7 resultados para TFP

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The reaction rates of MTPP with oxygen in air are Inas than that with pure oxygen, the ratio is roughly the same as to the partial presence of imygen in air, The influences of S-ligand etbanethiol and O- litand Vc on the above Systems have also been investigated, the former makes the MP hands having more changes and the reaction rate constants becoming greater, the latter has less influence.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Some kinds of rare earth beta-diketone complexes with blue-violet light absorption edge were synthesized using the ligands of thenoyltrifluoroacctone (HTTA), 2, 2'-dipyridyl (BIPY) and different metal ions (Gd3+, Sm3+ and La3+). Their contents, structures and optoelectronic parameters were monitored by elemental analysis, MS, IR and UV spectra. The solubility of rare earth beta-diketone complexes in 2, 2, 3, 3-tetrafluoro-1-propanol (TFP) and absorption properties of their films in the region 300-800 nm were measured. The influence on the difference of absorption maximum from rare earth beta-diketone complexes to beta-diketone ligand by different metal ions was studied. In addition, the thermal stability of rare earth beta-diketone complexes was also reported. (C) 2005 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Two new azo dyes of alpha-isoxazolylazo-beta-dilcetones and their Ni(II) and Cu(II) complexes with blue-violet light wavelength were synthesized using a coupling component, different diazo components and metal (II) ions (Ni2+ and Cu2+). Based on the elemental analysis, MS spectra and FT-IR spectral analyses, azo dyes were unequivocally shown to exist as hydrazoketo and azoenol forms which were respectively obtained from the solution forms and from the solid forms. The action of sodium methoxide (NaOMe) on azo dyes in solutions converts hydrazoketo form into azoenol form, so azo dyes are coordinated with metal (II) ions as co-ligands in the azoenol forms. The solubility of all the compounds in common organic solvents such as 2,2,3,3-tetrafluoro-1-propanol (TFP) or chloroform (CHCl3) and absorption properties of spin-coating thin films were measured. The difference of absorption maxima from the complexes to their ligands was discussed. In addition, the TG analysis of the complexes was also determined, and their thermal stability was evaluated. It is found that these new metal (II) complexes had potential application for high-density digital versatile disc-recordable (HD-DVD-R) system due to their good solubility in organic solvents, reasonable and controllable absorption spectra in blue-violet light region and high thermal stability. (c) 2004 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A novel azo dye containing isoxazole ring and beta-diketone derivative (TIAD) and its two nickel (II) complexes (Ni (II)-ETIAD and Ni (II)-HTIAD) were synthesized in order to obtain a blue-violet light absorption and better thermal stability as a promising organic storage material for next generation of high density digital versatile disc-recordable (HD-DVD-R) systems that uses a high numerical aperture of 0.85 at 405 nm wavelength. Their structures were confirmed on the basis of elemental analysis, MS, FT-IR, UV-Vis and magnetic data. Their solubility in 2,2,3,3-tetrafluoro-1-propanol (TFP) and absorption properties of thin film were measured. The difference of absorption maximum from the complexes to their ligands was discussed. In addition, the TG analysis of the complexes was also determined, and their thermal stability was evaluated. (C) 2004 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Er3+:Yb3+ codoped tellurite-fluorophosphate (TFP) glass ceramic exhibits much stronger upconversion luminescence. The intensity of the 540 nm green light and 651 nm red light of the TFP glass ceramic is 120 times and 44 times stronger than that of the fluorophospahte (FP) glass, respectively. XRD analysis shows that the nanocrystal in TFP glass ceramic is SrTe5O11. TFP glass ceramic also displays much higher upconversion fluorescence lifetime and crystallization stability. The narrow and strong peak at 540 nm is very ideal for practical upconversion luminescence realization. This work is a new trial for exploring non-PbF2 involved nanocrystal upconversion glass ceramics.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

花粉管是种子植物受精过程中雄性生殖单位的载体,具有典型的极性顶端生长模式,因此成为研究细胞极性生长机理的理想模式体系。本研究以裸子植物白杄(Picea meyeri Rehd.et Wils)花粉为材料,并以对花粉萌发和花粉管生长起关键作用的Ca2+作为切入点,分析钙-钙调素在花粉萌发及花粉管极性生长中的作用,同时也为进一步探讨它们在其他植物细胞中的作用机理研究提供重要参考。 通过细胞化学定位证明,白杄花粉中含有丰富的游离钙离子和钙调素,在花粉管顶端呈现明显的梯度分布;钙调素特异拮抗剂三氟拉嗪(trifluoperazine,简称TFP)可以在钙离子存在的情况下与钙调素特异性结合,从而抑制钙-钙调素复合物对下游效应蛋白的激活。微摩尔浓度的TFP明显抑制白杄花粉萌发以及花粉管的生长,并导致大部分花粉管畸形生长。TFP处理后的花粉管(约80%以上)中游离钙离子梯度消失或梯度不明显,由此说明钙调素参与花粉管顶端游离钙离子梯度的维持。抑制剂处理显著影响钙调素在花粉管顶端的梯度分布模式,梯度落差明显减小。 应用鬼笔环肽标记花粉管微丝骨架表明,正常生长的花粉管中微丝骨架沿花粉管长轴平行的方向呈网络状分布,但是在花粉管顶端仅有杂乱的微丝片断分布;低浓度TFP处理之后,微丝骨架分布的方向性丧失并开始卷曲,花粉管顶端的微丝片断消失,高浓度TFP处理之后微丝骨架完全断裂,聚集成短粗的束状。FM4-64标记花粉管后发现,经TFP处理的花粉管顶端胞吞速度明显加快,最终染料集中分布在紧贴质膜下很小的区域内,同时胞吞过程加快主要表现在染料进入花粉管细胞的速度加快,而随后染料在细胞内的扩散速度并无明显变化。以酸性磷酸酶为标志的胞吐活性也显著下降。通过MitoTracker染色发现,TFP处理之后花粉管中线粒体的形态和分布都发生了显著变化;在电子显微镜下观察显示,抑制剂处理的花粉管中液泡化现象严重,线粒体膨大变形,其内嵴的结构遭到严重破坏,同时高尔基体和内质网的形态也都发生了不同程度的异常变化,另外线粒体和液泡还出现了类似于自体吞噬的现象。 在荧光显微镜下观察发现,在标准培养基中培养的花粉管经苯胺兰染色后,胼胝质分布于整根花粉管侧壁上,而顶端区域胼胝质分布却很少或不存在。但经TFP处理之后,在花粉管细胞壁的个别区域有胼胝质大量沉积,同时在花粉管中还出现能被苯胺兰特异染色的许多颗粒状物质。此时花粉管顶端细胞壁中的纤维素含量明显减少。以单克隆抗体JIM5、JIM7标记果胶质,在激光扫描共聚焦显微镜下观察发现,标准培养基中培养的花粉管,酸性果胶质分布于整根花粉管的侧壁中,但在其顶端的含量很低或不存在,与此相反,酯化果胶质只分布在花粉管的顶端;而经TFP处理的花粉管中,酸性果胶质均匀分布于花粉管细胞壁上,酯化果胶质仅出现在花粉管基部的细胞壁中。单克隆抗体LM2和LM6标记结果显示,正常生长的花粉管细胞壁中AGPs呈周期性的环状分布,TFP处理后AGPs仅仅分布在花粉管基部的细胞壁中。SDS-PAGE电泳分析显示,抑制剂处理之后花粉管细胞壁蛋白的表达也发生明显变化。由FT-IR分析进一步证实了上述两种果胶质及纤维素在花粉管顶端细胞壁中相对含量的变化趋势。 利用双向电泳技术分离花粉管全蛋白,结果发现正常生长和TFP处理后的花粉管的大部分蛋白斑点都处于pI 4-8以及分子量在14-97 KD的范围内,主要是一些中等分子量大小、微酸性和中性的蛋白类群。由软件分析显示,除其中76个蛋白外,大部分蛋白质的表达并未发生变化。将上述76个表达量发生变化的差异蛋白进行胶内酶解,并经ESI-MS/MS分析鉴定,以及质谱数据库搜索,最终鉴定出57个蛋白,其中23个表达量上调,其余34个表达量下调。根据其生物学功能可以分为碳水化合物及能量代谢、胁迫及防御反应、细胞扩展、信号转导等功能蛋白类群。经TFP处理后,花粉管中碳水化合物及能量代谢过程整体水平下降,氧化磷酸化水平减低,但是丙酮酸脱羧酶旁路代谢水平却略有上升。由此暗示,花粉管在生长停滞的环境条件下,该途径可作为能量供应的替代机制;参与转一碳单位反应的蛋白表达量普遍上调,参与细胞延展(如细胞骨架重构、细胞壁多糖合成)的蛋白表达量下调,此项研究结果与上述的细胞生物学分析结论基本一致。 综上所述,当钙调素蛋白功能受到抑制后,顶端游离钙离子浓度梯度消失同时胞质钙离子浓度显著升高;细胞代谢水平(糖酵解和三羧酸酸循环)整体下降,而可能通过丙酮酸脱羧酶旁路来维持最低限度的能量供应;同时花粉管微丝骨架发生解聚,花粉管细胞壁组成成分合成水平下降,细胞延展相关的能力减弱,最终导致花粉管生长的停滞。钙-钙调素信号存在于白杄花粉萌发和花粉管生长这一特定的细胞生物学事件中,并参与花粉管顶端游离钙离子梯度的维持和定向生长。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

采用体外药物诱导的方法,研究了5-羟色胺(5-hydroxytryptamine,5-HT)诱导的硬壳蛤卵母细胞成熟过程中cAMP信号通路的作用。结果表明,5-HT (0.01—100µM)均能够显著地诱导硬壳蛤卵母细胞的成熟。磷酸二酯酶抑制剂—咖啡因、茶碱和IBMX(3-异丁基-1-甲基黄嘌呤)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。dbcAMP(双丁酰基环腺苷一磷酸)不但能够抑制卵母细胞的自发成熟,而且还可以抑制5-HT诱导的成熟。因此,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,并且该信号通路起着负调控的作用。 研究了PLC(磷脂酶C)和PKC(蛋白激酶C)的激活剂/抑制剂对5-羟色胺诱导的卵母细胞成熟的影响。高浓度的新霉素(PLC抑制剂)可以抑制5-HT诱导的卵母细胞的成熟,而DMBA(9,10-Dimethy-1,2-benzanthracene,9,10–二甲基胆蒽,PLC激活剂)则能够促进成熟。PMA(phorbol 12-myristate 13-acetate,佛波十四烷酸乙酸酯,PKC激活剂)能够抑制5-HT诱导的成熟,而Spingosine(PKC抑制剂)则可以促进卵母细胞的成熟。从而推测,5-HT诱导的卵母细胞成熟需要磷脂酰肌醇信号通路的激活。PLC浓度的降低能够抑制5-HT诱导的卵母细胞成熟;PKC浓度的降低则会促进卵母细胞的成熟。因此,在硬壳蛤卵母细胞的成熟过程中,PLC起促进的作用,DAG(二酰肌甘油)–PKC通路则起抑制的作用。 细胞外高浓度Ca2+能够促进硬壳蛤卵母细胞的成熟,Ca2+离子载体A23187也可以促进硬壳蛤卵母细胞的成熟。1-100µM异搏定(Verapamil,钙离子通道阻断剂)能够抑制卵母细胞的成熟,而100µM的Verapamil能够完全抑制其成熟。上述结果表明细胞外Ca2+对硬壳蛤卵母细胞的成熟是必需的,而且起到促进卵母细胞成熟的作用。三氟拉嗪(TFP,Ca2+与CaM结合的拮抗剂)能够抑制卵母细胞的成熟,高浓度的三氟拉嗪(1mM)能够完全抑制卵母细胞的成熟。说明CaM起到促进卵母细胞成熟的作用。可见,Ca2+通过与CaM的相互作用,共同起到促进硬壳蛤卵母细胞成熟的作用。 5-HT诱导成熟的卵母细胞可以完成受精过程,其受精过程以及幼虫发育情况与正常受精发育过程类似,没有显著差异。高浓度的新霉素可以抑制受精过程,而茶碱和咖啡因对受精没有影响。从而推测,磷脂酰肌醇信号通路参与了硬壳蛤卵母细胞的受精过程,而cAMP信号通路可能没有参与受精过程。 发现硬壳蛤的性腺发育与我国常见的双壳类如泥蚶相似。硬壳蛤卵母细胞中卵黄粒主要由线粒体、高尔基液泡、内质网和微吞饮泡形成。