Ag~+-Li~+离子交换制作Er~(3+)/Yb~(3+)共掺磷酸盐玻璃平面光波导(英文)

制备了化学稳定的Er^3＋／Yb^3＋共掺的磷酸盐玻璃，并在其中制作了用于光放大器和激光器的平面光波导．这种磷酸盐玻璃的失重速率为4．7×10^-5g·cm^-2·hr^-1，小于Kigre公司商业化的磷酸盐玻璃QX／Er的失重速率．采用Ag^＋-Li^＋交换技术制作了平面光波导并用m-线光谱在632．8nm测量了平面光波导的有效折射率．根据反WKB法得到折射率形貌，计算了离子交换参数如：离子交换深度、表面折射率，折射率改变和扩散系数等．

Enhanced broadband near-infrared luminescence in transparent silicate glass ceramics containing Yb3+ ions and Ni2+-doped Li Ga5 O8 nanocrystals

Spectral properties of Yb3+/Ni2+ codoped transparent silicate glass ceramics containing LiGa5O8 nanocrystals were investigated. The near-infrared emission intensity of Ni2+ was largely increased with Yb3+ codoping due to Yb3+-> Ni2+ energy transfer. The qualitative calculation of the energy transfer constant Cs-a and rate Ps-a showed that the Yb3+-> Ni2+ energy transfer was much greater than in the opposite direction. Yb3+/Ni2+ codoped glass ceramics with 0.75 mol % Yb2O3 exhibited a near-infrared emission with full width at half maximum of 290 nm and fluorescent lifetime of 920 mu s. The glass ceramics are promising for broadband optical amplification.

太行花属（Taihangia Yu et Li）种质资源的研究

本文报道了太行花属（Taihangia Yu et Li）的种群分布、生物学特性和离体培养的初步结果。 太行花种群由于环境和生物等方面的原因仅在太行山区有狭小分布。来源于不同地区种群的太行花其形态特征具有丰富的表型，在引种条件下更为显著。而酯酶同工酶和过氧化物酶同工酶分析进一步证实了其遗传的稳定性和同源性。 实验表明，太行花在北纬39°58'，最低温度-11℃的北京北京植物园，露地越冬正常。温度提高至40℃时生长发育受抑制而迟滞，以25℃最为适宜，增殖率最高。太行花对土壤的适应范围较广，在泥炭培养土上移殖的幼苗成活率达97.20%，主根须根发达，叶生长良好。不同强度光照处理12000Lux效果最好。 太行花生育期为230多天，生长积温为3763℃左右。物候期受环境条件和当年气候的影响，不同种群和个体之间有一定的差异。花的性别、花期和开花量等与纬度、海拔主要与温湿度相关。 太行花的茎尖、花芽、花梗、萼片、花瓣和叶子等外植体均能在MS附加不同种类和浓度植物激素的培养基中分化，其分化途径和分化效果因附加成分、外植体类别而异。在含有0.1mg/L IAA和0.5mg/L 6-BA的培养基中，不但能启动花芽正常生长、开花、形成合子胚，而且也能诱导花芽、花梗、茎尖产生花芽和营养芽。在芽的继代培养中，细胞分裂素能大量诱导芽的分化，最好的配比是0.5mg/L 6-BA、0.1mg/L ZJ;只含生长素时可以诱导生根或脱分化，其中生根最好的是0.5mg/L IAA;2.4-D单独使用时，能较好地使花芽、叶等脱分化，其最佳浓度为1.0mg/L。

Moderate mutation rate in the SARS coronavirus genome and its implications

Background: The outbreak of severe acute respiratory syndrome (SARS) caused a severe global epidemic in 2003 which led to hundreds of deaths and many thousands of hospitalizations. The virus causing SARS was identified as a novel coronavirus (SARS-CoV) an

Redescription of Balantidium polyvacuolum Li 1963 (Class: Litostomatea) inhabiting the intestines of Xenocyprinae fishes in Hubei, China

Redescription of Balantidium polyvacuolum Li 1963, collected from the hindgut of Xenocypris davidi and Xenocypris argentea, from Niushan Lake Fishery (30A degrees 19' N, 114A degrees 31' E) in Wuhan City, Hubei Province, China in April and June 2007 is presented in this paper to complete Li's description at both light and scanning electronic microscopic levels. The unique body shape of B. polyvacuolum-highly arched dorsal side and flattened ventral surface-as well as its remarkable concave platelet present in the centroventral were well described and compared with other close Balantidium species. Besides, two types of vestibulum shape are observed in our present work, which may suggest the existence of two subspecies or genotype species of these balantidia.

Application of methyl parathion hydrolase (MPH) as a labeling enzyme

Methyl parathion hydrolase (MPH) is an enzyme that catalyzes the degradation of methyl parathion, generating a yellow product with specific absorption at 405 nm. The application of MPH as a new labeling enzyme was illustrated in this study. The key advantages of using MPH as a labeling enzyme are as follows: (1) unlike alkaline phosphatase (AP), horseradish peroxidase (HRP), and glucose oxidase (GOD), MPH is rarely found in animal cells, and it therefore produces less background noise; (2) its active form in solution is the monomer, with a molecular weight of 37 kDa; (3) its turnover number is 114.70 +/- 13.19 s(-1), which is sufficiently high to yield a significant signal for sensitive detection; and (4) its 3D structure is known and its C-terminal that is exposed to the surface can be easily subjected to the construction of genetic engineering monocloning antibody-enzyme fusion for enzyme-linked immunosorbent assay (ELISA). To demonstrate its utility, MPH was ligated to an single-chain variable fragment (scFv), known as A1E, against a white spot syndrome virus (WSSV) with the insertion of a [-(Gly-Ser)(5)-] linker peptide. The resulting fusion protein MPH-A1E possessed both the binding specificity of the scFv segment and the catalytic activity of the MPH segment. When MPH-A1E was used as an ELISA reagent, 25 ng purified WSSV was detected; this was similar to the detection sensitivity obtained using A1E scFv and the HRP/Anti-E Tag Conjugate protocol. The fusion protein also recognized the WSSV in 1 mu L hemolymph from an infected shrimp and differentiated it from a healthy shrimp.

Electroless-plated gold films for sensitive surface plasmon resonance detection of white spot syndrome virus

The paper describes the rapid and label-free detection of the white spot syndrome virus (WSSV) using a surface plasmon resonance (SPR) device based on gold films prepared by electroless plating. The plating condition for obtaining films suitable for SPR measurements was optimized. Gold nanoparticles adsorbed on glass slides were characterized by transmission electron microscopy (TEM). Detection of the WSSV was performed through the binding between WSSV in solution and the anti-WSSV single chain variable fragment (scFv antibody) preimmobilized onto the sensor surface. Morphologies of the as-prepared gold films, gold films modified with self-assembled alkanethiol monolayers, and films covered with antibody were examined using an atomic force microscope (AFM). To demonstrate the viability of the method for real sample analysis, WSSV of different concentrations present in a shrimp hemolymph matrix was determined upon optimizing the surface density of the antibody molecules. The SPR device based on the electroless-plated gold films is capable of detecting concentration of WSSV as low as 2.5 ng/mL in 2% shrimp hemolymph, which is one to two orders of magnitude lower than the level measurable by enzyme-linked immunosorbant assays. (c) 2007 Elsevier B.V. All rights reserved.