593 results on '"Ke WU"'
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2. Effect of Compounded Aluminum Hydroxide Flame Retardants on the Flammability and Smoke Suppression Performance of Asphalt Binders
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Kai Zhu, Yapeng Yang, Chenghang Lin, Qiang Wang, Dong Ye, Haojia Jiang, and Ke Wu
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Chemistry ,QD1-999 - Published
- 2024
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3. Shape Control of a Carbon Fiber-Reinforced Polymer Reflector and Placement Optimization of the Actuators
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Ke Wu, Wenhai Yang, and Pengbo Liu
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shape control ,CFRC ,PZT actuators ,multi-objective optimization ,genetic algorithm ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In this study, a method for the active shape control for carbon fiber-reinforced polymer (CFRC) reflectors using piezoelectric lead zirconate titanate (PZT) actuators is proposed. According to this method, a finite element model considering higher transverse shear deformation with independent voltage degrees of freedom is formulated by the Hamilton principle. An optimal shape controller that minimizes the discrete root mean square (RMS) error of a reflecting surface is applied. Then, the optimal arrangements of the PZT actuators are determined by numerical optimization methods, which are developed by modifying the classical Genetic Algorithm, with both single and multi-objective optimizations being studied. In the single optimization formulation, the number of actuators is considered as a constraint, and the RMS error of the reflector is regarded as the optimizing target. A hybrid method that combines the gradient projection method with an adaptive Genetic Algorithm is proposed to solve this problem. In the multi-objective optimization, the residual RMS errors and power consumption of the actuators are considered as the optimization targets. Pareto optimal solutions are obtained by an improved multi-objective Genetic Algorithm. Numerical examples are provided to show the effectiveness of the proposed methods.
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- 2024
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4. DeepSub: Utilizing Deep Learning for Predicting the Number of Subunits in Homo-Oligomeric Protein Complexes
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Rui Deng, Ke Wu, Jiawei Lin, Dehang Wang, Yuanyuan Huang, Yang Li, Zhenkun Shi, Zihan Zhang, Zhiwen Wang, Zhitao Mao, Xiaoping Liao, and Hongwu Ma
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homo-oligomers ,subunit ,deep learning ,protein language model ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The molecular weight (MW) of an enzyme is a critical parameter in enzyme-constrained models (ecModels). It is determined by two factors: the presence of subunits and the abundance of each subunit. Although the number of subunits (NS) can potentially be obtained from UniProt, this information is not readily available for most proteins. In this study, we addressed this gap by extracting and curating subunit information from the UniProt database to establish a robust benchmark dataset. Subsequently, we propose a novel model named DeepSub, which leverages the protein language model and Bi-directional Gated Recurrent Unit (GRU), to predict NS in homo-oligomers solely based on protein sequences. DeepSub demonstrates remarkable accuracy, achieving an accuracy rate as high as 0.967, surpassing the performance of QUEEN. To validate the effectiveness of DeepSub, we performed predictions for protein homo-oligomers that have been reported in the literature but are not documented in the UniProt database. Examples include homoserine dehydrogenase from Corynebacterium glutamicum, Matrilin-4 from Mus musculus and Homo sapiens, and the Multimerins protein family from M. musculus and H. sapiens. The predicted results align closely with the reported findings in the literature, underscoring the reliability and utility of DeepSub.
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- 2024
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5. Bounding Volume Hierarchy-Assisted Fast SAR Image Simulation Based on Spatial Segmentation
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Ke Wu, Guowang Jin, Xin Xiong, and Quanjie Shi
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SAR image simulation ,ray tracing ,multiple backscatter ,echo simulation ,bounding volume hierarchies ,CUDA ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In order to improve the simulation efficiency under the premise of ensuring the fidelity of synthetic aperture radar (SAR) simulation images, we propose a BVH-assisted fast SAR image simulation method based on spatial segmentation. The beam scanning model is established based on RD imaging geometric relation, and the bounding volume hierarchy (BVH) algorithm is used to assist in obtaining the time-varying latticed radiation and shadow areas within the radar beam, combining them with the real-time position of the sensors to complete the simulation of the electromagnetic (EM) wave transmission. The ray tracing algorithm is used to calculate the multiple backscatter fields of EM waves, including various material properties of the target surface. The SAR spatial traversal is adopted to spatially segment the latticed radiation area, and the compute unified device architecture (CUDA) kernel function is designed using the echo matrix cell method to make each cell of the target echo matrix as a subfield of the backscattering field, and the position of the echo matrix cell is traversed to obtain the target backscattering field. The target simulated echo is processed by the range Doppler (RD) imaging algorithm to obtain the SAR-simulated image. The simulation results show that compared with a CPU single-thread simulation, the simulation speed of the proposed method is significantly improved, and the SAR simulation image has high structural similarity with the real image, which fully verifies the effectiveness of the proposed method.
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- 2024
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6. Study on Hydration Heat Release Model and Its Influence Coefficient of Addition Concrete
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Ke Wu, Zhongyu Dou, Zhenhua Liu, and Jiaxiang Xu
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concrete ,exothermic hydration ,additions ,numerical calculations ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The concrete of the main structure of subway stations is highly constrained, so the temperature effect and shrinkage effect generated during the construction process often cause large restraint stress, thus causing the problem of structural cracking. Therefore, low-heat-of-hydration cements are usually used in such construction work to reduce the temperature during the aging of concrete. Therefore, based on the hydration heat release subprogram of concrete, an effective numerical simulation was carried out, and compared with the semi-adiabatic temperature rise test, a method of numerical calculation and parameter fitting to solve the influence coefficient of the hydration heat model was proposed, and the sensitivity of the hydration heat release model and the influence coefficient for several concrete mixtures with additives was studied. The main conclusions are as follows: (1) Combined with the measured temperature curves of several types of mineral-admixed concrete, the composite exponential exothermic model of several types of mineral-admixed concrete can be obtained by adjusting the parameter fitting to solve the influence coefficient of the exothermic hydration model proposed in this paper. (2) One can adjust the influencing coefficient a to control the maximum temperature of concrete. Similarly, the temperature curve of concrete can be adjusted by modifying the influencing coefficient b.
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- 2024
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7. Clean Synthesis of Ti-MWW by Utilizing the Recycled Mother Liquor
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Yiqiang Wen, Feifei Zhang, Ke Wu, Xin Gao, Xiangyu Wang, and Meng Liu
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Chemistry ,QD1-999 - Published
- 2021
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8. Synthesis and Applications of Copper-Based Catalysts
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Ke Wu, Liwen Xing, and Yongjun Ji
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n/a ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
The increasing demand for fine and high-value-added chemicals has motivated the lasting exploration of high-performance catalysts with desirable activity, selectivity, and durability [...]
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- 2023
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9. The Clean Synthesis of Small-Particle TS‑1 with High-Content Framework Ti by Using NH4HCO3 and Suspended Seeds as an Assistant
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Mengtian Huang, Yiqiang Wen, Huijuan Wei, Lukuan Zong, Xin Gao, Ke Wu, Xiangyu Wang, and Meng Liu
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Chemistry ,QD1-999 - Published
- 2021
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10. Green synthesis and application of nanoscale zero-valent iron/rectorite composite material for P-chlorophenol degradation via heterogeneous Fenton reaction
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Teng Bao, Jie Jin, Mekdimu Mezemir Damtie, Ke Wu, Zhi Ming Yu, Lie Wang, Jun Chen, Yong Zhang, and Ray L. Frost
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Chemistry ,QD1-999 - Abstract
A zero-valent iron/rectorite nanocomposite (NZVI/rectorite) was developed as a heterogeneous H2O2 catalyst for P-chlorophenol degradation. The physicochemical properties of NZVI/rectorite were characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. Results showed that NZVI sphere nanoparticles were successfully loaded on the rectorite surface with less aggregation and good dispersion. Moreover, compared with acid-leached rectorite (30.91 m2/g), the NZVI/rectorite appeared to have larger surface area (50.75 m2/g). In addition, the effects of pH, reaction time, initial P-chlorophenol concentration, catalyst amount, and H2O2 dosage on the P-chlorophenol degradation were systematically investigated. Results showed that NZVI/rectorite presents better properties for the degradation and mineralization of P-chlorophenol compared with pristine NZVI due to the large surface area, low aggregation, and good dispersion of the former. The degradation mechanisms of P-chlorophenol by NZVI/rectorite were adsorption and reduction coupled with a Fenton-like reaction. Four successive runs of the stability and regeneration study also showed that the NZVI/rectorite were unchanged even after 100% of P-chlorophenol degradation ratio. This study has extended the application of NZVI/rectorite as environment function material for the removal of P-chlorophenol from the environment. Keywords: Nano zero-valent iron, Rectorite, Heterogeneous Fenton oxidation, P-chlorophenol degradation
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- 2019
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11. Humidity Sensors Based on Metal–Organic Frameworks
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Ke Wu, Teng Fei, and Tong Zhang
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metal−organic frameworks ,humidity sensor ,sensing materials ,sensing mechanism ,impedance ,QCM ,Chemistry ,QD1-999 - Abstract
Humidity sensors are important in industrial fields and human activities. Metal−organic frameworks (MOFs) and their derivatives are a class of promising humidity−sensing materials with the characteristics of a large specific surface area, high porosity, modifiable frameworks, and high stability. The drawbacks of MOFs, such as poor film formation, low electrical conductivity, and limited hydrophilicity, have been gradually overcome with the development of material science. Currently, it is moving towards a critical development stage of MOF−based humidity sensors from usability to ease of use, of which great challenges remain unsolved. In order to better understand the related challenges and point out the direction for the future development of MOF−based humidity sensors, we reviewed the development of such sensors based on related published work, focusing on six primary types (impedance, capacitive, resistive, fluorescent, quartz crystal microbalance (QCM), and others) and analyzed the sensing mechanism, material design, and sensing performance involved, and presented our thoughts on the possible future research directions.
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- 2022
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12. Recent Advances of Cu-Based Catalysts for NO Reduction by CO under O2-Containing Conditions
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Xiaoli Chen, Yaqi Liu, Yan Liu, Dianxing Lian, Mohaoyang Chen, Yongjun Ji, Liwen Xing, Ke Wu, and Shaomian Liu
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Cu-based catalysts ,CO + NO ,catalytic performances ,O2 resistance ,H2O and SO2 resistance ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
Selective catalytic reduction of NOx by CO (CO-SCR) to both N2 and CO2 is a promising way to simultaneously remove two harmful gases, CO and NOx, in automobile and factory exhaust gases. The development of efficient catalysts is the key challenge for the technology to be commercialized. The low-cost Cu-based catalysts have shown promising performance in CO-SCR, but there are some technical problems that obstruct their practical implementation, such as high reduction temperature and low O2, H2O, and SO2 resistance. This paper provides a comprehensive overview and insights into CO-SCR under O2-containing conditions over the Cu-based catalysts, including catalytic performances of non-supported, supported mono-metallic, supported bimetallic, and supported multi-metallic Cu-based catalysts. In addition, the effects of O2 concentration, reaction temperature, H2O, and SO2 on the catalytic performance are discussed. Furthermore, the reaction mechanism of CO-SCR on Cu-based catalysts is briefly summarized. Lastly, challenges and perspectives with respect to this reaction are discussed. We hope this work can provide theoretical guidance for the rational design of efficient Cu-based catalysts in the CO-SCR reaction for commercial applications.
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- 2022
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13. Reconstruction of Isolated Moving Objects by Motion-Induced Phase Shift Based on PSP
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Ke Wu, Min Li, Lei Lu, and Jiangtao Xi
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phase shifting profilometry ,phase retrieval ,phase unwrapping ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The reconstruction of moving objects based on phase shifting profilometry has attracted intensive interests. Most of the methods introduce the phase shift by projecting multiple fringe patterns, which is undesirable in moving object reconstruction as the errors caused by the motion will be intensified when the number of the fringe pattern is increased. This paper proposes the reconstruction of the isolated moving object by projecting two fringe patterns with different frequencies. The phase shift required by the phase shifting profilometry is generated by the object motion, and the model describing the motion-induced phase shift is presented. Then, the phase information in different frequencies is retrieved by analyzing the influence introduced by movement. Finally, the mismatch on the phase information between the two frequencies is compensated and the isolated moving object is reconstructed. Experiments are presented to verify the effectiveness of the proposed method.
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- 2021
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14. Environmental Impact of Discharge Patterns and Ambient Wind on the Jet Discharge from a Mechanical Upper Vent of a Tunnel
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Xin Zhang, Ke Wu, and Kai Zhu
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urban tunnel ,mechanical upper vent ,environmental impact radius ,computational fluid dynamics (CFD) ,ambient wind ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Flow characteristics and pollutant dispersion characteristics of a mechanical upper vent of a tunnel under various discharge patterns and ambient wind were studied by using the computational fluid dynamics (CFD) numerical method and an experimental model. On this basis, variations in the environmental impact radius rcriti changing with the ambient wind velocity U for pollutants from vertical and horizontal outlets were also analyzed with the set discharge capacity. According to our findings, the pollutant emission of the upper vent under a vertical discharge pattern can be considered as free buoyant jet diffusion under the impact of the momentum of ambient wind, while the emission under the horizontal discharge pattern can be regarded as semi-confined buoyant jet diffusion under the impact of the momentum of ambient wind. Moreover, the rcriti of the vertical outlet increased with the increase of U when U ≤ 3 m/s and was minimally affected by U for U > 3 m/s. Additionally, the rcriti of the horizontal outlet decreased with the increase of U. When the discharge capacity was constant, the rcriti of the upper vent under both vertical and horizontal discharge patterns declined with the increase of the discharge velocity V0. Note that the rcriti of the vertical outlet was smaller than that of the horizontal one for the range of parameters considered. These results can provide a theoretical reference for optimizing the design of a vent on the top of an urban tunnel.
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- 2021
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15. Application of Monolayer Graphene and Its Derivative in Cryo-EM Sample Preparation
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Ke Wu, Di Wu, Li Zhu, and Yi Wu
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cryo-EM ,single-particle ,sample preparation ,graphene ,graphene oxide ,chemical modification ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Cryo-electron microscopy (Cryo-EM) has become a routine technology for resolving the structure of biological macromolecules due to the resolution revolution in recent years. The specimens are typically prepared in a very thin layer of vitrified ice suspending in the holes of the perforated amorphous carbon film. However, the samples prepared by directly applying to the conventional support membranes may suffer from partial or complete denaturation caused by sticking to the air–water interface (AWI). With the application in materials, graphene has also been used recently to improve frozen sample preparation instead of a suspended conventional amorphous thin carbon. It has been proven that graphene or graphene oxide and various chemical modifications on its surface can effectively prevent particles from adsorbing to the AWI, which improves the dispersion, adsorbed number, and orientation preference of frozen particles in the ice layer. Their excellent properties and thinner thickness can significantly reduce the background noise, allowing high-resolution three-dimensional reconstructions using a minimum data set.
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- 2021
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16. Study on Mechanism of Series-Flow of Pollutants between Consecutive Tunnels by Numerical Simulation
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Honghu Zhang, Yunge Hou, Kaijie Wu, Tianhang Zhang, Ke Wu, and Xin Zhang
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consecutive tunnels ,series-flow ,prediction formula ,computational fluid dynamics (cfd) ,three-dimensional wall jet theory ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The characteristics of series-flow between two consecutive tunnels with distance ranging from 20 m to 250 m are explored by computational fluid dynamics (CFD) parametric simulations of structure and operation parameters. The research indicates that series-flow can be considered the three-dimensional wall jet diffusion of upstream tunnel pollutants under the effects of the negative pressure area of the downstream tunnel entrance. The jet characteristics are primarily related to the tunnel distance between upstream and downstream tunnels and hydraulic diameters, and only influenced by the negative pressure in the area very close to downstream entrance where the tunnel air velocity ratio, i.e., the velocity of upstream tunnel air divided by the velocity of downstream tunnel air, decides the degree of the influence. If ignoring the effects of ambient wind and traffic flow, the series-flow ratio decreases with the increasing of parameters of the normalized tunnel distance, i.e., the tunnel distance divided by tunnel hydraulic diameter, and the tunnel air velocity ratio. Based on the three-dimensional wall jet theory, a series-flow model covering all jet characteristic sections is built. The experiment results indicate that the model applies to consecutive tunnels with any spacing and exhibits higher prediction accuracy.
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- 2019
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17. Investigation on Smoke Suppression Mechanism of Hydrated Lime in Asphalt Combustion
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Kai Zhu, Yunhe Wang, Qi Zhou, Daquan Tang, Lingzhu Gu, and Ke Wu
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Chemistry ,QD1-999 - Abstract
In this study, cone calorimeter and thermogravimetric analyses were used to simulate the asphalt combustion process under the conditions of fire radiation and programmed temperature increase. The gaseous compositions and release rules were analyzed by infrared spectroscopy to investigate the influence of hydrated lime on the smoke suppression mechanism in the asphalt combustion process. The experimental results show that hydrated lime can promote the asphalt mastic surface to form a barrier layer during the combustion process. This barrier layer can reduce the burning intensity of asphalt. Although the compositions of gaseous products do not change much, the rates of CO production and smoke release are decreased. In addition, hydrated lime is alkaline and can thus neutralize acidic gases such as SO2 and reduce the toxicity of gaseous products. With the addition of 40 wt.% hydrated lime, the total smoke release and the CO release rate both decrease by more than 20% relative to the addition of the same amount of limestone fillers and decrease by more than 10% relative to the addition of the same amount of magnesium hydroxide flame retardant.
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- 2018
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18. Numerical Research on the Mixture Mechanism of Polluted and Fresh Air at the Staggered Tunnel Portals
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Xin Zhang, Tianhang Zhang, Kai Zhu, Zhiyi Huang, and Ke Wu
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closely spaced twin tunnel ,staggered inlet and outlet ,circulating air ,mixing ratio ,computational fluid dynamics (CFD) ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In longitudinal ventilation, circulating air is formed in portals for closely spaced twin tunnels, which causes mixing between the polluted air exhausted from one tunnel and the fresh air flow of another tunnel, thus leading to the rising costs of ventilation system construction and operation. In this study, for the closely spaced tunnel with staggered inlet and outlet, the computational fluid dynamics (CFD) numerical simulation method was adopted to reveal flow characteristics of the circulating air as well as variation rules of the circulating air mixing ratio φc with tunnel structure and operation parameters. Results show that both reducing inlet air velocity and increasing outlet air velocity and lateral distance can reduce the impact of the negative-pressure zone at the tunnel entrance on the jet flow structure at the tunnel exit, thus weakening the circulating air. When the inlet is placed behind or aligned with the outlet (staggered distance ∆l ≤ 0), φc will increase linearly along with the increase of staggered distance; when the inlet is placed before the outlet (∆l > 0), φc will first increase and then decrease with the increase of staggered distance. An expression to predict circulating air mixing ratio was created by sections. The predictions show a good correlation with the measurements and indicate that the front slope gradient of the tunnel portal is also one of the factors affecting the circulating air mixing ratio.
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- 2018
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19. Investigations of the Montmorillonite and Aluminium Trihydrate Addition Effects on the Ignitability and Thermal Stability of Asphalt
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Kai Zhu, Ke Wu, Bin Wu, and Zhiyi Huang
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Chemistry ,QD1-999 - Abstract
By means of limiting oxygen index (LOI), cone calorimeter, and TG-DSC tests, this paper investigated the effect of unmodified montmorillonite (MMT), organically modified montmorillonite (OMMT), and aluminium trihydrate (ATH) additions on the flame retardancy for asphalt combustion. Experimental results showed that adding a small amount of montmorillonite did not significantly increase the oxygen index of the asphalt but reduced the heat release rate during asphalt combustion. TGA tests had indicated that the montmorillonite (MMT and OMMT) could suppress the release of flammable volatiles and form more asphaltenes, which hence postponed the burnout time of asphalt. Furthermore, the combination of montmorillonite (MMT and OMMT) and ATH had yielded a synergistic effect, which had further reduced the heat release rate and also increased the oxygen index of asphalt. In particular, after further addition of OMMT, the barrier layer showed less crack, leading to a significant decrease in the heat release rate as compared to the adding of ATH alone.
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- 2014
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20. β2-Adrenoceptor Activation Stimulates IL-6 Production via PKA, ERK1/2, Src, and Beta-Arrestin2 Signaling Pathways in Human Bronchial Epithelia
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Chung Yin Yip, Ya Niu, Rui Gang Zhang, Ke Wu Pan, Hao Pang, Wing-Hung Ko, and Chung Ling Chen
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Pulmonary and Respiratory Medicine ,MAPK/ERK pathway ,Chemistry ,medicine.medical_treatment ,Cell biology ,Cytokine ,Isoprenaline ,medicine ,Phosphorylation ,Signal transduction ,Receptor ,Protein kinase A ,Proto-oncogene tyrosine-protein kinase Src ,medicine.drug - Abstract
Objective β2-Adrenoceptor agonists are widely used to treat asthma because of their bronchial-dilation effects. We previously reported that isoprenaline, via the apical and basolateral β2-adrenoceptor, induced Cl− secretion by activating cyclic AMP (cAMP)-dependent pathways in human bronchial epithelia. Despite these results, whether and how the β2-adrenoceptor-mediated cAMP-dependent pathway contributes to pro-inflammatory cytokine release in human bronchial epithelia remains poorly understood. Methods We investigated β2-adrenoceptor-mediated signaling pathways involved in the production of two pro-inflammatory cytokines, interleukin (IL)-6 and IL-8, in 16HBE14o- human bronchial epithelia. The effects of isoprenaline or formoterol were assessed in the presence of protein kinase A (PKA), exchange protein directly activated by cAMP (EPAC), Src, and extracellular signal-regulated protein kinase (ERK)1/2 inhibitors. The involvement of β-arrestin2 was examined using siRNA knockdown. Results Isoprenaline and formoterol (both β2 agonists) induced IL-6, but not IL-8, release, which could be inhibited by ICI 118,551 (β2 antagonist). The PKA-specific inhibitor, H89, partially inhibited IL-6 release. Another intracellular cAMP receptor, EPAC, was not involved in IL-6 release. Isoprenaline-mediated IL-6 secretion was attenuated by dasatinib, a Src inhibitor, and PD98059, an ERK1/2 inhibitor. Isoprenaline treatment also led to ERK1/2 phosphorylation. In addition, knockdown of β-arrestin2 by siRNA specifically suppressed cytokine release when a high concentration of isoprenaline (1 mM) was used. Conclusion Our results suggest that activation of the β2-adrenoceptor in 16HBE14o- cells stimulated the PKA/Src/ERK1/2 and/or β-arrestin2 signaling pathways, leading to IL-6 release. Therefore, our data reveal that β2-adrenoceptor signaling plays a role in the immune regulation of human airway epithelia.
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- 2021
21. Clean Synthesis of Ti-MWW by Utilizing the Recycled Mother Liquor
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Gao Xin, Meng Liu, Yiqiang Wen, Xiangyu Wang, Zhang Feifei, and Ke Wu
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Precipitated silica ,Silicon ,Chemistry ,General Chemical Engineering ,chemistry.chemical_element ,Cyclohexanone ,General Chemistry ,Pulp and paper industry ,Article ,Catalysis ,chemistry.chemical_compound ,Mother liquor ,QD1-999 ,Titanium - Abstract
This article introduces a clean and efficient method for the synthesis of Ti-MWW by utilizing the recycled mother liquor. The effects of titanium and silicon sources on the synthesis of Ti-MWW and the recycling of the mother liquor are discussed in detail. Precipitated silica prepared with Na2SiO3 and CO2 was selected as the silicon source, and TiCl3 was selected as the titanium source. The mother liquor was recycled five times, and the obtained samples showed good catalytic activity in cyclohexanone ammoximation. This work can be conducive to reducing the influence on the environment and economizing on materials for the industrial production of Ti-MWW.
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- 2021
22. Very high loading oxidized copper supported on ceria to catalyze the water-gas shift reaction
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Chun-Hua Yan, Jin-Ze Zhu, Wen-Zhu Yu, Hao-Ran Zhao, Shan-Qing Li, Wei-Wei Wang, Chao Ma, Ke Wu, and Chun-Jiang Jia
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Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Heterogeneous catalysis ,Oxygen ,Copper ,Catalysis ,Water-gas shift reaction ,Metal ,Adsorption ,visual_art ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,Dispersion (chemistry) - Abstract
To prepare supported catalysts with high loading and high dispersion of active metals is a crucial challenge in heterogeneous catalysis. Here we report the fabrication of very reactive catalyst that contains finely dispersed copper with 20 wt% content supported on high-surface area CeO2 for the water–gas shift (WGS) reaction. This copper-ceria catalyst shows superb activity with a CO consumption rate of 116.7 μmolCO gcat-1 s−1 at 300 ℃, nearly one order of magnitude more active than other copper-based catalysts ever reported. Based on the precise and integrated characterizations, the oxidized not the metallic Cu are proved to be active centers where the adsorbed CO directly reacted with bridged —OH groups to finish the WGS reaction. The oxidized Cu sites are confirmed to be originated from the activation effect from Cu to CeO2, which promotes the oxygen of CeO2 diffuse from the bulk to surface, making Cu oxidized even under reductive atmosphere.
- Published
- 2021
23. Microstructure and mechanical properties of magnesia refractories containing metallic Al by the incorporation of glucose and citric acid as binders
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Guoqiang Zheng, Ke Wu, Yan Ma, Wang Honghong, Zhoufu Wang, Xitang Wang, Hao Liu, Chuang Jie, and Zhongzhuang Zhang
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Gluconates ,Thermal shock ,Toughness ,Curing (food preservation) ,Materials science ,Process Chemistry and Technology ,Whiskers ,Microstructure ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Materials Chemistry ,Ceramics and Composites ,Citric acid ,Pyrolysis - Abstract
A study of magnesia refractories containing glucose, citric acid, and metallic Al and their influences on structure, mechanical strength, and thermal shock resistance, is presented. Combined with thermodynamic calculation, microstructure, and properties analysis, the results show that formation of gluconates and citrates from the introduced glucose and citric acid enhanced the bonding of raw materials and the curing strength of samples. The pyrolysis of gluconates and citrates, and the oxidation and nitridation of metallic Al had significant effects on the microstructural evolution of magnesia refractories after high temperature treatments, mainly AlN and MgAl2O4 whiskers in pores and particle gaps. The formation and development of whiskers give rise to samples improved toughness and thermal shock resistance. Increasing the metallic Al content from 0 wt% to 2 wt% enhanced the fracture surface energy of samples heat treated at 1400 °C from 82.22 kJ/m2 to 119.75 kJ/m2. Meanwhile, after three thermal-shock cycles, the residual strength ratios of heat treated samples were elevated from 52.8% to 67.9%. On the basis of influences of phase transformation on the structure and properties of samples at different temperatures, considering the structural compactness and ability to withstand external stress for magnesia refractories used in metallurgical field, it is suggested that when glucose and citric acid are used as binders, the addition of metallic Al should be less than 3 wt%.
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- 2021
24. Cerium and ruthenium co-doped La0.7Sr0.3FeO3– as a high-efficiency electrode for symmetrical solid oxide fuel cell
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Lei Fu, Ke Wu, Kai Wu, Junkai Wang, Jun Zhou, and Jiaming Yang
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Materials science ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Cerium ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Geochemistry and Petrology ,Oxidizing agent ,Electrode ,Solid oxide fuel cell ,0210 nano-technology ,Polarization (electrochemistry) ,Perovskite (structure) - Abstract
Symmetrical solid oxide fuel cells (SSOFCs) could be alternative energy conversion devices due to their simple fabrication process and low cost. Herein, perovskite La0.6Ce0.1Sr0.3Fe0.95Ru0.05O3–δ (LCSFR) was synthesized and evaluated as a high-performance electrode for SSOFCs based on the electrolyte of La0.9Sr0.1Ga0.8Mg0.2O3–δ (LSGM). LCSFR retains their stable perovskite crystal structure in both reducing and oxidizing atmospheres, though a minor amount of LaSrFeO4 phase is present under reducing conditions. Morphology investigation shows that homogeneously dispersed Ru metallic nanoparticles are exsolved on the surface of LCSFR after being reduced. The polarization resistance (Rp) of LCSFR-CGO (Ce0.9Gd0.1O2–δ) is about 0.11 Ω⋅cm2 at 800 °C in air, while the value of Rp for LCSFR-CGO in wet H2 (3% H2O) increases up to 0.32 Ω⋅cm2. The symmetrical LCSFR-CGO|LSGM|LCSFR-CGO cell demonstrates a performance with an open circuit potential (OCV) of 1.07 V and a maximum peak power density of 904 mW/cm2 at 800 °C using wet H2 as the fuel. This high performance indicates that LCSFR is a candidate electrode for SSOFCs.
- Published
- 2021
25. CCL2 produced by pancreatic ductal adenocarcinoma is essential for the accumulation and activation of monocytic myeloid‐derived suppressor cells
- Author
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Haitao Gu, Sun Feng, Zhong Zheng, Ke Wu, and Wensheng Deng
- Subjects
Chemokine ,T cell ,CD14 ,Immunology ,pancreatic ductal adenocarcinoma ,CCL2 ,Adenocarcinoma ,CD8-Positive T-Lymphocytes ,Flow cytometry ,M‐MDSCs ,Immune system ,medicine ,Immunology and Allergy ,Humans ,Cells, Cultured ,Chemokine CCL2 ,medicine.diagnostic_test ,biology ,Chemistry ,Myeloid-Derived Suppressor Cells ,Original Articles ,RC581-607 ,Pancreatic Neoplasms ,medicine.anatomical_structure ,Myeloid-derived Suppressor Cell ,Cancer research ,biology.protein ,Original Article ,immune suppression ,Immunologic diseases. Allergy ,CD8 - Abstract
Introduction The development of pancreatic ductal adenocarcinoma (PDAC) is closely tied with the immune system. C‐C motif chemokine ligands (CCL) were proved to lead to immune recruitment and training. Thus, we reckoned CCL2 to be the kernel of immune suppression in PDAC tissues. Methods We compared normal pancreatic tissues with PDAC tissues according to The Cancer Genome Atlas (TCGA) and clinical samples. Flow cytometry was used to identify M‐MDSCs. We further demonstrated immune suppression of M‐MDSCs according to proliferation rates of CD8+ T cells/CD4+ T cells. Levels of reactive oxygen species (ROS) and Arginase were also tested by flow cytometry, enzyme‐linked immunosorbent assay, and western blot analysis. We also analyzed the specific mechanisms by cluster analysis after CCL2 stimulating M‐MDSCs. Results We found that CCL2 highly increased in PDAC tissues. CCL2 is positively related to CD33 and CD14, markers of monocytic myeloid‐derived suppressor cells (M‐MDSCs). We have demonstrated that CCL2 recruited M‐MDSCs into PDAC tissues both in vitro and in vivo. M‐MDSCs recruitment is accompanied by sustained immune suppression. Furthermore, we have found that M‐MDSCs impeded T cell proliferation and produced high levels of ROS and Arginase, which can be enhanced by CCL2. Mechanistically, CCL2 stimulated M‐MDSCs led to a significant upregulation of genes, a large part of which accumulated in the mitogen‐activated protein kinase signaling pathway. Treatment of aloesin, MAPK signaling inhibitor, relieved the associated immunosuppressive phenotype induced by CCL2. Conclusions Our study indicates that PDAC cells produced CCL2, which promoted localized M‐MDSC recruitment and immune suppression, thereby promoting tumor progression., Our data indicate that CCL2 performs a significant role in PDAC progression by recruiting and activating M‐MDSCs. Targeting MDSCs is able to improve antitumoral immunological responses providing with potential applicability of immune‐based combination therapies against an extensive spectrum of solid tumors. These miscellaneous approaches might prove available for tumor therapeutics against solid carcinomas in which M‐MDSCs perform a major role in immune evasion of tumors. These results are promising and need further assessment of the M‐MDSCs‐targeting combination or vaccination approaches for the whole therapeutic capacity of these tactics in PDAC and other carcinomas, Highlights CCL2 is significantly upregulated in colon adenocarcinoma CCL2 influences M‐MDSC recruitment and functionality in colon adenocarcinoma CCL2 stimulates immune‐suppressive functions of M‐MDSC by activating MAPK signaling
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- 2021
26. Nickel‐Catalyzed Amination of Aryl Nitriles for Accessing Diarylamines through C−CN Bond Activation
- Author
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Baoxiang Hu, Ke Wu, Qiang Rong, Xinquan Hu, Zhenlu Shen, Nan Sun, and Liqun Jin
- Subjects
Nickel ,chemistry.chemical_compound ,chemistry ,Aryl ,chemistry.chemical_element ,General Chemistry ,Medicinal chemistry ,Amination ,Catalysis - Published
- 2021
27. Aqueous solution thickening of amino acid‐based surfactant by alkylpyrrolidone
- Author
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Liu Xuemin, Pan Jiajia, Qiuyun Lei, Ge Xin, Ke Wu, Weili Song, and Hui Zhang
- Subjects
chemistry.chemical_classification ,Sodium lauroyl sarcosinate ,chemistry.chemical_compound ,Aqueous solution ,Pulmonary surfactant ,chemistry ,Rheology ,General Chemical Engineering ,Thickening ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Nuclear chemistry ,Amino acid - Published
- 2021
28. KIF11 as a potential cancer prognostic marker promotes tumorigenesis in children with Wilms tumor
- Author
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Wei Liu, Li Ding, Linghua Ji, Yongshen Tian, Wenwen Zhang, Ke Wu, Tingting Gao, Yinmei Zhu, Xiaoqin Liu, Yishu Luo, and Jun Zhao
- Subjects
Vascular Endothelial Growth Factor A ,Proliferation index ,Carcinogenesis ,Angiogenesis ,Kinesins ,Apoptosis ,medicine.disease_cause ,Wilms Tumor ,chemistry.chemical_compound ,Humans ,Medicine ,Child ,Cell Proliferation ,Gene knockdown ,business.industry ,Cell growth ,Wilms' tumor ,Hematology ,Prognosis ,medicine.disease ,Kidney Neoplasms ,Vascular endothelial growth factor ,Oncology ,chemistry ,Pediatrics, Perinatology and Child Health ,Cancer research ,Immunohistochemistry ,business - Abstract
Emerging evidence suggests that KIF11 could play a pivotal role in cancer cell proliferation; however, its biological functions and molecular mechanisms in Wilms tumor (WT) cells are largely unknown. The aim of this study was to evaluate the clinical significance and therapeutic potential of KIF11 proteins in WT. KIF11 expression in WT tissues and adjacent nontumor tissues was determined using qRT-PCR, Western blotting, immunohistochemistry (IHC) and bioinformatics. The function of KIF11 protein was determined by its correlation with tumor cell growth, angiogenesis, and apoptosis using IHC and lentiviral vector-mediated KIF11 depletion. KIF11 expression was upregulated in WT tissues and was associated with WT clinical outcomes. Tumor KIF11 expression was significantly associated with the Ki67 proliferation index. CCK-8, flow-cytometric analysis, and Western blotting revealed that KIF11 knockdown significantly inhibited WT cell growth. Functional studies have indicated that increased KIF11 expression is significantly correlated with vascular endothelial growth factor (VEGF) expression and intratumoral microvessel density. We further confirmed that downregulated expression of KIF11 promoted cell apoptosis and significantly increased Bcl-2 and Bax expression. Our findings demonstrate that KIF11 plays a role in promoting the development of human WT and can serve as a potential molecular marker for the treatment of WT.
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- 2021
29. Biochar in Combination with Nitrogen Fertilizer is a Technique: To Enhance Physiological and Morphological Traits of Rice (Oryza sativa L.) by Improving Soil Physio-biochemical Properties
- Author
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Izhar Ali, Amanullah, Ligeng Jiang, Ihsan Muhammad, Anas Iqbal, Asad Ali Khan, Saif Ullah, Quan Zhao, Abdullah Khan, He Liang, Ke Wu, and Jing Zhang
- Subjects
Soil health ,Oryza sativa ,biology ,Chemistry ,chemistry.chemical_element ,Biomass ,Plant Science ,Photosynthesis ,Nitrate reductase ,Nitrogen ,Agronomy ,Biochar ,biology.protein ,Agronomy and Crop Science ,Glutamine oxoglutarate aminotransferase - Abstract
The over use of synthetic nitrogen (N) fertilizers is the major anthropogenic cause of low N-use efficiency and environmental damage in wetland rice production. Biochar (B) addition to soil is suggested as a climate change mitigation tool that supports carbon sequestration and reduces N losses and greenhouse gas emissions from the soil. Therefore, this study assessed the effect of four levels of B (0, 10, 20 and 30 t ha−1) combined with two levels of N (135 and 180 kg ha−1) on soil health, roots dynamics, physiological attributes, and yield components of rice. The addition of B at 30 t ha−1 combined with 135 N kg ha−1 increased chlorophyll content, net photosynthetic rate, biomass, and grain yield by 104%, 64%, 12%, and 30%, respectively, over control. Further, root traits such as total root length (TRL), total root volume (TRV), total root surface area (TRSA), and total average root diameter (TARD) were improved under 30 t ha−1 combined with 135 N kg ha−1 by 20%, 13%, 13%, and 25%, respectively, than non-biochar treatment under lower N application. Improvements in these traits resulted from higher N uptake due to improved soil physiochemical properties and soil microbial biomass combined with biochar. Interestingly, enhanced N metabolizing enzyme activities, including nitrate reductase (NR), glutamine synthetase (GS), and glutamine oxoglutarate aminotransferase (GOGAT) in biochar-treated plots, further supported the increases in these traits. Our results revealed that the integration of 30 t B ha−1 with 135 kg N ha−1 is a favorable option for enhancing soil health and rice grain yield.
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- 2021
30. Enhanced Recovery of Per- and Polyfluoroalkyl Substances (PFASs) from Impacted Soils Using Heat Activated Persulfate
- Author
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Ke Wu, Michelle Crimi, Jennifer L. Guelfo, Suparada Chaobol, Naveen Kumar, and Marzieh Shojaei
- Subjects
Fluorocarbons ,Hot Temperature ,Aqueous solution ,Environmental remediation ,Chemistry ,Extraction (chemistry) ,General Chemistry ,Contamination ,Persulfate ,complex mixtures ,Soil ,In situ chemical oxidation ,Environmental chemistry ,Desorption ,Environmental Chemistry ,Leaching (metallurgy) ,Groundwater ,Water Pollutants, Chemical - Abstract
Varying transport potential of cationic, zwitterionic, and anionic per- and polyfluoroalkyl substances (PFASs) may pose challenges for remediation of aqueous film forming foam (AFFF) impacted sites, particularly during groundwater extraction. Slow desorption of stronger sorbing, zwitterionic, and cationic PFASs may cause extended remediation times and rebound in aqueous PFAS concentrations. Persulfate oxidation has the potential to convert a complex mixture of PFASs into a simpler and more recoverable mixture of perfluoroalkyl acids (PFAAs). AFFF-impacted soils were treated with heat-activated persulfate in batch reactors and subjected to 7-day leaching experiments. Soil and water were analyzed using a combination of targeted and high resolution liquid chromatography mass spectrometry techniques as well as the total oxidizable precursors assay. Following oxidation, total PFAS composition showed the expected shift to a higher fraction of PFAAs, and this led to higher total PFAS leaching in pretreated reactors (108-110%) vs control reactors (62-90%). In both pretreated and control soils, precursors that remained following leaching experiments were 61-100% cationic and zwitterionic. Results suggest that persulfate pretreatment of soils has promise as an enhanced recovery technique for remediation of total PFASs in impacted soils. They also demonstrate that PFAS distribution may have been altered at sites where in situ chemical oxidation was applied to treat co-occurring contaminants of concern.
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- 2021
31. Biochar application to rice with 15N-labelled fertilizers, enhanced leaf nitrogen concentration and assimilation by improving morpho-physiological traits and soil quality
- Author
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Shazma Anwar, Izhar Ali, Shanqing Wei, Amanullah, Ke Wu, Syeda Wajeeha Gillani, Shakeel Ahmad, Ligeng Jiang, Saif Ullah, Zaid Khan, Fangwei Cheng, Anas Iqbal, Quan Zhao, and He Liang
- Subjects
0106 biological sciences ,0301 basic medicine ,Ammonium sulfate ,Nitrogen concentration ,QH301-705.5 ,Ammonium nitrate ,chemistry.chemical_element ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Biochar ,Biology (General) ,ComputingMethodologies_COMPUTERGRAPHICS ,Chemistry ,Nutrient management ,food and beverages ,Soil carbon ,Soil quality ,Nitrogen ,Root morphology ,030104 developmental biology ,Agronomy ,Chlorophyll ,Photosynthetic pigments ,Rice ,General Agricultural and Biological Sciences ,010606 plant biology & botany ,Research Article - Abstract
Graphical abstract, Leaf nitrogen (N) concentration plays an important role in biochemical and physiological functions, and N availability directly influences rice yield. However, excessive N fertilization is considered to be a root cause of environmental issues and low nitrogen use efficiency. Therefore, the selection of appropriate nutrient management practices and organic amendments is key to maximizing nitrogen uptake and maintaining high and sustainable rice production. Here, we evaluated the effects of different 15N-labelled nitrogen sources (urea, ammonium nitrate, and ammonium sulfate at 315 kg ha−1) with or without biochar (30 t ha−1) on paddy soil properties, root growth, leaf gas exchange, N metabolism enzymes, and N uptake in the early and late seasons of 2019. We found significant differences among N fertilizer sources applied with or without biochar (P
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- 2021
32. Dibenzocyclooctadiene lignans from Artemisia sieversiana and their anti-inflammatory activities
- Author
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Xi-Kang Zheng, Chao-Xi Chen, Xu-Dong Zhou, Li-Min Gong, Ke-Wu Zeng, Peng-Fei Tu, and Wei Wang
- Subjects
Artemisia sieversiana ,Circular dichroism ,biology ,Traditional medicine ,010405 organic chemistry ,medicine.drug_class ,food and beverages ,Positive control ,biology.organism_classification ,01 natural sciences ,Anti-inflammatory ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,medicine ,Ic50 values ,Molecular Medicine ,Artemisia ,Quercetin ,IC50 - Abstract
Two previously undescribed dibenzocyclooctadiene lignans, named sieverlignans D–E (1–2), as well as eight known ones (3–10), were isolated from the aerial parts of Artemisia sieversiana. Their structures were elucidated from extensive spectroscopic analysis, including HRMS, NMR and electronic circular dichroism (ECD) experiments. This study is the first to report dibenzocyclooctadiene lignans in the genus Artemisia and this plant. All the compounds were evaluated for their anti-neuroinflammatory activities on the lipopolysaccharides (LPS)-induced nitric oxide production in BV-2 murine microglial cells. Compounds 1 and 6 exhibited the moderate activities with their IC50 values of 47.7 and 21.9 μM, compared to a positive control quercetin with the IC50 value of 16.0 μM.
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- 2021
33. The Clean Synthesis of Small-Particle TS-1 with High-Content Framework Ti by Using NH4HCO3 and Suspended Seeds as an Assistant
- Author
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Ke Wu, Yiqiang Wen, Gao Xin, Meng Liu, Lukuan Zong, Xiangyu Wang, Huang Mengtian, and Huijuan Wei
- Subjects
Chemistry ,Materials science ,Chemical engineering ,General Chemical Engineering ,Particle ,General Chemistry ,Small particles ,Zeolite ,QD1-999 ,Decomposition ,Article ,Catalysis - Abstract
The synthesis of a TS-1 zeolite with high-content framework Ti and small particles has been developed by adding NH4HCO3 and suspended seeds as an assistant. With the addition of NH4HCO3, the Hofmann decomposition of the tetrapropylammonium cation (TPA+) decreased, and the framework Ti content of the zeolite increased first and then decreased while the particle became larger. With the assistance of suspended seeds, the TS-1 synthesized under a low-alkalinity system possesses small particle size and high-content framework Ti, and it shows the best catalytic activity among the prepared catalysts. Because the decomposition of TPA+ decreased, the mother liquid could be reused in the next run of preparation. Even though the recycled mother liquid was reused five times, all obtained TS-1 samples exhibited similar catalytic performances in propylene epoxidation. This work provides an efficient process for preparing TS-1 with good catalytic performance and reduces the discharge of the waste liquid.
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- 2021
34. Tetrandrine inhibits proliferation of colon cancer cells by BMP9/ PTEN/ PI3K/AKT signaling
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Ke Wu, Fu-Shu Li, Bai-Cheng He, Li-Xuan Ding, Qin Li, Wen-Juan Sun, Li Mu, Ya Zhou, Xiao-Lu Liu, Hong-Chuan Chen, and Ying Hu
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0301 basic medicine ,PTEN ,Medicine (General) ,Akt1/2/3 ,QH426-470 ,BMP9 ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,R5-920 ,0302 clinical medicine ,Full Length Article ,Genetics ,Gene silencing ,Viability assay ,Molecular Biology ,Protein kinase B ,Genetics (clinical) ,PI3K/AKT/mTOR pathway ,biology ,Cell Biology ,Colon cancer ,Tetrandrine ,030104 developmental biology ,chemistry ,Apoptosis ,030220 oncology & carcinogenesis ,Tetrandrine (Tet) ,biology.protein ,Cancer research ,Phosphorylation - Abstract
Despite advances in screening and treatment, colon cancer remains one of the leading causes of cancer-related death. Finding novel and useful drug treatment targets is also an urgent need for clinical applications. Tetrandrine (Tet) is extracted from the Chinese medicinal herbal medicine, which is a well-known calcium blocker with a variety of pharmacological activities, including anti-cancer. In this study, we recruited cell viability assay, flow cytometry analysis, cloning formation to confirm that Tet can inhibit the proliferation of SW620 cells, and induce apoptosis. Mechanically, we confirmed that Tet up-regulates the mRNA and protein level of BMP9 in SW620 cells. Over-expression BMP9 enhances the anti-cancer effects of Tet in SW620 cells, but these effects can be partly reversed by silencing BMP9. Also, Tet reduces phosphorylation of Aktl/2/3 in SW620 cells, which could be elevated by overexpressed BMP9 and impaired by silencing BMP9. Furthermore, we demonstrated that Tet reduces phosphorylated PTEN, which can be promoted by overexpressed BMP9, analogously also be attenuated through silencing BMP9. Finally, we introduced a xenograft tumor model to investigate the anti-proliferative effect of Tet, further to explore the effects of BMP9 and PTEN in SW620 cells. Our findings suggested that the anti-cancer activity of Tet in SW620 cells may be mediated partly by up-regulating BMP9, followed by inactivation PI3K/Akt through up-regulating PTEN at least.
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- 2021
35. A chromatography-free and aqueous waste-free process for thioamide preparation with Lawesson’s reagent
- Author
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Xinquan Hu, An Ding, Baoxiang Hu, Zhenlu Shen, Ke Wu, Liqun Jin, Yichen Ling, and Nan Sun
- Subjects
scale-up ,chemistry.chemical_classification ,Aqueous solution ,Chromatography ,Recrystallization (geology) ,Science ,Organic Chemistry ,Extraction (chemistry) ,chromatography-free ,thioamide ,thionation ,Decomposition ,Full Research Paper ,Chemistry ,chemistry.chemical_compound ,QD241-441 ,chemistry ,Reagent ,Lawesson's reagent ,Ethylene glycol ,Lawesson’s reagent ,Thioamide - Abstract
After completing the thio-substitution with Lawesson’s reagent, ethanol was found to be effective in the decomposition of the inherent stoichiometric six-membered-ring byproduct from the Lawesson’s reagent to a highly polarized diethyl thiophosphonate. The treatment significantly simplified the following chromatography purification of the desired thioamide in a small scale preparation. As scaling up the preparation of two pincer-type thioamides, we have successfully developed a convenient process with ethylene glycol to replace ethanol during the workup, including a traditional phase separation, extraction, and recrystallization. The newly developed chromatography-free procedure did not generate P-containing aqueous waste, and only organic effluents were discharged. It is believed that the optimized procedure offers the great opportunity of applying the Lawesson’s reagent for various thio-substitution reactions on a large scale.
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- 2021
36. Advance in Novel Methods for Enrichment and Precise Analysis of Circulating Tumor Cells
- Author
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Hua Zhang, Cheng-Ke Wu, Jianxiu Wang, Cong-Cong Shen, Minghui Yang, and Yue-Hua Chen
- Subjects
medicine.diagnostic_test ,Chemistry ,010401 analytical chemistry ,Molecular phenotype ,02 engineering and technology ,Computational biology ,021001 nanoscience & nanotechnology ,Immunomagnetic separation ,01 natural sciences ,Peripheral blood ,0104 chemical sciences ,Analytical Chemistry ,Flow cytometry ,Clinical Practice ,Circulating tumor cell ,medicine ,Separation method ,Liquid biopsy ,0210 nano-technology - Abstract
The dissemination of circulating tumor cells (CTCs) in peripheral blood is an important intermediate step for cancer metastasis. It has become one of the most promising targets of “liquid biopsy”, on account of providing complete information of cell biology. However, due to the extremely rarity, complex environment and strong heterogeneity of CTC in peripheral blood, the development of efficient enrichment and separation methods are the key in the accurate detection of CTC. Currently reported CTC enrichment and analysis techniques are mainly based on the physical or biological characteristics of CTC. They are commonly combined with the traditional techniques including density gradient centrifugation, superfine membrane filtration and immunomagnetic separation, the novel methods such as microfluidic chip separation and two-dimensional electrophoresis-field separation, and the analysis techniques such as reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, photoacoustic imaging, surface-enhancement Raman scattering and electrochemistry to realize accurate detection of CTC. In this review, we summarized the recent processes on enrichment and novel detection methods of CTC and discussed the challenges and their clinical application status, which could provide reference for the further improvement of the technology of enrichment, accurate counting and molecular phenotype analysis for CTC, as well as the application in scientific research and clinical practice.
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- 2021
37. A polymer controlled nucleation route towards the generalized growth of organic-inorganic perovskite single crystals
- Author
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Zheng-Guang Yan, Xiaodong Han, Chunqiang Zhuang, Yiqun Pi, Xiaoyuan Zhou, Lin Ma, Ke Wu, Yiping Du, Jie Huang, and Kaiwen Wang
- Subjects
Materials science ,Science ,Nucleation ,General Physics and Astronomy ,Halide ,Crystal growth ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Perovskite (structure) ,chemistry.chemical_classification ,Multidisciplinary ,General Chemistry ,Carrier lifetime ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical physics ,Materials chemistry ,0210 nano-technology ,Ternary operation ,Single crystal ,Materials for energy and catalysis - Abstract
Recently, there are significant progresses in the growth of organic-inorganic lead halide perovskite single crystals, however, due to their susceptible nucleation and growth mechanisms and solvent requirements, the efficient and generalized growth for these single crystals is still challenging. Here we report the work towards this target with a polymer-controlled nucleation process for the highly efficient growth of large-size high-quality simple ternary, mixed-cations and mixed-halide perovskite single crystals. Among them, the carrier lifetime of FAPbBr3 single crystals is largely improved to 10199 ns. Mixed MA/FAPbBr3 single crystals are synthesized. The crucial point in this process is suggested to be an appropriate coordinative interaction between polymer oxygen groups and Pb2+, greatly decreasing the nuclei concentrations by as much as 4 orders of magnitudes. This polymer-controlled route would help optimizing the solution-based OIHPs crystal growth and promoting applications of perovskite single crystals., Research into single crystal organic-inorganic halide perovskites have gained momentum due to the potential applications, yet the growth is still a challenge. Here, the authors demonstrate a universal method based on polymer controlled nucleation process to achieve large-size and high-quality perovskite single crystals.
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- 2021
38. Discovery of novel indole‐1,2,4‐triazole derivatives as tubulin polymerization inhibitors
- Author
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Hai-Liang Zhu, Zhu-Gui Zhou, Ruo-Jun Man, Yan-Juan Liao, and Meng-Ke Wu
- Subjects
Indoles ,Cell ,Antineoplastic Agents ,Apoptosis ,HeLa ,Structure-Activity Relationship ,03 medical and health sciences ,0302 clinical medicine ,Microtubule ,Cell Line, Tumor ,Drug Discovery ,medicine ,Humans ,Cell Proliferation ,Indole test ,A549 cell ,Cyclin-dependent kinase 1 ,Molecular Structure ,biology ,Chemistry ,Triazoles ,Cell cycle ,biology.organism_classification ,Tubulin Modulators ,Molecular Docking Simulation ,Tubulin ,medicine.anatomical_structure ,Biochemistry ,030220 oncology & carcinogenesis ,biology.protein ,Drug Screening Assays, Antitumor ,030217 neurology & neurosurgery - Abstract
A series of novel indole-1,2,4-triazole derivatives have been designed, synthesized, and evaluated as potential tubulin polymerization inhibitors. The top hit 12, bearing the 3,4,5-trimethoxyphenyl moiety, exhibited substantial anti-proliferative activity against HepG2, HeLa, MCF-7, and A549 cells in vitro with IC50 values of 0.23 ± 0.08 μM, 0.15 ± 0.18 μM, 0.38 ± 0.12 μM, and 0.30 ± 0.13 μM, respectively. It also inhibited tubulin polymerization with the IC50 value of 2.1 ± 0.12 μM, which was comparable with that of the positive controls. Furthermore, compound 12 regulated the expression of cell cycle-related proteins (Cyclin B1, Cdc25c, and Cdc2) and apoptosis-related proteins (Bcl-2, Bcl-x, and Mcl-1). Mechanistically, compound 12 could arrest cell cycle at the G2/M phase, thus induce an increase of apoptotic cell death. In addition, molecular docking hinted the possible interaction mode of compound 12 into the colchicine binding site of tubulin heterodimers. According to the applications of microtubule-targeting agents in both direct and synergistic cancer therapies, we hope this work might be of significance for future researches.
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- 2021
39. Triazolylthioacetamides Confer Inhibitory Efficacy against Metallo-β- Lactamase IMP-1
- Author
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Yi Wan, Le Zhai, Yue-Juan Zhang, and Ke-Wu Yang
- Subjects
Chemistry ,Drug Discovery ,Pharmaceutical Science ,Molecular Medicine ,Inhibitory postsynaptic potential ,Metallo β lactamase ,Microbiology - Abstract
Background: : The appearance of antibiotic resistance caused by metallo-β-lactamases (MβLs) is a global public health threat. Developing MβLs inhibitor is an effective way to overcome antibiotic resistance. Recently, azolylthioacetamides were reported to be promising MβLs inhibitors. Methods:: Triazolylthioacetamides were synthesized and tested for inhibition activity against the purified MβL IMP-1. Antimicrobial activities of these inhibitors in combination with cefazolin were evaluated. Isothermal Titration Calorimetry (ITC) was employed to characterize the binding of the inhibitor to IMP-1, and their action mechanism was studied by molecular docking. Results: Twenty compounds exhibited specific inhibitory activity against IMP-1 with an IC50 value in the range of 3.1-62.5 μM. Eight of the compounds can restore the antibacterial efficacy of cefazolin against E. coli BL21 strain producing IMP-1 by 2-4 fold. ITC monitoring showed that 1c exhibited dose-dependent inhibition on IMP-1. Docking studies revealed that the triazole group in 1c and 2d played an essential role in the inhibition activity. Cytotoxicity assay showed that 1c and 2d have low toxicity in L929 mouse fibroblastic cells. Conclusion: : The triazolylthioacetamides are efficient inhibitors of IMP-1 in vitro and in vivo.
- Published
- 2021
40. Partial substitution of organic nitrogen with synthetic nitrogen enhances rice yield, grain starch metabolism and related genes expression under the dual cropping system
- Author
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Shakeel Ahmad, Izhar Ali, Zhao Quan, Abdullah Khan, Ke Wu, Huimin Xie, Anas Iqbal, Liang He, Izhar Hussain, Ligeng Jiang, Haneef Raza, and Shangqin Wei
- Subjects
0106 biological sciences ,0301 basic medicine ,Starch ,Field experiment ,AC, amylose content ,chemistry.chemical_element ,Amylose content ,engineering.material ,01 natural sciences ,PM, poultry manure ,AGPase, ADP-glucose pyrophosphorylase ,03 medical and health sciences ,chemistry.chemical_compound ,Animal science ,Amylose ,SBE, starch branching enzyme ,SSS, soluble starch synthase ,DBE, starch debranching enzyme ,Grain yield ,Cropping system ,lcsh:QH301-705.5 ,biology ,Temperature ,food and beverages ,CF, chemical fertilizer ,Manure ,Nitrogen ,CM, cattle manure ,DAA, days after anthesis ,030104 developmental biology ,lcsh:Biology (General) ,chemistry ,Enzyme ,GBBS, granule bound starch synthase ,biology.protein ,engineering ,Original Article ,Rice ,Starch synthesis ,Fertilizer ,General Agricultural and Biological Sciences ,Starch synthase ,N, nitrogen ,SS, sucrose synthase ,010606 plant biology & botany - Abstract
Improving grain filling in the presernt farming systems is crucial where grain filling is a concern due to the extreme use of chemical fertilizers (CF). A field experiment was conducted at the experimental station of Guangxi University, China in 2019 to test the hypothesis that cattle manure (CM) and poultry manure (PM) combined with CF could improve rice grain filling rate, yield, biochemical and qualitative attributes. A total of six treatments, i.e., no fertilizer (T1), 100% CF (T2), 60% CM + 40% CF (T3), 30% CM + 70% CF (T4), 60% PM + 40% CF (T5), and 30% PM + 70% CF (T6) were used in this study. Results showed that the combined treatment T6increased starch metabolizing enzymes activity (SMEs), such as ADP-glucose phosphorylase (ADGPase) by 8 and 12%, soluble starch synthase (SSS) by 7 and 10%, granule bound starch synthesis (GBSS) by 7 and 9%, and starch branching enzyme (SBE) by 14 and 21% in the early and late seasons, respectively, compared with T2. Similarly, higher rice grain yield, grain filling rate, starch, and amylose content were also recorded in combined treatments. In terms of seasons, higher activity of SMEs , grain starch, and amylose content was noted in the late-season compared to the early season. The increment in these traits was mainly attributed to a lower temperature in the late season during the grain filling period. Furthermore, our results suggested that an increment in starch accumulation and grain filling rate were mainly associated with the enhanced sink capacity by regulating key enzyme activities involved in Suc-to-starch conversion. In-addition, RT-qPCR analysis showed higher expression levels of AGPS2b, SSS1, GBSS1, and GBSE11b genes, which resultantly increased the activities of SMEs during the grain filling period under combined treatments. Linear regression analysis revealed that the activity of ADGPase, SSS, GBSS, and SBE were highly positively correlated with starch and amylose accumulation. Thus, we concluded that a combination of 30% N from PM or CM with 70% N from CF is a promising option in terms of improving rice grain yield and quality. Our study provides a sustainable fertilizer management strategy to enhance rice grain yield and quality at the lowest environmental cost.
- Published
- 2021
41. Electrospun Core–Shell Fibers for High-Efficient Composite Cathode-Based Solid Oxide Fuel Cells
- Author
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Kai Wu, Jiaming Yang, Jun Zhou, Ke Wu, Lei Fu, Junkai Wang, and Zhengrong Liu
- Subjects
Materials science ,General Chemical Engineering ,Oxide ,Energy Engineering and Power Technology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Cathode ,law.invention ,Core shell ,chemistry.chemical_compound ,Fuel Technology ,020401 chemical engineering ,Chemical engineering ,chemistry ,law ,Fuel cells ,Fiber ,Composite cathode ,0204 chemical engineering ,0210 nano-technology ,Perovskite (structure) - Abstract
Fibrous perovskite oxide has been the most promising cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs) due to its efficient mass and charge transfer. Herein, a core–shell fiber...
- Published
- 2021
42. Ni-catalyzed reductive decyanation of nitriles with ethanol as the reductant
- Author
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Baoxiang Hu, Xinquan Hu, Liqun Jin, Yichen Ling, Ke Wu, Nan Sun, and Zhenlu Shen
- Subjects
Ethanol ,Hydride ,Chemistry ,Metals and Alloys ,Aromaticity ,General Chemistry ,Combinatorial chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Amide ,Materials Chemistry ,Ceramics and Composites ,Alkoxy group - Abstract
A nickel-catalyzed reductive decyanation of aromatic nitriles has been developed, in which the readily available and abundant ethanol was applied as the hydride donor. Various functional groups on the aromatic rings, such as alkoxyl, amino, imino and amide, were compatible in this catalytic protocol. Heteroaryl, benzylic and alkenyl nitriles were also tolerated. Mechanistic investigation indicated that ethanol provided hydride efficiently via β-hydride elimination in this reductive decyanation.
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- 2021
43. Pharmacologically targeting molecular motor promotes mitochondrial fission for anti-cancer
- Author
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Hong Liang, Dan Liu, Meimei Zhao, Li-Xi Liao, Ke-Wu Zeng, Yi Qian, Qing-Hua Han, Peng-Fei Tu, Jing-Kang Wang, and Heng Yang
- Subjects
Molecular motor ,MMP, mitochondrial membrane potential ,CAM, chick embryo chorioallantoic membrane ,SPR, surface plasmon resonance ,RM1-950 ,macromolecular substances ,HSPA9, heat-shock protein A9 ,MYH9 ,ER, endoplasmic reticulum ,03 medical and health sciences ,CETSA, cellular thermal shift assay ,0302 clinical medicine ,Stable isotope labeling by amino acids in cell culture ,Target identification ,Myosin ,HUVEC, human umbilical vein endothelial cells ,LIHC, liver hepatocellular carcinoma ,General Pharmacology, Toxicology and Pharmaceutics ,Cytoskeleton ,SILAC, stable isotope labeling with amino acids in cell culture ,030304 developmental biology ,HSPA9 ,TUNEL, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling ,0303 health sciences ,Chemistry ,Anti-cancer ,Mitochondrial fission ,Signal transducing adaptor protein ,Liver hepatocellular carcinoma ,Cell biology ,030220 oncology & carcinogenesis ,Cancer cell ,HE, hematoxylin–eosin staining ,Original Article ,Therapeutics. Pharmacology ,Co-IP, co-immunoprecipitation ,MYH9, myosin-9 ,Small molecule ,IHC, immunohistochemistry ,DAPI, 4′,6-diamidino-2-phenylindole - Abstract
Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells. Mitochondrial dynamics balance is exactly regulated by molecular motor consisted of myosin and actin cytoskeleton proteins. Thus, targeting myosin–actin molecular motor is considered as a promising strategy for anti-cancer. In this study, we performed a proof-of-concept study with a natural-derived small-molecule J13 to test the feasibility of anti-cancer therapeutics via pharmacologically targeting molecular motor. Here, we found J13 could directly target myosin-9 (MYH9)–actin molecular motor to promote mitochondrial fission progression, and markedly inhibited cancer cells survival, proliferation and migration. Mechanism study revealed that J13 impaired MYH9–actin interaction to inactivate molecular motor, and caused a cytoskeleton-dependent mitochondrial dynamics imbalance. Moreover, stable isotope labeling with amino acids in cell culture (SILAC) technology-coupled with pulldown analysis identified HSPA9 as a crucial adaptor protein connecting MYH9–actin molecular motor to mitochondrial fission. Taken together, we reported the first natural small-molecule directly targeting MYH9–actin molecular motor for anti-cancer translational research. Besides, our study also proved the conceptual practicability of pharmacologically disrupting mitochondrial fission/fusion dynamics in human cancer therapy., Graphical abstract Natural-derived small-molecule J13 restrained the interaction between myosin-9 (MYH9) and actin molecular motor via prompting heat-shock protein A9 (HSPA9) attached to MYH9, resulting in excessive mitochondrial fission with implications for human cancer therapy.Image 1
- Published
- 2021
44. A quinine-based quaternized polymer: a potent scaffold with bactericidal properties without resistance
- Author
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Jian-Bin Zhen, Huan-Huan Ding, Le Zhai, Mu-Han Zhao, Le-Yun Sun, Cheng Chen, Jia-Qi Li, Jia-Zhu Chigan, Han Gao, and Ke-Wu Yang
- Subjects
chemistry.chemical_classification ,Quinine ,Polymers and Plastics ,biology ,medicine.drug_class ,Organic Chemistry ,Antibiotics ,Bioengineering ,Biological activity ,Polymer ,Drug resistance ,biology.organism_classification ,Biochemistry ,Combinatorial chemistry ,chemistry.chemical_compound ,chemistry ,Reagent ,medicine ,Ammonium chloride ,Bacteria ,medicine.drug - Abstract
The drug resistance caused due to the overuse of antibiotics has grown into an emerging threat. It is urgent to develop novel strategies to combat bacterial resistance. In this work, a quinine-based quaternized polymer with amphiphilicity (QMTA) was prepared by free-radical copolymerization of quinine and (2-methacryloyloxyethyl) trimethyl ammonium chloride (MTA). Biological activity assays revealed that the polymer sterilized the drug-resistant Gram-negative E. coli and non-resistant Gram-positive bacteria B. subtilis, exhibiting a MIC value of 2 μg mL−1 and a bactericidal rate of more than 95%. Most importantly, both E. coli and B. subtilis treated with the polymer didn't develop resistance even after their 16th passages. Also, the polymer has low toxicity at a dose of up to 128 μg mL−1. The mechanism studies through SEM and 3D-SIM images, fluorescence staining and membrane potential determination reveal that the positively charged QMTA initially concentrates on the surface of bacteria by electrostatic adsorption, changes the membrane potential, binds to the bacteria by its quinine chain, and destroys the membrane structure of the bacteria. This study provides a potential approach through the existing drug to develop new bactericidal reagent/polymer materials without resistance.
- Published
- 2021
45. Sustainable synthesis of vinyl methyl ether from biomass-derived ethylene glycol dimethyl ether over solid base catalysts
- Author
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Haichao Liu, Ke Wu, Xin Wen, and Xin He
- Subjects
chemistry.chemical_compound ,chemistry ,Acetylene ,Environmental Chemistry ,Organic chemistry ,Ether ,Dimethyl ether ,Methanol ,Functional polymers ,Selectivity ,Pollution ,Ethylene glycol ,Catalysis - Abstract
Vinyl methyl ether (VME) is an important chemical intermediate for the production of functional polymers and fine chemicals. It is primarily produced in industry via the addition of methanol to acetylene, known as Reppe vinylation. However, the requirement for high pressures and caustic bases as catalysts limits its practical applications. Here, we report a novel route for the sustainable synthesis of VME from biomass-derived ethylene glycol dimethyl ether (EGDE) via the methanol elimination reaction catalyzed by CaO-based solid bases at atmospheric pressure. The co-precipitated CaO–MgO catalyst with a Ca/Mg molar ratio of 2 exhibited high efficiency and stability, achieving 100% EGDE conversion and 93.5% selectivity to VME at 400 °C. The strongly basic sites facilitated the formation of VME on the CaO–MgO surfaces, whereas, for comparison, the weakly basic sites on MgO or acidic sites on amphoteric oxides (e.g. CeO2) and solid acids (e.g. H-ZSM-5) were found to promote the degradation of VME. This work provides a viable and sustainable strategy for the synthesis of VME and other high-value vinyl compounds from biomass.
- Published
- 2021
46. Flexible temperature sensors made of aligned electrospun carbon nanofiber films with outstanding sensitivity and selectivity towards temperature
- Author
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Seokwoo Jeon, Jinglei Yang, Haomin Chen, Heng Zhang, Xi Shen, Hongming Zhang, Ke Wu, Qingbin Zheng, Eunyoung Kim, Jeng-hun Lee, and Jang Kyo Kim
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Materials science ,Nanofibers ,chemistry.chemical_element ,law.invention ,Wearable Electronic Devices ,Electrical resistivity and conductivity ,law ,Humans ,General Materials Science ,Electrical and Electronic Engineering ,business.industry ,Carbonization ,Carbon nanofiber ,Graphene ,Process Chemistry and Technology ,Electric Conductivity ,Temperature ,Carbon ,Flexible electronics ,chemistry ,Mechanics of Materials ,Optoelectronics ,business ,Temperature coefficient ,Thermal energy - Abstract
Continuous real-time measurement of body temperature using a wearable sensor is an essential part of human health monitoring. Electrospun aligned carbon nanofiber (ACNF) films are employed to assemble flexible temperature sensors. The temperature sensor prepared at a low carbonization temperature of 650 °C yields an outstanding sensitivity of 1.52% °C−1, high accuracy, good linearity, fast response time and excellent long-term durability. Moreover, it exhibits high discriminability towards temperature amidst other unwanted stimuli and maintains its original performance even after repeated stretch/release cycles because of highly-aligned structures. The correlation between the atomic structure and the temperature sensing performance of ACNF sensors is established. Contrary to conventional highly conductive temperature sensors, the ACNF sensor with a low electrical conductivity prepared at a low carbonization temperature ameliorates the temperature sensing performance. This anomaly is explained by (i) the smaller and more disordered sp2 carbon crystallites yielding a high negative temperature coefficient, (ii) a larger number of defects, and (iii) a higher pyridinic-N content generating abundant entrapped and localized electrons which are activated once sufficient thermal energy is available. Flexible ACNF sensor's overall performance is among the best-known carbon material-based flexible temperature sensors, demonstrating potential applications in emerging healthcare and flexible electronics technologies.
- Published
- 2021
47. Cholesteroled polymer (Chol-b-Lys)-based nanoparticles (CL-NPs) confer antibacterial efficacy without resistance
- Author
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Yin-Sui Xu, Jia-Zhu Chigan, Huan-Huan Ding, Jian-Bin Zhen, Lu Liu, Ke-Wu Yang, and Cheng Chen
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biology ,Membrane permeability ,Chemistry ,Nanoparticle ,General Chemistry ,biology.organism_classification ,Catalysis ,Cell membrane ,medicine.anatomical_structure ,Membrane ,Reagent ,Materials Chemistry ,Biophysics ,medicine ,Lipid bilayer ,Bacteria ,Conjugate - Abstract
It is imperative to develop innovative and efficient antibacterial agents, on account of the mounting prevalence of complicated infections induced by multidrug-resistant bacteria. In this work, Chol-b-Lys nanoparticles (CL-NPs) with a diameter of 304.9 nm were prepared by ring-opening polymerization of the monomers cholesterol-ethylenediamine conjugate (Chol-NH2) and L-Lys-N-carboxyanhydrides (L-Lys-NCAs) and further self-assembly. The nanoparticles exhibited biological activity against the drug-resistant and non-resistant bacteria, including Gram-negative E. coli and Gram-positive B. subtilis, E. faecalis and S. aureus, with a MIC value in the range of 32–2 μg mL−1 and a more than 95% bactericidal rate. Importantly, both bacteria treated with CL-NPs didn’t develop resistance even after their 16th passages. Also, the CL-NPs have low toxicity (32 μg mL−1). The mechanism characterization shows that the positively charged nanoparticles are initially gathered on the surface of bacteria by electrostatic adsorption, changes the membrane permeability, inserts into the lipid bilayer bacteria membrane with cholesterol groups, destroys the membrane structure and results in bacterial apoptosis. This work provides a potential approach by mimicking the structure of cell membrane to develop new bactericidal reagent/nanoparticle materials which is hard to cause resistance.
- Published
- 2021
48. Lightweight and flexible conducting polymer sponges and hydrogels for electromagnetic interference shielding
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Eric Quenneville, Louis-Philippe Carignan, Ke Wu, Biporjoy Sarkar, Fabio Cicoira, and Xinda Li
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Conductive polymer ,Materials science ,General Chemistry ,Electromagnetic interference ,Polystyrene sulfonate ,chemistry.chemical_compound ,chemistry ,PEDOT:PSS ,Electromagnetic shielding ,Self-healing hydrogels ,Materials Chemistry ,Composite material ,Porosity ,Absorption (electromagnetic radiation) - Abstract
The massive usage of electronic and telecommunication devices has led to serious concerns regarding undesired electromagnetic pollution. While metals such as silver, aluminum and copper are the mostly used materials to shield electromagnetic interference, organic conducting polymers are gaining momentum for lightweight, flexible and wearable systems. In this work, we used three dimensional (3D) sponges and hydrogel films based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) to demonstrate electromagnetic interference (EMI) shielding applications in the X-band frequency range (8–12.4 GHz). The 3D PEDOT:PSS sponges showed a porous structure composed of thread-like and sheet-like micro-features that offer an excellent electromechanical response under compressive strain, due to the collapse of micropores in the sponge structure. Interestingly, the compressive strain remarkably enhanced the shielding effectiveness (SE) value of PEDOT:PSS sponges from about 15 dB to 24 dB. PEDOT:PSS hydrogel films with a compact morphology showed a high SE value of about 105 dB. For both PEDOT:PSS sponges and hydrogel films, reflection and absorption processes contributed to the total SE.
- Published
- 2021
49. Transplanting Rac1-silenced bone marrow mesenchymal stem cells promote neurological function recovery in TBI mice
- Author
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Chun Li Zhang, Hao Wang, Ke Wu, Qichuan Zhuge, Kankai Wang, Jiayu Chen, Felix Siaw-Debrah, Lin Yan, Jianjing Yang, Ying Zhang, Hua Wang, Chaojie Yao, Sheng Ye, and Dongdong Huang
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Aging ,Programmed cell death ,Gene knockdown ,business.industry ,Cell Biology ,medicine.disease_cause ,Transplantation ,chemistry.chemical_compound ,Vascular endothelial growth factor A ,chemistry ,Apoptosis ,Cancer research ,medicine ,Gene silencing ,business ,Nicotinamide adenine dinucleotide phosphate ,Oxidative stress - Abstract
Bone marrow mesenchymal stem cells (BMMSCs)-based therapy has emerged as a promising novel therapy for Traumatic Brain Injury (TBI). However, the therapeutic quantity of viable implanted BMMSCs necessary to initiate efficacy is still undetermined. Increased oxidative stress following TBI, which leads to the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase signaling pathway, has been implicated in accounting for the diminished graft survival and therapeutic effect. To prove this assertion, we silenced the expression of NADPH subunits (p22-phox, p47-phox, and p67-phox) and small GTPase Rac1 in BMMSCs using shRNA. Our results showed that silencing these proteins significantly reduced oxidative stress and cell death/apoptosis, and promoted implanted BMMSCs proliferation after TBI. The most significant result was however seen with Rac1 silencing, which demonstrated decreased expression of apoptotic proteins, enhanced in vitro survival ratio, reduction in TBI lesional volume and significant improvement in neurological function post shRac1-BMMSCs transplantation. Additionally, two RNA-seq hub genes (VEGFA and MMP-2) were identified to play critical roles in shRac1-mediated cell survival. In summary, we propose that knockdown of Rac1 gene could significantly boost cell survival and promote the recovery of neurological functions after BMMSCs transplantation in TBI mice.
- Published
- 2020
50. Comp34 displays potent preclinical antitumor efficacy in triple-negative breast cancer via inhibition of NUDT3-AS4, a novel oncogenic long noncoding RNA
- Author
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Kun Wang, Katrina M. Schrode, Qiongyu Hao, Piwen Wang, Jieqing Li, Yong Wu, Seyung Chung, Qun Li, Wenhong Deng, Jay Vadgama, Qiao-Hong Chen, Wei Cao, Ke Wu, Pranabananda Dutta, Magda Shaheen, Donghui Zhu, Qing Geng, Guanglin Chen, and Yahya Elshimali
- Subjects
Cancer Research ,Transcription, Genetic ,AKT1 ,Diseases ,Triple Negative Breast Neoplasms ,Cytotoxicity ,Triple-negative breast cancer ,Cancer ,Tumor ,Chemistry ,Drug discovery ,lcsh:Cytology ,TOR Serine-Threonine Kinases ,Long non-coding RNA ,Gene Expression Regulation, Neoplastic ,Disease Progression ,Neoplastic Stem Cells ,Long Noncoding ,RNA, Long Noncoding ,Transcription ,Biotechnology ,Signal Transduction ,Curcumin ,Oncology and Carcinogenesis ,Immunology ,Antineoplastic Agents ,Article ,Cell Line ,Cellular and Molecular Neuroscience ,Breast cancer ,Genetic ,Cell Line, Tumor ,Breast Cancer ,microRNA ,Genetics ,medicine ,Humans ,lcsh:QH573-671 ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Sirolimus ,Neoplastic ,Base Sequence ,Cell Biology ,medicine.disease ,MicroRNAs ,Gene Expression Regulation ,Cancer research ,RNA ,Biochemistry and Cell Biology ,Proto-Oncogene Proteins c-akt - Abstract
The abnormal PI3K/AKT/mTOR pathway is one of the most common genomic abnormalities in breast cancers including triple-negative breast cancer (TNBC), and pharmacologic inhibition of these aberrations has shown activity in TNBC patients. Here, we designed and identified a small-molecule Comp34 that suppresses both AKT and mTOR protein expression and exhibits robust cytotoxicity towards TNBC cells but not nontumorigenic normal breast epithelial cells. Mechanically, long noncoding RNA (lncRNA) AL354740.1-204 (also named as NUDT3-AS4) acts as a microRNA sponge to compete with AKT1/mTOR mRNAs for binding to miR-99s, leading to decrease in degradation of AKT1/mTOR mRNAs and subsequent increase in AKT1/mTOR protein expression. Inhibition of lncRNA-NUDT3-AS4 and suppression of the NUDT3-AS4/miR-99s association contribute to Comp34-affected biologic pathways. In addition, Comp34 alone is effective in cells with secondary resistance to rapamycin, the best-known inhibitor of mTOR, and displays a greater in vivo antitumor efficacy and lower toxicity than rapamycin in TNBC xenografted models. In conclusion, NUDT3-AS4 may play a proproliferative role in TNBC and be considered a relevant therapeutic target, and Comp34 presents promising activity as a single agent to inhibit TNBC through regulation of NUDT3-AS4 and miR-99s.
- Published
- 2020
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