Citrinin Is a Potential Quorum Sensing Inhibitor against Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an opportunistic pathogen that infects patients by regulating virulence factors and biofilms through a quorum sensing (QS) system to protect itself from antibiotics and environmental stress. Therefore, the development of quorum sensing inhibitors (QSIs) is expected to become a new strategy for studying drug resistance to P. aeruginosa infections. Marine fungi are valuable resources for screening QSIs. A marine fungus, Penicillium sp. JH1, with anti-QS activity was isolated from the offshore waters of Qingdao (China), and citrinin, a novel QSI, was purified from secondary metabolites of this fungus. Citrinin could significantly inhibit the production of violacein in Chromobacterium violaceum CV12472 and the production of three virulence factors (elastase, rhamnolipid and pyocyanin) in P. aeruginosa PAO1. It could also inhibit the biofilm formation and motility of PAO1. In addition, citrinin downregulated the transcript levels of nine genes (lasI, rhlI, pqsA, lasR, rhlR, pqsR, lasB, rhlA and phzH) associated with QS. Molecular docking results showed that citrinin bound to PqsR and LasR with better affinity than the natural ligands. This study laid a foundation for the further study of the structure optimization and structure-activity relationship of citrinin.

Vibration-Based Recognition of Wheel-Terrain Interaction for Terramechanics Model Selection and Terrain Parameter Identification for Lugged-Wheel Planetary Rovers.

Identifying terrain parameters is important for high-fidelity simulation and high-performance control of planetary rovers. The wheel-terrain interaction classes (WTICs) are usually different for rovers traversing various types of terrain. Every terramechanics model corresponds to its wheel-terrain interaction class (WTIC). Therefore, for terrain parameter identification of the terramechanics model when rovers traverse various terrains, terramechanics model switching corresponding to the WTIC needs to be solved. This paper proposes a speed-independent vibration-based method for WTIC recognition to switch the terramechanics model and then identify its terrain parameters. In order to switch terramechanics models, wheel-terrain interactions are divided into three classes. Three vibration models of wheels under three WTICs have been built and analyzed. Vibration features in the models are extracted and non-dimensionalized to be independent of wheel speed. A vibration-feature-based recognition method of the WTIC is proposed. Then, the terrain parameters of the terramechanics model corresponding to the recognized WTIC are identified. Experiment results obtained using a Planetary Rover Prototype show that the identification method of terrain parameters is effective for rovers traversing various terrains. The relative errors of estimated wheel-terrain interaction force with identified terrain parameters are less than 16%, 12%, and 9% for rovers traversing hard, gravel, and sandy terrain, respectively.

Multifaceted characterization of the biological and transcriptomic signatures of natural killer cells derived from cord blood and placental blood.

BACKGROUND: Perinatal blood including umbilical cord blood and placental blood are splendid sources for allogeneic NK cell generation with high cytotoxicity of combating pathogenic microorganism and malignant tumor. Despite the generation of NK cells from the aforementioned perinatal blood, yet the systematical and detailed information of the biological and transcriptomic signatures of UC-NKs and P-NKs before large-scale clinical applications in disease remodeling is still largely obscure. METHODS: Herein, we took advantage of the "3IL"-based strategy for high-efficient generation of NK cells from umbilical cord blood and placental blood (UC-NKs and P-NKs), respectively. On the one hand, we conducted flow cytometry (FCM) assay and coculture to evaluate the subpopulations, cellular vitality and cytotoxic activity of the aforementioned NK cells. On the other hand, with the aid of RNA-SEQ and multiple bioinformatics analyses, we further dissected the potential diversities of UC-NKs and P-NKs from the perspectives of transcriptomes. RESULTS: On the basis of the "3IL" strategy, high-efficient NKs were generated from mononuclear cells (MNCs) in perinatal blood. P-NKs revealed comparable ex vivo expansion but preferable activation and cytotoxicity upon K562 cells over UC-NKs. Both of the two NKs showed diversity in cellular vitality and transcriptome including apoptotic cells, cell cycle, gene expression profiling and the accompanied multifaceted biological processes. CONCLUSIONS: Our data revealed the multifaceted similarities and differences of UC-NKs and P-NKs both at the cellular and molecular levels. Our findings supply new references for allogeneic NK cell-based immunotherapy in regenerative medicine and will benefit the further exploration for illuminating the underlying mechanism as well.

Distinct features of H3K4me3 and H3K27me3 chromatin domains in pre-implantation embryos.

Histone modifications have critical roles in regulating the expression of developmental genes during embryo development in mammals. However, genome-wide analyses of histone modifications in pre-implantation embryos have been impeded by the scarcity of the required materials. Here, by using a small-scale chromatin immunoprecipitation followed by sequencing (ChIP-seq) method, we map the genome-wide profiles of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3), which are associated with gene activation and repression, respectively, in mouse pre-implantation embryos. We find that the re-establishment of H3K4me3, especially on promoter regions, occurs much more rapidly than that of H3K27me3 following fertilization, which is consistent with the major wave of zygotic genome activation at the two-cell stage. Furthermore, H3K4me3 and H3K27me3 possess distinct features of sequence preference and dynamics in pre-implantation embryos. Although H3K4me3 modifications occur consistently at transcription start sites, the breadth of the H3K4me3 domain is a highly dynamic feature. Notably, the broad H3K4me3 domain (wider than 5 kb) is associated with higher transcription activity and cell identity not only in pre-implantation development but also in the process of deriving embryonic stem cells from the inner cell mass and trophoblast stem cells from the trophectoderm. Compared to embryonic stem cells, we found that the bivalency (that is, co-occurrence of H3K4me3 and H3K27me3) in early embryos is relatively infrequent and unstable. Taken together, our results provide a genome-wide map of H3K4me3 and H3K27me3 modifications in pre-implantation embryos, facilitating further exploration of the mechanism for epigenetic regulation in early embryos.

Highly Accurate Visual Method of Mars Terrain Classification for Rovers Based on Novel Image Features.

It is important for Mars exploration rovers to achieve autonomous and safe mobility over rough terrain. Terrain classification can help rovers to select a safe terrain to traverse and avoid sinking and/or damaging the vehicle. Mars terrains are often classified using visual methods. However, the accuracy of terrain classification has been less than 90% in read operations. A high-accuracy vision-based method for Mars terrain classification is presented in this paper. By analyzing Mars terrain characteristics, novel image features, including multiscale gray gradient-grade features, multiscale edges strength-grade features, multiscale frequency-domain mean amplitude features, multiscale spectrum symmetry features, and multiscale spectrum amplitude-moment features, are proposed that are specifically targeted for terrain classification. Three classifiers, K-nearest neighbor (KNN), support vector machine (SVM), and random forests (RF), are adopted to classify the terrain using the proposed features. The Mars image dataset MSLNet that was collected by the Mars Science Laboratory (MSL, Curiosity) rover is used to conduct terrain classification experiments. The resolution of Mars images in the dataset is 256 × 256. Experimental results indicate that the RF classifies Mars terrain at the highest level of accuracy of 94.66%.

Inhibition of long noncoding RNA MALAT1 suppresses high glucose-induced apoptosis and inflammation in human umbilical vein endothelial cells by suppressing the NF-κB signaling pathway.

The study investigated the expression of long noncoding RNA (lncRNA) MALAT1 in high glucose (HG)-induced human vascular endothelial cells (HUVECs) and the role of MALAT1 in the apoptosis of HG-induced HUVECs. The HUVECs were cultured and induced with 25 mmol/L HG. After that, the HUVECs were transfected with MALAT1 siRNA. The expression levels of MALAT1 were detected with qPCR, whereas the expression levels of Bax, Bcl-2, cleaved-caspase-3, cleaved-caspase-9, p-65, and p-p65 were detected using Western blot. The roles of MALAT1 in cell activities, including apoptosis, were evaluated using the CCK-8 assay, TUNEL staining, and flow cytometry. The expression levels of inflammatory factors (TNF-α and IL-6) were measured using ELISA. The expression levels of MALAT1, TNF-α, and IL-6 in HUVECs were increased in the HG environment; however, when MALAT1 was silenced in the HUVECs, cell proliferation increased significantly, the expression levels of TNF-α, IL-6, Bax, cleaved-caspase-3, and cleaved-caspase-9 decreased, and the rate of apoptosis also decreased. Silencing MALAT1 inhibited the expression of p-p65 in HG-induced HUVECs. In conclusion, our study demonstrated that MALAT1 is upregulated in HG-induced HUVECs, and inhibition of MALAT1 inhibits HG-induced apoptosis and inflammation in HUVECs by suppression of the NF-κB signaling pathway.

Intelligent Sea States Identification Based on Maximum Likelihood Evidential Reasoning Rule.

It is necessary to switch the control strategies for propulsion system frequently according to the changes of sea states in order to ensure the stability and safety of the navigation. Therefore, identifying the current sea state timely and effectively is of great significance to ensure ship safety. To this end, a reasoning model that is based on maximum likelihood evidential reasoning (MAKER) rule is developed to identify the propeller ventilation type, and the result is used as the basis for the sea states identification. Firstly, a data-driven MAKER model is constructed, which fully considers the interdependence between the input features. Secondly, the genetic algorithm (GA) is used to optimize the parameters of the MAKER model in order to improve the evaluation accuracy. Finally, a simulation is built to obtain experimental data to train the MAKER model, and the validity of the model is verified. The results show that the intelligent sea state identification model that is based on the MAKER rule can identify the propeller ventilation type more accurately, and finally realize intelligent identification of sea states.

Identification of MSX1 and DCLK1 as mRNA Biomarkers for Colorectal Cancer Detection Through DNA Methylation Information.

Colorectal cancer is the second most deadly malignancy in the United States. However, the currently screening options had their limitation. Novel biomarkers for colorectal cancer detections are necessary to reduce the mortality. The clinical information, mRNA expression levels and DNA methylation information of colorectal cancer were downloaded from TCGA. The patients were separated into training group and testing group based on their platforms for DNA methylation. Beta values of DNA methylation from tumor tissues and normal tissues were utilized to figure out the position that were differentially methylated. The expression levels of mRNA of thirteen genes, whose CpG islands were differentially methylated, were extracted from the RNA-Seq results from TCGA. The probabilities whether the mRNA was differentially expressed between tumor and normal samples were calculated using Student's t-test. Logistic regression and decision tree were built for cancer detection and their performances were evaluated by the area under the curve (AUC). Twenty-four genomic locations were differentially methylated, which could be mapped to eleven genes. Nine out of eleven genes had differentially expressed mRNA levels, which were used to build the model for cancer detection. The final detection models consisting of mRNA expression levels of these nine genes had great performances on both training group and testing group. The model that constructed in this study suggested MSX1 and DCLK1 might be used in colorectal cancer detection or as target of cancer therapies. J. Cell. Physiol. 232: 1879-1884, 2017. © 2016 Wiley Periodicals, Inc.

The role of plasma membrane H(+) -ATPase in jasmonate-induced ion fluxes and stomatal closure in Arabidopsis thaliana.

Methyl jasmonate (MeJA) elicits stomatal closure in many plant species. Stomatal closure is accompanied by large ion fluxes across the plasma membrane (PM). Here, we recorded the transmembrane ion fluxes of H(+) , Ca(2+) and K(+) in guard cells of wild-type (Col-0) Arabidopsis, the CORONATINE INSENSITIVE1 (COI1) mutant coi1-1 and the PM H(+) -ATPase mutants aha1-6 and aha1-7, using a non-invasive micro-test technique. We showed that MeJA induced transmembrane H(+) efflux, Ca(2+) influx and K(+) efflux across the PM of Col-0 guard cells. However, this ion transport was abolished in coi1-1 guard cells, suggesting that MeJA-induced transmembrane ion flux requires COI1. Furthermore, the H(+) efflux and Ca(2+) influx in Col-0 guard cells was impaired by vanadate pre-treatment or PM H(+) -ATPase mutation, suggesting that the rapid H(+) efflux mediated by PM H(+) -ATPases could function upstream of the Ca(2+) flux. After the rapid H(+) efflux, the Col-0 guard cells had a longer oscillation period than before MeJA treatment, indicating that the activity of the PM H(+) -ATPase was reduced. Finally, the elevation of cytosolic Ca(2+) concentration and the depolarized PM drive the efflux of K(+) from the cell, resulting in loss of turgor and closure of the stomata.

Path-following control of wheeled planetary exploration robots moving on deformable rough terrain.

The control of planetary rovers, which are high performance mobile robots that move on deformable rough terrain, is a challenging problem. Taking lateral skid into account, this paper presents a rough terrain model and nonholonomic kinematics model for planetary rovers. An approach is proposed in which the reference path is generated according to the planned path by combining look-ahead distance and path updating distance on the basis of the carrot following method. A path-following strategy for wheeled planetary exploration robots incorporating slip compensation is designed. Simulation results of a four-wheeled robot on deformable rough terrain verify that it can be controlled to follow a planned path with good precision, despite the fact that the wheels will obviously skid and slip.

Cumulative remnant cholesterol as a causal risk factor for ischemic heart disease: A prospective cohort study.

BACKGROUND: While previous studies have established a significant correlation between baseline remnant cholesterol (RC) and ischemic heart disease (IHD), the enduring impact of RC on incident IHD remains to be elucidated. This study aimed to investigate the association between cumulative remnant cholesterol(cumRC) and IHD susceptibility. METHODS: Participating from the Kailuan Study (2006-2010) were enrolled, excluding those with prior myocardial infarction, coronary artery revascularization and cancer across three consecutive examinations. The cumRC derived by multiplying the average RC with the interval between the two consecutive assessments. Participants were segmented into quartiles based on cumRC levels: Q1 (cumRC < 2.69 mmol/l); Q2 (2.69 ≤ cumRC < 4.04 mmol/l); Q3(4.04 ≤ cumRC < 5.65 mmol/l) and Q4 (cumRC ≥ 5.65 mmol/l). The correlation between cumRC and IHD risk was ascertained by using multivariable Cox proportional hazard models. RESULT: The analysis encompassed 42,639 participants. Over an average tracking period of 9.97 years, 1,205 instances of IHD were identified. IHD susceptibility augmented with rising cumRC quartiles. After adjusting for potential confounders, the hazard ratios for IHD events were 1.06 (0.88-1.29) for Q2, 1.30 (1.08-1.56) for Q3 and 1.69 (1.42-2.01) for Q4, relative to Q1. Elevated cumRC was significantly associated with a heightened IHD risk, a trend consistent in both subgroup and sensitivity analyses. CONCLUSION: Elevated cumRC significantly correlates with a higher risk of IHD, suggesting that consistent monitoring and regulation of RC might be instrumental in IHD prevention.

Weight fluctuations preceding and succeeding heart failure diagnosis: Implications for all-cause mortality.

OBJECTIVE: This study aims to explore the ramifications of weight fluctuations preceding and succeeding the identification of heart failure (HF) on all-cause mortality. METHODS: The research cohort comprised individuals engaged in the Kailuan Group's health assessments from 2006 to 2018, who were subsequently diagnosed with HF. The moment of HF recognition marked the commencement of the monitoring period, culminating either at the instance of comprehensive mortality or at the conclusion of the monitoring phase (December 31, 2021). RESULTS: Throughout an average monitoring span of 5.8±3.5 years, from the 3115 qualified participants, 957 instances (30.7%) encountered comprehensive mortality. The COX proportional hazards regression model's outcomes revealed that, post the adjustment for potential confounders, in comparison to the Q3 category, the Q1 category had the highest hazard ratios (95% confidence intervals) of 1.71 (1.43-2.05). CONCLUSION: Weight reduction before and post the HF diagnosis stands as an autonomous risk determinant for comprehensive mortality.

Lunar rock investigation and tri-aspect characterization of lunar farside regolith by a digital twin.

Yutu-2 rover conducted an exciting expedition on the 41st lunar day to investigate a fin-shaped rock at Longji site (45.44°S, 177.56°E) by extending its locomotion margin on perilous peaks. The varied locomotion encountered, especially multi-form wheel slippage, during the journey to the target rock, established unique conditions for a fin-grained lunar regolith analysis regarding bearing, shear and lateral properties based on terramechanics. Here, we show a tri-aspect characterization of lunar regolith and infer the rock's origin using a digital twin. We estimate internal friction angle within 21.5°-42.0° and associated cohesion of 520-3154 Pa in the Chang'E-4 operational site. These findings suggest shear characteristics similar to Apollo 12 mission samples but notably higher cohesion compared to regolith investigated on most nearside lunar missions. We estimate external friction angle in lateral properties to be within 8.3°-16.5°, which fills the gaps of the lateral property estimation of the lunar farside regolith and serves as a foundational parameter for subsequent engineering verifications. Our in-situ spectral investigations of the target rock unveil its composition of iron/magnesium-rich low-calcium pyroxene, linking it to the Zhinyu crater (45.34°S, 176.15°E) ejecta. Our results indicate that the combination of in-situ measurements with robotics technology in planetary exploration reveal the possibility of additional source regions contributing to the local materials at the Chang'E-4 site, implying a more complicated geological history in the vicinity.

In Situ Quantification of Strain-Induced Piezoelectric Potential of Dynamically Bending ZnO Microwires.

The piezoelectric properties of semiconductor micro/nanowires (M/NWs) are crucial for optimizing semiconductors' electronic structure and carrier dynamics. However, the dynamic characterization of the piezoelectric properties of M/NWs remains challenging. Here, a Kelvin probe force microscopy technique based on a dual-probe atomic force microscope is developed to achieve in situ piezoelectric potential measurements of dynamic bending MWs. This technique can not only characterize the surface potential on different crystal faces of ZnO MWs in a natural state through controllable axial rotation, but also investigate the piezoelectric potential of the dynamically bending flake-like ZnO MW at different points and under different strain loads. The results show that the surface potentials of different faces/positions of the ZnO MWs are varied significantly, and determine that the quasi-static conditions piezo-strain factor of the flake-like ZnO MW is 0.28 V/%, while the factor was 0.14 V/% under low-frequency (⩽5 Hz) sinusoidal strain loading. This work provides a significant methodology to further study piezoelectric materials, and it aims to facilitate their applications in piezoelectric devices and systems.

NN-Based Reinforcement Learning Optimal Control for Inequality-Constrained Nonlinear Discrete-Time Systems With Disturbances.

Based on actor-critic neural networks (NNs), an optimal controller is proposed for solving the constrained control problem of an affine nonlinear discrete-time system with disturbances. The actor NNs provide the control signals and the critic NNs work as the performance indicators of the controller. By converting the original state constraints into new input constraints and state constraints, the penalty functions are introduced into the cost function, and then the constrained optimal control problem is transformed into an unconstrained one. Further, the relationship between the optimal control input and worst-case disturbance is obtained using the Game theory. With Lyapunov stability theory, the control signals are ensured to be uniformly ultimately bounded (UUB). Finally, the effectiveness of the control algorithms is tested through a numeral simulation using a third-order dynamic system.

Hybrid achromatic microlenses with high numerical apertures and focusing efficiencies across the visible.

Compact visible wavelength achromats are essential for miniaturized and lightweight optics. However, fabrication of such achromats has proved to be exceptionally challenging. Here, using subsurface 3D printing inside mesoporous hosts we densely integrate aligned refractive and diffractive elements, forming thin high performance hybrid achromatic imaging micro-optics. Focusing efficiencies of 51-70% are achieved for 15µm thick, 90µm diameter, 0.3 numerical aperture microlenses. Chromatic focal length errors of less than 3% allow these microlenses to form high-quality images under broadband illumination (400-700 nm). Numerical apertures upwards of 0.47 are also achieved at the cost of some focusing efficiency, demonstrating the flexibility of this approach. Furthermore, larger area images are reconstructed from an array of hybrid achromatic microlenses, laying the groundwork for achromatic light-field imagers and displays. The presented approach precisely combines optical components within 3D space to achieve thin lens systems with high focusing efficiencies, high numerical apertures, and low chromatic focusing errors, providing a pathway towards achromatic micro-optical systems.

Learning physical characteristics like animals for legged robots.

Physical characteristics of terrains, such as softness and friction, provide essential information for legged robots to avoid non-geometric obstacles, like mires and slippery stones, in the wild. The perception of such characteristics often relies on tactile perception and vision prediction. Although tactile perception is more accurate, it is limited to close-range use; by contrast, establishing a supervised or self-supervised contactless prediction system using computer vision requires adequate labeled data and lacks the ability to adapt to the dynamic environment. In this paper, we simulate the behavior of animals and propose an unsupervised learning framework for legged robots to learn the physical characteristics of terrains, which is the first report to manage it online, incrementally and with the ability to solve cognitive conflicts. The proposed scheme allows robots to interact with the environment and adjust their cognition in real time, therefore endowing robots with the adaptation ability. Indoor and outdoor experiments on a hexapod robot are carried out to show that the robot can extract tactile and visual features of terrains to create cognitive networks independently; an associative layer between visual and tactile features is created during the robot's exploration; with the layer, the robot can autonomously generate a physical segmentation model of terrains and solve cognitive conflicts in an ever-changing environment, facilitating its safe navigation.

Enabling High Precision Gradient Index Control in Subsurface Multiphoton Lithography.

Multiphoton lithography inside a mesoporous host can create optical components with continuously tunable refractive indices in three-dimensional (3D) space. However, the process is very sensitive at exposure doses near the photoresist threshold, leading previous work to reliably achieve only a fraction of the available refractive index range for a given material system. Here, we present a method for greatly enhancing the uniformity of the subsurface micro-optics, increasing the reliable index range from 0.12 (in prior work) to 0.37 and decreasing the standard deviation (SD) at threshold from 0.13 to 0.0021. Three modifications to the previous method enable higher uniformity in all three spatial dimensions: (1) calibrating the planar write field of mirror galvanometers using a spatially varying optical transmission function which corrects for large-scale optical aberrations; (2) periodically relocating the piezoelectrically driven stage, termed piezo-galvo dithering, to reduce small-scale errors in writing; and (3) enforcing a constant time between each lateral cross section to reduce variation across all writing depths. With this new method, accurate fabrication of optics of any index between n = 1.20 and 1.57 (SD < 0.012 across the full range) was achieved inside a volume of porous silica. We demonstrate the importance of this increased accuracy and precision by fabricating and characterizing calibrated two-dimensional (2D) line gratings and flat gradient index lenses with significantly better performance than the corresponding control devices. As a visual representation, the University of Illinois logo made with 2D line gratings shows significant improvement in its color uniformity across its width.

Effect of pioglitazone on transdifferentiation of preosteoblasts from rat bone mesenchymal stem cells into adipocytes.

We aimed to examine the effect of pioglitazone on transdifferentiation of preosteoblasts from rat bone marrow mesenchymal stem cells (BMSCs) into adipocytes and investigate its effect on bone metabolism. BMSCs were harvested from the femurs and tibias of a rat, then separated, purified, proliferated for 3 generations and differentiated into preosteoblasts for 5 days and 14 days respectively in the presence of osteogenic medium. Thereafter, the preosteoblasts were cultured for 21 days in the presence of adipogenic medium with and without pioglitazone (1 µg/mL). Partially-differentiated osteoblasts were identified by mineralized nodules with Alizarin red S staining. Transdifferentiated adipocytes were identified by Oil Red O staining. Reverse transcription PCR (RT-PCR) was performed to assay the expression levels of osteogenic markers Runx2 and ALP, and an adipogenic marker PPARγ. Those cells cultured for 5 days did not show mineralized nodules as detected by staining of Alizarin red S, while those cultured for 14 days showed dispersed mineralized centers in the form of brown spots, although without obvious red mineralized nodules. After adipogenic transdifferentiation for 21 days, adipose-drops were found in cells of 5CG and 5EG earlier than those of 14CG and 14EG, and the former showed much more adipocytes separately as detected by Oil Red O staining. Whatever the time was 5 days or 14 days of BMSCs osteogenic differentiation, the cells cultured with pioglitazone showed much more adipocytes than those without pioglitazone. Our experiment showed that the less time it took for BMSCs osteogenic differentiation, a stronger ability remained for BMSCs to transdifferentiate into adipocytes. The mRNA expression levels of Runx2 and ALP were decreased by 1.79 and 1.90 times respectively in 5EG (P< 0.05) as compared with 5CG, and that of PPARγ was increased by 1.31 times in 5EG (P<0.05) as compared with 5CG. The mRNA expression levels of Runx2 and ALP were decreased by 1.45 and 1.54 times respectively in 14EG (P<0.05) as compared with 14CG, and that of PPARγ was increased by 1.39 times in 14EG (P<0.05) as compared with 14CG. It was concluded that pioglitazone stimulated the transdifferentiation of BMSCs into adipocytes. These observations provided a potential mechanism of imbalance in thiazolidinedione induced bone metabolism.

Adaptive Fuzzy Finite-Time Tracking Control for Nonstrict Full States Constrained Nonlinear System With Coupled Dead-Zone Input.

This article proposes an adaptive finite-time tracking control based on fuzzy-logic systems (FLSs) for an uncertain nonstrict nonlinear multi-input-multi-output (MIMO) full-state-constrained system with the coupled uncertain dead-zone input. By using three kinds of FLSs: the uncertain system, the uncertain dead zone, and the uncertain input transfer inverse matrix are approximated using the system function FLS, dead-zone FLS, and input transfer inverse matrix FLS, respectively. After defining the barrier Lyapunov function, the fuzzy-based adaptive tracking controllers are designed, and the fuzzy weights are updated through the proposed adaptive laws. Then, based on the extended finite-time convergence theorem, with the design parameters chosen properly, the target uncertain nonlinear system is guaranteed to be semiglobal practical finite-time stable (SGPFS); and the full-state constraints are not violated while avoiding the effects of the dead zones. Furthermore, a simulation is presented to verify the validity of the proposed algorithm.