Texture analysis of poly-adenylated mRNA staining following global brain ischemia and reperfusion

Texture analysis provides a means to quantify complex changes in microscope images. We previously showed that cytoplasmic poly-adenylated mRNAs form mRNA granules in post-ischemic neurons and that these granules correlated with protein synthesis inhibition and hence cell death. Here we utilized the texture analysis software MaZda to quantify mRNA granules in photomicrographs of the pyramidal cell layer of rat hippocampal region CA3 around 1 h of reperfusion after 10 min of normothermic global cerebral ischemia. At 1 h reperfusion, we observed variations in the texture of mRNA granules amongst samples that were readily quantified by texture analysis. Individual sample variation was consistent with the interpretation that animal-to-animal variations in mRNA granules reflected the time-course of mRNA granule formation. We also used texture analysis to quantify the effect of cycloheximide, given either before or after brain ischemia, on mRNA granules. If administered before ischemia, cycloheximide inhibited mRNA granule formation, but if administered after ischemia did not prevent mRNA granulation, indicating mRNA granule formation is dependent on dissociation of polysomes. We conclude that texture analysis is an effective means for quantifying the complex morphological changes induced in neurons by brain ischemia and reperfusion.     

图像分解与色彩先验下的多曝光图像融合

目的 多曝光图像融合（multi-exposure fusion，MEF）是利用一组不同曝光度的低动态范围（low dynamic range，LDR）图像进行合成，得到类似高动态范围（high dynamic range，HDR）图像视觉效果图像的过程。传统多曝光图像融合在一定程度上存在图像细节信息受损、边界不清晰以及部分色彩失真等问题。为了充分综合待融合图像的有效信息，提出了一种基于图像分解和色彩先验的双尺度多曝光图像融合方法。方法 使用快速导向滤波进行图像分解，分离出细节层对其进行增强处理，保留更多的细节信息，同时减少融合图像的光晕伪影；根据色彩先验，利用亮度和饱和度之差判断图像曝光程度，并联合亮度与饱和度之差以及图像对比度计算多曝光图像融合权重，同时保障融合图像的亮度和对比度；利用导向滤波对权重图进行优化，抑制噪声，增加像素之间的相关性，提升融合图像的视觉效果。结果 在24组多曝光图像序列上进行实验，从主观评价角度来看，该融合方法能够提升图像整体对比度及色彩饱和度，并兼顾过曝光区域和欠曝光区域的细节提升。从客观评价标准分析，采用两种不同的多曝光图像序列融合结果的质量评估算法，评价结果显示融合性能均有所提高，对应的指标均值分别为0.982和0.970。与其他对比算法的数据结果比较，在两种不同的结构相似性指标上均有所提升，平均提升分别为1.2%和1.1%。结论 通过主观和客观评价，证实了所提方法在图像对比度、色彩饱和度以及细节信息保留的处理效果十分显著，具有良好的融合性能。     

以太网业务MEF 2.0认证研究与实现

MEF CE 2.0 认证一直广受国际大型运营商和设备商的关注与支持,成为新一代以太网业务互联互通、透明传送管理的标准。通过对MEF CE 2.0认证相关的标准、方法及技术细节的深入研究,总结并提供了认证测试相关的业务范围、定义、操作流程、测试拓扑、测试项目与指标等,并在实际业务认证中得以验证实现,可为电信运营商进行类似国际认证提供技术参考。     

客户观点的以太网业务模型与应用方案

文章基于IEEE 802．3以太网协议,通过加入业务相关曼性和参数来定义适合运营的以太网业务,并从业务的基本模型、业务的框架结构、典型业务的定义和典型应用方案几个方面进行了阐述。     

融合结构域MM蛋白在杆状病毒中的表达和细胞定位

目的将C-Myb的DNA结合域与MEF的AML1结合区组合成的MM融合基因在杆状病毒中进行表达和细胞定位。方法将氨基酸融合有绿色荧光蛋白的MM基因插入到杆状病毒转移载体中,通过重组质粒和亲本病毒AcPak6共转染昆虫Tn5细胞,获得重组病毒AcNPV-GFP-MM,并对该重组病毒在Tn5细胞中进行表达和定位观察。结果通过荧光显微镜观察,在病毒感染48h后的Tn5细胞中,可见表达产物大量集聚在细胞核内,Westernblot证明表达的融合蛋白在相对分子质量约60000处出现特异条带,与预计的蛋白理论值相符。结论由杆状病毒表达系统表达的MM蛋白比较稳定,能正确地趋向于核内。可以通过这种表达方式获得大量产物。     

Extraction Using Moderate Electric Fields

ABSTRACT: During moderate electric field (MEF) processing, a voltage applied across a food material may affect the permeability of cell membranes. It is known that high electric fields can cause either reversible or irreversible rupture of cell membranes. In this research, the effect of MEF processing on permeability was studied. Effects of frequency and electric field strength were investigated. Cellular structure was investigated by transmission electron microscopy (TEM). Fermented black tea leaves and fresh or dry mint leaves were placed in tea bags or cut in 1 cm² squares, depending on the experiment, and immersed in an aqueous fluid medium. Control samples were heated on a hot plate. MEF treatments were conducted by applying a voltage across electrodes immersed in opposite sides of the beaker. Control and MEF‐treated fresh mint leaf samples heated to 50°C were analyzed by TEM. MEF processing significantly increased the extraction yield for fresh mint leaves because of additional electric field effects during heating. Dried mint leaves and fermented black tea leaves were not affected by the treatment type. Low frequency resulted in higher extraction rates for fresh mint leaves. The electric field strength study showed that electrical breakdown is achieved even at low electric field strengths. MEF treatment shows potential to be used as an alternative to conventional heating for extraction from cellular materials.     

Metal-enhanced fluorescence based calcium detection: Greater than 100-fold increase in signal/noise using Fluo-3 or Fluo-4 and silver nanostructures

In this paper we describe metal-enhanced fluorescence (MEF) of the Ca²⁺ indicators: Fluo-3 and Fluo-4 in close proximity to silver nano-particles, SiFs. When the concentration of Ca²⁺ increases, the MEF enhancement factor decreases, which is consistent with our previous findings that the greatest fluorescence enhancements occur for fluorophores with the lowest free-space quantum yield. Over 100-fold enhanced fluorescence intensities (signal/noise) were observed. In addition, the photostability of the fluorophore (Fluo-3) is much more prolonged from the SIFs as compared to glass (a control sample). Our findings strongly suggest the widespread use and the general approach of nanoparticulate SiFs surfaces for the enhanced detection of both intra and extra-cellular calcium and indeed other analytes of interest.     

Modifications of starch by electric field based techniques

BackgroundNative starches have limited applications and are commonly modified for desired properties. There has been increasing demand for physically and non-chemically modified starches from the market as consumers prefer “natural and healthy” food products. Among various physical means, electric field based techniques have been gaining a research focus for starch modifications during the last few years. Another trend is to produce modified starches using cleaner process. Electric fields of certain conditions can facilitate the “cleaner production” of food and industrial ingredients.Scope and approachThis mini-review summarises the modifications of starches from different botanical sources by the electric field based techniques. The techniques are based on pulsed electric field, induced electric field, moderate electric field, and ohmic heating. Physicochemical properties, granular and molecular structures, applications of starch as affected by the electric field based modifications are reviewed. Structure-function relationships of starch as affected by the electric fields are discussed. Impact of electric fields on food systems rich in starch (e.g., flour) is also reviewed. Research gaps to better utilize these techniques for starch modifications are suggested.Key findings and conclusionsDifferent electric field based methods greatly modify the starch physicochemical properties to different extents. Factors affecting the outcomes of the modifications include the starch type and concentrations, electrical conductivity, and electric field type, strength, and duration. Starch modification processes such as hydrolysis and substitutions can be efficiently optimized by applying electric fields. The functionalities of food systems rich in starch can also be modified by these techniques. It becomes evident that electric field based techniques have potential to be used in starch modifications to create a range of functionalities and to help meet the ever-rising market of clean label ingredients.     

PON系统承载TDM技术研究

作为综合接入系统,PON系统不仅要能承载数据、视频和语音等业务,还应能承载TDM业务。本文结合TDM业务的传输特性,研究了TDM over EPON/GPON的各种电路仿真协议,提出了TDM over EPON/GPON的协议参考模型,详细分析了PON系统承载TDM业务的关键技术。     

基于多光刻胶有效扩散长度的光学临近效应修正模型校准方法

提出了基于多光刻胶有效扩散长度的光学临近效应修正模型校准方法,其考虑了一维和二维图形之间光刻胶有效扩散长度的不同. 该方法的一个重要步骤在于建立起全新的校准流程,使得一维图形和二维图形具有相同的光学参数和不同的光刻胶有效扩散长度. 另外,在该模型校准流程中提出了一种基于可制造性设计理念的交互. 从校准结果的关键尺寸误差及仿真轮廓和扫描电子显微镜图像的对比来看,基于多光刻胶有效扩散长度的光学临近效应修正模型校准方法的输出模型更加精确和稳定.