396 results on '"Yajun Wang"'
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2. Nanoplastic Exposure Mediates Neurodevelopmental Toxicity by Activating the Oxidative Stress Response in Zebrafish (Danio rerio)
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Xiaoqian Cao, Wenjie Xie, Meilan Feng, Juntao Chen, Jiannan Zhang, Juanjuan Luo, and Yajun Wang
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Chemistry ,QD1-999 - Published
- 2024
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3. Facial Construction of Hydroxyl Functional Modified Ultrafine BiPO4 with Variation of Dipole Moment Induced by –OH Group
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Zhuang Yang, Zengshou Qiang, Jian Wang, Yajun Wang, and Wenqing Yao
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BiPO4 ,dipole moments ,hydroxyl functional groups ,photocatalysis ,synchronous illumination ,XPS ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The hydroxyl groups generated by hydrolysis are grafted onto the surface of BiPO4, and a stable surface hydroxylation structure is formed during the subsequent calcination process. This would facilitate the formation of a new hydroxyl functional structure on the surface of the parent photocatalyst without damaging its intrinsic structure. Synchronous illumination X‐Ray photoelectron spectroscopy shows that the hydroxyl functional ultrafine BiPO4 can realize the conversion of defective oxygen to lattice oxygen, which is more conducive in improving the photocatalytic efficiency. The process of filling hydroxyl oxygen vacancies and forming a stable structure is explored using in‐ situ infrared spectroscopy. The induced dipole moment promotes the separation of photogenerated electron–hole pairs, which is beneficial for the enhancement of photocatalytic activity. The dipole moment of the hydroxyl functional‐modified ultrafine BiPO4 is −1.409 D compared to −1.385 D for ordinary BiPO4. The results of this study indicate that hydroxyl functional structure and reduced sample granularity are effective strategies to improve the photocatalytic performance of BiPO4.
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- 2024
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4. Study on Adsorption of Cd in Solution and Soil by Modified Biochar–Calcium Alginate Hydrogel
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Shuyue Wang, Yajun Wang, Xinyi Wang, Sijia Sun, Yanru Zhang, Weixiong Jiao, and Dasong Lin
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modified biochar ,calcium alginate ,Cd pollution ,in situ passivation ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Contamination with cadmium (Cd) is a prominent issue in agricultural non-point source pollution in China. With the deposition and activation of numerous Cd metal elements in farmland, the problem of excessive pollution of agricultural produce can no longer be disregarded. Considering the issue of Cd pollution in farmland, this study proposes the utilization of cross-linked modified biochar (prepared from pine wood) and calcium alginate hydrogels to fabricate a composite material which is called MB-CA for short. The aim is to investigate the adsorption and passivation mechanism of soil Cd by this innovative composite. The MB-CA exhibits a higher heavy metal adsorption capacity compared to traditional biochar and hydrogel due to its increased oxygen-containing functional groups and heavy metal adsorption sites. In the Cd solution adsorption experiment, the highest Cd2+ removal rate reached 85.48%. In addition, it was found that the material also has an excellent pH improvement effect. Through the adsorption kinetics experiment and the soil culture experiments, it was determined that MB-CA adheres to the quasi-second-order kinetic model and is capable of adsorbing 35.94% of Cd2+ in soil. This study validates the efficacy of MB-CA in the adsorption and passivation of Cd in soil, offering a novel approach for managing Cd-contaminated cultivated land.
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- 2024
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5. A clean and efficient route for extraction of vanadium from vanadium slag by electro-oxidation combined with ultrasound cavitation
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Bao Liu, Luyang Duan, Shuang Cai, Qianqian Ren, Junguo Li, Yajun Wang, and Yanan Zeng
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Vanadium slag ,Electro-oxidation ,Ultrasound cavitation ,Vanadium leaching ,Mineralogy ,Chemistry ,QD1-999 ,Acoustics. Sound ,QC221-246 - Abstract
Extracting vanadium (V) from vanadium slag (VS) by the traditional roasting-leaching process has disadvantages of high energy consumption and high poisonous gases emission. In this work, a green and efficient route was developed to extract V from VS without roasting by electro-oxidation combined with ultrasound cavitation (EOUC) intensification in sulfuric acid solution. The leaching parameters (e.g., leaching temperature, sulfuric acid concentration, anodic current density, ultrasound power, liquid to solid ratio, leaching time and particle size) were optimized. The leaching mechanism was explored by comparing the leaching behavior and mineralogical evolution of the direct sulfuric acidic leaching (DSL), electro-oxidation-assisted sulfuric acidic leaching (EOSL), ultrasound cavitation-assisted sulfuric acidic leaching (UCSL) and EOUC methods. The results show that introducing electric field strengthens the ultrasound cavitation effect on slag particles in sulfuric acid solution. Under the optimum parameter of EOUC method, the leaching rate of V from VS is as high as 94.64 %. Using EOUC method can open the silicate-wrapped structure of the spinel, increase pore volume of VS from 0.00127 cm3 g−1 to 0.01124 cm3 g−1, decrease slag particle size from 26.8 μm to 16.4 μm and improve specific surface area from 0.508 m2 g−1 to 10.855 m2 g−1, which significantly accelerate V leaching process. The exposed spinel was oxidized by both electrochemical route and chemical route, forming a mixture of V3+ ion and VO2+ ion after leaching.
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- 2024
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6. LDH/MXene Synergistic Carrier Separation Effects to Improve the Photoelectric Catalytic Activities of Bi2WO6 Nanosheet Arrays
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Yuting Wang, Runhua Li, Jiaying Zhang, Liming Liu, Weiwei Huang, and Yajun Wang
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Bi2WO6 ,MXene ,NiFe-LDH ,photoelectrocatalytic ,bisphenol A ,Chemistry ,QD1-999 - Abstract
Photoelectric catalysis is a green and efficient way to degrade pollutants, which has been paid more and more attention by researchers. Among them, Bi2WO3 has been proved to have excellent photocatalytic oxidation activity on its {001} facets. In this study, {001}-oriented facets with high exposure were successfully integrated into Bi2WO6 nanoplate arrays (Bi2WO6 NAs) to create a photoelectrode. This structure was grown in situ on an indium tin oxide (ITO) substrate. To promote photogenerated carrier separation efficiency and reduce agglomeration of Bi2WO6 photocatalysts, the electrochemical deposition of NiFe–layered double hydroxide (NiFe-LDH) and Ti3C2 (MXene) were introduced in this research to synergistically catalyze pollutant degradation. Morphology, spectral characterization, and electrochemical analysis jointly confirmed that the outstanding performance of hole capture behavior with LDH and electron conduction properties with MXene were the main reasons for the improvement in catalytic activity of the photoelectrode. Taking bisphenol A (BPA) as the model pollutant, the rate constant k of the NiFe-LDH/Ti3C2/Bi2WO6 NAs photoelectrode reaches 0.00196 min−1 under photoelectrocatalytic (PEC) conditions, which is 4.5 times that of the pure Bi2WO6 NAs photoelectrode. This work provides a new way to improve the reaction kinetics of the PEC degradation of pollutants.
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- 2024
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7. Bmp4 in Zebrafish Enhances Antiviral Innate Immunity through p38 MAPK (Mitogen-Activated Protein Kinases) Pathway
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Lihui Chen, Shenjie Zhong, Yajun Wang, Xinyuan Wang, Zhenhui Liu, and Guobin Hu
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zebrafish ,BMP4 ,antiviral innate immunity ,IFN ,p38 MAPK pathway ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Bone morphogenetic proteins (BMPs) are a group of structurally and functionally related signaling molecules that comprise a subfamily, belonging to the TGF-β superfamily. Most BMPs play roles in the regulation of embryonic development, stem cell differentiation, tumor growth and some cardiovascular and cerebrovascular diseases. Although evidence is emerging for the antiviral immunity of a few BMPs, more BMPs are needed to determine whether this function is universal. Here, we identified the zebrafish bmp4 ortholog, whose expression is up-regulated through challenge with grass carp reovirus (GCRV) or its mimic poly(I:C). The overexpression of bmp4 in epithelioma papulosum cyprini (EPC) cells significantly decreased the viral titer of GCRV-infected cells. Moreover, compared to wild-type zebrafish, viral load and mortality were significantly increased in both larvae and adults of bmp4−/− mutant zebrafish infected with GCRV virus. We further demonstrated that Bmp4 promotes the phosphorylation of Tbk1 and Irf3 through the p38 MAPK pathway, thereby inducing the production of type I IFNs in response to virus infection. These data suggest that Bmp4 plays an important role in the host defense against virus infection. Our study expands the understanding of BMP protein functions and opens up new targets for the control of viral infection.
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- 2023
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8. One-Pot Synthesis of Ultra-Small Pt Nanoparticles-Loaded Nitrogen-Doped Mesoporous Carbon Nanotube for Efficient Catalytic Reaction
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Qian Zhang, Minying Wu, Yuanyuan Fang, Chao Deng, Hsin-Hui Shen, Yi Tang, and Yajun Wang
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platinum ,nitrogen doping ,mesoporous carbon nanotubes ,catalysis ,Chemistry ,QD1-999 - Abstract
In this study, Pt nanoparticles-loaded nitrogen-doped mesoporous carbon nanotube (Pt/NMCT) was successfully synthesized through a polydopamine-mediated “one-pot” co-deposition strategy. The Pt source was introduced during the co-deposition of polydopamine and silica on the surface of SiO2 nanowire (SiO2 NW), and Pt atoms were fixed in the skeleton by the chelation of polydopamine. Thus, in the subsequent calcination process in nitrogen atmosphere, the growth and agglomeration of Pt nanoparticles were effectively restricted, achieving the in situ loading of uniformly dispersed, ultra-small (~2 nm) Pt nanoparticles. The method is mild, convenient, and does not require additional surfactants, reducing agents, or stabilizers. At the same time, the use of the dual silica templates (SiO2 NW and the co-deposited silica nanoclusters) brought about a hierarchical pore structure with a high specific surface area (620 m2 g−1) and a large pore volume (1.46 cm3 g−1). The loading process of Pt was studied by analyzing the electron microscope and X-ray photoelectron spectroscopy of the intermediate products. The catalytic performance of Pt/NMCT was investigated in the reduction of 4-nitrophenol. The Pt/NMCT with a hierarchical pore structure had an apparent reaction rate constant of 0.184 min−1, significantly higher than that of the sample, without the removal of the silica templates to generate the hierarchical porosity (0.017 min−1). This work provides an outstanding contribution to the design of supported noble metal catalysts and also highlights the importance of the hierarchical pore structure for catalytic activity.
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- 2023
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9. DESTformer: A Transformer Based on Explicit Seasonal–Trend Decomposition for Long-Term Series Forecasting
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Yajun Wang, Jianping Zhu, and Renke Kang
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long-term time series prediction ,transformer ,seasonal–trend decomposition ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Seasonal–trend-decomposed transformer has empowered long-term time series forecasting via capturing global temporal dependencies (e.g., period-based dependencies) in disentangled temporal patterns. However, existing methods design various auto-correlation or attention mechanisms in the seasonal view while ignoring the fine-grained temporal patterns in the trend view in the series decomposition component, which causes an information utilization bottleneck. To this end, a Transformer-based seasonal–trend decomposition methodology with a multi-scale attention mechanism in the trend view and a multi-view attention mechanism in the seasonal view is proposed, called DESTformer. Specifically, rather than utilizing the moving average operation in obtaining trend data, a frequency domain transform is first applied to extract seasonal (high-frequency) and trend (low-frequency) components, explicitly capturing different temporal patterns in both seasonal and trend views. For the trend component, a multi-scale attention mechanism is designed to capture fine-grained sub-trends under different receptive fields. For the seasonal component, instead of the frequency-only attention mechanism, a multi-view frequency domain (i.e., frequency, amplitude, and phase) attention mechanism is designed to enhance the ability to capture the complex periodic changes. Extensive experiments are conducted on six benchmark datasets covering five practical applications: energy, transportation, economics, weather, and disease. Compared to the state-of-the-art FEDformer, our model shows reduced MSE and MAE by averages of 6.5% and 3.7%, respectively. Such experimental results verify the effectiveness of our method and point out a new way towards handling trends and seasonal patterns in long-term time series forecasting tasks.
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- 2023
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10. Efficient Iterative Dynamic Kernel Principal Component Analysis Monitoring Method for the Batch Process with Super-large-scale Data Sets
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Yajun Wang, Hongli Yu, and Xiaohui Li
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Chemistry ,QD1-999 - Published
- 2021
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11. Directional Structure Modification of Poplar Biomass-Inspired High Efficacy of Enzymatic Hydrolysis by Sequential Dilute Acid–Alkali Treatment
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Fuxi Shi, Yajun Wang, Maryam Davaritouchaee, Yiqing Yao, and Kang Kang
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Chemistry ,QD1-999 - Published
- 2020
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12. Decontamination and Ecological Restoration Performance of a Bioretention Cell-Microbial Fuel Cell under Multiple-Antibiotics Stress
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Yuan Yan, Yajun Wang, Tianjing Chen, Hongwei Sun, and Lijuan Cai
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bioretention cell ,antibiotic removal ,denitrifying functional genes ,ofloxacin ,tetracycline ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Antibiotics are refractory pollutants that have been widely found in various environmental media such as soil and surface water. Existing sewage treatments perform poorly at preventing antibiotics in urban sewage from polluting natural environments. In this study, we designed a bioelectrically enhanced bioretention cell system (bioretention cell-microbial fuel cell, BRC-MFC) that utilizes the unique structure of the BRC system to improve the removal of sewage antibiotics. This new system can efficiently remove antibiotics by using a synergy of plant absorption, filler adsorption, filler filtration and microbial degradation. To study the influences of multiple-antibiotics stress on the decontamination performance of BRC-MFC, ofloxacin (OFLX) and tetracycline (TC) were selected as target antibiotics, and five BRC-MFCs were built to treat sewage containing antibiotics of different concentrations. The concentrations of pollutant in the influent and effluent were measured and the pollutant removal performance of BRC-MFC was studied. The diversity of rhizosphere microorganisms and the abundance of denitrifying functional genes were analyzed. Experimental results showed that over 90% of OFLX and TC in each BRC-MFC were removed, with the removal rates positively correlating with the concentration of antibiotics. In addition, the removal rates of chemical oxygen demand (COD) in BRC-MFC were both over 90%, while the removal rate of total nitrogen (TN) was around 70%. Meanwhile, antibiotics could significantly improve the removal of ammonia nitrogen (NH4+-N, p < 0.01). The microbial richness decreased, and we found that combined antibiotic stress on microorganisms was stronger than single antibiotic stress. The abundance of denitrifying functional genes was reduced by antibiotic stress. The results of this study provide reference values for other projects focusing on removing various antibiotics from domestic sewage using BRC-MFC.
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- 2023
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13. Energy Spatial Distribution of Behind-Armor Debris Generated by Penetration of Explosively Formed Projectiles with Different Length–Diameter Ratio
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Xuanning Huang, Weibing Li, Wenbin Li, Guixiang Yin, Yajun Wang, and Tengfei Guo
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behind-armor debris (BAD) ,explosively formed projectile (EFP) ,length–diameter ratio (L/D) ,radial scattering distance ,energy spatial distribution ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
To understand the influence of the length–diameter ratio (L/D) of explosively formed projectiles (EFPs) on the energy spatial distribution of behind-armor debris (BAD), three EFPs with different L/Ds were designed in this study. The scattering characteristics of the BAD formed by the EFP penetrating a steel target were investigated. High-speed photography was used to observe the shape of the BAD cloud. Fiber and foam plates were sequentially stacked to recover the fragments. The three-dimensional damaged area by the BAD was obtained based on the spatial position information of a large amount of BAD. Finally, the energy spatial distribution characteristics of the EFP and target material fragments were analyzed. The results showed that a large EFP L/D increased the total energy of the BAD, and the proportion of the energy of projectile fragments increased. The difference in the energy spatial distribution between EFPs with varying L/Ds was mainly in the scattering angle range of 3–17°. The total energy of fragments within 17° of scattering angle accounted for 85% of the total energy of all fragments. The BAD energy of the EFP with a large L/D (L/D = 3.86) was concentrated in a small scattering angle range in which the residual projectile was located. The average projectile fragment energy of the EFP with a moderate L/D (L/D = 2.4) was evenly distributed in the scattering angle range of 5–20°. As a result, the energy distribution of the BAD from EFP (L/D = 2.4) shifted towards the large scattering angle, thus leading to a uniform radial distribution of the striking area within the range of 500–1100 mm behind the target. However, with the increase in the distance behind the target, the radial direction of the striking area of the other two EFPs was gradually reduced. The reason was explained according to the force analysis of the fragments resulting from the bulge fracture of target. The spatial energy distribution of BAD is closely related to the damage ability of EFP in relation to the armored target. Thus, it is necessary to design EFPs with appropriate L/Ds in order to maximize the damaging effect behind the armor.
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- 2023
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14. Morphological and Molecular Functional Evidence of the Pharyngeal Sac in the Digestive Tract of Silver Pomfret, Pampus argenteus
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Huan Jiang, Jiabao Hu, Huihui Xie, Man Zhang, Chunyang Guo, Youyi Zhang, Yaya Li, Cheng Zhang, Shanliang Xu, Danli Wang, Xiaojun Yan, Yajun Wang, and Xubo Wang
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Pampus argenteus ,pharyngeal sac ,morphology ,papilla ,transcriptome ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The pharyngeal sac is a comparatively rare organ in the digestive tract among teleost fishes. However, our understanding of this remarkable organ in the silver pomfret (Pampus argenteus) is limited. In the present study, we examined the various morphological and histological characteristics of the pharyngeal sac using histochemical techniques and electron microscopy. The pharyngeal sac showed unique characteristics such as well-developed muscular walls, weakly keratinized epithelium, numerous goblet cells, and needle-like processes on the papillae. The porous cavity of the papillae contained numerous adipocytes and was tightly enveloped by type I collagen fibers. These structures might provide mechanical protection and excellent biomechanical properties for grinding and shredding prey. A comparison of gene expression levels between the pharyngeal sac and esophagus using RNA-seq showed that phenotype-associated genes (epithelial genes and muscle genes) were upregulated, whereas genes related to nutrient digestion and absorption were downregulated in the pharyngeal sac. These results support the role of the pharyngeal sac in shredding and predigesting food. Overall, these findings provide a clearer understanding of the pharyngeal sac morphology and explain the morphological adaptations of the digestive tract for feeding on gelatinous prey. To our knowledge, this is the first report on pharyngeal sac gene expression in P. argenteus.
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- 2023
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15. A Coupled Darcy-Forchheimer Flow Model in Fractured Porous Media
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Feng Xiong, Yijun Jiang, Chun Zhu, Lin Teng, Hao Cheng, and Yajun Wang
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fractured rocks ,Forchheimer flow ,Darcy flow ,finite volume method ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Aiming at nonlinear flow in fractured porous media, based on the finite volume method, the discrete equations of Darcy flow in porous and Forchheimer flow in fracture were derived, and a solution method for coupling flow is proposed. The flow solution by the proposed method for single fracture and intersecting fracture is verified against Frih’s solution. Based on this method, nonlinear flow behavior for fractured rock deep-buried tunnels under high water heads was discussed. The results show that the hydraulic gradient of surrounding rock is characterized by “large at the bottom and small at the top”, with a maximum difference of 2.5 times. Therefore, the flow rate at the bottom of the tunnel is greater than that at the top. The fracture flow rate along the flow direction is also greater than that in the vertical flow direction, with a maximum difference of 60 times. The distribution homogeneity and density of fracture are the most important factors that affect the hydraulic behavior of fractured rock tunnels. The more fractures concentrated in the direction of water pressure and the greater the density, the greater the surrounding rock conductivity and the greater the flow rate of the tunnel. Under this condition, the water-inflow accident of the tunnel would be prone to occur. The research results provide a reference for the waterproof design and engineering practice of fractured rock tunnels.
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- 2022
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16. A Method for Dynamic Insertion Order Scheduling in Flexible Job Shops Based on Digital Twins
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Yajun Wang, Junyu Leng, Xiaoqi Liu, Jiajia Wang, and Qiunan Meng
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digital twin ,rush order insertion ,genetic algorithm ,dynamic scheduling ,disturbance ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Various production disturbances occurring in the flexible job shop production process may affect the production of the workshop, some of which may lead to the prolongation of production completion time. Therefore, a flexible job shop dynamic scheduling method based on digital twins is proposed and a dynamic scheduling framework is constructed. Compared with the traditional workshop, the digital twin-based flexible job shop can upload the relevant production data of the physical workshop to the data management center in real time, and after fusion processing the data can work cooperatively with the upper application system. Taking the dynamic disturbance of rush order insertion as an example, the dynamic scheduling of insertion order is realized based on the dynamic scheduling framework, and then the production efficiency is improved. To achieve the shortest completion time, a mathematical model for dynamic scheduling optimization is established and a genetic algorithm (GA) is applied to solve the model. Finally, a practical case is applied to show that the completion time of this algorithm is reduced by 35%, which verifies the feasibility of the proposed dynamic scheduling method.
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- 2022
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17. Recent Progress of Ga-Based Catalysts for Catalytic Conversion of Light Alkanes
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Yuming Li, Shuting Fu, Qiyang Zhang, Hongyu Liu, and Yajun Wang
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light alkane ,gallium ,catalysis ,olefins ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
The efficient and clean conversion of light alkanes is a research hotspot in the petrochemical industry, and the development of effective and eco-friendly non-noble metal-based catalysts is a key factor in this field. Among them, gallium is a metal component with good catalytic performance, which has been extensively used for light alkanes conversion. Herein, we critically summarize recent developments in the preparation of gallium-based catalysts and their applications in the catalytic conversion of light alkanes. First, we briefly describe the different routes of light alkane conversion. Following that, the remarkable preparation methods for gallium-based catalysts are discussed, with their state-of-the-art application in light alkane conversion. It should be noticed that the directional preparation of specific Ga species, strengthening metal-support interactions to anchor Ga species, and the application of new kinds of methods for Ga-based catalysts preparation are at the leading edge. Finally, the review provides some current limitations and future perspectives for the development of gallium-based catalysts. Recently, different kinds of Ga species were reported to be active in alkane conversion, and how to separate them with advanced in situ and ex situ characterizations is still a problem that needs to be solved. We believe that this review can provide base information for the preparation and application of Ga-based catalysts in the current stage. With these summarizations, this review can inspire new research directions of gallium-based catalysts in the catalysis conversion of light alkanes with ameliorated performances.
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- 2022
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18. Recent Advances in the Development of Lipid-, Metal-, Carbon-, and Polymer-Based Nanomaterials for Antibacterial Applications
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Ruohua Ren, Chiaxin Lim, Shiqi Li, Yajun Wang, Jiangning Song, Tsung-Wu Lin, Benjamin W. Muir, Hsien-Yi Hsu, and Hsin-Hui Shen
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nanomaterials ,multidrug-resistant bacteria ,antimicrobial ,drug delivery systems ,nanoparticles ,Chemistry ,QD1-999 - Abstract
Infections caused by multidrug-resistant (MDR) bacteria are becoming a serious threat to public health worldwide. With an ever-reducing pipeline of last-resort drugs further complicating the current dire situation arising due to antibiotic resistance, there has never been a greater urgency to attempt to discover potential new antibiotics. The use of nanotechnology, encompassing a broad range of organic and inorganic nanomaterials, offers promising solutions. Organic nanomaterials, including lipid-, polymer-, and carbon-based nanomaterials, have inherent antibacterial activity or can act as nanocarriers in delivering antibacterial agents. Nanocarriers, owing to the protection and enhanced bioavailability of the encapsulated drugs, have the ability to enable an increased concentration of a drug to be delivered to an infected site and reduce the associated toxicity elsewhere. On the other hand, inorganic metal-based nanomaterials exhibit multivalent antibacterial mechanisms that combat MDR bacteria effectively and reduce the occurrence of bacterial resistance. These nanomaterials have great potential for the prevention and treatment of MDR bacterial infection. Recent advances in the field of nanotechnology are enabling researchers to utilize nanomaterial building blocks in intriguing ways to create multi-functional nanocomposite materials. These nanocomposite materials, formed by lipid-, polymer-, carbon-, and metal-based nanomaterial building blocks, have opened a new avenue for researchers due to the unprecedented physiochemical properties and enhanced antibacterial activities being observed when compared to their mono-constituent parts. This review covers the latest advances of nanotechnologies used in the design and development of nano- and nanocomposite materials to fight MDR bacteria with different purposes. Our aim is to discuss and summarize these recently established nanomaterials and the respective nanocomposites, their current application, and challenges for use in applications treating MDR bacteria. In addition, we discuss the prospects for antimicrobial nanomaterials and look forward to further develop these materials, emphasizing their potential for clinical translation.
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- 2022
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19. Templated Assembly of pH-Labile Covalent Organic Framework Hierarchical Particles for Intracellular Drug Delivery
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Fangzhou Zhou, Yuanyuan Fang, Chao Deng, Qian Zhang, Minying Wu, Hsin-Hui Shen, Yi Tang, and Yajun Wang
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mesoporous silica ,covalent organic framework ,hierarchically porous ,templated assembly ,anticancer ,drug delivery ,Chemistry ,QD1-999 - Abstract
Covalent organic frameworks (COF), a class of emerging microporous polymers, have been restrained for drug delivery applications due to their limited controllability over particle sizes and degradability. Herein, a dendritic mesoporous silica nanosphere (DMSN)-mediated growth strategy is proposed to fabricate hierarchical DMSN@COF hybrids through in situ growing of 1,3,5-tris(4-aminophenyl)benzene and 2,5-dimethoxyterephthaldehyde connected COF with acid cleavable C=N bonds. After the removal of the DMSN template, COF hierarchical particles (COF HP) with tailored particle sizes and degradability were obtained. Notably, the COF HP could be degraded by 55% after 24 h of incubation at pH 5.5, whereas the counterpart bulk COF only showed 15% of degradation in the same conditions. Due to the improved porosity and surface area, the COF HP can be utilized to load the chemotherapeutic drug, doxorubicin (DOX), with a high loading (46.8 wt%), outperforming the bulk COF (32.1 wt%). Moreover, around 90% of the loaded DOX can be discharged from the COF HP within 8 h of incubation at pH 5.5, whereas, only ~55% of the loaded DOX was released from the bulk COF. Cell experiments demonstrated that the IC50 value of the DOX loaded in COF HP was 2–3 times lower than that of the DOX loaded in the bulk COF and the hybrid DMSN@COF. Attributed to the high loading capacity and more pH-labile particle deconstruction properties, COF HP shows great potential in the application as vehicles for drug delivery.
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- 2022
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20. Dendritic Mesoporous Silica Hollow Spheres for Nano-Bioreactor Application
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Qian Zhang, Minying Wu, Yuanyuan Fang, Chao Deng, Hsin-Hui Shen, Yi Tang, and Yajun Wang
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hollow mesoporous silica nanoparticles ,dendritic mesopores ,co-deposition ,barium sulfate ,enzyme immobilization ,bioreactors ,Chemistry ,QD1-999 - Abstract
Mesoporous silica materials have attracted great research interest for various applications ranging from (bio)catalysis and sensing to drug delivery. It remains challenging to prepare hollow mesoporous silica nanoparticles (HMSN) with large center-radial mesopores that could provide a more efficient transport channel through the cell for guest molecules. Here, we propose a novel strategy for the preparation of HMSN with large dendritic mesopores to achieve higher enzyme loading capacity and more efficient bioreactors. The materials were prepared by combining barium sulfate nanoparticles (BaSO4 NP) as a hard template and the in situ-formed 3-aminophenol/formaldehyde resin as a porogen for directing the dendritic mesopores’ formation. HMSNs with different particle sizes, shell thicknesses, and pore structures have been prepared by choosing BaSO4 NP of various sizes and adjusting the amount of tetraethyl orthosilicate added in synthesis. The obtained HMSN-1.1 possesses a high pore volume (1.07 cm3 g−1), a large average pore size (10.9 nm), and dendritic mesopores that penetrated through the shell. The advantages of HMSNs are also demonstrated for enzyme (catalase) immobilization and subsequent use of catalase-loaded HMSNs as bioreactors for catalyzing the H2O2 degradation reaction. The hollow and dendritic mesoporous shell features of HMSNs provide abundant tunnels for molecular transport and more accessible surfaces for molecular adsorption, showing great promise in developing efficient nanoreactors and drug delivery vehicles.
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- 2022
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21. Comprehensive Study on Surrounding Rock Failure Characteristics of Longwall Roadway and Control Techniques
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Xiaojie Yang, Gang Yang, Ruifeng Huang, Yajun Wang, Jianning Liu, Jun Zhang, and Shilin Hou
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longwall mining ,roadway stability ,mining rock mechanics ,numerical modeling ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Research on underground coal mines has primarily focused on the stability of roadways. Mining activities lead to significant damage to the surrounding rocks and also degrade the support to the roadways. Considering the 21309 roadway of the Huojitu coal mine as a case study, this work comprehensively analyzed the characteristics of the surrounding rock using three methods: theoretical calculations, FLAC3D numerical modeling, and field observations. The results indicate that, under the influence of secondary mining, the failure range and stress concentration degree of the surrounding rock are considerably higher than those under the influence of primary mining. In this case, the maximum damage range in the surrounding rock can reach 1.8 m, the maximum principal stress can reach 19.82 MPa, and the ratio of the maximum principal stress to the minimum principal stress can reach 1.95. According to the results, the previous support design for roadways was optimized and applied in the field. Field monitoring revealed that the roadway deformation was effectively controlled, and the optimized support design was safe and reliable. This study is expected to serve as a reference for support designs or optimization under similar geological conditions.
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- 2021
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22. Targeted Disruption of Mouse Dip2B Leads to Abnormal Lung Development and Prenatal Lethality
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Rajiv Kumar Sah, Jun Ma, Fatoumata Binta Bah, Zhenkai Xing, Salah Adlat, Zin Ma Oo, Yajun Wang, Noor Bahadar, Ameer Ali Bohio, Farooq Hayel Nagi, Xuechao Feng, Luqing Zhang, and Yaowu Zheng
- Subjects
Dip2b ,LacZ expression ,growth restriction ,fetal lung development ,prenatal lethality ,RNA sequencing ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Molecular and anatomical functions of mammalian Dip2 family members (Dip2A, Dip2B and Dip2C) during organogenesis are largely unknown. Here, we explored the indispensable role of Dip2B in mouse lung development. Using a LacZ reporter, we explored Dip2B expression during embryogenesis. This study shows that Dip2B expression is widely distributed in various neuronal, myocardial, endothelial, and epithelial cell types during embryogenesis. Target disruption of Dip2b leads to intrauterine growth restriction, defective lung formation and perinatal mortality. Dip2B is crucial for late lung maturation rather than early-branching morphogenesis. The morphological analysis shows that Dip2b loss leads to disrupted air sac formation, interstitium septation and increased cellularity. In BrdU incorporation assay, it is shown that Dip2b loss results in increased cell proliferation at the saccular stage of lung development. RNA-seq analysis reveals that 1431 genes are affected in Dip2b deficient lungs at E18.5 gestation age. Gene ontology analysis indicates cell cycle-related genes are upregulated and immune system related genes are downregulated. KEGG analysis identifies oxidative phosphorylation as the most overrepresented pathways along with the G2/M phase transition pathway. Loss of Dip2b de-represses the expression of alveolar type I and type II molecular markers. Altogether, the study demonstrates an important role of Dip2B in lung maturation and survival.
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- 2020
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23. Melanocortin Receptor 4 (MC4R) Signaling System in Nile Tilapia
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Tianqiang Liu, Yue Deng, Zheng Zhang, Baolong Cao, Jing Li, Caiyun Sun, Zhixing Hu, Jiannan Zhang, Juan Li, and Yajun Wang
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Nile tilapia ,MC4R ,MRAP2 ,ACTH ,AgRP ,α-MSH ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The melanocortin receptor 4 (MC4R) signaling system consists of MC4R, MC4R ligands [melanocyte-stimulating hormone (MSH), adrenocorticotropin (ACTH), agouti-related protein (AgRP)], and melanocortin-2 receptor accessory protein 2 (MRAP2), and it has been proposed to play important roles in feeding and growth in vertebrates. However, the expression and functionality of this system have not been fully characterized in teleosts. Here, we cloned tilapia MC4R, MRAP2b, AgRPs (AgRP, AgRP2), and POMCs (POMCa1, POMCb) genes and characterized the interaction of tilapia MC4R with MRAP2b, AgRP, α-MSH, and ACTH in vitro. The results indicate the following. (1) Tilapia MC4R, MRAP2b, AgRPs, and POMCs share high amino acid identity with their mammalian counterparts. (2) Tilapia MRAP2b could interact with MC4R expressed in CHO cells, as demonstrated by Co-IP assay, and thus decrease MC4R constitutive activity and enhance its sensitivity to ACTH1-40. (3) As in mammals, AgRP can function as an inverse agonist and antagonist of MC4R, either in the presence or absence of MRAP2b. These data, together with the co-expression of MC4R, MRAP2b, AgRPs, and POMCs in tilapia hypothalamus, suggest that as in mammals, ACTH/α-MSH, AgRP, and MRAP2 can interact with MC4R to control energy balance and thus play conserved roles in the feeding and growth of teleosts.
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- 2020
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24. Root Proteomics Reveals the Effects of Wood Vinegar on Wheat Growth and Subsequent Tolerance to Drought Stress
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Yuying Wang, Ling Qiu, Qilu Song, Shuping Wang, Yajun Wang, and Yihong Ge
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wheat ,root ,wood vinegar ,drought stress ,ROS ,ABA ,proteome ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Wood vinegar (WV) or pyroligneous acid (PA) is a reddish-brown liquid created during the dry distillation of biomass, a process called pyrolysis. WV contains important biologically active components, which can enhance plant growth and tolerance to drought stress. However, its mechanism of action remains unknown. Our results after presoaking wheat seeds with various concentrations of WV indicate that a 1:900 WV concentration can significantly enhance growth. To investigate the response of wheat roots to drought stress, we compared quantitative proteomic profiles in the roots of wheat plants grown from seeds either presoaked (treatment) or non-presoaked (control) with WV. Our results indicated that the abscisic acid (ABA) content of wheat roots in the WV treatment was significantly increased. Reactive oxygen species (ROS) and malonaldehyde (MDA) levels roots were significantly lower than in the control treatment under drought stress, while the activity of major antioxidant enzymes was significantly increased. Two-dimensional electrophoresis (2D-PAGE) identified 138 differentially accumulated protein (DAP) spots representing 103 unique protein species responding to drought stress in wheat roots of the control and WV-treated groups. These DAPs are mostly involved in the stress response, carbohydrate metabolism, protein metabolism, and secondary metabolism. Proteome profiles showed the DAPs involved in carbohydrate metabolism, stress response, and secondary metabolism had increased accumulation in roots of the WV-treated groups. These findings suggest that the roots from wheat seeds presoaked with WV can initiate an early defense mechanism to mitigate drought stress. These results provide an explanation of how WV enhances the tolerance of wheat plants to drought stress.
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- 2019
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25. The Fabrication of Ga2O3/ZSM-5 Hollow Fibers for Efficient Catalytic Conversion of n-Butane into Light Olefins and Aromatics
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Jing Han, Guiyuan Jiang, Shanlei Han, Jia Liu, Yaoyuan Zhang, Yeming Liu, Ruipu Wang, Zhen Zhao, Chunming Xu, Yajun Wang, Aijun Duan, Jian Liu, and Yuechang Wei
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n-butane ,catalytic conversion ,bifunctional catalyst ,ZSM-5 hollow fiber ,Ga2O3 ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
In this study, the dehydrogenation component of Ga2O3 was introduced into ZSM-5 nanocrystals to prepare Ga2O3/ZSM-5 hollow fiber-based bifunctional catalysts. The physicochemical features of as-prepared catalysts were characterized by means of XRD, BET, SEM, STEM, NH3-TPD, etc., and their performances for the catalytic conversion of n-butane to produce light olefins and aromatics were investigated. The results indicated that a very small amount of gallium can cause a marked enhancement in the catalytic activity of ZSM-5 because of the synergistic effect of the dehydrogenation and aromatization properties of Ga2O3 and the cracking function of ZSM-5. Compared with Ga2O3/ZSM-5 nanoparticles, the unique hierarchical macro-meso-microporosity of the as-prepared hollow fibers can effectively enlarge the bifunctionality by enhancing the accessibility of active sites and the diffusion. Consequently, Ga2O3/ZSM-5 hollow fibers show excellent catalytic conversion of n-butane, with the highest yield of light olefins plus aromatics at 600 °C by 87.6%, which is 56.3%, 24.6%, and 13.3% higher than that of ZSM-5, ZSM-5 zeolite fibers, and Ga2O3/ZSM-5, respectively.
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- 2016
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26. Inositol‐Requiring Enzyme 1α–Mediated Synthesis of Monounsaturated Fatty Acids as a Driver of B Cell Differentiation and Lupus‐like Autoimmune Disease
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Kezhong Zhang, Beixue Gao, Huabin Li, Shuvam Chaudhuri, Sabrina N Dumas, Yajun Wang, Yana Zhang, James M. Ntambi, Ming Gui, Nikita Mani, Deyu Fang, Sarah Lewis, and Yashpal S. Kanwar
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XBP1 ,Immunology ,Protein Serine-Threonine Kinases ,Article ,Autoimmune Diseases ,Fatty Acids, Monounsaturated ,Pathogenesis ,Mice ,Rheumatology ,Endoribonucleases ,Plasma cell differentiation ,medicine ,Animals ,Humans ,Lupus Erythematosus, Systemic ,Immunology and Allergy ,B cell ,Mice, Knockout ,Autoimmune disease ,B-Lymphocytes ,Systemic lupus erythematosus ,Chemistry ,fungi ,Cell Differentiation ,Lipid metabolism ,Lipid Metabolism ,medicine.disease ,Molecular biology ,medicine.anatomical_structure ,Stearoyl-CoA desaturase-1 ,Stearoyl-CoA Desaturase - Abstract
OBJECTIVE To explore the molecular mechanisms underlying dysregulation of lipid metabolism in the pathogenesis of systemic lupus erythematosus (SLE). METHODS B cells in peripheral blood from patients with SLE and healthy controls were stained with BODIPY dye for detection of lipids. Mice with targeted knockout of genes for B cell-specific inositol-requiring enzyme 1α (IRE-1α) and stearoyl-coenzyme A desaturase 1 (SCD-1) were used for studying the influence of the IRE-1α/SCD-1/SCD-2 pathway on B cell differentiation and autoantibody production. The preclinical efficacy of IRE-1α suppression as a treatment for lupus was tested in MRL.Faslpr mice. RESULTS In cultures with mouse IRE-1α-null B cells, supplementation with monounsaturated fatty acids largely rescued differentiation of plasma cells from B cells, indicating that the compromised capacity of B cell differentiation in the absence of IRE-1α may be attributable to a defect in monounsaturated fatty acid synthesis. Moreover, activation with IRE-1α/X-box binding protein 1 (XBP-1) was required to facilitate B cell expression of SCD-1 and SCD-2, which are 2 critical enzymes that catalyze monounsaturated fatty acid synthesis. Mice with targeted Scd1 gene deletion displayed a phenotype that was similar to that of IRE-1α-deficient mice, with diminished B cell differentiation into plasma cells. Importantly, in B cells from patients with lupus, both IRE-1α expression and Xbp1 messenger RNA splicing were significantly increased, and this was positively correlated with the expression of both Scd1 and Scd2 as well as with the amount of B cell lipid deposition. In MRL.Faslpr mice, both genetic and pharmacologic suppression of IRE-1α protected against the pathologic development and progression of lupus-like autoimmune disease. CONCLUSION The results of this study reveal a molecular link in the dysregulation of lipid metabolism in the pathogenesis of lupus, demonstrating that the IRE-1α/XBP-1 pathway controls plasma cell differentiation through SCD-1/SCD-2-mediated monounsaturated fatty acid synthesis. These findings provide a rationale for targeting IRE-1α and monounsaturated fatty acid synthesis in the treatment of patients with SLE.
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- 2021
27. Enhancement of high-temperature oxidation resistance of CoCrNiAlY–yttria-stabilized zirconia–LaMgAl11O19 dual-ceramic coating by arc Al plating
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Xue gong, Zhiwen Xie, Zhiguo Wang, Suying Hu, Rui Ma, Tianxin Liu, and Yajun Wang
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Materials science ,Process Chemistry and Technology ,Oxide ,engineering.material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Barrier layer ,chemistry.chemical_compound ,chemistry ,Coating ,visual_art ,Plating ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,engineering ,Cubic zirconia ,Ceramic ,Composite material ,Layer (electronics) ,Yttria-stabilized zirconia - Abstract
A novel Al plating was developed to enhance the oxidation resistance of CoCrNiAlY–yttria-stabilized zirconia (YSZ)–LaMgAl11O19 dual-ceramic coating. The results indicated that the lanthanum magnesium hexaaluminate (LMA) layer without the Al plating sustained severe volume shrinkage, consequently initiating the formation and propagation of longitudinal micro-cracks. These micro-cracks behaved as channels that accelerated the inner diffusion of oxygen. The rapid growth of the thermally grown oxide (TGO) layer induced high interface stress, resulting in the severe fracturing of the interface between the CoCrNiAlY and YSZ layers. However, the Al plating not only effectively suppressed the volume shrinkage of the LMA layer and the initiation of large-size longitudinal micro-cracks but also induced the formation of an in-suit Al2O3 barrier layer. The strong synergistic effect of the dense ceramic layer and Al2O3 layer effectively inhibited the inner diffusion of oxygen, consequently reducing the interface stress and rapid TGO layer growth. Accordingly, a considerably effective anti-oxidation performance was achieved by the dual-ceramic coating with the Al plating.
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- 2021
28. Apigenin exerts chemopreventive effects on lung injury induced by SiO2 nanoparticles through the activation of Nrf2
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Zhe Jiang, Yuan Feng, Bingxin Li, Di Zhou, Gang Chen, Ning Li, Yajun Wang, Xuezheng Li, and Wenhui Chang
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A549 cell ,chemistry.chemical_classification ,medicine.diagnostic_test ,Flavonoid ,respiratory system ,Pharmacology ,Lung injury ,In vitro ,chemistry.chemical_compound ,chemistry ,Western blot ,Apoptosis ,In vivo ,Apigenin ,medicine ,Molecular Medicine - Abstract
Apigenin (APG) is a flavonoid widely distributed in fruits, vegetables, and herbs, with comprehensive pharmacological effects. In this paper, we report that APG can elicit a protective effect, which is comparable to those induced by gymnoside II/n-BuOH extracts of Bletilla striata, on SiO2-induced lung injury in vitro and in vivo. In vitro experiments showed that APG (25 μM) could restore the SiO2-decreased A549 cell viability and lower the apoptotic rate and the production of intracellular reactive oxygen species (ROS) in A549 cells treated with nm SiO2. Western blot results showed that APG (25 μM) could increase the level of Nuclear factor E2-related factor 2 (Nrf2) and its downstream proteins. In vivo experiments showed that APG (20 mg/kg) could potently alleviate the SiO2-elicited lung injury by enhancing the Nrf2 expression and thereby suppressing Bax/Bcl-2 pathway. The present study suggests that APG can significantly alleviate the SiO2-induced lung injury both in vitro and in vivo through, at least partially, activating Nrf2 expression.
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- 2021
29. Isolation, characterization, and evaluation of a high-siderophore-yielding bacterium from heavy metal–contaminated soil
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Fangbo Yu, Yaqian Li, Yajun Wang, Wei Huang, and Petri Penttinen
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inorganic chemicals ,Siderophore ,Growth medium ,Strain (chemistry) ,biology ,Burkholderia ,Chemistry ,Inoculation ,Health, Toxicology and Mutagenesis ,Siderophores ,General Medicine ,biology.organism_classification ,Pollution ,Soil contamination ,Lolium perenne ,Soil ,Phytoremediation ,chemistry.chemical_compound ,Biodegradation, Environmental ,Germination ,Metals, Heavy ,Soil Pollutants ,Environmental Chemistry ,Food science ,Soil Microbiology - Abstract
Heavy metal-resistant siderophore-producing bacteria (SPB) with plant growth-promoting traits can assist in phytoremediation of heavy metal-contaminated soil. We isolated siderophore-producing bacteria from Pb and Zn mine soil in Shangyu, Zhejiang, China. The isolate with the highest siderophore production, strain SX9, was identified as Burkholderia sp. Burkholderia sp. SX9 produced catecholate-type siderophore, with the highest production at a pH range of 6.0 to 8.0, a temperature range of 20 to 30 °C and NaCl concentration below 2%. Siderophore production was highest without Fe3+ and became gradually lower with increasing Fe3+ concentration. Minimal inhibitory concentrations (MIC) of Pb2+, Zn2+, Cu2+, and Cd2+ were 4000, 22000, 5000, and 2000 μmol L-1, respectively. The strain had a strong metal solubilization ability: the contents of Cu2+, Zn2+, and Cd2+ in the supernatant were 47.4%, 133.0%, and 35.4% higher, respectively, in strain SX9-inoculated cultures than in the not inoculated controls. The siderophore produced by strain SX9 could combine with Fe3+, Zn2+, and Cd2+ with good effectiveness. The plant growth-promoting traits of the strain included indole acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and phosphate solubilization capability. Compared to the uninoculated growth medium and SX9 culture supernatant, the germination rate of Lolium perenne seeds was higher when inoculated with strain SX9 culture. In the experiment of seed germination, adding bacterial culture or supernatant could alleviate the toxicity of heavy metals to L. perenne seed germination. Under Cu2+ and Zn2+ stress, strain SX9 promoted the germination rate. Taken together, Burkholderia sp. SX9 had properties beneficial in the microbial enhancement of phytoremediation of soil contaminated with heavy metals.
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- 2021
30. Impact of urban density on carbon emissions in China
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Yaqin Li, Yajun Wang, Ji Qi, and Yanchun Yi
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Economics and Econometrics ,chemistry ,Environmental protection ,Greenhouse gas ,Population size ,Economics ,chemistry.chemical_element ,Urban density ,China ,Carbon ,Panel data - Abstract
Based on the panel data of 108 prefecture-level cities in China from 2003 to 2018, the carbon emission effect of urban density was studied by establishing a dynamic panel model. We found that there...
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- 2021
31. Bi N V bond: A hole-transfer bridge for high-efficient separation and transfer of carriers
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Wenjun Jiang, Zhe Liu, Lizhen Gao, Yuhong Wang, Lijie Shi, Zailun Liu, Yajun Wang, and Wei Yao
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Materials science ,Annealing (metallurgy) ,Kinetics ,Oxygen evolution ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Chemical engineering ,X-ray photoelectron spectroscopy ,Electric field ,Water splitting ,0210 nano-technology ,Carbon nitride - Abstract
Addressing the inherent holes transport limitation of BiVO4 photoanode is crucial to achieve efficient photoelectrochemical (PEC) water splitting. The construction of the hole-transfer bridge between co-catalysts and BiVO4 photoanode could be an effective way to overcome sluggish hole-transfer kinetics of BiVO4 photoanode. Herein, CxNy/BiVO4 photoanode was prepared by coupling carbon nitride hydrogel (CNH) containing unsaturated N on the BiVO4 photoanode during annealing. CxNy/BiVO4 photoanode exhibited excellent PEC performance and stability. Photoelectrochemical tests proved that the coupling of CxNy accelerated holes transfer and enhanced oxygen evolution kinetics. X-ray photoelectron spectroscopy (XPS) and theoretical calculations confirmed the existence of the Bi N V bond between BiVO4 photoanode and CxNy, which could serve as the hole-transfer bridge to significantly accelerate separation and transfer of carriers driven by the interfacial electric field. Moreover, it was found that the coupling of CxNy effectively inhibited the dissociation of metal ions through changing their coordination environment, resulting in the excellent stability of CxNy/BiVO4 photoanode. This result provides unique insights into vital roles of the interfacial structure, which might have a significant impact on the construction of PEC devices.
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- 2021
32. A Comparative Evaluation of Capillary Electrophoresis, Cation-Exchange High-Performance Liquid Chromatography, and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for the Screening of Hemoglobin Variants
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Miao Xu, Anping Xu, and Yajun Wang
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Detection limit ,Chromatography ,Chemistry ,Electrophoresis, Capillary ,Genetic Variation ,Hemoglobin variants ,General Medicine ,Mass spectrometry ,High-performance liquid chromatography ,Hemoglobins ,Capillary electrophoresis ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Humans ,Hemoglobin ,Time-of-flight mass spectrometry ,Tera ,Chromatography, High Pressure Liquid - Abstract
Objectives The present study was conducted to evaluate the usefulness of capillary electrophoresis (CE), cation-exchange high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) for the screening of hemoglobin (Hb) variants prevalent in southern China. Methods A total of 102 types of Hb variants in 1,083 variant carriers were identified over a 5-year period. These variants were analyzed by a CE method (Capillarys 3 TERA), a cation-exchange HPLC analyzer (Variant II Turbo 2.0), and a MALDI-TOF MS system (QuanTOF). Results The presence of 85 (83.3%, 85/102), 84 (82.4%, 84/102), and 62 (60.8%, 62/102) Hb variants was detected by Capillarys 3 TERA, Variant II Turbo 2.0, and QuanTOF, respectively. Of the three methods, only Capillarys 3 TERA recognized all 10 of the most frequent Hb variants in southern China. There were six, two, and three Hb variants that can only be detected by Capillarys 3 TERA, Variant II Turbo 2.0, and QuanTOF, respectively. The detection limit of mass difference for QuanTOF was approximately 11 to 20 Da. Conclusions MALDI-TOF MS is suitable for use as an auxiliary method rather than a stand-alone method for the screening of Hb variants prevalent in southern China.
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- 2021
33. NiFe‐layered Double Hydroxide/Vertical Bi2WO6Nanoplate Arrays with Oriented {001} Facets Supported on ITO Glass: Improved Photoelectrocatalytic Activity and Mechanism Insight
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Liming Liu, Guiyuan Jiang, Wencan Zhang, Yajun Wang, Wenqing Yao, and Jiaying Zhang
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Inorganic Chemistry ,Bisphenol A ,chemistry.chemical_compound ,Materials science ,chemistry ,Chemical engineering ,Organic Chemistry ,Hydroxide ,Physical and Theoretical Chemistry ,Catalysis ,Mechanism (sociology) - Published
- 2021
34. A biologically stable DNAzyme that efficiently silences gene expression in cells
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Kim Nguyen, Yajun Wang, Robert C. Spitale, and John C. Chaput
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chemistry.chemical_classification ,Messenger RNA ,010405 organic chemistry ,General Chemical Engineering ,Deoxyribozyme ,General Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Enzyme ,chemistry ,Biochemistry ,Product inhibition ,Gene expression ,Nucleic acid ,Gene silencing ,DNA - Abstract
Efforts to use RNA-cleaving DNA enzymes (DNAzymes) as gene-silencing agents in therapeutic applications have stalled due to their low efficacy in clinical trials. Here we report a xeno-nucleic-acid-modified version of the classic DNAzyme 10-23 that achieves multiple-turnover activity under cellular conditions and resists nuclease digestion. The new reagent, X10-23, overcomes the problem of product inhibition, which limited previous 10-23 designs, using molecular chemotypes with DNA, 2'-fluoroarabino nucleic acid and α-L-threofuranosyl nucleic acid backbone architectures that balance the effects of enhanced biological stability with RNA hybridization and divalent metal ion coordination. In cultured mammalian cells, X10-23 facilitates persistent gene silencing by efficiently degrading exogenous and endogenous messenger RNA transcripts. Together, these results demonstrate that new molecular chemotypes can improve the activity and stability of DNAzymes, and may provide a new route for nucleic acid enzymes to reach the clinic.
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- 2021
35. Allele-Specific RNA Knockdown with a Biologically Stable and Catalytically Efficient XNAzyme
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Yajun Wang, Kim Truc Nguyen, John C. Chaput, Robert C. Spitale, and Whitney England
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chemistry.chemical_classification ,Mutation ,Messenger RNA ,Gene knockdown ,RNA ,DNA, Catalytic ,General Chemistry ,medicine.disease_cause ,Biochemistry ,Small molecule ,Catalysis ,Cell biology ,Colloid and Surface Chemistry ,chemistry ,medicine ,Nucleotide ,KRAS ,Alleles ,Allele specific - Abstract
Therapeutic targeting of allele-specific single nucleotide mutations in RNA is a major challenge in biology and medicine. Herein, we describe the utility of the XNAzyme X10-23 to knock down allele-specific mRNA sequences in cells. We demonstrate the value of this approach by targeting the "undruggable" mutation G12V in oncogenic KRAS. Our results demonstrate how catalytic XNAs could be employed to suppress the expression of mRNAs carrying disease-causing mutations that are difficult to target at the protein level with small molecule therapeutics.
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- 2021
36. Polylysine-modified MXene nanosheets with highly loaded glucose oxidase as cascade nanoreactor for glucose decomposition and electrochemical sensing
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Qian Zhang, Minying Wu, Fangzhou Zhou, Yajun Wang, Yi Zhang, Xingdong Wang, Chao Deng, Yi Tang, and Fang Yuanyuan
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Immobilized enzyme ,Biosensing Techniques ,02 engineering and technology ,Nanoreactor ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Catalysis ,Biomaterials ,Glucose Oxidase ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Nanotechnology ,Polylysine ,Glucose oxidase ,Hydrogen peroxide ,biology ,Chemistry ,Substrate (chemistry) ,Hydrogen Peroxide ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Glucose ,Chemical engineering ,biology.protein ,0210 nano-technology ,Biosensor - Abstract
Two-dimensional (2D) nanoreactors with cascade catalytic activity for glucose oxidation and hydrogen peroxide decomposition are prepared via immobilizing glucose oxidase (GOx) on Ti3C2 MXene nanosheets. Amino-rich polypeptide, poly- l -lysine (PLL), is applied to modify the ultra-thin Ti3C2 MXene nanosheets with a compatible surface for GOx immobilization. The PLL-modified Ti3C2 nanosheets possess a positively charged surface and show an excellent GOx loading capacity as high as 50 wt% of the Ti3C2 nanosheets. The physically adsorbed enzymes are then cross-linked with the amine groups in the PLL chains to form a robust GOx-PLL network covered on the MXene nanosheets. The GOx-conjugated Ti3C2-PLL (Ti3C2-PLL-GOx) nanosheets showed superior enzymatic activities than the activities of GOx immobilized on an inert porous silica substrate, largely because that the Ti3C2 nanosheets can catalyze the decomposition of the toxic intermediate H2O2 generated from the glucose oxidation. Given the excellent electrical conductivity of Ti3C2 MXene, the Ti3C2-PLL-GOx nanosheets are further deposited on glassy carbon electrode to construct a high-performance biosensor with a glucose detection limit of 2.6 μM.
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- 2021
37. The effect of bifunctionality synergy of Pt/HZSM-5 based catalyst on reaction mechanism of n -butane catalytic cracking
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Guiling Jiang, Zhen Zhao, Yajun Wang, Guiyuan Jiang, Chunming Xu, Yaoyuan Zhang, Yuming Li, Manglai Gao, Huaqian Sun, and Shanlei Han
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chemistry.chemical_compound ,Reaction mechanism ,chemistry ,Chemical engineering ,General Chemical Engineering ,Materials Chemistry ,Butane ,General Chemistry ,Fluid catalytic cracking ,Biochemistry ,Catalysis - Published
- 2021
38. Effects of amino acids on olfactory‐related receptors regulating appetite in silver pomfret
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Qijun Le, Zhang Man, Youyi Zhang, Xiaojun Yan, Gu Weiwei, Yibo Sun, Yajun Wang, Shanliang Xu, Yang Yang, Hu Jiabao, Kimran Jean Jacques, Kuang Siwen, Jiachu Sun, and Yaya Li
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chemistry.chemical_classification ,Pomfret ,Olfactory receptor ,biology ,media_common.quotation_subject ,Appetite ,Aquatic Science ,biology.organism_classification ,Amino acid ,medicine.anatomical_structure ,Biochemistry ,chemistry ,medicine ,Pampus argenteus ,Receptor ,media_common - Published
- 2021
39. Ginsenoside-Rg3 inhibits the proliferation and invasion of hepatoma carcinoma cells via regulating long non-coding RNA HOX antisense intergenic
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Qijun Dai, Hua Liu, Fei Ge, Shukui Qin, Yajun Wang, Ziyu Jiang, Shilin Zhu, Zhongjian Pu, and Haiqing Hua
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0301 basic medicine ,ginsenoside-rg3 ,Carcinoma, Hepatocellular ,Ginsenosides ,Cell Survival ,Cell ,Bioengineering ,Applied Microbiology and Biotechnology ,hepatoma carcinoma ,Phosphatidylinositol 3-Kinases ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Cell Line, Tumor ,medicine ,Humans ,Neoplasm Invasiveness ,MTT assay ,Phosphorylation ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Cell growth ,Akt/PKB signaling pathway ,Chemistry ,Liver Neoplasms ,Cell migration ,HOTAIR ,General Medicine ,Transfection ,Gene Expression Regulation, Neoplastic ,pi3k/akt ,HEK293 Cells ,030104 developmental biology ,medicine.anatomical_structure ,Matrix Metalloproteinase 9 ,030220 oncology & carcinogenesis ,Cancer research ,Matrix Metalloproteinase 2 ,RNA, Long Noncoding ,lncrna hotair ,Proto-Oncogene Proteins c-akt ,TP248.13-248.65 ,Research Article ,Research Paper ,Biotechnology - Abstract
Ginsenoside Rg3, a natural compound, has been reported to function as an anticancer agent for hepatoma carcinoma, while the mechanisms underlying the anticancer effects are not clear. Therefore, the objective of our study was to explore the impact of RG3 on cell migration and invasion by regulating the lncRNA HOX antisense intergenic (HOTAIR) expression involving PI3K/AKT signaling pathway. qRT-PCR was utilized to measure the mRNA expression of HOTAIR. Furthermore, HOTAIR overexpression plasmids were transfected to SMMC-7721 and SK-Hep-1 cells. Additionally, MTT assay was used to evaluate the proliferation of transfected cells. The scratch and transwell assays were used to determine the migration and invasion ability of the cell. The protein levels were determined with Western blot. lncRNA HOTAIR was overexpressed in SMMC-7721 and SK-Hep-1 cells. Ginsenoside-Rg3 reduced the level of lncRNA HOTAIR. Overexpressed lncRNA HOTAIR offset ginsenoside-Rg3 inhibited proliferation, migration and invasion of HCC cells. Furthermore, ginsenoside-Rg3 decreased the expression of p-AKT, p-PI3K, matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9), which was reversed after the treatment of HOTAIR. LncRNA HOTAIR was overexpressed in SMMC-7721 cells. Ginsenoside-Rg3 could reduce the expression of lncRNA HOTAIR, resulting in the inhibited cell proliferation, migration and invasion. Furthermore, ginsenoside-Rg3 inhibited cell proliferation and invasion ability through the PI3k/AKT pathway. Thus, ginsenoside-Rg3 might be a potential and effective treatment for HCC., Graphical Abstract
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- 2021
40. MoC nanodots toward efficient electrocatalytic hydrogen evolution: an interlayer-confined strategy with a 2D-zeolite precursor
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Wenbiao Zhang, Xue Yang, Luyao Zheng, Yi Tang, Yanghuan Huang, Qingsheng Gao, Yajun Wang, Boxu Gao, Sinong Wang, Yahong Zhang, Haiyang Lu, and Xueliang Fan
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Carbonization ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Carbide ,Catalysis ,chemistry ,Chemical engineering ,Etching ,General Materials Science ,Nanodot ,0210 nano-technology ,Zeolite ,Carbon - Abstract
An efficient electrocatalyst of molybdenum carbide nanodots on carbon nanosheets (nano-MoC/C-Ns) is prepared via a novel interlayer-confined strategy with the aid of MCM-22(P), a kind of multilayered two-dimensional (2D) zeolite precursor. In this strategy, the confined space of the surfactant-swollen MCM-22(P) plays a critical role in creating a unique sandwich-like structure with Mo-based organic–inorganic nanohybrids which further in situ evolve into ultrafine ∼2 nm MoC nanodots on carbon nanosheets in the following carbonization process. After etching the zeolite layers, the nano-MoC/C-Ns is successfully obtained as an efficient noble-metal-free electrocatalyst for hydrogen evolution. The intimate contact between ultrafine MoC nanodots and C nanosheets, as well as their synergetic effects, endows this catalyst with large exposed active sites and accelerated electron transport. The optimal sample achieves excellent hydrogen evolution reaction performance in acidic, neutral and alkaline media with low η10 values of 126, 185 and 92 mV (vs. the values of 28, 36 and 37 mV for a Pt/C reference in acidic, neutral and alkaline media), respectively. This synthetic strategy provides some hints for designing high-performance carbides for energy conversion and storage.
- Published
- 2021
41. Rapid conversion of CO2 and propylene oxide into propylene carbonate over acetic acid/KI under relatively mild conditions
- Author
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Yajun Wang, Zheng Wang, and Yehua Shen
- Subjects
Steric effects ,Hydrogen bond ,Epoxide ,General Chemistry ,Production efficiency ,Medicinal chemistry ,Catalysis ,chemistry.chemical_compound ,Acetic acid ,chemistry ,Propylene carbonate ,Materials Chemistry ,Propylene oxide - Abstract
The coupling of CO2 and epoxides to form cyclic carbonates has been industrialized since the 1960s. The employment of an efficient and low-cost catalyst is one of the decisive factors to improve the production efficiency. Many catalysts with high activities have been developed; however, those that can convert CO2 and epoxides into cyclic carbonates in a short time or with high efficiency are still less reported. In this study, we developed such an efficient and low-cost catalytic system of hydrogen bond donor acetic acid (AA) in combination with KI (denoted as AA/KI) for the rapid conversion of CO2 and propylene oxide (PO). The optimal reaction condition for AA/KI catalyzing the coupling of CO2 and PO is screened by trial and error. Atime-dependent PO conversion study showed that the AA/KI catalytic system displays quite high activity to completely convert PO within a short time of 15 min under optimized conditions (0.9 MPa CO2 and 90 °C) for the best case. Moreover, AA/KI is also active for the coupling of other epoxides with CO2, and the reaction efficiency is significantly influenced by the electronic and steric effects of the epoxide substrates. In addition, the plausible mechanism was deduced. Herein, we provide an efficient and relatively mild route to catalyze the coupling of CO2 and epoxide within a short time using a non-toxic, cheap and facile catalyst.
- Published
- 2021
42. Synergistic construction of bifunctional and stable Pt/HZSM-5-based catalysts for efficient catalytic cracking of n-butane
- Author
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Junling Lu, Yajun Wang, Yingjie Ma, Hongjian Yu, Zhen Zhao, Manglai Gao, Yang Gao, Guiyuan Jiang, Chunming Xu, Qing Huan, Yuming Li, Yaoyuan Zhang, Guoqing Cui, Huaqian Sun, Shanlei Han, and Weiyu Song
- Subjects
Olefin fiber ,Materials science ,Oxide ,chemistry.chemical_element ,Butane ,Fluid catalytic cracking ,Catalysis ,Metal ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Bifunctional ,Platinum - Abstract
Efficient conversion of light alkanes is of essential significance for enhancing the utilization efficiency of resources and exploring the activation and evolution regulation of C-C and C-H bonds in stable molecules. The processes are often executed with catalysts under harsh conditions. The olefin yield and metal stability have been the long-standing concerns. Herein, we report a facile strategy of constructing a bifunctional Pt/HZSM-5-based catalyst by two-step atomic layer deposition (ALD) to achieve a high light olefin formation rate of 0.48 mmol gcat-1·min-1 in the catalytic cracking of n-butane at 600 °C, which is ∼2.2 times higher than that of the conventional Pt/HZSM-5 catalyst (0.22 mmol gcat-1·min-1). Moreover, the bifunctional Pt/HZSM-5-based catalyst exhibited outstanding recyclability and excellent metal stability against sintering in comparison with conventional Pt/HZSM-5. Detailed microscopic and spectroscopic characterization studies demonstrate that the metal oxide (TiO2 or Al2O3) coating not only prevents the metal from high-temperature sintering, but also regulates the proportion of coordinately unsaturated platinum surface atoms. Theoretical calculations further confirm the preference of nucleation of TiO2 or Al2O3 on coordinately unsaturated platinum sites, which in turn modulates the bifunctional dehydrogenation-cracking pathway to improve the olefin formation rate.
- Published
- 2021
43. Aliphatic carboxylic acid as a hydrogen-bond donor for converting CO2 and epoxide into cyclic carbonate under mild conditions
- Author
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Zhiying Fan, Qianjie Xie, Zheng Wang, Yehua Shen, and Yajun Wang
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,Carboxylic acid ,Epoxide ,General Chemistry ,Catalysis ,Coupling reaction ,Acetic acid ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Materials Chemistry ,Organic chemistry ,Propylene oxide - Abstract
The coupling of CO2 and epoxides is a promising way to reduce atmospheric carbon by converting it into value-added cyclic carbonate. Pursuing efficient catalysts is highly attractive for the title reaction. Herein, we developed simple and inexpensive catalyst systems of aliphatic carboxylic acids as the hydrogen-bond donor (HBD) and quaternary ammonium halides as the nucleophile to catalyze the CO2-epoxide coupling reaction with high efficiency and selectivity under mild conditions (80 °C and 4 bar CO2). The high activity of this catalyst system is retained even under ambient conditions. The effects of the acidity and steric hindrance of acids on the catalysis of CO2-epoxide coupling were systematically investigated. Lastly, the reaction mechanism was deduced and its rationality was further reinforced by exploring the interaction between a representative system AA/TBAB (acetic acid/tetrabutylammonium bromide) and propylene oxide (PO). The study of aliphatic carboxylic acids/quaternary ammonium halides provides a new way to design catalyst systems for the title reaction.
- Published
- 2021
44. Neural correlates of the association between depression and high density lipoprotein cholesterol change
- Author
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Yu Zhang, Cun Zhang, Jiajia Zhu, Yajun Wang, Wenming Zhao, Dao-min Zhu, Ying Yang, Biao Zhang, and Yongqiang Yu
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medicine.medical_specialty ,Brain Structure and Function ,Blood lipids ,Corpus callosum ,White matter ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,High-density lipoprotein ,Neuroimaging ,Internal medicine ,mental disorders ,Humans ,Medicine ,Gray Matter ,Biological Psychiatry ,Default mode network ,Depressive Disorder, Major ,Depression ,business.industry ,Cholesterol, HDL ,Brain ,medicine.disease ,Magnetic Resonance Imaging ,030227 psychiatry ,Psychiatry and Mental health ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Major depressive disorder ,lipids (amino acids, peptides, and proteins) ,business ,030217 neurology & neurosurgery - Abstract
There is evidence that major depressive disorder (MDD) is related to serum lipid level alterations. However, the neural correlates underlying this association remain poorly understood. Forty-nine patients with MDD and fifty healthy controls (HCs) underwent structural, resting-state functional and diffusion magnetic resonance imaging scans. Voxel-based morphometry, functional connectivity (FC) and tract-based spatial statistics analyses were performed to assess brain structure and function, respectively. Blood samples were collected to measure serum levels of lipid variables including total cholesterol, triglyceride and high density lipoprotein cholesterol (HDL-C). Correlation and mediation analyses were conducted to investigate the associations of serum lipid levels with brain imaging measures in MDD patients and HCs, respectively. We found that the serum HDL-C level in MDD patients was lower than that in HCs. The lower serum HDL-C level was associated with lower gray matter volume (GMV) in ventromedial prefrontal cortex (VMPFC), higher within-network FC of the default mode network, and lower micro-structural integrity in multiple white matter regions in MDD patients. Moreover, the within-default mode network FC mediated the relationship between GMV in VMPFC and serum HDL-C level; white matter integrity in genu of corpus callosum mediated the relationship between serum HDL-C level and depressive symptom severity. However, we did not observe any correlations between serum lipids and brain imaging parameters in HCs. These findings help to identify neural correlates underlying the association between depression and serum HDL-C change, which may provide new insight into intervention, treatment and prevention of depression from the perspective of regulating serum lipids.
- Published
- 2020
45. Novel aluminium/polyvinylidene fluoride metastable intermolecular composite film prepared by solution casting method
- Author
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Shihui Li, Pengfei He, Yi Wan, and Yajun Wang
- Subjects
Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,Biomedical Engineering ,Energy-dispersive X-ray spectroscopy ,Analytical chemistry ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Polyvinylidene fluoride ,Casting ,0104 chemical sciences ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Aluminium ,General Materials Science ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
One challenge in the application of traditional metastable intermolecular composite (MIC) material is that MIC particles are not compatible with micro-electro-mechanical system. In the authors’ work, a solution casting method was employed to prepare aluminium/polyvinylidene fluoride (Al/PVDF) MIC films. The morphological, structural and compositional information of the samples were characterised by scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy and Fourier transform infrared spectroscopy. The energy-release characteristics of Al/PVDF films were studied by thermogravimetric analysis and differential scanning calorimetry. The results show that heat output and mass loss increased as the thickness of MIC films reduced. The maximum heat release of the main exothermic peak was 1032 J/g. The kinetics process could be divided into three stages with apparent activation energy calculated by Kissinger and Starink methods of 128.86, 164.69 and 153.16 kJ/mol, respectively.
- Published
- 2020
46. Directional Structure Modification of Poplar Biomass-Inspired High Efficacy of Enzymatic Hydrolysis by Sequential Dilute Acid–Alkali Treatment
- Author
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Kang Kang, Fuxi Shi, Yiqing Yao, Maryam Davaritouchaee, and Yajun Wang
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Structure modification ,Aqueous solution ,General Chemical Engineering ,food and beverages ,Biomass ,Dilute acid ,General Chemistry ,Alkali metal ,complex mixtures ,Chemistry ,Ammonia ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Biofuel ,Enzymatic hydrolysis ,QD1-999 - Abstract
A major challenge in converting lignocellulose to biofuel is overcoming the resistance of the biomass structure. Herein, sequential dilute acid-alkali/aqueous ammonia treatment was evaluated to enhance enzymatic hydrolysis of poplar biomass by removing hemicellulose first and then removing lignin with acid and base, respectively. The results show that glucose release in sequential dilute acid-alkali treatments (61.4-71.4 mg/g) was 7.3-24.8% higher than sequential dilute acid-aqueous ammonia treatments (57.2-61.8 mg/g) and 283.8-346.3% higher than control (16.0 mg/g), respectively. Dilute acid treatment removed most hemicellulose (84.9%) of the biomass, followed by alkaline treatment with 27.5% removal of lignin. Roughness, surface area, and micropore volume of the biomass were crucial for the enzymatic hydrolysis. Furthermore, the ultrastructure changes observed using crystallinity, Fourier transform infrared spectroscopy, thermogravimetric analysis, and pyrolysis gas chromatography/mass spectrometry support the effects of sequential dilute acid-alkali treatment. The results provide an efficient approach to facilitate a better enzymatic hydrolysis of the poplar samples.
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- 2020
47. The design and synthesis of dextran-doxorubicin prodrug-based pH-sensitive drug delivery system for improving chemotherapy efficacy
- Author
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Jiucun Chen, Xiaohua Huang, Tian Zhang, Die Jia, Xiaoli Zhang, Feiqiu Wen, Yi Lu, Xianbin Ma, Yajun Wang, and Zhigang Xu
- Subjects
Pharmaceutical Science ,02 engineering and technology ,Tumor acidic microenvironment ,010402 general chemistry ,01 natural sciences ,Micelle ,chemistry.chemical_compound ,In vivo ,medicine ,Chemotherapy ,Controlled release ,Doxorubicin ,Prodrug ,Dextran ,Pharmacology ,lcsh:RM1-950 ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Original Research Paper ,lcsh:Therapeutics. Pharmacology ,chemistry ,Drug delivery ,Biophysics ,Nanocarriers ,0210 nano-technology ,medicine.drug - Abstract
Tumor cells show acidic conditions compared with normal cells, which further inspires scientist to build nanocarrier responsive to tumor microenvironment (TME) for enhancing tumor therapeutic efficacy. Here, we report a pH-sensitive and biocompatible polyprodrug based on dextran-doxorubicin (DOX) prodrug (DOXDT) for enhanced chemotherapy. High-density DOX component was covalently decorated on the nanocarrier and the drug molecules could be effectively released in the acidic tumor tissue/cells, improving chemotherapy efficacy. Specifically, a dextran-based copolymer was preliminarily prepared by one-step atom transfer radical polymerization (ATRP); then DOX was conjugated on the copolymer component via pH-responsive hydrazone bond. The structure of DOXDT can be well-controlled. The resulting DOXDT was able to further self-assemble into nanoscale micelles with a hydration diameter of about 32.4 nm, which presented excellent micellar stability. Compared to lipid-based drug delivery system, the DOXDT prodrug showed higher drug load capacity up to 23.6%. In addition, excellent stability and smaller size of the nanocarrier contributed to better tissue permeability and tumor suppressive effects in vivo. Hence, this amphipathic DOXDT prodrug is promising in the development of translational DOX formulations, which would be widely applied in cancer therapy., Graphical abstract Biocompatible polyprodrug based on dextran-doxorubicin (DOXDT) with high drug loading and pH-triggered release for enhanced chemotherapy. Image, graphical abstract
- Published
- 2020
48. Cathodic electrophoretic deposition and thermal properties of nano aluminum/fluoropolymer metastable intermolecular composite
- Author
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Yi Wan, Yajun Wang, Pengfei He, and Shihui Li
- Subjects
Materials science ,Polytetrafluoroethylene ,010304 chemical physics ,Physics and Astronomy (miscellaneous) ,Intermolecular force ,Composite number ,chemistry.chemical_element ,01 natural sciences ,Polyvinylidene fluoride ,010406 physical chemistry ,0104 chemical sciences ,Electrophoretic deposition ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Aluminium ,embryonic structures ,0103 physical sciences ,Nano ,Fluoropolymer - Abstract
One challenge in the application of traditional metastable intermolecular composite (MIC) material is that MIC particles are not compatible with micro-electro-mechanical system (MEMS) based pyrotec...
- Published
- 2020
49. Structural characterization of Lanzhou lily ( Lilium davidii var. unicolor ) polysaccharides and determination of their associated antioxidant activity
- Author
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Yajun Wang, Yang Qiu, Yubao Zhang, Guo Zhihong, Zhongkui Xie, Wenmei Li, Lingrong Wen, and Hailian Wei
- Subjects
China ,Antioxidant ,030309 nutrition & dietetics ,medicine.medical_treatment ,Mannose ,Polysaccharide ,Plant Roots ,Antioxidants ,Cell Line ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Polysaccharides ,Lilium davidii ,medicine ,Humans ,Monosaccharide ,Cellular Reprogramming Techniques ,Food science ,Glucans ,Cell Proliferation ,chemistry.chemical_classification ,0303 health sciences ,Nutrition and Dietetics ,biology ,Lilium ,Plant Extracts ,04 agricultural and veterinary sciences ,biology.organism_classification ,Trypsin ,040401 food science ,Enzyme ,chemistry ,Agronomy and Crop Science ,Food Science ,Biotechnology ,medicine.drug - Abstract
Backgroud The Lanzhou lily (Lilium davidii var. unicolor) is the only Lilium species that is used for both culinary and medicinal purposes in China. Its bulbs contain various bioactive substances, such as polysaccharides, saponins and colchicine. Lanzhou lily polysaccharides are known to have anti-immunity, anti-tumor and anti-oxidation functions. Results The present study used a Box-Behnken design to optimize the ultrasound-assisted extraction of Lanzhou lily polysaccharides. Compared to other enzymes, trypsin significantly increased the polysaccharide yields, whereas the protein content of polysaccharides extracted with trypsin was the lowest. Monosaccharide mainly includes glucose (> 50%) and mannose (> 10%). 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity, chelating activity, total antioxidant capacity and hydroxyl radical scavenging activity of Lanzhou lily polysaccharides extracted with trypsin were stronger than those extracted without enzymes (control). Structural characteristics of Lanzhou lily polysaccharides extracted with trypsin and extracted without enzymes were characterized by scanning electron microscopy and nuclear magnetic resonance spectroscopy. When water extracted polysaccharide and trypsin extracted polysaccharide concentrations were 200 μg mL-1 , Raw264.7 proliferation rates were 101.69% and 159.41%, respectively. Conclusion The Lanzhou lily polysaccharide was identified as α-(1 → 6)-d-glucan. Consequently, the effects of both potential antioxidant and proliferative activity of trypsin are significant. © 2020 Society of Chemical Industry.
- Published
- 2020
50. Hemoglobin variants in southern China: results obtained during the measurement of glycated hemoglobin in a large population
- Author
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Anping Xu, Weidong Chen, Weijie Xie, Yajun Wang, and Ling Ji
- Subjects
Male ,China ,Glycosylation ,Hemoglobins, Abnormal ,Thalassemia ,Clinical Biochemistry ,Population ,030204 cardiovascular system & hematology ,Biology ,Compound heterozygosity ,Polymerase Chain Reaction ,03 medical and health sciences ,chemistry.chemical_compound ,symbols.namesake ,0302 clinical medicine ,medicine ,Humans ,education ,Chromatography, High Pressure Liquid ,Glycated Hemoglobin ,Sanger sequencing ,education.field_of_study ,Hematologic Tests ,Biochemistry (medical) ,Electrophoresis, Capillary ,Hemoglobin variants ,General Medicine ,Middle Aged ,medicine.disease ,Molecular biology ,Biological Variation, Population ,Southern china ,chemistry ,030220 oncology & carcinogenesis ,Mutation ,symbols ,Female ,Hemoglobin ,Glycated hemoglobin - Abstract
Objectives Hemoglobin (Hb) variant is one of the most common monogenic inherited disorders. We aimed to explore the prevalence and hematological and molecular characteristics of Hb variants in southern China. Methods We collected blood samples from all patients with suspected variants found during HbA1c measurement via a cation-exchange high-performance liquid chromatography system (Bio-Rad Variant II Turbo 2.0) or a capillary electrophoresis method (Sebia Capillarys). Hematological analysis, Sanger sequencing, and gap-PCR were performed for these samples. Results Among the 311,024 patients tested, we found 1,074 Hb variant carriers, including 823 identified using Capillarys and 251 using Variant II Turbo 2.0, with a total carrier rate of 0.35%. We discovered 117 types of Hb variants (52 HBB, 47 HBA, and 18 HBD mutations) containing 18 new mutations. The most common variant found was Hb E, followed by Hb New York, Hb J-Bangkok, Hb Q-Thailand, Hb G-Coushatta, Hb G-Honolulu, Hb G-Taipei, and Hb Broomhill. Most heterozygotes for the Hb variant exhibited normal hematological parameters. However, most patients with compound heterozygotes for the Hb variant and thalassemia showed varied degrees of microcytic hypochromic anemia. Conclusions The prevalence of hemoglobin variants remains high and exhibits genetic diversity and widespread distribution in the population of southern China.
- Published
- 2020
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