检索结果-南通市图书馆

瓜蒌- 薤白调节肠道菌群治疗冠心病模型大鼠的作用及机制

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第5期29卷 917-927页

作者：孙广瀚谢珍聪孙咪徐洋郭栋山东中医药大学第一临床医学院山东省济南市250014 山东中医药大学教师发展中心山东省济南市250355 山东中医药大学药物研究院山东省济南市250355

背景:基于网络药理学方法发现瓜蒌-薤白药对中主要生物活性化合物对冠心病有多功能作用;然而其治疗冠心病的机制尚未得到充分阐释。目的:探讨瓜蒌-薤白通过调节肠道微生物的组成改善冠心病的作用及机制。方法:40只SD大鼠按随机数字表法... 详细信息

背景:基于网络药理学方法发现瓜蒌-薤白药对中主要生物活性化合物对冠心病有多功能作用;然而其治疗冠心病的机制尚未得到充分阐释。目的:探讨瓜蒌-薤白通过调节肠道微生物的组成改善冠心病的作用及机制。方法:40只SD大鼠按随机数字表法分为空白组、模型组、阳性药组、药对组,除空白组外,其余大鼠连续灌胃脂肪乳剂和注射垂体后叶素制备冠心病大鼠模型。造模后模型组大鼠灌胃蒸馏水(10 mL/kg)进行对照,阳性药组大鼠每日灌胃辛伐他汀4 mg/kg,药对组每日灌胃瓜蒌-薤白7.56 g/kg,各组大鼠给药均为14 d。观察大鼠心电图、心肌病理及血脂变化,并通过16S rDNA测序技术研究大鼠经干预后肠道微生物结构。结果与结论:①心电图结果显示模型组ST抬高;阳性药组与药对组心电图无明显问题。②与空白组相比,模型组总胆固醇、三酰甘油、低密度脂蛋白胆固醇水平均显著增高(P0.05),Simpson指数降低(P<0.05)。⑤与空白组相比,模型组Desulfovibrionia、Muribaculaceae_norank等相对丰度升高,Clostridia、[Eubacterium]_coprostanoligenes_group_norank等相对丰度降低;与模型组相比,药对组WPS-2_norank、Muribaculaceae_norank等相对丰度升高,Clostridia、[Eubacterium]_coprostanoligenes_group_norank等相对丰度降低;阳性药组Desulfobacterota、[Eubacterium]_coprostanoligenes_group_norank等相对丰度升高,Firmicutes、Muribaculaceae_norank等相对丰度降低;与阳性药相比,药对组Desulfobacterota、Bacteroides等相对丰度升高,Firmicutes、[Eubacterium]_coprostanoligenes_group_norank等相对丰度降低;LEfSe结果发现差异显著的种群富集于药对组最多,其次是空白组、阳性药组,模型组最少。⑥结论:瓜蒌-薤白可以通过调节肠道菌群改善冠心病的发生发展,为进一步研发瓜蒌-薤白提供新的启示。

关键词： “瓜蒌-薤白”药对 16S rDNA 冠心病肠道菌群大鼠

Spatial Characteristics and Influencing Factors of Urban Resilience from the Perspective of Daily Activity:A Case Study of Nanjing,China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2021年第3期31卷 387-399页

作者： sun Honghu zhen Feng School of Architecture and Urban Planning Nanjing UniversityNanjing 210093China Provincial Engineering Laboratory of Smart City Design Simulation&Visualization JiangsuNanjing UniversityNanjing 210093China

Based on the connotation of urban resilience and the main contradictions of China's urbanization,urban resilience is placed within the main daily activities contradictory scene of the urban man-land system to build a theoretical framework of urban activity *** on geographic big data,this study identifies the spatial characteristics of activity resilience,reveals the impact of activity environment on activity resilience in Nanjing,and proposes *** main conclusions are as follows.1)Activity resilience presents a composite spatial structure of circles and clusters,and most areas are resilient but at a low level.2)There are significantly positive and negative global autocorrelation between activity resilience and activity scale,and activity ***,there also exists a local spatial autocorrelation with the opposite positive and negative trends.3)Activity environment has a significant effect on activity resilience,and the degree and direction of influence among different dimensions and regions are heterogeneous.4)For activity resilience,it is necessary to increase the matching degree between the scale and stability of activities,and reduce the excessive concentration and flow of *** the activity environment,it is necessary to improve the accessibility of the ecological environment,strengthen the high-quality supply of the infrastructure environment,optimize the balance of the location environment,and promote the inclusiveness of the social environment.

关键词： urban resilience daily activity contradiction between supply and demand big data spatial characteristics Nanjing China

AN EXPANDED CHARACTERISTIC-MIXED FINITE ELEMENT METHOD FOR A CONVECTION-DOMINATED TRANSPORT PROBLEM

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2005年第5期23卷 479-490页

作者： Ling guo Huan-zhen Chen Department of Mathematics Shanghai Jiao Tong UniversityShanghai 200030China Department of Mathematics Shandong Normal UniversityJinan 250014China

In this paper, we propose an Expanded Characteristic-mixed Finite Element Method for approximating the solution to a convection dominated transport problem. The method is a combination of characteristic approximation to handle the convection part in time and an expanded mixed finite element spatial approximation to deal with the diffusion part. The scheme is stable since fluid is transported along the approximate characteristics on the discrete level. At the same time it expands the standard mixed finite element method in the sense that three variables are explicitly treated： the scalar unknown, its gradient, and its flux. Our analysis shows the method approximates the scalar unknown, its gradient, and its flux optimally and simultaneously. We also show this scheme has much smaller time-truncation errors than those of standard methods. A numerical example is presented to show that the scheme is of high performance.

关键词： Convection diffusion problems Expanded characteristic mixed finite elementmethod Optimal error estimates Numerical test

Dynamic Response Study of Steel Catenary Riser Based on Slender Rod Model

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

China Ocean Engineering 2019年第1期33卷 57-64页

作者： LIU zhen guo Hai-yan College of Engineering Ocean University of China

A numerical model of the steel catenary riser(SCR) is built based on the slender rod model. The slender rod model,which describes the behavior of the slender riser in terms of the center line position, can solve the geometrical nonlinearity effectively. In a marine environment, the SCR is under the combined internal flow and external loads,such as wave and current. A general analysis considers only the inertial force and the drag force caused by the wave and current. However, the internal flow has an effect on the SCR; it is essential to explore the dynamic response of the SCR with the internal flow. The SCR also suffers the lift force and the fluctuating drag force because of the current. Finite element method is utilized to solve the motion equations. The effects of the internal flow, wave and current on the dynamic response of the SCR are considered. The results indicate that the increase of the internal flow density leads to the decrease of the displacement of the SCR, while the internal flow velocity has little effect on the SCR. The displacement of the SCR increases with the increase of the wave height and period. And the increasing wave period results in an increase in the vibration period of the SCR. The current velocity changes the displacements of the SCR in x-and z-directions. The vibration frequency of the SCR in y-direction increases with the increase of the current velocity.

关键词： steel catenary riser slender rod model internal flow dynamic response

Rational Design of Electrode–Electrolyte Interphase and Electrolytes for Rechargeable Proton Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2023年第7期15卷 90-109页

作者： zhen Su Haocheng guo Chuan Zhao School of Chemistry Faculty of ScienceThe University of New South Wales SydneySydneyNSW 2052Australia

Rechargeable proton batteries have been regarded as a promising technology for next-generation energy storage devices,due to the smallest size,lightest weight,ultrafast diffusion kinetics and negligible cost of proton as charge ***,a proton battery possessing both high energy and power density is yet *** addition,poor cycling stability is another major challenge making the lifespan of proton batteries *** issues have motivated extensive research into electrode ***,the design of electrode–electrolyte interphase and electrolytes is underdeveloped for solving the *** this review,we summarize the development of interphase and electrolytes for proton batteries and elaborate on their importance in enhancing the energy density,power density and battery *** fundamental understanding of interphase is reviewed with respect to the desolvation process,interfacial reaction kinetics,solvent-electrode interactions,and analysis *** categorize the currently used electrolytes according to their physicochemical properties and analyze their electrochemical potential window,solvent(e.g.,water)activities,ionic conductivity,thermal stability,and ***,we offer our views on the challenges and opportunities toward the future research for both interphase and electrolytes for achieving high-performance proton batteries for energy storage.

关键词： Energy storage Proton batteries Aqueous batteries Interfacial chemistry Electrolytes

A dynamic regulation of nitrogen on floret primordia development in wheat

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第1期12卷 271-280页

作者： zhen Zhang Yujing Li Yuxun Wu Xiaoyu zheng Xiaolei guo Wan sun zhencai sun Zhimin Wang Yinghua Zhang College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China College of Biological Sciences China Agricultural UniversityBeijing 100193China Engineering Technology Research Center for Agriculture in Low Plain Areas Cangzhou 061800HebeiChina

Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilization is largely unknown.A high temporal-resolution investigation of floret primordia number and morphology,dry matter,and N availability was conducted under three N fertilization levels:0(N0),120(N1)and 240(N2)kg ha^(−1).Interestingly,fertile florets at anthesis stage were determined by those floret primordia with meiotic ability at booting stage:meiotic ability was a threshold that predicted whether a floret primordium became fertile or abortive *** the developmental rate of the 4th floret primordium in the central spikelet was accelerated and then they acquired meiotic ability,the NFFs increased gradually as N application increased,but the increase range decreased under *** were no differences in spike N concentration among treatments,but leaf N concentration was increased in the N1 and N2 ***,dry matter accumulation and N content of the leaf and spike in the N1 and N2 treatments was increased as compared to ***,optimal N fertilization increased leaf N availability and transport of assimilates to spikes,and allowed more floret primordia to acquire meiotic ability and become fertile florets,finally increasing *** was no difference in leaf N concentration between N1 and N2 treatment,whereas soil N concentration at 0–60 cm soil layers was higher in N2 than in N1 treatment,implying that there was still some N fertilization that remained ***,improving the leaf’s ability to further use N fertilizer is vital for greater NFFs.

关键词： Fertile florets Floret primordia Grain number Meiotic ability Morphological development

A multimode-fused sensory memory system based on a robust self-assembly nanoscaffolded BaTiO_(3):Eu_(2)O_(3) memristor

在线全文

学校读者我要写书评

暂无评论

InfoMat 2023年第9期5卷 51-63页

作者： Xiaobing Yan Yinxing Zhang Ziliang Fang Yong sun Pan Liu Jiameng sun Xiaotong Jia Shiqing sun zhenqiang guo zhen Zhao School of Life Sciences Institute of Life Science and Green DevelopmentKey Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei ProvinceCollege of Electron and Information EngineeringHebei UniversityBaodingthe People's Republic of China Department of Materials Science and Engineering National University of SingaporeSingaporeSingapore

Biologically inspired neuromorphic sensory memory systems based on memristor have received a lot of attention in the booming artificial intelligence industry due to significant potential to effectively process multi-sensory signals from complex external ***,many memristors have significant switching parameters disperse,which is a great challenge for using memristors in bionic neuromorphic sensory memory ***,a stable ferroelectric memristor based on the Pd/BaTiO_(3):Eu2O_(3)/La0.67Sr0.33MnO_(3)grown on Silicon structure with SrTiO_(3)as buffer layer is *** device possesses low coercive field voltage(-1.3-2.1 V)and robust endurance characteristic(~10^(10)cycles)through optimizing the growth *** importantly,an ultra-stable artificial multimodal sensory memory system with visual and tactile functions was reported for the first time by combining a pressure sensor,a photosensitive sensor,and a robotic *** the above system,the sensitivity value of the system is expressed by the conductance of the memristor to realize the gradual change of external stimulus,and multi signals inputs at the same time to this system have faithfully achieved sensory adaptation to multimodal *** work paves the way for future development of memristor-based perception systems in efficient multisensory neural robots.

关键词： artificial sensory memory system ferroelectric memristor multi signals ultra-stable

Towards fully automatic modelling of the fracture process in quasi-brittle and ductile materials:a unified crack growth criterion

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

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第7期9卷 867-877页

作者： zhen-jun YANG guo-hua LIU College of Civil Engineering and Architecture Zhejiang University Hangzhou 310027 China

Fully automatic finite element(FE) modelling of the fracture process in quasi-brittle materials such as concrete and rocks and ductile materials such as metals and alloys,is of great significance in assessing structural integrity and presents tre-mendous challenges to the engineering community. One challenge lies in the adoption of an objective and effective crack propagation criterion. This paper proposes a crack propagation criterion based on the principle of energy conservation and the cohesive zone model(CZM) . The virtual crack extension technique is used to calculate the differential terms in the criterion. A fully-automatic discrete crack modelling methodology,integrating the developed criterion,the CZM to model the crack,a simple remeshing procedure to accommodate crack propagation,the J2 flow theory implemented within the incremental plasticity framework to model the ductile materials,and a local arc-length solver to the nonlinear equation system,is developed and im-plemented in an in-house program. Three examples,i.e.,a plain concrete beam with a single shear crack,a reinforced concrete(RC) beam with multiple cracks and a compact-tension steel specimen,are simulated. Good agreement between numerical predictions and experimental data is found,which demonstrates the applicability of the criterion to both quasi-brittle and ductile materials.

关键词： Finite element method (FEM) Crack propagation criterion Cohesive zone model (CZM) Virtual crack extension(VCE) Arc-length method

Gas sensing selectivity of oxygen-regulated SnO2 films with different microstructure and texture

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第10期35卷 2232-2237页

作者： Ruiwu Li Yanwen Zhou Maolin sun zhen Gong Yuanyuan guo Xitao Yin Fayu Wu Wutong Ding School of Material Science and Metallurgy University of Science and Technology LiaoningAnshan114051China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou730050China

The selectivity of gas sensing materials is increasingly important for their applications. The oxygenregulated SnO2 films with(110) and(101) preferred orientation were obtained through magnetron sputtering, followed by annealing treatment. Their micro-structure, surface morphology and gas response were investigated by advanced structural characterization and property measurement. The results showed that the as-prepared(110)-oriented SnO2 film was oxygen-rich and had more adsorption sites while the as-prepared(101)-oriented SnO2 film was oxygen-poor and more sensitive to de-oxidation.H2 gas sensitivity, response speed, selectivity between H2 and CO of the(110)-orientated SnO2 film was superior to that of the(101)-orientated SnO2 film. After treated at high temperature and high vacuum,the reduction of gas-sensing properties of the annealed(110) SnO2 film was much more than that of the annealed(101) SnO2 film. The lattice oxygen was responsible for the difference in gas-sensing response between(110) and(101)-oriented SnO2 films under oxygen regulation. This work indicated the gassensing selectivity of the different crystal planes in SnO2 film, providing a significant reference for design and extension of the related materials.

关键词： Gas sensor SnO2 Oxygen regulation Preferred orientation H2 selectivity