266 results on '"Liu, Chen-An"'
Search Results
2. Resource Utilization of Waste Cooking Oil Catalyzed by Na2CO3/ZSM‑5
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Liu Chen, Lixiang He, Qiannan Liu, Aibin Wu, Wenming Shu, and Weichu Yu
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Chemistry ,QD1-999 - Published
- 2023
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3. Aerodynamic Enhancement of Vertical-Axis Wind Turbines Using Plain and Serrated Gurney Flaps
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Liu Chen, Pei Yang, Bingxia Zhang, and Lingjie Chen
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serrated gurney flap ,vertical-axis wind turbine ,aerodynamic performance ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In light of the escalating demand for renewable energy sources, vertical-axis wind turbines have emerged as a pivotal technical solution for addressing the challenge of clean energy supply in residential and urban areas. As a simple and feasible passive control method, the plain Gurney flap (PGF) is widely applied to improve turbine aerodynamic performance. In this paper, the influence of a novel serrated gurney flap (SGF) with different flap heights is studied on the NACA0021 airfoil by numerical simulations. The findings demonstrate that, compared with the PGF, the SGF reduces the trailing edge reverse vortices from a pair to a single vortex and possesses lower drag. When the flap height reaches 6% of the chord (6%c), the lift-to-drag ratio of SGF surpasses that of PGF. A turbine rotor is equipped with an SGF and a PGF to compare their performances. The result confirms the flap effect depending on the rotor’s tip speed. At a low tip speed ratio (TSR), the PGF works better than the SGF. The SGF is preferred over the PGF for a higher tip speed ratio (TSR > 2.5). With the 6%c flap height, the performance of the SGF rotor surpasses the PGF by 13.9% at TSR = 2.62.
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- 2023
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4. Asprosin in the Paraventricular Nucleus Induces Sympathetic Activation and Pressor Responses via cAMP-Dependent ROS Production
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Xiao-Li Wang, Jing-Xiao Wang, Jun-Liu Chen, Wen-Yuan Hao, Wen-Zhou Xu, Zhi-Qin Xu, Yu-Tong Jiang, Pei-Qi Luo, Qi Chen, Yue-Hua Li, Guo-Qing Zhu, and Xiu-Zhen Li
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asprosin ,paraventricular nucleus ,reactive oxygen species ,sympathetic activity ,blood pressure ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Asprosin is a newly discovered adipokine that is involved in regulating metabolism. Sympathetic overactivity contributes to the pathogenesis of several cardiovascular diseases. The paraventricular nucleus (PVN) of the hypothalamus plays a crucial role in the regulation of sympathetic outflow and blood pressure. This study was designed to determine the roles and underlying mechanisms of asprosin in the PVN in regulating sympathetic outflow and blood pressure. Experiments were carried out in male adult SD rats under anesthesia. Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP), and heart rate (HR) were recorded, and PVN microinjections were performed bilaterally. Asprosin mRNA and protein expressions were high in the PVN. The high asprosin expression in the PVN was involved in both the parvocellular and magnocellular regions according to immunohistochemical analysis. Microinjection of asprosin into the PVN produced dose-related increases in RSNA, MAP, and HR, which were abolished by superoxide scavenger tempol, antioxidant N-acetylcysteine (NAC), and NADPH oxidase inhibitor apocynin. The asprosin promoted superoxide production and increased NADPH oxidase activity in the PVN. Furthermore, it increased the cAMP level, adenylyl cyclase (AC) activity, and protein kinase A (PKA) activity in the PVN. The roles of asprosin in increasing RSNA, MAP, and HR were prevented by pretreatment with AC inhibitor SQ22536 or PKA inhibitor H89 in the PVN. Microinjection of cAMP analog db-cAMP into the PVN played similar roles with asprosin in increasing the RSNA, MAP, and HR, but failed to further augment the effects of asprosin. Pretreatment with PVN microinjection of SQ22536 or H89 abolished the roles of asprosin in increasing superoxide production and NADPH oxidase activity in the PVN. These results indicated that asprosin in the PVN increased the sympathetic outflow, blood pressure, and heart rate via cAMP–PKA signaling-mediated NADPH oxidase activation and the subsequent superoxide production.
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- 2022
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5. Accurate Inner Profile Measurement of a High Aspect Ratio Aspheric Workpiece Using a Two-Probe Measuring System
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Peng Hu, Xin Xiong, Wen-Hao Zhang, Bing-Feng Ju, and Yuan-Liu Chen
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high aspect ratio aspheric workpiece ,inner profile measurement ,error separation ,error compensation ,profile stitching ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This paper presents a novel method for inner profile measurement and geometric parameter evaluation, such as the radius of the bottom, steepness and straightness of the steep sidewall of a high aspect ratio aspheric workpiece, by utilizing a two-probe measuring system, which includes a lateral displacement gauge for the inner steep sidewall profile measurement and an axial displacement gauge for the inner deep underside profile measurement. To qualify the measurement accuracy, the systematic errors associated with the measurement procedure, including the miscalibration, misalignment and the roundness error of the gauge probes, as well as the slide motion error of the four-axis motion platform, are all evaluated and separated from the measurement results. A point cloud registration algorithm is employed to stitch the evaluated inner sidewall profile and the inner underside profile to form an entire inner profile of the workpiece. To verify the performance of the newly proposed method, the inner profile of a high aspect ratio aspheric workpiece, which has a tapered cone shape with a maximum inner radius of 40 mm, a maximum inner depth of 140 mm and a steep sidewall angle approaching 85°, is measured in experiments. The measurement result is compared with that of a coordinate measuring machine (CMM), and the comparison verifies the feasibility of the proposed measurement system.
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- 2022
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6. Measurement of Sub-Surface Microstructures Based on a Developed Ultrasonic Atomic Force Microscopy
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Yuyang Wang, Chengjian Wu, Jinyan Tang, Mingyu Duan, Jian Chen, Bing-Feng Ju, and Yuan-Liu Chen
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measurement ,sub-surface microstructure ,ultrasonic AFM ,contact-resonance AFM ,buried depth ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Accurate and non-destructive technology for detection of subsurface defect has become a key requirement with the emergence of various ultra-precision machining technologies and the application of ultra-precision components. The combination of acoustic technique for sub-surface detection and atomic force microscopy (AFM) for measurement with high resolution is a potential method for studying the subsurface structure of workpiece. For this purpose, contact-resonance AFM (CR-AFM) is a typical technique. In this paper, a CR-AFM system with a different principle from commercially available instruments is set up and used for the detection of sub-surface Si samples with grating structures and covered by different thickness of highly oriented pyrolytic graphite (HOPG). The influence of subsurface burial depth on the detection capability is studied by simulations and experiments. The thickest HOPG film allowing for sub-surface measurement by the proposed method is verified to be about 30 μm, which is much larger than the feature size of the subsurface microstructure. The manuscript introduces the difference between this subsurface topography measurement principle and the commercially available AFM measurement principle, and analyzes its advantages and disadvantages. The experimental results demonstrates that the technique has the capability to reveal sub-surface microstructures with relatively large buried depth and is potential for engineering application in ultra-precision technologies.
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- 2022
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7. Recent Advanced Metabolic and Genetic Engineering of Phenylpropanoid Biosynthetic Pathways
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Muhammad Anwar, Liu Chen, Yibo Xiao, Jinsong Wu, Lihui Zeng, Hui Li, Qingyu Wu, and Zhangli Hu
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tanshinones ,phenolic acid ,plant defense ,pdLNLD/ELxiG/S motif ,flavonoids ,repressor MYB ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The MYB transcription factors (TFs) are evolving as critical role in the regulation of the phenylpropanoid and tanshinones biosynthetic pathway. MYB TFs relate to a very important gene family, which are involved in the regulation of primary and secondary metabolisms, terpenoids, bioactive compounds, plant defense against various stresses and cell morphology. R2R3 MYB TFs contained a conserved N-terminal domain, but the domain at C-terminal sorts them different regarding their structures and functions. MYB TFs suppressors generally possess particular repressive motifs, such as pdLNLD/ELxiG/S and TLLLFR, which contribute to their suppression role through a diversity of complex regulatory mechanisms. A novel flower specific “NF/YWSV/MEDF/LW” conserved motif has a great potential to understand the mechanisms of flower development. In the current review, we summarize recent advanced progress of MYB TFs on transcription regulation, posttranscriptional, microRNA, conserved motif and propose directions to future prospective research. We further suggest there should be more focus on the investigation for the role of MYB TFs in microalgae, which has great potential for heterologous protein expression system for future perspectives.
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- 2021
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8. Cellulose mediated conjugated polymer nanoparticles with enhanced fluorescence efficiency for bioimaging
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Yuan Qiong, Tang Yan-Li, and Liu Chen-Rui
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chemistry.chemical_classification ,technology, industry, and agriculture ,Stacking ,Nanoparticle ,Nanotechnology ,Polymer ,Conjugated system ,Fluorescence ,Analytical Chemistry ,Carboxymethyl cellulose ,Hydrophobic effect ,chemistry.chemical_compound ,chemistry ,medicine ,Cellulose ,medicine.drug - Abstract
Conjugated polymers (CPs) attract a lot of attention in sensing, imaging, and biomedical applications by taking advantage of their extraordinary characteristics. However, most of them inevitably aggregate at higher concentrations, leading to attenuated fluorescence efficiency. Herein, we report a fluorescence enhancement strategy for conjugated polymers by using cellulose as a mediator. The composite nanoparticles CMC@PFE-1-NPs are prepared based on carboxymethyl cellulose (CMC) and poly(fluorene-co-phenylene ethynylene) derivative (PFE-1) via self-assembly through electrostatic and hydrophobic interactions. This spatial confinement effectively restricts π-π stacking effects and other nonradiative channels, leading to high luminescent efficiency of isolated PFE-1. A 5-folds enhancement in fluorescence quantum yield for CMC@PFE-1-NPs is obtained compared with conjugated polymers themselves. Furthermore, the nanoparticles realized more sensitive cell imaging. Therefore, this simple and effective method provides a new way for reducing the aggregation between rigid fluorescent molecules and improving their photophysical properties and biological application.
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- 2022
9. Soil fertility, enzyme activity, and microbial community structure diversity among different soil textures under different land use types in coastal saline soil
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Li Hua, Liu Chen, Fu Qinglin, Lin Yicheng, Yun Zhu, Li Ningyu, and Bin Guo
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Total organic carbon ,Soil salinity ,Chemistry ,Soil texture ,Stratigraphy ,04 agricultural and veterinary sciences ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Microbial population biology ,Agronomy ,Soil pH ,Loam ,Soil water ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Soil fertility ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This investigation assessed the responses of soil fertility, enzyme activity, and microbial community diversity to soil texture and land use type. The tested soils included five soil textures (sandy loam, medium loam, heavy loam, light clay, and medium clay soils) with two land use types (uncultivated and paddy soils) in the coastal zone of Zhejiang Province, China. Soil texture had a significant effect on soil pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), available nitrogen (AN), phosphorus (AP) and potassium (AK), catalase and protease activities, total phospholipid fatty acids (PLFAs), bacterial and actinomycetes PLFAs, and microbial diversity (MD). The clay content was significantly positively correlated to soil EC, OC, TN, AN, AP, AK, catalase activity, total PLFAs, bacterial and actinomycetes PLFAs, and MD but significantly negatively associated with soil pH and protease activity. Land use type also had significantly influenced soil pH, EC, OC, TN, AN, AP, AK, catalase, protease and urease activities, total PLFAs, bacterial, actinomycetes, and fungal PLFAs, and MD. The paddy soil had higher OC, TN, AN, AP, catalase, protease and urease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD but lower soil pH, EC, and AK than the uncultivated soil. The interaction with soil texture and land use type had significantly affected soil pH, EC, OC, TN, AN, AP, AK, catalase and protease activities, total PLFAs, bacterial and actinomycetes PLFAs, and MD. Soil texture and land use type could be considered important factors in improving soil fertility, enzyme activity, and microbial diversity in coastal saline soils.
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- 2021
10. Lithium mineralization in Qomolangma: First report of elbaite-lepidolite subtype pegmatite in the Himalaya leucogranite belt
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Liu XiaoChi, Xie Lei, WU FuYuan, Wang RuCheng, and Liu Chen
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Leucogranite ,Mineralization (geology) ,chemistry ,Geochemistry and Petrology ,engineering ,Elbaite ,Geochemistry ,chemistry.chemical_element ,Lithium ,Lepidolite ,engineering.material ,Geology ,Pegmatite - Published
- 2021
11. Ti3C2 supported transition metal oxides and silver as catalysts toward efficient electricity generation in microbial fuel cells
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Siyu Li, Jinlin Xie, Xiaobo Gong, Xinghong Wang, Yong Liu, and Liu Chen
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Microbial fuel cell ,Chemistry ,Maximum power density ,Kinetics ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Dissociation (chemistry) ,0104 chemical sciences ,Electricity generation ,Transition metal ,Chemical engineering ,0210 nano-technology - Abstract
The oxygen reduction reaction (ORR) has been regarded as a bottleneck in air-cathode microbial fuel cells (MFC). Herein, transition metal oxides and silver were used in combination with a conductive and hydrophilic MXene (Ti3C2) for ORR. The transition metal oxides could facilitate oxygen adsorption and OO bond dissociation to improve the ORR catalytic performance of catalysts, and silver was capable of increasing the ORR kinetics and decreasing the activation overpotential significantly. Ti3C2–MxOy–Ag exhibited high ORR activity with a direct four-electron and indirect four-electron pathway in a neutral medium. In MFCs, the maximum power density was achieved by Ti3C2–MnO2–Ag (418.09 mW m−2), which was 41% higher than that of Ag–Ti3C2 (295.78 mW m−2) and 10.8 times that of Ti3C2 (38.89 mW m−2). This could be attributed to the synergistic effect between transition metal oxides and silver to promote ORR.
- Published
- 2021
12. Simple Analogues of Quaternary Benzo[c]phenanthridine Alkaloids: Discovery of a Novel Antifungal 2-Phenylphthalazin-2-ium Scaffold with Excellent Potency against Phytopathogenic Fungi
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Bo-Hang Zhou, Chao Fu, Xin-Juan Yang, Zhiming Cui, Juan Fu, Liu Chen, Fang-Jun Cao, and Le Zhou
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biology ,Phenanthridine ,Hypha ,Stereochemistry ,fungi ,General Chemistry ,biology.organism_classification ,Fungicide ,chemistry.chemical_compound ,Chelerythrine ,chemistry ,Azoxystrobin ,Sanguinarine ,General Agricultural and Biological Sciences ,Fusarium solani ,EC50 - Abstract
Inspired by sanguinarine and chelerythrine, a novel antifungal 2-phenylphthalazin-2-ium scaffold as a simple analogue was designed. Most of the 30 compounds showed excellent inhibition activity against almost all eight phytopathogenic fungi, far superior to sanguinarine and chelerythrine. A third of the compounds were more active than azoxystrobin in most cases. Compounds 26 and 27 showed the highest total activity against all the fungi with EC50 means of ca. 4.6 μg/mL. Fusarium solani showed the highest susceptibility with an EC50 mean of 3.62 μg/mL to 19 compounds. A concentration of 25.0 μg/mL 27 can fully control the Colletotrichum gloeosporioides infection in apples over 9 days. Electron microscopic observations showed that 27 was able to damage the structures of the hypha and cell membrane. The structure-activity relationship showed that the presence of electron-withdrawing groups on the C-ring increases the activity against most of the fungi. Thus, 2-phenylphthalazin-2-ium compounds represent promising leads for the development of novel fungicides.
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- 2020
13. Efficient Preparation of Blast Furnace Burdens from Titanomagnetite Concentrate by Composite Agglomeration Process
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Guanghui Li, Qiang Zhong, Tao Jiang, Mingjun Rao, Zhiwei Peng, Huibo Liu, Liangping Xu, and Liu Chen
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Blast furnace ,Yield (engineering) ,Materials science ,Economies of agglomeration ,Metallurgy ,Composite number ,0211 other engineering and technologies ,General Engineering ,Sintering ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,chemistry ,Agglomerate ,Aluminium ,General Materials Science ,0210 nano-technology ,021102 mining & metallurgy ,Perovskite (structure) - Abstract
Titanomagnetite concentrate is difficult to agglomerate by the traditional sintering process (TSP). In this study, the agglomeration properties of titanomagnetite concentrate were studied using the composite agglomeration process (CAP). It was shown that, by adding 40 wt.% pelletized feed, an excellent sinter with yield of 74.33%, a tumbler index of 58.93%, and productivity of 1.65 t (m2 h)−1 were achieved, which were increased by 11.72%, 12.03%, and 37.16% compared with TSP, respectively. Meanwhile, for CAP, the solid fuel consumption was only 43.87 kgcoke/tproduct and the reduction disintegration index of RDI+3.15 was 73.53%. They were decreased by 6.34 kgcoke/tproduct and increased by 24.31%, respectively. The better product quality was mainly attributed to a larger proportion of calcium ferrite and silicoferrite of calcium and aluminum group minerals formed in CAP, which restrained the negative effect of perovskite on agglomeration in association with the matrix feed with ultra-high basicity. The results showed that CAP is an efficient method for agglomeration of titanomagnetite concentrate.
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- 2020
14. Progress in the Synthesis, Angiogenesis Activity and Mechanism of Chalcone Derivatives
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Chen Jie, Rao Guo-Wu, and Liu Chen-Fu
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Chalcone ,chemistry.chemical_compound ,Angiogenesis ,Chemistry ,Mechanism (biology) ,Organic Chemistry ,Combinatorial chemistry - Abstract
Cancer is a common disease that poses a serious threat to human health. Angiogenesis is essential for the growth and metabolism of tumors, providing oxygen and nutrition for the growth of cells and tissues. However, angiogenesis of tumors depends on the stimulation of growth factors. Vascular Endothelial Growth Factor (VEGFR) is the most unique factor. Therefore, VEGF/VEGFR targeting anticancer drugs are playing an increasingly significant role in clinical trials. In addition, it has been proved that chalcone, the precursor of natural flavonoids, has potential anti-tumor activity, especially anti-angiogenesis activity. This review summarizes the reports about the anti-angiogenesis of chalcone derivatives. Based on the chalcone skeleton, it is divided into substituted chalcones and modified chalcones. The anti-angiogenesis activities of natural or synthetic chalcones, benzene ring modified or connecting bridge modified chalcones are described in this review.
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- 2020
15. Comparison of Pharmacological Properties between the Kappa Opioid Receptor Agonist Nalfurafine and 42B, Its 3-Dehydroxy Analogue: Disconnect between in Vitro Agonist Bias and in Vivo Pharmacological Effects
- Author
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Mengchu Li, Huiqun Wang, Peng Huang, Frederick J. Ehlert, Yan Zhang, Yi-Ting Chiu, Yi Zheng, Chongguang Chen, Danni Cao, and Lee-Yuan Liu-Chen
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Agonist ,0303 health sciences ,Physiology ,medicine.drug_class ,Chemistry ,Cognitive Neuroscience ,Cell Biology ,General Medicine ,Pharmacology ,Biochemistry ,κ-opioid receptor ,Effective dose (pharmacology) ,03 medical and health sciences ,0302 clinical medicine ,Opioid receptor ,In vivo ,medicine ,Potency ,Receptor ,030217 neurology & neurosurgery ,Nalfurafine ,030304 developmental biology ,medicine.drug - Abstract
Nalfurafine, a moderately selective kappa opioid receptor (KOR) agonist, is used in Japan for treatment of itch without causing dysphoria or psychotomimesis. Here we characterized the pharmacology of compound 42B, a 3-dehydroxy analogue of nalfurafine and compared with that of nalfurafine. Nalfurafine and 42B acted as full KOR agonists and partial μ opioid receptor (MOR) agonists, but 42B showed much lower potency for both receptors and lower KOR/MOR selectivity, different from previous reports. Molecular modeling revealed that water-mediated hydrogen-bond formation between 3-OH of nalfurafine and KOR accounted for its higher KOR potency than 42B. The higher potency of both at KOR over MOR may be due to hydrogen-bond formation between nonconserved Y7.35 of KOR and their carbonyl groups. Both showed modest G protein signaling biases. In mice, like nalfurafine, 42B produced antinociceptive and antiscratch effects and did not cause conditioned place aversion (CPA) in the effective dose ranges. Unlike nalfurafine, 42B caused motor incoordination and hypolocomotion. As both agonists showed G protein biases, yet produced different effects on locomotor activity and motor incoordination, the findings and those in the literature suggest caution in correlating in vitro biochemical data with in vivo behavior effects. The factors contributing to the disconnect, including pharmacodynamic and pharmacokinetic issues, are discussed. In addition, our results suggest that among the KOR-induced adverse behaviors, CPA can be separated from motor incoordination and hypolocomotion.
- Published
- 2020
16. Effect of various doses of 3,4-dimethylpyrazole phosphate on mineral nitrogen losses in two paddy soils
- Author
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Li Hua, Chen Xiaodong, Liu Chen, Li Ningyu, Bin Guo, Xinqiang Liang, Fu Qinglin, Yuequn Jin, and Shaoxian Wang
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inorganic chemicals ,Stratigraphy ,Soil classification ,04 agricultural and veterinary sciences ,010501 environmental sciences ,engineering.material ,Soil type ,01 natural sciences ,chemistry.chemical_compound ,Animal science ,Nitrate ,chemistry ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Nitrification ,Ammonium ,Fertilizer ,Leachate ,Leaching (agriculture) ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) has been widely proposed to reduce nitrogen (N) loss and improve N availability in paddy soil. However, little knowledge exists regarding the optimum dose of DMPP required for inhibiting nitrification in different soil types. In undisturbed soil columns under greenhouse conditions, dynamics of ammonium (NH4+–N) and nitrate (NO3−–N) in floodwater and leachate, and ammonia (NH3) volatilization were studied in two paddy soils (hydragic and gleyed), amended with urea-N at 180 N kg/ha with DMPP applied at 0, 0.45, 0.675, and 0.90 kg/ha (0.25%, 0.375%, and 0.5% of urea-N, respectively). The source of DMPP was Entec® 46 (46% urea-N and DMPP at 0.5% of urea-N) that was mixed with pure urea (fertilizer mixture). DMPP application rates and soil types significantly influenced NH4+–N and NO3−–N concentrations in floodwater and leachate; however, DMPP application rates did not significantly impact NH4+–N concentrations in floodwater. Results indicate that concentrations of both NH4+– N and NO3−–N in leachate and floodwater were peaked between 10 and 20 days after fertilizer application. Increased DMPP application rates increased floodwater and leachate NH4+–N concentrations, while significantly decreasing NO3−–N concentrations in floodwater and leachate, with largest decrease seen in the 0.90-kg/ha DMPP treatment. NH3 emissions were observed after fertilizer was applied and decreased gradually, with no significant differences in response to the DMPP amount. The total N losses via leaching and NH3 emission were significantly decreased at treatments of 0.675 kg/ha and 0.90 kg/ha DMPP, and positively correlated with sand fraction in soil. Compared with the gleyed paddy soil, higher total N loss was observed in the hydragic paddy soil, which was related to the higher sand fraction of the hydragic paddy soil and the better behavior of DMPP in this soil type. Considering economic factors, mineral N concentrations in floodwater and leachate, together with N losses via leaching and volatilization, application of 0.675 kg/ha DMPP could significantly inhibit nitrification in the hydragic paddy soil while application of 0.90 kg/ha DMPP was shown to be the best choice to inhibit nitrification in the gleyed paddy soil.
- Published
- 2020
17. A new Cu(II)-based coordination polymer: protective activity against ulcerative colitis via regulating the level of pro-inflammatory and anti-inflammatory cytokines
- Author
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Ying Li, Liu Chen, Jie Sun, and Wen-Xiao Chen
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Chemistry ,Stereochemistry ,medicine.drug_class ,Coordination polymer ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,medicine.disease ,01 natural sciences ,Copper ,Ulcerative colitis ,Anti-inflammatory ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,medicine ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
A new one-dimensional (1-D) copper(II) coordination polymer, namely, {[Cu(L)(2,2’-bipy)]·0.5DMF}n (1) (H2L= 2,2’-[benzene-1,4-diylbis(methanediylsulfanediyl)]dibenzoic acid, 2,2’-bipy= 2,2’-bipyrid...
- Published
- 2020
18. First-principles modeling of the hydrogen evolution reaction and its application in electrochemical corrosion of Mg
- Author
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Xing-Qiu Chen, Changgang Wang, Dianzhong Li, Junhua Dong, Wei Ke, Hui Ma, Mingfeng Liu, Liping Wu, and Liu Chen
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010302 applied physics ,Tafel equation ,Materials science ,Polymers and Plastics ,Hydrogen ,Metals and Alloys ,Ab initio ,Analytical chemistry ,Exchange current density ,chemistry.chemical_element ,02 engineering and technology ,Hydrogen atom ,Overpotential ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Corrosion ,chemistry ,0103 physical sciences ,Ceramics and Composites ,0210 nano-technology ,Polarization (electrochemistry) - Abstract
By means of first-principles calculations, we have proposed an ab initio modeling to establish a formula between the hydrogen evolution rate and its overpotential of hydrogen evolution reaction (HER), relating with three different rate determining mechanisms, when Volmer reaction, Tafel reaction and Heyrowsky reaction are the rate determining steps of the entire reaction, respectively. Within this modeling, the free energy ( Δ G H * ) of the adsorbed hydrogen atom and the concentration of hydrogen ions in the solution have been correlated to the exchange current density. The hydrogen evolution modeling has been validated by available experimental results. Furthermore, by combining the previously proposed first-principles modeling of the anodic dissolution and this modeling of the HER in the electrochemical corrosion, the polarization curves of the 18 crystallographic surfaces of pure Mg have been theoretically derived. It has been found that in a neutral solution ( p H = 7 ) the corrosion current densities (icorr) of the 18 crystallographic surfaces range from 10 − 3.477 to 10 − 0.455 A/cm2 and their corresponding corrosion potentials (Ecorr) range from −1.36 to −0.892 VSHE, respectively. The base (0001) surface exhibits a lower corrosion rate of 10 − 3.345 A/cm2, whereas the crystal (21 3 ¯ 0) surface has a fast corrosion rate of 10 − 0.455 A/cm2. The calculations even reveal that except for Ag, all the other alloying elements considered here accelerate the rates of the cathodic HER. In agreement with theoretical results, the experimentally measured polarization curves of the Mg-1Zn and Mg-2Sn alloys verify that both Zn and Sn additions accelerate the rate of the HER of Mg.
- Published
- 2020
19. NASP maintains histone H3–H4 homeostasis through two distinct H3 binding modes
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Hongyu Bao, Min Luo, Hongda Huang, Valentin Flury, Yanhong Liu, Liu Chen, Anja Groth, and Massimo Carraro
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chemistry.chemical_classification ,biology ,Peptide ,Cell biology ,Histones ,Histone H3 ,Histone ,chemistry ,NASP ,Chaperone (protein) ,biology.protein ,Histone Chaperones ,Genetics ,Homeostasis ,Molecular Chaperones ,Protein Binding ,Histone binding - Abstract
Histone chaperones regulate all aspects of histone metabolism. NASP is a major histone chaperone for H3–H4 dimers critical for preventing histone degradation. Here, we identify two distinct histone binding modes of NASP and reveal how they cooperate to ensure histone H3–H4 supply. We determine the structures of a sNASP dimer, a complex of a sNASP dimer with two H3 α3 peptides, and the sNASP–H3–H4–ASF1b co-chaperone complex. This captures distinct functionalities of NASP and identifies two distinct binding modes involving the H3 α3 helix and the H3 αN region, respectively. Functional studies demonstrate the H3 αN-interaction represents the major binding mode of NASP in cells and shielding of the H3 αN region by NASP is essential in maintaining the H3–H4 histone soluble pool. In conclusion, our studies uncover the molecular basis of NASP as a major H3–H4 chaperone in guarding histone homeostasis.
- Published
- 2022
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20. Development of gallium-arsenide-based GCPW calibration kits for on-wafer measurements in the W-band
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Xiaobang Shang, Fu Xingchang, Liu Chen, Wang Yibang, Peng Luan, Wei Zhao, Faguo Liang, and Aihua Wu
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Materials science ,business.industry ,Coplanar waveguide ,Gallium arsenide ,chemistry.chemical_compound ,W band ,chemistry ,Calibration ,Device under test ,Optoelectronics ,Wafer ,Electrical and Electronic Engineering ,business ,Electrical impedance ,Electronic circuit - Abstract
We present details of on-wafer-level 16-term error model calibration kits used for the characterization of W-band circuits based on a grounded coplanar waveguide (GCPW). These circuits were fabricated on a thin gallium arsenide (GaAs) substrate, and via holes, were utilized to ensure single mode propagation (i.e., eliminating the parallel-plate mode or surface mode). To ensure the accuracy of the definition for the calibration kits, multi-line thru-reflect-line (MTRL) assistant standards were also fabricated on the same wafer and measured. The same wafer also contained passive and active devices, which were measured subject to both 16-term and conventional line-reflect-reflect-match calibrations. Measurement results show that 16-term calibration kits are capable of determining the cross-talk more accurately. Other typical calibration techniques were also implemented using the standards on the GCPW calibration kits, and were compared with the MTRL calibration using a passive device under test. This revealed that the proposed GCPW GaAs calibration substrate could be a feasible alternative to conventional CPW impedance standard substrates, for on-wafer measurements at W-band and above.
- Published
- 2019
21. Opioid receptors in GtoPdb v.2021.3
- Author
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Eric J. Simon, Nurulain T. Zaveri, Dominique Massot, Brian M. Cox, Lawrence Toll, Lakshmi A. Devi, Toni S. Shippenberg, Eamonn Kelly, John R. Traynor, Philip S. Portoghese, Mary Jeanne Kreek, Brigitte L. Kieffer, Hiroshi Ueda, Andreas Zimmer, Volker Höllt, Graeme Henderson, Charles Chavkin, Stephen M. Husbands, MacDonald J. Christie, Michael R. Bruchas, Mark Connor, Ian Kitchen, Girolamo Calò, Anna Borsodi, Stefan Schulz, Olivier Civelli, Jean-Claude Meunier, Lee-Yuan Liu-Chen, Yung Hou Wong, and Christopher J. Evans
- Subjects
chemistry.chemical_compound ,Nociceptin receptor ,chemistry ,Enkephalin ,Opioid ,Dynorphin B ,medicine ,Dynorphin A ,(+)-Naloxone ,Pharmacology ,Receptor ,Big dynorphin ,medicine.drug - Abstract
Opioid and opioid-like receptors are activated by a variety of endogenous peptides including [Met]enkephalin (met), [Leu]enkephalin (leu), β-endorphin (β-end), α-neodynorphin, dynorphin A (dynA), dynorphin B (dynB), big dynorphin (Big dyn), nociceptin/orphanin FQ (N/OFQ); endomorphin-1 and endomorphin-2 are also potential endogenous peptides. The Greek letter nomenclature for the opioid receptors, μ, δ and κ, is well established, and NC-IUPHAR considers this nomenclature appropriate, along with the symbols spelled out (mu, delta, and kappa), and the acronyms, MOP, DOP, and KOP. [121, 100, 91]. The human N/OFQ receptor, NOP, is considered 'opioid-related' rather than opioid because, while it exhibits a high degree of structural homology with the conventional opioid receptors [294], it displays a distinct pharmacology. Currently there are numerous clinically used drugs, such as morphine and many other opioid analgesics, as well as antagonists such as naloxone, however only for the μ receptor.
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- 2021
22. Recent Advanced Metabolic and Genetic Engineering of Phenylpropanoid Biosynthetic Pathways
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Zhangli Hu, Liu Chen, Muhammad Anwar, Yibo Xiao, Qingyu Wu, Jinsong Wu, Lihui Zeng, and Hui Li
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QH301-705.5 ,genetic processes ,Computational biology ,Review ,Biology ,Cell morphology ,Catalysis ,tanshinones ,Inorganic Chemistry ,plant defense ,pdLNLD/ELxiG/S motif ,Gene Expression Regulation, Plant ,microRNA ,Plant defense against herbivory ,Transcriptional regulation ,Gene family ,MYB ,natural sciences ,Physical and Theoretical Chemistry ,Biology (General) ,Molecular Biology ,Transcription factor ,QD1-999 ,Spectroscopy ,Plant Proteins ,bioactive compounds ,Phenylpropanoid ,phenolic acid ,repressor MYB ,Phenylpropionates ,Organic Chemistry ,fungi ,General Medicine ,Plants, Genetically Modified ,Computer Science Applications ,Biosynthetic Pathways ,Chemistry ,Metabolic Engineering ,flavonoids - Abstract
The MYB transcription factors (TFs) are evolving as critical role in the regulation of the phenylpropanoid and tanshinones biosynthetic pathway. MYB TFs relate to a very important gene family, which are involved in the regulation of primary and secondary metabolisms, terpenoids, bioactive compounds, plant defense against various stresses and cell morphology. R2R3 MYB TFs contained a conserved N-terminal domain, but the domain at C-terminal sorts them different regarding their structures and functions. MYB TFs suppressors generally possess particular repressive motifs, such as pdLNLD/ELxiG/S and TLLLFR, which contribute to their suppression role through a diversity of complex regulatory mechanisms. A novel flower specific “NF/YWSV/MEDF/LW” conserved motif has a great potential to understand the mechanisms of flower development. In the current review, we summarize recent advanced progress of MYB TFs on transcription regulation, posttranscriptional, microRNA, conserved motif and propose directions to future prospective research. We further suggest there should be more focus on the investigation for the role of MYB TFs in microalgae, which has great potential for heterologous protein expression system for future perspectives.
- Published
- 2021
23. Molecular basis of abasic site sensing in single-stranded DNA by the SRAP domain of E. coli yedK
- Author
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Hongda Huang, Yanhong Liu, Hongyu Bao, Liu Chen, Yue Li, Baixing Wu, and Na Wang
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Protein Conformation ,Thiazolidine ,DNA, Single-Stranded ,Biology ,DNA-binding protein ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,Residue (chemistry) ,0302 clinical medicine ,Structural Biology ,Escherichia coli ,Genetics ,Nucleotide ,AP site ,SOS Response, Genetics ,Uracil-DNA Glycosidase ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Binding Sites ,DNA-Binding Proteins ,chemistry ,Biophysics ,Thiazolidines ,030217 neurology & neurosurgery ,DNA - Abstract
HMCES and yedK were recently identified as sensors of abasic sites in ssDNA. In this study, we present multiple crystal structures captured in the apo-, nonspecific-substrate-binding, specific-substrate-binding, and product-binding states of yedK. In combination with biochemical data, we unveil the molecular basis of AP site sensing in ssDNA by yedK. Our results indicate that yedK has a strong preference for AP site-containing ssDNA over native ssDNA and that the conserved Glu105 residue is important for identifying AP sites in ssDNA. Moreover, our results reveal that a thiazolidine linkage is formed between yedK and AP sites in ssDNA, with the residues that stabilize the thiazolidine linkage important for the formation of DNA-protein crosslinks between yedK and the AP sites. We propose that our findings offer a unique platform to develop yedK and other SRAP domain-containing proteins as tools for detecting abasic sites in vitro and in vivo.
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- 2019
24. Porous Zirconium Hydroxyphosphonoacetate: Catalyst for Conversion of Furfural into Furfuryl Alcohol
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Haijun Wang, Liu Chen, Xu Guangzhi, Aiyun Hu, and Yongdi Xie
- Subjects
chemistry.chemical_compound ,Zirconium ,chemistry ,Organic chemistry ,chemistry.chemical_element ,General Chemistry ,Activation energy ,Porosity ,Furfural ,Transfer hydrogenation ,Furfuryl alcohol ,Catalysis - Published
- 2019
25. Effect of the particle size of magnesium hydroxide on the cellulose polymerization during the oxygen delignification of radiata pine kraft pulp
- Author
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Liu Chen, Yuantao Hu, Shilin Cao, Fang Huang, Changming Fu, Yonghao Ni, Dengwen Ning, and Hai Huang
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Polymers and Plastics ,Magnesium ,Pulp (paper) ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Kappa number ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Kraft process ,Chemical engineering ,Specific surface area ,engineering ,Particle size ,Cellulose ,0210 nano-technology - Abstract
Magnesium salt is a known cellulose protector during the oxygen delignification process and it has been widely used in commercial practice, in particular, for feedstocks with a low magnesium presence. Minimizing the negative impact of transition metals by magnesium is one of the main mechanisms. A key parameter affecting the magnesium salt performance for this purpose is its particle size. In this study, different particle sizes of magnesium hydroxide were used as additives to the oxygen delignification system, and various transition metal ions (Cu2+, Mn2+ and Fe3+) were added to the radiata pine Kraft pulp. The results show that the magnesium hydroxide particle sizes had negligible effects on the pulp yield, Kappa number and brightness; however, when large size magnesium hydroxide was used, handsheet physical properties suffered a great loss, which was accompanied with much lowered viscosity and degree of polymerization in the resultant pulp. The explanation is that small sized magnesium hydroxide particles have large specific surface area and can adsorb more transition metal ions than the magnesium hydroxide with larger particle size, consequently, the transition metal contents of resultant pulp in the former are significantly lowered, which then decreases the negative impact of transition metals on the cellulose degradation in the process. It is thus concluded that smaller particle size of magnesium hydroxide is favorable as a cellulose protector during the oxygen delignification process.
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- 2019
26. Biased signaling agonist of dopamine D3 receptor induces receptor internalization independent of β-arrestin recruitment
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Wei Xu, Lee-Yuan Liu-Chen, Sandhya Kortagere, and Maarten E. A. Reith
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0301 basic medicine ,Agonist ,medicine.drug_class ,Dopamine ,media_common.quotation_subject ,education ,CHO Cells ,Butylamines ,03 medical and health sciences ,Cricetulus ,0302 clinical medicine ,Dopamine receptor D3 ,Cell surface receptor ,Cell Line, Tumor ,Arrestin ,Functional selectivity ,medicine ,Animals ,Humans ,Receptor ,Internalization ,beta-Arrestins ,media_common ,G protein-coupled receptor ,Pharmacology ,Receptors, Dopamine D2 ,Chemistry ,Receptors, Dopamine D3 ,Cell biology ,Protein Transport ,HEK293 Cells ,030104 developmental biology ,030220 oncology & carcinogenesis ,Dopamine Agonists ,Signal Transduction - Abstract
Agonist-induced internalization of G protein-coupled receptors (GPCRs) is a significant step in receptor kinetics and is known to be involved in receptor down-regulation. However, the dopamine D3 receptor (D3R) has been an exception wherein agonist induces D3Rs to undergo desensitization followed by pharmacological sequestration - which is defined as the sequestration of cell surface receptors into a more hydrophobic fraction within the plasma membrane without undergoing the process of receptor internalization. Pharmacological sequestration renders the receptor in an inactive state on the membrane. In our previous study we demonstrated that a novel class of D3R agonists exemplified by SK608 have biased signaling properties via the G-protein dependent pathway and do not induce D3R desensitization. In this study, using radioligand binding assay, immunoblot or immunocytochemistry methods, we observed that SK608 induced internalization of human D3R stably expressed in CHO, HEK and SH-SY5Y cells which are derived from neuroblastoma cells, suggesting that it is not a cell-type specific event. Further, we have evaluated the potential mechanism of D3R internalization induced by these biased signaling agonists. SK608-induced D3R internalization was time- and concentration-dependent. In comparison, dopamine induced D3R upregulation and pharmacological sequestration in the same assays. GRK2 and clathrin/dynamin I/II are the key molecular players in the SK608-induced D3R internalization process, while β-arrestin 1/2 and GRK-interacting protein 1(GIT1) are not involved. These results suggest that SK608-promoted D3R internalization is similar to the type II internalization observed among peptide binding GPCRs.
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- 2019
27. Herbs-partitioned moxibustion alleviates aberrant intestinal epithelial cell apoptosis by upregulating A20 expression in a mouse model of Crohn’s disease
- Author
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Liu Chen, Yi Sun, Ya-Jing Guo, Jing Zhou, Luyi Wu, Yin Shi, Ji-Meng Zhao, Huangan Wu, Chunhui Bao, and Tao Li
- Subjects
Crohn’s disease ,Colon ,Moxibustion ,Apoptotic pathway ,Inflammation ,Apoptosis ,Permeability ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Mesalazine ,Western blot ,Downregulation and upregulation ,Crohn Disease ,medicine ,Animals ,Intestinal Mucosa ,Mesalamine ,Tumor Necrosis Factor alpha-Induced Protein 3 ,Crohn's disease ,Herbs-partitioned moxibustion ,medicine.diagnostic_test ,Gene Expression Profiling ,GTPase-Activating Proteins ,Gastroenterology ,Epithelial Cells ,General Medicine ,Basic Study ,medicine.disease ,Molecular biology ,TRADD ,TNF Receptor-Associated Death Domain Protein ,Up-Regulation ,Mice, Inbred C57BL ,Disease Models, Animal ,A20 ,chemistry ,Trinitrobenzenesulfonic Acid ,Receptors, Tumor Necrosis Factor, Type I ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Tumor necrosis factor receptor 1 ,medicine.symptom - Abstract
BACKGROUND A20 inhibits intestinal epithelial cell apoptosis in Crohn's disease, and herbs-partitioned moxibustion (HPM) has been demonstrated to be an effective treatment for Crohn's disease. However, the mechanism by which HPM reduces intestinal epithelial cell apoptosis in Crohn's disease has not been thoroughly elucidated to date. AIM To elucidate whether HPM exerts its effects by upregulating A20 to affect intestinal epithelial cell apoptosis in a Crohn's disease mouse model. METHODS In this study, mice with A20 deletion in intestinal epithelial cells (A20IEC-KO) were utilized to establish a Crohn's disease mouse model with 2,4,6-trinitrobenzene sulfonic acid (TNBS) administration, as well as wild-type mice. Mice were randomly divided into normal control (NC), model control (MC), mesalazine (MESA), and HPM groups. The morphology of the colonic mucosa was observed by hematoxylin-eosin staining, and serum endotoxin and apoptosis of epithelial cells were evaluated by enzyme-linked immunosorbent assay and terminal dUTP nick-end labeling assay accordingly. The protein expression levels of A20 and tumor necrosis factor receptor 1 (TNFR1)-related signaling molecules were evaluated by Western blot, and co-expression of A20 and TNFR1-associated death domain (TRADD) and co-expression of A20 and receptor-interacting protein 1 (RIP1) were observed by double immunofluorescence staining. RESULTS The intestinal epithelial barrier was noted to have an improvement in the HPM group of wild-type (WT) mice compared with that in A20IEC-KO mice. Compared with A20 IEC-KO HPM mice, serum endotoxin levels and apoptosis percentages were decreased (P < 0.01), A20 expression levels were increased (P < 0.01), and expression of TNFR1, TRADDD, and RIP1 was decreased in the HPM group of WT mice (PTNFR1 < 0.05, PTRADD < 0.01, PRIP1 < 0.01). Both of the co-expression of A20/TRADD and A20/RIP1 showed a predominantly yellow fluorescence in the HPM group of WT mice, while a predominantly red fluorescence was noted in the HPM group of A20IEC-KO mice. CONCLUSION Our findings suggest that HPM in treating Crohn's disease functions possibly via upregulation of the A20 expression level, resulting in downregulation of TNFR1, TRADD, and RIP1 to alleviate increased cell apoptosis in the intestinal epithelial barrier in Crohn's disease.
- Published
- 2019
28. Porous Zr–Thiophenedicarboxylate Hybrid for Catalytic Transfer Hydrogenation of Bio-Based Furfural to Furfuryl Alcohol
- Author
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Xia Yongmei, Liu Chen, Haijun Wang, Xu Guangzhi, Aiyun Hu, and Tao Wang
- Subjects
010405 organic chemistry ,General Chemistry ,010402 general chemistry ,Furfural ,01 natural sciences ,Catalysis ,Hydrothermal circulation ,0104 chemical sciences ,Furfuryl alcohol ,Acetic acid ,chemistry.chemical_compound ,chemistry ,X-ray photoelectron spectroscopy ,Specific surface area ,Yield (chemistry) ,Nuclear chemistry - Abstract
Furfural (FAL) is one of the most important biomass-derived platform compounds. The catalytic transformation of FAL was investigated with three porous Zr–thiophenedicarboxylate hybrids for the production of furfuryl alcohol (FOL). Three Zr-based catalysts, including DUT-67(Zr), DUT-68(Zr) and DUT-69(Zr) were synthesized through a facile assembly of 2,5-thiophenedicarboxylate acid with ZrCl4 using the acetic acid as a modulator under hydrothermal conditions. These catalysts were also characterized using FT-IR, XRD, SEM, TEM, N2 adsorption–desorption, XPS and TG. The specific surface area of the DUT-69(Zr) is smaller than that of the DUT-68(Zr) and slightly larger than that of the DUT-67(Zr), but it has a relatively large pore volume and pore diameter. Although all three catalysts showed excellent catalytic activity towards the catalytic transfer hydrogenation of FAL into FOL, the DUT-69(Zr) material has slightly higher catalytic activity than the other two catalysts. Besides, considering the cost of catalyst preparation, the DUT-69(Zr) material was used as the optimal catalyst and studied in detail. A high FOL yield of 92.2% at 95.9% FAL conversion was achieved at 120 °C for 4 h over DUT-69(Zr). Meanwhile, the DUT-69(Zr) could be reused more than six times with a minor decrease in catalytic activity. Finally, a plausible mechanism for catalytic transfer hydrogenation of carbonyl compounds to produce corresponding alcohols was presented based on the results of the experiments and previous reports.
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- 2019
29. Carbon intensity and emission reduction potential in China: spatial measuring method
- Author
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Sheng Xue, Minxi Wang, Liu Chen, Xin Li, and Lingfei Qu
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Economics and Econometrics ,020209 energy ,Economics, Econometrics and Finance (miscellaneous) ,Spatial and temporal distribution ,Carbon mitigation potential ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,Atmospheric sciences ,Spatial distribution ,01 natural sciences ,lcsh:HD72-88 ,Energy intensity ,lcsh:Economic growth, development, planning ,Sustainable development ,ddc:330 ,0202 electrical engineering, electronic engineering, information engineering ,China ,0105 earth and related environmental sciences ,lcsh:HB71-74 ,lcsh:Economics as a science ,Energy consumption ,Emission intensity ,chemistry ,Carbon emission intensity ,Greenhouse gas ,Environmental science ,Carbon ,Intensity (heat transfer) - Abstract
This paper analyzes the spatial and temporal distribution of CO2 emissions intensity and energy intensity in China by using spatial measuring method from 2000 to 2013 and estimates the potential for CO2 emissions reduction. The results obtained in this study include: (1) Both CO2 emissions intensity and energy intensity are declining; (2) the spatial distribution of carbon emission intensity and energy intensity in China shows the characteristics of lower from north to south; (3) China’s total growth of energy consumption and carbon emissions is clearly slowing, which will peak before 2030; the carbon emission reduction potential in China is great with 167,316.91 million tons, and Shanxi, Inner Mongolia and Hebei have the greatest potential to reduce CO2 emissions with 29,885.8 Mt, 32,704.49 Mt and 34,222.1 Mt, respectively; (4) the differences of CO2 emissions intensity and energy intensity among provinces are distinctive. This study can provide a reference for the sustainable development of China’s energy and environment.
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- 2019
30. Determination of formaldehyde in single cell by capillary electrophoresis with LIF detection
- Author
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Xiao-Feng Guo, Liu Chen, Hong Wang, and Yu-Jia Fu
- Subjects
Clinical Biochemistry ,Formaldehyde ,02 engineering and technology ,Derivative ,01 natural sciences ,Biochemistry ,Fluorescence ,Analytical Chemistry ,chemistry.chemical_compound ,Capillary electrophoresis ,Limit of Detection ,Humans ,Fluorescent Dyes ,Detection limit ,Chromatography ,Chemistry ,010401 analytical chemistry ,Hydrazones ,Electrophoresis, Capillary ,021001 nanoscience & nanotechnology ,Small molecule ,0104 chemical sciences ,Naphthalimides ,Reagent ,Single-Cell Analysis ,0210 nano-technology ,Intracellular ,HeLa Cells - Abstract
As a small molecule gas, formaldehyde (FA) is the simplest carbonyl active material and plays an important role in the carbon cycle of metabolism. However, due to the volatile nature of the gas, it is difficult to accurately quantify its content, which limits the study of the mechanism of action in life activities. Thus, an efficient approach to quantitative detection of FA in cells especially in single cell is urgent needed. Nevertheless, no method for quantifying FA in single cell has been reported to date. In this work, a fluorescent probe N-propyl-4-hydrazino-naphthalimide (NPHNA), which has highly desirable attributes and has been applied to living biological samples, was chosen as labeling reagent to detect endogenous FA at single cell level. After optimization of separation conditions, fast baseline separation of the FA derivative N-propyl-4-hydrazone-naphthalimide product (NPHNA-FA) and NPHNA was achieved in about 5 min by CE with LIF detection. The detection limit for FA was 5 amol (S/N ratio of 3). The developed method was validated by the measurements of intracellular levels of FA in single cell.
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- 2019
31. Cr(VI) reduction and adsorption by amino-functionalized magnetic loofah fiber composites
- Author
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Yan Chunjie, Liu Chen, Zhou Sen, and Liang Cheng
- Subjects
Chromium ,Adsorption ,Materials science ,chemistry ,chemistry.chemical_element ,Fiber ,Amino functionalized ,Nuclear chemistry - Published
- 2019
32. Deregulation of CSMD1 targeted by microRNA-10b drives gastric cancer progression through the NF-κB pathway
- Author
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Kai-Lai Wang, Xiang-Liu Chen, Zhiyuan Xu, Jiuli Wang, Xiang Liu, Lan Lei, Zhi-Qiang Ling, Lian-Lian Hong, and Xiangdong Cheng
- Subjects
Blotting, Western ,Cell ,Mice, Nude ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Metastasis ,Mice ,03 medical and health sciences ,Cyclin D1 ,CUB and sushi multiple domains protein 1 (CSMD1) ,gastric carcinoma (GC) ,Stomach Neoplasms ,medicine ,Animals ,Humans ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Mice, Inbred BALB C ,0303 health sciences ,Gene knockdown ,Reverse Transcriptase Polymerase Chain Reaction ,Cell growth ,Chemistry ,Tumor Suppressor Proteins ,Tumor metastasis ,NF-kappa B ,Membrane Proteins ,microRNA-10b ,Cell Biology ,Oncomir ,medicine.disease ,Reverse transcription polymerase chain reaction ,MicroRNAs ,epithelial-mesenchymal transition (EMT) ,medicine.anatomical_structure ,Cancer research ,Female ,Carcinogenesis ,Signal Transduction ,Research Paper ,Developmental Biology - Abstract
Aim: This study aimed to investigate the oncogenic activity of microRNA-10b by targeting CUB and sushi multiple domains protein 1 (CSMD1) in human gastric cancer (GC) and the underlying mechanisms. Methods: The expression of CSMD1 in human GC tissues was evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical analysis. The expressive abundance of microRNA-10b was detected by stem-loop RT-PCR. Molecular and cellular techniques, including lentiviral vector-mediated knockdown or overexpression, were used to elucidate the effect of microRNA-10b on the expression of CSMD1. Results: CSMD1 was targeted and downregulated by microRNA-10b in human GC tissues and cells, and the down-regulated expression of CSMD1 contributed to poor survival. The knockdown of microRNA-10b expression inhibited cell proliferation in GC cells in vitro and tumor growth in vivo. The inhibition of microRNA-10b expression repressed invasion and migration of HGC27 cells and retarded GC cells metastasis to the liver in Balb/c nude mice. The up-regulated expression of microRNA-10b promoted the proliferation and metastasis of MKN74 cell in vitro. Intratumoral injection of microRNA-10b mimic also promoted the growth and metastasis of tumor xenografts in Balb/c nude mice. Mechanistically, microRNA-10b promoted the invasion and metastasis of human GC cells through inhibiting the expression of CSMD1, leading to the activation of the nuclear factor-κB (NF-κB) pathway that links inflammation to carcinogenesis, subsequently resulting in the upregulation of c-Myc, cyclin D1 (CCND1), and epithelial-mesenchymal transition (EMT) markers. Conclusions: The findings established that microRNA-10b is an oncomiR that drives metastasis. Moreover, a set of critical tumor suppressor mechanisms was defined that microRNA-10b overcame to drive human GC progression.
- Published
- 2019
33. Fruit extracts from Phyllanthus emblica accentuate cadmium tolerance and accumulation in Platycladus orientalis: A new natural chelate for phytoextraction
- Author
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Li Hua, Li Ningyu, Guo Bin, Lin Yicheng, Fu Qinglin, Liu Chen, Haiping Yu, Wenbin Tong, and Liu Junli
- Subjects
010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,Phyllanthus emblica ,010501 environmental sciences ,Toxicology ,01 natural sciences ,chemistry.chemical_compound ,Soil ,Animals ,Soil Pollutants ,Chelation ,Gallic acid ,Food science ,Edetic Acid ,0105 earth and related environmental sciences ,Chelating Agents ,Cadmium ,biology ,Plant Extracts ,General Medicine ,Platycladus ,biology.organism_classification ,Pollution ,Phytoremediation ,Biodegradation, Environmental ,chemistry ,Polyphenol ,Fruit ,Toxicity - Abstract
A key challenge for phytoextraction is the identification of high efficiency, growth-supporting, and low cost chelating agents. To date, no substance has satisfied all above criteria. This study investigated nine traditional Chinese herbs and found that Phyllanthus emblica fruit (FPE) extract could be utilised as an optimal chelate for the phytoextraction of cadmium (Cd)-contaminated soils. FPE application into soil at a ratio of 0.1% (w/w) significantly increased extractable Cd (by 43%) compared to the control. The success of FPE as a chelating agent was attributed to high quantities of polyphenol compounds (0.76%) and organic acids (9.6%), in particular, gallic acid (7.6%). Furthermore, antioxidative properties (1.4%) and free amino acids in FPE alleviated Cd-induced oxidant toxicity and enhanced plant biomass. FPE promoted 78% higher phytoextraction efficiency in Platycladus orientalis compared to traditional chelating agents (EDTA). Furthermore, 76% of FPE was degraded 90 days after the initial application, and there was no difference in extractable Cd between the treatment and control. FPE has been commercially produced at a lower market price than other biodegradable chelates. As a commercially available and cost-effective chelator, FPE could be utilised to treat Cd-contaminated soils without adverse environmental impacts.
- Published
- 2021
34. Does GEC1 Enhance Expression and Forward Trafficking of the Kappa Opioid Receptor (KOR) via Its Ability to Interact with NSF Directly?
- Author
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Peng Huang, Chongguang Chen, Lee-Yuan Liu-Chen, Sidney W. Whiteheart, and Chunxia Zhao
- Subjects
0301 basic medicine ,GABARAP ,Cell ,κ-opioid receptor ,Article ,03 medical and health sciences ,0302 clinical medicine ,Cricetulus ,Cricetinae ,medicine ,Animals ,N-Ethylmaleimide-Sensitive Proteins ,biology ,Chemistry ,Chinese hamster ovary cell ,Vesicle ,Receptors, Opioid, kappa ,Lipid bilayer fusion ,Export pathway ,Cell biology ,Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins ,030104 developmental biology ,Tubulin ,medicine.anatomical_structure ,biology.protein ,Microtubule-Associated Proteins ,030217 neurology & neurosurgery - Abstract
We reported previously that GEC1 (glandular epithelial cell 1), a member of microtubule-associated proteins (MAPs), interacted directly with the C-tail of KOR (KCT) and tubulin, and enhanced cell surface expression of KOR in CHO cells by facilitating its trafficking along the export pathway. Two GEC1 analogs (GABARAP and GATE16) were also shown to increase KOR expression. In addition, to understand the underlying mechanism, we demonstrated that N-ethylmaleimide-sensitive factor (NSF), an essential component for membrane fusion, co-immunoprecipitated with GEC1 from brain extracts. In this study, using pull-down techniques, we have found that (1) GEC1 interacts with NSF directly, and prefers the ADP-bound NSF to the ATP-bound NSF; (2) D1 and/or D2 domain(s) of NSF interact with GEC1, but the N domain of NSF does not; (3) NSF does not interact with KCT directly, but forms a protein complex with KCT via GEC1; (4) NSF and/or α-SNAP do not affect KCT-GEC1 interaction. Thus, GEC1 (vs the α-SNAP/SNAREs complex) binds to NSF in distinctive ways in terms of the ADP- or ATP-bound form and domains of NSF involved. In conclusion, GEC1 may, via its direct interactions with KOR, NSF and tubulin, enhance trafficking and fusion of KOR-containing vesicles selectively along the export pathway, which leads to increase in surface expression of KOR. GABARAP and GATE16 may enhance KOR expression in a similar way.
- Published
- 2021
35. Activation of Toll‐like receptor 7 provides cardioprotection in septic cardiomyopathy‐induced systolic dysfunction
- Author
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Wu Qingqing, Xu Man, Chen Si, Wu Haiming, Xing Yun, Liu Chen, Xie Saiyang, Deng Wei, Tang Qi-zhu, Zhang Min, Zeng Xiaofeng, Guo Hai-peng, and Shi Wenke
- Subjects
0301 basic medicine ,Male ,SERCA ,Lipopolysaccharide ,Systole ,Medicine (miscellaneous) ,Pharmacology ,Ryanodine receptor 2 ,Sepsis ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Downregulation and upregulation ,Ca2+‐handling ,medicine ,Animals ,Receptor ,Research Articles ,TLR7 ,Cardioprotection ,Membrane Glycoproteins ,cardiac dysfunction ,Chemistry ,virus diseases ,medicine.disease ,Adenosine ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Toll-Like Receptor 7 ,030220 oncology & carcinogenesis ,septic cardiomyopathy ,Molecular Medicine ,Cardiomyopathies ,medicine.drug ,Research Article - Abstract
Background As a pattern recognition receptor, Toll‐like receptor 7 (TLR7) widely presented in the endosomal membrane of various cells. However, the precise role and mechanism of TLR7 in septic cardiomyopathy remain unknown. This study aims to determine the role of TLR7 in cardiac dysfunction during sepsis and explore the mechanism of TLR7 in septic cardiomyopathy. Methods We generated a mouse model of septic cardiomyopathy by challenging with lipopolysaccharide (LPS). TLR7‐knockout (TLR7−/−), wild‐type (WT) mice, cardiac‐specific TLR7‐transgenic (cTG‐TLR7) overexpression, and littermates WT (LWT) mice were subjected to septic model. Additionally, to verify the role and mechanism of TLR7 in vitro, we transfected neonatal rat ventricular myocytes (NRVMs) with Ad‐TLR7 and TLR7 siRNA before LPS administration. The effects of TLR7 were assessed by Ca2+ imaging, western blotting, immunostaining, and quantitative real‐time polymerase chain reaction (qPCR). Results We found that TLR7 knockout markedly exacerbated sepsis‐induced systolic dysfunction. Moreover, cardiomyocytes isolated from TLR7−/− mice displayed weaker Ca2+ handling than that in WT mice in response to LPS. Conversely, TLR7 overexpression alleviated LPS‐induced systolic dysfunction, and loxoribine (TLR7‐specific agonist) improved LPS‐induced cardiac dysfunction. Mechanistically, these optimized effects were associated with enhanced the adenosine (cAMP)‐protein kinase A (PKA) pathway, which upregulated phosphorylate‐phospholamban (p‐PLN) (Ser16) and promoted sarco/endoplasmic reticulum Ca2+ ATPase (Serca) and Ryanodine Receptor 2 (RyR2) expression in the sarcoplasmic reticulum (SR), and ultimately restored Ca2+ handling in response to sepsis. While improved Ca2+ handling was abrogated after H89 (a specific PKA inhibitor) pretreatment in cardiomyocytes isolated from cTG‐TLR7 mice. Consistently, TLR7 overexpression improved LPS‐induced Ca2+‐handling decrement in NRVMs. Nevertheless, TLR7 knockdown showed a deteriorative phenotype. Conclusions Our data demonstrated that activation of TLR7 protected against sepsis‐induced cardiac dysfunction through promoting cAMP‐PKA‐PLN pathway, and we revealed that TLR7 might be a novel therapeutic target to block the septic cardiomyopathy and support systolic function during sepsis., Our study explored the effect of TLR7 activation, by which TLR7 modulated Ca2+ handling in septic cardiomyopathy. TLR7 protected against sepsis‐induced cardiac dysfunction through activation of cAMP‐PKA‐PLN pathway. Targeting this newly identified TLR7 may yield novel interventional solutions against septic cardiomyopathy.
- Published
- 2021
36. Considerations on Using Antibodies for Studying the Dynorphins/Kappa Opioid Receptor System
- Author
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Lee-Yuan Liu-Chen, Christoph Schwarzer, Melanie Widmann, and Chongguang Chen
- Subjects
Mice, Knockout ,biology ,Receptors, Opioid, kappa ,Brain ,Reproducibility of Results ,Dynorphin A ,Dynorphin ,Dynorphins ,κ-opioid receptor ,Article ,Blot ,Mice ,chemistry.chemical_compound ,chemistry ,Immunology ,biology.protein ,Animals ,Immunohistochemistry ,Antibody ,Receptor ,G protein-coupled receptor - Abstract
Antibodies are important tools for protein and peptide research, including for the kappa opioid receptor (KOR) and dynorphins (Dyns). Well-characterized antibodies are essential for rigorous and reproducible research. However, lack of validation of antibody specificity has been thought to contribute significantly to the reproducibility crisis in biomedical research. Since 2003, many scientific journals have required documentation of validation of antibody specificity and use of knockout mouse tissues as a negative control is strongly recommended. Lack of specificity of antibodies against many G protein-coupled receptors (GPCRs) after extensive testing has been well-documented, but antibodies generated against partial sequences of the KOR have not been similarly investigated. For the dynorphins, differential processing has been described in distinct brain areas, resulting in controversial findings in immunohistochemistry (IHC) when different antibodies were used. In this chapter, we summarized accepted approaches for validation of antibody specificity. We discussed two KOR antibodies most commonly used in IHC and described generation and characterization of KOR antibodies and phospho-KOR specific antibodies in western blotting or immunoblotting (IB). In addition, applying antibodies targeting prodynorphin or mature dynorphin A illustrates the diversity of results obtained regarding the distribution of dynorphins in distinct brain areas.
- Published
- 2021
37. Identification of liver cancer-specific aptamers using whole live cells
- Author
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Shangguan, Dihua, Meng, Ling, Cao, Zehui Charles, Xiao, Zeyu, Fang, Xiaohong, Li, Ying, Cardona, Diana, Witek, Rafal P., Liu, Chen, and Tan, Weihong
- Subjects
Liver cancer -- Diagnosis ,Biological markers -- Properties ,Liver cells -- Properties ,Cancer -- Diagnosis ,Cancer -- Methods ,Chemistry - Abstract
Liver cancer is the third most deadly cancers in the world. Unfortunately, there is no effective treatment. One of the major problems is that most cancers are diagnosed in the later stage, when surgical resection is not feasible. Thus, accurate early diagnosis would significantly improve the clinical outcome of liver cancer. Currently, there are no effective molecular probes to recognize biomarkers that are specific for liver cancer. The objective of our current study is to identify liver cancer cell-specific molecular probes that could be used for liver cancer recognition and diagnosis. We applied a newly developed cell-SELEX (Systematic Evolution of Ligands by EXponential enrichment) method for the generation of molecular probes for specific recognition of liver cancer cells. The cell-SELEX uses whole live cells as targets to select aptamers (designed DNA/RNA) for cell recognition. In generating aptamers for liver cancer recognition, two liver cell lines were used: a liver cancer cell line BNL 1ME A.7R.1 (MEAR) and a noncancer cell line, BNL CL.2 (BNL). Both cell lines were originally derived from Balb/cJ mice. Through multiple rounds of selection using BNL as a control, we have identified a panel of aptamers that specifically recognize the cancer cell line MEAR with [K.sub.d] in the nanomolar range. We have also demonstrated that some of the selective aptamers could specifically bind liver cancer cells in a mouse model. There are two major new results (compared with our reported cell-SELEX methodology) in addition to the generation of aptamers specifically for liver cancer. The first one is that our current study demonstrates that cell-based aptamer selection can select specific aptamers for multiple cell lines, even for two cell lines with minor differences (MEAR cell is derived from BNL by chemical inducement); and the second result is that cell-SELEX can be used for adhesive cells and thus open the door for solid tumor selection and investigation. The newly generated cancer-specific aptamers hold great promise as molecular probes for cancer early diagnosis and basic mechanism studies.
- Published
- 2008
38. Verifying the role of 3-hydroxy of 17-cyclopropylmethyl-4,5α-epoxy-3,14β-dihydroxy-6β-[(4'-pyridyl) carboxamido]morphinan derivatives via their binding affinity and selectivity profiles on opioid receptors
- Author
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Lan-Hsuan M. Huang, Boshi Huang, Chongguang Chen, Rama Gunta, Mengchu Li, Yan Zhang, James C. Gillespie, Danni Cao, Huiqun Wang, Rolando E. Mendez, Lee-Yuan Liu-Chen, and Dana E. Selley
- Subjects
Models, Molecular ,Molecular model ,Stereochemistry ,01 natural sciences ,Biochemistry ,κ-opioid receptor ,Article ,Drug Discovery ,medicine ,Potency ,Receptor ,Molecular Biology ,Morphinan derivatives ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,0104 chemical sciences ,Molecular Docking Simulation ,010404 medicinal & biomolecular chemistry ,Opioid ,Morphinans ,Receptors, Opioid ,μ-opioid receptor ,Selectivity ,medicine.drug ,Protein Binding - Abstract
In the present study, the role of 3-hydroxy group of a series of epoxymorphinan derivatives in their binding affinity and selectivity profiles toward the opioid receptors (ORs) has been investigated. It was found that the 3-hydroxy group was crucial for the binding affinity of these derivatives for all three ORs due to the fact that all the analogues 1a-e exhibited significantly higher binding affinities compared to their counterpart 3-dehydroxy ones 6a-e. Meanwhile most compounds carrying the 3-hydroxy group possessed similar selectivity profiles for the kappa opioid receptor over the mu opioid receptor as their corresponding 3-dehydroxy derivatives. [(35)S]-GTPγS functional assay results indicated that the 3-hydroxy group of these epoxymorphinan derivatives was important for maintaining their potency on the ORs with various effects. Further molecular modeling studies helped comprehend the remarkably different binding affinity and functional profiles between compound 1c (NCP) and its 3-dehydroxy analogue 6c.
- Published
- 2020
39. Characterization of a Knock-In Mouse Line Expressing a Fusion Protein of κ Opioid Receptor Conjugated with tdTomato: 3-Dimensional Brain Imaging via CLARITY
- Author
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Brigitte L. Kieffer, Mary F. Barbe, Lan Hsuan Melody Huang, Alex H. Willhouse, Yujun Wang, Bin Xu, Nora Ko, Chongguang Chen, Lee-Yuan Liu-Chen, and Peng Huang
- Subjects
medicine.drug_class ,neuroanatomy ,Neuroimaging ,Nucleus accumbens ,Novel Tools and Methods ,3-D imaging ,κ opioid receptor ,Mice ,Opioid receptor ,medicine ,Animals ,Receptor ,Tyrosine hydroxylase ,Chemistry ,General Neuroscience ,Receptors, Opioid, kappa ,Substantia innominata ,Brain ,General Medicine ,Research Article: Methods/New Tools ,Cell biology ,Ventral tegmental area ,Mice, Inbred C57BL ,Luminescent Proteins ,medicine.anatomical_structure ,nervous system ,CLARITY ,Nucleus ,Neuroanatomy - Abstract
Activation of κ opioid receptor (KOR) produces analgesia, antipruritic effect, sedation and dysphoria. To characterize neuroanatomy of KOR at high resolutions and circumvent issues of specificity of KOR antibodies, we generated a knock-in mouse line expressing KOR fused at the C terminus with the fluorescent protein tdTomato (KtdT). The selective KOR agonist U50,488H caused anti-scratch effect and hypolocomotion, indicating intact KOR neuronal circuitries. Clearing of brains with CLARITY revealed three-dimensional (3-D) images of distribution of KOR, and any G-protein-coupled receptors, for the first time. 3-D brain images of KtdT and immunohistochemistry (IHC) on brain sections with antibodies against tdTomato show similar distribution to that of autoradiography of [3H]U69,593 binding to KOR in wild-type mice. KtdT was observed in regions involved in reward and aversion, pain modulation, and neuroendocrine regulation. KOR is present in several areas with unknown roles, including the claustrum (CLA), dorsal endopiriform nucleus, paraventricular nucleus of the thalamus (PVT), lateral habenula (LHb), and substantia nigra pars reticulata (SNr), which are discussed. Prominent KtdT-containing fibers were observed to project from caudate putamen (CP) and nucleus accumbens (ACB) to substantia innominata (SI) and SNr. Double IHC revealed co-localization of KtdT with tyrosine hydroxylase (TH) in brain regions, including CP, ACB, and ventral tegmental area (VTA). KOR was visualized at the cellular level, such as co-localization with TH and agonist-induced KOR translocation into intracellular space in some VTA neurons. These mice thus represent a powerful and heretofore unparalleled tool for neuroanatomy of KOR at both the 3-D and cellular levels.
- Published
- 2020
40. Pharmacological and phosphoproteomic approaches to roles of protein kinase C in kappa opioid receptor-mediated effects in mice
- Author
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Matthias Mann, Yi-Ting Chiu, Jeffrey J. Liu, Peng Huang, Chongguang Chen, and Lee-Yuan Liu-Chen
- Subjects
0301 basic medicine ,Male ,Proteomics ,Cannabinoid receptor ,Pharmacology ,Motor Activity ,κ-opioid receptor ,Article ,Receptors, G-Protein-Coupled ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Mice ,0302 clinical medicine ,Receptor, Cannabinoid, CB1 ,medicine ,Avoidance Learning ,Animals ,Phosphorylation ,Receptor ,Protein Kinase Inhibitors ,Wnt Signaling Pathway ,Protein kinase C ,Protein Kinase C ,Kinase ,Chemistry ,Receptors, Opioid, kappa ,TOR Serine-Threonine Kinases ,Wnt signaling pathway ,3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer ,Psychotomimetic ,G-Protein-Coupled Receptor Kinases ,Phosphoproteins ,030104 developmental biology ,Signal transduction ,030217 neurology & neurosurgery ,medicine.drug ,Signal Transduction - Abstract
Kappa opioid receptor (KOR) agonists possess adverse dysphoric and psychotomimetic effects, thus limiting their applications as non-addictive anti-pruritic and analgesic agents. Here, we showed that protein kinase C (PKC) inhibition preserved the beneficial antinociceptive and antipruritic effects of KOR agonists, but attenuated the adverse condition placed aversion (CPA), sedation, and motor incoordination in mice. Using a large-scale mass spectrometry-based phosphoproteomics of KOR-mediated signaling in the mouse brain, we observed PKC-dependent modulation of G protein-coupled receptor kinases and Wnt pathways at 5 min; stress signaling, cytoskeleton, mTOR signaling and receptor phosphorylation, including cannabinoid receptor CB1 at 30 min. We further demonstrated that inhibition of CB1 attenuated KOR-mediated CPA. Our results demonstrated the feasibility of in vivo biochemical dissection of signaling pathways that lead to side effects.
- Published
- 2020
41. MTH1 inhibitor amplifies the lethality of reactive oxygen species to tumor in photodynamic therapy
- Author
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Huijing Xiang, Yanli Zhao, Juanjuan Peng, Liqiang Yang, Junyao Li, Huijun Phoebe Tham, Lingzhi Zhao, Yajing Wang, Yaoquan Su, Liu Chen, Lei Qiang, School of Physical and Mathematical Sciences, and School of Materials Science and Engineering
- Subjects
DNA Repair ,Light ,medicine.medical_treatment ,Melanoma, Experimental ,Gene Expression ,Diseases ,Photodynamic therapy ,Apoptosis ,Enzyme Inhibitors ,Research Articles ,Cancer ,chemistry.chemical_classification ,Drug Carriers ,Multidisciplinary ,Photosensitizing Agents ,Cell Death ,Chlorophyllides ,Melanoma ,SciAdv r-articles ,Life Sciences ,DNA, Neoplasm ,Tumor Burden ,MCF-7 Cells ,Female ,medicine.symptom ,Research Article ,Porphyrins ,DNA damage ,Drug Compounding ,Mice, Nude ,Antineoplastic Agents ,medicine ,Animals ,Humans ,Medicine [Science] ,Reactive oxygen species ,Tumor hypoxia ,Hypoxia (medical) ,medicine.disease ,HCT116 Cells ,Xenograft Model Antitumor Assays ,Phosphoric Monoester Hydrolases ,DNA Repair Enzymes ,Pyrimidines ,chemistry ,Photochemotherapy ,Cancer cell ,Cancer research ,Nanoparticles ,Reactive Oxygen Species ,HeLa Cells - Abstract
An MTH1 inhibitor is integrated with nanoparticles to enhance therapy effect of reactive oxygen species in cancer treatment., Although photodynamic therapy (PDT) has been clinically applied tumor hypoxia still greatly restricts the performance of this oxygen-dependent oncological treatment. The delivery of oxygen donors to tumor may produce excessive reactive oxygen species (ROS) and damage the peripheral tissues. Herein, we developed a strategy to solve the hypoxia issue by enhancing the lethality of ROS. Before PDT, the ROS-defensing system of the cancer cells was obstructed by an inhibitor to MTH1, which is a key for the remediation of ROS-caused DNA damage. As a result, both nuclei and mitochondrial DNA damages were increased, remarkably promoting cellular apoptosis. The therapeutic results demonstrated that the performance of PDT can be improved by the MTH1 inhibitor, leading to efficient cancer cell killing effect in the hypoxic tumor. This strategy makes better use of the limited oxygen, holding the promise to achieve satisfactory therapeutic effect by PDT without generating redundant cytotoxic ROS.
- Published
- 2020
42. Establishment of Fluorescence Sensitization Method for Hydroxysafflor Yellow A
- Author
-
Ma Yu-Hui, Zhao Xinzhe, Zhang Guowei, Zhou Jingna, Cao Hai-Yan, Liu Chen, Liu Yu, Nie Hailiang, Qin Xiude, and G E Shaoqin
- Subjects
Active ingredient ,Detection limit ,Fluorescence-lifetime imaging microscopy ,Chromatography ,Article Subject ,Borax ,Absorption (skin) ,010402 general chemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Other systems of medicine ,0302 clinical medicine ,medicine.anatomical_structure ,Complementary and alternative medicine ,chemistry ,Pulmonary surfactant ,medicine ,030217 neurology & neurosurgery ,Sensitization ,RZ201-999 ,Research Article - Abstract
As the main active ingredient in Chinese medicine safflower, hydroxysafflor yellow A (HSYA) has multiple pharmacological effects. In the work, the absorption and fluorescence spectra of HSYA under different environmental conditions (such as acidity, temperature, ions, viscosity, and surfactant) were investigated. The fluorescence intensity of HSYA varied greatly with acidity, temperature, viscosity, and surfactant, but was less affected by common cations and anions. Among various surfactants, we found that borax can significantly enhance the HSYA fluorescence intensity, and thus, a borax-HSYA sensitization system for HSYA fluorescence was established. In the optimized sensitization system, the fluorescence intensity of HSYA increased by 20 times and showed a good linearity with HSYA concentrations in the range of 0∼10 μM with a detection limit of 8 nM. The borax-HSYA sensitization system is nontoxic to T24 cells and mice and can be used for the fluorescence imaging of HSYA in cells, thereby providing an effective method for analyzing HSYA in vitro and monitoring its metabolism in cells.
- Published
- 2020
43. Degradation of tetracycline hydrochloride through efficient peroxymonosulfate activation by B, N co-doped porous carbon materials derived from metal-organic frameworks: Nonradical pathway mechanism
- Author
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Siyu Li, Xuan Luo, Liu Chen, Li Huang, Xiaobo Gong, and Jinling Xie
- Subjects
inorganic chemicals ,Chemistry ,Singlet oxygen ,Advanced oxidation process ,Filtration and Separation ,Photochemistry ,Analytical Chemistry ,Catalysis ,law.invention ,Tetracycline Hydrochloride ,Electron transfer ,chemistry.chemical_compound ,Adsorption ,law ,Metal-organic framework ,Electron paramagnetic resonance - Abstract
Peroxymonosulfate (PMS) based advanced oxidation process has been proved to be an efficient method for Antibiotic treatment. B, N co-doped carbon porous material was derived from metal-organic frameworks. B-NC catalysts showed excellent efficiency for removal of tetracycline hydrochloride. Nitrogen doping essentially changed the degradation pathway of tetracycline hydrochloride, while boron doping provided more active sites. through more defect sites, which is closely related to the adsorption and catalytic performance of the catalyst. The major active species of B-NC/PMS system was singlet oxygen (1O2) through quenching experiments and electron paramagnetic resonance (EPR) studies. Electron transfer was another non-radical oxidation pathway of B-NC/PMS system. This provides a new idea for the selective oxidation of antibiotics by metal-free activated PMS.
- Published
- 2022
44. Agonist-promoted kappa opioid receptor (KOR) phosphorylation has behavioral endpoint-dependent and sex-specific effects
- Author
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Lee-Yuan Liu-Chen, Melody Huang, Danni Cao, Chongguang Chen, and Peng Huang
- Subjects
Male ,Agonist ,medicine.medical_specialty ,medicine.drug_class ,Mutant ,κ-opioid receptor ,Article ,Mice ,Cellular and Molecular Neuroscience ,In vivo ,Internal medicine ,medicine ,Animals ,p-Methoxy-N-methylphenethylamine ,Phosphorylation ,Cells, Cultured ,G protein-coupled receptor ,Pharmacology ,Sex Characteristics ,Behavior, Animal ,Chemistry ,Receptors, Opioid, kappa ,3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer ,Wild type ,Brain ,Mice, Mutant Strains ,In vitro ,Endocrinology ,Female ,Locomotion - Abstract
We reported previously that the selective agonist U50,488H promoted phosphorylation of the mouse kappa opioid receptor (mKOR) in vitro at four residues in the C-terminal domain. In this study, we generated a mutant mouse line in which all the four residues were mutated to Ala (K4A) to examine the in vivo functional significance of agonist-induced KOR phosphorylation. U50,488H promoted KOR phosphorylation in brains of the wildtype (WT), but not K4A, male and female mice. Autoradiography of [3H] 69,593 binding to KOR in brain sections showed that WT and K4A mice had similar KOR distribution and expression levels in brain regions without sex differences. In K4A mice, U50,488H inhibited compound 48/80-induced scratching and attenuated novelty-induced hyperlocomotion to similar extents as in WT mice without sex differences. Interestingly, repeated pretreatment with U50,488H (80 mg/kg, s.c.) resulted in profound tolerance to the anti-scratch effects of U50,488H (5 mg/kg, s.c.) in WT mice of both sexes and female K4A mice, while in male K4A mice tolerance was attenuated. Moreover, U50,488H (2 mg/kg) induced conditioned place aversion (CPA) in WT mice of both sexes and male K4A mice, but not in female K4A mice. In contrast, U50,488H (5 mg/kg) caused CPA in male, but not female, mice, regardless of genotype. Thus, agonist-promoted KOR phosphorylation plays important roles in U50,488H-induced tolerance and CPA in a sex-dependent manner, without affecting acute U50,488H-induced anti-pruritic and hypo-locomotor effects. These results are the first to demonstrate sex differences in the effects of GPCR phosphorylation on the GPCR-mediated behaviors.
- Published
- 2022
45. Screening of a highly effective fluorescent derivatization reagent for carbonyl compounds and its application in HPLC with fluorescence detection
- Author
-
Liu Chen, Yu-Jia Fu, Wen-Le Fang, Xiao-Feng Guo, and Hong Wang
- Subjects
Analyte ,Chromatography ,010405 organic chemistry ,010401 analytical chemistry ,Hydrazine ,Mass spectrometry ,01 natural sciences ,Fluorescence ,High-performance liquid chromatography ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Reagent ,Reactivity (chemistry) ,Derivatization - Abstract
Carbonyl compounds are widely distributed in organisms, and the commonly used methods for determination of them like UV/fluorescence/mass spectrometry always require derivatization reagents. However, the reported derivatization reagents have significant difference in reactivity, which is very unfavorable for developing highly reactive reagent. In this study, we theoretically investigated the factors affecting the reactivity of hydrazine-based derivatization reagents, and proposed a strategy for filtering highly reactive reagents by quantum chemical calculation. With this strategy, N-propyl-4-hydrazino-1,8-naphthalimide (NPHNA) was filtered out as a fluorescent derivatization reagent. Taking aliphatic aldehydes as representatives, we evaluated the reactivity of NPHNA for carbonyl compounds. The derivatization of NPHNA with aliphatic aldehydes could be finished at room temperature within 60 min or 35 °C within 35 min, which showed higher reactivity than the most popular UV/MS reagent, 2,4-dinitrophenylhydrazine (DNPH). We believe that the strategy we proposed in this work is of great potential to design highly reactive UV/fluorescent/MS labeling reagents for carbonyl compounds and even other analytes.
- Published
- 2018
46. Agrobacterium tumefaciens-mediated transformation system for the important medicinal plant Dendrobium catenatum Lindl
- Author
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Li Yang, Fan Liu, Rong Guo, Jianbin Chen, Liu Chen, Mengliang Tian, Ke Zhao, Fanlei Kong, Aby Grabon, Jin Huang, Li Wang, and Chen Ji
- Subjects
0106 biological sciences ,0301 basic medicine ,biology ,Agrobacterium ,Strain (biology) ,fungi ,Plant Science ,Agrobacterium tumefaciens ,Genetically modified crops ,biology.organism_classification ,01 natural sciences ,Green fluorescent protein ,Dendrobium ,03 medical and health sciences ,chemistry.chemical_compound ,Transformation (genetics) ,030104 developmental biology ,chemistry ,Botany ,DNA ,010606 plant biology & botany ,Biotechnology - Abstract
The orchid Dendrobium catenatum Lindl. has both ornamental and medicinal value. Studies on genetic transformation of other Dendrobium species have been reported; however, due to the heterogeneity among the Dendrobium species, an independent transformation system is required for optimum D. catenatum transformation. Agrobacterium tumefaciens-mediated transformation system for D. catenatum is reported herein. Three A. tumefaciens strains, GV3101, LBA4404, and EHA105, were tested for their ability to transform D. catenatum protocorms. It was found that infection with strain GV3101 at an OD600 of 0.6 yielded the highest transformation frequency of 56.5%. Addition of 0.001% (v/v) Triton™ X-100 or pretreatment with ultrasound (300 W, 40 kHz, 3 min) increased the transformation frequency by up to 2-fold. After 1 year, both green fluorescent protein (GFP) imaging and glucuronidase (GUS) histochemical analysis of transgenic plants demonstrated that DcObg-GFP and pDcObg-GUS construct DNA was transferred into the D. catenatum and expressed successfully. Functional and gene expression level analyses of transgenic plants containing a D. catenatum chloroplast-targeted homolog of Spo0B-associated GTP-binding protein (DcObgC) RNA interference construct (DcObgC-RNAi) further demonstrated that this transformation system was reliable and efficient for D. catenatum. The A. tumefaciens-based transformation protocol established and optimized in this current report could provide a powerful and efficient tool for academic research and genetic engineering-based breeding of D. catenatum.
- Published
- 2018
47. A long-wavelength fluorescent probe for amino compounds and its application in the determination of aliphatic amines
- Author
-
Liu Chen, Xiao-Feng Guo, Hong Wang, Li-Jun Xia, and Yan Ji
- Subjects
Detection limit ,Chromatography ,Trace Amounts ,General Chemical Engineering ,010401 analytical chemistry ,General Engineering ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,High-performance liquid chromatography ,Fluorescence ,0104 chemical sciences ,Analytical Chemistry ,Long wavelength ,chemistry.chemical_compound ,chemistry ,Reagent ,Boron ,Derivatization - Abstract
Herein, a highly reactive long-wavelength fluorescent labeling reagent, 1,7-dimethyl-3,5-distyryl-8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimidyl ester) difluoroboradiaza-s-indacene (DMDSPAB-OSu), was designed and synthesized for amino compounds. Using DMDSPAB-OSu as a pre-column derivatization reagent, an HPLC-fluorescence detection method was developed for the determination of trace amounts of aliphatic amines in samples. Prior to analysis, amines were derivatized with DMDSPAB-OSu at room temperature in 0.2 mol L−1 pH 8.8 borate buffer for only 5 min, and the baseline separation of 11 aliphatic amines was achieved within 25 min. Limits of detection between 0.8 to 1.2 nM were obtained at 630 nm with an excitation wavelength of 610 nm. Furthermore, the proposed DMDSPAB-OSu-based HPLC method was applied to the analysis of lake water and human urine with satisfying recoveries ranging from 93.0–109.7%.
- Published
- 2018
48. The seventh transmembrane domains of the delta and kappa opioid receptors have different accessibility patterns and interhelical interactions
- Author
-
Wei Xu, Campillo, Mercedes, Pardo, Leonardo, de Riel, J. Kim, and Lee-Yuan Liu-Chen
- Subjects
Membrane proteins -- Chemical properties ,Cysteine -- Chemical properties ,Opioids -- Receptors ,Opioids -- Chemical properties ,Biological sciences ,Chemistry - Abstract
The substituted cysteine accessibility method (SCAM) was applied to map the residues of the transmembrane helices (TMs) 7 of delta and kappa opioid receptors (delta QR and kappa QR) that are on the water-accessible surface of the binding-site crevices. Most mutants displayed similar binding affinity for [(super 3)H] diprenorphine an antagonist, as the wild types.
- Published
- 2005
49. The local environment at the cytoplasmic end of TM6 of the mu opioid receptor differes from those of rhodopsin and monoamine receptors: introduction of an ionic lock between the cytoplasmic ends of helices 3 and 6 by a L6.30(275)E mutation inactivates the mu opioid receptor and reduces the constitutive activity of its T6.34(279)K mutant
- Author
-
Huang, Peng, Visiers, Irache, Weinstein, Harel, and Liu-Chen, Lee-Yuan
- Subjects
Biochemistry -- Research ,Cytoplasm -- Genetic aspects ,Opioids -- Receptors ,Rhodopsin -- Physiological aspects ,Amines -- Physiological aspects ,Gene mutations -- Physiological aspects ,G proteins -- Physiological aspects ,Biological sciences ,Chemistry - Abstract
Research has been conducted on the rhodopsin and monoamine G protein-coupled receptors. The structural differences between these receptors and the mu opioid receptor and the role of these differences in the rhodopsin-like family have been investigated and the details are presented.
- Published
- 2002
50. Functional role of a conserved motif in TM6 of the Rat mu opioid receptor: constitutively active and inactive receptors result from substitutions of Thr6.34(279) with Lys and Asp
- Author
-
Huang, Peng, Li, Jin, Chen, Chongguang, Visiers, Irache, Weinstein, Harel, and Liu-Chen, Lee-Yuan
- Subjects
Biochemistry -- Research ,Opioids -- Receptors ,Gene mutations -- Physiological aspects ,G proteins -- Genetic aspects ,Biological sciences ,Chemistry - Abstract
Research has been conducted on the mutations within the X (sub)1 BBX (sub)2 X (sub)3 B motif that lead to the constitutive activation of the G protein-coupled receptors. The mutation of the Thr6.34(279) to Lys and Asp at the X (sub)3 locus of the rat mu opioid receptor has been carried out and the binding and signaling properties of the mutants have been examined.
- Published
- 2001
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