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A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： ai-guo wu Guang-Ren DUAN Yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

Design of an automated robotic microinjection system for batch injection of zebrafish embryos and larvae

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Microsystems & Nanoengineering 2024年第1期10卷 89-103页

作者： Zhongyi guo Nana ai Wei Ge Qingsong Xu Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina Department of Biomedical Sciences and Centre of Reproduction Development and Aging(CRDA)Faculty of Health SciencesUniversity of MacaoMacaoChina

This paper presents the design of a vision-based automated robotic microinjection system for batch injection of both zebrafish embryos and larvae.A novel visual recognition algorithm based on an automatic threshold and excessive dilatation is introduced to accurately identify the center of zebrafish embryos and larval yolks.A corresponding software system is developed using the producer-consumer model as the framework structure,and a friendly user interface is designed to allow operators to choose from a range of desired functions according to their different needs.In addition,a novel microstructural agarose device is designed and fabricated to simultaneously immobilize mixed batches of embryos and larvae.Moreover,a prototype microinjection system is fabricated by integrating hardware devices with visual algorithms.An experimental study is conducted to verify the performance of the robotic microinjection system.The results show that the reported system can accurately identify zebrafish embryos and larvae and efficiently complete batch microinjection tasks of the mixtures with an injection success rate of 92.05%in 13.88 s per sample.Compared with manual and existing microinjection systems,the proposed system demonstrates the merits of versatility,excellent efficiency,high success rate,high survival rate,and sufficient stability.

关键词： zebra automated hardware

Diabetes mellitus in patients with type 1 autoimmune pancreatitis at diagnosis and after corticosteroid therapy

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 393-398页

作者： Mei-Zi Li Tao guo Yun-Lu Feng Sheng-Yu Zhang Xiao-Yin Bai Xi wu Kai Xu ai-Ming Yang Department of Gastroenterology State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China Department of Radiology Peking Union Medical College HospitalPeking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China

Background:A high prevalence of diabetes mellitus(DM)coexisting with autoimmune pancreatitis(aiP)is observed.However,evidence on the circumstances under which corticosteroid therapy(CST)for aiP improves or worsens DM is scarce.This study aimed to demonstrate and identify predictors of DM control under the influence of CST.Methods:Patients diagnosed with type 1 aiP were enrolled from a prospectively maintained cohort and were classified into three groups according to the chronology in which aiP and DM were diagnosed:pre-existing DM(pDM),concurrent DM(cDM),and non-DM(nDM).The responses of DM to CST were assessed when corticosteroid was ceased or tapered to a maintenance dose and classified as‘improvement’and‘non-improvement’(including‘no change’and‘exacerbation’).Results:Among 101 patients with type 1 aiP,52(51.5%)patients were complicated with DM at the time of aiP diagnosis,with 36 patients in the cDM group and 16 patients in the pDM group.The incidences of diffuse pancreatic swelling(72.2%)and pancreatic body/tail involvement(91.7%)were significantly higher in the cDM group than in both the pDM and nDM groups.Of the 52 patients with DM,CST was administered in 48 cases.Multivariate logistic analysis identified that elevated serum gamma-glutamyl transferase(GGT)level at aiP diagnosis[odds ratio(OR)=0.032,95%confidence interval(CI):0.003-0.412,P=0.008]and pancreatic atrophy after CST(OR=0.027,95%CI:0.003-0.295,P=0.003)were negatively associated with DM control improvement.Conclusions:Patients with diffuse pancreatic swelling and pancreatic body/tail involvement in pancreatitis tended to be complicated with cDM at aiP diagnosis.CST exerted a beneficial effect on the clinical course of DM in nearly half of the aiP patients complicated with DM at diagnosis,particularly in those without elevated serum GGT levels at diagnosis and who did not experience pancreatic atrophy after CST.

关键词： Type 1 autoimmune pancreatitis Diabetes mellitus Corticosteroid therapy Predictive factor Pancreatic atrophy

A Fully Actuated System Approach for Stabilization of Discrete-Time Multiple-Input Nonlinear Systems with Distinct Input Delays

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Journal of Systems Science & Complexity 2022年第2期35卷 670-687页

作者： wu ai-guo ZHANG Jie JI Youzhou Harbin Institute of Technology(Shenzhen) Shenzhen 518055China HIT wuhu Robot Technology Research Institute Wuhu 241008China

In this paper,the problem of stabilization is considered for discrete-time multiple-input nonlinear systems with distinct input delays law based on the fully actuated system approach.In order to compensate the input delays,a prediction scheme is presented to predict future states based on the closed-loop linear system.Then,a stabilizing law is constructed for nonlinear delayed systems by replacing the future states in the control law for the corresponding delay-free systems with their prediction.Finally,numerical examples are given to verify the effectiveness of the proposed approach.

关键词： Fully actuated system approach input delays nonlinear systems prediction scheme

The photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis

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Acta Geochimica 2024年第1期43卷 174-179页

作者： Yanyou wu Shaogang guo State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical process in nature that can convert light energy into chemical energy. Some heavy oxygen isotopic(^(18)O) labeling experiments have"conclusively" demonstrated that the oxygen released by photosynthesis comes only from water and are written into textbooks. However, it is not difficult to find that bicarbonate has never been excluded from the direct substrate of photosynthesis from beginning to end during the history of photosynthesis research. No convincing mechanism can be used to explain photosynthetic oxygen evolution solely from water photolysis. The bicarbonate effect, the Dole effect, the thermodynamic convenience of bicarbonate photolysis, the crystal structure characteristics of photosystem Ⅱ, and the reinterpretation of heavy oxygen isotopic labeling(^(18)O)experiments all indicate that the photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis. The recently proposed view that bicarbonate photolysis is the premise of water photolysis, bicarbonate photolysis and water photolysis work together with a 1:1(mol/mol) stoichiometric relationship, and the stoichiometric relationship between oxygen and carbon dioxide released during photosynthetic oxygen evolution is also 1:1, has excellent applicability and objectivity, which can logically and reasonably explain the precise coordination between light and dark reactions during photosynthesis, the bicarbonate effect, the Dole effect, the Kok cycle and the neutrality of water and carbon in nature.This is of great significance for constructing the bionic artificial photosynthetic reactors and scientifically answering the question of the source of elemental stoichiometric relationships in nature.

关键词： Bicarbonate effect Dole effect Kok cycle Heavy oxygen isotope Artificial photosynthetic reactor

Recent progress in MOFs-based nanozymes for biosensing

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Nano Research 2024年第1期17卷 39-64页

作者： Imamdin Chandio Yongjian ai Lei wu Qionglin Liang MOE Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryLaboratory of Flexible Electronics TechnologyCenter for Synthetic and Systems BiologyTsinghua University-Peking University Joint Centre for Life SciencesTsinghua UniversityBeijing 100084China

Nanozymes are nanomaterials with enzyme-mimicking catalytic activity.Compared to natural enzymes,nanozymes show various properties such as easy to manufacture,stable,adjustable,and inexpensive.Nanozymes play key roles in biosensing,biocatalysis,and disease treatment.As an important kind of nanozymes,metal-organic framework(MOF)-based nanozymes are receiving a lot of attention due to their structural properties and composition.Rationally developing MOF with enzymes-like catalytic properties has opened new perspectives in biosensing.This review summarizes the up-to-date developments in synthesizing two-dimensional and three-dimensional MOF-based nanozymes and their applications in biosensing.Firstly,classification of nanozymes obtained by MOFs is categorized,and different properties of MOF-based nanozymes are described.Then,the distinctive applications of MOF-based nanozymes in identifying various analytes are thoroughly summarized.Finally,the recent challenges and progressive directions in this area are highlighted.

关键词： metal-organic frameworks nanozymes metal-organic framework (MOF)-based nanozymes biosensing analytes

Clinical Analysis and Mental Health Survey of Hemophilia Carriers:a Cross-sectional Study

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Current Medical Science 2024年第2期44卷 435-440页

作者： Wen WANG Li-juan JIANG Dong-yan CUI ai ZHANG Xiong WANG ai-guo LIU Qun HU Department of Pediatrics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Laboratory Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective:Hemophilia carriers(HCs),who are heterozygous for mutations in the clotting factor VIII/clotting factor IX gene(F8 or F9),may have a wide range of clotting factor levels,from very low,similar to afflicted males,to the upper limit of normal,and may experience mental health issues.The purpose of this study was to provide genetic information on mothers of hemophilia patients and to understand the clotting factor activity and phenotype of HCs.Additionally,we aimed to investigate the mental health status of HCs in China.Methods:A total of 127 hemophilia mothers,including 93 hemophilia A(HA)mothers and 34 hemophilia B(HB)mothers,were enrolled in this study.Long distance PCR,multiplex PCR,and Sanger sequencing were used to analyze mutations in F8 or F9.Coagulation factor activity was detected by a one-stage clotting assay.The Symptom Checklist 90(SCL-90,China/Mandarin version)was given to HCs at the same time to assess their mental health.Results:A total of 90.6%of hemophilia mothers were diagnosed genetically as carriers,with inversion in intron 22 and missense mutations being the most common mutation types in HA and HB carriers,respectively.The median clotting factor level in carriers was 0.74 IU/mL(ranging from 0.09 to 1.74 IU/mL)compared with 1.49 IU/mL(ranging from 0.93 to 1.89 IU/mL)in noncarriers,of which 14.3%of HCs had clotting factor levels of 0.40 IU/mL or below.A total of 53.8%(7/13)of HA carriers with low clotting factor levels(less than 0.50 IU/mL)had a history of bleeding,while none of the HB carriers displayed a bleeding phenotype.The total mean score and the global severity index of the SCL-90 for surveyed HCs were 171.00(±60.37)and 1.78(±0.59),respectively.A total of 67.7%of the respondents had psychological symptoms,with obsessive-compulsive disorder being the most prevalent and severe.The pooled estimates of all nine factors were significantly higher than those in the general population(P<0.05).Conclusions:The detection rate of gene mutations in hemophilia mothers was 90.6%,with a median cl

关键词： hemophilia A hemophilia B mutation carrier mental health

Global Phase Portraits of Uniform Isochronous Centers System of Degree Six with Polynomial Commutator

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 577-599页

作者： Li-na guo ai-yong CHEN Shuai-feng ZHAO School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang 471023China Department of Mathematics Hunan First Normal UniversityChangsha 410205China School of Mechatronics Engineering Henan University of Science and TechnologyLuoyang 471023China

This paper studies the global phase portraits of uniform isochronous centers system of degree six with polynomial commutator.Such systems have the form x=-y+xf(x,y),y=x+yf(x,y),where f(x,y)=a_(1)x+a_(2)xy+a_(3)xy^(2)+a_(4)xy^(3)+a_(5)xy^(4)=xσ(y),and any zero of 1+a_(1)y+a_(2)y^(2)+a_(3)y^(3)+a_(4)y^(4)+a_(5)y^(5),y=y is an invariant straight line.At last,all global phase portraits are drawn on the Poincare disk.

关键词： global phase portraits uniform isochronous center polynomial commutator invariant straight lines

Mixed H_(∞)/Passive Exponential Synchronization for Delayed Memristive Neural Networks with Switching Event-Triggered Control

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Journal of Systems Science & Complexity 2024年第1期37卷 294-317页

作者： wu Wenhuang guo Lulu CHEN Hong Shanghai Research Institute for Intelligent Autonomous Systems Tongji UniversityShanghai 200092China Department of Control Science and Engineering Tongji UniversityShanghai 201804China

This paper is devoted to event-triggered synchronization of delayed memristive neural networks with H∞and passivity performance.The aim is to guarantee the exponential synchronization and mixed H∞and passivity control for memristive neural networks by using event-triggered control.Firstly,a switching system is constructed under the event-triggered control strategy.Then,by adopting a piece-wise Lyapunov functional,a sufficient condition is established for the exponential synchronization and mixed H_(∞)and passivity performance.Moreover,an event-triggered controller design scheme is proposed using matrix decoupling method.Finally,the effectiveness of the designed controller is exemplified by a numerical example.

关键词： Event-triggered control exponential synchronization memristive neural networks time delays.