Microscopy under pressure--an optical chamber system for fluorescence microscopic analysis of living cells under high hydrostatic pressure

High hydrostatic pressure (HHP) becomes more and more interesting for life science research, since it can be employed to inactivate various cells. To directly monitor "cells under pressure," the development of an optical high-pressure chamber is required. Therefore, an optical pressure chamber that can be used for up to 300 MPa was constructed. This chamber has already been described as a tool for in situ observation of dynamic changes of microscopic structures in bright field as well as phase contrast. In combination with an inverted microscope, we obtained brilliant microscopic color pictures with an optical resolution more than 0.56 microm. Here, we demonstrate the capabilities of the HHP cell, in combination with epifluorescence microscopy. Using a nonadherent human B-cell line (Raji, ATCC CCL 86), stained with the fluorescent dyes propidium iodide, Hoechst 33342, or dihexyloxacarbocyanine iodide, we were able to show that the system is suitable to perform fluorescence microscopic analyses, with pressures up to 300 MPa, with viable mammalian cells.     

A guided tour into subcellular colocalization analysis in light microscopy

It is generally accepted that the functional compartmentalization of eukaryotic cells is reflected by the differential occurrence of proteins in their compartments. The location and physiological function of a protein are closely related; local information of a protein is thus crucial to understanding its role in biological processes. The visualization of proteins residing on intracellular structures by fluorescence microscopy has become a routine approach in cell biology and is increasingly used to assess their colocalization with well‐characterized markers. However, image‐analysis methods for colocalization studies are a field of contention and enigma. We have therefore undertaken to review the most currently used colocalization analysis methods, introducing the basic optical concepts important for image acquisition and subsequent analysis. We provide a summary of practical tips for image acquisition and treatment that should precede proper colocalization analysis. Furthermore, we discuss the application and feasibility of colocalization tools for various biological colocalization situations and discuss their respective strengths and weaknesses. We have created a novel toolbox for subcellular colocalization analysis under ImageJ, named JACoP, that integrates current global statistic methods and a novel object‐based approach.     

多重实时荧光定量聚合酶链式反应在芝麻酱掺假鉴别中的应用

目的 基于分子生物学技术,研究建立多重实时荧光定量聚合酶链式反应(Polymerase Chain Reaction,PCR)技术检测芝麻酱中的植物源性成分,实现芝麻酱的快速掺假鉴别,突破单标准单物种检测的局限性。方法 该研究以芝麻2S albumim mRNA基因、花生Ara b2基因、大豆Lectin基因、玉米adh1基因设计特异性引物和探针,优化反应体系,建立多重实时荧光定量PCR技术检测芝麻酱中的芝麻源性成分、花生源性成分、大豆源性成分、玉米源性成分,并应用于市售的芝麻酱样本检测分析。结果 该方法高效低成本,特异性好,对小米、绿豆等10种非目标源性成分无特异性扩增;对芝麻源性成分、花生源性成分、大豆源性成分、玉米源性成分的最低检出限为100 pg/μL,具有较高的灵敏度;应用建立的方法,对市售21份芝麻酱样本进行检测分析,检测结果与标签标注不符合的有4份,标签标注符合率80.95%,与参比方法检测结果一致。结论 建立的多重实时荧光定量PCR技术对加工成品的检测具有较好的适用性,为芝麻酱的掺假鉴别提供了一种新的分子生物学方法。     

贝叶斯反卷积在EAST电荷交换复合光谱分析中的应用

电荷交换复合光谱(Charge e Xchange Recombination Spectroscopy,CXRS)诊断是核聚变装置上测量等离子体离子温度和旋转速度的常规诊断之一。然而在实验中,诊断光通过光谱仪后,由于仪器函数的卷积效应,会使测量到的光谱出现明显展宽,影响数据处理的精度,所以需要对实验测量到的光谱进行反卷积处理。本文采用的反卷积方法是基于贝叶斯条件概率公式推导得出,并结合标准灯获取的仪器函数来进行反卷积,分别从仿真和实验两个方面验证了该方法的可靠性。结果表明将贝叶斯反卷积运用到先进实验超导托卡马克(Experimental Advanced Superconducting Tokamak,EAST)电荷交换复合光谱分析中,能有效提高实验测量精度。结合快速极紫外谱仪(Extreme ultraviolet,EUV),对EAST实验中经过贝叶斯反卷积后测量到的光谱进行了杂质谱线识别工作,进一步提高了精度。     

Size-resolved source apportionment of aerosol particles using polycapillary X-ray lens with a plateau in its focal spot

A laboratory micro X-ray fluorescence spectrometer based on a special polycapillary X-ray lens (PXRL) was used to carry out the source apportionment of aerosol particles. In the curve of the distribution of the X-ray intensity in the focal spot of the special PXRL, there was a plateau with a diameter of 21.3 μm in which the distribution of the X-ray intensity was homogeneous. The gain in flux density in the plateau of the PXRL is 1490. The uniformity of this plateau was 2.9%. This was helpful for the quantitative X-ray fluorescence analysis of a single aerosol particle with smaller size than that of the plateau of the PXRL. The fingerprint database of aerosol particles with given sizes from various air pollution sources was established with the single particle analysis method. The size-resolved source apportionment of aerosol particles in haze in Beijing city was performed with this fingerprint database.     

Calculation of neutron and gamma-ray energy spectra for fusion reactor shield design: Comparison with experiment-II

Measured and calculated neutron and gamma-ray energy spectra resulting from the transport of 14 MeV neutrons through a 0.30-m-thick lithium hydride slab and through a 0.05-m-thick lead slab followed by 0.30 m of lithium hydride are compared. Also reported are comparisons of the measured and calculated neutron energy spectra behind an 0.80-m-thick assembly comprised of stainless steel type 304 and borated polyethylene. The spatial dependence of the gamma-ray energy deposition rate measured using thermoluminescent detectors is compared with calculated data. The calculated data obtained using two-dimensional radiation transport methods and ENDF/B-IV cross-section data are in good agreement for all of the experimental configurations. Calculated integral neutron energy spectra agree with the measured data within 5 to 20% depending on neutron energy for the LiH and Pb plus LiH assemblies. The gamma-ray spectra agree within 20% for these slabs. The measured and calculated neutron energy spectra behind the SS-304-borated polyethylene assembly agree within 5% except at neutron energies below 5 MeV where background radiation influences the measured spectra. The gamma-ray energy deposition rates as a function of depth agree within a factor of two at all detector locations.     

放射性同位素XRF技术中一种与“特散比”法等效的新方法

在一定的条件下,待测元素特征X射线和康普顿散射强度比值,与待测元素特征X射线强度和带吸收滤片所测量的强度比值之间有着简单的双曲函数关系。利用这一函数关系,很容易在单道携带式放射性同位素X射线荧光分析仪上实现“特散比”法改善基体效应。用这种方法所得到的分析结果和用“特散比”法得到的分析结果,二者吻合很好,而且不需要增加任何设备,节省了测量时间和成本。已经测量了几种类型的锡矿样品和某些铜矿样品。     

热释光探测器在脉冲硬X射线能谱测量中的应用

介绍了TLD－3500热释光读出器和GR－100M型热释光剂量片构成的探测器在脉冲硬X射线辐射参数测量中的应用。详细论述了采用滤波荧光法与热释光探测器相结合测量10－10keV的硬X射线能谱的物理思想，在综合考虑了测量环境的具体情况下，设计研制了硬X射线测量系统，建立了热释光探测器对硬X射线绝对能量响应的标定方法。该方法已成功用于脉冲辐射装置“强光1号”的测量，并得到了实测数据。     

非特指型外周T细胞淋巴瘤FGR和TP73基因改变的研究

目的 研究非特指型外周T细胞淋巴瘤(PTCL-NOS)中FGR和TP73的基因改变,验证前期基于芯片的比较基因组杂交(a-CGH)研究结果,为PTCL-NOS的发生、发展提供科学依据.方法 间期双色荧光原位杂交(FISH)技术检测34例PTCL-NOS(其中19例经过a-CGH检测)中FGR和TP73的基因改变,所用探针为缺口平移法自制的FGR和TP73特异位点探针以及商品化1号染色体着丝粒探针(CEP1).结果 34例中出现基因改变者7例(20.6%),其中FGR扩增1例,TP73扩增2例;FGR和TP73同时出现基因改变4例(11.8%),其中同时杂合性缺失(LOH)1例,同时扩增3例.CEP1扩增4例(11.8%),与TP73/FGR基因扩增同时存在.Kaplan-Meier生存分析显示基因改变组较基因无改变组以及TP73改变组较TP73无改变组均有预后不良的趋势,但差异无统计学意义(均P>0.05).结论 FISH结果部分验证了前期a-CGH的研究发现;淋巴瘤相关基因FGR和TP73改变以及1号染色体多倍体可能在PTCL-NOS的发生、发展中起着重要的作用.     

岛津多道X射线荧光光谱仪测定高炉渣中硅钙镁铝钛

自制样品,粉末压片,用X荧光光谱仪测定炉渣中的硅钙镁铝钛,试验确定了炉渣试样粒度,压片压力,压片时间。试验测定结果与熔样法测定结果对得很好。分析结果准确,快速,成本低。适合高炉昼夜连续生产的需要。