Physical Sciences and Mathematics Commons^™

Influence Of Shelling Temperature And Time On The Optical And Structural Properties Of Cuins2/Zns Quantum Dots, Colette Robinson

Graduate Theses and Dissertations

CIS/ZnS core/shell QDs are an important class of nanomaterials for optoelectronic, photovoltaic and photoluminescence applications. They consist of lower toxicity materials than the prototypical II-VI Cd-based QDs and show long fluorescence lifetimes, which generates prospective in biological imaging applications. It is vital to develop reproducible synthetic methods for this new class of nanomaterials in order to maintain small sizes with high QYs. CIS core QDs have been shelled with ZnS at various temperatures from 90-210°C for reaction times ranging from 20-140 minutes to examine the role of thermodynamics and kinetics on the shell growth. Using HR-TEM and ICP-MS, it was …

Synthesis Of Medicinally Relevant Thiazolyl Aryl Ketones Under Mild Conditions, Danielle M. Gardner

Health, Human Performance and Recreation Undergraduate Honors Theses

Purpose: The growing amount of clinical resistance observed in current antifungal drugs and in anti-HIV pharmaceuticals is a concern in the medical community. The purpose of this study is to develop a mild synthetic process for biomedically relevant thiazolyl aryl ketones that can be used to develop antifungal and anti-HIV drugs. We hypothesized that the proposed synthetic technique would be more efficient, produce fewer unwanted byproducts, and be more tolerant of functional groups than existing methods.

Methods: Prior to each of the ketone reactions, the necessary salt was synthesized by mixing thiazole and 9-bromofluorene neat in a reaction tube heated …

Designing Fret Assays To Study Electrostatic Interactions Pertaining To The Binding Of Intrinsically Disordered Proteins, Ashley Ann Howard

Graduate Theses and Dissertations

Fibroblast growth factor receptor plays a major role in several biological processes. Without FGFR, a human cannot live. FGFR is involved in cell differentiation and wound healing. Of course, if FGFR signaling becomes unregulated, it causes severe distress in the body. Several cancers are contributed to high signaling levels, as well as developmental conditions like rickets and Kallmann’s syndrome. FGFR is thought to undergo an auto-inhibition (or self-regulatory) process in order to try to facilitate regulation. The exact method of this inhibition is currently unknown, but is proposed to involve the unstructured acid box region of FGFR. We developed a …

Asymmetric Synthesis And Transition Metal-Catalyzed Cross-Coupling Arylations Of Selected Organolithiums, Barry Kyle Sharp

Graduate Theses and Dissertations

My former boss, Dr. Gawley, always loved to say, “The world is chiral” (à la Pasteur). From DNA and proteins to hands and feet, it is obviously true. Also, a wide variety of chemical products exist as single enantiomers. Advances in chemical technology have greatly accelerated asymmetric synthesis in the past quarter century, and namely, organolithiums, have been shown to provide a versatile route to chiral natural products and biologically active molecules. Versatility arises from the array of methods that produce a chiral organolithium. Dynamic thermodynamic resolution (DTR) is considered one of the most practical methods, but among the others …

In Vitro Microdialysis Sampling Collection Of Volatile Organic Compounds (Voc's), Dodecafluoropentane (Ddfp) And Isoflurane, Valerie Shannon Mckinney

Graduate Theses and Dissertations

Death by stroke occurs every four minutes to human beings. Strokes cause necrosis within the tissue of the brain due to deprivation of oxygen. Perfluorocarbons have the ability to transport oxygen to tissue and in return decrease cell death. Dodecafluoropentane (DDFP) is a volatile fluorocarbon and collection in vivo can be a challenge since this compound evaporates at room temperature. There is currently not an efficient collection method in vivo for compounds that are volatile. Without a method to collect DDFP it is impossible to be approved for clinical use since exact concentrations of the drug within the body will …

Characterization Of Cellulase Enzyme Inhibitors Formed During The Chemical Pretreatments Of Rice Straw, Kalavathy Rajan

Graduate Theses and Dissertations

Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning …

Wave Profile For Anti-Force Waves With Maximum Possible Currents, M. Hemmati, R. Horn, W. P. Childs, A. K. Meredith

Journal of the Arkansas Academy of Science

In the theoretical investigation of the electrical breakdown of a gas, we apply a one-dimensional, steady state, constant velocity, three component fluid model and consider the electrons to be the main element in propagation of the wave. The electron gas temperature, and therefore the electron gas partial pressure, is considered to be large enough to provide the driving force. The wave is considered to have a shock front, followed by a thin dynamical transition region. Our set of electron fluid-dynamical equations consists of the equations of conservation of mass, momentum, and energy, plus the Poisson's equation. The set of equations …

Bond Length - Bond Valence Relationships For Carbon - Carbon And Carbon - Oxygen Bonds, C. Harris, F. D. Hardcastle

Journal of the Arkansas Academy of Science

In the present study, relationships are developed for determining bond orders (also referred to as bond valences or bond numbers) from published bond lengths for carbon-carbon (C-C) and carbon-oxygen (C-O) bonds. The relationships are based on Pauling’s empirical formula s = exp((Ro-R)/b)), where s is the bond order, R is the corresponding bond length, Ro is the unit valence bond length, and b is a fitting parameter. We use a recently derived relationship for the b parameter in terms of the bonding atoms’ published atomic orbital exponents. The resulting equations were checked against published x-ray diffraction (XRD) data for 176 …

Low-Level Mercury Causes Inappropriate Activation In T And B Lymphocytes In The Absence Of Antigen Stimulation, K. L. Weigand, J. L. Reno, B. M. Rowley

Journal of the Arkansas Academy of Science

The immune system primarily utilizes two cell types for adaptive immunity: T lymphocytes and B lymphocytes. T lymphocytes are activated when antigen presenting cells (APCs) present antigen to membrane-bound T cell receptors. B lymphocytes are activated when an antigen binds to receptors embedded in the plasma membrane. In both T and B cells this antigen binding crosslinks the receptor complexes and initiates the signal transduction cascade. These cascades frequently consist of a series of intracellular molecules becoming phosphorylated in a step-wise fashion. Once activated, these cells differentiate into effector cells that clear out the stimulating antigen. Mercury, which is a …