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ZrCl_4/Hantzsch 1,4-dihydropyridine as a new and efficient reagent combination for the direct reductive amination of aldehydes and ketones with weakly basic amines

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Chinese Chemical Letters 2007年第4期18卷 458-460页

作者： Zhen Gang liu Nan Li Li yang zhong Li liu Wei Yu State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromatic amines can be reductively alkylated with electron rich aldehydes and ketones under mild conditions to form the secondary amines in excellent yields.

关键词： Zirconium tetractfloride Hantzsch 1,4-dihydropyfidine Reductive amination

Isoflavone genistein protects high glucose-induced human aortic endothelial cell apoptosis through estrogen receptor-mediated pathway

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Journal of Geriatric Cardiology 2008年第2期5卷 86-90页

作者： Wenwen zhong yang liu Guang yang Hui Tian Department of Geriatric Endocrinology Chinese PLA General Hospital Beijing100853China Department of Geriatric EndocrinologyChinese PLA General Hospital Beijing100853China Department of Geriatric EndocrinologyChinese PLA General Hospital Beijing100853China Department of Geriatric EndocrinologyChinese PLA General Hospital Beijing100853China

Objective The aim of this study was to determine if isoflavone genistien has protective effects against high glucose-induced cell apoptosis in human aortic endlthelial cells, and investigate the possible mechanism for this protection. Methods Human aortic endothelial cells subjected to normal (5mmol/L) or high glucose (25mmol/L) were treated with genistein at 0, 50, 100nmol/L. Parallel experiments were performed with 100nM 17b-estradiol, and also in the presence and absence of the pure anti-estrogen ICI-182,780 (100nmol/L). The effects on cell apoptotic DNA fragmentation were determined using cell death ELISA, and the effects on cellular proliferation were determined using tritiated thymidine incorporation assay. Estrogen receptor expression was detected by Taqman quantitative PCR. Results Genistein at 100nmol/L significantly reduced high glucose-induced DNA fragmentation, and reversed cell DNA synthesis inhibition (P <0.001) after 24 hours' incubation. The effect of genistein was completely blocked by ICI-182,780 administration. Estrogen receptor beta, but not alpha was found to be expressed in these cells. Conclusion Isoflavone genistein shows protection against high glucose-induced cell damage through estrogen receptor beta, reducing apoptotic DNA damage and protecting from the inhibition of cell proliferation.

关键词： phytoestrogen endothelial cell high glucose estrogen receptor apoptosis

Pd/C-catalyzed selective reduction of aromatic azides with Hantzsch 1,4-dihydropyridine

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Chinese Chemical Letters 2008年第8期19卷 885-888页

作者： Zhen Gang liu Xiu Qin Niu Wei Yu Li yang zhong Li liu State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 China

The reagent combination of Hantzsch 1,4-dihydropyridine and Pd/C was found to be an efficient reducing system for the selective reduction of aromatic azides.

关键词： Reduction Hantzsch 1,4-dihydropyridine Pd/C Aromatic azides

Silencing of Bcl-2 gene expression by siRNA transfection in- hibits the protective effect of fluvastatin against cell apoptosis in human aortic endothelial cells

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Journal of Geriatric Cardiology 2008年第1期5卷 33-38页

作者： Wenwen zhong yang liu Jian Li Hui Tian Department of Geriatric Endocrinology Chinese PLA General HospitalBeijing 100853China Department of Geriatric EndocrinologyChinese PLA General HospitalBeijing 100853China Department of Geriatric EndocrinologyChinese PLA General HospitalBeijing 100853China Department of Geriatric EndocrinologyChinese PLA General HospitalBeijing 100853China

Objective To study the protective effect of fluvastatin,one of the HMG-CoA reductase inhibitors (statins),against oxygen radical-induced oxidative damages in human aortic endothelial cell,and the role of Bcl-2 in this *** Human aortic endothelial cells with or without Bcl-2 siRNA transfection were subjected to 1-100 nM of fluvastatin and 100 la hydrogen peroxide for 24 ***-2 mRNA and protein expression were measured by Taqman quantitative PCR and Western *** apoptosis was measured by normal and fluorescent microscopy and Cell Death Detection *** In the Bcl-2-expressed cells,fluvastatin significantly reversed hydrogen peroxide-induced microscopic apoptosis and apoptotic DNA fragmentation,which were accompanied by a markedly upregulation of Bcl-2 expression by ***,the endothelial protection by fluvastatin was completely lost in Bcl-2 siRNA transfected *** Fluvastatin protects human endothelial cells against oxygen radical-induced cell apoptosis in vitro,and this protection seemed to be mediated in a Bcl-2 dependent pathway.(J Geriatr Cardil 12008;5:33-38)

关键词： fluvastatin,Bcl-2,gene silencing,apoptosis

CaY-zeolite Catalyzed Etherification and Alkylation of Substituted Benzyl Alcohols

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Chinese Chemical Letters 2006年第1期17卷 15-18页

作者： Wei YU Miao WEN Guang Yu ZHAO Li yang zhong Li liu National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000

The reaction of p- and/ α-subtituted benzyl alcohols in CaY-zeolite produced the corresponding dibenzyl ethers and/or benzyl toluenes as the principal products.

关键词： Benzyl alcohols CaY-zeolite etherification alkylation.

Oxidation of Silicon and Boron in Boron Containing Molten Iron

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Journal of Iron and Steel Research International 2007年第6期14卷 32-36页

作者： yang zhong-dong liu Su-lan LI Zhe-fu XUE Xiang-xin School of Materials and Metallurgy Northeastern University Shenyang 110004 Liaoning China

A new process of directly smelting boron steel from boron-containing pig iron has been established. The starting material boron-containing pig iron was obtained from ludwigite ore, which is very abundant in the eastern area of Liaoning Province of China. The experiment was performed in a medium frequency induction furnace, and Fe2O3 powder was used as the oxidizing agent. The effects of temperature, addition of Fe2O3, basicity, stirring, and composition of melt on the oxidation of silicon and boron were investigated respectively. The results showed that sili- con and boron were oxidized simultaneously and their oxidation ratio exceeded 90% at 1 400℃. The favorable oxidation temperature of silicon was about 1 300-- 1 350℃. High oxygen potential of slag and strong stirring enhanced the oxidation of silicon and boron.

关键词： boron-containing pig iron oxidation silicon boron

Hydrophobic surface modification of chitosan gels by stearyl for improving the activity of immobilized lipase

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Chinese Chemical Letters 2009年第8期20卷 995-999页

作者： Hong Tao Deng Juan Juan Wang Miao Ma zhong yang liu Fei Zheng College of Chemistry Central China Normal University Wuhan 430079 China

The hydrophobic surface modification of chitosan gels was carried out using the amidating reaction of amido groups on a gel surface with stearic acid activated by 1-ethyl-3-（3-dimethylaminopropyl）-carbodiimide hydrochloride （EDC） and N-hydroxysuccinimide （NHS）. Lipases from Candida rugosa were adsorbed on the nascent chitosan gels （CS） and stearyl-modified gels （SCS） with different degrees of amidation. The increased surface hydrophobicity of chitosan gels improved the adsorption capacity and activity of the immobilized lipase. SCS with 31.46% amidation showed the maximum activity retention （83.43%）. The experimental results suggest that the moderate surface hydrophilicity/hydrophobicity of chitosan gels is necessary for the improvement of the activity of immobilized lipase. ？2009 Hong Tao Deng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Lipase Chitosan Surface modification Adsorption

Regulating solid electrolyte interphase film on fluorinedoped hard carbon anode for sodium-ion battery

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Carbon Energy 2024年第6期6卷 200-215页

作者： Cuiyun yang Wentao zhong Yuqiao liu Qiang Deng Qian Cheng Xiaozhao liu Chenghao yang Guangzhou Key Laboratory for Surface Chemistry of Energy Materials New Energy Research InstituteSchool of Environment and EnergySouth China University of TechnologyGuangzhouChina

For the performance optimization strategies of hard carbon,heteroatom doping is an effective way to enhance the intrinsic transfer properties of sodium ions and electrons for accelerating the reaction ***,the previous work focuses mainly on the intrinsic physicochemical property changes of the material,but little attention has been paid to the resulting interfacial regulation of the electrode surface,namely the formation of solid electrolyte interphase(SEI)*** this work,element F,which has the highest electronegativity,was chosen as the doping source to,more effectively,tune the electronic structure of the hard *** effect of F-doping on the physicochemical properties of hard carbon was not only systematically analyzed but also investigated with spectroscopy,optics,and in situ characterization techniques to further verify that appropriate F-doping plays a positive role in constructing a homogenous and inorganic-rich SEI *** experimentally demonstrated link between the electronic structure of the electrode and the SEI film properties can reframe the doping optimization strategy as well as provide a new idea for the design of electrode materials with low reduction kinetics to the *** a result,the optimized sample with the appropriate F-doping content exhibits the best electrochemical performance with high capacity(434.53 mA h g^(-1)at 20mA g^(-1))and excellent rate capability(141 mAh g^(-1)at 400 mA g^(-1)).

关键词： F-doping hard carbon reduction kinetics sodium-ion batteries solid electrolyte interphase film

Restraint effect of partition wall on the tunnel floor heave in layered rock mass

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Journal of Mountain Science 2024年第7期21卷 2462-2479页

作者： yang Yunyun HUANG Da zhong Zhu liu yang PENG Jianbing School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China College of Geology Engineering and Geomatics Chang’an UniversityXi’an 710054China College of Civil Engineering&Architecture China Three Gorges UniversityYichang 443002China.

The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the *** study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel *** results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal *** an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave *** primary cause of significant deformation in floor heave is upward buckling *** address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock *** results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave *** is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure *** simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor.

关键词： Layered rock Floor heave Horizontal compression test Failure behavior Partition wall