Analytical Chemistry Commons^™

Surface Modifications Of Capillary-Channeled Polymer (C-Cp) Fibers For Applications In Highly Selective Separations, Jennifer Pittman

All Dissertations

High Performance Liquid Chromatography (HPLC) is a key component in the purification and separation of biological samples. Stationary phases in HPLC are generally silica based porous particles or monoliths designed with high surface area and high capacities in mind. However, in the field of macromolecule separations, specifically proteins, the porous based stationary phases have inherent issues that include slow mass transfer, high operating back pressures, and analyte carryover. Recent research has looked to non-porous polymeric materials as stationary phases in HPLC to overcome these challenges. Specifically, fibrous based polymer stationary phases exhibit significant benefits for macromolecules that include improved mass …

An Examination Of Oxidative Passivated Surfaces On 19th Century Colt Revolver Barrels, Mckenzie Allison Floyd

Scripps Senior Theses

Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to examine a series of six revolver barrels manufactured by the Colt Patent Arms Manufacturing Company between 1853 and 1863. SEM micrographs revealed a vast range of surface morphologies among the corroded samples. XRD diffraction patterns showed varying levels of magnetite on the blackened samples, but hematite could not be identified. EDS was used to map elemental distribution and quantify elemental abundances on the gun surfaces; further investigation using this technique may reveal more definitive information on whether some elements present were deposited during patination.

Identification And Analysis Of Stereoselective Drug Interactions With Low Density Lipoprotein By High-Performance Affinity Chromatography, Matt Sobansky, David S. Hage

Department of Chemistry: Faculty Publications

Columns containing immobilized low density lipoprotein (LDL) were prepared for the analysis of drug interactions with this agent by high-performance affinity chromatography (HPAC). R/SPropranolol was used as a model drug for this study. The LDL columns gave reproducible binding to propranolol over 60 h of continuous use in the presence of pH 7.4, 0.067 M potassium phosphate buffer. Experiments conducted with this type of column through frontal analysis indicated that two types of interactions were occurring between R-propranolol and LDL, while only a single type of interaction was observed between S-propranolol and LDL. The first type …

Using Photoactive Nanoparticles As Photodynamic Antimicrobial Chemotherapeutic (Pact) Agent To Treat Chronic Wounds, Chaitanya Poola

All Capstone Projects

The purpose of this study is to use photoactive vitamin nanoparticles as photodynamic antimicrobial chemotherapeutic agent to treat patients with chronic wounds. Chronic wounds are considered as a pandemic health problem which affects millions of people and increases ~10 % annually. According to the American Academy of Dermatology, the expense of treating chronic wounds constitutes over half of the total cost for all skin diseases. The main cause of chronic wounds is due to the existence of biofilms. Biofilms are complex microbial communities containing and are reported to be major factor contributing to multiple chronic inflammatory diseases. Owing to bacterial …

Detection Of Folate Receptor From Fr+ Cells, Gopikrishna Pinnaka

All Capstone Projects

Targeted drug delivery is a newer and less explored arena that has potential scope in tumor targeting because the regular chemotherapy has lethal effects on the normal cells also. Our present Work was an attempt to specifically target receptors on cancerous cells, especially the Folate Receptor (FR). Folate is important for cells for DNA synthesis and the tissues that rapidly divide require folate, cancer cells are no exceptions for this. To cope with the increased demand for the folate the cancer cells express greater FR on the cell surface. This very fact was our basis for the construction of our …

Folate Nanoparticle Conjugates, Safwat A. Masood

All Capstone Projects

The folate receptor is overexpressed on the surface of numerous cancer cell types including those of the breast, lung, kidney, ovary, and brain. Recent interest has exploded in the use of folate to deliver payloads and imaging agents to folate receptor positive cancer cells based on several positive clinical trials including phase III trials of EC-145, which is poised to become the first folate targeted, FDA approved drug. Given the success of EC-145 and numerous other agents in the pharmaceutical pipeline, there remains a great interest in the exploitation of this technology in the delivery of nanoscale agents to folate …

Interaction Between Humic Acid And Dna, Sree Divya Bikki

All Student Theses and Dissertations

Humic acid (HA) are widely dispersed, naturally occurring biopolymers most commonly found in soil, drinking water, and plants. Humic acid is soluble in alkali and insoluble in an acidic medium or water. In the present study the interaction of Humic acid with DNA is determined by the calculation of the binding constant of humic acid with CT-DNA and the quenching phenomenon of humic acid in the presence of DNA is also studied using Stern Volmer Relationship.

Design Of In Vivo Assays For Study Of Transport, Biocompatibility And Toxicity Of Nanoparticles, Kerry Jean Lee

Theses and Dissertations in Biomedical Sciences

This dissertation focuses on the design of new in vivo assays for study of transport, biocompatibility and toxicity of nanoparticles (NPs) in zebrafish embryos. We synthesized and purified spherical silver (Ag) NPs with diameters, ranging from 12 to 95 nm, that are stable (non-aggregated) in egg-water media. We developed new imaging approaches to characterize the sizes of single Ag NPs in zebrafish embryos at nanometer resolution by measuring their size-dependent plasmonic spectra and scattering intensity using dark-field optical microscopy and spectroscopy (DFOMS). We used single Ag NPs because they exhibit the high quantum yield (QY) of Rayleigh scattering and resist …

Strawberry Growth, Yield, Fruit Nutrition, And Control Of Verticillium Wilt With Pre-Plant Soil Fumigants, Ozone, And Biological Control, Justin J. Scurich

Master's Theses

Verticillium wilt is a widespread soilborne disease of strawberry historically controlled by soil fumigation with methyl bromide (MB). MB was banned by the United Nations in 1995 and will be completely phased out by 2015. Research has concentrated on alternative methods of disease control without finding a single alternative able to replace MB in widespread disease control and yield increase. For the current study, strawberries were greenhouse grown in container pots filled with soil from both infested and non-infested areas of a commercial strawberry field in Watsonville, CA. Treatments included pre-plant soil fumigation with commercially available formulations of methyl bromide, …

K-Shell X-Ray Spectroscopy Of Atomic Nitrogen, M. M. Sant'anna, Gunnar Ohrwall, Wayne C. Stolte, Alfred S. Schlachter, Dennis W. Lindle, B. M. Mclaughlin

Chemistry and Biochemistry Faculty Research

Absolute K-shell photoionization cross sections for atomic nitrogen have been obtained from both experiment and state-of-the-art theoretical techniques. Because of the difficulty of creating a target of neutral atomic nitrogen, no high-resolution K-edge spectroscopy measurements have been reported for this important atom. Interplay between theory and experiment enabled identification and characterization of the strong 1s → np resonance features throughout the threshold region. An experimental value of 409.64 ± 0.02 eV was determined for the K-shell binding energy.

Electrochemical Behavior Of Imidacloprid, Jie-Qiong Wang, Wang Zhang, Ming Chen, Guo-Wang Diao

Journal of Electrochemistry

The electrochemical behavior of imidacloprid（IDP）on glassy carbon electrode has been investigated by cyclic voltammetry. The result shows that the electrochemical reduction of IDP is irreversible and controlled by diffusion. At 25 ℃, the numbers of the electrons transferred of IDP in the electrochemical reaction are four. The diffusion coefficient of IDP is 2.44×10⁶ cm²·s^-1 and the diffusion activation energy is calculated to be 9.33 kJ·mol^-1.

Preparation And Rapid Analysis Of Antibacterial Silver, Copper And Zinc Doped Sol–Gel Surfaces, Brendan Duffy, Swarna Jaiswal, Patrick Mchale

Articles

The colonisation of clinical and industrial surfaces with microorganisms, including antibiotic-resistant strains, has promoted increased research into the development of effective antibacterial and antifouling coatings. This study describes the preparation of metal nitrate (Ag, Cu, Zn) doped methyltriethoxysilane (MTEOS) coatings and the rapid assessment of their antibacterial activity using polyproylene microtitre plates. Microtitre plate wells were coated with different volumes of liquid sol–gel and cured under various conditions. Curing parameters were analysed by thermogravimetric analysis (TGA) and visual examination. The optimum curing conditions were determined to be 50–70C using a volume of 200ul. The coated wells were challenged with Gram-positive …

Unusual Activities Of The Thioesterase Domain For The Biosynthesis Of The Polycyclic Tetramate Macrolactam Hsaf In Lysobacter Enzymogenes C3, Lili Lou, Haotong Chen, Ronald Cerny, Yaoyao Li, Yuemao Shen, Liangcheng Du

Ronald Cerny Publications

HSAF is an antifungal natural product with a new mode of action. A rare bacterial iterative PKSNRPS assembles the HSAF skeleton. The biochemical characterization of the NRPS revealed that the thioesterase (TE) domain possesses the activities of both a protease and a peptide ligase. Active site mutagenesis, circular dichroism spectra and homology modeling of the TE structure suggested that the TE may possess uncommon features that may lead to the unusual activities. The iterative PKS-NRPS is found in all polycyclic tetramate macrolactam gene clusters, and the unusual activities of the TE may be common to this type of hybrid PKS-NRPS.

Plasma Spectroscopic Techniques Applied To Biological And Environmental Matrices, Morgan Steele Schmidt

Electronic Theses and Dissertations

The purpose of this research was to apply the use of direct ablation plasma spectroscopic techniques, including spark-induced breakdown spectroscopy (SIBS) and laser-induced breakdown spectroscopy (LIBS), to a variety of environmental matrices. These were applied to two different analytical problems. SIBS instrumentation was adapted in order to develop a fieldable monitor for the measurement of carbon in soil. SIBS spectra in the 200 nm to 400 nm region of several soils were collected, and the neutral carbon line (247.85 nm) was compared to total carbon concentration determined by standard dry combustion analysis. Additionally, Fe and Si were evaluated in a …

Dynamic Light Scattering And Microelectrophoresis: Main Prospects And Limitations, Vuk Uskoković

Pharmacy Faculty Articles and Research

Microelectrophoresis based on the dynamic light scattering (DLS) effect has been a major tool for assessing and controlling the conditions for stability of colloidal systems. However, both the DLS methods for characterization of the hydrodynamic size of dispersed submicron particles and the theory behind the electrokinetic phenomena are associated with fundamental and practical approximations that limit their sensitivity and information output. Some of these fundamental limitations, including the spherical approximation of DLS measurements and an inability of microelectrophoretic analyses of colloidal systems to detect discrete charges and differ between differently charged particle surfaces due to rotational diffusion and particle orientation …

Ƴ-Selective Directed Catalytic Asymmetric Hydroboration Of 1,1-Disubstituted Alkenes, Sean M Smith, Gia L. Hoang, Rhitankar Pal, Mohammad O. Bani Khaled, Liberty S. W. Pelter, Xiao Cheng Zeng, James M. Takacs

Xiao Cheng Zeng Publications

Directed catalytic asymmetric hydroborations of 1,1-disubstituted alkenes afford ƴ

-dioxaborato amides and esters in high enantiomeric purity (90–95% ee).

Development Of Mass Spectrometric Methods For The Analysis Of Serotonin And Related Compounds In Biological Matrices, Merisa Moriarty

Theses

Serotonin is a major neurotransmitter in the brain and affects various functions both in the brain and in the rest of the body. It has been linked to depression, migraines, and aggression, as well as many psychiatric disorders including schizophrenia, dementia and anorexia nervosa. It also has been associated with conditions like Alzheimer’s disease along with other neurotransmitters such as dopamine.

The aim of this research project is to develop various mass spectrometric methods for the analysis of serotonin, dopamine and similar indoles in both urine and serum matrices. This thesis provides extensive reviews detailing a general overview of serotonin …

Investigation Of Factors Influencing Trichloromethane Levels In Milk And Its Control., Siobhan Ryan

Theses

Trichloromethane (TCM) is an undesirable chemical residue that can develop in milk. While TCM levels in milk are not within ranges of public health concern, it is important that minimal levels are maintained in order to promote the marketing of Irish dairy products abroad. Germany has enacted strict regulations on TCM concentrations in foodstuffs with a recommended level of0.002 mg/kg and re-analyse those milks, subsequent to cause identification and provision of advice on reducing TCM levels in milk. Milk samples were analysed using Gas chromatography (GC) with electron capture detection. The GC method was adapted and a standard curve was …

Single Molecule Studies Of Rna-Target Interactions, Sharla Leann Wood

Wayne State University Dissertations

We have used FRET, single molecule spectroscopy, and several other biophysical techniques to study how the folding of RNA allows it to perform its various functions by recognizing and binding a target ligand. We have shown that the c-di-GMP riboswitch undergoes a large, global conformational change upon binding of the ligand. The folding dynamics of the c-di-GMP riboswitch upon Mg2+ binding help to pre-organize the aptamer for efficient ligand binding and ultimately efficient gene expression. We have also investigated two instances, a fluorophore-binding aptamer and molecular beacon, where the folding of RNA can be used to detect an analyte. We …

Effect Of Low Endogenous Brain-Derived Neurotrophic Factor Levels On Striatal Dopamine Dynamics, Francis Kabui Maina

Wayne State University Dissertations

Many neurological diseases and disorders are a result of alterations with neurotransmitters, neuromodulators, and/or proteins. Specifically, one protein that has been linked to numerous neurological diseases and disorders such as Parkinson's disease, Huntington's disease, addiction, attention deficit hyperactivity disorder (ADHD), and depression is brain-derived neurotrophic factor (BDNF). As a trophic factor, BDNF role is to assist in the growth, survival, and differentiation of neurons. However, there is increasing evidence that BDNF may mediate neurotransmitter dynamics. Our goals were to understand how endogenous BDNF levels and aging modulate the dopamine (DA) dynamics in the mouse striatum. Two complementary neurochemical techniques, slice …