Дисертації з теми "Fluorescence imaging systems"
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1
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.
Повний текст джерела
2
Robinson, Tom. "The application of multi-dimensional fluorescence imaging to microfluidic systems." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9285.
Повний текст джерелаАнотація:
This thesis describes the application of multidimensional fluorescence imaging to microfluidic systems. The work focuses on time- and polarisation-resolved fluorescence microscopy to extract information from microchannel environments. The methods are applied to polymerase chain reaction (PCR) and a DNA repair enzyme, uracil DNA glycosylase (UDG). The fluorescence lifetimes Rhodamine B are calibrated over a thermal gradient using time correlated single photon counting. The dye is then introduced in solution into a novel microfluidic PCR device. Fluorescence lifetime imaging microscopy (FLIM) is then performed, and using the calibration curve, the temperature distributions are accurately determined. The device is subsequently optimised for efficient DNA amplification. A line-scanning FLIM microscope is used to characterise a rapid microfluidic mixer via a fluorescence quenching experiment. Fluorescein and sodium iodide are mixed in a continuous flow format and imaged in 3-D. The spatial distributions of the fluorescence lifetimes are converted to the concentrations of sodium iodide to quantify mixing. Computational fluid dynamic (CFD) simulations are validated by comparison to the quantitative concentrations obtained experimentally. The binding reaction between UDG and a hexachlorofluorescein (HEX) labelled DNA strand is characterised spectrally. As well as an increase in fluorescence polarisation anisotropy, a 700 ps increase in the fluorescence lifetime is measured. Confocal microscopy shows the same spectral properties when the reaction is performed in both simple and rapid microfluidic mixers. In the latter experiment, a concentration series allows the determination of kinetics, which agree with conventional stopped-flow data. A two-colour two-photon (2c2p) FLIM microscope is developed and applied to the UDG-DNA system. An oligonucleotide containing 2-aminopurine, a reporter of DNA base flipping, and HEX is mixed with UDG in a microfluidic Y-mixer. The 2c2p excitation allows FLIM of both fluorophores and hence detection of binding and base flipping. Comparison to CFD with known kinetic rate constants confirms the experimental observations.
3
Fernando, Nilmi T. "Novel Near-Infrared Cyanine Dyes for Fluorescence Imaging in Biological Systems." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/chemistry_diss/57.
Повний текст джерелаАнотація:
Heptamethine cyanine dyes are attractive compounds for imaging purposes in biomedical applications because of their chemical and photophysical properties exhibited in the near-infrared region. A series of meso amino-substituted heptamethine cyanine dyes with indolenine, benz[e]indolenine and benz[c,d]indolenine heterocyclic moieties were synthesized and their spectral properties including fluorescence quntum yield were investigated in ethanol and ethanol/water mixture. Upon substitution with amines, the absorption maxima of the dyes shifted to the lower wavelength region (~600 nm), showed larger Stokes shifts and stronger fluorescence which can be attributed to an excited state intramolecular charge transfer (ICT). High quantum yields were observed for primary amine derivatives and lower quantum yields were observed for secondary amine derivatives. Fluorescence quantum yields are greater for dyes with 3H-indolenine terminal moieties than for dyes with benz[e]indolenine end groups. Benz[c,d]indolenine based heptamethine cyanine dyes exhibited the lowest quantum yield due to aggregation in solution. In general, the benz[e]indolenine hepatemethine cyanines showed high Stokes shifts compared to indolenine dyes. For the meso-chloro dyes, the absorption maxima for the dyes shifted bathochromically in the order of indolenine, benz[e]indolenine and benz[c,d]indolenine.
4
Vogt, Juergen. "Conception, design and assembly of a high speed, high dynamic range imaging system for fluorescence microscopy." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 96 p, 2007. http://proquest.umi.com/pqdweb?did=1338919451&sid=18&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Повний текст джерелаАнотація:
Thesis (M.S.E.C.E.)--University of Delaware, 2007.Principal faculty advisors: Fouad Kiamilev and Robert F. Rogers, Dept. of Electrical and Computer Engineering. Includes bibliographical references.
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Rose, Cornelia [Verfasser], and Achim [Akademischer Betreuer] Göpferich. "Particulate systems for fluorescence imaging and drug delivery / Cornelia Rose. Betreuer: Achim Göpferich." Regensburg : Universitätsbibliothek Regensburg, 2010. http://d-nb.info/1023312115/34.
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6
Concia, Massimo. "Fluorescence labeled PEI-based gene delivery systems for near infrared imaging in nude mice." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-113095.
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Dubaj, Vladimir, and n/a. "Novel optical fluorescence imaging probe for the investigation of biological function at the microscopic level." Swinburne University of Technology, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20060905.084615.
Повний текст джерелаАнотація:
Existing optic fibre-bundle based imaging probes have been successfully used to image
biological signals from tissue in direct contact with the probe tip (Hirano et al. 1996).
These fibre-bundle probe systems employed conventional fluorescence microscopy and
thus lacked spatial filtering or a scanned light source, two features used by laser
scanning confocal microscopes (LSCMs) to improve signal quality. Improving the
methods of imaging tissue in its natural state, deep in-vivo and at cellular resolution is
an ever-present goal in biological research. Within this study, a novel (580 μm
diameter) optic fibre-bundle direct-contact imaging probe, employing a LSCM, was
developed to allow for improved imaging of deep biological tissue in-vivo. The new
LSCM/probe system possessed a spatial resolution of 10 μm, and a temporal resolution
of 1 msec. The LSCM/probe system was compared to a previously used direct-contact
probe system that employed a conventional fluorescence microscope. Quantitative and
qualitative data indicated that the LSCM/probe system possessed superior image
contrast and quality. Furthermore, the LSCM/probe system was approximately 16 times
more effective at filtering unwanted contaminating light from regions below the
imaging plane (z-axis). The unique LSCM/probe system was applied to an exploratory
investigation of calcium activity of both glial and neuronal cells within the whisker
portion of the rat primary somatosensory cortex in-vivo. Fluorescence signals of 106
cells were recorded from 12 female Sprague Dawley rats aged between 7-8 weeks.
Fluo-3(AM) fluorophore based calcium fluctuations that coincided with 10 - 14 Hz
sinusoidal stimulation of rat whiskers for 0.5-1 second were observed in 8.5% of cells (9
of 106). Both increases and decreases in calcium levels that coincided with whisker
stimulation were observed. Of the 8.5 % of cells, 2.8% (3 cells) were categorized as
glial and 5.7% (6 cells) as neuronal, based on temporal characteristics of the observed
activity. The remaining cells (97 of 106) displayed sufficient calcium-based intensity
but no fluctuations that coincided with an applied stimulus. This was partially attributed
to electronic noise inherent in the prototype system obscuring potential very weak cell
signals. The results indicate that the novel LSCM/probe system is an advancement over
previously used systems that employed direct-contact imaging probes. The miniature
nature of the probe allows for insertion into soft tissue, like a hypodermic needle, and
provides access to a range of depths with minimal invasiveness. Furthermore, when
combined with selected dyes, the system allows for imaging of numerous forms of
activity at cellular resolution.
8
Adair, Kenneth Valloyd. "Diffusive, reactive and orientational dynamics of molecular systems using molecular Fourier imaging correlation spectroscopy /." view abstract or download file of text, 2006. http://proquest.umi.com/pqdweb?did=1251854551&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Oregon, 2006.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 103-108). Also available for download via the World Wide Web; free to University of Oregon users.
9
Ogden, Melinda Anne. "Two-photon total internal reflection microscopy for imaging live cells with high background fluorescence." Thesis, Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/34786.
Повний текст джерелаАнотація:
Fluorescence microscopy allows for spatial and temporal resolution of systems which are inherently fluorescent or which can be selectively labeled with fluorescent molecules. Temporal resolution is crucial for imaging real time processes in living samples. A common problem in fluorescence microscopy of biological samples is autofluorescence, fluorescence inherent to the system, which interferes with detection of fluorescence of interest by decreasing the signal to noise ratio.
Two current methods for improved imaging against autofluorescence are two-photon excitation and total internal reflection microscopy. Two-photon excitation occurs when two longer wavelength photons are absorbed quasi-simultaneously by a single fluorophore. For this to take place there must be a photon density on the order of 1030 photons/(cm2)(s), which is achieved through use of a femtosecond pulsed laser and a high magnification microscope objective. Two-photon excitation then only occurs at the focal spot, significantly reducing the focal volume and therefore background autofluorescence.
The second method, total internal reflection, is based on evanescent wave excitation, which decreases exponentially in intensity away from the imaging surface. This allows for excitation of a thin (~200 nm) slice of a sample. Since only a narrow region of interest is excited, an optical slice can be imaged, decreasing excitation of out-of-focus autofluorescence, and increasing the signal to noise ratio.
By coupling total internal reflection with two-photon excitation, an entire cell can be imaged while still maintaining the use of lower energy photons to irradiate the sample and achieve two-photon excitation along the length traveled by the evanescent wave. This system allows for more sensitive detection of fluorescence of interest from biological systems as a result of a significant decrease in excitation volume and therefore a decrease in autofluorescence signal. In the two-photon total internal reflection microscopy setup detailed in this work, an excitation area of 20 μm by 30 μm is achieved, and used to image FITC-stained actin filaments in BS-C-1 cells
10
Graham, Emmelyn M. "The application of fluorescence lifetime imaging microscopy to quantitatively map mixing and temperature in microfluidic systems." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/2432.
Повний текст джерелаАнотація:
The technique of Fluorescence Lifetime Imaging Microscopy (FLIM) has been employed to quantitatively and spatially map the fluid composition and temperature within microfluidic systems. A molecular probe with a solvent-sensitive fluorescence lifetime has been exploited to investigate and map the diffusional mixing of fluid streams under laminar flow conditions within a microfluidic device. Using FLIM, the fluid composition is mapped with high quantification and spatial resolution to assess the extent of mixing. This technique was extended to quantitatively evaluate the mixing efficiency of a range of commercial microfluidic mixers employing various mixing strategies, including the use of obstacles fabricated within the channels. A fluorescently labelled polymer has been investigated as a new probe for mapping temperature within microfluidic devices using FLIM. Time Correlated Single Photon Counting (TCSPC) measurements showed that the average fluorescence lifetime displayed by an aqueous solution of the polymer depended strongly on temperature, increasing from 3 ns to 13.5 ns between 23 and 38 oC. This effect was exploited using FLIM to provide high spatial resolution temperature mapping with sub-degree temperature resolution within microfluidic devices. A temperature-sensitive, water-soluble derivative of the rhodamine B fluorophore, effective over a wide dynamic temperature range (25 to 91 oC) has been used to map the temperature distribution during the mixing of fluid streams of different temperatures within a microchannel. In addition, this probe was employed to quantify the fluid temperature in a prototype microfluidic system for DNA amplification. FLIM has been demonstrated to provide a superior approach to the imaging within microfluidic systems over other commonly used techniques, such as fluorescence intensity and colourimetric imaging.
11
Kujala, Naresh Gandhi Yu Ping. "Frequency domain fluorescent molecular tomography and molecular probes for small animal imaging." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/7021.
Повний текст джерелаАнотація:
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Ping Yu. Vita. Includes bibliographical references.
12
Manhat, Beth Ann. "Understanding the Emission from Semiconductor Nanoparticles." PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/465.
Повний текст джерелаАнотація:
This dissertation describes the synthesis and characterization of fluorescent semiconductor nanoparticles (NPs) in order to optimize their biomedical utility for imaging and sensing applications. While both direct and indirect bandgap semiconductor NPs have been studied, control over their emission properties vary. Quantum confinement (QC), which primarily controls the emission wavelength of nanosized semiconductors, dictates that as the size of semiconductor NPs decrease, the magnitude of the bandgap increases, resulting in changes in the observed emission wavelength: smaller NPs have a larger bandgap, and thus a bluer emission. However, surface, interfacial, or shell defects can act as non-radiative or radiative recombination sites for excitons formed within the NP; the latter results in emission competition with the bandgap transition, as described Chapters 1 and 2. Because the emission wavelengths of direct bandgap semiconductor NPs correlate with size according to the expectations of QC, and are stable in aqueous environments with high quantum efficiencies (quantum yield, QY), current research focuses on their potential biomedical applications. Chapter 3 describes red-emitting CdSe/ZnS quantum dots (QDs) that exhibit a concentration-dependent decrease in fluorescence intensity in response to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). A mechanistic study was performed to understand a 5-HT-dependent decrease in QD emission and calibration curves relating QD intensity loss to 5-HT concentration in ensemble and single QD studies were generated. Unfortunately, the known toxicity of CdSe-based QDs has generated interest in more benign semiconductor NPs to replace these QDs in biological applications, while maintaining the same degree of control over the emission color and QY. Bulk indirect bandgap semiconductors, such as Si, have low efficiency inter-band transitions, and Si NPs are known to contain radiative defects that can alter the emission wavelength from QC-based size expectations; these competitive emission pathways must be controlled in order for Si NPs to be successfully used in biological applications. In general, synthetic methods that gives precise control over both the particle size and surface termination are needed in order to produce emission controlled Si NPs. Relative to groups II and VI QDs, synthetic routes to prepare Si NPs are few in numbers, and the size vs. defect emission events are difficult to assign. Not only do these assignments vary amongst reports, but they also vary with particle size, solvent, sample age, and identities of the surface ligands. Si NPs have been prepared through two synthetic routes using the Zintl salt, sodium silicide (NaSi) and ammonium bromide (NH4Br) as precursors. Chapter 4 describes the synthesis performed in the solvent N,N,-dimethylformamide (DMF). This reaction produces blue-emitting Si NPs (5.02 ± 1.21 nm) that bear partial hydride surface termination. However, it was determined that the solvent was able to interact with the Si NP surface, and prevent subsequent functionalization. This observation was used advantageously, and Chapter 5 describes a one-pot Zintl salt metathesis of Si NPs (3.9 + 9.8 nm) performed in a bi-functional (amine or carboxylic acid) solvent ligand, where the observations indicated that the solvent ligands coordinate to the Si NP. The emission maxima of the Si NPs prepared from the Zintl salt metathesis exhibited a dependence on the excitation energy, and is indicative of emission that is influenced by QC, which likely originates from deeply oxide embedded 1-2 nm crystalline cores. The Si NPs prepared from the one-pot Zintl salt metathesis were exposed to metals salt ions of varying reduction potentials to determine the band edges by what will or will not be reduced (Chapter 6). By monitoring the emission intensity of the Si NPs, in addition to the UV-Vis of the metal ions, the band edge of Si NPs may be determined. The value of the band edge may lend insight into the origin of Si NP emission. To utilize fluorescent Si NPs for biological applications, red emission is strongly preferred. Unfortunately, when preparing aqueous Si NPs, red emission usually changes to blue, likely from the oxidation of the Si NP surface. Therefore, the red emission needs to be efficiently protected from surface oxidants. Because both increased chain lengths and steric modalities have been found to protect the emission properties of Si NPs, red-emitting, ester-functionalized Si NPs (5.51+1.35 nm) with varying chain lengths and ester termination moieties were prepared to determine the best method of preserving the observed red emission in the presence of potential alcoholic oxidants. By determining the best was to protect Si NPs emission, the red-emission from Si NPs may be preserved for biological applications.
13
DIMAS, FIRMANDA AL RIZA. "Potato surface defect detection using machine vision systems based on spectral reflection and fluorescence characteristics in the UV-NIR region." Kyoto University, 2019. http://hdl.handle.net/2433/244556.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第22075号
農博第2367号
新制||農||1072(附属図書館)
学位論文||R1||N5229(農学部図書室)
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 近藤 直, 准教授 小川 雄一, 教授 清水 浩
学位規則第4条第1項該当
14
Merz, Simon Frederik [Verfasser], and Matthias [Akademischer Betreuer] Gunzer. "Mesoscopic whole organ imaging using light sheet fluorescence microscopy : from experimental systems to clinical application / Simon Frederik Merz ; Betreuer: Matthias Gunzer." Duisburg, 2021. http://d-nb.info/1236502027/34.
Повний текст джерела
15
Fantoni, Frédéric. "Méthodes d'illumination et de détection innovantes pour l'amélioration du contraste et de la résolution en imagerie moléculaire de fluorescence en rétrodiffusion." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU034/document.
Повний текст джерелаАнотація:
Depuis quelques années, les techniques d'imagerie de fluorescence font l'objet d'une attention particulière, celles-ci permettant d'étudier de manière non invasive un nombre important de processus cellulaires. En particulier, les techniques de fluorescence en rétrodiffusion (FRI pour Fluorescence Reflectance Imaging) présentent plusieurs avantages en termes de facilité de mise en oeuvre, de rapidité et de coût, mais elles sont aussi sujettes à des limites fortes : la pénétration des tissus reste relativement faible (quelques millimètres seulement), et il est impossible d'avoir une information quantitative du fait de la diffusion des photons. L'objectif de cette thèse a été de réduire les effets des signaux parasites afin d'améliorer les performances de la FRI aussi bien au niveau du contraste que de la résolution. Pour ce faire nous avons décidé d'utiliser de nouvelles techniques d'illumination et de détection. Contrairement aux systèmes classiques qui utilisent une illumination et une détection large champ, nous balayons l'objet d'étude avec une ligne laser, des images étant acquises à chaque position de la ligne. On a alors accès à une pile d'images contenant un nombre d'informations bien plus important que dans le cas classique. Trois axes ont été suivis pour l'exploitation de ces informations. Les méthodes développées ont été testées en simulation avec le logiciel NIRFAST et un algorithme de Monte-Carlo mais aussi expérimentalement. Les validations expérimentales ont été réalisées sur fantômes optiques et en in vivo sur petit animal en les comparant à une illumination uniforme plus classique. En améliorant à la fois le contraste et la résolution, ces différentes méthodes nous permettent d'obtenir de l'information exploitable plus loin en profondeur en réduisant les effets néfastes des signaux parasites et de la diffusionIntraoperative fluorescence imaging in reflectance geometry is an attractive imaging modality to noninvasively monitor fluorescence-targeted tumors. However, in some situations, this kind of imaging suffers from a lack of depth penetration and a poor resolution due to the diffusive nature of photons in tissue. The objective of the thesis was to tackle these limitations. Rather than using a wide-field illumination like usual systems, the technique developed relies on the scanning of the medium with a laser line illumination and the acquisition of images at each position of excitation. Several detection schemes are proposed to take advantage of the stack of images acquired to enhance the resolution and the contrast of the final image. These detection techniques were tested both in simulation with the NIRFAST software and a Monte-Carlo algorithm and experimentally. The experimental validation was performed on tissue-like phantoms and in vivo with a preliminary testing. The results are compared to those obtained with a classical wide-field illumination. As they enhance both the contrast and the resolution, these methods allow us to image deeper targets by reducing the negative effects of parasite signals and diffusion
16
Richards, Christopher I. "Dynamic dark state depletion." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31831.
Повний текст джерелаАнотація:
Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2010.Committee Chair: Dickson, Robert; Committee Member: Fahrni, Christoph; Committee Member: Payne, Christine; Committee Member: Petty, Jeff; Committee Member: Srinivasarao, Mohan. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Schädlich, Andreas Verfasser], Karsten [Akademischer Betreuer] [Mäder, Achim [Akademischer Betreuer] Göpferich, and Jörg [Akademischer Betreuer] Kreßler. "Pre‐clinical in vivo studies of parenteral drug delivery systems using non‐invasive multispectral fluorescence imaging : [kumulative Dissertation] / Andreas Schädlich. Betreuer: Karsten Mäder ; Achim Göpferich ; Jörg Kreßler." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2013. http://d-nb.info/1045194824/34.
Повний текст джерела
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Huisman, Maximiliaan. "Vision Beyond Optics: Standardization, Evaluation and Innovation for Fluorescence Microscopy in Life Sciences." eScholarship@UMMS, 2019. https://escholarship.umassmed.edu/gsbs_diss/1017.
Повний текст джерелаАнотація:
Fluorescence microscopy is an essential tool in biomedical sciences that allows specific molecules to be visualized in the complex and crowded environment of cells. The continuous introduction of new imaging techniques makes microscopes more powerful and versatile, but there is more than meets the eye. In addition to develop- ing new methods, we can work towards getting the most out of existing data and technologies. By harnessing unused potential, this work aims to increase the richness, reliability, and power of fluorescence microscopy data in three key ways: through standardization, evaluation and innovation.
A universal standard makes it easier to assess, compare and analyze imaging data – from the level of a single laboratory to the broader life sciences community. We propose a data-standard for fluorescence microscopy that can increase the confidence in experimental results, facilitate the exchange of data, and maximize compatibility with current and future data analysis techniques.
Cutting-edge imaging technologies often rely on sophisticated hardware and multi-layered algorithms for reconstruction and analysis. Consequently, the trustworthiness of new methods can be difficult to assess. To evaluate the reliability and limitations of complex methods, quantitative analyses – such as the one present here for the 3D SPEED method – are paramount.
The limited resolution of optical microscopes prevents direct observation of macro- molecules like DNA and RNA. We present a multi-color, achromatic, cryogenic fluorescence microscope that has the potential to produce multi-color images with sub-nanometer precision. This innovation would move fluorescence imaging beyond the limitations of optics and into the world of molecular resolution.
19
Somoza, Eduardo A. Jr. "UTILIZATION OF FLUORESCENCE MOLECULAR IMAGING TO OPTIMIZE RADIONUCLIDE IMAGING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1338904705.
Повний текст джерела
20
Agarwal, Abhiruchi. "Nanocarrier mediated therapies for the gliomas of the brain." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39468.
Повний текст джерелаАнотація:
Existing methods of treating glioma are not effective for eradicating the disease. Therefore, new and innovative methods of treatment alone or in combination with existing therapies are necessary. Delivery of therapeutic agents through delivery carriers such as liposomes diminishes the harmful effects of the agent in healthy tissues and allows increased accumulation in the tumor. In addition, targeted chemotherapy using liposomes provides the opportunity for further increase in drug accumulation in tumor. However, the current targeting strategies suffer accelerated plasma clearance and are not advantageous in improving efficacy. The search for new tumor targets, novel ligands, new strategies for targeting, and particle stabilization will advance our ability to improve delivery at the tumor level while decreasing toxicity to normal tissues.
The global objective of this thesis was to improve the status of current liposomal therapy to achieve higher efficacy in tumors. Here, we show a novel mechanism to increase targeting to tumor while uncompromising on the long circulation of stealth liposomes. Long circulation is essential for passive accumulation of the nanocarriers due to EPR effect, in order to see benefits of targeting. Using phage display technique, a variety of tumor specific peptides were identified for use as targeting moieties. One potential advantage of the approach proposed here is the rapid identification of patient tumor specific peptide that evades the RES. This could lead to the development of a nanocarrier system with high avidity and selectivity for tumors. Therefore, tumor accumulation of the targeted formulations will be higher than that of non‐targeted liposomes due to increased drug retention at the tumor site and uncompromised blood residence time.In addition, it has been shown that the distribution of nanocarriers, spatially within the tumor, is limited that might further hinder the distribution of the encapsulated drug, thereby limiting efficacy. It is necessary to release the drug from within the nanocarrier to promote increased efficacy. Here, we were able to address the problem of drug diffusion within the tumor interstitium using a combination therapy employing a remotely triggered thermosensitive liposomal chemotherapeutic. We fabricated a thermosensitive liposomal nanocarrier that maintained its stability at physiological temperature to minimize toxicity to healthy cells. We, then, showed a remote triggering mechanism mediated by gold nanorods heated via NIR can help in achieving precise control over the desired site for drug release. These strategies enabled increased drug availability at the tumor site and contributed to tumor retardation. Additionally, we show that the synergistic therapy employing gold nanorods and thermosensitive liposomes may have great potential to be translated to the clinic.
21
Wang, Thomas D. (Thomas Duen-Shyr). "Fluorescence endoscopic imaging system for detection of colonic adenomas." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/8972.
Повний текст джерелаАнотація:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Whitaker College of Health Sciences and Technology, 1996.Includes bibliographical references (p. [137]-144).
Background/Aims: Autofluorescence spectra have been collected from colonic mucosa with optical fiber contact probes. This technique was found to be sensitive to the biochemical and microarchitectural differences between normal and pre-malignant tissue. It is desired to extend this method to wide area surveillance using endoscopically-collected fluorescence images. Methods: An analytic model was developed to determine the number of photons collected endoscopically in terms of system parameters. This model was used to design a prototype fluorescence imaging instrument. Excitation light at 3 51 and 364 nm was delivered through an optical fiber at a power of 300 mW. Fluorescence images over the spectral bandwidth from 400 to 700 nm were collected from colonic mucosa in 33 ms frames . . fluorescence images were collected in vitro from colectomy specimens from patients with familial adenomatous polyposis and in vivo from patients undergoing routine colonoscopy. Each raw image was corrected for differences in distance and instrument light collection efficiency by normalizing to a spatially averaged image. Intensity thresholding was then used to identify diseased regions of mucosa. Results: For the in vitro studies, a sensitivity of 90% and a specificity of 92% were achieved with the threshold set to 75% of the average normal intensity. The average fluorescence intensity from normal mucosa was found to be greater than that from the adenomas by a factor of 2.2 ± 0.6. For the in vivo images, a sensitivity of 86% for adenomas and a specificity of 100% for hyperplastic polyps were achieved at a threshold of 75%. On average, the ratio between the fluorescence intensity of normal mucosa and that from adenomas was 2.0 ± 0.6 and that from hyperplastics was 1.1 ±. 0.2. The diseased regions on fluorescence were best localized when the colonoscope was directed at normal incidence to the mucosa. At higher angles there were greater effects of artifacts from shadows. Conclusions: Autofluorescence images of colonic mucosa can be collected endoscopically in vitro and in vivo. With image processing techniques, dysplasia can be detected and localized with high sensitivity and specificity. These results demonstrate the potential of this method to direct biopsy site selection.
by Thomas D. Wang.
Ph.D.
22
Kulyk, Olena. "Light-tissue interactions for developing portable and wearable optoelectronic devices for sensing of tissue condition, diagnostics and treatment in photodynamic therapy (PDT)." Thesis, University of St Andrews, 2016. http://hdl.handle.net/10023/13199.
Повний текст джерелаАнотація:
This thesis presents the development and in-vivo applications of wearable and portable devices for the investigation of light interaction with tissue involved in Photodynamic therapy (PDT) and during contraction of muscles. A hand-held device and a clinical method were developed for time course in-vivo imaging of the fluorescence of the photosensitizer Protoporphyrin IX (PpIX) in healthy and diseased skin with the aim to guide improvement of PDT protocols. The device was used in a small clinical study on 11 healthy volunteers and 13 patients diagnosed with non-melanoma skin cancer (NMSC). Two types of PpIX precursors were administered: Ameluz gel and Metvix® cream. The fluorescence was imaged with a 10 minute time step over three hours which was the recommended metabolism time before commencing PDT treatment at Ninewells Hospital, Dundee. The fluorescence time course was calculated by integrating the areas with the highest intensity. The fluorescence continued to grow in all subjects during the three hours. The time course varied between individuals. There was no statistical significance between either healthy volunteers or patients in Ameluz vs Metvix® groups; nor was there statistical difference between the three lesions groups (Actinic keratosis (AK) Ameluz vs AK Metvix® vs Basal cell carcinoma (BCC) Metvix®). The p-value was larger than 0.05 in a two sample t-test with unequal variances for all the groups. However, there was strong body site dependence between the head & neck compared to the lower leg & feet, or the trunk & hands body site groups (p-value < 0.01). One of the possible explanations for this was temperature and vasculature variation in skin at different body sites: the temperature is higher and the vasculature structure is denser at the head and the neck compared to the lower leg or the trunk. The temperature was not measured during the study. So in order to support this hypothesis, typical skin temperatures at the lesion sites were taken from the IR thermal images of healthy skin available in literature. PpIX fluorescence had a positive correlation to temperature. If this hypothesis is true, it will be highly important to PDT treatment. Increasing the temperature could speed up the metabolism and reduce the waiting time before starting the treatment; ambient temperature should be taken into account for daylight PDT; cooling air as pain management should be administered with caution. Potential improvements for wearable PDT light sources were investigated by modelling light transport in skin for the current LED-based Ambulight PDT device, a commercial OLED for future devices and a directional OLED developed in the group. The optical models were implemented in commercial optical software (with intrinsic Monte Carlo ray tracing and Henyey-Greenstein scattering approximation) which was validated on diffuse reflectance and transmittance measurements using in-house made tissue phantoms. The modelling was applied to investigate the benefits from diffusive and forward scattering properties of skin on light transmission in treatment light sources. 1 mm thick skin can only compensate approximately 10% of non-uniform irradiance. It means that uniform illumination is crucial for the treatment light sources. Forward scattering in skin showed a 10% improved light transmission from a collimated emission compared to a wide angle Lambertian emission. However, depth-dependent transmission measurements of directional vs Lambertian emission from organic light emitting films (a nano-imprinted grating was fabricated to provide directional emission in one of the films), collimated vs diffused HeNe laser light through fresh porcine skin did not show the expected improvement. This could be explained by skin roughness which was previously found to change the optical properties and may also affect light coupling. The modelling was applied to guide an optical design of another wearable device – a muscle contraction sensor. Muscle is fibrous and because of that scatters light differently in different directions. The sensor detects the change in backscattered light in parallel and perpendicular directions with respect to muscle fibres. The sensor was implemented on a wearable bandage on fully flexible substrate with flexible OLED and organic photodiodes. The major advantages of organic optoelectronic sensing compared to conventional electromyography (EMG) sensors are the ability to distinguish two types of contractions (isotonic and isometric), insensitivity to electromagnetic interference and the absence of an immune response due to non-invasive electrode-free sensing. Optical modelling was performed to understand the operation of the sensor. A 3D anisotropic optical model of scattering in muscle was created by geometrical manipulations with the standard Henyey-Greenstein scattering volumes. The penetration depth from the Super Yellow OLED was found to be 20-25 mm; the optimal separation between the source and the detector was found to be 20 mm. This distance provided a still detectable signal along with the best discrimination between the two backscatterings. When a 2 mm thick layer of skin and a 2 mm thick layer of adipose tissue were added to the model, the signal was hugely diffused. The discrimination between the two backscatterings decreased by three orders of magnitude, the penetration depth in muscle was reduced, and the intensity of the signal dropped down but was still detectable. With 5 mm thick adipose tissue and 2 mm thick skin the signal was too diffused and interacted with very shallow layers of muscle which approached the limits of the optical sensing of muscle activity.
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Sexton, Kristian. "System and Methodology for Receptor-Level Fluorescence Imaging during Surgery." Thesis, Dartmouth College, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3634175.
Повний текст джерелаАнотація:
Fluorescence molecular imaging will have an important clinical impact in the area of guided oncology surgery, where emerging technologies are poised to provide the surgeon with real-time molecular information to guide resection, using targeted molecular probes. The development of advanced surgical systems has gone hand in hand with probe development, and both aspects are analyzed in this work. A pulsed-light fluorescence guided surgical (FGS) system has been introduced to enable video rate visible light molecular imaging under normal room light conditions. The concepts behind this system design are presented and performance is compared with a commercial system in both phantom and in vivo animal studies using PpIX fluorescence.
The second critical advance in the emergence of these technologies has been the development of targeted near infrared (NIR) probes. A small, engineered three-helix protein was analyzed for imaging of glioma tumors. The blood brain barrier affects delivery of probes and the superior delivery of a smaller targeted protein (anti-EGFR Affibody) as compared to a full sized antibody is shown using a murine model, ex vivo tissue slices and a commercial imaging system. This small targeted probe is examined further for its possible application in FGS using the pulsed light imaging system. A concentration sensitivity analysis to determine the lower bounds on concentration needed for effective imaging is performed with this culminating analysis carried out in a murine orthotopic glioma tumor model.
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Souza, Geovane Grossi Araújo de. "X-Ray fluorescence imaging system based on Thick-GEM detectors." Universidade de São Paulo, 2019. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21032019-233121/.
Повний текст джерелаАнотація:
GEMs (Gas Electron Multiplier) and Thick-GEMs (Thick-Gas Electron Multiplier) are MPGDs (Micropattern Gas Detector) that make part of the new generation of gaseous detectors, allowing high counting rates, low cost when compared to solid state detectors, high radiation hardness and gain when using multiple structures. Besides that, the handling and maintenance of these detectors is relatively simple, being versatile to detect different types of radiation. Therefore, these detectors are an effective alternative to build imaging systems with large sensitive area. This work consists in the study and characterization of a set of gaseous detectors, more specifically the Thick-GEMs produced in the High Energy Physics and Instrumentation Center at IFUSP, which were tested showing promising results in terms of gain, energy resolution and operational stability. However, due to the low signal-to-noise ratio of the Thick-GEMs, the X-ray fluorescence imaging system was mounted using GEMs. During this work the necessary software tools for image processing and reconstruction were developed as a parallel study in computational simulations to better understand the operation of gaseous detectors. X-ray fluorescence techniques are essential in areas such as medicine and the study of historical and cultural heritage since they are non-invasive and non-destructive. Techniques to check the authenticity of masterpieces are required and museums are gradually becoming more interested in the Physics and instrumentation needed to characterize their patrimony.Os GEMs (Gas Electron Multiplier) e Thick-GEMs (Thick-Gas Electron Multiplier) são estruturas do tipo MPGD (Micropattern Gas Detector) que fazem parte da nova geração de detectores de radiação a gás e permitem altas taxas de contagens, baixo custo quando comparados com os detectores de estado sólido, uma elevada resistência à radiação e ganhos elevados, quando utilizadas estruturas múltiplas para multiplicação. Além disso, o manuseio e manutenção desses detectores é relativamente simples, sendo versáteis em relação à montagem podendo detectar diferentes tipos de radiação. Sendo assim, a utilização desses detectores é uma alternativa eficiente para montar um sistema de imagem com grande área sensível. Este trabalho consiste no estudo e caracterização de um conjunto de detectores gasosos, mais especificamente os Thick-GEMs produzidos pelo grupo de Física de altas energias e Instrumentação do IFUSP, que foram testados para serem empregados em um sistema de imagem de fluorescência de raios-X. Os Thick-GEMs testados apresentaram resultados promissores em termos de ganho, resolução em energia e estabilidade operacional. No entanto, devido à baixa relação sinal-ruído, um sistema de imagem de fluorescência de raios-X foi montado utilizando GEMs. Durante o trabalho as ferramentas de software necessárias para processamento e reconstrução de imagens foram desenvolvidas, assim como um estudo paralelo de simulações computacionais para entender melhor o funcionamento de detectores gasosos. Técnicas como o imageamento por fluorescência de raios-X são de suma importância pois são consideradas não invasivas e não destrutivas. Sua utilização tem uma importância imprescindível nas áreas da medicina e na análise de patrimônios histórico e cultural. Atualmente, a verificação e validação de autenticidade de obras é um requisito obrigatório e alguns museus começam a se interessar cada vez mais em áreas da Física e da instrumentação necessária para caracterizar o seu patrimônio.
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Salman, Aljebur Ali, and Yu Zholudov. "System for two photon imaging of biosamples." Thesis, Харків, ХНУРЕ, 2019. http://openarchive.nure.ua/handle/document/8366.
Повний текст джерелаАнотація:
The work is devoted to development of scanning imaging system for bioobjects based on two-photon fluorescence of nanoparticles. It is based on the use of nanomaterials in imagining systems and some of nonfluorescent imaging applications and labeling with fluorescent nanoparticles. The basics of two photon fluorescence, its imaging application, properties of nanoparticles and biological tissues, used for our system development were analyzed. Based on this analysis we developed the general scheme of the system for scanning imaging of bioobjects using CdTe quantum dot labels and method of two-photon fluorescence.
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Venius, Jonas. "Fluorescence spectroscopy and imaging studies of functionally different human heart tissues." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130124_081732-30187.
Повний текст джерелаАнотація:
Rhythmical contraction of the heart is controlled by the cardiac conduction system (CCS). However, this highly important system visually could not be distinguished from the surrounding heart tissues – myocardium (MC) and connective tissue (CT); therefore during surgical procedures CCS could be damaged. The reliable method for CCS identification either in vivo or ex vivo does not exist therefore there is a definite need for developing a CCS imaging method.
Fluorescence spectroscopy studies of cardiac tissues revealed, that most distinct spectral differences between CCS and the surrounding tissues were observed in 400 nm – 550 nm region under excitation from 330 nm – 380 nm region. The visualization method, based on the intensity ratios calculated for two excitation wavelengths, has been established. The calculated ratio R = I(330)/I(380) is different for CCS, CT and MC tissues, therefore the method may be used for identification of CCS.
Time resolved fluorescence spectroscopy revealed no significant difference in composition and lifetimes between CCS and MC. On the other hand, the lifetimes and the relative spectral composition of CT differed significantly from those of CCS.
Reflection confocal microscopy allows visualizing MC, CT, Purkinje cells and CCS bundles because of different reflection properties of tissue components and their specific distribution inside the tissue.
The results of in vivo performed procedure revealed, that the distribution of fluorescence intensities... [to full text]Tvarkingą širdies darbą užtikrina širdies laidžioji sistema (ŠLS). Ją pažeidus sutrinka širdies darbas. Pažeidimo rizika atsiranda operacijos metu, kadangi ŠLS yra raumeninės kilmės audinys ir vizualiai neatskiriamas nuo aplinkinių audinių. ŠLS pažeidimo galima būtų išvengti, jei būtų žinomas tikslus ŠLS išsidėstymas arba egzistuotų ŠLS vaizdinimo metodika. Deja, bet atskirų ŠLS dalių tikslus išsidėstymas vis dar tikslinamas, o patologijų atvejais apskritai nėra žinomas. ŠLS vaizdinimo metodikos, tinkančios in vivo taikymams, taipogi nėra. Atlikus širdies audinių tyrimus nustoviąja fluorescencine spektroskopija nustatyti charakteringi intensyvumų skirtumai. Remiantis šiais skirtumais sukurta ŠLS atskyrimo metodika, paremta intensyvumų santykių skaičiavimu. Suskaičiuota vertė R = I(330)/I(380) yra skirtinga ŠLS, miokardui (MK) ir jungiamąjam audiniui (JA).Tokia metodika yra nejautri tyrimo sąlygoms ir gali būti naudojama ŠLS nustatymui. Ištyrus širdies audinius laikinės skyros spektroskopija nustatyta, kad ŠLS ir MK fluorescencijos gyvavimo trukmė bei santykinė sudėtis reikšmingai nesiskiria, tuo tarpu JA ir ŠLS tiek fluorescencijos gyvavimo trukmės, tiek santykinė komponentinė sudėtis yra skirtinga. Ištyrus širdies audinius konfokaliniu atspindžio mikroskopu nustatyta, jog dėl skirtingų šviesą atspindinčių komponentų bei skirtingo jų išsidėstymo galima identifikuoti MK, JA, Purkinje ląsteles ir ŠLS pluoštus. Atlikus tyrimus in vivo nustatyta, jog operacijos metu... [toliau žr. visą tekstą]
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Steyer, Grant. "Imaging of Cardiovascular Cellular Therapeutics with a Cryo-imaging System." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1264865581.
Повний текст джерела
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Choi, Sungmoon. "Fluorescent noble metal nanodots for biological applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37195.
Повний текст джерелаАнотація:
Commercial organic dyes are widely used for cellular staining due to their small size, high brightness, and chemical functionality. However, their blinking and photobleaching are not ideal for studying dynamics inside live cells. An improvement over organics and much larger quantum dots, silver nanodots (Ag NDs) exhibit low cytotoxicity and excellent brightness and photostability, while retaining small size. We have utilized ssDNA hairpin structures to encapsulate Ag NDs with excellent spectral purity, high concentration, and good chemical and photophysical stability in a variety of biological media. Multi-color staining of fixed and live cells has been achieved, suggesting the promise of Ag NDs as good fluorophores for intracellular imaging. The great brightness and photostability of Ag nanodots indicate that they might be outstanding imaging agents for in vivo studies when encapsulated in delivery vehicles. In addition, Ag NDs can be optically modulated, resulting in increased sensitivity within high backgrounds. These good characteristics are combined with delivery vehicles such as PLGA and nanogels. After encapsulation, Ag nanodots still retain their good photophysical properties and modulation. It might be useful for in vivo applications in the near future
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Chen, Bing. "Dynamic Multispectral Imaging System with Spectral Zooming Capability and Its Applications." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/452.
Повний текст джерелаАнотація:
The main focus of this dissertation is to develop a multispectral imaging system with spectral zooming capability and also successfully demonstrate its promising medical applications through combining this technique with microscope system. The realization of the multispectral imaging method in this dissertation is based on the 4-f spatial filtering principle. When a collimated light is dispersed by the grating, there exists a clear linear distribution spectral line or spectrum at the Fourier plane of the Fourier transform lens group base on the Abbe imaging theory and optics Fourier Transform principle. The optical images, not the collimated light, are applied into this setup and the spectrum distribution still keeps linear relationship with the spatial positions at Fourier plane, even through there exists additional spectral crosstalk or overlap. The spatial filter or dynamic electrical filters used at the Fourier plane will facilitate randomly access the desired spectral waveband and agilely adjust the passband width. It offers the multispectral imaging functionality with spectral zooming capability. The system is flexible and efficiency. A dual-channel spectral imaging system based on the multispectral imaging method and acousto-optical tunable filter (AOTF) is proposed in the dissertation. The multispectral imaging method and the AOTF will form spate imaging channels and the two spectral channels work together to enhance the system efficiency. The AOTF retro reflection design is explored in the dissertation and experimental results demonstrate this design could effectively improve the spectral resolution of the passband. Moreover, a field lens is introduced into the multispectral imaging system to enhance the field of view of the system detection range. The application of field lens also improves the system spectral resolution, image quality and minimizes the system size. This spectral imaging system can be used for many applications. The compact prototype multispectral imaging system has been built and many outdoor remote spectral imaging tests have been performed. The spectral imaging design has also been successfully applied into microscope imaging. The prototype multispectral microscopy system shows excellent capability for normal optical detection of medical specimen and fluorescent emission imaging/diagnosis. Experiment results have demonstrated this design could realize both spectral zoom and optical zoom at the same time. This design facilitates fast spectral waveband adjustment as well as increasing speed, flexibility, and reduced cost.
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Rasmussen, John C. "Development of a radiative transport based, fluorescence-enhanced, frequency-domain small animal imaging system." Thesis, [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1067.
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Crane, Bryan Lee 1976. "DNA mutation detection via fluorescence imaging in a spatial thermal gradient, capillary electrophoresis system." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/88874.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001."February 2001."
Includes bibliographical references (leaves 122-126).
by Bryan Lee Crane.
S.M.
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Roy, Debashish. "3D Cryo-Imaging System For Whole Mouse." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1259006676.
Повний текст джерела
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Uthoff, Ross. "Design of a Smartphone-Camera-based Fluorescence Imaging System for the Detection of Oral Cancer." Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/593619.
Повний текст джерелаАнотація:
Shown is the design of the Smartphone Oral Cancer Detection System (SOCeeDS). The SOCeeDS attaches to a smartphone and utilizes its embedded imaging optics and sensors to capture images of the oral cavity to detect oral cancer. Violet illumination sources excite the oral tissues to induce fluorescence. Images are captured with the smartphone’s onboard camera. Areas where the tissues of the oral cavity are darkened signify an absence of fluorescence signal, indicating breakdown in tissue structure brought by precancerous or cancerous conditions. With this data the patient can seek further testing and diagnosis as needed. Proliferation of this device will allow communities with limited access to healthcare professionals a tool to detect cancer in its early stages, increasing the likelihood of cancer reversal.
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Godavarty, Anuradha. "Fluorescence enhanced optical tomography on breast phantoms with measurements using a gain modulated intensified CCD imaging system." Texas A&M University, 2003. http://hdl.handle.net/1969.1/2184.
Повний текст джерелаАнотація:
Fluorescence-enhanced optical imaging using near-infrared (NIR) light developed for in-vivo molecular targeting and reporting of cancer provides promising opportunities for diagnostic imaging. However, prior to the administration of unproven contrast agents, the benefits of fluorescence-enhanced optical imaging must be assessed in feasibility phantom studies.
A novel intensified charge-coupled device (ICCD) imaging system has been developed to perform 3-D fluorescence tomographic imaging in the frequency-domain using near-infrared contrast agents. This study is unique since it (i) employs a large tissue-mimicking phantom (~1087 cc), which is shaped and sized to resemble a female breast and part of the extended chest wall region, and (ii) enables rapid data acquisition in the frequency-domain by using a gain-modulated ICCD camera. Diagnostic 3-D fluorescence-enhanced optical tomography is demonstrated using 0.5-1 cc single and multiple targets contrasted from their surrounding by ??M concentrations of Indocyanine green (ICG) in the breast-shaped phantom (10 cm diameter), under varying conditions of target-to-background absorption contrast ratios (1:0 and 100:1) and target depths (up to 3 cm deep). Boundary surface fluorescence measurements of referenced amplitude and phase shift were used along with the coupled diffusion equation of light propagation in order to perform 3-D image reconstructions using the approximate extended Kalman filter (AEKF) algorithm, and hence differentiate the target from the background based on fluorescent optical contrast.
Detection of single and multiple targets is demonstrated under various conditions of target depths (up to 2 cm deep), absorption optical contrast ratio (1:0 and 100:1), target volumes (0.5-1 cc), and multiple targets (up to three 0.5 cc targets). The feasibility of 3-D image reconstructions from simultaneous multiple point excitation sources are presented. Preliminary lifetime imaging studies with 1:2 and 2:1 optical contrast in fluorescence lifetime of the contrast agents is also demonstrated. The specificity of the optical imager is further assessed from homogeneous phantom studies containing no fluorescently contrasted targets.
While nuclear imaging currently provides clinical diagnostic opportunities using radioactive tracers, molecular targeting of tumors using non-ionizing NIR contrast agents tomographically imaged using the frequency-domain ICCD imaging system could possibly become a new method of diagnostic imaging.
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Chang, Jean H. "Design and fabrication of a precision alignment system and package for a two-photon fluorescence imaging device." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45776.
Повний текст джерелаАнотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaf 24).
A compact, lightweight precision alignment system and package for an endomicroscope was designed and fabricated. The endomicroscope will consist of a millimeter-scale fiber resonator and a two-axis silicon optical bench. The alignment system provided five degrees of freedom and was designed to align the fiber resonator with the microchip with a resolution of one micron. The alignment system consisted of a system of ultra-fine screws and two compliant mechanisms to deamplify the motion of the screw. Finite element analysis was performed to optimize the compliant mechanisms for the desired transmission ratio of 20:1. The alignment system was fabricated and testing showed that the transmission ratios were lower than expected (18.6 for one compliant mechanism and 2.68 for the other). Testing also showed that the alignment system met the functional requirements for the ranges of motion.
by Jean H. Chang.
S.B.
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Makhlouf, Houssine. "Integrated Multi-Spectral Fluorescence Confocal Microendoscope and Spectral-Domain Optical Coherence Tomography Imaging System for Tissue Screening." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/202761.
Повний текст джерелаАнотація:
A multi-modality imaging system intended for clinical utilization has been developed. It is constructed around an existing fiber-bundle-based fluorescence confocal microendoscope. Additional imaging modalities have been implemented to expand the capabilities of the system and improve the accuracy of disease diagnosis. A multi-spectral mode of operation is one such modality. It acquires fluorescence images of a biological sample across a spectral range of sensitivity and explores the collected image data at any specified wavelength within that spectral range. Cellular structures can be differentiated according to their spectral properties. The relative distribution and concentration of the different cellular structures can potentially provide useful pathologic information about the imaged tissue. A spectral-domain optical coherence tomography (SDOCT) modality is another imaging technique integrated into the system. It provides a cross-sectional imaging perspective that is comparable to microscopic images obtained from histology slides and complementary to the en face view obtained from the confocal imaging modality. The imaging system uses a parallelized architecture (fiber-optic bundle, line of illumination) to increase the data acquisition speed. A one-dimensional scan is needed to capture 2D images in the confocal modality or a 3D data cube (two spatial dimensions and one spectral dimension) in the multi-spectral mode of operation. No scanning is required to capture a 2D OCT image. The fiber-bundle design is particularly critical for the SDOCT modality as it paves the way to novel fast endoscopic OCT imaging that has a high potential for translation into the clinic. The integrated multi-modality imaging system can readily switch between different imaging modalities, which will make it a powerful diagnostic tool in a clinical environment. It can provide valuable information about the morphology, the spectral and biochemical features, and the macroscopic architecture of tissue. It is believed that fast and accurate disease diagnosis can potentially be made based on all these characteristics.
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Martin, Phillip A., and Phillip A. Martin. "Investigation of the Feasibility of an Optical Imaging System for the Application of In Vivo Flow Cytometry." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/621197.
Повний текст джерелаАнотація:
This thesis investigates the feasibility of employing an optical imaging system for the application of in vivo flow cytometry for detecting rare circulating tumor cells (CTCs) in vasculature. This investigation presented used three optical imaging configurations: a Nikon Eclipse E600 fluorescence microscope with a PIXIS 2048B CCD camera; a Nikon Eclipse E600 fluorescence microscope with a ThorLabs DCC 3240N CMOS camera; and a custom built confocal microendoscope with a ThorLabs DCC 3240N CMOS camera. These systems were employed to gain insight as to what signal to noise ratios and sensitivities are required to sufficiently detect fluorescently labeled cancer cells. This work presents general concepts of fluorescence and confocal microscopy, the experimental setups employed, and experimental measurements and results obtained. The experimental measurements involved the following: the simulation of flow cytometry by imaging green fluorescent microspheres, with a fluorescence excitation range of 505-515 nm and a diameter of 15µm, in a square crit tube moving on a translational stage, and imaging a selection of cells that included MCF10A breast cells (non-cancerous), OVCAR3 ovarian cancer cells, and patient derived xenogram (PDX) breast cancer cells, which express folate-receptor proteins on their surface. We fluorescently labeled these cells with the introduction of a new folate-receptor targeted fluorescent contrast agent OTL38, made by On Target Laboratories. The results established that we were able to image and detect fluorescence microspheres with a minimum signal to noise ratio (SNR) of 2.3 using the ThorLabs DCC 3240N camera on the Nikon Fluorescence microscope. We were able to image and detect the cells used on all three system configurations. Analyzing the different cell uptake efficacies of the contrast agent OTL38, we established that the SNR levels were variable when imaging PDX breast cancer cells. We propose future work to investigate possible effects on the variability of SNR results, as well as, and future steps in designing a real-time optical fluorescence imaging system for in vivo flow cytometry.
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Crosby, Kevin C. "Macromolecular Organization and Cell Function: A Multi-System Analysis." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/30259.
Повний текст джерелаАнотація:
The interior of the cell is a densely crowded and complex arena, full of a vast and diverse array of molecules and macromolecules. A fundamental understanding of cellular physiology will depend not only upon a reductionist analysis of the chemistry, structure, and function of individual components and subsystems, but also on a sagacious exegesis of the dynamic and emergent properties that characterize the higher-level system of living cells. Here, we present work on two aspects of the supramolecular organization of the cell: the controlled assembly of the mitotic spindle during cell division and the regulation of cellular metabolism through the formation of multienzyme complexes.
During division, the cell undergoes a profound morphological and molecular reorganization that includes the creation of the mitotic spindle, a process that must be highly controlled in order to ensure that accurate segregation of hereditary material. Chapter 2 describes results that implicate the kinase, Zeste-white3/Shaggy (Zw3/Sgg), as having a role in regulating spindle morphology.
The congregation of metabolic enzymes into macromolecular complexes is a key feature of cellular physiology. Given the apparent pervasiveness of these assemblies, it seems likely that some of the mechanisms involved in their organization and regulation might be conserved across a range of biosynthetic pathways in diverse organisms. The Winkel laboratory makes use of the flavonoid biosynthetic pathway in Arabidopsis as an experimental model for studying the architecture, dynamics, and functional roles of metabolic complexes. Over the past several years, we have accumulated substantive and compelling evidence indicating that a number of these enzymes directly interact, perhaps as part of a dynamic globular complex involving multiple points of contact between proteins. Chapter 3 describes the functional analysis of a predicted flavonol synthase gene family in Arabidopsis. The first evidence for the interaction of flavonoid enzymes in living cells, using fluorescent lifetime imaging microscopy fluorescent resonance energy transfer analysis (FLIM-FRET), is presented in Chapter 4.Ph. D.
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Chen, Huiyi. "System-Wide Studies of Gene Expression in Escherichia coli by Fluorescence Microscopy and High Throughput Sequencing." Thesis, Harvard University, 2011. http://dissertations.umi.com/gsas.harvard:10044.
Повний текст джерелаАнотація:
Gene expression is a fundamental process in the cell and is made up of two parts – the information flow from DNA to RNA, and from RNA to protein. Here, we examined specific sub-processes in Escherichia coli gene expression using newly available tools that permit genome-wide analysis. We begin our studies measuring mRNA and protein abundances in single cells by single-molecule fluorescence microscopy, and then focus our attention to studying RNA generation and degradation by high throughput sequencing. The details of the dynamics of gene expression can be observed from fluctuations in mRNA and protein copy numbers in a cell over time, or the variations in copy numbers in an isogenic cell population. We constructed a yellow fluorescent fusion protein library in E. coli and measured protein and mRNA abundances in single cells. At below ten proteins per cell, a simple model of gene expression is sufficient to explain the observed distributions. At higher expression levels, the distributions are dominated by extrinsic noise, which is the systematic heterogeneity between cells. Unlike proteins which can be stable over many hours, mRNA is made and degraded on the order of minutes in E. coli. To measure the dynamics of RNA generation and degradation, we developed a protocol using high throughput sequencing to measure steady-state RNA abundances, RNA polymerase elongation rates and RNA degradation rates simultaneously with high nucleotide-resolution genome-wide. Our data shows that RNA has similar lifetime at all positions throughout the length of the transcript. We also find that our polymerase elongation rates measured in vivo on a chromosome are generally slower than rates measured on plasmids by other groups. Studying nascent RNA will allow further understanding of RNA generation and degradation. To this end, we have developed a labeling protocol with a nucleoside analog that is compatible with high throughput sequencing.
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Walde, Marie [Verfasser], Rainer [Gutachter] Heintzmann, and Ute [Gutachter] Neugebauer. "Development of a holoscopic imaging system and applied high-resolution fluorescence microscopy / Marie Walde ; Gutachter: Rainer Heintzmann, Ute Neugebauer." Jena : Friedrich-Schiller-Universität Jena, 2017. http://d-nb.info/1177597233/34.
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Venius, Jonas. "Funkciškai besiskiriančių žmogaus širdies audinių fluorescenciniai tyrimai ir vaizdinimas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130124_081724-06694.
Повний текст джерелаАнотація:
Tvarkingą širdies darbą užtikrina širdies laidžioji sistema (ŠLS). Ją pažeidus sutrinka širdies darbas. Pažeidimo rizika atsiranda operacijos metu, kadangi ŠLS yra raumeninės kilmės audinys ir vizualiai neatskiriamas nuo aplinkinių audinių. ŠLS pažeidimo galima būtų išvengti, jei būtų žinomas tikslus ŠLS išsidėstymas arba egzistuotų ŠLS vaizdinimo metodika. Deja, bet atskirų ŠLS dalių tikslus išsidėstymas vis dar tikslinamas, o patologijų atvejais apskritai nėra žinomas. ŠLS vaizdinimo metodikos, tinkančios in vivo taikymams, taipogi nėra.
Atlikus širdies audinių tyrimus nustoviąja fluorescencine spektroskopija nustatyti charakteringi intensyvumų skirtumai. Remiantis šiais skirtumais sukurta ŠLS atskyrimo metodika, paremta intensyvumų santykių skaičiavimu. Suskaičiuota vertė R = I(330)/I(380) yra skirtinga ŠLS, miokardui (MK) ir jungiamąjam audiniui (JA).Tokia metodika yra nejautri tyrimo sąlygoms ir gali būti naudojama ŠLS nustatymui.
Ištyrus širdies audinius laikinės skyros spektroskopija nustatyta, kad ŠLS ir MK fluorescencijos gyvavimo trukmė bei santykinė sudėtis reikšmingai nesiskiria, tuo tarpu JA ir ŠLS tiek fluorescencijos gyvavimo trukmės, tiek santykinė komponentinė sudėtis yra skirtinga.
Ištyrus širdies audinius konfokaliniu atspindžio mikroskopu nustatyta, jog dėl skirtingų šviesą atspindinčių komponentų bei skirtingo jų išsidėstymo galima identifikuoti MK, JA, Purkinje ląsteles ir ŠLS pluoštus.
Atlikus tyrimus in vivo nustatyta, jog operacijos metu... [toliau žr. visą tekstą]Rhythmical contraction of the heart is controlled by the cardiac conduction system (CCS). However, this highly important system visually could not be distinguished from the surrounding heart tissues – myocardium (MC) and connective tissue (CT); therefore during surgical procedures CCS could be damaged. The reliable method for CCS identification either in vivo or ex vivo does not exist therefore there is a definite need for developing a CCS imaging method. Fluorescence spectroscopy studies of cardiac tissues revealed, that most distinct spectral differences between CCS and the surrounding tissues were observed in 400 nm – 550 nm region under excitation from 330 nm – 380 nm region. The visualization method, based on the intensity ratios calculated for two excitation wavelengths, has been established. The calculated ratio R = I(330)/I(380) is different for CCS, CT and MC tissues, therefore the method may be used for identification of CCS. Time resolved fluorescence spectroscopy revealed no significant difference in composition and lifetimes between CCS and MC. On the other hand, the lifetimes and the relative spectral composition of CT differed significantly from those of CCS. Reflection confocal microscopy allows visualizing MC, CT, Purkinje cells and CCS bundles because of different reflection properties of tissue components and their specific distribution inside the tissue. The results of in vivo performed procedure revealed, that the distribution of fluorescence intensities... [to full text]
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Nishino, Hiroto. "Real-time Navigation for Liver Surgery Using Projection Mapping With Indocyanine Green Fluorescence: Development of the Novel Medical Imaging Projection System." Kyoto University, 2019. http://hdl.handle.net/2433/242358.
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Means, John A. "Fluorescence and NMR Characterization of a T Box Antiterminator-tRNA Complex." View abstract, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3289332.
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Bozhko, Dmitry [Verfasser], Vasilis [Akademischer Betreuer] Ntziachristos, Alexander W. [Gutachter] Koch, Vasilis [Gutachter] Ntziachristos, and Oliver [Gutachter] Hayden. "Development of a Hybrid System for Intravascular Fluorescence-Ultrasound Imaging / Dmitry Bozhko ; Gutachter: Alexander W. Koch, Vasilis Ntziachristos, Oliver Hayden ; Betreuer: Vasilis Ntziachristos." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/1201819679/34.
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Lillro, Ejla. "Image Sensor System for Detection of Bacteria and Antibiotic Resistance." Thesis, KTH, Skolan för teknik och hälsa (STH), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-179399.
Повний текст джерелаАнотація:
Antibiotic resistance is now a recognized problem in global health. In attempts to find solutions to detect bacteria causing antibiotic resistance we turn to technological solutions that are miniaturized, portable and cheap. The current diagnostic procedures cannot provide correct information outside laboratory settings, at the point-of-care, within necessary time. This has led to ineffective treatment of urinary tract infections causing recurrent infections and multi-drug resistant bacteria to spread. The bacteria genes show which antibiotic that is required to eliminate disease and spread of resistance. Hence, the solution would be to perform nucleic acid testing at the point-of-care. By using new DNA amplification methods it is possible to miniaturize the diagnostic test to a so-called Lab-on-a-chip. These solutions would enable sample-in-results-out capability of the system at the point-of-care. For this to work one of the most important factors is fluorescent signal read-out from DNA amplification products. In this project the design parameters of such a read-out device was investigated with focus on image sensor sensitivity and device integration. During the project it was found that a low-cost commercial image sensor could be used to record images of a (3.76 x 2.74 mm2) micro well array of nanoliter sized PCR chambers. Different imaging artifacts appearing during sample partitioning were observed, distance dependency between sensor surface well array was investigate, and finally the image sensor function was compared to a fluorescent microscope.
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Cho, Hoon-Sung. "Design and Development of a multifunctional nano carrier system for imaging, drug delivery, and cell targeting in cancer research." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1275936260.
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Madai, Vince István [Verfasser]. "Virtual pre-embedding labeling : a method for correlative fluorescence and electron microscopic imaging and double-labeling in the central nervous system of the rat / Vince István Madai." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2012. http://d-nb.info/1027307558/34.
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Madai, Vince Istvan [Verfasser]. "Virtual pre-embedding labeling : a method for correlative fluorescence and electron microscopic imaging and double-labeling in the central nervous system of the rat / Vince István Madai." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2012. http://d-nb.info/1027307558/34.
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Poon, Chien Sing. "Early Assessment of Burn Severity in Human Tissue with Multi-Wavelength Spatial Frequency Domain Imaging." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1484582176416423.
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PILLAI, Vinoshene. "Intravital two photon clcium imaging of glioblastoma mouse models." Doctoral thesis, Scuola Normale Superiore, 2021. http://hdl.handle.net/11384/109211.
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