Orientador: Rogério Custodio / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-23T02:21:16Z (GMT). No. of bitstreams: 1 Rocha_CarlosMuriloRomero_M.pdf: 3181887 bytes, checksum: 92221d4d84e390412b4bdcfb0ae7e206 (MD5) Previous issue date: 2013 / Resumo: No presente trabalho o pseudopotencial CEP foi implementado na teoria G3(MP2)B3 e a adaptação denominada G3CEP(MP2)B3. Tal método foi aplicado no estudo de 247 entalpias padrão de formação, 104 energias de ionização, 63 afinidades eletrônicas, 10 afinidades protônicas e 22 energias de atomização de um conjunto de moléculas contendo elementos representativos do 2º, 3º e 4º períodos da tabela periódica, totalizando 446 dados termoquímicos. Os desvios absolutos médios, em relação aos dados experimentais, foram 1,60 kcal mol e 1,41 kcal mol para as teorias G3CEP(MP2)B3 e G3(MP2)B3, respectivamente, com reduções de 10-40% nos tempos de CPU com a implementação do pseudopotencial CEP. Além disso, a avaliação de outras propriedades tais como cargas atômicas, momentos de dipolo e energias de orbitais HOMO resultou em desvios absolutos médios, em relação ao método G3(MP2)B3 original, de 0,203 e, 0,044 D e 0,002 Eh, respectivamente. Outro objetivo do presente trabalho foi a aplicação do método G3CEP(MP2)B3 no estudo do mecanismo de nitração do fenol, em fase gasosa, promovida pelo eletrófilo NO2 . Tal avaliação mecanística evidenciou-nos a ocorrência de transferências eletrônicas do sistema p aromático ao íon nitrônio em etapas que precedem a formação do complexo-s, resultados que são convergentes à hipótese do mecanismo SET (Single Electron Transfer). Além do mecanismo de substituição eletrofílica aromática, o presente estudo evidenciou a ocorrência, em fase gasosa, de caminhos reacionais alternativos, através dos quais a transferência da espécie O ao sistema p aromático do fenol seria observada. As excelentes concordâncias entre a teoria G3CEP(MP2)B3 e os demais métodos Gn mais acurados (como G3(MP2)B3, G3CEP e G3) na previsão de barreiras de ativação, revelou-nos interessantes perspectivas quanto à aplicabilidade da teoria G3CEP(MP2)B3 na determinação mecanística de reações orgânicas, bem como na previsão acurada de barreiras rotacionais internas, frente a reduzidos custos computacionais / Abstract: In this work, the CEP (Compact Effective Potential) pseudopotential was adapted in the G3(MP2)B3 theory providing a theoretical alternative referred to as G3CEP(MP2)B3 for calculations involving second-, third-, and fourth-row representative elements. The G3CEP(MP2) B3 theory was applied in the study of 247 standard enthalpies of formation, 104 ionization energies, 63 electron affinities, 20 proton affinities and 22 atomization energies of a test set comprising 446 experimental energies. The total mean absolute deviation was 1.60 kcal mol for G3CEP(MP2)B3 theory against 1.41 kcal mol from all-electron G3(MP2)B3 calculations, with reductions of 10-40% in CPU time for the implemented theory. Furthermore, the assessment of other properties such as atomic charges, dipole moments and highest occupied molecular orbital (HOMO) energies resulted in mean absolute deviations, compared with those predicted by the original G3(MP2)B3 theory, of 0.203 e, 0.044 D and 0.002 Eh, respectively. In addition to the adaptation and assessment of G3CEP(MP2)B3 theory, the purpose of this work was also the application of the implemented theory in the study of phenol nitration mechanism, in gaseous phase, promoted by NO2 elepctrophile. The mechanistic evaluation at G3CEP(MP2)B3 level showed the occurrence of a single-electron-transfer step from aromatic p-system to the nitronium ion prior to the s-complex formation, in agreement with the SET (Single Electron Transfer) mechanism. Besides electrophilic aromatic substitution reaction, the present work provided insights into alternative reaction mechanisms through which O species are transferred to the phenol aromatic p-system. Excellent agreement between G3CEP(MP2)B3 theory and other more accurate Gn theories (for instance G3(MP2)B3, G3 and G3CEP) in predicting activation barriers showed that the implemented theory would be a useful tool in the study of reaction mechanisms and also for predicting internal rotational barriers with a significantly reduced computational cost / Mestrado / Físico-Química / Mestre em Química

Im Nitratbericht 2005 werden die Nitratuntersuchungen auf Dauertestflächen sowie die Bewertung verschiedener Einflussgrössen dargestellt.

principal dificuldade na identificação de novos biomarcadores para doenças renais consiste em encontrar marcadores que são específicos do rim ou do processo patológico em que se encontra, além de conseguir caracterizar a doença renal independente de outras doenças pré-existentes. Assim, o objetivo deste estudo foi identificar novos candidatos a biomarcadores, predominantemente renais, de lesão renal em um modelo suíno controlado unilateral de lesão renal aguda (LRA) por isquemia/reperfusão (I/R) renal percutânea. Para isto, foram feitas análises do proteoma e do nitroproteoma de amostras de urina e soro nos períodos pré-isquemia, isquemia (60min) e pós-reperfusão (4 ou 6h, 11 e 16h), e das de amostras do córtex renal após 24h de reperfusão, todas no Q-ExactiveTM. Os resultados foram analisados no MaxQuant seguidos da análise de biologia de sistemas. A seleção das proteínas candidatas a biomarcadores de lesão renal foi baseada na predominância de expressão dessas proteínas no rim através do banco TiGER e/ou Atlas Human Protein. Foram identificadas 1365 proteínas no proteoma total dos córtices renais, das quais 535 estavam presentes em pelo menos 3 animais e mais expressas no rim isquêmico, com excessão da Xaa-pró aminopeptidase 2. Estas proteínas participam dos processos de transcrição, tradução, adesão celular, proliferação e reparo, importantes para a recuperação da lesão renal após 24h. A intersecção das proteínas sub ou superexpressas no rim isquêmico com os proteomas do soro ou da urina resultou em seis proteínas séricas (VIM, HPSA8, HSPD1, COL1A1, LCP1e TPI1) entre as 170 identificadas capazes de fornecer um painel para LRA ou processo degenerativo. Enquanto na urina, foram identificadas 49 de 501 proteínas presentes na intersecção, sendo 4 predominantemente renais (BHMT2, GBA3, DDC e DPPIV). A atividade da DPPIV na urina aumentou após 4h de reperfusão retornando aos níveis basais após este período validando o nosso candidato a biomarcador. A DPPIV também foi validada em uma coorte de pacientes com nefropatia diabética que apresentou uma moderada correlação com os parâmetros ligados a disfunção renal: MDRD, proteinúria, hemoglobina glicada, PTH e renina. Apesar de não haver diferença na concentração de proteínas nitradas no rim contralateral e isquêmico houve uma diferença no perfil de proteínas encontradas. Foram identificadas 843 proteínas no nitroproteoma dos córtices renais das quais 53 estavam superexpressas no rim isquêmico e 2 no rim contralateral. Das 55 proteínas, 38% eram mitocondriais e relacionadas com as vias energéticas. Foi possível validar a nitração de duas destas proteínas, a DPPIV e a BHMT2. No nitroproteoma da urina identificou-se 126 proteínas das quais 27 se agruparam de forma diferente para cada período do experimento baseado no comportamento da expressão proteica. A excreção de proteínas nitradas também foi observada no tempo basal, supondo um papel fisiológico da nitração. Além disso, o perfil de excreção de proteínas nitradas ao longo da I/R foi independente das mudanças ocorridas no perfil proteico total. Por fim, duas proteínas se destacaram como candidatas a biomarcador, a UMOD e a ALDOB. Já, o nitroproteoma sérico resultou em 55 proteínas, das quais as 33 mais representativas dos animais foram capazes de separar o período antes e após a reperfusão renal. Duas destas proteínas foram consideradas candidatas a biomarcadores de lesão renal, a SEMG2 e a DMGDH, esta última foi validada. A partir dos resultados gerados, foi possível identificar alterações proteicas ao longo da I/R renal, novas proteínas nitradas e novos candidatos a biomarcador de lesão renal. Novos estudos com uma abordagem mais direcionada e aprofundada devem ser desenvolvidos, tanto para confirmar os candidatos a biomarcadores e seu potencial uso clínico, quanto para analisar o comportamento fisiopatológico e bioquímico das proteínas com e sem nitração na LRA por I/R renal em rins morfo-fisiologicamente semelhantes aos encontrados em humanos / The main bottleneck in studies aiming to identify novel biomarkers in kidney disease has been the identification of markers that are organ and process specific and characterize the kidney disease regarding other other pre-existing diseases. The aim of this study was to identify new candidates, predominantly renal, that could be used as systemic biomarkes for acute kidney disease (AKI) in a unilateral percutaneous controlled porcine renal ischemia/reperfusion (I/R) model. The nitroproteome and proteome of urine and serum samples were analyzed in Q-ExactiveTM on the period pre-ischemia, ischemia (60 min) and 4, 11 and 16 h post-reperfusion. The renal cortex samples were analyzed only after 24 h of reperfusion. The results were analyzed in the MaxQuant followed by systems biology analysis. The selection of candidate proteins for renal injury was based on the predominance of expression of these proteins in the kidney through TiGER and Atlas Human Protein. In renal cortex proteome, it was identified 1365 proteins which 535 were present at least 3 animals and more expressed in ischemic kidney, with exception of Xaa-pro aminopeptidase 2. These proteins participate of transcription, translational, cellular adhesion, proliferation and repair, important for the recovery of renal injury after 24h. Intersecting the set of proteins up- or down-regulated in the ischemic tissue with both serum and urine proteomes, 6 serum proteins from 170 identified proteins (VIM, HPSA8, HSPD1, COL1A1, LCP1 and TPI1) were identified that may provide a set of targets for AKI or degenerative process. Additionally, 49 from 501 urinary proteins were identified in the intersection, being 4 predominantly renal (BHMT2, GBA3, DDC and DPPIV). As a proof of concept, the activity of DPPIV in the urine increased after 4h of reperfusion returning to baseline levels after this period and with subsequent translational validation in a cohort of patients with diabetic nephropathy who presented a moderate correlation with the parameters related to renal dysfunction: MDRD, proteinuria, glycated hemoglobin, PTH and renin Althought there was no diference between nitrated proteins levels in contralateral and ischemic kidneys, there was difference in the protein profile found. In niroproteome from cortex were identified 843 proteins, of which 53 were up-regulated in the ischemic kidney and 2 in the contralateral kidney. Of the 55 proteins, 38% were mitochondrial and related to the energy pathways. It was possible to validate the nitration of two of these proteins, DPPIV and BHMT2. In the urine nitroproteome, 126 proteins were identified, 27 of which were grouped differently for each period of the experiment based on the behavior of protein expression. The nitrated protein excretion was also observed at baseline, assuming a physiological role of nitration. In adition, the profile of urine proteins along I/R was independent of changes in the total protein profile. Finally, two proteins stood out as candidates for biomarker, UMOD and ALDOB. The serum nitroproteome resulted in 55 identified proteins, 33 were more representative from animals and they able to distinguish the periods before and after renal reperfusion. Two predominantly renal proteins, SEMG2 and DMGDH, were described as candidates to renal injury biomarkers and the last protein was validated. From these results, proteins changes were observed along the renal I/R, new nitrated proteins and new candidates for biomarkers of kidney injury were identified. New studies with a more focused and in-depth approach should be developed both to confirm the candidates for biomarkers and their potential clinical use and to analyze the pathophysiological and biochemical behavior of the proteins with and without nitration in AKI by I/R renal in kidneys morphologically and physiologically similar to those found in humans

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-08-07T20:04:03Z No. of bitstreams: 1 TUILLY DE FÁTIMA MACEDO FURTADO GUERRA – DISSERTAÇÃO (PPGECA) 2016.pdf: 2570702 bytes, checksum: dc3123f0ac79b6573767e39e1c19c4c4 (MD5) / Made available in DSpace on 2018-08-07T20:04:03Z (GMT). No. of bitstreams: 1 TUILLY DE FÁTIMA MACEDO FURTADO GUERRA – DISSERTAÇÃO (PPGECA) 2016.pdf: 2570702 bytes, checksum: dc3123f0ac79b6573767e39e1c19c4c4 (MD5) Previous issue date: 2017-03-17 / Capes / O processo Anammox essencialmente é a desnitrificação autotrófica na qual nitrogênio amoniacal é oxidado por nitrito para nitrogênio molecular. O nitrito pode ser produzido em águas residuárias pela oxidação da amônia pelas Nitrosomonas. Todavia, tem-se que evitar que as bactérias do gênero Nitrobacter se desenvolvam para evitar a oxidação do nitrito para nitrato. O processo Anammox se aplica particularmente em águas ricas em amônia e pobres em material orgânico, como por exemplo, efluentes de digestores anaeróbios. Na prática tem sido aplicado com sucesso para efluentes de digestores de lodo aquecidos a 37 °C, mas a aplicação à temperatura ambiente na Europa (5 a 15 °C) não tem sido eficiente, pela dificuldade de eliminação da etapa de nitratação. Na presente pesquisa, procurou-se estabelecer se a nitrificação parcial é factível para a faixa de temperatura de esgotos no Brasil, para uma possível aplicação do processo Anammox visando à remoção de nitrogênio dos efluentes de reatores UASB. Para tanto, foram determinadas as constantes cinéticas da nitritação e nitratação em um sistema de lodo ativado entre a faixa de temperaturas de 12,7°C a 31 °C e as constantes de meia saturação do oxigênio dissolvido. A respirometria foi a ferramenta utilizada para determinar as taxas de nitritação e de nitratação e estimar as outras constantes cinéticas relevantes, sendo mostrado pelos resultados que esta é uma ferramenta útil na determinação das constantes cinéticas. Os valores encontrados das constantes cinéticas de crescimento das nitritadoras e nitratadoras em função da temperatura mostraram uma tendência de prevalecimento da nitritação sobre a nitratação em toda a faixa avaliada. Através da determinação da idade lodo mínima para a nitritação e nitratação pode-se estimar que operando um sistema de lodo ativado a temperatura ambiente adotando uma idade de lodo de 4 dias é possível promover a nitrificação parcial. / The Anammox process is essentially autotrophic denitrification in which ammoniacal nitrogen is oxidized by nitrite to molecular nitrogen. Nitrite can be produced in wastewater by the oxidation of ammonia by Nitrosomonas. However, it has to be avoided that bacteria of the genus Nitrobacter develop to avoid the oxidation of nitrite to nitrate. The Anammox process is applied particularly in ammonium rich waters and poor in organic material, such as effluent from anaerobic digesters. In practice it has been successfully applied to effluent from sludge digesters heated to 37 ° C, but application at room temperature in Europe (5 to 15 ° C) has not been efficient due to the difficulty of eliminating the nitration step. In the present research, it was tried to establish if the partial nitrification is feasible for the range of sewage temperature in Brazil, for a possible application of the Anammox process aiming at the removal of nitrogen from UASB reactor effluents. For this, the kinetic constants of nitriding and nitration were determined in an activated sludge system between the temperature range of 12.7 ° C to 31 ° C and the half-saturation constants of the dissolved oxygen. The respirometry was the tool used to determine nitration and nitration rates and to estimate the other relevant kinetic constants, and it is shown by the results that this is a useful tool in the determination of kinetic constants. The values of the kinetic constants of the nitriding and nitrating agents as a function of temperature showed a tendency of nitriding over nitration over the entire range. By determining the age minimum sludge for nitriding and nitration it can be estimated that operating a sludge activated system at room temperature adopting a sludge age of 4 days can promote partial nitrification.

This work deals with tool steel Vanadis 6. It describes the preparation of samples for the three-point bending test, with which it examines the influence of surface roughness, the effect of nitriding, coating and duplex coatings on fracture behaviour of the steel. First, it examines bending strength and the total energy required to work of fracture. The work also includes mapping and measurement of surface roughness on different layers. This measurement is performed on a confocal microscope.

This dissertation describes the implementation of the molecular electronic structure calculations with an implicit solvent model using coupled-cluster theory. The theory for and the implementation of the solvent reaction field method (SCRF) and the reference interaction site model (RISM) at the coupled-cluster singles and doubles (CCSD) are presented. In the SCRF model a solute molecule is placed in a spherical cavity, and the outer solvent is represented by a dielectric continuum, which is characterized by the dielectric constant of the solvent. The reaction field is introduced to the system by using the multipole moment expansion of the electronic structure of the solute molecule and the dielectric constant. The SCRF method has been used to calculate the conformational equilibrium and the rotational barriers of 1,2-dichloroethane in vacuum and in different solvents. The calculated results are compared with experimental values. In addition, the solvent effects on the energetics of the mechanism of nitration of benzene are reported using the implemented CCSD-SCRF model. The idea of RISM is to replace the reaction field in continuum models by a microscopic expression in terms of the site-site radial distribution functions between solute and solvent, which can be calculated from the RISM integral equations. The statistical solvent distribution around the solute is determined based on the electronic structure of the solute, while the electronic structure of solute is influenced by the surrounding solvent distribution. Therefore, the wave function and the RISM equations are solved self-consistently with CCSD. Pair correlation functions, partial atomic charges, and solvation free energies of water and N-methylacetamide are calculated in liquid water using proposed theory. Both the CC-SCRF and CC-RISM methods have been implemented in a developmental version of the Q-Chem 3.2 quantum chemistry package.

No description available.

Reactive oxygen species (ROS) such as superoxide radical anion (O2•¯), hydroxylradical (OH•), hydrogen peroxide (H2O2) and peroxynitrite (ONOO-) that are produced during the metabolism of oxygen under oxidative stress in aerobic organisms destroy several key biomolecules and lead to a number of disease states. Mammalian systems possess several effective defense mechanisms including antioxidant enzymes to detoxify these ROS. The selenocysteine-containing Glutathione peroxidase (GPx) is particularly an efficient enzyme in the detoxification of H2O2 and other hydroperoxides by using glutathione (GSH) as cofactor. The chemistry at the active siteof GPx has been extensively investigated with the help of synthetic selenium compounds. Although the anti-inflammatory compound ebselen(2-phenyl-1,2-benzoisoselenazol-3(2H)-one) is undergoing phase III clinical trial as antioxidant, the chemistry of ebselen is still not understood. The present study on a number of ebselen derivatives with various N-substitutions reveals that the substitution at the N atom is important for the antioxidant activity. This study also suggests that the nature for thiol cofactor has a dramatic effect on the GPx activity of ebselen derivatives. It has been shown that ebselen exhibits very poor catalytic activity in the presence of aromatic thiols mainly due to strong Se….O nonbonded interactions that lead to extensive thiol exchange reactions in the selenenyl sulfide intermediate. To prevent the se….O interactions, a series of tertiary amide-based diselenides have been synthesized along with their secondary amide counterparts. Detailed structure-activity correlation studies reveal that the GPx-like activity of the sec-amide-based compounds can be significantly enhanced by the substitution at the free-NH group of sec-amide functionality. The N,N-dialkylbenzylamine-based diselenides exhibit their catalytic activities via the generation of selenols which was confirmed by the reaction with anti-arthritic gold(I) compounds. Interestingly, the replacement of the hydrogen atom at the 6th position of the benzene ring of N,N-dialkylbenzylamine-based diselenides by a methoxy group prevents the thiol exchange reactions mainly be weakening the Se…N interactions and thus enhances the GPx activity. On the other hand, the catalytic activity of the tert-amine-based diselenides can also be increased by replacing the tert-amino groups with the corresponding sec-amine moieties. It has been observed that the basic amino group in the amine-based diselenides deprotonates the selenol and also the thiol cofactor, which is crucial for the higher catalytic activities of the amine-based compounds. Peroxynitrite (PN, ONOO), a strong nitrating agent, is known to inactivate a number of proteins, enzymes and other biomolecules by nitration of tyrosine residues. In this study, we have shown that the commonly used antithyroid drugs and their analogues inhibit protein tyrosine nitration. This study reveals that antithyroid agents having PN scavenging activity may be beneficial of hyperthyroidism as these compounds may protect the thyroid gland from nitrative or nitrosative stress.

Explosive materials have always been attracting the attention of scientists. Various explosives either in pure bulk form or as admixtures are synthesized and investigated from different points of view. However, because of dangerous character of these materials, their syntheses and properties have to be forecasted by theoretical studies. The new research trends of explosive materials generally include the designs of novel derivatives of well&ndash / known explosives to improve their detonation performances (heats of explosion, detonation velocities and detonation pressures) and thermal stabilities and decrease their sensitivities towards friction, electric spark, shock and impact either experimentally or theoretically. NTO (5&ndash / nitro&ndash / 2,4&ndash / dihydro&ndash / 3H&ndash / 1,2,4&ndash / triazol&ndash / 3&ndash / one) and PATO (3&ndash / picrylamino&ndash / 1,2,4&ndash / triazole) are very important secondary explosives that take place in the literature for many years in terms of their explosive properties. In this thesis study, new species of these explosives have been designed to enhance their detonation performances (ballistic properties) and to lower their sensitivities and reactivities computationally. Additionally, aromatic nitration reactions and their mechanisms for unprotonated and protonated PATO species have been analyzed. The ab initio quantum chemistry methods, Hartree&ndash / Fock (HF) and Density Functional Theory (DFT), have been used in the calculations with Pople basis sets. Novel NTO and PATO tautomeric species have been designed and investigated to enlighten the effects of tautomerism on their quantum chemical properties and detonation performances in the gas phase. Various aromatic nitration mechanisms (carbon and nitrogen mono&ndash / nitration mechanisms) of unprotonated tautomeric PATO species as well as PATO have been designed in gas phase and the reaction states (pre&ndash / transition states, transition states, intermediates and nitration products) have been detected belonging to these mechanisms. Nitrations in solution phase have also been analyzed. The reaction states have been detected for carbon and nitrogen mono&ndash / nitrations of protonated PATO species in the gas phase. The detonation performances of unnitrated and nitrated PATO products have been presented.