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Full-Text Articles in Physical Sciences and Mathematics
An Investigation Of Urban Mobile Source Aerosol Using Optical Properties Measured By Crdt/N: Diesel Particulate Matter And The Impact Of Biodiesel, Monica Elizabeth Wright
An Investigation Of Urban Mobile Source Aerosol Using Optical Properties Measured By Crdt/N: Diesel Particulate Matter And The Impact Of Biodiesel, Monica Elizabeth Wright
Dissertations and Theses
Mobile source emissions are a major contributor to global and local air pollution. Governments and regulatory agencies have been increasing the stringency of regulations in the transportation sector for the last ten years to help curb transportation sector air pollution. The need for regulations has been emphasized by scientific research on the impacts from ambient pollution, especially research on the effect of particulate matter on human health. The particulate emissions from diesel vehicles, diesel particulate matter (DPM) is considered a known or probable carcinogen in various countries and increased exposure to DPM is linked to increased cardiovascular health problems in …
Understanding The Emission From Semiconductor Nanoparticles, Beth Ann Manhat
Understanding The Emission From Semiconductor Nanoparticles, Beth Ann Manhat
Dissertations and Theses
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 …
Spontaneous Cooperative Assembly Of Replicative Catalytic Rna Systems, Nilesh Vaidya
Spontaneous Cooperative Assembly Of Replicative Catalytic Rna Systems, Nilesh Vaidya
Dissertations and Theses
The RNA World hypothesis proposes a period of time during the origins of life in which RNA molecules were the only source of both genotypes and phenotypes. Although a vast amount of evidence has been obtained in support of this hypothesis, a few critical demonstrations are lacking. A most crucial one is a demonstration of self-replication of RNA molecule from prebiotic soup. Previously in the Lehman laboratory, it has been demonstrated that a 198-nucleotide molecule derived from the Azoarcus group I intron can self-assemble from up to four fragments of RNA via recombination. Furthermore, the covalent full-length molecules are catalytically …
Biosynthesis Of Marineosin, A Spiroaminal Undecylprodiginine Natural Product, Shaimaa Mohamed Salem
Biosynthesis Of Marineosin, A Spiroaminal Undecylprodiginine Natural Product, Shaimaa Mohamed Salem
Dissertations and Theses
Marineosins A and B are two spiroaminal-ring containing tripyrrole compounds isolated from the marine actinomycete, Streptomyces CNQ-617, and were found to possess potent and selective cytotoxic activity against leukemia and melanoma. Marineosins belong to the prodiginines class of natural products, examples of which are undecylprodiginine and streptorubin B. Unlike marineosins, prodiginines structures are characterized by the presence of fully conjugated tripyrrole nucleus linked to an alkyl chain (that lacks any oxygen). Cyclic prodiginines arise from an oxidative cyclization of the alkyl chain onto the tripyrrole, a step catalyzed by Rieske-oxygenase like enzymes such as RedG. The biosynthesis of prodiginines is …