No description available.

Thesis PlanA (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

No description available.

Thesis PlanA (M.S.)--University of Wisconsin--Stout, 2008. / Includes bibliographical references.

Thesis (Ph. D.)--Pennsylvania State University, 1980. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1983.

The purpose of this investigation is to study the effects of methylxanthines, catecholamines, and cyclic nucleotides on melanin synthesisand conidiation using the technique of phase contrast microscopy. Verticillium wild type (T9) strain was grown in both sucrose nitrate liquid medium and polygalacturonic acid media (SNLM and PGAM). These media allowed rapid production of conidia and synchronous development of microsclerotia respectively. Even though caffeine has a greater effect on conidiation, both caffeine and theophylline promoted melanization. Dibutyl cyclic AMP to lesser extent inhibited conidiation, while cyclic AMP had little to no effect on conidiation. Dibutyl cyclic AMP inhibited melanin production. Cyclic AMP had a stimulatory effect on melanin production. Isoproterenol a stimulant of adenylate cyclase activity, inhibited conidiation the first two days, but had no apparent effect after day 3. Isoproterenol also induced melanin production in the flask. Propranolol, an antagonist of hormonally induced adenylate cyclase activity, did not repress conidiation when compared to the drug-free SNLM. Melanin was not formed in either SNLM and PGAM, suggesting that the effect of propranolol was opposite that of isoproterenol. Propranolol, a beta blocking agent, reversed the isoproterenol induced inhibition of conidiation. This reversal indicates that there is a receptor which isoproterenol attached itself to - the binding beta receptor site. The isoproterenol effect on conidiation and melanin synthesis indicates that, there might be cyclic AMP involvement in development, since this agent affects cyclic AMP level. Since melanin is known to be associated with microsclerotia, it is possible that cyclic AMP might be involved in this development. In this study, the effects of methylxanthines, catecholamines and cyclic nucleotides on melanin synthesis and conidiation was determined. There is every possibility that cyclic AMP might be involved in the regulation of conidiation process and melanin synthesis.

This master's thesis deals with authenticity of chocolate with different content of cocoa solids. The theoretical part describes the production of chocolate products and the issue of food authenticity. Experimental part of this thesis is focused on the determination of total cocoa solids in the selected samples. Different samples of chocolate containing 50–90 % of cocoa were grated to fine particles, that were subjected to extraction without previous chemical treatment. The methylxanthines theobromine and caffeine were detected by HPLC to determine the content of fat–free cocoa solids. Fat–free cocoa solids content were found in the range 19,7–43,1 g/100 g of dry matter and the content of total fat was determined by the gravimetric method and was found in the range 30,9–55,4 g/100 g. The results of this thesis prove that, the producers meet the legislative requirements and the declared values are corectly declared on the wrappers of the product.

The aim of this work is to study the in-vitro aerodynamic performance of a new inhaled theophylline formulation prepared by supercritical fluids technique. For the analysis of the output from the in-vitro tests (and further in-vivo tests) a new, fast, sensitive high performance liquid chromatographic (HPLC) method was developed and validated for the determination of theophylline and other related derivatives in aqueous and urine samples using new packing materials (monolithic columns). These columns achieve efficient separation under lower backpressure and shorter time comparing to other traditionally or newly introduced C18 columns. Solution enhanced dispersion by supercritical fluid (SEDS) process has been applied for the production of anhydrous theophylline as pure crystals in the range 2-5 μm to be used as new inhaled dry powder formulation for asthma. Fifteen theophylline samples have been prepared under different experimental conditions. The drug produced by this method has been subject to a number of solid-phase analytical procedures designed to establish the crystal structure [X-ray powder diffraction (XRPD)], the structure and conformation [(FTIR), Fourier-transform Raman spectroscopy (FT-Raman)], and the morphology and particle size [scanning electron microscope (SEM)]. While, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) have been used to monitor any phase transition or polymorphic changes after processing. All these analytical techniques gave a satisfactory indication of the solid-state chemistry of the processed particles and assess the development of new inhalation product. The performance of inhaled SEDS theophylline with or without a carrier was evaluated using the developed HPLC method. Three samples having different particle sizes were selected out of the prepared powders by SEDS technique to be tested. The dose sampling unit and the Anderson Cascade Impactor were used to determine the in-vitro emitted dose and the deposition profiles of SEDS samples, respectively. The effect of different inhalation flows was studied using two different flows 28.3, and 60 L min-1 with 4 L inhalation volume. Different DPI devices were investigated in this study; Easyhaler® and Spinhaler®. The particle size has an important effect on the aerodynamic behaviour and deposition profile of inhaled drug, the smaller the particles the greater the total lung deposition. The presence of a carrier improves the respirable fraction for all the tested formulations.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-03-09T02:24:14Z No. of bitstreams: 1 116110001.pdf: 1574524 bytes, checksum: 48077bd97e3cbf3cc22e4347e94b7abf (MD5) / Made available in DSpace on 2015-03-09T02:24:14Z (GMT). No. of bitstreams: 1 116110001.pdf: 1574524 bytes, checksum: 48077bd97e3cbf3cc22e4347e94b7abf (MD5) Previous issue date: 2012-11-16 / A erva-mate, cientificamente denominada, Ilex paraguariensis St. Hil. Var. paraguariensis (Aquifoliaceae), trata-se de uma árvore que cresce naturalmente em florestas da América do Sul (na Argentina, sul do Brasil, Uruguai e Paraguai). Bebidas a base de ervas-mate denominadas “mate”, “chimarrão” ou “tererê” fazem parte dos hábitos e costumes da população local. Nos últimos anos, através da ampliação do conhecimento científico a respeito de seus efeitos na saúde, os usos da planta têm se expandido para outras partes do mundo e são descritas diversas possibilidades de aplicação. Suas ações incluem atividades antioxidante, antiinflamatória, antimutagênica, antiglicação entre outras, sendo estas diretamente relacionadas aos compostos bioativos presentes, especialmente na folha da árvore (principal parte utilizada para produção da erva-mate). Entre as substâncias conhecidas estão os polifenóis, saponinas, xantinas, minerais e vitaminas. Muitos fatores influenciam o teor desses compostos no produto final que é comercializado e por conseqüência no que é ingerido pelo consumidor. O presente estudo avaliou a composição fitoquímica e os potencias antioxidantes de extratos de ervas comercializados no Brasil, Argentina e Uruguai. Objetivando a obtenção de extratos com composição similar aos ingeridos pela população, preparou-se a bebida da forma tradicional e empregou-se uma forma de extração que mimetiza seu consumo. A partir desses extratos (mates) foram quantificados o conteúdo total de polifenóis, as concentrações das substâncias: ácido clorogênico, ácido cafeico, cafeína e teobromina e analisados os potenciais antioxidantes dos extratos. Para este fim foram utilizadas análises cromatográficas, espectrofotométricas e desenvolvidos ensaios, in vitro, que testaram a capacidade dos extratos seqüestrarem óxido nítrico e quelarem ferro. Foi possível verificar que a seqüência de extrações é um fator que influência no conteúdo extraído, visto que houveram diferenças significativas entre os primeiros e os últimos extratos. Além disso, verificou-se que a capacidade antioxidante dos extratos é expressiva e se mantêm mesmo em extratos onde a concentração de compostos apresenta decaimento significativo. No entanto, foram notadas variações relacionadas principalmente às nacionalidades das ervas. Este estudo sintetiza uma contribuição importante para futuras pesquisas, pois elucida o que é ingerido quando a bebida é consumida da forma que a população o faz, colocando a forma de extração como um importante fator, relacionado ao desfecho de seu consumo na saúde. / The yerba-mate, scientifically named, Ilex paraguariensis St. Hil. Var. paraguariensis (Aquifoliaceae), it is a tree that grows naturally in forests of South America (in Argentina, southern Brazil, Uruguay and Paraguay). Yerba mate based drinks are part of the customs and habits of the population and are called "mate", "chimarrão" or "tererê". In recent years, through the expansion of scientific knowledge about their effects in health, the plant uses has been expanded to other parts of the world and are described various possibilities of the application. Their actions include antioxidant capacity, anti-inflammatory, antimutagenic, anti-glycation and others, which are directly related to the bioactive compounds presents, especially in the leaves of the tree (the main part used for the production of yerba mate). Among the substances known are polyphenols, saponins, xanthines, vitamins and minerals. Many factors influence the content of these compounds in the end product that is marketed, and consequently in what is ingested by the consumer. The present study evaluated the phytochemical composition and the antioxidant potential of yerba-mate extracts sold in Brazil, Argentina and Uruguay. Aiming to get extracts with composition similar to the population consumes, the beverage was prepared in the traditional way and to extraction was used a method that mimics its consumption. From these extracts (mates) were quantified the total polyphenol content, the concentrations of the substances: chlorogenic acid, caffeic acid, caffeine and theobromine, and analyzed the antioxidant potential of the extracts. To this end were developed chromatographic, spectrophotometric analysis and, in vitro, carried out trials that tested the ability of the extracts to scavenger oxide nitric and to chelate iron. Was observed that the sequence of extraction is a factor that influences the extracted content, since there were significant differences between the first few and the last ones extracts. It was found that the antioxidant activity of the extracts is quite significant and remains in extracts where the concentration of compounds presents significant decline. However variations were noted, it’s related primarily to the nationalities of herbs. This study summarizes an important contribution to other research, because it clarifies what is ingested when it is drunk the way that people do it, putting the extraction as an important factor related to the outcome of their consumption on health.