A new fluorescent quantitative PCR-based in vitro neutralization assay for white spot syndrome virus

A fluorescent quantitative PCR (FQ-PCR) assay utilizing SYBR green I dye is described for quantitation of white spot syndrome virus (WSSV) particles isolated from infected crayfish, Cambarus clarkii. For this assay, a primer set was designed which amplifies, with high efficiency and specificity, a 129 bp target sequence within ORF167 of the WSSV genome. Conveniently, WSSV particles can be added into the FQ-PCR assay with a simple and convenient method to release its DNA. To establish the basis for an in vitro neutralization test, primary cultures of shrimp cells were challenged with WSSV that had been incubated with a polyclonal anti-WSSV serum or with control proteins. The number of WSSV particles released from the cells after these treatments were assayed by FQ-PCR. This test may serve as a method to screen monoclonal antibody pools or recombinant antibody pools for neutralizing activity prior to in vivo animal experiments. (c) 2007 Elsevier B.V. All rights reserved.

Differential expression of vasa RNA and protein during spermatogenesis and oogenesis in the gibel carp (Carassius auratus gibelio), a bisexually and gynogenetically reproducing vertebrate

The RNA helicase Vasa is a germ cell marker in animals, and its homolog in vertebrates to date has been limited to bisexual reproduction. We cloned and characterized CagVasa, a Vasa homolog from the gibel carp, a fish that reproduces bisexually or gynogenetically. CagVasa possesses 14 RGG repeats and eight conserved motifs of Vasa proteins. In bisexually reproducing gibel carp, vasa is maternally supplied and its zygotic expression is restricted to gonads. By in situ hybridization on testicular sections, vasa is low in spermatogonia, high in primary spermatocytes, reduced in secondary spermatocytes, but disappears in spermatids and sperm. In contrast, vasa persists throughout oogenesis, displaying low-high-low levels from oogonia over vitellogenic oocytes to maturing oocytes. A rabbit anti-Vasa antibody (alpha Vasa) was raised against the N-terminal CagVasa for fluorescent immunohistochemistry. On testicular sections, Vasa is the highest in spermatogonia, reduced in spermatocytes, low in spermatids, and absent in sperm. In the ovary, Vasa is the highest in oogonia but persists throughout oogenesis. Subcellular localization of vasa and its protein changes dynamically during oogenesis. The aVasa stains putative primordial germ cells in gibel carp fry. It detects gonadal germ cells also in several other teleosts. Therefore, Cagvasa encodes a Vasa ortholog that is differentially expressed in the testis and ovary. Interestingly, the alpha Vasa in combination with a nuclear dye can differentiate critical stages of spermatogenesis and oogenesis in fish. The cross-reactivity and the ability to stain stage-specific germ cells make this antibody a useful tool to identify fish germ cell development and differentiation. (c) 2005 Wiley-Liss, Inc.

Transient Reorientation of a Doped Liquid Crystal System under a Short Laser Pulse

The transient optical nonlinearity of a nematic liquid crystal doped with azo-dye DR19 is examined. The optical reorientation threshold of a 25-mu m-thick planar-aligned sample of 5CB using a 50 ns pulse duration 532 nm YAG laser pulse is observed to decrease from 800 mJ/mm(2) to 0.6 mJ/mm(2) after the addition of 1 vol% azo dopant, a reduction of three orders of magnitude. When using a laser pulse duration of 10 ns, no such effect is observed. Experimental results indicate that the azo dopant molecules undergo photoisomerization from trans-isomer to cis-isomer under exposure to light, and this conformation change reorients the 5CB molecules via intermolecular coupling between guest and host. This guest-host coupling also affects the azo photoisomerization process.

Quantum Confinement and Electronic Properties of Rutile TiO2 Nanowires

The quantum confinement effect, electronic properties, and optical properties of TiO2 nanowires in rutile structure are investigated via first-principles calculations. We calculate the size- and shape-dependent band gap of the nanowires and fit the results with the function E-g = E-g(bulk) + beta/d(alpha). We find that the quantum confinement effect becomes significant for d < 25 angstrom, and a notable anisotropy exists that arises from the anisotropy of the effective masses. We also evaluate the imaginary part of the frequency-dependent dielectric function [epsilon(2)(omega)] within the electric-dipole approximation, for both the polarization parallel [epsilon(parallel to)(2)(omega)] and the perpendicular [epsilon 1/2(omega)] to the axial (c) direction. The band structure of the nanowires is calculated, with which the fine structure of epsilon(parallel to)(2)(omega) has been analyzed.

Effects of subretinal implant materials on the viability, apoptosis and barrier function of cultured RPE cells

Background: Subretinal microphotodiode array (MPDA) is a type of visual prosthesis used for the implantation in the subretinal space of patients with progressive photoreceptor cell loss. The present study aimed to evaluate the effect of materials for MPDA on the viability, apoptosis and barrier function of cultured pig retinal pigment epithelium (RPE) cells.Methods: Primary culture of pig RPE cells was performed and 24 pig eyes were used to start RPE culture. The third passage of the cultures was plated on different materials for MPDA and MPDAs. The tetrazolium dye-reduction assay (MTT) was used to determine RPE cell viability. Flow cytometry was measured to indicate the apoptosis rates of RPE cells on different materials. RPE cells were also cultured on microporous filters, and the transepithelial resistance and permeability of the experimental molecule were measured to determine the barrier function.Results: The data from all the methods indicated no significant difference between the materials groups and the control group, and the materials tested showed good biocompatibility.Conclusions: The materials for MPDA used in the present study had no direct toxicity to the RPE cells and did not release harmful soluble factors that affected the barrier function of RPE in vitro.

Zinc phthalocyanine (ZnPc) incorporated into silicon matrix grown by plasma enhanced chemical vapor deposition (PECVD)

Hybrid composites composed of zinc phthalocyanine embedded in silicon matrixes have attracted attention because of the potential for solar energy conversion. We produce hybrid composites by thermal evaporation for the plithalocyanine and PECVD (Plasma Enhanced Chemical Vapor Deposition) for the silicon matrix. Deposition of ZnPc/a-Si(amorphous silicon) composites was achieved in a sequential manner. The compound films were characterized by optical transmittance spectra and photoconductivity measurement. The optical transmittance measurements were carried out in the visible region (500 - 800 nm). Compared to pure silicon film, the photosensitivity of compound functional films was enhanced by one order of magnitude. This demonstrates the Si sensitized by adding ZnPc.

Influence of interface modification on the performance of polymer/Bi2S3 nanorods bulk heterojunction solar cells

In this paper, bulk heterojunction photovoltaic devices based on the poly[2-methoxy-5-(3',7'-dimethyloctyloxy)- 1,4-phenylenevinylene] (MDMO-PPV):Bi2S3 nanorods hybrid material were present. To optimize the performance of the devices, the interface modification of the hybrid material that has a significant impact on the exciton dissociation efficiency was studied. An improvement in the device performance was achieved by modifying the Bi2S3 surface with a thin dye layer. Moreover, modifying the Bi2S3 surface with anthracene-9-carboxylic acid can enhance the performance further. Compared with the solar cells with Bi2S3 nanorods hybrid with the MDMO-PPV as the active layer, the anthracene-9carboxylic acid modified devices are better in performance, with the power conversion efficiency higher by about one order in magnitude.

Silver nanocrystals modified microstructured polymer optical fibres for chemical and optical sensing

In-fibre chemical and optical sensors based on silver nanocrystals modified microstructured polymer optical fibres (MPOFs) were demonstrated. The silver nanocrystals modified MPOFs were formed by direct chemical reduction of silver ammonia complex ions on the templates of array holes in the microstructure polymer optical fibres. The nanotube-like and nanoisland-like Ag-modified MPOFs could be obtained by adjusting the conditions of Ag-formation in the air holes of MPOFs. SEM images showed that the higher concentration of the reaction solution (silver ammonia 0.5 mol/L, glucose 0.25 mol/L), gave rise to a tubular silver layer in MPOF, while the lower concentration (silver ammonia 0.1 M, glucose 0.05 M) produced an island-like Ag nanocrystal modified MPOF. The tubular Ag-MPOF composite fibre was conductive and could be directly used as array electrodes in electrochemical analyses. It displayed high electrochemical activity on sensing nitrate or nitrite ions. The enhanced fluorescence of dye molecules was observed when the island-like Ag-modified MPOF was inserted into a fluorescent dye solution. (C) 2007 Elsevier B.V. All rights reserved.

Fluorescence pH probe based on microstructured polymer optical fiber

A kind of optical pH sensor was demonstrated that is based on a pH-sensitive fluorescence dye-doped (eosin) cellulose acetate (CA) thin-film modified microstructured polymer optical fiber (MPOF). It was obtained by directly inhaling an eosin-CA-acetic acid mixed solution into array holes in a MPOF and then removing the solvent (acetic acid). The sensing film showed different fluorescence intensities to different pH solutions in a pH range of 2.5-4.5. Furthermore, the pH response range could be tailored through doping a surfactant, hexadecyl trimethyl ammonium bromide (CTAB), in the sensing film. (c) 2007 Optical Society of America.

染料掺杂聚合物薄膜的激光行为研究

自20世纪60年代发展到现在，激光技术发展的速度十分惊人，应用的范围不断拓展，近年来随着有机/聚合物电致发光材料在有机发光二极管上的应用以及有机晶体管和有机太阳能电池的研制成功，科学家们开始了有机/聚合物材料放大自发发射和激光发射行为的研究。到目前为止，已经开发出了这种廉价、可以大面积成膜的、具有更广泛应用范围的有机/聚合物固体激光材料及光泵浦激光器。有机/聚合物激光器的出现不仅向传统激光理论提出了新的挑战，而且具有诸多潜在的应用价值。可以断言，在21世纪知识经济的大潮中，有机/聚合物激光器的研究必将推动传统学科的发展和新兴学科形成，也必将为人类带来巨大的经济效益。新的有机激光材料不断涌现、器件结构不断推陈出新、新的激发原理不断提出并得到修正已经成为有机/聚合物固体激光研究领域的三大特点。本论文进行了利用Förster能量传递对荧光染料DCJTB放大自发发射行为的优化、基于放大自发发射的红光染料DCJTB掺杂聚合物薄膜的白光发射、多孔结构对荧光染料放大自发发射行为的优化以及基于纳米结构的荧光染料DCJTB掺杂聚合物薄膜的激光行为等方面的研究工作，具体研究内容如下: 1、利用Förster能量传递理论，系统地研究了两种或三种染料共掺杂聚合物薄膜的放大自发发射（ASE）行为。研究表明，两种染料共掺杂显著改善了掺杂聚合物薄膜的ASE阈值、增益和损耗特性，而三种染料共掺杂，由于更多的Förster能量传递，使掺杂聚合物薄膜的ASE阈值、增益和损耗性能得到了进一步的改善。将Alq3和C545T两种绿光染料同时掺杂到DCJTB：PS中，通过利用Alq3和C545T同时的能量传递效应，已经使Alq3:C545T:DCJTB：PS薄膜的阈值、增益和损耗分别达到了0.007 mJ/pulse、52 cm-1和7 cm-1。 2、将红色荧光染料DCJTB掺杂到蓝色聚合物PFO中，通过控制DCJTB在PFO中的浓度，我们获得了具有放大自发发射的白光发射，当DCJTB在PFO的掺杂浓度为0.3%时显示了最好的白光ASE特性， 白光中DCJTB和PFO发射的阈值、增益和损耗分别达到了0.072 mJ pulse-1，0.035 mJ pulse-1；36.3 cm-1，22.35 cm-1和7.39 cm-1，15.88 cm-1。我们的结果表明，DCJTB掺杂聚合物PFO体系是实现ASE白光发射的有效方法，拓展了ASE的应用范围。 3、开发出了二维多孔SBA-15和三维TiO2反蛋白石光子晶体两种实现有机ASE有效发射的两种结构，通过利用有序结构的SBA-15的量子限域效应优化了蓝光染料C151的ASE阈值、增益和损耗特性，而通过利用三维TiO2反蛋白石光子晶体的量子限域效应，也使包埋其中的绿光染料C545T的ASE特性得到了明显改善。研究表明，无论是二维SBA-15多孔结构还是三维TiO2反蛋白石光子晶体结构，通过其量子限域效应都能很好地优化包埋其中的荧光染料的ASE特性，为进一步优化有机半导体的ASE特性提供了新的思路。 4、将聚苯乙烯纳米球分散到DCJTB:PS薄膜中和把DCJTB:PS薄膜旋涂在ZnO纳米柱阵列上两种方法，我们已经成功地研制出了多模随机有机激光发射器件。详细研究表明，多模随机有机激光发射特性显著地与聚苯乙烯纳米球的尺寸和浓度以及ZnO纳米柱的疏密程度密切相关，优化后的聚苯乙烯纳米球掺杂DCJTB:PS薄膜的阈值已经达到了0.06 mJ pulse-1cm-2，而ZnO纳米柱包埋DCJTB:PS薄膜的阈值达到了0.375 mJ pulse-1cm-2。我们的结果表明，聚苯乙烯纳米球和ZnO纳米柱都是实现随机有机激光的非常好的散射介质材料。

Photocatalytic degradation of AZO dyes by supported TiO2+UVin aqueous solution

The photocatalytic degradation performance of photocatalysts TiO2 supported on 13-X, Na-Y, 4A zeolites with different loading content was evaluated using the photocatalytic oxidation of dyes direct fast scarlet 4BS and acid red 3B in aqueous medium. The results showed that the best reaction dosage of TiO2-zeolite catalysts is about 2 g/l and the photocatalytic kinetics follows first order for all supported catalysts. The photocatalytic activity order of the three series catalysts is 13X type >Y type >4A type. The physical state of titanium dioxide on the supports is evaluated by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD), BET, and FTIR. (C) 2000 Elsevier Science Ltd. All rights reserved.

染料脱色菌株筛选及染料脱色作用研究

染料废水成分复杂，色度高，是主要的环境污染源之一。应用微生物对染料废水脱色具有处理费用低和操作管理方便等优势，具有较好的发展前景。 本文采用筛选到一株短刺小克银汉霉(Cuuninghamella echinulata) KM3及一株红酵母(Rhodotorula sp.)YR-1分别对偶氮染料刚果红废水和酸性红废水进行了脱色研究，同时利用KM3及YR-1组成的复合菌种脱色体系对酸性红废水进行了脱色实验，为染料脱色真菌的应用奠定了基础。 KM3形成的菌丝球对多种染料具有较好脱色效果。KM3最适菌丝球形成条件：pH6-7、装液量90ml、孢子悬液浓度105个/ml (接种5ml)、摇床转速120rpm、培养温度30℃、培养时间72h；成球机理为凝聚型发育。KM3菌丝球对刚果红最佳脱色条件为：染料溶液初始pH值7.0，温度为33℃，摇床转速为120rpm。在刚果红50~200mg/l 浓度范围内， KM3菌丝球对刚果红吸附脱色动力学可用拟二级动力学方程描述。菌丝球对刚果红的吸附行为符合Langmuir和Freundlich 等温方程模型，Langmuir方程能更好的描述菌丝球对刚果红的吸附行为。丙酮对刚果红的解吸率最高，其解吸动力学过程符合二级动力学方程。将KM3应用在真菌生物滤床反应器中，在非灭菌和灭菌情况下接种孢子悬液后处理刚果红废水的过程中，均需长时间挂膜，处理效果一般。反应器中投加菌丝球后处理刚果红废水在3小时内达到92%以上的脱色效果。 YR-1对酸性红脱色机制属于降解脱色。YR-1对酸性红的最佳脱色培养条件为：初始pH 5.0、接种量5%、温度30℃；最佳碳源是葡萄糖，其次是蔗糖；最佳氮源是酵母膏或蛋白胨。在替换分批脱色实验和连续补料脱色实验中，脱色率一直保持在75%以上，显示YR-1在上述脱色体系中均具有良好适应性。 在三种复合菌种对酸性红的脱色体系中，体系Ⅲ（菌丝球与海藻酸钠固定化的酵母细胞混合培养）的脱色效果可达98%以上。对该体系而言，3种粒径固定化酵母小球（Ø1.1mm、1.8mm、3.1mm）中Ø1.8mm、3.1mm小球脱色率较为理想，而酵母细胞初始密度对脱色效果的影响不大。 KM3、YR-1分别具有处理刚果红废水和酸性红废水的应用前景，而KM3与YR-1联合应用对酸性红的脱色效果更好。

Detection of Copper Ion with Laser-Induced Fluorescence in A Capillary Electrophoresis Microchip

A capillary electrophoresis microchip coupled with a confocal laser-induced fluorescence (LIF) detector was successfully constructed for the analysis of trace amounts of heavy metals in environmental sources. A new fluorescence dye, RBPhOH, synthesized from rhodamine B, was utilized in a glass microchip to selectively determine copper with high sensitivity. A series of factors including running buffer concentration, detection voltage, and sample loading time were optimized for maximum LIF detector response and, hence, method sensitivity.

超声与磁粉强化含单宁废水生物处理研究

单宁是一种典型的有毒难降解污染物，在制革、造纸、制药、印染等行业废水中广泛存在，对水环境造成污染并且影响废水生物处理效果。本研究针对含单宁废水生物处理效率低、较高浓度时微生物受抑制且污泥容易膨胀等问题，采用超声和磁粉来强化含单宁废水生物处理，研究超声和磁粉对微生物活性、污染物去除及污泥沉降性能的影响，并对其作用机理进行了分析和探讨。 研究结果表明，活性污泥系统中单宁酸容积负荷可以达到1.8kgCOD/(m3·d)，单宁酸和COD去除率分别达到85.2%和79.6%，但如果负荷进一步增大则微生物活性迅速降低。系统在pH 5~8、温度20~35℃、DO>1 mg/L的条件下具有较好的单宁酸降解效果和处理稳定性。单宁降解动力学参数为：μmax =0.208h-1；Ks=226mg/L；Ki=522mg/L；kd=0.0092h-1；Y =0.594。 磁粉对系统处理效果和污泥沉降性能有一定的促进作用，且效果要优于外磁场。适宜的磁粉粒径和投加量分别为0.05~0.15mm和1.0g/L，COD去除率比对照系统提高6.4%，SVI降低28.6%，污泥絮体结构紧密。磁粉强化主要是通过其对污泥菌胶团的凝聚、吸附作用以及对微生物活性的强化作用实现。 在适当强度（0.4W/cm2）和辐照时间（20min）的超声作用下污泥絮体和细胞膜通透性增大，酶分泌也增多，系统的COD去除率比对照提高了8.8%，单宁酶酶活提高了11%。但超声也使污泥絮体结构松散，沉降性能下降，SVI比对照系统升高9.3%。 由于污泥流失加剧导致污泥浓度相对较低，声磁联合强化系统相对于磁粉强化系统其处理效果并没有提高。但相对于单纯活性污泥系统，声磁联合作用下系统处理效果、污泥沉降性能以及系统运行稳定性都得到明显改善。本研究为难降解废水的生物处理提供了一个新的思路。 Tannins are typical refractory and toxic pollutants that commonly exist in wastewater from dye, medicine, paper and leather industries and cause many problems associated with environmental pollution and biological treatment of wastewater. Biological treatment efficiency of tannin-containing wastewater is usually low owing to its biological toxicity and low biodegradability, microbes are usually inhibited under high tannin concentration and sludge bulking frequently occurs. In this study, ultrasound and magnetic powder were used to improve the biological treatment performance of simulated tannic acid-containing wastewater. The effects of ultrasonic irradiation and magnetic powder on microbial activity, tannic acid degradation rate and sludge sedimentation were investigated. The augmentation mechanisms were analyzed and discussed. The experimental results showed that the microbes were prominently inhibited under high tannic acid concentration, but moderate degradation efficiency can be maintained under a tannic acid load of up to 1.8kgCOD/(m3·d), with the tannic acid degradation and COD removal percentage of 85.2% and 79.6% respectively. The highest degradation rates and treatment stability were achieved at pH range of 5~8, temperature range of 20~35℃ and DO concentration of above 1mg/L. The kinetic parameters were estimated, including: μmax =0.208h-1；Ks=226mg/L；Ki=522mg/L；kd=0.0092h-1；Y =0.594. The microbial activity, tannic acid degradation rate and sludge sedimentation were improved by adding Fe3O4 magnetic powder, and the augmentation performance was better than external magnetic field. The appropriate particle size and dosage of magnetic powder were found to be 0.05~0.15mm and 1.0g/L, respectively, under which the COD removal percentage was improved by 6.4% and SVI value decreased by 28.6%, and compact floc structure was observed. This was mainly caused by the flocculation and adsorption effects of magnetic powder against sludge floc and the stimulation of microbial activity under appropriate magnetic field. Under appropriate ultrasonic irradiation (ultrasonic intensity 0.4W/cm2, ultrasonic irradiation time 20min), the permeability of floc and cell membrane are improved, transfer of substrate and oxygen were reinforced; meanwhile, more enzyme were produced by microbes under the slight damage caused by ultrasound. However, the floc structure became loose under ultrasonic irradiation, leading to relatively poor sedimentation, with the SVI value 9.3% higher than the control system. Although the magnetic powder-ultrasonic irradiation combined augmentation system showed no improvement in treatment performance compared with sole magnetic augmentation system owing to its relatively low sludge concentration, it guaranteed the stable operation of system, meanwhile the tannic acid degradation and sludge sedimentation were significantly improved compared with sole activated sludge system. This study gives a new idea for biological treatment of refractory wastewater.