坛紫菜5.8S rDNA和ITS区片段的序列分析及应用

对坛紫菜(Porphyra haitanensis)野生(GL)和栽培(PXV)品系的5.8S rDNA-ITS兀区进行了PCR扩增和序列分析,扩增的GL和PXV的DNA片段长度分别为1213 bp和1221bp,包含完整的ITS1-5.8S-ITS2区.然后对紫菜7个种9个品系(其中6种7个品系从GenBank数据库中获得)的rDNA相应序列进行了排序和系统进化分析,结果表明:9个紫菜品系rDNA中5.8S区的长度和序列非常保守,而ITS区的长度和序列则变异较大;根据它们的序列差异,计算出这9个紫菜品系的遗传距离在0.010～0.551之间,遗传相似性在44.9%～99%之间;并且采用邻接法构建了这9个紫菜品系的系统发育树,发现可以明显分为4个进化枝,由此讨论了分子分类方法同传统分类方法的分歧.实验结果表明,5.8S rDNA.ITS区序列可以成为紫菜种质鉴定和系统进化研究的强有力工具.     

柱花草核rDNA的ITS1序列分析

首次对42个柱花草种质的ITS1序列进行了比较分析.结果表明:42个炭疽病敏感与抗病柱花草种质的ITS1序列长度变化范围为302～314 bp,G C含量的变化范围为44%～45%;在它们的 ITS1序列中,有8个插入位点,13个缺失位点,68个变异位点;并在15个限制性酶切位点上也存在差异;种质间的遗传分化距离变异范围为0.006～0.053,平均值为0.021.采用非加权成对平均数法(UPGMA)构建了聚类树系图,42个柱花草种质可分为两大类、15个小类.该结果较好地反映了这些种质的差异.     

小麦印度腥黑穗病菌的分子检测

根据GenBank中登录Tilletia属的20个种的核糖体转录间隔区(ITS)序列差异设计1对引物T1／T2，可以特异地从T.indica和T.wallceri菌株中扩增到一条450bp左右的条带，而从其他供试菌株中不能扩增出条带，表明该对引物可以将这二个种与Tilletia其他种区分开。进一步根据T．indica和T．walked的线粒体DNA序列的差异设计一对引物M1／M2，只能特异地从T．indica DNA中扩增到一条250bp左右的条带，表明该对引物可以将T．indica与T．walked区分开。利用上述2对引物分别与ITS区通用引物ITS1/ITS4．和线粒体引物Ti-1／Ti4组合建立套式PCR检测体系，能够直接将T．indica与其他相似或相关种区分开，且灵敏度可达1个冬孢子。此外，还观察到在反应体系中加入适量的(NH4)2SO4对PCR反应具有增效作用，可以提高检测灵敏度。上述结果提示建立的套式PCR反应体系可望能应用于口岸对T．indica的检疫。     

群体间黑线仓鼠DQA基因exon 2遗传结构分析

本研究以山东曲阜、沂南和临朐三个地区的黑线仓鼠(Cricetulus barabensis)为材料,使用已有特异性引物,经PCR法扩增得到了该基因的外显子2全序列,并在上述群体间进行了多态性统计分析.结果表明:(1)在74个实验样本的核苷酸序列中,目的序列长度均为249b P,检测到13个变异位点,16种单倍型;(2)平均核苷酸多样性指数(Pi)较低(0.010 78),而平均单倍掣多样性指数(Hd)较高(0.757);(3)三个群体间的Kimura 2P遗传分化指数为0.016 85～0.136 48,其中曲阜和沂南地区遗传分化指数(Fst=0.136 48)的卡平方检验结果小于0.05,出现遗传分化,基因流(Nm=1.581 77)强度较弱.分子方差分析(AMOVA)得出Fst=0.058 18(P＜0.01),即5.81%的变异来自群体间,94.18%的变异来自群体内.(4)在NJ聚类树中,三个群体的单倍型并没有按照相应的地理分布区进行聚类;单倍型网络结构呈星状辐射排列.     

小冰麦异附加系中携带BYDV抗性基因染色体的微分离及其文库的建立

采用微玻璃针法显微分离了小冰麦异附加系TAI 2 7中附加有中间偃麦草 (天蓝冰草 )的一对染色体 ,这对染色体上携带有抗大麦黄矮病的抗性基因。经过蛋白酶K消化和两轮寡聚核苷酸引物 PCR (degenerateoligonucleotideprimedPCR ,DOP PCR)扩增后 ,用TAI 2 7和中间偃麦草的总DNA为探针的Southern杂交证明PCR产物确是来自这对小染色体。第二轮PCR产物被连接至pGEM Tvector中并转化大肠杆菌 ,获得小染色体DNA文库。初步分析文库共有 2× 10 5个克隆子 ,插入片段长度在 2 50～ 12 0 0bp之间 ,平均 530bp ,其中单、低拷贝序列占 57% ,中、高拷贝序列占 4 3%。     

具有5+12优质亚基节节麦的低分子量谷蛋白基因序列分析

根据低分子量谷蛋白亚基(LMW-GS)基因编码区保守序列设计引物,对具优质高分子量谷蛋白亚基(HMW-GS)5 12的节节麦材料AS63进行扩增,得到长度约为900bp和1000bp的DNA片段,克隆测序后获得3个LMW-GS基因序列LMWD-1(GenBank登录号AY841013)、LMWD-2(GenBank登录号AY841014)和LMWD-3(GenBank登录号AY841015)。它们具有小麦低分子量谷蛋白基因的典型结构特征。其中,LMWD-1和LMWD-2具有完整编码区,长度分别为1065bp和972bp,可分别编码333和302个氨基酸残基的成熟蛋白,且第一个半胱氨酸残基均出现在重复区第13位。在重复区,LMW-1的两个疏水单元为PIIIL和PVIIL,而LMWD-2的两个疏水单元为PIIIL和SVIIL。LMW-1的重复区中还存在一个连续13个Q组成的短肽。LMWD-3由于编码区内存在提前终止密码子,为不表达的假基因。氨基酸序列比较发现,LMW-GS基因的N-末端区序列具有位点特异性,且LMW-1和LMWD-2与普通小麦Gtu-D3位点的LMW-GS基因有很高的一致性。     

海带栽培品系和长海带ITS区的PCR扩增及序列分析

对遗传背景清晰且具有显著表型差异的海带6个栽培品系(CUL002,CUL860,CUL1170,CUE017,CUE018,CUL901)和长海带(L．longissia)的ITS区进行了PCR扩增和序列测定,并分析了8个种17个品系(其中7种共10株从GenBank中获得)海带之间的系统进化关系。结果表明：表型各异的6个海带栽培品系ITS区差别很小,其中ITS1 5．8S rDNA序列完全相同,部分品系间ITS2序列有个别碱基差异;进化树显示与日本海带(L．japonica,AF319018)聚在一起,相似性大于98％,其中CUL901、CUL860和CULll70的ITS序列完全相同。长海带(L．longissia)的ITS 5．8S rDNA和日本海带(L．japonica,AF319018)的完全相同。以Undaria peterseniana为外类群,根据ITS 5．8S rDNA序列构建进化树,6栽培品系及长海带与日本海带聚在一起;17株海带基本构成两个大的进化枝。研究结果揭示了我国海域栽培的长海带可能与日本海带(L．iaponica,AF319018)为同一个种。     

cAMP信号通路在5-羟色胺诱导硬壳蛤卵母细胞成熟过程中的作用

采用体外药物诱导的方法,研究了5-羟色胺(5-HT)诱导的硬壳蛤(Mercenaria mercenaria) 卵母细胞成熟过程中 cAMP 信号通路的作用.结果表明,浓度为0.01～100μM的5-HT 均能够显著地诱导硬壳蛤卵母细胞的成熟,处理 60min 时生发泡破裂(GVBD)发生率均可达到 70% 左右.不同浓度 5-tHT 的诱导作用表现出时间依赖性,但未表现出浓度依赖效应.咖啡因、茶碱和 3- 异丁基-1-甲基黄嘌呤(IBMX)可以单独抑制卵母细胞的自发成熟,但效果不显著.10mM的咖啡因和茶碱以及 5mM 的 IBMX 能够显著地抑制 5-HT的诱导效果.1mM 的 IBMX 对 5-HT 的诱导效果影响不显著,1mM的咖啡因和茶碱能够促进 5-HT 的诱导作用,但差异不显著.研究结果表明,cAMP 信号通路参与了 5-HT 诱导的硬壳蛤卵母细胞的成熟过程,并且 cAMP 浓度的升高会抑制其成熟,cAMP 信号通路在硬壳蛤卵母细胞的成熟过程中可能起着负调控的作用.     

大豆NBS类抗病相关基因的克隆与序列分析

根据拟南芥RPS2基因、烟草N基因和亚麻L6基因的保守结构域设计简并引物,采用RT-PCR方法从大豆抗疫霉根腐病品种绥农10号的RNA中扩增获得两个通读的大豆NBS类抗病基因同源片段RNEAU-1和RNEAU-2,长度均为513bp,编码171个氨基酸。以RNEAU-1为靶序列,采用RACE方法获得了全长3574bp的大豆抗病相关基因SR1,该基因包括3411bp的开放读码框,72bp的5′非翻译区(non-translated region,NTR),68bp的3′非翻译区和20bp的多聚腺苷酸尾。编码1137个通读的蛋白质氨基酸序列,基因编码产物具有TIR、NBS、LRR、HD(conserved domain 1)和conserved domain 2等一系列抗病基因的保守结构域。同源性比较和序列分析显示,该基因为大豆中TIR-NBS-LRR类抗病相关基因。Southern杂交结果表明,SR1基因(或其同源基因)在大豆中具有2～4个拷贝。RT-PCR检测表明,SR1基因在大豆中为低丰度组成型表达,其表达不受病原菌接种和水杨酸的诱导,亦无组织特异性。以绥农10号基因组DNA为模板扩增得到长度为3972bp的SR1基因转录区核苷酸序列,其结构包含5个外显子和4个内含子。SR1基因在GenBank上的登录号为AY193892。     

雌核发育银鲫四种孵化酶基因全长cDNA的克隆及其特征分析

用抑制性差减杂交结合SMART cDNA合成和RACE-PCR技术，克隆得到雌核发育银鲫(Carassius auratus gibelio)4种孵化酶基因的全长eDNA。4种孵化酶基因分别被命名为GHEl、GHE2、GHE3、GHE4。序列分析表明，4种孵化酶基因cDNA的开放阅读框均为795bp，都编码265个氨基酸。它们推断的编码氨基酸序列同源性在79．6～95．1％之间。种系分析表明，GHEl、GHE2、GHE3、GHE4的进化地位位于日本鳗鲡(Anguilla japonica)孵化酶和青鳉(Oryzias latipes)孵化酶之间。不同发育时期胚胎的RT-PCR分析表明，银鲫GHEl、GHE2、GHE3、GHE4 4种孵化酶基因从尾芽期到幼苗期都检测到表达，且GHE3和GHE4在神经胚期也检测到表达。各种组织的RT-PCR表明，它们在成鱼组织中不表达。     

Photosymbiotic giant clams are transformers of solar flux

‘Giant’ tridacnid clams have evolved a three-dimensional, spatially efficient, photodamage-preventing system for photosymbiosis. We discovered that the mantle tissue of giant clams, which harbours symbiotic nutrition-providing microalgae, contains a layer of iridescent cells called iridocytes that serve to distribute photosynthetically productive wavelengths by lateral and forward-scattering of light into the tissue while back-reflecting non-productive wavelengths with a Bragg mirror. The wavelength- and angle-dependent scattering from the iridocytes is geometrically coupled to the vertically pillared microalgae, resulting in an even re-distribution of the incoming light along the sides of the pillars, thus enabling photosynthesis deep in the tissue. There is a physical analogy between the evolved function of the clam system and an electric transformer, which changes energy flux per area in a system while conserving total energy. At incident light levels found on shallow coral reefs, this arrangement may allow algae within the clam system to both efficiently use all incident solar energy and avoid the photodamage and efficiency losses due to non-photochemical quenching that occur in the reef-building coral photosymbiosis. Both intra-tissue radiometry and multiscale optical modelling support our interpretation of the system''s photophysics. This highly evolved ‘three-dimensional’ biophotonic system suggests a strategy for more efficient, damage-resistant photovoltaic materials and more spatially efficient solar production of algal biofuels, foods and chemicals.     

16S rRNA基因与16S-23S rRNA转录单元内间隔区序列分析及其在节旋藻和螺旋藻分类鉴定中的应用

测定了节旋藻属3个品系和螺旋藻属1个品系的全长16SrRNA基因基因和16S rRNA转录单元内间隔区序列（ITS）,分析了已知的节旋藻、螺旋藻和相关品系的相应序列的同源性,构建了系统发生树,并评价了这两段DNA序列在节旋藻、螺旋藻种属分类和种质鉴定中的意义。结果表明：（1）16SrRNA基因序列和ITS序列均可用于节旋藻属和螺旋藻属的属间分类,以两序列为基础的系统学分析结果一致;（2）ITS序列变异程度高于16SrRNA序列,适用于节旋藻和螺旋藻属内品系或种质鉴定;（3）节旋藻属可明确界定,16SrRNA基因序列相似性大于98％,ITS序列相 似性大于88％;（4）螺旋藻属某些品系间16SrRNA序列和ITS序列相似性较低,与不同属间的序列相似性程度为同一水平。     

Geometric Design of Scalable Forward Scatterers for Optimally Efficient Solar Transformers

It will be ideal to deliver equal, optimally efficient “doses” of sunlight to all cells in a photobioreactor system, while simultaneously utilizing the entire solar resource. Backed by the numerical scattering simulation and optimization, here, the design, synthesis, and characterization of the synthetic iridocytes that recapitulated the salient forward‐scattering behavior of the Tridacnid clam system are reported, which presents the first geometric solution to allow narrow, precise forward redistribution of flux, utilizing the solar resource at the maximum quantum efficiency possible in living cells. The synthetic iridocytes are composed of silica nanoparticles in microspheres embedded in gelatin, both are low refractive index materials and inexpensive. They show wavelength selectivity, have little loss (the back‐scattering intensity is reduced to less than ≈0.01% of the forward‐scattered intensity), and narrow forward scattering cone similar to giant clams. Moreover, by comparing experiments and theoretical calculation, it is confirmed that the nonuniformity of the scatter sizes is a “feature not a bug” of the design, allowing for efficient, forward redistribution of solar flux in a micrometer‐scaled paradigm. This method is environmentally benign, inexpensive, and scalable to produce optical components that will find uses in efficiency‐limited solar conversion technologies, heat sinks, and biofuel production.     

Safety improvements through Intelligent Transport Systems: a South African case study based on microscopic simulation modelling

Intelligent Transport Systems (ITS) can facilitate the delivery of a wide range of policy objectives. There are six main objectives/benefits identified in the international literature: Safety (reduction of (potential) crashes), mobility (reduction of delays and travel times), efficiency (optimise the use of existing infrastructure), productivity (cost saving), energy/environment and customer satisfaction [Mitretek Systems, 2001. Intelligent Transport System Benefits: 2001 update, Under Contract to the Federal Highway Administration, US Department of Transportation, Washington, DC, US]. In the South African context, there is an interest for measures that can reduce (potential) crashes. In South Africa the number of year on year traffic related fatalities is still increasing. In 2005 the number of fatalities was 15393 (from 14135 in 2004) while the estimated costs for the same period increased from R8.89-billion to R9.99-billion [RTMC, 2007. Interim Road Traffic and Fatal Crash Report 2006, Road Traffic Management Corporation, Pretoria, SA]. Given the extent of the road safety problem and the potential benefits of ITS, the need for further research is apparent. A study with regards to the potential of different types of models (macroscopic, mesoscopic and miscroscopic simulation models) led to the use of Paramics. Two corridors and three types of ITS measures were investigated and safety benefits were estimated.     

Biocompatibility and Biodegradation of novel PHB porous substrates with controlled multi-pore size by emulsion templates method

PHB porous substrates were prepared based on the mono-membrane fabricated by emulsion templates method. The key factors of the method affecting the pore size and porosity of the PHB porous substrates were studied. The surface of PHB porous substrates were investigated by scanning electron microscope (SEM), which showed the even pore size and regular arranged pore. The transect of the PHB porous substrates prepared using the templates method was good. Moreover, the effects of variation of surfactant content (P%) and water content (R) on the pore size and porosity of PHB films were discussed. Preliminary studies showed that when P% is less than 20%, the pore size made by emulsion templates ranged from 5 μm to 30 μm with the value of P increasing. As P% is up to 20%. It was interesting to see that the porous substrates had muti-pore size distribution, i.e., median pore sizes were about 5 μm and inside the wall of pore, there existed numerous micro-pores size can be controlled from 100 nm to 500 nm only by adjusting the parameter R of the microemulsion. The cell-compatibility was evaluated via Chinese Hamster Lung (CHL) fibroblast cultivation in vitro. The Cells were cultured on both the mono-pore size membrane prepared by emulsion templates and the multi-pore size membrane prepared by microemulsion templates. It can be seen that the cells cultured on multi-pore size membrane stretched their morphology and proliferated better than that of mono-pore size membrane. These results indicated that the multi-pore size membrane had better cell-compatibility and was more suitable for tissue engineering. The degradation experiment indicated that the degradation of PHB porous substrates were accelerated by enzyme in vitro and the porous configuration was favorable to its degradation.     

Effect of spacer arm length on protein retention on a strong cation exchange adsorbent

The retention of five proteins was compared on a set of three strong cation exchange adsorbents that differed in spacer arm chemical structure and length. The adsorbents included a commercial product, Amersham Biosciences SP Sepharose Fast Flow, containing a six-carbon spacer between the agarose matrix and the anionic ligand, and two custom-prepared materials. One of the custom adsorbents contained a spacer of about half the length of the SP Sepharose Fast Flow, and the other contained no spacer arm. The adsorbent with no spacer arm was found to be significantly more retentive for all of the test proteins examined, in both isocratic and gradient elution tests. Reducing the spacer arm length by half resulted in increased retention for four of the five proteins, but this increase was less than what was observed when the spacer arm was eliminated. Retention increases were obtained without increasing the density of the anionic charge groups and appear to result from an enhancement of electrostatic or secondary nonelectrostatic interactions, or both. The results indicate that spacer arm length may be a useful variable in manipulating stationary-phase retention properties.     

基于滤食特征的水面垃圾清理装备的仿生设计与评估

目的 探索海洋水面垃圾清理装备的仿生设计过程和模态分析的有效性。方法 前期采用自上而下的仿生学设计方法,分别模仿河蚌和火烈鸟的独特滤食结构,得出两种水面垃圾清理装备的仿生设计方案,并介绍了基本的设计流程;后期运用有限元方法对两种成果分别进行模态分析。结果 河蚌方案模型的一阶固有频率均低于30 Hz,满足设计要求;火烈鸟方案模型需改进后进行再次评价。结论 仿生设计方法可以为水面垃圾清理装备的设计过程提供参考。此外,采用有限元方法对产品外形、结构进行模态分析,具备有效性。整个设计与评估闭环过程,可以较好地指导仿生创新设计,实现产品的多样化创新。     

基于二次电子发射的FED中支撑结构的优化设计

基于二次电子发射的场致发射显示器(HOPFED)是一种新型的场致发射器件.其新颖之处在于其独特的支撑形状,这种结构的优点是充分提高了场致发射显示的性能,如对比度、色纯及像素内的发光均匀性,并减少了离子轰击发射源.在目前已有的结构中,环形的屏上光点不能使荧光粉得到充分的利用,而且光点尺寸较小,容易使荧光粉达到饱和.为了得到符合荧光粉要求的光点形状,本文提出了diabolo形状flu支撑、ZEUs形状hop支撑以及长flu支撑三种支撑形状,并采用数值计算的方法对这几种不同的支撑结构对屏上光点的影响进行了模拟计算.计算结果表明,对这三种不同的支撑形状进行优化以后都能得到符合荧光粉的要求的屏上光点.在现有的工艺条件下,长flu支撑是一种能改善光点和场强分布,而又易于制作的支撑结构.     

Predicting optimal resolving power for ambient pressure ion mobility spectrometry

Although diffusion theory predicts that IMS resolving power increases with the square root of the voltage applied across the drift tube, in practice, there exists an optimum voltage above which resolving power decreases. This optimum voltage was determined to be both compound and initial ion pulse width dependent. A "conditional" resolving power equation is introduced that can be used to quickly approximate realistic resolving powers for specific instrumental operating parameters and compounds. Using four common environmental contaminants (trichloroethylene, tetrachloroethylene, methyl tert-butyl ether, methyl isobutyl ketone), diffusion-limited (theoretical), R d, conditional, R c, and actual (or measured), R m, IMS resolving powers were determined and compared for a small IMS instrument designed for subsurface measurements. Detection limits determined at the optimal resolving power for the environmental contaminants ranged from 18 parts per trillion volume-to-volume (ppt v) to 80 parts per billion volume-to-volume (ppb v). The maximal measured resolving power for our small, ambient-pressure stand-alone IMS ranged from 42 to 54, yielding an IMS resolving power efficiency, defined as R m/ R c x 100%, of 56-74% of the maximal conditional resolving power possible.