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Robak, Andrew Joseph. "Development of coenzyme-imprinted molecularly imprinted polymers as catalysts /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1276397881&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
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Thesis (Ph. D.)--University of Oregon, 2007.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 94-100). Also available for download via the World Wide Web; free to University of Oregon users.
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Bates, Ferdia. "Design and development of molecularly imprinted polymers and imprinted sensors." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399170.
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Esta tesis se ha hecho principalmente para estudiar e investigar polímeros impresos (MIPs) con la intención de usarlos como sensores de larga vida. La línea de investigación de esta tesis es la dirigida a conseguir la integración de estas formaciones impresas dentro de una lengua electrónica (ET), que es la rama de especialización en la que se ha desarrollado principalmente este proyecto. Después de hacer una revisión de la literatura, que inicialmente se centraba en la aplicación de MIPs a un equipo electroquímico, un sensor voltamétrico impreso y un procedimiento sensitivo complementario, el procedimiento se creó a través de una combinación de protocolos tomados de la literatura. Este sensor, descrito en el Artículo 1, presentaba una buena selectividad hacia el analito primario, teofilina, además de la especificidad requerida frente a sus análogos estructurales. Aunque el diseño del sensor permitía una mejor regeneración de la superficie respecto a otros sistemas parecidos encontrados en la literatura, el comportamiento de los polímeros usados en el MIP retardaba la tasa de transferencia de electrones en la superficie del sensor. Por culpa de este fenómeno, la sensibilidad del sensor se reducía.
Justo después de estos experimentos iniciales, se hizo una colaboración con el grupo del Profesor Sergey Piletskey en la Universidad de Leicester (UoL) de Reino Unido. Durante este período, se realizó un estudio intensivo del proceso de diseño de impresión molecular asistido por un sistema computacional de modelización molecular ‘inhouse’. Se puso énfasis en el diseño de un receptor impreso para la molécula de baja solubilidad melanina, que se toma como ‘template modelo’. El MIP resultante se caracterizó y usó para la detección de melanina en muestras de leche, tal y como se describe y detalla en el Artículo 2.
Más tarde, utilizando los conocimientos adquirido durante la estancia en Leicester, se desarrollaron nuevas técnicas de modelización computacional para la evaluación de los métodos utilizados en la modelización de MIPs, con el objetivo de obtener una técnica de evaluación virtual para el diseño de receptores impresos, optimizados para los requerimientos necesarios para su posterior aplicación en un sensor ET, tal como se detalla en el Artículo 3.
Tal y como se detalla en el capítulo final de esta tesis, la experiencia y conocimientos adquiridos durante la investigación, se usaron para diseñar un grupo de sensores que funcionan asociados a ET. Este desarrollo podría ampliarse profundizando en la selección computacional de polielectrolitos, que luego serían inmovilizados en la superficie de un electrodo voltamétrico mediante una tinta de grafito conductora, de elevada robustez y estabilidad.
En este sentido, también se proponen otras recomendaciones para lograr la mejora de la capacidad de regeneración de los MIPs utilizados, por ejemplo mediante la separación de MIP y electrodo. Finalmente, se presentan algunas sugerencias para colaboraciones institucionales, con el propósito de crear un sistema ET móvil, que permita recoger y analizar muestras en campo.This thesis was predominantly undertaken to study and investigate molecular imprinted polymers (MIPs) with a view to their use as high longevity sensing elements in sensor arrays. The research line of the thesis was intended to lead to the integration of these imprinted arrays into an Electronic Tongue (ET) sensing system which is the area of expertise of the research group in which this project was primarily executed. Having initially executed a review of the literature, focusing initially on the application of the MIPs to an electrochemical device, an imprinted voltammetric sensor and a complimentary sensing procedure was developed using a combination of protocols extracted from the literature. This sensor, described in Article 1, had good selectivity toward the primary analyte, theophylline, and specificity against structural analogues. Though the design of the sensor allowed for significantly improved regeneratibility of the sensor relative to similar systems in the literature, the insulating nature of the polymers used in the MIP reduced the electron transfer rate at the sensor surface and thus resulted in a reduction in sensitivity. Following this initial experimental study, a secondment was undertaken in the University of Leicester under the supervision of Professor Sergey Piletsky. During this period, an intensive study of the design process of molecular imprinting, aided by an in-house computational molecular modelling platform, was conducted focusing on the design of an imprinted receptor for the low solubility 'model template', melamine. This MIP was successfully synthesised, characterised and used in the detection of melamine in milk samples, as detailed in Article 2. Further development of computational modelling techniques for the evaluation of MIP modelling techniques was also achieved with a view to create a virtual evaluation technique for the design of imprinted receptor sites optimised for the requirements of their application to an ET sensor array using the skills acquired during the Leicester secondment as detailed in Article 3. As detailed in the final chapter of this thesis, the insight into the imprinting process which was acquired during the research has been used to design a sensor array system which meets the specifications of ET experimental runs. This takes the form of the introduction of the research topic computationally selected polyelectrolytes, immobilised onto a voltammetric electrode surface via highly robust conducting graphite ink. Additional recommendations are also made to further enhance the on-going MIP projects within the laboratory, such as the separation of the MIP and the electrode to increase MIP regeneratibility. Some final suggestions for some other inter-institutional collaboration are also presented which aim to creating portable ET system for in-field sample collection and analysis.
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Morán, Barroso Verónica Fabiola. "Identification and analysis of imprinted and non-imprinted genes in distal human chromosome 20q13." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/23130.
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This thesis describes work that arose from studies of the imprinting of GNAS1, on human chromosome 20q13. Null mutations in GNAS1 cause the hormone-resistance syndrome pseudohpoparathyroidism type 1a (PHP1a). It was demonstrated that GNAS1 is imprinted, as predicted from the anomalous inheritance of PHP1a, but that its allele-specific regulation is highly complex. This gene is shown to encode several protein products: (i) the alpha subunit of the stimulatory G protein Gs; this protein is biallelically derived; (ii) NESP55, a neuroendocrine secretory protein, expressed exclusively from the maternal allele; (iii) XLas, a Golgi-specific G protein that is expressed exclusively from the paternal allele. Many known imprinted genes lie in clusters that may span several hundred of kb, and may be co-ordinately regulated by a imprinting control region. To assess whether GNAS1 is part of such an imprinted gene cluster, genomic clones were analysed for the presence of other nearby transcripts. This resulted in the identification of two novel genes, CTSZ and CGI107, as well as a number of putative transcripts that lie within GNASl. One of the latter forms part of a spliced polyadenylated antisense transcript that spans the upstream region of NESP55. The CTSZ gene was shown to comprise 6 exons and 5 introns, spanning ~ 12 kb. It encodes cathepsin Z, a cysteine protease whose precise function is undefined. The CG1107 gene was shown to comprise 6 exons and 5 introns, spanning ~ 10 kb, encoding 194 amino acid protein of unknown function, but showing sequence similarity to the kisir protein in Drosophila. Four chromosomally dispersed processed pseudogenes of CG1107 were identified. Together with the biallelic expression of another neighbouring gene TH1, these results suggest the possibility that GNAS1 may not after all be part of an extensive cluster of imprinted genes. This has implications for further studies of the mechanism of imprinting control in this region.
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O'Donnell, Elizabeth Anne. "Water-compatible molecularly imprinted polymers." Thesis, University of Strathclyde, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438467.
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Canfarotta, Francesco. "Molecularly imprinted nanoparticles for diagnostic applications." Thesis, University of Leicester, 2016. http://hdl.handle.net/2381/37775.
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Molecularly imprinted polymers (MIP) are gaining increasing interest thanks to their low cost of manufacturing, robustness and stability compared to their bio-analogues such as antibodies. The molecular imprinting process can be defined as the generation of molecular recognition sites in a synthetic polymer. The template-derived sites thus created within the polymeric matrix allow MIPs (often referred as plastic antibodies, due to their synthetic nature) to selectively recognise and bind the target molecule. In light of these properties, MIPs have been successfully applied in sensors, assays and separation applications. Due to their small size, MIP nanoparticles (NPs or nanoMIPs) can be used in biomedicine, since the nanoscale format is potentially suitable for cellular or in vivo applications. The aim of this work is to demonstrate the suitability of the nanoMIPs as tools for imaging in cells. For this purpose, the choice of appropriate fluorescent moieties to be included in the nanoMIPs is crucial and depends on the intended application. Several fluorescent monomers were characterised and chosen as imaging functionalities to be employed in the synthesis of MIP NPs (Chapter 2). The innovative solid-phase approach used in this work enables the synthesis of nanoMIPs both in organics (for small templates) and in water (for peptides and proteins), with the possibility to tailor the particle’s surface chemistry according to the intended use. (Chapter 3 and 4). Only few examples of MIP NPs for cellular imaging have been reported so far. Such nanosystems should be biocompatible and physiochemically stable under physiological conditions, as demonstrated in Chapter 5 and 6. Thanks to their good biocompatibility and recognition properties, MIP NPs were successfully applied as membrane-targeted diagnostic tools (Chapter 7) in both cancer and senescent cells, thus paving the way for their in vivo use as diagnostic and imaging tools.
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Bonini, Francesca. "Molecularly imprinted polymers for protome analysis." Thesis, Cranfield University, 2008. http://dspace.lib.cranfield.ac.uk/handle/1826/2716.
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Fast and efficient methods for the detection of insurgence and progression of diseases are at the basis of modern diagnostics and medicine. In this concern, biomarkers represent a powerful diagnostic tool, as their expression profiles well correlate with the pathology progression. Thus, the pathological state could be diagnosed by measuring the altered presence of a biomarker. In this direction, conspicuous help has been given by proteomics, intended as the study of the protein pattern of a sample and most frequently performed by two-dimensional electrophoresis. Although the proteome approach is a powerful analytical method, its application to biological samples for the detection and quantification of putative biomarkers is hampered by technical problems, in fact, the wide diversity in concentrations exhibited by the proteins present in the biological samples, with a concentration range spanning over nine orders of magnitude, and the relative abundance of each protein, are responsible of masking the less abundant species and of their loss in traceability. The aim of my PhD project is to apply Molecularly Imprinted Technology to the specific removal of a high abundance protein (Human Serum Albumin, HSA) frequently affecting proteomic analysis, in order to increase the detection of potential biomarkers. This technology allows the creation of artificial recognition sites in synthetic polymers for a specific protein. These sites are tailor-made in situ by co-polymerisation of functional monomers and cross-linkers around the template molecules. Two different approaches have been assayed in order to remove HSA: • Immobilisation of protein template on a rigid silica support (bead) and creation of polymer around beads. • Polymerisation in bulk of a polymer with protein template and application of this polymer to multicompartment electrolyser. In both of the cases, the chemical and structural features of the polymers have been analysed, after that they have been applied to complex proteome pre-treatment, obtaining encouraging results.
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Mistry, Reena. "Niacinamide analysis using molecularly imprinted polymers." Thesis, University of British Columbia, 2002. http://hdl.handle.net/2429/43182.
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The objectives of this research were to use molecularly imprinted polymers (MIP) and microfluidic chips as an approach to a rapid and low cost analytical method for niacinamide analysis. Lab-on-a-chip (microfluidics) devices are becoming increasingly popular due to their relatively low cost, sensitivity, and speed. MIPs may be able to serve as solid-phase extraction packing material in microfluidic chips.
To reach the objectives, it was necessary to identify the mechanisms by which binding of analyte to polymer occur, determine the optimal functional monomer to cross-linker ratio, and gain an understanding of the polymeric structure and characteristic bonds. An MIP was created using niacinamide (NAM) as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, azobisisobutyronitrile (AIBN) as the free-radical initiator, and chloroform as the porogen. It was hypothesized that rebinding occurs via hydrogen-bonding of the carbonyl and amide groups of NAM to the oxygen atoms in the carboxyl group of MAA.
Rebinding studies were conducted using compounds with similar functional groups to NAM to determine binding mechanism to the polymer. Both the pyridyl nitrogen and the amide group were found to be important in hydrogen bonding interactions with the polymer.
Polymers were optimized for rebinding by using different ratios of functional monomer:cross-linker (MAA:EGDMA) and determining imprint factor of NAM to each polymer. The 1:4 polymer yielded the highest imprinting factor, indicating that the polymer is most selective for NAM.
FTIR was conducted to determine the structure of polymers created and whether NAM detection and quantification was possible. There was a peak at 1725 cm⁻¹, which was a shift of the C=O stretching band from 1694 cm⁻¹ in MAA and 1717 cm⁻¹ in EGDMA, indicating a chemical interaction between the two compounds. The disappearance of a peak at 1633 cm⁻¹ showed a loss of conjugation in the carboxylic acid in the polymeric structure.
Through this research, knowledge was gained about the polymer optimization and structure. However, more studies need to be conducted to determine the feasibility of an MIP application for a lab-on-a-chip device.
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Mak, Wing Yin Winifred. "Developmental regulation of imprinted X inactivation." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407945.
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Wang, Jinfang. "Xanthine-imprinted polymers for decaffeination applications." Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431777.
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Abd, Bashar H. "Molecularly imprinted polymers for drug delivery." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/43042.
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Molecularly imprinted polymers (MIP) have received much attention and increased interest thanks to their excellent cost efficiency, robustness, high selectivity and simple short synthesis. The molecular imprinting process can be defined as creation of molecular recognition sites in a synthetic polymer. The template-derived sites thus created within the polymeric matrix allow MIP to selectively recognise and bind the target molecule. In light of these properties, MIP have been successfully applied in sensors, assays separation, and for drug delivery applications. Because of their small size, MIP nanoparticles (MIP NPs) can be used in biomedicine as specific drug delivery device, since the nanoscale format is potentially suitable for cellular or in vivo applications. This work has demonstrated that MIP NPs could be used as carriers for targeted drug delivery. For this purpose, the anti-inflammatory and anti-cancer agent curcumin was selected to develop a high throughput screening method which allows to optimise the controlled delivery of drugs using magnetic MIP NPs. Senescent cells which contribute to a number of pathophysiological conditions including fibrosis, diabetes, cancer, Alzheimer's and ageing, were selected as a model system to demonstrate the ability of specific MIP NPs to recognise them and deliver the cytotoxic drugs. Fluorescent MIP NPs specific for two epitopes of senescent cells B2M and DEP were prepared and characterised. In vitro tests based on two human cell lines have demonstrated the ability of the developed MIP NPs to recognise the senescent cells and confirmed that they were not toxic to the cells. In order to demonstrated the targeted drug delivery double-imprinted fluorescent MIP NPs with binding site specific for senescent cells and containing cytotoxic drugs Dasatnib and Gramicidin have been produced. In vitro tests with groups of old and young mice injected with MIP NPs demonstrated the targeted induction of cell death. It is possible to conclude that fluorescent MIP NPs could be effectively used as imaging tool for in vitro analysis as well as carriers for targeted delivery of the drugs in vivo. The protocols developed in this work are applicable for any other targets of clinical importance.
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Dent, Claire. "Imprinted genes, impulsivity and risk-taking." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/66461/.
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genes show monoallelic parent-of-origin specific expression and have an important role in mediating adult behaviour. Previous research has indicated that maternally expressed Nesp and paternally expressed Grb10, which are expressed in overlapping brain regions, may have a role in mediating risk-taking and/or impulsive behaviours. Impulsivity and risk taking are natural parts of human behaviour; however pathological levels of impulsivity and risk-taking are recognised as clinical traits of many psychiatric disorders. The aim of the current research is to explicitly test whether these two oppositely imprinted genes influence impulsivity and/or risk-taking behaviour in mice by examining mouse models that lack functional copies of paternal Grb10 (Grb10+/p) and maternal Nesp (Nespm/+) in a number of tests of impulsivity and risk-taking. Unlike previous findings in Nespm/+ mice, Grb10+/p mice had the same propensity to explore a novel environment as wild type (WT) controls. However, in a measure of delay-discounting behaviour it was discovered that Grb10+/p mice were less likely to discount delayed rewards. This is in contrast to previous work with Nespm/+ mice, which discounted delayed rewards more steeply. This is the first demonstration that oppositely expressed imprinted genes antagonistically affect behaviour. To further explore these behaviours, a novel test of risk-taking was developed. Using predator odours a perceived ‘risky’ environment was created in order to measure the decision between fear and reward seeking. Using the Predator Odour Risk-Taking (PORT) task it was demonstrated that Nespm/+ and Grb10+/p mice showed comparable levels of risk-taking behaviour to WT littermates. Finally, immunofluorescence was used to discover that Nesp55 and Grb10 are not only expressed in the same brain regions, but are co-expressed in some cells, particularly in serotonergic neurons. This suggests that these imprinted genes may be influencing delay discounting behaviour via the same integral neurotransmitter systems.
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Silva, Matteo. "Interactions in optically imprinted polariton lattices." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415858/.
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Microcavity exciton-polaritons results from the admixture of cavity photons and excitons in the strong coupling regime. Due to their hybrid nature, polaritons are a promising solid-state platform for both fundamental studies on light-matter interaction and applications in quantum and opto-electronics technologies. In this thesis, optically imprinted graphs of interacting polariton condensates are proposed and demonstrated to simulate universal spin models whose ground state brings about the solution of a bespoken optimisation task. The establishment, control and tailoring of a complex network of interactions across the graphs' nodes is an essential ingredient to map complex optimisation tasks to a polariton graph. Here, a method is proposed to quantify and measurecoupling strength between a pair of polariton condensates as a function of their physical separation. Furthermore, this thesis also outlines how the coupling is influenced by optically injecting a non-homogeneously polarised polariton graph.
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Whetton, Stephen. "Novel imprinted polymers as artificial enzymes." Thesis, Aston University, 2001. http://publications.aston.ac.uk/9644/.
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Derivatives of L-histidine were investigated as suitable models for the Asp-His couple found in the catalytic triad of serine proteases. A combination of molecular dynamics and IH NMR spectroscopy suggested that the most populous conformations of N-acetyl-L-histidine and the N-acetyl-L-histidine anion were predominated by those in which the carboxylate group was gauche to the imidazole ring overcoming steric and electrostatic repulsion, suggesting there is an interaction between the carboxylate group and the imidazole ring. Kinetic studies, using imidazole, N-acetyl-L-histidine and the N-acetyl-L-histidine anion showed that in a DMSO/H20 9: 1 v/v solution, the N-acetyl-L-histidine anion catalysed the hydrolysis of p-nitrophenyl acetate at a greater rate than using either imidazole or N-acetyl-L-histidine as catalyst. This indicates that the carboxylate group affects the nucleophilicity of the unprotonated imidazole ring. 31P MAS NMR spectroscopy was investigated as a new technique for the study of the template molecule environment within the polymer networks. It was found that it was possible to distinguish between template associated with the polymer and that which was precipitated onto the surface, though it was not possible to distinguish between polymer within imprinted cavities and that which was not. Attempts to study the effect of the carboxylate group/imidazole ring interaction in the imprinted cavity of a molecularly imprinted polymer network were hindered by the method used to follow the reaction. It was found though that in a pH 8.0 buffered solution the presence of imprinted cavities increased the rate of reaction for those polymers derived from L-histidine. Some preliminary investigations into the design and synthesis of an MIP which would catalyse the oxy-Cope rearrangement were carried out but the results were inconclusive.
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Alam, Shadab. "Mysteries of Universe Imprinted on Redshifts." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/992.
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Hu, Lucy Yue. "Binding studies on molecularly imprinted polymers." W&M ScholarWorks, 2004. https://scholarworks.wm.edu/etd/1539623453.
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Molecular imprinting is a rapidly developing technique for preparation of polymeric materials that are capable of molecular recognition for selective separation and chemical identification. to prepare molecularly imprinted polymers (MIPs), a functional monomer and a crosslinker are polymerized in the presence of a template molecule. Then the template is extracted leaving sites which are complementary in both shape and chemical functionality to those of the template. This resin then becomes capable of selectively absorbing the template species. Because of MIPs' stability, predesigned selectivity, and easy preparation, they have been used for separation, sensor, drug development and directed synthesis.;In this study, we focused on characterizing and understanding the mechanism underlying formation and recognition of MIPs. Three resins imprinted with 4-hydroxybenzoic acid, 3-hydroxybenzoic acid and 6-methoxy-alpha-methyl-2-napthaleneacetic acid ((S)-naproxen) were prepared in a free radical polymerization. Hydrogen bonding between the template and functional monomer is the main interaction: it not only controls the template molecules in and out of the binding sites, but also contributes a high concentration of specific binding sites in the resulting polymer resin. After polymerization, the amount of template that can be effectively removed during each extraction was quantified in the naproxen imprinted system. For comparison, another resin was prepared under the same condition without the presence of the template, which was designated as NIP.;The binding experiments were performed for the affinity and selectivity tests. The MIP showed a special affinity for the template, but not for other analytes, which is consistent with the principle that an imprinted resin's recognition ability is dependent on the analyte's size, shape, and functionality. The NIP had similar affinities for the analytes and thus it could not differentiate among them. The binding behavior of the MIP is characterized by an association constant and the density of each kind of site using a simple two-binding-site model with one kind of sites special for the template and the others being more general with similar affinities as the NIP. The binding sites common to both the imprinted resin and the non-imprinted resin were found to have higher affinity but are less numerous than the sites unique to the imprinted resin.
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Tshikhudo, Tshinyadzo Robert. "Development of nickel-selective molecularly imprinted polymers." Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1004449.
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A series of eight novel bidentate ligands, designed for use in the construction of nickel-selective molecularly imprinted polymers (MIP's), have been prepared. The synthetic pathway was established by retrosynthetic analysis of the target molecules to the readily available precursors, pyridine-2-carbaldehyde (or 6-methylpyridine-2-carbaldehyde) and ethyl bromoacetate. The ligands were designed to contain an allyl group for co-polymerisation and amine and pyridyl nitrogen donors, located to permit the formation of 5-membered nickel chelates. The eight novel ligands and their respective precursors were characterized by elemental (high-resolution MS) and spectroscopic (IR and ¹H and ¹³C NMR) analysis. High resolution electron-impact mass spectrometry has also been used, together with B/E linked scan data, to explore the fragmentation patterns of selected ligands. The various nickel(ll) complexes were analyzed using spectroscopic techniques and, in some cases, elemental analysis; computer modelling has also been used to explore conformational effects and complex stability. Numerous MIP's, containing nickel(II) complexes of the bidentate ligands, have been prepared, using ethylene glycol dimethylacrylate (EGDMA) as the cross-linker, azobis(isobutyronitrile) (AlBN) as the polymerization initiator and MeOH as the porogenic solvent. The template nickel(II) ions were leached out with conc. HCI, and the nickel(II) selectivity [in the presence of Fe(Ill)] of the nickel-imprinted polymers was examined by ICP-MS analysis. The ICP-MS data indicate that the MIP's examined exhibit extremely high selectivity for nickel over iron.KMBT_363
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Mandadi, Deepika. "A Characterization of Caffeine Imprinted Polypyrrole Electrode." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/130.
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Nanotechnology holds great potential for improving our lives by creating many new materials and devices in medical sciences, electronics and also in energy production. Molecularly imprinted polymers (MIPs) are highly stable synthetic polymers that possess molecular recognition properties due to cavities created in the polymer matrix that are complementary to an analyte both in shape and in positioning of functional groups. These MIPs have been widely employed for diverse applications (e.g., in chromatographic separation, drug screening, chemosensors, catalysis, immunoassays etc) due to their specificity towards the target molecules and high stability against physicochemical perturbations. Conductive polymers, (CPs) such as polypyrrole, can be likened to semiconductors because of small band gaps and low electronic mobility. CPs are exploited as an excellent tool for the preparation of nanocomposites with nano scaled biomolecules. Polypyrrole (Ppy) was the first of this key family of compounds to show high conductivity. So, electrically conducting polypyrrole (Ppy) has numerous applications.
In this study, caffeine imprinted electrodes (CIE) were prepared and characterized. This research project mainly focused on three important aspects: &#;To determine the thickness of the polymeric film. &#;To determine the Limit of detection (LOD) of the polymeric film at different conditions. &#;To determine the Analytical Sensitivity (γ) of the polymeric film at varied conditions.
In summary these are conclusions stated: •The thickness of the electrode increased with an increase in the number of pulses. The film thickness increased linearly up to an application of 30 pulses and after 30 pulses, an increase in slope occurred with again a linear correlation up to the maximum applied number of pulses, 42. This change in slope may indicate a different mechanism taking place.
•LOD is improved as the caffeine load is reduced from 10.0 to 3.0 mM and as the number of pulses is reduced from 36 to 24.
•γ increases the number of pulses increase from 24 to 36 and also increases as the caffeine load increases.
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Judson, Hannah. "Investigation of candidate imprinted tumour suppressor genes." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/28316.
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Imprinting is an epigenetic phenomenon that silences one allele of a gene, so that expression in one or more cell types is exclusively monoallelic, and dependent on parental origin. Approaches used to identify novel imprinted genes rely on characteristic features such as the clustering of imprinted genes, or their association with differentially methylated CpG islands. An imprinted tumour suppressor gene involved in pathogenesis of neuroblastoma is believed to lie within chromosome 1p36. In this region, a search was initiated for imprinted genes in the vicinity of the imprinted gene TP73. The DFFB gene, encoding the apoptotic nuclease DNA fragmentation factor, was identified, and its intron-exon structure was elucidated. A pseudogene was also identified on chromosome 9. The tumour suppressor candidacy of DFFB was assessed through a comprehensive mutation screen of 42 neuroblastoma DNAs. No tumour-specific mutations were identified. Imprinting was then assessed by RT-PCR, which revealed biallelic expression of DFFB. It is unlikely that DFFB acts as a tumour suppressor in neuroblastoma. During a systematic screen, a differentially methylated CpG island, NV149, had been identified. In the present study, this locus was mapped to 6q24. The nearest gene was found to be the cell-cycle control gene, ZAC. Monallelic expression of ZAC from the paternal allele only was demonstrated in a range of fetal tissues. ZAC may possess a dual role in disease, such that upregulation by paternal duplication or paternal uniparental disomy of chromosome 6 results in transient neonatal diabetes mellitus (TNDM), whereas loss or down regulation of ZAC results in a loss of cell cycle control, and hence tumorigenesis. Through analysis of a panel of B cell lymphomas, evidence was found for hypermethylation of the NV149 CpG island, which may be one mechanism through which expression of ZAC is lost in tumours.
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Rick, John Frank. "Molecularly imprinted polymers as biological receptor analogues." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249781.
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Kearton, Brian L. "Controlled free radical cyclisations in imprinted polymers." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367355.
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Noyes, Karen Lynn 1977. "Synthesis and evaluation of actinide imprinted resins." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/30012.
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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003.Includes bibliographical references (p. 143-146).
Organic resins have previously shown good results with application to actinide separations. Large portions of recent research have been dedicated to the synthesis and evaluation of resins with phenolic-type functional groups. Other recent chemical research with lighter metals has developed a technique known as ion imprinting which can provide greater selectivity for the target metal ion. Initial work with ion imprinting and phenolic-type resins has shown these two areas to be largely incompatible. Identifying the ion imprinting technique as potentially the more valuable of the two, further work was undertaken with resins that incorporate a carboxylic acid-type functionality. These new resins are synthesized via a radical polymerization method, which proved to be very compatible with both actinides and the ion imprinting procedure. Polymer-based resins were synthesized without a metal template as well as ion imprinted, or templated, with U(VI), Th(IV), Np(V), and a resin for use with Am(III). Each of these resins were individually characterized and evaluated for use with their respective target metals. Characterization provides a means of comparing theoretical binding capacities of various resins, which the evaluations define the binding characteristics of interest (capacity, selectivity, kinetics, etc.). Based on the initial results for the selectivity of the U(VI) and Th(IV) ions, a new type of resin was developed in an effort to further increase the selectivity of the resin for the target metal ion. This new resin, known as a "capped" resin, seeks to remove the binding capability of any potential binding sites not involved in the ion imprinting process.
(cont.) Results show that the ion imprinting technique can be successfully applied in the synthesis of resins for actinide separations with good success. The resins created through this process also show an affinity for their target metals over both competing ions as well as ions of similar ionic charge and radii. The removal of so-called random binding sites is also possible, with the addition of a few synthetic steps.
by Karen Lynn Noyes.
Sc.D.
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Corman, M. E., C. Armutcu, L. Uzun, R. Say, and A. Denizli. "L-Lysine Imprinted Nanoparticles for Antibody Biorecognition." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35007.
Full textAbstract:
The aim of this study was to prepare L-lysine-imprinted poly(HEMA-MAAsp) nanoparticles which can
be used for the adsorption of IgG from aqueous solutions. L-lysine was complexed with MAAsp and Llysine-
imprinted poly(HEMA-MAAsp) nanoparticles were synthesized by miniemulsion polymerization. Also,
non-imprinted nanoparticles were synthesized without L-lysine for control purpose. L-lysine-imprinted
poly(HEMA-MAAsp) nanoparticles were characterized by means of elemental analysis, Fourier transform
infrared spectroscopy (FTIR) and transmission electron microscopy (TEM).
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35007
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Li, Bin. "Molecularly imprinted polymers for applications in cosmetology." Thesis, Compiègne, 2013. http://www.theses.fr/2013COMP2083.
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Un polymère à empreintes moléculaires (MIP) est un récepteur synthétique supramoléculaire, un matériau possédant des cavités pouvant reconnaître spécifiquement une molécule cible. Il est synthétisé en mettant en contact la molécule cible, avec un mélange de monomères fonctionnels et réticulants qui permettent d'obtenir un réseau polymérique tridimensionnel rigide. L'élimination de la molécule empreinte laissera des sites vides complémentaires de cette dernière. Ces cavités sont maintenant capables de la recapturer spécifiquement. Ces polymères sont utilisés dans les domaines tels que l’extraction en phase solide, la chromatographie d’affinité, la catalyse enzymatique, les biocapteurs et la vectorisation des médicaments. Bien que le concept des MIPs a pour origine les travaux réalisés sur des matériaux sol-gel imprimés dans les années 1930, ces derniers sont restés dans l’ombre jusqu’à l'introduction de polymères organiques imprimés plus versatiles. Par rapport aux MIPs organiques, les MIPs sol-gel présentent quelques avantages comme une plus grande stabilité thermique, une meilleure compatibilité avec l'eau et une plus grande porosité. Dans cette thèse, nous avons développé des MIPs organiques et des MIPs sol-gel pour leur application en cosmétologie et pour la vectorisation de médicaments. Dans la première partie, nous présentons des MIPs pouvant adsorber d’une façon spécifique l’acide oléique (OA), un biomarqueur de l’état pelliculaire sur le cuir chevelu. Pour la préparation des MIPs organiques, nous avons employé plusieurs monomères basiques dont l’acryloylaminobenzamidine (AB), que nous avons tout spécialement synthétisé. Tous les MIPs pouvaient lier l’OA mais beaucoup d’interaction non-spécifique était observé. D’autre part, les MIPs sol-gel présentaient une bonne reconnaissance spécifique et une capacité élevée pour OA; par exemple, un MIP de composition OA:APTES:TEOS = 1:1.6:1.7 pouvait adsorber 625 μmol.g-1 de OA dans le sébum artificiel. Des tests pour capturer l’OA sur le stratum corneum et la peau reconstruite (Episkin) ont également été effectués. La pénétration de l’OA sur les deux types de peau était plus faible en présence de MIP que de NIP. Les MIPs comme matériaux désodorisants font l’objet de la deuxième partie de cette thèse. Des MIPs pouvant adsorber les précurseurs de molécules malodorantes comme les conjugués glutamine des acides (E)-3-méthyl-2-hexénoïque (3M2H) et 3-hydroxy-3-méthyl-hexanoïque (3H3MH) ont été préparés. Le N-hexanoyl glutamine et le N-hexanoyl glutamate ont été utilisés comme template. Nous observons que le MIP synthétisé avec AB comme monomère fonctionnel possède la plus grande capacité d'adsorption pour le N-hexanoyl glutamine, ainsi que pour les précurseurs glutamines des molécules malodorantes. Des résultats préliminaires et très prometteurs ont également été obtenus dans la sueur. La dernière partie de cette thèse concerne des MIPs pour la vectorisation de médicaments. L'acide salicylique (SA) est un médicament efficace utilisé dans le traitement de l’acné. Des MIPs organiques et sol-gel contre SA ont été synthétisés. Les MIPs sol-gel ont une plus grande capacité d’adsorption, 180 μmol.g-1, que les MIPs organiques et ils lient le SA sept fois plus que le NIP. Les tests de relargage du SA ont été effectués dans plusieurs milieux, avec la plus grande efficacité dans l’eau pure. En conclusion, les applications de MIPs en cosmétologie et en vectorisation de médicaments ont étés étudiés. Nos résultats montrent que les MIPs sol-gel sont les plus appropriés pour ce type de travailMolecularly imprinted polymers (MIPs) are tailor-made synthetic receptors possessing specific cavities for a given target molecule. They are produced by introducing, into the polymer precursors, guest molecules that act as templates at the molecular level. Interacting and cross-linking monomers are then copolymerized to form a cast-like shell. After removal of the template, cavities complementary to the template in size, shape and position of functional groups are revealed in the polymer, which can now specifically bind the template. Thanks to these specific molecular recognition properties, MIPs have found applications in areas like bio sensors, solid phase extraction, affinity chromatography, catalysis, and drug delivery. Although the MIP concept originated from imprinted silica in the 1930s, imprinted sol-gel materials received little attention afterwards due to the introduction of the more versatile organic polymers as imprinting matrix. However, compared to organic polymers, sol-gels possess higher thermal stability, better water compatibility and larger inner surface area. There have been many applications to biomolecules in aqueous conditions with sol-gel imprinting materials. In this thesis, we have developed organic and silica sol-gel MIPs for applications in cosmetics and drug delivery. MIPs able to adsorb the dandruff-inducing molecule oleic acid (OA) were produced via both the organic and inorganic routes. In the organic MIPs synthesis, different positively charged monomers were used, one of which, acryloyl aminobenzamidine, was specifically synthesized. Although some binding of oleic acid was obtained, specificity and capacity of these polymers were not satisfying. Sol-gel MIPs, on the other hand, exhibited good specific recognition and high binding capacity for OA. A MIP of the composition OA:APTES:TEOS= 1:1.6:1.7 yielded a capacity of 625 μmol.g-1 in artificial sebum. Furthermore, tests were carried out to capture OA on stratum corneum and reconstructed skin (Episkin). Less penetration of OA was observed in the presence of a MIP than with a non-imprinted control polymer. Deodorant materials are another topic of this thesis. MIPs that are able to adsorb certain precursors of odorant molecules, the glutamine conjugates of (E)-3-methyl-2-hexenoic acid (3M2H) and 3-hydroxy-3-methyl-hexanoic acid (3H3MH) were prepared. N-hexanoyl glutamine and N-hexanoyl glutamate were used as templates. After optimization of the MIP composition, we found that MIPs synthesized with acryloyl aminobenzamidine as functional monomer had the highest adsorption capacity for N-hexanoyl glutamine, and also recognised the glutamine targets of 3M2H and 3H3MH. Some preliminary promising binding results were obtained in artificial sweat. The third part of this work concerns a drug delivery MIP. Salicylic acid (SA) is a drug used to treat acne. SA-imprinted polymers were prepared via both organic imprinting and the sol-gel process.Compared to organic MIPs, sol-gel MIPs have a higher capacity, 180 μmol.g-1, and 7 times higher binding than to a non-imprinted control polymer was observed. Release tests were carried out in different aqueous media, the most efficient drug release was observed in pure water. In conclusion, applications of molecularly imprinted polymers for cosmetics and drug delivery have been investigated. Our results demonstrate the great potential of in particular sol-gel MIPs for these purposes
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Shi, Huaiqiu Galen. "Protein recognition of template imprinted polymer surfaces /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8075.
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Minor, Agata. "DNA methylation at imprinted and non-imprinted genes in the sperm of men affected by severe male factor infertility." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/29282.
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Abnormal DNA methylation at imprinted and non-imprinted genes has been associated with spermatogenesis failure. However, little information is available regarding DNA methylation at those genes in men affected by severe male factor infertility. We hypothesized a higher incidence of aberrant DNA methylation would be present in the ejaculate and testicular sperm of men affected by severe male factor infertility compared to that in fertile control men. Furthermore, we hypothesized abnormal DNA methylation would also affect non-imprinted genes in the sperm of men affected by severe oligozoospermia.
DNA methylation at the differentially methylated regions (DMRs) of imprinted genes, H19, IG-GTL2 and MEST, was studied in the ejaculate sperm of men affected by severe and very severe oligozoospermia, in the testicular sperm of men affected by obstructive azoospermia (OA) and non-obstructive azoospermia (NOA), and having undergone vasectomy reversal. The results were compared to that in the sperm of control men of proven fertility. Methylation at the DMRs was evaluated by bisulphite sequencing of multiple unique clones, representative of single sperm. DNA methylation was also studied at non-imprinted genes in sperm of men affected by severe and very severe oligozoospermia. DNA methylation was analyzed at 1,505 CpG sites using the Illumina GoldenGate methylation Cancer Panel I with the results at selected CpG sites being confirmed using pyrosequencing.
We found the H19 DMR to be most susceptible to methylation abnormalities and the IG-GTL2 DMR to be the most robust. We found a higher incidence of aberrant DNA methylation in the sperm of men affected by severe oligozoospermia, OA and in men undergoing vasectomy reversal compared to control men. The presence of aberrant imprinting in men with obstruction suggests that abnormal methylation at imprinted genes may not only be related to spermatogenesis failure, as seen in patients affected by severe oligozoospermia, but also to changes in testicular environment that may occur in response to obstruction. Lastly, our analysis of a limited number of samples suggests that abnormal DNA methylation in the sperm of men affected by severe oligozoospermia may also affect non-imprinted genes. Our results warrant further analysis of a larger sample size.
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Mohammad, Faizaan. "Long Noncoding RNA Mediated Regulation of Imprinted Genes." Doctoral thesis, Uppsala universitet, Institutionen för genetik och patologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-128882.
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Genomic imprinting is an epigenetic phenomenon that causes a subset of mammalian genes to be expressed from only one allele in a parent-of-origin manner. The defects in the imprinting regulation result in disorders that affect development, growth and metabolism. We have used the Kcnq1 imprinted cluster as a model to understand the mechanism of imprinted gene regulation. The imprinting at the Kcnq1 locus is regulated by a long noncoding RNA, Kcnq1ot1, whose transcription on the paternal chromosome is associated with the silencing of at least eight neighboring genes. By destabilizing Kcnq1ot1 in an episomal system, we have conclusively shown that it is the RNA and not the process of transcription that is required for the gene silencing in cis. Kcnq1ot1 RNA interacts with the chromatin modifying enzymes such as G9a and Ezh2 and recruits them to imprinted genes to establish repressive chromatin compartment and gene silencing. Using the episomal system, we have identified an 890 bp silencing domain (SD) at the 5’ end of Kcnq1ot1 RNA, which is required for silencing of neighboring reporter genes. The deletion of the SD in the mouse resulted in the relaxation of imprinting of ubiquitously imprinted genes (Cdkn1c, Kcnq1, Slc22a18, and Phlda2) as well as reduced DNA methylation over the somatic DMRs associated with the ubiquitously imprinted genes. Moreover, Kcnq1ot1 RNA interacts with Dnmt1 and recruits to the somatic DMRs and this recruitment was significantly affected in the SD mutant mice. By using a transgenic mouse, we have conditionally deleted Kcnq1ot1 promoter at different developmental stages and demonstrated that Kcnq1ot1 maintains imprinting of the ubiquitously imprinted genes by regulating DNA methylation over the somatic DMRs. Kcnq1ot1 is dispensable for the maintenance of repressive histone marks and the imprinting of placental-specific imprinted genes (Tssc4 and Osbpl5). In conclusion, we have described the mechanisms by which Kcnq1ot1 RNA establishes and maintains expression of multiple imprinted genes in cis.
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Myint, Mo Aung, and n/a. "Investigation of molecular interactions with molecularly imprinted polymers." University of Otago. Department of Chemistry, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090617.131516.
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Currently, very little information is available for an in-depth understanding of the molecular binding interactions with molecularly imprinted polymers (MIPs). To address this issue MIPs that have high binding affinities for their template compounds were made so that the nature of these interactions could be elucidated using spectroscopic techniques.
12 functional MIPs were prepared using a series of azobenzene and anthracenyl derivatives as the templates. Affinities of these MIPs for the corresponding templates and analogues were determined by performing batch and competitive binding tests. It was found that extensively conjugated compounds that contain at least two OH groups, an electron-withdrawing substituent and have limited conformational freedom were effective templates.
The most efficient MIP, M34, was prepared with 4-[(4-nitrophenyl)azo]-1,2-benzenediol (12). M34 exhibited high affinities for azobenzene derivatives of catechol, and bound those that did not contain non electron-withdrawing substituents more specifically. M34 did not lose affinity for 12 in the presence of analogues, and vice versa, in competitive binding tests. These observations suggested a distribution of different binding sites on M34.
M34 bound substrates rapidly, which was attributed to its highly porous polymer matrix giving ready access to binding sites. Formation of the porous matrix was facilitated by the use of DMF as the porogen in the preparation of M34. DMF is not a conventional choice of porogen because use of such highly polar H-bonding solvents is thought to disrupt complexation between template and polymer precursors, which is required for the formation of binding sites.
Significant changes in the wavenumbers and the intensities of absorption bands assigned to the catechol substructure of 12 were observed in the FT-Raman spectra of 12 bound to M34. These findings suggested that the catechol substructure was responsible for interactions of 12 with M34 that are critical to rebinding and imprinting.
In-situ analyses of dithranol (8) being removed from and bound to its MIP, M23, were performed using ATR-IR spectroscopy. Only one band, assigned to the aromatic substructure of 8, was not obstructed by solvent bands in the spectra of unwashed M23 and washed M23 that was treated with the rebinding solution. The wavenumbers of the corresponding bands in the two spectra were significantly different. This observation suggested that there were differences in the vibrational characteristics of 8 bound to M23 under the two conditions.
Evidence was found for H-bonding between OH groups of 8 and C=O group of methacrylic acid using transmission FT-IR spectroscopy. However, no evidence was found that showed significant interactions between 12 and 2-vinylpyridine. Methacrylic acid and 2-vinylpyridine were used as the functional monomers in the preparations of M23 and M34. The FT-IR spectra of mixtures of 12 and 4-vinylpyridine showed three new bands assigned to H-bonded OH stretches. These observations indicated that 4-vinylpyridine H-bonds with 12, and would be a more effective functional monomer than 2-vinylpyridine in the preparation of the MIPs for 12.
Titration of 12 with 2-vinylpyridine was analysed by �H NMR spectroscopy. Only small changes to the signals of the corresponding compounds were observed. This lack of change was attributed to the use of d₇DMF, which would compete against 2-vinylpyridine for H-bonding interactions.
The findings made using ATR-IR spectroscopy and FT-Raman were novel because previously reported data on bound templates obtained using the corresponding techniques did not show changes in the vibrational characteristics of templates as they bind to MIPs. This investigation has shown that rebinding and spectroscopic studies can provide information about the nature of the binding interactions in MIPs.
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Bourque, Danielle Kathleen. "Imprinted genes in the placenta and obstetrical complications." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/25509.
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Each year, many pregnancies are associated with obstetrical complications such as maternal pre-eclampsia (PET) and fetal intrauterine growth restriction (IUGR). Poor placentation is thought to contribute to these complications, but specific causes are largely unknown. Mouse models suggest that epigenetic mechanisms, in particular genomic imprinting, that alter gene regulation may help regulate placental development and embryonic growth. The first goal of this thesis is to examine if epigenetic modifications (i.e. DNA methylation) and altered expression of imprinted genes in the human placenta are contributing factors to PET and IUGR. The second goal of this thesis is to identify imprinted loci that are useful in the diagnosis of placental pathologies that associated with abnormal imprinting, including triploidy, hydatidiform moles, and placental mesenchymal dysplasia.
I found that DNA methylation at the imprinting control region 1 (ICR1) on chromosome 11p15.5 was significantly decreased in IUGR placentas (p < 0.001), but not in those associated with pre-eclampsia. Methylation at ICR2 (KvDMR1) was not significantly altered in PET or IUGR. No significant changes in expression levels were observed in the genes controlled by these ICRs. There were no significant methylation changes observed in any candidate imprinted gene evaluated by the Illumina array. LINE-1 methylation, a marker of whole genome methylation, was also similar in all groups. The establishment of biomarkers that could be used to accurately identify those women at an increased risk for pre-eclampsia or IUGR would be a major step forward in antenatal care.
All placental pathologies (triploidy, hydatidiform moles or placental mesenchymal dysplasia) were associated with altered ICR2 (KvDMR1) methylation. Pyrosequencing assays for SGCE, SNRPN, and MEST were also compared for their utility in diagnosing parental genomic imbalance in placental samples. SGCE showed the clearest separation between groups. The combined use of KvDMR1 and SGCE assays could provide a potentially valuable diagnostic tool in the rapid screening of methylation errors in placental disorders. These results also demonstrate the maintenance of imprinting status at these loci in the human placenta, even in the presence of abnormal pathology.
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Holmes, Rebecca Jane. "Analysis of a novel cluster of imprinted genes." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270370.
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Bowen, Jenna Louise. "Detection of lipopolysaccharide pyrogens by molecularly imprinted polymers." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/54444/.
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Lipopolysaccharide (LPS) is commonly implicated in the development and rapid progression of sepsis however no efficient diagnostic assay currently exists. The over-arching aim of this project was therefore to develop a novel biomimetic peptide-polymer hybrid system capable of recognising and binding LPS in a variety of biologically relevant environments. Target selective peptides (both commercially available and synthesised) have been used as high affinity 'functional monomers' in a molecular imprinting approach. To reduce the concept to practice, a bi-functionalised resin was prepared so as to allow the use of two independent surface attachment strategies. Controlled polymer growth was initiated from surface bound iniferter groups whilst the attachment of the peptide was achieved through amme-amine imidoester linkages or via azide-alkyne "click" chemistry. Polymyxin, a small, conformationally constrained cyclic peptide that possesses high affinity for lipopolysaccharide (LPS) was used to provide proof-of-principle. Polymyxin resins, produced via the immobilisation of alkyne derivitised polymyxin B on the surface of azidomethyl polystyrene via "click" chemistry, were able to efficiently bind LPS from aqueous solutions with an apparent Ka of 0.2 μM. Although the development of the peptide-polymer hybrid system using these resins appeared somewhat unsuccessful, whether the observed reduction in binding is due to changes in the Bmax or the Kd of the resin remains to be elucidated. The assay performed with the polymerisation samples produced using resin displaying polymyxin immobilised via a dimethyl adipimidate linker, suggest that the hypothesised approach is feasible but that optimisation of a number of variables is needed before definitive results can be obtained.
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Wood, Andrew James. "The identificaiton and characterisation of novel imprinted genes." Thesis, University of London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498013.
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McEwen, Kirsten Rose. "Epigenetic regulation of imprinted loci in the mouse." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609297.
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Nativio, Raffaella. "Chromatin conformation at the IGF2-H19 imprinted locus." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609006.
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Ottway, Charlotte Jane. "Characterisation of Nespas, a non-coding imprinted RNA." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:b159c1e9-8d49-460c-a808-d920e8e17779.
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Nespas is the non-coding antisense transcript of the imprinted Gnas cluster; it is expressed from the paternal allele and is located on mouse distal chromosome 2. In this thesis new transcripts of >10 kb and 0.8 kb have been identified. The 0.8 kb transcript is a spliced variant that is retained in the nucleus and its 3’ end lies approximately 30 kb from the start site. Transcription from the Nespas promoter does not proceed beyond this point. A collection of previously known splice variants have also been detected and are exported to the cytoplasm. Nespas is expressed in the embryo during the second half of gestation and peaks at 13.5 dpc. Nespas is imprinted in the placenta at 11.5, 15.5 and 17.5 dpc. The Nespastm4Jop allele, to truncate the Nespas transcript 10.5 kb from the start site, has been transmitted through the germline and a breeding colony established. Preliminary analysis shows Nespas has a regulatory function. A second targeting construct to truncate Nespas 12.5 kb from the start site has been designed and assembled to investigate whether the 3’ end of the Nespas transcript that is transcribed upstream of the Nesp promoter is required for Nespas-mediated silencing of Nesp.
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Ritt, Cody. "Assessment of Molecularly Imprinted Polymers as Phosphate Sorbents." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/28417.
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Wastewater effluents and agricultural runoff are major sources of phosphorus overloading in surface waters. Phosphorus overloading ignites eutrophication, which devastates aquatic ecosystems. On the other hand, phosphorus, which is currently produced from phosphate rock, is a critical component of fertilizer mixes. However, the world is predicted to face a shortage of phosphate supply beyond 2033 due to unsustainable mining. This research aims to develop a polymeric sorbent that recovers low-concentration phosphorus for eutrophication prevention and fertilizer reuse. Available polymer-based products have underwhelmed expectations by having poor selectivity or lacking appropriate biodegradation rates. This research identified molecularly imprinted polymers (MIPs) as possible sorbents for overcoming the deficiencies of reported technologies. Screening of several MIPs resulted in one potentially feasible MIP for phosphate sorption. Further studies showed a sorption capacity of ~28 mg PO43--P/g and partial phosphate-selectivity. Potential phosphate removal mechanisms were identified, providing foresight into MIPs? viability as phosphorus sorbents.North Dakota Department of Commerce (NDDoC Grant #: 14-11-J1-70); the National Institute of Food and Agriculture (NIFA-USDA Grant #: 2015-607022-22996); North Dakota Water Resources Research Institute (NDWRRI)
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Ali, Aisha. "Synthesis and characterisation of imprinted polymeric receptor mimics." Thesis, Aston University, 2005. http://publications.aston.ac.uk/11027/.
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Molecularly imprinted polymers (MIPs) are crosslinked polymers containing bespoke functionalised cavities arising from the inclusion of template molecules in the polymerisation mixture and their later extraction. When the polymers are prepared functional polymerisable monomers are included which become part of the polymer matrix and serve to decorate the cavities with functionality appropriate to the template molecules. Overall, binding sites are created which have a memory for the template both in terms of shape and matching functionality. Fluorescent molecularly imprinted polymers have the benefit of a fluorophore in their cavities that may respond to the presence of bound test compound by a change in their fluorescence output. The work presented falls into three main areas. A series of fluorescent MIPs was prepared with a view to generating material capable of mimicking the binding characteristics of the metabolically important cytochrome isoform CYP2D6. The MIPs re-bound their templates and various cross-reactivities were encountered for test compound/drug recognition. One MIP in particular exhibited a rational discrimination amongst the related synthetic templates and was reasonably successful in recognising CYP2D6 substrates from the drug set tested. In order to give some insights into binding modes in MIPs, attempts were made to produce functional monomers containing two or more fluorophores that could be interrogated independently. A model compound was prepared which fitted the dual-fluorophore criteria and which will be the basis for future incorporation into MIPs. A further strand to this thesis is the deliberate incorporation of hydrophobic moieties into fluorescent functional monomers so that the resulting imprinted cavities might be biomimetic in their impersonation of enzyme active sites. Thus the imprinted cavities had specific hydrophobic regions as well as the usual polar functionality with which to interact with binding test compounds.
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Leibl, Nadja. "Development of molecularly imprinted polymers for chemical sensors." Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2446.
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Cette thèse propose une approche rationnelle pour le design de polymères à empreintes moléculaires (MIPs) pour la détection de nitro-explosifs. Les polymères à empreintes moléculaires qui miment la reconnaissance moléculaire biologique, ont l’avantage d’être stables dans des environnements sévères et peuvent adopter différentes formes physiques pour le couplage avec des transducteurs. Leur synthèse est basée sur la co-polymérisation de monomères fonctionnels et réticulants en présence de la molécule cible, ou comme dans cette thèse, d’un analogue ayant une structure proche de celle de la molécule cible. Cela conduit à la formation d’un réseau polymérique tridimensionnel rigide avec des sites de liaison complémentaires en taille, forme et position des groupes fonctionnels de la molécule cible ou de l’analogue. Pour identifier le meilleur monomère fonctionnel pour notre molécule cible, une approche rationnelle basée sur la modélisation moléculaire, la résonance magnétique nucléaire (RMN) et le titrage par calorimétrie isotherme (ITC) a été utilisée. Elle permet d’optimiser le mélange de pré-polymérisation pour identifier le monomère fonctionnel interagissant le plus fortement avec la molécule cible. Les résultats obtenus ont été confrontés à des études de liaison à partir de polymères synthétisés. La formulation polymérique ainsi conçue est intégrée aux surfaces du transducteur sous forme de nanoparticules, de films et de nanoparticules incorporés dans des films de polydopamine électropolymérisés. En plus des polymères traditionnels obtenus par polymérisation radicalaire classique sous forme de particules, des films de MIP à base de polydopamine électropolymérisés ont été étudiés en tant qu'approche alternative pour la détection électrochimique de nitro-explosifsThis thesis proposes a rational design approach towards molecularly imprinted polymers (MIPs) for sensing nitro-explosives. Molecularly imprinted polymers are mimicking biological molecular recognition. They have the advantage to be stable in harsh environments and can be tailored into different physical forms for interfacing with transducers. Their synthesis is based on the co-polymerization of functional and cross-linking monomers in the presence of the target analyte or, as in this thesis, with a structural analogue leading to a rigid three-dimensional polymer network with binding sites complementary to the template in size, shape and position of the functional groups. The choice of the functional monomer was carried out with a rational design approach combining molecular modelling, nuclear magnetic resonance (NMR) and isothermal calorimetry (ITC) studies. This allows to optimize the pre-polymerization mixture in order to get strong complexation between the functional monomer and the template. The obtained results were confronted with binding studies performed on synthesized polymers. The thus designed polymer formulation was interfaced with transducer surfaces in form of nanoparticles, films and nanoparticles embedded into electro-polymerized polydopamine films. In addition to the traditional MIPs by free radical polymerization, molecularly imprinted in-situ electro-polymerized polydopamine films were investigated as an alternative approach for sensing nitro-explosives electrochemically
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Martucci, Mariane Ferracin. "Impactos das biotécnicas reprodutivas no controle epigenético de genes imprinted." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-20102015-082930/.
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Técnicas de reprodução assistida (TRAs) são utilizadas tanto na medicina humana quanto na medicina veterinária com o objetivo principal de corrigir infertilidades adquiridas ou herdadas. A transferência nuclear de célula somática (TNCS) ocupa um lugar de destaque na veterinária pela possibilidade de geração de indivíduos geneticamente idênticos, permitindo a produção de rebanhos homogêneos de alto mérito genético e servindo como modelo de estudo para técnicas de reprogramação. Porém, a utilização de TRAs, e em especial da TNCS, é considerada responsável pelo aumento na geração de conceptos portadores de alterações durante e após o desenvolvimento embrionário e fetal. A provável causa principal é a alteração na regulação da reprogramação epigenética devido à manipulação de gametas e embriões no período inicial do desenvolvimento, levando a alterações na regulação epigenética de genes imprinted. O presente estudo teve como objetivo principal avaliar marcas epigenéticas e expressão de genes imprinted no desenvolvimento de conceptos bovinos produzidos por TNCS ou inseminação artificial (IA). Para tal, foram coletadas amostras de tecido muscular e membranas corioalantoideana e amniótica de animais na fase pré natal (fetal) e tecidos muscular, nervoso e hepático na fase pós natal (animais nascidos saudáveis adultos ou não) de animais derivados de IA ou TNCS. Foi analisada a expressão dos genes imprinted H19, IGF2, IGF2R e Airn quando possível, assim como a metilação do DNA no locus H19/IGF2 na fase pós natal. Foi observado que na fase pré natal não foi detectada expressão do IGF2, enquanto que a expressão de H19 é aumentada em relação ao IGF2R, porém, sem diferenças entre os grupos nos tecidos estudados. Na fase pós natal, o padrão de expressão dos genes IGF2, H19 e IGF2R indica diminuição da expressão gênica relativa no fígado de animais TNCS e no aumento da expressão gênica do H19 na musculatura de animais adultos (saudáveis) bovinos produzidos por TNCS, apesar de o padrão de metilação dos genes imprinted IGF2/H19 não ser diferente entre organismos considerados saudáveis e não saudáveis. Os resultados deste projeto contribuem para o entendimento dos mecanismos epigenéticos relacionados ao desenvolvimento embrionário e fetal, em especial aqueles relacionados à dinâmica das alterações epigenéticas envolvidas no imprinting genômicoAssisted reproductive technologies (ARTs) are usually used in both human and veterinary medicine aiming the correction of heritable or acquired infertilities. The somatic cell nuclear transfer technique (SCNT) is of particular importance in veterinary as it enables the generation of genetically identical organisms, allowing the production of homogeneous genetically improved herds, and also serving as a model for reprogramming studies. However, the use of TRAs, SCNT in special, may be responsible for the increase of developmental-related abnormalities in the conceptuses. Such phenotypes are probably caused by a disruption during the epigenetic reprogramming due to the manipulation of gametes and embryos during the early development period, and therefore leading to disturbances in the epigenetic regulation of imprinted genes. The present study aimed to evaluate epigenetic marks and expression of imprinted genes in different developmental periods of cattle generated by SCNT or artificial insemination (AI). For that, corionic/alantoic and amniotic membranes from fetuses and muscular, nervous and hepatic tissues from born animals, healthy (adult) or not, produced by SCNT or AI were collected. The expression of the imprinted genes H19, IGF2, IGF2R and Airn was analyzed as well as the DNA methylation at locus H19/IGF2 in post-natal period. It was observed that IGF2 was not detected during pre-natal period, whereas H19 expression is increased when compared to IGF2R in the groups studied herein. At post-natal period the IGF2, H19 and IGF2R expression patterns infers the decrease of relative gene expression in the liver and the increase of H19 expression in the muscle of SCNT adult animals. The methylation pattern of IGF2/H19 locus, however, did not differ between healthy or not animals. The results described herein may contribute to the understanding of the epigenetic mechanisms related to embryonic and fetal development, and in special, to those related to the epigenetic dynamics during genomic imprinting
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Eppler, Stefan [Verfasser]. "Advanced strategies for characterizing molecular imprinted polymers / Stefan Eppler." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2014. http://d-nb.info/1052586007/34.
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Bolisay, Linden De Venecia. "Molecularly imprinted polymers for the recognition of tobacco viruses." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7277.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Chemical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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MacIsaac, Julia Lynn. "Developmental consequences of imprinted transcription at the Mest locus." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44537.
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The Mest locus is regulated by genomic imprinting in mammals and only the paternally inherited allele is expressed. A targeted mutation at this locus revealed that it plays an important role in the regulation of embryonic growth and adult behavior. The Mest locus is located in a conserved imprinted domain on mouse chromosome 6 where it is thought to play a key role in the regulation of neighboring maternally expressed genes Copg2 and Klf14 since it contains the only potential imprinting center (IC) identified thus far in this domain, a differentially methylated region (DMR) methylated in oogenesis. Here we describe new larger isoforms of the Mest mRNA, referred to as MestXL, that are generated via alternative polyadenylation and transcribed more than 10kb into the adjacent antisense gene Copg2 exclusively in the developing central nervous system. The MestXL isoforms appear to regulate the allelic usage at Copg2, but not at Klf14, in embryonic neural tissues, as Copg2 is preferentially maternally expressed only in these tissues presumably due to transcriptional interference from MestXL on the paternal chromosome. Our results therefore establish the Mest DMR as an IC and propose a new mechanism to regulate allelic usage and imprinting at sense-antisense gene pairs in mammalian genomes, via tissue-specific alternative polyadenylation and transcriptional interference. Imprinted transcription at the Mest locus also produces a microRNA, miR-335, that acts to down-regulate target genes via binding to their 3’UTRs and ultimately repressing their translation. Here we show that production of miR-335 is imprinted and that its levels are reduced from the mutant MestKO allele. Additionally, we identify several candidate target genes of miR-335 by RNA-seq analysis on primary mouse fibroblasts that under-express miR-335. Our investigation of MestXL and miR-335, two unique alternative functions of the Mest locus, demonstrates that the Mest locus is involved in two types of RNA-mediated regulation and ultimately contributes to the understanding of genomic imprinting and microRNAs in mammalian biology.
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Davies, Matthew Paul. "The use of molecularly imprinted polymers in pharmaceutical analysis." Thesis, Queen Mary, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408545.
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Revill, Kate. "Characterisation of the Imprinted Gene Neuronatin in Pituitary Tumorigensis." Thesis, Keele University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502941.
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Baker, J. "Identifying imprinted genes on mouse chromosome 12 : novel approaches." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596277.
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The distal portion of mouse chromosome 12 (chr.12) has been shown to be imprinted through translocation studies, with both maternal and paternal duplications and deficiencies causing embryonic lethality. The region shares homology primarily with human chromosome 14. An imprinted disorder has been attributed to maternal duplication/paternal deficiency of human chromosome 14 commonly referred to as maternal uniparental disomy (mUPD14). mUPD14 results in short stature, premature puberty, development delay, small hands with hyperextensible joints and other minor anomalies. These pieces of evidence suggest that mouse chromosome 12 and human chromosome 14 harbour imprinted genes with important roles in development. This dissertation discusses two approaches to identifying imprinted genes on mouse chr.12 with particular attention being given to identifying genes in the highly conserved homologous domain. A cDNA screen was devised which was expected to enrich a d8.5 embryonic cDNA library for chromosome 12 specific transcripts. The aim of the screen was to isolate highly conserved, developmental regulated candidate genes mapping to chr.12, which could also be assayed for imprinting. Genes already described to some extent and known to map within the region of homology were also chosen and assayed for imprinting using two candidate screening approaches; SSCP and Northern blotting of UPD and normal RNA. Candidate genes assay for imprinting using mRNA from normal, mUPD12 and pUPD12 embryos identified two new imprinted genes, Gtl-2 and Dlk. SSCP analysis eliminated Tgfβ3, which was considered as a candidate. The cDNA screen showed depletion for cDNA that did not map to chr.12 and there may have been some level of enrichment for clones mapping to chr.12. The results of these studies are described in detail.
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Coar, Elizabeth Anne. "Mapping candidate control elements at the Gnas imprinted locus." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615171.
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Allen, Sarah Elizabeth. "The role of an imprinted microRNA in mouse development." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608248.
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Kirsch, Nicole. "Molecular recognition of poorly functionalised molecules with imprinted polymers." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325167.
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Le, Strat Loïc. "Imprinted polymers and templated cyclic peptides : a combinatorial approach." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274468.
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Ishida, M. "The role of imprinted genes in human fetal growth." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1348482/.
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Identifying the genes important for fetal growth will help to understand common, serious complications of pregnancy such as intrauterine growth restriction (IUGR). Of particular interest are imprinted genes, which show monoallelic, parent-of-origin specific expression. Genes that are paternally derived tend to enhance fetal growth whereas maternally expressed genes suppress growth. A significant correlation between lower birth weight and increased expression of maternally expressed, pleckstrin homology-like domain, family A, member 2 (PHLDA2) in term placenta, without loss of imprinting, had been reported previously. We have identified a novel copy number variant (CNV1) in the PHLDA2 promoter which reduced the promoter efficiency in a luciferase reporter gene assay. Meta-analysis of CNV1 genotype data obtained from three independent white European normal birth cohorts (total n = 9,433) showed that maternal inheritance of CNV1 resulted in a 93 g increase in birth weight (P = 0.01). Moreover, when the mother was homozygous for CNV1, the influence on birth weight was 155 g (P = 0.04), a similar magnitude to the reduction caused by maternal smoking. The expression levels of paternally expressed gene 3 (PEG3), delta-like 1 homolog (DLK1) and maternally expressed gene 3 (MEG3) measured by real-time PCR in >110 normal term placentas from a white European cohort did not show correlation with fetal birth size measurements, except for a trend of positive association observed for DLK1 expression and birth weight (P = 0.072). Paternal inheritance of the type 1 diabetes (T1D) protective G allele of rs941576 SNP located in the DLK1-MEG3 locus was shown to be associated with a 132 g (P = 0.011) and 0.5 cm (P = 0.011) reduction in birth weight and head circumference respectively. This newly described PHLDA2 promoter CNV and rs941576 SNP, alongside their expressions, may provide useful genetic biomarkers/indicators for predicting birth size.
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Tamboli, Vibha. "Detection of prostate cancer biomarker using molecularly imprinted polymers." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/103518/.
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Successful treatment of prostate cancer (PCa) depends on early diagnosis and screening, which currently relies on the measurement of serum prostate specific antigen (PSA) levels. The overarching aim of the project was to generate molecularly imprinted polymers for PCa biomarkers, with subsequent integration with a sensing platform to allow for rapid, point of care detection and monitoring. The initial work involved the use of simple PSA epitopes for epitope imprinting using conventional imprinting techniques. A four amino acid sequence from the Cterminus of PSA was imprinted with MAA, Aam and Urea monomers to obtain bulk imprinted polymers. Apparent Kd of 102 μM, 154 μM, 194 μM was obtained for MAA, AAm, Urea based bulk mini-MIPs respectively. Epitope imprinting was further developed using a surface imprinting approach, via electropolymersiation of dopamine to detect an epitopic sequence from pro-PSA. An improvement in Kd from bulk-imprinted polymers, with an apparent Kd of 2.9 μM was obtained with the surface electrochemical MIP sensor. However, both epitope imprinting technique lacked sensitivity to measure clinical relevant concentrations of PSA (nM range). As a consequence, a more sophisticated technique called hybrid imprinting was developed to build an electrochemical MIP sensor. Hybrid MIP imprinting utilised an aptamer with established affinity towards PSA to trap the aptamer-PSA complex into a surface grown electropolymer (polydopamine). The resulting aptamer lined polymer pockets exhibited high selectivity and affinity towards PSA (apparent Kd 0.3 nM). The apta-MIP sensor was also able to discriminate from a homologous protein (human Kallikrein 2) and was resilient to fouling from serum proteins. The apta-MIP sensor was further translated to a MOSFET device whereby successful detection of PSA at clinically relevant concentration was obtained in human plasma. Although good sensitivity and selectivity was obtained with the hybrid-MIP sensors, further research is required to understand the binding mechanism of the template to the MIP.