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Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Structural Insights Into The Regulation Of Electron Transfer In Nitrogenase, And Modulating The Reactivity Of The Isolated Iron Molybdenum Cofactor, Andrew J. Rasmussen May 2016

Structural Insights Into The Regulation Of Electron Transfer In Nitrogenase, And Modulating The Reactivity Of The Isolated Iron Molybdenum Cofactor, Andrew J. Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the most important scientific advances in the last century was the Haber-Bosch process, the industrial process of fixing nitrogen from the atmosphere to ammonia. This allowed for the commercial production and sale of nitrogen for important uses such as fertilizer for farming. The Haber-Bosch process is partially credited with the population boom that has been seen in the last century and has greatly increased the standard of living in the developed world today. While this was a great scientific breakthrough, the cost of producing the required ammonia is high, and roughly 2% of worldwide energy is used annually …


Computational Studies Of Microscopic Superfluidity In 4he Clusters, Angeline R. Wairegi May 2016

Computational Studies Of Microscopic Superfluidity In 4he Clusters, Angeline R. Wairegi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The onset of microscopic superfluidity has been reported in ultracold droplets of bosons (4He atoms or para-H2 molecules) containing a variety of molecular dopants. The physics of these droplets involve both Bose-Einstein condensation (BEC) and superfluidity. The two phenomena, while closely related, are not exactly the same. Superfluidity is fundamentally a microscopic effect and thermodynamic limit is necessary; it is still remarkable, though, that the signature of superfluidity has been reported in doped droplets consisting of as few as 4 4He atoms. The studies presented here adopt a molecular vantage point to investigate the quantum mechanics …


Synthesis, Structure-Activity Relationship Study, And Mode Of Action Study Of 1,4-Naphthoquinone Based Anticancer And Antimicrobial Agents, Jaya P. Shrestha May 2016

Synthesis, Structure-Activity Relationship Study, And Mode Of Action Study Of 1,4-Naphthoquinone Based Anticancer And Antimicrobial Agents, Jaya P. Shrestha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The first three projects involve the synthesis and the mode of action study of 1,4-naphthoquinone based anticancer agents. These anticancer agents are highly potent against a wide range of cancer cell lines. These compounds showed ~8-fold selectivity towards the lung cancer cell line than the normal cell line. We also studied the mode of action and observed that generation of reactive oxygen species is the primary mode of action.

The final project involves the synthesis of multi-cationic antimicrobial agents. These compounds are active against both bacteria and fungi. These compounds are very easy to synthesize and can be scaled up …


Quantum Mechanical Studies Of Charge Assisted Hydrogen And Halogen Bonds, Binod Nepal May 2016

Quantum Mechanical Studies Of Charge Assisted Hydrogen And Halogen Bonds, Binod Nepal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Like cement bridges one brick to another, noncovalent forces also bridge two or more molecules together to form a molecular crystal or molecular cluster. Although weaker than the covalent bond, the existence of noncovalent forces can be seen everywhere from liquid water to construction of complex biomolecules like DNA, RNA, proteins etc. An introduction of suitable charge; positive or negative, on the binding units can increase the strength of noncovalent interaction by several orders of magnitude. The primary aim of this dissertation is to explore some fundamental properties of such charge assisted noncovalent interactions which will be helpful for the …


Oxidative Carbon-Carbon Bond Cleavage Reactions Of Metal Flavonolato And Chlorodiketonate Complexes, Sushma L. Saraf May 2016

Oxidative Carbon-Carbon Bond Cleavage Reactions Of Metal Flavonolato And Chlorodiketonate Complexes, Sushma L. Saraf

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research presented in this dissertation focuses on the oxidative cleavage of chemical bonds between two carbon atoms. This type of reactivity is of significant interest due to its potential application toward the development of ways to convert chemical feed stock into useful products such as pharmaceuticals, polymers and fuels in an environmentally benign and cost-efficient manner. Reactions that cleave specific carbon-carbon bonds, are catalyzed by earth-abundant metals, and involve O2 as the terminal oxidant, are of particular interest.

Our strategy has been to study the oxidative carbon-carbon bond cleavage reactivity of metal complexes containing components similar to structures …


Fluorescent Probes To Investigate Homologous Recombination Dynamics, Eric Parker Davenport May 2016

Fluorescent Probes To Investigate Homologous Recombination Dynamics, Eric Parker Davenport

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As the average cell’s DNA undergoes roughly 1 million molecular lesions per day, learning about one of the repair mechanisms which fixes damaged DNA is a worthwhile endeavor. Such work may provide insights into how to treat or prevent diseases such as cancers and associated genetic disorders. Homologous recombination (HR) is one pathway which is used by cells to repair a specific type of DNA damage, double-strand breaks. While HR is a complex process involving over 25 different proteins, exactly how HR works, including its regulation, is largely unknown. One protein in particular, Rad51, forms a filament on the damaged …


Computational Chemistry Of Non-Covalent Interaction And Its Application In Chemical Catalysis, Vincent De Paul Nzuwah Nziko May 2016

Computational Chemistry Of Non-Covalent Interaction And Its Application In Chemical Catalysis, Vincent De Paul Nzuwah Nziko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Known to be weaker than conventional covalent bonds, non-covalent bonds, especially hydrogen bond, has shown to be of great importance in molecular structures such as DNA, RNA, proteins and other organic frameworks. In this dissertation, we looked at non-covalent interactions other than the hydrogen bond. Replacement of the bridging hydrogen atom in a typical hydrogen bond by other atoms such a halogen, chalcogen and tetrel lead to the formation of interactions which are comparable in strength to the hydrogen bond. Unlike the hydrogen bond which arises mainly from electrostatics, these unconventional interactions mostly result from induction. Besides studying the fundamentals …


Heterogeneous And Homogeneous Nickel-Based Electrocatalysts For Oxygen Evolution And Carbon Dioxide Reduction, Meili Sheng May 2016

Heterogeneous And Homogeneous Nickel-Based Electrocatalysts For Oxygen Evolution And Carbon Dioxide Reduction, Meili Sheng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The growing global energy demand and the increasing concentration of CO2 in the atmosphere have encouraged the development of renewable energy to replace carbon-based fossil fuels. Electrocatalytic water splitting to form H2 and O2 and reduction of CO2 to CO are appealing processes and we can be directly utilize H2 and CO as fuels or commodity chemicals in mature industrial processes, which will not alter the current carbon cycle. However, the O2 evolution reaction of water splitting is a reaction of four-proton and four-electron transfer process, whose kinetics is very sluggish under normal conditions. …


Atp Usage In The Dark-Operative Protochlorophyllide Oxidoreductase, Mark S. Soffe May 2016

Atp Usage In The Dark-Operative Protochlorophyllide Oxidoreductase, Mark S. Soffe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chlorophylls are essential pigment molecules that function in photosynthesis, and serve to aid in utilizing energy from sunlight to power cellular processes in plants, and other organisms. To make chlorophyll, photosynthetic organisms devote an abundance of resources and energy to ensure their appropriate construction. This process of making chlorophylls is highlighted by the penultimate step in the pathway—the conversion of protochlorophyllide (Pchlide) to chlorophyllide a (Chlide).

This conversion can be mediated in two different ways, depending on the type of organism. The first method incorporates the use of a light-activated system called the light-dependent protochlorophyllide oxidoreductase (LPOR). This system, as …