应用荧光原位杂交技术定位水稻的端粒相关序列和BAC克隆

用ＰＣＲ扩增得到的水稻端粒相关序列（ＴＡＳ）Ｔａｓ３和一个ＢＡＣ克隆（ＢＡＣ）为探针，与间期核和中期细胞染色体进行荧光原位杂交（ＦＩＳＨ），确定了在染色体上的位置。     

激光扫描共聚焦显微镜在荧光原位杂交中的应用

简要介绍激光扫描共聚焦显微镜在荧光原位杂交中的应用方法及其优越性。     

基于表面反射率的赤潮卫星荧光线高度算法比较

采用现场实测和室内培养两种方式测定了甲藻、赤潮异弯藻和叉角藻等赤潮藻以及新月菱形藻、海洋蓝绿藻、叉鞭金藻、塔胞藻、扁藻和小球藻等非赤潮藻类光谱曲线。采用的各卫星(MERIS,GLI,MODIS)的荧光波段数据按照其中心波长,从实际测定的高光谱反射率曲线提取而来,并按照荧光高度的计算公式得到其荧光高度。同时,采用统计分析方法建立荧光高度与叶绿素浓度的关系。10种藻类水体的荧光线高度与叶绿素α的回归分析结果显示了良好的线性关系,但部分藻种出现了负相关的结果。因为在高叶绿素浓度即赤潮条件下,浮游植物在荧光波段(685nm附近)和近红外波段(700～750nm)复杂的光谱行为,使得采用星载遥感器的叶绿素荧光波段探测某些藻类的赤潮时会出现偏差。同时,由于不同藻类的荧光高度与叶绿素浓度的关系也不一致,本文建议针对单独的赤潮种类应建立特定的荧光算法。相关问题还需要在实测的基础上进行更深入的研究。     

赤潮生物原甲藻Prorocentrum分子识别和系统发育学研究

对东海原甲藻Prorocentrum donghaiense、海洋原甲藻P.micans、微小原甲藻P.minimum、立玛原甲藻P.lima(CCMP1966)四种赤潮生物的18S rDNA进行了PCR扩增和全序列测定及分析,比较了它们的遗传距离和相似系数,获得其18S rDNA序列中的三处高变异区,为设计快速识别原甲藻种间分子探针提供分子依据.同时结合12种具有代表性的重要赤潮甲藻的18S rDNA序列,采用邻接法(Neighbour-Joining,NJ)和最大似然法(Maximum Likelihood,ML)构建系统发育树,研究原甲藻的种间关系和进化地位,结果表明,营底栖生活的P.lima与营浮游生活的P.micans、P.minimum、P.donghaiense为多系起源,浮游型原甲藻与凯伦藻Karenia有更近的起源关系.     

大豆染色体端粒DNA的Southern及荧光原位杂交（FISH）分析

以拟南芥的端粒序列（Ｔ３ＡＧ３）ｎ为探针，经Ｂａｌ３１酶切检测和荧光原位杂交，证明端粒ＤＮＡ保守重复序列存在于大豆的全部２０对染色体端部，与拟南芥，番茄和人类不同，大豆全部２０对染色体端部上的这一序列的长度相似。     

聚合酶链式反应(PCR)荧光检测研究

本研究了荧光能量传递技术（fluorescence ersonance energy transfer,FRET),建立了一套基于该理论在聚合酶链式反应（PCR）中用于荧光检测和溯源性研究的实验装置,并进行了检验。     

基于高光谱反射率的藻类水体基线荧光峰高度与叶绿素α浓度关系研究

采用现场实测和室内培养两种方式测定了甲藻、赤潮异弯藻、叉角藻赤潮和新月菱形藻、海洋蓝绿藻、叉鞭金藻、塔胞藻、扁藻和小球藻等非赤潮藻类光谱曲线。采用度量太阳激发的叶绿素荧光峰高度的基线荧光高度法，建立了不同藻类基线荧光高度与叶绿素浓度的关系。基线荧光高度法所用的3个荧光高度波段分别为665nm、680nm和865nm。在采用线性方程对不同藻类水体基线荧光高度与叶绿素浓度进行回归分析时，不同藻类产生了明显不同的结果。其中赤潮异弯藻、海洋蓝绿藻和甲藻为负相关，其余为正相关。在正相关的藻类中，小球藻最低，为0．4692。结果偏差主要来自于两个方面：一是藻类荧光峰位置变化影响；二是浮游植物红光和近红外波段高反射率的影响。     

基于EM-MLC的高光谱图像方法识别海洋赤潮的研究

提出了一种综合利用小波变换高低通滤波数据的海洋赤潮识别方法.基于低通滤波数据,利用基于有限混合密度理论期望最大(EM)算法作为最大似然分类(MLC)参数估计的方法(EM-MLC)来进行赤潮、非赤潮和过渡水体的分类识别,并可进一步识别出不同优势种藻类引发的赤潮区域;利用高通滤波数据,可以分析赤潮爆发中非优势种藻类的信息,这就为引发赤潮的藻类种类的判断奠定了基础.通过实验验证了本方法可以有效地进行赤潮识别.同时,根据检测出的过渡水体区域信息,可以进行赤潮爆发前的预测.     

Eu(1-X)LnX(TTA)3Phen荧光配合物的原位合成和光固化荧光防伪油墨的性能研究

在EA基质中,合成了Eu(1-X)LnX(TTA)3Phen配合物(Ln=G d、Y和L a,TTA=噻吩甲酰三氟丙酮,Phen=1,10邻-菲咯啉,X=掺杂元素的摩尔分数)。红外光谱的分析表明,配合物的吸收峰被EA(EA=双酚A-环氧丙烯酸酯)基质掩盖,表现为EA的特征吸收;荧光激发光谱、荧光发射光谱的研究表明,在EA基质中Eu(1-X)LnX(TTA)3Phen配合物已经形成,并且表现出强的铕离子特征荧光。荧光体系经固化后的荧光强度明显低于固化前的荧光强度,并讨论了荧光猝灭机理。     

Pd(Ⅱ)与牛血清白蛋白相互作用的荧光光谱研究

采用荧光光谱法研究了Pd(Ⅱ)与牛血清白蛋白(BSA)的相互作用.使用高斯多峰拟合法对Pd(Ⅱ)-BSA体系荧光光谱的各荧光成分进行了解析.结果表明,BSA的荧光主要来源于色氨酸(Trp)残基,并推测Pd(Ⅱ)与BSA结合作用的位置在第212位Trp残基上.研究了Pd(Ⅱ)与BSA相互作用的荧光猝灭光谱,通过紫外吸收光谱的变化和猝灭速率常数Kq的比较对Pd(Ⅱ)与BSA相互作用的荧光猝灭机理进行了判别.结果表明,Pd(Ⅱ)对BSA的荧光猝灭属于静态猝灭.     

一种创造高频率易位系的方法--不同种属代换系杂交

首次报道了利用小麦－簇毛麦二体代换系农２２与小麦中间偃麦草二体代换系遗４２１２杂交,在其杂种Ｆ２群体中染色体易位频率高达３．７％,其中既有臂间易位也有双插入易位,并出现小麦－簇毛麦、小麦－中间偃麦草染色体易位系,而贵农２２、遗４２１２与中国春杂交种Ｆ２群体中易位频率分别为１．７％和０％。结果表明：利用小麦的不同种属异源二体代换系之间相互杂交,既有可能是一条能产生高频易位的新途径,也是创造特殊遗传和     

簇毛麦属与偃麦草属物种染色体组遗传关系探讨

根据簇毛麦长末端重复序列Sabrina设计引物,进行PCR筛选,获得了偃麦草属(Thinopyrum)物种的特异分子标记OPV1079,比对结果显示标记OPV1079与簇毛麦(Dasypyrum)基因组高度重复序列有95%的同源性,说明簇毛麦属与偃麦草属物种在重复序列的组成和分布上有较大的相似性.为了深入探讨该两属染色体组的关系,以二倍体簇毛麦(V染色体组)总DNA为探针,对八倍体小偃麦进行原位杂交,发现有5条染色体在除端部和着丝粒处外具有强烈的弥散状杂交信号;以四倍体簇毛麦(VbVb染色体组)总DNA为探针,对中间偃麦草(JJSSt染色体组)进行杂交,发现有14条染色体在端部有杂交信号.结果表明染色体组V形成Vb过程中发生了较大重组,并且V较Vb与St有更近的遗传关系,说明基因组重复序列在小麦族物种的遗传分化中发挥了巨大作用,同时对物种遗传关系研究也为外源物种优异基因向小麦中转移提供了理论指导.     

In situ alloying of elemental Al-Cu12 feedstock using selective laser melting

ABSTRACT

This investigation developed selective laser melting (SLM) processing parameters for the in situ fabrication of an Al-Cu12 alloy from pure elemental blends of aluminium and copper powders. Use of elevated pre-heat temperatures (400°C) created a coarser dendritic cell microstructure consisting of supersaturated Al-rich with a uniform Al₂Cu phase granular microstructure compared to non-pre-heated samples. Al-Cu12 in situ samples achieved maximum tensile strength values comparable to that of sand cast pre-alloyed Al-Cu12. Processing at elevated pre-heat temperatures created components with higher ultimate tensile strength and ductility compared to standard room temperature-built samples due to it assisting a more complete melting of Al and Cu particles. Additionally pre-heating enabled an artificial age hardening, producing an equilibrium α?+?θ microstructure. The creation of an alloy in situ through the use of elemental powder blends represents a low-cost and flexible methodology for exploration of new SLM material compositions and potential candidate materials for semi-solid processing using SLM.     

栉孔扇贝和虾夷扇贝杂交子代的细胞遗传学研究

采用基因组荧光原位杂交(GISH)技术,结合改进的染色体滴片和压片法,对栉孔扇贝和虾夷扇贝远缘杂交正、反交子代4-8细胞胚胎及担轮幼虫的染色体构成及其变异进行了研究.结果表明,在染色体数目上,绝大部分正、反交子代早期胚胎的染色体数目为38条,与其双亲一致; 在染色体构成上,绝大部分正、反交子代分别继承了栉孔扇贝和虾夷扇贝各一套染色体,为真正的杂交种,核型也为双亲染色体核型的综合:2n=6m 29(sm,st) 3t;正、反交子代之间在染色体构成上无明显差别,结果说明两种扇贝的属间杂交正反方向均能产生正常的杂交种胚胎,合子中两套染色体具有较强的亲合性.此外,杂交子代在胚胎发育早期还存在较小比例的染色体数目异常、不对称染色体继承等遗传学现象.在群体杂交所产生的正反交子代中还存在极小比例的疑为雌核发育的母本类型个体,但在单对杂交产生的正反交子代中均未见雌核发育的个体.本文就这些异常现象产生的可能原因进行了探讨.     

原位聚合法制备红色电子墨水微胶囊

采用十八胺对永固红F5R实施表面改性,使其与四氯乙烯之间的亲和性得到改善,获得分散性良好的悬浮液,并有效抑制微胶囊化过程中颗粒的转移.本文将十八胺改性永固红F5R颗粒分散在四氯乙烯中为电泳基液,通过原位聚合法制备了红色电子墨水微胶囊,并采用光学显微镜和扫描电镜研究了微胶囊的表面形貌.     

Classification of multicolor fluorescence in situ hybridization (M-FISH) images with sparse representation

There has been a considerable interest in sparse representation and compressive sensing in applied mathematics and signal processing in recent years but with limited success to medical image processing. In this paper we developed a sparse representation-based classification (SRC) algorithm based on L1-norm minimization for classifying chromosomes from multicolor fluorescence in situ hybridization (M-FISH) images. The algorithm has been tested on a comprehensive M-FISH database that we established, demonstrating improved performance in classification. When compared with other pixel-wise M-FISH image classifiers such as fuzzy c-means (FCM) clustering algorithms and adaptive fuzzy c-means (AFCM) clustering algorithms that we proposed earlier the current method gave the lowest classification error. In order to evaluate the performance of different SRC for M-FISH imaging analysis, three different sparse representation methods, namely, Homotopy method, Orthogonal Matching Pursuit (OMP), and Least Angle Regression (LARS), were tested and compared. Results from our statistical analysis have shown that Homotopy based method is significantly better than the other two methods. Our work indicates that sparse representations based classifiers with proper models can outperform many existing classifiers for M-FISH classification including those that we proposed before, which can significantly improve the multicolor imaging system for chromosome analysis in cancer and genetic disease diagnosis.     

in situ failure detection in thick film multilayer systems

By means of in situ e.m.f.-measurements, leakage current measurements and impedance spectroscopy, it has been possible for the first time to detect spontaneous and forced blistering in thick film multilayers during formation at high temperatures. Also the occurrence of high temperature shorts in Ag-dielectric-Ag multilayers under DC-bias was detectable.     

一步原位聚合法制备电泳显示微胶囊的研究

用一步原位聚合法制备了电泳显示微胶囊.考察了系统调节剂、搅拌、壁材用量对微胶囊的粒径分布及其形貌的影响.实验结果表明,在搅拌速度为700r/min,pH值为1.5～2.0条件下,以明胶作为系统调节剂,脲醛树脂作为壁材,可以制得具有透明囊壁的球形微胶囊,粒径分布在20～70μm之间.采用合适的壁材用量可以获得高紧密度的囊壁.该法制备的微胶囊可望在电泳显示材料中有较好的应用.     

Assessment of intestinal absorption of total flavones of Hippophae rhamnoides L. in rat using in situ absorption models

Purpose: The objective of this study was to investigate the absorption behavior of total flavones of Hippophae rhamnoides L. (TFH) (the sum of isorhamnetin and quercetin as the index component) in the rat intestine using in situ circulation method. Methods: The accumulated TFH absorption and related absorption parameters were calculated. Furthermore, the influences of Cremophor ELP and the P-glycoprotein inhibitor, verapamil, on the intestinal absorption of TFH were studied using the in situ circulation model. Results and Discussion: The results showed that the absorption of TFH increased linearly with its concentration, indicating that a passive diffusion process was dominated. There were no significant differences in the absorption of TFH in three small intestine segments of duodenum, jejunum, and ileum and at different concentrations of Cremophor ELP ranging from 0.25% to 1% (P > 0.05). With the presence of P-gp inhibitor, verapamil, in the circulation fluid, the accumulated absorption of TFH did not increase significantly (P > 0.05). Further studies on the solubility and permeability enhancement of TFH should be investigated to develop new TFH products with high bioavailability.     

Development of dorzolamide hydrochloride in situ gel nanoemulsion for ocular delivery

Background: Several in situ gel-forming systems have been developed to prolong the precorneal residence time of a drug and to improve ocular bioavailability. Poloxamer 407 with its thermoreversible gelation and surface active properties was utilized to formulate a novel dorzolamide hydrochloride in situ gel nanoemulsion (NE) delivery system for ocular use. Objective: Improvement of both ocular bioavailability and duration of action for dorzolamide hydrochloride was the aim of this study. Methods: Physicochemical properties, in vitro drug release studies and biological evaluation of the prepared NEs were investigated. Results: The optimum formulation of in situ gel NE consisted of Triacetin (7.80%), Poloxamer 407 (13.65%), Poloxamer 188 (3.41%), Miranol C2M (4.55%), and water (70.59%). Biological evaluation of the designed dorzolamide formulation on normotensive albino rabbits indicated that this formulation had better biological performance, faster onset of action, and prolonged effect relative to either drug solution or the market product. The formula showed a superior pharmacodynamic activity compared to the in situ gel dorzolamide eye drops. This indicated the effectiveness of the in situ gel properties of poloxamer 407, besides formulating the drug in an NE form for improving the therapeutic efficacy of the drug. Conclusion: These results demonstrate the superiority of in situ gel NE to conventional ocular eye drops and in situ gels to enhance ocular drug bioavailability.