Mobile Robot Path Planningin Dynamic Environments:A Survey

There are many challenges for robot navigation in densely populated dynamic environments.This paper presents a survey of the path planning methods for robot navigation in dense environments.Particularly,the path planning in the navigation framework of mobile robots is composed of global path planning and local path planning,with regard to the planning scope and the executability.Within this framework,the recent progress of the path planning methods is presented in the paper,while examining their strengths and weaknesses.Notably,the recent developed Velocity Obstacle method and its variants that serve as the local planner are analyzed comprehensively.Moreover,as a model-free method that is widely used in current robot applications,the reinforcement learning-based path planning algorithms are detailed in this paper.

Design and Selection of Servomotor for Radial Aircraft Tire Secondary Molding Machine

The company Meridian Air Tire using two method molding,molding machine transmission components design selection using mitsubishi J4 series servo motor and control system.Among them,the two-segment host pitch and rotary servo motor selection is the most typical,this paper on its design ideas and selection of a detailed discussion,for manufacturers to correctly select servo motor to provide reference.

基于MML-IGMA模型的燃气涡轮流量计异常表征识别

燃气涡轮流量计在工况运行中,异常表征数据较少且部分异常表征与用户用气行为表征高度相似,使得燃气涡轮流量计的异常表征识别难度大。为此,本文提出一种结合机理分析与机器学习的燃气涡轮流量计异常表征识别模型MML—IGMA(Mechanism and Machine Learning to Identify Gas Meter Abnormity,结合机理分析与机器学习的燃气涡轮流量计异常识别)。该模型基于燃气涡轮流量计运行机理,定义异常表征空间并利用基于密度的聚类算法标签化异常表征空间内的可识别异常,再采用梯度提升机分类算法识别异常表征空间内的标签化样本。实验结果表明,在某陶瓷工业燃气用户一年工况历史数据上,MML-IGMA模型可以有效标签化异常表征并进行识别,识别精度可达97%。

Analysis of vibration attenuation characteristics of large thickness carbon fiber composite laminates

The vibration attenuation and damping characteristics of carbon fiber reinforced composite laminates with different thicknesses were investigated by hammering experiments under free boundary constraints in different directions.The dynamic signal testing and analysis system is applied to collect and analyze the vibration signals of the composite specimens,and combine the self-spectrum analysis and logarithmic decay method to identify the fundamental frequencies of different specimens and calculate the damping ratios of different directions of the specimens.The results showed that the overall stiffness of the specimen increased with the increase of the specimen thickness,and when the thickness of the sample increases from 24mm to 32mm,the fundamental frequency increases by 35.1%,the vibration showed the same vibration attenuation and energy dissipation characteristics in the 0°and 90°directions of the specimen,compared with the specimen in the 45°direction,which was less likely to be excited and had poorer vibration attenuation ability,while the upper and lower surfaces of the same specimen showed slightly different attenuation characteristics to the vibration,the maximum difference of damping capacity between top and bottom surfaces of CFRP plates is about 70%.

In situ autophagy regulation in synergy with phototherapy for breast cancer treatment

Autophagy is an important factor in reducing the efficacy of tumor phototherapy(including PTT and PDT).Accurate regulation of autophagy in tumor cells is a new strategy to improve the anti-tumor efficiency of PTT/PDT.This project intended to construct a tumor-activated autophagy regulator to efficiently block PTT/PDT-induced autophagy and realize synergistic sensitization to tumor phototherapy.To achieve this goal,we first synthesized TRANSFERRIN(Tf)biomimetic mineralized nano-tellurium(Tf-Te)as photosensitizer and then used disulfide bond reconstruction technology to induce Tf-Te self-assembly.The autophagy inhibitor hydroxychloroquine(HCQ)and iron ions carried by Tf were simultaneously loaded to prepare a tumor-responsive drug reservoir Tf-Te/HCQ.After entering breast cancer cells through the“self-guidance system”,Tf-Te/HCQ can generate hyperpyrexia and ROS under NIR laser irradiation,to efficiently induce PTT/PDT effect.Meanwhile,the disulfide bond broke down in response to GSH,and the nanoparticles disintegrated to release Fe2+and HCQ at fixed points.They simultaneously induce lysosomal alkalinization and increased osmotic pressure,effectively inhibit autophagy,and synergistically enhance the therapeutic effect of phototherapy.In vivo anti-tumor results have proved that the tumor inhibition rate of Tf-Te/HCQ can be as high as 88.6%on 4T1 tumor-bearing mice.This multifunctional drug delivery system might provide a new alternative for more precise and effective tumor phototherapy.

Seismogenic Structure of the 1605 Qiongshan M7½ Earthquake and Its Holocene Activity History in Northern Hainan Island, China: Evidence from Cross-Section Drilling and Shallow Seismic Profile

The 1605 M7½ Earthquake is the only earthquake in the history of China that has caused large-scale land subsidence into the sea,with the total area of land subsidence exceeding 100 km2.The disaster has led to the sinking of 72 villages.There is still no clear understanding of the source seismogenic fault of this earthquake.In this work,we conducted a detailed study of the middle segment of the Maniao-Puqian fault(MPF),which is the epicenter area,through geomorphological survey,data collection,shallow seismic exploration,cross-section drilling,and chronological dating.The results showed that the middle segment of the MPF zone is composed of three nearly parallel normal faults with a dextral strike-slip:“Macun-Luodou fault(F2-1),Haixiu-Dongyuan fault(F2-2),and ChangliuZhuxihe fault(F2-3)”.And F2-2 is composed of two secondary faults,namely F2-2′and F2-2″,with a flower-shaped structure buried under the ground.It is distributed nearly east-west,dipping to the north and has experienced at least five stages of activities since the Miocene.The vertical activity rates of F2-2′and F2-2″are~2.32 and~2.5 mm/a,since the Holocene,respectively.There were eight cycles of transgression and regression since the Miocene.The fault activity resulted in the thickening of the Holocene strata with a slight dip to the south,on the hanging wall,showing V-shaped characteristics.The MPF is likely the source seismogenic fault of the M7½ earthquake that hit Qiongshan in 1605.

Pharmacokinetic enhancement of oncolytic virus M1 by inhibiting JAK-STAT pathway

Oncolytic viruses(OVs),a group of replication-competent viruses that can selectively infect and kill cancer cells while leaving healthy cells intact,are emerging as promising living anticancer agents.Unlike traditional drugs composed of non-replicating compounds or biomolecules,the replicative nature of viruses confer unique pharmacokinetic properties that require further studies.Despite some pharmacokinetics studies of OVs,mechanistic insights into the connection between OV pharmacokinetics and antitumor efficacy remain vague.Here,we characterized the pharmacokinetic profile of oncolytic virus M1(OVM)in immunocompetent mouse tumor models and identified the JAK-STAT pathway as a key modulator of OVM pharmacokinetics.By suppressing the JAK-STAT pathway,early OVM pharmacokinetics are ameliorated,leading to enhanced tumor-specific viral accumulation,increased AUC and Cmax,and improved antitumor efficacy.Rather than compromising antitumor immunity after JAK-STAT inhibition,the improved pharmacokinetics of OVM promotes T cell recruitment and activation in the tumor microenvironment,providing an optimal opportunity for the therapeutic outcome of immune checkpoint blockade,such as anti-PD-L1.Taken together,this study advances our understanding of the pharmacokinetic-pharmacodynamic relationship in OV therapy.

Variation of blubber thickness of the Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis)in human care:Adaptation to environmental temperature

Blubber thickness(BT)has a seasonal pattern in most small cetaceans in temperate and polar regions,which may be a crucial adaptive mechanism in response to environmental temperature changes.However,BT and environmental temperature correlations have never been tested experimentally in any cetacean species owing to logistical difficulties in the aquatic environment.The Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis,YFP)is one of the smallest cetacean species worldwide,which exclusively inhabits the middle and lower regions of the Yangtze River in China.Here,we investigated BT variation patterns in YFPs and their relationship to environmental temperature changes using ultrasound imaging technology by longitudinally monitoring four YFPs in human care.We found that blubber was not evenly distributed in the skin of YFPs.BT increased along the craniocaudal axis from the head to the umbilical girth,and decreased towards the fluke,with relatively thicker blubber in the dorsal region than in the ventral and lateral regions.Significant negative correlations between BT and seasonal water temperature changes were observed in YFPs.However,different body regions display different sensitivities to seasonal temperature changes.The BT in the anal girth region exhibited noticeable seasonal changes.In contrast,the umbilical lateral and ventral regions showed relatively blunt seasonal changes,indicating different adaptive functions of the blubber in different regions.BT in the dorsal region decreased linearly with increasing water temperature.In the lateral and ventral regions,BT significantly changed with water temperature at a threshold of 18C.The YFPs had relatively thinner BT than similar-sized harbor porpoises that inhabit relatively high latitudes with much lower water temperatures.This further demonstrates the adaptive function of BT in response to environmental temperatures in small cetaceans.This study elucidates the seasonal pattern of BT variation in small cetaceans and provides insight into adaptation mechanisms of small cetaceans to temperature changes.

Autonomous battery-changing system for UAV's lifelong flight

Unmanned aerial vehicles(UAVs)lifelong flight is essential to accomplish various tasks,e.g.,aerial patrol,aerial rescue,etc.However,traditional UAVs have limited power to sustain their flight and need skilled operators manually control their charging process.Manufacturers and users are eagerly seeking a reliable autonomous battery-changing solution.To address this need,we propose and design an autonomous battery-changing system for UAVs using the theory of inventive problem solving(TRIZ)and user-centered design(UCD)methods.For practical application,we employ UCD to thoroughly analyze user requirements,identify multiple pairs of technical contradictions,and solve these inconsistencies using TRIZ theory.Furthermore,we design an autonomous battery-changing hardware system that meets user requirements and realizes the battery change process after the automatic landing of UAVs.Finally,we conduct experiments to validate our system’s effectiveness.The experimental results show that our battery-changing system can implement the autonomous battery-changing task,and our system has high efficiency and robustness in the real environment.

罗霄山脉大型真菌区系分析与资源评价

本文采用踏查法对罗霄山脉地区大型真菌资源进行了为期5年的调查,共采集标本5,100多号。结合形态学与分子生物学方法,鉴定出大型真菌2门7纲20目72科218属672种,其中幕阜山脉115种、九岭山脉168种、武功山脉77种、万洋山脉220种、诸广山脉193种;新增罗霄山脉新记录属37个、新记录种514种。对罗霄山脉大型真菌物种组成分析表明,含10种以上的优势科有18科,其物种数占物种总数的73.36%,为多孔菌科、蘑菇科、粉褶蕈科等;含5种以上的优势属有34属,其物种数占物种总数的55.36%,包括粉褶蕈属(Entoloma)、鹅膏属(Amanita)、小皮伞属(Marasmius)等;在该山脉发现中国特有属2个,中国特有种46个。大型真菌资源利用价值评估表明,罗霄山脉有食用菌133种、药用菌136种、毒菌87种,部分种类具有良好的应用前景。本研究为该地区大型真菌资源的保护、利用和管理提供了较重要的科学依据。

Exosomal S100A4 derived from highly metastatic hepatocellular carcinoma cells promotes metastasis by activating STAT3

Intercellular cross-talk plays important roles in cancer progression and metastasis.Yet how these cancer cells interact with each other is still largely unknown.Exosomes released by tumor cells have been proved to be effective cell-to-cell signal mediators.We explored the functional roles of exosomes in metastasis and the potential prognostic values for hepatocellular carcinoma(HCC).Exosomes were extracted from HCC cells of different metastatic potentials.The metastatic effects of exosomes derived from highly metastatic HCC cells(HMH)were evaluated both in vitro and in vivo.Exosomal proteins were identified with iTRAQ mass spectrum and verified in cell lines,xenograft tumor samples,and functional analyses.Exosomes released by HMH significantly enhanced the in vitro invasion and in vivo metastasis of low metastatic HCC cells(LMH).S100 calcium-binding protein A4(S100A4)was identified as a functional factor in exosomes derived from HMH.S100A4r,ch exosomes significantly promoted tumor metastasis both in vitro and in vivo compared with S100A4^(rich) exosomes or controls.Moreover,exosomal S100A4 could induce expression of osteopontin(OPN),along with other tumor metastasis/stemness-related genes.Exosomal S100A4 activated OPN transcription via STAT3 phosphorylation.HCC patients with high exosomal S100A4 in plasma also had a poorer prognosis.In conclusion,exosomes from HMH could promote the metastatic potential of LMH,and exosomal S100A4 is a key enhancer for HCC metastasis,activating STAT3 phosphorylation and up-regulating OPN expression.This suggested exosomal S100A4 to be a novel prognostic marker and therapeutic target for HCC metastasis.

Insulin-like growth factor 1-induced enolase 2 deacetylation by HDAC3 promotes metastasis of pancreatic cancer

Enolase 2(ENO2)is a key glycolytic enzyme in the metabolic process of glycolysis,but its potential function in pancreatic ductal adenocarcinoma(PDAC)is unclear.In this study,we observed a significant overexpression of ENO2 in PDAC tissues,and its expression was correlated with metastasis and poor prognosis in PDAC patients.K394 was identified as a major acetylation site in ENO2 that regulates its enzymatic activity,cell metabolism and PDAC progression.Knockdown of ENO2 suppressed tumor growth and liver metastasis in PDAC.Re-expression of wild-type(WT)ENO2,but not the K394 acetylation mimetic mutant,could reverse the decreased tumor malignancy.We further characterized histone deacetylase 3(HDAC3)and P300/CBP-associated factor(PCAF)as the potential deacetylase and acetyltransferase for ENO2,respectively.HDAC3-mediated deacetylation was shown to lead to ENO2 activation and enhancement of glycolysis.Importantly,insulin-like growth factor-1(IGF-1)was found to decrease K394 acetylation and stimulate ENO2 activity in a dose-and time-dependent manner.The PI3K/AKT/mTOR pathway facilitated the phosphorylation of HDAC3 on S424,which promoted K394 deacetylation and activation of ENO2.Linsitinib,an oral small-molecule inhibitor of IGF-1R,could inhibit IGF-1-induced ENO2 deacetylation by HDAC3 and the PI3K/AKT/mTOR pathway.Furthermore,linsitinib showed a different effect on the growth and metastasis of PDAC depending on the overexpression of WT versus K394-mutant ENO2.Our results reveal a novel mechanism by which acetylation negatively regulates ENO2 activity in the metastasis of PDAC by modulating glycolysis.Blockade of IGF-1-induced ENO2 deacetylation represents a promising strategy to prevent the development of PDAC.

Autonomous live working robot navigation with real-time detection and motion planning system on distribution line

In this study,an autonomous robot navigation system is designed for live working on distribution line.The developed system features a real-time detection and motion planning system,incorporating a manipulator capable of grasping power components.In order to accurately identify targets,the authors propose an object detection method based on the Larger Scale‘You Only Look Once’Version 4(LS-YOLOv4)algorithm for detecting the insulators and drop fuses.The LS-YOLOv4 extracts features of power components by Convolutional Neural Network(CNN),and then performs feature fusion.Then the authors develop a motion planning method based on the Node Control Optimal Rapidly Exploring Random Trees(NC-RRT*),which can drive the robot to realise the autonomous robot motion planning and obstacle avoidance.On the grasping function,the authors present a reliable Lightweight-based Convolutional Neural Network(L-CNN)grasping point detection method.Finally,the authors evaluate fully autonomous robotic system in both simulated and real-world experiments.The experimental results demonstrate that the proposed system can effectively identify the target and complete the grasping task in an efficient way.Notably,the proposed motion planning method can take into account both planning efficiency and accuracy to manipulation tasks.

Old commercialized magnetic particles new trick: Intrinsic internal standard

Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. ^(197)Au/^(57)Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6-300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.

Scene text removal via cascaded text stroke detection and erasing

Recent learning-based approaches show promising performance improvement for the scene text removal task but usually leave several remnants of text and provide visually unpleasant results.In this work,a novel end-to-end framework is proposed based on accurate text stroke detection.Specifically,the text removal problem is decoupled into text stroke detection and stroke removal;we design separate networks to solve these two subproblems,the latter being a generative network.These two networks are combined as a processing unit,which is cascaded to obtain our final model for text removal.Experimental results demonstrate that the proposed method substantially outperforms the state-of-the-art for locating and erasing scene text.A new large-scale real-world dataset with 12,120 images has been constructed and is being made available to facilitate research,as current publicly available datasets are mainly synthetic so cannot properly measure the performance of different methods.

Influence of functional polymorphism in MIF promoter on sudden cardiac death in Chinese populations

Sudden cardiac death(SCD)is defined as an unexpected natural death without any obvious non-cardiac causes that occurs within 1 h with witnessed symptom onset or within 24 h without witnessed symptom onset.Genetic studies conducted during the past decade have markedly illuminated the genetic basis of the cardiac disorders associated with SCD.Macrophage migration inhibitory factor(MIF)is an upstream immunoregulatory cytokine associated with the pathogenesis of many inflammatory diseases including atherosclerosis and myocardial infarction.Previous studies have reported that the functional -794(CATT)_(5-8) polymorphism in MIF is unrelated to sudden infant deth syndrome susceptibility.However,there are no reports concerning the association between the polymorphism and adult SCD susceptibility.In the current study,we investigated the association between the-794(CATT)_(5-8) polymorphism and adult SCD susceptibility using 79 adult SCD cases and 313 healthy controls.All samples were analysed using a conventional polymerase chain reaction(PCR)technique.We found that CATT_(6) and 5-6 were the most common allele and genotype in both groups,respectively,while no significant association was found between the-794(CATT)_(5-8) polymorphism and SCD susceptibility.We also summarized the allele frequencies of 794(CATT)_(5-8) in cohorts of healthy people from different countries and found that the allele frequency distributions of the polymorphism in Chinese populations were quite different from that of American and European populations(P=0.005,P=0.0001,respectively),but similar to Japanese populations(P=0.827).In conclusion,this study indicates that the-794(CATT)_(5-8) polymorphism may not be associated with adult SCD susceptibility in Chinese populations.Different allele frequency distributions of the polymorphism in multiple populations may provide a useful reference for further genetic association studies.

A person-following method based on monocular camera for quadruped robots

This paper proposes a person-following method based on monocular vision,which allows quadruped robots to track a target person in both indoor and outdoor environments with different illumination conditions.Our method is composed of a person detector,a Kalman filter(KF)tracker,and a re-identification module.To be more specific,the person detector uses a human pose estimation method to detect persons.The KF is applied to predict the position of the target person and update its state with detection results.A re-identification module is proposed to deal with distractions,where the Convolutional Channel Features(CCF)is used to extract appearance features and Online Boosting is used to distinguish the target person from others.Especially,we design a target recapture mechanism based on the Recurrent Neural Network(RNN).Combining motion information with appearance features,the system can accurately re-identify the target person.Without extra customized markers,our method can track the target person steadily in real-time only using a monocular camera.Experiments results can validate the robustness and effectiveness of the proposed method.