Physical Sciences and Mathematics Commons^™

Molecular Mechanism Of Dream Dimerization And Interactions With A Non-Physiological Ligand Zn2+., Maria D. Santiago Estevez

FIU Electronic Theses and Dissertations

Downstream Regulatory Element Antagonist Modulator (DREAM) belongs to the family of neuronal calcium sensor proteins and it is involved in several processes in the brain.

Zinc has been shown to bind to recoverin, with submillimolar affinity. Based on the high sequence homology between the NCS family, it is proposed that DREAM can also serve as an intracellular target for Zn²⁺. Fluorescence and CD studies confirm that zinc binds to DREAM with a of K_d = 4 µM, triggering changes in the proteins’ tertiary structure.

The calcium association to DREAM leads to the formation of a Ca^{2+ …}

Consequences Of Non-Physiological Ligands Binding To Dream On Its Secondary And Tertiary Structures And Interactions With Intracellular Partners., Samiol Azam

FIU Electronic Theses and Dissertations

Downstream regulatory antagonist modulator (DREAM) is 29 kDa neuronal calcium sensor (NCS) protein which is expressed in the hippocampus of the brain. DREAM is a multifunctional protein which is involved in a wide spectrum of biological processes, including regulation of potassium current in brain, modulation of pain, presenilin-1 processing, regulation of memory and learning. Exposure to toxic metals such as Pb2+ and Cd2+ have been associated with different types of neurodegenerative diseases. However, how these toxic metals induce neurotoxicity remains an active area of research. In this study, utilizing a combination of spectroscopic and calorimetric techniques, we demonstrated binding of …

Topological Markers For Subcellular Chemical Mapping Using Tof-Sims, Anthony Castellanos

FIU Electronic Theses and Dissertations

Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is a powerful mass spectrometry imaging technique that is uniquely suited to the study of small and challenging biological samples. Mass spectrometry imaging permits the simultaneous detection of chemical species without a priori knowledge of a sample. In the present work, the use of endogenous chemical species, three-dimensional dual-beam depth profiling, and multi-modal mass spectrometry approaches are utilized to increase the specificity and reliability of sub-cellular chemical assignments. In addition, the use of these complimentary indicators serve as useful quality controls to ensure optimal preparation of samples for a high-vacuum environment. In the study …

Development Of Microfluidic Paper-Based Analytical Devices For The Detection Of Low Explosives, Kathryn R. Chabaud

FIU Electronic Theses and Dissertations

Incidents of terrorism have been on the rise despite increased government regulation of explosives. These regulations and the internet have made the application of improvised explosive devices (IEDs) such as fireworks and smokeless powders more prevalent. These devices contain low explosives which are easier to acquire than high explosives, which are more closely monitored. Pipe bombs typically contain smokeless powders, which are mostly comprised of energetics such as nitroglycerine (NG) and organic additives such as diphenylamine. Another type of easily obtainable material containing low explosives is pyrotechnics. Pyrotechnics are usually made up of a mixture of inorganic chemical oxidizers and …

Development Of Dna Methylation Markers To Infer Age, Smoking Status And Body Fluid Types For Forensic Application, Hussain J.H. Alghanim

FIU Electronic Theses and Dissertations

In forensic investigations, biological evidences have great potential to place a suspect at the scene of a crime. However, in many cases suspect(s) usually can’t be identified with any local or national databases. In such challenging cases, police need a tool that can provide investigative leads. Thus, different genetic biomarkers including DNA methylation markers have been developed for different phenotypic traits to serve as source of intelligence information to investigators in cases of unknown DNA profiles. In this project, novel sets of DNA methylation markers were developed for the forensic estimation of human age, determining the smoking status and body …

Functionalized Aptamers For Detection Of Small-Molecule Targets, Haixiang Yu

FIU Electronic Theses and Dissertations

Aptamers have recently gained considerable attention for small-molecule detection in diverse applications such as drug identification, medical diagnostics, and environmental monitoring. However, the performance of aptamer-based sensors has been greatly limited by the low target affinity and responsiveness of small-molecule binding aptamers. This dissertation describes several novel aptamer engineering and isolation strategies to remedy this problem. Specifically, we first develop a generally applicable strategy to engineer split aptamers containing two binding domains termed cooperative-binding split aptamers (CBSAs). CBSAs exhibit higher target binding affinity and are far more responsive in terms of target-induced split aptamer assembly compared to single-domain parent split …

Development Of Improved Extraction/Purification Methods And Comprehensive Screening/Confirmation By Lc-Qqq-Ms Analysis For Novel Psychoactive Substances, Ashley N. Kimble

FIU Electronic Theses and Dissertations

The presence of novel psychoactive substances (NPS) in forensic casework poses major difficulties for detection, since there are many structural variations of NPS circulating in the street market. There are currently no comprehensive screening/confirmatory/quantitation methods available that encompass the majority of NPS encountered in forensic toxicology. A major issue faced with developing such a method is that full validation is extremely time consuming. The use of a liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) method makes the detection of a large number of NPS possible because of high selectivity and sensitivity.

This research included four main tasks: 1) development …

Comprehensive Analysis Of Synthetic Cannabinoids And Metabolites In Oral Fluid By Liquid Chromatography Triple Quadrupole Mass Spectrometry, Carmen T. Mulet

FIU Electronic Theses and Dissertations

According to NIDA, synthetic cannabinoids (SC) include man-made, mind-altering chemicals. Their typically rapid metabolism and instability in biological matrices requires fast analytical methods for detection and confirmation; therefore, the use of oral fluid (OF) matrix is advantageous because collection is fast and non-invasive. The use of liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS) and online solid phase extraction (SPE) for sample pretreatment minimizes bias and facilitates low level detection.

This study demonstrates the first use of online SPE for sample pretreatment in the comprehensive analysis of 100 SC and metabolites in OF by LC-QqQ-MS. The method was validated according the …

Towards Trigonal Prismatic Hexanuclear Copper Complexes For Catalytic Water Oxidation, David I. Kreiger

FIU Electronic Theses and Dissertations

Our planet is running out of energy resources and traditional renewables are not easily transported nor will be sufficient to cover the void left by fossil fuels. Therefore, a new energy storage system needs to be adopted. The medium with highest energy density that is readily available is hydrogen from water. However, to access hydrogen, water needs to be oxidized and water oxidation catalysts (WOCs) will be required for widespread adoption. In pursuit of WOCs, several hexauclear copper complexes were synthesized and characterized, including the isolation and characterization of a mixed-valent Cu₆ (formally, Cu^II₅Cu^III) …

Phenolate Derivatives Of Octanuclear Iron-Oxo-Pyrazolato Complexes; Enantiomeric Resolution Of T-Symmetry Species, Konstantinos Lazarou

FIU Electronic Theses and Dissertations

Octanuclear ferric complexes involving achiral phenolates of the general formula [Fe₈(μ-O)₄(μ-pz)₁₂(R-C₆H₄O)₄], (R = 4-NO₂, 4-CN, 4-F, 4-Cl, 4-I, 4-CH₃O, and 3-NO₃), where synthesized and characterized by single crystal X-ray crystallography, elemental analysis, ¹H-NMR, UV-Vis, IR, ⁵⁷Fe Mössbauer spectroscopy and electrochemical methods (cyclic and differential pulse voltammetry). Results indicate that the nature of the phenolate substituents allows the fine tuning of the spectroscopic data of the compounds.

Subsequently, this project focused on the resolution of the racemic …

Tuning The Coordination Properties Of Pyrazoles Towards Specific Applications Via Judicial Choice Of Peripheral Substitution, Shambhu Kandel

FIU Electronic Theses and Dissertations

The tunability of pyrazoles make them probably the most versatile ligands, and this is one of the right reasons to its use. Pyrazolyl ligands have intrinsic antibacterial property. Synthesis of pyrazolyl complexes with silver can be of great interest in biological applications. The urgent need to find alternative of currently used antibiotics has been recognized as a major challenge of the 21^st century. Many ideas have been proposed, but re-emergence silver could be the most promising alternative to overcome the limitations of these antibiotics. In spite of the popularity of Sonogashira coupling reactions, there is still a room to …

Interrogation Of Ion-Neutral Complexes By Trapped Ion Mobility-Mass Spectrometry And Theoretical Calculations, Alan A. Mckenzie Coe

FIU Electronic Theses and Dissertations

In the present study, the fundamentals of molecular ion trapping and the application of trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) to the separation and identification of molecular components in complex mixtures are shown. In particular, ion-neutral complexes lifetimes, relative stability, binding energies and candidate structures are described for common explosives during TIMS-MS, as well as the effect of the micro-environment, during complex sample analysis. A novel TIMS-MS workflow was developed for the detection of both inorganic residues (IGSR; inorganic gunshot residues) and organic residues (OGSR) of firearm discharge residue from skin swabs, capable of high specificity and …