909 resultados para QUANTITATIVE-ANALYSIS
Resumo:
Thermal analysis has been widely used for obtaining information about drug-polymer interactions and for pre-formulation studies of pharmaceutical dosage forms. In this work, biodegradable microparticles Of Poly (D,L-lactide-co-glycolide) (PLGA) containing triamcinolone (TR) in various drug:polymer ratios were produced by spray drying. The main purpose of this study was to study the effect of the spray-drying process not only on the drug-polymer interactions but also on the stability of microparticles using differential scanning calorimetry (DSC), thermogravimetry (TG) and derivative thermogravimetry (DTG), X-ray analysis (XRD), and infrared spectroscopy (IR). The evaluation of drug-polymer interactions and the pre-formulation studies were assessed using the DSC, TG and DTG, and IR. The quantitative analysis of drugs entrapped in PLGA microparticles was performed by the HPLC method. The results showed high levels of drug-loading efficiency for all used drug: polymer ratio, and the polymorph used for preparing the microparticles was the form B. The DSC and TG/DTG profiles for drug-loaded microparticles were very similar to those for the physical mixtures of the components. Therefore, a correlation between drug content and the structural and thermal properties of drug-loaded PLGA microparticles was established. These data indicate that the spray-drying technique does not affect the physico-chemical stability of the microparticle components. These results are in agreement with the IR analysis demonstrating that no significant chemical interaction occurs between TR and PLGA in both physical mixtures and microparticles. The results of the X-ray analysis are in agreement with the thermal analysis data showing that the amorphous form of TR prevails over a small fraction of crystalline phase of the drug also present in the TR-loaded microparticles. From the pre-formulation studies, we have found that the spray-drying methodology is an efficient process for obtaining TR-loaded PLGA microparticles. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
The substitution of petroleum-based fuels with those from renewable sources has gained momentum worldwide. A UV-vis experiment for the quantitative analysis of biofuels (bioethanol or biodiesel) in (petroleum-based) diesel oil has been developed. Before the experiment, students were given a quiz on biofuels, and then they were asked to suggest a suitable UV-vis experiment for the quantification of biofuels in diesel oil. After discussing the results of the quiz, the experiment was conducted. This included the determination of lambda(max) of the medium-dependent, that is, solvatochromic, visible absorption band of the probe 2,6-bis[4-(tert-butyl)phenyl]-4-{2,4,6-tris[4-(tert-butyl)phenyl]pyridinium-1-yl}phenolate as a function of fuel composition. The students appreciated that the subject was linked to a daily situation and that they were asked to suggest the experiment. This experiment served to introduce the phenomena of solvation and solvatochromism.
Resumo:
Schistosomiasis is one of the world`s greatly neglected tropical diseases, and its control is largely dependent on a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentration of 15.8 mu M reduced the motor activity of worms and caused their death within 24 h in a RPMI 1640 medium. Similarly, the highest sub-lethal concentration of piplartine (6.3 mu M) caused a 75% reduction in egg production in spite of coupling. Additionally, piplartine induced morphological changes on the tegument, and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destruction and damage in the tubercles. This damage was dose-dependent in the range of 15.8-630.2 mu M. At doses higher than 157.6 mu M, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported for piplartine. Published by Elsevier Inc.
Resumo:
A low-cost method is proposed to classify wine and whisky samples using a disposable voltammetric electronic tongue that was fabricated using gold and copper substrates and a pattern recognition technique (Principal Component Analysis). The proposed device was successfully used to discriminate between expensive and cheap whisky samples and to detect adulteration processes using only a copper electrode. For wines, the electronic tongue was composed of copper and gold working electrodes and was able to classify three different brands of wine and to make distinctions regarding the wine type, i.e., dry red, soft red, dry white and soft white brands. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Resumo:
Raman and IR experiments have been carried out on formamide (FA) and pyridine (Py) mixtures at different compositions. The appearance of a new Raman band at 996 cm(-1) (nu(1) region of Py), whose intensity depends on the FA concentration, is assigned to an FA: Py adduct and this result is in excellent agreement with those of other authors who employed noisy light-based coherent Raman scattering spectroscopy (I((2)) CARS). Another band at 1587 cm(-1) (nu(8) region of Py) has been observed for the first time by using Raman and IR spectroscopies. Its intensity shows the same dependence on the FA concentration and this fact allows us to also attribute it to an FA: Py adduct. The good relationship between the Raman and IR data demonstrates the potential of the vibrational spectroscopy for this kind of study. Owing to higher absolute Raman scattering cross section, the nu(1) region of Py has been chosen for the quantitative analysis and a stoichiometry of 1 : 1 FA: Py is reported. The experimental data are very well supported by the density functional theory (OFT) calculation, which was employed for the first time to the present system. Furthermore, the actual investigation shows an excellent agreement with those reported from computational calculations for similar systems. A comparison with our previous studies confirms that: the solvent dielectric constant determines the stoichiometry of a given Lewis acid-base adduct in the infinite dilution limit. Copyright (C) 2009 John Wiley & Sons, Ltd.
Resumo:
The fungi Aspergillus sydowii Ce15, Aspergillus sydowii Ce19, Aspergillus sydowii Gc12, Bionectria sp. Ce5, Penicillium miczynskii Gc5, Penicillium raistrickii Ce16 and Trichoderma sp. Gc1, isolated from marine sponges Geodia corticostylifera and Chelonaplysylla erecta, were evaluated for their ability to grow in the presence of DDD pesticide. Increasing concentrations of DDD pesticide, i.e., 5.0 mg (1.56 x 10(-12) mmol), 10.0 mg (3.12 x 10(-2) mmol) and 15.0 mg (4.68 x 10(-2) mmol) in solid and liquid culture media were tested. The fungi Trichoderma sp. Gc1 and Penicillium miczynskii Gc5 were able to grow in the presence of up to 15.0 mg of DDD, suggesting their potential for biodegradation. A 100% degradation of DDD was attained in liquid culture medium when Trichoderma sp. Gc1 was previously cultivated for 5 days and supplemented with 5.0 mg of DDD in the presence of hydrogen peroxide. However, the quantitative analysis showed that DDD was accumulated on mycelium and biodegradation level reached a maximum value of 58% after 14 days.
Resumo:
A method is reported for the quantification of isoorientin (using a standard addition method) and total flavonoids (expressed as rutin, using the external standard method) in passion fruit pulp (Passiflora edulis Sims f. flavicarpa Degener, Passifloraceae). Extraction of flavonoids was optimized by experimental design methodology, and quantitative analysis was performed by high-performance liquid chromatography with photo-diode array detection (HPLC-UV/DAD). The method was developed and validated according to ICH requirements for specificity, linearity, accuracy, precision (repeatability and intermediate precision). LOD and LOQ. Rutin was chosen as standard for the quantification of total flavonoids in order to propose a HPLC method feasible for routine analysis of the flavonoids in the passion fruit pulp. The passion fruit pulp contained 16.226 +/- 0.050 mg L(-1) of isoorientin and 158.037 +/- 0.602 mg L(-1) of total flavonoid, suggesting that P. edulis fruits may be comparable with other flavonoid food sources such as orange juice or sugarcane juice. (C) 2010 Elsevier B.V. All rights reserved.
Resumo:
At the centre of this study lies the question if normative gender thinking affects the way poetry gets reviewed and how the reviews are written, this in relation to both the gender of the reviewer and the poet. The study crosses three academic fields; gender studies, poetry and journalism, and is based on the cultural studies theory of media affecting and even creating the world around it. The study is based on two types of analysis. One quantitative analysis based on the thematic criticism theory about detail studies that shows bigger patterns, this analysis focuses on how the poet and his/hers work are being treated in the reviews in areas such as how much space they´re given in the newspapers, how they are named by the reviewer and the tendency to quote the reviewed work. And one qualitative analysis based on the new criticism method of close reading, that focuses on the reviewers way of writing and how that may be connected with theories of gender differences, this both connected to the gender of the reviewers and the poets. The material chosen for this study are all the reviews that were published in the same newspapers and that reviewed two specific poetry works by two specific poets chosen with great sensibility to age and career so that their difference in gender would be the most significant difference between them. The works were chosen based on year of publishing, they were supposed to be published as newly as possible and as close to each other in time as possible. The works I ended up with were Dimman av allt (2001) and Svart som silver (2008) by Bruno K. Öijer and Silverskåp (2000) and Nu försvinner vi eller ingår (2007) by Birgitta Lillpers. The results of this study show several differences in how poetry is being judged and how poetry reviews are being written are connected with the gender of the poets and the reviewer. Lillpers got 35% less space in the newspapers and Öijers poetry got quoted a lot more which confirms that female poetry often is considered as less important than the male poetry, and that men in general tends to be judged as more professional than woman. The male reviewers tended to express themselves with greater certainty than the female reviewers who held a more professional tone in their reviews and focused more on the technical aspects of the poetry. This confirms the theory of the male words are being looked upon as the truth but contradicts the theory of women writing more based on personal experience and of women being less skilled in language techniques. In conclusion, there are differences in how poetry gets reviewed and how the reviews are written that are connected to the genders of the poet and the reviewer but these differences are complex and does not show a clear normative way of thinking about gender
Resumo:
O presente trabalho tem por objetivo abordar o tema microcrédito e analisar sua experiência mais bem sucedida no Brasil, o CrediAMIGO, do Banco do Nordeste. Há uma descrição do programa e uma análise quantitativa de sua atuação, que será feita a partir de uma base de dados composta pelas pesquisas Ecinf de 1997 e 2003, utilizando regressões logísticas e o método de diferenças em diferenças. Em termos substantivos concluímos que há experiência de microcrédito na região mais pobre do Brasil, baseada em aval solidário, proporcionando aumento no acesso a crédito superior ao resto do país.
Resumo:
É nítida e rápida a popularização da maioria dos bens duráveis de consumo no Estado de São Paulo, nos últimos vinte anos. Colaboram para isso a universalização da oferta domiciliar de eletricidade, água encanada, esgotos, e a tendência ao barateamento dos bens. Entre outros efeitos, tal popularização deteriora a eficácia das escalas de classificação sócio- econômica baseadas na posse de itens de conforto doméstico, suscitando freqüentes revisões e discórdias no interior da comunidade de marketing. Este estudo sistematiza estatísticas sobre situação domiciliar e posse de itens de conforto doméstico no Estado de S. Paulo, e mostra como isso afeta o consumo material e cultural. Finalmente, aponta que é chegada a hora de se usar mais e melhor variáveis como educação, profissão, qualidade do domicílio, tal como se faz em países desenvolvidos, para o entendimento mais pleno das mudanças que implantam no Brasil a moderna sociedade de consumo.
Resumo:
In this thesis, the basic research of Chase and Simon (1973) is questioned, and we seek new results by analyzing the errors of experts and beginners chess players in experiments to reproduce chess positions. Chess players with different levels of expertise participated in the study. The results were analyzed by a Brazilian grandmaster, and quantitative analysis was performed with the use of statistical methods data mining. The results challenge significantly, the current theories of expertise, memory and decision making in this area, because the present theory predicts piece on square encoding, in which players can recognize the strategic situation reproducing it faithfully, but commit several errors that the theory can¿t explain. The current theory can¿t fully explain the encoding used by players to register a board. The errors of intermediary players preserved fragments of the strategic situation, although they have committed a series of errors in the reconstruction of the positions. The encoding of chunks therefore includes more information than that predicted by current theories. Currently, research on perception, trial and decision is heavily concentrated on the idea of pattern recognition". Based on the results of this research, we explore a change of perspective. The idea of "pattern recognition" presupposes that the processing of relevant information is on "patterns" (or data) that exist independently of any interpretation. We propose that the theory suggests the vision of decision-making via the recognition of experience.
Resumo:
In this thesis, the basic research of Chase and Simon (1973) is questioned, and we seek new results by analyzing the errors of experts and beginners chess players in experiments to reproduce chess positions. Chess players with different levels of expertise participated in the study. The results were analyzed by a Brazilian grandmaster, and quantitative analysis was performed with the use of statistical methods data mining. The results challenge significantly, the current theories of expertise, memory and decision making in this area, because the present theory predicts piece on square encoding, in which players can recognize the strategic situation reproducing it faithfully, but commit several errors that the theory can¿t explain. The current theory can¿t fully explain the encoding used by players to register a board. The errors of intermediary players preserved fragments of the strategic situation, although they have committed a series of errors in the reconstruction of the positions. The encoding of chunks therefore includes more information than that predicted by current theories. Currently, research on perception, trial and decision is heavily concentrated on the idea of 'pattern recognition'. Based on the results of this research, we explore a change of perspective. The idea of 'pattern recognition' presupposes that the processing of relevant information is on 'patterns' (or data) that exist independently of any interpretation. We propose that the theory suggests the vision of decision-making via the recognition of experience.
Resumo:
o objetivo deste trabalho é analisar o modelo de gestão implantado na Fundação Oswaldo Cruz - FIOCRUZ, procurando identificar os limites e possibilidades de um processo de gestão democrática no Serviço Público, e de outro, inventariar, criticamente, os modelos administrativos disponíveis que tenham a questão da gestão democrática como pressuposto organizacional. Norteou o trabalho a trajetória institucional da FIOCRUZ, notadamente o período da realização dos Congressos Internos (de 1988 a 1996). Para alcance do objetivo, foram analisados, a partir de fontes primárias e secundárias, os aspectos que abrem espaço para um processo de gestão democrática. Na realização do trabalho foram selecionadas como categorias analíticas: poder decisório, autonomia e controle social. Baseamo-nos, ainda, no método que privilegiou a descrição utilizando, porém, a dedução apoiada na análise qualitativa e quantitativa. A análise dos dados possibilitou concluir que os procedimentos participativos como o processo eletivo de escolha do presidente e dos diretores das Unidades da FIOCRUZ, a constituição dos órgãos colegiados de decisão e a realização dos Congressos Internos abriram espaços para a democratização da gestão, representando a materialização da vontade e do desejo de certos atores, e garantiram a unidade de ação em uma instituição pouco integrada. Algumas questões são ponto de partida para pesquisas futuras: como esse modelo participativo é implantado em cada Unidade da FIOCRUZ? Esse modelo corresponde ao desejo efetivo dos servidores? Em que medida o processo participativo de gestão contribuiu para o ganho de eficiência administrativa?
Resumo:
The acts of public administration personnel are of great importance and various laws have been passed in attempt to limit the related expenses. The management of Public administration personnel is based on the principle of efficiency. The TCE/RJ (State of Rio de Janeiro/Audit Court) digital communication system is expected through telework to facilitate its auditing duties in compliance with the terms of the Federal and State constitutions. The TCE/RJ, the superior judicial body of auditing, has done more than just reduce costs and use flextime; it applies telework as an instrument to optimize public service through SICODI digital certification to maximize the resources applied to this constitutional act with greater efficiency for effective auditing. The focus of the first part of this study is to evaluate the tasks of positions that forward the TCE/RJ objectives and the profile characteristics of employees of the inspection area on personnel performance beginning with defined concepts and purposes. Questionnaires for auditors and technicians of the area were approved for this specific purpose to analyze the duties of positions and employee profiles. The second part of this study evaluates the TCE/RJ digital communication system according to theoretical reference and ISO/IEC Standard No. 9126-1, observing three dimensions: the content, usability and functionality. The results obtained, with the use of qualitative methods complemented by quantitative analysis, were positive for the implementation of telework in the inspection of personnel performance in relation to the analysts and technicians involved in this type of auditing as well as in relation to the TCE/RJ digital communication system.
Resumo:
The acts of public administration personnel are of great importance and various laws have been passed in attempt to limit the related expenses. The management of Public administration personnel is based on the principle of efficiency. The TCE/RJ (State of Rio de Janeiro/Audit Court) digital communication system is expected through telework to facilitate its auditing duties in compliance with the terms of the Federal and State constitutions. The TCE/RJ, the superior judicial body of auditing, has done more than just reduce costs and use flextime; it applies telework as an instrument to optimize public service through SICODI digital certification to maximize the resources applied to this constitutional act with greater efficiency for effective auditing. The focus of the first part of this study is to evaluate the tasks of positions that forward the TCE/RJ objectives and the profile characteristics of employees of the inspection area on personnel performance beginning with defined concepts and purposes. Questionnaires for auditors and technicians of the area were approved for this specific purpose to analyze the duties of positions and employee profiles. The second part of this study evaluates the TCE/RJ digital communication system according to theoretical reference and ISO/IEC Standard No. 9126-1, observing three dimensions: the content, usability and functionality. The results obtained, with the use of qualitative methods complemented by quantitative analysis, were positive for the implementation of telework in the inspection of personnel performance in relation to the analysts and technicians involved in this type of auditing as well as in relation to the TCE/RJ digital communication system.