The current research mainly focuses on the flow control for the two-stage proportional valve with hydraulic position feedback which is named as Valvistor valve.Essentially,the Valvistor valve is a proportional throttl...The current research mainly focuses on the flow control for the two-stage proportional valve with hydraulic position feedback which is named as Valvistor valve.Essentially,the Valvistor valve is a proportional throttle valve and the flow fluctuates with the change of load pressure.The flow fluctuation severely restricts the application of the Valvistor valve.In this paper,a novel flow control method the Valvistor valve is provided to suppress the flow fluctuation and develop a high performance proportional flow valve.The mathematical model of this valve is established and linearized.Fuzzy proportional-integral-derivative(PID)controller is adopted in the closed-loop flow control system.The feedback is obtained by the flow inference with back-propagation neural network(BPNN)based on the spool displacement in the pilot stage and the pressure differential across the main orifice.The results show that inference with BPNN can obtain the flow data fast and accurately.With the flow control method,the flow can keep at the set point when the pressure differential across the main orifice changes.The flow control method is effective and the Valvistor valve changes from proportional throttle valve to proportional flow valve.For the developed proportional flow valve,the settling time of the flow is very short when the load pressure changes abruptly.The performances of hysteresis,linearity and bandwidth are in a high range.The linear mathematical model can be verified and the assumptions in the system modeling is reasonable.展开更多
Background:U2AF homology motif kinase 1(UHMK1)has been associated with RNA processing and protein phosphorylation,thereby influencing tumor progression.The study aimed to explore its regulatory mechanisms and biologic...Background:U2AF homology motif kinase 1(UHMK1)has been associated with RNA processing and protein phosphorylation,thereby influencing tumor progression.The study aimed to explore its regulatory mechanisms and biological functions in human prostate cancer(PCa).Methods:In this study,we systematically evaluated the expression and prognostic significance of UHMK1 in public databases,followed by validation through immunohis-tochemistry(IHC)in PCa specimens.Both gain-of-function and loss-of-function experiments were conducted to elucidate the role of UHMK1 in vitro and in vivo.Additionally,a series of molecular and biochemical assays were performed to investigate the regulatory mechanisms underlying UHMK1 activity.Results:Our findings revealed that UHMK1 expression was significantly upregulated in PCa tissues and correlated with poor patient prognosis,as demonstrated by analysis of public datasets and confirmed by immunohistochemical staining.Functional studies showed that UHMK1 depletion suppressed tumor cell proliferation and metastasis,while its overexpression promoted these processes.Mechanistically,we identified that UHMK1 phosphorylates nuclear receptor coactivator 3(NCOA3),which subsequently activates activating transcription factor 4(ATF4)to upregulate methylenetetrahydrofolate dehy-drogenase 2(MTHFD2)transcription.Interestingly,MTHFD2 was found to reciprocally enhance UHMK1 expression,establishing a positive feedback loop.Conclusions:In conclusion,our data suggest that the UHMK1-MTHFD2 axis forms a positive feedback loop that drives PCa progression.Targeting this loop represents a promising therapeutic strategy for restraining prostate cancer development and progression.展开更多
Phospholipase D(PLD)lipid-signaling enzyme superfamily has been widely implicated in various human malignancies,but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma(NPC).Here,we analyze the...Phospholipase D(PLD)lipid-signaling enzyme superfamily has been widely implicated in various human malignancies,but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma(NPC).Here,we analyze the expressions of 6 PLD family members between 87 NPC and 10 control samples through transcriptome analysis.Our findings reveal a notable upregulation of PLD1 in both NPC tumors and cell lines,correlating with worse disease-free and overall survival in NPC patients.Functional assays further elucidate the oncogenic role of PLD1,demonstrating its pivotal promotion of critical tumorigenic processes such as cellproliferation and migration in vitro,as well as tumor growth in vivo.Notably,our study uncovers a positive feedback loop between PLD1 and the NF-κB signaling pathway to render NPC progression.Specifically,PLD1 enhances NF-kB activity by facilitating the phosphorylation and nuclear translocation of RELA,which in turn binds to the promoter of PLD1,augmenting its expression.Moreover,RELA over-expression markedly rescues the inhibitory effects in PLD1-depleted NPC cells.Importantly,the application of the PLD1 inhibitor,VU0155069,substantially inhibits NPC tumorigenesis in a patient-derived xenograft model.Together,our findings identify PLD1/NF-κB signaling as a positive feedback loop with promising therapeutic and prognostic potential in NPC.展开更多
Objective:Colorectal cancer(CRC)is a prevalent malignant tumor with a high fatality rate.CircPDIA4 has been shown to have a vital role in cancer development by acting as a facilitator.Nevertheless,the impact of the ci...Objective:Colorectal cancer(CRC)is a prevalent malignant tumor with a high fatality rate.CircPDIA4 has been shown to have a vital role in cancer development by acting as a facilitator.Nevertheless,the impact of the circPDIA4/miR-9-5p/SP1 axis on development of CRC has not been studied.Methods:Western blot,immunohistochemistry,and reverse transcription-quantitative polymerase chain reaction assays were used to analyze gene expression.The CCK-8 assay was used to assess cell growth.The Transwell assay was used to detect invasion and migration of cells.The luciferase reporter and RNA immunoprecipitation tests were used to determine if miR-9-5p and circPDIA4(or SP1)bind to one another.An in vivo assay was used to measure tumor growth.Results:It was shown that circPDIA4 expression was greater in CRC cell lines and tissues than healthy cell lines and tissues.CircPDIA4 knockdown prevented the invasion,migration,and proliferation of cells in CRC.Additionally,the combination of circPDIA4 and miR-9-5p was confirmed,as well as miR-9-5p binding to SP1.Rescue experiments also showed that the circPDIA4/miR-9-5p/SP1 axis accelerated the development of CRC.In addition,SP1 combined with the promoter region of circPDIA4 and induced circPDIA4 transcription.CircPDIA4 was shown to facilitate tumor growth in an in vivo assay.Conclusions:The circPDIA4/miR-9-5p/SP1 feedback loop was shown to aggravate CRC progression.This finding suggests that the ceRNA axis may be a promising biomarker for CRC patient treatment.展开更多
Oxidative therapies receive a limited antitumor efficiency due to the insufficient reactive oxygen species(ROS)levels at focal sites and the evolvement of antioxidant defense systems.Herein,we develop an albumin-based...Oxidative therapies receive a limited antitumor efficiency due to the insufficient reactive oxygen species(ROS)levels at focal sites and the evolvement of antioxidant defense systems.Herein,we develop an albumin-based nanomedicine to co-deliver chlorin e6(Ce6)and COH-SR4(CS),which can simultaneously enhance the yield and lethality of intracellular ROS for amplified photodynamic therapy(PDT).In which,CS acts as both an activator of AMP-activated protein kinase(AMPK)and an inhibitor of glutathione S-transferases(GSTs).Benefiting from it,the prepared HSA-Ce6@COH-SR4(HCCS)enables positive feed-back uptake by promoting AMPK phosphorylation,leading to rapid and extensive tumor accumulation of drugs.As a result,HCCS obviously increases the ROS production to elevate intracellular oxidative stress.Furthermore,HCCS can inhibit GSTs to disturb the antioxidant defense system of tumor cells,intensifying the oxidative damage of ROS.Ultimately,the PDT of HCCS is significantly strengthened by improving the ROS yield and lethality,which greatly declines the proliferation of breast cancer in vivo.This study may open a window in the development of drug co-delivery system for enhanced oxidative therapy of tumors.展开更多
There is a strong magnetic coupling between poloidal field coils of superconducting tokamak HT-7, especially between ohinic heating and vertical field coils. These coils are connected to individual power supply. The c...There is a strong magnetic coupling between poloidal field coils of superconducting tokamak HT-7, especially between ohinic heating and vertical field coils. These coils are connected to individual power supply. The control system for the plasma current and horizontal position control has been designed and showed satisfactory results with the feedback control of multivari- able feedforward-decoupling and var-parameter PID controller to simultaneously modulate power supplies. The design and analysls of the control system is presented.展开更多
This article introduces an underwater robot inspection anomaly localization feedback system comprising a real-time water surface tracking,detection,and positioning system located on the water surface,while the underwa...This article introduces an underwater robot inspection anomaly localization feedback system comprising a real-time water surface tracking,detection,and positioning system located on the water surface,while the underwater robot inspection anomaly feedback system is housed within the underwater robot.The system facilitates the issuance of corresponding mechanical responses based on the water surface’s real-time tracking,detection,and positioning,enabling recognition and feedback of anomaly information.Through sonar technology,the underwater robot inspection anomaly feedback system monitors the underwater robot in real-time,triggering responsive actions upon encountering anomalies.The real-time tracking,detection,and positioning system from the water surface identifies abnormal conditions of underwater robots based on changes in sonar images,subsequently notifying personnel for necessary intervention.展开更多
An aileron is a crucial control surface for rolling.Any jitter or shaking caused by the aileron mechatronics could have catastrophic consequences for the aircraft’s stability,maneuverability,safety,and lifespan.This ...An aileron is a crucial control surface for rolling.Any jitter or shaking caused by the aileron mechatronics could have catastrophic consequences for the aircraft’s stability,maneuverability,safety,and lifespan.This paper presents a robust solution in the form of a fast flutter suppression digital control logic of edge computing aileron mechatronics(ECAM).We have effectively eliminated passive and active oscillating response biases by integrating nonlinear functional parameters and an antiphase hysteresis Schmitt trigger.Our findings demonstrate that self-tuning nonlinear parameters can optimize stability,robustness,and accuracy.At the same time,the antiphase hysteresis Schmitt trigger effectively rejects flutters without the need for collaborative navigation and guidance.Our hardware-in-the-loop simulation results confirm that this approach can eliminate aircraft jitter and shaking while ensuring expected stability and maneuverability.In conclusion,this nonlinear aileron mechatronics with a Schmitt positive feedback mechanism is a highly effective solution for distributed flight control and active flutter rejection.展开更多
Constructing high-performance nanozymes for specific biomolecules is crucial but challenging for practical applications and fundamental research.Herein,through the examination of the catalytic reaction paths of natura...Constructing high-performance nanozymes for specific biomolecules is crucial but challenging for practical applications and fundamental research.Herein,through the examination of the catalytic reaction paths of natural nicotinamide adenine dinucleotide(NADH)oxidase(NOX),a novel and efficient single-atom rhodium catalyst(Rh1/NC)was developed to mimic NOX.The Rh_(1)/NC demonstrated the ability to catalyze the dehydrogenation of NADH and transfer electrons to O_(2)to generate H_(2)O_(2)through the typical two-electron pathway.Furthermore,our findings revealed that Rh_(1)/NC exhibits the ability to catalyze the conversion of produced H_(2)O_(2)into OH under mildly acidic conditions.This process amplifies the oxidation of NADH,showcasing NADH peroxidase-like activity(NPx-like).As a paradigm,this unique dual enzyme-like property of Rh_(1)/NC with a positive feedback effect holds significance in disrupting cancer cellular homeostasis.Rh_(1)/NC can effectively consume NADH via cascade biocatalytic reactions within cancer cells,further triggering the elevation of reactive oxygen species(ROS),leading to impaired oxidative phosphorylation and decreased mitochondrial membrane potential,thus damaging the adenosine triphosphate(ATP)synthesis.The resulting'domino effect'interferes with the energy metabolism homeostasis of cancer cells,ultimately promoting cell apoptosis.This study provides potential guidance for the rational design of materials with greater capabilities.展开更多
Numerical analysis of weak optical positive feedback （OPF） controlling chaos is studied in a semiconductor laser. The physical model of controlling chaos produced via modulating the current of semiconductor laser is...Numerical analysis of weak optical positive feedback （OPF） controlling chaos is studied in a semiconductor laser. The physical model of controlling chaos produced via modulating the current of semiconductor laser is presented under the condition of OPF. We find the physical mechanism that the nonlinear gain coefficient and linewidth enhance- ment factor of the laser are affected by OPF so that the dynamical behaviour of the system can be efficiently controlled. Chaos is controlled into a single-periodic state, a dual-periodic state, a tri-periodic state, a quadr-periodic state, a pentaperiodic state, and the laser emitting powers are increased by OPF in simulations. Lastly, another chaos-control method with modulating the amplitude of the feedback light is presented and numerically simulated to control chaotic laser into multi-periodic states.展开更多
In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an ex...In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external force.We applied the multiple scales method to get the solution from first approximation.Graphically and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system.展开更多
Synchronization is a process that describes the coherent dynamics of a large ensemble of interacting units.The study of explosive synchronization transition attracts considerable attention.Here,I report the explosive ...Synchronization is a process that describes the coherent dynamics of a large ensemble of interacting units.The study of explosive synchronization transition attracts considerable attention.Here,I report the explosive transition within the framework of a mobile network,while each oscillator is controlled by global-order parameters of the system.Using numerical simulation,I find that the explosive synchronization(ES)transition behavior can be controlled by simply adjusting the fraction of controlled oscillators.The influences of some parameters on explosive synchronization are studied.Moreover,due to the presence of the positive feedback mechanism,I prevent the occurrence of the synchronization of continuous-phase transition and make phase transition of the system a first-order phase transition accompanied by a hysteresis loop.展开更多
Recently, some researches indicate that positive feedback can benefit the control if appropriate time delay is intentionally introduced into control system. However, most work is theoretical one but few are experiment...Recently, some researches indicate that positive feedback can benefit the control if appropriate time delay is intentionally introduced into control system. However, most work is theoretical one but few are experimental. This paper presents theoretical and experimental studies of delayed positive feedback control technique using a flexible beam as research object. The positive feedback weighting coefficient is designed by using the optimal control method. The available time delay is determined by analyzing the maximal real part of characteristic roots of the system. A DSP-based experiment system is introduced. Simulation and experimental results indicate that the delayed positive feedback control may effectively reduce the beam vibration if time delay is appropriately selected.展开更多
Under some minor technical hypotheses, for each T larger than a certain rS > 0, Krisztin, Walther and Wu showed the existence of a periodic orbit for the positive feedback delay differential equation x(t) = -rμx(t...Under some minor technical hypotheses, for each T larger than a certain rS > 0, Krisztin, Walther and Wu showed the existence of a periodic orbit for the positive feedback delay differential equation x(t) = -rμx(t) + rf(x(t-1)), where r and μ are positive constants and f : R → R satisfies f(0) = 0 and f' > 0. Combining this with a unique result of Krisztin and Walther, we know that this periodic orbit is the one branched out from 0 through Hopf bifurcation. Using the normal form theory for delay differential equations, we show the same result under the condition that f ∈ C3(R,R) is such that f''(0) = 0 and f'''(0) < 0, which is weaker than those of Krisztin and Walther.展开更多
To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic array...To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic arrays,four stators and displacement sensors.The dynamics model of this stage was a complex nonlinear,strong coupling system which made the control strategy to be a focus research.The nonlinear controller of the system was proposed based on the theory of differential geometry.Both simulation and experimental results show that either the decoupling control of the movement can be realized in horizontal and vertical directions,and the control performance was improved by the damper,verifying the validity and efficiency of this method.展开更多
The positive Arctic-methane(CH_(4))feedback forms when more CH_(4)is released from the Arctic tundra to warm the climate,fu rther stimulating the Arctic to emit CH_(4).This study utilized the CLM-Microbe model to proj...The positive Arctic-methane(CH_(4))feedback forms when more CH_(4)is released from the Arctic tundra to warm the climate,fu rther stimulating the Arctic to emit CH_(4).This study utilized the CLM-Microbe model to project CH_(4)emissions across five distinct Arctic tundra ecosystems on the Alaska North Slo pe,considering three Shared Socioeconomic Pathway(SSP)scenarios using climate data from three climate models from 2016 to 2100.Employing a hyper-resolution of 5m×5m within 40,000m^(2)domains accounted for the Arctic tundra's high spatial heterogeneity;three sites were near Utqiagvik(US-Beo,US-Bes,and US-Brw),with one each in Atqasuk(US-Atq)and Ivotu k(US-Ivo).展开更多
In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out.Those four types are the linear velocity ...In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out.Those four types are the linear velocity feedback control,the cubic velocity feedback control,the non-linear saturation controller(NSC)and the positive position feedback(PPF)controller.The suitable type is the PPF controller for suppression the vibrations of the cantilever beam.The approximate solution obtained up to the first approximation by using the multiple scale method.The PPF controller effectiveness is studied on the system.We used frequency-response equations to investigate the stability of a cantilever beam.We notified that,there is a good agreement between the analytical solution and the numerical solution.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51805350)Key Technologies Research and Development Program of China(Grant No.2018YFB2001202)+1 种基金Natural Science Foundation of Shanxi Province of China(Grant No.201801D221226)Postdoctoral Science Foundation of China(Grant No.2019M651073).
文摘The current research mainly focuses on the flow control for the two-stage proportional valve with hydraulic position feedback which is named as Valvistor valve.Essentially,the Valvistor valve is a proportional throttle valve and the flow fluctuates with the change of load pressure.The flow fluctuation severely restricts the application of the Valvistor valve.In this paper,a novel flow control method the Valvistor valve is provided to suppress the flow fluctuation and develop a high performance proportional flow valve.The mathematical model of this valve is established and linearized.Fuzzy proportional-integral-derivative(PID)controller is adopted in the closed-loop flow control system.The feedback is obtained by the flow inference with back-propagation neural network(BPNN)based on the spool displacement in the pilot stage and the pressure differential across the main orifice.The results show that inference with BPNN can obtain the flow data fast and accurately.With the flow control method,the flow can keep at the set point when the pressure differential across the main orifice changes.The flow control method is effective and the Valvistor valve changes from proportional throttle valve to proportional flow valve.For the developed proportional flow valve,the settling time of the flow is very short when the load pressure changes abruptly.The performances of hysteresis,linearity and bandwidth are in a high range.The linear mathematical model can be verified and the assumptions in the system modeling is reasonable.
基金supported by the National Natural Science Foundation of China(Grant Nos.81902617 and 82100816)Guangdong Natural Science Foundation(Grant No.2021A1515012322)Guangzhou Basic and Applied Basic Research Subject-Young Doctor’s“Sailing”Project(Grant No.2024A04J4702).
文摘Background:U2AF homology motif kinase 1(UHMK1)has been associated with RNA processing and protein phosphorylation,thereby influencing tumor progression.The study aimed to explore its regulatory mechanisms and biological functions in human prostate cancer(PCa).Methods:In this study,we systematically evaluated the expression and prognostic significance of UHMK1 in public databases,followed by validation through immunohis-tochemistry(IHC)in PCa specimens.Both gain-of-function and loss-of-function experiments were conducted to elucidate the role of UHMK1 in vitro and in vivo.Additionally,a series of molecular and biochemical assays were performed to investigate the regulatory mechanisms underlying UHMK1 activity.Results:Our findings revealed that UHMK1 expression was significantly upregulated in PCa tissues and correlated with poor patient prognosis,as demonstrated by analysis of public datasets and confirmed by immunohistochemical staining.Functional studies showed that UHMK1 depletion suppressed tumor cell proliferation and metastasis,while its overexpression promoted these processes.Mechanistically,we identified that UHMK1 phosphorylates nuclear receptor coactivator 3(NCOA3),which subsequently activates activating transcription factor 4(ATF4)to upregulate methylenetetrahydrofolate dehy-drogenase 2(MTHFD2)transcription.Interestingly,MTHFD2 was found to reciprocally enhance UHMK1 expression,establishing a positive feedback loop.Conclusions:In conclusion,our data suggest that the UHMK1-MTHFD2 axis forms a positive feedback loop that drives PCa progression.Targeting this loop represents a promising therapeutic strategy for restraining prostate cancer development and progression.
基金This work was supported by the Guangdong Basic and Applied Basic Research Foundation(2024A1515013061)the Sci-Tech Project Foundation of Guangzhou City(2023A04J2141)+2 种基金National Natural Science Foundation(82261160657)Chang Jiang Scholars Program(J.-X.B.)Special Support Program of Guangdong(J.-X.B.)。
文摘Phospholipase D(PLD)lipid-signaling enzyme superfamily has been widely implicated in various human malignancies,but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma(NPC).Here,we analyze the expressions of 6 PLD family members between 87 NPC and 10 control samples through transcriptome analysis.Our findings reveal a notable upregulation of PLD1 in both NPC tumors and cell lines,correlating with worse disease-free and overall survival in NPC patients.Functional assays further elucidate the oncogenic role of PLD1,demonstrating its pivotal promotion of critical tumorigenic processes such as cellproliferation and migration in vitro,as well as tumor growth in vivo.Notably,our study uncovers a positive feedback loop between PLD1 and the NF-κB signaling pathway to render NPC progression.Specifically,PLD1 enhances NF-kB activity by facilitating the phosphorylation and nuclear translocation of RELA,which in turn binds to the promoter of PLD1,augmenting its expression.Moreover,RELA over-expression markedly rescues the inhibitory effects in PLD1-depleted NPC cells.Importantly,the application of the PLD1 inhibitor,VU0155069,substantially inhibits NPC tumorigenesis in a patient-derived xenograft model.Together,our findings identify PLD1/NF-κB signaling as a positive feedback loop with promising therapeutic and prognostic potential in NPC.
基金supported by the National Natural Science Foundation of China(Grant Nos.82073276 and 82273100)Science and Technology Project of Tianjin Binhai New Area Health Commission(Grant No.2022BWKY016)the China Digestive Tumor Clinical Scientific Research Public Welfare Project(Grant No.P014-058).
文摘Objective:Colorectal cancer(CRC)is a prevalent malignant tumor with a high fatality rate.CircPDIA4 has been shown to have a vital role in cancer development by acting as a facilitator.Nevertheless,the impact of the circPDIA4/miR-9-5p/SP1 axis on development of CRC has not been studied.Methods:Western blot,immunohistochemistry,and reverse transcription-quantitative polymerase chain reaction assays were used to analyze gene expression.The CCK-8 assay was used to assess cell growth.The Transwell assay was used to detect invasion and migration of cells.The luciferase reporter and RNA immunoprecipitation tests were used to determine if miR-9-5p and circPDIA4(or SP1)bind to one another.An in vivo assay was used to measure tumor growth.Results:It was shown that circPDIA4 expression was greater in CRC cell lines and tissues than healthy cell lines and tissues.CircPDIA4 knockdown prevented the invasion,migration,and proliferation of cells in CRC.Additionally,the combination of circPDIA4 and miR-9-5p was confirmed,as well as miR-9-5p binding to SP1.Rescue experiments also showed that the circPDIA4/miR-9-5p/SP1 axis accelerated the development of CRC.In addition,SP1 combined with the promoter region of circPDIA4 and induced circPDIA4 transcription.CircPDIA4 was shown to facilitate tumor growth in an in vivo assay.Conclusions:The circPDIA4/miR-9-5p/SP1 feedback loop was shown to aggravate CRC progression.This finding suggests that the ceRNA axis may be a promising biomarker for CRC patient treatment.
基金support of National Natural Science Foundation of China(No.52073140)the Guangdong Basic and Applied Basic Research Foundation(No.2022B1515020095).
文摘Oxidative therapies receive a limited antitumor efficiency due to the insufficient reactive oxygen species(ROS)levels at focal sites and the evolvement of antioxidant defense systems.Herein,we develop an albumin-based nanomedicine to co-deliver chlorin e6(Ce6)and COH-SR4(CS),which can simultaneously enhance the yield and lethality of intracellular ROS for amplified photodynamic therapy(PDT).In which,CS acts as both an activator of AMP-activated protein kinase(AMPK)and an inhibitor of glutathione S-transferases(GSTs).Benefiting from it,the prepared HSA-Ce6@COH-SR4(HCCS)enables positive feed-back uptake by promoting AMPK phosphorylation,leading to rapid and extensive tumor accumulation of drugs.As a result,HCCS obviously increases the ROS production to elevate intracellular oxidative stress.Furthermore,HCCS can inhibit GSTs to disturb the antioxidant defense system of tumor cells,intensifying the oxidative damage of ROS.Ultimately,the PDT of HCCS is significantly strengthened by improving the ROS yield and lethality,which greatly declines the proliferation of breast cancer in vivo.This study may open a window in the development of drug co-delivery system for enhanced oxidative therapy of tumors.
文摘There is a strong magnetic coupling between poloidal field coils of superconducting tokamak HT-7, especially between ohinic heating and vertical field coils. These coils are connected to individual power supply. The control system for the plasma current and horizontal position control has been designed and showed satisfactory results with the feedback control of multivari- able feedforward-decoupling and var-parameter PID controller to simultaneously modulate power supplies. The design and analysls of the control system is presented.
文摘This article introduces an underwater robot inspection anomaly localization feedback system comprising a real-time water surface tracking,detection,and positioning system located on the water surface,while the underwater robot inspection anomaly feedback system is housed within the underwater robot.The system facilitates the issuance of corresponding mechanical responses based on the water surface’s real-time tracking,detection,and positioning,enabling recognition and feedback of anomaly information.Through sonar technology,the underwater robot inspection anomaly feedback system monitors the underwater robot in real-time,triggering responsive actions upon encountering anomalies.The real-time tracking,detection,and positioning system from the water surface identifies abnormal conditions of underwater robots based on changes in sonar images,subsequently notifying personnel for necessary intervention.
基金supported in part by the Aeronautical Science Foundation of China under Grant 2022Z005057001the Joint Research Fund of Shanghai Commercial Aircraft System Engineering Science and Technology Innovation Center under CASEF-2023-M19.
文摘An aileron is a crucial control surface for rolling.Any jitter or shaking caused by the aileron mechatronics could have catastrophic consequences for the aircraft’s stability,maneuverability,safety,and lifespan.This paper presents a robust solution in the form of a fast flutter suppression digital control logic of edge computing aileron mechatronics(ECAM).We have effectively eliminated passive and active oscillating response biases by integrating nonlinear functional parameters and an antiphase hysteresis Schmitt trigger.Our findings demonstrate that self-tuning nonlinear parameters can optimize stability,robustness,and accuracy.At the same time,the antiphase hysteresis Schmitt trigger effectively rejects flutters without the need for collaborative navigation and guidance.Our hardware-in-the-loop simulation results confirm that this approach can eliminate aircraft jitter and shaking while ensuring expected stability and maneuverability.In conclusion,this nonlinear aileron mechatronics with a Schmitt positive feedback mechanism is a highly effective solution for distributed flight control and active flutter rejection.
基金financially supported by the National Natural Science Foundation of China(No.22207066)Taishan Scholars Program of Shandong Province(No.TS201712065)+2 种基金the Academic Promotion Program of Shandong First Medical University(No.2019QL009)the Science and Technology Funding from Jinan(No.2020GXRC018)the Traditional Chinese Medicine Science and Technology Project of Shandong Province(No.Q-2022142)。
文摘Constructing high-performance nanozymes for specific biomolecules is crucial but challenging for practical applications and fundamental research.Herein,through the examination of the catalytic reaction paths of natural nicotinamide adenine dinucleotide(NADH)oxidase(NOX),a novel and efficient single-atom rhodium catalyst(Rh1/NC)was developed to mimic NOX.The Rh_(1)/NC demonstrated the ability to catalyze the dehydrogenation of NADH and transfer electrons to O_(2)to generate H_(2)O_(2)through the typical two-electron pathway.Furthermore,our findings revealed that Rh_(1)/NC exhibits the ability to catalyze the conversion of produced H_(2)O_(2)into OH under mildly acidic conditions.This process amplifies the oxidation of NADH,showcasing NADH peroxidase-like activity(NPx-like).As a paradigm,this unique dual enzyme-like property of Rh_(1)/NC with a positive feedback effect holds significance in disrupting cancer cellular homeostasis.Rh_(1)/NC can effectively consume NADH via cascade biocatalytic reactions within cancer cells,further triggering the elevation of reactive oxygen species(ROS),leading to impaired oxidative phosphorylation and decreased mitochondrial membrane potential,thus damaging the adenosine triphosphate(ATP)synthesis.The resulting'domino effect'interferes with the energy metabolism homeostasis of cancer cells,ultimately promoting cell apoptosis.This study provides potential guidance for the rational design of materials with greater capabilities.
基金The project supported by Education Department of Jiangsu Province of China under Grant No. 06KJD140111
文摘Numerical analysis of weak optical positive feedback （OPF） controlling chaos is studied in a semiconductor laser. The physical model of controlling chaos produced via modulating the current of semiconductor laser is presented under the condition of OPF. We find the physical mechanism that the nonlinear gain coefficient and linewidth enhance- ment factor of the laser are affected by OPF so that the dynamical behaviour of the system can be efficiently controlled. Chaos is controlled into a single-periodic state, a dual-periodic state, a tri-periodic state, a quadr-periodic state, a pentaperiodic state, and the laser emitting powers are increased by OPF in simulations. Lastly, another chaos-control method with modulating the amplitude of the feedback light is presented and numerically simulated to control chaotic laser into multi-periodic states.
文摘In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external force.We applied the multiple scales method to get the solution from first approximation.Graphically and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system.
基金the Natural Science Foundation of Jiangsu Province,China(Grant No.20KJB470030).
文摘Synchronization is a process that describes the coherent dynamics of a large ensemble of interacting units.The study of explosive synchronization transition attracts considerable attention.Here,I report the explosive transition within the framework of a mobile network,while each oscillator is controlled by global-order parameters of the system.Using numerical simulation,I find that the explosive synchronization(ES)transition behavior can be controlled by simply adjusting the fraction of controlled oscillators.The influences of some parameters on explosive synchronization are studied.Moreover,due to the presence of the positive feedback mechanism,I prevent the occurrence of the synchronization of continuous-phase transition and make phase transition of the system a first-order phase transition accompanied by a hysteresis loop.
基金supported by the Key Project (11132001)the General Projects of the National Natural Science Foundation of China (11072146, 11002087)
文摘Recently, some researches indicate that positive feedback can benefit the control if appropriate time delay is intentionally introduced into control system. However, most work is theoretical one but few are experimental. This paper presents theoretical and experimental studies of delayed positive feedback control technique using a flexible beam as research object. The positive feedback weighting coefficient is designed by using the optimal control method. The available time delay is determined by analyzing the maximal real part of characteristic roots of the system. A DSP-based experiment system is introduced. Simulation and experimental results indicate that the delayed positive feedback control may effectively reduce the beam vibration if time delay is appropriately selected.
基金The start-up funds of Wilfrid Laurier University of Canada, the NNSF (10071016) of Chinathe Doctor Program Foundation (20010532002) of Chinese Ministry of Education the Key Project of Chinese Ministry of Education ([2002]78) and the
文摘Under some minor technical hypotheses, for each T larger than a certain rS > 0, Krisztin, Walther and Wu showed the existence of a periodic orbit for the positive feedback delay differential equation x(t) = -rμx(t) + rf(x(t-1)), where r and μ are positive constants and f : R → R satisfies f(0) = 0 and f' > 0. Combining this with a unique result of Krisztin and Walther, we know that this periodic orbit is the one branched out from 0 through Hopf bifurcation. Using the normal form theory for delay differential equations, we show the same result under the condition that f ∈ C3(R,R) is such that f''(0) = 0 and f'''(0) < 0, which is weaker than those of Krisztin and Walther.
基金Supported by the National Natural Science Foundation of China (60674052)
文摘To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic arrays,four stators and displacement sensors.The dynamics model of this stage was a complex nonlinear,strong coupling system which made the control strategy to be a focus research.The nonlinear controller of the system was proposed based on the theory of differential geometry.Both simulation and experimental results show that either the decoupling control of the movement can be realized in horizontal and vertical directions,and the control performance was improved by the damper,verifying the validity and efficiency of this method.
基金the financial and facility support from San Diego State Universitypartially provided by the SPRUCE and NGEE Arctic projects,which are supported by the Office of Biological and Environmental Research in the Department of Energy Office of Science+3 种基金partially supported by the U.S.National Science Foundation(2145130,1702797,2208656)provided by the Polar Geospatial Center under NSF OPP awards 1204263 and 1702797supported by NASA ABoVE program(NNX15AT74A and NNX16AF94A)the National Oceanic and Atmospheric Administration NOAA/EPP Grant(NA22SEC4810016)
文摘The positive Arctic-methane(CH_(4))feedback forms when more CH_(4)is released from the Arctic tundra to warm the climate,fu rther stimulating the Arctic to emit CH_(4).This study utilized the CLM-Microbe model to project CH_(4)emissions across five distinct Arctic tundra ecosystems on the Alaska North Slo pe,considering three Shared Socioeconomic Pathway(SSP)scenarios using climate data from three climate models from 2016 to 2100.Employing a hyper-resolution of 5m×5m within 40,000m^(2)domains accounted for the Arctic tundra's high spatial heterogeneity;three sites were near Utqiagvik(US-Beo,US-Bes,and US-Brw),with one each in Atqasuk(US-Atq)and Ivotu k(US-Ivo).
文摘In our consideration,a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out.Those four types are the linear velocity feedback control,the cubic velocity feedback control,the non-linear saturation controller(NSC)and the positive position feedback(PPF)controller.The suitable type is the PPF controller for suppression the vibrations of the cantilever beam.The approximate solution obtained up to the first approximation by using the multiple scale method.The PPF controller effectiveness is studied on the system.We used frequency-response equations to investigate the stability of a cantilever beam.We notified that,there is a good agreement between the analytical solution and the numerical solution.
