988 resultados para 1,2-DIHYDROXY-9,10-ANTHRACENEDIONE


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Five novel organotin complexes with the anthraquinone dyes alizarin (1,2-dihydroxyanthraquinone) and purpurin (1,2,4-trihydroxyanthraquinone) were synthesized and characterized by elemental analyses, FTIR and NMR spectroscopy ((1)H, (13)C and (119)Sn). The crystal and Molecular structures Of four complexes were determined by X-ray diffraction on single crystals: [Bu(2)Sn(aliz)(H(2)O)]center dot C(2)H(5)OH (A1 center dot EtO H), [Bu(2)Sn(aliz)(dmso)](2) (A3), [(Bu(2)Sn)(3)O(Hpurp)(2)] (P1) and [Bu(2)Sn(Hpurp)(dmso)](2) (P2), where H(2)aliz = alizarin and H(3)purp = purpurin. The coordination mode of the ligands is identical to that found in their Al/Ca complexes, where they act as dianionic tridentate ligands forming five and six-membered fused chelate rings. The coordination to the tin atoms occurs exclusively via the 1,2- phenolate oxygen and the adjacent quinoid oxygen atoms. The complexes A1, A3 and P1 are dimers with hepta-coordinated tin atoms in form of a slightly distorted pentagonal bipyramid. The trinuclear complex P2 contains two pentacoordinated and one heptacoordinated tin atoms.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Un mago y sus amigos ayudan a los niños a aprender y a practicar los conocimientos de gramática inglesa requeridos en la etapa clave dos (Key Stage 2). Diseñadas para captar la imaginación del estudiante las actividades están divididas en secciones, cada una centrada en una competencia básica:sinónimos, comas, frases, adjetivos, sujetos, pronombres, preposiciones, tiempos verbales, apóstrofes, adverbios. En la última página incluye un Certificado de Excelencia donde cada niño puede pegar una estrella dorada como recompensa por los logros alcanzados en cada actividad. Al final del libro están las soluciones a las actividades.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ameloblastoma and adenomatoid odontogenic tumor are odontogenic tumors arising from the odontogenic epithelium with distinct clinical behavior. In attempt to comprehend the interaction between the odontogenic tumor cells and the extracellular matrix, the present work evaluated and compared the immunohistochemical expression of the matrix metalloproteinases-1 (MMP-1), -2 (MMP-2) and -9 (MMP-9) in 20 cases of ameloblastoma and 10 adenomatoid odontogenic tumor. MMP-1 exhibited exuberant expression in the parenchyma and in the stroma of both studied tumors, while the MMP-2 showed varied expression with about of 80% and 60% of the neoplastic cells exhibiting positivity in the ameloblastoma and adenomatoid odontogenic tumor, respectively. With relation to the MMP-2 expression by the mesenchymal cells, it was observed that 65% of the ameloblastoma and 80% of the adenomatoid odontogenic tumor were positive. The immunoreactivity of MMP-9 was detected in all studied cases, although its expression had occurred predominantely in less than 50% of the parenchyma cells of the ameloblastoma, while in about of 60% of the adenomatoid odontogenic tumor more than 50% of cells were positive. The mesenchymal cells were positive to MMP-9 in 65% of the ameloblastoma and in 80% of the adenomatoid odontogenic tumor, respectively. Statistically significant difference was observed to the MMP-1 expression with relation to MMP-2 and MMP-9 in the ameloblastoma (p < 0.001). It was not possible to perform statistical analysis to the cases of adenomatoid odontogenic tumor, however there was a tendency toward a differential expression of the MMP-1 with relation to other studied MMPs. These results suggest that MMP-1, - 2 and -9 are implicated in the growth and progression of both tumors analyzed as well as the more pronounced participation of the stroma in the ameloblastoma could together to be related to the higher clinical aggressiveness

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

通过测量荧光寿命和荧光光谱,研究了1,2-苯并蒽(BA),9,10-二甲基-1,2-苯并蒽(DMBA)与β-环糊精(β-CD)络合过程及荧光猝灭。计算出络合平衡常数和猝灭常数。结果表明,BA与β-CD发生了络合作用,DMBA几乎不与β-CD络合。加入β-CD可使荧光分子的,聚集态与单体间的平衡向生成单体的方向移动,碘离子对BA的猝灭作用也明显减弱。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A mutant strain (UV4) of the soil bacterium Pseudomonas putida, containing toluene dioxygenase, has been used in the metabolic oxidation of 1,2-dihydrobenzocyclobutene 12 dagger and the related substrates 1,2-dihydrobenzocyclobuten-1-ol 13 and biphenylene 33. Stable angular cis-monohydrodiol metabolites (1R,2S)-bicyclo[4.2.0]octa-3,5-diene-1,2 7, (1S,2S,8S)-bicyclo[4.2.0]octa-3,5-diene-1,2,8-triol 8 and biphenylene-cis-1,8b-diol 9, isolated from each of these substrates, have been structurally and stereochemically assigned. The structure, enantiopurity and absolute configuration of the other cis-diol metabolites, (2R,3S)-bicyclo[4.2.0]octa-1(6),4-diene-2,3-diol 14 and cis-1,2-dihydroxy-1,2-dihydrobenzocyclobutene 16, and the benzylic oxidation bioproducts, 1,2-dihydrobenzocyclobuten-1-ol 13, 1,2-dihydrobenzocyclobuten-1-one 15 and 2-hydroxy-1,2-dihydrobenzocyclobuten-1-one 17, obtained from 1,2-dihydrobenzocyclobutene and 1,2-dihydrobenzocyclobuten-1-ol, have been determined with the aid of chiral stationary-phase HPLC, NMR and CD spectroscopy, and stereochemical correlation. X-Ray crystallographic methods have been used in the determination of absolute configuration of the di-camphanates 27 (from diol 7) and 32 (from diol 9), and the di-MTPA ester 29 (from diol 14) of the corresponding cis-diol metabolites. The metabolic sequence involved in the formation of bioproducts derived from 1,2-dihydrobenzocyclobutene 12 has been investigated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

以盆栽法研究了不同浓度1,2,4-三氯苯(TCB)胁迫对大豆下胚轴膜脂过氧化作用的影响。结果表明,100—300μg·g-1TCB胁迫初期(1—3d)促使萌发大豆下胚轴内过氧化氢(H2O2)的积累显著增加,同时伴随质膜电解质渗漏率和组织自动氧化速率升高,显示发生膜脂质过氧化作用。TCB胁迫1—6d使活性氧清除酶功能紊乱,其中过氧化物酶(POD)活性升高,过氧化氢酶(CAT)活性开始上升后转为下降。推测大豆下胚轴受TCB胁迫伤害过程中,活性氧代谢失衡造成的膜脂质过氧化起着重要作用。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

以盆栽法研究了不同浓度 1,2 ,4 三氯苯 (TCB)胁迫对萌发大豆种子中活性氧代谢的影响 .结果表明 ,10 0~ 30 0 μg·g-1TCB胁迫初期 (1~ 3天 )促使萌发大豆种子呼吸强度升高及其峰值提前出现 ,超氧阴离子自由基 (O2 - )及过氧化氢 (H2 O2 )的积累显著增加 ,同时伴随丙二醛 (MDA)含量升高 ,显示发生膜脂质过氧化作用 .TCB胁迫 1~ 6天使活性氧清除酶功能紊乱 ,其中过氧化物酶 (POD)活性升高 ,超氧化物岐化酶 (SOD)活性开始上升后转为下降 .在萌发大豆种子受TCB胁迫伤害过程中 ,活性氧代谢失衡造成的膜脂质过氧化将起着重要作用 .

Relevância:

100.00% 100.00%

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。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We reported previously that bone morphogenetic proteins (BMPs) potently suppress CYP17 expression and androgen production by bovine theca interna cells (TC) in vitro. In this study, real-time PCR was used to analyse gene expression in TC and granulosa cell (GC) layers from developing bovine antral follicles (1-18 mm). Abundance of mRNA transcripts for four BMPs (BMP2, BMP4, BMP6, and BMP7) and associated type I (BMPR1A, BMPR1B, ACVR1 and ACVR1B) and type II (BMPR2, ACVR2A and ACVR2B) receptors showed relatively modest, though significant, changes during follicle development. BMP2 was selectively expressed in GC, while BMP6, BMP7 and betaglycan (TGFBR3) were more abundant in TC. Abundance of betaglycan mRNA (inhibin co-receptor) in TC increased progressively (fivefold; P<0.001) as follicles grew from 1-2 to 9-10 mm. This suggests a shift in thecal responsiveness to GC-derived inhibin, produced in increasing amounts as follicles achieve dominance. This prompted us to investigate whether inhibin can function as a physiological antagonist of BMP action on bovine TC in vitro, in a manner comparable to that for activin signalling. BMP4, BMP6 and BMP7 abolished LH-induced androstenedione secretion and suppressed CYP17 mRNA >200-fold (P<0.001), while co-treatment with inhibin-A reversed the suppressive action of BMP in each case (P<0.001). Results support a physiological role for granulosa-derived inhibin as an antagonist of BMP action on thecal androgen synthesis. A shift in intrafollicular balance between thecal BMP signalling (inhibitory for androgen synthesis) and betaglycan-dependent inhibin signalling (stimulatory for androgen synthesis) accords with the physiological requirement to deliver an adequate supply of aromatase substrate to GC of developing follicles.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Vols. [1-2], Adventures of Captain Bonneville, accompanied by folded map in envelope.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

pt.1. March 24-28, 1958. 431 p.--pt.2. April 28, 29, May 1, 2, June 9, 10, 11, 16, 18-20, 1958. pp. 433-1016.