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"Chen, Zhiyu"
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A Mapless Local Path Planning Approach Using Deep Reinforcement Learning Framework
by
Liu, Gang
,
Chen, Zhiyu
,
Yin, Yan
in
Algorithms
,
Artificial intelligence
,
auxiliary reward functions
2023
The key module for autonomous mobile robots is path planning and obstacle avoidance. Global path planning based on known maps has been effectively achieved. Local path planning in unknown dynamic environments is still very challenging due to the lack of detailed environmental information and unpredictability. This paper proposes an end-to-end local path planner n-step dueling double DQN with reward-based ϵ-greedy (RND3QN) based on a deep reinforcement learning framework, which acquires environmental data from LiDAR as input and uses a neural network to fit Q-values to output the corresponding discrete actions. The bias is reduced using n-step bootstrapping based on deep Q-network (DQN). The ϵ-greedy exploration-exploitation strategy is improved with the reward value as a measure of exploration, and an auxiliary reward function is introduced to increase the reward distribution of the sparse reward environment. Simulation experiments are conducted on the gazebo to test the algorithm’s effectiveness. The experimental data demonstrate that the average total reward value of RND3QN is higher than that of algorithms such as dueling double DQN (D3QN), and the success rates are increased by 174%, 65%, and 61% over D3QN on three stages, respectively. We experimented on the turtlebot3 waffle pi robot, and the strategies learned from the simulation can be effectively transferred to the real robot.
Journal Article
Tumor-derived exosomal miR-934 induces macrophage M2 polarization to promote liver metastasis of colorectal cancer
2020
Background
Mounting evidence has demonstrated the vital importance of tumor-associated macrophages (TAMs) and exosomes in the formation of the premetastatic niche. However, the molecular mechanisms by which tumor-derived exosomal miRNAs interact with TAMs underlying premetastatic niche formation and colorectal cancer liver metastasis (CRLM) remain largely unknown.
Methods
Transmission electron microscopy and differential ultracentrifugation were used to verify the existence of exosomes. In vivo and in vitro assays were used to identify roles of exosomal miR-934. RNA pull-down assay, dual-luciferase reporter assay, etc. were applied to clarify the mechanism of exosomal miR-934 regulated the crosstalk between CRC cells and M2 macrophages.
Results
In the present study, we first demonstrated the aberrant overexpression of miR-934 in colorectal cancer (CRC), especially in CRLM, and its correlation with the poor prognosis of CRC patients. Then, we verified that CRC cell-derived exosomal miR-934 induced M2 macrophage polarization by downregulating PTEN expression and activating the PI3K/AKT signaling pathway. Moreover, we revealed that hnRNPA2B1 mediated miR-934 packaging into exosomes of CRC cells and then transferred exosomal miR-934 into macrophages. Interestingly, polarized M2 macrophages could induce premetastatic niche formation and promote CRLM by secreting CXCL13, which activated a CXCL13/CXCR5/NFκB/p65/miR-934 positive feedback loop in CRC cells.
Conclusions
These findings indicate that tumor-derived exosomal miR-934 can promote CRLM by regulating the crosstalk between CRC cells and TAMs. These findings reveal a tumor and TAM interaction in the metastatic microenvironment mediated by tumor-derived exosomes that affects CRLM. The present study also provides a theoretical basis for secondary liver cancer.
Journal Article
Analysis of catch rates of LED lamps using on the falling-net fishing vessels in South China Sea
2024
Falling nets are a type of fishing gear that appeared and developed rapidly in the northern of South China Sea in the early 1990s. We have developed Light-emitting diode (LED) fishing lamps to replace metal halide (MH) lamps that reduce fuel consumption without reducing the catches. We conducted marine light-fishing experiments in the northern South China Sea during September 20 to 26, 2019 and August 29 to 31, 2021. The results in the first fishing experiment show that there is no significant change in catch of the falling-net fishing vessel when the white LED lamps (with a total power of 36 kW) were used instead of MH lamps (with a total power of 120 kW). Coleoidea catches of the falling-net fishing vessel increased significantly when white LED lamps (with a total power of 36 kW) and cyan LED lamps (with a total power of 6.0 kW) were used. The results in the second fishing experiment show that the total weight of catches of the cyan LED fishing lamps is more than that of the white LED fishing lamps, and the cyan LED light can attract Penaeus merguiensis , Thryssa dussumieri and Sardinella zunasi more effectively than the white LED light.
Journal Article
Geographical characteristics and formation mechanisms of smallpox epidemics in Hubei Province, China, 1488–1949
by
Chen, Zhiyu
,
Gong, Shengsheng
,
Zeng, Yuxin
in
Analysis
,
Archives & records
,
Biology and life sciences
2025
Smallpox is a highly contagious and ancient disease influenced by natural and social factors. These factors led to the wide spread of smallpox in Hubei Province of China during the historical period. We conducted the spatial and temporal distribution patterns of smallpox epidemics and their formation mechanism in Hubei Province of China during 1488–1949. Based on epidemic history and environmental data, we used M-K test, wavelet analysis, spatial autocorrelation model, epidemic center of gravity model and geographically weighted regression models.In terms of temporal changes, the earliest smallpox in Hubei Province can be traced to the Ming Dynasty. Smallpox epidemics in the Republic of China showed fluctuating and changing trends; in 1939, incidences of smallpox grew abruptly. Smallpox epidemics in the Republic of China occurred on a fluctuating cycle of two time scales: 8 years and 18 years. The epidemic season was mainly spring and summer.Smallpox epidemics in Hubei Province had a wide spatial scope and exhibited spreading and diffusion characteristics; three towns of Wuhan, Suixian and Yichang were the centers of the epidemics. Smallpox epidemics exhibited significant spatial concentrations; high concentration areas occurred mainly in Wuchang, Hankou and Hanyang. The center of gravity of the epidemics exhibited a small swing from east to west and gradually shifted to the west.River networks, road networks, wars and other factors promoted smallpox epidemics; river networks and war factors were significant in eastern Hubei Province; road network factors were significant in southern Hubei Province; and droughts somewhat inhibited smallpox epidemics in western Hubei Province. Temperature fluctuations, droughts and floods, and war outbreaks played dominant roles in the temporal characteristics of smallpox epidemics in Hubei Province, and topography, population distribution and population movement played dominant roles in the spatial distribution pattern of smallpox epidemics in Hubei Province. We must establish and improve an epidemic monitoring and early warning system, pay attention to key areas, strengthen inspection and quarantine, stockpile smallpox vaccines, develop therapeutic drugs, and strengthen prevention of bioterrorism. Our study revealed how smallpox spreads in terms of both spatial and temporal patterns and mechanisms, and based on this, we can propose preventive and control measures against smallpox reemergence and its similar viruses.
Journal Article
The Dual Role of Macrophage Extracellular Traps in Host Defense and Disease: Mechanisms and Therapeutic Implications
2025
Macrophage extracellular traps (METs), which are extracellular immune structures released by macrophages, consist primarily of double-stranded DNA, histones, elastase, matrix metalloproteinase, myeloperoxidase, and other components. Recent studies have found that various pathogens (such as bacteria, fungi, and parasites) and environmental pollutants could induce the formation of METs through different mechanisms to help the host resist infection. However, accumulating evidence suggests that METs play a double-edged role in immune response, enhancing host defense while potentially contributing to tissue damage under certain pathological conditions. This review summarizes the mechanisms underlying the formation of METs, including different pathways triggered by various pathogens and environmental pollutants. We also discussed the role of METs in respiratory diseases, autoimmune diseases, metabolic diseases, tumors, and transplantation and injury, as well as recent advances in MET-targeted drugs, aiming to provide new insights for improving treatment strategies of relevant diseases.
Journal Article
The Role and Challenges of Women's Leadership in Community Development
2025
In China, the importance of community development is gradually becoming modified through the advancement of gender equality awareness. As a result, women's roles and their status in community development, such as community governance, decision making, resource integration and service innovation, have been increasingly emphasised. Yet, at the same time, women's leadership roles in promoting community development are still undervalued and face multiple challenges in the form of social constructs, institutional obstacles and conflicts in personal roles. Based on this disparity, the following study conducts in-depth research on the role of women's leadership in community development, elaborating on its importance and positive impact, and identifying the challenges it confronts. The study concludes by presenting strategies and practices to enhance women's leadership in community development.
Journal Article
A New Method for Extracting Three-Dimensional Surface Deformation in Underground Mining Areas Based on the Differentiability of D-InSAR Line-of-Sight Displacements
by
Chen, Zhiyu
,
Chen, Junjie
,
Zhao, Chunsu
in
Accuracy
,
Analysis
,
Artificial satellites in remote sensing
2024
Monitoring three-dimensional (3D) deformation in underground mining areas is crucial for the prevention and control of mining-induced disasters. Differential interferometric synthetic aperture radar (D-InSAR) is limited to detecting one-dimensional (1D) deformation along the line of sight (LOS). This paper proposes a new method for extracting 3D mining-induced deformation based on the differentiability of D-InSAR LOS deformation fields. The method approximates the D-InSAR LOS deformation field in underground mining areas as a differentiable function and constructs a 3D deformation extraction model utilizing directional derivatives of this function. The least squares method is used for estimating and evaluating the 3D deformation. Simulation and real data experiments have been used to verify the feasibility of the method in extracting mining-induced 3D deformation. The simulation results show relative root mean square errors (RRMSES) of 1.24%, 6.05%, 0.97%, and 11.47% for vertical and horizontal displacements along the east–west and south–north directions, respectively. The real data experiments using Sentinel-1 images show that the root mean square errors (RMSES) of the up–down, south–north, and east–west directions are 14.06 mm, 7.37 mm, and 11.56 mm, respectively. Experimental results show that the method can provide a certain basis for 3D surface deformation monitoring of mining subsidence.
Journal Article
Circular RNA expression alterations and function prediction in OSA-induced pancreatic injury in mice: New insights into pathogenesis
2023
Increasing studies have shown that circular RNAs (circRNAs) participate in the pathogenesis and progression of many diseases. However, the function of circRNAs in obstructive sleep apnea (OSA)-induced pancreatic damage has not been fully elucidated. In this study, the altered circRNA profiles in a chronic intermittent hypoxia (CIH) mouse model were investigated, aiming to provide novel clues for delineating the underlying mechanisms of OSA-induced pancreatic injury.
A CIH mouse model was established. circRNA microarray was then applied to profile circRNA expression in pancreatic samples from CIH groups and controls. Our preliminary findings were validated by qRT-PCR. Subsequently, GO and KEGG pathway analyses were carried out to annotate the biological functions of target genes of circRNAs. Lastly, we constructed a circRNA-miRNA-mRNA (ceRNA) network according to the predicted circRNA-miRNA and miRNA-mRNA pairs.
A total of 26 circRNAs were identified to be differentially expressed, with 5 downregulated and 21 upregulated in the CIH model mice. Six selected circRNAs were preliminarily used to confirm the results by qRT-PCR, which were consistent with microarray. GO and pathway analysis indicated that numerous mRNAs were involved in the MAPK signaling pathway. The ceRNA analysis displayed the broad potentials of the dysregulated circRNAs to modulate their target genes by acting as miRNAs sponges.
Taken together, our study first revealed the specific expression profile of circRNAs in CIH-induced pancreatic injury, which suggested a novel focus for investigating the molecular mechanism of OSA-induced pancreatic damage through modulating circRNAs.
Journal Article
Transcriptome analysis reveals insight into molecular hydrogen-induced cadmium tolerance in alfalfa: the prominent role of sulfur and (homo)glutathione metabolism
2020
Background
Hydrogen gas (H
2
) is hypothesised to play a role in plants that are coping with stresses by regulating signal transduction and gene expression. Although the beneficial role of H
2
in plant tolerance to cadmium (Cd) has been investigated previously, the corresponding mechanism has not been elucidated. In this report, the transcriptomes of alfalfa seedling roots under Cd and/or hydrogen-rich water (HRW) treatment were first analysed. Then, the sulfur metabolism pathways were focused on and further investigated by pharmacological and genetic approaches.
Results
A total of 1968 differentially expressed genes (DEGs) in alfalfa seedling roots under Cd and/or HRW treatment were identified by RNA-Seq. The DEGs were classified into many clusters, including glutathione (GSH) metabolism, oxidative stress, and ATP-binding cassette (ABC) transporters. The results validated by RT-qPCR showed that the levels of relevant genes involved in sulfur metabolism were enhanced by HRW under Cd treatment, especially the genes involved in (homo)glutathione metabolism. Additional experiments carried out with a glutathione synthesis inhibitor and
Arabidopsis thaliana cad2–1
mutant plants suggested the prominent role of glutathione in HRW-induced Cd tolerance. These results were in accordance with the effects of HRW on the contents of (homo)glutathione and (homo)phytochelatins and in alleviating oxidative stress under Cd stress. In addition, the HRW-induced alleviation of Cd toxicity might also be caused by a decrease in available Cd in seedling roots, achieved through ABC transporter-mediated secretion.
Conclusions
Taken together, the results of our study indicate that H
2
regulated the expression of genes relevant to sulfur and glutathione metabolism and enhanced glutathione metabolism which resulted in Cd tolerance by activating antioxidation and Cd chelation. These results may help to elucidate the mechanism governing H
2
-induced Cd tolerance in alfalfa.
Journal Article
Transcriptome Analysis of Apples in High-Temperature Treatments Reveals a Role of MdLBD37 in the Inhibition of Anthocyanin Accumulation
2022
Coloring in apple fruit due to anthocyanin accumulation is inhibited by high temperature; however, the underlying mechanism remains unclear. In the present study, total anthocyanin and cyanidin 3-galactoside contents were determined and compared between cv. ‘Redchief Delicious’ apple fruits at 25 °C and 35 °C treatments. The high temperature (35 °C) treatment substantially decreased total anthocyanin and cyanidin 3-galactoside contents. The transcriptomes of 25 °C- and 35 °C-treated apples were analyzed by high-throughput RNA sequencing. A total of 8354 differentially expressed genes (DEGs) were detected at four time points corresponding to the two temperature treatments. The up-regulated DEGs were annotated using GO as well as KEGG databases. A network module of 528 genes (including 21 transcription factors) most associated with the total anthocyanin and cyanidin 3-galactoside contents was constructed by weighted correlation network analysis (WGCNA). In the WGCNA module, we unearthed a LOB domain-containing gene designated as MdLBD37. The expression of MdLBD37 was sharply up-regulated by high temperature and negatively correlated with the total anthocyanin and cyanidin 3-galactoside contents. Overexpression of MdLBD37 in apple fruit and calli decreased the expression of anthocyanin biosynthetic genes, such as MdCHI, MdCHS, MdF3H, MdANS, MdDFR, and MdUFGT, along with anthocyanin accumulation. Our results suggested that MdLBD37 significantly influenced the high-temperature inhibition of anthocyanin accumulation in apples. The findings shed more light on the mechanism of anthocyanin inhibition during high-temperature stress in apples.
Journal Article