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
Electronic processes within atoms and molecules reside on the timescale of attoseconds. Recent advances in the laserbased pump-probe interrogation techniques have made possible the temporal resolution of ultrafast ele...Electronic processes within atoms and molecules reside on the timescale of attoseconds. Recent advances in the laserbased pump-probe interrogation techniques have made possible the temporal resolution of ultrafast electronic processes on the attosecond timescale, including photoionization and tunneling ionization. These interrogation techniques include the attosecond streak camera, the reconstruction of attosecond beating by interference of two-photon transitions, and the attoclock. While the former two are usually employed to study photoionization processes, the latter is typically used to investigate tunneling ionization. In this review, we briefly overview these timing techniques towards an attosecond temporal resolution of ionization processes in atoms and molecules under intense laser fields. In particular, we review the backpropagation method, which is a novel hybrid quantum-classical approach towards the full characterization of tunneling ionization dynamics. Continued advances in the interrogation techniques promise to pave the pathway towards the exploration of ever faster dynamical processes on an ever shorter timescale.展开更多
We consider how small delays affect the integral-input-to-state stability(iss)property for a system.Our result is similar to the input-to-state stability(Iss)result obtained in[1]:the iss property will be preserved in...We consider how small delays affect the integral-input-to-state stability(iss)property for a system.Our result is similar to the input-to-state stability(Iss)result obtained in[1]:the iss property will be preserved in a practical and semi-global manner if the delay interval is small enough.However,since the iss quantifies the robust stability in terms of a generalized Li norm of the inputs instead of a generalized Loo norm of the inputs for the Iss case,the techniques and proofs for the Iss case do not apply to the iss case directly.While the proofs in[1]are based on the Lyapunov-Razumikhin approach,our proofs are based on the iss-Lyapunov functions for the zero-delay system.In addition to the interest by its own in showing how the iss property is affected by small delays,the result also serves to the study of the iss property for singularly perturbed systems.展开更多
Pathological basal ganglia oscillations are associated with the hypokinetic motor symptoms of Parkinson’s disease.In this paper,a memoryless feedback control strategy is proposed to suppress pathological oscillations...Pathological basal ganglia oscillations are associated with the hypokinetic motor symptoms of Parkinson’s disease.In this paper,a memoryless feedback control strategy is proposed to suppress pathological oscillations in the basal ganglia.In the most of closed-loop control strategies,the excitatory subthalamic nucleus populations are both monitored and stimulated targets,neglecting the important contribution of the external globus pallidus populations in suppressing pathological oscillations.To this end,we transform the original model into a time-delay system with a lower-triangular structure,and construct a memoryless state feedback controller utilizing the gain scaling method.It is proved by the Lyapunov–Krasovskii functional method that all the signals of the resulting closed-loop system are bounded,and the system states converge to an adjustable region of the origin.In addition,the input delay in stimulating the target is considered and a corresponding controller is designed to achieve convergence of the states in the resulting closed-loop system with both state delays and input delay.Moreover,simulation tests are conducted to explore the performance of the control strategy.This paper further explores the intrinsic dynamics in the neural system,and provides an effective strategy for closed-loop deep brain stimulation control.展开更多
In this paper,we consider a 2-degrees-of-freedom(DOF)helicopter system subject to long input delays and uncertain system parameters.To address the challenges including unknown system parameters and input delays in con...In this paper,we consider a 2-degrees-of-freedom(DOF)helicopter system subject to long input delays and uncertain system parameters.To address the challenges including unknown system parameters and input delays in control design,we develop an adaptive predictor-feedback control law to achieve trajectory tracking.Stability of the closed-loop system is further established,where the tracking errors are shown to converge towards zero.Through simulation and experiments on the helicopter system,we illustrate that tracking of a desired trajectory is achieved with the proposed control scheme.展开更多
Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay di...Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay differential equations(DDEs)and delay integrodifferential equations(DIDEs)with constant delays,primarily due to their low regularity at delayinduced breaking points.In this paper,a DNN method that combines multi-task learning(MTL)which is proposed to solve both the forward and inverse problems of DIDEs.The core idea of this approach is to divide the original equation into multiple tasks based on the delay,using auxiliary outputs to represent the integral terms,followed by the use of MTL to seamlessly incorporate the properties at the breaking points into the loss function.Furthermore,given the increased training dificulty associated with multiple tasks and outputs,we employ a sequential training scheme to reduce training complexity and provide reference solutions for subsequent tasks.This approach significantly enhances the approximation accuracy of solving DIDEs with DNNs,as demonstrated by comparisons with traditional DNN methods.We validate the effectiveness of this method through several numerical experiments,test various parameter sharing structures in MTL and compare the testing results of these structures.Finally,this method is implemented to solve the inverse problem of nonlinear DIDE and the results show that the unknown parameters of DIDE can be discovered with sparse or noisy data.展开更多
In the realm of aerial warfare,the protection of Unmanned Aerial Vehicles(UAVs) against adversarial threats is crucial.In order to balance the impact of response delays and the demand for onboard applications,this pap...In the realm of aerial warfare,the protection of Unmanned Aerial Vehicles(UAVs) against adversarial threats is crucial.In order to balance the impact of response delays and the demand for onboard applications,this paper derives three analytical game strategies for the active defense of UAVs from differential game theory,accommodating the first-order dynamic delays.The targeted UAV executes evasive maneuvers and launches a defending missile to intercept the attacking missile,which constitutes a UAVMissile-Defender(UMD) three-body game problem.We explore two distinct operational paradigms:the first involves the UAV and the defender working collaboratively to intercept the incoming threat,while the second prioritizes UAV self-preservation,with independent maneuvering away from potentially sacrificial engagements.Starting with model linearization and order reduction,the Collaborative Interception Strategy(CIS) is first derived via a linear quadratic differential game formulation.Building upon CIS,we further explore two distinct strategies:the Informed Defender Interception Strategy(IDIS),which utilizes UAV maneuvering information,and the Unassisted Defender Interception Strategy(UDIS),which does not rely on UAV maneuvering information.Additionally,we investigate the conditions for the existence of saddle point solutions and their relationship with vehicle maneuverability and response agility.The simulations demonstrate the effectiveness and advantages of the proposed strategies.展开更多
Inflammatory bowel diseases(IBDs),including Crohn's disease(CD)and ulcerative colitis,are chronic inflammatory conditions of the gastrointestinal tract that necessitate timely diagnosis to prevent complications an...Inflammatory bowel diseases(IBDs),including Crohn's disease(CD)and ulcerative colitis,are chronic inflammatory conditions of the gastrointestinal tract that necessitate timely diagnosis to prevent complications and improve patient outcomes.Despite advancements in medical knowledge and diagnostic techniques,significant diagnostic delays persist,particularly in CD.The study by Blüthner et al,published in the World Journal of Gastroenterology,elucidates the diagnostic delays experienced by German patients with IBD and identifies key risk factors contributing to these delays.展开更多
The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled p...The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled phased array antenna system is a necessary trend for the future development of the phased array,and it is also a major focus and difficulty in the current research of integrated microwave photonics.This paper firstly introduces the basic principle and development history of optical true time delay phased array antenna system based on microwave photonics,and briefly introduces the main implementation methods and integration platform of optical true time delay.Then,the application and development prospect of optical true time delay technology in beam control of phased array antenna system are mainly presented.Finally,according to the current research progress,the possible research directions of integrated optically controlled phased array antenna systems in the future are proposed.展开更多
In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave so...In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model.展开更多
The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivativ...The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivative operator.Additionally,time delays in the potential field force and coupling force transmission are both considered.Firstly,based on the delay decoupling formula,combined with statistical mean method and the fractional-order Shapiro–Loginov formula,the“statistic synchronization”among particles is obtained,revealing the statistical equivalence between the mean field behavior of the system and the behavior of individual particles.Due to the existence of the coupling delay,the impact of the coupling force on synchronization exhibits non-monotonic,which is different from the previous monotonic effects.Then,two kinds of theoretical expression of output amplitude gains G and G are derived by time-delay decoupling formula and small delay approximation theorem,respectively.Compared to G,G is an exact theoretical solution,which means that G is not only more accurate in the region of small delay,but also applies to the region of large delay.Finally,the study of the output amplitude gain G and its resonance behavior are explored.Due to the presence of the potential field delay,a new resonance phenomenon termed“periodic resonance”is discovered,which arises from the periodic matching between the potential field delay and the driving frequency.This resonance phenomenon is analyzed qualitatively and quantitatively,uncovering undiscovered characteristics in previous studies.展开更多
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Project supported by the National Natural Science Foundation of China (Grant Nos.92150105,11834004,12227807,and 12241407)the Science and Technology Commission of Shanghai Municipality (Grant No.21ZR1420100)。
文摘Electronic processes within atoms and molecules reside on the timescale of attoseconds. Recent advances in the laserbased pump-probe interrogation techniques have made possible the temporal resolution of ultrafast electronic processes on the attosecond timescale, including photoionization and tunneling ionization. These interrogation techniques include the attosecond streak camera, the reconstruction of attosecond beating by interference of two-photon transitions, and the attoclock. While the former two are usually employed to study photoionization processes, the latter is typically used to investigate tunneling ionization. In this review, we briefly overview these timing techniques towards an attosecond temporal resolution of ionization processes in atoms and molecules under intense laser fields. In particular, we review the backpropagation method, which is a novel hybrid quantum-classical approach towards the full characterization of tunneling ionization dynamics. Continued advances in the interrogation techniques promise to pave the pathway towards the exploration of ever faster dynamical processes on an ever shorter timescale.
文摘We consider how small delays affect the integral-input-to-state stability(iss)property for a system.Our result is similar to the input-to-state stability(Iss)result obtained in[1]:the iss property will be preserved in a practical and semi-global manner if the delay interval is small enough.However,since the iss quantifies the robust stability in terms of a generalized Li norm of the inputs instead of a generalized Loo norm of the inputs for the Iss case,the techniques and proofs for the Iss case do not apply to the iss case directly.While the proofs in[1]are based on the Lyapunov-Razumikhin approach,our proofs are based on the iss-Lyapunov functions for the zero-delay system.In addition to the interest by its own in showing how the iss property is affected by small delays,the result also serves to the study of the iss property for singularly perturbed systems.
基金supported by the Major Fundamental Research Program of the Natural Science Foundation of Shandong Province,China(No.ZR2020ZD25)the Autonomous Innovation Team Foundation for“20 Items of the New University”of Jinan City(No.202228087).
文摘Pathological basal ganglia oscillations are associated with the hypokinetic motor symptoms of Parkinson’s disease.In this paper,a memoryless feedback control strategy is proposed to suppress pathological oscillations in the basal ganglia.In the most of closed-loop control strategies,the excitatory subthalamic nucleus populations are both monitored and stimulated targets,neglecting the important contribution of the external globus pallidus populations in suppressing pathological oscillations.To this end,we transform the original model into a time-delay system with a lower-triangular structure,and construct a memoryless state feedback controller utilizing the gain scaling method.It is proved by the Lyapunov–Krasovskii functional method that all the signals of the resulting closed-loop system are bounded,and the system states converge to an adjustable region of the origin.In addition,the input delay in stimulating the target is considered and a corresponding controller is designed to achieve convergence of the states in the resulting closed-loop system with both state delays and input delay.Moreover,simulation tests are conducted to explore the performance of the control strategy.This paper further explores the intrinsic dynamics in the neural system,and provides an effective strategy for closed-loop deep brain stimulation control.
基金partially supported by the DEEPCOBOT project under Grant 306640/O70 funded by the Research Council of Norway.
文摘In this paper,we consider a 2-degrees-of-freedom(DOF)helicopter system subject to long input delays and uncertain system parameters.To address the challenges including unknown system parameters and input delays in control design,we develop an adaptive predictor-feedback control law to achieve trajectory tracking.Stability of the closed-loop system is further established,where the tracking errors are shown to converge towards zero.Through simulation and experiments on the helicopter system,we illustrate that tracking of a desired trajectory is achieved with the proposed control scheme.
文摘Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay differential equations(DDEs)and delay integrodifferential equations(DIDEs)with constant delays,primarily due to their low regularity at delayinduced breaking points.In this paper,a DNN method that combines multi-task learning(MTL)which is proposed to solve both the forward and inverse problems of DIDEs.The core idea of this approach is to divide the original equation into multiple tasks based on the delay,using auxiliary outputs to represent the integral terms,followed by the use of MTL to seamlessly incorporate the properties at the breaking points into the loss function.Furthermore,given the increased training dificulty associated with multiple tasks and outputs,we employ a sequential training scheme to reduce training complexity and provide reference solutions for subsequent tasks.This approach significantly enhances the approximation accuracy of solving DIDEs with DNNs,as demonstrated by comparisons with traditional DNN methods.We validate the effectiveness of this method through several numerical experiments,test various parameter sharing structures in MTL and compare the testing results of these structures.Finally,this method is implemented to solve the inverse problem of nonlinear DIDE and the results show that the unknown parameters of DIDE can be discovered with sparse or noisy data.
基金supported by the China Postdoctoral Science Foundation (Grant No.2021M700321)the Fundamental Research Funds for the Central Universities (Grant No.YWF-23-Q1041)。
文摘In the realm of aerial warfare,the protection of Unmanned Aerial Vehicles(UAVs) against adversarial threats is crucial.In order to balance the impact of response delays and the demand for onboard applications,this paper derives three analytical game strategies for the active defense of UAVs from differential game theory,accommodating the first-order dynamic delays.The targeted UAV executes evasive maneuvers and launches a defending missile to intercept the attacking missile,which constitutes a UAVMissile-Defender(UMD) three-body game problem.We explore two distinct operational paradigms:the first involves the UAV and the defender working collaboratively to intercept the incoming threat,while the second prioritizes UAV self-preservation,with independent maneuvering away from potentially sacrificial engagements.Starting with model linearization and order reduction,the Collaborative Interception Strategy(CIS) is first derived via a linear quadratic differential game formulation.Building upon CIS,we further explore two distinct strategies:the Informed Defender Interception Strategy(IDIS),which utilizes UAV maneuvering information,and the Unassisted Defender Interception Strategy(UDIS),which does not rely on UAV maneuvering information.Additionally,we investigate the conditions for the existence of saddle point solutions and their relationship with vehicle maneuverability and response agility.The simulations demonstrate the effectiveness and advantages of the proposed strategies.
文摘Inflammatory bowel diseases(IBDs),including Crohn's disease(CD)and ulcerative colitis,are chronic inflammatory conditions of the gastrointestinal tract that necessitate timely diagnosis to prevent complications and improve patient outcomes.Despite advancements in medical knowledge and diagnostic techniques,significant diagnostic delays persist,particularly in CD.The study by Blüthner et al,published in the World Journal of Gastroenterology,elucidates the diagnostic delays experienced by German patients with IBD and identifies key risk factors contributing to these delays.
基金supported by Fund of State Key Laboratory of IPOC(BUPT)(No.IPOC2021ZT16),China.
文摘The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled phased array antenna system is a necessary trend for the future development of the phased array,and it is also a major focus and difficulty in the current research of integrated microwave photonics.This paper firstly introduces the basic principle and development history of optical true time delay phased array antenna system based on microwave photonics,and briefly introduces the main implementation methods and integration platform of optical true time delay.Then,the application and development prospect of optical true time delay technology in beam control of phased array antenna system are mainly presented.Finally,according to the current research progress,the possible research directions of integrated optically controlled phased array antenna systems in the future are proposed.
基金Supported by the National Natural Science Foundation of China(12261050)Science and Technology Project of Department of Education of Jiangxi Province(GJJ2201612 and GJJ211027)Natural Science Foundation of Jiangxi Province of China(20212BAB202021)。
文摘In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model.
基金supported by the Natural Science Foundation of Sichuan Province,China(Youth Science Foundation)(Grant No.2022NSFSC1952).
文摘The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivative operator.Additionally,time delays in the potential field force and coupling force transmission are both considered.Firstly,based on the delay decoupling formula,combined with statistical mean method and the fractional-order Shapiro–Loginov formula,the“statistic synchronization”among particles is obtained,revealing the statistical equivalence between the mean field behavior of the system and the behavior of individual particles.Due to the existence of the coupling delay,the impact of the coupling force on synchronization exhibits non-monotonic,which is different from the previous monotonic effects.Then,two kinds of theoretical expression of output amplitude gains G and G are derived by time-delay decoupling formula and small delay approximation theorem,respectively.Compared to G,G is an exact theoretical solution,which means that G is not only more accurate in the region of small delay,but also applies to the region of large delay.Finally,the study of the output amplitude gain G and its resonance behavior are explored.Due to the presence of the potential field delay,a new resonance phenomenon termed“periodic resonance”is discovered,which arises from the periodic matching between the potential field delay and the driving frequency.This resonance phenomenon is analyzed qualitatively and quantitatively,uncovering undiscovered characteristics in previous studies.
