Rapid quantitative detection of Yersinia pestis by lateral-flow immunoassay and up-converting phosphor technology-based biosensor

Up-converting phosphor technology (UPT)-based lateral-flow immunoassay has been developed for quantitative detection of Yersinia pestis rapidly and specifically. In this assay, 400 nm up-converting phosphor particles were used as the reporter. A sandwich immumoassay was employed by using a polyclonal antibody against F1 antigen of Y. pestis immobilized on the nitrocellulose membrane and the same antibody conjugated to the UPT particles. The signal detection of the strips was performed by the UPT-based biosensor that could provide a 980 nm IR laser to excite the phosphor particles, then collect the visible luminescence emitted by the UPT particles and finally convert it to the voltage as a signal. V-T and V-c stand for the multiplied voltage units for the test and the control line, respectively, and the ratio V-T/V-C is directly proportional to the number of Y pestis in a sample. We observed a good linearity between the ratio and log CFU/ml of Y pestis above the detection limit, which was approximately 10(4) CFU/mI. The precision of the intra- and inter-assay was below 15% (coefficient of variation, CV). Cross-reactivity with related Gram-negative enteric bacteria was not found. The UPT-LF immunoassay system presented here takes less than 30 min to perform from the sample treatment to the data analysis. The current paper includes only preliminary data concerning the biomedical aspects of the assay, but is more concentrated on the technical details of establishing a rapid manual assay using a state-of-the-art label chemistry. (c) 2006 Elsevier B.V. All rights reserved.

新型光折变晶体Mn：YAlO3的生长与光谱性质研究

采用提拉法成功生长了无散射掺杂0．5％原子分数的Mn：YAlO2（Mn：YAP）光折变单晶体，晶体尺寸约为φ25mm×47mm，原生态晶体呈桔黄色。XRD测试结果表明，Mn：YAP晶体具有与纯YAP相同的结构（Pnma）。但Mn离子掺杂后相应的晶胞参数略有减小。采用ICP方法测试计算得Mn离子在YAlO2晶体中的分凝系数约为0．11。在室温下测试了Mn：YAP晶体的吸收和荧光光谱，并初步分析了Mn：YAP晶体的光谱特征。研究表明Mn：YAP晶体中，Mn^4＋离子充当光折变中心，其吸收和发射峰分别对应于48

Eu:Y2O3 nano-phosphor prepared by novel energy-saving solution combustion method

A novel energy- and time-saving solution combustion method has been developed to prepare Eu:Y2O3 nano-crystal line phosphor. This novel method employs anhydrous ethanol as solvent and fuel. The prepared nano-crystals after heat-treatment own narrow size distribution, well dispersibility and sinterability, confirmed by XRD, TEM and FTIR. The emission spectra of nano-Eu:Y2O3 Samples show clear nano-size related phenomena. (c) 2007 Elsevier B.V. All rights reserved.

Studies of magnetic interactions in Mn-doped β-Ga2O3 from first-principles calculations

The magnetic behavior of Mn-doped beta-Ga2O3 is Studied from first-principles calculations within the generalized gradient approximation method. Calculations show that ferromagnetic ordering is always favorable for configurations in which two Mn ions substitute either tetrahedral or octahedral sites, and the ferromagnetic ground state is also sometimes favorable for configurations where one Mn ion substitutes a tetrahedral site and another Mn ion substitutes an octahedral site. However, the configurations of the latter case are less stable than those of the former. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

ZnO : Zn phosphor thin films prepared by face-to-face annealing

ZnO:Zn phosphor thin films were prepared by face-to-face annealing at 450 degrees C in air. The effects of the face-to-face annealing on the structural and optical properties of the ZnO films were investigated by X-ray diffraction (XRD), photoluminescence (PL), optical transmittance and absorption measurements. Measurement results showed that the crystal quality of ZnO films was improved by face-to-face annealing. Both UV light emission and visible light emission were enhanced compared to those of open annealing films. The UV emission peak was observed to have a blueshift towards higher energy. The optical band-gap edge of as-annealed films shifted towards longer wavelength. (c) 2005 Elsevier B.V.. All rights reserved.