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Novel Thermal Analytical Techniques To Characterize Drugs And Drug Delivery, Lakshmi Swetha Kaza

ETD Archive

This thesis encompasses three significant projects. The study includes the characterization and evaluation of the properties of a commercial contraceptive transdermal patch, Ortho Evra® by Dielectric Analysis and Differential Scanning Calorimetry (DSC). This study helps in monitoring the mobility of the drug and transport properties by Isothermal and Scanning Dielectric Analysis as a function of temperature and frequency. The drugs in this product are norelgestromin and ethinyl estradiol. DSC was used to detect any crystalline character of the drugs by their fusion properties. Having no melting endotherm and detecting a glass transition temperature suggested that the drugs in the patches …

A New Noncovalent Force: Comparison Of P∙∙∙N Interaction With Hydrogen And Halogen Bonds, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

When PH(3) is paired with NH(3), the two molecules are oriented such that the P and N atoms face one another directly, without the intermediacy of a H atom. Quantum calculations indicate that this attraction is due in part to the transfer of electron density from the lone pair of the N atom to the σ(∗) antibond of a P-H covalent bond. Unlike a H-bond, the pertinent hydrogen is oriented about 180° away from, instead of toward, the N, and the N lone pair overlaps with the lobe of the P-H σ(∗) orbital that is closest to the P. In …

Introductory Chemistry, David W. Ball

Textbooks

This is the textbook for CHEM 105 at Liberty University.

David W. Ball of Cleveland State University brings his new survey of general chemistry text, Introductory Chemistry, to the market with a fresh theme that will be sure to hold student interest: "Chemistry is Everywhere." Introductory Chemistry is intended for a one-semester introductory or preparatory chemistry course. Throughout the chapters, David presents two features that reinforce the theme of the textbook, that chemistry is everywhere.

Effect Of Intraligand Π-Delocalization On The Photophysical Properties Of Two New Ru(Ii) Complexes, Dean H. Johnston

Chemistry Faculty Scholarship

Two new Ru(II) complexes, [Ru(bpy)2(1-COO-iqu)]+ (2; bpy = 2,2_-bipyridine, 1-COO-iqu− = isoquinoline- 1-carboxylate) and [Ru(bpy)2(3-COO-iqu)]+ (3; 3-COO-iqu− = isoquinoline-3-carboxylate), were prepared and their crystal structures solved. The ground and excited state properties of 2 and 3 were characterized and compared to those of [Ru(bpy)3]2+ (1). The presence of the oxygen atom in the Ru(II) coordination sphere makes 2 and 3 easier to oxidize than 1. The Ru→bpy MLCT absorption and emission of 2 and 3 are red-shifted relative to that of 1 in CH2Cl2, and the E00 energies were estimated to be 1.89 eV and 1.95 eV from the low …

2-[(Naphthalen-1-Yl­Methyl­­Idene)Amino]-5-Methyl­Phenol, Ralph Isovitsch, Gabriella Orona, Vanessa Molinar, Frank R. Fronczek

Chemistry

No abstract provided.

Modifiable Hyperbranched Polyester Drug Delivery Systems, Dorothy Ogden

Browse all Theses and Dissertations

This work encompassed synthesis and characterization of biocompatible hyperbranched polyester drug delivery systems prepared with fumaric acid, glycerol and polyethylene glycol. The polymers were manufactured in the melt utilizing A2 + CB2 polymerization. The ratio of A2:CB2 was modified and excess B was added to end-cap the polymers to avoid cross-linking. Fumaric acid was selected as the A2 monomer because the double bond provided a site for polymer backbone modification or covalent attachment of active pharmaceutical ingredients. Acetaminophen and Ondansetron Hydrochloride were added to evaluate feasibility of using the polyesters as drug delivery systems. The weight average molecular weight of …

An Evaluation Study Of The Effectiveness Of Using A Reaction-Based Process For Hydrazine Waste Remediation, Cristina M. Oropeza

Electronic Theses and Dissertations

Hydrazine (HZ) and monomethylhydrazine (MMH) are used extensively as hypergolic propellants at Kennedy Space Center. These highly reactive fuels are considered highly toxic, and potentially carcinogenic. Consequently, the transport, handling, and disposal of hydrazines is strictly regulated to protect personnel and the environment. Currently, KSC generates large volumes of hydrazine-laden wastewater for disposal. This waste is contained and shipped on public highways for subsequent disposal by incineration presenting a potentially catastrophic threat to the environment and the general public in the event of an accidental release. Other existing remediation methods include oxidative and reductive pathways as well as biodegradation in …

Synthesis And Characterisation Of Macrocycles Containing Both Tetrazole And Pyridine Functionalities, Adrienne Fleming, Jackie Gaire, Fintan Kelleher, John Mcginley, Vickie Mckee

Articles

The syntheses of tetra-tetrazole macrocycles containing at least one 2,6-bis(tetrazole)pyridine unit, linked by a variety of n-alkyl (n = 3, 5, 7 or 9 carbon atoms) chain lengths, are described. There has been no previous incorporation of the pyridine moiety into a tetra-tetrazolophane macrocycle. The crystal structure of one such tetra-tetrazole macrocycle has also been structurally characterised and revealed a bowl-shaped conformation.

A Bulk Water-Dependent Desolvation Energy Model For Analyzing The Effects Of Secondary Solutes On Biological Equilibria, Daryl K. Eggers

Faculty Publications, Chemistry

A new phenomenological model for interpreting the effects of solutes on biological equilibria is presented. The model attributes changes in equilibria to differences in the desolvation energy of the reacting species that, in turn, reflect changes in the free energy of the bulk water upon addition of secondary solutes. The desolvation approach differs notably from that of other solute models by treating the free energy of bulk water as a variable and by not ascribing the observed shifts in reaction equilibria to accumulation or depletion of solutes next to the surfaces of the reacting species. On the contrary, the partitioning …

Microfluidic Paper-Based Analytical Devices: From Pocket To Paper-Based Elisa, Andres W. Martinez

Chemistry and Biochemistry

Microfluidic paper-based analytical devices (microPADs) began as a simple idea with an ambitious goal. The idea was to make microfluidic devices out of paper instead of plastic or glass. The goal was to develop low-cost and portable paper-based diagnostic devices to improve healthcare in developing countries. Over the past 6 years, many developments have been made in the emerging field of paper-based microfluidic devices. Reviewing the development of these devices in the Whitesides group at Harvard University (Cambridge, MA, USA) can provide some insight into the future of the field and encourage scientists from a variety of backgrounds to contribute …

Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro

Faculty Publications, Chemistry

4-(2-Methylbutyl)aminodipicolinic acid (H2MEBADPA) has been synthesized and fully characterized in terms of aqueous phase protonation constants (pKa's) and photophysical measurements. The pKa's were determined by spectrophotometric titrations, utilizing a fully sealed titration system. Photophysical measurements consisted of room temperature fluorescence and frozen solution phosphorescence as well as quantum yield determinations at various pH, which showed that only fully deprotonated MEBADPA2– is appreciably emissive. The fluorescence of MEBADPA2– has been determined to be quenched by hydroxide and methoxide anions, most likely through base-catalyzed excited-state tautomerism or proton transfer. This quenching phenomenon has been quantitatively explored through steady-state and time-resolved fluorescence measurements. …

Photosensitizer Drug Delivery Via An Optical Fiber, Matibur Zamadar, Goutam Ghosh, Adaic Kapillai Mahendran, Mihaela Minnis, Bonnie I. Kruft, Ashwini Ghogare, David Aebisher, Alexander Greer

Faculty Publications

: An optical fiber has been developed with a maneuverable miniprobe tip that sparges O2 gas and photodetaches pheophorbide (sensitizer) molecules. Singlet oxygen is produced at the probe tip surface which reacts with an alkene spacer group releasing sensitizer upon fragmentation of a dioxetane intermediate. Optimal sensitizer photorelease occurred when the probe tip was loaded with 60 nmol sensitizer, where crowding of the pheophorbide molecules and self-quenching were kept to a minimum. The fiber optic tip delivered pheophorbide molecules and singlet oxygen to discrete locations. The 60 nmol sensitizer was delivered into petrolatum; however, sensitizer release was less efficient in …

Better Biomolecule Thermodynamics From Kinetics, Kiran Girdhar, Gregory Scott, Yann R. Chemla, Martin Gruebele

Chemistry and Biochemistry

Protein stability is measured by denaturation: When solvent conditions are changed (e.g., temperature, denaturant concentration, or pH) the protein population switches between thermodynamic states. The resulting denaturation curves have baselines. If the baselines are steep, nonlinear, or incomplete, it becomes difficult to characterize protein denaturation. Baselines arise because the chromophore probing denaturation is sensitive to solvent conditions, or because the thermodynamic states evolve structurally when solvent conditions are changed, or because the barriers are very low (downhill folding). Kinetics can largely eliminate such baselines: Relaxation of chromophores, or within thermodynamic states, is much faster than the transition over activation …

Computational Models Of Chemical Systems Inspired By Braess’ Paradox, Dante Lepore, Carl Barratt, Pauline Schwartz

Chemistry and Chemical Engineering Faculty Publications

Systems chemistry is a new discipline which investigates the interactions within a network of chemical reactions. We have studied several computational models of chemical systems inspired by mathematical paradoxes and have found that even simple systems may behave in a counterintuitive, non-linear manner depending upon various conditions. In the present study, we modeled a set of reactions inspired by one such paradox, Braess’ paradox, an interesting phenomenon whereby the introduction of additional capacity (e.g. pathways) in some simple network systems can lead to an unexpected reduction in the overall flow rate of “traffic” through the system. We devised several chemical …

Chemical Characterization Of Lake Gregory, Eric Steven Torres

Theses Digitization Project

The purpose of this study is to characterize the water chemistry of Lake Gregory in Crestline, California. The collection of water samples occurred a short time after the end of the summer recreational season in the late fall. Several chemical parameters were measured in an effort to determine the overall water quality during this time.

The Fire Inventory From Ncar (Finn): A High Resolution Global Model To Estimate The Emissions From Open Burning, C. Wiedinmyer, S. K. Akagi, Robert J. Yokelson, L. K. Emmons, J. A. Al-Saadi, J. J. Orlando, A. J. Soja

Chemistry and Biochemistry Faculty Publications

The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions from open burning of biomass, which includes wildfire, agricultural fires, and prescribed burning and does not include biofuel use and trash burning. Emission factors used in the calculations have been updated with recent data, particularly for the non-methane organic compounds (NMOC). The resulting global annual NMOC emission estimates are as much as a factor of 5 greater than some prior estimates. Chemical speciation profiles, necessary to allocate the total NMOC emission estimates to lumped species for use by …

Emission Factors For Open And Domestic Biomass Burning For Use In Atmospheric Models, S. K. Akagi, Robert J. Yokelson, C. Wiedinmyer, M. Alvarado, J. S. Reid, T. Karl, J. D. Crounse, P. O. Wennberg

Chemistry and Biochemistry Faculty Publications

Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially true for non-methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New EF should improve regional to global BB emissions estimates and therefore, the input for atmospheric models. In this work we present an up-to-date, comprehensive tabulation of EF for known pyrogenic species based on measurements made in smoke that has cooled to ambient temperature, but not yet …

Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I. R. Burling, Robert J. Yokelson, S. K. Akagi, S. P. Urbanski, C. E. Wold, David W. T. Griffith, T. J. Johnson, J. Reardon, D. R. Weise

Chemistry and Biochemistry Faculty Publications

We have measured emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning …

Trace Gas And Particle Emissions From Open Biomass Burning In Mexico, Robert J. Yokelson, I. R. Burling, S. P. Urbanski, E. Atlas, K. Adachi, P. R. Buseck, C. Wiedinmyer, S. K. Akagi, D. W. Toohey, C. E. Wold

Chemistry and Biochemistry Faculty Publications

We report airborne measurements of emission factors (EF) for trace gases and PM(2.5) made in southern Mexico in March of 2006 on 6 crop residue fires, 3 tropical dry forest fires, 8 savanna fires, 1 garbage fire, and 7 mountain pine-oak forest fires. The savanna fire EF were measured early in the local dry season and when compared to EF measured late in the African dry season they were at least 1.7 times larger for NO(x), NH(3), H(2), and most non-methane organic compounds. Our measurements suggest that urban deposition and high windspeed may also be associated with significantly elevated NOx …

Boreal Forest Fire Emissions In Fresh Canadian Smoke Plumes: C-1-C-10 Volatile Organic Compounds (Vocs), Co2, Co, No2, No, Hcn And Ch3cn, Isobel J. Simpson, S. K. Akagi, B. Barletta, N. J. Blake, Y. Choi, G. S. Diskin, A. Fried, H. E. Fuelberg, S. Meinardi, F. S. Rowland, S. A. Vay, A. J. Weinheimer, P. O. Wennberg, P. Wiebring, A. Wisthaler, M. Yang, Robert J. Yokelson, Donald R. Blake

Chemistry and Biochemistry Faculty Publications

Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples …

A Topological Approach To Molecular Chirality, Erica Flapan

Pomona Faculty Publications and Research

Topology is the study of deformations of geometric figures. Chemistry is the study of molecular structures. At first glance these fields seem to have nothing in common. But let’s take a closer look to see how these fields come together in the study of molecular symmetries.

Density Functional Theory Study Of Molecules And Crystals Containing D And F Metals, Shruba Gangopadhyay

Electronic Theses and Dissertations

Density Functional Theory (DFT) method is applied to study the crystal structure of transition metal and lanthanide oxides, as well as molecular magnetic complexes. DFT is a widely popular computational approach because it recasts a many-body problem of interacting electrons into an equivalent problem of non-interacting electrons, greatly reducing computational cost. We show that for certain structural properties like phase stability, lattice parameter and oxygen migration energetics pure DFT can give good agreement with experiments. But moving to more sensitive properties like spin state energetic certain modifications of standard DFT are needed. First we investigated mixed ionic-electronic conducting perovskite type …

Development Of Bioanalytical Methods For Clinical Applications And Drug Screening, Xiaohan Cai

ETD Archive

In the past decade, bioanalytical method development has become an integral part of clinical diagnosis, biomarker discovery, and drug discovery and development. The new and emerged bioanalytical technologies allow the quantitative and qualitative analysis of small molecules and biomolecules with high sensitivity and specificity. Specifically, the bioanalytical methods based on LC-MS and methylation-specific PCR are well suited for detecting low-abundance metabolites, proteins, and DNA in biofluids and tissues for biomarker investigation. They offer great clinical promises for early diseases diagnosis and therapeutic interventions. Besides, the LC-MS/MS quantitative method is essential for the estimation of pharmacokinetic and toxicological properties in drug …

Capillary Gradient Chromatofocusing-Mass Spectrometry;A Sensitive Approach For Protein Analysis, James Anthony Hribar

ETD Archive

Gradient chromatofocusing-mass spectrometry is a new technique for protein analysis recently introduced by our research group. Capable of separating and identifying proteins according to pI values and molecular weight, gradient chromatofocusing-mass spectrometry has been achieved by integrating a new ion-exchange chromatography technique called gradient chromatofocusing with a newly discovered buffer system that promotes mass spectrometry detection. Differing from traditional ion-exchange chromatography techniques, gradient chromatofocusing employs specific low molecular weight, volatile buffer components that are introduced onto an ion-exchange HPLC column by programming a binary gradient pumping system to deliver the correct proportions of acidic mobile phase to overcome buffering of …

Development Of Quantitative Lc-Ms/Ms Methods For The Pharmacological Studies Of Anti-Cancer Drugs, Lan Li

ETD Archive

In the development of anti-cancer drugs, it is essential to study the pharmacological profiles of the drugs. Among the analytical tools utilized in the pharmacological studies, LC-MS/MS has gained increased popularity due to its unequivocal sensitivity and specificity, as well as the ability of handling a wide variety of compounds with relatively simple sample preparation procedures. In this work, a brief review on the method rational, instrumentations, analytical method validation, and work flow of the method development was included. The processes of LC-MS/MS method development for the pharmacological studies of three anti-cancer drugs (i.e., methoxyamine, fludarabine, and 6-benzylthioinosine) were illustrated. …

Factors Affecting Heme Transfer From "Gapdh": A Possible Heme Carrier Protein, Rajesh Vempati

ETD Archive

The aim of my research is to understand the mechanism of heme transfer by carrier proteins into heme proteins. The mechanism of heme insertion into proteins is poorly understood. Previous experiments reported from our lab identified GAPDH as a possible heme carrier protein involved in heme transfer (Ritu Chakravarti et al PNAS). This work focuses on 2 aspects of heme transfer. a.) Rate of transfer of heme from GAPDH to apomyoglobin. We examined the rate of transfer of native proto-heme and the analogue meso-heme. The results showed that the rate of heme transfer was twice as fast for meso-heme compared …

Nmr Solution Structures Of Two Hairpins Of E. Coli 16s Rrna: The Effects Of Mutations And Chemical Modifications On Structure And Function Of Rrna, Yu Liu

Wayne State University Dissertations

The structures of two functional mutants, the UC (G690U, U697C) and the QM mutants (G690A, G693C, A695C, U697A) of the 690 hairpin of E. coli 16S ribosomal RNA were determined by NMR. The UC mutant and the QM mutant with high biological function are able to fold into structures that are isomorphous with the wild-type 690 hairpin sequence. The structural comparisons among the functional mutants and the wild-type provides structural validation for previously identified specific functional groups that are crucial for maintaining function of the 690 hairpin. The key groups for maintaining the structure and function of the 690 loop …

Exploring Potential Drug Target Sites In The Ribosome Using Cisplatin And Its Analogues, Keshab Rijal

Wayne State University Dissertations

Cis-diamminodichloridoplatinum (II), cisplatin, is an antitumor drug that has been used to treat several types of cancers. The reaction of cisplatin with DNA has been studied and discussed extensively in the literature; however, the effects of cisplatin on RNA function are poorly understood. In this thesis, two aspects of cisplatin, its preferred sites of interaction with RNA and its use as a chemical probe to gain accessibility information, were explored.

To understand the site-selectivity of cisplatin with RNA, model RNA constructs and full-length 16S rRNA were employed. The binding studies revealed a cisplatin preference for guanosine-rich sequences. Primer extensions in …

Synthesis Of N-Acetyl And C-Tert-Butyl Natural Amino Acid Substrates That Mimic Residues Of Polypeptides And Their Reactivity With [Feiv(O)(N4py)]2+: Kinetic And Mechanistic Investigations, Ashley Ann Campanali

Wayne State University Dissertations

This dissertation is divided into two chapters, the first chapter includes an introduction to reactive oxygen species and their reactions with proteins. The introduction also covers metal-based oxidants, including both heme and non-heme enzymes that activate dioxygen as well as complexes that mimic these enzymes. The work discussed in chapter one concerns the synthesis of amino acid substrates that mimic amino acid residues. Substrates synthesized were derived from Gln, Asn, Ile, Cys and Tyr. Once synthesized, these substrates were reacted with [FeIV(O)(N4Py)]2+ under pseudo-first order conditions. The mechanisms for the reactions of the most reactive substrates were investigated. Electron-transfer proton-transfer …

Study Of Protein-Rna Interactions Using Fluorescence Resonance Energy Transfer (Fret) And Single-Molecule Fret, Rajan Lamichhane

Wayne State University Dissertations

In the cell, RNA and protein, interact to form ribonucleoprotein complexes (RNPs) that have vital structural, catalytic and regulatory roles. Despite their functional importance, the mechanistic details and dynamics of RNPs are poorly understood. Single-molecule Fluorescence Resonance Energy Transfer (smFRET) techniques that provide information about heterogeneity and dynamic behaviors of molecules have been developed to investigate inter- and intra-molecular interactions. Here we have used FRET in combination with smFRET to study three very different RNP systems.

Alternative splicing is a highly regulated biological process that plays a crucial role in proteomic diversity in eukaryotes. One splicing regulator, PTB, has been …