399 research outputs found
The Role of SNX8 in Alzheimer’s Disease
阿尔茨海默病(Alzheimer’sdisease,AD)一个重要的病理学特征是在神经细胞外形成主要由β淀粉样蛋白(βamyloid,Aβ)组成的淀粉样斑(amyloidplaques)。大脑内具有神经毒性的Aβ的累积在AD的发病过程中处于中心地位。β淀粉样蛋白前体蛋白(βamyloidprecursorprotein,APP)依次经过β分泌酶和γ分泌酶切割后可以产生Aβ和APP的胞内结构域(APPintracellulardomain,AICD)。APP还可以被α分泌酶切割产生具有神经保护作用的sAPPα。许多研究发现α分泌酶主要在细胞膜上对APP进行切割,而β分泌酶主要在内体(Endsom...One of the neuropathologic hallmarks of Alzheimer’s disease (AD) is the presence of senile plaques which consist of β-amyloid peptide (Aβ) in the brain. Accumulation of the neurotoxic Aβ in the brain is central to the pathogenesis of AD. Aβ is derived from β-amyloid precursor protein (APP) through sequential cleavages by the β-secretase and the γ-secretase. In addition to amyloidogenic processing,...学位:理学博士院系专业:生物医学研究院_化学生物学学号:3052010015394
尼罗罗非鱼TCP-1-beta和TCP-1-eta的分子特征及其低温诱导表达
为了研究尼罗罗非鱼耐寒性状的分子基础并为耐寒品种选育提供参考,研究从尼罗罗非鱼中克隆了HSP60家族TCP-1-beta和TCP-1-eta基因并对其在低温诱导下的表达特征进行了分析。尼罗罗非鱼TCP-1-beta cDNA长度为1755 bp,包括1605 bp的完整开放阅读框,编码534个氨基酸;尼罗罗非鱼TCP-1-eta cDNA长度1651 bp,包括1638 bp的完整开放阅读框,编码545个氨基酸。与其他物种同源基因的蛋白序列比对结果显示,TCP-1-beta和TCP-1-eta蛋白在物种间同源性很高,且都具有保守的ATP结合结构域等,预示其在物种间功能的保守性。实时荧光定量PCR结果表明:TCP-1-beta和TCP-1-eta在各组织中呈遍在表达,但在肌肉中表达量最高;诱导温度从22℃降至12℃,不同低温诱导48h后TCP-1-beta和TCP-1-eta均呈上调表达,在18℃时表达开始上调,随着低温胁迫程度加强,表达上调幅度增大,至12℃时表达量达到最高,TCP-1-beta和TCP-1-eta上调幅度分别达到常温的12.2倍和10.7倍。这些结果预示在尼罗罗非鱼中,TCP-1-beta和TCP-1-eta是潜在的耐寒相关基因
Finance Development and the Income Gap—A Study Based on the Uneven Distribution of Financial Resource
本文运用协整分析和格兰杰因果分析对我国地区间和城乡间的金融资源分布差距与居民人均收入差距关系进行探讨,并在此基础上,通过建立面板数据模型对我国金融发展影响居民收入水平的机制进行了实证分析,该研究揭示了金融发展水平提高与居民收入差距扩大同步存在的内在原因,为缩小居民收入差距提供了指导和思路。 对我国东中部地区间和东西部地区间的金融资源差距与居民收入差距进行协整检验和格兰杰因果检验,结果显示,地区间居民收入差距与地区间金融资源差距存在长期稳定的正向相关关系,而且,地区间金融资源差距是地区间居民收入差距的格兰杰原因,即地区间金融资源差距的变动能引起地区间居民收入差距同方向的变动。 对我国城乡间金...This paper studies the relationship between the uneven distribution of financial resources and the disparity of income by using the Co-integration test and Granger causality tests, and it involves the cases in different regions of China and in urban-rural areas of our country. Then, we probe into the effect mechanisms through which the financial development results in the income disparity. Through...学位:经济学硕士院系专业:经济学院_国际金融学学号:1562010115194
High Precision Data Collector Based on PIC Single Chip
介绍利用PIC单片机对24位的Δ ∑模数转换芯片进行应用而开发的一种通用高精度数据采集器。具体介绍了数据采 集器中的A/D转换芯片的工作原理,PIC单片机的通讯模块,实现数据采集工作的相应电路及程序流程图。In this paper, a common high precision data collector which uses PIC microchip to control the 24 bit Δ-∑ A/D converter is introduced. The principle of A/D converter, the communicating block of PIC microchip, the corresponding circuit and the flowchart are introduced in detail
The Study on Handling Sampling Weights Associated with the Survey Data When Applying Data Mining Methods——Based on the Method of Re-sampling with PPWWR
在将数据挖掘方法应用于抽样调查数据时,会遇到抽样权重的处理问题。本文提出采用放回的、与样本单元权数大小成比例的再抽样方法,简称PPWWr再抽样,来实现“事后“自加权设计。实现“事后“自加权设计后的子样本可忽略掉样本权数,直接采用常规的图示方法和数据挖掘算法进行分析。随后,基于2007中国公民科学素质调查贵州省数据,通过模拟分析讨论了PPWWr再抽样子样本的样本量问题,发现MAX(n,5%n)是一个比较合适的样本量。这一结论可能为其他大型复杂抽样调查数据的数据挖掘实施问题提供借鉴。The problem of how to deal with sampling weights appears when applying data mining methods to survey data.We suggest the method of re-sampling with probability proportional to the weights with replacement(PPWWR)to achieve post self-weighting design.Then,some ordinary statistical graphics and data mining algorithms can be used directly,ignoring the sample weights.Next,based on the survey data of GuiZhou Province from the survey of public understanding of science 2007,we discussed the sample size problem of the PPWWR re-sampling method by simulation and find max(n,5%N)is an appropriate sample size.This conclusion might be useful for the implementation of data mining on other large and complex survey data
Application of capacitance sensor in detecting system used in false tooth
详细给出了一种用微型电容式压力传感器镶入义齿基托的义齿受力检测系统。根据电容式压力传感器的工作原理,采用微机电系统(MEMS)工艺,研制出微型电容式压力传感器。通过传感器的埋入封装工艺,在与义齿基托相同材料的作底基的树脂上挖一个边长为2 mm平整的方形小坑,将传感器分布式埋植入底基,并用自制施加压力的装置对义齿对口腔下方组织的作用力进行测试。测量结果表明:本系统能够准确地测量出当牙齿咬合时,义齿基托所承受的力和力的分布。该传感器性能良好,具有比较稳定的输入与输出关系,适用于口腔恶劣环境下测量义齿对口腔下方的组织作用力。A detecting system which is used to detect the stress of false tooth is expressed,and a kind of MEMS capacitance pressure sensor is embedded in the pedestal of false tooth in the system.According to the principle of capacitance pressure sensor,the MEMS craft is adopted to develop the pressure sensor.By encapsulation craft of embedding sensor,some of square holes(its side length is 2 mm)are dug in the base of synthetic resin whose material is the same to the pedestal of false tooth,and the sensor is embedded distributedly in these holes.Then an equipment is made to load the pressure on the false tooth to test its action on the pedestal of false tooth.The test reaults show that the system is able to measure the stress on the pedestal of false teeth and its distributing when the teeth are occluded.The sensor is fine in its performance and has good stability to express the relationship between input and output and is applicable to measuring the strength on the lower structure of the oral cavity especially under the foul circumstance in oral cavity
福建漳江口红树林底质环境因子对底栖微藻初级生产力的影响
本研究于2014年7月至2015年7月在福建漳江口红树林国家级自然保护区潮间带滩涂采集表层底质沉积物样品,研究环境因子对红树林生境底质中的底栖微藻总初级生产力、群落呼吸速率和群落净生产力的影响和调控机制.结果表明,红树林滩涂生境底质中底栖微藻总初级生产力为(2. 4±0. 8) mmol C/(m~2·h),与温度正相关,呈夏季高、冬季低的特点,温度是影响底栖微藻总初级生产力的主要环境因子;受红树林凋落物的影响,红树林生境底质中群落呼吸速率较高,使得秋、冬、春季一些月份群落净生产力出现负值,群落净生产力全年均值为(0. 5±1. 8) mmol C/(m~2·h),基本上处于二氧化碳收支平衡的状态.本研究显示底栖微藻的初级生产力影响了红树林生境底质的二氧化碳源汇格局,在红树林湿地碳循环中扮演重要的角色.国家自然科学基金资助项目(41466001);;近海海洋环境国家重点实验室自主课题资助项目(MELRI1603);;滨海湿地生态系统教育部重点实验室自主课题资助项目(WELRI201601
构建平台 吸纳精英——分析测试中心的建设与管理创新
介绍了该校分析测试中心通过构建大型仪器设备共享平台,在管理体制、管理经验、队伍建设等的实践与探索。新机制的建立为学科建设、研究提供了高水平的研究平台。学院吸纳多名国内外学术精英
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