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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.
1

New approaches to anticoagulation in haemodialysis

Ryan, Katherine Elizabeth Rose January 1995 (has links)
No description available.
2

Improved Leaky-Mode Waveguide Spatial Light Modulators for Three Dimensional Displays

Gneiting, Scott Alexander 01 July 2017 (has links)
This thesis improves on the design of the leaky-mode spatial light modulator, LMW-SLM, presented by Dr. Smalley[1]. Improvements include: input coupling gratings, a pulsed laser input, output coupling gratings, and a 3D printed adjustable module for the stabilization of critical alignments. First, input coupling gratings reduce the cost of the LMW-SLM from $500 to around $2, a drop in cost of over two orders of magnitude. This enables multiple modulators to be used in a single display and allows for an inexpensive modular design to be created. Second, a pulsed laser input allows for image creation without the use of a polygon for derotation. Removal of the polygon allows for direct viewing of the LMW-SLM output enabling near-eye and flat panel displays. Third, output coupling gratings allow for bottom exit devices that are essential for thin substrates and flat panel displays. Fourth, the 3D printed module allows for the critical alignments of the LMW-SLM to become permanent. This in turns allows for transportation of the created displays without a trained technician by abstracting away the complexities of the device. The resulting changes simplify hardware, reduce cost, and enable the LMW-SLM to be modularized and the resulting 3D displays to be transportable. These improvements are made possible by the addition of a one new mask step during fabrication, a simple circuit design, and a 3D printed module designed in SOLIDWORKS. Included in this thesis as attachments are the MATLab, Eagle, and SOLIDWORKS files used to create the improved LMW-SLM.
3

Coagulation Inhibition and Development of Myocardial Damage in ST-Elevation Myocardial Infarction

Frostfeldt, Gunnar January 2002 (has links)
<p>In 101 patients with ST-elevation myocardial infarction treated with streptokinase the additional effects of lmw-heparin (dalteparin) were investigated. The prognostic value of troponin-T (TnT) was elucidated and the development of myocardial damage was investigated with Positron Emission Tomography (PET).</p><p>Dalteparin tended to provide a higher rate of TIMI grade 3 flow in the infarct-related artery at 24 h compared to placebo. In patients with signs of early reperfusion there was a higher rate of TIMI grade 3 flow in the dalteparin group compared to placebo. There were significantly fewer patients with ischemic episodes at 6-24 h in the dalteparin compared to placebo group.</p><p>The increase in coagulation activity was attenuated in the dalteparin group. There was a tendency to more ischemic episodes and lower frequency of TIMI grade 3 flow in patients with persistent elevation of coagulation activity at 18 h. Among deceased patients the coagulation activity was significantly higher than in survivors. </p><p>The association between elevated TnT on admission and long-term mortality might be explained by longer delay, episodes of chest pain during the last 24 h, less non-invasive signs of reperfusion at 90 minutes, and lower patency in the infarct-related artery at 24 h. </p><p>Eight patients were investigated with PET at 3h, 24 h and after 3 weeks. PET outlines the infarct region with reduced perfusion and metabolism. The oxidative metabolism in the infarct region at 3 h correlated with the water-Perfusable Tissue Fraction (PTF) and its improvement over time.</p><p>Dalteparin seems to improve maintenance of coronary patency, which can be explained by attenuation of the increased coagulation activity. Elevated TnT level on admission is associated with a worse outcome, which can partly be explained by less successful fibrinolytic treatment. PET investigations might to be a useful method in future trials evaluating new agents in the treatment of acute myocardial infarction.</p>
4

Coagulation Inhibition and Development of Myocardial Damage in ST-Elevation Myocardial Infarction

Frostfeldt, Gunnar January 2002 (has links)
In 101 patients with ST-elevation myocardial infarction treated with streptokinase the additional effects of lmw-heparin (dalteparin) were investigated. The prognostic value of troponin-T (TnT) was elucidated and the development of myocardial damage was investigated with Positron Emission Tomography (PET). Dalteparin tended to provide a higher rate of TIMI grade 3 flow in the infarct-related artery at 24 h compared to placebo. In patients with signs of early reperfusion there was a higher rate of TIMI grade 3 flow in the dalteparin group compared to placebo. There were significantly fewer patients with ischemic episodes at 6-24 h in the dalteparin compared to placebo group. The increase in coagulation activity was attenuated in the dalteparin group. There was a tendency to more ischemic episodes and lower frequency of TIMI grade 3 flow in patients with persistent elevation of coagulation activity at 18 h. Among deceased patients the coagulation activity was significantly higher than in survivors. The association between elevated TnT on admission and long-term mortality might be explained by longer delay, episodes of chest pain during the last 24 h, less non-invasive signs of reperfusion at 90 minutes, and lower patency in the infarct-related artery at 24 h. Eight patients were investigated with PET at 3h, 24 h and after 3 weeks. PET outlines the infarct region with reduced perfusion and metabolism. The oxidative metabolism in the infarct region at 3 h correlated with the water-Perfusable Tissue Fraction (PTF) and its improvement over time. Dalteparin seems to improve maintenance of coronary patency, which can be explained by attenuation of the increased coagulation activity. Elevated TnT level on admission is associated with a worse outcome, which can partly be explained by less successful fibrinolytic treatment. PET investigations might to be a useful method in future trials evaluating new agents in the treatment of acute myocardial infarction.
5

Identifikace alel pro zásobní proteiny obilky tritikale pomocí DNA markerů

Svojsíková, Nikola January 2016 (has links)
Triticale belongs to the amphiploid cereals and was derived by crossing wheat and rye. Its baking quality is substantially worse than in wheat. The baking quality is determined by a composition and a content of the storage proteins. Both high and low molecular glutenin subunits have a major effect on the final quality of dough. The secalins of rye belong amongst the storage proteins of triticale, which negatively influence the baking quality. These are the reasons why lineages having translocated chromosome 1R and containing subunit Glu-D1d, which positively influences the baking quality, were created. The thesis is focused on identification of the allelic composition of loci of high molecular glutenin subunits (HMW-GS), low molecular glutenin subunits (LMW-GS), loci Pina a Pinb and null alleles of Waxy genes. 23 selected genotypes of triticale were analysed by using DNA markers based on polymerase chain reaction (PCR). Allelic composition of loci HMW-GS (Glu-A1, Glu-B1, Glu-D1), LMW-GS (Glu-A3) and Pina-D1, Pinb-D1 was described and null alleles were detected in the loci Wx-A1 and Wx-B1.
6

The Role of Fibroblast Growth Factor-2 Isoforms in Ischemia-reperfusion Injury and Cardioprotection

Liao, Siyun 23 April 2008 (has links)
No description available.
7

Novos inibidores de LMW-PTP e CDC25B : planejamento baseado em fragmentos moleculares com uso de métodos in silico, ensaios de inibição e cristalografia de proteínas / New inhibitors of LMW-PTP and CDC25B : fragment-based drug design using in silico methods, inhibition assays and protein crystallography

Fonseca, Emanuella Maria Barreto, 1984- 27 August 2018 (has links)
Orientadores: Ricardo Aparicio, Munir Salomão Skaf / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T01:45:39Z (GMT). No. of bitstreams: 1 Fonseca_EmanuellaMariaBarreto_D.pdf: 13119998 bytes, checksum: 0b4e5f9502ec2b9b4e347bcd68c9e261 (MD5) Previous issue date: 2015 / Resumo: O câncer é uma doença cuja incidência e prevalência atinge proporções alarmantes, estabelecendo-se, hoje, como um problema mundial de saúde pública. A fosforilação de proteínas é um evento dinâmico e reversível, governado pela atividade oposta de proteínas tirosina quinases e proteínas tirosina fosfatases. Níveis elevados das fosfatases LMW-PTP e CDC25B foram observados em uma ampla variedade de tumores e, assim, estas foram selecionadas como alvo para o desenvolvimento de novos inibidores. Utilizando métodos in silico, uma coleção, contendo aproximadamente 500 mil fragmentos, foi montada a partir de um banco de compostos comerciais. Para cada enzima, esses fragmentos foram submetidos a distintos protocolos de docagem molecular, através dos quais 19 pequenas moléculas foram selecionadas e adquiridas comercialmente. Os resultados computacionais foram validados por ensaios de inibição enzimática, tendo sido identificados novos esqueletos moleculares capazes de inibir mais do que 50% da atividade enzimática, obtendo-se valores de eficiência do ligante de até 0,33 kcal mol-1 por átomo diferente de hidrogênio. Paralelamente, uma série de compostos derivados do ácido benzenofosfônico foi ensaiada frente à LMW-PTP após estudos de docagem, seguindo-se estudos cristalográficos que levaram à obtenção de duas estruturas inéditas: uma com a proteína na forma apo e outra de um complexo LMW-PTP:inibidor. Além do sítio ativo já conhecido, observou-se um segundo sítio cristalográfico cuja potencial função biológica, se confirmada, poderia abrir novas possibilidades para modular a atividade da LMW-PTP, perspectiva que demanda investigação / Abstract: Cancer is a disease whose incidence and prevalence have reached alarming proportions, emerging today as a major public health problem. Protein phosphorylation is a dynamic and reversible event, governed by the opposite activities of protein tyrosine kinases and protein tyrosine phosphatases. High levels of the phosphatases LMW-PTP and CDC25B have been observed in a wide variety of tumors and, for this reason, they have been selected as targets for inhibitor development. Using in silico methods, a collection of approximately 500,000 fragments was assembled from a database of commercial compounds. For each enzyme, these fragments were subjected to different molecular docking protocols, through which 19 small molecules have been selected and purchased. The computational results were validated by enzyme inhibition assays, with the identification of new molecular scaffolds capable of inhibiting in more than 50% the enzyme activity, resulting in ligand efficiency values up to 0.33 kcal mol-1 per non-H atom. Similarly, a number of compounds derived from benzenophosphonic acid was tested against the LMW-PTP after docking studies, followed by crystallographic studies which resulted in two new structures: one of the apo protein and another of a complex LMW-PTP:inhibitor. In addition to the previously described active site, a second crystallographic site was identified, whose potential biological function, if confirmed, might open new possibilities to modulate LMW-PTP activity, in a perspective which demands further investigation. / Doutorado / Físico-Química / Doutora em Ciências
8

Studium aktivity enzymových a nízkomolekulárních antioxidačních systémů / Study of Activity of Enzyma and Low Molecular Weight Antioxidant Systems

Macuchová, Simona January 2010 (has links)
Oxidative processes play important role in cell physiology and pathology as well. Balance of these processes is supplied by cooperating antioxidative systems; function of antioxidant defense systems depens on high levels of antioxidants in organism. Presented work is focused on developement and optimization of methods for analysis of important enzyme and non-enzyme antioxidants as well as total antioxidant capacity of selected types of biological material. Extractions and analyses of vitamin E, carotenoids, superoxide dismutase, catalase, peroxidase and lipoxygenase in barley and malt were optimized. RP-HPLC and HPLC/ESI-MS were used for analysis of vitamin E, phenolic and carotenoid content, spectrophotometry was used for enzymes activity analysis. A new methods for catalase and lipoxygenase activities were developed and compared with direct UV methods. Superoxide dismutase activity was determined by commercial diagnostic kit. A colorimetric method was used for peroxidase activity determination. Some kinetic parameters of enzymes were provided too. Optimized methods were used in the analyses of antioxidants in plant material - in barley and malt - in sets of samples of 6 varieties cultivated in four different locations for two years. Content of individual antioxidants differed depending on the variety, but usually were not found significant differences in the levels, depending on growing location. Perhaps climatic conditions have the greatest influence on levels of low molecular weight and enzymatic antioxidants at the specific location; oxidation processes are influenced both the quantity of moisture, both by sunlight, which induces oxidative processes in cultivated plants. The activity of antioxidants in barley caryopses is rapidly increasing during the malting process; an elevated temperature and moistness first induces activation the enzyme systems including antioxidant. In caryopsis is metabolic activity increased during which we can expect an increased production of radicals; for this purpose can antioxidant systems be activated that protect cells from damage by oxidative stress. In the second part of work optimized methods were applied in two clinical trials focused on study of the influence of exogenous antioxidants intake on metabolic and antioxidant status in human organism. In the first clinical study influence of food supplement containing polyunsaturated fatty acids and vitamin E on metabolism of hyperlipidaemics was evaluated. After 3-month supplemenation a lipid profile was improved and serum antioxidant levels increased. The second experiment was focused on enzyme and non-enzyme antioxidant levels in healthy subjects after temporarily intake of specific foods rich in antioxidants. After two-month intake plasma phenolic substances were slightly increased. Total antioxidant capacity and activities of enzyme antioxidants were not affected. Results of both clinical exeriments showed that supplying of antioxidants in natural form or in the form of food supplements does not markedly affect metabolism of healthy subjects, while in patients with chronic diseases antioxidant supplementation can positively influence metabolic status. Results of this work showed that optimized methods are suitable for analyses of antioxidant status parameters and also for monitoring of exogenous antioxidant intake.
9

Development of a label-free biosensor method for the identification of sticky compounds which disturb GPCR-assays

Mohammed Kader, Hamno January 2013 (has links)
It is widely known that early estimates about the binding properties of drug candidates are important in the drug discovery process. Surface plasmon resonance (SPR) biosensors have become a standard tool for characterizing interactions between a great variety of biomolecules and it offers a unique opportunity to study binding activity. The aim of this project was to develop a SPR based assay for pre-screening of low molecular weight (LMW) drug compounds, to enable filtering away disturbing compounds when interacting with drugs. The interaction between 47 LMW compounds and biological ligands were investigated using the instrument BiacoreTM, which is based on SPR-technology.
10

The Role of Low-Molecular Weight Fungal Metabolites in Eutypa Dieback Grapevine Trunk Disease

Sebestyen, Dana 20 October 2021 (has links)
Eutypa dieback, one of several grapevine trunk diseases (GTDs), is of serious concern to the grape industry globally. This disease is caused by the fungus Eutypa lata but it is often seen in consortia growth with Phaeoacremonium minimum and Phaeomoniella chlamydospora. It is vital to understand the mechanisms for how this disease functions to develop control measures to combat it. Brown rot fungi are able to use a complex of low molecular weight (LMW) metabolites to induce a Fenton reaction to deconstruct woody tissue. These metabolites are part of a chelator mediated Fenton (CMF) chemistry that produces reactive oxygen species that are capable of depolymerizing wood polymers. We propose that a mechanism similar to CMF chemistry may be occurring in grapevine trunk disease pathogens. This thesis investigates how LMW metabolites produced by the fungi contribute to the disease and decay progression in GTDs. Research on Mite control in the laboratory with abamectin was also investigated, as research in this area was required when mites infested our fungal cultures and suitable laboratory controls were not available. Research on the GTD fungi was initiated by first examining whether metabolites produced by the three fungi can function in a manner to promote reactions like the CMF system. We separated and identified specific metabolites that potentially could contribute to CMF chemistry. We found that all three GTD fungi were able to produced LMW metabolites that promoted CMF chemistry, and we hypothesized that this mechanism contributes to processes leading to tissue necrosis in grapevine trunk wood. To explore the development of effective control measures based on this newly discovered mechanism for pathogenesis, we also explored the use of antioxidant/chelator compounds, BHA and BHT, in the control of the consortia fungi. Biocontrol organisms, Bacillus subtilis and Trichoderma atroviride, that produce antioxidants were also tested as biocontrols against the fungi involved in Eutypa Dieback disease. We found that BHA was highly effective in inhibiting fungal growth for all three fungi at concentrations higher than 0.5mM, and both B. subtilis and T. atroviride proved to be effective biocontrol agents in inhibiting E. lata, P. minimum, and P. chlamydospora.

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