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Single-cell transcriptome sequencing (scRNA-seq) is an unparalleled technology in the field of transcriptomics, which can study cells in a comprehensive and unbiased manner, thus characterizing complex biological processes at the cellular level. At the same time, scRNA-seq can produce a large amount of experimental data; therefore, the extraction of important information is required. In this review, we summarize the common applications of scRNA-seq analysis, such as of cellular communication, pseudo-timing, transcription factors, and functional enrichment, to mine cellular information and reveal the regulatory relationships between genes and trajectories of different cell lineages during development. We also describe the latest technological progress of scRNA-seq use in organoid, pathogenic gene variants, tumor tissues, stem cells, viruses, antibody preparation, and so on, in order to improve its applicability in future research in the life science field.

Acute kidney injury (AKI) can progress to renal fibrosis and chronic kidney disease (CKD), which reduces quality of life and increases the economic burden on patients. However, the molecular mechanisms underlying renal fibrosis following AKI remain unclear. This study tested the hypothesis that the Krüppel-like factor 4 (KLF4)/miR-101/Collagen alpha-1X (COL10A1) axis could inhibit epithelial-mesenchymal transition (EMT) and renal fibrosis after AKI in a mouse model of ischemia-reperfusion (I/R)-induced renal fibrosis and HK-2 cells by gene silencing, overexpression, immunofluorescence, immunohistochemistry, real-time quantitative PCR, Western blotting, dual-luciferase reporter assay, fluorescence in situ hybridization (FISH) and ELISA. Compared with the Sham group, I/R induced renal tubular and glomerular injury and fibrosis, and increased the levels of BUN, serum Scr and neutrophil gelatinase-associated lipocalin (NGAL), Col10a1 and Vimentin expression, but decreased E-cadherin expression in the kidney tissues of mice at 42 days post-I/R. Similarly, hypoxia promoted fibroblastic morphological changes in HK-2 cells and enhanced NGAL, COL10A1, Vimentin, and α-SMA expression, but reduced E-cadherin expression in HK-2 cells. These pathological changes were significantly mitigated in COL10A1-silenced renal tissues and HK-2 cells. KLF4 induces miR-101 transcription. More importantly, hypoxia upregulated Vimentin and COL10A1 expression, but decreased miR-101, KLF4, and E-cadherin expression in HK-2 cells. These hypoxic effects were significantly mitigated or abrogated by KLF4 over-expression in the HK-2 cells. Our data indicate that KLF4 up-regulates miR-101 expression, leading to the downregulation of COL10A1 expression, inhibition of EMT and renal fibrosis during the pathogenic process of I/R-related renal fibrosis. [ABSTRACT FROM AUTHOR]

In the water transportation, ship speed estimation has become a key subject of intelligent shipping research. Traditionally, Automatic Identification System (AIS) is used to extract the ship speed information. However, transportation environment is gradually becoming complex, especially in the busy water, leading to the loss of some AIS data and resulting in a variety of maritime accidents. To make up for this deficiency, this paper proposes a vessel speed extraction framework, based on Unmanned Aerial Vehicle (UAV) airborne video. Firstly, YOLO v4 is employed to detect the ship targets in UAV image precisely. Secondly, a simple online and real time tracking method with a Deep association metric (Deep SORT) is applied to track ship targets with high quality. Finally, the ship motion pixel is computed based on the bounding box information of the ship trajectories, at the same time, the ship speed is estimated according to the mapping relationship between image space and the real space. Exhaustive experiments are conducted on the various scenarios. Results verify that the proposed framework has an excellent performance with average speed measurement accuracy is above 93% in complex waters. This paper also paves a way to further predict ship traffic flow in water transportation., Author(s): Jiansen Zhao [1]; Yanjun Chen [1]; Zhenzhen Zhou [1]; Jingying Zhao [1]; Shengzheng Wang [1]; Xinqiang Chen (corresponding author) [2] 1. Introduction In recent years, the development of economy [...]

In the process of underbalance drilling,the rubber core of rotating control head is subject to the alternating cycle load,which is prone to fatigue failure.Firstly,the sealing principle of rotating control head is analyzed and the stress of rubber core in dynamic sealing process is obtained.Then,the Yeoh constitutive model in the deformation process was established by the tensile test of the rubber core material. Then ABAQUS software was used to establish the finite element model of the dynamic sealing of the rubber core,and the simulation of the sealing process of the rubber core during the drilling and the optimization analysis of the factors affecting the fatigue life of the sealing surface of the rubber core were carried out.In this paper,the inner diameter of rubber core is optimized,and the inner diameter size of rubber core should be matched with different outer diameter drill pipes is optimized.The paper also optimizes the lowering and lifting speed of drill pipe under different wellhead pressures.The higher the well pressure,the more likely the rubber core fatigue failure will be. The safe lowering and lifting speed of drill pipe under different pressures is obtained.At last,according to the Chinese standard,indoor seal test and field application test were carried out in the well control equipment quality supervision and inspection center of China national petroleum industry to confirm the reliability of finite element optimization,which is of great practical significance to improve the service life of rubber core and oilfield operation safety.

This study aimed to analyze the effects of salt stress on the growth physiology and plant-cell ultrastructure of Isatis indigotica Fort. (I. indigotica) to evaluate its adaptability under salt stress. The effects of different concentrations of salt (NaCl; 0, 25, and 300 mmol·L−1) on the agronomic traits, activities of related enzymes, ion balance, and mesophyll-cell ultrastructure of I. indigotica were studied in a controlled pot experiment. Results showed that compared with those of the control group, the aerial-part fresh weight, underground fresh weight, tiller number, root length, root diameter, plant height, and leaf area of salt-stressed I. indigotica increased at 25 mmol·L−1 and then decreased at 300 mmol·L−1. The changes in levels of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase showed a similar trend, with significant differences compared with control group. Salt stress altered the ion balance of I. indigotica, resulting in a significant increase in Na+ content and a significant decrease in K+ content. The contents of Ca2+ and Mg2+ changed to varying degrees. The analysis of the microstructure of the root showed that under salt treatment, the epidermal cells of the root significantly thickened and the diameter of the xylem decreased. The results of ultrastructural analysis of mesophylls showed that salt stress can cause cell-membrane contraction, cell-gap enlargement, disorder in the structures of chloroplasts and mitochondria, and an increase in the number of osmiophilic particles. These changes were aggravated by the increase in NaCl concentration. This study reveals the response of I. indigotica to salt stress and provides a basis for further study on the salt-tolerance mechanism of I. indigotica. [ABSTRACT FROM AUTHOR]

Fluorescent nitrogen‐doped carbon dots (N‐CDs) are obtained by a straightforward hydrothermal method, and tartaric acid and L‐histidine hydrochloride are used as precursors. The obtained N‐CDs exhibit nanoscale structure, good water solubility, photostability, and excellent fluorescence (FL) properties with a high FL quantum yield of 19%. The designed N‐CDs are used as fluorescent probes for detecting Fe3+ with the FL "on‐off" strategy. Two good linear relationships can be observed for the concentration of Fe3+ from 0 to 80 μm and from 80 to 600 μm, and the calculated detection limit for Fe3+ is 0.88 μm (3σ/slope). Moreover, the N‐CDs‐based FL probe can also be used for detecting Fe3+ in tap water and possesses great potential application in the field of anti‐fake information encryption. [ABSTRACT FROM AUTHOR]