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The production plan of an open-pit mine depends on the block model, so it's crucial to determine the appropriate method and size for partitioning it. This study proposes a new method based on a closed shell three-dimensional geological model for determining block model size in open-pit mines. Instead of using regular block models, the shell model is directly cut, and the discrete geological body is referred to as the "mining model." Mining parameters and the shovel-truck's performance are integrated into the method. Bench height determines the Z-axis size, bench slope angle determines the inclination angle, and shovel width determines the X-axis size of the block model. The operation efficiency of the shovel-truck considers the probability distribution of simultaneous operations, allowing the determination of the Y-axis size of block models for different types of shovels. The developed "Mining Model" module in the software "Life Cycle Mining System" is used for practical implementation. By comparing the results with traditional block models, the superiority of the proposed method is demonstrated. This study provides a more accurate model for optimizing the production plan of open-pit mines throughout their life cycle. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Research on the method of determining the block size for an open-pit mine integrating mining parameters and shovel-truck's operation efficiency." The original article contained an error in the Acknowledgements section, specifically the grant number for the National Natural Science Foundation of China. The corrected version of the article acknowledges the correct grant number. The authors of the article are Weiqiang Guo, Guangwei Liu, Jiaming Li, Senlin Chai, and Shupeng Guo. [Extracted from the article]

Mesenchymal stem cells (MSCs) can be effective in alleviating the progression of osteoarthritis (OA). However, low MSC retention and survival at the injection site frequently require high doses of cells and/or repeated injections, which are not economically viable and create additional risks of complications. In this study, we produced MSC-laden microcarriers in spinner flask culture as cell delivery vehicles. These microcarriers containing a low initial dose of MSCs administered through a single injection in a rat anterior cruciate ligament (ACL) transection model of OA achieved similar reparative effects as repeated high doses of MSCs, as evaluated through imaging and histological analyses. Mechanistic investigations were conducted using a co-culture model involving human primary chondrocytes grown in monolayer, together with MSCs grown either within 3D constructs or as a monolayer. Co-culture supernatants subjected to secretome analysis showed significant decrease of inflammatory factors in the 3D group. RNA-seq of co-cultured MSCs and chondrocytes using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed processes relating to early chondrogenesis and increased extracellular matrix interactions in MSCs of the 3D group, as well as phenotypic maintenance in the co-cultured chondrocytes. The cell delivery platform we investigated may be effective in reducing the cell dose and injection frequency required for therapeutic applications., Competing Interests: Wei Liu is employed by Beijing CytoNiche Biotechnology Co. Ltd. The other authors declare no financial and personal relationships with other people or organizations that can inappropriately influence our work., (© 2021 The Authors.)

The aim of this study was to investigate the effects of melatonin on oxidative stress, the expression of transient receptor potential melastatin-2 (TRPM2) in guinea pig brains, and the influence of melatonin on oxidative stress in lungs and airway inflammation induced by particulate matter 2.5 (PM2.5). A particle suspension (0.1 g/ml) was nasally administered to the guinea pigs to prepare a PM2.5 exposure model. Cough frequency and cough incubation period were determined through RM6240B biological signal collection and disposal system. Oxidative stress markers, including malondialdehyde (MDA), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-Px), in the medulla oblongata were examined through spectrophotometer. Reactive oxygen species (ROS) were detected in the hypoglossal nucleus, cuneate nucleus, Botzinger complex, dorsal vagal complex, and airway through dihydroethidium fluorescence. Hematoxylin-eosin (HE) staining and substance P expression via immunohistochemistry revealed the inflammatory levels in the airway. TRPM2 was observed in the medulla oblongata through immunofluorescence and Western blot. The ultrastructure of the blood-brain barrier and neuronal mitochondria was determined by using a transmission electron microscope. Our study suggests that melatonin treatment decreased PM2.5-induced oxidative stress level in the brains and lungs and relieved airway inflammation and chronic cough. TRPM2 might participate in oxidative stress in the cough center by regulating cough.