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"Ren Yingjie"
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High-Performance Flexible Microneedle Array as a Low-Impedance Surface Biopotential Dry Electrode for Wearable Electrophysiological Recording and Polysomnography
2022
Highlights Polyimide-based flexible microneedle array (PI-MNA) electrodes realize high electrical/mechanical performance and are compatible with wearable wireless recording systems.The normalized electrode–skin interface impedance (EII) of the PI-MNA electrodes reaches 0.98 kΩ cm2 at 1 kHz and 1.50 kΩ cm2 at 10 Hz, approximately 1/250 of clinical standard electrodes.This is the first report on the clinical study of microneedle electrodes. The PI-MNA electrodes are applied to clinical long-term continuous monitoring for polysomnography.Microneedle array (MNA) electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications. Existing schemes are limited by flexibility, biosafety, and manufacturing costs, which create large barriers for wider applications. Here, we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface, robustness of microneedles to penetrate the skin without fracture, and a simplified process to allow mass production. The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording. The normalized electrode–skin contact impedance reaches 0.98 kΩ cm2 at 1 kHz and 1.50 kΩ cm2 at 10 Hz, a record low value compared to previous reports and approximately 1/250 of the standard electrodes. The morphology, biosafety, and electrical/mechanical properties are fully characterized, and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized. The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording (over 8 h per night), providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.
Journal Article
Six New Compounds from the Herbaceous Stems of Ephedra intermedia Schrenket C. A. Meyer and Their Lung-Protective Activity
2024
Six new compounds, (7R,8S,8′R)-balanophorone (1), (7′S,8′R,8R)-yunnanensin A (2), (3S)-thunberginol C (3), (8R,8′R)-maninsigin B (4), (7S,8R)-4,7,8-dihydroxy-9,9-dimethyl-chroman (5), and 4-hydroxy-1-(4-hydroxy-3-methoxyphenyl)butan-1-one (6), along with eight known compounds (7–14), were isolated from the herbaceous stems of Ephedra intermedia Schrenket C. A. Meyer. Their structures were elucidated based on their spectroscopic (MS, NMR, IR, and UV) data, and their absolute configurations were determined by comparing their calculated and experimental electronic circular dichroic (ECD) spectra. Moreover, compounds 1 and 3–6 were evaluated for their ability to protect human pulmonary epithelial cells (BEAS-2B) from injury induced by lipopolysaccharide (LPS) in vitro. The results showed that compound 6 exhibited a significant protective effect against LPS-induced injury in BEAS-2B, and compound 5 exhibited a slightly protective effect at the concentration of 10 μM.
Journal Article
Impacts of underground coal mining on phreatic water level variation in arid and semiarid mining areas: a case study from the Yushenfu mining area, China
2022
Underground coal mining destroys overlying strata, and phreatic aquifer above the panel is destabilized, causing phreatic water level (PWL) variation. On-site monitoring of the PWL variation throughout the mining period is of great significance to the management and conservation of groundwater resources in arid and semiarid mining areas. The research on the decline of the PWL when phreatic aquifer leakage is concentrated, but there is little research on the fluctuation characteristics of PWL under the condition of phreatic aquifer without leakage. Therefore, using the #108 coalface in the Jinjitan colliery of the Yushenfu mining area as a case study to carry out the research on PWL fluctuation induced by underground coal mining. First, phreatic water without leakage throughout the coal mining period in the #108 coalface was determined. Second, considering surface subsidence induced by mining activities and PWL in fluviograph comprehensively, true PWL fluctuation characteristics were analyzed throughout the whole coal seam mining period. It is concluded that the buried depth of PWL presented a trend of “decreasing sharply—increasing sharply—decreasing slowly—increasing slowly—becoming stable” in the monitoring period of 1 year. Furthermore, a well flow model was established to simulate the PWL variation process before and after coal mining and to predict the PWL recovery time after coal mining. On these bases, the error analysis of the measured and predicted PWL recovery time, the relationship between the PWL fluctuation and the residual aquiclude thickness, the impact of rainfall on PWL recovery, the response of surface vegetation eco-environment, and phreatic water resources management and conservation were discussed. These research results are important for achieving a win–win situation strategy that balances the exploitation of coal resources and the conservation of phreatic water resources, promoting the sustainable development of coal mining.
Journal Article
A Bibliometric and Visualized Overview of Hydrogen Embrittlement from 1997 to 2022
by
Zhou, Chilou
,
Ren, Yingjie
,
Liu, Baoqing
in
bibliometric analysis
,
Bibliometrics
,
Cooperation
2022
The mechanical properties of materials deteriorate when hydrogen embrittlement (HE) occurs, seriously threatening the reliability and durability of the hydrogen system. Therefore, it is important to summarize the status and development trends of research on HE. This study reviewed 6676 publications concerned with HE from 1997 to 2022 based on the Web of Science Core Collection. VOSviewer was used to conduct the bibliometric analysis and produce visualizations of the publications. The results showed that the number of publications on HE increased after 2007, especially between 2017 and 2019. Japan was the country with the highest numbers of productive authors and citations of publications, and the total number of citations of Japanese publications was 24,589. Kyushu University was the most influential university, and the total number of citations of Kyushu University publications was 7999. Akiyama was the most prolific and influential author, publishing 88 publications with a total of 2565 citations. The USA, South Korea and some European countries are also leading in HE research; these countries have published more than 200 publications. It was also found that the HE publications generally covered five topics: “Hydrogen embrittlement in different materials”, “Effect of hydrogen on mechanical properties of materials”, “Effect of alloying elements or microstructure on hydrogen embrittlement”, “Hydrogen transport”, and “Characteristics and mechanisms of hydrogen related failures”. Research hotspots included “Fracture failure behavior and analysis”, “Microstructure”, “Hydrogen diffusion and transport”, “Mechanical properties”, “Hydrogen resistance”, and so on. These covered the basic methods and purposes of HE research. Finally, the distribution of the main subject categories of the publications was determined, and these categories covered various topics and disciplines. This study establishes valuable reference information for the application and development of HE research and provides a convenient resource to help researchers and scholars understand the development trends and research directions in this field.
Journal Article
Hsa_(c)irc₀000313/miR-1224-3p/MKNK2 Axis Modulates CD4sup.+ T Cells by Activating p38 MAPK Signaling in Myasthenia Gravis
2026
Myasthenia gravis (MG) is an autoimmune disorder in which circular RNAs (circRNAs) are increasingly implicated, with growing evidence supporting their critical role in autoimmune pathogenesis. The role of hsa_(c)irc₀000313 in MG, including its biological functions and mechanisms, remains unknown. Agarose gel electrophoresis, RNase R digestion, and Sanger sequencing were employed to verify the circular structure of hsa_(c)irc₀000313, while nucleoplasmic separation experiment was used to determine its subcellular localization. Analysis of hsa_(c)irc₀000313, miR-1224-3p, and MKNK2 expression was conducted via quantitative real-time PCR (qRT-PCR). CCK-8 assay and flow cytometry were employed to evaluate the proliferative capacity and apoptotic rate of Jurkat cells. ELISA detected inflammatory cytokine secretion. Potential interactions involving miR-1224-3p with either hsa_(c)irc₀000313 or MKNK2 were predicted using bioinformatics tools and subsequently validated through dual-luciferase reporter assays. FISH assay was used to detect subcellular colocalization of hsa_(c)irc₀000313 and miR-1224-3p. We observed that compared to healthy controls, MG patients exhibited increased expression of hsa_(c)irc₀000313 and MKNK2, along with decreased expression of miR-1224-3p. Knockdown of hsa_(c)irc₀000313 and MKNK2, along with overexpression of miR-1224-3p, inhibited the proliferation and secretion of inflammatory factors in Jurkat cells and promoted their apoptosis. Additionally, miR-144-3p was identified as the target miRNA of hsa_(c)irc₀000313, and MKNK2 was identified as the target gene of miR-1244-3p. Hsa_(c)irc_(A)A0000313 was confirmed to be circular and resistant to RNase R digestion. There was significant colocalization of hsa_(c)irc₀000313 with miR-1224-3p within the cytoplasm. Inhibition of miR-1244-3p reversed the effects of hsa_(c)irc₀000313 knockdown and MKNK2 knockdown on Jurkat cells proliferation, apoptosis, and inflammatory cytokine secretion. In LPS-stimulated Jurkat cells, hsa_(c)irc₀000313 knockdown suppressed the p38 MAPK pathway via the miR-1224-3p/MKNK2 axis, which reduced inflammatory cytokine secretion and cell proliferation as well as promoted apoptosis. Hsa_(c)irc₀000313 is involved in MG progression by regulating the miR-1224-3p/MKNK2 axis and can act on the p38MAPK pathway to participate in the progression of MG concomitant inflammatory infections, which may provide a promising therapeutic target in MG.
Journal Article
Chemical Constituents from the Flowers of Carthamus tinctorius L. and Their Lung Protective Activity
2022
A new flavonoid, saffloflavanside (1), a new sesquiterpene, safflomegastigside (2), and a new amide, saffloamide (3), together with twenty-two known compounds (4–25), were isolated from the flowers of Carthamus tinctorius L. Their structures were determined based on interpretation of their spectroscopic data and comparison with those reported in the literature. The protective effects against lipopolysaccharide (LPS)-stimulated damage on human normal lung epithelial (BEAS-2B) cells of the compounds were evaluated using MTT assay and cellular immunofluorescence assay. The results showed that compounds 2–3, 8–11, and 15–19 exhibited protective effects against LPS-induced damage to BEAS-2B cells. Moreover, compounds 2–3, 8–11, and 15–19 can significantly downregulate the level of nuclear translocation of NF-κB p-p65. In summary, this study revealed chemical constituents with lung protective activity from C. tinctorius, which may be developed as a drug for the treatment of lung injury.
Journal Article
FOSL1-mediated LINC01566 negatively regulates CD4+ T-cell activation in myasthenia gravis
2024
Background
Myasthenia gravis (MG) is an autoimmune disease characterized by pathogenic antibodies that target structures of the neuromuscular junction. The evidence suggests that the regulation of long noncoding RNAs (lncRNAs) that is mediated by transcription factors (TFs) plays a key role in the pathophysiology of MG. Nevertheless, the detailed molecular mechanisms of lncRNAs in MG remain largely undetermined.
Methods
Using microarray analysis, we analyzed the lncRNA levels in MG. By bioinformatics analysis, LINC01566 was found to potentially play an important role in MG. First, qRT‒PCR was performed to verify the LINC1566 expressions in MG patients. Then, fluorescence in situ hybridization was conducted to determine the localization of LINC01566 in CD4 + T cells. Finally, the impact of LINC01566 knockdown or overexpression on CD4 + T-cell function was also analyzed using flow cytometry and CCK-8 assay. A dual-luciferase reporter assay was used to validate the binding of the TF FOSL1 to the LINC01566 promoter.
Results
Based on the lncRNA microarray and differential expression analyses, we identified 563 differentially expressed (DE) lncRNAs, 450 DE mRNAs and 19 DE TFs in MG. We then constructed a lncRNA-TF-mRNA network. Through network analysis, we found that LINC01566 may play a crucial role in MG by regulating T-cell-related pathways. Further experiments indicated that LINC01566 is expressed at low levels in MG patients. Functionally, LINC01566 is primarily distributed in the nucleus and can facilitate CD4 + T-cell apoptosis and inhibit cell proliferation. Mechanistically, we hypothesized that LINC01566 may negatively regulate the expressions of DUSP3, CCR2, FADD, SIRPB1, LGALS3 and SIRPB1, which are involved in the T-cell activation pathway, to further influence the cellular proliferation and apoptosis in MG. Moreover, we found that the effect of LINC01566 on CD4 + T cells in MG was mediated by the TF FOSL1, and in vitro experiments indicated that FOSL1 can bind to the promoter region of LINC01566.
Conclusions
In summary, our research revealed the protective roles of LINC01566 in clinical samples and cellular experiments, illustrating the potential roles and mechanism by which FOSL1/LINC01566 negatively regulates CD4 + T-cell activation in MG.
Journal Article
Customized flexible hollow microneedles for psoriasis treatment with reduced‐dose drug
by
Ren, Yingjie
,
Chen, Yuxuan
,
Li, Zhihong
in
3-D printers
,
Biocompatibility
,
Biomedical materials
2023
Microneedles, especially hollow microneedles (HMNs), play an important role in drug delivery, but most of the current HMNs are manufactured based on silicon microfabrication (lithography, etching, etc.), which are slightly conservative due to the lack of low‐cost, batch‐scale and customized preparation approach, especially for the HMNs with flexible substrate. For the first time, we propose the use of a high‐precision 3D printed master mold followed by a dual‐molding process for the preparation of HMNs with different shapes, heights, and inner and outer diameters to satisfy different drug delivery needs. The 3D printed master mold and negative mold can be reused, thereby significantly reducing the cost. HMNs are based on biocompatible materials, such as heat‐curing polymers or light‐curing resins. The thickness and rigidity/flexibility characteristics of the substrate can be customized for different applications. The drug delivery efficiency of the fabricated HMNs was verified by the in situ treatment of psoriasis on the backs of mice, which required only a 0.1‐fold oral dose to achieve similar efficacy, and the associated side effects and drug toxicity were reduced. Thus, this dual‐molding process can reinvigorate HMNs development.
Journal Article
MLF-PointNet++: A Multifeature-Assisted and Multilayer Fused Neural Network for LiDAR-UAS Point Cloud Classification in Estuarine Areas
2024
LiDAR-unmanned aerial system (LiDAR-UAS) technology can accurately and efficiently obtain detailed and accurate three-dimensional spatial information of objects. The classification of objects in estuarine areas is highly important for management, planning, and ecosystem protection. Owing to the presence of slopes in estuarine areas, distinguishing between dense vegetation (lawns and trees) on slopes and the ground at the tops of slopes is difficult. In addition, the imbalance in the number of point clouds also poses a challenge for accurate classification directly from point cloud data. A multifeature-assisted and multilayer fused neural network (MLF-PointNet++) is proposed for LiDAR-UAS point cloud classification in estuarine areas. First, the 3D shape features that characterize the geometric characteristics of targets and the visible-band difference vegetation index (VDVI) that can characterize vegetation distribution are used as auxiliary features to enhance the distinguishability of dense vegetation (lawns and trees) on slopes and the ground at the tops of slopes. Second, to enhance the extraction of target spatial information and contextual relationships, the feature vectors output by different layers of set abstraction in the PointNet++ model are fused to form a combined feature vector that integrates low and high-level information. Finally, the focal loss function is adopted as the loss function in the MLF-PointNet++ model to reduce the effect of imbalance in the number of point clouds in each category on the classification accuracy. A classification evaluation was conducted using LiDAR-UAS data from the Moshui River estuarine area in Qingdao, China. The experimental results revealed that MLF-PointNet++ had an overall accuracy (OA), mean intersection over union (mIOU), kappa coefficient, precision, recall, and F1-score of 0.976, 0.913, 0.960, 0.953, 0.953, and 0.953, respectively, for object classification in the three representative areas, which were better than the corresponding values for the classification methods of random forest, BP neural network, Naive Bayes, PointNet, PointNet++, and RandLA-Net. The study results provide effective methodological support for the classification of objects in estuarine areas and offer a scientific basis for the sustainable development of these areas.
Journal Article
A Low-Cost Flexible Perforated Respiratory Sensor Based on Platinum for Continuous Respiratory Monitoring
2022
Monitoring sleep conditions is of importance for sleep quality evaluation and sleep disease diagnosis. Accurate respiration detection provides key information about sleep conditions. Here, we propose a perforated temperature sensor that can be worn below the nasal cavity to monitor breath. The sensing system consists of two perforated temperature sensors, signal conditioning circuits, a transmission module, and a supporting analysis algorithm. The perforated structure effectively enhances the sensitivity of the system and shortens the response time. The sensor’s response time is 0.07 s in air and sensitivity is 1.4‰°C−1. The device can achieve a monitoring respiratory temperature range between normal room temperature and 40 °C. The simple and standard micromachining process ensures low cost and high reproducibility. We achieved the monitoring of different breathing patterns, such as normal breathing, panting, and apnea, which can be applied to sleep breath monitoring and exercise information recording.
Journal Article