At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, th...At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion（BCB3DBM）is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system（LTS）. Furthermore, block confusion based on position sequence group（BCBPSG） is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed.展开更多
Background and Aims:Platelet-to-lymphocyte ratio(PLR)has been shown to predict prognosis of cancers.We aimed to evaluate the prognostic value of stratification of PLR in patients after curative liver resection(CLR)for...Background and Aims:Platelet-to-lymphocyte ratio(PLR)has been shown to predict prognosis of cancers.We aimed to evaluate the prognostic value of stratification of PLR in patients after curative liver resection(CLR)for hepatocellular carcinoma(HCC).Methods:A total of 1804 patients who underwent CLR for suspected HCC between January 2007 and January 2014 were screened for the study.All of the patients were categorized into equal tertiles according to the number of patients and the distribution of PLR.Prognostic significance was determined for overall survival(OS)and was assessed using Kaplan-Meier analysis.Univariate and multi-variate Cox proportional hazard regression analyses were evaluated for association of all independent parameters with disease prognosis.Results:The optimal cut-off points of preoperative PLR were:(T1)11.98-75.00,(T2)75.00-113.33 and(T3)113.33-567.50.There were obvious differences in each PLR tertile with mortality within 36 months of CLR(Plog-rank<0.001).Multivariable analysis suggested that the level of PLR(HR=1.004,95%CI:1.001-1.008,P=0.006),portal vein thrombosis(HR=3.406,95%CI:1.185-9.794,P=0.023),number of nodules(HR=1.810,95%CI:1.345-2.437,P<0.001),Child-Turcotte-Pugh score(HR=1.741,95%CI:1.129-2.684,P=0.012)and microvascular invasion(HR=2.730,95%CI:1.777-4.196,P<0.001)were significant predictors of mortality.Kaplan-Meier analysis of overall survival(OS)demonstrated that each PLR tertile showed a progressively worse OS and apparent separation(Plog-rank=0.016).The highest 5-year OS rate following CLR(58%)was revealed in tertile 1.In contrast,the lowest 5-year OS rate(30%)was revealed in tertile 3.Conclusion:Stratified preoperative PLR could strengthen the predictive power for OS in HCC patients with CLR.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41571417 and 61305042)the National Science Foundation of the United States(Grant Nos.CNS-1253424 and ECCS-1202225)+4 种基金the Science and Technology Foundation of Henan Province,China(Grant No.152102210048)the Foundation and Frontier Project of Henan Province,China(Grant No.162300410196)China Postdoctoral Science Foundation(Grant No.2016M602235)the Natural Science Foundation of Educational Committee of Henan Province,China(Grant No.14A413015)the Research Foundation of Henan University,China(Grant No.xxjc20140006)
文摘At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion（BCB3DBM）is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system（LTS）. Furthermore, block confusion based on position sequence group（BCBPSG） is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed.
基金grants from the National Natural Science Foundation of China(81500665)Scientific Research Foundation of Wenzhou(Y20160223)High Level Creative Talents from Department of Public Health in Zhejiang Province,and the Project of New Century 551 Talent Nurturing in Wenzhou to MH Zheng
文摘Background and Aims:Platelet-to-lymphocyte ratio(PLR)has been shown to predict prognosis of cancers.We aimed to evaluate the prognostic value of stratification of PLR in patients after curative liver resection(CLR)for hepatocellular carcinoma(HCC).Methods:A total of 1804 patients who underwent CLR for suspected HCC between January 2007 and January 2014 were screened for the study.All of the patients were categorized into equal tertiles according to the number of patients and the distribution of PLR.Prognostic significance was determined for overall survival(OS)and was assessed using Kaplan-Meier analysis.Univariate and multi-variate Cox proportional hazard regression analyses were evaluated for association of all independent parameters with disease prognosis.Results:The optimal cut-off points of preoperative PLR were:(T1)11.98-75.00,(T2)75.00-113.33 and(T3)113.33-567.50.There were obvious differences in each PLR tertile with mortality within 36 months of CLR(Plog-rank<0.001).Multivariable analysis suggested that the level of PLR(HR=1.004,95%CI:1.001-1.008,P=0.006),portal vein thrombosis(HR=3.406,95%CI:1.185-9.794,P=0.023),number of nodules(HR=1.810,95%CI:1.345-2.437,P<0.001),Child-Turcotte-Pugh score(HR=1.741,95%CI:1.129-2.684,P=0.012)and microvascular invasion(HR=2.730,95%CI:1.777-4.196,P<0.001)were significant predictors of mortality.Kaplan-Meier analysis of overall survival(OS)demonstrated that each PLR tertile showed a progressively worse OS and apparent separation(Plog-rank=0.016).The highest 5-year OS rate following CLR(58%)was revealed in tertile 1.In contrast,the lowest 5-year OS rate(30%)was revealed in tertile 3.Conclusion:Stratified preoperative PLR could strengthen the predictive power for OS in HCC patients with CLR.
