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Dissertations / Theses on the topic 'Chromophobia'
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Gordon, Kelly Jo. "Chromophoric dissolved organic matter in coastal rainwater /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-1/gordonk/kellygordon.pdf.
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Reid, Seth Neil. "Chromophoric dissolved organic matter in coastal rainwater /." Electronic version (PDF), 2003. http://dl.uncw.edu/etd/2003/reids/sethreid.html.
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Halbert, Jason Paul. "A New Chromophoric Organic Molecule Toward Improved Molecular Optoelectronic Devices." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc177207/.
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The characterization of 2,3,6,7,10,11-hexabromotriphenylene, Br6TP, is presented toward its potential use as an n-type organic semiconductor and metal-free room temperature phosphor. The crystal structure shows both anisotropic two-dimensional BrBr interactions and inter-layer ?-stacking interactions. Photophysical characteristics were evaluated using solid-state photoluminescence and diffuse reflectance spectroscopies, revealing significantly red-shifted excitations in the visible region for the yellow solid material (compared to ultraviolet absorption bands for the colorless dilute solutions). Correlation of spectral, electrochemical, and computational data suggest the presence of an n-type semiconducting behavior due to the electron-poor aromatic ring. The material shows excellent thermal stability as demonstrated by thermogravimetric analysis and infrared spectra of a thin film deposited by thermal evaporation. The potential for Br6TP and its analogues toward use in several types of photonic and electronic devices is discussed.
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Huang, Yiming. "Synthesis of Perylenediimide Derivatives for Multi-Chromophoric Surface Bound Molecular Heterojunctions." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556864.
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Perylenediimide (PDI) derivatives are lightfast red dyes that exhibit excellent optical and electronic properties for modern organic semiconductor applications. In this dissertation, several multi-chromophoric donor-acceptor systems containing PDI moieties are synthesized and assembled as electroactive monolayers covalently attached to transparent conducting oxides (TCOs). These surface assemblies provide platforms to study of interfacial charge injection rates that have a major influence on overall organic photovoltaic (OPV) efficiency. Chapter 1 provides a brief introduction to OPVs and physical processes involved. Developments and multiple synthetic strategies of PDI derivatives are also reviewed. Examples of photoinduced energy and charge transfer studies with multi-chromophoric dyads and triads in the literature are analyzed for rational molecular design. Surface-bound molecular level heterojunction models are introduced with the effort of understanding interfacial charge injection. Chapter 2 discusses the synthesis of multi-chromophoric Pc-PDI ensembles by Cu(I) catalyzed azide-alkyne cycloaddition. With the tool of click chemistry, a small library of compounds was built upon an alkyne-terminated asymmetric phthalocyanine (Pc) core and functionalized azides. Click reaction with PDI-azide was tracked by spectroscopic methods to optimize the reaction conditions including time, choice of catalyst, and stoichiometry. A similar ensemble was achieved on ITO surfaces as well, with reaction progress monitored by attenuated total reflectance (ATR) UV-vis spectroscopy. Chapter 3 demonstrates the synthesis of a series of Pc-PDI dyads with varying PDI bay-substituent groups that alter the electronic properties of the PDI component. Fluorescence quenching was observed as preliminary evidence of charge separation in solution. Phosphonic acid pendant dyads were able to form a robust monolayer on ITO and TiO2 for studies of electron injections. Surface orientation of each chromophore was calculated by NEXAFS and polarized ATR spectra. Potential dependent spectra provide useful information of the radical species absorption profiles for subsequent surface transient spectral measurements and the calculations of charge separated state lifetime. Chapter 4 discusses the synthesis of a pair of ZnP-PDI dyads that are able to bind to TCOs. Fluorescence of the PDI component was quenched in all dyads in solution. Carboxylic acid bearing dyads were able to adsorb to a TiO2 surface and correlations of surface coverage and orientation are discussed. The orientations of ZnP and PDI chromophores observed by polarized ATR spectra are also explained in details. Preliminary spectroelectrochemical results are included at the end of the chapter. Chapter 5 briefly reviews the chapters 2-4 and discusses future research directions based on current progress. Preliminary results of this research are also included.
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Resetar, Lorri. "Characterization of chromophoric dissolved organic matter with iron chelates in rain water /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/resetarl/lorriresetar.html.
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Quan, Wen-Dong. "The design, construction and characterisation of self-assembled biomimetic multi-chromophoric photosystems." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/91766/.
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The potential of a maleimide based fluorophore as well as the utilisation of simple methodologies to produce synthetic mimics of natural light harvesting complex (LHC) were explored. In Chapter 1, the inspiration for the current work is discussed, followed by a brief guide for the interpretation of the work presented in subsequent chapters. Finally, the ultimate aim and concept for the thesis is detailed. The general instruments and methodologies applicable to all experiments conducted are then described in Chapter 2. Chapter 3 presents the first set of results from the thesis work. This work focused on unravelling the previously unexplained fluorescence quenching observed in maleimide based fluorophores in protic solvent. This was achieved through the use of computational chemistry, ultrafast spectroscopy and synthetic chemistry. The work identified a photochemical process, in the form of electron driven proton transfer, as the fluorescence quenching mechanism. Such understandings should provide a much needed insight towards future designs of maleimide based fluorophores that fully realise the potential of this class of photoactive pigments. This was then followed by the attempt to produce the platform for which inter-chromophoric assemblies could occur in aqueous media, documented in Chapter 4. The main body of the work involved the selection of the most effective synthetic method readily reported in the literature: the synthesis of functionalised porphyrin through the condensation reaction between dipyrrolemethane and functionalised aldehyde; and the conjugation between porphyrin and polymers with the copper catalysed alkyne-azide cyclo addition click reaction. The resulting platform was successfully demonstrated to be capable of self-assembly, without the need of covalently linking the chromophores to one another. Furthermore, and most importantly, the photophysical properties of these chromophores were largely retained in the assembled structure. The results presented could lead to a new class of photoactive nanostructures that closely mimic natural LHCs, in which the properties of individual chromophores could be fully exploited and assembled without the need of covalent linkage. The potential of using the platform documented in Chapter 4 to produce functional natural LHC mimics was then explored in the final results chapter, Chapter 5, where a pseudo reaction centre (RC) was introduced. The spectroscopic experiments demonstrated that the photodynamics of the assembly was significantly altered in the presence of the RC. This was proposed to be based on a push-pull mechanism facilitated by the presence of metal to N donor coordinated complex. Furthermore, the N donor in the chosen RC proved to be instrumental for the assembly and spectral differences observed. Therefore, these presented properties of the platform described could likely produce much more complex, functional multi-chromophoric assemblies. The thesis then closed with a brief overview and an outlook which discussed two multi-chromophoric assemblies, based on the work presented in Chapter 3–5.
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Xiao, Yi [Verfasser]. "Integrated proteome and metabolome profiling of chromophobe renal cell carcinoma / Yi Xiao." Berlin : Freie Universität Berlin, 2021. http://d-nb.info/1233986759/34.
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Norlin, Nils. "Extended Förster Theory of Electronic Energy Transport within Pairs of Reorienting Chromophoric Molecules." Doctoral thesis, Umeå universitet, Kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-22471.
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An extended Förster theory (EFT), previously derived (L. B.-Å. Johansson et al. J. Chem. Phys., 1996,105) has theoretically been adapted and used in simulations of donor-acceptor energy transfer (DAET), which is a process often referred to as FRET. It was shown that the classical Förster theory is only valid in the initial part of the fluorescence decay. In this thesis an EFT is derived and outlined for electronic energy transport between two fluorescent molecules which are chemically identical, but photophysically non-identical. The energy migration within such asymmetric pairs is partially reversible and therefore referred to as partial donor-donor energy migration (PDDEM). The previously derived model of PDDEM (S. V. Kalinin et al. Spectrochim Acta Part A, 2002,58) is an approximation of the EFT. In particular, the EFT accounts for the time-dependent reorientations as well as the distance that influence the rate of electronic energy migration. The reorientation of the fluorophores transition dipole moments has been simulated using Brownian dynamics. As a result, the related “k2-problem” has been solved. The EFT of PDDEM has also been studied regarding the effect of PDDEM on experimental observables e.g. quantum yield of fluorescence and steady-state anisotropies
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Jones, Jennifer Elizabeth. "Novel chromophoric ligand scaffolds for d- and f- metal ions towards luminescent probes." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/55133/.
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This thesis discusses the development of chromophoric ligand scaffolds for application in d- and f- metal ion coordination chemistry, investigating the photophysical properties of the complexes towards bimodal agents and probes of biological application. Chapter 2 presents the synthesis and characterisation of four novel 3-picolyl functionalised amino-substituted anthraquinone chromophores, and their subsequent coordination chemistry with Re1. X-ray crystallography confirmed the predicted structure of three of the ligands and two of the mono-metallic complexes, confirming coordination via the axial pyridyl donor. The ligands have tuneable electronic properties depending on the functionalisation of the anthraquinone core, and are dominated by charge transfer characteristics, the assignment of which is supported by solvatochromic behaviour. The complexes are dual emissive following visible excitation, with emission assigned as ligand centred fluorescence and 3MLCT. Chapter 3 extends the use of ammc-anthraquinone chromophores for lanthanide sensitisation. Incorporation of two 1-amino anthraquinone chromophores into an aza-macrocyclic framework derived from cyclen, affords a chromophoric system for lanthanide coordination and subsequent near-IR sensitisated emission of Ybm, Ndm and Er"1 using visible light Chapter 4 investigates the functionalisation of bis-animo-anthraquinone chromophores as bridging units between two aza-macrocyclic frameworks, affording sensitised near-IR emission of Ybm, Ndm and Erm upon absorption of visible light. The complexes interact with calf thymus DNA and highlight the LI derivative with the strongest binding interaction. Theoretical docking studies are utilised for probing the nature of the DNA-AQ interaction and *H NMRD profiles examine relaxivity enhancements upon DNA binding. Finally, Chapter 5 discusses the functionalisation of the djroyrido 3,2-a:2',3'- cjphenazine ligand and its subsequent coordination chemistry with Cr11 Irm, Lnm and d-f hybrid systems. Low temperature phosphorescence spectra of the associated Cr complexes exhibit metal centred phosphorescence at ca. 730 nm, with substitution patterns affecting the wavelength of emission as well as the structure of the profile. Functionalised It111 complexes exhibit dual emission from *IL and 3MLCT as well as demonstrating solvent dependent and wavelength of excitation dependent emission. The dppz derived chromophores are suitable for sensitisation of near-IR emitting lanthanides including Ybm, Ndra and Er111 following visible light excitation. Functionalisation of the Ir111 and Crm chloroacetamides on the periphery of the complexes facilitates the formation of aza-macrocyclic complexes, and the corresponding Ybm and Gdffl complexes. Irradiation of the dppz derived chromophore prompts sensitised NIR emission off or both the Cr111 and Ir species, and low temperature steady state spectra of the CrIII-GdUI complexes demonstrating metal centred phosphorescence (2E 4A2) with vibronic structure.
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Norlin, Nils. "Extended Förster theory of electronic energy transport within pairs of reorienting chromophoric molecules /." Umeå : Department of Chemistry, Umeå University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-22471.
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Huang, Zirou. "Measurement of Phytase Activity in a Clymer Forest Soil Using the TInsP5 Probe." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/43877.
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Measurement of soil phytase activity (PA) and delineation of the impact of this important phosphomonoesterase on the P-cycling process in soil and sediments suffer from the lack of a reliable assay. A method for measuring PA in soil that promises to be accurate and reliable has been recently published. The method involves the use of a novel chromophoric analog of phytic acid, referred to as T(tethered)InsP5 (5-O-[6-(benzoylamino)hexyl]-D-myo-inositol-1,2,3,4,6-pentakisphosphate). This study was conducted to measure PA in a Clymer forest soil, which contained over twice the amount of soil organic C as previously tested soils, using the TInsP5 PA assay. This investigation specifically addresses: (1) the development of a soil dilution technique for determining maximal PA, (2) identification of previously unsubstantiated soil-produced dephosphorylated intermediate probe species, (3) the impact of increasing assay buffer pH on soil PA and (4) testing stability of the probeâ s amide bond in a highly (bio)active forest soil. PA assays were conducted by measuring dephosphorylation of TInsP5 in citrate-acetate buffered (pH 4.2) active and autoclaved (Control) soil suspensions. Phosphorylated probe intermediates (i.e., TInsP4, TInsP3, TInsP2 and TInsP1) and T-myo-inositol were extracted from samples of soil suspension following incubation. Probe species were quantified using reversed phase high-performance liquid chromatography (RPHPLC) with UV detection. PA was calculated based on a mass balance approach. A soil dilution technique was developed to address the challenge of determining maximal PA in soils containing higher organic matter content. In the initial report on use of the TInsP5 method for measuring PA in soil, two â soil-generatedâ UV-adsorbing compounds (designated Y and Z) were observed, but never confirmed as probe species. The experimental evidence presented in this report supports inclusion of compound Y as a phosphorylated probe intermediate species (i.e. TInsPy), based primarily on its UV adsorption spectra (diode-array detection analysis). Compound Z could not be substantiated as a probe species based on the evidence presented in this study. PA of Claymer forest soil decreased with an increase in assay buffer pH. Further, the probeâ s amide bond linkage was stable in a forest soil exhibiting high PA.Master of Science
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Floge, Sheri Ann. "Seasonal Variations in Colloidal Chromophoric Dissolved Organic Matter (CDOM) in the Damariscotta River Estuary, Maine." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/FlogeSA2005.pdf.
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Goldstone, Jared Verrill 1971. "Direct and indirect photoreactions of chromophoric dissolved organic matter : roles of reactive oxygen species and iron." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/29053.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, and the Woods Hole Oceanographic Institution), 2002.Vita.
Includes bibliographical references.
Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02-) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.
(cont.) However, addition of iron to several coastal seawater samples neither increased the rate of photobleaching nor the apparent quantum yield (AQY) of CO. Similarly, the addition of the siderophore desferrioxamine B did not change the photobleaching rates or the CO AQYs. The addition of 2[mu]M Fe to solutions of Suwannee River Fulvic Acid did not increase the photobleaching rates. In combination with prior results, these findings suggest that indirect photoreactions do not increase the photobleaching rates of CDOM in coastal systems. A model of CDOM photobleaching based on the assumption of negligible indirect photobleaching processes and multiple non-interacting chromophores was created utilizing photobleaching data produced with monochromatic light to calculate the spectra and exponential decay rates of independent components. These components were then used to calculate bleaching spectra for broadband light and compared with actual bleaching spectra.
by Jared Verrill Goldstone.
Ph.D.
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Rose, Kevin C. "CAUSES AND CONSEQUENCES OF VARIATION IN UV TRANSPARENCY FOR FRESHWATER ECOSYSTEMS." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1304107334.
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Brown, Jennifer Louise Dickson. "Optical properties of chromophoric dissolved organic matter as a tracer of terrestrial carbon to the coastal ocean." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-2/r1/brownj/jenniferbrown.pdf.
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Sabbaghzadeh, Bita. "Surfactants and chromophoric dissolved organic matter (CDOM) in the Atlantic Ocean surface microlayer and the corresponding underlying waters." Thesis, University of Newcastle upon Tyne, 2018. http://hdl.handle.net/10443/4127.
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The sea surface microlayer (SML; depth < 400 μm) is a physically and biogeochemically distinct interface covering the entire ocean surface. Biologically-derived surfactants are ubiquitous in the SML, where they limit air-sea gas exchange and the formation of marine boundary layer aerosols that impact atmospheric chemistry and climate. Total surfactant activity (SA) and chromophoric dissolved organic matter (CDOM) were measured in the SML, in depth profiles (≤ 100 m) and semi-continuously in sub-surface water (SSW: 7 m non-toxic seawater supply) on Atlantic Meridional Transect (AMT) cruises 24 (2014) and 25 (2015), from 50°N to 50°S. On-board estimates of the gas transfer velocity (kw) of CH4 (custom gas exchange tank) were related to SA distributions in the SML to evaluate surfactant control of air-sea gas exchange. SML and SSW SA (mg L-1 eq. T-X-100) was always higher in the Northern Hemisphere than in the Southern Hemisphere (0.10 - 1.76 in the Northern Hemisphere; 0.08 - 0.63 in the Southern Hemisphere). A constant enrichment of SA in the SML was observed at all wind speeds encountered. SA enrichment factors (EF = SASML/SASSW) ranged between 0.95 - 4.25 in the Atlantic Ocean, higher in the Northern Hemisphere than in the Southern Hemisphere. EF >1 up to the maximum mean wind speed recorded (~13 m s-1) challenges the idea that high latitude wind speeds > 12 m s-1 preclude high EFs and implies that the SML is self-sustaining concerning SA. CDOM absorption coefficient (a300) in general was higher in the Northern Hemisphere (range 0.10 - 1.52 m-1) than in the Southern Hemisphere (range 0.17 - 0.82 m-1). CDOM spectral slope (S275-295) showed an inverse correlation with CDOM (a300) and was significantly lower (t-test, p < 0.001) in the SML than in the SSW (SML; 0.033 ± 0.005 nm-1, SSW; 0.038 ± 0.007 nm-1) suggesting in-situ CDOM production in the SML and more refractory CDOM in the SSW. CH4 k660 (kw for CO2 in seawater at 20°C) derived from the gas exchange tank (6.9 - 9.8 cm h-1) gave film factors (R660´; sample kw / surfactant-free MilliQ kw) that strongly correlated with SML SA (r2 = 0.63, p = 0.001, n = 13). Corresponding R660´ suppressions ~ 25% imply a strong control of Atlantic Ocean gas exchange by surfactant.
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Hipsher, Carissa. "Assessment of Chromophoric Dissolved Organic Matter and Thamnocephalus platyurus as Tools to Monitor Cyanobacterial Bloom Development and Toxicity." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1566210122121367.
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Trujillo, Rebollo Andres. "ROLE OF BRILLIANT GREEN ON THE DETECTION AND SEPARATION OF NON-CHROMOPHORIC ANALYTES BY REVERSED-PHASE LIQUID CHROMATOGRAPHY (DIMERIZATION)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275434.
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Hewat, Tracy Elizabeth. "Exploring copper(I) and ruthenium(II) dyes for their use in dye-sensitised solar cells." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/17075.
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Dye design is one of the most important and challenging areas in dye-sensitised solar cell research. The purpose of the work in this thesis is to synthesise and characterise novel ruthenium(II) and copper(I) dyes that will provide insight into the number of binding groups required and the potential use of chromophoric ligands. A series of four simple Ru(II) dyes have been synthesised with the general formula Ru(4,4’- (R)-bipyridine)2(NCS)2 where R represents CH3 or CO2H. The study investigates the number of acid groups required to successfully bind to TiO2 whilst maintaining efficient charge injection. The series consists of one acid group, two acids, two acids on adjacent bipyridines, and three acids groups. Dye uptake was studied via optical waveguide spectroscopy, providing information on dye diffusion, adsorption and desorption kinetics, and surface coverage. Interestingly, the two acid groups on adjacent ligands suggested poor/slow binding to TiO2 surface and a high degree of dye aggregation in comparison to two acid groups on the same ligand. The dye with three binding groups showed strong adsorption to TiO2 and better dye coverage, resulting in a high efficiency. The complexes were all fully characterised by electrochemistry, photoluminescence, absorption spectroscopy, DFT calculations and solar cell performance testing. To date, there has been limited exploration of copper(I) complexes as potential alternatives to ruthenium(II) sensitisers, with even fewer publications reported for Cu(I) heteroleptic species. The neutral complexes that were synthesised are of the general formula: Cu(4,4’- (R)-6,6’-(CH3)-bipyridine)(β-diketonate) and Cu(4,4’-(R)-6,6’-(CH3)-bipyridine)(dipyrrin) where R represents CH3 or CO2Et. Additional blocking groups on the ligands are introduced to minimise structural change during oxidation or MLCT excitation. Improved stability and reproducibility have been shown for complexes containing the dipyrrin ligand, likely due to better steric constraints and better π-overlap with the bipyridine. There has also been a remarkable improvement in light absorption, from 450 nm to 600 nm. In-situ solar studies have been carried out on the Cu(4,4’-(R)-6,6’-(CH3)-bipyridine)(dipyrrin) series and a 0.41% efficiency has been achieved. Computational studies supports the experimental data in which the main transition appears to be ligand centred (dipyrrin) with a small MLCT contribution.
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Montravers, Françoise. "Analyse comparative de différents traceurs pour la détection tumorale par scintigraphie : application aux tumeurs rénales et neuroendocrines." Paris 11, 1999. http://www.theses.fr/1999PA11T048.
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Nous avons comparé l'intérêt de différents traceurs dans le diagnostic scintigraphique de deux groupes de tumeurs humaines (carcinomes neuroendocrines et carcinomes rénaux). Dans l'étude des carcinomes neuroendocrines, nous avons observé la supériorité de la scintigraphie à la métaiodobenzylguanidine (miBG, représentant la capacité de la tumeur à capter les catécholamines) par rapport la scintigraphie au thallium (traceur de vas ularisation et d'hypermétabolisme) en cas de phéochromocytome et de neuroblastome et au contraire la supériorité de la scintigraphie au thallium par rapport à la scintigraphie à la miBG en cas de cancer médullaire de la thyroïde et pour certains paragangliomes. Les caractéristiques histologiques de ces tumeurs nous paraissent expliquer ces résultats. Dans le cas des carcinomes du rein, nous avons observé la supériorité de la scintigraphie au fluorodésoxyglucose (FDG, traceur rendant compte d'une augmentation de l'utilisation du glucose par la cellule maligne) par rapport aux scintigraphies au thallium et au pentétréotide (indiquant la présence de récepteurs de la somatostatine), pour la mise en évidence des métastases mais aucun de ces trois traceurs ne s'est révélé performant pour la caractérisation de la tumeur rénale primitive. L'hypothèse d'une inaccessibilité des traceurs dans les tumeurs rénales primitives était donc évoquée. Cette hypothèse était confortée par notre observation, grâce à une étude autoradiographique in vitro, de la présence de récepteurs de la somatostatine sur les cellules de tumeur rénale primitive alors que l'analogue n'était pas fixé in vivo. Nous discutons les mécanismes pouvant expliquer cette captation faible ou absente des traceurs scintigraphiques par les carcinomes rénaux primitifs. La compréhension des mécanismes s'opposant à l'accès des molécules jusqu'à ces tumeurs particulièrement résistantes aux traitements apparaît en effet très importante dans un but d'amélioration de la prise en charge thérapeutique.
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Batra, Kamal [Verfasser], Thomas [Akademischer Betreuer] Heine, Thomas [Gutachter] Heine, and Renhao [Gutachter] Dong. "Theoretical Investigations of the Photophysical Properties of Chromophoric Metal-Organic Frameworks / Kamal Batra ; Gutachter: Thomas Heine, Renhao Dong ; Betreuer: Thomas Heine." Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1231917482/34.
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Woods, Wendy Lynn. "Hydrography, suspended sediments, chlorophyll A, chromophoric dissolved organic matter and optical characteristics of the Pearl River (Zhujiang) estuary during July and November 1998 /." View online ; access limited to URI, 2005. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3186927.
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Suryaputra, I. Gusti Ngurah Agung. "Are subterranean estuaries a source of chromophoric dissolved organic matter (CDOM) to the coastal ocean? a case study in the Northern Gulf Of Mexico /." Tallahassee, Florida : Florida State University, 2009. http://etd.lib.fsu.edu/theses/available/etd-06132009-215302/.
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Thesis (M.S.)--Florida State University, 2009.Advisor: Markus Huettel, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed on Nov. 19, 2009). Document formatted into pages; contains vii, 32 pages. Includes bibliographical references.
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Sánchez-Pérez, Elvia Denisse. "Rôle des mécanismes biotiques et abiotiques dans la dynamique de la matière organique dissoute dans les écosystèmes marins pélagiques (Méditerranée Nord Occidentale)." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066474/document.
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La matière organique dissoute chromophorique (CDOM) est une fraction significative du pool global de matière organique dissoute (MOD) dans les océans. La CDOM absorbe une partie de la lumière dans le domaine du rayonnement ultraviolet (UV-R) et du visible. Une fraction de cette CDOM peut émettre une fluorescence lorsqu'elle est excitée par un UV-R. Cette fraction est alors appelée matière organique dissoute fluorescente (FDOM). La CDOM a donc d'une part, un effet positif, en protégeant les cellules contre les dommages causés par les UV-R, mais d'autre part, un effet négatif en réduisant la quantité de radiation disponible pour la photosynthèse. Les propriétés optiques de la CDOM, particulièrement sensibles aux processus physiques (abiotiques) et biologiques (biotiques), renseignent sur l'intensité des processus biogéochimiques en milieux aquatiques. Des suivis de la dynamique de la CDOM en zones côtière et hauturière en Méditerranée Nord occidentale ont permis de décrire différentes tendances temporelles claires, qui vont d’une faible à une forte saisonnalité et qui peuvent être découplées des variations du pool global de MOD caractérisé par les concentrations en carbone organique dissous (COD). Dans les zones tempérées, les événements météorologiques conduisent à des changements beaucoup plus brusques dans la frange littorale que dans l’océan, où les variations tendent à être plus progressives au cours de l'année. En outre, l'apport de nutriments et de polluants dans les zones côtières est fortement influencé par l'activité anthropogénique et ces entrées ne suivent pas nécessairement de tendances saisonnières nettes. Dans la présente étude qui effectue un premier bilan de la distribution et du devenir de la CDOM/FDOM aux stations d'observation à long terme du laboratoire Arago (stations côtière SOLA et hauturière MOLA) à partir respectivement d'un suivi hebdomadaire et mensuel, nous nous sommes attachés à extraire un signal cohérent et une variabilité claire des sources des différentes fractions de la MOD entre février 2013 et avril 2014 ceci, de manière à mieux comprendre les rôles respectifs des facteurs biotiques et abiotiques. Nos observations ont ensuite pu être replacées dans un contexte synoptique d'évolution climatologique des écosystèmes méditerranéensChromophoric dissolved organic matter (CDOM) is a major fraction of dissolved organic matter (DOM). CDOM absorbs light over a broad range of ultraviolet (UV-R) and visible wavelengths. A small fraction of CDOM can emit fluorescence when excited by ultraviolet radiation; so called fluorescent dissolved organic matter (FDOM). CDOM plays a key role in regulating light penetration into the ocean, absorbing high-energy electromagnetic spectrum (visible and ultraviolet light) waves. On one hand, it protects aquatic organisms of potential photo-damage; in the other hand it induces a negative effect by reducing light for photosynthesis. The optical properties of the CDOM are sensitive to biological (biotic) and physical (abiotic) processes and for this reason the colored matter can provide valuable information about the biogeochemical processes in aquatic environments. CDOM monitoring in Mediterranean coastal areas has shown different temporal trends, which go from weak to strong seasonality. Interestedly, these temporal trends were uncoupled with those of the total dissolved organic carbon. In temperate areas, episodic meteorological events can induce much more abrupt changes in the littoral than in the open sea, where changes tend to be more gradual along the year. In addition, the input of nutrients and pollutants in coastal areas is strongly influenced by the anthropogenic activity on land, and those inputs do not necessarily follow seasonal trends. In the present study, weekly and monthly samplings were performed to investigate the temporal variability in SOLA and MOLA stations, respectively. The fluctuation of different fractions of dissolved organic matter (DOM) was evaluated from February 2013 to April 2014 and referred to long time-frame databases of SOLA and MOLA stations. Inorganic nutrients and chlorophyll shown the classical seasonal patterns, with a winter period characterized by an enrichment of surface waters favoring the spring bloom, followed by a calm period that allows the summer stratification and the depletion of nutrients in the photic zone. The stratification extended until autumn winds and low temperatures eroded the thermocline. In contrast, colored DOM fractions did not follow a clear temporal trend. Interestingly, dissolved organic carbon (DOC) exhibited the highest variability in summer, when the rest of parameters showed minimum variations. To explain this mismatch we proposed a sequence of abiotic and biotic phenomena driving the DOC dynamics. In the suggested conceptual frame, DOC dynamics depended strongly on episodic meteorological events (winds, rains, etc.) along the year, except in summer, where the biological factors were more relevant. In order to better understand the influence of biological factors, we examined the temporal trends of phytoplankton composition in relation to those of the different colored DOM fractions. We found that both phytoplankton and CDOM were strongly influenced by abiotic factors such as the intrusions of fresh waters, the vertical mixing due to convection and the light exposure. However we did not find a correlation between any of the CDOM fractions and any of phytoplankton groups. In addition, we use the dust deposition database of ADEPT project (ICM-CSIC, Barcelona) to investigate the potential role of atmospheric deposition in the CDOM temporal variability, and also performed two dust addition experiments with natural plankton communities collected in the Catalan coast
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Alves, Paulo Henrique Moreira. "Diferenciação de angiomiolipomas pobres em gordura de neoplasias renais malignas, com uso de ressonância magnética multiparamétrica." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17158/tde-01022016-154034/.
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Introdução: com o uso generalizado de métodos de imagem, aumentou-se a detecção de lesões renais como achados incidentais. Tais lesões podem ser tanto benignas, tais como os angiomiolipomas, e outras malignas, como os carcinomas de células renais, portanto torna-se importante um método não-invasivo com boa acurácia para sua distinção . A ultrassonografia é pouco específica para este fim. A tomografia computadorizada e a ressonância magnética são os métodos mais utilizados na caracterização de lesões incidentais renais. Na Ressonância Magnética, o uso de sequências convencionais ponderadas em T2W e T1W, antes e após a administração endovenosa de contraste paramagnético, mostrou-se pouco eficaz para este fim. Técnicas quantitativas associadas às imagens convencionais, tais como a oposição de fase e a restrição a difusão da água, vêm sendo estudadas, devido ao potencial para melhorar a caracterização não-invasiva, evitando nefrectomias parciais ou totais, e outras intervenções invasivas por lesões benignas. Objetivos: avaliar a acuidade diagnóstica de técnicas combinadas de ressonância magnética para diferenciação de angiomiolipomas pobres em gordura de lesões malignas do rim. Métodos: pacientes que obtiveram o diagnóstico histológico das lesões renais entre os anos de 2010 e 2014 e que realizaram exame pré-operatório. As lesões foram estudadas, colocando-se um ROI (region of interest, no inglês) na maior parte da lesão e córtex renal normal, evitando-se área de não-lesões, calculando a intensidade de sinal nas seqüências T1W in e out-phase, T2W, o Wash in, Wash out relativo e absoluto das lesões e o cálculo absoluto do sinal da lesão no ADC (coeficiente de difusão aparente, do inglês). Os resultados foram obtidos na forma de índices padronizados pelo córtex renal e baço, pelas fases pré e pós-contraste, e de forma absoluta pelo ADC. Os resultados foram confrontados com o diagnóstico final e feito associações estatísticas para observar a relevância. Resultados:Foram estudadas 85 lesões em 74 pacientes, sendo 40 do gênero masculino e 34 do feminino. O cálculo do teor de gordura se mostrou ineficaz para distinção entre CCRs e AMLpg; o índice de intensidade de sinal em T2W, lesão/córtex normal foi útil na diferenciação dos CCRs CC de AMLpg. Outro parâmetro importante foi a cálculo de wash out relativo que se mostrou mais acentuado no AMLpg que em todos os subtipos de CCRs estudados e da medida do ADC médio, que apresentou valores maiores nos casos de CCR CC, em comparação com os outros subtipos e com os AMLpg. Conclusão: As técnicas combinadas de RM, principalmente o índice de sinal T2W da lesão, Wash out relativo e IS do ADC, associados a dados epidemiológicos são viáveis, quando utilizados em conjunto, para a diferenciação de lesões malignas renais dos angiomiolipomas, podendo ter implicações na conduta terapêutica, com redução do número de nefrectomias por lesão benignas.Introduction: With the widespread use of imaging methods, detection of incidental renal masses has steadily increased in recent years, and these may be either benign, such as angiomyolipoma, or malignant, such as renal cell carcinomas. Therefore, it is important to have a method that allows accurate characterization. Ultrassonography is not very specific for this purpose. CT and MRI are the methods used in the characterization of renal incidental lesions. In MRI, the use of conventional sequences, such as T1W and T2W before and after intravenous administration of paramagnetic contrast media, has proved ineffective for this purpose. Quantitative techniques associated with conventional images, such as chemical shift and diffusion weighted imaging (DWI), have played a key role in this differentiation, which aims to improve characterization, avoiding partial or total nephrectomy, and other invasive interventions for benign lesions. Objectives: to evaluate the diagnostic accuracy of combined techniques of MRI to differentiate fat-poor angiomyolipoma from renal cell carcinomas. Methods: Patients who had a histological diagnosis of renal lesions between 2010 and 2014 and underwent pre-operative exam. An ROI (region of interest)cwas placed in most of the lesion and normal renal cortex, avoiding area of non lesions, by calculating the signal intensity in all sequences, in and out phase T1W, T2W, and the wash in, wash out, relative and absolute, of the lesions and estimation of the ADC. The results were obtained in the form of standardized indices for renal cortex and spleen, the pre- and post-contrast phases, and absolute values for ADC. Results were confronted with the final diagnosis and statistical analysis to observe the relevancy. Results: the estimation of intracellular fat content was ineffective for characterization, while the T2W signal intensity index was used for differentiation between CCRs clear cells from fat-poor AML. Another important parameter was the \"wash out\", which was more prominent for AMLpg. ADC values was higher for CCR CC. Conclusion: We concluded that the combined techniques of MRI mainly T2W signal ratio, \"Wash out\" and ADC values, when used in association and correlated with epidemiological data may be feasible for the differentiation among fat-poor angiomyolipomas and renal malignancies, with important therapeutics implications, reducing unnecessary nephrectomies for benign lesions.
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Crawford-Mendoza, Alma. "The Beige Conundrum." 2021. https://scholarworks.umass.edu/masters_theses_2/1042.
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Color is an essential part of everyday life, but it is often not given the consideration it deserves. Simply, waking up in the morning and pulling on a pair of blue jeans and a white t-shirt is an example of a decision made about color. What behooves a person to dress in a certain color? Is it related to their mood? Is it related to the kind of work they do? Similar questions can be asked about the exterior color of a person’s home. Why did they choose that color? How do they feel about their house’s color? Did they choose its color? Did they choose the color because it looked harmonious with their neighbor’s house? Is it fair to wonder whether there is a discernible reason behind every color decision that is made?
The prevalence of the unassuming color beige on residences throughout Western Massachusetts and the curiosity to know why it is so common, was the specific impetus for this project. Why has beige, in particular, been selected as an acceptable house color? Moreover, why aren’t other colors like pink or orange, often seen on houses? There are regional, historical, and larger cultural investigations that can shed light on why some colors are favored over others.
It must be acknowledged that to dwell in the realm of color, is inevitably to dwell in the realm of opinion. This project seeks to explore color in a conciliatory, strategic manner, that does not polarize those who prefer one color against those who do not. Rather, a case is made for how color’s treasure trove of untapped potential can be given a greater purpose amongst the built environment.
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Batra, Kamal. "Theoretical Investigations of the Photophysical Properties of Chromophoric Metal-Organic Frameworks." 2020. https://tud.qucosa.de/id/qucosa%3A74078.
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For inorganic semiconductors such as silicon, crystalline order leads to bands in the electronic structure which give rise to drastic differences with respect to disordered materials. Distinct band features lead to photo-effect, and the band structure can be tuned to optimize the performance of the photovoltaic (PV) device. An example is the presence of an indirect band gap. For organic semiconductors, such effects are typically precluded, since most organic materials employed are disordered, which hampers their characterization and theoretical analysis.
The inspiration for this thesis came from the very first evidence of an indirect band gap exhibited by highly ordered and crystalline porphyrin-based surface-mounted metal-organic framework (PP-based SURMOF) material [J. Liu et al. Angew. Chem. Int. Ed. 2015, 54, 7441]. The presence of an indirect band gap should in principle result in suppressed charge recombination and efficient charge separations which would significantly enhance the PV device performance. However, the energy gain from the electronic band dispersion in the reported Pd-PP-Zn-SURMOF is far too low (≈5 meV) and results in a very low photocurrent generation (efficiency 0.2%), which is certainly not sufficient for the application. Another noticeable shortcoming is the weakly absorbing Q-bands of the employed PP chromophore (Pd-metal containing porphyrinoid, Pd-PP) in the visible region of the solar spectrum. Nevertheless, this novel research has highlighted the potential to improve the photophysical properties of PP-based SURMOFs by (i) introducing various functional groups or metal ions to the PP-core and (ii) controlling the PP-stacking behavior in layered materials.
To overcome the posed shortcomings of the PP-MOF prototype PV material and to exploit the potential of PP-based SURMOFs, we have employed the following approach to increase the light absorption and the electronic band dispersion. Firstly, we proposed a computationally feasible simplified time-dependent approach to investigate the light absorption properties of PP derivatives or related PP-containing materials. Secondly, we predicted the light absorption properties of multi-functionalized PPs (i.e. tuning the weakly absorbing Q-bands), thus allowing us to identify different PP linkers with different light absorption properties, allowing to bridge the so-called green gap. Finally, we incorporated the most promising PP linkers for the construction of SURMOFs and applied state-of-the-art DFT methods in various approximations to optimize the PP-stacking behavior to achieve the desired photophysical properties. Besides PPs, we have extended our investigations to phthalocyanines (PCs) as alternative individual SURMOF building blocks, because they do not only exhibit structural robustness and stability but also possess enhanced absorption in the visible and the near IR spectral regions in comparison to PPs. Hence, the exploitation of PCs could enrich the library of SURMOFs with the desired optical quality.
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Méndez, Silvagnoli María M. "Spatial and temporal variation of chromophoric dissolved organic matter absorption in the Caribbean /." 2008. http://grad.uprm.edu/tesis/mendezsilvagnoli.pdf.
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Walker, Sally Annette. "Sources and Fate of Chromophoric Dissolved Organic Matter in the Arctic Ocean and Surrounding Watersheds." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11527.
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Given the pace of climate change in the Arctic, it is vital to better constrain terrigenous dissolved organic matter (tDOM) fluctuations in large Arctic Rivers and the role that climate change may bring to tDOM inputs into the Arctic Ocean and to the global carbon cycle. This project uses the optical properties of chromophoric dissolved organic matter (CDOM) to investigate the quality, quantity and fate of dissolved organic matter (DOM) in large Arctic Rivers and the interior Arctic Basin. In large rivers surrounding the Arctic, peak discharge CDOM is largely derived from fresh terrestrial plant material whereas during base flow the CDOM pool has a greater microbial imprint, particularly in the Mackenzie. The higher microbial imprint in the Mackenzie can be explained by longer water residence times, which may be important in a warming climate where increased precipitation rates will likely lead to increased hydrological connectivity and therefore longer water residence times. In surface waters of the Canadian Archipelago, 17 % of the DOM pool is of terrestrial origin, even though waters are diluted with sea ice melt, suggesting the likelihood of a subsurface plume of tDOM entrained within river runoff from Arctic Rivers. In the interior Arctic, an elevated terrestrial CDOM signal in the Eurasian Basin (EB) points to the presence of Eurasian river CDOM entrained within river runoff in the Transpolar Drift. In contrast, autochthonous/microbial CDOM sources become more important the Canadian Basin (CB) and the terrestrial CDOM signal is much lower relative to the EB.
A good constraint on the nature and distributions of freshwater (FW) in the Arctic Ocean is paramount to understand the role climate change may play for the Arctic’s hydrological cycle. During this study, we used the spatial patterns of terrestrially derived CDOM to better understand the distribution and nature of river runoff across the upper Arctic Basin. This study illustrates the usefulness of CDOM to finger-print water masses within the Arctic Ocean and shows promise to improve our understanding of upper Arctic Ocean ventilation patterns.
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Zhu, Weining. "Inversion and analysis of chromophoric dissolved organic matter in estuarine and coastal regions using hyperspectral remote sensing." 2012. https://scholarworks.umass.edu/dissertations/AAI3518399.
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CDOM (chromophoric dissolved organic matter) plays an important role in determining underwater light field and aquatic photochemical and biological processes. Knowing CDOM properties, origin, sink, content, and distribution is able to provide us not only a useful approach to evaluate, but also a new perspective to understand water quality, carbon cycle, as well as the climate change. Remote sensing inversion of CDOM bears the potential capability to assess CDOM at large scale, but it has not been fully investigated yet. Particularly, the previous approaches cannot meet the accuracy and spatial resolution requirement for analyzing complex waters in estuarine and coastal regions. Therefore, a new scheme, which combines a newly developed inversion algorithm and hyperspectral remote sensing, is proposed to solve problems encountered in CDOM evaluation. This research covers three study sites, in the estuarine and coastal regions of the Mississippi River, Hudson River, and Neponset River. Very high resolution in situ data were collected in these sites and EO-1 Hyperion satellite images were also acquired accordingly. Based on a quasi-analytical algorithm (QAA), a QAA-CDOM algorithm was developed, by which CDOM absorption coefficient ag(440) is separated from adg(440)(total absorption coefficient of CDOM and non-algal particles). Some QAA's parameters and functions were also optimized, using available datasets (in situ, IOCCG, and NOMAD). Result validation in the Atchafalaya plume has proved that QAA-CDOM is capable of estimating ag(440) in excellent accuracy (RMSE=0.11 m−1 and R2=0.73 in the Atchafalaya River plume region). More importantly, applying QAA-CDOM to other locations, including the Mississippi River, Amazon River, and Moreton Bay, also derived very reasonable and accurate ag(440), covering a wide range from 0.01 to 15 m −1. This confirms that our method is applicable to a wide range of estuarine regions. The uncertainties involved in CDOM inversion were also analyzed, aiming to know the origin, magnitude, and propagation of uncertainty in different inversion phases. This work strongly indicates that the proposed scheme, QAA-CDOM hyperspectral remote sensing inversion, is robust and reliable to quantify CDOM's concentration, distribution and dynamic for diverse waters, and hence can be applied to other regions.
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Ying-Chi, Chiang. "Classical Theory Of Multi-Chromophoric Energy Transfer And Surface-Plasmon-Polariton Enhancement With Applications To Supra-Molecular Structures." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2007200614504200.
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Chiang, Ying-Chi, and 江瑛芝. "Classical Theory Of Multi-Chromophoric Energy Transfer And Surface-Plasmon-Polariton Enhancement With Applications To Supra-Molecular Structures." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/72783749723968147518.
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