The work presented in this thesis is divided into two research areas. In part I, the synthesis and guest intercalation of inorganic-organic metal halide ammonium layered perovskites is discussed. Comparisons are made between the solid matrix before and after the intercalations, and all solids are characterized using thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). In part II, “templateree” hydrothermal synthesis of tin oxide spheres in the presence of different ortho-substituted anilines is discussed. The aim is to determine whether there are differences in the structures, shapes and surface morphology of the tin oxide spheres that correspond to the identity/shape of the ortho-substituent on the anilines. Solids were characterized by XRD, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques.

No description available.

The potential benefits of plant genetic engineering for disease and pest resistance have been widely acknowledged in many studies, and although genetically modified crops are still encountering public wariness, these benefits warrant continued exploration. Because of its intrinsic economic benefits, the development of true potato seed (TPS) cropping systems has been instituted in many regions of the world. The incorporation of transgenic resistance could further the economic gain of farmers who are seeking ways to sustain their livelihood in the most efficient way possible. It is, however, largely unresearched how sexual hybridization of a transgenic crop would affect the behavior of a transgene in the resultant progeny. In the initial part of this study, transgenic lines were developed with a Cry3Aa transgene. These plants were then used in 4x-4x reciprocal crosses and 4x-2x hybridization schemes to determine the stability of the transgene after sexual hybridization. There was no observed parent of origin effect on transgene expression; however, a highly significant, non-mendelian inheritance of the Cry3Aa transgene was seen in the maternally inherited transgene of one set of progeny from a reciprocal cross. Additional transgenic lines of potato were developed with a PVY-O coat protein transgene. These plants were challenged with PVY-O and monitored for symptoms visually and for virus serologically. One transgenic line exhibited complete resistance to PVY-O while two others showed a delay in symptom occurrence. Further examination of the expression levels of the PVY-O coat protein transgene will be necessary to determine the type and usefulness of the observed resistance. / Master of Science

Yes / The association of the arene ruthenium metallacycle [Ru4(p-cymene)4(bpe)2(donq)2][DOS]4 (bpe = 1,2-bis(4-pyridyl)ethylene, donq = 5,8-dioxydo-1,4-naphtoquinonato, DOS = dodecyl sulfate) with pyrenyl-functionalized poly(arylester) dendrimers bearing cyanobiphenyl end-groups is reported. The supramolecular dendritic systems display mesomorphic properties as revealed by polarized optical microscopy, differential scanning calorimetry and small-angle X-ray scattering measurements. The multicomponent nature of the dendrimers and of the corresponding host–guest supramolecules (i.e., end-group mesogens, dendritic core, pyrene unit, aliphatic spacers, and metallacycle) leads to the formation of highly segregated mesophases with a complex multilayered structure due to the tendency of the various constitutive building-blocks to separate in different organized zones. The pyrenyl dendrimers exhibit a multilayered smectic A-like phase, thereafter referred to as LamSmA phase to emphasize this unaccustomed morphology. As for the corresponding Ru4–metallacycle adducts, they self-organize into a multicontinuous thermotropic cubic phase with the Im3̅m space group symmetry. This represents a unique example of liquid-crystalline behavior observed for such large and complex supramolecular host–guest assemblies. Models of their supramolecular organizations within both mesophases are proposed. / R.D. thanks the Swiss National Science Foundation (Grant No 200020-140298) for financial support.

This thesis details the development of a novel photovoltaic device based on organometal halide perovskites. The initial focus of this thesis begins with the study of lighttrapping strategies in solid-state dye-sensitised solar cells (detailed in chapter 3). While I report enhancement in device performance through the application of near and far-field light-trapping techniques, I find that improvements remain step-wise due to fundamental limitations currently employed in dye-sensitised solar cell technology— notably, the available light-sensitising materials. I found a promising yet under researched family of materials in the methyl ammonium tri-halide plumbate perovskite (detailed in chapter 4). The perovskite light-sensitiser was applied to the traditional mesoscopic sensitised solar cell device architecture as a replacement to conventional dye yielding world-record breaking photo-conversion e!ciencies for solid-state sensitised solar cells as high as 8.5%. The system was further developed leading to the conception of a novel device architecture, termed the mesoporous superstructured solar cell (MSSC), this new architecture replaces the conventional mesoporous titanium dioxide semiconductor with a porous insulating oxide in aluminium oxide, resulting in very low fundamental losses evidenced through high photo-generated open-circuit voltages of over 1.1 V. This development has delivered striking photo-conversion ef- ficiencies of 10.9% (detailed in chapter 6).

O etanol contribui significativamente para que a matriz energética do país se apresente extremamente favorável quanto à participação da energia renovável. A demanda por este biocombustível é crescente e tecnologias que permitam a sua produção de forma sustentável é de suma importância, como a fermentação com alto teor de etanol, já empregada em alguns países. Linhagens de leveduras com tolerância a múltiplos estresses muito contribuíram para a implantação de tal tecnologia no Brasil. Neste contexto se insere o presente trabalho, o qual busca linhagens de leveduras capazes de suportar os estresses impostos por uma fermentação com alto teor alcoólico. Para tal, 3 entre as melhores linhagens industriais de Saccharomyces cerevisiae atualmente disponíveis (CAT-1, PE-2 e SA- 1), foram utilizadas num programa para a seleção de híbridos para tolerância múltipla aos estresses etanólico, osmótico, ácido, além de outros, inerentes à fermentação com alto teor de etanol. Estas linhagens foram esporuladas e dissecadas para obtenção de células haplóides, as quais foram submetidas a cruzamentos entre- e intra-linhagens. Foram conduzidos cruzamentos massais (aleatórios) cujos produtos foram submetidos à evolução adaptativa em meios com os fatores estressantes em intensidades crescentes no transcorrer de 80 gerações. Ao final da evolução buscou-se variantes prevalentes na população de híbridos, os quais foram submetidos a novos procedimentos seletivos com imposições de várias condições estressantes. Igualmente foram conduzidos cruzamentos direcionados entre haplóides mediante micromanipulação, sendo tais híbridos submetidos ao mesmo procedimento seletivo nos meios estressantes. Assim, a partir de 230 haplóides das 3 linhagens, 174 isolados (120 oriundos dos cruzamentos massais e 54 dos cruzamentos direcionados) foram pré-selecionados pela maior tolerância aos meios seletivos, tendo os seus cariótipos estabelecidos mediante a cariotipagem eletroforética. Os isolados com maior tolerância (27) foram novamente avaliados em fermentações com reciclo de células e sob condições de elevado teor alcoólico (até 14,5% v/v) em mosto de melaço e água. Em todas as etapas da seleção os isolados foram comparados com as linhagens parentais (CAT-1, PE-2 e SA-1), sendo que ao final do processo seletivo destacou-se a linhagem 35B (híbrido entre CAT-1 e PE-2) com atributos fermentativos superiores aos exibidos pelos parentais. Tais atributos fermentativos contemplaram parâmetros bioquímicos, fisiológicos e tecnológicos (rendimento em etanol, viabilidade celular, crescimento em biomassa, formação de glicerol e teores celulares de carboidratos de reserva glicogênio e trealose). Os resultados permitem sugerir que devido às características fermentativas desejáveis do híbrido 35B, o mesmo possa ser empregado no processo industrial para ser avaliado como uma promissora linhagem a conduzir a fermentação com alto teor alcoólico. / Ethanol contributes significantly to the energy country matrix, which presents itself as extremely favorable to the share of renewable energy. The demand for this biofuel is increasing and technologies for its production in a sustainable way is of paramount importance such as fermentation with very high gravity, already used in some countries. Yeast strains tolerant to multiple stresses greatly contributed to the deployment of such technology in Brazil. In this context the present work is inserted, which seeks yeast strains capable of withstanding the stresses imposed by high ethanol content fermentation. In order that, three of the best industrial strains of Saccharomyces cerevisiae currently available (CAT-1, PE-2 and SA-1), were used in a program to select hybrids with tolerance towards multiples stresses: ethanolic, osmotic and acid, besides other factors involved in a high ethanol content fermentation. These strains were sporulated and dissected to obtain haploid cells, which were submitted to inter- and intra-strains crossings. Hybrids from polycrossings (random crossings) were subjected to an adaptative evolution in media with increasing stressing action over the course of 80 generations. At the end of evolution, prevalent variants were sought in the hybrids population, and submitted to new selective procedures with several stressing conditions. In the same way, directed crossings (between identified haplois) were performed by micromanipulation, and the resulting hybrids were subjected to the same selective procedure. Therefore, from 230 haploid from the 3 parent strains, 174 were isolated (120 from polycrossings and 54 from directed crossings) and pre-selected for higher tolerance in selective media; moreover their karyotypes were established by electrophoretic karyotyping. Strains showing greater tolerance (27) were again evaluated during cell recycling fermentations with high ethanol content (up to 14.5% v/v) using must formulated with water and molasses. At all stages, the isolates were compared with the parental strains (CAT-1, PE-2 and SA-1), and at the end of the selection process, the strain 35B (hybrid between CAT-1 and PE-2) standed out with fermentative attributes higher than the parentals. The fermentative performance was assessed by biochemical, physiological and technological parameters (ethanol efficiency, cell viability, biomass gain, glycerol formation and cellular levels of reserve carbohydrates - glycogen and trehalose). The results suggest that due to desirable fermentation traits, the hybrid 35B, could be used as starter in industrial fermentation process with high ethanol content.

Regulações ambientais cada vez mais rigorosas em relação ao gerenciamento dos resíduos orgânicos estão impelindo a indústria para uma maior sustentabilidade no sentido de melhorar a relação beneficio/custo e também atender a demanda dos clientes. A valorização dos resíduos orgânicos é uma das áreas de investigação atuais que tem atraído grande atenção nos últimos anos como uma alternativa potencial à eliminação de uma vasta gama de resíduos em aterros sanitários. Os resíduos orgânicos como o lodo de esgoto têm sido encarados como um recurso com um potencial significativo para ser empregado como matéria-prima para a produção de vários tipos de produtos, materiais e combustíveis. Este estudo tem como objetivo fornecer subsídios sobre o potencial de uso de lodo de esgoto para produzir carvões ativados e novos materiais adsorventes misturando com diferentes materiais polissiloxanos para adsorção de poluentes orgânicos a partir de soluções aquosas. Os materiais adsorventes foram caracterizados por varias técnicas analíticas e funcionais e utilizados na adsorção de diclofenaco (DCF) , nimesulida (NM) e alguns compostos fenólicos a partir de soluções aquosas Esta tese visa contribuir em (i) comparar os métodos de pirólise (pirólise convencional e aquecimento assistido por micro-ondas) na preparação de carvões ativados a partir de lodo de esgoto. Para isso foi aplicado um planejamento experimental e metodologia de superfície de resposta no sentido de determinar quais as variáveis dos dois processos são as que influenciam na qualidade do carvão produzido; (ii) a combinação de lodo de esgoto com polissiloxanos para preparar adsorventes para adsorção de fármacos a partir de soluções aquosas por processos de adsorção. Os achados gerais desta tese mostraram (i) que ambos os métodos de pirólise produzem carvões ativados com elevadas porosidades e áreas superficiais; (ii) demonstrou-se também que lodo de esgoto pode ser um excelente precursor para a preparação de carvões ativados e que pode com sucesso ser combinado com outros precursores (como polissiloxanos) a fim de se obter novos materiais com diferentes funcionalidades e características; (iii) foi demonstrado que os carvões ativados, híbridos e materiais compósitos desenvolvidos durante o presente estudo são ótimos adsorventes, especialmente para a remoção de diclofenaco DCF e NM a partir de solução aquosa e; (iv) tanto por microondas ou por pirólise convencional, é possível desenvolver CAs de lodo de esgoto com alta eficiência para a remoção de compostos fenólicos em comparação com outros tipos de CAs relatados na literatura. Estes resultados indicam que o lodo de esgoto e polissiloxanos têm grande potencial como precursores para a preparação de materiais adsorventes para o tratamento de água poluída por compostos orgânicos. / Increasingly tighter regulations regarding organic waste are pushing the manufacturing industry toward higher sustainability to improve cost-effectiveness and meet customers’ demand. Organic waste valorisation is one of the current research areas that have attracted a great deal of attention over the past few years as a potential alternative to the disposal of a wide range of residues in landfill sites. Bio-waste like sewage sludge emerged as a resource with a significant potential to be employed as a raw material for the production of chemicals, materials and fuels given its abundant volumes generated globally. This study aims at providing insights into the potential of the use of the sewage sludge to produce activated carbons (ACs) and novel adsorbent materials mixing with different polysiloxanes materials for adsorption of organic pollutants from aqueous solutions. The characterization of adsorbents were achieved by several analytical and functional techniques and used for adsorption of diclofenac (DCF) and nimesulide (NM) from aqueous solutions. The novelties of the present study are (i) to compare both pyrolysis methods (conventional pyrolysis and microwave assisted heating) for preparation of activated carbons from sewage sludge for that It was applied an experimental design and response surface methodology were used for the preparation and comparison of activated carbon produced by both methods, conventional furnace and microwave; (ii) the combination of sewage sludge with polysiloxanes to prepare adsorbents to uptake pharmaceuticals and phenolic compounds from aqueous solutions by adsorption processes. The general findings of this thesis showed (i) that both methods of pyrolysis produce very good activated carbons from sewage sludge with high specific surface areas and high developed porosities; (ii) It was also shown that the sewage sludge can be an excellent precursor to prepare activated carbons and novels materials by mixing it with other precursors such polysiloxanes; (iii) It was shown that the activated carbons, hybrids and composites materials developed during the present study are good adsorbents, especially for the removal of a model diclofenac (DCF) and nimesulide (NM) from aqueous solution and; (iv) that by microwave and conventional pyrolysis it is possible to develop sludge-ACs with very high efficiency for phenolic compounds compared with others kind of ACs reported in literature. These results indicate that sewage sludge and polysiloxanes have great potential as precursors for preparation of adsorbent materials for water treatment polluted by organic pollutants compounds.

Further investigations intending illucidate the mechanism of a newly discovered redox-alkylation reaction of azo dyes are presented. Preliminary results indicate that this reaction most probably proceeds via initial N-alkylation of the anion derived from an alpha-ketohydrazone. An investigation is continued to study the synthesis of macrocycle-carbohydrate-dye hybrids. The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites. A central dye scaffold, prepared from the SNAr reaction between halo-substituted azo dye and a disubstituted phenol, was decorated with a representative carbohydrate or macrocycle using Sharpless click chemistry. Also an "S3N-ligand azo-dye" conjugate has been synthesised with a view to the development of a sensor for heavy metal ions. Complexation of this system with Ag(I), Hg(II) and Cu(II) salts has been investigated. Complexation of the dye to metals results in a bathochromic shift in the absorption maximum of the azo dye, an effect which is most pronounced for Cu(II).The Kobayashi fragmentation has transformed the area of benzyne chemistry as it enables its generation from readily available precursors under mild reaction conditions. The controlled generation of benzyne in this manner has been utilised by many groups, allowing readily access to a variety of functionalised aromatic and heteroaromatic from simple precursors. During the course of a synthetic project, which was to utilise the Kobayashi fragmentation in a key intramolecular Diels-Alder reaction, we noticed that alternate modes of fragmentation/rearrangement accompanied the desired elimination reaction leading to benzyne generation. In particular, competing Fries or Smiles rearrangements became the major routes of fragmentation in appropriately functionalised substrates. The results of an investigation into the factors affecting the course of the Kobayashi fragmentation, together with the development of a novel bi-aryl synthesis are presented in this thesis.

Viruses are obligate intracellular pathogens. Therefore, their successful replication, at every stage from attachment to assembly and egress, is dependent on host cell functions. The host cell in turn engages mechanisms to counteract virus replication. As a result, viruses have evolved mechanisms to evade these counteracting measures as well as ways to reshape the cellular environment into one that’s favourable for successful replication. Systematic studies offer a platform for unravelling virus-cell interactions and in particular can address three important aspects 1) increase our understanding of basic biology of the virus, 2) identify and characterise novel cellular functions 3) provide important leads for novel targets for antiviral therapy. In this study, I investigated two aspects of virus host interaction; the role of microRNAs (miRNAs) in virus infection and the role of interferon inducible genes in virus infection. Human cytomegalovirus (HCMV) is a β herpes virus that infects humans. HCMV maintains a persistent lifelong infection in the host involving a cycle of latency and reactivation. Infection of healthy individuals with HCMV results in relatively minor symptoms. In contrast, infection of individuals with a compromised immune system, as in the case of organ transplant recipients and AIDS patients, can cause significant morbidity and mortality. In common with other herpes viruses, HCMV expresses multiple small regulatory RNAs called miRNAs. HCMV encodes at least 14 miRNAs. Identifying the targets of these miRNAs will help us understand their functional importance during infection. Recently, a biochemical technique called Cross-Linking, Ligation and Sequencing of Hybrids (CLASH), was developed by Tollervey and colleagues, representing the most advanced systematic technique for the identification of miRNA targets. We adapted this approach to identify high confidence miRNA targets during HCMV infection. However, the protocol was sub-optimal and presented us with technical challenges. Although high quality data sets were not generated, the work was crucial for the establishment of the system which is now generating promising data. Virus-cell interactions can also be elucidated by probing for host factors that are important for virus replication. Type I interferon is a highly effective inhibitor of HCMV replication. Treatment of cells with interferon results in up regulation of multiple effectors known as interferon stimulated genes (ISGs). How these genes block HCMV replication is poorly understood. A library of more than 380 ISG expressing lentiviruses was screened to determine the effects of individual ISGs on HCMV replication. The screen was performed in primary human fibroblast cells and a glioblastoma cell line called U373s. Multiple inhibitory ISGs were identified including well characterised ISGs such as cGAS, STAT2, NOD2, DDX60 and HPSE as well as novel candidates TXNIP, ELF1, FAM46C, MT1H and CHMP5. Five ISGs were identified as HCMV replication enhancers including previously published ISGs BST2 and IFITM1 and novel enhancers ODC1, BCL3 and IL28RA. siRNA screens against top hits demonstrated that STAT2, CPT1A and cGAS are dominant inhibitory factors during HCMV infection and knockdown of these genes can partially rescue HCMV replication following interferon treatment. Finally, using a corresponding rhesus ISG library we show that rhesus SAMHD1 effectively inhibits HCMV replication while human SAMHD1 has no effect, suggesting that HCMV expresses a species-specific inhibitor of SAMHD1. This study defines interferon stimulated pathways important for HCMV replication and identifies multiple novel host factors that both restrict and enhance HCMV replication. These studies demonstrate the effectiveness of using systematic approaches for the identification of novel host virus interactions.

Resumo: O presente experimento teve como objetivo avaliar a produtividade e o valor nutritivo de plantas de milho para silagem por meio da produtividade por hectare e da análise química dos nutrientes, bem como da digestibilidade in vitro da matéria seca. Os dados foram analisados no delineamento inteiramente casualisado em um esquema fatorial 2 x 3 (dois híbridos de milho de textura dura AG 4051 e dentada DAS 2B710 e três maturidades de colheita u leitoso, o leitoso e camada preta). Após a colheita, as plantas foram separadas em folha, caule mais bainha e espiga, para subseqüente determinação das análises bromatológicas (MS, PB, FDN, FDA, celulose e lignina) e digestibilidade in vitro. O híbrido de textura dentada apresentou maior produtividade de massa seca que o híbrido de textura dura. Com o avanço da maturidade houve redução na proporção de folha e aumento na de espiga, sem alteração na proporção de caule. A folha e fração volumosa apresentaram os maiores teores de MS, no híbrido de textura dentada. O menor valor do dry down foi observado no híbrido de textura dentada na maturação fisiológica. As médias do FDN das frações caule e espiga foram diferentes, e os maiores teores de FDN observados no híbrido de textura dura. Para a FDA as maiores médias foram na fração caule para o híbrido de textura dura. Observou que os maiores teores de celulose e PB foram do híbrido de textura dentada na maturidade fisiológica na planta inteira e em todas as frações, os teores de lignina aumentaram com avanço da maturidade. Verificou-se que os maiores valores de digestibilidade foram da fração espiga e não houve diferença entre híbridos nesta fração. / Abstract: The present experiment had as objective to evaluate the productivity and nutritive value of corn plants for ensilage by means of productivity per hectare and chemical analysis of the nutrients, as well as the in vitro digestibility of the dry matter. The experimental delineation used was entirely causalized in a factorial project of 2 x 3, being: two corn hybrids, one of hard texture (AG 4051) and one of soft texture (DAS 2B710) in three maturity stages of harvest. After the harvest, the plants had been separated in leaf, stem more sheath and spike, for subsequent determination of the bromatology analysis (DM, CP, NDF, ADF, cellulose and lignin) and in vitro digestibility. The soft texture hybrid presented better productivity of dry matter than the hard texture hybrid. With the advance of the maturity, there was a reduction in the rate of leaves and an increase of in the spikes’, with no alteration in the rate of stems. The leaves and the voluminous fraction showed the highest DM rates, in the soft texture hybrid. The lowest dry down value was observed in the soft texture hydrid in the physiologic maturation. The average values of NDF of the stem and the spike were significant, and the highest NDF values were observed in the hard texture hybrid. For the ADF, the highest averages were in the stem fraction for the hard texture hybrid. It was observed that the highest celluloses and CP rates were in the soft texture hybrid during the physiologic maturity in the whole plant and in all fractions, the lignin rates increased with the advance of the maturity. It was reported that the highest digestibility values were in the spike and there was no difference between the hybrids in this fraction. / Orientador: Ciniro Costa / Coorientador: Paulo Roberto de Lima Meirelles / Banca: Silvio José Bicudo / Banca: Heraldo César Gonçalves / Mestre