检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2009年第6期24卷 956-960页

作者：吴斌郑启新 department of Orthopaedics Union HospitalTongji Medical CollegeHuazhong University ofScience & Technology

A biomimetic scaffold based on mineralized recombinant collagen, nano-hydroxyapatite/recombinant human-like collagen/poly（lactic acid）（nHA/RHLC/PLA）, was prepared with recombinant human bone morphogenic protein-2.（rhBMP-2. for improving the osteoinductive property of the scaffold. The nHA/RHLC/PLA scaffolds loaded with 10 μg rhBMP-2.and the unloaded scaffolds were implanted subcutaneously in the rat model. The osteogenetic capacity of these composites was evaluated by CT scan, ALP activity test and histological observation at 4 and 8 weeks after implantation. The experimental results indicated that the osteogenic capability of the scaffolds loaded with rhBMP-2.was superior to the unloaded scaffold. It was concluded that rhBMP-2.can enhance the osteoinductive property of the nHA/RHLC/PLA scaffold and the nHA/RHLC/PLA scaffold loaded with rhBMP-2.have the good potential of being used in bone tissue engineering.

关键词： rhBMP-2 bone tissue engineering osteogenesis biomaterial

Effects of water phase concentration on the emulsion polymerization of polyaniline

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University of Technology 2001年第2期8卷 140-142页

作者： PAN Chun yue 1,CHEN Zhen hua 2.HUANG Yong li 1,HUANG Ke long 1 (1.college of Chemistry and Chemical Engineering, Central South University, Changsha 410083, china {2. of Materials Science and Engineering, Central South University, Cha 1. college of Chemistry and Chemical Engineering Central South University 410083 Changsha China 2. department of Materials Science and Engineering Central South University 410083 Changsha China

The emulsion polymerization of aniline in three phase system of xylene functionalized protonic acid water was carried out using (NH 4) 2. 2. 4 as oxidant. The influences of water phase concentration on the viscosity, conductivity, transmittance of polyaniline(PAN) latex and its powders were studied. The results show that the properties of PAN prepared through the emulsion polymerization are influenced by the amount of water used in the polymerization. The morphology of PAN varies with the water phase concentration used in the polymerization, which may result in the change of properties of PAN latex and its powders. When the volume fraction of water (φ) is about 2.% 30%, the prepared PAN powder has higher conductivity, and the PAN latex has appropriate viscosity and particle size. The consumption of xylene was reduced at high φ value.

关键词： polyaniline emulsion polymerization water concentration property

First-principles study on the electronic structure and optical properties of CrSi_2

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2009年第1期52卷 46-51页

作者： ZHOU ShiYun1,2. XIE Quan1, YAN WanJun1 & CHEN Qian1 1 college of Electronic Science & Information Technology, Guizhou University, Guiyang 55002., china {2. of Physics, Anshun college, Anshun 561000, china college of Electronic Science & Information Technology Guizhou University Guiyang 550025 China department of Physics Anshun College Anshun 561000 China

Using the first principle methods based on the plane-wave pseudo-potential theory, band structure, density of states and optical properties of CrSi2.were studied. The calculation of band structure shows that CrSi2.is an indirect semiconductor whose band gap is 0.353 eV. Density of states is mainly composed of 3d electron of Cr and 3p electron of Si. Dielectric function, refractive index, reflectivity, and absorption coefficient of CrSi2.are also calculated. The calculation results of optical properties are in agreement with the experiments.

关键词： CrSi2 electronic structure optical properties first principles

Influential Factors on Deicing Performance of Electrically Conductive Concrete Pavement

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2006年第2期21卷 123-127页

作者：唐祖全 college of Materials Science & Engineering Chongqing UniversityChongqing 400045China

The deicing experiment of carbon fiber reinforced electrically conductive concrete （CFRC） slab was conducted in laboratory at first, then the deicing process of CFRC parement was analyzed by means of finite element method （FEM）. At last, based on the energy conservation law and the computing restdts of finite element method, the influential factors including the setting of electric heating layer, environmental temperature, the thickness of ice, material parameters, and deicing power on deicing performance and energy consumption were discussed.

关键词： electrically conductive concrete deicing performance electrothermal effect energy consumption influence factors

Empirical likelihood-based inference in a partially linear model for longitudinal data

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第1期51卷 115-130页

作者： XUE LiuGen~(1+) & ZHU LiXing~2.1 college of Applied Sciences, Beijing University of Technology, Beijing 10002., china {2. of Mathematics, Hong Kong Baptist University, Hong Kong, china college of Applied Sciences Beijing University of Technology Beijing 100022 China department of Mathematics Hong Kong Baptist University Hong Kong China

A partially linear model with longitudinal data is considered, empirical likelihood to infer- ence for the regression coefficients and the baseline function is investigated, the empirical log-likelihood ratios is proven to be asymptotically chi-squared, and the corresponding confidence regions for the pa- rameters of interest are then constructed. Also by the empirical likelihood ratio functions, we can obtain the maximum empirical likelihood estimates of the regression coefficients and the baseline function, and prove the asymptotic normality. The numerical results are conducted to compare the performance of the empirical likelihood and the normal approximation-based method, and a real example is analysed.

关键词： partially linear model empirical likelihood confidence region longitudinal data 62.05 62.15 62.2.

TLR4 signaling induced TLR2.expression in the process of mimic cerebral ischemia/reperfusion in vitro

在线全文

学校读者我要写书评

暂无评论

中国科学：生命科学英文版 2010年第2期53卷 223-228页

作者： SUN Peng1,ZHANG Qing2.HAN JiYuan1,TIAN Yuan3 & ZHANG JingHui3 1department of Emergency,Union Hospital,Tongji medical {2.,Huazhong University of Science and Technology,Wuhan 43002.,china 2.0} of Anesthesia,Union Hospital,Tongji medical {2.,Huazhong University of Science and Technology,Wuhan 43002.,china 3department of General Surgery,Union Hospital,Tongji medical {2.,Huazhong University of Science and Technology,Wuhan 43002.,china 1. department of Emergency Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China2. Department of Anesthesia Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China3. Department of General Surgery Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China

Both TLR4 and TLR2.participated in the mediation of the inflammatory injury in the process of partial cerebral ischemia/***,it still remains unclear whether a crosstalk exists between TLR2.and TLR4 in ischemic cerebral *** the present study,we investigated the effect of TLR4 signaling on TLR2.expression during mimic cerebral I/R in ***-2.cells were cultured and treated with ischemia/reperfusion,then transfected with the plasmid pEGFP-H1/TLR4-siRNA,the plasmid pEGFP-H1/control sequence-siRNA and the blank plasmid,***,the expression of TLR2.and TLR4 mRNA and protein,NF-κB p65 mRNA and supernatant TNF-α level were significantly higher in ischemia/reperfusion treated cells than those lack of ischemia/reperfusion treatment,and as compared with those in ischemia/reperfusion treated cells without transfection,no significant differences about the above mentioned gene and protein expression were found in the blank plasmid tranfected cells and the plasmid pEGFP-H1/control sequence-siRNA transfected cells respectively,while the expression levels in the plasmid pEGFP-H1/TLR4-siRNA transfected cells were significantly ***,in order to determine the effects of pyrrolidinediethyldithiocarbamate (PDTC),an NF-κB inhibitor,on the TLR4-induced TLR2.expression in BV-2.cells treated with ischemia/reperfusion,it was found that TLR4 and TLR2.mRNA expressions in PDTC pretreated cells were significantly lower in comparison with normal saline pretreated cells and non-pretreated *** data suggested that TLR2.activation,signaled by TLR4 and regulated by NF-κB,might be directly involved play an important role in ischemia/reperfusion induced brain damage.

关键词： Toll-like receptor 4 Toll-like receptor 2 cerebral ischemia/reperfusion microglia

Two-photon spectroscopic behaviors and photodynamic effect on the BEL-7402.cancer cells of the new chlorophyll photosensitizer

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2008年第6期51卷 529-538页

作者： ZHAO PeiDe1,2.CHEN Ping1,TANG GuoQing1,LIU JinWei2.LIN Lie1,GUO Peng1,YU Qing2. YAO JianZhong3,MA DongMing4,ZHANG GuiLan1 & CHEN WenJu1 1 Key Laboratory of Optoelectronic Information Science and Technology,Ministry of Education,Institute of Modern Optics,Nankai University,Tianjin 300071,china 2.department of Physics,Hebei University of Technology,Tianjin 300130,china 3 college of Pharmacy,Second Military medical University,Shanghai 2.0433,china 4 Tianjin college of the Traditional Chinese Medicine,Tianjin 300193,china 1. Key Laboratory of Optoelectronic Information Science and Technology Ministry of Education Institute of Modern Optics Nankai University Tianjin 300071 China 2. department of Physics Hebei University of Technology Tianjin 300130 China 3. college of Pharmacy Second Military Medical University Shanghai 200433 China 4. Tianjin college of the Traditional Chinese Medicine Tianjin 300193 China

The spectroscopic properties of a new chlorophyll derivate photosensitizer (CDP) are studied under the excitation wavelengths at 800 and 400 nm using femtosecond pulses from a Ti: sapphire laser. The damaging effect of CDP on the BEL-7402.cancer cells is also investigated upon two-photon illumination at 800 nm. The normalized fluorescence spectra of CDP in tetrahydrofuran (THF) show that two-photon and one-photon spectra have the same distributions and the same emission bands (675 nm). The lifetimes of two- and one-photon induced fluorescence of this molecule are of the order of 5.0 ns. By comparing the data it is shown that there is some difference between the two lifetimes, but the difference is less than one nanosecond. The two-photon absorption cross section of the molecule is also measured at 800 nm and estimated as about σ'_2.≈ 31.5x10^(-50)cm^4·s·photon^(-1). The results of two-photon photodynamic therapy (TPPDT) tests show that CDP can kill all of the tested cancer cells according to the usual Eosine assessment. Our results indicate that the two-photon-induced photophysical, photochemical and photosensitizing processes of CDP may be basically similar to those of one-photon excitation. These behaviors of the sample suggest that one may find other possible methods to estimate some photosensitizers' effects in details such as their distribution in cells and the reactive targets of the sub-cellular parts of some tumor cells via two-photon excitation techniques.

关键词： photosensitizer chlorophyll derivate two-photon fluorescence two-photon absorption cross-section TPPDT BEL-7402 cell

Effect of calcitonin gene-related peptide and nerve growth factor on spatial learning and memory abilities of rats following focal cerebral ischemia/reperfusion

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第8期1卷 673-676页

作者： Guangshun Zheng1, Yongjie Yang2. Xiubin Fang3 1department of Neurosurgery, Second Hospital of Xiamen, Xiamen 36102., Fujian Province, china 2.0} of Neurosurgery, Second Hospital Affiliated to china medical University, Shenyang 110004, Liaoning Province, china 3department of Neurobiology, Basic medical college of china medical University, Shenyang 110001, Liaoning Province, china department of Neurosurgery Second Hospital of Xiamen Xiamen 361021 Fujian Province China department of Neurosurgery China Medical University Shenyang 110004 Liaoning Province China department of Neurobiology Basic Medical College China Medical University Shenyang 110001 Liaoning Province China

BACKGROUND: Calcitonin gene-related peptide (CGRP) and nerve growth actor (NGF) cam improve spatial learning and memory abilities of rats with cerebral ischemia/reperfusion; however, the effect of combination of them on relieving learning and memory injury following cerebral ischemia/reperfusion should be further studied. OBJECTIVE: To study the effects of exogenous CGRP and NGF on learning and memory abilities of rats with focal cerebral ischemia/reperfusion. DESIGN: Randomized controlled animal study. SETTING: department of Neurosurgery, the Second Hospital of Xiamen; department of Neurosurgery, the Second Affiliated Hospital of{2. medical University; department of Neurobiology, Basic medical college of{2. medical University. MATERIALS: A total of 30 healthy male SD rats, aged 8 weeks, of clean grade, weighing 2.0-300 g, were provided by Experimental Animal department of{2. medical University. All rats were randomly divided into sham-operation group, ischemia/reperfusion group and treatment group with 10 in each group. The main reagents were detailed as the follows: 100 g/L chloral hydrate, 0.5 mL CGRP (2.mg/L, Sigma Company, USA), and NGF (1× 106 U/L, 0.5 mL, Siweite Company, Dalian). METHODS: The experiment was carried out in the department of Neurobiology, Basic medical college of{2. medical University from February to July 2.05. Rat models of middle cerebral artery occlusion were established by method of occlusion, 2.hours after that rats were anesthetized and the thread was slightly drawn out for 10 mm under direct staring to perform reperfusion. Rats in the ischemia/reperfusion group received intraperitoneal injection of 1 mL saline via the abdomen at two hours later, while rats in the treatment group at 2.hours later received intraperitoneal injection of 2.mg/L CGRP (0.5 mL) and 1×106 U/L NGF (0.5 mL) once a day for 10 successive days. First administration was accomplished within 15 minutes after ischemia/reperfusion. Rats in the sham-operation

关键词： Effect of calcitonin gene-related peptide and nerve growth factor on spatial learning and memory abilities of rats following focal cerebral ischemia/reperfusion CGRP MCAO gene

First passage failure of dynamical power systems under random perturbations

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第9期53卷 2495-2500页

作者： CHEN LinCong1 & ZHU WeiQiu2.1 college of Civil Engineering,Huaqiao University,Xiamen 36102.,china {2. of Mechanics,State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University,Hangzhou 31002.,china 1. college of Civil Engineering Huaqiao University Xiamen 361021 China2. Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

The first-passage problem of dynamical power system of a single-machine-infinite-bus (SMIB) system under random perturbations is ***,the stochastic averaging method for quasi non-integrable generalized Hamiltonian systems is applied to reduce the equations of the SMIB system under random perturbations to a set of averaged It ***,the backward Kolmogorov equation governing the conditional reliability function and the Pontryagin equation governing the conditional mean of first passage time are established and solved numerically,***,the proposed method is verified by using the Monte Carlo simulation of the original system.

关键词： dynamical power system random perturbation stochastic averaging first passage failure

Geodynamic significance of the A-type granites in the Sawuer region in west Junggar, Xinjiang: Rock geochemistry and SHRIMP zircon age evidence

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第2期49卷 113-123页

作者： ZHOU Taofa1, YUAN Feng1, TAN Lugui1,2. FAN Yu1 & YUE Shucang1 1. School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 2.0009, china 2. department of Geography and Environment Science, Wanxi {2., Liuan 2.7012. china 1. School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China 2. department of Geography and Environment Science Wanxi College Liuan 237012 China

Sawuer region is located in west Junggar, Jimunai County of Altay district and Hefeng County of Tacheng district, Xinjiang. The region is along the north margin of Kazakstan-Junggar plate. The intrusions (mainly acid) are widespread. Qiaqihai and Kuoyitasi intrusions are important in the region, with the characteristics of A-type granite. Further investigations indicate that they belong to A2.type granite that formed in extension tectonic setting of post collision. The REE chon-drite-normalized patterns of the intrusions show LREE enrichment and the δ Eu values are lower. The Nd, Sr, Pb isotope compositions of the intrusions indicate a mantle source, while the low δ 18O values resulted from the isotope exchange between intrusion and meteoric water. According to SHRIMP U-Pb age analysis results, the crystallization age of Qiaqihai intrusion is 2.0.7 ± 9.3 Ma (1σ ), and that of Kuoyitasi intrusion is 2.7.9 ± 4.6 Ma (1σ ), corresponding to the beginning of early Permian. The A2.type granites indicate that the region was in the extension period of the post-collisional stage at the beginning of early Permian in the Sawuer region. The A-type granites in the Sawuer region in west Junggar discovered from this work is analogous to the A-type granites found in east Junggar of the Ulungur alkali granites belt. The confirmation of post-collisional A-type granites of early Permian in the Sawuer region provides new evidence for the regional vertical continental crust growth in early Per-mian. The former proposed Ulungur alkali granites belt can extend from east Ulungur through west Ulungur and to Zhaisang in Kazakstan westwards.

关键词： A-type granite, zircon, SHRIMP age, post-collision, Junggar, Xinjiang.