HIV-1, the virus that causes AIDS, is spreading at an alarming rate. Subtype C, which accounts for approximately 50% of infections worldwide, and 98% of infections in Southern Africa, is by far the most prevalent form of the virus. Most molecular and biochemical studies have been performed on HIV-1 subtype B isolates and products, however, and there is a relative scarcity of corresponding data on subtype C. It is therefore of crucial importance to study subtype C HIV-1 strains in order to understand their characteristic pathogenic effects and to develop effective treatment strategies. The aim of research in our laboratory is the development of novel treatment strategies, with particular focus on identifying novel Subtype C Env-binding peptide ligands. This necessitates the development of reagents for use in the discovery and testing of these compounds. In line with this, the aim of this project was the production and characterisation of recombinant Subtype C gp120s generated from a recently compiled HIV-1 virus cohort. To this end, the gp160-coding regions of 20 South African Subtype C HIV-1 strains isolated from AIDS patients presenting at the Johannesburg General hospital in 2005 were amplified by PCR and sequenced. The gp160 amplicons were used to amplify and clone the gp120-encoding regions of these isolates. Two clones, pTriEx- FV3 and pTriEx-FV5, originating from CXCR4- and CCR5-utilising strains respectively, were selected for further use. These clones were cotransfected into insect cells together with a baculoviral DNA backbone in order to generate gp120-expressing baculoviruses by homologous recombination. Recombinant baculoviruses were used to infect Sf9 insect cell cultures for expression of recombinant gp120, which was then purified using a combination of lectin affinity chromatography and ion exchange chromatography. In order to determine the functionality and conformational integrity of the recombinant gp120, the ability of these purified gp120s to bind CD4 and a panel of well-characterised monoclonal antibodies against various epitopes on gp120 (F425 A1g8, 2G12, F425 B4a1, F425 B4e8, 48d, 17b, IgG1 b12, 5F7, 4G10, 9301, ID6, Chessie 13-39.1, 654-30D and 670-30D) was assessed. Gp120 from the CXCR4-using isolate, FV3, appeared to have an intact, functional CD4 binding site as measured by its ability to bind to CD4 and the CD4 binding site antibody 654-30D. It showed low binding to the monoclonal antibody 654- 30D, moderate binding to 2G12, Chessie 13-39.1 and 9301, and high binding to ID6, but did not show binding to any of the other antibodies used in the recognition profile. Gp120 from the CCR5-using isolate, FV5, showed low binding to the monoclonal antibodies F425 B4a1 and Chessie 13-39.1, moderate binding to 2G12, and showed good binding to 9301and ID6. FV5 gp120 could not, however, bind to CD4. This is likely to be related to a D368G substitution, a mutation affecting a critical structural determinant of CD4 binding. The lack of CD4-binding activity of this gp120 highlights the importance of Asp368 for CD4 binding and hints at a region vulnerable for therapeutic targeting. Our results also highlight the challenges of developing broadly therapeutic drugs for HIV-1, as well as the importance of investigating the specific biochemical and pathogenic properties associated with subtype C HIV-1.

Five pyrimidine C-nucleosides were prepared via Heck-type coupling reactions. These derivatives are designed to mimic dC and dU (or T). The minor groove O2 carbonyl in each derivative is replaced by a hydrogen, a fluorine, or a methyl group. The hydrogen-substituted dC analogue was converted into a 2’,3’-dideoxynucleoside, which was converted into a 5’-triphosphate derivative. The other two dC analogues were transformed into 5’-triphosphate derivatives immediately after Heck coupling reactions. These analogues will allow an examination of the nature and role of minor groove interactions between incoming triphosphates and various polymerases. / Thesis (MS) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Foram preparados eletrocatalisadores PtRu/C e PtSn/C utilizando feixe de elétrons para a redução dos íons metálicos em solução. Neste procedimento submeteu-se ao feixe de elétrons, sob agitação, soluções de água/etileno glicol (EG) e água/2- propanol, ambas contendo íons dos metais precursores e o suporte de carbono. Foram variadas as razões volumétricas água/2-propanol e água/etileno glicol, a razão atômica entre os metais, o tempo de irradiação e a taxa de dose. Os eletrocatalisadores obtidos foram caracterizados por análise de raios X por energia dispersiva (EDX), por difração de raios X (DRX), por voltametria cíclica (VC) e por espectroscopia Mössbauer. A atividade destes eletrocatalisadores na oxidação eletroquímica do metanol e do etanol foi avaliada por voltametria cíclica e cronoamperometria, utilizando a técnica do eletrodo de camada fina porosa, e pelas curvas de polarização obtidas em células a combustível unitárias operando diretamente com metanol e etanol. Os eletrocatalisadores PtRu/C preparados no meio reacional água/etileno glicol(EG) apresentaram razões atômicas diferentes das razões atômicas nominais. Os resultados sugerem que parte dos íons Ru(III) presentes no meio reacional não foram reduzidos. Os materiais obtidos apresentaram a fase cúbica de face centrada (cfc) da Pt e suas ligas e tamanhos de cristalito na faixa de 2 a 3 nm. Os eletrocatalisadores PtRu/C preparados em água/2- propanol apresentaram razões atômicas Pt:Ru similares às razões nominais. Os materiais obtidos apresentaram as fases cfc da platina e suas ligas e tamanhos de cristalito entre 3 e 4 nm. Os eletrocatalisadores PtSn/C preparados no meio reacional água/EG e água/2-propanol apresentaram razões atômicas Pt:Sn similares às razões nominais. Os materiais obtidos apresentaram as fases cfc da platina com tamanho de cristalitos na faixa de 2 a 4 nm e SnO2 (cassiterita). Os estudos sobre a oxidação eletroquímica de metanol e etanol mostraram que foi possível obter materiais com atividades similares e/ou superiores às atividades dos eletrocatalisadores comerciais PtRu/C (E-TEK) e PtSn/C (BASF), tidos como referência na área. / PtRu/C and PtSn/C electrocatalysts were prepared using electron beam irradiation. The metal ions were dissolved in water/2-propanol and water/ethylene glycol solutions and the carbon support was added. The resulting mixtures were irradiated under stirring. The effect of water/ethylene glycol and water/2-propanol (v/v) ratio, Pt:Ru and Pt:Sn atomic ratios, the irradiation time and dose rate were studied. The obtained materials were characterized by Energy dispersive analysis of X-rays (EDX), X-ray diffraction (XRD), cyclic voltammetry (CV) and Mössbauer spectroscopy. The electro-oxidation of methanol and ethanol were studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were also tested on the Direct Methanol and Ethanol Fuel Cells. PtRu/C electrocatalysts prepared in water/ethylene glycol showed Pt:Ru atomic ratios different from the nominal ones. The results suggested that part of the Ru(III) ions were not reduced. The obtained materials showed the face-centered cubic (fcc) structure of Pt and Pt alloys with crystallite sizes of 2-3 nm. PtRu/C electrocatalysts prepared in water/2-propanol showed Pt:Ru atomic ratios similar to the nominal ones. The obtained materials also showed the fcc structure of platinum and platinum alloys with crystallite sizes of 3-4 nm. PtSn/C electrocatalysts prepared in water/ethylene glycol and water/2-propanol showed Pt:Sn atomic ratios similar to the nominal ones. The obtained materials showed the platinum (fcc) phase with crystallite sizes in the range of 2 - 4 nm and a SnO2 (cassiterite) phase. The obtained PtRu/C and PtSn/C electrocatalysts showed similar or superior performance for methanol and ethanol electro-oxidation compared to commercial PtRu/C (E-TEK) and PtSn/C (BASF) electrocatalysts.

Os eletrocatalisadores quartenários PtSnAuRh/C e PtRuAuRh/C foram preparados nas proporções 50:40:5:5, 60:30:5:5, 70:20:5:5, 80:10:5:5, 90:4:3:3 e para as composições terciárias PtSnAu/C, PtSnRh/C, PtRuAu/C, PtRuRh/C preparados na proporção atômica 50:45:5 com (20% em massa) pelo método da redução por álcool utilizando H2PtCl6.6H2O, RuCl3·xH2O, SnCl2.2H2O, HAuCl4.3H2O e RhCl3.xH2O, como fonte de metais e carbono Vulcan XC72 como suporte e, por último, etileno glicol como agente redutor. Os eletrocatalisadores obtidos foram caracterizados fisicamente por difração de raios-X (DRX), energia dispersiva de raios X (EDX) e microscopia eletrônica de transmissão (MET). As análises por EDX mostraram que as razões atômicas dos diferentes eletrocatalisadores, preparados pelo método da redução por álcool, foram similares às composições nominais de partida indicando que esta metodologia é eficiente para a preparação destes eletrocatalisadores. Em todos os difratogramas para os eletrocatalisadores preparados observa-se um pico largo em aproximadamente 2θ = 25°, o qual é associado ao suporte de carbono e quatro outros picos de difração em aproximadamente 2θ = 40°, 47°, 67° e 82°, que por sua vez são associados aos planos (111), (200), (220) e (311), respectivamente, da estrutura cúbica de face centrada (CFC) de platina. Os resultados de difração de raios X apresentaram tamanhos médios de cristalitos entre 2,0 e 5,2 nm para PtSnAuRh/C, PtSnAu/C, PtSnRh/C e 2,0 a 2,6 nm para PtRuAuRh/C, PtRuAu/C, PtRuRh/C. Os estudos para a oxidação eletroquímica do etanol em meio ácido foram realizados utilizando as técnicas de voltametria cíclica e de cronoamperometria em uma solução 0,5 mol.L-1 H2SO4, + 1,0 mol.L-1 de C2H5OH. As curvas de polarização obtidas na célula a combustível unitária, alimentada diretamente por etanol, estão de acordo com os resultados de voltametria e cronoamperometria constatando o efeito benéfico da adição do ouro e ródio na composição dos eletrocatalisadores. / The electrocatalysts quaternary PtSnAuRh/C and PtRuAuRh/C were prepared in the proportions 50:40:5:5, 60:30:5:5, 70:20:5:5, 80:10:5:5, 90:4:3:3 and for compositions PtSnAu/C, PtSnRh/C, PtRuAu/C, PtRuRh/C prepared in atomic ratio 50: 45: 5 with (20 mass%) by the method of alcohol reduction using H2PtCl6.6H2O, RuCl3·xH2O, SnCl2.2H2O, HAuCl4.3H2O and RhCl3.xH2O as a source of carbon and Vulcan XC72 as support and, lastly, ethylene glycol as a reducing agent. The obtained electrocatalysts were physically characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) and transmission electron microscopy (TEM). The EDX analyzes showed that the atomic ratios of the various electrocatalysts prepared by the method of alcohol reduction were similar to the nominal compositions of departure indicating that this method is efficient for preparing these electrocatalysts. In all diffraction patterns for the prepared electrocatalysts observed a broad peak at about 2θ = 25, which is associated with the carbon and four other diffraction peaks support at about 2θ = 40, 47, 67 and 82, which in turn they are associated with the planes (111), (200), (220) and (311) respectively of the face-centered cubic structure (FCC) of platinum. The results of X-ray diffraction showed average crystallite size between 2.0 and 5.2 nm for PtSnAuRh/C, PtSnAu/C, PtSnRh/C and 2.0 to 2.6 nm for PtRuAuRh/C, PtRuAu/C , PtRuRh/C. The studies for the electrochemical oxidation of ethanol in acidic medium were performed using cyclic voltammetry and chronoamperometry in a 0.5 mol L-1 solution H2SO4 + 1.0 mol L-1 C2H5OH. The polarization curves obtained on the unit fuel cell, fed directly with ethanol, are in agreement with the results of voltammetry and chronoamperometry stating the beneficial effect of adding gold and rhodium in the composition of the electrocatalysts.

Made available in DSpace on 2017-07-25T19:30:58Z (GMT). No. of bitstreams: 1 Daiani Cruz Hartman.pdf: 1884563 bytes, checksum: e16a5b42a86658f86cfd68e490069ec0 (MD5) Previous issue date: 2016-04-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The soil organic matter (SOM) perform an important role in the agriculture sustainability, and depending of the management system used, the soil can behave as a source or drainage of carbon (C) to the atmosphere. The objective of this study was to comprehend the impact of the use of phosphorous (P) sources in the soil organic carbon (SOC) pools and in the soil aggregation, managed in the crop-livestock integration system (CLIS), in no-till, adopting as a reference the native vegetation. The experiment design was completely randomized blocks in factorial 2x3, with four replicates. The experiment was established in April 2009 with five treatments: (i) control: without P application; (ii) TSP60: application of 60 kg ha-1 in the form of triple superphosphate (TSP); (iii) TSP120: application of 120 kg ha-1 of P in the form of TSP; (iv) MTP60: application of 60 kg ha-1 of P in the form of magnesium thermophosphate (MTP); (v) MTP120: application of 120 kg ha-1 of P in the form of MTP. In addition, we used as a reference a nearby native vegetation area. The soil was sampled in march 2013, at the depths of 0-5, 5-10, 10-20 cm for aggregate analysis and 0-5, 5-10, 10-20, 20-40, 40-60, 60-80 and 8-100 cm for total organic carbon (TOC) analysis, total and labile polysaccharides (PT and PL), hot water extractable organic carbon (HWEOC), permanganate oxidizable organic carbon (POXC), pyrophosphate oxidizable organic carbon (PIOC), recalcitrant carbon (Crec), particulate organic carbon (POC) and mineral associated organic carbon (MAOC). The treatments with TSP promoted higher stocks in all the SOC labile pools at 0-100 layer. The treatment with TSP presented higher POC, HWEOC and POXC stocks, which was 22.65 and 22.53; 21.99 and 22.49; 4.98 and 4.85 Mg ha-1, respectively, for TSP60 and TSP120, respectively at 0-100 cm layer. The extra-large macroaggregate class (8-19 mm) at the depth of 0-20 cm presented the highest TOC stocks regarding the other aggregate classes and the TSP at the rate of 60 kg ha-1 promoted the highest TOC stock. The C sequestration rate estimated by the unicompartimental model of C balance was 10 times higher in the 8-19 aggregate class at the depth of 0-20 regarding the 0.053-0.25 mm aggregate class. The C sequestration rate for the treatments control, TSP60, TSP120 MTP60 and MTP120 were 0.82, 1.06, 1.14, 1.09 and 1.06 Mg ha-1, respectively. The minimum amount of crop residue necessary to maintain the carbon balance for the treatments control, TSP60, TSP120 MTP60 and MTP120 respectively were from 6.98, 8.17, 7.93, 7.98 and 8.0 Mg ha-1 to 0.32, 0.23, 0.27, 0.20 and 0.22 Mg ha-1, in the 2-19 and 0.25-0.053 classes, respectively. The phosphate fertilization with soluble source in no-till in CLIS in short-term promoted higher benefits to soil structure and higher C stock in the SOC pools and in the aggregates, than the partial soluble source, indicating higher potential in reverting the soil degradation process. / A matéria orgânica do solo (MOS) desempenha um papel importante, na sustentabilidade agrícola e dependendo do manejo adotado o solo pode atuar como fonte ou dreno de Carbono (C) para a atmosfera. O objetivo deste trabalho foi compreender o impacto do uso de fontes de fósforo, nos compartimentos de Carbono orgânico e na agregação do solo, manejado no sistema integrado de produção agropecuária (SIPA), em plantio direto (PD), tendo como referência a vegetação nativa (VN). O experimento foi realizado em um Cambissolo Háplico argiloso no município de Castro, PR. O delineamento experimental foi o de blocos aleatorizados, em arranjo fatorial (2X3), com quatro repetições. O experimento foi implantado em abril de 2009 e constitui-se de 5 tratamentos: (i) Controle – sem aplicação de P; (ii) SFT60 - aplicação de 60 kg ha-1 de P2O5 na forma de superfosfato triplo (SFT); (iii) SFT120 – aplicação de120 kg ha-1 de P2O5 na forma de SFT; (iv) TFM60 - aplicação de 60 kg ha-1 de P2O5 na forma de termofosfato magnesiano (TFM); (v) TFM120 –aplicação de 120 kg ha-1 de P2O5 na forma de TFM, também, foi adicionado como tratamento o solo sob VN adjacente ao experimento, caracterizando a referência. O solo foi coletado em março de 2013, nas profundidades 0-5, 5-10, 10-20 cm para análise de agregados e 0-5, 5-10, -10-20, 20-40, 40-60, 60-80 e 80-100 cm para análise de C orgânico total (COT), C organico particulado (COP) e C associado aos minerais, C extraído por água quente (CAQ), C oxidado por permanganato de potássio (COXP), C extraído por pirofosfato de sódio (CPIR), polissacarídeos totais e lábeis (PT e PL respectivamente), e C recalcitrante (Crec), compreendendo os compartimentos do C. Os tratamentos com SFT promoveram estoque superior nos compartimentos lábeis na camada de 0-100 cm. Os tratamentos com fonte SFT resultaram em maior estoque de COP, CAQ e COXP que foi de 22,65 e 22,53; 21,99 e 22,49; 4,98 e 4,85 Mg ha-1, respectivamente, para o SFT60 e SFT120, respectivamente na camada de 0-100 cm. A classe de macroagregado extra-grande (8-19 mm) na camada de 0-20 cm constituiu-se no maior estoque de COT em relação as demais classes de agregados e o tratamento com SFT na dose de 60 kg ha-1 promoveu o maior estoque de COT. A taxa de sequestro de C estimada pelo modelo unicompartimental de balanço de C foi de quase 10 vezes superior na classe de macroagregados (8-19 mm) na camada de 0-20 cm em relação a classe de microagregados (0,053- 0,25 mm). A taxa de de sequestro de C para os tratamentos Controle, SFT60, SFT120 TFM60 e TFM120 foi de 0,82, 1,06, 1,14, 1,09 e 1,06 Mg ha-1ano-1, respectivamente. A quantidade mínima de resíduos culturais na forma de palhada para manter o balanço de C em equilíbrio estável para os tratamentos Controle, SFT60, SFT120, TFM60 e TFM120 foi de 6,98, 8,17, 7,93, 7,98 e 8,03 Mg ha-1 e 0,32, 0,23, 0,27, 0,20 e 0,22 Mg ha-1, respectivamente, nas classes 2-19 e 0,25-0,053 mm, respectivamente, A adubação fosfatada com fonte solúvel em PD em experimento sob SIPA de curto prazo, promoveu maiores benefícios à estruturação do solo e maior estoque de C nos compartimentos de C e nos agregados, do que a fonte parcialmente solúvel, indicando maior potencial em reverter o processo de degradação da qualidade do solo.

Cette recherche doctorale vise une meilleure compréhension des facteurs sous-tendant les phénomènes de conservation et de dépossession des biens de consommation, et se focalise plus spécifiquement sur le comportement de dépossession volontaire de vente d’occasion C to C (Consumer to Consumer). L’état de l’art de ce champ d’études, peu développé en comportement du consommateur, met en exergue des manques conceptuels et empiriques que nous investiguons au travers de trois axes de recherche : 1) les comportements du consommateur à l’égard des possessions dont il n’a plus l’utilité ; 2) les mécanismes motivationnels en œuvre dans la dépossession volontaire des biens via la vente d’occasion ; 3) les profils des consommateurs s’improvisant vendeurs, que nous nommons les «consommerçants» (contraction de «consommateur» et «commerçant»). Cinq études qualitatives exploratoires sont réalisées - une netnographie, deux vagues d’entretiens semi-directifs, un focus group, des entretiens d’expert- puis complétées par deux collectes de données quantitatives (N=127 et N=646). Le construit de Motivations à la Vente d’Occasion (MVO) apparait notamment lié au choix du circuit de vente (virtuel ou physique). Les analyses confirmatoires menées au moyen de modèles de premier et second ordre révèlent quatre dimensions du construit : récréationnelle, économique, générative, et critique. A partir de l'élaboration de l'échelle de mesure des MVO présentant des qualités psychométriques satisfaisantes (fiabilité et validité convergente, discriminante et prédictive), et des variables sociodémographiques, psychologiques et comportementales mobilisées, quatre profils de consommerçants sont identifiés. / This doctoral research aims at understanding the underlying factors associated with conservation and dispossession of consumer goods. We particularly focus on voluntary dispossession behavior through C to C (Consumer to Consumer) secondhand resale. The literature on this topic is underdeveloped by consumer behavior researchers. We address these theoretical and empirical gaps along three main research axes: 1) consumer behavior towards possessions of which they have no further use; 2) motivational mechanisms associated with voluntary dispossession through secondhand resale; 3) a typology analysis of consumers who improvise as salesmen (we classify them as “consommerçants”, by means of a French neologism combining the terms “consumer” and “tradesman” ). Five exploratory qualitative studies – a netnography, two series of semi-structured interviews, a focus group, and expert interviews – are carried out, and supplemented by two quantitative data collections (N=127 and N=646). Among other primary results, the Secondhand Selling Motivations construct (SSM) is related to the choice of distribution channel (virtual or physical). Moreover, confirmatory analyses conducted via first and second order measurement models reveals four dimensions defining this construct : recreational, economic, generative, and critical. Through the use of the SSM measurement scale, which demonstrates satisfactory psychometric qualities (reliability, as well as convergent, discriminate and predictive validity), and other demographical, psychological and behavioral variables, we establish four profiles of consommerçants via cluster analysis.

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Typescript. / Digitized by Kansas Correctional Industries

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / This work shows for the first time the antinociceptive effect of the citronellyl acetate (CAT) and aimed to characterize the profile of effect and identify possible antinociceptive mechanisms of the cat, in models of acute nociception in mice. The CAT was testeed standardized animal models of pain using mice Swiss (24-32g). The CAT was administered at doses of 25, 50, 75, 100 or 200 mg/kg, by gavage. It was used in the tests of abdominal writhings by acetic acid; hot plate; formalin test; mechanic sensitivity; inflamatory hipernociception induced by carrageennan; Nociception test induced by capsaicin, cinnamaldeide, menthol, acid saline, PMA, 8-Br-cAMP, bradykinin or glutamate, as well as in behavioural models (open field and rota rod tests) that allowed to exclude the possibility of a muscle relaxant action or to induce false-positive result in the earlier models. The results showed that the CAT have antinociceptive effect in the visceral nociception model induced by acetic acid (in the 100 or 200 mg/kg doses, with ED50 of 74.42 mg/kg), this effect was verified after 30 minutes of aplication and continued until 240 minutes (200 mg/kg). Pretreatment with CAT showed antinociceptive effect in licking model induced by intraplantar formalin application and in the thermal nociception model (hot plate). CAT showed the decreasing of mechanical sencibility using the von Frey hair. In the antinociceptive mechanism investigation, CAT showed effect related with K+ATP channels, TRPV1, TRPM8, ASIC, glutamatergics receptors, bradykinin receptors, PKA and PKC. IN the investigation of neurotramitters pathways involved in antinociceptive effect of CAT, we can suggest the involvement of serotonergics system (5-HT1A, 5-HT2A/C receptors) and muscarinic, dopaminergic and α2-adrenergics receptors. With the results showed, we can conclude the CAT have antinociceptive effect in mice, and as possible mechanism the modulation of intracellular mediators PKC and/or PKA, relacted with moleculars mechanisms of K+ATP channels, TRPV1, TRPM8, ASIC, glutamatergics receptors, bradykinin receptors, serotonergics system (5-HT1, 5-HT2A/C receptors) and muscarinic, dopaminergic and α2-adrenergics receptors. / Esse trabalho, atà onde se sabe, mostra pela primeira vez o efeito antinociceptivo do acetato de citronelila (CAT) e teve como objetivo caracterizar o perfil do efeito e identificar possÃveis mecanismos antinociceptivos do CAT, em modelos de nocicepÃÃo aguda em camundongos. O CAT foi testado em modelos animais padronizados de dor utilizando camundongos Swiss (24-32g). O CAT foi administrado nas doses de 25, 50, 75, 100 ou 200 mg/kg, por via oral. Foram utilizados os testes de contorÃÃes abdominais induzidas por Ãcido acÃtico; placa quente; teste da formalina; nocicepÃÃo mecÃnica, hipernocicepÃÃo inflamatÃria induzida pela carragenina; teste da nocicepÃÃo induzida por capsaicina, cinamaldeÃdo, mentol, salina Ãcida, PMA, 8-Br-cAMP, bradicinina ou glutamato, bem como em modelos comportamentais (testes do campo aberto e rota Rod) que permitiram excluir a possibilidade de uma atividade relaxante muscular ou induzir resultados falso-positivos nos modelos anteriores. Os resultados mostraram que o CAT possui efeito antinociceptivo no modelo de nocicepÃÃo visceral induzida por Ãcido acÃtico (nas doses de 100 ou 200 mg/kg, com DE50 de 74,42 mg/kg), esse efeito foi verificado apÃs 30 minutos da aplicaÃÃo e persistiu por atà 240 minutos (200 mg/kg). O prÃ-tratamento com o CAT mostrou efeito antinociceptivo no modelo de lambedura induzida pela aplicaÃÃo intraplantar de formalina e no modelo de nocicepÃÃo tÃrmica (placa quente). O CAT mostrou diminuiÃÃo da sensibilidade mecÃnica utilizando o filamento de von Frey. Na investigaÃÃo do mecanismo antinociceptivo, o CAT mostrou efeito relacionado com os canais K+ATP, TRPV1, TRPM8, ASIC, receptores glutamatÃrgicos, receptores de bradicinina, PKA e PKC. Na investigaÃÃo das vias de neurotransmissÃo envolvidas no efeito antinociceptivo do CAT, podemos sugerir o envolvimento dos receptores α2-adrenÃrgicos, sistema serotonÃrgico (receptores 5-HT1A, 5-HT2A/C), receptores muscarÃnicos e dopaminÃrgicos. Com os resultados mostrados, podemos concluir que o CAT possui efeito antinociceptivo em camundongos, e como possÃveis mecanismos a modulaÃÃo de mediadores intracelulares PKA e/ou PKC, relacionados com os mecanismos moleculares dos canais K+ATP, TRPV1, TRPM8, ASIC, receptores glutamatÃrgico, receptores de bradicinina, receptores α2-adrenÃrgico, sistema serotonÃrgico (receptores 5-HT1, 5-HT2A/C), receptores muscarÃnicos e dopaminÃrgicos.

Os eletrocatalisadores quartenários PtSnAuRh/C e PtRuAuRh/C foram preparados nas proporções 50:40:5:5, 60:30:5:5, 70:20:5:5, 80:10:5:5, 90:4:3:3 e para as composições terciárias PtSnAu/C, PtSnRh/C, PtRuAu/C, PtRuRh/C preparados na proporção atômica 50:45:5 com (20% em massa) pelo método da redução por álcool utilizando H2PtCl6.6H2O, RuCl3·xH2O, SnCl2.2H2O, HAuCl4.3H2O e RhCl3.xH2O, como fonte de metais e carbono Vulcan XC72 como suporte e, por último, etileno glicol como agente redutor. Os eletrocatalisadores obtidos foram caracterizados fisicamente por difração de raios-X (DRX), energia dispersiva de raios X (EDX) e microscopia eletrônica de transmissão (MET). As análises por EDX mostraram que as razões atômicas dos diferentes eletrocatalisadores, preparados pelo método da redução por álcool, foram similares às composições nominais de partida indicando que esta metodologia é eficiente para a preparação destes eletrocatalisadores. Em todos os difratogramas para os eletrocatalisadores preparados observa-se um pico largo em aproximadamente 2θ = 25°, o qual é associado ao suporte de carbono e quatro outros picos de difração em aproximadamente 2θ = 40°, 47°, 67° e 82°, que por sua vez são associados aos planos (111), (200), (220) e (311), respectivamente, da estrutura cúbica de face centrada (CFC) de platina. Os resultados de difração de raios X apresentaram tamanhos médios de cristalitos entre 2,0 e 5,2 nm para PtSnAuRh/C, PtSnAu/C, PtSnRh/C e 2,0 a 2,6 nm para PtRuAuRh/C, PtRuAu/C, PtRuRh/C. Os estudos para a oxidação eletroquímica do etanol em meio ácido foram realizados utilizando as técnicas de voltametria cíclica e de cronoamperometria em uma solução 0,5 mol.L-1 H2SO4, + 1,0 mol.L-1 de C2H5OH. As curvas de polarização obtidas na célula a combustível unitária, alimentada diretamente por etanol, estão de acordo com os resultados de voltametria e cronoamperometria constatando o efeito benéfico da adição do ouro e ródio na composição dos eletrocatalisadores. / The electrocatalysts quaternary PtSnAuRh/C and PtRuAuRh/C were prepared in the proportions 50:40:5:5, 60:30:5:5, 70:20:5:5, 80:10:5:5, 90:4:3:3 and for compositions PtSnAu/C, PtSnRh/C, PtRuAu/C, PtRuRh/C prepared in atomic ratio 50: 45: 5 with (20 mass%) by the method of alcohol reduction using H2PtCl6.6H2O, RuCl3·xH2O, SnCl2.2H2O, HAuCl4.3H2O and RhCl3.xH2O as a source of carbon and Vulcan XC72 as support and, lastly, ethylene glycol as a reducing agent. The obtained electrocatalysts were physically characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) and transmission electron microscopy (TEM). The EDX analyzes showed that the atomic ratios of the various electrocatalysts prepared by the method of alcohol reduction were similar to the nominal compositions of departure indicating that this method is efficient for preparing these electrocatalysts. In all diffraction patterns for the prepared electrocatalysts observed a broad peak at about 2θ = 25, which is associated with the carbon and four other diffraction peaks support at about 2θ = 40, 47, 67 and 82, which in turn they are associated with the planes (111), (200), (220) and (311) respectively of the face-centered cubic structure (FCC) of platinum. The results of X-ray diffraction showed average crystallite size between 2.0 and 5.2 nm for PtSnAuRh/C, PtSnAu/C, PtSnRh/C and 2.0 to 2.6 nm for PtRuAuRh/C, PtRuAu/C , PtRuRh/C. The studies for the electrochemical oxidation of ethanol in acidic medium were performed using cyclic voltammetry and chronoamperometry in a 0.5 mol L-1 solution H2SO4 + 1.0 mol L-1 C2H5OH. The polarization curves obtained on the unit fuel cell, fed directly with ethanol, are in agreement with the results of voltammetry and chronoamperometry stating the beneficial effect of adding gold and rhodium in the composition of the electrocatalysts.