We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.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
We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the...We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the conventional telecom band.展开更多
To provide an energy-efficient and slab-demand-compliant rolling delay strategy,the simulation software is utilized to calculate the rolling delay process of the reheating furnace.Based on energy consumption evaluatio...To provide an energy-efficient and slab-demand-compliant rolling delay strategy,the simulation software is utilized to calculate the rolling delay process of the reheating furnace.Based on energy consumption evaluation,two optimization methods were employed.The bisection approach uses the needs of the slab to estimate the rolling delay temperature,and the golden section search method uses the energy consumption analysis of the slab to determine the high-temperature insulation duration.Generally,the slab closest to the discharge position in the control zone is selected as the optimization target.The optimized slab does not show a significant temperature rise after the end of the rolling delay process.When comparing the optimized rolling delay strategies with the traditional ones,the optimized rolling delay strategies not only meet the output requirements for slabs but also offer significant advantages in terms of energy efficiency,and this advantage increases with rolling delay time.展开更多
Research Background: Cervical cancer is the second most common cancer in women and the third leading cause of female cancer death in Bangladesh. Delay in initiation of treatment in advanced stage cervical cancer patie...Research Background: Cervical cancer is the second most common cancer in women and the third leading cause of female cancer death in Bangladesh. Delay in initiation of treatment in advanced stage cervical cancer patients is an important modifiable risk factor for cancer-related mortality. Identifying elements associated with delay of diagnosis will help reduce barriers to timely treatment of cervical cancer. Research Objectives: The objective of this study was to analyze the factors leading to delay in diagnosis and treatment of women with advanced stage cervical cancer. Methods: A cross-sectional observational study analyzed the factors associated with delay in initiation of treatment for 138 patients with advanced-stage cervical cancer from November 2019 to October 2020 at the National Institute of Cancer Research and Hospital (NICRH) in Dhaka, Bangladesh. Advanced-stage cervical cancer patients between the ages of 30 to 70 years were included in this study. Face-to-face interviews with the participants used a predesigned data collection sheet. In this study, three components of delay were identified: primary delay due to patient factors, healthcare provider delay, and healthcare-system infrastructure delay. Factors associated with delay were the independent variables and durations of delay were the outcome variables. Descriptive statistics were expressed as mean + standard deviation, median, percentage, and frequency. Results: One hundred and thirty-eight patients with advanced stage cervical cancer were included in the study. The mean age of the patients was 48.74 (±9.57) years. Thirty-four percent of patients were illiterate. More than half (57.25%) of the patients were from lower middle-class families. Delays were categorized as patient-related, healthcare provider delay, and healthcare-system infrastructure related. Patient-related factors included low monthly income, residence in a rural area, embarrassment, fear, lack of knowledge regarding cervical cancer, delay in contacting a spouse, family member or friend prior to the first medical encounter. These elements predicted a primary delay of more than 60 days (P value Conclusion: Three broad categories of delay in diagnosis and treatment of cervical cancer: patient-related factors, healthcare provider-related factors, and healthcare-system infrastructure factors were analyzed. Illiteracy, lack of awareness regarding cervical cancer, lack of health-seeking behavior, and poor income status were associated with patient-related primary delay. Nonperformance of speculum examination in the initial consultation, misdiagnosis, inappropriate management, and delay in referral to the cancer treatment center by primary healthcare providers were the contributing factors for healthcare provider delay. Lack of availability and accessibility of health services and limitation of radiotherapy resources led to healthcare-system infrastructure delays. All three categories of delay must be addressed through the education of communities, the gynecologic training of community healthcare providers, the improvement of medical infrastructure, and the increase of medical resources.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
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
Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid...Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.展开更多
BACKGROUND Visual impairment during early childhood can hinder motor,language,and social development,yet data on its developmental impact across common pediatric ocular diseases remain limited.AIM To investigate the d...BACKGROUND Visual impairment during early childhood can hinder motor,language,and social development,yet data on its developmental impact across common pediatric ocular diseases remain limited.AIM To investigate the developmental impact of low vision and blindness on children under six with common ocular diseases.METHODS This retrospective study reviewed records of new patients under six with visual impairment at Siriraj Hospital’s low vision rehabilitation center(January 2017-October 2022).We collected ocular,systemic,and developmental data;recorded visual acuity in the better-seeing eye after refractive correction;and assessed developmental domains with the DenverⅡ.Univariable and multi-variable logistic regression identified factors associated with developmental delay.RESULTS A total of 161 pediatric patients(mean age 24.9±18.9 months)were enrolled and evaluated based on their ability to fix on and follow an object or light source.Some were further assessed using the Allen picture chart and all had visual acuity worse than 1.07±0.58 LogMAR,and 83.2%were identified as having global developmental delay(GDD).The three most common ocular causes were cortical visual impairment(CVI),optic neuropathy/atrophy,and optic nerve hypoplasia.Extremely poor visual acuity(inability to fixate and follow)was significantly associated with GDD[adjusted odds ratio(AOR)41.0]and delays in all developmental domains:Gross motor(AOR 10.0),fine motor(AOR 12.8),language(AOR 5.3),and personal-social skills(AOR 13.4)(P≤0.002).Multiple disabilities,most often visual impairment with cerebral palsy,were also significantly associated with gross motor delays(AOR 7.7)and fine motor delays(AOR 4.0)(P<0.05).CVI was also related to delays in language and personal-social skills(AOR 9.1 each)(P<0.05).CONCLUSION This study underscores the developmental issues in children with visual impairment,especially those with poorer acuity,CVI,and multiple disabilities.Significant delays were observed in all domains,including GDD.A timely referral to specialists is strongly recommended.展开更多
In this article,the global attractors of 2D g-Navier-Stokes equations are obtained in the space of C_(Hg) and CVg respectively.When the external force f is sufficiently small,the studies indicate that the global attra...In this article,the global attractors of 2D g-Navier-Stokes equations are obtained in the space of C_(Hg) and CVg respectively.When the external force f is sufficiently small,the studies indicate that the global attractor in C_(Hg) is equal to the global attractor in C_(Vg).展开更多
This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of ...This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of FxTS is independent of the initial values and parameters of the CNs,a modified fixed-time(FxT)stability theorem is proposed,where the ST is determined by an arbitrary positive number given in advance.Then,continuous controller and discontinuous controller are designed to realize the modified FxTS target of CNs.In addition,based on the designed controllers,CNs can achieve synchronization at any given time,or even earlier.And control strategies effectively solve the problem of ST related to the parameters of CNs.Finally,an appropriate simulation example is conducted to examine the effectiveness of the designed control strategies.展开更多
Wireless communication-enabled Cooperative Adaptive Cruise Control(CACC)is expected to improve the safety and traffic capacity of vehicle platoons.Existing CACC considers a conventional communication delay with fixed ...Wireless communication-enabled Cooperative Adaptive Cruise Control(CACC)is expected to improve the safety and traffic capacity of vehicle platoons.Existing CACC considers a conventional communication delay with fixed Vehicular Communication Network(VCN)topologies.However,when the network is under attack,the communication delay may be much higher,and the stability of the system may not be guaranteed.This paper proposes a novel communication Delay Aware CACC with Dynamic Network Topologies(DADNT).The main idea is that for various communication delays,in order to maximize the traffic capacity while guaranteeing stability and minimizing the following error,the CACC should dynamically adjust the VCN network topology to achieve the minimum inter-vehicle spacing.To this end,a multi-objective optimization problem is formulated,and a 3-step Divide-And-Conquer sub-optimal solution(3DAC)is proposed.Simulation results show that with 3DAC,the proposed DADNT with CACC can reduce the inter-vehicle spacing by 5%,10%,and 14%,respectively,compared with the traditional CACC with fixed one-vehicle,two-vehicle,and three-vehicle look-ahead network topologies,thereby improving the traffic efficiency.展开更多
This paper considers the fundamental channel estimation problem for the multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)system in the presence of multi-cell interference.Specificall...This paper considers the fundamental channel estimation problem for the multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)system in the presence of multi-cell interference.Specifically,this paper focuses on both channel modelling and receiver design for interference estimation and mitigation.We propose a delay-calibrated block-wise linear model,which extracts the delay of the dominant tap of each interference as a key parameter and approximates the residual channel coefficients by the recently developed blockwise linear model.Based on the delay-calibrated block-wise linear model and the angle-domain channel sparsity,we further conceive a message passing algorithm to solve the channel estimation problem.Numerical results demonstrate the superior performance of the proposed algorithm over the state-of-the-art algorithms.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
A promising avenue to control mosquito-borne diseases such as dengue,malaria,and Zika involves releasing male mosquitoes carrying the bacterium Wolbachia in wild areas to drive female sterility by a mechanism called c...A promising avenue to control mosquito-borne diseases such as dengue,malaria,and Zika involves releasing male mosquitoes carrying the bacterium Wolbachia in wild areas to drive female sterility by a mechanism called cytoplasmic incompatibility(CI).In this work,we initiate a preliminary assessment of how the combined impact of dispersal,incomplete CI and mating competitiveness on mosquito population suppression by a delay differential equation model.Our theoretical analyses indicate that the immigration of eggs plays a significant role in the suppression dynamics.For the case without egg immigration,we identify a threshold dispersal rate v*of adult mosquitoes,threshold CI densityξ*,and threshold release ratio r*.A successful mosquito suppression would be established only when v<v*,ξ>ξ*,and r(t)≥r*uniformly.The immigration of eggs causes the threshold dynamics to be invalid,and warns an absolute failure of population suppression.The monotonicity of the adult steady-state in the dispersal rate and CI intensity indicates that choosing a suitable Wolbachia strain with strong CI intensity,or bringing down the dispersal rate of mosquitoes by blocking the suppression zones is a feasible strategy to obtain a better suppression level.展开更多
This paper is concerned with design-ing symbol labeling for a low-density parity-check(LDPC)-coded delayed bit-interleaved coded modu-lation(DBICM)scheme in a two-way relay channel(TWRC).We first present some properti...This paper is concerned with design-ing symbol labeling for a low-density parity-check(LDPC)-coded delayed bit-interleaved coded modu-lation(DBICM)scheme in a two-way relay channel(TWRC).We first present some properties of symbol labeling within a phase shift keying(PSK)modula-tion.These properties reduce the candidate labeling search space.Based on this search space,we take DBICM capacity as the cost function and propose a general method for optimizing symbol labeling by em-ploying the differential evolution algorithm.Numeri-cal results show that our labeling obtains a signal-to-noise ratio(SNR)gain up to 0.45 dB with respect to Gray labeling.展开更多
In this paper,we focus on the admissible transcendental meromorphic solutions of the following delay Schwarzian differential equations with rational coefficients f(z+1)-f(z-1)+a(z)S(f,z)=P(z,f(z))/Q(z,f(z)).We obtain ...In this paper,we focus on the admissible transcendental meromorphic solutions of the following delay Schwarzian differential equations with rational coefficients f(z+1)-f(z-1)+a(z)S(f,z)=P(z,f(z))/Q(z,f(z)).We obtain the necessary conditions on the degree of R(z,f)for these delay differential equations and give a classification of the delay Schwarzian differential equations according to the multiplicities of the root of Q(z,f)on f.Finally,we provide some examples to illustrate that all cases occur.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
Background:Contrast-enhanced magnetic resonance neurography(ceMRN)can enhance brachial plexus visualization and quality of imaging.However,the interval between contrast injection and scanning that provides the highest...Background:Contrast-enhanced magnetic resonance neurography(ceMRN)can enhance brachial plexus visualization and quality of imaging.However,the interval between contrast injection and scanning that provides the highest-quality images is not known.Methods:Fifteen patients underwent brachial plexus imaging using the 3D T2-NerveView sequence with a scanning duration of 5 min.A consecutive six-phase scan was initiated immediately at the start of contrast agent injection.Subsequently,all patients'images were classified into six groups according to the phases:group A(phase 1,delay 0 min),group B(phase 2,delay 5 min),group C(phase 3,delay 10 min),group D(phase 4,delay 15 min),group E(phase 5,delay 20 min),and group F(phase 6,delay 25 min).The image quality in each group was assessed based on nerve signal(signalnerve),muscle signal(signalmuscle),lymph node signal(signallymph node),background noise(BN),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and subjective score.Results:Signalnerve,signalmuscle,BN,and SNR did not significantly differ among the six groups(p>0.05).However,significant differences(p<0.05)were observed in signallymph node(F=16.067),CNR(F=9.495),and subjective score(χ^(2)=23.586).As the scanning delay increased,signallymph node intensity gradually increased whereas the CNR gradually decreased.The subjective score was significantly higher in groups B(4.830.24),C(4.900.21),D(4.870.30),E(4.830.31),and F(4.830.31)than in group A(4.470.30).Conclusion:We recommend performing brachial plexus ceMRN 5 min after contrast injection.With this delay,the brachial plexus can be visualized optimally with minimal interference from background signals.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
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.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,92480001,12134001,12304418,12274130,12274133,12474378,and 12404378)the National Key R&D Program of China(Grant Nos.2022YFA1404600 and 2022YFA1205100)+2 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005)。
文摘We report the fabrication of an 8-meter-long thin-flm lithium niobate optical true delay line using the photolithography-assisted chemomechanical etching technique,showing a low transmission loss of 0.036 dB/cm in the conventional telecom band.
文摘To provide an energy-efficient and slab-demand-compliant rolling delay strategy,the simulation software is utilized to calculate the rolling delay process of the reheating furnace.Based on energy consumption evaluation,two optimization methods were employed.The bisection approach uses the needs of the slab to estimate the rolling delay temperature,and the golden section search method uses the energy consumption analysis of the slab to determine the high-temperature insulation duration.Generally,the slab closest to the discharge position in the control zone is selected as the optimization target.The optimized slab does not show a significant temperature rise after the end of the rolling delay process.When comparing the optimized rolling delay strategies with the traditional ones,the optimized rolling delay strategies not only meet the output requirements for slabs but also offer significant advantages in terms of energy efficiency,and this advantage increases with rolling delay time.
文摘Research Background: Cervical cancer is the second most common cancer in women and the third leading cause of female cancer death in Bangladesh. Delay in initiation of treatment in advanced stage cervical cancer patients is an important modifiable risk factor for cancer-related mortality. Identifying elements associated with delay of diagnosis will help reduce barriers to timely treatment of cervical cancer. Research Objectives: The objective of this study was to analyze the factors leading to delay in diagnosis and treatment of women with advanced stage cervical cancer. Methods: A cross-sectional observational study analyzed the factors associated with delay in initiation of treatment for 138 patients with advanced-stage cervical cancer from November 2019 to October 2020 at the National Institute of Cancer Research and Hospital (NICRH) in Dhaka, Bangladesh. Advanced-stage cervical cancer patients between the ages of 30 to 70 years were included in this study. Face-to-face interviews with the participants used a predesigned data collection sheet. In this study, three components of delay were identified: primary delay due to patient factors, healthcare provider delay, and healthcare-system infrastructure delay. Factors associated with delay were the independent variables and durations of delay were the outcome variables. Descriptive statistics were expressed as mean + standard deviation, median, percentage, and frequency. Results: One hundred and thirty-eight patients with advanced stage cervical cancer were included in the study. The mean age of the patients was 48.74 (±9.57) years. Thirty-four percent of patients were illiterate. More than half (57.25%) of the patients were from lower middle-class families. Delays were categorized as patient-related, healthcare provider delay, and healthcare-system infrastructure related. Patient-related factors included low monthly income, residence in a rural area, embarrassment, fear, lack of knowledge regarding cervical cancer, delay in contacting a spouse, family member or friend prior to the first medical encounter. These elements predicted a primary delay of more than 60 days (P value Conclusion: Three broad categories of delay in diagnosis and treatment of cervical cancer: patient-related factors, healthcare provider-related factors, and healthcare-system infrastructure factors were analyzed. Illiteracy, lack of awareness regarding cervical cancer, lack of health-seeking behavior, and poor income status were associated with patient-related primary delay. Nonperformance of speculum examination in the initial consultation, misdiagnosis, inappropriate management, and delay in referral to the cancer treatment center by primary healthcare providers were the contributing factors for healthcare provider delay. Lack of availability and accessibility of health services and limitation of radiotherapy resources led to healthcare-system infrastructure delays. All three categories of delay must be addressed through the education of communities, the gynecologic training of community healthcare providers, the improvement of medical infrastructure, and the increase of medical resources.
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 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 Hunan Province(2021JJ31089)the Scientific Research Project of Health Commission of Hunan Province(202203104548),China。
文摘Objective:The neurotoxicity of carbon monoxide(CO)to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Our previous study found that retinoic acid(RA)can suppress the neurotoxic effects of CO.This study further explores,in vivo and in vitro,the molecular mechanisms by which RA alleviates CO-induced central nervous system damage.Methods:A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO,and a DEACMP animal model was established in adult Kunming mice.Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay and Annexin V/propidium iodide(PI)double staining.The transcriptional and protein expression of each gene was detected using real time fluorescence quantitative PCR(RT-qPCR)and Western blotting.Long noncoding RNA(lncRNA)SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes.In DEACMP mice,SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression.Results:RA at 10 and 20μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes,downregulation of SNHG15 and LINGO-1,and upregulation of brain-derived neurotrophic factor(BDNF)and tyrosine kinase receptor B(TrkB)(all P<0.05).Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity(all P<0.05).Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels(all P<0.05).Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP(all P<0.05).Conclusion:RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes,thereby reducing central nervous system injury and exerting neuroprotective effects.LncRNA SNHG15 and LINGO-1 are key molecules mediating RA induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway.These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
文摘BACKGROUND Visual impairment during early childhood can hinder motor,language,and social development,yet data on its developmental impact across common pediatric ocular diseases remain limited.AIM To investigate the developmental impact of low vision and blindness on children under six with common ocular diseases.METHODS This retrospective study reviewed records of new patients under six with visual impairment at Siriraj Hospital’s low vision rehabilitation center(January 2017-October 2022).We collected ocular,systemic,and developmental data;recorded visual acuity in the better-seeing eye after refractive correction;and assessed developmental domains with the DenverⅡ.Univariable and multi-variable logistic regression identified factors associated with developmental delay.RESULTS A total of 161 pediatric patients(mean age 24.9±18.9 months)were enrolled and evaluated based on their ability to fix on and follow an object or light source.Some were further assessed using the Allen picture chart and all had visual acuity worse than 1.07±0.58 LogMAR,and 83.2%were identified as having global developmental delay(GDD).The three most common ocular causes were cortical visual impairment(CVI),optic neuropathy/atrophy,and optic nerve hypoplasia.Extremely poor visual acuity(inability to fixate and follow)was significantly associated with GDD[adjusted odds ratio(AOR)41.0]and delays in all developmental domains:Gross motor(AOR 10.0),fine motor(AOR 12.8),language(AOR 5.3),and personal-social skills(AOR 13.4)(P≤0.002).Multiple disabilities,most often visual impairment with cerebral palsy,were also significantly associated with gross motor delays(AOR 7.7)and fine motor delays(AOR 4.0)(P<0.05).CVI was also related to delays in language and personal-social skills(AOR 9.1 each)(P<0.05).CONCLUSION This study underscores the developmental issues in children with visual impairment,especially those with poorer acuity,CVI,and multiple disabilities.Significant delays were observed in all domains,including GDD.A timely referral to specialists is strongly recommended.
基金Supported by the National Natural Science Foundation of China(11971378)Shaanxi Fundamental Science Research Project for Mathematics and Physics(23JSY050)Shaanxi Innovative Training Program for College Students(S202410719114)。
文摘In this article,the global attractors of 2D g-Navier-Stokes equations are obtained in the space of C_(Hg) and CVg respectively.When the external force f is sufficiently small,the studies indicate that the global attractor in C_(Hg) is equal to the global attractor in C_(Vg).
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.
基金supported by the National Natural Science Foundation of China under Grant U21A20449in part by Jiangsu Provincial Key Research and Development Program under Grant BE2021013-2。
文摘Wireless communication-enabled Cooperative Adaptive Cruise Control(CACC)is expected to improve the safety and traffic capacity of vehicle platoons.Existing CACC considers a conventional communication delay with fixed Vehicular Communication Network(VCN)topologies.However,when the network is under attack,the communication delay may be much higher,and the stability of the system may not be guaranteed.This paper proposes a novel communication Delay Aware CACC with Dynamic Network Topologies(DADNT).The main idea is that for various communication delays,in order to maximize the traffic capacity while guaranteeing stability and minimizing the following error,the CACC should dynamically adjust the VCN network topology to achieve the minimum inter-vehicle spacing.To this end,a multi-objective optimization problem is formulated,and a 3-step Divide-And-Conquer sub-optimal solution(3DAC)is proposed.Simulation results show that with 3DAC,the proposed DADNT with CACC can reduce the inter-vehicle spacing by 5%,10%,and 14%,respectively,compared with the traditional CACC with fixed one-vehicle,two-vehicle,and three-vehicle look-ahead network topologies,thereby improving the traffic efficiency.
基金supported in part by the National Key Research and Development Program of China under Grant 2020YFB1804800。
文摘This paper considers the fundamental channel estimation problem for the multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)system in the presence of multi-cell interference.Specifically,this paper focuses on both channel modelling and receiver design for interference estimation and mitigation.We propose a delay-calibrated block-wise linear model,which extracts the delay of the dominant tap of each interference as a key parameter and approximates the residual channel coefficients by the recently developed blockwise linear model.Based on the delay-calibrated block-wise linear model and the angle-domain channel sparsity,we further conceive a message passing algorithm to solve the channel estimation problem.Numerical results demonstrate the superior performance of the proposed algorithm over the state-of-the-art algorithms.
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 the National Natural Science Foundation of China(12226414,11471085,11631005,12171112)。
文摘A promising avenue to control mosquito-borne diseases such as dengue,malaria,and Zika involves releasing male mosquitoes carrying the bacterium Wolbachia in wild areas to drive female sterility by a mechanism called cytoplasmic incompatibility(CI).In this work,we initiate a preliminary assessment of how the combined impact of dispersal,incomplete CI and mating competitiveness on mosquito population suppression by a delay differential equation model.Our theoretical analyses indicate that the immigration of eggs plays a significant role in the suppression dynamics.For the case without egg immigration,we identify a threshold dispersal rate v*of adult mosquitoes,threshold CI densityξ*,and threshold release ratio r*.A successful mosquito suppression would be established only when v<v*,ξ>ξ*,and r(t)≥r*uniformly.The immigration of eggs causes the threshold dynamics to be invalid,and warns an absolute failure of population suppression.The monotonicity of the adult steady-state in the dispersal rate and CI intensity indicates that choosing a suitable Wolbachia strain with strong CI intensity,or bringing down the dispersal rate of mosquitoes by blocking the suppression zones is a feasible strategy to obtain a better suppression level.
文摘This paper is concerned with design-ing symbol labeling for a low-density parity-check(LDPC)-coded delayed bit-interleaved coded modu-lation(DBICM)scheme in a two-way relay channel(TWRC).We first present some properties of symbol labeling within a phase shift keying(PSK)modula-tion.These properties reduce the candidate labeling search space.Based on this search space,we take DBICM capacity as the cost function and propose a general method for optimizing symbol labeling by em-ploying the differential evolution algorithm.Numeri-cal results show that our labeling obtains a signal-to-noise ratio(SNR)gain up to 0.45 dB with respect to Gray labeling.
基金supported by the National Natural Science Foundation of China(12201420,12231013,11701382 and 11971288)the Guangdong Basic and Applied Basic Research Foundation,China(2021A1515010054)and NCAMS.
文摘In this paper,we focus on the admissible transcendental meromorphic solutions of the following delay Schwarzian differential equations with rational coefficients f(z+1)-f(z-1)+a(z)S(f,z)=P(z,f(z))/Q(z,f(z)).We obtain the necessary conditions on the degree of R(z,f)for these delay differential equations and give a classification of the delay Schwarzian differential equations according to the multiplicities of the root of Q(z,f)on f.Finally,we provide some examples to illustrate that all cases occur.
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(Grant No.82302173).
文摘Background:Contrast-enhanced magnetic resonance neurography(ceMRN)can enhance brachial plexus visualization and quality of imaging.However,the interval between contrast injection and scanning that provides the highest-quality images is not known.Methods:Fifteen patients underwent brachial plexus imaging using the 3D T2-NerveView sequence with a scanning duration of 5 min.A consecutive six-phase scan was initiated immediately at the start of contrast agent injection.Subsequently,all patients'images were classified into six groups according to the phases:group A(phase 1,delay 0 min),group B(phase 2,delay 5 min),group C(phase 3,delay 10 min),group D(phase 4,delay 15 min),group E(phase 5,delay 20 min),and group F(phase 6,delay 25 min).The image quality in each group was assessed based on nerve signal(signalnerve),muscle signal(signalmuscle),lymph node signal(signallymph node),background noise(BN),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and subjective score.Results:Signalnerve,signalmuscle,BN,and SNR did not significantly differ among the six groups(p>0.05).However,significant differences(p<0.05)were observed in signallymph node(F=16.067),CNR(F=9.495),and subjective score(χ^(2)=23.586).As the scanning delay increased,signallymph node intensity gradually increased whereas the CNR gradually decreased.The subjective score was significantly higher in groups B(4.830.24),C(4.900.21),D(4.870.30),E(4.830.31),and F(4.830.31)than in group A(4.470.30).Conclusion:We recommend performing brachial plexus ceMRN 5 min after contrast injection.With this delay,the brachial plexus can be visualized optimally with minimal interference from background signals.
