大黄鱼小黄鱼实时荧光PCR鉴定

目的:建立一种快速、准确的大黄鱼小黄鱼实时荧光PCR鉴定方法.方法:根据GenBank中大黄鱼、小黄鱼线粒体中ND6基因的序列,设计并合成特异性引物和cycling探针,以草鱼为阴性对照,进行实时荧光PCR反应.结果:利用设计合成的大黄鱼和小黄鱼特异性引物和cycling探针进行实时荧光PCR反应,大黄鱼和小黄鱼均产生特异扩增曲线,对照的草鱼没有产生扩增曲线.结论:利用设计的引物和cycling探针,可准确快速鉴定大黄鱼和小黄鱼.     

一种补偿因子区域不变的CS成像算法

为提高星载合成孔径雷达（SAR）成像的实时性,减小补偿因子的运算量,提出了一种补偿因子区域不变的Chirp Scaling（CS）成像算法. 这种改进的CS算法根据补偿因子的相位误差确定一个更新步长,在每个步长内更新一次补偿因子,即相邻单元内的数据与相同的补偿因子相乘. 利用这种改进的CS算法对点阵目标和实测目标进行了仿真验证,得到的SAR图像质量与传统CS算法的结果相差很小. 这种补偿因子区域不变的CS成像算法在满足精度的前提下使得补偿因子的运算量成倍减小,大大减小了实时成像的压力,能够有效降低星上实时处理系统的规模,从而降低系统功耗.      

Factors affecting the voxel-based analysis of diffusion tensor imaging

Diffusion tensor imaging （DTI） provides a unique method to reveal the integrity of white matter microstructure noninvasively. Voxel-based analysis （VBA）, which is a highly reproducible and user-independent tech- nique, has been used to analyze DTI data in a number of studies. Fractional anisotropy （FA）, which is derived from DTI, is the most frequently used parameter. The parameter setting during the DTI data preprocessing might affect the FA analysis results. However, there is no reliable evidence on how the parameters affect the results of FA analysis. This study sought to quantitatively investigate the factors that might affect the voxel-based analysis of FA; these include the interpolation during spatial normalization, smoothing kernel and statistical threshold. Because it is difficult to obtain the true information of the lesion in the patients, we simulated lesions on the healthy FA maps. The DTI data were obtained from 20 healthy subjects. The FA maps were calculated using DTIStudio. We randomly divided these FA maps into two groups. One was used as a model patient group, and the other was used as a normal control group. Simulated lesions were added to the model patient group by decreasing the FA intensities in a specified region by 5 %- 50 %. The model patient group and the normal control groupwere compared by two-sample t test statistic analysis voxel- by-voxel to detect the simulated lesions. We evaluated these factors by comparing the difference between the detected lesion through VBA and the simulated lesion. The result showed that the space normalization of FA image should use the trilinear interpolation, and the smoothing kernel should be 2-3 times the voxel size of spatially normalized FA image. For lesions with small intensity change, FWE correction must be cautiously used. This study provided an important reference to the analysis of FA with VBA method.     

A machine learning-based method to detect fluorescent spots and an accelerated,parallel implementation of this method

Under most microscopes, the fluorescent sig- nals emitted from biological structures, such as vesicles, as well as the signals from single molecules will appear as small puncta, which contribute to a Gaussian-like distri- bution. Accurate segmentation of these spots will funda- mentally affect our interpretation of a specific biological progress. Because of the complicated backgrounds in images, many algorithms fail to identify all of the inter- esting signals; the tremendous amount of time required for algorithms to process large datasets can also decrease their utility. Here, we introduce an excellent robust detection method based on the machine learning algorithm Ada- Boost, which outperforms threshold-based segmentation, wavelets, and FDA under most situations. We also provide a GPU/multi-core CPU implementation of this algorithm; this implementation accelerates the algorithm approxi- mately 10- and 7-fold acceleration compared with a single CPU implementation. The great reduction of time should make this method a promising candidate in the processing of large datasets. Furthermore, we demonstrate the use of our algorithm on true fluorescent micrographs, and the results show that machine learning-based detection meth- ods outperform the four other previously reported methods.     

基于LIF技术的煤矿水源识别系统应用

本文主要叙述LIF(激光诱导荧光光谱分析)技术的基本原理以及在水源识别中的应用,重点分析LIF技术的系统构成和主要模块的选择设计。通过该系统对某矿的送检水样和标准水样进行荧光实验,得到水样的荧光光谱图。传统的水源识别主要依据水中代表离子的离子浓度进行分析,但是从荧光光谱分析水中代表离子的离子浓度难度较大。本文提出一种较为简单且实用的方法由荧光光谱进行水源的精确识别,即使用相应分析软件分别测量未知水样与标准水样的欧氏距离,得出未知水样的精确分类。对未知水样的水源识别验证了该系统的可行性,解决了当前煤矿无法对突水情况进行实时在线监测的难题,对于煤矿的安全生产具有重要意义。     

光谱法研究EDTA-Fe(Ⅲ)与牛血清白蛋白的相互作用

应用紫外光谱法和荧光光谱法研究了乙二胺四乙酸铁(Ⅲ)(EDTA-Fe(Ⅲ))与牛血清白蛋白的相互作用.结果表明:EDTA-Fe(Ⅲ)可以进入牛血清白蛋白的疏水腔,使蛋白质非极性区的生色基暴露于极性溶剂;EDTA-Fe(Ⅲ)通过静态猝灭的方式使牛血清白蛋白的荧光强度显著降低;EDTA-Fe(Ⅲ)与牛血清白蛋白主要以氢键和范德华力相结合.测定了EDTA-Fe(Ⅲ)与牛血清白蛋白的结合常数KA和结合位点数n,利用Forster非辐射能量转移机制确定了牛血清白蛋白与EDTA-Fe(Ⅲ)的结合距离和能量转移效率,并使用同步荧光技术探讨了EDTA-Fe(Ⅲ)对牛血清白蛋白构象的影响.     

Multifractal analysis of resting state fMRI series in default mode network: age and gender effects

Age-related changes of resting state in default mode network （DMN） may provide new clues to the developing mechanism of normal brain as well as early diagnosis and therapy of some neuropsychiatric disorders. The application of multifractal theory to functional magnetic resonance imaging （fMRI） signals has recently raised increasing attention. We aim to explore the multifractal characteristics underlying the resting state functional magnetic resonance imaging （rs-fMRI） series extracted from DMN, and two issues are mainly discussed： （1） whether there exist multifractals in rs-fMRI series; （2） whether it is possible to distinguish between the different ages or genders by means of multifractal characteristics. Results demon- strated the existence of multifractals in rs-fMRI series in DMN. In addition, slight differences between young subjects and middle-aged or elderly subjects can be successfully detected by △asα, a modified measure we proposed. Furthermore, it is revealed that the rs-fMRI series from young subjects possess smaller averaged scale index and weaker long range correlation, while those from middle-aged or elderly people present increasing averaged scale index andstronger long range correlation. Whereas no significant statistical differences has been found between male and female group. Our results, therefore, highlight the potential useful- ness of multifractal analysis in fMRI series of a certain brain region, and provide important insights into healthy aging in DMN.     

光谱法研究马来酸氯苯那敏与牛血清白蛋白的相互作用

采用紫外光谱和荧光猝灭光谱研究了马来酸氯苯那敏(CM)与牛血清白蛋白(BSA)的相互作用机理.结果表明,CM对BSA是动态猝灭机理,以疏水作用为主;通过计算获得二者在不同温度下的结合常数及结合位点数;利用同步荧光光谱探讨了作用前后BSA的构型变化,确定结合位置位于BSA的亚结构ⅡA中;Hill系数nH1,表明CM有正协同作用.此外,讨论了共存金属离子Mn2+,Fe3+,Cr3+,Pb2+,Ni 2+对CM与BSA结合作用的影响.     

硫化镉量子点的可控制备及荧光性能研究

采用溶剂热法,以Cd(NO3)2·4H2O和升华硫为镉、硫来源,油胺为反应溶剂和表面活性剂,制备了硫化镉量子点(CdS QDs),并研究了反应温度、反应时间对硫化镉量子点尺寸的影响.通过X射线衍射(XRD)和透射电镜(TEM)对所制备产物的结构和形貌进行了表征.结果表明,所制备的硫化镉量子点结晶度较高,单分散性好,尺寸均一.通过紫外可见吸收光谱(UV-Vis)和荧光光谱(PL)表征了硫化镉量子点随反应温度和时间的变化,结果发现,随反应温度的升高和反应时间的延长,其吸收峰出现了明显的红移,即通过控制反应温度和时间可以控制硫化镉量子点的尺寸和发光颜色.     

一种用于皮层信号检测的LED光源系统研制

在视觉皮层的功能结构研究中,内源信号光学成像具有广泛的应用,由于信号成分的特殊性和强度水平较低,为了获取稳定可靠的信号,整套实验装置必须进行精细地设计.随着光源照明技术的发展与进步,本研究将LED照明技术应用于皮层信号检测,自行研制了适用于内源信号光学成像的LED光源,通过物理信号测试以及生物信号的检测表明,自制LED光源的稳定性与适用性均达到了科研要求,并且具有极强的拓展性,可以广泛应用于其他生物研究领域.