Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 4 uppsatser.

[EN] This PhD Thesis focuses on characterizing potential emissions of ammonia (NH3) and methane (CH4) from pig slurries. In particular, it analyses the relationships between nutrient consumption and excretion, slurry composition and potential NH3 and CH4 emissions, as well as the potential fertilizer value of slurries. Besides, the methodologies to determine in vitro potential NH3 and CH4 emissions are analysed and optimization alternatives are proposed. The objectives of this PhD Thesis are to: i) Characterize the composition, potential NH3 and CH4 emissions, and potential fertilizer value of slurries from Spanish commercial farms, ii) Evaluate the influence of incorporating to feedstuffs a fat source (calcium soap of palm fatty acid distillate, CSP) and fibre source (citrus pulp, CP) on slurry composition and potential NH3 and CH4 emissions in growing pigs, and iii) Optimize the in vitro measurement techniques of potential NH3 and CH4 emissions from pig slurries. The results of this Thesis show that physicochemical characteristics of slurries from Spanish commercial farms vary widely, and the type of animal (e.g. sows against growing animals) affect in a relevant way the contents of total nitrogen, ammonia nitrogen, potassium, calcium, cupper, sodium, zinc, volatile fatty acids, as well as the pH of slurries. Consequently, the type of animal also affected potential NH3 and CH4 emissions. Therefore, the optimum utilization of slurries from commercial farms, either as fertilizer or as feedstock for biogas production, requires a previous characterization. On the other hand, it was found that management factors and feedstuff waste probably influenced the slurry characteristics and potential NH3 and CH4 emissions. Including CSP as fat source and CP as fibre source in growing pig diets changed significantly slurry composition. Including CSP increased the excretion of ether extract and crude protein. Regarding gaseous emissions from slurries, including CSP increased potential CH4 emissions and reduced NH3 emissions. Including CP affected faecal composition, but potential emissions were not affected. On the other hand, evidences were found that lower crude protein consumptions (-14% CP) could be associated to higher reductions of NH3 emissions (-66%). The same tendency was found regarding the effect of crude energy intake on CH4 emissions: a 20% reduction of crude energy would be associated to 46% reductions of CH4 emissions. Additionally, the evaluation of in vitro measurement techniques for potential NH3 and CH4 emissions from pig slurries suggest that it could be possible to reduce up to 50% the resources (time and material) which are used following the standard procedures, without significant effects on the results. Additionally, prediction models of potential NH3 and CH4 emissions are proposed, based on the physicochemical characteristics of slurries and the dynamics of in vitro emissions. In overall, this PhD Thesis provides valuable information to improve the use of pig slurries, to mitigate the associated NH3 and CH4 emissions, and to optimize in vitro measurement methods for potential NH3 and CH4 emissions. Additionally, evidences were found on how to optimize the use of protein and energy in growing pigs from a sustainable perspective both in economic and environmental terms. / [ES] La presente Tesis Doctoral está enfocada a la caracterización de las emisiones potenciales de amoniaco (NH3) y metano (CH4) a partir de purines porcinos. En concreto, estudia la relación entre el consumo y la excreción de nutrientes, la composición de los purines y las emisiones potenciales de NH3 y CH4 y el valor agrícola potencial de los purines. Además, evalúa las metodologías de medición de las emisiones potenciales de NH3 y CH4 in vitro y propone estrategias para su optimización. Los objetivos de la presente Tesis Doctoral son: i) Caracterizar la composición, el potencial de emisión de NH3 y CH4 y el valor agrícola potencial de purines de granjas comerciales de España, ii) Evaluar la influencia de la inclusión en el pienso de una fuente de grasa (jabón cálcico de palma) y una fuente de fibra (pulpa de naranja) sobre la composición del purín y emisiones potenciales de NH3 y CH4 en cerdos en crecimiento y iii) Optimizar las técnicas de medición de las emisiones potenciales de NH3 y CH4 in vitro de purines de cerdo. Los resultados de esta Tesis indican que las características fisicoquímicas de purines de granjas comerciales de España varían ampliamente y el tipo de animal (madres vs. animales en crecimiento) afecta de forma relevante a los contenidos de nitrógeno total, nitrógeno amoniacal, potasio, calcio, cobre, sodio, zinc, ácidos grasos volátiles y el pH de los purines, y en consecuencia afectan también sus emisiones potenciales de NH3 y CH4. Por lo tanto, la utilización óptima de purines de granjas comerciales como fertilizante agrícola o como insumo para la producción de biogás requiere su previa caracterización. Por otra parte, es probable que factores de manejo y el desperdicio del pienso por los cerdos en granjas comerciales influyan de forma relevante sobre las características de los purines y como tal sobre sus emisiones de NH3 y CH4. La inclusión de jabón cálcico de palma (como fuente de grasa) y pulpa de naranja (como fuente de fibra) en dietas de cerdo de engorde produjo cambios significativos en la composición de purín. La inclusión de jabón cálcico de palma provocó mayores excreciones de extracto etéreo y proteína bruta, así mismo causó mayores emisiones de CH4 y menores emisiones de NH3. La inclusión de pulpa de naranja alteró la composición fecal, pero no afectó significativamente a las emisiones de NH3 y CH4. Por otro lado, se encontró evidencias de que menores consumos de proteína bruta (PB) (-14% de PB) permitiría reducir proporcionalmente mayores cantidades de emisiones de NH3 (-66%). Esta misma tendencia se encontró entre la ingesta de energía bruta y las emisiones de CH4, de forma que reducciones de -20% en la ingesta de energía bruta permitiría reducciones de -46% de emisiones de CH4. Por otra parte, los resultados de la evaluación de las metodologías de mediciones de las emisiones potenciales de NH3 y CH4 in vitro de purines de cerdo sugieren la posibilidad de reducir hasta en un 50% los recursos (tiempo y reactivos) dedicados a la medición de las emisiones potenciales de NH3 y CH4 in vitro. Adicionalmente, se proponen modelos de predicción de las emisiones potenciales de NH3 y CH4 basados en las características fisicoquímicas de purines y en las dinámicas de emisión in vitro. En su conjunto, la presente Tesis Doctoral proporciona información que permitirá mejorar la utilización de los purines de cerdos, mitigar las emisiones de NH3 y CH4, optimizar las mediciones de las emisiones de NH3 y CH4 in vitro. Al mismo tiempo se encontraron evidencias que indican la posibilidad de optimizar la utilización de la proteína y la energía en la alimentación de cerdos de engorde con una perspectiva sostenible económica y ambientalmente. / [CAT] La present Tesi Doctoral està enfocada en la caracterització de les emissions potencials d'amoníac (NH3) i metà (CH4) a partir de purins porcins. En concret, estudia la relació entre el consum i l'excreció de nutrients, la composició dels purins i les emissions potencials de NH3 i CH4 i el valor agrícola potencial dels purins. A més, avalua les metodologies de mesurament de les emissions potencials de NH3 i CH4 in vitro i proposa estratègies per a la seua optimització. Els objectius de la present Tesi Doctoral són: i) Caracteritzar la composició, el potencial d'emissió de NH3 i CH4 i el valor agrícola potencial de purins de granges comercials d'Espanya, ii) Avaluar la influència de la inclusió en el pinso d'una font de greix (sabó càlcic de palma) i una font de fibra (polpa de taronja) sobre la composició del purí i emissions potencials de NH3 i CH4 en porcs en creixement i, iii) Optimitzar les tècniques de mesurament de les emissions potencials de NH3 i CH4 in vitro de purins de porc. Els resultats d'aquesta Tesi indiquen que les característiques fisicoquímiques de purins de granges comercials d'Espanya varien àmpliament i el tipus d'animal (mares vs. animals en creixement) afecta de forma rellevant als continguts de nitrogen total, nitrogen amoniacal, potassi, calci, coure, sodi, zinc, àcids grassos volàtils i el pH dels purins, i en conseqüència afecten també les seues emissions potencials de NH3 i CH4. Per tant, la utilització òptima de purins de granges comercials com a fertilitzant agrícola o com entrada per a la producció de biogàs requereix una caracterització prèvia. D'altra banda, és probable que factors de maneig i el desaprofitament del pinso pels porcs en granges comercials influïxen de forma rellevant sobre les característiques dels purins i com a tal sobre les seues emissions de NH3 i CH4. La inclusió de sabó càlcic de palma (com a font de greix) i polpa de taronja (com a font de fibra) en dietes de porc d'engreix va produir canvis significatius en la composició del purí. La inclusió de sabó càlcic de palma va provocar majors excrecions d'extracte eteri i proteïna bruta, així mateix va causar majors emissions de CH4 i menors emissions de NH3. La inclusió de polpa de taronja va alterar la composició fecal, però no va afectar significativament les emissions de NH3 i CH4. D'altra banda, es van trobar evidències que menors consums de proteïna bruta (PB) (-14% de PB) permetria reduir proporcionalment majors quantitats d'emissions de NH3 (-66%). Aquesta mateixa tendència es va trobar entre la ingesta d'energia bruta i les emissions de CH4, de manera que reduccions de -20% en la ingesta d'energia bruta permetria reduccions de -46% d'emissions de CH4. D'altra banda, els resultats de l'avaluació de les metodologies de mesuraments de les emissions potencials de NH3 i CH4 in vitro de purins de porc suggereixen la possibilitat de reduir fins un 50% els recursos (temps i reactius) dedicats al mesurament de les emissions potencials de NH3 i CH4 in vitro. Addicionalment, es proposen models de predicció de les emissions potencials de NH3 i CH4 basats en les característiques fisicoquímiques de purins i en les dinàmiques d'emissió in vitro. En el seu conjunt, la present Tesi Doctoral proporciona informació que permetrà millorar la utilització dels purins de porcs, mitigar les emissions de NH3 i CH4, optimitzar els mesuraments de les emissions de NH3 i CH4 in vitro. Al mateix temps es van trobar evidències que indiquen la possibilitat d'optimitzar la utilització de la proteïna i l'energia en l'alimentació de porcs d'engreix amb una perspectiva sostenible econòmica i ambientalment / Antezana Julián, WO. (2016). Análisis de los factores que influyen en las emisiones de amoniaco y metano de purines porcinos: composición del purín y factores nutricionales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68050 / TESIS

La Sclérose Tubéreuse de Bourneville est une pathologie génétique rare qui se caractérise par la survenue de crises épileptiques précoces à l’origine du développement de nombreux troubles neurologiques tels que des symptômes autistiques ou des retards mentaux. Les épilepsies retrouvées dans la Sclérose Tubéreuse de Bourneville sont souvent résistantes aux traitements pharmacologiques disponibles soulevant la nécessité de trouver de nouvelles approches médicamenteuses plus efficaces pour traiter les patients. Dans cette étude nous avons mis en évidence que l’AppCH2ppA est une molécule efficace pour bloquer la survenue des crises épileptiques dans un modèle de souris pour la Sclérose Tubéreuse de Bourneville ainsi que sur des résections chirurgicales de tissu provenant de patients humains atteints par la Sclérose Tubéreuse de Bourneville. Nous avons montré que les propriétés antiépileptiques de l’AppCH2ppA s’appuient sur une libération autocrine d’adénosine par les neurones de la couche IV du cortex somatosensoriel et d’une activation consécutive des récepteurs à l’adénosine de type A1. Cette activation a lieu spécifiquement au niveau du compartiment postsynaptique et est responsable d’une activation de conductances potassiques et d’une diminution de l’excitabilité des neurones. L’administration d’AppCH2ppA n’est associé à aucun effet secondaire notables sur la santé des souris. Ainsi l’AppCH2ppA semble être un outil thérapeutique prometteur et peu risqué qui stimule des mécanismes antiépileptiques endogènes naturellement sollicités par le cerveau et efficaces pour stopper et limiter la survenue des crises épileptiques. / Tuberous Sclerosis Complex (TSC) is a rare genetic disease characterized by the presence of epilepsies that appear early and in the life of patients and are responsible for the development of several neurological disorders such as autistic symptoms or mental retardations.In TSC, epileptic seizures often resist to pharmacological approaches raising the importance to find new molecules to treat more efficiently the patients.In this study we showed that AppCH2ppA is an effective molecule to block the onset of epileptic seizures in a mouse model for Tuberous Sclerosis as well as on human patients tissues.We have shown that AppCH2ppA nduce an autocrine release of adenosine by the spiny stellate cells present in the layer IV of the somatosensory cortex. This release is responsible for a subsequent activation of adenosine A1 receptors that occur specifically in the postsynaptic compartment of neurons and is responsible for an activation of potassium channels and a decrease of the excitability of neurons. The administration of AppCH2ppA is not associated with any significant side effects on mouse health. Thus, AppCH2ppA appears to be a promising and low-risk therapeutic tool that stimulates an endogenous antiepileptic pathway that is naturally used in the brain and that is efficient to stop and limit the appearance of epileptic seizures.

Gold compounds have been used in medicine dating back as early as 2500 BC. Over the years gold(I) and gold(III) compounds have been used and designed to target rheumatoid arthritis, cancer, and viral diseases. New drug targets have been found for gold compounds that give insight into their mechanisms of action. Here we focus on the synthesis of Au(III) compounds designed to selectively target zinc finger (ZF) proteins. ZF proteins exhibit a variety of functions, including transcription, DNA repair, and apoptosis. Displacement of the central zinc ion, along with mutation of coordinated amino acids can result in a loss of biological function. Synthesis of complexes that selectively target zinc finger proteins, in turn inhibiting DNA/ZF interactions and therefore resulting in loss of protein function, is of great interest. Of particular interest here is the Cys3His (Cys = cysteine, His = histidine) HIV nucleocapsid zinc finger protein, NCp7. NCp7 is involved in multiple steps of the HIV life cycle, thus making it a desirable drug target. Previous studies from our group show platinated nucleobases such as [Pt(dien)(9-EtG)]2+ (dien = diethylenetriamine; 9-EtG = 9-ethylguanine) to stack effectively in a non-covalent manner with tryptophan of the C-terminal finger of HIV Nucleocapsid, NCp7(F2), a key residue involved in nucleic acid recognition. Due to the isoelectronic and isostructural relationship of Au(III) to Pt(II), we have expanded this system to Au(III)-(nucleobase/N-heterocycle) compounds. Novel Au(III)(dien)(N-heterocycle) compounds, including the first Au(III)N3(N-purine) examples, were synthesized. As previously reported for [AuCl(dien)]Cl2, these compounds exhibit pH dependency of the 1H NMR chemical shifts of the dien ligand. The acidity of the dien ligand is affected by the nature of the fourth ligand as a leaving group. The presence of an inert nitrogen donor, compared to that of the more labile Cl-, as the leaving group stabilizes the Au(III) metal center towards reduction, resulting in significant enhancement of π−π stacking interactions with tryptophan relative to platinum(II) and palladium(II) compounds. The presence of a more inert N-donor as the leaving group slows down the reaction with the sulfur-containing amino acid N-Acetylmethionine (N-AcMet); essentially no reaction was observed for the Au(III)-N-heterocycle compounds. All compounds react readily with N-Acetylcysteine (N-AcCys), however lack of N-heterocycle ligand dissociation indicates, to our knowledge, the first long-lived N-heterocycle-Au-S species in solution. Electrospray ionization mass spectrometry (ESI-MS) studies with NCp7(F2) indicate [Au(dien)(DMAP)]3+ (DMAP = 4-dimethylaminopyridine) to be the least reactive of the Au(III) compounds studied, showing the presence of intact NCp7(F2) zinc finger at initial reaction times. Reactivity of the Au-compounds was compared with that of Sp1(F3), a Cys2His2 ZF; in contrast, no intact ZF was observed for any of the compounds studied, suggesting the mode of action of these compounds is dependent on the nature of the zinc binding core. ESI-MS studies were expanded to that of the full HIV NCp7 zinc finger. [Au(dien)(9-EtG)]3+ reacts quickly with NCp7, resulting in immediate zinc ejection and replacement with up to three gold ions. Unlike with [Au(dien)(DMAP)]3+, no intact NCp7 was observed. Addition of [Au(dien)(9-EtG)]3+ to preformed NC-SL2 complex results in release of free RNA; based on EMSA (electrophoretic mobility shift assay) studies, [Au(dien)(9-EtG)]3+ disrupts the NCp7-RNA complex with an IC50 of ~450 µM. It is possible that this HIV nucleocapsid-nucleic acid antagonism may result in a loss of viral activity.

Esta tesis doctoral aborda el estudio del ciclo de vida de varias especies de sírfidos saprófagos de la tribu de los Eristalini: Eristalis tenax (Linneo, 1758), Eristalinus aeneus (Scopile, 1763) y Eristalinus taeniops (Wiedemann, 1818). Se ha incidido especialmente en múltiples aspectos de su biología larvaria así como en parámetros básicos de la biología imaginal implicados en su cría artificial y el establecimiento de colonias permanentes. A continuación se exponen brevemente los objetivos planteados y los resultados en cada uno de los capítulos, organizados en dos grandes bloques referentes al estudio de la biología larvaria y de la biología de los imagos. Bloque I. Estudio de la biología preimaginal de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus. Capítulo 1: Influencia del tipo de medio de desarrollo larvario en el ciclo de vida. En este capítulo se analiza el efecto de diferentes medios de desarrollo larvario sobre varios parámetros biológicos relacionados con el ciclo biológico de cada especie. En concreto se comparan tres medios de tipos artificial basados en cereal en grano (avena, arroz y cebada) frente a un medio natural elaborado con purín procedente de explotaciones porcinas. Capítulo 2: Influencia de la competencia intraespecífica durante el desarrollo preimaginal. En este capítulo se planteó el estudio de la influencia de la densidad larvaria sobre desarrollo larvario mediante el análisis de parámetros biológicos de relevada importancia como la supervivencia, la duración del periodo preimaginal, y el tamaño/peso seco de los imagos. Los resultados indican que, para todas las especies, el incremento de la densidad larvaria en medios artificiales de desarrollo (cereales) provoca un aumento en los periodos de desarrollo, una disminución en la supervivencia y una reducción en el tamaño final de los imagos. Este efecto fue también observado en Eristalis tenax utilizando un medio de desarrollo con purines porcinos. Capítulo 3: Estudios mediante microscopía electrónica de barrido (SEM) de los estados inmaduros de sírfidos eristalinos Eristalis similis (Fallen, 1817) y Eristalis tenax (Linnaeus, 1758). Este capítulo presenta la primera descripción de la larva y el pupario de E. similis, incluyendo un estudio morfológico comparativo de los estados preimaginales de la especie sinatrópica y cosmopolita E. tenax. Las descripciones de ambas especies se han llevado a cabo utilizando por vez primera microscopía electrónica de barrido (SEM). La morfología preimaginal de E. similis fue comparada con todas las descripciones larvarias conocidas del género Eristalis. Capítulo 4: Biología de Rhembobius quadrispinus (Gravenhörst) (Hymenoptera: Ichneumonidae) y su efecto como parasitoide de pupas de especies de sírfidos saprófagos. En este capítulo se presenta la biología e importantes detalles del ciclo de vida del parasitoide de pupas R. quadrispinus, tanto en condiciones naturales como en experimentos controlados en laboratorio. El comportamiento de cópula y de ovoposición fue filmado en video para su posterior análisis. La idoneidad del hospedador y la influencia tanto de la edad de la pupa como de la edad de la hembra de parasitoide en el desarrollo de su progenie fue evaluada mediante experimentos en condiciones controladas. Bloque II. Estudio de la biología imaginal de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus. Capítulo 5: Análisis de los principales parámetros biológicos relacionados con la cría artificial de sírfidos eristalinos. En este capítulo se presentan resultados preliminares sobre varios parámetros relacionados con la cría artificial de sírfidos eristalinos. En el caso de Eristalis tenax, se evaluaron diferentes tipos de polen resultando como el más óptimo el polen fresco de abeja sin ser sometido a procesamientos por deshidratación. Respecto a la disponibilidad de polen en la colonia, una mayor frecuencia en el aporte de polen fresco proporciona a las hembras de E. tenax una longevidad mayor, llegando a superar los 30 días si se alimentan cada 3 días frente a los 18 días de media si se oferta cada 10 días. Capítulo 6: Análisis de los principales parámetros biológicos relacionados con la fertilidad y la maduración de los imagos. En este capítulo se describe el desarrollo ovárico de las hembras de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus, evaluándose la idoneidad de diversos tipos de alimentación y su repercusión en la fertilidad. También se analizó la influencia de la densidad larvaria en el proceso de maduración sexual de las hembras. En las colonias de E. tenax, las hembras no lograron una maduración completa de sus ovarios hasta una edad media de unos 20 días. El número medio de huevos en la primera puesta fue de unos 200 huevos y las hembras alcanzaron longevidades próximas a los 3 meses. En el caso de E. aeneus se han obtenido unos resultados muy positivos en todos los parámetros estudiados con relación a su fertilidad. La longevidad media de las hembras fue de 60 días en media, alcanzando frecuentemente los cuatro meses. Es la especie con un periodo de preovoposición más corto. El número medio de huevos por puesta fue de unos 135 huevos. En el caso de E. taeniops, se ha detectado una reducida longevidad de las hembras en condiciones artificiales, con un periodo de vida de poco más de un mes y con un prolongado periodo de maduración de las hembras. / European LIFE project ECODIPTERA (LIFE05-ENV/E/000302)

Objetivou-se avaliar o efeito da adição de sais de cálcio de ácidos graxos (SCAG) e de diferentes teores de proteína degradável no rúmen (PDR) na dieta de vacas leiteiras sobre: consumo, fermentação e metabolismo de nitrogênio ruminal, desempenho produtivo e balanço de nitrogênio; as estimativas de síntese microbiana utilizando 15N e bases purinas (BP) como indicadores microbianos, a composição dos pellets de bactéria, a recuperação de derivados purina (DP) na urina e a excreção urinária de DP de origem endógena; o fluxo omasal de ácidos graxos, a extensão de bio-hidrogenação e o perfil lipídico das bactérias. Oito vacas em lactação, multíparas e canuladas no rúmen foram usadas em um delineamento em quadrado Latino 4 × 4 replicado, distribuídas em arranjo fatorial 2 × 2 de tratamentos. Os tratamentos foram obtidos pela combinação da adição de SCAG (-SCAG: sem suplementação; e +SCAG: com 3,32% matéria seca (MS) de SCAG) e os teores de PDR (BPDR: baixo PDR, com 9,8% MS de PDR; e APDR: alto PDR: com 11,0% de PDR na MS da dieta). A suplementação lipídica reduziu (P ≤ 0,049) o consumo, tendeu (P = 0,076) a aumentar o tempo de ruminação e aumentou (P = 0,015) o pH ruminal. A adição de SCAG diminuiu (P ≤ 0,013) a digestibilidade aparente ruminal da MS e matéria orgânica, e tendeu a reduzir (P = 0,096) a digestibilidade ruminal da fibra em detergente neutro (FDN) e reduziu (P = 0,043) o nitrogênio (N) verdadeiramente digerido no rúmen. Apesar de afetar (P = 0,039) negativamente o fluxo de nitrogênio não amoniacal (NNA) associado com as grandes partículas, SCAG não afetou (P ≥ 0,634) o fluxo total de NNA e o fluxo de NNA microbiano, e aumentou (P = 0,032) a eficiência de síntese proteica microbiana. Animais alimentados com SCAG apresentaram maior (P = 0,043) produção de leite, com menor (P < 0,001) teor de gordura, maior (P < 0,001) eficiência alimentar e de uso do N. Animais alimentados com BPDR tenderam (P ≤ 0,096) a apresentar maior consumo de proteína bruta e relação entre as concentrações ruminais de acetato e propionato. Ainda, APDR elevou (P ≤ 0,048) a digestibilidade aparente total do amido e a digestibilidade ruminal verdadeira do N. O nível de PDR não afetou (P ≥ 0,719) a síntese de proteína microbiana e a eficiência de síntese, enquanto que BPDR aumentou (P ≤ 0,055) a produção de leite e reduziu o teor de proteína do leite. O alto nível de PDR tendeu (P ≤ 0,088) a reduzir a excreção fecal e o balanço de N, enquanto aumentou (P = 0,021) a excreção urinária relativa ao consumo de N. As bactérias associadas à partícula (BAP) apresentaram menor (P ≤ 0,008) enriquecimento com 15N e relação N purinas: N total microbiano do que as bactérias associadas à fase líquida (BAL). A utilização de BP como indicador superestimou (P ≤ 0,002) o fluxo microbiano, especialmente de BAL. No entanto, para o fluxo microbiano associado à partícula, houve tendência à interação (P = 0,067) entre os efeitos de indicador e da suplementação lipídica. Na presença de SCAG, BP e 15N apresentaram (P > 0,05) estimativas similares, enquanto que na ausência de SCAG, BP subestimou (P ≤ 0,05) o fluxo de BAP, em relação ao 15N. O aumento do nível de PDR da dieta tendeu a reduzir (P = 0,061) o fluxo omasal de BP e reduziu (P = 0,007) a recuperação urinária desta. A recuperação urinária de DP foi extremamente variável (33,9% de coeficiente de variação). As estratégias nutricionais avaliadas não afetaram (P ≥ 0,108) a excreção urinária de creatinina e DP de origem endógena. As excreções diárias de creatinina e DP de origem endógena foram de 0,262 mmol/kg e 640 mmol/kg0,75, respectivamente. O aumento do nível de PDR da dieta resultou na redução (P < 0,001) do consumo dos ácidos graxos C4:0, C12:0, C14:0, C16:0 e C18:0, e tendeu (P = 0,068) a reduzir o consumo de C18:1 trans. Houve interação ou tendência (P ≤ 0,095) à interação entre os efeitos do nível de PDR e adição de SCAG sobre o fluxo omasal de ácidos graxos totais e alguns ácidos graxos específicos (C15:0, C16:0, C17:0, C18:0, C18:1 cis-9, C18:2 cis-9 cis-12, C18:3 cis e C22:0). Nas dietas contendo SCAG, nenhum efeito do nível de PDR foi observado sobre o fluxo omasal de ácidos graxos (P > 0,05), enquanto que nas dietas -SCAG, o aumento do nível de PDR aumentou (P ≤ 0,05) o fluxo omasal total de ácidos graxos. Consequentemente, o aumento do nível de PDR reduziu (P ≤ 0,05) a extensão de bio-hidrogenação do C18:1 cis e C18:3 nas dietas -SCAG, sem efeitos (P > 0,05) nas dietas +SCAG. A adição de SCAG aumentou (P ≤ 0,001) a extensão de bio-hidrogenação do C18:2, assim como o teor de AG dos pellets de bactéria. O nível de PDR da dieta não afetou (P ≥ 0,116) o perfil de ácidos graxos dos microrganismos, nem o perfil de ácidos graxos do leite. A adição de SCAG reduziu ou tendeu (P ≤ 0,080) a reduzir os teores de C15:0, C16:0, C16:1, C17:0 e C18:0, e aumentou (P ≤ 0,005) as concentrações de ácidos graxos insaturados de 18 carbonos nos microrganismos. Além disso, a adição de SCAG reduziu (P ≤ 0,009) a concentração de todos os ácidos graxos menores do que 18 carbonos e a razão entre saturados e insaturados na gordura do leite, bem como aumentou (P ≤ 0,001) as concentrações dos ácidos graxos com 18 carbonos ou mais e dos ácidos graxos insaturados. Desta forma, a adição de SCAG na dieta reduz o consumo, aumenta o tempo de ruminação, a eficiência microbiana e a produção de leite, sem afetar o fluxo microbiano. O aumento do nível de PDR da dieta reduz as perdas fecais de N e a produção de leite. As BP superestimam o fluxo microbiano, especialmente das BAL, pela presença de BP de origem dietética. A suplementação lipídica afeta a relação entre as estimativas de fluxo de BAP utilizando 15N e BP, levando à baixa correlação entre as estimativas com as duas técnicas. A recuperação urinária dos DP foi extremamente variável e aumentou com o aumento do nível de PDR da dieta. As excreções de creatinina e a excreção endógena de DP não são afetadas pela suplementação lipídica e pelo teor de PDR da dieta. A suplementação lipídica afeta consideravelmente o consumo e fluxo omasal de ácidos graxos, assim como o perfil lipídico dos microrganismos e o perfil de ácidos graxos do leite. Apesar de potencialmente aumentar o fluxo de alguns ácidos graxos insaturados e reduzir a extensão de bio-hidrogenação do C18:1 e C18:3, nas dietas sem SCAG, o nível de PDR tem poucos efeitos sobre o perfil de ácidos graxos das bactérias e do leite. / This study aimed to evaluate the effects of calcium salts of fatty acids (CSFA) addition and different levels of rumen degradable protein (RDP) in the diet of dairy cows on: feed intake, ruminal fermentation and nitrogen metabolism, productive performance and nitrogen balance; microbial protein synthesis estimates using 15N and purines basis (PB) as microbial markers, composition of bacterial pellets, urinary recovery of purines derivatives (PD) and endogenous PD excretion; omasal flow of fatty acids (FA), the bio-hydrogenation extent and FA profile of bacteria. Eight lactating, multiparous and rumen cannulated cows were used in a replicated 4 × 4 Latin square design, with a 2 × 2 factorial arrangement of treatments. The treatments were obtained by the combination of CSFA addition (-CSFA: without supplementation, and +CSFA: with 3.32% CSFA per kg dry matter - DM) and the RDP level (LRDP: low RDP, with 9.8% MS of RDP, and HRDP, high RDP: with 11.0% RDP of diet DM). Fat supplementation reduced (P ≤ 0.049) feed intake, while tended (P = 0.076) to increase rumination time, and increased (P = 0.015) ruminal pH. In addition, CSFA supplementation decreased (P ≤ 0.013) DM and organic matter ruminal digestibility, and tended (P ≤ 0.096) to reduce NDF ruminal digestibility, and reduced (P = 0.043) N truly digested in the rumen. Besides negative effect (P = 0.039) on non-ammonia nitrogen (NAN) associated with large phase, CSFA showed no effect (P ≥ 0.634) on total NAN and microbial NAN flow, and increased (P = 0.032) microbial efficiency. Animals fed CSFA had higher (P = 0.043) milk yield, with lower (P < 0.001) fat content, and improved (P < 0.001) feed efficiency and N usage efficiency, in relation to those animals fed with non-supplemented diets. Animals fed LRDP tended to show higher (P ≤ 0.096) CP intake, and acetate to propionate ruminal ratio, in relation to animals fed HRDP. In addition, HRDP increased (P ≤ 0.048) starch total tract apparent digestibility and ruminal truly digestibility of N. The level of RDP showed no effect (P ≥ 0.719) on microbial N synthesis and microbial efficiency, and lower RDP level increased (P ≤ 0.055) milk yield and decreased milk protein content. Decreased RDP level tended (P = 0.074) to reduce N fecal excretion, and increased (P = 0.021) fractional urinary excretion. Particle-associated bacteria (PAB) showed lower (P ≤ 0.008) enrichment with 15N and purines N to total microbial N ratio, than liquid associated bacteria (LAB). Purine basis overestimated (P ≤ 0.002) microbial flow, especially LAB flow. However, there was interaction (P = 0.067) between the effects of marker and lipid supplementation on PAB flow. In diets containing CSFA, PB and 15N showed similar (P > 0.05) estimates, whereas in the absence of CSFA, PB underestimated (P ≤ 0.05) PAB flow, in relation to 15N. Increased dietary RDP levels tended (P = 0.061) to reduce omasal PB flow and decreased (P = 0.007) it\'s urinary recovery. Urinary recovery of PD was extremely variable (33.9% variation coefficient). Different evaluated factors had no effect (P ≥ 0.108) on urinary excretion of creatinine, and PD of endogenous origin. Daily excretions of creatinine and endogenous PD were 0.262 mmol/kg and 640 mmol/0.75, respectively. Higher RDP level resulted in reduced (P < 0.001) C4:0, C12:0, C14:0, C16:0 and C18:0 FA intake, and tended (P = 0.068) to reduce C18:1 trans intake. There was an interaction (P ≤ 0.095) between effects of the RDP and CSFA on the omasal flow of total FA and some specific FA (C15:0, C16:0, C17:0, C18:0, C18:1 cis-9, C18:2 cis-9 cis-12, C18: 3 cis and C22:0). This interaction occurred due to the higher (P ≤ 0.05) omasal flow as consequence of increased RDP level, in the diets without CSFA. In diets containing CSFA, no effect (P > 0.05) of the RDP level was observed on the omasal flow of FA. Consequently, the increase of RDP reduced (P ≤ 0.05) the bio-hydrogenation extent of these FA in the diets -CSFA, with no effects (P > 0.05) on the diets +CSFA. The addition of CSFA increased (P ≤ 0.001) C18:2 bio-hydrogenation extent, as well as FA content of bacterial pellets. Dietary level of RDP had no effect (P ≥ 0.116) on microorganisms and milk FA profile. The addition of CSFA decreased or tended (P ≤ 0.080) to decrease the levels of C15:0, C16:0, C16:1, C17:0 and C18:0 FA, while increased (P ≤ 0.005) the concentrations of 18-carbon unsaturated fatty acids in the microorganisms. In addition, CSFA reduced (P ≤ 0.009) the concentration of all FA lower than 18 carbons, saturated and unsaturated ratio in milk fat, and increased (P ≤ 0.001) the concentrations of FA with 18 carbons or more, as well as unsaturated fatty acids. Thus, CSFA dietary addition decreases feed intake, increases rumination time, microbial efficiency, and milk yield. Higher level of RDP reduces N fecal losses and milk yield, and increases urinary losses of N. Purine basis overestimate microbial flow, especially LAB flow, by the presence of PB of dietary origin. Lipid supplementation affects the relationship between PAB flow estimates using 15N and PB, leading to a low correlation between the estimates with the two techniques. The urinary recovery of the PD was extremely variable and increased with the increase of the dietary RDP level. Creatinine excretions and endogenous excretion of PD are not affected by evaluated treatments. Lipid supplementation affects FA intake and omasal flow, as well as microorganisms and the milk FA profile. Although potentially increase the flow of some unsaturated FA and reduce the extent of bio-hydrogenation of C18:1 and C18:3 FA in the diets without CSFA, the level of RDP has no effects on microorganisms and milk FA profile.

A la suite de la découverte au laboratoire d'une nouvelle réaction entre le méthylglyoxal et un α-aminoazahétérocycle, une nouvelle famille de modulateurs (famille I) de la protéine CFTR (Cystic Fibrosis Transmembrane conductance Regulator) a été mise en évidence. Les dysfonctionnements de cette protéine, qui constitue un canal chlorure transmembranaire, sont responsables de plusieurs pathologies de la mucoviscidose résultant de mutations du gêne correspondant.<br />Nous avons tout d'abord cherché à confirmer la structure du pharmacophore supposé en sélectionnant et évaluant des petites molécules contenant le pharmacophore ou en modifiant les groupements à proximité du pharmacophore. Cette étude a permis l'accès à de nouveaux composés issus de la réaction entre un autre α-oxoaldéhyde (éthylglyoxal) et des α-aminoazahétérocycles et, à deux autres familles de composés dérivés de la première (familles II et III). <br />Par ailleurs, en nous basant sur la structure des deux « chef de files », l'inhibiteur GPinh-5a et le potentiateur/activateur GPact-11a, nous avons développé une pharmacomodulation de la structure de base des composés actifs qui sont des dérivés de purine. Un grand nombre d'analogues ont ainsi été synthétisés.<br />Ces deux approches ont permis la mise en évidence de plusieurs nouveaux inhibiteurs et de deux nouveaux potentiateurs de la protéine CFTR. <br />Au regard des caractéristiques et des propriétés des composés les plus actifs, leur étude biologique doit donc être poursuivie dans le but d'aboutir à une utilisation thérapeutique

Here, for the first time, the formation of adenine, hypoxanthine, and guanine from formamide solutions with heating only to 130 degrees C and UV-irradiation in the absence of minerals or inorganic salts is shown using LC-MS/MS as the analysis technique. The thesis goes on to demonstrate that the product distributions change drastically when the temperature is increased to 160 degrees C from 130 degrees C, specifically that the amount of hypoxanthine increases with the addition of UV light, and the amount of adenine increases with an increase in temperature. Along with showing the formation of purines in these reactions, the identification of pyrimidines was also achieved by GCxGC-MS. GCxGC-MS was also used to study additional samples, specifically bio-oils, where the type of compounds in the samples were easily identifiable, which allowed for a direct comparison between different types of bio-oils (e.g. Douglas-fir bark, Southern pine bark, and a Southern pine bark-wood mixture).

Some compounds, analogous to those found in naturally occurring systems, are found to possess chemotherapeutic activity. Some, in the form of their nucleoside or nucleotide derivatives, are valuable antimetabolites in that they may block normal RNA or DNA polymerisation, or may be incorporated into nucleic acids to form fraudulent, but not necessarily defective, polymers. Modification of natural ring systems, with a view to promoting chemotherapeutic activity is therefore of considerable interest; variation in the position and nature of the modification or ring substituent having a marked effect on chemotherapeutic activity. It is the purpose of this thesis to suggest methods for the facile synthesis of various uracils, pyrazoles and pyrazolo [3,4-d] - pyrimidines with alkyl, aryl and glycosyl substituents such that the nature of the ring substituents is easily varied. To this end a number of ethoxymethylene reagents were prepared which, by reaction with primary amines and hydrazines, would give acyclic intermediates capable of easy cyclisation into the uracil, pyrazole and pyrazolo [3,4-d] pyrimidine ring systems. Variation in the nature of specific substituents being determined by the choice of amine or hydrazine, other substituents being varied by modification of the original reagent.

The thesis topic entitled above involves the use of small molecules as a general means to drive nucleic acid assembly and structural transitions. We have shown that coralyne, a crescent-shaped small molecule, can assemble homo-adenine DNA and RNA sequences into anti-parallel duplexes at neutral pH, a structure containing putative purine-purine (A*A) base pairs that is otherwise unstable. The importance of the structure of the small molecule in the recognition and stabilization of A*A base pairing has been established by experimental evidence. We further provide structural evidence for the putative A*A base pairing that is stabilized by coralyne and molecules of similar size and shape. Our hypothesis that planar molecules that are slightly too large to intercalate Watson-Crick base pairs might intercalate the larger purine-purine base pairs has led to the design of a new class of small molecules that tightly bind purine-purine duplexes with excellent selectively. We have demonstrated that azacyanines can exhibit strong and selective association with a human telomeric sequence that forms a unimolecular G-quadruplex in solution. The synthetic accessibility of azacyanines makes this class of molecules amenable to library preparation for high-throughput screening. Together, the findings reported in this thesis provide further evidence for the robust and versatile nature of selective small molecule recognition of nucleic acids, especially purine-purine duplexes.