This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relativ...This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relative motion dynamics model,a prescribed time output feedback control strategy is proposed.A prescribed-time extended state observer is designed to estimate the relative velocity and external disturbances.The disturbance estimates are then used as the feedforward component of the controller.Building on this framework,a novel prescribed-time active disturbance rejection control strategy for position tracking is developed via a backstepping control design.The convergence of the extended state observer and the stability of the closed-loop system are rigorously analyzed using Lyapunov stability theory.Numerical simulations are performed to validate the effectiveness of the proposed controller.展开更多
Antibody-mediated rejection(AMR)remains a leading cause of kidney allograft failure,posing significant clinical and economic challenges.Donor-specific antibodies against human leukocyte antigens or non-human leukocyte...Antibody-mediated rejection(AMR)remains a leading cause of kidney allograft failure,posing significant clinical and economic challenges.Donor-specific antibodies against human leukocyte antigens or non-human leukocyte antigens are critical risk factors for AMR and graft loss.The diagnostic criteria and classification of AMR have evolved considerably over the past three decades,driven largely by the Banff classification.The latest Banff 2022 classification introduced two additional subcategories of“microvascular inflammation,donor-specific antibody-negative,C4d-negative”and“probable AMR”.Traditionally,graft monitoring has relied on non-specific markers such as serum creatinine and proteinuria,and the invasive biopsies.Noninvasive tools using blood and urine biomarkers,including cellular assays and molecular profiling,are increasingly being investigated.Technologies such as the Molecular Microscope Diagnostic System show promise,with studies reporting 80%sensitivity and 90%specificity in detecting AMR.Treatment of AMR remains inconsistent.Recent advances,including CD38 antibodies,have demonstrated up to 60%efficacy in reversing AMR,while complement inhibition shows potential in severe early cases.Ongoing clinical trials evaluating high-dose intravenous immunoglobulin,efgartigimod,fostamatinib,and other novel therapies aim to expand treatment options.These developments highlight the need for well-designed clinical trials to validate biomarkers and therapies and to improve long-term outcomes for kidney transplant recipients.展开更多
Objectives:Loneliness among left-behind adolescents is the most frequently reported emotional problem because of parental neglect.The present study explored the relationship between maternal absence and adolescent lon...Objectives:Loneliness among left-behind adolescents is the most frequently reported emotional problem because of parental neglect.The present study explored the relationship between maternal absence and adolescent loneliness as well as its mechanisms.Methods:The study included 305 participants(Meanage=15.99±0.81,48.9%females)in southeast China,and constructed a chain mediation model to test the roles of rejection sensitivity and friendship quality.Parent absence types,rejection sensitivity,friendship quality,and adolescent loneliness were all assessed with questionnaires.Results:The results showed that adolescents with a mother absent(both-parent absent,mother-only absent)experienced higher levels of loneliness than those with a mother not absent(father-only absent,non-parent absent)(β=0.3137,95%CI[0.0849,0.5425],p<0.01).Besides,the mediating roles of rejection sensitivity(β=0.0344,95%CI[0.0020,0.0808])and friendship quality(β=0.1198,95%CI[0.0049,0.2428])and their chain mediating role were found significant between maternal absence and loneliness(β=0.0245,95%CI[0.0015,0.0575]).Conclusions:These findings have revealed the significant impact of maternal absence on adolescent loneliness and provide important practical implications for educators to reduce adolescent loneliness.展开更多
Spaceborne optomechanical systems face the dual challenges of extreme thermal disturbances and millikelvin-level temperature control precision during orbital operations,demanding robust control strategies.To address t...Spaceborne optomechanical systems face the dual challenges of extreme thermal disturbances and millikelvin-level temperature control precision during orbital operations,demanding robust control strategies.To address the performance limitations of conventional fixed-parameter active disturbance rejection control(ADRC)under complex operating conditions,this work proposes a Qlearning-enhanced adaptive ADRC framework.A thermal-transfer model incorporating multisource disturbances(solar radiation,structural conduction,and contact thermal resistance)is established,coupled with a reinforcement learning-driven parameter optimization mechanism.The ε-greedy policy dynamically adjusts observer bandwidth(ω_(o)∈[0.01,0.2])and controller bandwidth(ω_(c)∈[0.01,0.1])to enable real-time estimation and compensation of total disturbances.Simulation results demonstrate significant improvements over fixed-parameter ADRC and a self-tuning internal model control proportional-integral(SIMC-PI)controller:31.3% and 15.4% reduction in settling time during setpoint responses,respectively;21.8% lower integral absolute error(IAE)than the fixed-parameter ADRC during setpoint step responses;12.7% and 52.5% enhancement in control precision over conventional fixed-parameter and SIMC-PI controllers,respectively,under±10 K periodic and step thermal disturbances.Monte Carlo robustness tests reveal smaller fluctuation ranges of IAE,settling time,and overshoot under±5% parameter perturbations.This methodology establishes a new paradigm for millikelvin-level thermal control in space optical payloads.展开更多
Given the growing importance of social media in digital rural development, this study systematically investigated the influence pathways of social media use among rural women in China, drawing on the Technology Accept...Given the growing importance of social media in digital rural development, this study systematically investigated the influence pathways of social media use among rural women in China, drawing on the Technology Acceptance Model(TAM). Employing quantitative research methods, the study conducted empirical tests based on 367 valid questionnaires using Partial Least Squares Structural Equation Modeling(PLS-SEM) via SmartPLS 4.0 software. Results indicate that significant associations exist between perceived ease of use, perceived usefulness, attitudes toward use, behavioral intention, and actual usage behavior. Specifically, the study finds that rural women's perceived ease of use of social media has a significant and positive influence on both perceived usefulness and attitudes toward use. Perceived usefulness further significantly promotes attitudes toward use and behavioral intention. Moreover, positive attitudes toward usage and strong behavioral intentions were effectively converted into actual social media usage behaviors. This study not only validates the applicability and explanatory power of the TAM model in understanding the digital behavior of Chinese rural women but also provides quantitative evidence for how social media enhances their “digital visibility.” These findings offer practical insights for governments and platform providers to optimize user experiences and strengthen digital skills training. Despite its limitations, including a cross-sectional design and a regional sample, this research holds significant theoretical and practical implications.展开更多
Recently,the zeroing neural network(ZNN)has demonstrated remarkable effectiveness in tackling time-varying problems,delivering robust performance across both noise-free and noisy environments.However,existing ZNN mode...Recently,the zeroing neural network(ZNN)has demonstrated remarkable effectiveness in tackling time-varying problems,delivering robust performance across both noise-free and noisy environments.However,existing ZNN models are limited in their ability to actively suppress noise,which constrains their robustness and precision in solving time-varying problems.This paper introduces a novel active noise rejection ZNN(ANR-ZNN)design that enhances noise suppression by integrating computational error dynamics and harmonic behaviour.Through rigorous theoretical analysis,we demonstrate that the proposed ANR-ZNN maintains robust convergence in computational error performance under environmental noise.As a case study,the ANR-ZNN model is specifically applied to time-varying matrix inversion.Comprehensive computer simulations and robotic experiments further validate the ANR-ZNN's effectiveness,emphasising the proposed design's superiority and potential for solving time-varying problems.展开更多
Post-kidney transplant rejection is a critical factor influencing transplant success rates and the survival of transplanted organs.With the rapid advancement of artificial intelligence technologies,machine learning(ML...Post-kidney transplant rejection is a critical factor influencing transplant success rates and the survival of transplanted organs.With the rapid advancement of artificial intelligence technologies,machine learning(ML)has emerged as a powerful data analysis tool,widely applied in the prediction,diagnosis,and mechanistic study of kidney transplant rejection.This mini-review systematically summarizes the recent applications of ML techniques in post-kidney transplant rejection,covering areas such as the construction of predictive models,identification of biomarkers,analysis of pathological images,assessment of immune cell infiltration,and formulation of personalized treatment strategies.By integrating multi-omics data and clinical information,ML has significantly enhanced the accuracy of early rejection diagnosis and the capability for prognostic evaluation,driving the development of precision medicine in the field of kidney transplantation.Furthermore,this article discusses the challenges faced in existing research and potential future directions,providing a theoretical basis and technical references for related studies.展开更多
In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both e...In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both external disturbances and internal dynamic uncertainties,as well as parameter deviations arising from parameter uncertainty,while maintaining a relatively small number of adjustable parameters.Furthermore,it addresses the limitation that conventional active disturbance rejection control methods cannot be rigorously analyzed for stability.The total disturbance of unmanned helicopter is estimated and compensated by designed LADRC.The introduction of adaptive control realizes online parameter tuning,which eliminates parameter deviation and further improves control precision.Moreover,it also provides a novel idea to prove the stability of controller,so that it can be analyzed by Lyapunov function.Finally,the anti-disturbance performance and effectiveness of proposed method are verified by numerical simulation.展开更多
The evaluation of the immunosuppression state in liver transplanted patients is crucial for a correct posttransplant management and a major step towards the personalisation of the immunosuppressive therapy. However, c...The evaluation of the immunosuppression state in liver transplanted patients is crucial for a correct posttransplant management and a major step towards the personalisation of the immunosuppressive therapy. However, current immunological monitoring after liver transplantation relies mainly on clinical judgment and on immunosuppressive drug levels, without a proper assessment of the real suppression of theimmunological system. Various markers have been studied in an attempt to identify a specific indicator of graft rejection and graft acceptance after liver transplantation. Considering acute rejection, the most studied markers are pro-inflammatory and immunoregulatory cytokines and other proteins related to inflammation. However there is considerable overlap with other conditions, and only few of them have been validated. Standard liver tests cannot be used as markers of graft rejection due to their low sensitivity and specificity and the weak correlation with the severity of histopathological findings. Several studies have been performed to identify biomarkers of tolerance in liver transplanted patients. Most of them are based on the analysis of peripheral blood samples and on the use of transcriptional profiling techniques. Amongst these, NK cell-related molecules seem to be the most valid marker of graft acceptance, whereas the role CD4+CD25+Foxp3+ T cells has still to be properly defined.展开更多
Metropolis-Hastings algorithms are slowed down by the computation of complex target distributions. To solve this problem, one can use the delayed acceptance Metropolis-Hastings algorithm (MHDA) of Christen and Fox (20...Metropolis-Hastings algorithms are slowed down by the computation of complex target distributions. To solve this problem, one can use the delayed acceptance Metropolis-Hastings algorithm (MHDA) of Christen and Fox (2005). However, the acceptance rate of a proposed value will always be less than in the standard Metropolis-Hastings. We can fix this problem by using the Metropolis-Hastings algorithm with delayed rejection (MHDR) proposed by Tierney and Mira (1999). In this paper, we combine the ideas of MHDA and MHDR to propose a new MH algorithm, named the Metropolis-Hastings algorithm with delayed acceptance and rejection (MHDAR). The new algorithm reduces the computational cost by division of the prior or likelihood functions and increase the acceptance probability by delay rejection of the second stage. We illustrate those accelerating features by a realistic example.展开更多
The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses ...The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.展开更多
Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical...Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.展开更多
1 I Like Me follows a cheerful and confident little pig who celebrates everything about herself.From her curly tail to her big feet,she loves every part of herself.In the book,I remember that the pig enthusiastically ...1 I Like Me follows a cheerful and confident little pig who celebrates everything about herself.From her curly tail to her big feet,she loves every part of herself.In the book,I remember that the pig enthusiastically declares that no matter what she does,even if she's making mistakes,being silly or being a clumsy rookie(笨拙的新手)of trying something new,she will always like herself.展开更多
The study of Mecanum mobile robots typically assumes motion on planar surfaces,while the challenges posed by inclined terrains remain largely unexplored,leaving a significant gap in control applications for such scena...The study of Mecanum mobile robots typically assumes motion on planar surfaces,while the challenges posed by inclined terrains remain largely unexplored,leaving a significant gap in control applications for such scenarios.In this context,two critical issues emerge:the gravitational pull caused by adding a potential energy term in the robot dynamics,which drives the vehicle downhill,and several positioning errors due to vibrations and slippage of the Mecanum wheel.To address these challenges,this work presents an Active Disturbance Rejection Control(ADRC)-based framework designed to enable accurate tracking on inclined surfaces,despite the compounded effects of gravitational forces and slippage.Unlike conventional controllers,the proposed method requires minimal model knowledge while actively compensates for unknown dynamics and external disturbances in real time.A complete theoretical formulation is provided,supported by numerical simulations and comprehensive experimental validation.Results demonstrate that the ADRC structure significantly outperforms not only the traditional proportional-integral-derivative(PID)control but also a robust variant of PID combined with a Quasi-Sliding Mode control(PID-QSMC)strategy,achieving superior tracking.Notably,this study offers an important experimental validation of ADRC for Mecanum-wheeled robots operating on inclined surfaces.It contributes a practical and scalable solution to extend their operational capabilities beyond flat environments.展开更多
Antibody-mediated rejection(AMR)represents a major challenge in kidney transplantation,significantly contributing to tissue injury and graft failure.AMR is primarily driven by donor-specific alloantibodies(DSAs),which...Antibody-mediated rejection(AMR)represents a major challenge in kidney transplantation,significantly contributing to tissue injury and graft failure.AMR is primarily driven by donor-specific alloantibodies(DSAs),which recognize and bind to specific target antigens present within the transplanted kidney tissue.Upon binding,these DSAs commonly initiate activation of the complement system within the graft.The activation of the complement cascade sets off a powerful inflammatory response characterized by the recruitment and activation of immune cells,endothelial damage,and subsequent tissue injury.This inflammation underlies many clinical and histological manifestations of AMR,making complement activation a critical player in the disease process.Advancements in our understanding of how complement pathways contribute to kidney graft injury have opened new avenues for therapeutic intervention.Recent research has facilitated the development and application of novel therapies specifically designed to inhibit complement activation.Such targeted complement-inhibitory strategies have shown promise in improving graft outcomes by inhibiting complement-mediated damage and extending graft survival.This review comprehensively discusses the critical role of complement activation in inducing kidney graft injury with a focus on its role in AMR.By elucidating the detailed mechanisms and contributions of complement pathways,the review seeks to enhance the understanding necessary for developing targeted therapeutic interventions to prevent or treat AMR effectively.展开更多
Organ transplantation has long been recognized as an effective treatment for endstage organ failure,metabolic diseases,and malignant tumors.However,graft rejection caused by major histocompatibility complex mismatch r...Organ transplantation has long been recognized as an effective treatment for endstage organ failure,metabolic diseases,and malignant tumors.However,graft rejection caused by major histocompatibility complex mismatch remains a significant challenge.While modern immunosuppressants have made significant strides in reducing the incidence and risk of rejection,they have not been able to eliminate it completely.The intricate mechanisms underlying transplant rejection have been the subject of intense investigation by transplant immunologists.Among these factors,autophagy has emerged as a key player.Autophagy is an evolutionarily conserved mechanism in eukaryotic cells that mediates autophagocytosis and cellular protection.This process is regulated by autophagy-related genes and their encoded protein families,which maintain the material and energetic balance within cells.Additionally,autophagy has been reported to play crucial roles in the development,maturation,differentiation,and responses of immune cells.In the complex immune environment following transplantation,the role and mechanisms of autophagy are gradually being revealed.In this review,we aim to explore the current understanding of the role of autophagy in solid organ rejection after transplantation.Furthermore,we delve into the therapeutic advancements achieved by targeting autophagy involved in the rejection process.展开更多
BACKGROUND The Luminex platform,where beads are coated with single human leukocyte antigens(HLA),detects HLA antibodies with higher sensitivity and specificity compared to complement-dependent cytotoxicity(CDC)assay a...BACKGROUND The Luminex platform,where beads are coated with single human leukocyte antigens(HLA),detects HLA antibodies with higher sensitivity and specificity compared to complement-dependent cytotoxicity(CDC)assay and flow crossmatch(FCXM).The clinical significance of donor-specific antibodies(DSAs)detected by this method is still under investigation.AIM To report the impact of low-level pretransplant DSAs detected by the Luminex platform on the rates of acute rejection(AR),allograft function,and long-term graft survival.METHODS This retrospective study was conducted at the Immunology Department of Sindh Institute of Urology and Transplantation,Karachi,Pakistan between January 2013 and December 2022.During this period 2714 patients were transplanted.Out of these patients 78(2.9%)patients had low-level DSAs detected by the Luminex flow beads method and were negative by CDC and FCXM with their donors.All recipients received ABO-compatible live-related kidney transplants.All patients had a minimum follow-up of 1 year.Graft rejection rates,graft function,and patient and graft survival were analyzed.The estimated glomerular filtration rate was calculated by the full CKD-EPI formula.RESULTS The mean age of all recipients was 29.57±10.11 years and 34.53±9.09 years for the donors.In 48(61.5%)patients,the cause of end-stage kidney disease was unknown.DSA against HLA class I was detected in 36(46.1%)patients,class II in 35(44.8%)patients,and both class I and II in 7(8.9%)patients.AR episodes were encountered in 8(10.3%)cases.Seven(87.5%)had T cell mediated rejection(type IA)and one acute antibody-mediated rejection.Antibody status was re-evaluated at the time of biopsy-proven ARs.Five(62.5%)patients lost their DSAs,while three(37.5%)had persistent DSAs.The mean estimated glomerular filtration rate at 1 year was 80.56±27.48 mL/min/1.73 m2 and at the last follow-up 73.41±28.80 mL/min/1.73 m2.The 1-year and 10-year patient and graft survival rates were 99%and 79%and 95%and 75%,respectively.During the follow-up period,10(12.8%)patients died,8 patients had a functioning graft,and 2 patients had failed grafts.Eight patients died due to cardiopulmonary arrest,and two died due to sepsis with failed grafts.CONCLUSION Patients with pretransplant low-level DSAs on Luminex without CDC and FCXM reactivity had good allograft outcomes at 1 year and 10 years as long as they are induced with biological agents and given potent maintenance immunosuppressants.展开更多
The output regulation approach has effectively addressed the speed tracking and disturbance rejection problem of permanent magnet synchronous motor(PMSM).Although accurate speed tracking under time-varying load torque...The output regulation approach has effectively addressed the speed tracking and disturbance rejection problem of permanent magnet synchronous motor(PMSM).Although accurate speed tracking under time-varying load torque disturbance has been achieved,the number of disturbance frequencies should be known.In this paper,an adaptive observer-based error feedback control method is proposed,which can solve the speed tracking control problem of PMSM subject to completely unknown multi-frequency sinusoidal load torque disturbance,requiring only the upper bound of the number of disturbance frequencies.The design steps of this method can be divided into the following three steps.In step one,a filtered transformation is applied to convert the observer canonical form of the error system and the transformed exosystem into an adaptive observer form.In step two,an adaptive observer is designed to estimate the unknown parameters of the exosystem and states of the adaptive observer form.In step three,an adaptive observer-based error feedback controller is designed to solve this control problem.The effectiveness of the proposed method is demonstrated by experimental results.展开更多
The integration of Learning Management Systems(LMSs)into educational settings is becoming increasingly common,especially in the digital field.Understanding the factors influencing the acceptance and effective use of L...The integration of Learning Management Systems(LMSs)into educational settings is becoming increasingly common,especially in the digital field.Understanding the factors influencing the acceptance and effective use of LMS is essential to ensure successful implementation.The Technology Acceptance Model(TAM)has been widely used to check user acceptance of various technologies,including LMS.This study conducted a systematic literature review(SLR)to analyze existing research on the application of TAM in the context of LMS.A comprehensive search of the academic database was conducted to identify relevant studies published in 2010-2025.The review synthesizes findings related to the core constructs of TAM—Perceived Usability,Perceived Ease of Use,Behavioral Intent,and Actual Use—as well as extended factors such as system quality,self-efficacy,and social influence.The results reveal circumstantial evidence supporting the predictive power of TAM in LMS adoption,while also highlighting emerging trends and gaps in the literature.This review contributes to a deeper understanding of user acceptance in a digital learning environment and provides recommendations for future research and practical LMS implementation strategies.展开更多
Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the...Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the acceptance process.The findings indicate that primary challenges include low seedling survival rates,incongruities between tree species selection and site conditions,structural deficiencies within the forest belts,insufficient post-planting maintenance and management,and irregularities in documentation.To address these problems,the study proposes targeted countermeasures,such as optimizing tree species selection,enhancing supervision of planting techniques,and establishing a long-term ecological compensation-based management model.These recommendations are framed within the contexts of scientific planning,precise implementation,strengthened oversight,and innovative management mechanisms.The research aims to improve the construction quality and long-term fire prevention efficacy of biological firebreak forest belts,thereby providing practical guidance for analogous firebreak forest belt construction and acceptance initiatives in forest areas of South China.展开更多
文摘This study investigates prescribed-time position tracking control for electromagnetic satellite formations subject to model uncertainties and external disturbances.Using the Clohessy-Wiltshire equations as the relative motion dynamics model,a prescribed time output feedback control strategy is proposed.A prescribed-time extended state observer is designed to estimate the relative velocity and external disturbances.The disturbance estimates are then used as the feedforward component of the controller.Building on this framework,a novel prescribed-time active disturbance rejection control strategy for position tracking is developed via a backstepping control design.The convergence of the extended state observer and the stability of the closed-loop system are rigorously analyzed using Lyapunov stability theory.Numerical simulations are performed to validate the effectiveness of the proposed controller.
文摘Antibody-mediated rejection(AMR)remains a leading cause of kidney allograft failure,posing significant clinical and economic challenges.Donor-specific antibodies against human leukocyte antigens or non-human leukocyte antigens are critical risk factors for AMR and graft loss.The diagnostic criteria and classification of AMR have evolved considerably over the past three decades,driven largely by the Banff classification.The latest Banff 2022 classification introduced two additional subcategories of“microvascular inflammation,donor-specific antibody-negative,C4d-negative”and“probable AMR”.Traditionally,graft monitoring has relied on non-specific markers such as serum creatinine and proteinuria,and the invasive biopsies.Noninvasive tools using blood and urine biomarkers,including cellular assays and molecular profiling,are increasingly being investigated.Technologies such as the Molecular Microscope Diagnostic System show promise,with studies reporting 80%sensitivity and 90%specificity in detecting AMR.Treatment of AMR remains inconsistent.Recent advances,including CD38 antibodies,have demonstrated up to 60%efficacy in reversing AMR,while complement inhibition shows potential in severe early cases.Ongoing clinical trials evaluating high-dose intravenous immunoglobulin,efgartigimod,fostamatinib,and other novel therapies aim to expand treatment options.These developments highlight the need for well-designed clinical trials to validate biomarkers and therapies and to improve long-term outcomes for kidney transplant recipients.
基金supported by the National Natural Science Foundation of China(32171069).
文摘Objectives:Loneliness among left-behind adolescents is the most frequently reported emotional problem because of parental neglect.The present study explored the relationship between maternal absence and adolescent loneliness as well as its mechanisms.Methods:The study included 305 participants(Meanage=15.99±0.81,48.9%females)in southeast China,and constructed a chain mediation model to test the roles of rejection sensitivity and friendship quality.Parent absence types,rejection sensitivity,friendship quality,and adolescent loneliness were all assessed with questionnaires.Results:The results showed that adolescents with a mother absent(both-parent absent,mother-only absent)experienced higher levels of loneliness than those with a mother not absent(father-only absent,non-parent absent)(β=0.3137,95%CI[0.0849,0.5425],p<0.01).Besides,the mediating roles of rejection sensitivity(β=0.0344,95%CI[0.0020,0.0808])and friendship quality(β=0.1198,95%CI[0.0049,0.2428])and their chain mediating role were found significant between maternal absence and loneliness(β=0.0245,95%CI[0.0015,0.0575]).Conclusions:These findings have revealed the significant impact of maternal absence on adolescent loneliness and provide important practical implications for educators to reduce adolescent loneliness.
基金The National Key R&D Program of China(No.2022YFB3902902)the National Natural Science Foundation of China(No.52276003).
文摘Spaceborne optomechanical systems face the dual challenges of extreme thermal disturbances and millikelvin-level temperature control precision during orbital operations,demanding robust control strategies.To address the performance limitations of conventional fixed-parameter active disturbance rejection control(ADRC)under complex operating conditions,this work proposes a Qlearning-enhanced adaptive ADRC framework.A thermal-transfer model incorporating multisource disturbances(solar radiation,structural conduction,and contact thermal resistance)is established,coupled with a reinforcement learning-driven parameter optimization mechanism.The ε-greedy policy dynamically adjusts observer bandwidth(ω_(o)∈[0.01,0.2])and controller bandwidth(ω_(c)∈[0.01,0.1])to enable real-time estimation and compensation of total disturbances.Simulation results demonstrate significant improvements over fixed-parameter ADRC and a self-tuning internal model control proportional-integral(SIMC-PI)controller:31.3% and 15.4% reduction in settling time during setpoint responses,respectively;21.8% lower integral absolute error(IAE)than the fixed-parameter ADRC during setpoint step responses;12.7% and 52.5% enhancement in control precision over conventional fixed-parameter and SIMC-PI controllers,respectively,under±10 K periodic and step thermal disturbances.Monte Carlo robustness tests reveal smaller fluctuation ranges of IAE,settling time,and overshoot under±5% parameter perturbations.This methodology establishes a new paradigm for millikelvin-level thermal control in space optical payloads.
文摘Given the growing importance of social media in digital rural development, this study systematically investigated the influence pathways of social media use among rural women in China, drawing on the Technology Acceptance Model(TAM). Employing quantitative research methods, the study conducted empirical tests based on 367 valid questionnaires using Partial Least Squares Structural Equation Modeling(PLS-SEM) via SmartPLS 4.0 software. Results indicate that significant associations exist between perceived ease of use, perceived usefulness, attitudes toward use, behavioral intention, and actual usage behavior. Specifically, the study finds that rural women's perceived ease of use of social media has a significant and positive influence on both perceived usefulness and attitudes toward use. Perceived usefulness further significantly promotes attitudes toward use and behavioral intention. Moreover, positive attitudes toward usage and strong behavioral intentions were effectively converted into actual social media usage behaviors. This study not only validates the applicability and explanatory power of the TAM model in understanding the digital behavior of Chinese rural women but also provides quantitative evidence for how social media enhances their “digital visibility.” These findings offer practical insights for governments and platform providers to optimize user experiences and strengthen digital skills training. Despite its limitations, including a cross-sectional design and a regional sample, this research holds significant theoretical and practical implications.
基金supported by the National Science and Technology Major Project(2022ZD0119901)the National Natural Science Foundation of China under Grant(U2141234,62463004 and U24A20260)+1 种基金the Hainan Province Science and Technology Special Fund(ZDYF2024GXJS003)the Scientific Research Fund of Hainan University(KYQD(ZR)23025).
文摘Recently,the zeroing neural network(ZNN)has demonstrated remarkable effectiveness in tackling time-varying problems,delivering robust performance across both noise-free and noisy environments.However,existing ZNN models are limited in their ability to actively suppress noise,which constrains their robustness and precision in solving time-varying problems.This paper introduces a novel active noise rejection ZNN(ANR-ZNN)design that enhances noise suppression by integrating computational error dynamics and harmonic behaviour.Through rigorous theoretical analysis,we demonstrate that the proposed ANR-ZNN maintains robust convergence in computational error performance under environmental noise.As a case study,the ANR-ZNN model is specifically applied to time-varying matrix inversion.Comprehensive computer simulations and robotic experiments further validate the ANR-ZNN's effectiveness,emphasising the proposed design's superiority and potential for solving time-varying problems.
文摘Post-kidney transplant rejection is a critical factor influencing transplant success rates and the survival of transplanted organs.With the rapid advancement of artificial intelligence technologies,machine learning(ML)has emerged as a powerful data analysis tool,widely applied in the prediction,diagnosis,and mechanistic study of kidney transplant rejection.This mini-review systematically summarizes the recent applications of ML techniques in post-kidney transplant rejection,covering areas such as the construction of predictive models,identification of biomarkers,analysis of pathological images,assessment of immune cell infiltration,and formulation of personalized treatment strategies.By integrating multi-omics data and clinical information,ML has significantly enhanced the accuracy of early rejection diagnosis and the capability for prognostic evaluation,driving the development of precision medicine in the field of kidney transplantation.Furthermore,this article discusses the challenges faced in existing research and potential future directions,providing a theoretical basis and technical references for related studies.
基金supported by the Aeronautical Science Foundation of China(Nos.20220058052002,20240007052001)。
文摘In this paper,a practical method named linear active disturbance rejection control(LADRC)with adaptive tuning is proposed for attitude control of small-scale unmanned helicopter.The proposed method accounts for both external disturbances and internal dynamic uncertainties,as well as parameter deviations arising from parameter uncertainty,while maintaining a relatively small number of adjustable parameters.Furthermore,it addresses the limitation that conventional active disturbance rejection control methods cannot be rigorously analyzed for stability.The total disturbance of unmanned helicopter is estimated and compensated by designed LADRC.The introduction of adaptive control realizes online parameter tuning,which eliminates parameter deviation and further improves control precision.Moreover,it also provides a novel idea to prove the stability of controller,so that it can be analyzed by Lyapunov function.Finally,the anti-disturbance performance and effectiveness of proposed method are verified by numerical simulation.
文摘The evaluation of the immunosuppression state in liver transplanted patients is crucial for a correct posttransplant management and a major step towards the personalisation of the immunosuppressive therapy. However, current immunological monitoring after liver transplantation relies mainly on clinical judgment and on immunosuppressive drug levels, without a proper assessment of the real suppression of theimmunological system. Various markers have been studied in an attempt to identify a specific indicator of graft rejection and graft acceptance after liver transplantation. Considering acute rejection, the most studied markers are pro-inflammatory and immunoregulatory cytokines and other proteins related to inflammation. However there is considerable overlap with other conditions, and only few of them have been validated. Standard liver tests cannot be used as markers of graft rejection due to their low sensitivity and specificity and the weak correlation with the severity of histopathological findings. Several studies have been performed to identify biomarkers of tolerance in liver transplanted patients. Most of them are based on the analysis of peripheral blood samples and on the use of transcriptional profiling techniques. Amongst these, NK cell-related molecules seem to be the most valid marker of graft acceptance, whereas the role CD4+CD25+Foxp3+ T cells has still to be properly defined.
文摘Metropolis-Hastings algorithms are slowed down by the computation of complex target distributions. To solve this problem, one can use the delayed acceptance Metropolis-Hastings algorithm (MHDA) of Christen and Fox (2005). However, the acceptance rate of a proposed value will always be less than in the standard Metropolis-Hastings. We can fix this problem by using the Metropolis-Hastings algorithm with delayed rejection (MHDR) proposed by Tierney and Mira (1999). In this paper, we combine the ideas of MHDA and MHDR to propose a new MH algorithm, named the Metropolis-Hastings algorithm with delayed acceptance and rejection (MHDAR). The new algorithm reduces the computational cost by division of the prior or likelihood functions and increase the acceptance probability by delay rejection of the second stage. We illustrate those accelerating features by a realistic example.
基金supported by the National Key R&D Program of China(No.2021YFB2011300)the Special Funds Project for the Transformation of Scientific and Technological Achievements of Jiangsu Province,China(No.BA2023039)+1 种基金the National Natural Science Foundation of China(No.52075262)the Fundamental Research Funds for the Central Universities,China(No.30922010706).
文摘The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.
基金supported by the National Natural Science Foundation of China(Nos.52177059 and 52407064).
文摘Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.
文摘1 I Like Me follows a cheerful and confident little pig who celebrates everything about herself.From her curly tail to her big feet,she loves every part of herself.In the book,I remember that the pig enthusiastically declares that no matter what she does,even if she's making mistakes,being silly or being a clumsy rookie(笨拙的新手)of trying something new,she will always like herself.
文摘The study of Mecanum mobile robots typically assumes motion on planar surfaces,while the challenges posed by inclined terrains remain largely unexplored,leaving a significant gap in control applications for such scenarios.In this context,two critical issues emerge:the gravitational pull caused by adding a potential energy term in the robot dynamics,which drives the vehicle downhill,and several positioning errors due to vibrations and slippage of the Mecanum wheel.To address these challenges,this work presents an Active Disturbance Rejection Control(ADRC)-based framework designed to enable accurate tracking on inclined surfaces,despite the compounded effects of gravitational forces and slippage.Unlike conventional controllers,the proposed method requires minimal model knowledge while actively compensates for unknown dynamics and external disturbances in real time.A complete theoretical formulation is provided,supported by numerical simulations and comprehensive experimental validation.Results demonstrate that the ADRC structure significantly outperforms not only the traditional proportional-integral-derivative(PID)control but also a robust variant of PID combined with a Quasi-Sliding Mode control(PID-QSMC)strategy,achieving superior tracking.Notably,this study offers an important experimental validation of ADRC for Mecanum-wheeled robots operating on inclined surfaces.It contributes a practical and scalable solution to extend their operational capabilities beyond flat environments.
文摘Antibody-mediated rejection(AMR)represents a major challenge in kidney transplantation,significantly contributing to tissue injury and graft failure.AMR is primarily driven by donor-specific alloantibodies(DSAs),which recognize and bind to specific target antigens present within the transplanted kidney tissue.Upon binding,these DSAs commonly initiate activation of the complement system within the graft.The activation of the complement cascade sets off a powerful inflammatory response characterized by the recruitment and activation of immune cells,endothelial damage,and subsequent tissue injury.This inflammation underlies many clinical and histological manifestations of AMR,making complement activation a critical player in the disease process.Advancements in our understanding of how complement pathways contribute to kidney graft injury have opened new avenues for therapeutic intervention.Recent research has facilitated the development and application of novel therapies specifically designed to inhibit complement activation.Such targeted complement-inhibitory strategies have shown promise in improving graft outcomes by inhibiting complement-mediated damage and extending graft survival.This review comprehensively discusses the critical role of complement activation in inducing kidney graft injury with a focus on its role in AMR.By elucidating the detailed mechanisms and contributions of complement pathways,the review seeks to enhance the understanding necessary for developing targeted therapeutic interventions to prevent or treat AMR effectively.
基金Supported by the National Natural Science Foundation of China,No.82100691China Postdoctoral Science Foundation,No.2021M693631.
文摘Organ transplantation has long been recognized as an effective treatment for endstage organ failure,metabolic diseases,and malignant tumors.However,graft rejection caused by major histocompatibility complex mismatch remains a significant challenge.While modern immunosuppressants have made significant strides in reducing the incidence and risk of rejection,they have not been able to eliminate it completely.The intricate mechanisms underlying transplant rejection have been the subject of intense investigation by transplant immunologists.Among these factors,autophagy has emerged as a key player.Autophagy is an evolutionarily conserved mechanism in eukaryotic cells that mediates autophagocytosis and cellular protection.This process is regulated by autophagy-related genes and their encoded protein families,which maintain the material and energetic balance within cells.Additionally,autophagy has been reported to play crucial roles in the development,maturation,differentiation,and responses of immune cells.In the complex immune environment following transplantation,the role and mechanisms of autophagy are gradually being revealed.In this review,we aim to explore the current understanding of the role of autophagy in solid organ rejection after transplantation.Furthermore,we delve into the therapeutic advancements achieved by targeting autophagy involved in the rejection process.
文摘BACKGROUND The Luminex platform,where beads are coated with single human leukocyte antigens(HLA),detects HLA antibodies with higher sensitivity and specificity compared to complement-dependent cytotoxicity(CDC)assay and flow crossmatch(FCXM).The clinical significance of donor-specific antibodies(DSAs)detected by this method is still under investigation.AIM To report the impact of low-level pretransplant DSAs detected by the Luminex platform on the rates of acute rejection(AR),allograft function,and long-term graft survival.METHODS This retrospective study was conducted at the Immunology Department of Sindh Institute of Urology and Transplantation,Karachi,Pakistan between January 2013 and December 2022.During this period 2714 patients were transplanted.Out of these patients 78(2.9%)patients had low-level DSAs detected by the Luminex flow beads method and were negative by CDC and FCXM with their donors.All recipients received ABO-compatible live-related kidney transplants.All patients had a minimum follow-up of 1 year.Graft rejection rates,graft function,and patient and graft survival were analyzed.The estimated glomerular filtration rate was calculated by the full CKD-EPI formula.RESULTS The mean age of all recipients was 29.57±10.11 years and 34.53±9.09 years for the donors.In 48(61.5%)patients,the cause of end-stage kidney disease was unknown.DSA against HLA class I was detected in 36(46.1%)patients,class II in 35(44.8%)patients,and both class I and II in 7(8.9%)patients.AR episodes were encountered in 8(10.3%)cases.Seven(87.5%)had T cell mediated rejection(type IA)and one acute antibody-mediated rejection.Antibody status was re-evaluated at the time of biopsy-proven ARs.Five(62.5%)patients lost their DSAs,while three(37.5%)had persistent DSAs.The mean estimated glomerular filtration rate at 1 year was 80.56±27.48 mL/min/1.73 m2 and at the last follow-up 73.41±28.80 mL/min/1.73 m2.The 1-year and 10-year patient and graft survival rates were 99%and 79%and 95%and 75%,respectively.During the follow-up period,10(12.8%)patients died,8 patients had a functioning graft,and 2 patients had failed grafts.Eight patients died due to cardiopulmonary arrest,and two died due to sepsis with failed grafts.CONCLUSION Patients with pretransplant low-level DSAs on Luminex without CDC and FCXM reactivity had good allograft outcomes at 1 year and 10 years as long as they are induced with biological agents and given potent maintenance immunosuppressants.
基金supported by the National Natural Science Foundation of China(Nos.62273127 and 62073217)the Dreams Foundation of Jianghuai Advance Technology Center(No.2023-ZM01J006)the Anhui Provincial Key Research and Development Project(No.2022a05020025).
文摘The output regulation approach has effectively addressed the speed tracking and disturbance rejection problem of permanent magnet synchronous motor(PMSM).Although accurate speed tracking under time-varying load torque disturbance has been achieved,the number of disturbance frequencies should be known.In this paper,an adaptive observer-based error feedback control method is proposed,which can solve the speed tracking control problem of PMSM subject to completely unknown multi-frequency sinusoidal load torque disturbance,requiring only the upper bound of the number of disturbance frequencies.The design steps of this method can be divided into the following three steps.In step one,a filtered transformation is applied to convert the observer canonical form of the error system and the transformed exosystem into an adaptive observer form.In step two,an adaptive observer is designed to estimate the unknown parameters of the exosystem and states of the adaptive observer form.In step three,an adaptive observer-based error feedback controller is designed to solve this control problem.The effectiveness of the proposed method is demonstrated by experimental results.
文摘The integration of Learning Management Systems(LMSs)into educational settings is becoming increasingly common,especially in the digital field.Understanding the factors influencing the acceptance and effective use of LMS is essential to ensure successful implementation.The Technology Acceptance Model(TAM)has been widely used to check user acceptance of various technologies,including LMS.This study conducted a systematic literature review(SLR)to analyze existing research on the application of TAM in the context of LMS.A comprehensive search of the academic database was conducted to identify relevant studies published in 2010-2025.The review synthesizes findings related to the core constructs of TAM—Perceived Usability,Perceived Ease of Use,Behavioral Intent,and Actual Use—as well as extended factors such as system quality,self-efficacy,and social influence.The results reveal circumstantial evidence supporting the predictive power of TAM in LMS adoption,while also highlighting emerging trends and gaps in the literature.This review contributes to a deeper understanding of user acceptance in a digital learning environment and provides recommendations for future research and practical LMS implementation strategies.
文摘Based on a comprehensive inspection and acceptance evaluation of the biological firebreak forest belt construction project in Huiyang Forest Area,this study systematically analyzes common issues encountered during the acceptance process.The findings indicate that primary challenges include low seedling survival rates,incongruities between tree species selection and site conditions,structural deficiencies within the forest belts,insufficient post-planting maintenance and management,and irregularities in documentation.To address these problems,the study proposes targeted countermeasures,such as optimizing tree species selection,enhancing supervision of planting techniques,and establishing a long-term ecological compensation-based management model.These recommendations are framed within the contexts of scientific planning,precise implementation,strengthened oversight,and innovative management mechanisms.The research aims to improve the construction quality and long-term fire prevention efficacy of biological firebreak forest belts,thereby providing practical guidance for analogous firebreak forest belt construction and acceptance initiatives in forest areas of South China.
