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Neural Regeneration Research 2011年第2期6卷 118-124页

作者： Juegang Ju sheng-tian li Laboratory of Synaptic Signaling and Behavioral Neurosciences School of Life Science and Biotechnology Shanghai Jiao Tong UniversityShanghai 200240 China

Previous reports have shown that N-methyl-D-aspartate （NMDA） receptors are extensively involved in epilepsy genesis and recurrence. Recent studies have shown that synaptic and extrasynaptic NMDA receptors play different, or even opposing, roles in various signaling pathways, including synaptic plasticity and neuronal death. The present study analyzed changes in synaptic and extrasynaptic NMDA receptor-mediated currents during epilepsy onset. Mouse models of lithium chloride pilocarpLne-induced epilepsy were established, and hippocampal slices were prepared at 24 hours after the onset of status epilepticus. Synaptic and extrasynaptic NMDA receptor-mediated excitatory post-synaptic currents （NMDA-EPSCs） were recorded in CA1 pyramidal neurons by whole-cell patch clamp technique. Results demonstrated no significant difference in rise and delay time of synaptic NMDA-EPSCs compared with normal neurons. Peak amplitude, area-to-peak ratio, and rising time of extrasynaptic NMDA-EPSCs remained unchanged, but decay of extrasynaptic NMDA-EPSCs was faster than that of normal neurons, These results suggest that extrasynaptic NMDA receptors play a role in epileptogenesis.

关键词： N-methyl-D-aspartate receptor excitatory postsynaptic current epilepsy epileptogenesis hippocampus

Study on the Constitutive Model of Marble Based on the Conventional Triaxial Compression Test

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上海交通大学学报 2004年第Z2期38卷 8-13页

作者： tian sheng-li Lu Yun-de Ge Xiu-run School of Civil Engineering and Mechanics Shanghai Jiaotong University Shanghai200240China School of Civil Engineering and Mechanics Shanghai Jiaotong University Shanghai200240China School of Civil Engineering and Mechanics Shanghai Jiaotong University Shanghai200240China Institute of Rock and Soil Mechanics The Chinese Academy of Sciences Wuhan430071 China

The RMB-150B rock mechanics test system was employed to obtain the complete stress-strain test curves under confining pressures of 0-30MPa for marble samples from Ya'an ,Sichuan province. On the basis of former study and the convention triaxial pressure test results ,the complete procedures curves which described the relationships between yielding strength、 peak strength、 residual strength and confining pressure was obtained. Taking the strain softening of rock into account, the bilinear elastic-linear softening-residual perfect plasticity four-linear model was put forward in this paper on the basis of the test results and theory of plasticity. This model was adopted to describe the behaviors of marble in different phases under triaxial compression with the constitutive equation of strain softening phase as focus. The results indicated that the theoretic model fitted in well with the test results.

关键词： theory of plasticity conventional triaxial compression test constitutive model control equation linear softening bilinear elastic

Construction and Cleavage Characterization of Single Targeted Multi-ribozyme Expression Systems in vitro

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Chemical Research in Chinese Universities 2009年第4期25卷 506-512页

作者： tian sheng-li XU Dong-ping OHNUMA Takao Shenzhen Key Laboratory of Microbiology and Gene Engineering College of Life Sciences Shenzhen University Shenzhen 518060 P. R. China The 302 Hospital of Beijing Beijing 100039 P R. China Mount Sinai School of Medicine New York 10029 USA

In order to clarify cleavage efficiency of a multi-ribozyme expression system on their substrates,plasmids containing 20 cis-acting hammerhead ribozymes for self-cleavage and 10 trans-acting hammerhead ribozymes targeted on MDR1 and MRP1 substrates,the target plasmids pGEM-MDR1 and pGEM-MRP1 were constructed by employing PCR and DNA *** endonuclease＇s digestion and DNA sequencing confirmed exactness of the multi-ribozyme expression systems and the target *** repeated self-cleavage tests revealed that the cisacting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and trans-acting hammerhead ribozymes 196 Rz and 210 Rz were *** cleavage efficiencies of liberated ribozymes on their targets were evaluated in vitro and the results indicate that 196 Rz and 210 Rz were able to cleave the MDR1 and MRP1 RNA *** profile of cleavage reaction shows that the cleavage efficiencies were correlated with the numbers of transacting hammerhead ribozymes contained in the multi-ribozyme expression systems,as well as the multi-ribozyme system is much better than the single *** of various concentrations of Mg^2＋ reveals that ribozyme cleavage reactions were dependent on Mg^2＋ *** plot of lg（kobs） ***[Mg^2＋] displays a linear relationship in the concentration range observed（2.5―20 mmol/L）.

关键词： Multi-ribozyme expression systems Hammerhead ribozyme RNA substrate

Warm Deformation Behavior of Steels Containing Carbon of 0.45% to 1.26% With Martensite Starting Structure

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Journal of Iron and Steel Research International 2010年第5期17卷 34-37页

作者： li Qun WANG tian-sheng li Hong-biao GAO Yu-wei liNing JING tian-fu State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004 Hebei China

Warm deformation was investigated for steels containing carbon of 0. 45%,0. 79%, and 1. 26% respeetively with martensite starting structure, using Gleeble 3500 thermomechanical simulator at the temperature ranging from 873 K to 973 K and the strain rate ranging from 0.1 s^-1 to 0. 001 s^-1. The effect of carbon content on the deformation activation energy, Z value and the deformation resistance was analyzed, The results showed that the deformation resistance decreased with increasing carbon content. The peak stress of the steel containing earbon of 1.26% was decreased by 16.2% compared to the steel containing carbon of 0.45% under the same condition. This may be attributed to the weakening effect of solid solution strengthening which outweighs the precipitation strengthening of cementite.

关键词： carbon steel martensite starting structure warm deformation deformation resistance

Carbide Evolution in High Molybdenum Nb-microalloyed H13 Steel during Annealing Process

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Journal of Iron and Steel Research International 2015年第4期22卷 330-336页

作者： tian-sheng li Fu-ming WANG Chang-rong li Guo-qing ZHANG Qing-yong MENG State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Mechanical Engineering Hunan Institute of Technology School of Materials Science and Engineering University of Science and Technology Beijing

Based on the Thermo-Calc thermodynamic software, the type of equilibrium precipitated carbides and their contents in high Mo Nb-microalloyed H13 steel （NMH13 steel） were calculated. The composition, morphology, and distribution of carbides after spheroidal annealing of two forged experimental steels were comparatively examined by means of optical microscopy （OM）, scanning electron microscopy （SEM）, electron dispersive spectroscopy （EDS） and transmission electron microscopy （TEM）. VC, M23 C6 and M6C are identified in H13 steel after spheroidizing annealing, while （V,Nb）C, M23C6 , M2C and M6C are observed in NMH13 steel. Moreover, it is found that the ad- dition of Nb significantly enhances the stability of MC phase and the high Mo content accelerates the precipitation of small rod-shape M2C phase in NMH13 steel. The amount of the fine carbides in NMH13 steel obviously increased with M2 C and M6 C precipitated from the ferrite phase, which is in accordance with the results of thermodynamic cal- culations.

关键词： niobium microalloying high molybdenum H13 steel spheroidizing annealing carbide

Construction of Multi-ribozyme Expression System and Its Characterization of Cleavage on the MDR1/MRP1 Double Target Substrate in vitro

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Chemical Research in Chinese Universities 2009年第2期25卷 203-210页

作者： tian sheng-li ZHENG Suo liU Shi-de ZHANG Jian-hua XU Dong-ping OHNUMA Takao Shenzhen Key Laboratory of Microbiology and Gene Engineering College of Life Sciences Shenzhen University Shenzhen 518060 P. R. China Department of Bioengineering 302 Hospital of Beijing Beijing 100039 P. R. China Department of Hematology and Oncology Mount Sinai School of Medicine New York 10029 USA

To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.

关键词： Multidrug resistance(MDR) Multidrug resistance-associated protein(MRP1) Multi-ribozyme expression system RNA substrate

Ni_(3)S_(2) nanocrystals in-situ grown on Ni foam as highly efficient electrocatalysts for alkaline hydrogen evolution

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Rare Metals 2023年第10期42卷 3420-3429页

作者： Rui Sun Zhan-Hua Su Zhi-Feng Zhao Mei-Qi Yang tian-sheng li Jing-Xiang Zhao Yong-Chen Shang College of Chemistry Guangdong University of Petrochemical TechnologyMaoming525000China College of Chemistry and Chemical Engineering Harbin Normal UniversityHarbin150025China

The exploitation of cost-efficient electrocatalysts is critical to develop the hydrogen evolution reaction(HER) for hydrogen ***,Ni_(3)S_(2)/NF-x h(x=12,16 and 20,reaction time) nanocrystals in-situ grown on Ni foam(NF) were prepared via a facile hydrothermal *** results demonstrate that the reaction time plays key roles in the morphology,the hydrogen evolution performance of the samples,and the hydrogen brittleness of NF ***,the Ni_(3)S_(2)/NF-16 h displays outstanding catalytic activity for HER in alkaline solution and avoids the hydrogen brittleness of the NF skeletons *** afford a catalytic current of20 mA·cm^(-2),Ni_(3)S_(2)/NF-16 h presents ultra-low overpotential of 48 mV for hydrogen evolution and sufficient stability for 40 ***,the density functional theory(DFT) calculations revealed that the excellent electrocatalytic HER activity of Ni_(3)S_(2) could be attributed to its exposed(015) plane,which exhibited good capability for water adsorption and dissociation in an alkaline electrolyte,leading to the optimal free energy for H^(*) *** present work offers a novel strategy to design,synthesize and develop highly efficient electrocatalysts for HER.

关键词： Ni_(3)S_(2) Electrocatalysts Hydrogen evolution reaction Density functional theory calculations

Original article： Anterior and middle skull base reconstruction after tumor resection

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Chinese Medical Journal 2010年第3期 281-285页

作者： WANG Bo WU sheng-tian li Zhi liU Pi-nan Department of Neurosurgery Beijing Tiantan Hospital Affiliated to Capital Medical University Beijing 100050 China

Background Surgical management of skull base tumors is still challenging today due to its sophisticated operation procedure. Surgeons who specialize in skull base surgery are making endeavor to promote the outcome of patients with skull base tumor. A reliable skull base reconstruction after tumor resection is of paramount importance in avoiding life-threatening complications, such as cerebrospinal fluid leakage and intracranial infection. This study aimed at investigating the indication, operation approach and operation technique of anterior and middle skull base reconstruction. Methods A retrospective analysis was carried out on 44 patients who underwent anterior and middle skull base reconstruction in the Department of Neurosurgery at Beijing tiantan Hospital between March 2005 and March 2008. Different surgical approaches were selected according to the different regions involved by the tumor. Microsurgery was carried out for tumor resection and combined endoscopic surgery was performed in some cases. According to the different locations and sizes of various defects after tumor resection, an individualized skull base soft tissue reconstruction was carried out for each case with artificial materials, pedicled flaps, free autologous tissue, and free vascularized muscle flaps, separately. A skull base bone reconstruction was carried out in some cases simultaneously. Results Soft tissue reconstruction was performed in all 44 cases with a fascia lata repair in 9 cases, a free vascularized muscle flap in 1 case, a pedicled muscle flap in 14 cases, and a pedicled periosteal flap in 20 cases. Skull base bone reconstruction was performed on 10 cases simultaneously. The materials for bone reconstruction included titanium mesh, free autogenous bone, and a Medpor implant. The result of skull base reconstruction was satisfactory in all patients. Postoperative early-stage complications occurred in 10 cases with full recovery after conventional treatment. Conclusions The specifi

关键词： skull base neoplasms microsurgery endoscopes skull base reconstruction

Preoperative preparation and surgical separation of conjoined pygopagus twins

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Chinese Medical Journal 2010年第13期123卷 1800-1803页

作者： SUN tian-sheng li Shao-guang ZHANG Zhi-cheng li Fang GUAN Kai Department of Orthopedic Surgery Beijing Army General Hospital Beijing 100700 China

Conjoined twins are very rare with an estimated ,incidence of about 1 in 200 000 births with a male-female ratio of 1：3 The separation ot conjolned twins presents a challenge to surgeons and also a test for comprehensive efficiency of a hospital. Recently, a rare pair of pygopagus twins were admitted to our hospital and a successful surgical separation was carded out.

关键词： pygopagus conjoined twins preoperative care separation

Recombinant scFv Antibodies against E Protein and N Protein of Severe Acute Respiratory Syndrome Virus

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Acta Biochimica et Biophysica Sinica 2004年第8期36卷 541-547页

作者： Hui liU , Yan-li DING, Wei HAN, Mei-Yun liU, Rui-Yang tian, sheng-li YANG, and Yi GONGShanghai Research Center of Biotechnology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences,Graduate School of the Chinese Academy of Sciences, Shanghai 200233, China Shanghai Research Center of Biotechnology Shanghai Institutes of Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Shanghai 200233 China. huiliu@***

Three single chain antibodies (scFv) against the proteins of severe acute respiratory syndrome coronavirus (SARS-CoV) were isolated by phage display from an scFv antibody library. Bio-panning was carried out against immobilized purified envelope (E) and nucleocapsid (N) proteins of SARS-CoV. Their binding activity and specificity to E or N protein of SARS-CoV were characterized by phage-EliSA. Two of them, B10 and C20, could recognize non-overlapping epitopes of the E protein according to the two-site binding test result. Clone A17 could recognize N protein. The sequence of the epitope or overlapping epitope of scFv antibody A17 was PTDSTDNNQNGGRNGARPKQRRPQ. The affinity (equilibrium dissociation constant, Kd) of SARS-CoV E protein was 5.7×10–8 M for B10 and 8.9×10–8 M for C20. The affinity of A17 for N protein was 2.1×10–6 M. All three scFv antibodies were purified with affinity chromatography and determined by Western blot.

关键词： SARS-CoV antibody scFv phage display affinity chromatography