A Langevin delayed fractional system with multiple delays in control,is a delayed fractional system that includes delay parameters in both state and control,is first introduced.This paper is devoted to investigating t...A Langevin delayed fractional system with multiple delays in control,is a delayed fractional system that includes delay parameters in both state and control,is first introduced.This paper is devoted to investigating the relative controllability of the Langevin delayed fractional system with multiple delays in control.For linear systems to be relatively controllable,necessary and sufficient circumstances are identified by introducing and employing the Gramian matrix.The sufficient conditions for the relative controllability of semilinear systems are ofered based on Schauder's fixed point theorem.As an unusual approach,the controllability results of the delayed system are built for the first time on the exact solution produced by the MittagLeffler type function although controllability ones in the literature are built on the Volterra integral equations or the mild solutions produced by resolvent families.展开更多
This paper deals with the problem of robust stabilization for uncertain Takagi-Sugeno(T-S)fuzzy neutral systems with input delays and distributed delays.The purpose is to design a state feedback fuzzy controller with ...This paper deals with the problem of robust stabilization for uncertain Takagi-Sugeno(T-S)fuzzy neutral systems with input delays and distributed delays.The purpose is to design a state feedback fuzzy controller with a H∞performance such that the resulting closed-loop system is robustly stable.Sufficient conditions for the solvability of the problem are obtained by utilizing proper Lyapunov functional together with the linear matrix inequality(LMI)approach,especially two different improved results on robust H∞controller design with relaxed conditions are obtained.Finally,we provide two examples to verify the effectiveness of our design method and give some principle for choosing the proper controller under certain circumstances.展开更多
This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of ...This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of FxTS is independent of the initial values and parameters of the CNs,a modified fixed-time(FxT)stability theorem is proposed,where the ST is determined by an arbitrary positive number given in advance.Then,continuous controller and discontinuous controller are designed to realize the modified FxTS target of CNs.In addition,based on the designed controllers,CNs can achieve synchronization at any given time,or even earlier.And control strategies effectively solve the problem of ST related to the parameters of CNs.Finally,an appropriate simulation example is conducted to examine the effectiveness of the designed control strategies.展开更多
In this article,we comment on the article by Blüthner et al.The article provides a comprehensive analysis of the factors contributing to the late detection of Crohn’s disease and ulcerative colitis within a Germ...In this article,we comment on the article by Blüthner et al.The article provides a comprehensive analysis of the factors contributing to the late detection of Crohn’s disease and ulcerative colitis within a German cohort.It highlights the conse-quences on patient outcomes,particularly disease progression and the increased risk of developing complications.The study identifies specific predictors asso-ciated with both patient-related and physician-related delays,offering a detailed exploration of the initial approach.Additionally,the article delves into the distinct patterns observed in the German population,stressing the unique aspects of diagnostic delays that may differ from those reported in other regions.This detailed examination offers valuable insights into the specific challenges faced within the German healthcare system and underscores the necessity of targeted interventions to facilitate early diagnosis.The importance of improved screening tools,patient education,and better healthcare infrastructure is emphasized as crucial steps toward improving patient care in inflammatory bowel disease.展开更多
BACKGROUND Studies investigating diagnostic delays and their effects on patients with alcoholic cirrhosis.AIM To investigate the current status and associated factors influencing diagnostic delays in 401 patients with...BACKGROUND Studies investigating diagnostic delays and their effects on patients with alcoholic cirrhosis.AIM To investigate the current status and associated factors influencing diagnostic delays in 401 patients with alcoholic cirrhosis.METHODS A cross-sectional analysis was conducted at a tertiary hospital in China from June 2020 to December 2023.Data were collected through telephone follow-ups and questionnaires.The Wilcoxon and Kruskal-Wallis H tests were used to compare diagnostic delays across various characteristics.Multivariate linear regression was employed to identify factors associated with diagnostic delays.RESULTS The median diagnostic delay was 5 months,with an interquartile range of 2-11 months.The proportions of patients with alcoholic cirrhosis who initially visited tertiary,secondary,and primary hospitals were 38.9%,37.91%,and 23.19%,respectively.Furthermore,the rates of patients undergoing liver computed tomography(CT)during their first visit at tertiary,secondary,and primary hospitals were 92.95%,13.82%,and 1.08%,respectively(P<0.001).Significant differences were observed in diagnostic delay-related characteristics,including residence,resident type,initial diagnosis,medical insurance,liver CT,and liver ultrasound during the first visit,age,years of education,family size,marital status,annual family income,years of drinking,daily alcohol consumption,and type of alcohol consumed(P<0.01).Furthermore,diagnostic delays were variably associated with daily alcohol consumption and other characteristics(i.e.residence,years of drinking,medical insurance,years of education,annual family income,liver CT and ultrasound during the first visit).Significant predictors of diagnostic delay identified on multivariate linear regression analysis included years of education,daily alcohol consumption,annual family income and blood ammonia levels(P<0.01).Patients with alcoholic cirrhosis experience varying degrees of diagnostic delays,necessitating interventions targeting potential contributing factors.CONCLUSION Our study indicates that patients with alcoholic cirrhosis may experience varying degrees of diagnostic delay.Interventions targeting potential factors contributing to diagnostic delay are necessary.展开更多
BACKGROUND Neurodevelopmental delays encompass a wide range of conditions that impair cognitive,motor,and social functioning,often increasing the risk of psychiatric comorbidities.Children with these delays frequently...BACKGROUND Neurodevelopmental delays encompass a wide range of conditions that impair cognitive,motor,and social functioning,often increasing the risk of psychiatric comorbidities.Children with these delays frequently present with disorders such as attention-deficit/hyperactivity disorder(ADHD),anxiety,and behavioral disturbances,which can significantly affect development and quality of life.While genetic predisposition has been linked to these comorbidities,growing evidence highlights the role of environmental factors,including prenatal and early-life stressors.However,the interaction between genetic susceptibility and environmental influences remains poorly understood.Identifying specific genetic variants,environmental risks,and their interactions is essential for early detection and targeted interventions.AIM To investigate the combined effects of genetic and environmental factors on psychiatric comorbidities in children with neurodevelopmental delays,elucidate underlying mechanisms,and inform clinical management strategies.METHODS This retrospective cohort study included 80 children with confirmed neurodevelopmental delays and 40 age-and sex-matched typically developing controls.Comprehensive clinical and psychiatric evaluations,genetic testing(chromosomal microarray analysis and targeted next-generation sequencing),and environmental exposure assessments were conducted.Statistical analyses explored associations between genetic variants and psychiatric comorbidities,environmental risk factors,and gene-environment interactions.RESULTS Children with neurodevelopmental delays exhibited significantly higher rates of psychiatric comorbidities(70.0%)compared to controls(15.0%),with ADHD(42.5%),anxiety disorders(28.8%),and behavioral disorders(23.8%)being the most common.Pathogenic genetic variants were identified in specific pathways associated with distinct psychiatric presentations:Glutamatergic signaling variants were linked to anxiety disorders(odds ratio=3.8),dopaminergic system variants to ADHD(odds ratio=4.2),and synaptic function variants to both behavioral and anxiety disorders.Environmental factors,particularly prenatal maternal stress,early childhood adversity,and family dysfunction were strong predictors of psychiatric outcomes(β=0.42).Significant gene-environment interactions were identified,indicating that environmental exposure can moderate the effects of genetic risks on psychiatric outcomes.CONCLUSION Psychiatric comorbidities in children with neurodevelopmental delays are significantly influenced by both genetic and environmental factors,with complex interactions between the two.These findings underscore the need for integrated assessments and targeted interventions addressing both biological and environmental contributors to improve outcomes in this vulnerable population.展开更多
Objective:To investigate the association between diagnosis delays and mortality in patients with haemorrhagic fever in Upper Southern Thailand.Methods:A hospital-based case control study was conducted between December...Objective:To investigate the association between diagnosis delays and mortality in patients with haemorrhagic fever in Upper Southern Thailand.Methods:A hospital-based case control study was conducted between December 2019 and January 2020.Cases were defined as patients who had been diagnosed with haemorrhagic fever and died during hospitalization,while controls were patients with similar conditions who survived.Medical records were retrospectively reviewed,with the primary variable being a diagnosis delay of more than three days after the onset of illness.The outcome of interest was mortality during hospitalization.Data analysis involved descriptive statistics and multiple logistic regression.Results:A total of 38815 haemorrhagic fever cases were reported from 2014 to 2019.The case-to-control ratio was 1:3,comprising 66 cases and 198 controls.Among 66 cases and 198 controls,the median(IQR)time from illness onset to diagnosis was 4(4)days in cases vs.1(0)day in controls.Diagnosis delays significantly increased mortality risk[adjusted OR(aOR)5.60,95%CI 2.74-11.46].Other risk factors for mortality included age≤5 years(aOR 16.15,95%CI 3.70-70.42)and overweight status(aOR 3.43,95%CI 1.57-7.52).Conclusions:Delayed diagnosis in patients with haemorrhagic fever was strongly associated with higher mortality rates.These findings highlight the critical importance of early diagnosis to reduce mortality in haemorrhagic fever cases.展开更多
This paper investigates the problem of dynamic event-triggered control for a class of large-scale nonlinear systems.In particular,both neutral delays and unknown backlash-like hysteresis are considered.This requires t...This paper investigates the problem of dynamic event-triggered control for a class of large-scale nonlinear systems.In particular,both neutral delays and unknown backlash-like hysteresis are considered.This requires to integrate a compensation mechanism into the event-triggered control architecture.To this end,dynamic gain and adaptive control techniques are introduced to address the effects of neutral delays,unknown hysteresis and parameter uncertainties simultaneously.By introducing a non-negative internal dynamic variable,a dynamic event-triggered controller is designed using the hyperbolic tangent function to reduce the communication burden.By means of the Lyapunov–Krasovskii method,it is demonstrated that all signals of the closed-loop system are globally bounded and eventually converge to a tunable bounded region.Moreover,the Zeno behavior is avoided.Finally,a simulation example is presented to verify the validity of the control scheme.展开更多
In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabili...In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabilization of the addressed neural networks. In order to complete the targets, based on set-valued map, differential inclusions theory, coincidence theorem and Hölder inequality technique, some new proportional delay-dependent criteria shown by the inequalities are derived. Based on the fact of the existence of solution, further by applying the FXT stability lemmas and equivalent transformation, the zero solution of closed-loop system achieves FXT stabilization and the corresponding settling-times are estimated. Some previous related works on NTNNs are extended. Finally, one typical example is provided to show the effectiveness of the established results.展开更多
This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter...This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first modeled.Subject to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is designed.Moreover,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error system.Finally,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions.展开更多
The dynamic behaviors of a large-scale ring neural network with a triangular coupling structure are investigated.The characteristic equation of the high-dimensional system using Coate’s flow graph method is calculate...The dynamic behaviors of a large-scale ring neural network with a triangular coupling structure are investigated.The characteristic equation of the high-dimensional system using Coate’s flow graph method is calculated.Time delay is selected as the bifurcation parameter,and sufficient conditions for stability and Hopf bifurcation are derived.It is found that the connection coefficient and time delay play a crucial role in the dynamic behaviors of the model.Furthermore,a phase diagram of multiple equilibrium points with one saddle point and two stable nodes is presented.Finally,the effectiveness of the theory is verified through simulation results.展开更多
BACKGROUND Celiac disease(CeD),an autoimmune disorder triggered by gluten ingestion,is characterized by non-specific clinical manifestations such as fatigue,abdominal pain,and nutritional deficiencies,often leading to...BACKGROUND Celiac disease(CeD),an autoimmune disorder triggered by gluten ingestion,is characterized by non-specific clinical manifestations such as fatigue,abdominal pain,and nutritional deficiencies,often leading to substantial diagnostic delays.Prolonged delays(≥2 years from symptom onset)are associated with increased risks of complications like osteoporosis,small intestinal lymphoma,and reduced quality of life.AIM To estimate diagnostic delay prevalence and identify risk factors in Chinese CeD patients.METHODS We reviewed clinical records of 166 patients diagnosed with CeD from 2017 onward.Patient-attributed delays were measured from symptom onset to first consultation,while physician-related delays were measured from initial visit to diagnosis/treatment.Data on demographics,symptoms,time from onset to diagnosis,and laboratory results were analyzed.Logistic regression models were used to identify associations,while restricted cubic splines explored nonlinearities.Mediation analysis assessed the roles of intermediate factors in delayed diagnosis.RESULTS Delayed diagnosis(over 2 years from symptom onset)was observed in 42.2%of patients.Patients with diagnostic delay exceeding 5 years accounted for 18.7%.The mean interval from symptom onset to the first medical visit was 12.32 months,with an average of 20.57 months from the first visit to diagnosis.The time from first consultation to diagnosis significantly increased with prolonged delay(P<0.001).Multivariate analysis showed that blood urea nitrogen(BUN)was an independent risk factor(OR=1.29,95%CI:1.01–1.65,P=0.038).A nonlinear association was observed between BUN and delayed diagnosis,with a threshold of 4.3 mmol/L;the risk significantly increased above this threshold(OR=1.39,P=0.04).Subgroup analyses indicated that the risk effect of BUN was stronger in females,non-classical CeD patients,Kazak ethnic group members,individuals without vitamin D deficiency/anemia,and those with MarshⅢpathology(all P<0.05).Mediation analysis revealed that folic acid deficiency and anemia mediated 11.9%(P=0.028)and 13.0%(P=0.044)of the effect of BUN on diagnostic delay,respectively.CONCLUSION Elevated BUN levels are independent predictors of diagnostic delay in CeD,with heterogeneity observed across gender,disease subtype,ethnicity,and pathological type.Clinicians should prioritize high-risk populations with BUN≥4.3 mmol/L,particularly female patients with non-classical CeD and Kazak individuals,to reduce diagnostic delay.展开更多
Unknown time-varying periodic disturbances and input delays can degrade control performance and even lead to system instability.This paper presents a novel direct adaptive output feedback controller based on the inter...Unknown time-varying periodic disturbances and input delays can degrade control performance and even lead to system instability.This paper presents a novel direct adaptive output feedback controller based on the internal model principle(IMP)to compensate for the unknown time-varying periodic disturbance in input delay systems.To reduce the design difficulty of the controller,the input delay system is equivalent to an input delay-free system by constructing stable auxiliary systems.Next,all the stabilizing controllers of the input delay system are derived by using the Youla parameterization method.Based on the IMP,an interpolation condition to completely compensate for periodic disturbances is formulated.Then,to compensate for the unknown time-varying periodic disturbance,a parameter adaptive algorithm is designed to update the Q-parameters online.The convergence of adaptive algorithms is analyzed by the Lyapunov function theory.Simulation and experimental results validated the effectiveness of the proposed method.展开更多
Dear Editor,This letter investigates the grid-forming control for power converters.Recently,grid-forming control based on matching of synchronous machines was suggested by using continuous measurements.In the present ...Dear Editor,This letter investigates the grid-forming control for power converters.Recently,grid-forming control based on matching of synchronous machines was suggested by using continuous measurements.In the present letter,we suggest a digital implementation using artificial delays where the controller employs the discrete-time measurements only.展开更多
Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the ...Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the authors present a machine learning-based risk prediction approach using routinely available clinical and laboratory parameters.Among the evaluated algorithms,a decision tree model demonstrated excellent discrimination,achieving an area under the curve of 0.951 in the validation set and notably identifying all true cases of delayed wound healing at the Youden index threshold.The inclusion of variables such as drainage duration,preoperative white blood cell and neutrophil counts,alongside age and sex,highlights the pragmatic appeal of the model for early postoperative monitoring.Nevertheless,several aspects warrant critical reflection,including the reliance on a postoperative variable(drainage duration),internal validation only,and certain reporting inconsistencies.This letter underscores both the promise and the limitations of adopting interpretable machine learning models in perioperative care.We advocate for transparent reporting,external validation,and careful consideration of clinically actionable timepoints before integration into practice.Ultimately,this work represents a valuable step toward precision risk stratification in gastric cancer surgery,and sets the stage for multicenter,prospective evaluations.展开更多
The exponential stability of a class of neural networks with continuously distributed delays is investigated by employing a novel Lyapunov-Krasovskii functional. Through introducing some free-weighting matrices and th...The exponential stability of a class of neural networks with continuously distributed delays is investigated by employing a novel Lyapunov-Krasovskii functional. Through introducing some free-weighting matrices and the equivalent descriptor form, a delay-dependent stability criterion is established for the addressed systems. The condition is expressed in terms of a linear matrix inequality （LMI）, and it can be checked by resorting to the LMI in the Matlab toolbox. In addition, the proposed stability criteria do not require the monotonicity of the activation functions and the derivative of a time-varying delay being less than 1, which generalize and improve earlier methods. Finally, numerical examples are given to show the effectiveness of the obtained methods.展开更多
Both the global exponential stability and the existence of periodic solutions for a class of recurrent neural networks with continuously distributed delays （RNNs） are studied. By employing the inequality α∏k=1^m ...Both the global exponential stability and the existence of periodic solutions for a class of recurrent neural networks with continuously distributed delays （RNNs） are studied. By employing the inequality α∏k=1^m bk^qk≤1/r ∑qkbk^r＋1/rα^r（α≥0,bk≥0,qk〉0,with ∑k=1^m qk=r-1,r≥1, constructing suitable Lyapunov r k=l k=l functions and applying the homeomorphism theory, a family of simple and new sufficient conditions are given ensuring the global exponential stability and the existence of periodic solutions of RNNs. The results extend and improve the results of earlier publications.展开更多
The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is...The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.展开更多
A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that th...A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that the time varying original-destination demand and passenger path choice probability were given. Passengers were assumed not to change their destinations and travel paths after delay occurs. CapaciW constraints of train and queue rules of alighting and boarding were taken into account. By using the time-driven simulation, the states of passengers, trains and other facilities in the network were updated every time step. The proposed methodology was also tested in a real network, for demonstration. The results reveal that short train delay does not necessarily result in passenger delays, while, on the contrary, some passengers may get benefits from the short delay. However, large initial train delay may result in not only knock-on train and passenger delays along the same line, but also the passenger delays across the entire rail transit network.展开更多
Consensus problems of first-order multi-agent systems with multiple time delays are investigated in this paper. We discuss three cases： 1） continuous, 2） discrete, and 3） a continuous system with a proportional pl...Consensus problems of first-order multi-agent systems with multiple time delays are investigated in this paper. We discuss three cases： 1） continuous, 2） discrete, and 3） a continuous system with a proportional plus derivative controller. In each case, the system contains simultaneous communication and input time delays. Supposing a dynamic multi-agent system with directed topology that contains a globally reachable node, the sufficient convergence condition of the system is discussed with respect to each of the three cases based on the generalized Nyquist criterion and the frequency-domain analysis approach, yielding conclusions that are either less conservative than or agree with previously published results. We know that the convergence condition of the system depends mainly on each agent’s input time delay and the adjacent weights but is independent of the communication delay between agents, whether the system is continuous or discrete. Finally, simulation examples are given to verify the theoretical analysis.展开更多
文摘A Langevin delayed fractional system with multiple delays in control,is a delayed fractional system that includes delay parameters in both state and control,is first introduced.This paper is devoted to investigating the relative controllability of the Langevin delayed fractional system with multiple delays in control.For linear systems to be relatively controllable,necessary and sufficient circumstances are identified by introducing and employing the Gramian matrix.The sufficient conditions for the relative controllability of semilinear systems are ofered based on Schauder's fixed point theorem.As an unusual approach,the controllability results of the delayed system are built for the first time on the exact solution produced by the MittagLeffler type function although controllability ones in the literature are built on the Volterra integral equations or the mild solutions produced by resolvent families.
基金Research Project of Huzhou University under Grunt KYL21223。
文摘This paper deals with the problem of robust stabilization for uncertain Takagi-Sugeno(T-S)fuzzy neutral systems with input delays and distributed delays.The purpose is to design a state feedback fuzzy controller with a H∞performance such that the resulting closed-loop system is robustly stable.Sufficient conditions for the solvability of the problem are obtained by utilizing proper Lyapunov functional together with the linear matrix inequality(LMI)approach,especially two different improved results on robust H∞controller design with relaxed conditions are obtained.Finally,we provide two examples to verify the effectiveness of our design method and give some principle for choosing the proper controller under certain circumstances.
基金Supported by the National Natural Science Foundation of China(62476082)。
文摘This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of FxTS is independent of the initial values and parameters of the CNs,a modified fixed-time(FxT)stability theorem is proposed,where the ST is determined by an arbitrary positive number given in advance.Then,continuous controller and discontinuous controller are designed to realize the modified FxTS target of CNs.In addition,based on the designed controllers,CNs can achieve synchronization at any given time,or even earlier.And control strategies effectively solve the problem of ST related to the parameters of CNs.Finally,an appropriate simulation example is conducted to examine the effectiveness of the designed control strategies.
文摘In this article,we comment on the article by Blüthner et al.The article provides a comprehensive analysis of the factors contributing to the late detection of Crohn’s disease and ulcerative colitis within a German cohort.It highlights the conse-quences on patient outcomes,particularly disease progression and the increased risk of developing complications.The study identifies specific predictors asso-ciated with both patient-related and physician-related delays,offering a detailed exploration of the initial approach.Additionally,the article delves into the distinct patterns observed in the German population,stressing the unique aspects of diagnostic delays that may differ from those reported in other regions.This detailed examination offers valuable insights into the specific challenges faced within the German healthcare system and underscores the necessity of targeted interventions to facilitate early diagnosis.The importance of improved screening tools,patient education,and better healthcare infrastructure is emphasized as crucial steps toward improving patient care in inflammatory bowel disease.
基金Supported by National Key Research and Development Program of China,No.2019YFE0190800.
文摘BACKGROUND Studies investigating diagnostic delays and their effects on patients with alcoholic cirrhosis.AIM To investigate the current status and associated factors influencing diagnostic delays in 401 patients with alcoholic cirrhosis.METHODS A cross-sectional analysis was conducted at a tertiary hospital in China from June 2020 to December 2023.Data were collected through telephone follow-ups and questionnaires.The Wilcoxon and Kruskal-Wallis H tests were used to compare diagnostic delays across various characteristics.Multivariate linear regression was employed to identify factors associated with diagnostic delays.RESULTS The median diagnostic delay was 5 months,with an interquartile range of 2-11 months.The proportions of patients with alcoholic cirrhosis who initially visited tertiary,secondary,and primary hospitals were 38.9%,37.91%,and 23.19%,respectively.Furthermore,the rates of patients undergoing liver computed tomography(CT)during their first visit at tertiary,secondary,and primary hospitals were 92.95%,13.82%,and 1.08%,respectively(P<0.001).Significant differences were observed in diagnostic delay-related characteristics,including residence,resident type,initial diagnosis,medical insurance,liver CT,and liver ultrasound during the first visit,age,years of education,family size,marital status,annual family income,years of drinking,daily alcohol consumption,and type of alcohol consumed(P<0.01).Furthermore,diagnostic delays were variably associated with daily alcohol consumption and other characteristics(i.e.residence,years of drinking,medical insurance,years of education,annual family income,liver CT and ultrasound during the first visit).Significant predictors of diagnostic delay identified on multivariate linear regression analysis included years of education,daily alcohol consumption,annual family income and blood ammonia levels(P<0.01).Patients with alcoholic cirrhosis experience varying degrees of diagnostic delays,necessitating interventions targeting potential contributing factors.CONCLUSION Our study indicates that patients with alcoholic cirrhosis may experience varying degrees of diagnostic delay.Interventions targeting potential factors contributing to diagnostic delay are necessary.
文摘BACKGROUND Neurodevelopmental delays encompass a wide range of conditions that impair cognitive,motor,and social functioning,often increasing the risk of psychiatric comorbidities.Children with these delays frequently present with disorders such as attention-deficit/hyperactivity disorder(ADHD),anxiety,and behavioral disturbances,which can significantly affect development and quality of life.While genetic predisposition has been linked to these comorbidities,growing evidence highlights the role of environmental factors,including prenatal and early-life stressors.However,the interaction between genetic susceptibility and environmental influences remains poorly understood.Identifying specific genetic variants,environmental risks,and their interactions is essential for early detection and targeted interventions.AIM To investigate the combined effects of genetic and environmental factors on psychiatric comorbidities in children with neurodevelopmental delays,elucidate underlying mechanisms,and inform clinical management strategies.METHODS This retrospective cohort study included 80 children with confirmed neurodevelopmental delays and 40 age-and sex-matched typically developing controls.Comprehensive clinical and psychiatric evaluations,genetic testing(chromosomal microarray analysis and targeted next-generation sequencing),and environmental exposure assessments were conducted.Statistical analyses explored associations between genetic variants and psychiatric comorbidities,environmental risk factors,and gene-environment interactions.RESULTS Children with neurodevelopmental delays exhibited significantly higher rates of psychiatric comorbidities(70.0%)compared to controls(15.0%),with ADHD(42.5%),anxiety disorders(28.8%),and behavioral disorders(23.8%)being the most common.Pathogenic genetic variants were identified in specific pathways associated with distinct psychiatric presentations:Glutamatergic signaling variants were linked to anxiety disorders(odds ratio=3.8),dopaminergic system variants to ADHD(odds ratio=4.2),and synaptic function variants to both behavioral and anxiety disorders.Environmental factors,particularly prenatal maternal stress,early childhood adversity,and family dysfunction were strong predictors of psychiatric outcomes(β=0.42).Significant gene-environment interactions were identified,indicating that environmental exposure can moderate the effects of genetic risks on psychiatric outcomes.CONCLUSION Psychiatric comorbidities in children with neurodevelopmental delays are significantly influenced by both genetic and environmental factors,with complex interactions between the two.These findings underscore the need for integrated assessments and targeted interventions addressing both biological and environmental contributors to improve outcomes in this vulnerable population.
文摘Objective:To investigate the association between diagnosis delays and mortality in patients with haemorrhagic fever in Upper Southern Thailand.Methods:A hospital-based case control study was conducted between December 2019 and January 2020.Cases were defined as patients who had been diagnosed with haemorrhagic fever and died during hospitalization,while controls were patients with similar conditions who survived.Medical records were retrospectively reviewed,with the primary variable being a diagnosis delay of more than three days after the onset of illness.The outcome of interest was mortality during hospitalization.Data analysis involved descriptive statistics and multiple logistic regression.Results:A total of 38815 haemorrhagic fever cases were reported from 2014 to 2019.The case-to-control ratio was 1:3,comprising 66 cases and 198 controls.Among 66 cases and 198 controls,the median(IQR)time from illness onset to diagnosis was 4(4)days in cases vs.1(0)day in controls.Diagnosis delays significantly increased mortality risk[adjusted OR(aOR)5.60,95%CI 2.74-11.46].Other risk factors for mortality included age≤5 years(aOR 16.15,95%CI 3.70-70.42)and overweight status(aOR 3.43,95%CI 1.57-7.52).Conclusions:Delayed diagnosis in patients with haemorrhagic fever was strongly associated with higher mortality rates.These findings highlight the critical importance of early diagnosis to reduce mortality in haemorrhagic fever cases.
基金supported by the National Natural Science Foundation of China under Grant 62073190the Science Center Program of National Natural Science Foundation of China under Grant 62188101.
文摘This paper investigates the problem of dynamic event-triggered control for a class of large-scale nonlinear systems.In particular,both neutral delays and unknown backlash-like hysteresis are considered.This requires to integrate a compensation mechanism into the event-triggered control architecture.To this end,dynamic gain and adaptive control techniques are introduced to address the effects of neutral delays,unknown hysteresis and parameter uncertainties simultaneously.By introducing a non-negative internal dynamic variable,a dynamic event-triggered controller is designed using the hyperbolic tangent function to reduce the communication burden.By means of the Lyapunov–Krasovskii method,it is demonstrated that all signals of the closed-loop system are globally bounded and eventually converge to a tunable bounded region.Moreover,the Zeno behavior is avoided.Finally,a simulation example is presented to verify the validity of the control scheme.
基金supported by Social Science Fund of Hunan province(Grant No.22JD074)the Research Foundation of Education Bureau of Hunan province(Grant No.22B0912).
文摘In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabilization of the addressed neural networks. In order to complete the targets, based on set-valued map, differential inclusions theory, coincidence theorem and Hölder inequality technique, some new proportional delay-dependent criteria shown by the inequalities are derived. Based on the fact of the existence of solution, further by applying the FXT stability lemmas and equivalent transformation, the zero solution of closed-loop system achieves FXT stabilization and the corresponding settling-times are estimated. Some previous related works on NTNNs are extended. Finally, one typical example is provided to show the effectiveness of the established results.
基金supported by the Na⁃tional Key R&D Program of China(No.2022YFC2204800)the Graduate Student Independent Exploration and Innovation Program of Central South University(No.2024ZZTS 0767).
文摘This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first modeled.Subject to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is designed.Moreover,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error system.Finally,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions.
基金Supported by Natural Science Foundation of Shandong Province of China(Grant Nos.ZR2020MF080 and ZR2020MF065).
文摘The dynamic behaviors of a large-scale ring neural network with a triangular coupling structure are investigated.The characteristic equation of the high-dimensional system using Coate’s flow graph method is calculated.Time delay is selected as the bifurcation parameter,and sufficient conditions for stability and Hopf bifurcation are derived.It is found that the connection coefficient and time delay play a crucial role in the dynamic behaviors of the model.Furthermore,a phase diagram of multiple equilibrium points with one saddle point and two stable nodes is presented.Finally,the effectiveness of the theory is verified through simulation results.
基金Supported by Natural Science Foundation of the Xinjiang AutSupported by Natural Science Foundation of the Xinjiang Autonomous Region,No.2023D01C76Central Government Guide Local Science and Technology Development Special Fund Project,No.ZYYD2024JD1。
文摘BACKGROUND Celiac disease(CeD),an autoimmune disorder triggered by gluten ingestion,is characterized by non-specific clinical manifestations such as fatigue,abdominal pain,and nutritional deficiencies,often leading to substantial diagnostic delays.Prolonged delays(≥2 years from symptom onset)are associated with increased risks of complications like osteoporosis,small intestinal lymphoma,and reduced quality of life.AIM To estimate diagnostic delay prevalence and identify risk factors in Chinese CeD patients.METHODS We reviewed clinical records of 166 patients diagnosed with CeD from 2017 onward.Patient-attributed delays were measured from symptom onset to first consultation,while physician-related delays were measured from initial visit to diagnosis/treatment.Data on demographics,symptoms,time from onset to diagnosis,and laboratory results were analyzed.Logistic regression models were used to identify associations,while restricted cubic splines explored nonlinearities.Mediation analysis assessed the roles of intermediate factors in delayed diagnosis.RESULTS Delayed diagnosis(over 2 years from symptom onset)was observed in 42.2%of patients.Patients with diagnostic delay exceeding 5 years accounted for 18.7%.The mean interval from symptom onset to the first medical visit was 12.32 months,with an average of 20.57 months from the first visit to diagnosis.The time from first consultation to diagnosis significantly increased with prolonged delay(P<0.001).Multivariate analysis showed that blood urea nitrogen(BUN)was an independent risk factor(OR=1.29,95%CI:1.01–1.65,P=0.038).A nonlinear association was observed between BUN and delayed diagnosis,with a threshold of 4.3 mmol/L;the risk significantly increased above this threshold(OR=1.39,P=0.04).Subgroup analyses indicated that the risk effect of BUN was stronger in females,non-classical CeD patients,Kazak ethnic group members,individuals without vitamin D deficiency/anemia,and those with MarshⅢpathology(all P<0.05).Mediation analysis revealed that folic acid deficiency and anemia mediated 11.9%(P=0.028)and 13.0%(P=0.044)of the effect of BUN on diagnostic delay,respectively.CONCLUSION Elevated BUN levels are independent predictors of diagnostic delay in CeD,with heterogeneity observed across gender,disease subtype,ethnicity,and pathological type.Clinicians should prioritize high-risk populations with BUN≥4.3 mmol/L,particularly female patients with non-classical CeD and Kazak individuals,to reduce diagnostic delay.
基金supported in part by the National Natural Science Foundation of China(62325302,62203076,62103065,62033001,62303079)the China Postdoctoral Science Foundation(2021M700584)+1 种基金the Natural Science Foundation of Chongqing,China(cstc2020jcyj-zdxmX0014)the Program of Shanghai Academic/Technology Research Leader(21XD1421400).
文摘Unknown time-varying periodic disturbances and input delays can degrade control performance and even lead to system instability.This paper presents a novel direct adaptive output feedback controller based on the internal model principle(IMP)to compensate for the unknown time-varying periodic disturbance in input delay systems.To reduce the design difficulty of the controller,the input delay system is equivalent to an input delay-free system by constructing stable auxiliary systems.Next,all the stabilizing controllers of the input delay system are derived by using the Youla parameterization method.Based on the IMP,an interpolation condition to completely compensate for periodic disturbances is formulated.Then,to compensate for the unknown time-varying periodic disturbance,a parameter adaptive algorithm is designed to update the Q-parameters online.The convergence of adaptive algorithms is analyzed by the Lyapunov function theory.Simulation and experimental results validated the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(62403296,62303292,62173218).
文摘Dear Editor,This letter investigates the grid-forming control for power converters.Recently,grid-forming control based on matching of synchronous machines was suggested by using continuous measurements.In the present letter,we suggest a digital implementation using artificial delays where the controller employs the discrete-time measurements only.
文摘Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the authors present a machine learning-based risk prediction approach using routinely available clinical and laboratory parameters.Among the evaluated algorithms,a decision tree model demonstrated excellent discrimination,achieving an area under the curve of 0.951 in the validation set and notably identifying all true cases of delayed wound healing at the Youden index threshold.The inclusion of variables such as drainage duration,preoperative white blood cell and neutrophil counts,alongside age and sex,highlights the pragmatic appeal of the model for early postoperative monitoring.Nevertheless,several aspects warrant critical reflection,including the reliance on a postoperative variable(drainage duration),internal validation only,and certain reporting inconsistencies.This letter underscores both the promise and the limitations of adopting interpretable machine learning models in perioperative care.We advocate for transparent reporting,external validation,and careful consideration of clinically actionable timepoints before integration into practice.Ultimately,this work represents a valuable step toward precision risk stratification in gastric cancer surgery,and sets the stage for multicenter,prospective evaluations.
基金The National Natural Science Foundation of China (No60574006)
文摘The exponential stability of a class of neural networks with continuously distributed delays is investigated by employing a novel Lyapunov-Krasovskii functional. Through introducing some free-weighting matrices and the equivalent descriptor form, a delay-dependent stability criterion is established for the addressed systems. The condition is expressed in terms of a linear matrix inequality （LMI）, and it can be checked by resorting to the LMI in the Matlab toolbox. In addition, the proposed stability criteria do not require the monotonicity of the activation functions and the derivative of a time-varying delay being less than 1, which generalize and improve earlier methods. Finally, numerical examples are given to show the effectiveness of the obtained methods.
文摘Both the global exponential stability and the existence of periodic solutions for a class of recurrent neural networks with continuously distributed delays （RNNs） are studied. By employing the inequality α∏k=1^m bk^qk≤1/r ∑qkbk^r＋1/rα^r（α≥0,bk≥0,qk〉0,with ∑k=1^m qk=r-1,r≥1, constructing suitable Lyapunov r k=l k=l functions and applying the homeomorphism theory, a family of simple and new sufficient conditions are given ensuring the global exponential stability and the existence of periodic solutions of RNNs. The results extend and improve the results of earlier publications.
文摘The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.
基金Project(51008229)supported by the National Natural Science Foundation of ChinaProject supported by Key Laboratory of Road and Traffic Engineering of Tongji University,China
文摘A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that the time varying original-destination demand and passenger path choice probability were given. Passengers were assumed not to change their destinations and travel paths after delay occurs. CapaciW constraints of train and queue rules of alighting and boarding were taken into account. By using the time-driven simulation, the states of passengers, trains and other facilities in the network were updated every time step. The proposed methodology was also tested in a real network, for demonstration. The results reveal that short train delay does not necessarily result in passenger delays, while, on the contrary, some passengers may get benefits from the short delay. However, large initial train delay may result in not only knock-on train and passenger delays along the same line, but also the passenger delays across the entire rail transit network.
基金Project supported in part by the National Natural Science Foundation of China (Grant Nos. 60973114 and 61170249)in part by the Natural Science Foundation of CQCSTC (Grant Nos. 2009BA2024 and cstc2011jjA1320)in part by the State Key Laboratory of Power Transmission Equipment & System Securityand New Technology, Chongqing University (Grant No. 2007DA10512711206)
文摘Consensus problems of first-order multi-agent systems with multiple time delays are investigated in this paper. We discuss three cases： 1） continuous, 2） discrete, and 3） a continuous system with a proportional plus derivative controller. In each case, the system contains simultaneous communication and input time delays. Supposing a dynamic multi-agent system with directed topology that contains a globally reachable node, the sufficient convergence condition of the system is discussed with respect to each of the three cases based on the generalized Nyquist criterion and the frequency-domain analysis approach, yielding conclusions that are either less conservative than or agree with previously published results. We know that the convergence condition of the system depends mainly on each agent’s input time delay and the adjacent weights but is independent of the communication delay between agents, whether the system is continuous or discrete. Finally, simulation examples are given to verify the theoretical analysis.
