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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.
341

Development and application of a capillary electrophoresis immunoassay for DNA lesions induced by ultraviolet light

Goulko, Alevtina Unknown Date
No description available.
342

A metaproteomics-based method for environmental assessment : A pilot study

Fröberg, Henric January 2013 (has links)
Metaproteomics, as a proteomic approach to analyse environmental samples, is a new and expanding field of research. The field promises new ways of determining the status of the organisms present in a sample, and could provide additional information compared to metagenomics. Being a novel field of research, robust methods and protocols have not yet been established. In this thesis, we examine several methods for a reliable extraction of protein from soil and periphyton samples. The extraction should preferably be fast, compatible with downstream analysis by mass spectrometry and extract proteins in proportion to their presence in the original sample. A variety of methods and buffers were used to extract proteins from soil and periphyton samples. Concentration determinations showed that all of these methods extracted enough protein for further analysis. For purification and digestion of the samples, several methods were used. The purified samples were analysed on three different mass spectrometers, with the Orbitrap Velos Pro delivering the best results. The results were matched against four genomic and metagenomic databases for identification of proteins, of which the UniProt/SwissProt database gave the best result. A maximum of 52 proteins were identified from periphyton samples when searching against UniProt/SwissProt with strict settings, of which the majority were highly conserved proteins. The main limitation for this type of work is currently the lack of proper metagenomic databases.
343

Identification of potential plasma biomarkers of inflammation in farmers with musculoskeletal disorders : A proteomic study

Carlsson, Anders January 2012 (has links)
In this thesis we look for potential chronic inflammation biomarkers because studies have shown that farmers with musculoskeletal disorders might be affected by the environment to develop musculoskeletal disorders. Animal farmers are highly exposed to dust, aerosols, molds and other toxins in the air and environment leading to musculoskeletal disorders, respiratory disorders, airway symptoms and febrile reactions. There is reason to believe that the farmers have a constant or chronic inflammation that develops into musculoskeletal disorders. By using a proteomic approach with Two-dimensional Gel Electrophoresis and silver staining our goal was to find biomarkers by quantifying protein spots that differ significantly from farmers with musculoskeletal disorders compared to rural controls. In our study we found 8 significant proteins, two from Alpha-2-HS-glycoprotein, one from Apolipoprotein A1, three from Haptoglobin, one from Hemopexin and 1 from Antithrombin. All 5 proteins are involved in inflammation response in some way and some proteins are linked to chronic inflammation. Out of the 5 proteins Alpha-2-HS-glycoprotein, Apolipoprotein A1 and Hemopexin seem like the most likely proteins to investigate further as potential inflammation biomarkers.
344

Anti-prothrombin antibodies and the lupus anticoagulant : immunochemical and electrophoretic characterization

Murphy, Timothy Lynn January 1992 (has links)
The purpose of this study was to characterize the association between anti-prothrombin antibodies and the lupus anticoagulant (LA) in order to elucidate the antigenic site of the LA. Plasma from 8 patients with the LA had evidence of anti-prothrombin antibodies on prothrombin crossed immunoelectrophoresis as characterized by material moving slower in the first dimension of electrophoresis than normal prothrombin, i.e., a trailing shoulder. Four of 5 LA patients with a prolonged prothrombin time demonstrated the most pronounced evidence of anti-prothrombin antibodies. All patients were shown to have an essentially normal level of prothrombin antigen. Using an enzyme-linked immunosorbent assay (ELISA), six of 8 LA patients tested positive for anticardiolipin antibodies (aCL) of the IgG isotype while 7 of 8 LA patients tested positive for antiphosphatidylserine antibodies (aPS) of the IgG isotype.An anti-human Factor II (prothrombin) ELISA was developed to confirm the presence of anti-Factor II (aFII) activity in LA patients. Seven of 8 LA patients were positive for aFII activity. A strong parallel existed between the presence of aPS activity, anti-human Factor II activity, and the LA, i.e., 7 of 8 LA plasmas were aPS (+)/aFII (+). An antibovine Factor II ELISA was developed to determine if the aFII activity associated with LA patients is speciesspecific. Three of 5 LA patients positive for anti-human Factor II activity were also shown to be positive for antibovine Factor II activity. Antibodies with specificity for human prothrombin were purified from LA plasmas using a prothrombin affinity column. Three of 8 LA patient eluates were shown to be positive for aPS (IgG) while none were positive for aCL (IgG or IgM) or human aFII activity. Affinity-purified eluates were assayed for LA activity using the dilute Russell viper venom time (dRVVT). None of the LA patient eluates were shown to prolong the dRVVT when present with normal plasma in concentrations up to 100 micrograms/mL. / Department of Chemistry
345

Visualizing Invisibles with Single-molecule Techniques: from Protein Folding to Clinical Applications

Mazouchi, Amir Mohammad 08 August 2013 (has links)
Single-molecule fluorescence spectroscopy techniques such as Fluorescence Correlation Spectroscopy (FCS) and single-molecule Förster Resonance Energy Transfer (smFRET) not only possess an unprecedented high sensitivity but also have high temporal and spatial resolution. Therefore, they have an immense potential both in investigation of fundamental biological principles and in clinical applications. FCS analyses are based on both theoretical approximations of the beam geometry and assumptions of the underlying molecular processes. To address the accuracy of analysis, firstly the experimental conditions that should be fulfilled in order to obtain reliable physical parameters are discussed and the input parameters are carefully controlled accordingly to demonstrate the performance of FCS measurements on our home-built confocal multiparameter photon-counting microscope in several in vitro and in-vivo applications. Secondly, we performed a comprehensive FCS analysis of rhodamine family of dyes to evaluate the validity of assigning the correlation relaxation times to the time constant of conformational dynamics of biomolecules. While it is the common approach in literature our data suggests that conformational dynamics mainly appear in the correlation curve via modulation of the dark states of the fluorophores. The size and shape of the folded, unfolded and chemically-denatured states of the N-terminal Src-homology-3 of downstream of receptor kinases (DrkN SH3) were investigated by FCS and smFRET burst experiments. Based on the data, we conclude that a considerable sub-population of the denatured protein is in a closed loop state which is most likely formed by cooperative hydrogen bonds, salt bridges and nonpolar contacts. As a clinical application, we developed and characterized an ultrasensitive capillary electrophoresis method on our multiparameter confocal microscope. This allowed us to perform Direct Quantitative Analysis of Multiple microRNAs (DQAMmiR) with about 500 times better sensivity than a commercial instrument. Quite remarkably, we were able to analyze samples of cell lysate down to the contents of a single cell.
346

A Method for Selective Concentrating of DNA Targets by Capillary Affinity Gel Electrophoresis

Chan, Andrew 02 August 2013 (has links)
A method for the selective concentrating of DNA targets using capillary affinity gel electrophoresis is presented. Complementary ssDNA targets are retained through hybridization with oligonucleotide probes immobilized within polyacrylamide gels while non-complementary targets are removed. The captured DNA targets were concentrated by step elution, where a localized thermal zone was applied in small steps along the capillary. Evaluation of the selective capture of a 150 nt DNA target in a complicated mixture was carried out by factorial analysis. Gels with a smaller average pore size were found to retain a higher amount of complementary targets. This was thought to be due to the ssDNA target migrating through the gel by reptation, eliminating hairpin structures, making the complementary region of the target available for hybridization. This method was applied to a series of DNA targets of different lengths, 19 nt, 150 nt, 250 nt and 400 nt. The recovery of the method ranged from 0.5 to 4% for the PCR targets, and 13 to 18% for the 19 nt oligonucleotide target. The purity was calculated to be up to 44% for the PCR targets and up to 86% for the 19 nt target. This was an improvement in purity of up to 15 times and 1100 times in comparison to the original samples for the PCR targets and 19 nt oligonucleotide, respectively. The 19 nt targets were selective concentrated and delivered into a microfluidic based DNA biosensing platform. The purity of the sample improved from 0.01% to 50% while recovery decreased from 100% to 20% for a sample with 0.5 nM complementary and 1 μM non-complementary targets. An improvement in the response of the sensing platform was demonstrated on 19 nt oligonucleotide targets delivered by selective concentration versus concentration alone into the microfluidic biosensing system.
347

A Method for Selective Concentrating of DNA Targets by Capillary Affinity Gel Electrophoresis

Chan, Andrew 02 August 2013 (has links)
A method for the selective concentrating of DNA targets using capillary affinity gel electrophoresis is presented. Complementary ssDNA targets are retained through hybridization with oligonucleotide probes immobilized within polyacrylamide gels while non-complementary targets are removed. The captured DNA targets were concentrated by step elution, where a localized thermal zone was applied in small steps along the capillary. Evaluation of the selective capture of a 150 nt DNA target in a complicated mixture was carried out by factorial analysis. Gels with a smaller average pore size were found to retain a higher amount of complementary targets. This was thought to be due to the ssDNA target migrating through the gel by reptation, eliminating hairpin structures, making the complementary region of the target available for hybridization. This method was applied to a series of DNA targets of different lengths, 19 nt, 150 nt, 250 nt and 400 nt. The recovery of the method ranged from 0.5 to 4% for the PCR targets, and 13 to 18% for the 19 nt oligonucleotide target. The purity was calculated to be up to 44% for the PCR targets and up to 86% for the 19 nt target. This was an improvement in purity of up to 15 times and 1100 times in comparison to the original samples for the PCR targets and 19 nt oligonucleotide, respectively. The 19 nt targets were selective concentrated and delivered into a microfluidic based DNA biosensing platform. The purity of the sample improved from 0.01% to 50% while recovery decreased from 100% to 20% for a sample with 0.5 nM complementary and 1 μM non-complementary targets. An improvement in the response of the sensing platform was demonstrated on 19 nt oligonucleotide targets delivered by selective concentration versus concentration alone into the microfluidic biosensing system.
348

Visualizing Invisibles with Single-molecule Techniques: from Protein Folding to Clinical Applications

Mazouchi, Amir Mohammad 08 August 2013 (has links)
Single-molecule fluorescence spectroscopy techniques such as Fluorescence Correlation Spectroscopy (FCS) and single-molecule Förster Resonance Energy Transfer (smFRET) not only possess an unprecedented high sensitivity but also have high temporal and spatial resolution. Therefore, they have an immense potential both in investigation of fundamental biological principles and in clinical applications. FCS analyses are based on both theoretical approximations of the beam geometry and assumptions of the underlying molecular processes. To address the accuracy of analysis, firstly the experimental conditions that should be fulfilled in order to obtain reliable physical parameters are discussed and the input parameters are carefully controlled accordingly to demonstrate the performance of FCS measurements on our home-built confocal multiparameter photon-counting microscope in several in vitro and in-vivo applications. Secondly, we performed a comprehensive FCS analysis of rhodamine family of dyes to evaluate the validity of assigning the correlation relaxation times to the time constant of conformational dynamics of biomolecules. While it is the common approach in literature our data suggests that conformational dynamics mainly appear in the correlation curve via modulation of the dark states of the fluorophores. The size and shape of the folded, unfolded and chemically-denatured states of the N-terminal Src-homology-3 of downstream of receptor kinases (DrkN SH3) were investigated by FCS and smFRET burst experiments. Based on the data, we conclude that a considerable sub-population of the denatured protein is in a closed loop state which is most likely formed by cooperative hydrogen bonds, salt bridges and nonpolar contacts. As a clinical application, we developed and characterized an ultrasensitive capillary electrophoresis method on our multiparameter confocal microscope. This allowed us to perform Direct Quantitative Analysis of Multiple microRNAs (DQAMmiR) with about 500 times better sensivity than a commercial instrument. Quite remarkably, we were able to analyze samples of cell lysate down to the contents of a single cell.
349

Occurrence and Charactrisation of Superoxide Dismutases in the Female Reproductive Structures of Petunia

YeYing Wang, Ying January 2006 (has links)
Superoxide Dismutase (SOD) activity in cell-free extracts prepared from healthy mature flowers of Petunia hybrida (variety 'Hurrah') was studied. The SOD activity in the crude extracts was stable for more than one month when stored at -20 oC. It was found that pH 7.8 is optimal for SOD activity. Different flower tissues of petunia (stigma, style and ovary) at various stages of development were extracted and analysed for SOD activity. SOD activity was found to be significantly highest in the ovary tissue of dehiscent petunia flowers. Three SOD isozymes were detected after crude extracts of the different female reproductive tissues of petunia flowers were analysed on a non-denaturing polyacrylamide gel electrophoresis system. Based on a difference in the sensitivity of the SOD isoforms to H2O2 and KCN, it is suggested that Mn-SOD, Fe-SOD and Cu/Zn-SOD were present in the crude extracts of the female reproductive tissues of petunia flowers. The response of the female reproductive parts of petunia flowers was also tested under water deficiency and high temperature (35 oC) stress. The SOD activity seemed to increase more in response to the high temperature than the water deficiency stress. Intense blue staining was observed from developing younger buds, and much lower formazan deposition was detected at the later stage. This indicates the lower O2- produced during later stages mainly due to increasing SOD synthesis. DEAE cellulose chromatography was successfully used to partially purify SOD from the ovaries of petunia flowers. The characteristics of the partially purified enzyme fraction were found to be very similar to those of the crude extracts.
350

Nanopore analysis of nucleic acids /

Butler, Thomas, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 98-104).

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