Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 108 for “"singlet oxygen"”.
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Microchemical systems for singlet oxygen generation
Chemical Oxygen-Iodine Lasers (COIL) are a technology of interest for industrial and military audiences. COILs are flowing gas lasers where the gain medium of iodine atoms is collisionally pumped by singlet delta oxygen molecules, which are created through the catalyzed multiphase reaction of …
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Singlet Oxygen Production and Its Kinetics in Nanoparticle-Photosensitizer Hybrid Systems
Oxygen is inarguably among the most important molecules which sustain the majority of life as we know it. However, in its lowest excited state, singlet oxygen is a powerful cytotoxic agent capable of damaging DNA, proteins, and cell membranes. In medicinal context, production of singlet oxygen from …
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Light-activated materials for singlet oxygen generation and the degradation of pollutants
… which involve the generation of reactive oxygen species (ROS), are highly potent oxidizing processes and have emerged as an essential class of technologies to accelerate the non-selective oxidation resulting in the inactivation of a wide range of organic pollutants found in wastewater. …
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Part One: Ozonolysis of Diphenylvinylene Carbonate. Synthesis and Thermolysis of Dibenzoyl Monoperoxycarbonate. Part Two: Singlet Oxygen: The Lifetime of Singlet Oxygen in Solution and Its Reaction With Ene-Type Olefins
The reaction of ozone and diphenylvinylene carbonate is found to give dibenzoyl monoperoxycarbonate in good yield. A mechanism for the formation of this peroxide is proposed and is consistent with the Criegee mechanism for ozonolysis of most olefins. The thermolysis of dibenzoyl monoperoxycarbonate …
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Singlet oxygen generating luminescent lanthanide complexes with naphthalimide-based and oligothiophene-based sensitizers
… lanthanide (LnIII) complexes that also generate singlet oxygen (1O2) are of interest to medical, biological, and analytical fields, as they can provide cytotoxicity and luminescence using light excitation. Because of the interest in these compounds, systematic studies were used to help understand …
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Singlet Oxygen Generation Via Irradiation of 4-Benzylamino-7-Nitrobenz-2-Oxa-1, 3-Diazole
… (BBD) generates the first excited singlet state of molecular oxygen in liquid solution. The problem was first approached using the sensitized photooxidation method of singlet oxygen detection with 1, 3-cyclohexadiene (CHD) as acceptor. A reaction between BBD and the acceptor …
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The synthesis of aza-dipyrromethenes as potential pdt agents and measurement of singlet oxygen generation.
… using a photosensistiser that produces cytotoxic singlet oxygen (1O2) after light irradiation. Current approved photosensitisers have limitations, such as a low extinction coefficient in the desired therapeutic wavelength of absorption (600 “ 900 nm), as in the case of Photofrin®. The discovery …
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Dynamics and Kinetics of Singlet Oxygen Mediated Oxidation of Methionine in the Gas Phase, Hydrated Clusters and Solution
… methionine (Met) and electronically excited singlet molecular oxygen (O<sub>2</sub>[a<sup>1</sup>Δ<sub>g</sub>]) has been investigated in a systematic fashion, using a home-built electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer (MS). The study started from probing the …
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Understanding the singlet oxygen reactivity of salarin C through synthesis of a simplified macrocyclic analogue; multicomponent, enantioselective organocatalytic synthesis of tetrahydropyridazinones.
… the marked reactivity of its oxazole moiety with singlet oxygen that converts salarin C to its biologically inactive congener, salarin A. While this photocatalyzed rearrangement, i.e., Wasserman rearrangement, is known typically requiring UV irradiation and a photosensitizer to generate singlet …
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Roles of singlet oxygen and triplet excited state of dissolved organic matter formed by different organic matters in bacteriophage MS2 inactivation
Inactivation of bacteriophage MS2 by reactive oxygen species (ROS) produced by irradiation with simulated sunlight, containing visible light and ultraviolet light with wavelengths greater than 320 nm, was investigated. The results from experiments with synthetic sensitizers Rose Bengal, …
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Method For Determination Of Singlet Oxygen Quantum Yields For New Fluorene-based Photosensitizers In Aqueous Media For The Advancement Of Photodynamic Therapy
… generates cytotoxic species such as reactive singlet oxygen, leading to irreversible destruction of the treated tissue. The measurement of the singlet oxygen quantum yield is an important determinant used to evaluate the efficiency of new photodynamic therapy agents developed in the …
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Singlet Oxygen Oxidation of Guanine, 9-Methylguanine and Guanine-Cytosine Base Pair: Dynamics and Kinetics Revealed by Parallel Gas- and Solution-Phase Experiments and Computations
<p>Singlet oxygen (<sup>1</sup>O<sub>2</sub>) oxidatively generated damage of DNA gives rise to mutagenesis, carcinogenesis, and cellular death. Guanine is the most susceptible DNA target of <sup>1</sup>O<sub>2</sub>. The related process has been studied over three decades but the mechanism has …
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A Role For Reactive Oxygen Species In Photodynamic Therapy
… the photosensitizer was transferred to dissolved oxygen to form singlet oxygen. This product has a very brief half-life and will cause cellular damage only in the immediate vicinity of its formation. But an excited-state photosensitizer can also interact with oxygen to form superoxide anion …
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Oxidation of waxes using microwave-generated singlet molecular oxygen
… For certain of the latter, a wax containing Oxygen groups is often the most appropriate type. While there are a number of such waxes that occur naturally, there are also many more in which the raw wax has undergone oxidation by chemical processes. Generally, this is done utilising elevated …
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The micro-optical ring electrode: Development of a novel thin ring based device for spectrophotoelectrochemistry and its application to the study of rose bengal
… been investigated and found to correspond to the singlet-to-singlet, metal-to-ligand charge transfer band of the UV-Visible spectrum of ruthenium(II) 2,2'-trisbipyridine complex. The value of the Stern-Volmer constant for the quenching of photoexcited Ru(bipy)3 2 by Fe3 obtained at the MORE …
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Mechanistic Studies of the Structure-Photostability Relationship of Organic Conjugated Polymers
… anion and the other mechanism is initiated by singlet oxygen. C8-diCN-PPV has a lower LUMO level compared to RO-diCN-PPV, yet photodegrades more quickly. RO-diCN-PPV and C8-diCN-PPV both photodegrade through a singlet oxygen mechanism. If DABCO, a singlet oxygen quencher, is introduced into the …
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The Development and Evaluation of a Range of Phototherapeutic Dyes Towards Infection Control
… These dyes were tested to determine the singlet oxygen yield and how the change in the structure affected the singlet oxygen production. The growth inhibition of these compounds were also tested to see how the changing the derivative affected the growth inhibition of each family of …
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METAL NANOSTRUCTURES-ENHANCED AIE-BASED PHOTOSENSITIZERS FOR PHOTODYNAMIC THERAPY
… are two main strategies to enhance the rate of singlet oxygen generation (SOG) and the photostability of the photosensitizers. The first approach is based on the molecular design, where the new generation of photosensitizers such as aggregation-induced emission photosensitizers (AIE-PS), could …
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(A). Regulation of B-/Z-DNA transition in modified oligonucleotides; (B). Synthesis of cationic BODIPY analogues for antimicrobial and anticancer applications
… iodide 111 was successfully synthesized. Singlet oxygen generation experiments suggested that BODIPY 111 is ~2.5 times more efficient with respect to Rose Bengal (RB) in generating singlet oxygen. However, based on the cell-culture experiment, BODIPY 111 treated culture plates showed only …
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Weathering of wood surfaces: characteristics, mechanisms, and prevention
… when wood was irradiated in the presence of singlet oxygen generators. The hydroperoxide concentration decreased when wood was irradiated in the presence of singlet oxygen quenchers. These findings imply the participation of singlet oxygen and the formation of hydroperoxides at the …
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