Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Nmr And Computational Characterization Of Protein Structure And Ligand Binding, Terrence Neumann Oct 2013

Nmr And Computational Characterization Of Protein Structure And Ligand Binding, Terrence Neumann

Dissertations (1934 -)

Nuclear magnetic resonance (NMR) techniques combined with computational methods such as docking and cheminformatics were used to characterize protein structure and ligand binding. The thioredoxin system of Mycobacterium tuberculosis consists of a thioredoxin reductase and at least three thioredoxins. This system is responsible for maintaining the cellular protein thiol redox state in normal state. This maintenance is important as the bacterium is engulfed by the human macrophage. Here it is bombarded by reactive oxygen and nitrogen species in an attempt to disrupt normal cellular function in part by perturbing the protein thiols. To this end, the solution structures of the …


Synthesis, Characterization And Application Of Two-Dimensional Layered Metal Hydroxides For Environmental Remediation Purposes, Cleopas Machingauta Oct 2013

Synthesis, Characterization And Application Of Two-Dimensional Layered Metal Hydroxides For Environmental Remediation Purposes, Cleopas Machingauta

Dissertations (1934 -)

Two-dimensional layered nano composites, which include layered double hydroxides (LDHs), hydroxy double salts (HDSs) and layered hydroxide salts (LHSs) are able to intercalate different molecular species within their gallery space. These materials have a tunable structural composition which has made them applicable as fire retardants, adsorbents, catalysts, catalyst support materials, and ion exchangers. Thermal treatment of these materials results in destruction of the layers and formation of mixed metal oxides (MMOs) and spinels. MMOs have the ability to adsorb anions from solution and may also regenerate layered structures through a phenomenon known as “memory effect”. Zinc-nickel hydroxy nitrate was used …


Supramolecular Polysaccharide Composite Materials: Green And Recyclable Synthesis, Characterization, Analytical And Biomedical Applications, Simon Duri Sep 2013

Supramolecular Polysaccharide Composite Materials: Green And Recyclable Synthesis, Characterization, Analytical And Biomedical Applications, Simon Duri

Dissertations (1934 -)

A simple novel recyclable synthetic method was successfully developed for the synthesis of polysaccharide composite materials. The method involves the use of 1-butyl-3-methylimidazolium chloride [BMIm+Cl-], a simple ionic liquid, as the sole solvent. Naturally abundant and renewable materials such as cellulose (CEL) and chitosan (CS) were used for the preparation of the composite materials. CEL is the most abundant compound on earth, while CS is a product of deacetylation of chitin, which is the second most abundant material on earth. [BMIm+Cl-] is relatively non toxic, non volatile and stable over a wide range of temperature eliminating one of the major …


Preparation Of Cyclohexenones From Acyclic (Pentadienyl)Iron(1+) Cations: Synthesis Of Carvone Metabolites And Synthetic Studies Directed Toward Dihydrotachysterols, Charles Felix Manful Sep 2013

Preparation Of Cyclohexenones From Acyclic (Pentadienyl)Iron(1+) Cations: Synthesis Of Carvone Metabolites And Synthetic Studies Directed Toward Dihydrotachysterols, Charles Felix Manful

Dissertations (1934 -)

ABSTRACT

PREPARATION OF CYCLOHEXENONES FROM ACYCLIC (PENTADIENYL)IRON(1+) CATIONS: SYNTHESIS OF CARVONE METABOLITES AND SYNTHETIC STUDIES DIRECTED TOWARD DIHYDROTACHYSTEROLS

Charles Felix Manful, BSc.

Marquette University, 2013

Six-membered carbocycles are abundant in natural products. This structural feature is present in terpenes, secosteroids, antibiotics, and even imbedded in the polycyclic framework of complex alkaloids. A wide variety of methodologies have been utilized for the preparation of six-membered carbocycles including Robinson annulation, Diels-Alder cycloaddition, Dieckmann condensation, ring closing metathesis, photochemical carbonylation of alkenylcyclopropanes, addition of soft nucleophiles to acyclic (ç5-pentadienyl)iron cations, etc.

Acyclic (ç5-pentadienyl)iron(+1) cations were first prepared about 50 years ago. The reactivity …


Expulsion Of Leaving Groups From Zwitterionic Intermediates Generated Via Photochemical Electrocyclic Ring Closure Reactions And An Investigation On Tpe Oligomers, Tasnuva Shahrin Apr 2013

Expulsion Of Leaving Groups From Zwitterionic Intermediates Generated Via Photochemical Electrocyclic Ring Closure Reactions And An Investigation On Tpe Oligomers, Tasnuva Shahrin

Dissertations (1934 -)

Photochemical cleavage reactions have been found widespread use in biological applications that require intracellular photochemical release of biologically active substrates such as peptides, proteins, neurotransmitters, or nucleotide phosphates. The research is to devise photoremovable protecting groups (cage compounds) that can be used to deprotect those biological substrates by irradiation. A number of photocleavage reactions have been developed in recent years which release chlorides, hydroxides, carboxylates, thiolates, and phenolates leaving groups for use in such applications. Nevertheless, photochemical elimination reactions that expel such leaving group anions remain quite uncommon. The cleavage of cage compounds via photolysis requires heterolysis of a bond …


"Molecular Spectroscopy And Dynamics Of Reactive Chemical Intermediates Studied Using Laser Induced Fluorescence (Lif), Single Vibronic Level (Svl) Emission And Resonance Enhanced Multiphoton Ionization (Rempi) Spectrometry.", Lloyd Godfrey Muzangwa Jan 2013

"Molecular Spectroscopy And Dynamics Of Reactive Chemical Intermediates Studied Using Laser Induced Fluorescence (Lif), Single Vibronic Level (Svl) Emission And Resonance Enhanced Multiphoton Ionization (Rempi) Spectrometry.", Lloyd Godfrey Muzangwa

Dissertations (1934 -)

ABSTRACT

"MOLECULAR SPECTROSCOPY AND DYNAMICS OF REACTIVE CHEMICAL INTERMEDIATES STUDIED USING LASER INDUCED FLUORESCENCE (LIF), SINGLE VIBRONIC LEVEL (SVL) EMISSION AND RESONANCE ENHANCED MULTIPHOTON IONIZATION (REMPI) SPECTROMETRY"

Lloyd Muzangwa, B.Sc. (Hons, Biochemistry).

Marquette University, 2013

In the studies of complex chemical processes, it is necessary to postulate mechanisms involving transient intermediates such as radicals, ions, and pre-reactive complexes. The detection and characterization of these intermediates affords in ideal cases determination of the detailed chemical mechanism, which, in turn, can permit the development of rational strategies for removing undesired products and enhancing the yield of the desired species. This dissertation describes …


Matrix-Isolation And Computational Studies Of Transient Polyhalogenated Intermediates And Weakly-Bound Complexes., Aimable Kalume Jan 2013

Matrix-Isolation And Computational Studies Of Transient Polyhalogenated Intermediates And Weakly-Bound Complexes., Aimable Kalume

Dissertations (1934 -)

As time goes by and new innovations are brought up to improve living conditions, the human impact on the environment becomes more significant. It has been shown that man-made halogenated compounds play a key role in many real-world chemical processes. For example, in combustion, these compounds are used as fire retardant agents, and in atmospheric chemistry, they initiate ozone depletion reactions.

However little is known about the mechanisms governing these processes and many intermediates involved in these processes have been elusive to researchers for diverse reasons such as short lifetime and difficulty in distinguishing products from parents molecules. The studies …


Ensuring Application Specific Security, Privacy And Performance Goals In Rfid Systems, Farzana Rahman Jan 2013

Ensuring Application Specific Security, Privacy And Performance Goals In Rfid Systems, Farzana Rahman

Dissertations (1934 -)

Radio Frequency IDentification (RFID) is an automatic identification technology that uses radio frequency to identify objects. Securing RFID systems and providing privacy in RFID applications has been the focus of much academic work lately. To ensure universal acceptance of RFID technology, security and privacy issued must be addressed into the design of any RFID application. Due to the constraints on memory, power, storage capacity, and amount of logic on RFID devices, traditional public key based strong security mechanisms are unsuitable for them. Usually, low cost general authentication protocols are used to secure RFID systems. However, the generic authentication protocols provide …


Molecular Tweezers: Studies Directed Towards The Preparation Of Effective Charge Transport Materials, Khushabu Thakur Jan 2013

Molecular Tweezers: Studies Directed Towards The Preparation Of Effective Charge Transport Materials, Khushabu Thakur

Dissertations (1934 -)

ABSTRACT

MOLECULAR TWEEZERS: STUDIES DIRECTED TOWARDS THE PREPARATION OF EFFECTIVE CHARGE TRANSPORT MATERIALS

Khushabu Thakur, B.Sc, M.Sc.

Marquette University, 2013

An important focus of the modern areas of photovoltaics and molecular electronics is to identify molecules or molecular assemblies that can promote effective charge/exciton transport over long distances. In order to be able to exert control and establish necessary structural parameters for reproducible production of self-assembled structures for long-distance charge transport, our laboratory has been actively engaged towards the preparation of a variety of well-defined, cofacially-arrayed polybenzenoid nanostructures in which aromatic donors are cofacially stacked.

Herein, we undertake the design …