion for
arbitrary dimensional bipartite systems. We show by detailed examples that our
criterion is more powerful than the existing ones in entanglement detection.Comment: 8 pages, 5 figure
Online Statistical Inference for Stochastic Optimization via Kiefer-Wolfowitz Methods
This paper investigates the problem of online statistical inference of model
parameters in stochastic optimization problems via the Kiefer-Wolfowitz
algorithm with random search directions. We first present the asymptotic
distribution for the Polyak-Ruppert-averaging type Kiefer-Wolfowitz (AKW)
estimators, whose asymptotic covariance matrices depend on the function-value
query complexity and the distribution of search directions. The distributional
result reflects the trade-off between statistical efficiency and function query
complexity. We further analyze the choices of random search directions to
minimize the asymptotic covariance matrix, and conclude that the optimal search
direction depends on the optimality criteria with respect to different summary
statistics of the Fisher information matrix. Based on the asymptotic
distribution result, we conduct online statistical inference by providing two
construction procedures of valid confidence intervals. We provide numerical
experiments verifying our theoretical results with the practical effectiveness
of the procedures
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