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Study on the two and three-parameter working stability regions of 3.-TZP suspension

Science china(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEn Youqiang1, 2, ZHAnG Xinni3. CHEn Sha’ou3.& QI Ping3.1. department of chemistry, Qingdao university, Qingdao 266071,{3. 2. department of chemistry, Tsinghua university, Beijing 100084,{3. 3. department of Physics, Qingdao university, Qingdao 266071,{3. department of chemistry Qingdao University Qingdao China department of chemistry Tsinghua University Beijing China department of Physics Qingdao University Qingdao China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.

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Theoretical study on the reaction mechanism of(CH_3._3.O+CO

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Science china chemistry 2005年第1期48卷 18-24页

作者： ZHAO Hongmei1,2,3. SUn Chengke1,4, ZHAnG Rongchang3. XI Hongmin3.& LI Zonghe1 1. department of chemistry, Beijing normal university, Beijing 100875,{3. 2. The Laboratory of Molecular Reaction Dynamics, Institute of chemistry, Chinese Academy of Sciences, Beijing 100080,{3. 3. department of chemistry, beihua university, jilin 1.2.1.,{3. 4. department of chemistry, Qujing normal university, Yunnan 655000,{3. department of chemistry Beijing Normal University Beijing China The Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing China department of chemistry Beihua University Jilin China department of chemistry Qujing Normal University Yunnan China

The reaction mechanism of (CH3.3.O with CO has been theoretically investigated using density-functional theory (DFT) calculations at B3.YP/6-3.G* level. In order to get more reliable energy values the single-point energy is evaluated at CCSD (T)/6-3.++G** level. The results show that the reaction is multi-channel and the reaction of (CH3.3.O radical with CO mostly produces (CH3.3. + CO2. The reaction could play a role in eliminating air pollution.

关键词： DFT, B3.YP, (CH3.3.O, radical.

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mA reader YTHDF2 governs the onset of atrial fibrillation by modulating Cacna1c translation

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Science china Life Sciences 2024年

作者： Chuansheng Chen Guanghua Wang Qicheng Zou Ke Xiong Zhiwen Chen beihua Shao Yi Liu Duanyang Xie Yong ji Key Laboratory of Cardiovascular and Cerebrovascular Medicine Nanjing Medical University State Key Laboratory of Cardiovascular Diseases Shanghai East Hospital School of Medicine Tongji University department of Pathology and Pathophysiology School of Medicine Tongji University department of Cardiology School of Medicine Tongji University Shanghai Arrhythmia Research Center Shanghai East Hospital School of Medicine Tongji University

Atrial fibrillation（AF） is the most common arrhythmia, which is tightly associated with the abnormal expression and function of ion channels in the atrial cardiomyocytes. n6-methyladenosine（m6A）, a widespread chemical modification in eukaryotic m RnA, is known to play a significant regulatory role in the pathogenesis of heart disease. However, the significance of m6A regulatory proteins in the onset of AF remains unclear. Here, we demonstrate that the m6A reader protein YTHDF2 regulates atrial electrical remodeling and AF onset by modulating the Cav1.2 expression. Firstly, YTHDF2 expression was selectively upregulated in rat atrial cardiomyocytes with AF. Secondly,YTHDF2 knockout reduced AF susceptibility in mice. Thirdly, the knockout of YTHDF2 increased Cav1.2 protein levels in an m6A-independent manner, ultimately prolonging the atrial myocardial refractory period, a critical electrophysiological substrate for the onset of AF. Fourthly, the n-terminal domain of YTHDF2 was identified as critical for Cacna1c m RnA translation regulation. Overall, our findings unveil that YTHDF2 can alter Cav1.2 protein expression in an m6A-independent manner, thereby facilitating the onset of AF. Our study suggests that YTHDF2 may be a potential intervention target for AF.

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Simultaneously inducing synthesis of semiconductor selenium multi-armed nanorods and nanobars through bio-membrane bi-templates

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Science china chemistry 2004年第6期47卷 507-511页

作者： LI Li1, WU Qingsheng1 DInG Yaping2 & LI Ping3.1. department of chemistry, Tongji university, Shanghai 200092,{3. 2. department of chemistry, Shanghai university, Shanghai 20043.,{3. 3. department of Food, Anhui Agricultural university, Hefei 23.03.,{3. department of chemistry Tongji University Shanghai China department of chemistry Shanghai University Shanghai China department of Food Anhui Agricultural University Hefei China

Multi-armed nanorods and nanobars of semiconductor selenium were simultane- ously synthesized in the light of biomineralization process through bio-membrane bi-templates of rush at room temperature. The multi-armed nanorods are 60 nm in diameter and 1.5 μm in length; the nanobars are 150 nm in diameter and 1000—1100 nm in length. The XRD pattern indicates that these nanocrystals were crystallized in the hexagonal structure with lattice constants a = 0.43. nm, c = 0.495 nm. The possible formation mechanism was investigated.

关键词： selenium, multi-armed nanorods, nanobars, bio-membrane, bi-templates.

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Mathematic Expression of Kinetic Compensation Effect and Relationship between the Exothermic Decomposition Temperature and Critical Temperature of Thermal Explosion of Eighty-six Energetic Materials

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含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YAnG De suo 2, ZHAnG jiao qiang 3. (1. department of chemistry,northwest university, Xi′an 710065,{3. 2. department of chemistry and Chemical Engineering, Baoji College of Arts and Science, Baoji 721007,{3. 3. department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

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Surface effects of monolayer-protected gold nanoparticles on the redox reactions between ferricyanide and thiosulfate

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Science china chemistry 2005年第5期48卷 424-430页

作者： LI Di1, SUn Chunyan1, HUAnG Yunjie1, LI jinghong1,2 & CHEn Shaowei3.1. State Key Laboratory of Electroanalytical chemistry, Changchun Institute of Applied chemistry, Chinese Academy of Sciences, Changchun 13.022, china 2. {3. of chemistry, Tsinghua university, Beijing 100084, china 3. department of chemistry, university of California, Santa Cruz, Santa Cruz, CA 95064, USA State Key Laboratory of Electroanalytical chemistry Changchun Institute of Applied chemistry Chinese Academy of Sciences Changchun China department of chemistry Tsinghua University Beijing China department of chemistry University of California Santa Cruz Santa Cruz USA

Electron transfer through the self-assembled monolayers (SAMs) on gold nanopar-ticles is investigated by using the monolayer protected gold nanoclusters (MPCs) as elec-tron-transfer mediators. 3.Mercaptopropionic acid (MPA) and 11-meraptoundecanoic acid (MUA) MPCs were employed to catalyze the redox reaction between potassium ferricyanide and sodium thiosulfate. The catalytic mechanism was proposed that the MPCs act as diffusing elec-tron-mediators and electron transfers to and from the MPCs surface. Therefore the electron transfer rate through the capping layers would be proportional to the MPCs catalyzed reaction rate, which was monitored by the UV absorbance of ferricyanide. The calculated apparent rate constant was orders of magnitude smaller than that of the maximum of tunneling current, which was attributed to the splited energy level of the nanoscale particles.

关键词： electron transfer, three-dimensional self-assembled monolayers, redox reaction, electron transfer mediator, surface effect.

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Theoretical study on the reaction mechanism of (CH3.3.O(.) radical with nO

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Science china chemistry 2004年第4期47卷 289-294页

作者： ZHAO Hongmei1,2, LIU Kun1, SUn Chengke1 & LI Zonghe1 1. department of chemistry, Beijing normal university, Beijing 100875,{3. 2. department of chemistry, beihua university, jilin 1.2.1.,{3. department of chemistry Beijing Normal University Beijing China department of chemistry Beihua University Jilin China

The reaction mechanism of (CH3.3.O? radical with nO is theoretically investigated at the B3.YP/6-3.G* level. The results show that the reaction is multi-channel in the single state and triplet state. The potential energy surfaces of reaction paths in the single state are lower than that in the triple state. The balance reaction: (CH3.3.OnO(CH3.3.O?+nO, whose potential energy surface is the lowest in all the reaction paths, makes the probability of measuring (CH3.3.O? radical increase. So nO may be considered as a stabilizing reagent for the (CH3.3.O? radical.

关键词： (CH3.3.O. radical DFT reaction mechanism nO

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Syntheses,characterization,crystal structure and magnetic properties of copper(Ⅱ) α,β-unsaturated carboxylate complexes with trimethyl phosphate

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Chinese Science Bulletin 2001年第12期46卷 987-991页

作者： WAnG Yaoyu, LIU Ping, SHI Qian, GAO Yici & SHI Qizhen1. department of chemistry, northwest university, Xi’an 710069,{3. 2. department of chemistry, Wenzhou Teachers College, Wenzhou 3.5003.{3. 3. department of chemistry, Lanzhou university, Lanzhou 73.000,{3. department of chemistry Northwest University Xi’an China department of chemistry Wenzhou Teachers College Wenzhou China department of chemistry Lanzhou University Lanzhou China

Two ternary complexes Cu2A4[OP(OCH3.3.2 (A represents CH2=CH-COO- and CH2=C(CH3.-COO-) have been synthesized, and elemental analyses, IR, ESR, electronic reflectance spectra and magnetic studies were carried out. The single crystal X-ray diffraction shows that Cu2[CH2=C(CH3.-COO]4[OP(OCH3.3.2 is triclinic, with space group P1, a = 1.05128(13., b = 1.7559(5), c = 1.94479(3. nm, α =91.263.14)°,(β = 102.559(6)°,γ= 106.3.9(13.°, Z = 4 and R = 0.0668. Two copper(Ⅱ) atoms are bridged by four (a-methacrylate groups, and each copper(Ⅱ) atom is coordinated with a trimethyl phosphate molecule in the axial position, forming a distorted square pyramidal configuration. The symmetric center is between the two copper(Ⅱ) atoms, and the Cu-Cu bond distance is 0.26098(6) nm. The Cu-Cu distance and magnetic studies suggest that there exist anti-ferromagnetic interactions between the two copper(Ⅱ) atoms.

关键词： copper(Ⅱ ) complex α β-unsaturated carboxylate trimethyl phosphate magnetic property crystal structure.

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A local spin evaluation into the active site models of [2Fe2S] ferrodoxin [Fe_2S_2(SR)_4]^(2-) (R=-H, -CH_3.

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Science china chemistry 2007年第3期50卷 327-334页

作者： WEI jiChong1,2, WAnG Yan3.& JU GuanZhi2,3.1 department of chemistry, Hainan normal university, Haikou 571158,{3. 2 State Key Laboratory of Theoretical and Computational chemistry, jilin university, Changchun 13.023.{3. 3.department of chemistry, nanjing university, nanjing 210093.{3. department of chemistry Hainan Normal University Haikou China State Key Laboratory of Theoretical and Computational chemistry Jilin University Changchun China department of chemistry Nanjing University Nanjing China

To test the feasibility of local spin theory of Davidson and Clark for ferrodoxin clusters, the models [Fe2S2(SR)4]2- (R=-H, -CH3. are chosen for evaluation. This purpose is realized by calculating the local spin expectation values , , and mA and discussing the connection between these expected values and the Heisenberg spin model (HSM) and the noodleman broken-symmetry approach. In practical calculation, the spin-unrestricted Hartree-Fock (UHF) and spin-polarized density functional theory (DFT) are used and the calculational qualities of these two methods are also discussed. In addition, the theoretical magnetic coupling constants JAB of these models are calculated by various computational schemes for comparison with both theoretical and experimental results previously reported.

关键词： local spin iron-sulfur protein model density function theory magnetic coupling constant

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Effect of daidzin,genistin,and glycitin on osteogenic and adipogenic differentiation of bone marrow stromal cells and adipocytic transdifferentiation of osteoblasts

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Acta Pharmacologica Sinica 2005年第9期26卷 1081-1086页

作者： Xiang-hui LI~1 jin-chao ZHAnG~(2,3. Sen-fang SUI~(1,4) Meng-su YAnG~(3.4)1 State Key Laboratory of Biomembrane department of Biological Sciences and Biotechnology,Tsinghua university,Beijing 100084,china 2 department of chemistry College of chemistry and Environmental Science,Hebei university,Baoding 071002,china 3.department of Biology and chemistry,City university of Hong Kong,Hong Kong,china department of Biological Sciences and Biotechnology State Key Laboratory of Biomembrane Tsinghua University Beijing China department of chemistry College of Chemistry and Environmental Science Hebei University Baoding China department of Biology and chemistry City University of Hong Kong Hong Kong China

Aim:To examine the effect of daidzin,genistin,and glycitin on the osteogenic andadipogenic differentiation of bone marrow stromal cells（MSC）and the adipogenictransdifferentiation of ***:MTT test,alkaline phosphatase（ALP）activity measurement,Oil Red O stain and measurement were ***:Daidzin,genistin,and glycitin 1×10-8,5×10-7,1×10-6,5×10-6,and 1×10-5mol/L all promoted the proliferation of primary mouse bone MSC and *** 5×10-7mol/L and genistin 1×10-6mol/L promoted the osteogenesis *** 1×10-8,5×10-7,1×10-6,5×10-6,and 1×10-5mol/L and glycitin 1×10-8,1×10-6,and 1×10-5mol/L inhibited the adipogenesis of ***,genistin,and glycitin 1×10-8,5×10-7,1×10-6,5×10-6,and 1×10-5mol/L all inhibited the adipocytictransdifferentiation of ***:Daidzin,genistin,and glycitinmay modulate differentiation of MSC to cause a lineage shift toward the osteo-blast and away from the adipocytes,and could inhibit adipocytic transdifferen-tiation of *** could also be helpful in preventing the developmentof osteonecrosis.

关键词： daidzin genistin glycitin bone marrow stro-real cells osteogenic differentiation adipogenic differentiation osteoblasts adipocytic transdifferentiation

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