Search

The accurate perception of external environment information through the robot foot is crucial for the mobile robot to evaluate its ability to traverse terrain. Adequate foot-end contact signals can provide robust support for robot motion control and decision-making processes. The shape and uncertain rotation of the wheel-legged robot foot end represent a significant challenge to sensing the robot foot-end contact state, which current foot-end sensing schemes cannot solve. This paper presents a sensing method for the tire stress field of wheel-legged robots. A finite element analysis was conducted to study the deformation characteristics of the foot-end tire under force. Based on this analysis, a heuristic contact position estimator was designed that utilizes symmetrical deformation characteristics. Strain sensors, arranged in an array, extract the deformation information on the inner surface of the tire at a frequency of 200 Hz. The contact position estimator reduces the dimensionality of the data and fits the eigenvalues to the estimated contact position. Using support vector regression, the force estimator utilizes the estimated contact position and sensor signal to estimate the normal reaction force, designated as FZ. The sensing system is capable of detecting the contact position on the wheel circumference (with a root mean square error of 1.150°), as well as the normal force of 160 N on the Z axis (with a root mean square error of 6.04%). To validate the efficacy of the sensor detection method, a series of randomized and repeated experiments were conducted on a self-constructed test platform. This novel approach offers a promising avenue for perceiving contact states in wheel-legged robots.

With the steady increase in allergy prevalence worldwide, there is a strong need for novel diagnostic tools for precise, fast, and less invasive testing methods. Herein, a miniatured fluorescence-based biosensing system is developed for the rapid and quantitative detection of allergen-specific immunoglobulin-E. An antibody-based fluorescence assay in a microfluidic-patterned slide, combined with a custom-made portable fluorescence reader for image acquisition and user-friendly software for the data analysis, enables obtaining results for multiple allergens in just ~1 h with only 80 μL of blood serum. The multiplexed detection of common birch, timothy grass, cat epithelia, house dust mite, and dog epithelia shows quantitative IgE-mediated allergic responses to specific allergens in control serum samples with known total IgE concentration. The responses are verified with different control tests and measurements with a commercial fluorescence reader. These results open the door to point-of-care allergy screening for early diagnosis and broader access and for large-scale research in allergies.

Quadruped robots equipped with manipulators need fast and precise grasping and detection algorithms for the transportation of disaster relief supplies. To address this, we developed a framework for these robots, comprising a Grasp Detection Controller (GDC), a Joint Trajectory Planner (JTP), a Leg Joint Controller (LJC), and a Manipulator Joint Controller (MJC). In the GDC, we proposed a lightweight grasp detection CNN based on DenseBlock called DES-LGCNN, which reduced algorithm complexity while maintaining accuracy by incorporating UP and DOWN modules with DenseBlock. For JTP, we optimized the model based on quadruped robot kinematics to enhance wrist camera visibility in dynamic environments. We integrated the network and model into our homemade robot control system and verified our framework through multiple experiments. First, we evaluated the accuracy of the grasp detection algorithm using the Cornell and Jacquard datasets. On the Jacquard dataset, we achieved a detection accuracy of 92.49% for grasp points within 6 ms. Second, we verified its visibility through simulation. Finally, we conducted dynamic scene experiments which consisted of a dynamic target scenario (DTS), a dynamic base scenario (DBS), and a dynamic target and base scenario (DTBS) using an SDU-150 physical robot. In all three scenarios, the object was successfully grasped. The results demonstrate the effectiveness of our framework in managing dynamic environments throughout task execution.

When two manipulators cooperate to clamp a rigid object, a closed chain with both ends fixed is formed. The singularity of a single manipulator causes the closed chain to be at a singularity, which results in uncertainty in the velocity mapping between the terminal and joint space. This study proposes a closed-chain singularity processing method for dual-arm collaboration, adopting the Jacobian pseudoinverse method based on damped least squares to obtain an approximate solution. During the solution process, the adaptive damping factor is improved by cubic polynomials, and the optimal damping factor is determined by quadratic sequence programming. Furthermore, this study analyzes the kinematic constraints of the closed-chain system and constructs a closed-chain Jacobian to judge whether the system is in a singular region. Finally, the effectiveness of the proposed method is verified through simulations.

The shear wave velocity (Vs) is significant for quantitative seismic interpretation. Although numerous studies have proved the effectiveness of the machine learning method in estimating the Vs using well-logging parameters, the real-world application is still hindered because of the black-box nature of machine learning models. With the rapid development of the interpretable machine learning (ML) technique, the drawback of ML can be overcome by various interpretation methods. This study applies the Light Gradient Boosting Machine (LightGBM) to predict the Vs of a carbonate reservoir and uses the Shapley Additive Explanations (SHAP) to interpret the model. The application of ML in Vs estimation normally involves using conventional well-log data that are highly correlated with Vs to train the model. To expand the model’s applicability in wells that lack essential logs, such as the density and neutron logs, we introduce three geologically important features, temperature, pressure, and formation, into the model. The LightGBM model is tuned by the automatic hyperparameter optimization framework; the result is compared with the Xu-Payne rock physics model and four machine learning models tuned with the same process. The results show that the LightGBM model can fit the training data and provide accurate predictions in the test well. The model outperforms the rock physics model and other ML models in both accuracy and training time. The SHAP analysis provides a detailed explanation of the contribution of each input variable to the model and demonstrates the variation of feature contribution in different reservoir conditions. Moreover, the validity of the LightGBM model is further proved by the consistency of the deduced information from feature dependency with the geological understanding of the carbonate formation. The study demonstrates that the newly added features can effectively improve model performance, and the importance of the input feature is not necessarily related to its correlation with Vs

Abstract The large and heavy‐duty hexapod robot has strong motion stability and load capacity, which promises to have a wide range of application prospects in rescue and disaster relief. Multi‐mode gait and static stability during walking make the hexapod robot adapt to more diverse terrains, while little research has been conducted on the motion control methods of heavy‐duty hexapod robots in complex environments. A novel heuristic whole‐body motion control framework for the heavy‐duty hexapod robot to traverse complex terrain is presented. By splitting the legged locomotion into a single task, the whole‐body motion could be planned in a reasonable time. The terrain adaptation strategy is designed to improve the complex terrain passability. Ground reaction forces are then optimised based on single rigid‐body dynamics with heuristics. This framework utilised simple but powerful heuristics to approximate complex dynamics and allows for a single set of parameters for all task conditions. Simulation results demonstrate the robustness and adaptability of the proposed framework.

Abstract A systematic solution is developed to improve the autonomous capability of the quadruped robot with a manipulator, such as navigation, recognition and operation. The developed system adopts novel software, hardware system and system architecture, including a specially designed environment awareness system (EAS). Based on the camera and LiDAR on the EAS, the recognition of multiple common targets, such as the leader, door, window and bag, is achieved. In terms of navigation, a location method is built, that combines the laser odometer and global positioning system. A mapping and path planning module is designed by the Robot‐centric Elevation Mapping algorithm and the rapidly exploring rand tree algorithm. For operation, a real‐time target grasp detection system is proposed based on the You Only Look Once v5 algorithm to improve the success rate of tasks. The whole system is integrated based on the task relevance scheduling strategy to reduce the computational complexity. The tightly integrated system and the subsystems are evaluated by conducting simulations and physical experiments in robot recognition, navigation and operation. Extensive experiments show that the proposed framework can better achieve the autonomous navigation and operation of the quadruped robot with a manipulator. Notably, the proposed framework is still effective when facing dynamic objects. In addition, the system can be easily extended to other forms of mobile robot.

China is rich in abundant lithium resources characterized by considerable reserves and a concentrated distribution of metallogenic zones or belts, with proven reserves of 4046.8×103 t (calculated based on Li2O) by 2021. China is also a big consumer of lithium. By 2019, China ’s lithium consumption in the battery sector alone had reached 99×103 t, with an average annual growth rate of nearly 26%. China has become the world ’s largest importer of lithium resources, showing a severely unbalanced relationship between supply and demand for lithium resources. Therefore, there is an urgent need for the prospecting, exploitation, and study of lithium resources in China. This study collected, organized, and summarized the data on the major lithium deposits in China, analyzed and compared the spatial-temporal distribution patterns, geological characteristics, and metallogenic regularity of these lithium deposits, and summarized the prospecting and research achievements over the last decade. The major lithium deposits in China are distributed in provinces and regions such as Qinghai, Jiangxi, Sichuan, Tibet, and Xinjiang. These deposits are mostly small in scale. According to different genetic types, this study divided lithium deposits into granitic pegmatite type, granite type, saline lake brine type, underground brine type, and sedimentary type, as well as new types including hot spring type and magmatic-hydrothermal type, and summarized the characteristics and key metallogenic factors of these different types of deposits. Sixteen metallogenic prospect areas of lithium deposits were delineated according to the deposit types and the distribution patterns of metallogenic belts. The paper introduced the research progress in major metallogenic models and lithium extraction techniques made over the past decade. Based on the comprehensive analysis of the prospecting potential of lithium deposits, the authors concluded that the future prospecting of lithium resources in China should focus on lithium metallogenic belts, the deep and peripheral areas of currently determined large-scale pegmatite-type lithium deposits, geophysical-geochemical anomalous areas with mineralization clues, and areas with developed large-scale low-grade associated granite-type and sedimentary lithium resources. The study aims to serve as a guide for the future prospecting of lithium deposits in China.©2022 China Geology Editorial Office.

Polysaccharides in boletes (Boletales) are economically significant to both function food and medicinal industries. The polysaccharides were extracted from the fruit bodies of eight boletes, namely, Aureoboletus longicollis, Butyriboletus hainanensis, Crocinoboletus rufoaureus, Hemioporus japonicus, Neoboletus infuscatus, Neoboletus obscureumbrinus, Tylopilus otsuensis, Xanthoconium fusciceps, which were collected from tropical China; their physicochemical properties and antioxidant activities were characterised and evaluated, respectively. The results revealed that the polysaccharides among the eight boletes were mainly composed of glucose, mannose, and galactose, with a broad molecular weight range, and contained a pyranose ring revealed by FT-IR and NMR spectral analyses. Many factors such as different species of boletes, geographic conditions, molecular weight, configuration, and monosaccharide content may affect the antioxidant power of polysaccharides, simultaneously, instead of one single factor. The antioxidant activities of the polysaccharides were measured according to in vitro assays of DPPH scavenging, superoxide anion scavenging, and ferrous ion reducing tests. The polysaccharide of C. rufoaureus has greatly superior antioxidant activity and it could serve as potential functional food or medicine.

The current research develops a mathematical model and control strategies to address two major problems force fighting and precise position tracking for a hybrid actuation system composed of servo-hydraulic actuator and electro-mechanical actuator (SHA/EMA). The force fighting and desired position tracking are two essential problems of the SHA/EMA actuation system for a large civil aircraft. The trajectory-based fractional order proportional integral derivative (FOPID) control for the SHA/EMA actuation system is proposed, tuned with the help of the particle swarm optimization (PSO) technique and implemented with the support of the FOMCON toolbox in Matlab. The experiments are performed under different external aerodynamic loads that the aircraft usually experiences during flight operations. The results show that the proposed method shows better results for tracking performance, force fighting and load rejection ability.

AbstractThe Amu Darya Right Bank Block is located northeast of the Amu Darya basin, a large petroliferous sedimentary basin, with abundant natural gas resources in carbonate rocks under the ultra-thick gypsum-salt layer. Oil fields producing crude oils have recently been found around large gas fields. Unraveling the origins of the crude oils is crucial for effective petroleum exploration and exploitation. The origin of gas condensates and crude oils was unraveled through the use of comprehensively analytical and interpretative geochemical approaches. Based on oil-source correlation, the reservoir forming process has been restored. The bulk geochemical parameters of the local source rocks of the ADRBB indicated that the local sources have hydrocarbon generation and accumulation potential. The middle-lower Jurassic coal-bearing mudstone is gas prone, while the mudstone of the Callovian-Oxfordian gap layer is oil prone, and the organic matter type of Callovian-Oxfordian carbonate rocks is the mixed type between the two previous source rocks. The interpretation schemes for compositions of n-alkanes, pristane and phytane, C27–C28–C29 sterane distributions, C19+C20–C21–C23 tricyclic terpane distributions, extended tricyclic terpane ratio, and δ13C indicated that crude oil is likely from marine organic matter, while condensates mainly originate from terrestrial organic matter. However, from the perspective of the 18α-trisnorneohopane/17α-trisnorhopane and isomerization ratio of C29 sterane, condensates are too mature to have originated in the local source rocks of the ADRBB, whose maturity is well comparable with that of crude oils. The geochemical, geologic, and tectonic evolutions collectively indicate that the crude oils were most likely generated and migrated from the relatively shallow, lowly mature gap layer and Callovian-Oxfordian carbonate rocks of the ADRBB, while the condensates mostly originated from the relatively deep and highly mature middle-lower coal-bearing mudstone and Callovian-Oxfordian carbonate rocks in the Murgab depression in the southeast of the basin. Basement faults are the key factors affecting the types of oil and gas reservoirs. During the periods of oil and gas migration, traps with basement faults mainly captured natural gas and condensates and traps without basement faults were enriched with crude oils generated from local source rocks.

Multiple myeloma (MM) is an incurable hematological malignancy that lacks effective therapeutic interventions. Ferroptosis is a newly discovered form of cell death that has shown great potential for MM therapy. As a proteasome inhibitor and necroptosis inducer, shikonin (SHK) performs dual functions in MM cells. However, whether SHK inhibits the development of MM via ferroptosis or any other mechanism remains elusive. Here, we provide evidence that SHK treatment was capable of inducing ferroptosis and immunogenic cell death (ICD) in MM. The results showed that SHK treatment induced lactate dehydrogenase release, triggered cell death, evoked oxidative stress, and enhanced ferrous iron and lipid peroxidation levels. Furthermore, treatment with ferroptosis inhibitors reversed SHK-induced cell death, which indicated that ferroptosis contributed to this phenomenon. Meanwhile, ferroptosis was accompanied by the extracellular release of Adenosine 5’-triphosphate (ATP) and High mobility group protein B1 (HMGB1), which are characteristics of ICD. Further investigation showed that glutamic-oxaloacetic transaminase 1 (GOT1) acted as a critical mediator of SHK-induced ferroptosis by promoting ferritinophagy. In conclusion, our findings suggest that SHK exerts ferroptotic effects on MM by regulating GOT1-mediated ferritinophagy. Thus, SHK is a potential therapeutic agent for MM.

Human action recognition based on skeleton information has been extensively used in various areas, such as human–computer interaction. In this paper, we extracted human skeleton data by constructing a two-stage human pose estimation model, which combined the improved single shot detector (SSD) algorithm with convolutional pose machines (CPM) to obtain human skeleton heatmaps. The backbone of the SSD algorithm was replaced with ResNet, which can characterize images effectively. In addition, we designed multiscale transformation rules for CPM to fuse the information of different scales and a convolutional neural network for the classification of the skeleton keypoints heatmaps to complete action recognition. Indoor and outdoor experiments were conducted on the Caster Moma mobile robot platform, and without an external remote control, the real-time movement of the robot was controlled by the leader through command actions.

ObjectivePermanent pacemaker implantation (PPI) is a common complication after transcatheter aortic valve replacement (TAVR). Recently, the cusp-overlap projection (COP) technique was thought to be a feasible method to reduce PPI risk. However, the evidence is still relatively scarce. Therefore, this meta-analysis was performed to compare COP and standard three-cusp coplanar (TCC) projection technique.MethodsPubMed and EMBASE databases were systematically searched for relevant literature published from the inception (EMBASE from 1974 and PubMed from 1966) to 16 April 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome of interest was post-operative (including in-hospital and 30-day) PPI.ResultsTotal of 3,647 subjects from 11 studies were included in this meta-analysis. Of those, 1,453 underwent self-expanding TAVR using COP and 2,194 using TCC technique. In a pooled analysis, the cumulative PPI incidence was 9.3% [95% confidence interval (CI): 6.9–11.7%] and 18.9% (95% CI: 15.5–22.3%) in the COP group and TCC group, respectively. The application of the COP technique was associated with a significant PPI risk reduction (I2 = 40.3% and heterogeneity Chi-square p = 0.070, random-effects OR: 0.49, 95% CI: 0.36–0.66, p < 0.001). A higher implantation depth was achieved in the COP group compared with the TCC group [standardized mean difference (SMD) = −0.324, 95% CI: (−0.469, −0.180)]. There was no significant difference between the two groups in second valve implantation, prosthesis pop-out, fluoroscopic time, post-operative left bundle branch block, mortality, stroke, moderate/severe paravalvular leakage, mean gradient, and length of hospital stay. However, radiation doses were higher in the COP group [SMD = 0.394, 95% CI: (0.216, 0.572), p < 0.001].ConclusionIn self-expanding TAVR, the application of the cusp overlap projection technique was associated with a lower risk of PPI compared with the standard TCC technique.Systematic review registration[https://inplasy.com/inplasy-2022-4-0092/], identifier [INPLASY202240092].

Abstract Background Lipotoxicity-induced cell death plays a detrimental role in the pathogenesis of metabolic diseases. Ferulic acid, widespread in plant-based food, is a radical scavenger with multiple bioactivities. However, the benefits of ferulic acid against hepatic lipotoxicity are largely unclear. Here, we investigated the protective effect of ferulic acid against palmitate-induced lipotoxicity and clarified its potential mechanisms in AML-12 hepatocytes. Methods AML-12 mouse hepatocytes were exposed to palmitate to mimic lipotoxicity. Different doses (25, 50, and 100 μM) of ferulic acid were added 2 h before palmitate treatment. Cell viability was detected by measuring lactate dehydrogenase release, nuclear staining, and the expression of cleaved-caspase-3. Intracellular reactive oxygen species content and mitochondrial membrane potential were analysed by fluorescent probes. The potential mechanisms were explored by molecular biological methods, including Western blotting and quantitative real-time PCR, and were further verified by siRNA interference. Results Our data showed that ferulic acid significantly inhibited palmitate-induced cell death, rescued mitochondrial membrane potential, reduced reactive oxygen species accumulation, and decreased inflammatory factor activation, including IL-6 and IL-1beta. Ferulic acid significantly stimulated autophagy in hepatocytes, whereas autophagy suppression blocked the protective effect of ferulic acid against lipotoxicity. Ferulic acid-activated autophagy, which was triggered by SIRT1 upregulation, was mechanistically involved in its anti-lipotoxicity effects. SIRT1 silencing blocked most beneficial changes induced by ferulic acid. Conclusions We demonstrated that the phytochemical ferulic acid, which is found in plant-based food, protected against hepatic lipotoxicity, through the SIRT1/autophagy pathway. Increased intake of ferulic acid-enriched food is a potential strategy to prevent and/or improve metabolic diseases with lipotoxicity as a typical pathological feature.

Some quadruped robots developed recently show better dynamic performance and environmental adaptability than ever, and have been preliminarily applied in the field of emergency disposal, military reconnaissance and infrastructure construction. The development route, mechanisms design, control methods and mobile manipulating approaches of the quadruped robots are surveyed in this article. Firstly, the development route of the quadruped robot is combed, as the references of the forecast of the future work on quadruped robots. Then the bionic structure and the motion control method of the quadruped robot is summarized, the advantages and disadvantages are analyzed in aspects of gait switching, terrain adaption and disturbance resistance. Subsequently, aiming at the mobile manipulation of the quadruped robot, the representative leg-arm collaborative robots and the multi-task-oriented Whole-body Control (WBC) methods are introduced. Finally, the summary and future work of the quadruped robots is given.

This paper presents a detailed experimental investigation on the effects of projectile hardness on the behaviour of thermoplastic composites under impact loading. In this research, gas-gun experiments employ gelatine and high-density polyethylene (HDPE) projectiles, of the same mass and diameter, to impact against woven carbon-fibre reinforced poly (ether-ether ketone) (CF/PEEK) composite specimens. During the experiments, a high-speed camera is employed to capture the deformation of the projectiles and a three-dimensional (3D) Digital Image Correlation (DIC) system is employed to record the major strain and out-of-plane displacement of the thermoplastic composite specimens. Experimental results, including the Digital Image Correlation (DIC) output and the post-impact status, are obtained and compared to show the effects of harder projectiles on increasing the impact damage. The composite specimens, impacted by gelatine and high-density polyethylene (HDPE) projectiles, presented similar values of the major strain and out-of-plane displacement, but the high-density polyethylene (HDPE)-impacted composite specimens show more severe damage than the gelatine-impacted composite specimens. Keywords: Soft impact, Projectile hardness, Digital Image Correlation, Damage mechanisms, Composites

The quadruped robots have superior adaptability to complex terrains, compared with tracked and wheeled robots. Therefore, leader-following can help quadruped robots accomplish long-distance transportation tasks. However, long-term following has to face the change of day and night as well as the presence of interference. To solve this problem, we present a day/night leader-following method for quadruped robots toward robustness and fault-tolerant person following in complex environments. In this approach, we construct an Adaptive Federated Filter algorithm framework, which fuses the visual leader-following method and the LiDAR detection algorithm based on reflective intensity. Moreover, the framework uses the Kalman filter and adaptively adjusts the information sharing factor according to the light condition. In particular, the framework uses fault detection and multisensors information to stably achieve day/night leader-following. The approach is experimentally verified on the quadruped robot SDU-150 (Shandong University, Shandong, China). Extensive experiments reveal that robots can identify leaders stably and effectively indoors and outdoors with illumination variations and unknown interference day and night.

The morphology, ecology, and phylogenetic relationships of specimens of the family Boletaceae from subtropical and tropical China were investigated. Four species, Butyriboletus huangnianlaii, Lanmaoa macrocarpa, Neoboletus multipunctatus, and Sutorius subrufus, are new to science. Chalciporus radiatus and Caloboletus xiangtoushanensis are redescribed. Caloboletus guanyui is proposed to replace Boletus quercinus Hongo, an illegitimate later homonym. The recently described Tylopilus callainus is synonymized with the Japanese Boletus virescens, and the new combination T. virescens (Har. Takah. & Taneyama) N.K. Zeng et al. is proposed. Moreover, Neoboletus is treated as an independent genus based on evidence from morphology and molecular phylogenetic data in the present study, and many previously described taxa of Sutorius are recombined into Neoboletus: N. ferrugineus (G. Wu et al.) N.K. Zeng et al., N. flavidus (G. Wu & Zhu L. Yang) N.K. Zeng et al., N. hainanensis (T.H. Li & M. Zang) N.K. Zeng et al., N. obscureumbrinus (Hongo) N.K. Zeng et al., N. rubriporus (G. Wu & Zhu L. Yang) N.K. Zeng et al., N. sanguineoides (G. Wu & Zhu L. Yang) N.K. Zeng et al. , N. sanguineus (G. Wu & Zhu L. Yang) N.K. Zeng et al., and N. tomentulosus (M. Zang et al.) N.K. Zeng et al.

The control technique for generating whole body motions on wheel-leg robot for dynamic locomotion and balance is a challenging topic. In this paper, a whole body dynamic model is built. It consisted by the torso dynamic model, the wheel-leg dynamic model and the contact force constraint between the wheels and the ground. A whole body control frame is proposed which composed by a torso motion controller, two torque solvers, a slippage predictor and an online trajectory generator. The torso controller plans the coupling wrenches between wheel-legs and torso. The torque solvers for every wheel-leg compute joint torques based on the coupling wrenches computed from the torso controller synchronously. The contact forces can be calculated by the slippage predictor based on the joint torques, then a boolean signal will be transmitted to the online trajectories generator to indicate whether the friction cone constraint will be broken. The online trajectory generator can plan reasonable acceleration trajectory with different boolean signals. The efficiency of this control frame is illustrated by several simulations in virtual simulation environment.

A hydraulic servo actuator with passive compliance (HPCA) is designed for hydraulic actuated quadruped robots, aiming to solve the response discrepancy of the low-bandwidth servo valve to impact forces between robot's feet and the ground. This paper focuses on the performance of this passive compliance method combined with an active compliance control strategy when used on quadruped robots. First, the frequency-response characteristics of the HPCA are further discussed. Then, combined with the requirements of the quadruped robot, a compliant method characterized by incorporating dynamic feedforward control and joint angle feedback control items into the virtual model is proposed. Finally, both the new algorithm and the performance of the HPCA are verified by simulation and experiment. The results demonstrate that, compared with the original actuator, the frequency-response characteristics of the HPCA have better adaptability for the quadruped robot, while the efficiency of the active compliance control is also improved by this novel passive compliance strategy.

In order to control the posture, balance and movements of a wheel-leg robot(WLR) precisely, some problems have to be solved. The major problems involve the strongly coupling of movement states, the composite uncertainty with modeling errors, the time-varying internal and the external disturbances. In this paper, a force controller based on the uncertainty and disturbance estimation(UDE) method is designed. The feedforward compensation based on dynamic model allows for compliant and more precise motion control. The UDE can estimate and compensate the composite uncertainty without any priori information effectively. The posture controller is designed based on the virtual model control. The whole controller which includes the posture controller and the movements balance controller is proposed and applied for WLR that built in Webots. The simulation results of trajectory control, balance control and robust test are presented to demonstrate the effectiveness of the whole controller.

The occurrence of lipotoxicity during obesity-associated cardiomyopathy is detrimental to health. Salvianolic acid A (SAA), a natural polyphenol extract of Salvia miltiorrhiza Bunge (Danshen in China), is known to be cardioprotective. However, its clinical benefits against obesity-associated cardiomyocyte injuries are unclear. This study aimed at evaluating the protective effects of SAA against lipotoxicity-induced myocardial injury and its underlying mechanisms in high fat diet (HFD)-fed mice and in palmitate-treated cardiomyocyte cells (H9c2). Our analysis of aspartate aminotransferase and creatine kinase isoenzyme-MB (CM-KB) levels revealed that SAA significantly reversed HFD-induced myocardium morphological changes and improved myocardial damage. Salvianolic acid A pretreatment ameliorated palmitic acid-induced myocardial cell death and was accompanied by mitochondrial membrane potential and intracellular reactive oxygen species improvement. Analysis of the underlying mechanisms showed that SAA reversed myocardial TLR4 induction in HFD-fed mice and H9c2 cells. Palmitic acid-induced cell death was significantly reversed by CLI-95, a specific TLR4 inhibitor. TLR4 activation by LPS significantly suppressed SAA-mediated lipotoxicity protection. Additionally, SAA inhibited lipotoxicity-mediated expression of TLR4 target genes, including MyD88 and p-JNK/MAPK in HFD-fed mice and H9c2 cells. However, SAA did not exert any effect on palmitic acid-induced SIRT1 suppression and p-AMPK induction. In conclusion, our data shows that SAA protects against lipotoxicity-induced myocardial damage through a TLR4/MAPKs mediated mechanism.

Background: Salvianolic acid A (Sal A), a natural polyphenol compound extracted from Radix Salvia miltiorrhiza (known as Danshen in China), possesses a variety of potential pharmacological activities. The aim of this study is to determine mechanisms of hepatoprotective effects of Sal A against lipotoxicity both in cultured hepatocytes and in a mouse model of fatty liver disease.Methods: High-fat and high-carbohydrate diet (HFCD)-fed C57BL/6J mice were employed to establish hepatic lipotoxicity in a mouse model. Two doses of Sal A were administered every other day via intraperitoneal injection (20 and 40 mg/kg BW, respectively). After a 10-week intervention, liver injury was detected by immunohistochemical and biochemical analyses. For in vitro studies, we used HepG2, a human hepatoma cell line, and exposed them to palmitic acid to induce lipotoxicity. The protective effects of Sal A on palmitic acid-induced lipotoxicity were examined in Sal A-pretreated HepG2 cells.Results: Sal A treatments attenuated body weight gain, liver injury, and hepatic steatosis in mice exposed to HFCD. Sal A pretreatments ameliorated palmitic acid-induced cell death but did not reverse effects of HFCD- or palmitate-induced activations of JNK, ERK1/2, and PKA. Induction of p38 phosphorylation was significantly reversed by Sal A in HFCD-fed mice but not in palmitate-treated HepG2 cells. However, Sal A rescued hepatic AMP-activated protein kinase (AMPK) suppression and sirtuin 1 (SIRT1) downregulation by both HFCD feeding in mice and exposure to palmitate in HepG2 cells. Sal A dose-dependently up-regulated p-AMPK and SIRT1 protein levels. Importantly, siRNA silencing of either AMPK or SIRT1 gene expression abolished the protective effects of Sal A on lipotoxicity. Moreover, while AMPK silencing blocked Sal A-induced SIRT1, silencing of SIRT1 had no effect on Sal A-triggered AMPK activation, suggesting SIRT1 upregulation by Sal A is mediated by AMPK activation.Conclusion: Our data uncover a novel mechanism for hepatoprotective effects of Sal A against lipotoxicity both in livers from HFCD-fed mice and palmitic acid-treated hepatocytes.

This paper studies the H ∞ fault estimation problem for a class of discrete-time nonlinear systems subject to time-variant coefficient matrices, online available input, and exogenous disturbances. By assuming that the concerned nonlinearity is continuously differentiable and by using Taylor series expansions, the dynamic system is transferred as a linear time-variant system with modeling uncertainties. A non-conservative but nominal system and its corresponding H ∞ indefinite quadratic performance function are, respectively, given in place of the transferred uncertain system and the conventional performance metric, such that the estimation problem is converted as a two-stage optimization issue. By introducing an auxiliary model in Krein space, the so-called orthogonal projection technique is utilized to search an appropriate choice serving as the estimation of the fault signal. A necessary and sufficient condition on the existence of the fault estimator is given, and a recursive algorithm for computing the gain matrix of the estimator is proposed. The addressed method is applied to an indoor robot localization system to show its effectiveness.

Knee revision arthroplasty following peri-prosthetic joint infections is a formidable challenge. Patients are at a high risk of recurrent infection, and the soft tissue over the revised implant is often of questionable quality. Flap reconstruction has improved the salvage rates of infected arthroplasties, and should be considered in all cases of revision arthroplasty. We present a challenging case requiring staged reconstruction with two free latissimus dorsi flaps after the initial use of a medial gastrocnemius flap.

Fatty liver disease: spent antioxidant and liver cell death An imbalance between ROS and antioxidant molecules, induced by a high-fat diet, is a major contributor to non-alcoholic fatty liver disease in a mouse model. Dr. Zhenyuan Song from the University of Illinois at Chicago, USA, and colleagues showed that a 12-week high-fat diet consumption led to increased expression of the pro-inflammatory signaling molecule TNFα in the liver. It also resulted in conversion of the antioxidant molecule glutathione (GSH) into a “spent” form called glutathione disulfide (GSSG), a sign that the liver has dealt with a lot of cellular stress. Experiments in human liver cells showed that intracellualr GSSG accumulation sensitizes hepatocytes to cell death via a molecular cascade triggered by TNFα activity. These findings point to GSSG as a potential drug target for treating non-alcoholic fatty liver disease.

BackgroundAlcoholic liver disease (ALD) is a type of chronic liver disease caused by chronic ethanol overconsumption. The pathogenesis of ALD is complex and there is no effective clinical treatment thus far. SIRT3 is an NAD+-dependent deacetylase primarily located inside mitochondria, and reports on the effect of chronic alcohol exposure on liver SIRT3 expression are scarce. This study aims to investigate the effect of chronic alcohol consumption on hepatic SIRT3 expression and its role in alcoholic-induced liver injury.MethodsUsing the Lieber-DeCarli mouse model of ALD, we analyzed the regulation of SIRT3 and the effect of liver-specific knocking-down of SIRT3 on alcohol-induced liver injury. HepG2 and AML12 hepatocytes were employed to detect the biological function of SIRT3 on alcohol-induced hepatic cytotoxicity and its potential mechanism.ResultsChronic alcohol exposure led to hepatic SIRT3 upregulation and liver-specific SIRT3 knockdown alleviated alcoholic feeding-induced liver injury and lipid accumulation, which is associated with improved autophagy induction. In addition, autophagy induction contributed to the cytoprotective effect of SIRT3 knockdown on ethanol-induced hepatocyte cell death.ConclusionIn summary, our data suggest that hepatic SIRT3 upregulation in response to chronic alcohol exposure and liver-specific SIRT3 knockdown, induced autophagy activation further alleviating alcoholic-induced liver injury, which represents a novel mechanism in this process.

Research in the field of tribo-mechatronics has been gaining popularity in recent decades. The objective of the current research is to improve static/dynamics characteristics of hydrostatic bearings. Hydrostatic bearings always work in harsh environmental conditions that effect their performance, and which may even result in their failure. The current research proposes a mathematical model-based system for hydrostatic bearings that helps to improve its static/dynamic characteristics under varying conditions of performance-influencing variables such as temperature, spindle speed, external load, and clearance gap. To achieve these objectives, the capillary restrictors are replaced with servo valves, and a mathematical model is developed along with robust control design systems. The control system consists of feedforward and feedback control techniques that have not been applied before for hydrostatic bearings in the published literature. The feedforward control tries to remove a disturbance before it enters the system while feedback control achieves the objective of disturbance rejection and improves steady-state characteristics. The feedforward control is a trajectory-based controller and the feedback controller is a sliding mode controller with a PID sliding surface. The particle swarm optimization algorithm is used to tune the 6-dimensional vector of the tuning parameters with multi-objective performance criteria. Numerical investigations have been carried out to check the performance of the proposed system under varying conditions of viscosity, clearance gap, external load and the spindle speed. The comparison of our results with the published literature shows the effectiveness of the proposed system.

Current treatments of multiple sclerosis are aimed at immunosuppression. Here the authors show that kappa opioid receptor is important for oligodendrocyte differentiation and myelination and the receptor agonists are protective in a mouse model of multiple sclerosis.

Abstract Background Appropriate recipient vessel selection is a crucial aspect of microsurgical reconstruction. The chest wall presents several options for microvascular anastomosis, the most popular being the internal mammary and thoracodorsal vessels, although they may not always be available or suitable for breast reconstruction. We propose that the lateral thoracic vessels are a useful alternative, given their central position and intraoperative exposure in a skin-sparing mastectomy. Methods and Results We have performed four abdominal flaps based on the deep inferior epigastric artery and lateral thoracic vessels as the recipient vessels. The average diameter of the lateral thoracic artery was 2 mm and the vein was 2.75 mm. There were no vessel conversions, flap failures, or complications. Excellent aesthetic results were achieved. The anatomy of the lateral thoracic artery is described. Conclusion The lateral thoracic vessels are advantageous and safe recipient vessels. Their consistent anatomy, central location, and intraoperative exposure make them useful recipient vessels in breast reconstruction.

The hydraulic servo actuator with passive compliance (HPCA) is designed for hydraulically-driven quadruped robots. It is characterized by an accumulator that connects to the piston chamber of the hydraulic cylinder to buffer impact forces between a robot’s feet and the ground. This paper studies the energy efficiency of this actuator in the dynamic locomotion of a quadruped robot. Different from the traditional methods of storing potentially recyclable energy using accumulators, the energy-saving principle of HPCA is to utilize the pressure-transition characteristics of the asymmetric hydraulic cylinder with control of the symmetrical valve. The accumulator can store and release oil during the switching of the transition point in each gait cycle of the robot, thereby improving the energy efficiency of the actuator. The influence of the initial inflation pressure and working volume of the accumulator on the energy efficiency of the HPCA is studied by simulation and physical experiments. The results show that the HPCA has a higher energy efficiency that is independent of the physical parameters of the accumulator.

A motion control approach is proposed for hydraulic actuated quadruped robots, aiming to achieve active compliance and robust motion control. The approach is designed with a structure of three layers. Servo valve-controlled asymmetric hydraulic cylinder model is established to obtain the relationship between the desired torque and the control current signal, which is the bottom layer. The middle layer is based on the virtual model of the leg for active compliance. The upper layer considers the torso posture and velocity into planning the foot trajectories based on the spring loaded inverted pendulum model. Trotting gait simulations are conducted based on the proposed framework in the simulation software environment Webots. The motion control approach has been implemented on a robot prototype SCalf-II (SDU calf), where experiments have been conducted including omnidirectional trotting gait, lateral impact recovery and climbing slopes. The experiments demonstrate that the proposed approach can effectively control the hydraulic actuated robots.

To improve the mobility of the quadruped robot, a planar hopping control approach is proposed based on trotting gait. With the proposed approach, three joints of the stance legs are active and the fourth leg is passive. A planar kinematic model of the supporting phase is built and the calculated positions and posture of the torso are used as feedback for motion control. The forces and torque acting at the CoM of the robot torso in the plane are fully controllable and decoupled with the control approach based on a virtual model. The planar motions on three axes are controlled independently. For the hopping control, the total energy in a hopping cycle on the vertical direction is planned according to the desired hopping height of the torso's CoM and the virtual vertical stiffness of the torso is generated using the elastic potential energy of the virtual model. We verify the approach and its robustness using simulation experiments and show the results at the end of this paper.

Music tourism, a growing segment of the tourism industry, has significant socio-economic benefits but also poses environmental challenges. This study investigates the relationship between the perceived impact of music tourism and local community support in Kuala Lumpur, Malaysia, with a particular focus on the moderating effect of psychological egoism. Using Partial Least Square Structural Equation Modeling (PLS-SEM) and survey data from 134 local residents, we found that positive perceived impacts of tourism correlate with higher community support. However, psychological egoism influences this relationship, as individuals with higher egoism levels still support music tourism despite recognizing its negative impacts. These findings highlight the need for targeted educational campaigns to promote environmental sustainability and community well-being. Local governments and event organizers should focus on enhancing the positive impacts and mitigating the negative ones to foster sustainable tourism practices that align with conservation goals and contribute to UNESCO Sustainable Development Goal 8. [ABSTRACT FROM AUTHOR]