Spectral characterization of transparent (Nd0.01Y0.94La0.05)(2)O-3 laser ceramics

The spectrum properties of transparent (Nd0.01Y0.94La0.05)(2)O-3 ceramics were investigated. It was found that all absorption bands of (Nd0.01Y0.94La0.05)(2)O-3 ceramics are broadened, of which the full width at half maximum of the peak centered at 804 nm is 8 nm and its absorption cross section is 1.02x10(-20) cm(2). The emission cross section of (Nd0.01Y0.94La0.05)(2)O-3 ceramics located at 1078 nm is 5.71x10(-20) cm(2) and its fluorescent lifetime is 0.214 ms, which are similar to those of 1.0 at. %Nd:Y2O3 ceramics. These indicate that (Nd0.01Y0.94La0.05)(2)O-3 transparent ceramics has excellent spectroscopic properties.

La2O3对Yb：Y2O3透明陶瓷光谱性能的影响

研究了La2O3对Yb：Y2O3透明陶瓷光谱性能的影响，添加适量La2O3以后，Yb：Y2O3透明陶瓷的吸收峰和发射峰的位置不变，但由于La^3＋的离子半径大于Y^3＋的离子半径，在Y2O3中引入La^3＋离子后，导致Y2O3晶格常数变大，晶场强度变弱，同时降低了Y2O3晶体的有序度，致使发射峰强度有所下降，发射截面变小．过量的№La2O3（x=0．16）造成yb^3＋激活离子发射强度明显下降；其荧光寿命在添加La2O3后总体增大45％-60％.

Nd：YbVO4晶体的拉曼光谱和荧光光谱研究

用群论的方法计算了Nd：YbVO4晶体的拉曼活性振动模数目，在室温下测得了其极化拉曼谱线，并指认了在不同几何配置下，各振动模式所对应的频率。同时，测得了室温下晶体的吸收谱，得到了中心波长为808am吸收峰的半高宽为12nm，并在J-O理论的基础上计算了晶体的光学参数，其三个晶场参数分别为Ω2=6．88945×10^-20cm^2。Ω4=4．13394×10^-20cm^2、Ω6=4．54503×10^-20cm^2，并由此得到^4F3／2能级的荧光寿命为178．69炉，1062nm处的荧光分支比为48．85％，积分发射截面为2．786710^-18cm^2。分别在808nm、940nm激发下测得晶体室温发射谱，观察到了Nd→Yb以及Nd←Yb间的能量传递现象。

Tm:Y_2SiO_5晶体的生长和光谱性质研究

采用中频感应提拉法生长了高质量的Tm:Y2SiO5(Tm:YSO)晶体,测定了晶体的晶格常数和分凝系数.运用劳厄照相法确定了单斜晶系Tm:YSO晶体的三个偏振轴〈010〉,D1和D2,在室温下测量了三个偏振轴方向的吸收光谱、荧光光谱和荧光寿命,计算了晶体吸收峰的吸收线宽和吸收截面.研究发现,相对于其他两个偏振轴方向,D1方向在790 nm处出现较强的吸收峰,同时在2μm附近出现了一定强度的发射峰,D1方向的吸收截面较大,荧光寿命较长.Tm:YSO晶体适用于AlGaAs二极管抽运固体激光器,在2μm波段固体激光器的应用上将有很大的发展潜力.

吡唑啉衍生物有机电致发光器件中激基复合物的发射

以两种吡唑啉衍生物为空穴传输材料(HTM)和BBOT为电子传输材料组成双层器件，获得了相对于组成材料的荧光光谱红移和宽化的电致发光．双层器件和HTM：BBOT等摩尔混蒸薄膜的光致发光及电致发光测量表明，该谱带来自HTM／BBOT界面激基复合物的发射，根据器件的能级图，激基复合物的类型为BBOT的激发态BBOT^

花粉管通道遗传转化方法的新证据

将pBIN35S-mGFP4质粒转入受体菌DH5α中，扩繁后提取纯化质粒DNA，待棉花盛花期时，用花粉管通道转化方法将其注射到授粉24小时左右的子房中。在被检测的950个发育10～20天左右的幼胚中，发现七个幼胚在蓝光(460～490nm)激发下发出绿色荧光，而对照发出程度不同的红色荧光。将收获的“转化种子”浸泡萌发得到生长5～6天的黄化无菌苗，在200粒种子来源的无菌苗中，检出两棵转化植株。在紫外光照射灯下转化植株发出绿色荧光，其叶片和下胚轴横切面在蓝光激发下也与对照明显不同。PCR及Southern blotting结果均证实转化植株的真实性，从而为花粉管通道转化方法的可行性提供了直接可靠的细胞及分子生物学证据。 将GFPmut1质粒的gfp通过一端平接一端粘接后重组到pBI121的BamH1和Sal1限制性酶切位点从而代替GUS基因，然后将新的重组质粒用三亲交配法转入到LBA4404菌株中得到双元载体，用于棉花下胚轴切段的转化。结果表明，gfp象gus一样可作为报告基因用于农杆菌介导的棉花转化。在对筛选培养基上生长的“抗性愈伤”进一步进行报告基因检测时，只需手持紫外灯就可以检出GFP阳性愈伤，大大减少了工作量和试验费用。 另外，在进行农杆菌转化前的棉花卡那霉素敏感性实验中发现，卡那霉素对棉花下胚轴的愈伤组织形成和增殖均有明显的抑制作用，随其浓度的增加，愈伤组织形成的频率降低，增殖的倍数减小;当浓度增加到100mg/L时，愈伤组织严重褐化，其正常生长受到完全抑制;下胚轴形态学上端切段较下端更易受卡那霉素的影响。

油菜内源和外源蛋白的表达及环境因素的影响

植物与昆虫的互作关系是个长期进化的过程，虫害给农业生产带来巨大损失。本研究以甘蓝型油菜（Brassica napus）为例，研究了不同环境条件和遗传背景下外源基因的表达与效用，同时利用蛋白质组技术，研究了虫害损伤模拟条件下植物可能存在的内源抗性机制。甘蓝型油菜中转入了人工合成的Bt（Bacillus thuringiensis）杀虫基因，能使植物产生抗虫蛋白抵御虫害。我们在湖北湖南两个实验点进行了大田实验，按植株生长发育的4个不同时期从转基因植株的叶片上采样，研究抗虫蛋白在植物体内的表达动态。植株顶部第三片展开叶的Bt毒蛋白浓度在结荚期前随植物生长而不断增加，而在结荚期出现或增或减的现象。采样叶片的可溶性总蛋白浓度含量一直呈增加的趋势，直到结荚以后出现含量的明显降低。同时，收集了转基因油菜与湘油15号在田间自然杂交形成的杂交后代种子用于栽培，用GFP仪检测杂交后代的绿色荧光蛋白（green fluorescent protein），并用聚合酶链式反应（polymerase chain reaction, PCR）检测并确认带有转基因的杂交植株。为了检测带有转基因的杂交后代油菜中Bt毒蛋白的杀虫效率，用对Bt毒蛋白敏感的试虫品系——初孵棉铃虫幼虫（Helicoverpa armigera）进行杀虫活性检测实验。结果表明，携带Bt基因的杂交湘油及其转基因亲本对试虫的体重增长量均产生了负面影响，可以推断在调查取样的植株生长发育阶段，转基因杂交后代与其转基因亲本植株的杀虫效率没有显著差异。转基因植物及其杂交后代中抗虫蛋白的持续表达及田间带有转基因的自播植物的出现会使害虫产生耐受抗性的潜在可能性增加。 相对于人为增加的抗虫基因，植物在长期对抗昆虫的过程中也进化形成了自我防御机制，能够产生特异的抗性蛋白来应对昆虫的取食。本研究用机械损伤模拟害虫取食，对比了油菜受到物理损伤前后可溶性总蛋白的含量变化并试图通过蛋白质组学技术来检测可能发生变化的蛋白质。Bradford定量测定发现，同一植株同一叶片损伤前后可溶性总蛋白含量差异显著，损伤后蛋白表达量显著增高。蛋白质组双向凝胶电泳及其差异分析显示，损伤前后有8个蛋白质点发生明显的上调或下调。选择其中2个差异蛋白点经过MALDI-TOF质谱鉴定，它们分别是Rubisco小亚基前体以及果糖－1，6－二磷酸醛缩酶和粪卟啉－3－氧化酶的混合物，这些蛋白质在其他植物的抗逆研究中也有报道，它们可能在油菜叶片应答机械损伤过程中对维持植物的生理功能也有重要作用。

Defining the orientation of the tandem fusions that occurred during the evolution of Indian muntjac chromosomes by BAC mapping

The Indian muntjac (Muntiacus muntjak vaginalis) has a karyotype of 2n=6 in the female and 7 in the male, the karyotypic evolution of which through extensive tandem fusions and several centric fusions has been well-documented by recent molecular cytogenetic studies. In an attempt to define the fusion orientations of conserved chromosomal segments and the molecular mechanisms underlying the tandem fusions, we have constructed a highly redundant (more than six times of whole genome coverage) bacterial artificial chromosome (BAC) library of Indian muntjac. The BAC library contains 124,800 clones with no chromosome bias and has an average insert DNA size of 120 kb. A total of 223 clones have been mapped by fluorescent in situ hybridization onto the chromosomes of both Indian muntjac and Chinese muntjac and a high-resolution comparative map has been established. Our mapping results demonstrate that all tandem fusions that occurred during the evolution of Indian muntjac karyotype from the acrocentric 2n=70 hypothetical ancestral karyotype are centromere-telomere (head-tail) fusions.

基因组中新遗传结构的起源与进化

生物遗传物质的多样性从根本上决定了当今地球上生命世界的丰富多 彩。然而生命在漫长的进化历程中如何从最原始的生命形态不断演变，创造 出如此巨大的多样性，是自然留给我们最吸引人的奥秘之一。因此对于分子 进化生物学或进化基因组学的研究者来说，承载生命遗传信息的基因组如何 进化一直以来都是大家关注的一个基本科学命题。本研究主要从两个方面探 讨了基因组中新遗传结构起源的分子机制和进化模式，一方面我们以实验的 方法在黑腹果蝇亚种组中大规模地对新基因进行筛选和鉴定，探讨了果蝇基 因组中新基因起源的分子机制和进化模式；另一方面我们以生物信息学手段 对啮齿类动物大鼠和小鼠进行比较基因组研究，以人和猪的转录序列作为外 群，鉴定了大量啮齿类特有的新外显子，并对这些新外显子的进化特征和产 生机制做了研究。 在果蝇基因组新基因起源与进化的研究工作中，我们综合运用了荧光原 位杂交(fluorescent in situ hybridization, FISH)，Southern 印迹 (Southern blotting)，表达转录分析，生物信息确认和进化速率分析等技术和分析手段， 通过对黑腹果蝇约7000 个基因在黑腹果蝇亚种组8 个近缘物种中同源拷贝数 分布的筛选，鉴定了17 个年轻的散在重复新基因，并对这些新基因的结构、 表达和进化进行了全面的分析。结果表明，DNA 水平的重组机制产生了大量 的新的与祖先基因结构没有冗余的散在重复基因，它们的基因结构以很高的 频率形成了嵌合结构。这些新散在重复基因形成嵌合基因的机会有可能大大 高于预期。同时，我们提供了有力证据证明，重复序列特别是DNAREP1 转 座子很可能通过了非等位同源重组方式介导了散在重复基因的形成。最后， 运用多种行之有效的分析方法，我们证明绝大部分的这些新的嵌合重复基因 是有功能的。在啮齿类新外显子的起源与进化研究中，我们首先利用有完整序列信息 的人和小鼠的基因组，通过同源比对确定了人和小鼠间12,419 个直系同源的 基因组转录单元，这些基因组转录单元中71,039 个大、小鼠共有且相位定义 清晰的外显子被用作后续的分析。通过与人的基因组序列相比较，并进一步 以猪的转录组序列作为第二外群排除掉可能是在人的基因组中丢失的外显子 后，我们共确定了2,695 个啮齿类特有的新外显子。随后对这些新外显子产 生的机制、进化速率、潜在功能以及与选择性剪接之间的关系进行了讨论。 结果显示多数新外显子来自内含子的非重复序列，存在快速的碱基非同义替 换和插入缺失，功能分布上最多的是参与细胞外结合和蛋白间相互作用，提 示这些新外显子的产生可能与啮齿类与外界环境的适应性进化相关。对这些 新外显子与选择性剪接之间关系所做的分析表明，大多数的新外显子存在于 表达量较低的选择性剪接形式中，这说明这些外显子通常参与形成执行组织 特异功能的表达形式，也从一定程度上解释了这些外显子何以能够摆脱对基 因的功能限制而产生较快的进化速度。 总之，上述对果蝇基因组中新基因和啮齿类基因组中新外显子的起源和 进化的研究结果表明，基因组中通过新基因或新外显子等基因组新材料产生 新功能的进化过程是常见的和重要的遗传机制。

Single UV excitation of Hoechst 33342 and propidium iodide for viability assessment of rhesus monkey spermatozoa using flow cytometry

Many fluorescent probes excited by visible light have been used to assess sperm quality by flow cytometry. Developing a viability evaluation method using UV excited stains would be useful for multiparameter analysis of sperm function. This investigation was conducted to determine the efficacy of Hoechst 33342 (H342) and propidium iodide (PI) dual staining for evaluating rhesus monkey sperm viability through use of flow cytometry and excited by a single UV laser. The results showed that the live cells stained only with H342 strongly correlated with expected sperm viability, and flow cytometric analyses were highly correlated with fluorescence microscopic observation. Using H342/PI/SYBR-14 triple staining method, it was found that the live/dead sperm distributions were completely concordant in both H342/PI and SYBR-14/PI assays. In addition, this dual staining was extended with fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) to simultaneously analyze viability and acrosome integrity of sperm cryopreserved using two different extenders, TTE and TEST, and indicated that TTE offered better Preservation of plasma and acrosome integrity than TEST Therefore, the H342/PI dual staining provides an accurate technique for evaluating viability of rhesus monkey sperm and should be valuable for multiparameter flow cytometric analysis of sperm function.

噬菌蛭弧菌的分离及初步鉴定

采用双层平板法,以滤膜过滤的方法来收集噬菌蛭弧菌,以嗜水气单胞菌(Aeromonas hudrophila)、荧光假单胞菌(Pseudomonas fluorescent)和绿脓杆菌(Pseudomonas aeruginosa)为宿主菌,进行噬菌蛭弧菌的分离研究;并在此基础上,通过接触酶检测和寄生性确认对噬菌蛭弧菌(Bdellovibrio bacteriovorus)进行了初步的鉴定。结果表明未使用滤膜过滤,采用自来水琼脂双层平板法分离噬菌蛭弧菌的效果较好;并经过接触酶和寄生性检测初步鉴定此BD-SP

Identification of Prorocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified, cloned and sequenced. and these sequence data were deposited in the GenBank. Eight oligonucleotide probes (DNA probes) were designed based on the sequence analysis. The probes were employed to detect and identify P. minimum and T. pulchella in unialgal and mixed algal samples with a fluorescence in situ hybridization method using flow cytometry. Epifluorescence micrographs showed that these specific probes labeled with fluorescein isothiocyanate entered the algal cells and bound to target sequences, and the fluorescence signal resulting from whole-cell hybridization varied from probe to probe. These DNA probes and the hybridization protocol we developed were specific and effective for P. minimum and T. pulchella, without any specific binding to other algal species. The hybridization efficiency of different probes specific to P. minimum was in the order: PM18S02 > PM28S02 > PM28S01 > PM18S01, and that of the probes specific to T. pulchella was TP18S02 > TP28S01 > TP28S02 > TP18S01. The different hybridization efficiency of the DNA probes could also be shown in the fluorescent signals between the labeled and unlabeled cells demonstrated using flow cytometry. The DNA probes PM18S02, PM28S02; TP18S02 and TP28S01, and the protocol, were also useful for the detection of algae in natural samples.

Cytochemical changes in the developmental process of Nostoc sphaeroides (cyanobacterium)

There are several apparent developmental stages in the life cycle of Nostoc sphaeroides Kutzing, an edible cyanobacterium found mainly in paddy fields in central China. The cytochemical changes in developmental stages such as hormogonia, aseriate stage, filamentous stage and colony in N. sphaeroides were examined using fluorescent staining and colorimetric methods. The staining of acidic and sulfated polysaccharides increased with development when hormogonia were used as the starting point. Acidic polysaccharides (AP) were most abundant at the aseriate stage and then decreased, while the sulfated polysaccharides (SP) were highest at the colony stage. Quantitatively, along the developmental process from hormogonia to colony, total carbohydrates first increased, then became stable, and then reached their highest level at the colony stage, while reducing sugars were highest at the hormogonia stage and then decreased sharply once development began. SP were not detectable in the hot water soluble polysaccharides (HWSP), and hormogonia had the lowest content of AP, while old colonies had the highest. The AP content of the aseriate stage, filamentous stage and young colony stage were very similar. The evolutionary relationships reflected in the developmental stages of N. sphaeroides are discussed.

Establishment of a Chinese sturgeon Acipenser sinensis tail-fin cell line and its susceptibility to frog iridovirus

Chinese sturgeon Acipenser sinensis, a cartilaginous ganoid, is a 'living fossil' on a deeply isolated evolutionary branch. A cell line was established from Chinese sturgeon tail-fin tissue (CSTF) . These epithelial CSTF cells grew well in Dulbecco's modified Eagle's medium at 25 degrees C. Karyotypic analysis revealed a normal diploid karyotype with 2n = 264 and large numbers of punctate chromosomes. A strain of frog iridoviruses [Rana grylio virus (RGV)] was used to test the susceptibility of this cell line to infection. Infection was confirmed by cytopathic effect, immunofluorescence and electron-microscope observations, which detected the viral antigens or particles in the cytoplasm of RGV-infected cells. Molecular analysis further suggested that c. 550 bp DNA fragment could be cloned from the RGV-infected CSTF cells' DNA with major capsid protein gene polymerase chain reaction primers. Furthermore, after transfection with pEGFP vector DNA, the CSTF cell line produced significant fluorescent signals indicating its utility in exogenous studies.

Hybrid cytomegalovirus-U6 promoter-based plasmid vectors improve efficiency of RNA interference in zebrafish

Short hairpin RNA (shRNA) directed by RNA polymerase III (Pol III) or Pol II promoter was shown to be capable of silencing gene expression, which should permit analyses of gene functions or as a potential therapeutic tool. However, the inhibitory effect of shRNA remains problematic in fish. We demonstrated that silencing efficiency by shRNA produced from the hybrid construct composed of the CMV enhancer or entire CMV promoter placed immediately upstream of a U6 promoter. When tested the exogenous gene, silencing of an enhanced green fluorescent protein (EGFP) target gene was 89.18 +/- 5.06% for CMVE-U6 promoter group and 88.26 +/- 6.46% for CMV-U6 promoter group. To test the hybrid promoters driving shRNA efficiency against an endogenous gene, we used shRNA against no tail (NTL) gene. When vectorized in the zebrafish, the hybrid constructs strongly repressed NTL gene expression. The NTL phenotype occupied 52.09 +/- 3.06% and 51.56 +/- 3.68% for CMVE-U6 promoter and CMV-U6 promoter groups, respectively. The NTL gene expression reduced 82.17 +/- 2.96% for CMVE-U6 promoter group and 83.06 +/- 2.38% for CMV-U6 promoter group. We concluded that the CMV enhancer or entire CMV promoter locating upstream of the U6-promoter could significantly improve inhibitory effect induced by the shRNA for both exogenous and endogenous genes compared with the CMV promoter or U6 promoter alone. In contrast, the two hybrid promoter constructs had similar effects on driving shRNA.