Zeolite encapsulated complexes of ruthenium: synthesis, characterisation and catalytic activity studies

The work presented in this thesis is mainly centered on the synthesis and characterization of some encapsulated transition metal complexes and the catalytic activity of the synthesized complexes in certain organic reactions.thesis deals with the catalytic activity of ruthenium-exchanged zeolite and the zeolite encapsulated complexes of SSC, SOD, SPD, AA, ABA, DMG, PCO, PCP, CPO and CPP in the hydroxylation of phenol using hydrogen peroxide. The products were analyzed with a GC to determine the percentage conversion and the chromatograms indicate the presence of different products like hydroquinone, catechol,benzoquinone, benzophenone etc. The major product formed is hydroquinone. From the screening studies, RuYSSC was found to be the most effective catalyst for phenol hydroxylation with 94.4% conversion and 76% hydroquinone selectivity. The influence of different factors like reaction time, temperature, amount of catalyst, effect of various solvents and oxidant to substrate ratio in the catalytic activity were studied in order to find out the optimum conditions for the hydroxylation reaction. The influence of time on the percentage conversion of phenol was studied by conducting the reactions for different durations varying from one hour to four hours. There is an induction period for all the complexes and the length of the induction period depends on the nature of the active components. Though the conversion of phenol and selectivity for hydroquinone. increases with time, the amount of benzoquinone formed decreases with time. This is probably due to the decomposition of benzoquinone formed during the initial stages of the reaction into other degradation products like benzophenones. The effect of temperature was studied by carrying out the reaction at three different temperatures, 30°C, 50°C and 70°C. Reactions carried at temperatures higher than 70°C result either in the decomposition of the products or in the formation of tarry products. Activity increased with increase in the amount of the catalyst up to a certain level. However further increase in the weight of the catalyst did not have any noticeable effect on the percentage conversion. The catalytic studies indicate that the oxidation reaction increases with increase in the volume of hydrogen peroxide till a certain volume. But further increase in the volume of H202 is detrimental as some dark mass is obtained after four hours of reaction. The catalytic activity is largely dependent on the nature of the solvent and maximum percentage conversion occurred when the solvent used is water. The intactness of the complexes within the zeolite cages enhances their possibility of recycling and the activities of the recycled catalysts show only a slight decrease when compared to the fresh samples .

Mercurous dimethylglyoximato nitrate, Hg-2(Dmg)(2)(NO3)(2)

Colourless needles of mercurous dimethylglyoximato nitrate, Hg-2(Dmg)(2)(NO3)(2), grow from a diluted nitric acid solution of mercurous nitrate and dimethylglyoxime. The crystal structure (triclinic, P (1) over bar, a = 728.50(13), b = 1066.8(2), c = 1167.9(2) pm, alpha = 93.78(2)degrees, beta = 94.16(2)degrees, gamma = 98.61(2)degrees, R-all = 0,0726) contains the cations [Hg-2(Dmg)(2)](2+) and

Formation of out of plane oxime metallacycles in [Cu(2)] and [Cu(4)] complexes

The reaction Of Cu(ClO(4))(2)center dot 6H(2)O with dimethylglyoxime (H(2)dmg) in a 1:1 mole ratio in aqueous methanol at room temperature affords the dinuclear complex [Cu(2)(mu-Hdmg)(4)] (1). Reaction of 1 with [Cu(bpy)(H(2)O)(2)](ClO(4))(2) (bpy = 2,2`-bipyridine) in a 1:1 mole ratio in aqueous methanol at room temperature yields the tetranuclear complex [Cu(2)(mu-HdMg)(2)(mu-dMg)(2)(bpy)(2)(H(2)O)(2)](ClO(4))(2) (2). The direct reaction of Cu(ClO(4))(2)center dot 6H(2)O with H(2)dmg and bpy in a 2:21 mole ratio in aqueous methanol at room temperature also yields 2 quantitatively. The complexes 1 and 2 were structurally characterized by X-ray crystallography. Unlike the binding in Ni/Co-dmg, two different types of N-O bridging modes during the oxime based metallacycle formation and stacking of square planar units have been identified in these complexes. The neutral dinuclear complex 1 has CuN(4)O coordination spheres and complex 2 consists of a dicationic [Cu(2)(mu-HdMg)(2)(mu-dMg)(2)(bpy)(2)(H(2)O)(2)](2+) unit and two uncoordinated ClO(4)(-) anions having CuN(4)O and CuN(2)O(3) coordination spheres. The two copper(II) ions are at a distance of 3.846(8) angstrom in 1 for the trans out of plane link and at 3.419(10) and 3.684(10) angstrom in 2 for the trans out of plane and cis in plane arrangements, respectively. The average Cu-N(oxime) distances are 1.953 and 1.935 angstrom, respectively. The average basal and apical Cu-N(oxime) distances are 1.945, 2.295 and 2.429 angstrom. The UV-Vis spectra of 2 is similar to the spectrum of the reaction mixture of 1 and [Cu(bpy)(H(2)O)(2)](2+). Variable temperature magnetic properties measurement shows that the interaction between the paramagnetic copper centers in complex I is antiferromagnetic in nature. The EPR spectra of frozen solution of the complexes at 77 K consist of axially symmetric fine-structure transitions (Delta M(S) = 1) and half-field signals (Delta M(S) = 2) at ca. 1600 G, suggesting the presence of appreciable Cu-Cu interactions. (C) 2009 Elsevier Ltd. All rights reserved.

Determination of nickel in fuel ethanol using a carbon paste modified electrode containing dimethylglyoxime

A mercury-free electrode chemically modified with carbon paste containing dimethylglyoxime was used for determination of nickel in fuel ethanol. The instrumental parameters and composition of the modified paste were optimized. The analytical curve for nickel determination from 5.0 x 10(-9) to 5.0 x10(-7) mol(-1) was obtained using 25 min of accumulation time. The detection limit and amperometric sensitivity obtained for this method were 2.7 x 10 mol(-1) and 5.2 x 10(8) mu A mol(-1) L, respectively. The values for nickel concentration in four commercial samples of fuel ethanol were obtained in the range of 1.1 x 10(-8) to 6.9 x 10(-8) mol(-1). A comparison to graphite furnace atomic absorption spectrometry (GFAAS) was performed for nickel determination in commercial samples of ethanol.

Atividade física na gestação: aplicabilidade de um questionário específico para gestantes (PPAQ) e sua associação com Diabete Melito Gestacional (DMG), sobrepeso/obesidade

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

Avaliação dos protocolos de diagnóstico e de controle da hiperglicemia materna: impacto na prevalência de Diabetes Melito Gestacional (DMG) e de Hiperglicemia Gestacional Leve (HGL) e nos resultados perinatais

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

DMG-Lib - The Digital Mechanism and Gear Library

Motion systems are important parts of technical products. Those are mostly composed of mechanisms and gears. Today mechanism and gear technology is essential for the whole industry and it will become even more important due to the introduction of new technologies and respective new fields of applications.

Low ML-Decoding Complexity, Large Coding Gain, Full-Rate, Full-Diversity STBCs for 2 x 2 and 4 x 2 MIMO Systems

This paper deals with low maximum-likelihood (ML)-decoding complexity, full-rate and full-diversity space-time block codes (STBCs), which also offer large coding gain, for the 2 transmit antenna, 2 receive antenna (2 x 2) and the 4 transmit antenna, 2 receive antenna (4 x 2) MIMO systems. Presently, the best known STBC for the 2 2 system is the Golden code and that for the 4 x 2 system is the DjABBA code. Following the approach by Biglieri, Hong, and Viterbo, a new STBC is presented in this paper for the 2 x 2 system. This code matches the Golden code in performance and ML-decoding complexity for square QAM constellations while it has lower ML-decoding complexity with the same performance for non-rectangular QAM constellations. This code is also shown to be information-lossless and diversity-multiplexing gain (DMG) tradeoff optimal. This design procedure is then extended to the 4 x 2 system and a code, which outperforms the DjABBA code for QAM constellations with lower ML-decoding complexity, is presented. So far, the Golden code has been reported to have an ML-decoding complexity of the order of for square QAM of size. In this paper, a scheme that reduces its ML-decoding complexity to M-2 root M is presented.

Attaching chelating ligands to polybenzimidazole via epoxidation to obtain metal selective sorbents

Microporous polybenzimidazole of 250–500 μm spherical bead size from Celanese has been reacted with epichlorohydrin and sodium hydroxide and the resulting product with pendant epoxy groups has been reacted with various chelating ligands in order to augment the metal sorption capacity and selectivity of the resin. The chelating ligands used include ethylenediamine, diethylenetriamine, diethanolamine, dimethylglyoxime, L-cysteine, thiourea, dithiooxamide, glyoxal-bis-2-hydroxyanil, salicylaldehyde-ethylenediimine, and glyoxal-bis-2-mercaptoanil. The aminolysis of the pendant epoxy groups with the oligoamines has been performed in pyridine under reflux conditions, while the addition reactions with the other ligands which are alkali soluble have been carried out at room temperature in a mixture of dioxane and aqueous KOH using tetra-n-butylammonium iodide as the phase transfer catalyst. The products are found to possess high capacity and selectivity in metal sorption depending on the ligand attached.

Achieving the D-MG and DMD Tradeoffs of MIMO fading channels

An overview of our recent results relating to the explicit construction of space-time block codes achieving the DMG tradeoff of the quasi-static fading channel is presented. The results include the explicit construction of D-MG optimal codes,generalization of perfect codes to any number of transmit antennas as well as optimal diversity-multiplexing-delay constructions for the MIMO ARQ Channel.

Alterações histopatológicas pancreáticas, placentárias e na matriz extracelular hipofisária durante a diabetes mellitus gestacional

A Diabetes Mellitus Gestacional (DMG) pode ser definida como intolerância a carboidrato durante a gravidez e estima-se que pode afetar 10-22% de todas as pacientes grávidas. Durante a gravidez podem surgir diversas complicações para o feto como risco elevado de aborto espontâneo, anormalidades congênitas e morbidade e mortalidade neonatal. Entretanto, podem surgir também alterações morfofuncionais em diversos órgãos da mãe diabética, porém isso não é bem estabelecido. Investigar se haverá ou não alterações bioquímicas e histopatológicas em diversos órgãos, como hipófise, útero, placenta e pâncreas de ratas grávidas com diabetes mellitus durante e no final da gravidez e compará-las . Além disso, investigar se há alteração na matriz extracelular (MEC) da hipófise desses animais. No 5 dia de vida, ratas Wistar foram divididas em dois grupos: um tratado com estreptozotocina (Grupo Diabético / DIAB), na dose de 90 mg/kg, subcutâneo e outro grupo, que foi tratado com veículo (tampão citrato/CTR). Aos 90 dias de vidas, foram submetidas ao cruzamento. Após isso, foram sacrificadas no 11 e 21 dia de gravidez. Foram avaliados glicemia e bioquímica maternal e número de implantes .O pâncreas, útero, placenta e hipófises foram coradas com Hematoxilina e Eosina e somente as hipófises foram coradas com Massom e Picrosirius, para avaliação da MEC.Os animais diabéticos tanto do 11 quanto do 21 dia apresentaram uma redução no número de implantes, menor peso e maior glicemia e colesterol total, em relação aos animais controle independente do dia da gravidez. Não foi verificada diferença dos níveis de triglicerídeos entre os grupos não diabéticos e diabéticos, independente dos dias. Entretanto, os animais diabéticos que finalizaram o período de gestação apresentaram uma maior glicemia maternal em relação ao grupo diabético do 11 dia. Pâncreas de ratas diabéticas do 21 dia apresentaram vacuolização intracitoplasmática das ilhotas, insulite,migração de células inflamatórias, espessamento da parede do vaso e fibrose periductal e vascular. Essas alterações foram verificadas com bem menor intensidade nos animais diabéticos do 11 dia. Foi verificado que a placenta de animais diabéticos apresenta congestão na interface materno-fetal, migração celular, maior concentração de vasos maternos e fetais, mas em forma irregular , necrose e vacuolização. A hipófise de animais diabéticos mostraram células cromófobas agregadas, aumento da espessura de fibras de colágeno vermelhas da MEC, em contraste com o controle, que foi visualizado fibras em verde e em formato de feixe. A diabetes desempenhou um total remodelamento da hipófise. Gravidez de animais diabeticos mostraram maior dano ao pâncreas e placenta, especialmente no final da gravidez. Em consequência dessa alterações, esses animais diabéticos apresentaram hiperglicemia, maior colesterol total, porém menor peso materno, número de implantes e sem alterações nos triglicerídeos. Esse é o primeiro estudo a demonstrar remodelamento tecidual em alguns elementos da MEC na hipófise, como espessamento da camada da MEC e fibras de colágeno em verde. Alterações da MEC da hipófise são provavelmente devido ao processo de diabetes na gestação.

现代NMR技术在生物医学中的应用－－稀土对大鼠代谢产物的影响及磁共振造影剂性质的研究

近年来，随着脉冲傅里叶变换核磁共振波谱仪灵敏度的提高及计算机技术的进步，使NMR技术在生物领域的应用有了飞速的发展。论文应用NMR技术研究了稀土化合物（硝酸镧）对大鼠体内代谢产物的影响。对Wistar种大鼠按不同剂量给药（灌胃和腹腔注射两种方式）后的尿液和血清中的代谢物质的~1H NMR谱数据进行研究，并结合血清、尿液中生化指标的检测结果，指出稀土作用后大鼠肾脏的肾小管及肝脏线粒体均受到一定程度的损害，随稀土摄入量的增多，损害程度越严重。并提出代谢物中尿素、Suc、Kg、Cit、DMA、DMG、TMAO和氨基酸等可以作为肾脏受损伤的NMR markers，而乙醇、Lac和Tau可作为肝脏受损伤的NMR markers。实验中最小剂量为0.05 mg La(NO_3)_3/kg体重，仍有机体受损的NMR信号，说明稀土的安全剂量小于这一数值。在临床磁共振成像中，造影剂是医学诊断中的一种重要辅助试剂。本文采用NMR水弛豫分析法研究了GdDTPA及Gd(cycle-DTPA-1,2-PN)、Gd(DTPA－BIN)在水溶液和BSA溶液中的弛豫性质，为研究顺磁性金属配合物与蛋白质间相互作用情况提供了有效方法；对配体cycle-DTPA-1,2-pn、DTPA－BIN做了~1H NMR滴定研究，得出其质子解离过程和解离常数，并采用半经验量化计算方法计算了两种配体的质子化过程，得到了与~1H NMR滴定一致的结果。结果表明将NMR实验和量化计算方法结合，是考察复杂配体热力学稳定性的有效方法。

Evaluation of bioeffects of a long-term administering ChangLe on rat by proton NMR method and biochemical examination

High resolution H-1 nuclear magnetic resonance ( NMR) spectroscopy has been employed to assess long-term toxicological effects of ChangLe (a kind of rare earth complex applied in agriculture). Male Wistar rats were administrated orally with ChangLe at doses of 0, 0.1, 0.2, 2.0, 10 and 20 mg/kg body weight daily, respectively, for 6 months. Urine was collected at-day 30, 60, go and serum samples were taken after 6 months. Many low-molecular weight metabolites were identified by H-1 NMR spectra of rat urine. A decrease in citrate and an increase in ketone bodies, creatinine, DMA, DMG, TMAO, and taurine in the urine of the rats. receiving high doses were found by H-1 NMR spectra. These may mean that high-dosage of ChangLe impairs the specific region of liver and kidney, such as renal tubule and mitochondria. The decrease in citrate and the increase in succinate and alpha-ketoglutarate were attributed to a combination of the inhibition of certain citric acid enzymes, renal tubular acidosis and the abnormal fatty acid catabolism. The information of the renal capillary necrosis could be derived from the increase in DMIA, DMG and TMAO. The increase in taurine was due to hepatic mitochondria dysfunction. The conclusions were supported by the results of biochemical measure. merits and enzymatic assay.

Nuclear magnetic resonance studies on the effects of Rare Earth in rats urine

Male Wistar rats were administrated orally with La(NO3)(3) at doses of 0. 05, 0. 2, 2. 0, 10 and 20 mg/kg body weight. Urine was collected over a 24 h period after dosing. Resonances for a large number of low molecular weight metabolites were assigned in a high resolution H-1 NMR spectra of rat urine. The variation of some low molecular weight metabolites in urine provided a sensitive measurement of Rare Earth induced renal and liver lesions, in which DMA, DMG, urea, Kg, TMAO, succinate, citrate and amino acids have been suggested as NMR markers for renal damage and ethanol, lactate, taurine as the markers for liver damage. The method could be applicable to study of the toxicological effects of other compounds and drugs.

ADVANCED ELECTROANALYTICAL CHEMISTRY IN CHINA .1. GENERAL ASPECT AND SOME METHODOLOGIES

The Research on Electroanalytical chemistry in China started mainly from the beginning of new China in 1949. It has already good basis and development nowadays. A review with references to the end of seventies has been published in "Reviews in Analytical Chemistry" 1) and in a book titled "Fifty years of Chinese Chemistry" edited by the Chinese Chemical Society in 1985 2). Since then more than thousand papers have been published, and it is impossible and also not necessary to describe all of them. This review only deals with the main progress of electroanalytical chemistry in China in recent years. Some new developed methodologies will be reviewed by S. Dong in the next article.