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Patient and physician factors contributing to delays in inflammatory bowel diseases:Enhancing timely diagnosis
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作者 Horia Minea Ana-Maria Singeap +3 位作者 Laura Huiban Cristina Maria Muzica Carol Stanciu Anca Trifan 《World Journal of Gastroenterology》 2025年第6期115-120,共6页
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
关键词 Inflammatory bowel disease Diagnostic delay Disease awareness Healthcare system Screening tools
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Exponential Decay of Laminated Beam with Nonlinear Time-varying Delay and Microtemperature Effect
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作者 Imene LARIBI Ali KRELIFA +3 位作者 Djamel OUCHENANE Fares YAZID Salah BOULAARAS Salah ZITOUNI 《Acta Mathematicae Applicatae Sinica》 2025年第1期270-285,共16页
This research paper addresses a topic of interest to many researchers and engineers due to its effective applications in various industrial areas.It focuses on the thermoelastic laminated beam model with nonlinear str... This research paper addresses a topic of interest to many researchers and engineers due to its effective applications in various industrial areas.It focuses on the thermoelastic laminated beam model with nonlinear structural damping,nonlinear time-varying delay,and microtemperature effects.Our primary goal is to establish the stability of the solution.To achieve this,and under suitable hypotheses,we demonstrate energy decay and construct a Lyapunov functional that leads to our results. 展开更多
关键词 structural damping energy decay laminated beam microtemperature time-varying delay partial differential equations nonlinear equations
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Frequency domain identification of non-integer order dynamical systems 被引量:1
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作者 李远禄 于盛林 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期47-50,共4页
Two new methods, the generalized Levy method and the weighted iteration method, are presented for identification of non-integer order systems. The first method generalizes the Levy identification method from the integ... Two new methods, the generalized Levy method and the weighted iteration method, are presented for identification of non-integer order systems. The first method generalizes the Levy identification method from the integer order systems to the non-integer order systems. Then, the weighted iteration method is presented to overcome the shortcomings of the first method. Results show that the proposed methods have better performance compared with the integer order identification method. For the non-integer order systems, the proposed methods have the better fitting for the system frequency response. For the integer order system, if commensurate order scanning is applied, the proposed methods can also achieve the best integer order model which fits the system frequency response. At the same time, the proposed algorithms are more stable. 展开更多
关键词 non-integer order dynamical system non-integer order system identification generalized Levy method weighted iteration method
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Generation of non-integer high-order harmonics and significant enhancement of harmonic intensity 被引量:1
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作者 Chang-Long Xia Yue-Yue Lan Xiang-Yang Miao 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第4期221-225,共5页
High-order harmonics from helium atom in the orthogonally two-color(OTC) laser field are investigated by solving the two-dimensional time-dependent Schrodinger equation.Non-integer high-order harmonics are obtained in... High-order harmonics from helium atom in the orthogonally two-color(OTC) laser field are investigated by solving the two-dimensional time-dependent Schrodinger equation.Non-integer high-order harmonics are obtained in some ratio of frequencies of two components.Pure odd and even harmonics from atoms could be separated in two components by adjusting the ratio of frequencies in OTC scheme,and the resolution of harmonics is improved at the same time.The physical mechanism is explained by the periodicity of dipole.With the same intensity of the incident laser,the intensity of the high-order harmonics from the OTC field scheme is improved by three orders of magnitude compared to the monochromatic laser field scheme.A theoretical scheme is provided for experimentally achieving improving energy resolution and separation of pure odd and even harmonics in atoms.Also,we provide a means for improving harmonic intensity. 展开更多
关键词 non-integer high-order harmonic generation the orthogonally two-color laser field the enhancement of harmonic intensity
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Diagnostic delay in inflammatory bowel diseases in a German population 被引量:5
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作者 Elisabeth Blüthner Annalena Dehe +11 位作者 Carsten Büning Britta Siegmund Matthias Prager Jochen Maul Alexander Krannich Jan Preiß Bertram Wiedenmann Florian Rieder Raneem Khedraki Frank Tacke Andreas Sturm Anja Schirbel 《World Journal of Gastroenterology》 SCIE CAS 2024年第29期3465-3478,共14页
BACKGROUND Early diagnosis is key to prevent bowel damage in inflammatory bowel disease(IBD).Risk factor analyses linked with delayed diagnosis in European IBD patients are scarce and no data in German IBD patients ex... BACKGROUND Early diagnosis is key to prevent bowel damage in inflammatory bowel disease(IBD).Risk factor analyses linked with delayed diagnosis in European IBD patients are scarce and no data in German IBD patients exists.AIM To identify risk factors leading to prolonged diagnostic time in a German IBD cohort.METHODS Between 2012 and 2022,430 IBD patients from four Berlin hospitals were enrolled in a prospective study and asked to complete a 16-item questionnaire to determine features of the path leading to IBD diagnosis.Total diagnostic time was defined as the time from symptom onset to consulting a physician(patient waiting time)and from first consultation to IBD diagnosis(physician diagnostic time).Univariate and multivariate analyses were performed to identify risk factors for each time period.RESULTS The total diagnostic time was significantly longer in Crohn’s disease(CD)compared to ulcerative colitis(UC)patients(12.0 vs 4.0 mo;P<0.001),mainly due to increased physician diagnostic time(5.5 vs 1.0 mo;P<0.001).In a multivariate analysis,the predominant symptoms diarrhea(P=0.012)and skin lesions(P=0.028)as well as performed gastroscopy(P=0.042)were associated with longer physician diagnostic time in CD patients.In UC,fever was correlated(P=0.020)with shorter physician diagnostic time,while fatigue(P=0.011)and positive family history(P=0.046)were correlated with longer physician diagnostic time.CONCLUSION We demonstrated that CD patients compared to UC are at risk of long diagnostic delay.Future efforts should focus on shortening the diagnostic delay for a better outcome in these patients. 展开更多
关键词 Diagnostic time Diagnostic delay Crohn’s disease Ulcerative colitis GERMANY
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Effect of nonlinear impact damping with non-integer compliance exponent on gear dynamic characteristics
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作者 吴丽娟 唐进元 陈思雨 《Journal of Central South University》 SCIE EI CAS 2014年第10期3713-3721,共9页
A nonlinear impact damping model of single-degree-of-freedom spur cylindrical gear with backlash and time-varying stiffness was established. Systematic analyses of the dynamic responses were performed. First, the nonl... A nonlinear impact damping model of single-degree-of-freedom spur cylindrical gear with backlash and time-varying stiffness was established. Systematic analyses of the dynamic responses were performed. First, the nonlinear damping coefficient was considered as a constant parameter with two types of compliance exponent, meanwhile, dynamic factors were adopted to depict the dynamic characteristics. Second, the bifurcation graphs were plotted, where the damping coefficient was obtained along with the impact velocity and coefficient of restitution. The results show that light and heavy load conditions have an effect on the responses when the compliance exponent is integer. On the contrary, when the compliance exponent is non-integer, the dynamic responses are slightly affected, namely the system is more stable than the former situation. 展开更多
关键词 spur cylindrical gear nonlinear impact damping backlash non-integer compliance exponent
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Non-integer Order Control Scheme for Pressurized Water Reactor Core Power
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作者 Ibrahim M.Mehedi Maher H.AL-Sereihy +1 位作者 Asmaa Ubaid Al-Saggaf Ubaid M.Al-Saggaf 《Computers, Materials & Continua》 SCIE EI 2022年第7期651-662,共12页
Tracking load changes in a pressurized water reactor(PWR)with the help of an efficient core power control scheme in a nuclear power station is very important.The reason is that it is challenging to maintain a stable c... Tracking load changes in a pressurized water reactor(PWR)with the help of an efficient core power control scheme in a nuclear power station is very important.The reason is that it is challenging to maintain a stable core power according to the reference value within an acceptable tolerance for the safety of PWR.To overcome the uncertainties,a non-integer-based fractional order control method is demonstrated to control the core power of PWR.The available dynamic model of the reactor core is used in this analysis.Core power is controlled using a modified state feedback approach with a non-integer integral scheme through two different approximations,CRONE(Commande Robuste d’Ordre Non Entier,meaning Non-integer orderRobust Control)and FOMCON(non-integer order modeling and control).Simulation results are produced using MATLAB■program.Both non-integer results are compared with an integer order PI(Proportional Integral)algorithm to justify the effectiveness of the proposed scheme.Sate-spacemodel Core power control Non-integer control Pressurized water reactor PI controller CRONE FOMCON. 展开更多
关键词 Sate-space model core power control non-integer control pressurized water reactor PI controller CRONE FOMCON
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Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints 被引量:1
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作者 Jin-Xi Zhang Kai-Di Xu Qing-Guo Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1557-1565,共9页
The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requ... The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this paper.Herein, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings. 展开更多
关键词 Nonlinear systems output constraints prescribed performance reference tracking time delays
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An analytical model to estimate the time delay to reach spontaneous ignition considering heat loss in oil reservoirs 被引量:1
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作者 James J.Sheng Er-Long Yang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2469-2474,共6页
During air injection into an oil reservoir,an oxidation reaction generates some heat to raise the reservoir temperature.When the reservoir temperature reaches an ignition temperature,spontaneous ignition occurs.There ... During air injection into an oil reservoir,an oxidation reaction generates some heat to raise the reservoir temperature.When the reservoir temperature reaches an ignition temperature,spontaneous ignition occurs.There is a time delay from the injection to ignition.There are mixed results regarding the feasibility of spontaneous ignition in real-field projects and in laboratory experiments.No analytical model is available in the literature to estimate the oxidation time required to reach spontaneous ignition with heat loss.This paper discusses the feasibility of spontaneous ignition from theoretical points and experimental and field project observations.An analytical model considering heat loss is proposed.Analytical models with and without heat loss investigate the factors that affect spontaneous ignition.Based on the discussion and investigations,we find that it is more difficult for spontaneous ignition to occur in laboratory experiments than in oil reservoirs;spontaneous ignition is strongly affected by the initial reservoir temperature,oil activity,and heat loss;spontaneous ignition is only possible when the initial reservoir temperature is high,the oil oxidation rate is high,and the heat loss is low. 展开更多
关键词 Spontaneous ignition Time delay Air injection Heat loss Low temperature oxidation COMBUSTION
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Analysis of Logistic Model with Constant Harvesting in a View of Non-Integer Derivative
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作者 Fahad M.Alharbi 《Journal of Mathematics and System Science》 2020年第2期27-32,共6页
The conformable fractional derivative method has been utilized in order to examine the logistic model with constant harvesting.Such method introduces a generalization to the classical analysis of Logistic model,and he... The conformable fractional derivative method has been utilized in order to examine the logistic model with constant harvesting.Such method introduces a generalization to the classical analysis of Logistic model,and hence the features of the Logistic model,such as subcritical and supercritical harvesting,have been investigated in a view of fractional calculus.The positive auxiliary parameter,σ,with dimension of time is implemented to maintain the dimensionality of the system.The significant information of such parameter to the population has been discussed.The population expressions,obtained by conformable description,are compared with the expressions of the classical derivative.This comparison shows that the non-integer expressions are in a parallel line with that of the classical one. 展开更多
关键词 Logistic model conformable description non-integer derivative conformable differential equations fractional calculus.
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An algorithm for train delay propagation on double-track railway lines under FCFS management
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作者 Junfeng MA Chaoyu TANG +2 位作者 Wentao XU Shan MA Huawei WU 《Frontiers of Engineering Management》 CSCD 2024年第4期721-733,共13页
This paper proposes an algorithm for train delay propagation on double-track railway lines under First-Come-First-Serve(FCFS)management.The objective is to handle the challenges faced by the dispatchers as they encoun... This paper proposes an algorithm for train delay propagation on double-track railway lines under First-Come-First-Serve(FCFS)management.The objective is to handle the challenges faced by the dispatchers as they encounter train delays and their effects on the functioning of the railway system.We assume that the location and duration of disruptions are known,which are important inputs to the algorithm.This data enables calculation of delays experienced by each affected train.Our method analyzes factors such as train schedules,track capacities,and operation constraints to assess the manner in which delays would get propagated along railway lines.Key indicators of delay propagation,consisting of the number of delayed trains and stations,disruption settling time,and cumulative delays,are considered.Moreover,a numerical example is given to explain the practical application of this algorithm.Finally,we show that a tool like this would facilitate the dispatchers in managing and rescheduling trains in case of delays and will be improving resilience and efficiency of railway operations. 展开更多
关键词 train delay propagation FCFS management cumulative delays
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Attosecond ionization time delays in strong-field physics
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作者 马永哲 倪宏程 吴健 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期102-121,共20页
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
关键词 strong-field ionization ATTOSECOND time delay photoionization time delay tunneling time delay attosecond streak camera reconstruction of attosecond beating by interference of two-photon transitions(RABBITT) attoclock backpropagation
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Polynomial Functions Composed of Terms with Non-Integer Powers
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作者 Serdar Beji 《Advances in Pure Mathematics》 2021年第10期791-806,共16页
Polynomial functions containing terms with non-integer powers are studied to disclose possible approaches for obtaining their roots as well as employing them for curve-fitting purposes. Several special cases represent... Polynomial functions containing terms with non-integer powers are studied to disclose possible approaches for obtaining their roots as well as employing them for curve-fitting purposes. Several special cases representing equations from different categories are investigated for their roots. Curve-fitting applications to physically meaningful data by the use of fractional functions are worked out in detail. Relevance of this rarely worked subject to solutions of fractional differential equations is pointed out and existing potential in related future work is emphasized. 展开更多
关键词 RATIONAL Irrational Imaginary and Transcendental Powers Roots of Functions with Variables of non-integer Powers Curve-Fitting by Functions Incorporating Terms with Rational Powers Fractional Differential Equations
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Examining the association between delay discounting,delay aversion and physical activity in Chinese adults with type-2 diabetes mellitus
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作者 Yong-Dong An Guo-Xia Ma +3 位作者 Xing-Kui Cai Ying Yang Fang Wang Zhan-Lin Zhang 《World Journal of Diabetes》 SCIE 2024年第4期675-685,共11页
BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity r... BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration and government consider delay discounting and delay aversion when formulating behavioral intervention strategies and treatment guidelines involving physical activity for patients with T2DM,which may increase participation in physical activity.This study contributes a novel perspective to the research on physical activity in adults with T2DM by examining the significance of future health considerations and the role of emotional responses to delays. 展开更多
关键词 Type 2 diabetes mellitus delay discounting delay aversion Physical activity
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Spectrum of delayed post-hypoxic leukoencephalopathy syndrome:A systematic review
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作者 Bahadar S Srichawla Maria A Garcia-Dominguez 《World Journal of Clinical Cases》 SCIE 2024年第29期6285-6301,共17页
BACKGROUND Delayed post hypoxic leukoencephalopathy syndrome(DPHLS),also known as Grinker’s myelinopathy,is a rare but significant neurological condition that manifests days to weeks after a hypoxic event.Characteriz... BACKGROUND Delayed post hypoxic leukoencephalopathy syndrome(DPHLS),also known as Grinker’s myelinopathy,is a rare but significant neurological condition that manifests days to weeks after a hypoxic event.Characterized by delayed onset of neurological and cognitive deficits,DPHLS presents substantial diagnostic and therapeutic challenges.AIM To consolidate current knowledge on pathophysiology,clinical features,diagnostic approaches,and management strategies for DPHLS,providing a comprehensive overview and highlighting gaps for future research.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines,we systematically searched PubMed,ScienceDirect and Hinari databases using terms related to delayed post-hypoxic leukoencephalopathy.Inclusion criteria were original research articles,case reports,and case series involving human subjects with detailed clinical,neuroimaging,or pathological data on DPHLS.Data were extracted on study characteristics,participant demographics,clinical features,neuroimaging findings,pathological findings,treatment,and outcomes.The quality assessment was performed using the Joanna Briggs Institute critical appraisal checklist.RESULTS A total of 73 cases were reviewed.Common comorbidities included schizoaffective disorder,bipolar disorder,hypertension,and substance use disorder.The primary causes of hypoxia were benzodiazepine overdose,opioid overdose,polysubstance overdose,and carbon monoxide(CO)poisoning.Symptoms frequently include decreased level of consciousness,psychomotor agitation,cognitive decline,parkinsonism,and encephalopathy.Neuroimaging commonly revealed diffuse T2 hyperintensities in cerebral white matter,sometimes involving the basal ganglia and the globus pallidus.Magnetic resonance spectroscopy often showed decreased N-acetylaspartate,elevated choline,choline-to-creatinine ratio,and normal or elevated lactate.Treatment is often supportive,including amantadine,an antioxidant cocktail,and steroids.Hyperbaric oxygen therapy may be beneficial in those with CO poisoning.Parkinsonism was often treated with levodopa.Most of the patients had substantial recovery over the course of months and many cases had some residual neurocognitive deficits.CONCLUSION DPHLS remains a complex and multifaceted condition with various etiologies and clinical manifestations.Early recognition and appropriate management are crucial to improving patient outcomes.Future research should focus on standardizing diagnostic criteria,using advanced imaging techniques,and exploring therapeutic interventions to improve understanding and treatment of DPHLS.Conducting prospective cohort studies and developing biomarkers for early diagnosis and monitoring will be essential to advance patient care. 展开更多
关键词 delayed post hypoxic leukoencephalopathy syndrome Anoxic encephalopathy delayed post hypoxic leukoencephalopathy Hypoxic-ischemic brain injury Grinker's myelinopathy Toxic leukoencephalopathy Toxic leukoencephalopathy delayed postanoxic encephalopathy Carbon monoxide poisoning
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A nonlocal dispersal and time delayed HIV infection model with general incidences
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作者 WU Peng ZHANG Yu-huai WANG Ling 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第3期448-457,共10页
Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with n... Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be considered.In this paper,we establish an HIV infection model with nonlocal dispersal and infection age.Moreover,applying the theory of Fourier transformation and von Foerster rule,we transform the model to an integrodifferential equation with nonlocal time delay and dispersal.The well-posedness,positivity,and boundedness of the solution for the model are studied. 展开更多
关键词 HIV model nonlocal dispersal time delay general incidences
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Surgical techniques to prevent delayed gastric emptying after pancreaticoduodenectomy
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作者 Peng Duan Lu Sun +2 位作者 Kai Kou Xin-Rui Li Ping Zhang 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2024年第5期449-457,共9页
Background: Delayed gastric emptying(DGE) is one of the most common complications after pancreaticoduodenectomy(PD). DGE represents impaired gastric motility without significant mechanical obstruction and is associate... Background: Delayed gastric emptying(DGE) is one of the most common complications after pancreaticoduodenectomy(PD). DGE represents impaired gastric motility without significant mechanical obstruction and is associated with an increased length of hospital stay, increased healthcare costs, and a high readmission rate. We reviewed published studies on various technical modifications to reduce the incidence of DGE. Data sources: Studies were identified by searching Pub Med for relevant articles published up to December 2022. The following search terms were used: “pancreaticoduodenectomy”, “pancreaticojejunostomy”, “pancreaticogastrostomy”, “gastric emptying”, “gastroparesis” and “postoperative complications”. The search was limited to English publications. Additional articles were identified by a manual search of references from key articles. Results: In recent years, various surgical procedures and techniques have been explored to reduce the incidence of DGE. Pyloric resection, Billroth II reconstruction, Braun's enteroenterostomy, and antecolic reconstruction may be associated with a decreased incidence of DGE, but more high-powered studies are needed in the future. Neither laparoscopic nor robotic surgery has demonstrated superiority in preventing DGE, and the use of staplers is controversial regarding whether they can reduce the incidence of DGE. Conclusions: Despite many innovations in surgical techniques, there is no surgical procedure that is superior to others to reduce DGE. Further larger prospective randomized studies are needed. 展开更多
关键词 PANCREATICODUODENECTOMY delayed gastric emptying Postoperative complications Surgical techniques
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Analysis and Design of Time-Delay Impulsive Systems Subject to Actuator Saturation
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作者 Chenhong Zhu Xiuping Han Xiaodi Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期196-204,共9页
This paper investigates the exponential stability and performance analysis of nonlinear time-delay impulsive systems subject to actuator saturation. When continuous dynamics is unstable, under some conditions, it is s... This paper investigates the exponential stability and performance analysis of nonlinear time-delay impulsive systems subject to actuator saturation. When continuous dynamics is unstable, under some conditions, it is shown that the system can be stabilized by a class of saturated delayed-impulses regardless of the length of input delays. Conversely, when the system is originally stable, it is shown that under some conditions, the system is robust with respect to sufficient small delayed-impulses. Moreover, the design problem of the controller with the goal of obtaining a maximized estimate of the domain of attraction is formulated via a convex optimization problem. Three examples are provided to demonstrate the validity of the main results. 展开更多
关键词 delayed impulses impulsive control impulsive disturbance nonlinear systems SATURATION
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Designing Proportional-Integral Consensus Protocols for Second-Order Multi-Agent Systems Using Delayed and Memorized State Information
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作者 Honghai Wang Qing-Long Han 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期878-892,共15页
This paper is concerned with consensus of a secondorder linear time-invariant multi-agent system in the situation that there exists a communication delay among the agents in the network.A proportional-integral consens... This paper is concerned with consensus of a secondorder linear time-invariant multi-agent system in the situation that there exists a communication delay among the agents in the network.A proportional-integral consensus protocol is designed by using delayed and memorized state information.Under the proportional-integral consensus protocol,the consensus problem of the multi-agent system is transformed into the problem of asymptotic stability of the corresponding linear time-invariant time-delay system.Note that the location of the eigenvalues of the corresponding characteristic function of the linear time-invariant time-delay system not only determines the stability of the system,but also plays a critical role in the dynamic performance of the system.In this paper,based on recent results on the distribution of roots of quasi-polynomials,several necessary conditions for Hurwitz stability for a class of quasi-polynomials are first derived.Then allowable regions of consensus protocol parameters are estimated.Some necessary and sufficient conditions for determining effective protocol parameters are provided.The designed protocol can achieve consensus and improve the dynamic performance of the second-order multi-agent system.Moreover,the effects of delays on consensus of systems of harmonic oscillators/double integrators under proportional-integral consensus protocols are investigated.Furthermore,some results on proportional-integral consensus are derived for a class of high-order linear time-invariant multi-agent systems. 展开更多
关键词 Consensus protocol Hurwitz stability multi-agent systems quasi-polynomials time delay
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Boundedness and Positivity Preserving Numerical Analysis of a Fuzzy-Parameterized Delayed Model for Foot and Mouth Disease Dynamics
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作者 Muhammad Tashfeen Fazal Dayan +2 位作者 Muhammad Aziz ur Rehman Thabet Abdeljawad Aiman Mukheimer 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第12期2527-2554,共28页
Foot-and-mouth disease(FMD)is a viral disease that affects cloven-hoofed animals including cattle,pigs,and sheep,hence causing export bans among others,causing high economic losses due to reduced productivity.The glob... Foot-and-mouth disease(FMD)is a viral disease that affects cloven-hoofed animals including cattle,pigs,and sheep,hence causing export bans among others,causing high economic losses due to reduced productivity.The global effect of FMD is most felt where livestock rearing forms an important source of income.It is therefore important to understand the modes of transmission of FMD to control its spread and prevent its occurrence.This work intends to address these dynamics by including the efficacy of active migrant animals transporting the disease from one area to another in a fuzzy mathematical modeling framework.Historical models of epidemics are determinable with a set of deterministic parameters and this does not reflect on real-life scenarios as observed in FMD.Fuzzy theory is used in this model as it permits the inclusion of uncertainties in the model;this makes the model more of a reality regarding disease transmission.A time lag,in this case,denotes the incubation period and other time-related factors affecting the spread of FMD and,therefore,is added to the current model for FMD.To that purpose,the analysis of steady states and the basic reproduction number are performed and,in addition,the stability checks are conveyed in the fuzzy environment.For the numerical solution of the model,we derive the Forward Euler Method and the fuzzy delayed non-standard finite difference(FDNSFD)method.Analytical studies of the FDNSFD scheme are performed for convergence,non-negativity,boundedness,and consistency analysis of the numerical projection to guarantee that the numerical model is an accurate discretization of the continuous dynamics of FMD transmission over time.In the following simulation study,we show that the FDNSFD method preserves the characteristics of the constant model and still works if relatively large time steps are employed;this is a bonus over the normal finite difference technique.The study shows how valuable it is to adopt fuzzy theory and time delays when simulating the transmission of the epidemic,especially for such diseases as FMD where uncertainty and migration have a defining role in transmission.This approach gives more sound and flexible grounds for analyzing and controlling the outbreak of FMD in various situations. 展开更多
关键词 FMD Virus delay epidemic model fuzzy parameters stability CONSISTENCY
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