检索结果-南通市图书馆

抑制Hmga2促进小鼠脂肪间充质干细胞成骨分化并加速骨缺损修复

在线全文

学校读者我要写书评

暂无评论

南方医科大学学报 2024年第7期44卷 1227-1235页

作者：柯志勇黄子城何若琳张倩陈思旭崔忠凯丁晶南方医科大学基础医学院细胞生物学教研室广东广州510515 上海交通大学医学院附属新华医院儿骨科上海200092

目的探讨高迁移率族蛋白A2(HMGA2)在脂肪间充质干细胞(ADSCs)成骨分化进程中的作用及其在骨缺损修复中的应用。方法通过GEO数据库和Rstudio软件,挖掘出在ADSCs“成脂-成骨”分化平衡中的关键节点因子HMGA2,并通过在线蛋白互作网络分析工... 详细信息

目的探讨高迁移率族蛋白A2(HMGA2)在脂肪间充质干细胞(ADSCs)成骨分化进程中的作用及其在骨缺损修复中的应用。方法通过GEO数据库和Rstudio软件,挖掘出在ADSCs“成脂-成骨”分化平衡中的关键节点因子HMGA2,并通过在线蛋白互作网络分析工具String和绘图软件Cytoscape,绘制HMGA2在成骨分化中的互作关系网络,预测其下游作用靶点。设计Hmga2 siRNA并转染小鼠原代脂肪间充质干细胞(mADSCs),诱导其体外成骨分化,在不同时间点(Day 3,Day 7,Day 14)收集样本,通过碱性磷酸酶染色和茜素红染色评估成骨分化能力,并通过RT-qPCR和Western blotting检测成骨特异性标志物Runt相关转录因子2(RUNX2)、骨桥蛋白(OPN)和骨钙素(OCN)的表达。将敲低Hmga2的mADSCs移植至小鼠不可自愈合颅骨缺损处,术后6周通过μCT扫描、骨组织学染色检测成骨标志物,评价骨缺损修复效果。结果GEO数据库分析结果显示HMGA2在ADSCs成脂分化进程中表达上调。蛋白互作网络分析提示在ADSCs成骨分化中,HMGA2的潜在作用靶点包括SMAD7、CDH1、CDH2、SNAI1、SMAD9、IGF2BP3、ALDH1A1。抑制Hmga2后,mADSCs中成骨分化相关标志物RUNX2、OPN和OCN的表达显著上调,且碱性磷酸酶的表达和钙结节的形成增加(P<0.05)。在小鼠颅骨缺损模型中,敲低Hmga2促进了骨缺损部位的新骨形成(P<0.05)。结论HMGA2是调控ADSCs成骨分化的重要因子,抑制Hmga2能显著促进ADSCs成骨分化,并加速体内骨缺损的修复。

关键词：脂肪间充质干细胞高迁移率族蛋白A2 成骨分化骨缺损修复

Discretization error of irregular sampling approximations of stochastic integrals

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2016年第3期31卷 296-306页

作者： ZHOU Li-kai SU Zhong-gen Department of Mathematics Zhejiang University

This paper studies the limit distributions for discretization error of irregular sam- pling approximations of stochastic integral. The irregular sampling approximation was first presented in Hayashi et al.[3], which was more general than the sampling approximation in Lindberg and Rootzen [10]. As applications, we derive the asymptotic distribution of hedging error and the Euler scheme of stochastic differential equation respectively.

关键词： Euler scheme irregular sampling stochastic integral weak convergence hedging error

A Scalable Infrastructure for Online Performance Analysis on CFD Application

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2012年第4期25卷 546-558页

作者： HU kai DING Yi ZHANG Xinyu JIANG Shu School of Computer Science and Engineering Beihang UniversityBeijing 100191China

The fast-growing demand of computational fluid dynamics（CFD） application for computing resources stimulates the development of high performance computing（HPC） and meanwhile raises new requirements for the technology of parallel application performance monitor and *** response to large-scale and long-time running for the application of CFD,online and scalable performance analysis technology is required to optimize the parallel programs as well as to improve their operational *** a result,this research implements a scalable infrastructure for online performance analysis on CFD application with homogeneous or heterogeneous *** infrastructure is part of the parallel application performance monitor and analysis system（PAPMAS） and is composed of two modules which are scalable data transmission module and data storage *** paper analyzes and elaborates this infrastructure in detail with respect to its design and ***,some experiments are carried out to verify the rationality and high efficiency of this infrastructure that could be adopted to meet the practical needs.

关键词： computational aerodynamics computational fluid dynamics scalability online analysis data transmission data storage

退化高寒草甸土壤真菌群落水平分布格局及驱动因子

在线全文

学校读者我要写书评

暂无评论

草地学报 2024年第4期32卷 1105-1111页

作者：王英成芦光新郑开福金鑫周学丽姚世庭青海大学青海西宁810016

为探讨退化高寒草甸土壤真菌群落水平分布格局及驱动因子,本研究采用嵌套式取样方法在1000 m×1000 m的中度退化草甸区域内,综合分析了土壤真菌群落在不同取样距离上物种多样性和功能组成的变化规律及驱动土壤真菌群落分布的主要环境因... 详细信息

为探讨退化高寒草甸土壤真菌群落水平分布格局及驱动因子,本研究采用嵌套式取样方法在1000 m×1000 m的中度退化草甸区域内,综合分析了土壤真菌群落在不同取样距离上物种多样性和功能组成的变化规律及驱动土壤真菌群落分布的主要环境因子。结果表明:在不同取样距离上,土壤真菌的α多样性和群落结构存在显著的差异,退化草甸环境异质性可导致真菌群落的变化。FunGuil功能预测表明草甸退化使得腐生型和病理性土壤真菌增加,草甸退化过程中地上植被群落的改变可导致土壤真菌营养型的变化。此外,土壤营养成分是驱动退化草甸土壤真菌群落水平分布格局的主要环境因子。因此,微生物多样性空间分布受控于不同的环境因素,而土壤营养成分的改变容易引起退化草地生态系统中微生物的空间分布变化。

关键词：退化草甸土壤真菌群落组成功能组成水平分布

Linear stability of plane creeping Couette flow for Burgers fluid

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2013年第1期29卷 12-23页

作者： kai-Xin Hu Jie Peng Ke-Qin Zhu Department of Engineering Mechanics Tsinghua University

It is well known that plane creeping Couette flow of UCM and Oldroy-B fluids are linearly stable. However, for Burges fluid, which includes UCM and Oldroyd-B fluids as special cases, unstable modes are detected in the present work. The wave speed, critical parameters and perturbation mode are studied for neutral waves. Energy analysis shows that the sustaining of perturbation energy in Poiseuille flow and Couette flow is completely different. At low Reynolds number limit, analytical solutions are obtained for simpli- fied perturbation equations. The essential difference between Burgers fluid and Oldroyd-B fluid is revealed to be the fact that neutral mode exists only in the former.

关键词： Linear stability theory Burgers fluid Creeping Couette flow - Elastic instability

Perspectives on studying molecular adaptations of amphibians in the genomic era

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2020年第4期41卷 351-364页

作者： Yan-Bo Sun Yi Zhang kai Wang Laboratory of Ecology and Evolutionary Biology Yunnan UniversityKunmingYunnan 650091China State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Sam Noble Oklahoma Museum of Natural History and Department of Biology University of OklahomaNormanOklahoma 73072USA

Understanding the genetic mechanisms underlying particular adaptations/phenotypes of organisms is one of the core issues of evolutionary *** use of genomic data has greatly advanced our understandings on this issue,as well as other aspects of evolutionary biology,including molecular adaptation,speciation,and even conservation of endangered *** the well-recognized advantages,usages of genomic data are still limited to non-mammal vertebrate groups,partly due to the difficulties in assembling large or highly heterozygous *** this is particularly the case for amphibians,nonetheless,several comparative and population genomic analyses have shed lights into the speciation and adaptation processes of amphibians in a complex landscape,giving a promising hope for a wider application of genomics in the previously believed challenging groups of *** the same time,these pioneer studies also allow us to realize numerous challenges in studying the molecular adaptations and/or phenotypic evolutionary mechanisms of *** this review,we first summarize the recent progresses in the study of adaptive evolution of amphibians based on genomic data,and then we give perspectives regarding how to effectively identify key pathways underlying the evolution of complex traits in the genomic era,as well as directions for future research.

关键词： Molecular adaptation Gene subnetwork Phenotypic evolution Transposable element Amphibians

Recent developments in microfluidic device-based preparation, functionalization, and manipulation of nano- and micro-materials

在线全文

学校读者我要写书评

暂无评论

Particuology 2019年第4期17卷 1-19页

作者： Guangsheng Luo Le Du Yujun Wang kai Wang The State Key Lab of Chemical Engineering Department of Chemical Engineering Tsinghua University Beijing 100084 China The State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Membrane Science and Technology Beijing University of Chemical Technology Beijing 100029 China

Microfluidic systems provide a powerful platform for preparing,functionalizing,and manipulating nano-/*** this review,we summarize the characteristics of state-of-the-art microfluidic techniques and their application to processing novel nano-/micro-materials with tunable size,shape,morphology,composition,and properties.A variety of synthesis strategies based on novel microfiuidic devices are presented and compared,including their integration with real-time monitoring,external fields,and automatic feedback *** functional nano-/micro-materials with complex structures have been controllably prepared and post-processed to obtain high-quality *** for controlling and tuning physical and chemical properties are also examined in terms of the design and function of microfluidic *** provide an outlook on future developments in the processing of nano-/micro-materials by microfluidic technologies.

关键词： Microfluidics Microchemical systems Nanomaterials Micro-materials Scale-up

NewBalance: Efficient Data Space Management and Algorithmic Optimization for Large-Scale Storage Systems

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 Electronics 2017年第3期26卷 493-501页

作者： XU Guangping LIN Sheng SHI kai ZHANG Hua Tianjin Key Laboratory of Intelligence Computing and New Software Technology Computer and Communication Engineering School Tianjin University of Technology

Fragmentation usually occurs when data space of original storage nodes has to be reallocated to new added storage nodes during the scale-out evolution of the large-scale storage *** greatly influences its performance and becomes a challenge to manage the whole *** present an efficient space management framework,called New Balance,to reduce fragmentation with the minimum data movement while keeping the storage system load *** space management framework has two phases including the collection phase and the allocation *** the collection phase,we propose a novel algorithm,called the greedy bi-direction collector,which collects enough space for the new storage *** the allocation phase,we formally represent it as a variant of the bin packing problem and then utilize some bin packing heuristics including the first fitting and the best fitting to allocate collected intervals to new added storage *** experimental results show that the amount of intervals can be reduced by 20%;5%and our algorithmic optimization improves the data lookup performance by at least 10%and the scale-out performance by 2X;X.

关键词： Large-scale storage systems Space management Algorithmic optimization Performance evaluation

Compressed Sensing of IR-UWB Wireless Sensor Network Data Based on Two-Dimensional Measurements

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2015年第3期24卷 627-632页

作者： WANG kai LIU Yulin WAN Qun JING Xiaojun Chongqing Communication Institute China Electronic System Engineering Company University of Electronic Science and Technology of China Beijing University of Posts and Telecommunications

A novel Compressed sensing(CS) method based on two-dimensional measurements is proposed that can be effectively utilized in Impulse radio ultra-wideband wireless sensor networks(IR-UWB WSNs) to significantly reduce the energy consumption and sampling rate in sensor data transferring. We start by establishing the CS measurement model by taking both spatial and temporal correlations of Wireless sensor network(WSN) data into account. Since our model incorporates a new type of measurement matrix: the block quasi-Toeplitz structured matrix, we derive the Restricted isometry property(RIP)of the block quasi-Toeplitz structured matrix to ensure the performance of the two-dimensional recovery of WSNs data. We substantiate our mathematical analysis by numerical examples in the context of ideal spares vector and real WSN data, and results demonstrate that the approach achieves significantly saving of energy and sampling rate with small reconstruction error.

关键词： Compressed sensing Wireless sensor net-works IR-UWB Measurement Restricted isometry property