Digital Commons Network^™

Using Caulobacter Crescentus As A Model To Probe The Environmental Reactivity Of Silver Nanoparticles, Madeline M. Farber , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are an increasingly common environmental pollutant with antimicrobial and antibacterial properties. The elucidation of their interaction with cellular membranes and subsequent mechanisms of toxicity are critical areas of research that need to be better understood in order to manage potential adverse environmental effects. This work investigates the interaction of AgNPs with large unilamellar vesicles (LUVs) as a model membrane system. Similar studies conducted by others in this field have largely been conducted with uncoated AgNPs, ignoring the effect of environmental conditions on the formation of an eco-corona on AgNPs. Thus, in this study, the spent medium (SM) …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Paul C. Seth , '23

Senior Theses, Projects, and Awards

G-quadruplex (GQ) and i-motif (iM) non-canonical DNA structures can be formed by G- and C-rich sequences within the genome, respectively. GQ and iM DNA play important roles in different biological processes and are promising therapeutic targets. Recently, the first left-handed GQ (LHGQ) was discovered and much remains to be learned about the structure and function of LHGQ DNA.

In this thesis, we investigate the biophysical and structural behavior of two LHGQ-forming sequences from the human genome, from the Human Solute Carrier 1 (SLC) and nuclear receptor binding SET domain (NSD) genes. We found that flanking bases play an important role …

Using Capillary Electrophoresis To Quantify Competitive Binding Of Adsorbates To Silver Nanoparticles, Christopher D. Chung , '23

Senior Theses, Projects, and Awards

Silver nanoparticles (AgNPs) are increasingly used commercially and medically due to their antimicrobial and antibacterial properties. With increased use comes increased release of AgNPs into the environment, and once released, AgNPs can form coronas with molecules ranging from biomolecules to proteins to natural organic matter (NOM). The molecules in the corona adsorb to the surface of the AgNPs, drastically altering their innate properties such as cytotoxicity and binding behavior. In this study, we characterize and quantify model AgNP-adsorbate systems by obtaining their relevant reaction parameters through three different affordable analytical techniques, including dynamic light scattering (DLS), UV-vis spectroscopy, and capillary …

Master Equation Modeling Of Prompt Dissociation Kinetics For Isoprene Derived Criegee Intermediates, Rory R. Schmidt , '23

Senior Theses, Projects, and Awards

Isoprene ozonolysis is a major atmospheric producer of atmospheric oxidizers and aerosols. This complex reaction pathway forms an exothermic cascade, where constant competition between bimolecular sinks, unimolecular isomerizations, and collisional relaxation dictate reactivity. This work focuses on two isoprene derived Criegee intermediates, methacrolein oxide (MACR oxide) and formaldehyde oxide (FO). While the potential energy surface of FO is well understood, the reactivity of energetically excited FO has not been explored in detail. MACR oxide isomerization and primary products have been adequately characterized and explored computationally and experimentally, but the potential energy surface beyond isopropenyl dioxirane has not received the same …

Biophysical And X-Ray Crystallographic Characterizations On Complexes Of G-Quadruplexes With Small-Molecule Ligands, Ming Ye , '23

Senior Theses, Projects, and Awards

DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets for anticancer and antiviral drugs. Therefore, investigating the interaction between GQs and small-molecule ligands is important.

This thesis work surveyed the DNA-ligand interactions of over 20 GQ-ligand complexes via biophysical and X-ray crystallographic methods. Two sets of GQ-ligand complexes were characterized in detail. One set is a group of purine-only sequences, named GA, with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). The other set is a human telomeric sequence, Tel22, with …

Method Design For Separation Of Non-Canonical Dna Structures Via Capillary Electrophoresis, Erin V. Chen , '23

Senior Theses, Projects, and Awards

G-quadruplex DNA structures are highly relevant subjects of biochemical study, implicated in human diseases and cancer. Conventional methods for G-quadruplex DNA structure separation are time-consuming, environmentally unfriendly, and low throughput. Thus, there is a pressing need for alternative methods of separation to be developed for G-quadruplex DNAs. Here we present work in designing a separation method using the capillary electrophoresis instrument. Capillary electrophoresis is a highly automated, reusable, and quantitative technique that separates analytes based on their size and charge. A capillary method for G-quadruplex separation would be a valuable analytical tool to supplement the biophysical methods available by addressing …

Synthesis And Kinetic Investigation Of Oxidation In A Palladium-Methyl System, Richard A. Cardrino , '23

Senior Theses, Projects, and Awards

The current industrial syngas process for transforming methane to methanol is an indirect process that requires the initial oxidation of methane to carbon monoxide with a subsequent reduction to form methanol under high pressure and temperature conditions. An alternative green chemical process is desirable, especially one that directly oxidizes gaseous methane to liquid methanol under mild conditions with an environmentally benign oxidant, such as dioxygen. The current study investigates the synthesis of a novel palladium complex with activated methane and the selective oxidation of this complex resulting in the liberation of methanol under more ambient conditions, a model system for …