检索结果-南通市图书馆

An optimized micro-assay of myosin Ⅱ ATPase activity based on the molybdenum blue method and its application in screening natural product inhibitors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2016年第6期14卷 421-426页

作者： CHEN Hong-Lin ZHAO Jing zhang guan-jun KOU jun-Ping YU Bo-Yang Jiangsu Key Laboratory of TCM Evaluation and Translational Research Department of Complex Prescription of TCM China Pharmaceutical University

Myosin Ⅱ plays multiple roles in physiological and pathological functions through its ATPase activity. The present study was designed to optimize a micro-assay of myosin Ⅱ ATPase activity based on molybdenum blue method, using a known myosin Ⅱ ATPase inhibitor, blebbistatin. Several parameters were observed in the enzymatic reaction procedure, including the concentrations of the substrate(ATP) and calcium chloride, p H, and the reaction and incubation times. The proportion of coloration agent was also investigated. The sensitivity of this assay was compared with the malachite green method and bioluminescence method. Additionally, 20 natural compounds were studied for myosin Ⅱ ATPase inhibitory activity using the optimized method. Our results showed that ATP at the concentration of 5 mmol·L^(-1) and ammonium molybdate : stannous chloride at the ratio of 15 : 1 could greatly improve the sensitivity of this method. The IC50 of blebbistatin obtained by this method was consistent with literature. Compound 8 was screened with inhibitory activity on myosin Ⅱ ATPase. The optimized method showed similar accuracy, lower detecting limit, and wider linear range, which could be a promising approach to screening myosin Ⅱ ATPase inhibitors in vitro.

关键词： Myosin Ⅱ ATPase activity Blebbistatin Bioluminescence Natural products Malachite green

Effect of organic moieties(phenyl,naphthalene,and biphenyl)in Zr-MIL-140 on the hydrogenation activity of Pd nanoparticles

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2016年第11期27卷 1679-1682页

作者： Jie Yang Jian-jun Ma Da-Min zhang Teng Xue Ye-jun guan School of Mathematics and Physics Shanghai University of Electric Power Shanghai Key Laboratory of Green Chemistry and Chemical Processes East China Normal University

MIL-140-type metal organic frameworks （isoreticular zirconium oxide MOFs） with different aromatic moieties （phenyl, naphthalene, and biphenyl） have been synthesized and employed as the supports of palladium nanoparticles （Pd NiPs）. The catalysts were characterized by XRD, BET, TEM and CO chemisorption. The results reveal that Pd NPs are homogeneously dispersed on all materials whereas different accessibility to CO is observed. The hydrogenation performance in C=C saturation with respect to the effect of the aromatic moiety is compared. The Pd/MIL-140A MOF with the highest hydrogenation activity among the three catalysts comprised of different aromatic rings points to a unique Pd-π interaction between Pd and frameworks consisting of mono-phenyl groups （C6H4）.

关键词： Metal-organic-framework Palladium Selective hydrogenation Zirconium

Skeletal phenotypes and molecular mechanisms in aging mice

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2024年第4期45卷 724-746页

作者： Qiao guan Yuan zhang Zhi-Kun Wang Xiao-Hua Liu jun Zou Ling-Li zhang School of Exercise and Health Shanghai University of SportShanghai 200438China College of Athletic Performance Shanghai University of SportShanghai 200438China

Aging is an inevitable physiological process,often accompanied by age-related bone loss and subsequent bone-related diseases that pose serious health *** on skeletal diseases caused by aging in humans is challenging due to lengthy study durations,difficulties in sampling,regional variability,and substantial ***,mice are preferred for such studies due to their similar motor system structure and function to humans,ease of handling and care,low cost,and short generation *** this review,we present a comprehensive overview of the characteristics,limitations,applicability,bone phenotypes,and treatment methods in naturally aging mice and prematurely aging mouse models(including SAMP6,POLG mutant,LMNA,SIRT6,ZMPSTE24,TFAM,ERCC1,WERNER,and KL/KL-deficient mice).We also summarize the molecular mechanisms of these aging mouse models,including cellular DNA damage response,senescence-related secretory phenotype,telomere shortening,oxidative stress,bone marrow mesenchymal stem cell(BMSC)abnormalities,and mitochondrial ***,this review aims to enhance our understanding of the pathogenesis of aging-related bone diseases.

关键词： Aging Premature aging Mice Bone Gene knockout

Effect of cement on the stabilization of loess

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2017年第11期14卷 2325-2336页

作者： zhang Chong-lei JIANG guan-lu SU Li-jun ZHOU Gong-dan Key Laboratory of Mountain Hazards and Earth Surface Processes Institute of Mountain Hazards and Environment Chinese Academy of Sciences Key Laboratory of High-speed Railway Engineering of Ministry of Education School of Civil Engineering Southwest Jiaotong University CAS Center for Excellence in Tibetan Plateau Earth Sciences University of Chinese Academy of Sciences

Considering the potential use of cementstabilized loess(CSL) as a construction material for structures that are subjected to frequent loess landslides, this paper explores the stabilization and improvement of geotechnical characteristics of loess achieved by the addition of 0%-9% cement by dry weight. Laboratory evaluations investigated the consistency limits, compaction, compressibility, California bearing ratio(CBR), direct shear strength, and unconfined compression strength(UCS) of CSL for different curing stages. A durability index was quantified to estimate the influence of wetting-drying(w-d) cycles on CSL strength, and an optimum cement dosage was also identified. The results reveal that the cohesion of CSL is substantially more sensitive to structure than its friction angle and that cohesion is responsible for shear strength increase after remoulding. The cement proportions have an effective role in the enhancement of compressibility. The development of UCS can be categorized into the early stage(14 days). The increase in strength primarily occurred in the first 14 days. The w-d cycles have a significantinfluence on the decrease in compression strength. The CBR value increases with increments of additional proportions and compaction times. The relationships of UCS versus the compressibility modulus and UCS versus CBR are established to facilitate the mix design for strength. A rational predictive exponential equation is proposed to predict the durability index for different w-d cycles.

关键词： Landslide Cement Loess stabilization Durability index Wetting-drying cycle

Static analysis of synchronism deployable antenna

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1365-1371页

作者： guan Fu-ling SHOU Jian-jun HOU Guo-yong zhang Jing-jie Department of Civil Engeering Zhejiang University Hangzhou 310027 China Chongqing Research Institute of Building Science Chongqing 400015 China

A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This an-tenna consists of tetrahedral elements from central element. Because there are springs at the ends of some of the rods, spider joints are applied. For analysis purpose, the structure is simplified and modelled by using 2D beam elements that have no bending stiffness. Displacement vectors are defined to include two translational displacements and one torsional displacement. The stiff-ness matrix derived by this method is relatively simple and well defined. The analysis results generated by using software de-veloped by our research group agreed very well with available test data.

关键词： Space deployable structures Analysis design Reflector antenna

Dynamic behaviour of weathered red mudstone in Sichuan(China)under triaxial cyclic loading

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2018年第8期15卷 1789-1806页

作者： zhang Chong-lei JIANG guan-lu SU Li-jun LIU Wei-ming Key Laboratory of Mountain Hazards and Earth Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China Ministry of Education Key Laboratory of High-speed Railway EngineeringSchool of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China. CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The construction of a high-speed railway(HSR) in Southwest China is being hindered by a severe shortage of high-quality subgrade materials. However, red mudstone is widely distributed in the Sichuan Basin of China. The ability to use weathered red mudstone(WRM) to fill subgrade beds by controlling its critical stress and cumulative strain would enable substantial savings in project investments and mitigate damage to the ecological environment. To better understand the dynamic behaviour of WRM, both monotonic and cyclic triaxial tests were performed. The evolution of the cumulative strain vs. increased loading cycles was measured. The influences of confining pressure and loading cycles on the dynamic modulus, damping ratio, critical cyclic stress ratio(CSR), and dynamic stress level(DSL) were investigated. The relationship between the CSR and loading cycles under different failure strain criteria(0.1%-1.0%) was analysed. The prediction model of cumulative strain was also evaluated. The results indicated that the shear strength of WRM sufficiently meets the static strength requirements of subgrade. The critical dynamic stress of WRM can thus satisfy the dynamic stress-bearing requirement of the HSR subgrade. The critical CSR decreases and displays a power function with increasing confining pressure. As the confining pressure increases, the DSL remains relatively stable, ranging between 0.153 and 0.163. Furthermore, the relationship between the dynamic strength and loading cycles required to cause failure was established. Finally, a newly developed model for determining cumulative strain was established. A prediction exercise showed that the model is in good agreement with the experimental data.

关键词： Cyclic triaxial tests Cyclic stress ratio Red mudstone Critical dynamic stress Cumulative strain Railway subgrade

3D HYBRID DEPTH MIGRATION AND FOUR-WAY SPLITTING SCHEMES

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2006年第4期24卷 463-474页

作者： Wen-sheng zhang guan-quan zhang LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The alternately directional implicit （ADI） scheme is usually used in 3D depth migration. It splits the 3D square-root operator along crossline and inline directions alternately. In this paper, based on the ideal of data line, the four-way splitting schemes and their splitting errors for the finite-difference （FD） method and the hybrid method are investigated. The wavefield extrapolation of four-way splitting scheme is accomplished on a data line and is stable unconditionally. Numerical analysis of splitting errors show that the two-way FD migration have visible numerical anisotropic errors, and that four-way FD migration has much less splitting errors than two-way FD migration has. For the hybrid method, the differences of numerical anisotropic errors between two-way scheme and four-way scheme are small in the case of lower lateral velocity variations. The schemes presented in this paper can be used in 3D post-stack or prestack depth migration. Two numerical calculations of 3D depth migration are completed. One is the four-way FD and hybrid 3D post-stack depth migration for an impulse response, which shows that the anisotropic errors can be eliminated effectively in the cases of constant and variable velocity variations. The other is the 3D shot-profile prestack depth migration for SEG/EAEG benchmark model with two-way hybrid splitting scheme, which presents good imaging results. The Message Passing Interface （MPI） programme based on shot number is adopted.

关键词： 3D depth migration Multiway splitting Data line Wavefield computation Finite-difference Hybrid method.

Design, Implementation and Verification of Topology Network Architecture of Smart Home Tree

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第8期68卷 2399-2411页

作者： Youbang guan Bong jun Choi Department of Advanced Research and Development QingdaoChina Department of Engineering University of LeicesterLeicesterEngland School of Computer Science and Engineering Soongsil UniversitySeoulKorea

Smart home technology provides consumers with network connectivity,automation or enhanced services for home *** the Internet of Things era,a vast data flow makes business platforms have to own the same computing power to match their business *** achieves computing power through implementing big data algorithms deployed in the cloud data ***,because of the far long geographical distance between the client and the data center or the massive data capacity gap,potentially high latency and high packet loss will reduce the usability of smart home systems if service providers deploy all services in the cloud data *** computing and fog computing can significantly improve the utilization of network resources and reconstruct the network architecture for the user’s *** article enables a fog resource-based resource allocation management *** provides a method that can more reasonably allocate network resources through a virtualized middle-tier method to ensure low response time and configure Quality of Service to ensure the use of delay-sensitive critical applications to improve the reliability of smart home communication ***,the proposed method has is tested and verified by adjusting the variables of the network *** realize the optimization of resource allocation of client network without changing the hardware of client.

关键词： Topology network smart home tree resource allocation internet of things

Laser cladding of NiCrSiB on Monel 400 to enhance cavitation erosion and corrosion resistance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2022年第12期41卷 4257-4265页

作者： Chun-Hua zhang Chen-Liang Wu Song zhang Yong-Feng Jia Meng guan jun-Zhe Tan Bin Lin School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Nuclear Power Pump Industry Co. Ltd.Shenyang Blower Works Group CorporationShenyang 110869China

NiCrSiB modified layer was synthesized on Monel 400 by laser cladding,aiming at improving cavitation erosion and corrosion *** microstructure,chemical composition,phase constituents and microhardness were investigated using scanning electron microscope(SEM),energy-dispersive spectrometer(EDS),X-ray diffractometry(XRD) and microhardness *** cavitation erosion and corrosion behaviors of the modified layer were also evaluated using an ultrasonic vibrator and potentiodynamic polarization measurement,*** results show that by varying the laser fluence,a hard NiCrSiB modified layer with little airholes,cracks or other defects could be *** modified layer is ~1.1 mm in *** microstructure of the modified layer exhibits cellular dendrite,flake-like dendrite and multiple eutectic *** modified layer is mainly composed of γ-Ni solid solution,chromium carbide(Cr_(7)C_(3)and Cr_(23)C_(6)) and Ni_(3)*** microhardness of the modified layer is ~6.8 times that of Monel 400 *** the cavitation erosion and corrosion resistance of the modified layer are *** the cavitation erosion test,the cumulative erosion loss and erosion loss rate of the modified layer are one order of magnitude lower than that of the *** the electrochemical corrosion test,the corrosion potentials of the substrate and the modified layer are *** corrosion current densities of the substrate and the modified layer are 11.12 and 1.95 μA·cm^(-2),*** comparing their corrosion current densities,the corrosion resistance of the modified layer is about 5.7 times that of the substrate.

关键词： NiCrSiB Laser cladding Microstructure Cavitation erosion Corrosion