What is already known about this topic?Previous studies indicate that an increase in physical activity can diminish the risk of mortality.However,the relationship between longitudinal changes in physical activity and ...What is already known about this topic?Previous studies indicate that an increase in physical activity can diminish the risk of mortality.However,the relationship between longitudinal changes in physical activity and health improvement among Chinese adults with or without hypertension has not been explored.What is added by this report?This study found that increasing or maintaining moderate to high physical activity levels reduced the risk of all-cause mortality,irrespective of the baseline physical activity level.In addition,the beneficial effects were particularly pronounced in people with hypertension.What are the implications for public health practice?It may be beneficial to encourage adults in China,especially those with hypertension,to actively increase physical activity and deter the issue of physical inactivity that accompanies aging.展开更多
In this paper,an efficient image encryption scheme based on a novel mixed linear–nonlinear coupled map lattice(NMLNCML)system and DNA operations is presented.The proposed NMLNCML system strengthens the chaotic charac...In this paper,an efficient image encryption scheme based on a novel mixed linear–nonlinear coupled map lattice(NMLNCML)system and DNA operations is presented.The proposed NMLNCML system strengthens the chaotic characteristics of the system,and is applicable for image encryption.The main advantages of the proposed method are embodied in its extensive key space;high sensitivity to secret keys;great resistance to chosen-plaintext attack,statistical attack,and differential attack;and good robustness to noise and data loss.Our image cryptosystem adopts the architecture of scrambling,compression,and diffusion.First,a plain image is transformed to a sparsity coefficient matrix by discrete wavelet transform,and plaintext-related Arnold scrambling is performed on the coefficient matrix.Then,semi-tensor product(STP)compressive sensing is employed to compress and encrypt the coefficient matrix.Finally,the compressed coefficient matrix is diffused by DNA random encoding,DNA addition,and bit XOR operation.The NMLNCML system is applied to generate chaotic elements in the STP measurement matrix of compressive sensing and the pseudo-random sequence in DNA operations.An SHA-384 function is used to produce plaintext secret keys and thus makes the proposed encryption algorithm highly sensitive to the original image.Simulation results and performance analyses verify the security and effectiveness of our scheme.展开更多
基金supported by the National Key Research and Development Program of China(2018YFC1313900,2018YFC1313904).
文摘What is already known about this topic?Previous studies indicate that an increase in physical activity can diminish the risk of mortality.However,the relationship between longitudinal changes in physical activity and health improvement among Chinese adults with or without hypertension has not been explored.What is added by this report?This study found that increasing or maintaining moderate to high physical activity levels reduced the risk of all-cause mortality,irrespective of the baseline physical activity level.In addition,the beneficial effects were particularly pronounced in people with hypertension.What are the implications for public health practice?It may be beneficial to encourage adults in China,especially those with hypertension,to actively increase physical activity and deter the issue of physical inactivity that accompanies aging.
基金supported by the National Natural Science Foundation of China(Nos.11901297 and 61973078)。
文摘In this paper,an efficient image encryption scheme based on a novel mixed linear–nonlinear coupled map lattice(NMLNCML)system and DNA operations is presented.The proposed NMLNCML system strengthens the chaotic characteristics of the system,and is applicable for image encryption.The main advantages of the proposed method are embodied in its extensive key space;high sensitivity to secret keys;great resistance to chosen-plaintext attack,statistical attack,and differential attack;and good robustness to noise and data loss.Our image cryptosystem adopts the architecture of scrambling,compression,and diffusion.First,a plain image is transformed to a sparsity coefficient matrix by discrete wavelet transform,and plaintext-related Arnold scrambling is performed on the coefficient matrix.Then,semi-tensor product(STP)compressive sensing is employed to compress and encrypt the coefficient matrix.Finally,the compressed coefficient matrix is diffused by DNA random encoding,DNA addition,and bit XOR operation.The NMLNCML system is applied to generate chaotic elements in the STP measurement matrix of compressive sensing and the pseudo-random sequence in DNA operations.An SHA-384 function is used to produce plaintext secret keys and thus makes the proposed encryption algorithm highly sensitive to the original image.Simulation results and performance analyses verify the security and effectiveness of our scheme.
