Este estudo avaliou, in vitro, tempo de endurecimento (TE), alteração dimensional (AD), solubilidade (Sl) e radiopacidade (Rp) dos cimentos AH Plus, GuttaFlow, RoekoSeal, Activ GP, Endofill e um cimento experimental à base de MTA. Para estes testes o cimentos Activ GP foi manipulado na relação pó/líquido de 28 mg para 50 µL de líquido. Para determinar o TE, moldes (10 X 2 mm) foram preenchidos com cimento e, decorridos 150 s, os cimentos foram testados com agulha tipo Gillmore (100 g), a cada 60 s, até que não houvesse marcas na superfície. Para o teste de alteração dimensional, 5 corpos-de-prova cilíndricos (3,58 x 3,0 mm) foram obtidos. Após a mensuração de seus comprimentos por meio de parquímetro digital, foram imersos em 2,24 mL de água destilada e deionizada por 30 dias e mensurados novamente. Para o teste de Sl, foram obtidos 10 corpos-de-prova (1,5 X 7,75 mm). Após serem pesados, dois a dois, foram imersos em 7,5 mL de água destilada por 7 dias e pesados novamente, determinando-se a perda percentual da massa. Os líquidos de imersão foram submetidos à espectrometria para detecção dos íons Ca2+, K+, Ni2+, Pb2+, Zn2+, Ag+. Para a Rp, 5 placas de acrílico com 4 perfurações (5 X 1 mm) foram preenchidas com cimento e, ao lado de escada de alumínio padronizada, foram radiografadas com distância foco-objeto de 30 cm e exposição de 0,2 s. A densidade radiográfica foi determinada por meio do Digora for Windows 1.51. Os resultados mostraram que os cimentos GuttaFlow e RoekoSeal estavam de acordo com a Especificação n° 57 da ANSI/ADA para os testes de TE e Rp. Em relação a ED, somente o Guttaflow estava de acordo com esta Especificação. Em relação à Sl, somente o cimento Activ GP (11,80%) não atendeu os padrões exigidos pela ANSI/ADA. A espectrometria de absorção atômica mostrou que o cimento Activ GP apresentou liberação expressiva de ions Ca2+. A liberação de ions Zn2+ foi evidenciada no cimento Activ GPl. Concluiu-se que somente cimento Guttaflow atendeu às exigências da ANSI/ADA em relação à radiopacidade, estabilidade dimensional e solubilidade. / This study evaluated, in vitro, the setting time (ST), dimensional alteration (DA), solubility (Sl) and radiopacity (Rp) of the sealers AH Plus, GuttaFlow, RoekoSeal, Activ GP, Endofill and a MTA-based experimental sealer. For these tests, the sealer Activ GP was prepared using a powder/liquid mixing ratio of 28 mg to 50 µL of liquid. In order to determine the ST, moulds (10 x 2 mm) were filled with sealer. After 150 s, the sealers were tested with a Gilmore needle (100 g) at 60-s intervals until no marks were visible on the material surface. For the DA test, 5 cylindrical specimens (3.58 x 3.0 mm) were obtained. After having their dimensions checked with a digital caliper, the specimens were stored in 2.24 mL distilled deionized water for 30 days and their dimensions were rechecked. For the Sl test, 10 specimens (1.5 x 7.75 mm) were obtained. After being weighed in pairs, the specimens were stored in 7.5 mL distilled water for 7 days and reweighed to determine the percent mass loss. The liquids in which the specimens were immersed were subjected to spectrometry for detection of ions Ca2+, K+, Na+, Ni2+, Pb2+, Zn2+and Ag+. For the Rp test, 5 acrylic plates with 4 perforations (5 x 1 mm) were filled with sealer and were radiographed near to a graduated aluminum stepwedge with 30-cm focus-object distance and 0.2-s exposure time. The radiographic density was determined using the Digora for Windows 1.51 software. The results showed that GuttaFlow and RoekoSeal were in compliance with the ANSI/ADAs specification no. 57 for the TE and Rp tests. Regarding DA, only GuttaFlow was in accordance with this specification. Regarding Sl, only Activ GP (11.80%) did not meet the ANSI/ADAs requirements. The atomic absorbance spectrometry showed that the sealer Activ GP presented significant release of Ca2+. Release of Zn2+ ions was observed for the sealer Activ GP. In conclusion, only the sealer Guttaflow met the ANSI/ADAs requirements for radiopacity, dimensional stability and solubility.

Orientador: Carlos Alberto Gasparetto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T09:22:43Z (GMT). No. of bitstreams: 1 Santana_MaristeladeFatimaSimpliciode_D.pdf: 7985534 bytes, checksum: 0c6da4f8f15db4829b97079092849637 (MD5) Previous issue date: 2005 / Resumo: O Brasil é o principal produtor mundial de laranja e maracujá, frutas que após extração de seu suco geram resíduo com alto teor de fibra alimentar. Hoje se tem, nas sociedades ocidentais, grande carência deste nutriente nas dietas e grandes problemas ambientais com este resíduo ou bagaço, que representa cerca de 50% em peso dos frutos. Por outro lado, registra-se o aumento no interesse das indústrias pelo enriquecimento de alimentos com fibra alimentar e a falta de informações científicas quanto às características físicas das partículas e propriedades tecnológicas para processamento desse tipo de material. O objetivo deste estudo foi caracterizar as fibras utilizando técnicas clássicas do sistema de tecnologias de partícula, estudar as propriedades tecnológicas e composição química, avaliando os métodos de secagem convencional em leito fixo e liofilização. Os resultados da avaliação das frações de laranja (albedo, membrana carpelar e vesícula de suco) e maracujá (albedo) mostraram altos índices de fibra total e uma composição química (proteína, lipídios, cinzas, pH, umidade, acidez e atividade de água) adequada para enriquecer alimentos. A secagem convencional promoveu uma grande redução na microestrutura, mas não afetou as propriedades tecnológicas. Foi possível estabelecer tendência de comportamento do tamanho de partícula com a área superficial, a porosidade e a densidade. Portanto, o método de secagem convencional em leito fixo pode ser considerado viável como processo de preparação / Abstract: Brazil is the main producer of orange and passion fruit which produce a large amount of fiber rich residue after juice extraction. Considering today¿s demand for dietary fiber supplementation and environmental pollution, it is a promising opportunity to research on the practical use of those residues which amounts to 50% of the fruit weight. This research work was aimed to evaluate physicochemical properties of those fibers which are of utmost importance in the technology of it¿s processing and use. Fibers were tray and freeze dryed in order to compare results from two different drying methods. Analysis showed high fiber content and protein, lipid, ash, moisture, water activity, pH and acidity compatible to utilization as ingredients in processed food. Surface area, porosity and density were strongly related to particle size. The conventional tray drying promoted a dramatic shrinking on the microstructure although not affecting properties of technological importance thus indicating this as a feasible process / Doutorado / Engenharia de Alimentos / Doutor em Engenharia de Alimentos

Reduction of the Archangel Michael, is one of seven people missionaries who settled in Rio Grande do Sul, is dated approximately 1687 in the current site. Today the remains of their remaining part of National Heritage and Declared a World Heritage Site by UNESCO since 1983. The great importance of this historic site suggests research in studies on the mortar coating still exists in parts of the ruin. Discover the physical and chemical composition is one of the objectives of the research, which aims to identify the main constituents of the mortar materials, as well as whether or not the lime and the way it presents itself. In addition, to hypothesize the origin of the lime used or not of the Misiones region of RS. It also aims to demonstrate the importance of laboratory tests, such as X-Ray Diffraction, Thermogravimetric Analysis, Scanning Electron Microscopy (SEM), among others, in research and conservation of monuments. Through the XRD analysis and ATR-IR was verified using mortar nature calcite as well as the presence of aragonite in the second set (sacristy) and hydroxyapatite in the first set (front north). According to the history of the monument there is a probability of calcium carbonate is, the variation of aragonite, originated from the snail shell snail Physa SP. Kaolin analysis of this X-ray diffraction (XRD) analysis suggests a contamination of the substrate because the clay brick was spot. With the images obtained by SEM and EDS, showed the presence of organic fibers and a binder rich in calcium. The need for preventive conservation of monuments or buildings of historical interest makes this work of investigative and scientific nature. The knowledge of the original materials and the use of compatible materials for restoration is the first step to a good intervention and not to accelerate the deterioration of historic buildings. / A Redução de São Miguel Arcanjo é um dos sete povos missioneiros que se instalaram no Rio Grande do Sul, sendo datada de aproximadamente 1687 no atual sítio. Hoje os vestígios de seus remanescentes, fazem parte do Patrimônio Nacional e Declarados Patrimônio da Humanidade pela UNESCO desde 1983. A grande importância deste sítio histórico sugere a pesquisa, em realizar estudos sobre as argamassas de revestimento ainda existente em partes da ruína. Descobrir a composição química e física é um dos objetivos da pesquisa, que visa identificar os principais materiais constituintes da argamassa, bem como a existência ou não da cal e a forma com que esta se apresenta, além de levantar a hipótese da procedência da cal utilizada ser ou não da região missioneira do RS. Também visa demonstrar a importância das análises laboratoriais, como Difração de Raios-X, Análise Termogravimétrica, Microscopia Eletrônica de Varredura (MEV), entre outras, em trabalhos de investigação e conservação de monumentos. Através da análise de DRX e ATR-IR foi possível verificar o uso de argamassa de natureza calcítica, como também a presença de aragonita no conjunto 2 (sacristia) e hidroxiapatita no conjunto 1 (fachada Norte). De acordo com o histórico do monumento existe uma probabilidade do carbonato de cálcio ser, na variação da aragonita, originado da carapaça de caramujo molusco Physa SP. O caulim presente na análise de difração de raios X (DRX) sugere uma contaminação do substrato, pois o tijolo era de argila local. Com as imagens obtidas por MEV e EDS, constatou-se a presença de fibras orgânicas e de um ligante rico em cálcio. A necessidade de uma conservação preventiva em monumentos ou em edificações de interesse histórico torna este trabalho de cunho investigativo e cientifico. O conhecimento dos materiais originais e o uso de materiais compatíveis para restauro é o passo inicial para uma boa intervenção e para não acelerar o processo de degradação de construções históricas.

O presente estudo teve como objetivo avaliar a ação do campo magnético pulsado sobre as propriedades físico-químicas e microbiológicas do caldo de cana armazenado sob refrigeração. As amostras de caldo de cana foram expostas ao campo magnético pulsado nas frequências de 40 Hz e 60 Hz por 30 e 210 minutos, e na frequência de 50 Hz por 2 horas. Amostras controles não foram expostas ao campo magnético. As amostras foram armazenadas por até 6 dias a 4ºC e analisadas no tempo de armazenamento de 6, 12, 24, 48, 96 e 144 horas por meio de análises físico-químicas para todas as amostras, e microbiológicas para as amostras tratadas com campo magnético de 50 e 60 Hz. O campo magnético de 40 Hz aumentou os parâmetros de cor L* e a* e diminuiu o parâmetro b*, efeito contrário ao campo de 60 Hz. O tratamento a 50 Hz aumentou o parâmetro de cor L* e diminuiu os parâmetros a* e b*. A exposição ao campo magnético de 50 Hz e 60 Hz reduziu o crescimento de bactérias totais, sendo maior a redução nas amostras tratadas a 50 Hz, e para as amostras de 60 Hz, quanto maior o tempo de tratamento, maior a inibição do crescimento microbiano. O tratamento por campo magnético de 60 Hz por 30 minutos reduziu a atividade antioxidante e a concentração de compostos fenólicos, enquanto que o tratamento a 40 Hz por 30 minutos reduziu somente o primeiro índice e a 60 Hz por 210 minutos reduziu o segundo. Os demais parâmetros físico-químicos não sofreram alteração significativa com relação ao controle durante o armazenamento. Conclui-se que, apesar de serem necessários mais estudos para entendimento do mecanismo de ação do campo magnético em alimentos, o campo magnético pulsado de baixa intensidade (ordem de mili Tesla) possui potencial para ser utilizado como tecnologia inovadora no tratamento de alimentos para controle microbiológico. / This study aimed to evaluate the action of pulsed magnetic field in the physicochemical and microbiological properties of sugar cane juice during refrigerated storage. Sugar cane juice samples were exposed to pulsed magnetic field at frequencies of 40 and 60 Hz for 30 and 210 minutes and at frequency of 50 Hz for 120 minutes. Control samples were not exposed to magnetic field. Samples were stored at 4ºC for up to 6 days, and evaluated at times of storage of 6, 12, 24, 48, 96 e 144 hours through physicochemical analysis for all samples and through microbiological analysis for samples treated with 50 and 60 Hz magnetic field. Exposure to 40 Hz magnetic field raised the color parameters L* and a*, and decreased the b* parameter, while de 60 Hz magnetic field had the opposite effect. The treatment with 50 Hz magnetic field raised the color parameter L* and decreased a* and b* parameters. Exposure to 50 and 60 Hz magnetic field reduced the growth of total bacteria, where the frequency of 50 Hz was more effective. The treatment with 60 Hz magnetic field for 30 minutes reduced the antioxidant activity and the total phenolic compound, while the 40 Hz treatment for 30 minutes reduces only the first analysis and at 60 Hz for 210 minutes reduced only the second. The other physicochemical properties did not changed significantly during storage compared with the controls. We concluded that, although more studies is needed for better understand the action mechanism of magnetic field in foods, the low intensity pulsed magnetic field (order of mili tesla) has the potential to be used as innovative technology in food treatment for microbiological control.

Thesis (M. Sc. (Microbiology)) -- University of limpopo, 2016 / Human activities are known to be the major contributors to contamination of natural water sources. This becomes a serious health risk when the communities rely on the same water sources for their household water needs. The current study investigated the bio-physicochemical quality of surface and ground waters found in a mining area in the Tubatse locality, for their suitability for drinking and other household use. The bacteriological analyses of surface waters showed dominance by genera of the phylum Proteobacteria, followed by Actinobacteria and Firmicutes. The isolates included the genera Aeromonas, Pseudomonas, Cronobacter, Acinetobacter, Enterobacter, Pantoea, Serratia, Bordetella, Kocuria and Streptococcus. This dominance pattern is proportionately similar to the pattern reported on human skin and of gut biota. Enterobacter spp. were the predominant species in the surface waters, followed by Bordetella spp. With regard to ground water, one sample was laden with coliforms whereas the other sample was free of coliforms. Physical quality parameters such as turbidity, colour and (total suspended solids) TSS of the surface and ground water samples were compliant with the set standards for drinking water according to South African water quality guidelines (2005). The concentrations of Zn, [SCN-], Cr, Co, Fe, Ni, Cu, H2O2, Cl2 were determined in the surface and ground waters in dry and wet seasons as well. A non-significant decrease in the levels of Cl2 and [SCN-] and an increase in TDS and Cr were observed in the wet season. All metal and chemical levels in surface and ground water, except Cr, were lower than permitted concentration for drinking water. However the concentrations of Zn, Fe and Co exceeded the normal expected concentrations of < 3.5 μg/L, 0.5 mg/L, < 0.01 mg/L and < 5 μg/L respectively. The sediments and soil samples were digested with aqua regia for Cu, Cr, Fe, Co and Zn analyses. An increase in the levels of Zn, Cr and Co in the wet season was observed. The concentrations of the heavy metals such as Co, Cu and Cr were higher in sediments at the sampling points closer to the mining sites. Cytotoxicity assay was performed with different concentrations, as detected in the water and sediment samples, of Zn, [SCN-], Cr, Co, and Fe on C2C12 (mammalian) cells. An increase in viable cells was observed after treatment with Cr (0.2, 0.45 and 0.9 mg/L), Zn and Fe (1.0 and 2 mg/L), Co (2, 5 and 10 mg/L). Only cells treated with SCN- (3.3, 5.4 and 7.2 mg/L) exhibited a significant decrease in viability. These results demonstrate that the water in the Tubatse municipality is not suitable for drinking and other household purposes without prior treatment which will remove contaminating microorganisms and chemicals and heavy metals.

Le Commissariat à l’Energie atomique et aux énergies alternatives (CEA) a développé une poudre extinctrice efficace capable d'éteindre le feu de sodium. Elle est une poudre à base d'un mélange de carbonate de lithium (Li2CO3) et de carbonate de sodium à basse hydraté (Na2CO3.H2O) dans une proportion proche de l'eutectique, avec une température de fusion d'environ 500°C, associée à du graphite. Cependant, depuis le démantèlement de plusieurs anciennes installations de sodium, le CEA dispose d'un stock important de lots de poudre inutilisés. L'idée de réutiliser ces poudres initie la question sur leur efficacité pour éteindre un feu de sodium après un stockage à long terme. Cette étude a proposé des analyses physicochimiques de ces poudres afin d'identifier leurs compositions et les caractéristiques des différents lots. Les résultats mettent en évidence la présence de carbonate de lithium de sodium (LiNaCO3) et trona (Na2CO3.NaHCO3.2H2O) qui ne sont pas mentionnés dans le brevet. Les expériences de vieillissement ont été développées pour étudier le rôle de l'humidité et du dioxyde de carbone à l’air ambiant au cours du stockage. Les résultats montrent que LiNaCO3 est sensible à la présence d'humidité, capable de transformer en carbonate de lithium et le carbonate de sodium monohydrate, quant à celui-ci réagit avec de l'eau et du dioxyde de carbone pour former du trona. Une étude de la formation de LiNaCO3 a permis d’avoir la compréhension du procédé de fabrication de la poudre. Ce composé se trouve à se produire grâce aux réactions mécanochimiques entre Li2CO3 et Na2CO3.H2O au cours du processus de broyage. Le Chris(X)ti-Na installation expérimentale est construit pour comprendre les mécanismes d'extinction en particulier concernant le rôle des propriétés physicochimiques sur l'extinction. Deux étapes de mécanismes d'extinction sont proposés, qui comprend (1) la formation d'hydroxyde de sodium liquide (NaOH) et (2) la fusion des carbonates eutectique. La première étape peut se produire directement (par la réaction directe du trôna et / ou Na2CO3.H2O avec Na(g) et / ou Na2O(s)), soit indirectement (par l'intermédiaire de la réaction de décomposition du trôna et Na2CO3.H2O avant la réaction de H2O(g) libéré avec Na(g) et / ou Na2O(s)). Les deux réactions mènent la possibilité de la formation d'hydrogène (H2) qui pourrait être représenté par la flamme flash observée avant l'extinction. Ils contribuent également à la diminution rapide de la température due à la formation d'hydroxyde de sodium liquide (NaOH) en tant que couche protectrice. Cette couche est nécessaire pour couvrir la surface de sodium d'un contact prolongé avec de l'oxygène. La présence de trona semble ne pas altérer la capacité d'extinction de la poudre. Avec la même quantité de NaOH produit par les deux composés, trona libère plus de quantité de H2 et plus exothermique que celle de Na2CO3.H2O. Dans l'ensemble, 0,5-0,9g d'eau est nécessaire pour éteindre 19,6 cm2 de sodium feu en nappe, ce qui équivalent à 1-2g de NaOH. Sur la base de ces tests, la teneur minimale en eau nécessaire à l'extinction est 5.6w%. Les poudres dont la teneur en eau d'hydratation est proche de 13w% semblent plus susceptibles de produire une flamme vigoureuse élevée avant l'extinction. La deuxième étape est considérée comme étant plus lent que l'étape précédente. La couche de carbonates eutectique a une viscosité supérieure à celle de NaOH qui le rend moins avantageux pour former la couche étanche à la surface de sodium. Par conséquent, son rôle pourrait être moins important en particulier pour le feu de sodium ayant commencé à basse température. Néanmoins, son effet est considéré comme plus important lorsqu'il est appliqué au feu de sodium à température élevée (supérieure à 500°C). Enfin, la taille des particules apparemment ne démontre pas une contribution significative à la performance d'extinction outre qu’affecter les performances d'épandage. / The French Atomic and alternatives Energy Commission (CEA) developed an effective powder capable of extinguishing sodium fire. It is a powder based on a mixture of lithium carbonate (Li2CO3) and low-hydrated sodium carbonate (Na2CO3.H2O) in a near eutectic proportion, with a melting temperature of around 500°C, associated with graphite. However, ever since the dismantling of several old sodium installations, CEA has at its disposal an important stock of unused powder batches. The idea of reutilizing these powders initiates the question about their efficiency to extinguish a sodium fire after long term storage. This study proposed the physicochemical analyses of these powders in order to identify their compositions and characteristics for different batches. The results highlight the presence of lithium sodium carbonate (LiNaCO3) and trona (Na2CO3.NaHCO3.2H2O), which are not mentioned in the patent. The aging experiments were developed to study the role of moisture and ambient carbon dioxide during the storage. The results showed that LiNaCO3 is sensitive to the presence of moisture, able to transform it into lithium carbonate and sodium carbonate monohydrate, meanwhile the latter reacts with water and carbon dioxide to form trona. A study of the formation of LiNaCO3 allowed the understanding of the fabrication method of the powder. This compound is found to be produced as the results of mechanochemical reactions between Li2CO3 and Na2CO3.H2O during the grinding process. The Chris(X)ti-Na experimental facility is built to understand the mechanisms of extinction especially related to the role of physicochemical properties on extinction. Two steps of extinction mechanisms are proposed that includes (1) the formation of liquid sodium hydroxide (NaOH) and (2) the melting of eutectic carbonates. The first step can happen directly (via the direct reaction of trona and/or Na2CO3.H2O with Na(g) and/or Na2O(s)) or indirectly (via the decomposition reaction of trona and Na2CO3.H2O prior to reaction of H2O(g) released with Na(g) and Na2O(s)). Both reactions explore the possibility of hydrogen (H2) formation that might be represented by the flash flame observed prior to extinction. They also contribute to the rapid decrease of temperature due to the formation of liquid sodium hydroxide (NaOH) as a protective layer. This layer is essential to cover the sodium surface from prolonged contact with oxygen. The presence of trona appears to be not altering the extinction capacity of the powder. With the same amount of NaOH produced by both compounds, trona releases more quantity of H2 and more exothermic in terms of energy release than that of Na2CO3.H2O. Overall, 0.5-0.9 g of water is necessary to extinguish 19.6 cm2 of sodium pool fire, which equivalent to 1-2g of NaOH. Based on these tests, the minimum water content required for extinction is 5.6w%. Meanwhile, powders whose hydration water content is close to 13w% seem more likely to produce a high vigorous H2 flame prior to the extinction. The second step is considered to be slower than the previous step. The eutectic carbonates layer has higher viscosity than NaOH that makes it less beneficial to form sealed layer on the sodium surface. Therefore, its role might be less significant especially for the sodium fire starts at low temperature. Nevertheless, the effect is considered to be more important when applied to sodium fire at higher temperature (more than 500°C). Finally, the particle size apparently doesn’t demonstrate a significant contribution in the extinguishing performance other than affecting the spreading performance.

The physicochemical properties and chemical reactivity of dissolved organic matter (DOM) are of tremendous practical significance in both natural and engineered aquatic and terrestrial systems. DOM is frequently extracted, fractionated, and concentrated from environmental samples using a variety of operationally defined physical and chemical processes in order to facilitate study of specific physicochemical properties and aspects of its chemical reactivity. This study was conducted to systematically examine the influence of operationally defined physical and chemical characterization methods on observed DOM physicochemical properties and reactivity with aqueous chlorine. The effects of chemical separation were evaluated by applying an existing resin adsorption based procedure which simultaneously extracts and fractionates DOM and inorganic constituents into hydrophobic and hydrophilic acid, base, and neutral dissolved material matrix (DMM) fractions. Physical separation based on DOM apparent molecular weight (AMW) was also evaluated using batch ultrafiltration (UF) data in conjunction with a suitable membrane permeation model. Linear independence of membrane solute transport was theoretically described using non-equilibrium thermodynamics and experimentally demonstrated for AMICON® YC/YM series UF membranes. Mass balances on DMM fraction constituents in untreated and previously coagulated natural waters indicated that quantitative recovery (100 ± 2%) of DOM constituents was achieved, while recovery of inorganic constituents such as iron and aluminum was substantially incomplete (30%-74%). Comparison of whole-water DOM properties with those mathematically reconstituted from DMM fractions demonstrated a marked shift in DOM properties toward lower AMW. Evidence of pH induced partial hydrolysis of protein, polysaccharide, and ester DOM components was also observed. Decreased specific Cl2 demand (mmol DCl2/ mmol DOM) and specific trihalomethane formation (mmol THM/mmol DOM) following chemical fractionation were attributed to increased molar DOM concentration and decreased DOM association with colloidal iron oxide surfaces. Collectively, the results of this research indicate that operational characterization methods result in alteration of DOM physicochemical properties and reactivity with aqueous chlorine, and caution is therefore advisable when interpreting the results of studies conducted using chemically extracted or fractionated DOM. / Ph. D.

Researchers use multiple sequence alignment algorithms to detect conserved regions in genetic sequences and to identify drug docking sites for drug development. In this dissertation, a novel algorithm is presented for using physicochemical properties to increase the accuracy of multiple sequence alignments. Secondary structures are also incorporated in the evaluation function. Additionally, the location of the secondary structures is assimilated into the function. Multiple properties are combined with weights, determined from prediction accuracies of protein secondary structures using artificial neural networks. A new metric, the PPD Score is developed, that captures the average change in physicochemical properties. Using the physicochemical properties and the secondary structures for multiple sequence alignment results in alignments that are more accurate, biologically relevant and useful for drug development and other medical uses. In addition to a novel multiple sequence alignment algorithm, we also propose a new protein-coding DNA reference alignment database. This database is a collection of multiple sequence alignment data sets derived from tertiary structural alignments. The primary purpose of the database is to benchmark new and existing multiple sequence alignment algorithms with DNA data. The first known comparative study of protein-coding DNA alignment accuracies is also included in this work.

No description available.

Amorphous active pharmaceutical ingredients remain in the research focus as an avenue to achieve a better solubility of drugs. Several processing techniques are applied to produce amorphous materials. Main two approaches applied to production of amorphous phases are comminution of crystalline materials in order to break down molecular long-range order of their crystal lattices and amorphous phase precipitation from solutions. This thesis is focused on processing challenges in preparation of amorphous API phases from solutions by spray drying and evaporative antisolvent sonoprecipitation. Budesonide (BUD) and simvastatin (SMV) were used as model poorly soluble APIs. Amorphous phases of relatively low-glass transition (Tg) APIs are physically unstable and crystallise upon storage and/or processing conditions. To tackle this issue, for the first time in this work a selection of polyvinylpyrrolidone vinyl acetate (PVP-VA) co-polymers has been applied to investigate impact of sonoprecipitation processing parameters and a composition of PVP-VA on physicochemical and micromeritic properties of BUD/PVP-VA nanoparticulate composites. Studies confirmed that in solid-state BUD is miscible with PVP-VA polymers. Application of factorial design revealed that processing parameters: polymer type, surfactant concentrations, time and amplitude of sonication impact the entrapment efficiency, drug loading, polydispersity and particle size properties of produced nanoparticles. The largest fraction of polymer to drug in produced nanoparticles has been achieved with PVP VA E-535. As it is known that polymer content in formulation of APIs may slow down its dissolution, novel approach to processing and dissolution enhancement of amorphous composites of SMV produced by spray drying has been applied. Introduction of easily crystallising inorganic salt- sodium chloride into spray drying feed rendered SMV-polyvinyl pyrrolidone (PVP) amorphous microparticles loaded with nanocrystalline NaCl. Addition of NaCl successfully facilitated generation of discrete microparticles post spray drying with low-Tg polymers, which otherwise were not processable as binary mixtures. In addition, NaCl content aided tabletability and dissolution of amorphous API composites with more viscous and high-Tg PVP polymers. Studies confirmed that application of factorial design facilitates robust design of production process of amorphous nanocomposites by sonoprecipitation as well as that introduction of soluble nanocrystalline phase into amorphous binary solid dispersion by spray drying aids its processing and dissolution.