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mRNA expression of Rho GTPase-related signaling molecules during rat hippocampal development

Neural Regeneration Research 2009年第10期4卷 786-790页

作者： Guoqing Guo Jifeng Zhang Li Xin Jing Chen Weizai shen Lin yuan Shizhen zhong Department of Anatomy Medical College of Jinan University Guangzhou 510630 Guangdong Province China Institute of Clinical Anatomy Southern Medical University Guangdong Key Laboratory of Tissue Construction and Detection 510150 Guangdong Province China

BACKGROUND： Rho GTPase family members have been shown to participate in neurite growth by regulating the neuronal cytoskeleton. However, there are very few reports of developmental roles of signaling molecules related to Rho GTPases. OBJECTIVE： To investigate messenger ribonucleic acid mRNA expression of signaling molecules associated with Rho GTPases, including Rho-A, Rac-1, collapsin response mediator protein 1 （CRMP-1）, and tubulin 133 （Tub/33） during rat hippocampus development. DESIGN, TIME AND SETTING- A non-randomized, controlled, animal experiment, based on different developmental stages of the rat hippocampus, was performed at the Guangdong Key Laboratory of Tissue Construction and Detection, Institute of Clinical Anatomy, Southern Medical University between December 2005 and July 2007. MATERIALS： Trizol reagent was purchased from Invitrogen, USA. RNA PCR kit （AMV） Ver 3.0 and 150 bp DNA Ladder Marker were purchased from TaKaRa, Japan. Unless otherwise specified, all other reagents were purchased from Sigma-Aldrich, USA. METHODS： Twenty-five Sprague Dawley rats were assigned to five groups （n = 5） according to developmental stages： embryonic （embryonic 15 days）, neonatal （postnatal 5 days）, juvenile （postnatal 1 month）, adult （postnatal 3 months）, and senile （postnatal 18 months）. MAIN OUTCOME MEASURES： Detection of mRNA expression of Rho-A, Rac-1, CRMP-1, and Tub β3 during various hippocampal developmental stages by reverse-transcription polymerase chain reaction. RESULTS： Hippocampal mRNA expression of Rho-A, as well as Rac-1, reached peak levels at embryonic, juvenile, and senile stages, and was relatively less during neonatal and adult stages. mRNA expression of Rac-1 was greater than Rho-A during each hippocampal developmental stage. CRMP-1 mRNA expression levels were as follows： embryonic 〉 neonatal 〉 juvenile 〉 adult 〈 senile, while Tubβ3 mRNA expression was embryonic 〉 neonatal 〉 juvenile 〉 adult = senile. CONCLUSION： Rho-A and Rac-1 shared similar

关键词： Rho GTPases collapsin response mediator protein 1 tubulin hippocampus development rat

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SUB-NANOMETER POLISHING OF MAGNETIC RIGID DISK HEADS TO AVOID POLE TIP RECESSION

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 7-10页

作者： shen Rulin ZHOU Li zhong Jue School of Mechanicaland Electrical Engineedng CentralSouth University Changsha 410083 China

For the purpose of solving the problem that too large pole tip recession （PTR） is produced in magnetic rigid disk heads by mechanical polishing, a chemical mechanical nano-grinding experiment is performed by using a float-piece polisher with a tin plate to achieve a more plane and smoother surface. A basal solution, addition agents and a range of pH value are suitably selected to find a kind of slurry, with which the PTR can be controlled on sub-nanometer scale and the giant magnetic resistance （GMR） corrosion and electrostatic damage （ESD） can be avoided. Moreover, the cause that TiC protrudes from the substrate surface of the heads is studied. The appropriate shape and size of diamond abrasive are selected according to the chemical activation of A1203 and TiC in the same slurry. In this way, the chemical and mechanical interactions are optimized and the optimal surface that has small PTR and TiC asperity is achieved. Ultimatily, the chemical mechanical nano-grinding in combination with mechanical nano-grinding is adopted. Sub-nanometer PTR is achieved and the TiC asperity is eliminated by the chemical mechanical nano-grinding with large size ofmonocrystalline followed by mechanical nano-grinding with smalle polycrystalline diamonds.

关键词： Polishing Magnetic rigid disk head Pole tip recession (PTR) Chemical mechanical nano-grinding

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CrOx supported on high-silica HZSM-5 for propane dehydrogenation

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Journal of Energy Chemistry 2020年第8期29卷 225-233,I0008页

作者： zhong-Pan Hu Yansu Wang Dandan Yang zhong-Yong yuan National Institute for Advanced Materials School of Materials Science and EngineeringNankai UniversityTianjin 300350China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education).Nankai University Tianjin 300071China

Industrial propane dehydrogenation(PDH)catalysts generally suffer from low catalytic stability due to the coke formation onto the catalyst surface to cover the active *** exploitation of an efficient catalyst with both high catalytic selectivity and long-term stability toward PDH is of great importance but challenging to *** CrOx supported on high-silica HZSM-5 with a SiO2/Al2O3 ratio of 260(Cr/Z-5(260)is synthesized by a simple wet impregnation method,which exhibits high catalytic activity,good selectivity and excellent stability for *** a weight hourly space velocity(WHSV)of 0.59 h-1,a propylene formation rate of 4.1 mmol g-1cath-1(~32.6% propane conversion and ~94.2% propylene selectivity)can be maintained over the 5%Cr/Z-5(260)catalyst after 50 h time on stream,which is much better than commercial Cr/Al2O3(Catofin process,catalyst life is several hours)at the same reaction *** increasing the WHSV to 5.9 h-1,a high propylene formation rate of 27.9 mmol gcat-1h-1can be obtained over the 5%Cr/Z-5(260)catalyst after 50 h time on stream,demonstrating a very promising PDH *** results and Na+doping experiments reveal that the Cr species combined with Br?nsted acid sites in Cr/HZSM-5 catalysts are responsible for the high catalytic *** particular,the Br?nsted acid sites in HZSM-5 zeolite could increase the propane adsorption and enhance the C–H bond ***,the high surface area and well-defined pores of HZSM-5 zeolite can provide a special environment for the dispersion and stabilization of Cr species,thus guaranteeing high catalytic activity and stability.

关键词： Propane dehydrogenation ZSM-5 zeolite Chromium oxide Propylene BrΦnsted acid sites

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Methane conversion in the presence of oxygen under low-temperature radio frequency plasma

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Journal of Natural Gas Chemistry 2010年第6期19卷 605-610页

作者： Jinhai yuan Xuejun zhong Shiyu Tan College of Chemistry and Chemical Engineering Chongqing University of Science ＆ Technology Chongqing 401331 China Chongqing Chemical Engineering Design and Research Institute Chongqing 400039 China College of Chemistry and Chemical Engineering Chongqing University Chongqing 40004 China

Methane conversion in the presence of oxygen under low-temperature radio frequency （RF） plasma was *** experiment results indicated that the following four factors,i.e.,discharge voltage,discharge area,O2/CH4 molar ratio and total gas flowrate,affected remarkably the reaction *** optimum reaction conditions of methane conversion in the presence of O2 under RF plasma are as follows：discharge voltage 1050 V,discharge area 989.1mm 2,O2/CH4 molar ratio 1/10 and total gas flowrate 200 ml/min.A methane conversion of 91% could be reached under the optimum *** is good for the breaking of C-H bonds and also acts as a sort of *** to the low-temperature plasma characteristics,the macroscopic kinetics model of methane conversion in the presence of O2 under radio frequency plasma was studied.

关键词： methane oxygen radio frequency plasma C2 hydrocarbons kinetics

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Stability Analysis of Distributed Parameter Systems on Temperature Measurement of Large-scale Objects

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Journal of Thermal Science 2007年第3期16卷 248-253页

作者： Zhenliang DING Li zhong Feng yuan Department of Electronic Engineering School of Automatic Measurement and Control Harbin Institute of Technology 150001 Harbin China

In this paper, the mechanical construction, thermal regulator design and temperature measurement system of a local area were set up for large-scale linear measurement. Numerical analysis based on temperature correlated characteristic is discussed to obtain optimal observation points for the measurements. The horizontal temperature distribution of the measured area is compared with the measurement of the variation of temperature at 15℃ and 20℃ over time, and characteristic of dynamic response is also discussed. In addition, the long-time stability of measured temperature is analyzed by means of using the standard deviation. It characterizes the temperature distribution performance of a large area and how it may impact the measurement of a large-scale object.

关键词： temperature control temperature measurement distribution parameter linear measurement.

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The Impact of Storm-Induced SST Cooling on Storm Size and Destructiveness: Results from Atmosphere-Ocean Coupled Simulations

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Journal of Meteorological Research 2020年第5期34卷 1068-1081页

作者： Tao GUO yuan SUN Lei LIU zhong zhong College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101

In this study, both an atmospheric model [Weather Research and Forecasting(WRF) model] and an atmosphere(WRF)–ocean(Princeton Ocean Model;POM) coupled model are used to simulate the tropical cyclone(TC) Kaemi(2006). By comparing the simulation results of the models, effects of oceanic elements, especially the TC-induced sea surface temperature(SST) cooling, on the simulated TC size and destructiveness are identified and analyzed. The results show that there are no notable differences in the simulated TC track and its intensity between the uncoupled and coupled experiments;however, there are large differences in the TC size(i.e., the radius of gale-force wind)between the two experiments, and it is the TC-induced SST cooling that decreases the TC size. The SST cooling contributes to the decrease of air–sea moisture difference(ASMD) outside the TC eyewall, which subsequently leads to the decreases in surface enthalpy flux(SEF), radial sea-level pressure gradient, absolute vorticity advection, and wind speed outside the TC eyewall. As a result, the TC size and size-dependent TC destructive potential all decrease remarkably.

关键词： tropical cyclone(TC)size destructiveness sea surface temperature(SST)cooling

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Meso-macroporous Al_2O_3 supported Ru catalysts for CO preferential oxidation in hydrogen-rich gases

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Journal of Natural Gas Chemistry 2012年第6期21卷 653-660页

作者： Limiao shen Cheng Zhang yuan Liu Tianjin Key Laboratory of Applied Catalysis Science and Engineering Department of Catalysis Science and TechnologySchool of Chemical EngineeringTianjin UniversityTianjin 300072China

Series of meso-macroporous Al2O3 supported Ru catalysts with different loadings were prepared by incipient wetness method and applied to preferential oxidation of CO in hydrogen-rich gases. N2 adsorption-desorption, SEM, XRD, TEM, CO chemisorption and H2-TPR techniques were employed to characterize the catalysts. The results indicate that Ru/Al2O3 catalysts have meso-macroporous structure, high surface area and high metal dispersion. The characterization results of XRD and CO chemisorption indicate the entry of Ru ions into Al2O3 lattice. The results of catalytic performance tests indicate that the meso-macroporous Al2O3 supported Ru catalysts for CO preferential oxidation showed good activity under high space velocity. It is proposed that the macropores in the Ru/Al2O3 catalyst favor mass transfer and mesopores help to improve the dispersion of metal, resulting in the excellent catalytic performance.

关键词： preferential oxidation carbon monoxide mesoporous macroporous alumina ruthenium

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Effect of lubricant sulfur on the morphology and elemental composition of diesel exhaust particles

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Journal of Environmental Sciences 2017年第5期29卷 354-362页

作者： Piqiang Tan yuan Li Hanyan shen School of Automobile Tongji University Shanghai 201804 China

This work investigates the effects of lubricant sulfur contents on the morphology,nanostructure,size distribution and elemental composition of diesel exhaust particle on a light-duty diesel engine. Three kinds of lubricant（LS-oil,MS-oil and HS-oil,all of which have different sulfur contents：0.182%,0.583% and 1.06%,respectively）were used in this study. The morphologies and nanostructures of exhaust particles were analyzed using high-resolution transmission electron microscopy（TEM）. Size distributions of primary particles were determined through advanced image-processing software. Elemental compositions of exhaust particles were obtained through X-ray energy dispersive spectroscopy（EDS）. Results show that as lubricant sulfur contents increase,the macroscopic structure of diesel exhaust particles turn from chain-like to a more complex agglomerate. The inner cores of the core-shell structure belonging to these primary particles change little; the shell thickness decreases,and the spacing of carbon layer gradually descends,and amorphous materials that attached onto outer carbon layer of primary particles increase. Size distributions of primary particles present a unimodal and normal distribution,and higher sulfur contents lead to larger size primary particles. The sulfur content in lubricants directly affects the chemical composition in the particles. The content of C（carbon）decreases as sulfur increases in the lubricants,while the contents of O（oxygen）,S（sulfur）and trace elements（including S,Si（silicon）,Fe（ferrum）,P（phosphorus）,Ca（calcium）,Zn（zinc）,Mg（magnesium）,Cl（chlorine）and Ni（nickel））all increase in particles.

关键词： Diesel exhaust particle Lubricant sulfur Morphology Nanostructure Primary particle size Elemental composition

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A New Hybrid Model Rotor Flux Observer and Its Application

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Journal of China University of Mining and Technology 2006年第1期16卷 71-76页

作者： ZHOU yuan-shen Department of Electronic Engineering Huaihai Institute of Technology Lianyungang Jiangsu 222005 China

A new hybrid model rotor flux observer, based on a new voltage model, is presented. In the first place, the voltage model of an induction machine was constructed by using the modeling method discussed in this paper and then the current model using a flux feedback was adopted in this flux observer. Secondly, the two models were com- bined via a filter and then the rotor flux observer was established. In the M-T synchronous coordinate, the observer was analyzed theoretically and several important functions were derived. A comparison between the observer and the traditional models was made using Matlab software. The simulation results show that the observer model had a better performance than the traditional model.

关键词： new hybrid model rotor flux observer induction machine: cycloconverter

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The contribution of absorption of integral nanocrystals to enhancement of oral bioavailability of quercetin

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Acta Pharmaceutica Sinica B 2021年第4期11卷 978-988页

作者： Baode shen Chengying shen Weifeng Zhu Hailong yuan Department of Pharmacy Air Force Medical CenterPLABeijing 100142China Key Lab of Modern Preparation of Traditional Chinese Medicine(TCM) Ministry of EducationJiangxi University of TCMNanchang 330004China

In this study,self-discriminating hybrid nanocrystals was utilized to explore the biological fate of quercetin hybrid nanocrystals(QT-HNCs)with diameter around 280 nm(QT-HNCs-280)and550 nm(QT-HNCs-550)following oral and intravenous administration and the contribution of integral nanocrystals to oral bioavailability enhancement of QT was estimated by comparing the absolute exposure of integral QT-HNCs and total QT in the *** showed that QT-HNCs could reside in vivo as intact nanocrystals for as long as 48 h following oral and intravenous administration.A higher accumulation of integral QT-HNCs in liver and lung was observed for both oral and intravenous administration of *** particle size affects the absorption and biodistribution of integral QT-HNCs and total *** compared to QT-HNCs-550,QT-HNCs-280 with smaller particle size is more easily absorbed,but dissolves faster in vivo,leading to higher distribution of QT(146.90 vs.117.91 h·mg/mL)but lower accumulation of integral nanocrystals(6.82 e10 vs.15.27 e10 h·[p/s]/[μW/cm2])in liver following oral *** to its slower dissolution and enhanced recognition by RES,QT-HNCs-550 with larger diameter shows higher liver distribution for both of QT(1015.80 h·mg/mL)and integral nanocrystals(259.63 e10 h·[p/s]/[μW/cm2])than those of QT-HNCs-280(673.82&77.66 e10 h·[p/s]/[μW/cm2])following intravenous *** absolute exposure of integral QT-HNCs in liver following oral administration of QT-HNCs are 8.78%for QT-HNCs-280 and 5.88%for QT-HNCs-550,while the absolute exposure of total QT for QT-HNCs-280 and QT-HNCs-550 are 21.80%and 11.61%,*** to imprecise quantifcation method,a surprisingly high contribution of integral QT-HNCs to oral bioavailability enhancement of QT(40.27%for QT-HNCs-280 and 50.65%for QT-HNCs-550)was *** results revealed signifcant difference in absorption and biodistrbution between integral nanocrystals and overall drugs following oral and intr

关键词： Nanocrystals Biological fate Quercetin Pharmacokinetics Biodistribution Oral bioavailability Contribution Drug delivery

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