By adopting the method of controlling parameters this paper describes the construction of various kinds of cubic curve segment and curved surface fragment with rational and non rational parameters, and discusses the ...By adopting the method of controlling parameters this paper describes the construction of various kinds of cubic curve segment and curved surface fragment with rational and non rational parameters, and discusses the relationship between controlling parameters, weighted factors and types, kinds and characteristics of curve segments and curved surface fragments. A mathematical method is provided for CAGD with abundant connotations, broad covering region, convenience, flexibility and direct simplicity.展开更多
The J-integral as a controlling parameter was applied to the crack growing process in an elastic-plastic state by Hutchinson and Paris[1], and Shih et. al[2]. An engineering approach based on J-integral was proposed b...The J-integral as a controlling parameter was applied to the crack growing process in an elastic-plastic state by Hutchinson and Paris[1], and Shih et. al[2]. An engineering approach based on J-integral was proposed by Ref.[3]. Obviously, it is necessary to determine whether J is really a bask controlling parameter. It has been shown from the results given in this paper that it is not bask, but the Jn-integral defined in this paper is a proper controlling parameter for crack growth in an clastic-plastic state.展开更多
Optimal formation reconfiguration control of multiple Uninhabited Combat Air Vehicles （UCAVs） is a complicated global optimum problem. Particle Swarm Optimization （PSO） is a population based stochastic optimizatio...Optimal formation reconfiguration control of multiple Uninhabited Combat Air Vehicles （UCAVs） is a complicated global optimum problem. Particle Swarm Optimization （PSO） is a population based stochastic optimization technique inspired by social behaviour of bird flocking or fish schooling. PSO can achieve better results in a faster, cheaper way compared with other bio-inspired computational methods, and there are few parameters to adjust in PSO. In this paper, we propose an improved PSO model for solving the optimal formation reconfiguration control problem for multiple UCAVs. Firstly, the Control Parameterization and Time Diseretization （CPTD） method is designed in detail. Then, the mutation strategy and a special mutation-escape operator are adopted in the improved PSO model to make particles explore the search space more efficiently. The proposed strategy can produce a large speed value dynamically according to the variation of the speed, which makes the algorithm explore the local and global minima thoroughly at the same time. Series experimental results demonstrate the feasibility and effectiveness of the proposed method in solving the optimal formation reconfiguration control problem for multiple UCAVs.展开更多
BACKGROUND Polycystic ovary disease(PCOS)may be a risk factor for nonalcoholic fatty liver disease(NAFLD)due to common pathogenetic pathways,including insulin resistance and obesity.Both PCOS and NAFLD are more severe...BACKGROUND Polycystic ovary disease(PCOS)may be a risk factor for nonalcoholic fatty liver disease(NAFLD)due to common pathogenetic pathways,including insulin resistance and obesity.Both PCOS and NAFLD are more severe in South Asian women.Data on NAFLD in South Asian women with PCOS are lacking.AIM To investigate prevalence and predictors of NAFLD and liver fibrosis in PCOS patients from South Asia.METHODS We conducted an observational routine screening program by means of transient elastography(TE)with associated controlled attenuation parameter(CAP).NAFLD was defined as CAP≥288 decibels per meter.Significant liver fibrosis(stage 2 and higher out of 4)was defined as TE measurement≥8.0 kilopascals.Elevated alanine aminotransferase(ALT)was defined as ALT>24 IU/L,as per upper limit of normal reported in South Asian women.Biochemical hyperandrogenism was defined as free androgen index>5.Predictors of NAFLD were determined by logistic regression analysis.RESULTS 101 PCOS patients(mean age 36.3 years)with no significant alcohol intake or viral hepatitis were included.Prevalence of NAFLD and significant liver fibrosis was 39.6% and 6.9%,respectively.Elevated ALT was observed in 40%and 11.5%of patients with and without NAFLD,respectively.After adjusting for duration of PCOS and insulin resistance measured by homeostasis model for assessment of insulin resistance,independent predictors of NAFLD were higher body mass index[adjusted odds ratio(aOR)1.30,95% confidence interval(CI):1.13-1.52],hyperandrogenism(aOR:5.32,95%CI:1.56-18.17)and elevated ALT(aOR:3.54,95%CI:1.10-11.47).Lifetime cardiovascular risk was higher in patients with NAFLD compared to those without NAFLD(0.31±0.11 vs 0.26±0.13).CONCLUSION Despite their young age,NAFLD diagnosed by TE with CAP is a frequent comorbidity in South Asian women with PCOS and is strongly associated with higher body mass index and hyperandrogenism.Non-invasive screening strategies could help early diagnosis and initiation of interventions,including counselling on weight loss,cardiovascular risk stratification and linkage to hepatology care where appropriate.展开更多
BACKGROUND: Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing hepatic steatosis based on vibration-controlled transient elastography. The objective of this study was to investigate the eff...BACKGROUND: Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing hepatic steatosis based on vibration-controlled transient elastography. The objective of this study was to investigate the effect of high value of CAP on antiviral therapy in patients with chronic hepatitis B (CHB). METHODS: Patients with CHB receiving enticavir for initial antiviral therapy were studied; they were divided into the high CAP group and normal CAP group at baseline according to the CAP values. The effect of the antiviral therapy between the two groups were compared at week 12, 24 and 48. Patients with high CAP value at baseline were divided into three subgroups, mild, moderate and severe elevation; the therapeutic response were compared among patients with normal CAP and subgroups of patients with elevated CAP. RESULTS: A total of 153 patients were enrolled. Among them, 63 were in the high CAP group and 90 in the normal CAP group. Patients with high CAP had lower rates of ALT normalization and HBV DNA clearance in response to antiviral therapy compared with those with normal CAP at week 12, 24 and 48. Further analysis showed that the rate of ALT normalization in patients with mildly and moderately elevated CAP were significant lower than those with normal CAP at week 12 and 24; while the difference was not significant between the patients with normal CAP and those with severely elevated CAP. The rate of HBV DNA clearance was significantly lower in patients with severely elevated CAP compared with those with normal CAP at week 12, 24 and 48. CONCLUSION: CHB patients with high CAP had poor response to antiviral therapy.展开更多
Mastering the influence laws of parameters on the solution structure of nonlinear systems is the basis of carrying out vibration isolation and control.Many researches on solution structure and bifurcation phenomenon i...Mastering the influence laws of parameters on the solution structure of nonlinear systems is the basis of carrying out vibration isolation and control.Many researches on solution structure and bifurcation phenomenon in parameter spaces are carried out broadly in many fields,and the research on nonlinear gear systems has attracted the attention of many scholars.But there is little study on the solution domain boundary of nonlinear gear systems.For a periodic non-autonomous nonlinear dynamic system with several control parameters,a solution domain boundary analysis method of nonlinear systems in parameter spaces is proposed,which combines the cell mapping method based on Poincaré point mapping in phase spaces with the domain decomposition technique of parameter spaces.The cell mapping is known as a global analysis method to analyze the global behavior of a nonlinear dynamic system with finite dimensions,and the basic idea of domain decomposition techniques is to divide and rule.The method is applied to analyze the solution domain boundaries in parameter spaces of a nonlinear gear system.The distribution of different period domains,chaos domain and the domain boundaries between different period domains and chaotic domain are obtained in control parameter spaces constituted by meshing damping ratio with excitation frequency,fluctuation coefficient of meshing stiffness and average exciting force respectively by calculation.The calculation results show that as the meshing damping increases,the responses of the system change towards a single motion,while the variations of the excitation frequency,meshing stiffness and exciting force make the solution domain presenting diversity.The proposed research contribution provides evidence for vibration control and parameter design of the gear system,and confirms the validity of the solution domain boundary analysis method.展开更多
This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively...This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively adjusting multiple parameters of conventional multi-parameter control, this paper introduces a unified step function controlled by a single parameter for constructing various multi-wing chaotic and hyperchaotic systems. In particular, to the best of the authors＇ knowledge, this is also the first time to find a non-equilibrium multi-wing hyperchaotic system by means of the unified step function control. According to the heteroclinic loop Shilnikov theorem, some properties for multi-wing attractors and its chaos mechanism are further discussed and analyzed. A circuit for multi-wing systems is designed and implemented for demonstration, which verifies the effectiveness of the proposed approach.展开更多
AIM:To compare ultrasound-based acoustic structure quantification(ASQ) with established non-invasive techniques for grading and staging fatty liver disease.METHODS:Type 2 diabetic patients at risk of nonalcoholic fatt...AIM:To compare ultrasound-based acoustic structure quantification(ASQ) with established non-invasive techniques for grading and staging fatty liver disease.METHODS:Type 2 diabetic patients at risk of nonalcoholic fatty liver disease(n = 50) and healthy volunteers(n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography(TE), controlled attenuation parameter(CAP), proton magnetic resonance spectroscopy(1H-MRS; only available for the diabetic cohort), and ASQ.ASQ parameters mode, average and focal disturbance(FD) ratio were compared with:(1) the extent of liver fibrosis estimated from TE and nonalcoholic fatty liver disease(NAFLD) fibrosis scores; and(2) the amount of steatosis, which was classified according to CAP values.RESULTS:Forty-seven diabetic patients(age 67.0±8.6 years;body mass index 29.4±4.5 kg/m2)with reliable CAP measurements and all controls(age 26.5±3.2 years;body mass index 22.0±2.7 kg/m2)were included in the analysis.All ASQ parameters showed differences between healthy controls and diabetic patients(P<0.001,respectively).The ASQ FD ratio(logarithmic)correlated with the CAP(r=-0.81,P<0.001)and 1H-MRS(r=-0.43,P=0.004)results.The FD ratio[CAP<250 d B/m:107(102-109),CAP between 250 and 300 d B/m:106(102-114);CAP between 300 and 350 d B/m:105(100-112),CAP≥350 d B/m:102(99-108)]as well as mode and average parameters,were reduced in cases with advanced steatosis(ANOVA P<0.05).However,none of the ASQ parameters showed a significant difference in patients with advanced fibrosis,as determined by TE and the NAFLD fibrosis score(P>0.08,respectively).CONCLUSION:ASQ parameters correlate with steatosis,but not with fibrosis in fatty liver disease.Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies.展开更多
In this paper, we use a kind of univariate multiquadric quasi-interpolation to solve a parabolic equation with overspecified data, which has arisen in many physical phenomena. We obtain the numerical scheme by using t...In this paper, we use a kind of univariate multiquadric quasi-interpolation to solve a parabolic equation with overspecified data, which has arisen in many physical phenomena. We obtain the numerical scheme by using the derivative of the quasi-interpolation to approximate the spatial derivative of the dependent variable and a simple forward difference to approximate the temporal derivative of the dependent variable. The advantage of the presented scheme is that the algorithm is very simple so it is very easy to implement. The results of the numerical experiment are presented and are compared with the exact solution to confirm the good accuracy of the presented scheme.展开更多
AIM: To study the diagnostic value of controlled attenuation parameter (CAP), evaluated by transient elastography, for liver steatosis in patients with chronic hepatitis B (CHB).
In this paper,the stabilization of a continuous time-delayed system is considered.To control the bifurcation and chaos in a time-delayed system,a parameter perturbation control and a hybrid control are proposed.Then,t...In this paper,the stabilization of a continuous time-delayed system is considered.To control the bifurcation and chaos in a time-delayed system,a parameter perturbation control and a hybrid control are proposed.Then,to ensure the asymptotic stability of the system in the presence of unexpected system parameter changes,the adaptive control idea is introduced,i.e.,the perturbation control parameter and the hybrid control parameter are automatically tuned according to the adaptation laws,respectively.The adaptation algorithms are constructed based on the Lyapunov-Krasovskii stability theorem.The adaptive parameter perturbation control and the adaptive hybrid control methods improve the corresponding constant control methods.They have the advantages of increased stability,adaptability to the changes of the system parameters,control cost saving,and simplicity.Numerical simulations for a well-known chaotic time-delayed system are performed to demonstrate the feasibility and superiority of the proposed control methods.A comparison of the two adaptive control methods is also made in an experimental study.展开更多
A modified harmony search algorithm with co-evolutional control parameters(DEHS), applied through differential evolution optimization, is proposed. In DEHS, two control parameters, i.e., harmony memory considering rat...A modified harmony search algorithm with co-evolutional control parameters(DEHS), applied through differential evolution optimization, is proposed. In DEHS, two control parameters, i.e., harmony memory considering rate and pitch adjusting rate, are encoded as a symbiotic individual of an original individual(i.e., harmony vector). Harmony search operators are applied to evolving the original population. DE is applied to co-evolving the symbiotic population based on feedback information from the original population. Thus, with the evolution of the original population in DEHS, the symbiotic population is dynamically and self-adaptively adjusted, and real-time optimum control parameters are obtained. The proposed DEHS algorithm has been applied to various benchmark functions and two typical dynamic optimization problems. The experimental results show that the performance of the proposed algorithm is better than that of other HS variants. Satisfactory results are obtained in the application.展开更多
In this paper, we present a new algorithm to solve a two-dimensional parabolic inverse problem with a source parameter, which appears in many physical phenomena. A linearized compact difference scheme for this problem...In this paper, we present a new algorithm to solve a two-dimensional parabolic inverse problem with a source parameter, which appears in many physical phenomena. A linearized compact difference scheme for this problem is constructed using the finite difference method. The discretization accuracy is second-order in time and fourth-order in space. We obtain the unique solvability and present an alternating direction implicit algorithm to solve this difference scheme. The results of numerical experiments are presented to demonstrate the accuracy of this algorithm.展开更多
BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic st...BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic steatosis in patients with autoimmune liver diseases(AILDs).METHODS Patients who were suspected of having AILDs and underwent liver biopsy were consistently enrolled.Liver stiffness measurement(LSM)and CAP were performed by transient elastography.The area under the receiver operating characteristic(AUROC)curve was used to evaluate the performance of CAP for diagnosing hepatic steatosis compared with biopsy.RESULTS Among 190 patients with biopsy-proven hepatic steatosis,69 were diagnosed with autoimmune hepatitis(AIH),18 with primary biliary cholangitis(PBC),and 27 with AIH-PBC overlap syndrome.The AUROCs of CAP for the diagnosis of steatosis in AILDS were 0.878(0.791-0.965)for S1,0.764(0.676-0.853)for S2,and 0.821(0.716-0.926)for S3.The CAP value was significantly related to hepatic steatosis grade(P<0.001).Among 69 patients with AIH,the median CAP score was 205.63±47.36 dB/m for S0,258.41±42.83 dB/m for S1,293.00±37.18 dB/m for S2,and 313.60±27.89 dB/m for S3.Compared with patients with nonalcoholic fatty liver disease(NAFLD)presenting with autoimmune markers,patients with AIH concomitant with NAFLD were much older and had higher serum IgG levels and LSM values.CONCLUSION CAP can be used as a noninvasive diagnostic method to evaluate hepatic steatosis in patients with AILDs.Determination of LSM combined with CAP may help to identify patients with AIH concomitant with NAFLD from those with NAFLD with autoimmune phenomena.展开更多
Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-di...Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-differentiable or explicit mathematical descriptions do not exist. Recently, evolutionary algorithms are gaining popularity for DOPs as they can be used as robust alternatives when the deterministic techniques are invalid. In this article, a technology named ranking-based mutation operator(RMO) is presented to enhance the previous differential evolution(DE) algorithms to solve DOPs using control vector parameterization. In the RMO, better individuals have higher probabilities to produce offspring, which is helpful for the performance enhancement of DE algorithms. Three DE-RMO algorithms are designed by incorporating the RMO. The three DE-RMO algorithms and their three original DE algorithms are applied to solve four constrained DOPs from the literature. Our simulation results indicate that DE-RMO algorithms exhibit better performance than previous non-ranking DE algorithms and other four evolutionary algorithms.展开更多
BACKGROUND Nonalcoholic fatty liver disease(NAFLD)and nonalcoholic steatohepatitis(NASH)seem common after liver transplantation.AIM To investigate incidence and predictors of NAFLD and NASH by employing noninvasive te...BACKGROUND Nonalcoholic fatty liver disease(NAFLD)and nonalcoholic steatohepatitis(NASH)seem common after liver transplantation.AIM To investigate incidence and predictors of NAFLD and NASH by employing noninvasive testing in liver transplant recipients,namely controlled attenuation parameter(CAP)and the serum biomarker cytokeratin 18(CK-18).We also evaluated the diagnostic accuracy of CK-18 and CAP compared to liver histology.METHODS We prospectively recruited consecutive adult patients who received liver transplant at the McGill University Health Centre between 2015-2018.Serial measurements of CK-18 and CAP were recorded.NAFLD and NASH were diagnosed by CAP≥270 dB/m,and a combination of CAP≥270 dB/m with CK-18>130.5 U/L,respectively.Incidences and predictors of NAFLD and NASH were investigated using survival analysis and Cox proportional hazards.RESULTS Overall,40 liver transplant recipients(mean age 57 years;70%males)were included.During a median follow-up of 16.8 mo(interquartile range 15.6-18.0),63.0%and 48.5%of patients developed NAFLD and NASH,respectively.On multivariable analysis,after adjusting for sex and alanine aminotransferase,body mass index was an independent predictor of development of NAFLD[adjusted hazard ratio(aHR):1.21,95%confidence interval(CI):1.04-1.41;P=0.01]and NASH(aHR:1.26,95%CI:1.06-1.49;P<0.01).Compared to liver histology,CAP had a 76%accuracy to diagnose NAFLD,while the accuracy of CAP plus CK-18 to diagnose NASH was 82%.CONCLUSION NAFLD and NASH diagnosed non-invasively are frequent in liver transplant recipients within the first 18 mo.Close follow-up and nutritional counselling should be planned in overweight patients.展开更多
文摘By adopting the method of controlling parameters this paper describes the construction of various kinds of cubic curve segment and curved surface fragment with rational and non rational parameters, and discusses the relationship between controlling parameters, weighted factors and types, kinds and characteristics of curve segments and curved surface fragments. A mathematical method is provided for CAGD with abundant connotations, broad covering region, convenience, flexibility and direct simplicity.
文摘The J-integral as a controlling parameter was applied to the crack growing process in an elastic-plastic state by Hutchinson and Paris[1], and Shih et. al[2]. An engineering approach based on J-integral was proposed by Ref.[3]. Obviously, it is necessary to determine whether J is really a bask controlling parameter. It has been shown from the results given in this paper that it is not bask, but the Jn-integral defined in this paper is a proper controlling parameter for crack growth in an clastic-plastic state.
基金supported by National Natural Science Foundation of China(61273108)the Fundamental Research Funds for the Central Universities(106112013CDJZR175501)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
基金Supported by The National Key Basic Research Project,No.2012CB517501Chinese Foundation for Hepatitis Prevention and Control–"WANG Bao-En"Liver Fibrosis Research Fund,No.XJS20120501+1 种基金Shanghai Science and Technology Committee,No.09140903500 and No.10411956300the 100-Talents Program of the Shanghai Municipal Health Bureau,No.XBR2011007
文摘AIM: To evaluate the performance of a novel non-invasive controlled attenuation parameter (CAP) to assess liver steatosis.
基金supported by the Natural Science Foundation of China (Grant No.60604009)the Aero-nautical Science Foundation of China (Grant No. 2006ZC51039)+1 种基金the Beijing NOVA Program Foundation of China (Grant No. 2007A017)the Open Fund of the Provincial Key Laboratory for Information Proc-essing Technology, Suzhou University (Grant No. KJS0821)
文摘Optimal formation reconfiguration control of multiple Uninhabited Combat Air Vehicles （UCAVs） is a complicated global optimum problem. Particle Swarm Optimization （PSO） is a population based stochastic optimization technique inspired by social behaviour of bird flocking or fish schooling. PSO can achieve better results in a faster, cheaper way compared with other bio-inspired computational methods, and there are few parameters to adjust in PSO. In this paper, we propose an improved PSO model for solving the optimal formation reconfiguration control problem for multiple UCAVs. Firstly, the Control Parameterization and Time Diseretization （CPTD） method is designed in detail. Then, the mutation strategy and a special mutation-escape operator are adopted in the improved PSO model to make particles explore the search space more efficiently. The proposed strategy can produce a large speed value dynamically according to the variation of the speed, which makes the algorithm explore the local and global minima thoroughly at the same time. Series experimental results demonstrate the feasibility and effectiveness of the proposed method in solving the optimal formation reconfiguration control problem for multiple UCAVs.
基金Supported by Libyan Ministry of Higher Education and Scientific Research sponsored through Canadian Bureau for International Education,No.2979.
文摘BACKGROUND Polycystic ovary disease(PCOS)may be a risk factor for nonalcoholic fatty liver disease(NAFLD)due to common pathogenetic pathways,including insulin resistance and obesity.Both PCOS and NAFLD are more severe in South Asian women.Data on NAFLD in South Asian women with PCOS are lacking.AIM To investigate prevalence and predictors of NAFLD and liver fibrosis in PCOS patients from South Asia.METHODS We conducted an observational routine screening program by means of transient elastography(TE)with associated controlled attenuation parameter(CAP).NAFLD was defined as CAP≥288 decibels per meter.Significant liver fibrosis(stage 2 and higher out of 4)was defined as TE measurement≥8.0 kilopascals.Elevated alanine aminotransferase(ALT)was defined as ALT>24 IU/L,as per upper limit of normal reported in South Asian women.Biochemical hyperandrogenism was defined as free androgen index>5.Predictors of NAFLD were determined by logistic regression analysis.RESULTS 101 PCOS patients(mean age 36.3 years)with no significant alcohol intake or viral hepatitis were included.Prevalence of NAFLD and significant liver fibrosis was 39.6% and 6.9%,respectively.Elevated ALT was observed in 40%and 11.5%of patients with and without NAFLD,respectively.After adjusting for duration of PCOS and insulin resistance measured by homeostasis model for assessment of insulin resistance,independent predictors of NAFLD were higher body mass index[adjusted odds ratio(aOR)1.30,95% confidence interval(CI):1.13-1.52],hyperandrogenism(aOR:5.32,95%CI:1.56-18.17)and elevated ALT(aOR:3.54,95%CI:1.10-11.47).Lifetime cardiovascular risk was higher in patients with NAFLD compared to those without NAFLD(0.31±0.11 vs 0.26±0.13).CONCLUSION Despite their young age,NAFLD diagnosed by TE with CAP is a frequent comorbidity in South Asian women with PCOS and is strongly associated with higher body mass index and hyperandrogenism.Non-invasive screening strategies could help early diagnosis and initiation of interventions,including counselling on weight loss,cardiovascular risk stratification and linkage to hepatology care where appropriate.
基金supported by grants from the National Science and Technology Major Project of China(2012ZX10002007-001-003 and 2013ZX10002005-002-003)the WBE Liver Fibrosis Foundation(XJS20120204)
文摘BACKGROUND: Controlled attenuation parameter (CAP) is a non-invasive method for diagnosing hepatic steatosis based on vibration-controlled transient elastography. The objective of this study was to investigate the effect of high value of CAP on antiviral therapy in patients with chronic hepatitis B (CHB). METHODS: Patients with CHB receiving enticavir for initial antiviral therapy were studied; they were divided into the high CAP group and normal CAP group at baseline according to the CAP values. The effect of the antiviral therapy between the two groups were compared at week 12, 24 and 48. Patients with high CAP value at baseline were divided into three subgroups, mild, moderate and severe elevation; the therapeutic response were compared among patients with normal CAP and subgroups of patients with elevated CAP. RESULTS: A total of 153 patients were enrolled. Among them, 63 were in the high CAP group and 90 in the normal CAP group. Patients with high CAP had lower rates of ALT normalization and HBV DNA clearance in response to antiviral therapy compared with those with normal CAP at week 12, 24 and 48. Further analysis showed that the rate of ALT normalization in patients with mildly and moderately elevated CAP were significant lower than those with normal CAP at week 12 and 24; while the difference was not significant between the patients with normal CAP and those with severely elevated CAP. The rate of HBV DNA clearance was significantly lower in patients with severely elevated CAP compared with those with normal CAP at week 12, 24 and 48. CONCLUSION: CHB patients with high CAP had poor response to antiviral therapy.
基金supported by National Hi-tech Research and Development Program of China (863 Program,Grant No.2009AA04Z404)
文摘Mastering the influence laws of parameters on the solution structure of nonlinear systems is the basis of carrying out vibration isolation and control.Many researches on solution structure and bifurcation phenomenon in parameter spaces are carried out broadly in many fields,and the research on nonlinear gear systems has attracted the attention of many scholars.But there is little study on the solution domain boundary of nonlinear gear systems.For a periodic non-autonomous nonlinear dynamic system with several control parameters,a solution domain boundary analysis method of nonlinear systems in parameter spaces is proposed,which combines the cell mapping method based on Poincaré point mapping in phase spaces with the domain decomposition technique of parameter spaces.The cell mapping is known as a global analysis method to analyze the global behavior of a nonlinear dynamic system with finite dimensions,and the basic idea of domain decomposition techniques is to divide and rule.The method is applied to analyze the solution domain boundaries in parameter spaces of a nonlinear gear system.The distribution of different period domains,chaos domain and the domain boundaries between different period domains and chaotic domain are obtained in control parameter spaces constituted by meshing damping ratio with excitation frequency,fluctuation coefficient of meshing stiffness and average exciting force respectively by calculation.The calculation results show that as the meshing damping increases,the responses of the system change towards a single motion,while the variations of the excitation frequency,meshing stiffness and exciting force make the solution domain presenting diversity.The proposed research contribution provides evidence for vibration control and parameter design of the gear system,and confirms the validity of the solution domain boundary analysis method.
基金Project supported by the National Natural Science Foundation of China(Grant No.61403143)the Natural Science Foundation of Guangdong Province,China(Grant No.2014A030313739)+1 种基金the Science and Technology Foundation Program of Guangzhou City,China(Grant No.201510010124)the Excellent Doctorial Dissertation Foundation of Guangdong Province,China(Grant No.XM080054)
文摘This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively adjusting multiple parameters of conventional multi-parameter control, this paper introduces a unified step function controlled by a single parameter for constructing various multi-wing chaotic and hyperchaotic systems. In particular, to the best of the authors＇ knowledge, this is also the first time to find a non-equilibrium multi-wing hyperchaotic system by means of the unified step function control. According to the heteroclinic loop Shilnikov theorem, some properties for multi-wing attractors and its chaos mechanism are further discussed and analyzed. A circuit for multi-wing systems is designed and implemented for demonstration, which verifies the effectiveness of the proposed approach.
基金Supported by Federal Ministry of Education and Research(BMBF),Germany,FKZ:01EO1001(Project No.K7-40)the German Research Foundation(DFG)the University of Leipzig within the program of Open Access Publishing
文摘AIM:To compare ultrasound-based acoustic structure quantification(ASQ) with established non-invasive techniques for grading and staging fatty liver disease.METHODS:Type 2 diabetic patients at risk of nonalcoholic fatty liver disease(n = 50) and healthy volunteers(n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography(TE), controlled attenuation parameter(CAP), proton magnetic resonance spectroscopy(1H-MRS; only available for the diabetic cohort), and ASQ.ASQ parameters mode, average and focal disturbance(FD) ratio were compared with:(1) the extent of liver fibrosis estimated from TE and nonalcoholic fatty liver disease(NAFLD) fibrosis scores; and(2) the amount of steatosis, which was classified according to CAP values.RESULTS:Forty-seven diabetic patients(age 67.0±8.6 years;body mass index 29.4±4.5 kg/m2)with reliable CAP measurements and all controls(age 26.5±3.2 years;body mass index 22.0±2.7 kg/m2)were included in the analysis.All ASQ parameters showed differences between healthy controls and diabetic patients(P<0.001,respectively).The ASQ FD ratio(logarithmic)correlated with the CAP(r=-0.81,P<0.001)and 1H-MRS(r=-0.43,P=0.004)results.The FD ratio[CAP<250 d B/m:107(102-109),CAP between 250 and 300 d B/m:106(102-114);CAP between 300 and 350 d B/m:105(100-112),CAP≥350 d B/m:102(99-108)]as well as mode and average parameters,were reduced in cases with advanced steatosis(ANOVA P<0.05).However,none of the ASQ parameters showed a significant difference in patients with advanced fibrosis,as determined by TE and the NAFLD fibrosis score(P>0.08,respectively).CONCLUSION:ASQ parameters correlate with steatosis,but not with fibrosis in fatty liver disease.Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies.
基金Project supported by the National Key Basic Research Program of China (Grant No. 2006CB303102)Science and Technology Commission of Shanghai Municipality, China (Grant No. 09DZ2272900)
文摘In this paper, we use a kind of univariate multiquadric quasi-interpolation to solve a parabolic equation with overspecified data, which has arisen in many physical phenomena. We obtain the numerical scheme by using the derivative of the quasi-interpolation to approximate the spatial derivative of the dependent variable and a simple forward difference to approximate the temporal derivative of the dependent variable. The advantage of the presented scheme is that the algorithm is very simple so it is very easy to implement. The results of the numerical experiment are presented and are compared with the exact solution to confirm the good accuracy of the presented scheme.
基金Supported by China Hepatitis Prevention and Treatment Foundation Wang Baoen Liver Fibrosis Research Fund,No.xjs20110402
文摘AIM: To study the diagnostic value of controlled attenuation parameter (CAP), evaluated by transient elastography, for liver steatosis in patients with chronic hepatitis B (CHB).
基金Project supported by the National Natural Science Foundation of China (Grant No. 10772043)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20090042110003)the Science Research Project of Education Department of Liaoning Province,China (Grant No. L2012208)
文摘In this paper,the stabilization of a continuous time-delayed system is considered.To control the bifurcation and chaos in a time-delayed system,a parameter perturbation control and a hybrid control are proposed.Then,to ensure the asymptotic stability of the system in the presence of unexpected system parameter changes,the adaptive control idea is introduced,i.e.,the perturbation control parameter and the hybrid control parameter are automatically tuned according to the adaptation laws,respectively.The adaptation algorithms are constructed based on the Lyapunov-Krasovskii stability theorem.The adaptive parameter perturbation control and the adaptive hybrid control methods improve the corresponding constant control methods.They have the advantages of increased stability,adaptability to the changes of the system parameters,control cost saving,and simplicity.Numerical simulations for a well-known chaotic time-delayed system are performed to demonstrate the feasibility and superiority of the proposed control methods.A comparison of the two adaptive control methods is also made in an experimental study.
基金Project(2013CB733605)supported by the National Basic Research Program of ChinaProject(21176073)supported by the National Natural Science Foundation of China
文摘A modified harmony search algorithm with co-evolutional control parameters(DEHS), applied through differential evolution optimization, is proposed. In DEHS, two control parameters, i.e., harmony memory considering rate and pitch adjusting rate, are encoded as a symbiotic individual of an original individual(i.e., harmony vector). Harmony search operators are applied to evolving the original population. DE is applied to co-evolving the symbiotic population based on feedback information from the original population. Thus, with the evolution of the original population in DEHS, the symbiotic population is dynamically and self-adaptively adjusted, and real-time optimum control parameters are obtained. The proposed DEHS algorithm has been applied to various benchmark functions and two typical dynamic optimization problems. The experimental results show that the performance of the proposed algorithm is better than that of other HS variants. Satisfactory results are obtained in the application.
基金supported by the Natural Science Foundation of Shandong Province of China (Grant No. ZR2009AL012)the Scienceand Technology Program of Education Bureau of Shandong Province, China (Grant No. J09LA12)
文摘In this paper, we present a new algorithm to solve a two-dimensional parabolic inverse problem with a source parameter, which appears in many physical phenomena. A linearized compact difference scheme for this problem is constructed using the finite difference method. The discretization accuracy is second-order in time and fourth-order in space. We obtain the unique solvability and present an alternating direction implicit algorithm to solve this difference scheme. The results of numerical experiments are presented to demonstrate the accuracy of this algorithm.
基金Supported by National Natural Science Foundation of China,No.81470842 and No.81770572.
文摘BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic steatosis in patients with autoimmune liver diseases(AILDs).METHODS Patients who were suspected of having AILDs and underwent liver biopsy were consistently enrolled.Liver stiffness measurement(LSM)and CAP were performed by transient elastography.The area under the receiver operating characteristic(AUROC)curve was used to evaluate the performance of CAP for diagnosing hepatic steatosis compared with biopsy.RESULTS Among 190 patients with biopsy-proven hepatic steatosis,69 were diagnosed with autoimmune hepatitis(AIH),18 with primary biliary cholangitis(PBC),and 27 with AIH-PBC overlap syndrome.The AUROCs of CAP for the diagnosis of steatosis in AILDS were 0.878(0.791-0.965)for S1,0.764(0.676-0.853)for S2,and 0.821(0.716-0.926)for S3.The CAP value was significantly related to hepatic steatosis grade(P<0.001).Among 69 patients with AIH,the median CAP score was 205.63±47.36 dB/m for S0,258.41±42.83 dB/m for S1,293.00±37.18 dB/m for S2,and 313.60±27.89 dB/m for S3.Compared with patients with nonalcoholic fatty liver disease(NAFLD)presenting with autoimmune markers,patients with AIH concomitant with NAFLD were much older and had higher serum IgG levels and LSM values.CONCLUSION CAP can be used as a noninvasive diagnostic method to evaluate hepatic steatosis in patients with AILDs.Determination of LSM combined with CAP may help to identify patients with AIH concomitant with NAFLD from those with NAFLD with autoimmune phenomena.
基金Supported by the National Natural Science Foundation of China(61333010,61134007and 21276078)“Shu Guang”project of Shanghai Municipal Education Commission,the Research Talents Startup Foundation of Jiangsu University(15JDG139)China Postdoctoral Science Foundation(2016M591783)
文摘Dynamic optimization problems(DOPs) described by differential equations are often encountered in chemical engineering. Deterministic techniques based on mathematic programming become invalid when the models are non-differentiable or explicit mathematical descriptions do not exist. Recently, evolutionary algorithms are gaining popularity for DOPs as they can be used as robust alternatives when the deterministic techniques are invalid. In this article, a technology named ranking-based mutation operator(RMO) is presented to enhance the previous differential evolution(DE) algorithms to solve DOPs using control vector parameterization. In the RMO, better individuals have higher probabilities to produce offspring, which is helpful for the performance enhancement of DE algorithms. Three DE-RMO algorithms are designed by incorporating the RMO. The three DE-RMO algorithms and their three original DE algorithms are applied to solve four constrained DOPs from the literature. Our simulation results indicate that DE-RMO algorithms exhibit better performance than previous non-ranking DE algorithms and other four evolutionary algorithms.
基金the Canadian Donation and Transplantation Research Program of the Canadian Society of Transplantation(grant competition 2014)Sebastiani G is supported by a Senior Salary Award from Fonds de la Recherche en Santédu Quebéc(FRQS)(No.#296306).
文摘BACKGROUND Nonalcoholic fatty liver disease(NAFLD)and nonalcoholic steatohepatitis(NASH)seem common after liver transplantation.AIM To investigate incidence and predictors of NAFLD and NASH by employing noninvasive testing in liver transplant recipients,namely controlled attenuation parameter(CAP)and the serum biomarker cytokeratin 18(CK-18).We also evaluated the diagnostic accuracy of CK-18 and CAP compared to liver histology.METHODS We prospectively recruited consecutive adult patients who received liver transplant at the McGill University Health Centre between 2015-2018.Serial measurements of CK-18 and CAP were recorded.NAFLD and NASH were diagnosed by CAP≥270 dB/m,and a combination of CAP≥270 dB/m with CK-18>130.5 U/L,respectively.Incidences and predictors of NAFLD and NASH were investigated using survival analysis and Cox proportional hazards.RESULTS Overall,40 liver transplant recipients(mean age 57 years;70%males)were included.During a median follow-up of 16.8 mo(interquartile range 15.6-18.0),63.0%and 48.5%of patients developed NAFLD and NASH,respectively.On multivariable analysis,after adjusting for sex and alanine aminotransferase,body mass index was an independent predictor of development of NAFLD[adjusted hazard ratio(aHR):1.21,95%confidence interval(CI):1.04-1.41;P=0.01]and NASH(aHR:1.26,95%CI:1.06-1.49;P<0.01).Compared to liver histology,CAP had a 76%accuracy to diagnose NAFLD,while the accuracy of CAP plus CK-18 to diagnose NASH was 82%.CONCLUSION NAFLD and NASH diagnosed non-invasively are frequent in liver transplant recipients within the first 18 mo.Close follow-up and nutritional counselling should be planned in overweight patients.
