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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.
31

Intracellular unbound drug concentrations : Methodology and application for understanding cellular drug exposure

Mateus, André January 2016 (has links)
Most known drug targets and metabolizing enzymes are located inside cells. Interactions with these proteins are determined by intracellular unbound drug concentrations. Assessing intracellular drug exposure is technically challenging, but essential for predicting pharmacokinetic, pharmacological, and toxicological profiles of new drugs. This thesis aims at establishing and applying a straightforward methodology to measure intracellular unbound drug concentrations. This was achieved by separately measuring cellular drug binding (fu,cell), and total intracellular drug accumulation (Kp). This allowed the calculation of intracellular drug bioavailability (Fic), which represents the fraction of the concentration added to the cells that is unbound in the cell interior. The methodology was initially developed in HEK293 cells, where the Fic of 189 drug-like compounds was measured. Binding to HEK293 cells was governed by compound lipophilicity and was correlated with binding to more complex systems, such as hepatocytes and brain. Due to negligible expression of drug transporters, Fic in this cell line was consistent with pH-dependent subcellular sequestration of lipophilic cations in low pH compartments. The methodology was then applied to study the effects of drug transporters on Fic. The uptake transporter OATP1B1 increased the Fic of its substrates in a concentration-dependent manner. In contrast, the Fic of P-gp substrates was decreased when P-gp was present. In human hepatocytes, the methodology allowed the determination of Fic without prior knowledge of transporter mechanisms or metabolic activity. Finally, the methodology was applied to measure the impact of Fic on target binding and cellular drug response. Intracellular concentrations of active metabolites of pro-drugs targeting the intracellular target thymidylate synthase were in agreement with the level of binding to this target. Further, high Fic was generally required for kinase and protease inhibitors to be active in cellular assays. In conclusion, the methodology can be used to predict if new drug candidates reach their intracellular targets in sufficient amounts. Furthermore, the methodology can improve in vitro predictions of drug clearance and drug-drug interactions, by measuring the drug available for intracellular enzymes. Finally, this work can be expanded to other xenobiotics, e.g., to predict their intracellular toxicity.
32

Persian Orthography : Modification or Changeover? (1850-2000)

Hashabeiky, Forogh January 2005 (has links)
The present study provides a description of the standardization process of Persian orthography since the introduction of the Arabic alphabet, with a focus on this process in modern times (1850-2000). Using theories related to orthography standardization as its background, this work seeks an explanation for the prolonged standardization process of Persian orthography, and presents the frameworks within which this standardization has been carried out. The most recent state of Persian orthography is presented through an investigation of the current attitudes towards the problems of Persian orthography and possible frameworks for a potential reform, as well as through an investigation of the current tendencies in the manner of presenting different orthographic parameters within Persian contemporary texts. How and by whom the orthography of today’s Persian texts is governed is another aspect to be examined here. The most important conclusion to be drawn from the present study is that there is a strong tendency towards approving reform proposals that can be integrated with the present orthography, and maintain the present appearance of Persian orthography as much as possible. One of the main reasons behind this tendency is the concern of an interruption in cultural continuity in the event of an alphabet reform or any other drastic change in the present appearance of the orthography. This concern takes into account the political, social, cultural, structural, and economic conditions in Iran, as well as the complexity of language planning projects.
33

Avaliação de resíduos da fabricação de telhas cerâmicas para seu emprego em camadas de pavimento de baixo custo. / Evaluation of the waste from ceramic roofing tiles manufacturing for its use in unbound pavement layers.

Dias, João Fernando 02 December 2004 (has links)
Este trabalho apresenta a análise de agregados reciclados de telhas de cerâmica vermelha, visando seu emprego em camadas de pavimentos de baixo custo, baseado em estudos de laboratório. A indústria de cerâmica vermelha gera refugos da queima que são tratados como resíduos, mas se constituem em materiais de alto conteúdo energético e matéria prima de qualidade. O quadro da geração desses resíduos foi diagnosticado nas cidades de Monte Carmelo e Ituiutaba, em Minas Gerais. Os dados quantitativos obtidos indicam que é justificável a sua reciclagem. Somente na cidade de Monte Carmelo, as quantidades geradas permitiriam executar 10,8 km de camada de base de pavimento, ao se misturar 40% de solo poderia atingir 32 km por ano. Aproximadamente 10 t destes resíduos foram britadas obtendo-se o agregado reciclado de telha (ART). Estes agregados foram caracterizados mediante os ensaios físicos e mecânicos, e submetidos aos ensaios empregados na pavimentação, como a metodologia tradicional, metodologia MCT, método da pastilha, resistência ao cisalhamento, outros ensaios denominados índices de qualidade, ensaio de módulo resiliente e deformação permanente. Apesar deste material atender aos principais requisitos da metodologia tradicional, identificou-se que ele quebra com a aplicação de energia de compactação e de tensões nos ensaios, e apresenta alta resiliência - grandes deformações resilientes-, o que levaria à perda da capacidade de suporte da estrutura do pavimento, por fadiga. Desenvolveu-se uma metodologia para a determinação da absorção no estado saturado superfície seca, de agregados porosos, com fração fina inclusive, pois os métodos conhecidos não são aplicáveis; esta metodologia pode ser aprimorada para se constituir em norma de ensaio. Estudou-se um método inédito para a otimização do volume compactado da mistura de agregado com solo, baseado na porosidade do material granular, como uma alternativa ao método da estabilização granulométrica que se mostrou inadequado, no caso. As misturas produzidas com solos lateríticos foram avaliadas após a compactação não apresentando mais a quebra dos grãos do agregado, e mostraram ganhos expressivos no valor do módulo de resiliência, chegando em um caso a atingir 288% acima do módulo do agregado. Os resultados dos ensaios de laboratório indicaram ser possível a aplicação deste material em misturas com solos lateríticos, em camadas de pavimentos de baixo custo. / The purpose of this work is to use recycled aggregate of ceramics roofing tiles for low cost pavement layers, based on laboratory studies. The heavy-clay ceramic industry generates wastes, originated from the calcination stage, that are considered as residues which demand resources for its deposition. However they are high energy content materials which can be useful. The generation of these residues in the cities of Monte Carmelo and Ituiutaba, in the State of Minas Gerais indicated that its recycling is valid. For instance, in the city of Monte Carmelo, it is generated such a large amount of residues that it should be enough to execute about 10,8 km of base course of pavement; moreover if 40% of soil is mixed 32 km pavement per year can be produced. For this study, approximately 10 metric tones of these residues had been crushed to produce the recycled aggregate from roofing tile. The aggregates produced had been characterized by physical and mechanical tests. They were also submitted to the tests used for aggregates for pavement, such as the traditional methodology, methodology MCT (tropical compacted miniature), shear strength, resilient module, permanent deformation, and other tests called quality rates. These residues comply with the main requirements of the traditional methodology, however it is necessary to point out that the material breaks with the application of energy for compaction and under the tensions during the mechanical tests, it also presents high resilience, or great resilient deformations, which will lead to the loss of the supporting capacity of the pavement due to fatigue. An appropriate methodology was developed for the porous aggregate absorption measurement, including its fraction, in the saturated dry surface state. As the known methods for absorption are not applicable, this methodology with improvements can be proposed as standard test. A new method to optimize the compacted volume of the mixture was studied, based on the porosity of the granular material, as an alternative to the traditional method of the grain sized stabilization, which is not adequate for this purpose. The mixtures produced with lateritics soils were evaluated after the compacting, they have not presented the broken grains. These mixtures performed very well with significant increase in the value of the resilience module, up to 288% above of the module of the aggregate. The results of the laboratory indicate that it is possible to use these residues in mixtures with laterític soil, for layers of low cost pavements.
34

Avaliação de resíduos da fabricação de telhas cerâmicas para seu emprego em camadas de pavimento de baixo custo. / Evaluation of the waste from ceramic roofing tiles manufacturing for its use in unbound pavement layers.

João Fernando Dias 02 December 2004 (has links)
Este trabalho apresenta a análise de agregados reciclados de telhas de cerâmica vermelha, visando seu emprego em camadas de pavimentos de baixo custo, baseado em estudos de laboratório. A indústria de cerâmica vermelha gera refugos da queima que são tratados como resíduos, mas se constituem em materiais de alto conteúdo energético e matéria prima de qualidade. O quadro da geração desses resíduos foi diagnosticado nas cidades de Monte Carmelo e Ituiutaba, em Minas Gerais. Os dados quantitativos obtidos indicam que é justificável a sua reciclagem. Somente na cidade de Monte Carmelo, as quantidades geradas permitiriam executar 10,8 km de camada de base de pavimento, ao se misturar 40% de solo poderia atingir 32 km por ano. Aproximadamente 10 t destes resíduos foram britadas obtendo-se o agregado reciclado de telha (ART). Estes agregados foram caracterizados mediante os ensaios físicos e mecânicos, e submetidos aos ensaios empregados na pavimentação, como a metodologia tradicional, metodologia MCT, método da pastilha, resistência ao cisalhamento, outros ensaios denominados índices de qualidade, ensaio de módulo resiliente e deformação permanente. Apesar deste material atender aos principais requisitos da metodologia tradicional, identificou-se que ele quebra com a aplicação de energia de compactação e de tensões nos ensaios, e apresenta alta resiliência - grandes deformações resilientes-, o que levaria à perda da capacidade de suporte da estrutura do pavimento, por fadiga. Desenvolveu-se uma metodologia para a determinação da absorção no estado saturado superfície seca, de agregados porosos, com fração fina inclusive, pois os métodos conhecidos não são aplicáveis; esta metodologia pode ser aprimorada para se constituir em norma de ensaio. Estudou-se um método inédito para a otimização do volume compactado da mistura de agregado com solo, baseado na porosidade do material granular, como uma alternativa ao método da estabilização granulométrica que se mostrou inadequado, no caso. As misturas produzidas com solos lateríticos foram avaliadas após a compactação não apresentando mais a quebra dos grãos do agregado, e mostraram ganhos expressivos no valor do módulo de resiliência, chegando em um caso a atingir 288% acima do módulo do agregado. Os resultados dos ensaios de laboratório indicaram ser possível a aplicação deste material em misturas com solos lateríticos, em camadas de pavimentos de baixo custo. / The purpose of this work is to use recycled aggregate of ceramics roofing tiles for low cost pavement layers, based on laboratory studies. The heavy-clay ceramic industry generates wastes, originated from the calcination stage, that are considered as residues which demand resources for its deposition. However they are high energy content materials which can be useful. The generation of these residues in the cities of Monte Carmelo and Ituiutaba, in the State of Minas Gerais indicated that its recycling is valid. For instance, in the city of Monte Carmelo, it is generated such a large amount of residues that it should be enough to execute about 10,8 km of base course of pavement; moreover if 40% of soil is mixed 32 km pavement per year can be produced. For this study, approximately 10 metric tones of these residues had been crushed to produce the recycled aggregate from roofing tile. The aggregates produced had been characterized by physical and mechanical tests. They were also submitted to the tests used for aggregates for pavement, such as the traditional methodology, methodology MCT (tropical compacted miniature), shear strength, resilient module, permanent deformation, and other tests called quality rates. These residues comply with the main requirements of the traditional methodology, however it is necessary to point out that the material breaks with the application of energy for compaction and under the tensions during the mechanical tests, it also presents high resilience, or great resilient deformations, which will lead to the loss of the supporting capacity of the pavement due to fatigue. An appropriate methodology was developed for the porous aggregate absorption measurement, including its fraction, in the saturated dry surface state. As the known methods for absorption are not applicable, this methodology with improvements can be proposed as standard test. A new method to optimize the compacted volume of the mixture was studied, based on the porosity of the granular material, as an alternative to the traditional method of the grain sized stabilization, which is not adequate for this purpose. The mixtures produced with lateritics soils were evaluated after the compacting, they have not presented the broken grains. These mixtures performed very well with significant increase in the value of the resilience module, up to 288% above of the module of the aggregate. The results of the laboratory indicate that it is possible to use these residues in mixtures with laterític soil, for layers of low cost pavements.
35

Etude du noyau très riche en neutrons 10He par réaction de transfert d'un proton 11Li(d,3He) / Study of the very neutron-rich 10He by one-proton transfer reaction 11Li(d,3He)

Matta, Adrien 27 February 2012 (has links)
La physique à la drip-line offre l'opportunité d'étudier les noyaux à la limite du paysage couvert par la physique nucléaire, où l'addition de nouveaux protons et neutrons ne peut plus être supportée. A l'approche de la drip-line, la structure même des noyaux se trouve modifiée par rapport aux plus stables. Les fermetures de couches classiques disparaissent et de nouveaux phénomènes surgissent, tels que la clusterisation et les halos. Dans ce travail, nous avons revisité la spectroscopie du noyau non-lié 10He par l'intermédiaire d'une réaction de transfert d'un proton 11Li(d,3He) à 50 AMeV étudiée par la méthode de masse manquante. Pour ce faire, nous avons utilisé le détecteur MUST2 sur la ligne RIPS du RIKEN Nishina center. La partie expérimentale de ce travail repose sur un dispositif novateur utilisant des détecteurs de silicium très fins. Pour la première fois, la mise en oeuvre de ces derniers en conjonction avec des détecteurs sensibles en position de haute granularité a été démontrée. L'approche par réaction de transfert conduit à des résultats très clairs sur la position du premier état résonant du 10He, trouvé dans ce travail à 1.4(3) MeV, en accord avec la plupart des précédents travaux expérimentaux. L'obtention pour la première fois d'un facteur spectroscopique permet de nous renseigner sur la nature du recouvrement <10He|11Li>, trouvé égale à 0.13(6). / Physics at the drip-line offer the opportunity to study nuclei at the limits of the nuclear landscape, where additional protons or neutrons can no longer be kept in the nucleus. In the vicinity of the drip-lines, the structural features of the nuclei change with respect to the more stable nuclei, the normal shell closure of particles disappear and new phenomena appear, such as clusterization and halo. In this work we have revisited the spectroscopy of the unbound 10He by means of the 11 Li(d,3 He) reaction at 50 AMeV studied in missing mass method with the MUST2 array at the RIPS beam line of RIKEN. The experimental part of this study rely on new detection set-up using very thin silicon detectors. For the first time, the effective operability of these detectors, in conjunction with high granularity position sensitive detectors, was proved. The transfer reaction approach led to clear results on the 10He first resonant state position, found in this work at 1.4(3) MeV, in agreement with most of the previous experimental works. The extraction of a spectroscopic factor for the first time shed light on the <10He|11Li> overlap, found to be 0.13(6).
36

Untersuchungen zur Wasserdurchlässigkeit von Tragschichten ohne Bindemittel in Straßenbefestigungen

Wolf, Mike 29 August 2014 (has links)
Im Rahmen der Dissertation wurde untersucht, wie die Wasserdurchlässigkeit von ToB unter Baustellenbedingungen geprüft werden kann und welcher Zusammenhang zwischen Verformungsmodul und Wasserdurchlässigkeit besteht und ob diese Eigenschaften baustofftech-nisch oder bautechnologisch beeinflussbar sind. Dazu wurden bei einer Vielzahl von Baumaßnahmen beim Ausbau des Autobahnnetzes in den neuen Bundesländern baubegleitende Messungen auf Tragschichten durchgeführt. Außerdem wurden auf verschiedenen ToB-Versuchsfeldern in einem Lysimeter Vergleichsuntersuchungen mit den Prüfgeräten Tropf-, Doppelring- und Standrohr-Infiltrometer durchgeführt. Außerdem fanden Untersuchungen auf zwei Versuchs-Baustraßen in Schotterwerken statt. Untersucht wurde zunächst, wie sich die Variation der Parameter Korngrößenverteilung, Kornform und Sandtyp sowie Verdich-tungswassergehalt und Verdichtungsgrad auf die Eigenschaften der ToB im Neuzustand auswirken. Es wurde außerdem Untersucht, inwieweit sich ein Zusammenhang darstellen lässt zwischen dem Anstieg der Tragfähigkeit (Ev2-Wert) über eine bestimmte Schichtdicke der ToB und ihrer Wasserdurchlässigkeit.
37

Performance model for unbound grnular materials pavements

Yideti, Tatek Fekadu January 2012 (has links)
Recently, there has been growing interest on the behaviour of unbound granular material in road base layers. Researchers have studied that the design of a new pavement and prediction of service life need proper characterization of unbound granular materials, which is one of the requirements for a new mechanistic design method in flexible pavement. Adequate knowledge of the strength and deformation characteristics of unbound layer in pavements is a prerequisite for proper thickness design, residual life determination, and overall economic optimization of the pavement structure. The current knowledge concerning the granular materials employed in pavement structures is limited. In addition, to date, no general framework has been established to explain satisfactorily the behaviour of unbound granular materials under the complex repeated loading which they experience. In this study, a conceptual method, packing theory-based model is introduced; this framework evaluates the stability and performance of granular materials based on their packing arrangement. In the framework two basic aggregate structures named as Primary Structure (PS), and Secondary Structure (SS). The Primary Structure (PS) is a range of interactive grain sizes that forms the network of unbound granular materials. The Secondary Structure (SS) includes granular materials smaller than the primary structure. The Secondary Structures fill the gaps between the particles in the Primary Structure and larger particles essentially float in the skeleton. In this particular packing theory-based model; the Primary Structure porosity, the average contact points (coordination number) of Primary Structure, and a new parameter named Disruption Potential are the key parameters that determine whether or not a particular gradation results in a suitable aggregate structure. Parameters mentioned above play major role in the aggregate skeleton to perform well in terms of resistance to permanent deformation as well as load carrying capacity (resilient modulus). The skeleton of the materials must be composed of both coarse enough and a limited amount of fine granular materials to effectively resist deformation and carry traffic loads. / QC 20120601
38

Utvärdering av kalkstens egenskaper med laboratorie- och fältmetoder.

Rashid Ahmad, Haval, Tüdes, Serafettin January 2011 (has links)
A pavement construction designed to cope with the different type of traffic loads; it is exposed to and at the same time it can resist the effect of the climate. A road structure consists of sub- and superstructure which is divided by a boundary known as terrace. During the construction of unbound layers (base course and sub-base course) in the superstructure, it is always ensured that the material meet the requirements for bearing capacity and the degree of compaction. These parameters are controlled by various laboratory tests and control methods. To obtain increased knowledge of the material and improve the quality of the compaction in the field, it is necessary to perform laboratory tests in order to determine material properties. A base course material 0/ 32 mm limestone from Gotland (Hejdeby) was investigated in this study. To determine properties of the material various laboratory tests such as proctor compaction test, Micro-Deval, Los Angeles, and grain distribution curve are conducted. To investigate how grain size distribution affects technical properties of the material, the 0/32 mm material was modified with two different samples; grain size distribution of 2/32 mm excluding superior material content, and 0+/32 mm with enhanced superior material content. The purpose of this study was to examine changes in material behavior during proctor compaction. Two aspects of changes in material behavior were emphasized in this study; the optimal water content and maximum dry density, as well as changes of both. As a reference for the limestone features, a traditional 0/32 mm tonalite material (granite) from Vällstaverket was used relating to proctor investigation. Material's resistance to abrasion and fragmentation was investigated by two methods: Micro-Deval and Los Angeles. The results were compared with other rock materials. Furthermore the bearing capacity of the material was verified by examination of the Young's modulus and degree of compaction, as well as properties of water content and dry density, at three trial areas on Gotland. This is performed with various methods such as static plate loading test, light weight deflectometer, density gauge/SDG200, and water/sand volume meter measurement test. By comparing results from different methods of measurement, it may indicate a relationship between these. Test area 3 consists of two smaller test areas which have different water content. The bearing capacity (Young's modulus) and the degree of compaction were measured after each roller passage. Different relationships were obtained between the amount of roller overpass, with Young's modulus of material; as well as degree of compaction. It was found in this study that limestone from Gotland (Hejdeby) maintain its position as construction material for the unbound layers of the road. The result from static plate load which indicated high E V2 values (Young's modulus) was obtained from the field, and it suggests that a fine bearing capacity can be achieved in the use of limestone.
39

Development and validation of an ultrafiltration-UHPLC-MS/MS method for the quantification of unbound Beta-Lactam antibiotics cefotaxime, piperacillin, cloxacillin and flucloxacillin in plasma / Utveckling och validering av en UHPLC-MS/MS-metod med ultrafiltrering för kvantifiering av icke-proteinbunden beta-lactam-antibiotika cefotaxim, piperacillin, kloxacillin och flukloxacillin i plasma

Clarin, Leona January 2020 (has links)
Kritiskt sjuka patienter med infektioner är en börda för sjukvården och 70 % av alla patienter på intensivvårdsavdelningar är ordinerade antibiotika. Antibiotika binder till proteiner i blodet, men enbart den icke-proteinbundna (fria) fraktionen kan diffundera över kapillära membran och binda till receptorer. Standardproteinbindningsgrad för olika antibiotika har utvecklats från studier på friska frivilliga och doseringen av läkemedlen är anpassade därefter. Den totala koncentrationen av antibiotika i patienters blod är vanligen representativ för den farmakologiska effekten. Dock kan vissa sjukdomar påverka proteinbindningsgraden vilket resulterar i en större eller mindre mängd fria antibiotika i blodcirkulationen. Det här kan i sin tur resultera i toxicitet eller otillräcklig effekt av läkemedlet. Syftet med det här projektet var att utveckla en analytisk metod för att bestämma den fria koncentrationen av Beta-Lactam antibiotikan cefotaxim, flukloxacillin, kloxacillin och piperacillin i plasma. En metod utvecklades med ultrafiltrering för extraktion av den fria fraktionen och högupplösande vätskekromatografi och tandem masspektrometri, UHPLC-MS/MS, för kvantifiering av analyterna. Metoden validerades delvis enligt den Europeiska Läkemedelsmyndighetens riktlinjer för bioanalytisk metodvalidering. / Infections in critically ill patients are a problem for the healthcare system and at any one time, 70 % of all intensive care unit (ICU) patients are treated with antibiotics. Antibiotics bind to proteins in the blood, but only unbound drug can diffuse over capillary membranes and bind to the targeted receptor. Standard protein binding percentages for antibiotics have been developed from studies on healthy volunteers and dosing regimens for patients are adapted accordingly. The determination of the total concentration of antibiotics in patients’ blood samples is, based on the standard percentages, ordinarily representative for the pharmacological effect of the antibiotic. However, certain conditions that are common in critically ill patients can alter protein binding percentages, resulting in a larger or smaller unbound fraction. This in turn can result in toxicity or therapeutic failure. The aim of this project was to develop an analytical method for the determination of the unbound concentration of the Beta-Lactam antibiotics cefotaxime, flucloxacillin, cloxacillin and piperacillin in plasma. A method was successfully developed using ultrafiltration for the extraction of unbound analytes and ultra high performance liquid chromatography tandem mass spectrometry, UHPLC-MS/MS, for their quantification. The method was partly validated according to the European Medicines Agency’s guidelines on bioanalytical method validation.
40

Does it matter who was where? Learning identity-to-location binding from faces

Wan, Michael 06 1900 (has links)
People unconsciously learn spatial information about places they encounter frequently, leading them to search through familiar scenes faster than for unfamiliar scenes. We explored this phenomenon—the contextual cueing effect—in scenes containing images of different human faces. Participants searched through a series of scenes for a target among distractors, characterized as a letter T among letter L’s with each letter positioned on top of a face image (Experiment 1) or as a female face among male faces (Experiment 2). Experiment 1 showed that when the binding of identity and location was manipulated during learning, slightly greater (but not statistically significant) contextual cueing effects were found for repeated scenes with constant identity-to-location binding than those repeated scenes with constant spatial configurations but shuffled identity-to-location binding. Experiment 2 showed that if the binding of identity-to-location changed after the learning of a set of identity-to-location binding, small (but not statistically significant) costs of contextual cueing were found. The results suggest that in the contextual cueing paradigm, repeated identity-to-location binding might be learned but the learning of repeated spatial configurations alone account for a major portion of the learning. / Thesis / Master of Science (MSc)

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