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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

The causes of victory and defeat in the light of chapter eight of the Holy Qur'an

al-Mushawwah, Khalid bin Addallah 30 November 2002 (has links)
The present study covers the causes of victory and defeat in the light of chapter eight of the Holy Qur'an. It has been prompted by the current situation facing Muslims in many parts of the world, which is characterized by despair, reversals and loss, This study is thus reflexive in nature. In order to obtain a satisfactory response to this predicament, the relevant text in addition to several of its commentaries were scrutinized. The latter search remained unsatisfactory since their focus of inquiry was merely exegetical and failed to reveal any didactic element, which is crucial for obtaining guidance. This work has successfully managed to deduce this aspect from the text which amplifies the importance of extensive sacrifice for gaining glory. / Religious Studies and Arabic / M.A. (Islamic studies)
172

Desenvolvimento de instrumentação e procedimentos analíticos automáticos empregando fotometria em fase sólida para determinação de zinco em produtos farmacêuticos e água / Combining multicommuted flow injection analysis and solid phase photometry for the determination of zinc in pharmaceutical preparation and water

Dias, Tuanne dos Reis 25 August 2010 (has links)
Neste trabalho, é proposto o desenvolvimento de instrumentação e procedimentos analíticos automáticos empregando fotometria em fase sólida para determinação de zinco em produtos farmacêuticos e água. Para implementação do procedimento analítico, todo o sistema foi acoplado a um computador através de uma interface eletrônica. Um software escrito em linguagem QuickBASIC 4.5 permite que o computador efetue o controle da adição das soluções da amostra e do eluente e faça aquisição de dados. O sistema de detecção é constituído de uma cela de fluxo contendo, um LED e um fotodiodo. A geometria da cela de fluxo possibilitava variar o comprimento do caminho óptico. O procedimento para determinação do zinco foi baseado na retenção do analito na fase sólida (TAN-C18), previamente inserida na cela de fluxo, seguido de uma etapa de eluição. Com os parâmetros analíticos otimizados obteve-se resposta linear na faixa de 0,05 a 0,85 mg L-1 (R=0,995), limite detecção de 9,3 \'mü\'g L-1, coeficiente de variação de 1,4% (n=10) e frequência de amostragem de 36 det h-1. O módulo de análise foi aplicado em amostras de produtos farmacêuticos e a exatidão dos resultados foi averiguada comparando com os resultados obtidos por espectrometria de emissão óptica com plasma acoplado indutivamente ICP-OES. Aplicando-se tratamento estatístico apropriado, observou-se que não havia diferença significativa ao nível de confiança de 95 %. Estes resultados comprovam a viabilidade do emprego de fotômetro de LED em fotometria em fase sólida / In this work, it is propose the instrumentation and automatic analytic procedures development using solid phase spectrophotometry for determination of zinc in pharmaceutical preparations and water. For analytic procedure implementation, the whole system was coupled to a computer through an electronic interface. A written software in language QuickBASIC 4.5 allows the computer makes the sample solutions addition control and of eluent and do data acquisition. The detection system is constituted of a flow cell contend, a LED and a photodiode. The flow cell geometry enabled vary the length of the optical path. The procedure for zinc determination was going based in analyte retention in the solid phase (TAN-C18), previously inserted in the flow cell, followed by an elution stage. With the optimized analytic parameters it btained lineal answer in the band of 0,05 to 0,85 mg L-1 (R=0,995), limit detection of 9,3 \'mü\'g L-1, variation coefficient of 1,4% (n=10) and sampling throughput of 36 det h-1. The analysis module was going applied in pharmaceutical preparations samples and the exactness of the results was going ascertained comparing with the results obtained for inductively coupled plasma optic emission spectrometry of with ICP- its. Applying appropriated statistical treatment, it observed that there wasn\'t significant difference to the reliable level of 95 %. These results prove photometer job viability of LED in photometry in solid phase
173

MECHANISMS AND THERMODYNAMICS OF THE INFLUENCE OF SOLUTION-STATE INTERACTIONS BETWEEN HPMC AND SURFACTANTS ON MIXED ADSORPTION ONTO MODEL NANOPARTICLES

Gupta Patel, Salin 01 January 2019 (has links)
Nanoparticulate drug delivery systems (NDDS) such as nanocrystals, nanosuspensions, solid-lipid nanoparticles often formulated for the bioavailability enhancement of poorly soluble drug candidates are stabilized by a mixture of excipients including surfactants and polymers. Most literature studies have focused on the interaction of excipients with the NDDS surfaces while ignoring the interaction of excipients in solution and the extent to which the solution-state interactions influence the affinity and capacity of adsorption. Mechanisms by which excipients stabilize NDDS and how this information can be utilized by formulators a priori to make a rational selection of excipients is not known. The goals of this dissertation work were (a) to determine the energetics of interactions between HPMC and model surfactants and the extent to which these solution-state interactions modulate the adsorption of these excipients onto solid surfaces, (b) to determine and characterize the structures of various aggregate species formed by the interaction between hydroxypropyl methylcellulose (HPMC) and model surfactants (nonionic and ionic) in solution-state, and (c) to extend these quantitative relationships to interpret probable mechanisms of mixed adsorption of excipients onto the model NDDS surface. A unique approach utilizing fluorescence, solution calorimetry and adsorption isotherms was applied to tease apart the effect of solution state interactions of polymer and surfactant on the extent of simultaneous adsorption of the two excipients on a model surface. The onset of aggregation and changes in aggregate structures were quantified by a fluorescence probe approach with successive addition of surfactant. In the presence of HPMC, the structures of the aggregates formed were much smaller with an aggregation number (Nagg) of 34 as compared to micelles (Nagg ~ 68) formed in the absence of HPMC. The strength of polymer-surfactant interactions was determined to be a function of ionic strength and hydrophobicity of surfactant. The nature of these structures was characterized using their solubilization power for a hydrophobic probe molecule. This was determined to be approximately 35% higher in the polymer-surfactant aggregates as compared to micelles alone and was attributed to a significant increase in the number of aggregates formed and the increased hydrophobic microenvironment within these aggregates at a given concentration of surfactant. The energetics of the adsorption of SDS, HPMC, and SDS-HPMC aggregate onto nanosuspensions of silica, which is the model solid surface were quantified. A strong adsorption enthalpy of 1.25 kJ/mol was determined for SDS adsorption onto silica in the presence of HPMC as compared to the negligible adsorption enthalpy of 0.1 kJ/mol for SDS alone on the silica surface. The solution depletion and HPMC/ELSD methods showed a marked increase in the adsorption of SDS onto silica in the presence of HPMC. However, at high SDS concentrations, a significant decrease in the adsorbed amount of HPMC onto silica was determined. This was further corroborated by the adsorption enthalpy that showed that the silica-HPMC-SDS aggregation process became less endothermic upon addition of SDS. This suggested that the decrease in adsorption of HPMC onto silica at high SDS concentrations was due to competitive adsorption of SDS-HPMC aggregates wherein SDS is displaced/desorbed from silica in the presence of HPMC. At low SDS concentrations, an increase in adsorption of SDS was due to cooperative adsorption wherein SDS is preferentially adsorbed onto silica in the presence of HPMC. This adsorption behavior confirmed the hypothesis that the solution-state interactions between pharmaceutical excipients such as polymers and surfactants would significantly impact the affinity and capacity of adsorption of these excipients on NDDS surfaces.
174

Development and Characterization of Anti-Inflammatory Coatings for Implanted Neural Probes

Zhong, Yinghui 21 November 2006 (has links)
Stable single-unit recordings from the nervous system using microelectrode arrays can have significant implications for the treatment of a wide variety of sensory and movement disorders. However, the long-term performance of the implanted neural electrodes is compromised by the formation of glial scar around these devices, which is a typical consequence of the inflammatory tissue reaction to implantation-induced injury in the CNS. The glial scar is inhibitory to neurons and forms a barrier between the electrode and neurons in the surrounding brain tissue. Therefore, to maintain long-term recording stability, reactive gliosis and other inflammatory processes around the electrode need to be minimized. This work has succeeded in the development of neural electrode coatings that are capable of sustained release of anti-inflammatory agents while not adversely affecting the electrical performance of the electrodes. The effects of coating methods, initial drug loadings on release kinetics were investigated to optimize the coatings. The physical properties of the coatings and the bioactivity of released anti-inflammatory agents were characterized. The effect of the coatings on the electrical property of the electrodes was tested. Two candidate anti-inflammatory agents were screened by evaluating their anti-inflammatory potency in vitro. Finally, neural electrodes coated with the anti-inflammatory coatings were implanted into rat brains to assess the anti-inflammatory potential of the coatings in vivo. This work represents a promising approach to attenuate astroglial scar around the implanted silicon neural electrodes, and may provide a promising strategy to improve the long-term recording stability of silicon neural electrodes.
175

QUANTIFICATION OF FACTORS GOVERNING DRUG RELEASE KINETICS FROM NANOPARTICLES: A COMBINED EXPERIMENTAL AND MECHANISTIC MODELING APPROACH

Fugit, Kyle Daniel 01 January 2014 (has links)
Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies. A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release data. This method also quantified the effects of topotecan dimerization and surface potential on total amount of drug released from these liposomal formulations. The pH-sensitive release of topotecan from unilamellar vesicles was subsequently evaluated with this method. A mechanistic model identified three permeable species in which the zwitterionic lactone form of topotecan was the most permeable. Ring-closing kinetics of topotecan from its carboxylate to lactone form were found to be rate-limiting for topotecan drug release in the neutral pH region. Models were also developed to non-invasively analyze release kinetics of actively-loaded liposomal formulations of topotecan in vivo. The fluorescence excitation spectra of released topotecan were used to observe release kinetics in aqueous solution and human plasma. Simulations of the intravesicular pH in the various release media indicated accelerated release in plasma was a consequence of increased intravesicular pH due to ammonia levels in the plasma instead of alterations in bilayer integrity. Further studies were performed to understand the roles of dimerization, ion-pairing, and precipitation on loading and release kinetics obtained from actively-loaded topotecan. Extension of this type of modeling for other types of nanoparticles was illustrated with doxorubicin-conjugated polymeric micelles. Mathematical modeling of experimental studies monitoring doxorubicin release identified conjugation stability during storage, hydrazone hydrolysis kinetics, and unconjugated doxorubicin partitioning affected micellar doxorubicin release. This work identifies several of the key parameters governing drug release from these liposomal and micellar nanoparticles and lays the framework for future development of in vivo release models for these formulations.
176

A pharmaceutical risk management model

Bui, Thu-Tam T. January 2006 (has links) (PDF)
Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 113-119.
177

Postmortem toxicology : aspects on interpretation /

Holmgren, Per, January 2004 (has links) (PDF)
Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 4 uppsatser.
178

Depåneuroleptika på gott och ont : patienters och sjuksköterskors erfarenheter av långtidsbehandling i psykiatrisk öppenvård /

Svedberg, Bodil, January 2003 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.
179

Hippocratic recipes : oral and written transmission of pharmacological knowledge in fifth- and fourth-century Greece /

Totelin, Laurence M.V. January 2009 (has links)
Thesis Univ. College London, 2006. / Includes bibliographical references and indexes.
180

Alteração de conservantes no pós-registro e possíveis impactos na qualidade dos medicamentos fabricados no Brasil /

Pereira, Silvio Luiz Gonçalves. January 2011 (has links)
Resumo: Na sua quase totalidade, as formas farmacêuticas líquidas apresentam agentes conservantes em suas fórmulas visando a proteção contra o desenvolvimento microbiano. Entretanto, pesquisas indicam que conservantes são substâncias tóxicas, pois dependendo da concentração administrada podem provocar reações adversas ou intoxicações. A inclusão desses agentes na fórmula de um medicamento deve seguir rigorosamente os parâmetros de eficácia e segurança, garantindo assim proteção antimicrobiana máxima sem provocar danos aos usuários. Por essas razões, este estudo teve como objetivo analisar os possíveis impactos na qualidade das dispersões moleculares de uso oral comercializadas no Brasil em decorrência das alterações na concentração de excipientes no pós-registro de medicamentos, em especial a modificação "moderada" de conservantes (5 - 10%). Foram analisadas as fórmulas de todas as dispersões moleculares de uso oral, de referência, registradas na ANVISA em março de 2009, e os respectivos sistemas conservantes foram identificados. A elaboração de uma matriz "medicamentos versus sistemas conservantes" propiciou a definição dos principais sistemas conservantes empregados industrialmente e sua inserção em oito fórmulas de bancada. Os testes de efetividade antimicrobiana realizados nestas fórmulas indicaram que metade delas não atendeu aos critérios de aceitação propostos na monografia oficial (USP 32), além de outras duas que apresentaram frágil proteção antimicrobiana, pois nelas o crescimento microbiano esteve muito próximo do limite máximo permitido. Em se tratando dos riscos que tais alterações possam provocar na conservação de um medicamento, estes valores são preocupantes, especialmente em escala industrial e, no mínimo, as fórmulas não aprovadas deveriam ser retestadas / Abstract: Almost all liquid dosage forms have preservative agents in their formulas in order to protect against microbial growth. However, researches indicate that preservatives are toxic, because depending on the administered concentration they can cause adverse reactions or intoxications. The inclusion of these agents in the formulation of a product should strictly follow the parameters of efficacy and safety, thus ensuring maximum antimicrobial protection without causing harm to users. For these reasons, this study aimed to examine the possible impacts on the quality of molecular dispersions for oral administration commercialized in Brazil as a result of changes in the concentration of excipients in the post-registration of medicines, particularly the "moderate" modification of preservative agents (5 - 10%). All formulas of molecular dispersions for oral use, as reference drugs, recorded at ANVISA in March 2009 were analyzed and the preservative agents were identified. The development of a matrix "drugs versus preservative systems" led to the definition of major preservative systems used industrially and their inclusions in eight formulas studied. The antimicrobial effectiveness tests conducted on these formulas indicated that half of them did not meet the acceptance criteria proposed in the official monograph (USP 32), beyond two other formulas that presented weak antimicrobial protection, because microbial growth in them was very close to the maximum allowed. Considering the risks that such changes may result in the conservation of a drug these negative values are worrisome, especially on an industrial scale and, at least, the formulas not approved should be retested / Orientador: Taís Maria Bauab / Coorientador: Ana Dóris de Castro / Banca: Lauro Domingos Moretto / Banca: Hérida Regina Nunes Salgado / Mestre

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