738 results on '"Le, Wang"'
Search Results
2. Quantitative analysis of pyrolysis characteristics and chemical components of tobacco materials based on machine learning
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Zhifeng Wu, Qi Zhang, Hongxiao Yu, Lili Fu, Zhen Yang, Yan Lu, Zhongya Guo, Yasen Li, Xiansheng Zhou, Yingjie Liu, and Le Wang
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tobacco material ,chemical components ,thermogravimetric analysis ,machine learning ,characteristic temperature range ,Chemistry ,QD1-999 - Abstract
To investigate the quantitative relationship between the pyrolysis characteristics and chemical components of tobacco materials, various machine learning methods were used to establish a quantitative analysis model of tobacco. The model relates the thermal weight loss rate to 19 chemical components, and identifies the characteristic temperature intervals of the pyrolysis process that significantly relate to the chemical components. The results showed that: 1) Among various machine learning methods, partial least squares (PLS), support vector regression (SVR) and Gaussian process regression (GPR) demonstrated superior regression performance on thermogravimetric data and chemical components. 2) The PLS model showed the best performance on fitting and prediction effects, and has good generalization ability to predict the 19 chemical components. For most components, the determination coefficients R2 are above 0.85. While the performance of SVR and GPR models was comparable, the R2 for most chemical components were below 0.75. 3) The significant temperature intervals for various chemical components were different, and most of the affected temperature intervals were within 130°C–400°C. The results can provide a reference for the materials selection of cigarette and reveal the possible interactions of various chemical components of tobacco materials in the pyrolysis process.
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- 2024
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3. Determination of four residual solvents in cefepime by headspace gas chromatography
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Le Wang
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Headspace ,Gas chromatography ,Cefepime ,Residual solvents ,Chemistry ,QD1-999 - Abstract
Objective: To establish a headspace gas chromatography method to determine the residual solvents of methanol, acetone, dichloromethane, and toluene in cefepime. Methods: Headspace gas chromatography using a DB-624 capillary column and temperature program was performed to detect four residual solvents in cefepime. The temperature program consisted of an initial temperature of 60 ℃maintained for 4 min, a temperature increased to 120 ℃ at 20 ℃·min−1 maintained for 3 min, and then a temperature increased to 200 ℃ at 40 ℃·min−1 maintained for 3 min. Results: Linear relationships were found between the peak areas and mass concentrations of the four solvents mentioned above within the defined ranges. The limits of detection for methanol, acetone, dichloromethane and toluene were 0.50, 0.15, 0.10 and 0.08 mg·L-1, respectively. The recoveries obtained using the standard addition method ranged from 98.41 % to 100.94 %. Conclusion: This method demonstrated high sensitivity and good reproducibility, and it can be used to effectively control the residual amounts of methanol, acetone, dichloromethane, and toluene, to further improve the quality of cefepime.
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- 2024
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4. Multi-Feature-Enhanced Academic Paper Recommendation Model with Knowledge Graph
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Le Wang, Wenna Du, and Zehua Chen
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academic paper recommendation ,knowledge graph ,neural networks ,attention mechanism ,sequential recommendation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This paper addresses the challenges of data sparsity and personalization limitations inherent in current recommendation systems when processing extensive academic paper datasets. To overcome these issues, the present work introduces an innovative recommendation model that integrates the wealth of structured information from knowledge graphs and refines the amalgamation of temporal and relational data. By applying attention mechanisms and neural network technologies, the model thoroughly explores the text characteristics of papers and the evolving patterns of user behaviors. Additionally, the model elevates the accuracy and personalization of recommendations by meticulously examining citation patterns among papers and the networks of author collaboration. The experimental findings show that the present model surpasses baseline models on all evaluation metrics, thereby enhancing the precision and personalization of academic paper recommendations.
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- 2024
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5. Genome-Wide Identification of CHYR Gene Family in Sophora alopecuroides and Functional Analysis of SaCHYR4 in Response to Abiotic Stress
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Youcheng Zhu, Ying Wang, Zhipeng Ma, Di Wang, Fan Yan, Yajing Liu, Jingwen Li, Xuguang Yang, Ziwei Gao, Xu Liu, Le Wang, and Qingyu Wang
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Sophora alopecuroides ,CHYR gene ,abiotic stress ,genome-wide identification ,expression profile ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Sophora alopecuroides has important uses in medicine, wind breaking, and sand fixation. The CHY-zinc-finger and RING-finger (CHYR) proteins are crucial for plant growth, development, and environmental adaptation; however, genetic data regarding the CHYR family remain scarce. We aimed to investigate the CHYR gene family in S. alopecuroides and its response to abiotic stress, and identified 18 new SaCHYR genes from S. alopecuroides whole-genome data, categorized into 3 subclasses through a phylogenetic analysis. Gene structure, protein domains, and conserved motifs analyses revealed an exon–intron structure and conserved domain similarities. A chromosome localization analysis showed distribution across 12 chromosomes. A promoter analysis revealed abiotic stress-, light-, and hormone-responsive elements. An RNA-sequencing expression pattern analysis revealed positive responses of SaCHYR genes to salt, alkali, and drought stress. SaCHYR4 overexpression considerably enhanced alkali and drought tolerance in Arabidopsis thaliana. These findings shed light on SaCHYR’s function and the resistance mechanisms of S. alopecuroides, presenting new genetic resources for crop resistance breeding.
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- 2024
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6. PolyI:C Maternal Immune Activation on E9.5 Causes the Deregulation of Microglia and the Complement System in Mice, Leading to Decreased Synaptic Spine Density
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Shuxin Yan, Le Wang, James Nicholas Samsom, Daniel Ujic, and Fang Liu
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maternal immune activation ,synaptic pruning ,dendritic spine density ,microglia ,complement ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Maternal immune activation (MIA) is a risk factor for multiple neurodevelopmental disorders; however, animal models developed to explore MIA mechanisms are sensitive to experimental factors, which has led to complexity in previous reports of the MIA phenotype. We sought to characterize an MIA protocol throughout development to understand how prenatal immune insult alters the trajectory of important neurodevelopmental processes, including the microglial regulation of synaptic spines and complement signaling. We used polyinosinic:polycytidylic acid (polyI:C) to induce MIA on gestational day 9.5 in CD-1 mice, and measured their synaptic spine density, microglial synaptic pruning, and complement protein expression. We found reduced dendritic spine density in the somatosensory cortex starting at 3-weeks-of-age with requisite increases in microglial synaptic pruning and phagocytosis, suggesting spine density loss was caused by increased microglial synaptic pruning. Additionally, we showed dysregulation in complement protein expression persisting into adulthood. Our findings highlight disruptions in the prenatal environment leading to alterations in multiple dynamic processes through to postnatal development. This could potentially suggest developmental time points during which synaptic processes could be measured as risk factors or targeted with therapeutics for neurodevelopmental disorders.
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- 2024
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7. Transcriptomic Responses of Salvia hispanica to the Infestation of Red Spider Mites (Tetranychus neocaledonicus)
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May Lee, Le Wang, and Gen Hua Yue
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plant ,agriculture ,pest resistance ,defense response ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Salvia hispanica (chia) is a highly nutritious food source and has gained popularity due to its high omega-3 fatty acid content. Red spider mites are a serious problem in the production of S. hispanica. However, no study has been conducted to analyze the defensive response to the infestation of red spider mites in S. hispanica. To elucidate the molecular mechanisms of the defensive response of S. hispanica to red spider mites, we performed a transcriptomic analysis of S. hispanica when infested by red spider mites. In the comparative assessment of leaf transcriptomes, a total of 1743 differentially expressed genes (DEGs) were identified between control and mite-infested S. hispanica. From these, 1208 (69%) transcripts were upregulated and 535 (31%) were downregulated. The DEGs included transcription factors, defense hormones, and secondary metabolites that were either suppressed or activated in response to spider mite herbivory. Gene Ontology (GO) enrichment analysis revealed that plant secondary metabolites, such as glucosinolates, and signaling pathways, including the jasmonic acid signaling pathway, may play an important role in the defense against red spider mites. This study provides novel insights into the defense response of S. hispanica to insect herbivory and could be a resource for the improvement of pest resistance in the chia.
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- 2023
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8. A Red-Emitting COF Ionic Exchanged With Green-Emitting Tb(III) Complex Anion: Synthesis, Characterization, Ratiometric Emission Sensing, and Removal of Picric Acid
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Ming Xu, Li-Le Wang, Gang Chen, Yin-Yun Chen, Dan Liu, and Jiang-Tao Liao
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optical sensing ,pollutant adsorption ,pollutant removal ,picronitric acid ,COF ,Chemistry ,QD1-999 - Abstract
Picric acid (PA) is an important chemical product which has been widely used in dye manufacturing, antiseptics, and pharmaceuticals. Owing to PA’s extreme electron-deficient structure, its natural degradation is hard, leading to accumulation in the environment and finally threatening the ecosystem and human health. In this case, PA detection and removal becomes more and more important, concerning environmental protection and human health. In this study, an ionic covalent organic framework (I-COF) was synthesized and modified with a luminescent Tb(III) emitter (Tb(DPA)33-, DPA = pyridine-2,6-dicarboxylic acid), via ionic exchange. The resulting composite material (Tb-COF) was fully characterized by geometric analysis, IR, XRD, porosity analysis, SEM/TEM, and elemental analysis. It was found that Tb(DPA)33- was loaded into the hexagonal cage in an I-COF host with an ionic exchange ratio of 41%. The as-synthesized Tb-COF showed weak Tb(III) emission and strong red COF emission, after adding PA, Tb(III) emission was increased whereas COF emission weakened greatly, showing sensing behavior. Linear working curves were observed with good selectivity. The sensing mechanism was revealed as follows. PA molecules replaced the [Tb(PDA)3]3- component trapped in Tb-COF, releasing free luminescent [Tb(PDA)3]3-. After incorporating PA in the hexagonal cage, the COF emission was quenched. This sensing mechanism ensured a good selectivity over competing species, including cations, anions, and nitrocompounds. The adsorption and removal performance of I-COF for PA were investigated as well.
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- 2022
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9. Effect of Asymmetric Feathering Angle on the Aerodynamic Performance of a Flyable Bionic Flapping-Wing Rotor
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Si Chen, Le Wang, Shijun Guo, Mingbo Tong, Yuanyuan He, and Jie Hu
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bio-inspired robots ,asymmetric feathering amplitude ,flapping-wing rotor ,lift efficiency ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The current study involves an experimental as well as numerical study on the aerodynamic behavior of a flapping-wing rotor (FWR) with different feathering amplitudes (−20°–50°, −50°–20°, and −35°–35°). In order to fulfil the experimental test, an FWR which weighs 18.7 g is designed in this manuscript. According to the experimental and numerical results, it was observed that, compared with the cases under a zero average stroke angle, the cases under a positive average stroke angle or negative average stroke angle share a higher rotary speed given the same input voltage. Despite the fact that the negative average stroke angle would facilitate the generation of a higher rotary speed, the negative average stroke angle cases tend to generate the smallest lift-to-power ratio. On the other hand, the cases with a positive average stroke angle tend to share the largest lift-to-power ratio (about 1.25 times those of zero average stroke angle cases and about 1.6 times those of negative average stroke angle cases). The above study indicates that the application of a positive average stroke angle can provide an effective solution to further increase the aerodynamic performance of a bio-inspired FWR.
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- 2023
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10. Robust Full-Screen Wavelength Calibration Algorithm
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Baisong Jiang, Chunxia Zhang, Nanqi Zhao, Hongguang Li, Liang Yuan, Juan Chen, Haowen Bai, and Le Wang
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scanning ,double-layer ,secondary diffraction ,linear-array CCD spectrometer ,full-screen ,wavelength calibration ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In spectrometer measurement, it is very important to accurately calibrate the wavelength of all target characteristic spectra. Although wavelength calibration methods have long been investigated, no techniques have been designed for the scanning, double-layer, secondary diffraction, linear-array CCD spectrometer, to the best of our knowledge. Based on the grating diffraction equation and experimental results, a mathematical model of wavelength calibration was established for the scanning, double-layer, secondary diffraction, linear-array CCD spectrometer. In this study, a robust, full-screen, wavelength calibration algorithm is proposed, based on the related working principle and the requirements of both accuracy and robustness. The detailed steps are as follows. First, we established a wavelength calibration model at central pixels, following the grating diffraction equation. Then, according to the relationship between the difference in pixels and the feedback values of the grating ruler, a model was established to show the association between these factors. Finally, we combined the two models and built a full-screen wavelength calibration model. We theoretically and experimentally demonstrate that the proposed calibration algorithm is an excellent calibration tool, which can conveniently and accurately calibrate the wavelengths of central and non-central pixels at the same time.
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- 2023
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11. A Series of Photosensitizes for Fe3+ in Aqueous Solution and Cells With Colorimetric and Fluorescent Channels: Synthesis and Performance
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Ming Xu, Jiang-Tao Liao, Gang Chen, Yin-Yun Chen, Dan Liu, and Li-Le Wang
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fluorescent imaging ,rhodamine chemosensor ,fe 3+ imaging ,colormetric sensing ,luminescence ,Chemistry ,QD1-999 - Abstract
Ferrum (Fe) is a widely existing metal element and nearly the most important trace element in living species, including human beings. The design of chemosensors for Fe ions faces issues related to the d-d transition of Fe(II) and Fe(III) ions, which makes them efficient electron trappers and energy quenchers. Most fluorescent dyes cannot afford such d-d quenching, showing emission turn off effect towards both Fe(II) and Fe(III) ions with poor selectivity. As a consequence, the development for Fe with emission turn on effect and good selectivity shall be continued and updated. In this work, three rhodamine-derived chemosensors modified by different lengths of alkyl chains having electron-donating N and O atoms were synthesized and explored for the selective optical sensing of Fe(III). These chemosensors showed colorimetric and fluorescent emission turn on sensing for Fe(III), showing two sensing channels. These chemosensors showed good selectivity, which was assigned to the sieving effect of alkyl chains with electron-donating N and O atoms. The N atom was found to be more effective in associating with Fe(III), compared to the O atom. Their fluorescent cell imaging experiment was carried out to confirm the possibility of being used for cell imaging.
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- 2022
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12. Co-Immobilization of Lactase and Glucose Isomerase on the Novel g-C3N4/CF Composite Carrier for Lactulose Production
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Le Wang, Bingyu Jiao, Yan Shen, Rong Du, Qipeng Yuan, and Jinshui Wang
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g-C3N4/CF ,carbon fiber ,co-immobilization ,lactulose ,enzyme stability ,Chemistry ,QD1-999 - Abstract
The g-C3N4/CF composite carrier was prepared by ultrasound-assisted maceration and high-temperature calcination. The enzyme immobilization using the g-C3N4/CF as the novel carrier to immobilize lactase and glucose isomerase was enhanced for lactulose production. The carbon fiber (CF) was mixed with melamine powder in the mass ratio of 1:8. The g-C3N4/CF composite carrier was obtained by calcination at 550 °C for 3 h. After the analysis of characteristics, the g-C3N4/CF was successfully composited with the carbon nitride and CF, displaying the improvement of co-immobilization efficiency with the positive effects on the stability of the enzyme. The immobilization efficiency of the co-immobilized enzyme was 37% by the novel carrier of g-C3N4/CF, with the enzyme activity of 13.89 U g−1 at 60 °C. The relative activities of co-immobilized enzymes maintained much more steadily at the wider pH and higher temperature than those of the free dual enzymes, respectively. In the multi-batches of lactulose production, the relative conversion rates in enzymes co-immobilized by the composite carrier were higher than that of the free enzymes during the first four batches, as well as maintaining about a 90% relative conversation rate after the sixth batch. This study provides a novel method for the application of g-C3N4/CF in the field of immobilizing enzymes for the production of lactulose.
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- 2022
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13. Efficient Machine Learning Models for the Uplift Behavior of Helical Anchors in Dense Sand for Wind Energy Harvesting
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Le Wang, Mengting Wu, Hongzhen Chen, Dongxue Hao, Yinghui Tian, and Chongchong Qi
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helical anchor ,sand ,artificial intelligence techniques ,gradient-boosting decision trees ,particle swarm optimization ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Helical anchors are widely used in engineering to resist tension, especially during offshore wind energy harvesting, and their uplift behavior in sand is influenced by many factors. Experimental studies are often used to investigate these anchors; however, scale effects are inevitable in 1× g model tests, soil conditions for in situ tests are challenging to control, and centrifuge tests are expensive and rare. To make full use of the limited valid data and to gain more knowledge about the uplift behaviors of helical anchors in sand, a prediction model integrating gradient-boosting decision trees (GBDT) and particle swarm optimization (PSO) was proposed in this study. Data obtained from a series of centrifuge tests formed the dataset of the prediction model. The relative density of soil, embedment ratio, helix spacing ratio, and the number of helices were used as input parameters, while the anchor mobilization distance and the ultimate monotonic uplift resistance were set as output parameters. A GBDT algorithm was used to construct the model, and a PSO algorithm was used for hyperparameter tuning. The results show that the optimal GBDT model accurately predicted the anchor mobilization distance and the ultimate monotonic uplift resistance of helical anchors in dense fine silica sand. By analyzing the relative importance of influencing variables, the embedment ratio was found to be the most significant variable in the model, while the relative density of the fine silica sand soil, the helix spacing ratio, and the number of helices had relatively minor influence. In particular, the helix spacing ratio was found to have no influence on the capacity of adjacent helices when S/D > 6.
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- 2022
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14. CO Oxidation over Alumina-Supported Copper Catalysts
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Guoyan Ma, Le Wang, Xiaorong Wang, Lu Li, and Hongfei Ma
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carbon monoxide ,oxidation ,copper ,kinetic ,reaction mechanism ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
CO oxidation, one of the most important chemical reactions, has been commonly studied in both academia and the industry. It is one good probe reaction in the fields of surface science and heterogeneous catalysis, by which we can gain a better understanding and knowledge of the reaction mechanism. Herein, we studied the oxidation state of the Cu species to seek insight into the role of the copper species in the reaction activity. The catalysts were characterized by XRD, N2 adsorption-desorption, X-ray absorption spectroscopy, and temperature-programmed reduction. The obtained results suggested that adding of Fe into the Cu/Al2O3 catalyst can greatly shift the light-off curve of the CO conversion to a much lower temperature, which means the activity was significantly improved by the Fe promoter. From the transient and temperature-programmed reduction experiments, we conclude that oxygen vacancy plays an important role in influencing CO oxidation activity. Adding Fe into the Cu/Al2O3 catalyst can remove part of the oxygen from the Cu species and form more oxygen vacancy. These oxygen vacancy sites are the main active sites for CO oxidation reaction and follow a Mars-van Krevelen-type reaction mechanism.
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- 2022
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15. The AP2/ERF GmERF113 Positively Regulates the Drought Response by Activating GmPR10-1 in Soybean
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Xin Fang, Jia Ma, Fengcai Guo, Dongyue Qi, Ming Zhao, Chuanzhong Zhang, Le Wang, Bo Song, Shanshan Liu, Shengfu He, Yaguang Liu, Junjiang Wu, Pengfei Xu, and Shuzhen Zhang
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soybean ,drought tolerance ,GmERF113 ,GmPR10-1 ,ABA ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Ethylene response factors (ERFs) are involved in biotic and abiotic stress; however, the drought resistance mechanisms of many ERFs in soybeans have not been resolved. Previously, we proved that GmERF113 enhances resistance to the pathogen Phytophthora sojae in soybean. Here, we determined that GmERF113 is induced by 20% PEG-6000. Compared to the wild-type plants, soybean plants overexpressing GmERF113 (GmERF113-OE) displayed increased drought tolerance which was characterized by milder leaf wilting, less water loss from detached leaves, smaller stomatal aperture, lower Malondialdehyde (MDA) content, increased proline accumulation, and higher Superoxide dismutase (SOD) and Peroxidase (POD) activities under drought stress, whereas plants with GmERF113 silenced through RNA interference were the opposite. Chromatin immunoprecipitation and dual effector-reporter assays showed that GmERF113 binds to the GCC-box in the GmPR10-1 promoter, activating GmPR10-1 expression directly. Overexpressing GmPR10-1 improved drought resistance in the composite soybean plants with transgenic hairy roots. RNA-seq analysis revealed that GmERF113 downregulates abscisic acid 8′-hydroxylase 3 (GmABA8’-OH 3) and upregulates various drought-related genes. Overexpressing GmERF113 and GmPR10-1 increased the abscisic acid (ABA) content and reduced the expression of GmABA8’-OH3 in transgenic soybean plants and hairy roots, respectively. These results reveal that the GmERF113-GmPR10-1 pathway improves drought resistance and affects the ABA content in soybean, providing a theoretical basis for the molecular breeding of drought-tolerant soybean.
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- 2022
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16. Investigation of the Effect of Capillary Barrier on Water–Oil Movement in Water Flooding
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Bingtao Hu, Zhaolin Gu, Chenxing Zhou, Le Wang, Chuanqing Huang, and Junwei Su
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capillary barrier ,flow in porous media ,pore-scale simulation ,enhanced oil recovery ,wettability ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Water flooding technology is widely used to improve oil recovery efficiency in oilfields. The capillary barrier effect induced by the complex pore structures in the reservoir rocks is a crucial reason for the trapping of a great deal of residual oil in oil reservoirs after water flooding. However, the formation condition along with the effect on the recovery rate of the capillary barrier under different wettability conditions should be investigated further. To bridge the gap between the microscopic mechanism of the capillary barrier effect and the macroscopic mechanism of oil displacement efficiency, a simple conceptual capillary model is constructed to obtain the formation conditions of the capillary barrier using the analysis method, and its influence on macroscopic oil displacement efficiency in the porous media model with an opening angle of 45° is systematically investigated in this study using direct numerical simulations (DNS) coupled with the volume of fluid method. The results showed that the capillary barrier effect plays a significant role in the formation of the residual oil in the reservoir rock and the contact angle and the opening angle are the primary factors for the formation of the capillary barrier. The capillary force is the driving force when the oil–water interface advances in the throat channel under water-wet conditions, while the capillary force hinders the movement of oil–water movement when the liquid flows out of the throat channel and when θ + β > 90o. Furthermore, the highest oil displacement efficiency is achieved at the intermediate capillary number and in the case that the minimum conditions of occurrence of the capillary barrier phenomenon are satisfied. This is of great significance for controlling the optimized contact angle to further enhance the oil recovery rate of current oil reservoirs using waterflooding technology.
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- 2022
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17. EgSPEECHLESS Responses to Salt Stress by Regulating Stomatal Development in Oil Palm
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Zhuojun Song, Le Wang, Chongcheong Lai, May Lee, Zituo Yang, and Genhua Yue
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oil palm ,salt stress ,stomata ,signalling ,SPEECHLESS ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Oil palm is the most productive oil producing plant. Salt stress leads to growth damage and a decrease in yield of oil palm. However, the physiological responses of oil palm to salt stress and their underlying mechanisms are not clear. RNA-Seq was conducted on control and leaf samples from young palms challenged under three levels of salts (100, 250, and 500 mM NaCl) for 14 days. All three levels of salt stress activated EgSPCH expression and increased stomatal density of oil palm. Around 41% of differential expressed genes (DEGs) were putative EgSPCH binding target and were involved in multiple bioprocesses related to salt response. Overexpression of EgSPCH in Arabidopsis increased the stomatal production and lowered the salt tolerance. These data indicate that, in oil palm, salt activates EgSPCH to generate more stomata in response to salt stress, which differs from herbaceous plants. Our results might mirror the difference of salt-induced stomatal development between ligneous and herbaceous crops.
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- 2022
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18. DEK48 Is Required for RNA Editing at Multiple Mitochondrial Sites and Seed Development in Maize
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Dalin Yang, Shi-Kai Cao, Huanhuan Yang, Rui Liu, Feng Sun, Le Wang, Miaodi Wang, and Bao-Cai Tan
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PPR-DYW protein ,seed development ,mitochondria ,complex I ,RNA editing ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
In flowering plants, C-to-U RNA editing can be critical to normal functions of mitochondrion-encoded proteins. Mitochondrial C-to-U RNA editing is facilitated by many factors from diverse protein families, of which the pentatricopeptide repeat (PPR) proteins play an important role. Owing to their large number and frequent embryo lethality in mutants, functions of many PPRs remain unknown. In this study, we characterized a mitochondrion-localized DYW-type PPR protein, DEK48, functioning in the C-to-U RNA editing at multiple mitochondrial transcripts in maize. Null mutation of Dek48 severely arrests embryo and endosperm development, causing a defective kernel (dek) phenotype, named dek48. DEK48 loss of function abolishes the C-to-U editing at nad3-185, -215, and nad4-376, -977 sites and decreases the editing at 11 other sites, resulting in the alteration of the corresponding amino acids. Consequently, the absence of editing caused reduced assembly and activity of complex I in dek48. Interestingly, we identified a point mutation in dek48-3 causing a deletion of the Tryptophan (W) residue in the DYW motif that abolishes the editing function. In sum, this study reveals the function of DEK48 in the C-to-U editing in mitochondrial transcripts and seed development in maize, and it demonstrates a critical role of the W residue in the DYW triplet motif of DEK48 for the C-to-U editing function in vivo.
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- 2022
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19. Sandbur Drought Tolerance Reflects Phenotypic Plasticity Based on the Accumulation of Sugars, Lipids, and Flavonoid Intermediates and the Scavenging of Reactive Oxygen Species in the Root
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Zhiyuan Yang, Chao Bai, Peng Wang, Weidong Fu, Le Wang, Zhen Song, Xin Xi, Hanwen Wu, Guoliang Zhang, and Jiahe Wu
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Cenchrus spinifex Cav. ,drought ,phenotypic plasticity ,flavonoids ,reactive oxygen species ,antioxidant ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The perennial grass Cenchrus spinifex (common sandbur) is an invasive species that grows in arid and semi-arid regions due to its remarkable phenotypic plasticity, which confers the ability to withstand drought and other forms of abiotic stress. Exploring the molecular mechanisms of drought tolerance in common sandbur could lead to the development of new strategies for the protection of natural and agricultural environments from this weed. To determine the molecular basis of drought tolerance in C. spinifex, we used isobaric tags for relative and absolute quantitation (iTRAQ) to identify proteins differing in abundance between roots growing in normal soil and roots subjected to moderate or severe drought stress. The analysis of these proteins revealed that drought tolerance in C. spinifex primarily reflects the modulation of core physiological activities such as protein synthesis, transport and energy utilization as well as the accumulation of flavonoid intermediates and the scavenging of reactive oxygen species. Accordingly, plants subjected to drought stress accumulated sucrose, fatty acids, and ascorbate, shifted their redox potential (as determined by the NADH/NAD ratio), accumulated flavonoid intermediates at the expense of anthocyanins and lignin, and produced less actin, indicating fundamental reorganization of the cytoskeleton. Our results show that C. spinifex responds to drought stress by coordinating multiple metabolic pathways along with other adaptations. It is likely that the underlying metabolic plasticity of this species plays a key role in its invasive success, particularly in semi-arid and arid environments.
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- 2021
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20. Optimization of Stop Plan for Skip-Stop Operation on Suburban Railway Line
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Jun Xu, Qinghuai Liang, Xiaoyu Huang, and Le Wang
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urban rail transit ,suburban rail ,skip-stop ,stop plan ,overtaking ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A combination of express and local trains (E/L mode) is generally used to operate a suburban rail service, it can meet the rapid and direct service needs of long-distance travelers as well the needs of short-distance travelers. Generally, a stop plan is the core of the E/L mode. A stop plan optimization model in E/L mode, which aims to minimize the total passenger travel time and the number of operating trains during the peak period with the safe headway and departure frequency constraints, is proposed in this study. Meanwhile, an algorithm based on a genetic algorithm is designed to solve the proposed model. A case study of the Jiangjin Line, a suburban railway in Chongqing, China, is carried out. The results show the efficiency and feasibility of the proposed method. The calculation results also show that the total passenger travel time under E/L mode with the overtaking condition is significantly reduced compared with the all-stops (AS) mode and E/L mode without overtaking condition. The superiority of the E/L mode can be enhanced by reducing the dwell time at stations and adopting the overtaking condition.
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- 2021
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21. Preparation of ZIF@ADH/NAD-MSN/LDH Core Shell Nanocomposites for the Enhancement of Coenzyme Catalyzed Double Enzyme Cascade
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Le Wang, Pengxue Sun, Yiyu Yang, Hanzhen Qiao, Hailong Tian, Dapeng Wu, Shuoye Yang, Qipeng Yuan, and Jinshui Wang
- Subjects
confinement effect ,multi-enzyme catalytic cascade ,in-situ synthesis ,coenzyme recycling ,co-immobilization enzyme ,Chemistry ,QD1-999 - Abstract
The field of enzyme cascades in limited microscale or nanoscale environments has undergone a quick growth and attracted increasing interests in the field of rapid development of systems chemistry. In this study, alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and mesoporous silica nanoparticles (MSN) immobilized nicotinamide adenine dinucleotide (NAD+) were successfully immobilized on the zeolitic imidazolate frameworks (ZIFs). This immobilized product was named ZIF@ADH/NAD-MSN/LDH, and the effect of the multi-enzyme cascade was studied by measuring the catalytic synthesis of lactic acid. The loading efficiency of the enzyme in the in-situ co-immobilization method reached 92.65%. The synthesis rate of lactic acid was increased to 70.10%, which was about 2.82 times that of the free enzyme under the optimal conditions (40 °C, pH = 8). Additionally, ZIF@ADH/NAD-MSN/LDH had experimental stability (71.67% relative activity after four experiments) and storage stability (93.45% relative activity after three weeks of storage at 4 °C; 76.89% relative activity after incubation in acetonitrile-aqueous solution for 1 h; 27.42% relative activity after incubation in 15% N, N-Dimethylformamide (DMF) solution for 1 h). In summary, in this paper, the cyclic regeneration of coenzymes was achieved, and the reaction efficiency of the multi-enzyme biocatalytic cascade was improved due to the reduction of substrate diffusion.
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- 2021
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22. Effect of Nano-Y2O3 Content on Microstructure and Mechanical Properties of Fe18Cr Films Fabricated by RF Magnetron Sputtering
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Bang-Lei Zhao, Le Wang, Li-Feng Zhang, Jian-Gang Ke, Zhuo-Ming Xie, Jun-Feng Yang, Xian-Ping Wang, Ting Hao, Chang-Song Liu, and Xue-Bang Wu
- Subjects
FeCr-based films ,oxide dispersion strengthening ,nanoindentation hardness ,Chemistry ,QD1-999 - Abstract
In this work, FeCr-based films with different Y2O3 contents were fabricated using radio frequency (RF) magnetron sputtering. The effects of Y2O3 content on their microstructure and mechanical properties were investigated through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), inductive coupled plasma emission spectrometer (ICP) and a nanoindenter. It was found that the Y2O3-doped FeCr films exhibited a nanocomposite structure with nanosized Y2O3 particles uniformly distributed into a FeCr matrix. With the increase of Y2O3 content from 0 to 1.97 wt.%, the average grain size of the FeCr films decreased from 12.65 nm to 7.34 nm, demonstrating a grain refining effect of Y2O3. Furthermore, the hardness of the Y2O3-doped FeCr films showed an increasing trend with Y2O3 concentration, owing to the synergetic effect of dispersion strengthening and grain refinement strengthening. This work provides a beneficial guidance on the development and research of composite materials of nanocrystalline metal with a rare earth oxide dispersion phase.
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- 2021
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23. A BN-Doped U-Shaped Heteroacene as a Molecular Floating Gate for Ambipolar Charge Trapping Memory
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Yang Yu, Le Wang, Dongqing Lin, Shammi Rana, Kunal S. Mali, Haifeng Ling, Linghai Xie, Steven De Feyter, and Junzhi Liu
- Subjects
TRANSISTOR MEMORIES ,Chemistry ,Science & Technology ,Charge Trapping Memory ,Chemistry, Multidisciplinary ,Physical Sciences ,ELEMENTS ,Polycyclic Aromatic Hydrocarbon ,General Medicine ,General Chemistry ,Boron-Nitrogen ,Catalysis ,Supramolecular-Doped Polymer - Abstract
Two wide-band gap U-shaped polycyclic aromatic hydrocarbons with/without boron and nitrogen (BN-) doping (BN-1 and C-1) were synthesized to tune the electronic features to suit the performance requirements for organic field-effect transistor memory (OFET-NVM). The chemical structures were characterized by scanning tunneling microscopy and single-crystal diffraction. Owing to the electron-donor effect of N and the high electron affinity of B, the BN-1-based OFET-NVM displays large ambipolar memory windows and an enhanced charge storage density compared to C-1 and most reported small molecules. A novel supramolecular system formed from BN-1 and PMMA contributes to fabricating uniform films with homogeneous microstructures, which serve as a two-in-one tunnelling dielectric and charge-trapping layer to realize long-term charge retention and reliable endurance. Our results demonstrate that both BN doping and supramolecular engineering are crucial for the charge trapping of OFET-NVM. ispartof: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION vol:62 issue:22 ispartof: location:Germany status: Published online
- Published
- 2023
24. AuNP aggregation-induced quantitative colorimetric aptasensing of sulfadimethoxine with a smartphone
- Author
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Xiaoliang Zhang, Xiaochun Li, Le Wang, and Xiujun Li
- Subjects
Detection limit ,Chromatography ,Chemistry ,Aptamer ,medicine ,Sulfadimethoxine ,General Chemistry ,Quantitative analysis (chemistry) ,medicine.drug - Abstract
A gold nanoparticle (AuNP) aggregation-induced colorimetric aptasensing method for quantitative detection of sulfadimethoxine (SDM) with a smartphone was developed. AuNPs were complexed with aptamers which protected AuNPs from aggregating in high-concentration salt solutions. In the presence of SDM, SDM bound with the aptamer on the surface of AuNPs with higher affinity, which competitively desorbed the aptamer from the AuNP surface and resulted in AuNPs aggregation, accompanied with a color change from red to purple-blue. The R, G and B values of images taken by a smartphone camera were analyzed with an app on the smartphone, and were utilized for quantitative analysis of SDM. Under the optimized conditions, the colorimetric aptasensing method using a smartphone showed high sensitivity for SDM, with the limit of detection of 0.023 ppm, lower than the allowed maximum SDM residue limit. This study provides a simple, fast, and easy to read method for on-site quantitative biochemical and cellular analysis.
- Published
- 2022
25. An Experimental Investigation of Turbulence Features Induced by Typical Artificial M-Shaped Unit Reefs
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Anping Shu, Jiping Qin, Matteo Rubinato, Tao Sun, Mengyao Wang, Shu Wang, Le Wang, Jiapin Zhu, and Fuyang Zhu
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Liaodong Bay ,Bohai Sea ,artificial reef ,turbulence ,particle image velocimetry ,experimental modeling ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Artificial reefs are considered to have the function of repairing and improving the coastal habitat and increasing the fishery production, which are mainly achieved by changing the regional hydrodynamic conditions. The characteristics of flow turbulence structure are an important part of the regional hydrodynamic characteristics. Different methods are used to evaluate the performance of artificial reefs according to their shape and the purpose for which the reef was built. For this study, the M-shaped unit reefs, which are to be put into the area of Liaodong Bay, were selected as the research object and have never been fully investigated before. Experimental tests were conducted to assess the effect of these M-shaped artificial reefs on the vertical and longitudinal turbulent intensity under different hydraulic conditions and geometries, and datasets were collected by using the Particle Image Velocimetry technique implemented within the experimental facility. The distribution and variation characteristics of the turbulence intensity were analyzed, and the main results obtained can confirm that in the artificial reef area, there was an extremely clear turbulent boundary. Furthermore, the area of influence of the longitudinal turbulence was identified to be larger than that of the vertical turbulence, and the position where the maximum turbulence intensity appeared was close to where the maximum velocity was measured. Finally, results demonstrate that low turbulence conditions are typically located in front of the unit reef, the general turbulence area is located within the upwelling zone, and the more intense turbulence area is located between the two M-shaped monocases. These results are extremely important, because they provide the local authorities with specific knowledge about what could be the effect of these M-shaped reefs within the area where they will be implemented, and therefore, specific actions can be taken in consideration with the geometrical setup suggested as an optimal solution within this study.
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- 2021
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26. LAMP for the rapid diagnosis of iridovirus in aquaculture
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Qiwei Qin, Le Wang, Yepin Yu, Fei Sun, Yanfei Wen, Zituo Yang, May Lee, and Gen Hua Yue
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food.ingredient ,Ecology ,biology ,business.industry ,Chemistry ,Iridovirus ,Loop-mediated isothermal amplification ,DNA virus ,Aquatic Science ,biology.organism_classification ,Molecular biology ,DNA extraction ,food ,Aquaculture ,Grouper ,Asian seabass ,Dna viral ,business ,Ecology, Evolution, Behavior and Systematics - Abstract
Iridoviruses are DNA virus and have caused huge economic losses in the aquaculture industry. The aim of this study was to establish a colorimetric loop-mediated isothermal amplification (LAMP) protocol for the on-site detection of Singapore grouper iridovirus (SGIV). The SGIV-VP61 gene was chosen as the target gene to develop a colorimetric LAMP assay. The optimized condition of the colorimetric LAMP assay was incubation at 63 °C for 1 h. Samples infected with SGIV could be detected with the color change from yellow into pink. The sensitivity of the developed assay is 5.66 copies/μL of the viral DNA template. This sensitivity was about 1000 times higher than that of conventional PCR while it was slightly lower than the one-step semi-nested PCR assay. A total of 60 DNA samples extracted from the fin tissue of the SGIV-infected Asian seabass were examined for SGIV by colorimetric LAMP, semi-nested PCR and conventional PCR. The results of the colorimetric LAMP assay showed 94.87 % agreement with the semi-nested PCR. In addition, the DNA extraction method using NaOH showed a better performance in the colorimetric LAMP assay. Taken together, the colorimetric LAMP established was a sensitive, rapid and specific method for the detection of SGIV. SGIV was not detected in samples randomly taken from a genetically improved line of the Asian seabass. However, some seabass obtained from the local markets were found to contain SGIV. Thus, the LAMP assay has the potential application in the diagnosis of iridovirus diseases in the aquaculture industry.
- Published
- 2022
27. Natural diterpenoid eriocalyxin B covalently modifies glutathione and selectively inhibits thioredoxin reductase inducing potent oxidative stress-mediated apoptosis in colorectal carcinoma RKO cells
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Yanru Wang, Xiaojie Jin, Dong-Zhu Duan, Xiaoling Wang, Jian Xiao, Mi Li, Yunyun Yan, Le Wang, and Peng Song
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chemistry.chemical_classification ,Thioredoxin-Disulfide Reductase ,Thioredoxin reductase ,Apoptosis ,Glutathione ,Synthetic lethality ,medicine.disease_cause ,Biochemistry ,Small molecule ,Oxidative Stress ,chemistry.chemical_compound ,Enzyme ,chemistry ,Cell Line, Tumor ,Physiology (medical) ,medicine ,Cancer research ,Humans ,Diterpenes ,Colorectal Neoplasms ,Carcinogenesis ,Oxidative stress ,Signal Transduction - Abstract
Increasing evidence suggests the significant contribution of high levels of thioredoxin reductase (TrxR) in various stages of tumorigenesis and resistance to tumor chemotherapy. Thus, inhibition of TrxR with small molecules is an attractive strategy for cancer therapy. Eriocalyxin B (EriB), a naturally occurring diterpenoid extracted from Isodon eriocalyx, has reflected potential anticancer activities through numerous pathways. Here, we describe that EriB covalently modifies GSH and selectively inhibits TrxR activity by targeting the Sec residue of the enzyme. Pharmacological inhibition of TrxR by EriB results in elevated ROS levels, reduced total GSH and thiols content, which ultimately induced potent RKO cell apoptosis mediated by oxidative stress. Importantly, EriB indicates potent synthetic lethality with GSH inhibitors, BSO, in RKO cells. In summary, our results highlight that targeting TrxR by EriB explores a novel mechanism for the biological action of EriB. This opened up a new therapeutic indication for using EriB to combat cancers.
- Published
- 2021
28. Nocardioides lacusdianchii sp. nov., an attached bacterium of Microcystis aeruginosa
- Author
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Zhang Binghuo, Le Wang, Baoyu Tian, Min Chen, Yao Xiao, Xin Wang, and Jian Chen
- Subjects
food.ingredient ,biology ,Strain (chemistry) ,Nocardioides ,General Medicine ,biology.organism_classification ,medicine.disease_cause ,Microbiology ,chemistry.chemical_compound ,food ,chemistry ,Microcystis ,medicine ,Microcystis aeruginosa ,Peptidoglycan ,Nocardioides alpinus ,Molecular Biology ,Bacteria ,Nocardioides furvisabuli - Abstract
Attached bacteria of Microcystis play important roles in the occurence, outbreak and decline of Microcystis water blooms. In this study, a novel actinobacterium, designated strain JXJ CY 38 T, was isolated from the culture mass of Microcystis aeruginosa FACHB-905 (MAF), collected from Lake Dianchi, south-west, China. The strain was found to be a Gram-stain positive, short rod, catalase positive and oxidase negative. The isolate was found to be able to grow at 5.0-38.0 °C (optimum, 28.0 °C), pH 4.0-11.0 (optimum, 7.0-8.0) and 0-3.0% (w/v, optimum, 0%) NaCl. Based on 16S rRNA gene sequences, strain JXJ CY 38 T shows high similarities to Nocardioides furvisabuli JCM 13813 T (99.0%) and Nocardioides alpinus JCM 18960 T (98.7%), and less than 98.2% similarities to other members of the genus. The major cellular fatty acids (> 10.0%) were identified as iso-C16:0 (23.6%), C18:1ω9c (18.2%) and C17:1ω8c (16.4%), while the predominant menaquinone was found to be MK-8 (H4). The diagnostic diamino acids in the cell wall peptidoglycan were identified as aspartic acid, glutamic acid, glycine and alanine, with mannose, ribose and arabinose as whole cell sugars. The polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, a phospholipid, phosphatidylcholine and an unidentified lipid. The DNA G + C content was determined to be 71.3%. The digital DNA-DNA hybridization and average nucleotide identity values between strain JXJ CY 38 T and the type strains N. furvisabuli JCM 13813 T and N. alpinus JCM 18960 T were 49.4% and 37.7%, and 92.0% and 83.4%, respectively. On the basis of the above taxonomic data and differences in physiological characteristics from the closely related type strains, strain JXJ CY 38 T was determined to represent a novel species of genus Nocardioides, for which the name Nocardioides lacusdianchii sp. nov. is proposed. The type strain is JXJ CY 38 T (= KCTC 49381 T = CGMCC 4.7665 T). Strain JXJ CY 38 T apparently exhibits complex effects on the interactions between MAF and other attached bacteria, including the promotion or inhibition of the growth of MAF and bacteria, and the synthesis and release of microcystins by MAF.
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- 2021
29. Catalytic Deoxygenative Cyclopropanation of 1,2-Dicarbonyl or Monocarbonyl Compounds via Molybdenum Catalysis
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Jia-Le Wang and Chun-Xiang Zhuo
- Subjects
chemistry.chemical_compound ,chemistry ,Molybdenum ,Cyclopropanation ,Organic Chemistry ,chemistry.chemical_element ,Diazo ,Combinatorial chemistry ,Decomposition ,Catalysis ,Cyclopropane - Abstract
The cyclopropanation of alkenes through the transition-metal-catalyzed decomposition of diazo compounds is a powerful and straightforward strategy to produce cyclopropanes. Nevertheless, the appeal of further application of this strategy is tempered by the potentially explosive nature of the diazo substrates. Therefore, it is highly desirable to develop sustainable and operationally safe surrogates for diazo compounds. In this Synpacts article, we discuss recent advances on the cyclopropane syntheses through the catalytic cyclopropanation of alkenes and metal carbenes generated in situ from nondiazo precursors as well as highlight our recent progress on the unprecedented molybdenum-catalyzed deoxygenative cyclopropanation reaction of 1,2-dicarbonyl or monocarbonyl compounds.
- Published
- 2021
30. Structural characterization, physicochemical properties and in vitro digestion of finger millet–resistant starch prepared by different methods
- Author
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Panfei Xiao, Jiali Chen, Chiling Li, Cuiping Yi, Shaochuang Lu, and Le Wang
- Subjects
Preparation method ,food.ingredient ,food ,Chemistry ,Food science ,Resistant starch ,In vitro digestion ,Finger millet ,Industrial and Manufacturing Engineering ,Food Science - Published
- 2021
31. Fluorescent and Antibacterial Aminobenzeneboronic Acid (ABA)-Modified Gold Nanoclusters for Self-Monitoring Residual Dosage and Smart Wound Care
- Author
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Le Wang, Xingyu Jiang, Wenfu Zheng, and Qinghong Hou
- Subjects
Bacteria ,integumentary system ,Chemistry ,General Engineering ,General Physics and Astronomy ,equipment and supplies ,Bandages ,Fluorescence ,Anti-Bacterial Agents ,Nanocomposites ,Nanoclusters ,Wound care ,chemistry.chemical_compound ,Bacterial cellulose ,Wound dressing ,General Materials Science ,Gold ,Cellulose ,Antibacterial activity ,human activities ,Biomedical engineering - Abstract
The replacement of dressings may cause secondary damage to the wounds; thus, the real-time monitoring of the state of wound dressings is crucial for evaluating wound care processes. Herein, we report a smart dressing to self-monitor residue nanomedicine on it during the application. We load aminobenzeneboronic acid (ABA)-modified gold nanoclusters (A-GNCs) on bacterial cellulose (BC) membranes as an antibacterial wound dressing to display the amount of residual nanomedicine (A-GNCs) by
- Published
- 2021
32. Organocatalytic Direct Asymmetric Indolization from Anilines by Enantioselective [3 + 2] Annulation
- Author
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Jia Zhou, He-Yuan Bai, Le Wang, Guo-Dong Zhu, Shu-Yu Zhang, and Guan-Jun Wang
- Subjects
Annulation ,Organic Chemistry ,Synthon ,Enantioselective synthesis ,Substrate (chemistry) ,Optically active ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,Aniline ,chemistry ,Amine gas treating ,Organic synthesis ,Physical and Theoretical Chemistry - Abstract
We report the efficient syntheses of chiral tetrahydroindole pyrazolinones by the asymmetric [3 + 2] cascade cyclizations (indolizations) of simple aniline derivatives with pyrazolinone ketimines as 2C synthons. The chiral phosphoric-acid-catalyzed system uses a concerted π-π interaction/dual H-bond control strategy to catalytically direct the asymmetric aniline, which undergoes a highly chemo-, regio-, and enantioselective [3 + 2] cascade annulation, furnishing a series of optically active tetra-hydroindole pyrazolinones with two contiguous chiral aza-quaternary carbon centers in excellent yields with excellent enantioselectivities. This method features a relatively broad substrate scope for amines and 2-naphthylamines and highlights the emerging value of direct chiral indolizations from simple amine sources in organic synthesis.
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- 2021
33. Coumarin-based Fluorescent Probes for Bioimaging: Recent Applications and Developments
- Author
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Jin-Hua Xie, Xiqi Su, João Rodrigues, and Le Wang
- Subjects
chemistry.chemical_compound ,Chemistry ,Organic Chemistry ,Nanotechnology ,Coumarin ,Fluorescence - Abstract
Coumarin-based derivatives have easy modification and tunable properties and have been synthesized and applied in many areas including pro-drugs, biomedical materials, and chemical and biological sensing. In this review, recent advances of coumarin-based fluorescent probes for biosensing are reported for metal ion imaging. Metal detection in living cells are highlighted with representative examples together with fluorescence response mechanisms such as Photoinduced Electron Transfer (PET), Intramolecular Charge Transfer (ICT), and Fluorescence Resonance Energy Transfer (FRET). Some future perspectives are also briefly mentioned.
- Published
- 2021
34. Angiopoietin-2 silence alleviates lipopolysaccharide-induced inflammation, barrier dysfunction and endoplasmic reticulum stress of intestinal epithelial cells by blocking Notch signaling pathway
- Author
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Shuangshuang Jie, Le Wang, Liying Dai, Shaohua Bi, Qing Qing, and Jun Chen
- Subjects
Lipopolysaccharides ,Notch signaling pathway ,Bioengineering ,Inflammation ,Applied Microbiology and Biotechnology ,Models, Biological ,Cell Line ,Angiopoietin-2 ,ANGPT2 ,Necrotizing enterocolitis ,Enterocolitis, Necrotizing ,medicine ,Humans ,Viability assay ,Gene Silencing ,inflammation response ,barrier dysfunction ,Gene knockdown ,Tight junction ,Receptors, Notch ,Chemistry ,Endoplasmic reticulum ,General Medicine ,Endoplasmic Reticulum Stress ,Cell biology ,Up-Regulation ,Apoptosis ,Unfolded protein response ,medicine.symptom ,TP248.13-248.65 ,Jagged-1 Protein ,Biotechnology ,Research Article ,Research Paper ,Signal Transduction - Abstract
Necrotizing enterocolitis, a devastating gastrointestinal disease with high mortality, poses great threats to global health. Therefore, we conducted this study to explore the role of ANGPT2, as well as the potential mechanism, in necrotizing enterocolitis. IEC-6 cells were stimulated with lipopolysaccharide (LPS) to induce necrotizing enterocolitis model in vitro. The expression of ANGPT2 was measured by RT-qPCR. The cell viability was detected using CCK-8. Besides, the expressions of endoplasmic reticulum (ER) stress-related proteins, Notch signaling pathway-related proteins and tight junction proteins were checked by western blot. The apoptosis and inflammatory response were detected by TUNEL and ELISA, respectively. Moreover, with the adoption of TEER, the cell monolayer permeability was detected. The results showed that ANGPT2 expression was greatly increased after LPS induction. In addition, ANGPT2 knockdown significantly decreased the apoptosis, inflammatory response, barrier dysfunction and endoplasmic reticulum stress of LPS-induced IEC-6 cells. What is more, ANGPT2 knockdown could block Notch signaling pathway. Additionally, with the treatment of Jagged-1, the protective effect of ANGPT2 knockdown on LPS-induced intestinal injury was partly abolished. To sum up, silencing ANGPT2 could improve LPS-induced inflammation, barrier dysfunction and ER stress of intestinal epithelial cells via blocking Notch signaling pathway.
- Published
- 2021
35. Genome-Wide Identification of CsATGs in Tea Plant and the Involvement of CsATG8e in Nitrogen Utilization
- Author
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Wei Huang, Dan-Ni Ma, Hong-Ling Liu, Jie Luo, Pu Wang, Ming-Le Wang, Fei Guo, Yu Wang, Hua Zhao, and De-Jiang Ni
- Subjects
autophagy-related genes ,Camellia sinensis ,CsATG8e ,nitrogen ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Nitrogen (N) is a macroelement with an indispensable role in the growth and development of plants, and tea plant (Camellia sinensis) is an evergreen perennial woody species with young shoots for harvest. During senescence or upon N stress, autophagy has been shown to be induced in leaves, involving a variety of autophagy-related genes (ATGs), which have not been characterized in tea plant yet. In this study, a genome-wide survey in tea plant genome identified a total of 80 Camellia Sinensis autophagy-related genes, CsATGs. The expression of CsATG8s in the tea plant showed an obvious increase from S1 (stage 1) to S4 (stage 4), especially for CsATG8e. The expression levels of AtATGs (Arabidopsis thaliana) and genes involved in N transport and assimilation were greatly improved in CsATG8e-overexpressed Arabidopsis. Compared with wild type, the overexpression plants showed earlier bolting, an increase in amino N content, as well as a decrease in biomass and the levels of N, phosphorus and potassium. However, the N level was found significantly higher in APER (aerial part excluding rosette) in the overexpression plants relative to wild type. All these results demonstrated a convincing function of CsATG8e in N remobilization and plant development, indicating CsATG8e as a potential gene for modifying plant nutrient utilization.
- Published
- 2020
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36. Genome-Wide Profiling and Phylogenetic Analysis of the SWEET Sugar Transporter Gene Family in Walnut and Their Lack of Responsiveness to Xanthomonas arboricola pv. juglandis Infection
- Author
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Shijiao Jiang, Bipin Balan, Renata de A. B. Assis, Cintia H. D. Sagawa, Xueqin Wan, Shan Han, Le Wang, Lanlan Zhang, Paulo A. Zaini, Sriema L. Walawage, Aaron Jacobson, Steven H. Lee, Leandro M. Moreira, Charles A. Leslie, and Abhaya M. Dandekar
- Subjects
sweet sugar transporters ,gene family ,phylogeny ,tal effector ,gene expression ,walnut blight ,xanthomonas ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Following photosynthesis, sucrose is translocated to sink organs, where it provides the primary source of carbon and energy to sustain plant growth and development. Sugar transporters from the SWEET (sugar will eventually be exported transporter) family are rate-limiting factors that mediate sucrose transport across concentration gradients, sustain yields, and participate in reproductive development, plant senescence, stress responses, as well as support plant−pathogen interaction, the focus of this study. We identified 25 SWEET genes in the walnut genome and distinguished each by its individual gene structure and pattern of expression in different walnut tissues. Their chromosomal locations, cis-acting motifs within their 5′ regulatory elements, and phylogenetic relationship patterns provided the first comprehensive analysis of the SWEET gene family of sugar transporters in walnut. This family is divided into four clades, the analysis of which suggests duplication and expansion of the SWEET gene family in Juglans regia. In addition, tissue-specific gene expression signatures suggest diverse possible functions for JrSWEET genes. Although these are commonly used by pathogens to harness sugar products from their plant hosts, little was known about their role during Xanthomonas arboricola pv. juglandis (Xaj) infection. We monitored the expression profiles of the JrSWEET genes in different tissues of “Chandler” walnuts when challenged with pathogen Xaj417 and concluded that SWEET-mediated sugar translocation from the host is not a trigger for walnut blight disease development. This may be directly related to the absence of type III secretion system-dependent transcription activator-like effectors (TALEs) in Xaj417, which suggests different strategies are employed by this pathogen to promote susceptibility to this major aboveground disease of walnuts.
- Published
- 2020
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37. A Bio-Inspired Flapping Wing Rotor of Variant Frequency Driven by Ultrasonic Motor
- Author
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Si Chen, Le Wang, Shijun Guo, Chunsheng Zhao, and Mingbo Tong
- Subjects
flapping wing rotor ,ultrasonic motor ,variable actuation frequency ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
By combining the flapping and rotary motion, a bio-inspired flapping wing rotor (FWR) is a unique kinematics of motion. It can produce a significantly greater aerodynamic lift and efficiency than mimicking the insect wings in a vertical take-off and landing (VTOL). To produce the same lift, the FWR’s flapping frequency, twist angle, and self-propelling rotational speed is significantly smaller than the insect-like flapping wings and rotors. Like its opponents, however, the effect of variant flapping frequency (VFF) of a FWR, during a flapping cycle on its aerodynamic characteristics and efficiency, remains to be evaluated. A FWR model is built to carry out experimental work. To be able to vary the flapping frequency rapidly during a stroke, an ultrasonic motor (USM) is used to drive the FWR. Experiment and numerical simulation using computational fluid dynamics (CFD) are performed in a VFF range versus the usual constant flapping frequency (CFF) cases. The measured lifting forces agree very well with the CFD results. Flapping frequency in an up-stroke is smaller than a down-stroke, and the negative lift and inertia forces can be reduced significantly. The average lift of the FWR where the motion in VFF is greater than the CFF, in the same input motor power or equivalent flapping frequency. In other words, the required power for a VFF case to produce a specified lift is less than a CFF case. For this FWR model, the optimal installation angle of the wings for high lift and efficiency is found to be 30° and the Strouhal number of the VFF cases is between 0.3−0.36.
- Published
- 2020
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38. The Recycling Torque of a Single-Plate Helical Pile for Offshore Wind Turbines in Dense Sand
- Author
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Hongyan Ding, Le Wang, Puyang Zhang, Yuguo Liang, Yinghui Tian, and Xin Qi
- Subjects
helical pile ,sand ,recycling ,test model ,theoretical model ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The helical piles have been being treated as a kind of novel foundation for offshore wind turbines recently, due their fast installation, high uplift capacity, convenience for recycling, and other advantages. The recycling of the helical pile especially will reduce the cost significantly and protect the environment as much as possible. However, the research for this area is basically in infancy and there is no reference for predicting the recycling torque of a helical pile in sand. In order to predict the recycling torque of single-plate helical piles in dense sand: a theoretical model, which was inspired by the way to predict the installation torque of single-plate helical pile in sand, was developed, and a series of single gravity model tests were conducted to verify that theoretical model. The theoretical model can predict the recycling torque of single-plate helical pile considering the influences of the size of helix and the vertical force on the shaft. This model fills in the blank of predicting the recycling torque of a single-plate helical pile in sand and it is also useful guidance for the choice of suitable recycling equipment.
- Published
- 2019
- Full Text
- View/download PDF
39. Combined effects of sulfate attack under drying–wetting cycles and loading on the fatigue behavior of concrete
- Author
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Chun Liu, Le Wang, Yunfeng Zhao, Song Ren, Nengzeng Long, Ping Zhang, and Fan Chen
- Subjects
Materials science ,business.industry ,Building and Construction ,Structural engineering ,chemistry.chemical_compound ,Properties of concrete ,chemistry ,Fatigue loading ,Cyclic loading ,Wetting ,Sulfate ,Composite material ,business ,Civil and Structural Engineering - Abstract
Concrete structures often undergo both fatigue loading and environmental impacts during their useful lifetime. This study aims to explore the fatigue properties of concrete subjected to sulfate attacks under drying–wetting cycles and loading. The coupled influences of major cycle number and sodium sulfate solution on the residual deformation, elastic modulus, and damage variable were investigated by uniaxial cyclic loading tests. Moreover, the phase composition of concrete samples was examined by X-ray diffraction. Results indicate that the concrete residual deformation and damage variable could be classified into initial and stable stages, while the elastic modulus fluctuated within a certain range. The fatigue strength of concrete was found to increase with an increase in the major cycle number and sodium sulfate concentration in the early stages, whereas the fatigue performance of concrete decreased as the major cycle number and sodium sulfate concentration increased in the later stage. The degree of influence of major cycle number and sodium sulfate concentration on the fatigue properties of concrete differed in each stage. These findings can contribute to understand the variation pattern of concrete properties in complicated environments and provide an important reference for associated construction projects.
- Published
- 2021
40. Performance simulation and thermodynamics analysis of hydrogen production based on supercritical water gasification of coal
- Author
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Shanke Liu, Le Wang, Liejin Guo, Runyu Wang, Libo Lu, Jia Chen, Zening Cheng, Deming Zhang, and Hui Jin
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Raw material ,Condensed Matter Physics ,Oxygen ,Supercritical fluid ,Volumetric flow rate ,Fuel Technology ,chemistry ,Scientific method ,Coal ,Process engineering ,business ,Hydrogen production ,Coal slurry - Abstract
The heating method of SCWG reactor is critical to system construction, and almost all existing reactors rely on external heat sources. In this article, the thermodynamic equilibrium model is established to predict the distribution of gasification products from supercritical water gasification of coal. The transformation rule of gas components in the SCWG process of coal and oxidation process of gasification products is explored. Especially, the influence of key parameters such as feedstock concentration, gasification temperature and pressure on the hydrogen yield during the gasification and oxidation processes is also discussed. Based on the above research, the autothermal gasification system for hydrogen production integrated supercritical water gasification of coal and oxidation of gasification products is proposed. The flow matching of supercritical water, coal slurry, and oxygen and its effect on the autothermal hydrogen yield are discussed. By optimizing the flow rate of the reactants, 80% of the hydrogen production efficiency is achieved.
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- 2021
41. Molecular mechanism study of HGF/c-MET pathway activation and immune regulation for a tumor diagnosis model
- Author
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Zhirui Fan, Jie Zhao, Wenhua Xue, Zhibo Shen, Yuanyuan Zheng, Yunkai Zhai, Ying Yue, Geng Qishun, Lifeng Li, Wang Wenbin, and Le Wang
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0301 basic medicine ,Cancer Research ,C-Met ,Biology ,Transcriptome ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,Genetics ,medicine ,HGF ,Pathway score ,Receptor ,RC254-282 ,c-MET ,Tumor microenvironment ,Diagnostic predictor ,QH573-671 ,Immune cells ,Cancer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Prognosis ,medicine.disease ,RNAseq ,Immune infiltration ,030104 developmental biology ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,Hepatocyte growth factor ,Signal transduction ,Primary Research ,Cytology ,medicine.drug - Abstract
Background Hepatocyte growth factor (HGF) binds to the c-mesenchymal-epithelial transition (C-MET) receptor and activates downstream signaling pathways, playing an essential role in the development of various cancers. Given the role of this signaling pathway, the primary therapeutic direction focuses on identifying and designing HGF inhibitors, antagonists and other molecules to block the binding of HGF to C-MET, thereby limiting the abnormal state of other downstream genes. Methods This study focuses on the analysis of immune-related genes and corresponding immune functions that are significantly associated with the HGF/c-MET pathway using transcriptome data from 11 solid tumors. Results We systematically analyzed 11 different cancers, including expression correlation, immune infiltration, tumor diagnosis and survival prognosis from HGF/c-MET pathway and immune regulation, two biological mechanisms having received extensive attention in cancer analysis. Conclusion We found that the HGF/c-MET pathway affected the tumor microenvironment mainly by interfering with expression levels of other genes. Immune infiltration is another critical factor involved in changes to the tumor microenvironment. The downstream immune-related genes activated by the HGF/c-MET pathway regulate immune-related pathways, which in turn affect the degree of infiltration of immune cells. Immune infiltration is significantly associated with cancer development and prognosis.
- Published
- 2021
42. Mesoporous Ag/ZnO hybrid cages derived from ZIF-8 for enhanced photocatalytic and antibacterial activities
- Author
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Le Wang, Dapeng Wu, Jinshui Wang, Bingxuan Niu, Guoan Zhao, Junwei Cui, and Zhenyun Li
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010302 applied physics ,Materials science ,Eosin ,Process Chemistry and Technology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Photocatalysis ,Rhodamine B ,Methylene ,0210 nano-technology ,Mesoporous material ,Pyrolysis ,Methylene blue - Abstract
Ag/ZnO hybrid cages with well-preserved polyhedron shape and rich mesoporous structures were prepared thorough in situ pyrolysis of AgNO3 impregnated ZIF-8 precursor. Due to the bi-template function of ZIF-8, the as-prepared cages show well-defined hollow chamber inherited from the precursor and uniformly embedded Ag nanoparticles (NPs). The as-introduced Ag NPs could enhance the light absorption and promote charge separation, which finally improve the antibacterial performances. Therefore, compared with pure ZnO, the Ag/ZnO hybrid cages demonstrate prominent photocatalytic degradation of different organic dyes, such as Methylene Blue, Methylene Orange, Eosin and Rhodamine B under simulated sunlight. In addition, the hybrid Ag/ZnO cages exhibit outstanding inhibition performances against Escherichia coli, Staphylococcus aureus, and the highly infective Mycobacterium-tuberculosis. The photocatalytic and antibacterial mechanism of the hybrid Ag/ZnO cages were also studied in detail by means of optical/electrochemical dynamic tests and Ag+ and Zn2+ release measurements.
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- 2021
43. Silencing Hoxa2 reverses dexamethasone-induced dysfunction of MC3T3-E1 osteoblasts and osteoporosis in rats
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Jianbin Xiong, Le Wang, Youguo Yang, and Yuan Liu
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musculoskeletal diseases ,medicine.medical_specialty ,Medicine (miscellaneous) ,Dexamethasone ,General Biochemistry, Genetics and Molecular Biology ,Bone resorption ,Cell Line ,Bone remodeling ,Small hairpin RNA ,Osteoprotegerin ,Osteogenesis ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Pharmacology (medical) ,Genetics (clinical) ,Osteoblasts ,biology ,Chemistry ,Acid phosphatase ,Cell Differentiation ,Osteoblast ,Rats ,RUNX2 ,medicine.anatomical_structure ,Endocrinology ,RANKL ,Reviews and References (medical) ,biology.protein ,Osteoporosis - Abstract
Background Osteoporosis is damaging the health of women worldwide. Osteoporosis results from the imbalance between bone resorption and formation, which may be regulated by homeobox A2 (Hoxa2). However, the specific role and mechanism of Hoxa2 in osteogenesis and dexamethasone (Dex)-induced osteoporosis remain unknown. Objectives The present study investigated the effect of Hoxa2 on differentiation and osteoblastogenesis. Material and methods Alkaline phosphatase staining and immunofluorescence staining were performed to evaluate the differentiation of MC3T3-E1 cells. Runt-related transcription factor 2 (Runx2), osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa B ligand (RANKL) in Dex stimulated osteoblastic MC3T3-E1 cells, and Dex-induced osteoporotic rats were estimated using western blot and quantitative polymerase chain reaction (qPCR). Serum markers of bone turnover were determined using enzyme-linked immunosorbent assay (ELISA). Trabecular bones of femur tissues were observed using hematoxylin and eosin (H&E) staining. Results Hoxa2 short hairpin RNA significantly promoted the differentiation of MC3T3-E1 cells and expression of Runx2 and OPG in Dex-treated MC3T3-E1 cells and osteoporotic rats but inhibited the expression of RANKL. Furthermore, silencing Hoxa2 resulted in the upregulation of bone alkaline phosphatase but suppressed the expression of tartrate-resistant acid phosphatase and C-terminal cross-linked telopeptides of type I collagen. Conclusions Silencing Hoxa2 reversed the Dex-induced inhibition of osteoblastogenesis by modulating Runx2 and RANK-RANKL-OPG axis.
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- 2021
44. Advanced oxidation protein products induce inflammatory responses and invasive behaviour in fibroblast-like synoviocytes via the RAGE-NF-κB pathway
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Le Wang, Zhao Wang, Weirong Wu, Min Yang, Dingji Zhu, Aiju Lou, Weinan Lai, and Zihong Cai
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Fibroblast-like synoviocyte ,Diseases of the musculoskeletal system ,medicine.disease_cause ,RAGE (receptor) ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Synovium ,medicine ,Orthopedics and Sports Medicine ,Rheumatoid arthritis ,Fibroblast ,030304 developmental biology ,0303 health sciences ,Chemistry ,Advanced oxidation protein products ,NF-κB ,medicine.disease ,medicine.anatomical_structure ,RC925-935 ,030220 oncology & carcinogenesis ,Cancer research ,Surgery ,Receptor for advanced glycation end products ,Oxidative stress - Abstract
Aims Rheumatoid arthritis (RA), which mainly results from fibroblast-like synoviocyte (FLS) dysfunction, is related to oxidative stress. Advanced oxidation protein products (AOPPs), which are proinflammatory mediators and a novel biomarker of oxidative stress, have been observed to accumulate significantly in the serum of RA patients. Here, we present the first investigation of the effects of AOPPs on RA-FLSs and the signalling pathway involved in AOPP-induced inflammatory responses and invasive behaviour. Methods We used different concentrations of AOPPs (50 to 200 µg/ml) to treat RA-FLSs. Cell migration and invasion and the expression levels of tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), matrix metalloproteinase-3 (MMP-3), and MMP-13 were investigated. Western blot and immunofluorescence were used to analyze nuclear factor-κB (NF-κB) activation. Results AOPPs promoted RA-FLS migration and invasion in vitro and significantly induced the messenger RNA (mRNA) and protein expression of TNF-α, IL-6, MMP-3, and MMP-13 in dose- and time-dependent manners. Moreover, AOPPs markedly activated the phosphorylation of nuclear factor-κB (NF-κB) p65 protein, which triggered inhibitory kappa B-alpha (IκBα) degradation, NF-κB p65 protein phosphorylation, and NF-κB p65 translocation into the nucleus. Furthermore, treatment with a neutralizing antibody specific to receptor for advanced glycation end products (RAGE) significantly suppressed aggressive behaviour and inflammation, decreased TNF-α, IL-6, MMP-3, and MMP-13 expression, and blocked AOPP-induced NF-κB pathway activation. Conclusion The results indicate that AOPPs can enhance aggressive behaviour and the inflammatory response in RA-FLSs via the RAGE–NF-κB pathway. These results present AOPPs as a new class of potentially important mediators of progressive disease in RA patients. Cite this article: Bone Joint Res 2021;10(4):259–268.
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- 2021
45. Effects of mesh aluminium alloy and aluminium velvet on the explosion of H2/air, CH4/air and C2H2/air mixtures
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Le Wang, Shangyong Zhou, Ruikang Li, Bin Su, Jiancun Gao, Zhenmin Luo, and Hu Shoutao
- Subjects
Flammable liquid ,Materials science ,Renewable Energy, Sustainability and the Environment ,Metallurgy ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Dual effect ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Fuel Technology ,Safety risk ,chemistry ,Aluminium ,visual_art ,Flammable gas ,Aluminium alloy ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
MAA (mesh aluminium alloy) is one of the most widely used explosion suppression materials in military and civilian applications. To systematically research the effect of MAA on the explosion reactions of flammable gases, we investigated the effect of MAA and AV (aluminium velvet) on the explosion of hydrogen-air, methane-air and acetylene-air mixtures. The results indicated that MAA and AV suppress the methane-air mixture explosion but significantly promote the explosions of the hydrogen-air mixture and the acetylene-air mixture. MAA and AV have the dual effect of promoting and suppressing an explosion. In addition, with an increase in filling density, the promotion of MAA and AV first strengthens and then weakens. The results of this study show that the properties of flammable gas, not the shapes of the explosion suppression materials, determine whether the dominant effect of explosion suppression material is promotion or suppression. Use of explosion suppression materials is not suitable for all flammable gases, especially highly reactive chemical fuels. Applying explosion suppression materials blindly may greatly increase safety risk.
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- 2021
46. Incorporation of Polyoxometalates into Polymers to Create Linear Poly(polyoxometalate)s with Catalytic Function
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Yu Xiao, Xiao-Le Wang, Yu-Kun Yan, Chunhong Wang, Li-Jun Ren, Wei Wang, Wen-Ke Miao, Ping Zheng, and Li-Xia Ren
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Polymer ,Catalysis ,Inorganic Chemistry ,Grubbs' catalyst ,chemistry.chemical_compound ,Monomer ,Polymerization ,chemistry ,Polymer chemistry ,Polyoxometalate ,Materials Chemistry ,Derivative (chemistry) ,Norbornene - Abstract
Organic polymers have been found widespread commercial applications due to their easy processing and attractive mechanical properties. Concurrently, inorganic polyoxometalates (POMs), a class of metal-oxygen anionic and nanosized clusters of early transition metals, have a wide range of attractive functions and are used in industrial catalysis. In this communication, we report a new approach to creating the first linear poly(polyoxometalate)s that combine the advantages of polymers and POM clusters. In the experiment, a POM-containing norbornene monomer was first synthesized by linking a Wells-Dawson-type POM with a norbornene derivative. The monomer was polymerized in the presence of a Grubbs catalyst under mild conditions with yields nearly 100% in a living and controllable manner. The resulting poly(polyoxometalate)s have controllable molecular weights and a well-defined hybrid structure of an organic polynorbornene backbone with large pendant groups of the nanosized POM clusters. Thus, they form good films and have a good catalytic performance. Our findings not only pave the way for incorporating the POM clusters into polymers with well-defined structures and high molecular weights, but also offer a competitive strategy for developing more novel catalytic systems by introducing the poly(polyoxometalate)s.
- Published
- 2022
47. Increased frequency of β cells with abnormal NKX6.1 expression in type 2 diabetes but not in subjects with higher risk for type 2 diabetes
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Jiaqi Zou, Peng Sun, Le Wang, Tengli Liu, Shusen Wang, Guanqiao Wang, Xuejie Ding, Zhongyang Shen, Yaojuan Liu, Boya Zhang, Rui Liang, and Na Liu
- Subjects
Male ,0301 basic medicine ,endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Cell ,Cell Count ,Chromosomal translocation ,Type 2 diabetes ,lcsh:Diseases of the endocrine glands. Clinical endocrinology ,chemistry.chemical_compound ,0302 clinical medicine ,Risk Factors ,Insulin-Secreting Cells ,Medicine ,Cell Differentiation ,General Medicine ,Middle Aged ,medicine.anatomical_structure ,embryonic structures ,Female ,Autopsy ,Research Article ,Adult ,medicine.medical_specialty ,animal structures ,HbA1c ,030209 endocrinology & metabolism ,Prediabetic State ,03 medical and health sciences ,Age ,Diabetes mellitus ,Internal medicine ,Humans ,Obesity ,NKX6.1 ,Aged ,Glycated Hemoglobin ,Homeodomain Proteins ,β-Cell dedifferentiation ,lcsh:RC648-665 ,business.industry ,Insulin ,Type 2 Diabetes Mellitus ,nutritional and metabolic diseases ,medicine.disease ,030104 developmental biology ,Endocrinology ,Diabetes Mellitus, Type 2 ,chemistry ,Cytoplasm ,Case-Control Studies ,Glycated hemoglobin ,business - Abstract
Background NKX6.1 is a transcription factor for insulin, as well as a marker for β cell maturity. Abnormal NKX6.1 expression in β cells, such as translocation from the nucleus to cytoplasm or lost expression, has been shown as a marker for β cell dedifferentiation. Methods We obtained pancreatic sections from organ donors and immunofluorescence staining with NKX6.1 and insulin was performed to characterize NKX6.1 expression in subjects with or without type 2 diabetes mellitus (T2DM). Results Our results showed that cells with insulin expression but no nucleic NKX6.1 expression (NKX6.1Nuc-Ins+), and cells with cytoplasmic NKX6.1 expression but no insulin expression (NKX6.1cytIns−) were significantly increased in T2DM subjects and positively correlated with glycated hemoglobin (HbA1c), indicating the elevated β cell dedifferentiation with NKX6.1 inactivation in T2DM. To investigate whether β cell dedifferentiation has initiated in subjects with higher risks for T2DM, we next analyzed the association between β-cell dedifferentiation level in ND subjects with different ages, body mass index, and HbA1c. The results showed the absolute number and percentage of dedifferentiated β cells with NKX6.1 inactivation did not significantly change in subjects with advanced aging, obesity, or modest hyperglycemia, indicating that the β cell dedifferentiation might mainly occur after T2DM was diagnosed. Conclusion Our results suggested that NKX6.1 expression in β cells was changed in type 2 diabetic subjects, evidenced by significantly increased NKX6.1Nuc-Ins+ and NKX6.1cytIns− cells. This abnormality did not occur more frequently in subjects with a higher risk for T2DM, suggesting that β cell dedifferentiation might be secondary to the pathological changes in T2DM.
- Published
- 2021
48. Wetting of molten cerium on typical carbon materials (graphite, CVD-diamond and NWCNT) and molten Cu–Ce alloys on graphite at 950 °C
- Author
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Fan Yang, Ran Sui, Le Wang, and Qiaoli Lin
- Subjects
Materials science ,chemistry.chemical_element ,Buckypaper ,02 engineering and technology ,General Chemistry ,Chemical vapor deposition ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contact angle ,Cerium ,Sessile drop technique ,chemistry ,Geochemistry and Petrology ,Graphite ,Wetting ,Composite material ,0210 nano-technology ,Carbon - Abstract
A series of experiments were conducted to investigate the wettability of graphite plate, graphite paper, NWCNTs Buckypaper, CVD-diamond by molten Ce and graphite plate by Cu–Ce binary alloy using a modified sessile drop method at 950 °C. The remarkable apparent equilibrium contact angles (graphite plate (0°)
- Published
- 2021
49. Adsorption Performance and Mechanism of Synthetic Schwertmannite to Remove Low-Concentration Fluorine in Water
- Author
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Lin Fan, Bo Zhou, Yaoguo Wu, Zehong Zhang, Sichang Wang, Sihai Hu, and Le Wang
- Subjects
Exothermic reaction ,Langmuir ,Health, Toxicology and Mutagenesis ,Inorganic chemistry ,chemistry.chemical_element ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Adsorption ,X-ray photoelectron spectroscopy ,Spectroscopy, Fourier Transform Infrared ,Humans ,0105 earth and related environmental sciences ,Ion exchange ,Chemistry ,Schwertmannite ,Water ,Fluorine ,04 agricultural and veterinary sciences ,General Medicine ,Hydrogen-Ion Concentration ,Pollution ,Kinetics ,Wastewater ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Iron Compounds ,Water Pollutants, Chemical - Abstract
Fluorine (F) in water has a negative effect on the environment and human health. Schwertmannite has potential remediation to contamination in solution. In this study, the adsorption mechanism and influencing factors of synthetic schwertmannite for low-concentration F were studied through batch experiments. The results suggested that the adsorption of F by schwertmannite reached equilibrium after about 60 min, and the adsorption efficiency exceeded 94%. The experimental data can be best-fit by the pseudo-second-order kinetic and Langmuir models well. Schwertmannite showed effective adsorption at pH 4, dosage 1.5 g L−1, low temperature, and low concentration of co-existing anion. The adsorption process was a spontaneous and exothermic reaction, which was dominated by chemical adsorption. FT-IR and XPS spectra analysis revealed that F adsorption on schwertmannite through the surface complexation and anion exchange reaction between SO42− and OH− with F−, especially the primary role of OH−. The results can provide theoretical support for the schwertmannite application in the treatment of F-containing wastewater.
- Published
- 2021
50. Electrochemical Utilization of Iron IV in the Li 1.3 Fe 0.4 Nb 0.3 O 2 Disordered Rocksalt Cathode
- Author
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Jatinkumar Rana, Ying Shirley Meng, Michael A. Jones, Carlos Mejia, Zachary W. Lebens-Higgins, Hyeseung Chung, Louis F. J. Piper, Israel Temprano, Clare P. Grey, Le Wang, Yingge Du, Mateusz Zuba, Wanli Yang, and Jinpeng Wu
- Subjects
High energy ,Materials science ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Gas release ,Manganese ,Electrochemistry ,Redox ,Oxygen ,Cathode ,law.invention ,Hysteresis ,chemistry ,law ,Electrical and Electronic Engineering - Abstract
Author(s): Lebens-Higgins, Z; Chung, H; Temprano, I; Zuba, M; Wu, J; Rana, J; Mejia, C; Jones, MA; Wang, L; Grey, CP; Du, Y; Yang, W; Meng, YS; Piper, LFJ | Abstract: Interest in alkali-rich oxide cathodes has grown in an effort to identify systems that provide high energy densities through reversible oxygen redox. However, some of the most promising compositions such as those based solely on earth abundant elements, e. g., iron and manganese, suffer from poor capacity retention and large hysteresis. Here, we use the disordered rocksalt cathode, Li1.3Fe0.4Nb0.3O2, as a model system to identify the underlying origin for the poor performance of Li-rich iron-based cathodes. Using elementally specific spectroscopic probes, we find the first charge is primarily accounted for by iron oxidation to 4+ below 4.25 V and O2 gas release beyond 4.25 V with no evidence of bulk oxygen redox. Although the Li1.3Fe0.4Nb0.3O2 is not a viable oxygen redox cathode, the iron 3+/4+ redox couple can be used reversibly during cycling.
- Published
- 2021
Catalog
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