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Active site of praseodymium orthovanadate catalyst in oxidative dehydrogenation of propane

Chinese Science Bulletin 1998年第3期43卷 217-220页

作者： Weide Zhang Chaktong Au Huilin Wan Xiamen Univ Dept Chem Xiamen 361005 Peoples R China Xiamen Univ State Key Lab Phys Chem Solid Surface Xiamen 361005 Peoples R China Hong Kong Baptist Univ Dept Chem Hong Kong Hong Kong

The pure phase of praseodymium orthovanadate (PrVO\-4) has been prepared by the citrate method. The active site of PrVO\-4 was studied by ESR, NO_TPD, O\-2_TPD and 18 O\-2_isotope exchange methods. The results of ESR and NO_TPD confirmed the presence of V 4+ in the catalyst. 18 O\-2_isotope exchange was through a single exchange procedure. From the result of O\-2+TPD and the kinetic study of 18 O\-2_isotope exchange, one can reach a conclusion that the V 4+ species associated with oxygen vacancies are the site for O\-2 activation. The adsorbed O\-2 or O\+- are the active oxygen species in propane oxidative dehydrogenation.

关键词： praseodymium orthovanadate active site propane oxidative dehydrogenation catalyst.

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Investigation on Spin Hamiltonian Parameters for Tetragonal Ytterbium Center in Lutetium orthovanadate

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Journal of Rare Earths 2007年第S1期25卷 541-543页

作者：董会宁帅欣关鸣刘俊 Institute of Applied Physics Chongqing University of Posts and Telecommunications

Rare earth doped orthovanadate crystal LuVO4∶Yb3+ shows high power laser applications because of the low quantum defect and the high thermal conductivity. Since electronic paramagnetic resonance (EPR) is a powerful tool to analyze the electronic properties and the local structures of paramagnetic impurity centers in crystals, the EPR spectra of the Yb3+ centers in LuVO4 crystal were measured recently. However, the above experimental results have not been theoretically interpreted. In this work, The EPR g factors and the hyperfine structure constants of 171Yb3+ and 173Yb3+ isotopes in LuVO4 crystal were theoretically studied from the perturbation formulae of the spin Hamiltonian parameters for 4f13 ion in tetragonal symmetry. The needed crystal parameters were obtained from the superposition model and the local structure of the studied system. The calculated results were in reasonable agreement with the observed values.

关键词： ytterbium orthovanadate electronic paramagnetic resonance superposition model crystal field theory rare earths

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Epidermal Growth Factor Enhances orthovanadate-Induced Contraction via Src and Myosin Phosphatase Target Subunit 1 in Rat Vascular Smooth Muscle

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Pharmacology & Pharmacy 2015年第7期6卷 329-340页

作者： Tomoya Sasahara Natsumi Ohkura Mariko Shin Akira Onodera Katsutoshi Yayama Laboratory of Cardiovascular Pharmacology Department of Biopharmaceutical Sciences Kobe Gakuin University Kobe Japan

Inhibition of protein tyrosine phosphatase by orthovanadate induces vasoconstriction, which is mediated by the Rho kinase-dependent inactivation of myosin light chain phosphatase (MLCP) via signaling downstream of Src-induced activation of the epidermal growth factor (EGF) receptor. The present study investigated the potential role of EGF in orthovanadate (OVA)-dependent vaso-constriction. OVA-induced aortic contraction significantly increased in the presence of EGF, and was abolished by inhibitors of Rho kinase (Y27632), extracellular signal-regulated kinase 1 and 2 (Erk1/2) (FR180204), Erk1/2 kinase (PD98059), EGF receptor (AG1478), and Src (PP2). Treatment of the rat endothelium-denuded thoracic aorta with either EGF or OVA augmented the phosphorylation of myosin phosphatase target subunit 1 (MYPT1) at Thr-853 and of the EGF receptor at Tyr-1173. The phosphorylation of MYPT1 was further increased by co-stimulation with EGF and OVA. EGF receptor phosphorylation at Tyr-845 was also increased by EGF or OVA;this effect was augmented by co-stimulation with EGF and OVA, and was abolished by Src inhibition. In addition, Erk1/2 was phosphorylated by EGF or by co-treatment with EGF and OVA;this was abolished by an EGF receptor inhibitor, but not by Src inhibition. These results suggested that OVA-induced EGF-related contraction was mediated by the Rho kinase-dependent inactivation of MLCP via two different signaling cascades: Src-dependent phosphorylation of the EGF receptor at Tyr-845 and EGF-dependent phosphorylation of Erk1/2.

关键词： Epidermal Growth Factor Myosin Light Chain Phosphatase Mitogen-Activated Kinase orthovanadate

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蛋白酪氨酸激酶与糖尿病大鼠主动脉平滑肌高反应性的关系

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中国药理学通报 2001年第5期17卷 511-514页

作者：周家国朱邦豪关永源贺华庞瑞萍林默君中山医科大学药理学教研室广州510089 中山医科大学附属一院消化内科广州510089 福建医科大学生理学教研室福州350004

目的　探讨蛋白酪氨酸激酶在糖尿病大鼠主动脉平滑肌高反应性中的作用。方法　离体主动脉环张力实验。结果　在 8～ 10wk的糖尿病大鼠 :①主动脉平滑肌对苯肾上腺素的浓度依赖性收缩反应显著增加 ,最大收缩反应为( 167± 2 3 ) g·g-1... 详细信息

目的　探讨蛋白酪氨酸激酶在糖尿病大鼠主动脉平滑肌高反应性中的作用。方法　离体主动脉环张力实验。结果　在 8～ 10wk的糖尿病大鼠 :①主动脉平滑肌对苯肾上腺素的浓度依赖性收缩反应显著增加 ,最大收缩反应为( 167± 2 3 ) g·g-1组织净重 ,较对照组 ( 10 0± 17) g·g-1组织净重增加了约 67% ,②蛋白酪氨酸磷酸酶抑制剂sodiumor thovanadate的浓度依赖性收缩反应也明显增强 ,1mmol·L-1sodiumorthovanadate的收缩反应为 ( 2 0 8± 2 5 )g·g-1组织净重 ,较对照组 ( 113± 18) g·g-1组织净重增加了约 85 % ,③蛋白酪氨酸激酶抑制剂 genistein均浓度依赖性地抑制糖尿病组和对照组主动脉平滑肌对苯肾上腺素的收缩反应 ,但在对照组的抑制率显著大于糖尿病组。结论　糖尿病大鼠主动脉平滑肌的高反应性可能与糖尿病时蛋白酪氨酸激酶的活性增加有关。

关键词：糖尿病主动脉平滑肌苯肾上腺素蛋白酪氧酸激酶蛋白酪氨酸磷酸酶 genistein sodium orthovanadate

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