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Dissertations / Theses on the topic 'Fluorescence spectroscopy'

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Published: 4 June 2021

Last updated: 14 June 2025

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1

Nicovich, Philip R. "Widefield fluorescence correlation spectroscopy." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33849.

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Fluorescence correlation spectroscopy has become a standard technique for modern biophysics and single molecule spectroscopy research. Here is presented a novel widefield extension of the established single-point technique. Flow in microfluidic devices was used as a model system for microscopic motion and through widefield fluorescence correlation spectroscopy flow profiles were mapped in three dimensions. The technique presented is shown to be more tolerant to low signal strength, allowing image data with signal-to-noise values as low as 1.4 to produce accurate flow maps as well as utilizing dye-labeled single antibodies as flow tracers. With proper instrumentation flows along the axial direction can also be measured. Widefield fluorescence correlation spectroscopy has also been utilized to produce super-resolution confocal microscopic images relying on the single-molecule microsecond blinking dynamics of fluorescent silver clusters. A method for fluorescence modulation signal extraction as well as synthesis of several novel noble metal fluorophores is also presented.

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2

Summerfield, Stephen. "Near infrared fluorescence spectroscopy." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/10601.

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Fluorimetry in the very near infrared region ca. 600-1000nm is a new approach to photochemical analysis. The advantages include greatly reduced background fluorescence signals from important sample matrices (such as blood serum), reduced scattering, and reduced probability of sample decomposition. Also, the availability of low cost, efficient, stable and robust optical components (e.g. laser diodes and light emitting diodes), solid state detectors (e.g. single silicon photodiodes and diode arrays) and fibre optics, allows the construction of an inexpensive fluorimeter. In the near infrared region, there are some very bright fluorophores that can be adapted for use as fluorescent probes, labels for immunoassay, and as ion-pair agents. The advantageous performance of most types of fluorimetric analysis now undertaken In the ultraviolet and visible region of the spectrum may therefore be extended into the longer wavelength region. Excellent limits of detection are attainable, and some near infrared fluorophores show invaluable fluorescence probe properties, such as Nile Red. The most useful of the dye groups investigated were the phenoxazines and thiazines. Reactive derivatives of these dyes show great potential as fluorescent labels for Immunoassay. These dyes have also been used as probes due to their solvatochromism and sensitivity to pH.

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3

Dertinger, Thomas. "Two-Focus fluorescence correlation spectroscopy." Jülich : Forschungszentrum, Zentralbibliothek, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016575922&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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4

Olmstead, Jennifer Anne. "Fluorescence spectroscopy of mechanical pulps." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68232.

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Corrected steady-state fluorescence emission spectra of various mechanical pulps and celluloses were measured using an excitation wavelength of 320 nm. Regardless of its source, cellulose displayed a relatively high characteristic emission. The emission spectra of mechanical pulps were red-shifted with respect to that of cellulose, and peak shapes were influenced by the pulping process, by hydrogen peroxide bleaching and by monochromatic UV irradiation of the sheets. Changes in emission spectra due to bleaching or UV-irradiation occurred principally in the 370-440 and 500-550 nm regions, and were similar to changes in reflectance spectra reported in the literature. Fluorescence emission spectra of commercial lignins and lignin model compounds were blue-shifted with respect to mechanical pulps, even upon absorption of the fluorophores on solid substrates. Concentration and inner filter effects were evident in emission spectra of commercial lignins, at concentrations as low as 60 ppm. These results suggest that, to a first approximation, emission spectra of mechanical pulps may be interpreted as a decrease in emission of cellulose caused by light absorption by lignin; changes due to bleaching and irradiation may be attributed to changes in lignin absorption.

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5

Tajima, T. "Folding during ribosomal biosynthesis of yellow fluorescent protein : investigations by fluorescence spectroscopy and NMR spectroscopy." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1467146/.

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During biosynthesis on the ribosome, the nascent polypeptide chain emerges in a vectorial fashion, one amino acid at a time and it has its first opportunity to sample conformational space. Study of structural and molecular biology has shown that nascent chains (NC) can co-translationally acquire its native structure, however how an emerging NC forms the native conformation is a fundamental question in modern biology. Yellow fluorescent protein (YFP), a red shifted yellow emission variant of green fluorescent protein (GFP) that is consisted of 238 amino acid residues is highly distinct because of its fast maturation of fluorophore and its rapid folding kinetics. In addition, YFP has been extensively studied using X-ray crystallography, nuclear magnetic resonance (NMR), and biophysics, which make it an ideal system for examining protein folding on the ribosome. In this study, therefore, we created a series of ribosome-nascent chain complex (RNC) of YFP to simulate the progressive emergence of NC. We also developed an in vitro transcription translation system to generate isotopically-labelled RNCs for both biophysics and NMR spectroscopy. To complement the RNC study, we also created a co-translational folding mimetic using C-terminal truncations of isolated YFP to evaluate folding in vitro. Using these approaches, the co-translational folding of YFP was observed using both spectroscopies of fluorescence and NMR at a residue specific level. Here we demonstrate that native folding can take place very close to the ribosome in which YFP is separated by 19 amino acids from the ribosome’s peptidyl transferase centre (PTC), and that YFP can tolerate the absence of up to 14 amino acids from its C-terminus and still acquire a native fold.

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6

Brewster, Victoria Louise. "Investigating protein modifications using vibrational spectroscopy and fluorescence spectroscopy." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/investigating-protein-modifications-using-vibrational-spectroscopy-and-fluorescence-spectroscopy(32ff24c8-326a-41cf-a076-11e067376525).html.

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Protein based biopharmaceuticals are becoming increasingly popular therapeutic agents. Recent changes to the legislation governing stem cell technologies will allow many further developments in this field. Characterisation of these therapeutic proteins poses numerous analytical challenges. In this work we address several of the key characterisation problems; detecting glycosylation, monitoring conformational changes, and identifying contamination, using vibrational spectroscopy. Raman and infrared spectroscopies are ideal techniques for the in situ monitoring of bioprocesses as they are non-destructive, inexpensive, rapid and quantitative. We unequivocally demonstrate that Raman spectroscopy is capable of detecting glycosylation in three independent systems; ribonuclease (a model system), transferrin (a recombinant biopharmaceutical product), and GFP (a synthetically glycosylated system). Raman data, coupled with multivariate analysis, have allowed the discrimination of a glycoprotein and the equivalent protein, deglycosylated forms of the glycoprotein, and also different glycoforms of a glycoprotein. Further to this, through the use of PLSR, we have achieved quantification of glycosylation in a mixture of protein and glycoprotein. We have shown that the vibrational modes which are discriminatory in the monitoring of glycosylation are relatively consistent over the three systems investigated and that these bands always include vibrations assigned to structural changes in the protein, and sugar vibrations that are arising from the glycan component. The sensitivity of Raman bands arising from vibrations of the protein backbone to changes in conformation is evident throughout the work presented in this thesis. We used these vibrations, specifically in the amide I region, to monitor chemically induced protein unfolding. By comparing these results to fluorescence spectroscopy and other regions of the Raman spectrum we have shown that this new method provides improved sensitivity to small structural changes. Finally, FT-IR spectroscopy, in tandem with supervised machine learning methods, has been applied to the detection of protein based contaminants in biopharmaceutical products. We present a high throughput vibrational spectroscopic method which, when combined with appropriate chemometric modelling, is able to reliably classify pure proteins and proteins ‘spiked’ with a protein contaminant, in some cases at contaminant concentrations as low as 0.25%.

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7

Liao, Qiuhong. "Fluorescence Spectroscopy Prediction of Fish Freshness." Kyoto University, 2017. http://hdl.handle.net/2433/228242.

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8

Dolezal, Vit [Verfasser]. "Multifocus fluorescence correlation spectroscopy / Vit Dolezal." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2016. http://d-nb.info/1121535380/34.

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9

Gallagher, Joseph. "Adaptive optics for fluorescence correlation spectroscopy." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY054/document.

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Ce projet de recherche conjugue deux aspects complémentaires : le développement d’un montage de microscopie intégrant un système d'Optique Adaptative (OA) et l’étude de masses cancéreuses (Sphéroïdes Multicellulaires) sous pression mécanique.Ces deux axes seront mutuellement bénéfiques puisque l’implémentation de l’OA rendra possible l’imagerie et les mesures physiques au sein des sphéroïdes ; d’un autre côté, l’étude des sphéroïdes permettra de caractériser les aberrations induites par ce type d’échantillons et de mieux comprendre les exigences sur le système d’OA qu’imposent l’observation de ces échantillons ainsi que les limites de la microscopie optique dans les tissus biologiques<br>This research project combines two complementary aspects: the development of an assembly incorporating an Adaptive Optics microscope system and the study of cancerous masses (multicellular spheroids) under mechanical pressure.These two axes are mutually beneficial since the implementation of the adaptive optics will enable imaging and physical measurements in spheroids; On the other hand, the study of spheroids will characterize the aberrations induced by this type of samples and understand the requirements of the adaptive optics system imposed by the observation of these samples as well as the limits of optical microscopy in biological tissues

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10

Fenske, Roger William Peter. "Tunable supercontinuum source for fluorescence spectroscopy." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2745.

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This thesis describes the experimental investigations concerning the integration and optimisation of a supercontinuum source into a fluorescence lifetime spectrometer. [Fluorescence lifetime spectrometers based on Time Correlated Single Photon Counting (TCSPC) have long suffered from the lack of a compact, broadband excitation source. The source should ideally emit picosecond pulses with a repetition rate adjustable up to megahertz. Supercontinuum sources are an ideal candidate.] Various commercial supercontinuum sources were evaluated. Initial work was carried out on a source with a standard endlessly single-mode photonic crystal fibre (PCF) with a short wavelength limit of 450 nm, followed by later work with a source using high- PCF (a PCF with a large air filling fraction), that had an emission down to 400 nm, and a prototype source with a tapered fibre that had emission to ~320 nm. Key parameters including pulse width, pulse position and pulse height distribution were found to be very wavelength dependent, and their behaviour is explained by theory. The measured pulse widths of the supercontinuum sources were found to be typically ~100 ps, with longer durations found at the blue extreme of the spectra. Analysis of the data showed that this was due to the broadened pulses being a superposition of two pulse sequences with different dispersion characteristics. It was shown that, by taking account of the particular optical and temporal properties of a supercontinuum source, it was possible to make high quality fluorescence lifetime measurements of standard fluorophores such as fluorescein, anthrascene and erythrosine B. A novel device was constructed and evaluated for the wavelength separation of a supercontinuum source based on wedge interference filters. Initial prototypes of the device were able to measure the fluorescence emission spectra of common fluorophores and adequately separate a supercontinuum. Further iterations of the design, employing multiple filters, allowed for the construction of a device that included bandwidth control. The device allowed the transmission bandwidth to be tuned from ~6 nm to >50 nm with a transmission of >70 % for bandwidths >8 nm. The transmission figures achieved are better than any alternative form of wavelength separation, for example devices based on acousto-optic tunable filters (AOTFs) and diffraction gratings. A novel monochromator for fluorescence studies was also constructed using a wedge interference filter simultaneously with a diffraction grating. The design had improved performance compared to a single grating based monochromator in terms of stray light, with only a small drop in throughput and no change in instrument footprint. The stray light performance was found to be comparable to that of a double monochromator over the spectral range of the filter.

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11

O'Toole, Peter John. "Spectrin-lipid interactions : investigations by fluorescence spectroscopy and digital fluorescence microscopy." Thesis, University of Essex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242333.

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12

Hocht, Iris von der. "Fluorescence spectroscopy of recoverin function and conformation." Jülich Forschungszentrum, Zentralbibliothek, 2008. http://d-nb.info/1000288463/34.

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13

Walker, Melinda. "Laser induced fluorescence spectroscopy of aromatic systems." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282580.

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14

Brown, Alan Jeffrey. "Time resolved evanescent wave induced fluorescence spectroscopy." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/47790.

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15

O'Brien, Jonathan Paul 1969. "Acetylene--dispersed fluorescence spectroscopy and intramolecular dynamics." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43548.

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16

Green, Sarah A. "Applications of fluorescence spectroscopy to environmental chemistry." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13167.

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17

Petrášek, Zdeněk, Susan Derenko, and Petra Schwille. "Diffusion measured with scanning fluorescence correlation spectroscopy." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-191800.

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18

Gryte, Kristofer. "Analysis methods for single molecule fluorescence spectroscopy." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:148969c6-78aa-49c2-8f0e-2d5e5018fd98.

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This thesis describes signal analysis methods for single-molecule fluorescence data. The primary factor motivating method development is the need to distinguish single-molecule FRET fluctuations due to conformational dynamics from fluctuations due to distance-independent FRET changes. Single-molecule Förster resonance energy transfer (FRET) promises a distinct advantage compared to alternative biochemical methods in its potential to relate biomolecular structure to function. Standard measurements assume that the mean transfer efficiency between two fluorescent probes, a donor and an acceptor, corresponds to the mean donor-acceptor distance, thus providing structural information. Accordingly, measurement analysis assumes that mean transfer efficiency fluctuations entail mean donor-acceptor distance fluctuations. Detecting such fluctuations is important in resolving molecular dynamics, as molecular function often necessitates structural changes. A problem arises, however, in that factors other than donor-acceptor distance changes may induce mean transfer efficiency fluctuations. We refer to these factors as distance-independent FRET changes. We present analysis methods to detect distance-independent photophysical dynamics and to determine their correlation with distance-dependent FRET dynamics. First, we review a theory of photon statistics and show how we can use the theory to detect FRET fluctuations. Second, we extend the theory to alternating laser excitation (ALEx) measurements and demonstrate how fluorophore stoichiometry, a measure of fluorophore brightness, reports on distance-independent photophysical dynamics. Next, we provide a measure to determine the extent to which stoichiometry fluctuations account for FRET dynamics. Finally, we use a framework similar to the preceding along with recent advances in the theory of total internal reflection fluorescence (TIRF) microscopy FRET measurements to detect TIRF FRET fluctuations which occur on a timescale faster than the measurement temporal resolution. We validate our methods with simulations and demonstrate their utility in delineating RNA polymerase open complex conformational dynamics.

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19

Petrášek, Zdeněk, Susan Derenko, and Petra Schwille. "Diffusion measured with scanning fluorescence correlation spectroscopy." Diffusion fundamentals 11 (2009) 114, S. 1-2, 2009. https://ul.qucosa.de/id/qucosa%3A14088.

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20

Lin, Wumei. "Fluorescence spectroscopy of tissue : instrumentation and algorithms /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?BIEN%202003%20LIN.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 78-84). Also available in electronic version. Access restricted to campus users.

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21

Vega, Marienette Morales. "RAMAN AND FLUORESCENCE SPECTROSCOPY OF BIOMEDICAL NANOMATERIALS." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10900.

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2013/2014<br>Stabilized zirconia exhibits unsurpassed mechanical properties and biocompatibility, making it an indispensable ceramic material for biomedical implants. One of the most problematic features of stabilized zirconia has been its low-temperature degradation(LTD), which is associated to the observed transformation of its crystalline structure from tetragonal to monoclinic phase. The presence of monoclinic phases, therefore, is the red-flag for the impending catastrophic breakdown of mechanical properties. In this work, we establish characterization protocols to extend the sensitivity limit of conventional Raman spectroscopy for determination of extremely little amounts of monoclinic phase in zirconia implant prototypes. We accomplish this in two ways. First, we employ Raman spectroscopy and multivariate statistical analysis on a series of fully-dense and partially transformed Y-TZP zironia prototypes. Incipient t-m transformation is only revealed with high resolution spectral mapping and principal component analysis. The technique reveals the presence of islands of monoclinic phase that are otherwise not visible by simple observation and fitting of individual spectra. High resolution mapping likewise allows for probing homogenieties in the sample, which is a critical component in the development of implants. The second protocol utilizes surface-enhanced Raman spectroscopy (SERS) with colloidal gold nanostars as substrate. The nanostars used have localized surface plasmon resonance (LSPR) at 690 nm. Two spectral maps, on clean and on nanostars-covered surface, were obtained exactly at the same position using confocal Raman spectroscopy. Comparison of the two maps shows that there are more monoclinic phases detected in the nanostars-covered surface possibly due to the “lightning rod” effect in the nanostar tips. We report an unprecedented attempt on SERS on solid zirconia, which provides early evidence of the effectivity of the technique even on non-porous materials. With further improvement in sensitivity, SERS is a promising technique for the early detection of monoclinic phase in zirconia-based implants.<br>XXVII Ciclo<br>1978

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22

Drezek, Rebekah Anna. "The biophysical origins of cervical tissue fluorescence and reflectance spectra modeling, measurements, and clinical implications /." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3031044.

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23

Henderson, Julius Nathan. "Crystallographic and spectroscopic studies of photoswitching in fluorescent proteins /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1417810431&sid=5&Fmt=2&clientId=11238&RQT=309&VName=PQD.

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Thesis (Ph. D.)--University of Oregon, 2007.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 143-151). Also available for download via the World Wide Web; free to University of Oregon users.

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24

Makoui, Anali. "Transient fluorescence spectroscopy and laser induced fluorescence lifetimes of terbium doped dipicolinic acid." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002183.

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25

Wu, Yicong. "Autofluorescence spectroscopy of epithelial tissue /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20WU.

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26

Graf, Urs. "Characterization of molecules by time-resolved fluorescence spectroscopy /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10746.

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27

Hoeller, Matthias. "Advanced Fluorescence Fluctuation Spectroscopy with Pulsed Interleaved Excitation." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-128621.

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28

Cargill, Holly Beth. "Assaying protein import into mitochondria using fluorescence spectroscopy." Texas A&M University, 2003. http://hdl.handle.net/1969.1/3971.

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Most proteins residing in the mitochondrial matrix are synthesized in the cytosol and post-translationally imported into the mitochondrial matrix. The matrix-targeted preproteins traverse the outer mitochondrial membrane (OM) via the Translocase of the Outer Membrane (TOM) complex, and the inner mitochondrial membrane (IM) via the Translocase of the Inner Membrane 23 (TIM23) complex. A novel system was set up to examine the import of matrix-targeted preproteins into mitochondria using fluorescence spectroscopy. The fluorescent probe 6-(7-nitrobenz-2-oxa-1,3-diazol-4- yl)aminohexanoic acid (NBD) was site-specifically incorporated into different positions along the model matrix protein Su9-DHFR. The fluorescent-labeled polypeptides were either fully imported into isolated mitochondria or were arrested along the translocation pathway by the binding of methotrexate (MTX) to the DHFR moiety, creating NBDSu9- DHFRÂMTX import intermediates. The NBD-Su9-DHFR polypeptides were able to be fully imported into the mitochondrial matrix in the absence of MTX, and were inaccessible to externally-added iodide ion quenchers. Treatment of the mitochondria with the pore-forming antibiotic alamethicin allowed the iodide ion quenchers access to the matrix through pores in the inner membrane (IM). After Alamethicin treatment the fully-imported NBD-Su9-DHFR polypeptides were accessible to the externally-added iodide ions. The extent of collisional quenching of the NBD fluorophores by the iodide ions was measured as the Stern-Volmer quenching constant, Ksv. Ksv values were obtained for the NBD-Su9-DHFR polypeptides in the presence of MTX (import intermediates) or in the absence of MTX (fully-imported). The Ksv values for NBD-Su9- DHFR import intermediates were similar, despite the location of the NBD probe along the translocation pathway. These Ksv values were similar to those obtained for the fullyimported NBD-Su9-DHFR polypeptides (-MTX). The locations of the varying probe positions along the import pathway were addressed using chemical crosslinking of Su9- DHFR Cys mutants. The use of fluorescence spectroscopy, in association with chemical crosslinking, to analyze the mitochondrial protein import pathways will prove a useful tool to probe the environment of the nascent chain as it is crossing the import pathway (the TOM, TIM23 complexes).

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Kunnil, Joseph. "Identification Studies of Bacillus Spores Using Fluorescence Spectroscopy." Thesis, University of Canterbury. Physics and Astronomy, 2005. http://hdl.handle.net/10092/1311.

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Fluorescence spectroscopy was examined as a potential technique for identifying aerosol particles like bacterial spores. This technique was used for laboratory measurements on some common biological agent simulants. We have measured the intrinsic steady-state fluorescence emission spectra as a function of the excitation wavelength for several bacterial spores (washed and unwashed) in dry and aqueous suspensions at room temperature using excitation wavelengths from 200 to 600 nm. These measurements were compared to those of common, naturally occurring biological components like fungal spores and pollen and non spore samples like ovalbumin. The spectra of samples were combined into fluorescence profiles or fluorescence fingerprints. Different substrates were used for collection and detection of spores. Each bacterium produces a unique in vitro fluorescence profile when measured in dried and aqueous suspension and exhibits a strong maximum in its fluorescence emission spectrum near 330-340 nm. The fluorescence profiles were reproducible. The complexity of microorganisms made the interpretation of their spectral signature a difficult task. Principal components analysis (PCA) and cluster analysis were done as a data reduction technique for detection and identification from different backgrounds. PCA illustrates that linear combination of detected fluorescence intensities, which are present in different ratios in each of samples studied, can be used to discriminate biological agent simulants from other biological samples. The hydration effects, washing effects and the role of tryptophan on spore fluorescence were also investigated. The emission spectra of the dried spores showed a maximum near 330 nm, suggesting a hydrophobic environment for its tryptophan residues. The aqueous solution of tryptophan showed fluorescence shifted to 360 nm and in ethanol solution the maximum was shifted to 340 nm, suggesting a rather more polar average location of the tryptophan. To find the limit of detection we measured the quantum efficiency (QE) of a few samples. We concluded that spectroscopy techniques coupled with effective interpretation models are applicable to biological simulants agents. Index Heading: Bacteria; Spores; Identification; Fluorescence; Fluorescence Quantum Efficiency; Principal Components Analysis; Cluster Analysis.

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Liu, Jinjun. "Laser-induced fluorescence spectroscopy of the alkoxy radicals." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1169752930.

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Nadeau, Valerie J. "Fluorescence imaging and spectroscopy systems for cancer diagnostics." Thesis, University of Glasgow, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269513.

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32

Carter, James Andrew. "Lunar surface composition from X-ray fluorescence spectroscopy." Thesis, Aberystwyth University, 2013. http://hdl.handle.net/2160/bda827d4-7dc7-46d5-b92a-ff18dc37d7a0.

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What is the composition of the surface of the Moon? This investigation aims to map the abundances of some of the main rock-forming elements over the surface of the Moon. Accurately determining the magnesium, aluminium and silicon abundances would have great advantages when performing geological and geochemical studies of the Earth-Moon system, helping to answer questions about its formation and evolution. This thesis uses data from the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument on Chandryanaan-1, a high quality instrument that nevertheless flew in one of the lowest solar minima on record. Modelling software is described and written to predict the performance of an orbiting X-ray spectrometer (XRS) under different conditions, a vital task for premission planning and post-mission analysis. Surface factors, such as compositional modification by crater rays and the enhancement of X-ray returns by volatile sodium, are modelled to assess their effects on XRS signals. The C1XS data is processed using a data pipeline, and inspected and analysed. After some post-pipeline processing maps are produced, first elemental line intensity ratio maps, and then absolute elemental abundance maps. These are produced for the southern nearside lunar highlands, and are then compared to previous datasets and ground truth.

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Bieroza, Magdalena Zofia. "Characterising water treatment works performance using fluorescence spectroscopy." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/651/.

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Organic matter (OM) in drinking water treatment is a common impediment responsible for increased coagulant and disinfectant dosages, formation of carcinogenic disinfection-by products (DBPs), and microbial re-growth in distribution system. The inherent heterogeneity of OM implies the utilization of advanced analytical techniques for its characterisation and assessment of removal efficiency. Here, the application of simple fluorescence excitation-emission (EEM) spectroscopy to OM characterisation in drinking water treatment was presented. Monthly raw and clarified water samples were obtained for 16 UK surface water treatment works. Fluorescence EEM spectroscopy was used for the assessment of total organic carbon (TOC) removal and OM characterisation. Fluorescence peak C intensity was found to be a sensitive and reliable measure of OM content and hence an indicator of DBPs presence. Fluorescence peak C emission wavelength and peak T intensity (reflecting the degree of hydrophobicity and the microbial fraction respectively) were found to characterise the OM; the impact of both on TOC removal efficiency was apparent. OM fluorescence properties were shown to predict TOC removal, and identify spatial and temporal variations. The simplicity, sensitivity, speed of analysis and low cost, combined with potential for incorporation into on-line monitoring systems, mean that fluorescence spectroscopy offers distinct advantages over other THM precursors characterisation techniques.

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Aknine, Nathan. "Nouvelles sondes fluorescentes pour la bioimagerie des structures lipidiques cellulaires." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAF035.

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Ce projet de doctorat vise la conception de sondes fluorescentes innovantes, pour une meilleure visualisation et compréhension des structures lipidiques cellulaires par bioimagerie. Ainsi, trois familles de nouvelles sondes fluorescentes ont été générées dans le cadre de cette thèse, visant à cibler et éclairer différentes localisations cellulaires. Premièrement, le ciblage covalent de la membrane plasmique par une stratégie nommée MemGraft, a permis de développer de nouveaux outils pour le marquage et la fonctionnalisation de la surface cellulaire. Ces sondes permettent un marquage robuste et efficace, une imagerie long-terme, un suivi de plusieurs populations par étiquetage fluorescent multiplexé, mais également la manipulation du comportement des cellules, sans porter atteinte à leur phénotype par ingénierie de la surface cellulaire. Ensuite, des sondes sensibles à leur environnement, basées sur un groupement trifluoroacétyle a permis l’imagerie de la polarité et de l’hétérogénéité des gouttelettes lipidiques intracellulaires. Cette stratégie a également rendu possible l’imagerie en super-résolution de la polarité de membranes intracellulaires. Finalement, nous avons exploré des stratégies de ciblage des organites par des sondes solvatochromes, en particulier la mitochondrie, mais également le réticulum endoplasmique, l’appareil de Golgi, ou encore les lysosomes, fournissant des informations sur l’organisation lipidique de leur membrane. En combinant chimie organique, chimie biologique, et microscopies de fluorescence, ces nouveaux outils ont été conçus et démontrent leur potentiel pour améliorer notre compréhension des structures et des processus cellulaires<br>This PhD project is focused on the design of innovative fluorescent probes for better visualization and understanding of cellular lipidic structures by bioimaging. Three families of novel fluorescent probes have been generated in this thesis, targeting and shedding light on different cellular localizations. First, the lipiddirected covalent targeting of the plasma membrane was introduced and enabled the development of new fluorescent tools for the labeling and functionalization of the cell surface. These probes allowed robust longterm cell imaging and barcoding as well as cell manipulation and cell surface engineering. Secondly, environment-sensitive probes based on a trifluoroacetyl electron acceptor were obtained, enabling the imaging of the polarity and heterogeneity of intracellular lipid droplets. This strategy also yielded probes for super-resolution imaging of the polarity in intracellular membranes. Finally, we explored the strategy for targeting organelles with solvatochromic probes, in particular mitochondria, but also the endoplasmic reticulum, Golgi apparatus and lysosomes, providing insights on the lipid organization of their membranes through polarity imaging. Combining organic chemistry, chemical biology, and fluorescence microscopy, these new advanced molecular tools have been obtained and showed their potential to improve our understanding of cellular structures and processes

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35

Brookner, Carrie Kazinoff. "Biological basis of cervical tissue autofluorescence /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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36

Álvarez, Ruiz Jesús. "Synchrotron radiation induced fluorescence spectroscopy of gas phase molecules." Doctoral thesis, KTH, Physics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-43.

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<p>A new experimental set-up for gas phase fluorescence studies using synchrotron radiation has been designed and constructed to perform simultaneously total and dispersed fluorescence measurements. </p><p>Neutral photodissociation of CO has been investigated after excitation with 19-26 eV photons. Fluorescence from 3p 3P, 3p 3S and 3p 1D excited states in carbon was recorded and interpreted by ab initio calculations. The population and dissociation of states belonging to the C and D Rydberg series in CO seem to explain the production of the observed triplet states but not the 3p 1D state. </p><p>Neutral photodissociation of NO is reported in the 17-26 eV energy range. No known molecular states can account for the collected data. New information regarding the precursor states of the observed neutral dissociation is provided by ab initio calculations. </p><p>Autoionization of superexcited states in molecular nitrogen is evidenced by strong deviations of the Franck-Condon ratio in the fluorescence of the N2+ B state. Ab initio calculations predict the existence of autoionizing-excited states that may account for some of the observed structures in the 20-46 eV energy range. </p><p>Selective molecular fluorescence from the npó1Óu+ and npð 1Ðu (n=3-7) Rydberg levels to the E,F 1Óg+ state in H2 was recorded and rotationally analyzed. Vibrational levels of the E,F 1Óg+ state (vEF =0,1,3,6-10) are determined. The predissociation of npð 1Ð+ levels is observed in agreement with the literature. </p><p>Fragmentation of SF6 was investigated after excitation with 25–80 eV photons. Dispersed fluorescence measurements reveal the emission of S, S+, F and F+ excited atoms. These fragments are produced after single, double and triple excitations as well as direct ionizations and shake-ups in SF6. </p><p>Photoabsorption and fluorescence yield have been measured in SF5CF3 using 10-30eV photons. The photoabsorption spectrum can be explained in terms of its similarities to those of the SF6 and CF4 molecules. The dispersed and un-dispersed fluorescence resemble those of the CF3X family. Several features suggest the migration of an F atom across the S-C bond that fragments the molecule producing excited CF4. </p><p>Doubly excited states of H2 have been investigated in the range of 26-60 eV by monitoring Balmer á emission. The experimental data show the already known emission correlated with the fragmentation of the Q1 and Q2 states, and new features which could be attributed to dissociative photoionization and higher lying doubly excited states Qn (n>2) of the hydrogen molecule</p>

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Persson, Gustav. "Time-Varying Excitation in Fluorescence Spectroscopy for Biological Applications." Licentiate thesis, Stockholm : Fysik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4399.

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38

Bramble, Simon Kenneth. "Laser induced fluorescence spectroscopy of radicals, ions and complexes." Thesis, Queen Mary, University of London, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289028.

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39

Tojira, Opas. "Single-molecule fluorescence spectroscopy : Implementation of alternating-laser excitation." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531514.

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40

Shin, Yongdae. "Single molecule fluorescence spectroscopy of ClpXP-mediated substrate degradation." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50562.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.<br>Includes bibliographical references (leaves 67-71).<br>Energy-dependent proteases, such as ClpXP, are responsible for the regulated destruction of proteins in prokaryotes and organelles of eukaryotes. AAA+ ATPases in these proteases recognize protein substrates and power their mechanical denaturation and subsequent translocation into a sequestered degradation chamber where polypeptide cleavage occurs. Here, we present the single molecule fluorescence assay for probing the interaction between the ClpXP enzyme and its substrates. A covalently crosslinked ClpX hexamer maintain functionally stable form at the low concentration of single molecule level. Surface passivation through polyethylene glycol (PEG) remove unwanted nonspecific binding of substrates, providing specific immobilization of ClpXP protease on the glass surface illuminated by total internal reflection fluorescence (TIRF). Cy3-labeled engineered substrates containing nondegradable GFP in the prescence of ATP[gamma]S form stable pre-engaged substrate-ClpXP complexes where the whole substrate degradation pathway, from unfolding to egress of degraded products, can be monitored without competing with dissociation or additional background characteristic of free labeled substrate in solution. We directly observe some terminal processes that are encountered by ClpXP at the end of substrate degradation process. It is also shown that GFP tail domain stably bind to the ClpX in the presence of ATP[gamma]S and even in the absence of ATP hydrolysis. With the developement of single molecule assay for AAA+ protease, we can expand our knowledge on the mechanism of this crucial motor protein family.<br>by Yongdae Shin.<br>S.M.

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41

Qiu, Weihong. "Ultrafast Protein Hydration Dynamics Investigated by Femtosecond Fluorescence Spectroscopy." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1222202233.

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42

Williams, Gareth Owen Scott. "Photochemical kinetics and fluorescence spectroscopy in photonic crystal fibres." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/11747.

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This thesis describes work carried out to demonstrate the use of photonic crystal fibres for the study of photochemistry reaction kinetics and fluorescence spectroscopy. Photonic crystal fibre allows the guidance of light, in a well-defined mode, over long path lengths. When the fibre’s microstructure is filled with a sample solution this, therefore, provides a greatly increased measurement path length and greater light-sample interaction than is possible in conventional spectroscopic systems, leading to enhanced sensitivity whilst greatly reducing the required sample volumes. The use of photonic crystal fibre as a micro reaction chamber for carrying out photochemical reactions and the study of their kinetics was achieved through monitoring the photoisomerisation of two azobenzene-based dyes, Disperse Red 1 and Disperse Orange 1, using real-time UV/Vis absorption spectroscopy. Both the 488 nm excitation laser and the broadband light source for the measurements were co-coupled through the fibre, giving perfect overlap of both with the sample. The fibre used for the measurements was a hollow core kagomé-type fibre with a core diameter of 19μm, giving a sample volume of 2.8 nL cm-1. The 30 cm path-length of the fibre allowed the use of sample concentrations down to 5×10-6 M, over an order of magnitude lower than in a conventional 1cm cuvette, with a sample volume of 90 nl in the core, a reduction of five orders of magnitude over conventional measurements. The kinetics of the photoisomerisation from the trans to the cis isomers of the dyes and the thermally driven cis-to-trans isomerisation could be tracked on the ms timescale, using a grating spectrometer which recorded the entire absorption spectrum of the dye. The data were numerically fitted using a custom model to take into account the properties of the fibre system. This led to the calculation of rate constants for the isomerisation processes in good agreement with those previously measured for these dye systems in bulk solution. Furthermore, the measurement of the dyes in pentane, in which they are highly insoluble, could be achieved due to the low concentrations that could be used; such measurements have not previously been reported. For the study of photonic crystal fibre as a system for the excitation and collection of fluorescence, two types of fibre were used; the same kagomé hollow-core fibre used for the photochemistry absorption measurements and a suspended-core “Mercedes” fibre. This allowed for the excitation of fluorophores in two contrasting environments. In the kagomé fibre fluorophores in bulk solution are excited whilst, in the Mercedes fibre, only fluorophores either on or in close proximity to the silica core interact with the evanescent field of the excitation light. The Fluorescein fluorophore was used initially to measure the detection limits in both fibre types and limits of 2x10-11 M in the kagomé and 10-9 M in the Mercedes fibre were obtained. This equates to 106 molecules in the kagomé fibre, which displays the lower detection limit due to greater light-sample interaction. Two-photon excitation of the Fluorescein fluorophore was then carried out using a mode-locked Ti-Sapphire laser as an excitation source, demonstrating the ability of the fibre system to sustain two-photon excitation of a long (30 cm) path length. The two-photon measurements showed remarkable detection sensitivity allowing detection of fluorescence from 10-9 M solutions of Fluorescein, showing the potential of using PCF for two-photon based experiments which are of particular interest in fields such as photodynamic therapy. A further study was carried out, using the two fibre types, for measurement of the fluorescence lifetime of the Rhodamine B fluorophore. Unperturbed lifetimes could be measured in the fibres showing no interference from the fibre. The measurements confirmed, in reference to known lifetime values, that in the kagomé fibre the excited fluorophores are in the bulk solution with only a minor influence from surface effects, whilst in the Mercedes fibre all of the excited molecules experience interaction with the surface of the silica core. This, therefore, gives a method of locating the fluorophores with respect to the fibre surface and the ability to choose between measurement of bulk solution and long path-length evanescent field-induced fluorescence.

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43

Kastrup, Lars. "Fluorescence depletion by stimulated emission in single-molecule spectroscopy." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11513777.

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44

Shi, Jianxin. "Identifying conformational changes in mouse acetylcholinesterase by fluorescence spectroscopy /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3070995.

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45

Hasegawa, Makoto. "Micro-spectroscopy and anti-Stokes fluorescence for photosynthesis research." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142404.

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46

De, Mello Lebre Marques Vareiro Margarida. "Antigen-antibody interactions measurements using surface plasmon fluorescence spectroscopy." Thesis, University of Bath, 2006. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428371.

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47

Han, Hongling. "Investigation of Properties of Polyamido Amine (PAMAM) Dendrimers by Flourescence Spectroscopy." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/HanH2004.pdf.

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48

Gould, Travis John. "Nanoscale Imaging and Spectroscopy of Membrane Organization." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/GouldTJ2009.pdf.

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Worthing, Philip Thomas. "Molecular fluorescence from microcavities." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302668.

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Paprocki, Eric Daniel. "Characterization of long pathlength capillary waveguides for evanescent fluorescence characterization." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-08272007-155204/.

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