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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

Avaliação pré-clínica do perfil farmacocinético do complexo de rutênio II/ triptofano em ratos por espectrofotometria UV-Vis / Pre-clinical profile of pharmacokinetic ruthenium complex II/ triptofano mice spectrophotometric UV-Vis

Zoghaib, Alarisse Arçari Fachetti 28 September 2015 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-09T14:22:46Z No. of bitstreams: 2 Dissertação - Alarisse Arçari Fachetti Zoghaib - 2015.pdf: 1188040 bytes, checksum: 9ab52dc612351ab19ab98e90e7ce6ec9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-09T14:24:14Z (GMT) No. of bitstreams: 2 Dissertação - Alarisse Arçari Fachetti Zoghaib - 2015.pdf: 1188040 bytes, checksum: 9ab52dc612351ab19ab98e90e7ce6ec9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-09T14:24:14Z (GMT). No. of bitstreams: 2 Dissertação - Alarisse Arçari Fachetti Zoghaib - 2015.pdf: 1188040 bytes, checksum: 9ab52dc612351ab19ab98e90e7ce6ec9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-28 / The ruthenium (II)/amino acid complex (rutrpII) demonstrated high anticancer activity against murine breast cancer (tumor of Ehrlich) in vitro and in vivo, and increased the median survival of animals. There was then necessary to investigate the pharmacokinetic parameters of the drug prototype as a requirement to pre-clinical knowledge of it. This study aimed to obtain the pharmacokinetic profile of ruthenium (II) / tryptophan administered to rats intraperitoneally in a single dose by quantifying this substance in plasma using validated analytical methodology in UV-VIS spectrophotometer. The methodology consisted of the administration of the prototype rutrpII to 3 rats at a dose of 6 mg/kg, intraperitoneally. Samples of blood 1.0 ml were collected by cannulation of the left jugular vein with heparinized syringe, the intervals from 0 to 9 hr. After centrifugation the plasma was frozen at -20 until the time of analysis. The bioanalytical method to quantify rutrpII was developed and validated in UV-VIS at a wavelength of 417 nm. From the construction of the concentration versus time curve, the kinetic parameters were calculated (Software WinNonlin 5.0 (Pharsight ™) Results were: Tmax = 8 h, Cmax = 169.86 mg/mL, t1/2 = 1.04 ± 0.02 h, ClT/F = 1.32 ± 0.05 mL/min/kg, Vd/F = 1,98 ± 0,05 L/kg. The developed and validated bioanalytical method was suitable for the detection and quantification of RutrpII in rat plasma. The values of pharmacokinetic profiles found, and extrapolated on allometric scaling allow us to understand that the compound studied showed a slow tissue distribution profile and / or was eliminated slowly (Vd low and low value CLT), due to a possible affinity between RutrpII and plasma proteins. This affinity may be explained by the similarity of their chemical structure with iron, enabling it to be transported by biomolecules such as transferrin, albumin or any other, and having as a target the DNA of cancer cells. In general, the compounds of ruthenium (II) / amino acids may be promising drugs for the amino acids present in the complex, may facilitate the recognition of the complex as a whole by DNA, and thus less toxic. / O complexo de rutênio(II)/aminoácido (rutrpII) demonstrou alta atividade antineoplásica contra carcinoma de mama murino (tumor de Ehrlich) in vitro e in vivo, sendo que neste último, aumentou a média de sobrevida dos animais. Fez-se necessária então a investigação dos parâmetros farmacocinéticos deste protótipo de fármaco como requisito ao conhecimento pré-clínico do mesmo. O objetivo deste trabalho foi obter o perfil farmacocinético do rutênio(II)/triptofano administrado a ratos, via intraperitoneal, em dose única por meio da quantificação desta substância em plasma utilizando metodologia analítica validada em espectrofotômetro UV-VIS. A metodologia consistiu na administração do protótipo rutrpII a 3 ratos em dose de 6 mg/kg, por via intraperitonal. Foram coletadas amostras de 1,0 mL de sangue, por canulação da veia jugular esquerda, com seringa heparinizada, nos intervalos de tempo de 0 a 9 h. Após centrifugação, o plasma foi congelado a -20ºC até o momento da análise. O método bioanalítico de quantificação do rutrpII foi desenvolvido e validado em espectrofotômetro UV-VIS no comprimento de onda de 417 nm. A partir da construção da curva de concentração versus tempo, foram calculados os parâmetros cinéticos (Software Winnonlin 5.0 (Pharsight™)). Os resultados encontrados foram: Tmax= 8h, Cmax= 169,86 µg/mL, t(1/2) =1,04 ± 0,02 h,ClT/F = 1,32 ± 0,05 mL/min/kg, Vd/F = 1,98 ± 0,05 L/kg. O método bioanalítico desenvolvido e validado foi adequado para a detecção e quantificação do RutrpII em plasma de rato. Os valores dos perfis farmacocinéticos encontrados, e extrapolados em escala alométrica, permitem entender que o composto estudado apresentou um perfil lento de distribuição tecidual e/ou foi eliminado lentamente (baixo Vd e baixo valor de CLT), devido a uma possível afinidade entre o RutrpII e as proteínas plasmáticas. Esta afinidade pode ser explicada pela semelhança de sua estrutura química com o ferro, possibilitando que ele seja transportado por biomoléculas como a transferrina, albumina ou alguma outra, e tendo como alvo, o DNA da células cancerosas. De maneira geral os compostos de rutênio(II)/ aminoácidos podem ser fármacos promissores pois os aminoácidos presentes nos complexos, podem facilitar o reconhecimento do complexo como um todo pelo DNA, sendo assim menos tóxicos.
522

Formas de nitrogênio e doses de potássio no capim-marandu: atributos morfológicos, produtivos, nutricionais e bioquímicos e transformações do nitrogênio em um Neossolo / Nitrogen forms and potassium rates on Marandu palisadegrass: morfologic, productive, nutritional and biochemical attributes and nitrogen transformations in an Entisol

Marcio Mahmoud Megda 28 June 2013 (has links)
A disponibilidade de nitrogênio no solo e o fornecimento de doses de potássio podem alterar a nutrição do capim-marandu, com reflexos diretos na morfologia, atividade de enzimas e acúmulo de poliaminas nas plantas. Objetivou-se: i) identificar a forma de nitrogênio e a dose de potássio que promovem a maximização dos atributos morfológicos da parte aérea e das raízes e, consequentemente, a produção de forragem do capim-marandu (Brachiaria brizantha cv. Marandu); ii) avaliar as concentrações de nitrogênio, nitrato, amônio, potássio, prolina, poliaminas e clorofila, além do valor SPAD e da redutase do nitrato nas folhas diagnósticas, em função da adubação de formas de nitrogênio com doses de potássio e iii) quantificar as transformações do nitrogênio do solo, em função da aplicação de formas de nitrogênio e adição de material vegetal de capim-marandu. Os experimentos foram realizados em duas etapas: a) em casa de vegetação onde as plantas de capim-marandu foram cultivadas em solo classificado como Neossolo Quartzarênico. Quatro formas de nitrogênio (nitrato, amônio, 70%nitrato+30%amônio e amídica) mais controle e quatro doses de potássio (0, 150; 300 e 450 mg dm-3) foram combinados em um fatorial completo 5x4. As unidades experimentais consistiram em 80 vasos e o delineamento experimental foi o de blocos inteiramente casualizados, com quatro repetições; b) em laboratório, seis combinações envolvendo formas de nitrogênio (nitrato e amônio enriquecidos com 15N e controle) e presença/ausência de material vegetal de capim-marandu foram avaliados em incubação aeróbica. Cada combinação foi repetida três vezes e todos foram incubados por oito períodos de avaliação (0, 1, 2, 4, 8, 12, 16 e 20 semanas) com o Neossolo Quartzarênico, em delineamento completamente causalizado. Os resultados demonstraram que o fornecimento de nitrogênio associado ao de potássio foi fundamental para elevar a produção de forragem e das raízes e a concentração desses elementos nas folhas diagnósticas do capim-marandu. A forma nitrato+amônio, na dose de potássio de 450 mg dm-3, proporcionou mais elevada área foliar, a qual foi determinante no incremento da produção de forragem. O fornecimento das formas de nitrato, nitrato+amônio e amídica, associados à máxima dose de potássio proporcionaram incrementos nos números de perfilhos e folhas, área foliar, e consequentemente na produção de forragem. O não fornecimento de nitrogênio e a aplicação na forma de amônio proporcionaram as mais baixas produções de forragem. O incremento das doses de potássio reduziu os sintomas de toxicidade de amônio nas plantas de capim. Os atributos produtivos do sistema radicular foram alterados positivamente pelas formas nitrato, nitrato+amônio e amídica e pelas doses de potássio. O valor SPAD foi incrementado pelas formas nitrato, nitrato+amônio e amídica e a aplicação de potássio de 336 mg dm-3 que resultou em 38 unidades SPAD. A concentração de clorofila de 35 ?g g-1 correspondeu à de nitrogênio total de 22,5 g kg-1. A enzima redutase do nitrato teve sua atividade aumentada com o incremento das doses de potássio e o fornecimento de nitrato+amônio. As concentrações de putrescina, espermidina, espermina e prolina aumentaram mediante o fornecimento de amônio e diminuíram com incremento das doses de potássio. Os baixos teores de 15NH4 + no solo após a segunda semana permitiram verificar que todo amônio foi imobilizado pelos microrganismos do solo, em todas as combinações. A aplicação de amônio, com material vegetal de capimmarandu, resultou nos mais elevados teores de amônio, aminoácido, aminoaçúcar e nitrogênio total hidrolisados. / Soil nitrogen availability and potassium supply rates can influence Marandu palisadegrass nutrition, with direct effect on the morphology, enzyme activity and polyamines accumulation in plants. This study aimed to: i) identify the nitrogen form and the potassium rate that maximizes the morphological attributes of shoots and roots, and consequently, the forage production of Marandu palisadegrass (Brachiaria brizantha cv. Marandu), ii) evaluate the nitrogen, nitrate, ammonium, potassium, proline, polyamines and chlorophyll concentration, as well as the SPAD value and the nitrate reductase activity in diagnostic leaves, as a function of nitrogen forms and potassium rates, and iii) quantify the soil nitrogen changes according to different forms of nitrogen and addition of Marandu residue. The experiments were carried out in two stages: a) in a greenhouse, where Marandu plants were grown in an Entisol. Four nitrogen forms (nitrate, ammonium, 70% nitrate+30% ammonium, urea) plus the control (no nitrogen) and four potassium rates (0, 150, 300 and 450 mg dm-3) were arranged in a 5x4 complete factorial design. The experimental units consisted on 80 pots. The twenty combinations were evaluated in a completely randomized block design with four replications; b) in the laboratory experiment, six combinations involving three forms of N (nitrate and ammonium enriched with15N atoms 1% and no nitrogen) and Marandu residue (presence/absence) were evaluated using aerobic incubation. Each combination was replicated three times and incubated under eight incubation periods (0, 1, 2, 4, 8, 12, 16 and 20 weeks) in an Entisol. In total, 144 experimental units were evaluated using a completely randomized design. The results from the first experiment showed that nitrogen supply associated with potassium rates were important for increasing the forage and roots biomass and the concentration of these elements in the diagnostic leaves. Nitrate+ammonium and potassium at 450 mg dm-3 provided with the largest leaf area, which was decisive for high forage production. The supply of nitrate, nitrate+ammonium and urea, associated with the maximum potassium rate resulted in increased number of tillers, leaves, leaf area, and consequently, increased forage production. Combinations involving ammonium and no nitrogen provided with the lowest forage production. High potassium rates were associated with less ammonium toxicity symptoms on the plants. The productive attributes of the root system were positively modified by nitrate, nitrate+ammonium and urea and by the high potassium rates. The SPAD value increased with nitrate, nitrate+ammonium and urea and potassium at 336 mg dm-3 resulted in 38 SPAD units. Chlorophyll concentration of 35 mg g-1 corresponded to a total nitrogen concentration of 22.5 g kg-1. Nitrate reductase activity increased with higher potassium rates and nitrate+ammonium supply. Higher concentrations of putrescine, spermidine, spermine and proline were observed with ammonium supply, but they decreased with higher potassium rates. The low concentration of 15NH4 + in the soil after the second week indicates that all ammonium was immobilized by soil microorganisms, for all combinations. The application of ammonium in combination with Marandu residue resulted in higher concentration of ammonium, amino acid, amino sugar and total nitrogen hydrolysates.
523

Estudo estrutural, térmico e vibracional do crista de Bis (L-alaninato) de Níquel (II) di-hidratado / STRUCTURAL, THERMAL AND VIBRATIONAL STUDY OF BIS (L-ALANINATE) CRYSTAL OF NICKEL (II) DIHYDRATE

Baldez, Thays Silva 06 July 2016 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-05T20:04:11Z No. of bitstreams: 1 ThaysSilvaBaldez.pdf: 2095828 bytes, checksum: 9de3dacfb0850842d669bc07ee7407eb (MD5) / Made available in DSpace on 2017-05-05T20:04:11Z (GMT). No. of bitstreams: 1 ThaysSilvaBaldez.pdf: 2095828 bytes, checksum: 9de3dacfb0850842d669bc07ee7407eb (MD5) Previous issue date: 2016-07-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Amino acids complex of transition metals has increasingly attracted the interest of researchers due to their wide range of physical properties for understanding metal-amino acid interactions. In this work [Bis(L-Alaninato)Diaqua] Nickel(II) Dihydrate [Ni(C3H6O2N)2(H2O)2.2H2O] crystals were obtained by slow evaporation method using 0,1 mol/L of NiCl2.6H2O, 0,2 mol/L of L-alanine and NaOH. Rietveld refinement of X-ray data confirmed the structure. The structural properties of these crystals were studied by X-ray diffraction (XRD) in the temperature range from 25 to 150 °C. Thermal analysis experiments were performed by TG/DTA between 25 and 500 °C, and by DSC between 25 and 250 °C. The results obtained by TG/DTA indicate the loss of water molecules by [Bis(L-Alaninato)Diaqua] Nickel(II) Dihydrate crystals at temperatures of 64 and 117 °C, which was also confirmed by the results obtained by DSC. The X-ray diffraction pattern show new peaks, in temperatures around 55 and 110 ° C, indicating to loss of water by crystals. The transformation is irreversible because the diffraction pattern obtained after the sample return to the room temperature differs from that obtained before heating of the sample. The vibrational properties were analyzed by Raman spectroscopy between 25 and 185 °C. The Raman spectroscopy measurements as a function of the temperature show the loss of water molecules. The spectra at high temperatures resemble the spectrum at room temperature, showing that the crystal undergoes phase transformation, but probably do not change the crystal symmetry. / Aminoácidos complexados com metais de transição têm atraído cada vez mais o interesse de pesquisadores devido à grande variedade de propriedades físicas que eles apresentam para o entendimento das interações metal-aminoácido. Neste trabalho, cristais de Bis(L-alaninato) de Níquel (II) di-hidratado [Ni(C3H6O2N)2(H2O)2.2H2O] foram obtidos por meio da evaporação lenta do solvente de uma solução saturada contendo 0,1 mol/L de NiCl2.6H2O, 0,2 mol/L de L-alanina e NaOH. Após a obtenção da amostra, a confirmação da estrutura deu-se por refinamento de Rietveld. As propriedades estruturais desses cristais foram estudadas por medidas de difração de raios-X em função da temperatura na faixa de 25 a 150 °C. Experimentos de análise térmica foram realizados por TG/DTA entre 25 e 500 °C e por DSC entre 25 e 250 °C. Os resultados obtidos por TG/DTA evidenciam a saída das moléculas de água do cristal de Bis(L-alaninato) de Níquel (II) di-hidratado nas temperaturas de 64,51 e 117,25 °C, que também foi confirmada pelos resultados obtidos por DSC. O padrão de difração de raios-X mostrou desaparecimento e o surgimento de novos picos no difratograma, para temperaturas próximas a 55 °C e 110 °C, indicando a saída de água do cristal. Essa transformação é irreversível, pois o padrão de difração obtido após a amostra retornar à temperatura ambiente difere significativamente daquele obtido antes do aquecimento. As propriedades vibracionais foram analisadas por Espectroscopia Raman entre 25 e 185 °C. As medidas dos espectros Raman em função da temperatura evidenciam a saída das moléculas de água. O espectro à alta temperatura se assemelha ao espectro à temperatura ambiente, mostrando que o cristal sofre transformação de fase, mas provavelmente permanece com a mesma simetria cristalina.
524

Estudo de espalhamento Raman em cristais de L-tirosina hidroclorídrica submetidos a altas pressões / Raman scattering study on hydrochloric L-tyrosine crystals subjected to high pressures

Santos, Carlos Alberto Andrade Serra dos 28 February 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-07-21T18:04:23Z No. of bitstreams: 1 CarlosSantos.pdf: 7721249 bytes, checksum: ee220ca2d9a3d156b8c575c28854ffea (MD5) / Made available in DSpace on 2017-07-21T18:04:23Z (GMT). No. of bitstreams: 1 CarlosSantos.pdf: 7721249 bytes, checksum: ee220ca2d9a3d156b8c575c28854ffea (MD5) Previous issue date: 2017-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / In this work L-tyrosine hydrochloride crystals (LTHCl) were prepared by slow evaporation technique at room temperature and characterization by X-ray diffraction, thermogravimetry, differential thermal analysis, differential scanning calorimetry and Raman scattering at room temperature and under high pressures. After four weeks, it was possible obtain various crystals of good crystalline quality. The solution was acidic with pH 1.2. From the XRD pattern of the material and the Rietveld analysis, it was found that at room temperature LTHCl crystallizes in monoclinic space group (P21) with two molecules per unit cell. The refinement quality parameters were satisfactory with Rp = 6.29 %, Rwp = 8.49 % and S = 1.34. The thermal analysis showed that the material undergoes fusion around 231°C and presented no thermal event that features phase transition before the fusion. Furthermore, thermal analysis showed that the crystal is stable up to 220°C. Calculations using DFT (Functional Density Theory) were performed to identify the vibrational modes in the LTHCl crystal. Raman scattering measurements as a function of pressure (0,0-7,2 GPa) showed as major changes: the occurrence of an inversion of intensity between a strong band (attributed to torsion of L-tyrosine molecule) and an imperceptible band (at ambient pressure) for pressures above 2,5 GPa and a discontinuity of dω/dP associated with the strong band between 1.0 and 1.5 GPa, suggesting a conformational transition above 1.5 GPa stabilizing the structure up to 7,2 GPa. In the region of the internal modes few changes were observed, with the downshift of the COOH and NH3+ units as one of them. Finally, the decompression reinforced that the conformational phase transition is reversible, demonstrating a great capacity of this material to regenerate its original structure without presenting hysteresis. / Neste trabalho foram sintetizados cristais de L-tirosina hidroclorídrica (LTHCl) pela técnica de evaporação lenta do solvente à temperatura ambiente e realizadas medidas de caracterização por difração de raios X, análise térmica diferencial, análise termogravimétrica, calorimetria exploratória diferencial e espalhamento Raman à temperatura ambiente e a altas pressões neste sal de aminoácido. Após quatro semanas foram obtidos vários cristais, que apresentaram, visualmente, boa qualidade cristalina. A solução de crescimento era ácida com pH 1,2. Através do difratograma do material e da análise pelo método de Rietveld, constatouse que à temperatura ambiente a LTHCl cristaliza-se numa estrutura monoclínica (P21) com duas moléculas por célula unitária. Os parâmetros de qualidade do refinamento foram satisfatórios, com Rp = 6,29 %, Rwp = 8,49 % e S = 1,34. As análises térmicas mostraram que o material sofre fusão por volta de 231°C e que não há evento térmico que caracterize uma transição de fase antes da fusão. Além disso, as análises térmicas mostraram que o cristal é estável até 220°C. Cálculos usando a Teoria do Funcional de Densidade (DFT, density funcional theory) foram realizados para a identificação dos modos vibracionais no cristal de LTHCl. As medidas de espalhamento Raman em função da pressão (0,0-7,2 GPa) apresentaram como principais mudanças: A ocorrência de uma inversão de intensidade entre uma forte banda (associada à torção da molécula de L-tirosina) e uma banda imperceptível (à pressão ambiente) para pressões acima de 2,5 GPa, bem como a descontinuidade em dω/dP da forte banda entre 1,0 e 1,5 GPa, sugerindo uma mudança conformacional indicada pela torção da molécula de L-tirosina para pressões acima de 1,5 GPa deixando a estrutura estável até 7,2. Na região dos modos internos foram observadas poucas mudanças, tendo o downshift das unidades COOH e NH3 + como uma delas. Finalmente, a descompressão reforçou que a transição de fase conformacional é reversível, demonstrando uma grande capacidade desse material para se regenerar, sem apresentar histerese.
525

Exig?ncia de lisina e restri??o alimentar qualitativa para frangos de corte de menor potencial gen?tico para crescimento / .Lysine requirement and qualitative food restriction for broilers with lower genetic potential for growth

Moura, Barbara Brandt 28 April 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-08-23T14:07:16Z No. of bitstreams: 1 2017 - Barbara Brandt Moura.pdf: 2285485 bytes, checksum: 9eae3c35e652afad0a110dc64eafec10 (MD5) / Made available in DSpace on 2018-08-23T14:07:16Z (GMT). No. of bitstreams: 1 2017 - Barbara Brandt Moura.pdf: 2285485 bytes, checksum: 9eae3c35e652afad0a110dc64eafec10 (MD5) Previous issue date: 2017-04-28 / Summary chapter 1 Lysine is an essential amino acid used as a reference in diet formulations based on the ideal protein concept and is also the main nutrient involved in the muscular development of broilers. Research related to the requirement of lysine for broilers with lower genetic potential for growth are scarce and sometimes quite divergent. The objective of this study is to determine digestible lysine requirements for male broilers with lower genetic potential for growth. A total of 520 male broilers of the RedBro-plum? commercial strain from 42 to 72 days of age and slaughtered at 73 days of age were used. The experimental design was completely randomized (DIC), with five treatments with four replicates with 26 broilers each. The treatments were constituted with the values 0.689, 0.842, 0.995, 1.148 and 1.301% of digestible lysine obtained from the addition of L-Lysine HCl to the basal diet, replacing the corn starch. In parameter of negative linear recess performance for feed conversion and linear and line use efficiency positive for lysine consumption. In carcass traits, there was a negative linear regression in absolute carcass, breast, wing, thigh + overcook and heart and quadratic effects for absolute fat weight, back yield and relative fat weight. The lowest digestible lysine in the feed, 0.689%, determining adequate performance and carcass characteristics. However, lower abdominal fat deposition would be obtained with 1.05% digestible lysine in the diet, it can be considered the requirement value for slow-growing male broilers in the evaluated phase. The qualitative food restriction consists in the dilution of the diets, through the inclusion of ingredients with low nutritional value, in order to reduce the amount of nutrients absorbed. The objective of this experiment was to evaluate the rates with different inclusion levels of ground Tifton 85 hay in the proportions of 0, 5, 10 and 15%. A total of 288 male broilers of the RedBro-plum? lineage were used, in a completely randomized design, in 4 treatments and 4 replicates of 18 broilers each. As broilers received as experimental feeds from 42 to 72 days of age. At 73 days the chickens were slaughtered for carcass analysis and intestine collections were performed in 8 broilers per replicate for morphological and morphometric analysis. A studied hay inclusion influenced linearly negative for weight gain and, in a positive way, feed consumption and feed conversion. Linear reductions without absolute carcass and breast weight, carcass yield and our liver and gizzard weights were also observed. Quadratic effect was observed for absolute weight of dorsum, liver and fat, yield of dorsum and villus height. The inclusion of Tifton 85 hay in the broiler ration of lower potential for growth from 42 to 72 days of age resulted in worsening performance and carcass yield. The use of hay was effective as a measure of qualitative restriction Summary chapter 2 The qualitative food restriction consists in the dilution of the diets, by means of the inclusion of ingredients with low nutritional value, usually, rich in fibers to reduce the amount of nutrients absorbed. The aim of this study was to evaluate rations with different inclusion levels of ground Tifton 85 hay in rations at the proportions of 0%, 5%, 10% and 15%. A total of 288 male Red Bro-plum? commercial broilers were distributed in a completely randomized design in 4 treatments and 4 replicates of 18 broilers per treatment. The broilers received the experimental rations from 42 to 72 days of age. At 73 days all broilers were slaughtered for carcass analysis, and intestine samples from 8 broilers were collected per replicate for morphological and intestinal morphometric analysis. Increasing the inclusion values of dietary hay influenced linearly performance of broilers, with the decrease in weight gain, increase in feed consumption and impacting negatively in feed conversion values. Likewise, elevating the addition of hay in the ration showed linear reductions in absolute weight, carcass yield, and linear increases in the relative weights of liver and gizzard. The inclusion of Tifton 85 hay in broiler ration of lower potential for growth from 42 to 72 days of age affected negatively performance and carcass yield. The use of hay was effective as a measure of qualitative restriction of the ration if there is intention to control the growth of broilers according to a certain slaughter age / Resumo Cap?tulo 1 A lisina ? um amino?cido essencial utilizado como refer?ncia nas formula??es de dietas com base no conceito de prote?na ideal, sendo a lisina um dos principais nutrientes envolvidos no desenvolvimento das aves. A maioria das pesquisas relacionadas a exig?ncia de lisina para frangos de corte s?o realizadas com frangos de linhagens convencionais, no entanto para frangos de corte de menor potencial gen?tico para crescimento as refer?ncias s?o escassas e por vezes bastante divergentes. Assim, o objetivo deste estudo foi determinar as exig?ncias em lisina digest?vel para frangos de corte machos de menor potencial gen?tico para crescimento. Foram utilizados 520 frangos de corte, machos, da linhagem comercial RedBro-plum? (Caipira Franc?s Vermelho Escuro), de 42 a 72 dias de idade e abatidos aos 73 dias de idade. O delineamento experimental utilizado foi o inteiramente casualizado (DIC), sendo cinco tratamentos e quatro repeti??es por tratamento, totalizando 20 unidades experimentais de 26 aves cada. Os tratamentos foram constitu?dos com valores crescentes de lisina digest?vel obtidos a partir da adi??o de L-Lisina HCl ? dieta basal, em substitui??o ao ingrediente amido de milho, sendo 0,689, 0,842, 0,995, 1,148 e 1,301% de lisina digest?vel. Em par?metros de desempenho foi observada regress?o linear negativa para convers?o alimentar e efici?ncia da utiliza??o de lisina e linear positiva para consumo de lisina, de acordo com o aumento nos valores de lisina digest?vel na ra??o. Tal efeito pode ter sido influenciado pela necessidade dos frangos em aumentar o consumo de ra??o nos tratamentos iniciais, para suprir o aporte limitante de lisina na ra??o. Para as caracter?sticas de carca?a foi verificado regress?o linear negativa nos pesos absolutos de carca?a, peito, asa, coxa + sobrecoxa e cora??o e efeito quadr?tico para peso absoluto de gordura, rendimento de dorso e peso relativo de gordura com o aumento nos valores de lisina digest?vel. O menor valor em lisina digest?vel na ra??o, 0,689%, foi suficiente para determinar resultados adequados de desempenho e caracter?sticas de carca?a. Entretanto, para propiciar menor deposi??o de gordura abdominal o valor de 1,05 % de lisina digest?vel na ra??o pode ser considerado o valor de exig?ncia para os frangos machos de crescimento lento na fase de 42 a 72 dias de idade. Resumo cap?tulo 2 A restri??o alimentar qualitativa consiste na dilui??o das dietas, por meio da inclus?o de ingredientes com baixo valor nutricional, normalmente ricos em fibras, a fim de reduzir a quantidade de nutrientes absorvidos. O objetivo deste experimento foi avaliar ra??es com diferentes n?veis de inclus?o de feno de Tifton 85 mo?do na ra??o, nas propor??es de 0, 5, 10 e 15 %. Foram utilizados 288 frangos de corte de crescimento lento, machos, da linhagem comercial RedBro-plum? (Caipira Franc?s Vermelho Escuro), distribu?das em um delineamento inteiramente casualizado, em 4 tratamentos e 4 repeti??es de 18 aves por tratamento. As aves receberam as ra??es experimentais dos 42 aos 72 dias de idade. Aos 73 dias foram abatidos todos os frangos para analise de carca?a e foram realizadas coletas de intestino em 8 frangos por repeti??o para a an?lise morfol?gica e morfom?trica intestinal. Os aumentos nos valores de inclus?o de feno estudados na dieta influenciaram de forma linear o desempenho dos frangos, com diminui??o no ganho de peso, aumento no consumo de ra??o, no consumo de fibra bruta e piora nos valores de convers?o alimentar e aumento. Foram observadas ainda, com o aumento de adi??o de feno na ra??o, redu??es lineares no peso absoluto e no rendimento de carca?a e aumentos lineares nos pesos relativos do f?gado e da moela. A avalia??o da morfometria intestinal demonstrou que houve efeito quadr?tico na altura de vilosidade. A an?lise econ?mica demonstrou efeito linear decrescente para o ?ndice de rentabilidade. A inclus?o de feno de Tifton 85 na ra??o de frangos de corte de menor potencial de crescimento no per?odo de 42 a 72 dias de idade resultou na piora dos resultados de desempenho, rendimento de carca?a e analise econ?mica. A utiliza??o do feno foi eficaz como medida de restri??o qualitativa da ra??o se houver inten??o de controle do crescimento do frango em fun??o de uma determinada idade de abate
526

Structure-Function Analysis of Grapefruit Glucosyltransferase Protein – Identification of Key Amino Acid Residues for its Rigid Substrate Specificity

Sathanantham, Preethi, Devaiah, Shiva K., McIntosh, Cecelia A. 09 April 2015 (has links)
Flavonoids are an important class of secondary metabolites widely distributed in plants. The majority of naturally occurring flavonoids are found in glucosylated form. Glucosyltransferases are enzymes that enable transfer of glucose from an activated donor (UDP-glucose) to the acceptor flavonoid substrates. A flavonol specific glucosyltransferase cloned from Citrus paradisi (Cp3OGT) has strict substrate and regiospecificity. In this study, amino acid residues that could potentially alter the rigidity observed in this enzyme were mutated to position equivalent residues of a putative anthocyanin specific glucosyltransferase from Clitorea ternatea and a GT from Vitis vinifera that can glucosylate both flavonols and anthocyanidins. Using homology modeling followed by site directed mutagenesis to identify candidate regions, three double mutations were made. To test the basis of substrate specificity, biochemical analysis of the three recombinant mutant proteins was carried out. Recombinant protein with mutation S20G+T21S revealed that the enzyme retained activity similar to the wildtype (Cp3OGT) (WT- Km app-104.8 µM; Vmax = 24.6 pmol/min/µg, Mutant- Km app-136.42 µM; Vmax -25pmol/min/µg) but the mutant was more thermostable compared to the WT. The (S290C+S319A) mutant protein retained 40% activity relative to wildtype and has an optimum pH shifted towards the acidic side (pH 6) (Km app-8.27 µM; Vmax-90.9 pmol/min/µg). Mutation of Glutamine87 and Histine154 (H154Y+Q87I) have rendered this recombinant protein inactive with every class of flavonoid tested. Interestingly, the single point mutations H154Y and Q871I had significant activity, slightly greater than that of wildtype enzyme. The two active recombinant proteins will further be analyzed to determine whether the mutations have altered regiospecificity of the original enzyme. Product identification is being conducted using HPLC.
527

Pyridazinediones and amino acid receptors: theoretical studies, design, synthesis, and evaluation of novel analogues

Greenwood, Jeremy Robert January 1999 (has links)
http://www.pharmacol.usyd.edu.au/thesis This thesis is primarily concerned with a class of chemical compounds known as pyridazinediones, being 6-membered aromatic rings containing two adjacent nitrogen atoms (pyridazine), doubly substituted with oxygen. In particular, the work focuses on pyridazine-3,6-diones, derivatives of maleic hydrazide (1). Understanding of the chemistry of these compounds is extended, using theoretical and synthetic techniques. This thesis is also concerned with two very important classes of receptors which bind amino acids in the brain: firstly, the inhibitory GABA receptor, which binds g-aminobutyric acid (GABA) (2) in vivo, and for which muscimol (3) is an agonist of the GABAA subclass; secondly, Excitatory Amino Acid (EAA) receptors, which bind glutamate (4) in vivo, and in particular the AMPA subclass, for which (S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) (5) is an agonist. The connection between pyridazinediones and amino acid receptors is the design, synthesis, and evaluation of structures based on pyridazinediones as potential GABA and EAA receptor ligands. Techniques of theoretical chemistry, molecular modelling, synthetic chemistry, and in vitro pharmacology are used to explore pyridazine-3,6-dione derivatives as ligands.
528

Resource aquisition and allocation in lichens

Dahlman, Lena January 2003 (has links)
<p>Lichens are fascinating symbiotic systems, where a fungus and a unicellular alga, most often green (bipartite green algal lichens; 90% of all lichens), or a fi lamentous cyanobacterium (bipartite cyanobacterial lichens; 10% of all lichens) form a new entity (a thallus) appearing as a new and integrated organism: in about 500 lichens the fungus is associated with both a cyanobacterium and an alga (tripartite lichens). In the thallus, the lichen bionts function both as individual organisms, and as a symbiont partner. Hence, in lichens, the participating partners must both be able to receive and acquire resources from the other partner(s) in a controlled way.</p><p>Lichens are particularly successful in harsh terrestrial environments. In part this is related to their poikilohydric nature and subsequent ability to repeatedly become desiccated and hydrated. Metabolic activity, i.e. photosynthesis, respiration, and for cyanobacterial lichens N2-fixation, is limited to periods when the thallus is suffi ciently hydrated. Mineral nutrients are mainly acquired from dry or wet deposition directly on the thallus. Taken together it then appears that lichens are to a large extent passively controlled by their environment, making their control over resource allocation and acquisition particularly challenging.</p><p>The aim of this thesis was to investigate resource acquisition and allocation processes in different lichens, and to see how these respond to changes in resource availability. This was done by following lichen growth in the fi eld during manipulation of water, light, and nutrient supply, and by assessing the responses of both the integrated thallus as well as the individual bionts. As a fi rst step, resource allocation and acquisition was investigated for a broad range of lichens aiming to determine the magnitude of metabolic variation across lichens. Seventy-fi ve lichen species were selected to cover as broad a spectrum as possible regarding taxonomy, morphology, habitat, and nitrogen requirements. The lichens had invested their nitrogen resources so that photosynthetic capacity matched respiratory carbon demand around a similar equilibrium across the contrasting species. Regulation of lichen growth was investigated in another study, using the two tripartite species <i>Nephroma arcticum</i> and <i>Peltigera aphthosa</i>, emphasizing the contribution of both internal and external factors. The empirical growth models for the two lichens were similar, showing that weight gain is to a higher extent dependent on those external factors that regulate their photosynthesis, whilst area gain is more controlled by internal factors, such as their nitrogen metabolism. This might be inferred from another study of the same species, where nitrogen manipulations resulted in an undisturbed weight gain, a similar resource allocation pattern between the bionts, but a distorted area gain. </p><p>Aiming to investigate lichen nitrogen relations even further, lichens’ capacities to assimilate combined nitrogen in the form of ammonium, nitrate and amino acids were assessed using 14 contrasting boreal species. All these had the capacity to assimilate all the three nitrogen forms, with ammonium absorption being more passive, and nitrate uptake being low in bipartite cyanobacterial lichens. Differences in uptake capacities between species were more correlated to photobiont than to morphology or substrate preferences. Finally, to investigate intra-specifi c plasticity in relation to altered nutrient supply, resource investments between photo- and mycobiont were investigated in the two bipartite green algal lichens <i>Hypogymnia physodes </i>and and <i>Platismatia glauca</i> in a low and a high nutrient environ- in a low and a high nutrient environ- ment. In both species, more of the resources had been directed to the photobiont in the high nutrient environment also increasing their overall carbon status. Taken together, my studies indicate that in spite of the apparent passive environmental control on lichen metabolism, these symbiotic organisms are able to both optimize and control their resource acquisition and allocation processes.</p>
529

Asymmetric Synthesis of C-Glycosylated Amino Acids : Incorporation in Collagen Glycopeptides and Evaluation in a Model for Rheumatoid Arthritis

Gustafsson, Tomas January 2005 (has links)
<p>This thesis describes stereoselective syntheses of four amino acids, three of which are C-glycosidic analogues of glycosylated amino acids. The overall goal of the project was to probe the interactions between MHC molecules, glycopeptide antigens and T cell receptors, that are essential for development of collagen induced arthritis. Collagen induced arthritis is a frequently used mouse model for rheumatoid arthritis, an autoimmune disease that attacks joint cartilage and leads to a painful and eventually crippling condition.</p><p>The thesis is based on four studies. The first study describes the synthesis of hydroxylysine, an amino acid that is found in collagen and is an important constituent of the glycopeptide proposed as an antigen in collagen induced arthritis. During the synthesis of hydroxylysine some new insight into the mechanism of the reductive opening of <i>p</i>-methoxybenzylidene acetals was obtained.</p><p>The remaining three studies deals with the synthesis of C-glycosidic analogues of glycosylated amino acids, hydroxy norvaline, threonine and hydroxylysine.The synthesis of each amino acid required control of several stereogenic centra and utilizes a variety of approaches such as use of stereoselective reactions, chiral auxilaries, chiral templates and asymmetric catalysis.</p><p>The C-glycosidic analogues of galactosylated hydroxynorvaline and hydroxylysine were incorporated in glycopeptides from type II collagen and evaluated in T cell response assays. It was found that the T cells were stimulated by the C-glycopeptides, but that higher concentrations were required than for the native O-glycopeptide</p>
530

Clinical and experimental studies of organ-specific autoimmune diseases : With special reference to Addison's disease and autoimmune hepatitis : by Gennet Gebre-Medhin

Gebre-Medhin, Gennet January 2001 (has links)
<p>Organ-specific autoimmunity constitutes a large health problem, where both the clinical management and our understanding of the pathogenetic mechanisms need to improve. Women with Addison's disease have abnormally low levels of dehydroepiandrosterone (DHEA), its sulphate ester (DHEA-S) and androgens relative to age, and many patients complain of physical and mental fatigue and low stress tolerance. To define a suitable dose, the effect of oral DHEA replacement was evaluated in women with Addison's disease. </p><p> DHEA was administered for three months to nine women with Addison's disease in either of two doses, 50 mg (n=5) or 200 mg (n=4). A dose of 50 mg restored the DHEA(S) and androgen levels to normal without altering the insulin sensitivity, body composition or serum lipid profile.</p><p> Autoimmune polyendocrine syndrome type I (APS I) is a rare but useful model disorder of autoimmunity, characterised by multiple organ-specific autoimmune manifestations and high-titre autoantibodies and with adrenocortical insufficiency, Addison's disease, as one of its cardinal manifestations. Approximately 10-20% of APS I patients suffer from autoimmune hepatitis, which carries a high mortality, if untreated. The presence of putative antigenic targets in the liver was investigated.</p><p> Cytochrome P4501A2 (CYP1A2) and aromatic L-amino acid decarboxylase (AADC) were identified as hepatic autoantigens with the use of APS I sera for immunofluorescent staining of normal human liver, Western blot of microsomal and cytosol fractions of human liver homogenate, and immunoprecipitation of <i>in vitro</i> transcribed and translated radioactively labelled proteins. The presence of CYP1A2- and AADC-antibodies was significantly correlated to AIH, and CYP1A2 antibodies inhibited enzyme activity <i>in vitro</i>.</p><p><i> In conclusion</i>, a daily replacement dose of 50 mg of DHEA sufficiently restores levels of DHEA, DHEA(S) and androgens in women with Addison's disease, without severe side-effects. We have further identified CYP1A2 and AADC as hepatic autoantigens associated with autoimmune hepatitis in APS I.</p>

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