20 resultados para HEPES SIMPLEX

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The absorptivities of color elements in a mixture can be obtained by using Gauas' elimination with selection of principal element in matrix to the standards. These values can be applied to flexible tolerance simplex method to give the composition of samples. In the exprimental design and data treatment, an effort was made to minimize the errors of results according the principal of optimization. When the difference of absorptivities of color material is significant to the exprimental error, the pr...

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本文提出一个不用 Kuhn- Tucker条件而直接搜索严格凸二次规划最优目标点的鲁棒方法 .在搜索过程中 ,目标点沿约束多面体边界上的一条折线移动 .这种移动目标点的思想可以被认为是线性规划单纯形法的自然推广 ,在单纯形法中 ,目标点从一个顶点移到另一个顶点。

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We propose an integrated algorithm named low dimensional simplex evolution extension (LDSEE) for expensive global optimization in which only a very limited number of function evaluations is allowed. The new algorithm accelerates an existing global optimization, low dimensional simplex evolution (LDSE), by using radial basis function (RBF) interpolation and tabu search. Different from other expensive global optimization methods, LDSEE integrates the RBF interpolation and tabu search with the LDSE algorithm rather than just calling existing global optimization algorithms as subroutines. As a result, it can keep a good balance between the model approximation and the global search. Meanwhile it is self-contained. It does not rely on other GO algorithms and is very easy to use. Numerical results show that it is a competitive alternative for expensive global optimization.

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星间激光通讯中,精跟踪起着十分重要的作用,而精密偏转镜(FSM)是精跟踪系统中最为关键的部件.基于光学矢量反射定律,推导得到了FSM的精确光学特性,这一特性为精跟踪控制系统提供了精确的理论依据.设计了基于FSM精确光学特性的精跟踪控制系统,对系统整定所用的单纯形法进行了两点重要改进,并对所设计的精跟踪系统进行了数字模拟,由此实现了对FSM的精确控制,提高了精跟踪系统的精确性;将光学衍射超分辨原理应用到星间激光通讯中.利用三区位相光瞳滤波器的超分辨性能,改变光学系统的点扩散函数,从而改变接收端焦平面上的光强

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以含MnSO4或Na2CrO4的无钼无氨的修改Burk’s培养基, 培养不能合成含钼固氮酶体系的棕色固氮菌 (Azotobacter vinelandii Lipmann) 突变种UW3, 发现在一定浓度范围内, MnSO4或Na2CrO4的加入有助于促进其生长。 菌体生长和C2H2还原活性曲线测定结果表明, 这种促进作用很可能是通过Mn或Cr取代Mo, 参与组装固氮酶中心原子簇, 从而影响固氮活性而实现的。 利用阴离子交换 (DEAE-52和Q-Sepharose FF) 和凝胶过滤 (Sephacryl S-200) 柱层析从两种菌体中纯化得到固氮酶组分Ⅰ蛋白 (分别命名为MnFe蛋白和CrFe蛋白), 并对其进行了特性研究。 厌氧天然聚丙烯酰胺凝胶电泳 (PAGE) 和SDS-PAGE结果显示, 两种蛋白均为两种亚基组成的四聚体。 亚基可以与OP MoFe蛋白抗体发生免疫反应, 分子量分别略小于野生种OP MoFe蛋白的α和β亚基。 CrFe蛋白的C2H2还原活性, Ar下放氢活性和固氮活性分别相当于OP MoFe蛋白的36%, 38%和43%, 而MnFe蛋白活性相当于OP MoFe蛋白的50%左右, 并且两种蛋白与OP MoFe蛋白具有相似的固氮电子利用率。 对两种蛋白金属含量的测定证实其中分别含有Mn和Cr, 但仍存在少量Mo污染。 与OP MoFe蛋白相比,这两种蛋白圆二色谱的摩尔椭圆率 ([θ]) 除在450nm较接近外,在可见光区的其它波长处均显著降低。 与DT还原OP MoFe蛋白相似, CrFe蛋白和MnFe蛋白具有g≈4。3、3。7和2。0的特征EPR信号, 但各处信号强度比例不同。 在对污染Mo可能引起的信号进行校正后,CrFe蛋白的三个信号强度分别相当于DT还原OP MoFe蛋白的20%, 0%和10%, 而MnFe蛋白则分别相当于112%, 49%和65%。 上述结果表明, CrFe蛋白和MnFe蛋白与OP MoFe蛋白金属原子簇的主要差异很可能在于FeMco (M=Cr, Mn或Mo)的M种类, 而P-cluster结构和组成均未见大的差异。 利用气相扩散悬滴法对MnFe蛋白和CrFe蛋白结晶条件进行了筛选和初步优化, 确定了以Tris/Hepes, NaCl, MgCl2和PEG 8000为主要变量的沉淀剂体系, 寻找各组分对于晶体生长的最适浓度。 以此为基础探讨了应用气相扩散坐滴法和液-液扩散法对两种蛋白结晶条件的优化。 在一定条件下, 两种蛋白分别通过液-液扩散法获得了优质大单晶。 对从CrFe蛋白和MnFe蛋白制备物中培养出的蛋白质晶体的SDS-PAGE鉴定显示, 晶体由与OP MoFe蛋白相似的两种亚基组成。 通过 “神舟三号” 飞船搭载实验探讨了空间微重力对于厌氧蛋白质结晶的影响, 结果表明, 微重力有助于避免孪晶形成, 并具有长期培养后获得适于进行X-射线衍射分析的优质大单晶的潜在前景。 结合空间科学使固氮酶结构与功能研究得以发展, 这项工作是有意义并且可行的。

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用Triton X--100增溶菠菜叶绿体,分离到高放氧活性的PSII颗粒。对增溶过程中的缓冲液pH Triton与叶绿素比例、Na~+ 浓度等因素进行分析,结果表明各因素相互间作用不大;pH的最佳范围为6.7~7.1。制备的PS-II颗粒放氧活性达210μmoles/mgchl.hr、DCIP→MV的光还原活性约为54μmoles O_2/mgchl.hr. P700与叶绿素比例为1/1900。放氧活性相当稳定,在0℃水浴保存的活性半衰期为80小时左右。该PSII颗粒的多肽分子量主要分布在68、56、46、34、28.5、25、20和17KD区域,其中25KD多肽占总蛋白质含量的40%经上。上述PSII颗粒经胆酸钠或Tris处理后,放氧活性和DPC→DCIP的希尔反应活性都有不同程度的下降,同时有一些蛋白质被抽提。胆酸钠抽提到的组分是65、58和15KD多肽;Tris则对34KD多肽的抽提作用最为显著。本文初步讨论了这些多肽与PSII氧化侧的关系。文中缩写:Tris-三羟甲基氨基甲烷;EDTA-乙二胺四乙酸;Tricine-一三(羟甲基)甲基甘氨酸;HEPES--N-2-羟乙基呱嗪-N-2-乙磺酸;DTT-二硫苏糖醇,DMBQ:2,5-二甲基对苯醌;DCIP-一二氯酚靛酚;ASC-抗环血酸;DPC-NN二苯氨基脲;MV-甲基紫精;SDS-十二烷基磺酸钠;Chl-叶绿素;LHCP-捕光色素蛋白复合体;PS-光系统;RuBP-二磷酸核酮糖;CF-叶绿体偶联因子;DCMU-二氯苯基二甲脲;Cyt-细胞色素。

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Trichosanthin (TCS) is a type I ribosome-inactivating protein that has a wide range of pharmacological activities. The present study investigated the effectiveness of TCS on herpes simplex virus (HSV-1). The anti-viral activity and toxicity of TCS on Vero

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本发明涉及一种肉、奶牛B超活体取卵方法,属生物技术领域。本方法的吸卵真空泵的压力为50-90mmHg,吸卵液为含0.5-1%,青-链霉素和5-10IU肝素的磷酸缓冲液,洗卵液为含5-12%,BCS的磷酸缓冲液和改良的基础培养液-Hepes液;采卵频率为1次/4天/头;穿刺对象为所有直径≥2mm的卵泡;取1-3级的卵母细胞分装、备用;对7-8岁的供体经产牛按程序注射等量的外源性FSH,总量为30-55μg;对≥14岁的老年牛按程序肌肉注射总量为150-200μg的外源性FSH,以提高卵母细胞发育潜能。本发明的优点在于,从活体可重复、无损伤获取卵母细胞;≥2mm直径卵泡作为穿刺对象和每4天1次的取卵频率保证了卵母细胞的质量和发育同步性;用外源性FSH诱导可提高卵母细胞的发育潜能;本方法的取卵效果佳。

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Sodium rutin sulfate (SRS) is a sulfated rutin modified from the natural flavonol glycoside rutin. Here, we investigated its in vitro anti-HIV and -HSV activities and its cytotoxic profile. Fifty percent inhibitory concentration (IC50) values of SRS against HIV-1 X4 virus IIIB, HIV-1 R5 isolates Ada-M and Ba-L were 2.3 +/- 0.2, 4.5 +/- 2.0 and 8.5 +/- 3.8 mu M with a selectivity index (SI) of 563, 575 and 329, respectively. Its IC50 against primary R5 HIV-1 isolate from Yunnan province in China was 13.1 +/- 5.5 mu M, with a Sl of 197. In contrast, unsulfated rutin had no activity against any of the HIV-1 isolates tested. Further study indicated that SRS blocked viral entry and virus-cell fusion likely through interacting with the HIV- I envelope glycoprotein. SRS also demonstrated some activity against human herpes simplex virus (HSV) with an IC50 of 88.3 +/- 0.1 mu M and a Sl of 30. The 50% cytotoxicity concentration (CC50) of SRS was >3.0 mM, as determined in human genital ME 180, HeLa and primary human foreskin fibroblast cells. Minimum inhibitory concentration of SRS for vaginal lactobacilli was >3.0 mM. These results collectively indicate that SRS represents a novel candidate for anti-HIV-1/HSV microbicide development. (C) 2007 Elsevier B.V. All rights reserved.

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Six species, belonging to two genera of Lemaneaceae in China are described. They are Lemanea Bory (including L. sinica Jao, L. crassa S. L. Xie et Z. X. Shi, L. ramosa S. L. Xie et Z. X. Shi and L. simplex Jao) and Paralemanea (Silva) Vis et Sheath (including P catenata (Kutzing) Vis et Sheath and P. parvula (Sirodot) S. L. Xie et Z. X. Shi). Among them L. crassa S. L. Xie et Z. X. Shi and L. ramosa S. L. Xie et Z. X. Shi are new species. Moreover, Paralemanea (Silva) Vis et Sheath and P. catenata (Kutzing) Vis et Sheath, P. parvula (Sirodot) S. L. Xie et Z. X. Shi are newly recorded in China.

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The gene targeting technique is a powerful tool for analyzing functions of cloned genes and for generating transgenic animals with site-directed integration of foreign genes. In order to develop this technique in fish, positive-negative selection (PNS) and homologous recombination vectors were constructed, and their expression was examined in fish cells. A vector (pNK) for PNS consists of the neomycin resistance gene (neo) as a positive selectable marker gene and the herpes simplex virus (HSV) thymidine kinase (tk) gene as a negative selectable marker gene. Positive selection with geneticin (G418) of epithelioma papulosum of carp (EPC) cells transfected with linearized pNK vector yielded 350 colonies, while double selection of transfected EPC cells with G418 and gancyclovir (Gc) resulted in nearly complete cell death, demonstrating that the PNS procedure is effective in fish cells. Homologous recombination vectors consist of the Xiphophorus melanoma receptor kinase (X mrk(Y)) gene as homologous sequence in addition to the neo and tk genes. Conditions for homologous recombination vector transfection and drug selection were established. After verification of the feasibility of expression of homologous recombination vectors in EPC cells, the first gene targeting experiments were attempted in the Xiphophorus melanoma cell line, PSM. Positive-negative selection of the targeting vector-transfectants led to a low enrichment in this particular cell line. The reasons for the low enrichment in PSM cells were discussed. (C) 2002 Elsevier Science B.V. All rights reserved.

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High dimensional biomimetic informatics (HDBI) is a novel theory of informatics developed in recent years. Its primary object of research is points in high dimensional Euclidean space, and its exploratory and resolving procedures are based on simple geometric computations. However, the mathematical descriptions and computing of geometric objects are inconvenient because of the characters of geometry. With the increase of the dimension and the multiformity of geometric objects, these descriptions are more complicated and prolix especially in high dimensional space. In this paper, we give some definitions and mathematical symbols, and discuss some symbolic computing methods in high dimensional space systematically from the viewpoint of HDBI. With these methods, some multi-variables problems in high dimensional space can be solved easily. Three detailed algorithms are presented as examples to show the efficiency of our symbolic computing methods: the algorithm for judging the center of a circle given three points on this circle, the algorithm for judging whether two points are on the same side of a hyperplane, and the algorithm for judging whether a point is in a simplex constructed by points in high dimensional space. Two experiments in blurred image restoration and uneven lighting image correction are presented for all these algorithms to show their good behaviors.