Study on stability of landslide at different moisture content in northern slope of Bailu tableland

In this paper, Phase2 software is used to simulate six groups of natural loess specimens in the northern slope of Bailu Plateau landslide area. The effective steady-state shear strength of loess specimens under different moisture content (6%, 11%, 21%, 26%, 30%, 32%) is simulated. We analyzed the stress and displacement, and we used residual thrust method to calculate the stability of sliding surface at different moisture content. The stability of the northern slope of Bailu tableland is analyzed at different moisture content. The "9.17 northern slope landslide of Bailu tableland" is summarized. The comprehensive evaluation of the northern slope landslide of Bailu tableland is carried out, the paper analyzed treatment measures of landslide. © International Journal of Ground Sediment & Water, © Sun Jichao, The website is http://ijgsw.comze.com

A sketch-and-project method for solving the matrix equation AXB = C

In this paper, based on an optimization problem, a sketch-and-project method for solving the linear matrix equation AXB = C is proposed. We provide a thorough convergence analysis for the new method and derive a lower bound on the convergence rate and some convergence conditions including the case that the coefficient matrix is rank deficient. By varying three parameters in the new method and convergence theorems, the new method recovers an array of well-known algorithms and their convergence results. Meanwhile, with the use of Gaussian sampling, we can obtain the Gaussian global randomized Kaczmarz (GaussGRK) method which shows some advantages in solving the matrix equation AXB = C. Finally, numerical experiments are given to illustrate the effectiveness of recovered methods.Comment: arXiv admin note: text overlap with arXiv:1506.03296, arXiv:1612.06013, arXiv:2204.13920 by other author

Dimethyl Sulfoxide Damages Mitochondrial Integrity and Membrane Potential in Cultured Astrocytes

Dimethyl sulfoxide (DMSO) is a polar organic solvent that is used to dissolve neuroprotective or neurotoxic agents in neuroscience research. However, DMSO itself also has pharmacological and pathological effects on the nervous system. Astrocytes play a central role in maintaining brain homeostasis, but the effect and mechanism of DMSO on astrocytes has not been studied. The present study showed that exposure of astrocyte cultures to 1% DMSO for 24 h did not significantly affect cell survival, but decreased cell viability and glial glutamate transporter expression, and caused mitochondrial swelling, membrane potential impairment and reactive oxygen species production, and subsequent cytochrome c release and caspase-3 activation. DMSO at concentrations of 5% significantly inhibited cell variability and promoted apoptosis of astrocytes, accompanied with more severe mitochondrial damage. These results suggest that mitochondrial impairment is a primary event in DMSO-induced astrocyte toxicity. The potential cytotoxic effects on astrocytes need to be carefully considered during investigating neuroprotective or neurotoxic effects of hydrophobic agents dissolved by DMSO

NCOA3 Loss Disrupts Molecular Signature of Chondrocytes and Promotes Posttraumatic Osteoarthritis Progression

Background/Aims: Osteoarthritis (OA) is the most common joint disease. Recently, a novel variant near the nuclear receptor coactivator 3 (NCOA3) has been identified in association with greater risk of developing OA. However, how NCOA3 is regulated in chondrocytes and involved in OA pathogenesis remain elusive. Methods: The expression and DNA methylation of NCOA3 in knee OA cartilage and in vitro dedifferentiated chondrocytes with or without rs6094710 SNP were analyzed by qRT-PCR, immunoblotting, methylation-specific PCR and bisulfite sequencing. NCOA3 was depleted by siRNA or shRNA or inhibited by a chemical inhibitor to assess its role in chondrocyte dedifferentiation or OA pathogenesis in posttraumatic OA animal model established by cruciate ligament transection surgery. Results: We found that compared with normal counterparts, samples with rs6094710 SNP failed to upregulate NCOA3. Further evidence associated this phenotype with DNMT1-mediated hypermethylation in gene promoter region. Moreover, we showed that NCOA3 maintained the molecular signature of chondrocytes dedifferentiating in vitro or exposed to IL-1β, nevertheless, NCOA3 appeared dispensable for preventing OA initiation, since NCOA3 loss did not trigger OA in young mice. Instead, NCOA3 loss promoted posttraumatic OA progression, and in parallel, enhanced NF-κB activation. Finally, the promoted posttraumatic OA progression was significantly retarded when administrated with NF-κB pathway inhibitor, suggesting that NCOA3 lose promotes posttraumatic OA at least partially by enhancing NF-κB activation. Conclusion: Thus, our findings indicate a critical role of NCOA3 in chondrocytes, and imply that manipulating NCOA3 might present a potential therapeutic approach to interfere OA progression

SNAP23 is selectively expressed in airway secretory cells and mediates baseline and stimulated mucin secretion

Airway mucin secretion is important pathophysiologically and as a model of polarized epithelial regulated exocytosis. We find the trafficking protein, SNAP23 (23-kDa paralogue of synaptosome-associated protein of 25 kDa), selectively expressed in secretory cells compared with ciliated and basal cells of airway epithelium by immunohistochemistry and FACS, suggesting that SNAP23 functions in regulated but not constitutive epithelial secretion. Heterozygous SNAP23 deletant mutant mice show spontaneous accumulation of intracellular mucin, indicating a defect in baseline secretion. However mucins are released from perfused tracheas of mutant and wild-type (WT) mice at the same rate, suggesting that increased intracellular stores balance reduced release efficiency to yield a fully compensated baseline steady state. In contrast, acute stimulated release of intracellular mucin from mutant mice is impaired whether measured by a static imaging assay 5 min after exposure to the secretagogue ATP or by kinetic analysis of mucins released from perfused tracheas during the first 10 min of ATP exposure. Together, these data indicate that increased intracellular stores cannot fully compensate for the defect in release efficiency during intense stimulation. The lungs of mutant mice develop normally and clear bacteria and instilled polystyrene beads comparable to WT mice, consistent with these functions depending on baseline secretion that is fully compensated

Design and research of permanent magnet synchronous motor controller for electric vehicle

Abstract Permanent magnet synchronous motors (PMSM) have high power density, stable output torque, low noise, and good speed regulation performance, making them very suitable for electric vehicle propulsion. In this paper, a PMSM controller, based on Renesas MCU, is designed. To meet the requirements of small size, lightweight, wide speed range, and power generation of the PMSM controller the design has been carried out from three aspects: hardware circuit, structural components, and software algorithm, including electronic component selection, hardware protection circuit, printed circuit board layout, control algorithm, structural strength, and the cooling channel. The controller prototype was produced and an experimental platform was built. The controller efficiency test, generator test, field weakening test, and temperature rise test were carried out. The experimental results verify the rationality of the design scheme. Compared with earlier motor controllers, this controller is small in size, light in weight with low cost

Exploring the risk transmission characteristics among unsafe behaviors within urban railway construction accidents

Various construction accidents are proven to be caused by multiple unsafe behaviors (e.g., wrong use of PPE), but the risk transmission among different behaviors remains unclear. This paper provides insight into risk transmission through behavioral risk chain that leads to accidents from a system safety perspective. To better understand the coupling mechanism of various unsafe behaviors, integrate different behavioral risk chains and present the risk transmission process, a directed-weighted complex network (DWCN) method was adopted. Historical urban railway construction accidents in China are investigated to extract behavioral risk chain. A DW-BRCNA is applied to integrated behavioral risk chain and the behavioral risk transmission characteristics are explored and clarified by the five network properties, including degree and degree distribution, node strength and node strength distribution, average path length and diameter, weighted clustering coefficient and betweenness centrality. The results show that DW-BRCNA has the characteristics of a small-world, scale-free and hierarchical network, indicating that some unsafe behaviors are of greater importance in the process of risk transmission through behavioral risk chains. In addition, risk transmission in critical behavioral risk chains is more potentially to lead to accidents. This study proposed a new perspective of accident causation analysis from risk transmission among unsafe behaviors. It explains the risk transmission characteristics by a DWCN method based on behavioral risk chains. The findings also provide a practical guidance for developing control strategies on sites to prevent risk transmission and reduce accidents

Trajectory Planning of Aerial Robotic Manipulator Using Hybrid Particle Swarm Optimization

The trajectory planning of an aerial robotic manipulator system is studied using Hybrid Particle Swarm Optimization (HPSO). The aerial robotic manipulator is composed of an unmanned aerial vehicle (UAV) base and a robotic manipulator. The robotic manipulator is dynamically singular. In addition, strong coupling exists between the UAV base and the robotic manipulator. To overcome the problems, the trajectory planning is studied in the join space using HPSO. HPSO combines superiorities of PSO and GA (Genetic Algorithm), prohibiting particles from becoming trapped in a local minimum. In addition, the control parameters are self-adaptive and contribute to fast searching for the global optimum. The trajectory planning problem is converted into a parameter optimization problem. Each joint trajectory is parameterized with a Bézier curve. The HPSO is implemented to optimize joint trajectories, satisfying specific objectives and imposed constraints. Numerical simulations are also carried out to validate the effectiveness of the proposed method

An improved YOLOv3-tiny method for fire detection in the construction industry

To prevent fire accidents on construction site and improve the accuracy of fire detection, an improved YOLOv3-tiny method (I-YOLOv3-tiny) is proposed in this paper. Although the YOLOv3-tiny has a fast detection speed and low equipment requirement, the accuracy is relatively low on fire detection. The improvement of the I-YOLOv3-tiny method is followed by three steps. Firstly, the feature extraction of fire images is enhanced by optimizing the network structure. Secondly, a multi-scale fusion is used to improve the detection effect of fire targets. Finally, the anchor boxes that are suitable for fire data sets are selected by k-means clustering. The results show that I-YOLOv3-tiny has an increased percentage of 4 on the mAP, the Recall rate has an increased percentage of 4, and AVG IOU has an increased percentage of 6. The proposed model meets the real-time performance of fire detection. This study is of theoretical and practical significance on fire safety management and accident prevention in the construction industry