956 resultados para 1-4
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The X-ray crystal structures of 4-butyl-1,2-diphenylpyrazolidine-3,5-dione (phenylbutazone)(I). and its 2 : 1 complex (II) with piperazine have been determined by direct methods and the structures refined to R 0.096 (2 300 observed reflections measured by diffractometer) and 0.074 (2 494 observed reflections visuallyestimated). Crystals are monoclinic, space group P21/c; for (I)a= 21.695(4), b= 5.823(2), c= 27.881(4)Å, = 108.06 (10)°, Z= 8, and for (II)a= 8.048(4), b= 15.081(4), c= 15.583(7)Å, = 95.9(3)°, Z= 2. The two crystallographically independant molecules in the structure of (I) are similar except for the conformation of the butyl group, which is disordered in one of the molecules. In the pyrazolidinedione group, the two C–C bonds are single and the two C–O bonds double. The two nitrogen atoms in the five-membered ring are pyramidal with the attached phenyl groups lying on the opposite sides of the mean plane of the ring. The phenylbutazone molecule in (II) exists as a negative ion owing to deprotonation of C-4. C-4 is therefore trigonal and the orientation of the Bu group with respect to the pyrazolidinedione group is considerably different from that in (I); there is also considerable electron delocalization along the C–O and C–C bonds. These changes in geometry and electronic structure may relate to biological activity. The doubly charged cationic piperazine molecule exists in the chair form with the nitrogen atoms at the apices. The crystal structure of (II) is stabilized by ionic interactions and N–H O hydrogen bonds.
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Synthesis of 5, 5-dimethyl- 7-methoxy-4 -oxatricyclo[4,3,1,0(3,7)]- decan-2-one 3a, a novel heterocyclic ring system present in morellin 1, and its 3-substituted derivatives 3b-e, is described from the Diels-Alder adducts 7, available from 1-methoxycyclohexa-1,4-dienes 4. Two routes, which involved the halocyclisation and the oxidative addition, were investigated for the conversion of the adducts 7 into 3. While the halocyclisation method resulted in mixtures, excellent yields of the target molecule were obtained by the second method. Solvolysis of the bromoether 9 resulted in a mixture of rearranged products 10, 13, 15 and 16.
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In the title compound, C17H18N2O2S, the 1,3-diazinane-2-thione ring system is not coplanar with the benzene ring and methoxyphenyl ring system, the dihedral angle between the planes being 65.58 (13) and 89.18 (10)degrees, respectively. The crystal structure is characterized by intermolecular O-H...S, N-H...S, N-H...O and C-H...S hydrogen bonding.
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The title compound, C(18)H(16)ClN(3)S, adopts an extended molecular structure. The thiazole ring is inclined by 9.2 (1) and 15.3 (1)degrees with respect to the chlorophenyl and 4-(dimethylamino)phenyl rings, respectively, while the benzene ring planes make an angle of 19.0 (1)degrees. A weak intermolecular C-H center dot center dot center dot pi contact is observed in the crystal structure.
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】目的: 研究4'- 乙酰胺苯基4- 胍基苯甲酸酯(AGB)抗 HIV-1 活性及作用靶点。方法: 通过 AGB对宿主细胞的毒性实验、合胞体抑制实验、融合阻断实验、对HIV-1感染细胞的保护作用实 验和对HIV-1急性感染细胞p24抗原产生的抑制作用等试验,观察AGB对HIV-1复制的影响和作 关键词: AGB; HIV-1; 病毒进入; 杀微生物剂; 杀精子活性 中图分类号: R967; 文献标识码: A 文章编号: 0253-357X(2005)11-0660-05 本研究为国家高技术研究发展计划(2003AA219142)、国 家科技攻关计划 (2004BA719A14)、中国科学院知识创新 工程重要方向(KSCX2-SW-216; KSCX12-SW-11)、云南 省科技攻关计划(2004NG12)和云南省生育调节与少数民 族优生研究重点实验室资助项目 通讯作者: 郑永唐; Tel: +86-871-5195684; Fax:+86-871-5191823; E-mail: zhengyt@mail.kiz.ac.cn 在我国, 人免疫缺陷病毒(human immunodeficiency virus, HIV)危害日趋严重,处在全国低流行 与局部地区及特定人群高流行并存的态势。卫生部 的数据显示,截止2005 年3 月底,全国累计报告 HIV 感染者114 703 例。专家估计我国实际HIV 感 染者超过100 万人。预计到2010 年, 全国HIV感染 者将突破千万。截止2004 年底, 云南省累计报告的 HIV 感染者已达28 391 人, 是全国流行最严重的地 区。艾滋病流行正由高危人群向一般人群传播。 新的证据显示近年来由性传播途径感染的比例有所 上升, 女性感染者的比例有较大幅度的上升, 迫切需 要发展一种女性可自主控制的方法 [1]。杀微生物剂 是可以局部用药于阴道和宫颈、能够杀灭或抑制 包括HIV等病毒性和细菌性病原体、人工合成或天 然的药物。具有避孕作用的杀微生物剂更是近年 来的研究热点,也具有广阔的应用前景[2,3]。 顶体酶是存在于精子顶体内的一种类胰蛋白 酶, 它是受精过程中的一种重要的蛋白水解酶, 此酶 能水解卵细胞的透明带, 使精子能够与卵细胞相融 合; 顶体酶还能促进生殖系统中激肽的释放, 后者能 够增强精子的活力和促进精子的运动, 顶体酶的失 活将导致不孕[4]。AGB(4'- 乙酰胺苯基 4- 胍基苯甲 酸酯)是顶体酶的抑制剂, 实验表明在多种动物中有 很好的杀精子作用[5-7]。Bourimbaiar等[8]曾报道AGB 还具有体外抗HIV-1的作用, 活性较N-9高, 且毒性 较小。在本实验中, 我们发现AGB 的体外抗HIV-1 活性主要是阻断HIV-1 进入细胞。 用机制。结果: AGB抑制HIV-1IIIB诱导C8166细胞形成合胞体, EC50为39.5 μg/ml; 抑制HIV-1感染 细胞上清中HIV-1 p24抗原的表达, EC50为33.36 μg/ml; 阻断HIV-1慢性感染H9细胞与正常C8166 细胞间融合的作用。结论: AGB具有阻断HIV-1 进入宿主细胞的作用,是一种有前景的具杀精子 作用的杀微生物剂。
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High-quality Ge film was epitaxially grown on silicon on insulator using the ultrahigh vacuum chemical vapor deposition. In this paper, we demonstrated that the efficient 1 4 germanium-on-silicon p-i-n photodetector arrays with 1.0 mu m Ge film had a responsivity as high as 0.65 A/W at 1.31 mu m and 0.32 A/W at 1.55 mu m, respectively. The dark current density was about 0.75 mA/cm(2) at 0 V and 13.9 mA/cm(2) at 1.0 V reverse bias. The detectors with a diameter of 25 mu m were measured at 1550 nm incident light under 0 V bias, and the result showed that the 3-dB bandwidth is 2.48 GHz. At a reverse bias of 3 V, the bandwidth is about 13.3 GHz. The four devices showed a good consistency.
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A series of sulfonated polyimides (SPIs) were synthesized in in-cresol from 4,4'-binaphthyl- 1,11,8,8'-tetracarboxylic dianhydride (BNTDA), 4.4'-diaminodiphenylether-2,2-disulfonicacid (ODADS), and 4.4'-diamino-diphenyl ether (ODA) in the presence of triethylamine and benzoic acid. The resulted polyimides showed much better water resistance than the corresponding sulfonated polyimides from 1,4,5,8-naphthatenetetracarboxylic dianhydride (NTDA) and ODADS, which is contributed to the higher electron density in the carbonyl carbon atoms of BNTDA. Copolyimides S-75 and S-50 maintained their mechanical properties and proton conductivities after aging in water at 100 degrees C for 800 h. The proton conductivity of these SPIs was 0.0250-0.3565 S/cm at 20 degrees C and 100% relative humidity (RH), and increased to 0.11490.9470 S/cm at 80 degrees C and 100% RH. The methanol permeability values of these SPIs were in the range of 0.99-2.36 x 10(-7) cm(2)/S, which are much lower than that of Nafion 117 (2 x 10(-6) cm(2)/s).
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Four new iridium(III) complexes 1-4, with 1,3,4-oxadiazole derivative as cyclometalated ligand for the first time, have been synthesized and structurally characterized by NMR, EA, MS and X-ray diffraction analysis (except 1). The stronger ligand field strength of the dithiolate ancillary ligands results in higher oxidation potentials and lower HOMO energy levels of complexes than acetylacetone. The absorption spectra of these complexes display low-energy metal-to-ligand charge transfer transition ranging from 350 to 500 nm. Complexes with dithiolate ancillary ligand emit at maximum wavelengths of ca. 500 nm, blue shifting 17 and 11 nm with respect to their counterpart with acetylacetone ligand. The electrophosphorescent devices with 2-4 as phosphorescent dopant in emitting layer have been fabricated. All devices have a low turn-on voltage in the range of 4.5 and 4.9 V. A high-efficiency green emission with maximum luminous efficiency of 5.28 cd/A at current density of 1.37 mA/cm(2) and a maximum brightness of 2592 cd/m(2) at 15.2 V has been achieved in device using 2 as emitter.
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Heterogeneous immobilized ionic liquid catalysts were prepared via grafting of 1,3-dimethyl-3-(3-triethoxysilylpropyl)-imidazolium tetrafluoroborate or bist{(trifluoromethyl)sulfonyl} imide ([NTf2](-)) on silica supports with different surfaces and pore size. In addition to the adsorption-desorption isotherms of nitrogen at -196C, the catalysts were characterized by TG-DTA, XPS, DRIFTS, DR-UV-vis, NMR, and XRD techniques. The catalytic behavior was checked in the acylation of three different sulfonamines: benzenesulfonamine, p-nitrobenzene-sulfonamine, and p-methoxybenzene-sulfonamine with acetic acid, acetic anhydride and maleic anhydride. These tests confirmed the acid Lewis properties of these catalysts. (c) 2007 Elsevier B.V. All rights reserved.
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The night-time atmospheric chemistry of the biogenic volatile organic compounds (Z)-hex-4-en-1-ol, (Z)-hex-3-en-1-ol ('leaf alcohol'), (E)-hex-3-en-1-ol, (Z)-hex-2-en-1-ol and (E)-hex-2-en-1-ol, has been studied at room temperature. Rate coefficients for reactions of the nitrate radical (NO3) with these stress-induced plant emissions were measured using the discharge-flow technique. We employed off-axis continuous-wave cavity-enhanced absorption spectroscopy (CEAS) for the detection of NO3, which enabled us to work in excess of the hexenol compounds over NO3. The rate coefficients determined were (2.93 +/- 0.58) x 10(-13) cm(3) molecule(-1) s(-1), (2.67 +/- 0.42) x 10(-13) cm(3) molecule(-1) s(-1), (4.43 +/- 0.91) x 10(-13) cm(3) molecule(-1) s(-1), (1.56 +/- 0.24) x 10(-13) cm(3) molecule(-1) s(-1), and (1.30 +/- 0.24) x 10(-13) cm(3) molecule(-1) s(-1) for (Z)-hex-4-en-1-ol, (Z)-hex-3en-1-ol, (E)-hex-3-en-1-ol, (Z)-hex-2-en-1-ol and (E)-hex-2-en-1-ol. The rate coefficient for the reaction of NO3 with (Z)-hex-3-en-1-ol agrees with the single published determination of the rate coefficient using a relative method. The other rate coefficients have not been measured before and are compared to estimated values. Relative-rate studies were also performed, but required modification of the standard technique because N2O5 (used as the source of NO3) itself reacts with the hexenols. We used varying excesses of NO2 to determine simultaneously rate coefficients for reactions of NO3 and N2O5 with (E)-hex-3-en-1-ol of (5.2 +/- 1.8) x 10(-13) cm(3) molecule(-1) s(-1) and (3.1 +/- 2.3) x 10(-18) cm(3) molecule(-1) s(-1). Our new determinations suggest atmospheric lifetimes with respect to NO3-initiated oxidation of roughly 1-4 h for the hexenols, comparable with lifetimes estimated for the atmospheric degradation by OH and shorter lifetimes than for attack by O-3. Recent measurements of [N2O5] suggest that the gas-phase reactions of N2O5 with unsaturated alcohols will not be of importance under usual atmospheric conditions, but they certainly can be in laboratory systems when determining rate coefficients.
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The quadridentate N-heterocyclic ligand 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin- 3-yl)-2,2′ : 6′,2′′-terpyridine (CyMe4-hemi-BTBP) has been synthesized and its interactions with Am(III),U(VI), Ln(III) and some transition metal cations have been evaluated by X-ray crystallographic analysis, Am(III)/Eu(III) solvent extraction experiments, UVabsorption spectrophotometry, NMR studies and ESI-MS. Structures of 1 : 1 complexes with Eu(III), Ce(III) and the linear uranyl (UO2 2+) ion were obtained by X-ray crystallographic analysis, and they showed similar coordination behavior to related BTBP complexes. In methanol, the stability constants of the Ln(III) complexes are slightly lower than those of the analogous quadridentate bis-triazine BTBP ligands, while the stability constant for the Yb(III)complex is higher. 1H NMR titrations and ESI-MS with lanthanide nitrates showed that the ligand forms only 1 : 1 complexes with Eu(III), Ce(III) and Yb(III), while both 1 : 1 and 1 : 2 complexes were formed with La(III) and Y(III) in acetonitrile. A mixture of isomeric chiral 2 : 2 helical complexes was formed with Cu(I), with a slight preference (1.4 : 1) for a single directional isomer. In contrast, a 1 : 1 complex was observed with the larger Ag(I) ion. The ligand was unable to extract Am(III) or Eu(III) from nitric acid solutions into 1-octanol, except in the presence of a synergist at low acidity. The results show that the presence of two outer 1,2,4-triazine rings is required for the efficient extraction and separation of An(III)from Ln(III) by quadridentate N-donor ligands.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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OBJETIVO: Elaborar uma bateria de provas que se propõe a avaliar o processamento de habilidades necessárias para a aquisição do sistema de escrita alfabético do Português do Brasil, e caracterizar e comparar o desempenho dos escolares de 1ª a 4ª série do ensino fundamental nas provas desta bateria. MÉTODOS: Foram elaboradas provas específicas para este fim, seguindo os princípios fonológicos da língua portuguesa do Brasil. Foram avaliados 120 escolares de 1ª a 4ª séries, sendo 30 de cada série escolar divididos em quatro grupos, respectivamente GI, GII, GIII e GIV. As provas elaboradas e aplicadas foram: prova de habilidades metafonológicas (identificação e manipulação de sílabas e fonemas, além de repetição de não-palavras); prova de leitura (leitura de palavras reais e de pseudopalavras). RESULTADOS: Houve diferenças estatisticamente significantes entre os grupos nas habilidades metafonológicas com as médias diminuindo da 1ª à 4ª série sucessivamente. Também houve diferenças quanto ao tempo de leitura de palavras reais e de pseudopalavras, com as médias diminuindo da 1ª à 3ª série, mantendo-se igual ou próximo entre esta e a 4ª série. CONCLUSÃO: Os desempenhos foram se tornando superiores da 1ª à 4ª série, sendo que os escolares obtiveram desempenhos superiores nas provas de identificação em relação às provas de manipulação, assim como os desempenhos nas provas silábicas foram superiores aos das provas fonêmicas. Há uma prevalência da rota fonológica nas séries iniciais (1ª e 2ª) com as outras séries, especialmente a 4ª, usando mais a rota lexical.
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The synthesis, characterization and thermal analysis of the novel cyclometallated compounds [Pd-2(dmba)(2)Cl-2(mu-bpe)] (1), [Pd-2(dmba)(2)(N-3)(2)(mu-bpe)] (2), [Pd-2(dmba)(2)(NCO)(2)(mu-bpe)] (3), [Pd-2(dmba)(2)(SCN)(2)(mu-bpe)] (4), [Pd-2(dmba)(2)(NO3)(2)(mu-bpe)] (5) (bpe=trans-1,2-bis(4-pyridyl)ethylene; dmba=N,N-dimethylbenzylamine) are described. The thermal stability of [Pd-2(dmba)(2)X-2(mu-bpe)] complexes varies in the sequence 1 > 4 > 3 > 2 > 5. The final residues of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.