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Properties Of Carbon Nanotubes Under External Factors: Adsorption, Mechanical Deformations, Defects, And External Electric Fields, Yaroslav Shtogun

USF Tampa Graduate Theses and Dissertations

Carbon nanotubes have unique electronic, optical, mechanical, and transport properties which make them an important element of nanoscience and nanotechnology. However, successful application and integration of carbon nanotubes into new nanodevices requires fundamental understanding of their property changes under the influence of many external factors. This dissertation presents qualitative and quantitative theoretical understanding of property changes, while carbon nanotubes are exposed to the deformations, defects, external electric fields, and adsorption. Adsorption mechanisms due to Van der Waals dispersion forces are analyzed first for the interactions of graphitic materials and biological molecules with carbon nanotubes. In particular, the calculations are performed …

Non-Calanoid Copepods At The Bermuda Atlantic Time-Series Study (Bats) Station: Community Structure And Ecology, 1995-1999, Hussain Ali Al-Mutairi

USF Tampa Graduate Theses and Dissertations

Zooplankton were sampled on a monthly basis at the Bermuda Atlantic Time-series Study (BATS) site from January 1995 to December 1999. Samples were collected using a 1-m², 200 µm mesh net. The net sampled the water column in an oblique manner from the surface to a mean depth of 200 m. One day and one night tow from each cruise was examined microscopically to determine the community structure of the non-calanoid copepods. In addition, a three year set of nighttime samples were examined taken by 0.5-m², 20 and 35 µm mesh nets (1995-1996 and 1997, respectively) towed obliquely to 150 …

Synthesis Of Small Molecule Inhibitors Targeting Signal Transduction Pathways, Divya Ramamoorthy

USF Tampa Graduate Theses and Dissertations

The main aim of the study described in this thesis is the development of small molecules as inhibitors targeting signal transduction pathways, thereby treating cancer. We attempted to synthesize compounds based on the hits obtained from high throughput screening of the Chemdiv diversity set compounds. Chapter One is a general introduction to cancer, history of chemotherapeutic drugs and an introduction to signal transduction pathways. The following two chapters briefly introduce the biological targets in the authors study. Chapter Two describes the role of B-cell lymphoma type xL (Bcl-xL), in apoptosis and the development of drugs targeting Bcl-xL. Examples of Bcl-xL …

Optimization And Characterization Of Lab-On-A-Chip Elements: Microfluidic Chambers And Microneedles, Puneet Khanna

USF Tampa Graduate Theses and Dissertations

In this work, MEMS based fabrication is used to engineer multifaceted enhancements to microfluidic systems such as lab-on-a-chip devices. Two specific elements of microfluidic systems are the focus of this study: microfluidic chambers and microneedles. Microfluidic chambers, which are back-end passive elements, via proposed material and structural modifications, are shown to exhibit reduced non-specific DNA binding and enable increased cell lysis efficiency. Microneedles, which are front-end interfacing elements, have been fabricated in silicon and in silicon dioxide varieties. The geometry of silicon microneedles has been varied via DRIE processing to yield sharpened tips. Sharpening of microneedle tips provides reduced skin …

Determination Of Decay Rates And Differential Survival Of Escherichia Coli And Enterococcus Spp. Strains Under Hydrodynamically Active Conditions Using Box-Pcr Typing, Phoebe West Koch

USF Tampa Graduate Theses and Dissertations

Indicator organisms (IOs) such as Escherichia coli and Enterococcus spp. are used to predict the presence of pathogens in waters. Determining the relationships between environmental factors, IOs, and pathogens is a key to assessing water quality and ensuring public health, yet certain strains of E. coli and Enterococcus spp. survive for long periods in natural waters. Molecular subtyping, using repetitive extragenic palindromic DNA sequences (BOX-PCR), has been used to discriminate among environmental E. coli and Enterococcus spp. isolates. The reproducibility of BOX-PCR patterns varies with DNA purification methods; therefore, it is important to develop a standardized, rapid, high throughput DNA …

The Bioinorganic Chemistry Of Copper-Containing Systems: From Type-3 Systems Pertinent To Alzheimer’S Disease To Mononuclear Hydrolysis Involved In Biological Development, Giordano Faustini Zimmerer Da Silva

USF Tampa Graduate Theses and Dissertations

Although transition metals are essential for life, misregulation of redox-active metal uptake, delivery, storage, and excretion has been linked with a series of neurodegenerative disorders. Alzheimer's disease (AD) is considered an epidemic and is the most widespread of all forms of dementia. Copper ions found in large concentrations localized in amyloid-ß plaques in the brain of AD patients have been linked with the generation of reactive oxygen species which are suspected to be the culprits leading to neuronal cell death. Herein a series of mechanistic and spectroscopic studies elucidate the chemistry about the metal-centered oxidation of biomolecules, including catecholamine neurotransmitters …

Glyconanobiotics: Novel Carbohydrated Nanoparticle Polymers, Thotaha Wijayahewage Sampath Chrysantha Abeylath

USF Tampa Graduate Theses and Dissertations

Carbohydrates on the cell surface conjugates to proteins and lipids and participates in biological processes as glycoconjugates. Carbohydrate functionalized nanoparticles (glyconanoparticles) constitute a good bio-mimetic model of carbohydrate presentation at the cell surface and are currently centered on many glycobiological and biomedical applications. The most of the applications have been reported using gold glyconanoparticles. A brief review of gold glyconanoparticles and some of their applications will be discussed in Chapter I. Although metallic, semiconductor and magnetic glyconanoparticles have been reported, no polyacrylate glyconanoparticles have yet to be described.

Chapter II describes the first preparation of carbohydrate functionalized polymer nanoparticles by …

Analysis Of E2f1 Target Genes Involved In Cell Cycle And Apoptosis, Scott N. Freeman

USF Tampa Graduate Theses and Dissertations

One of the main results of Rb-E2F pathway disruption is deregulation of the E2F family of transcription factors, which can lead to inappropriate proliferation, oncogenic transformation, or the induction of apoptosis. Given the potential negative biological effects associated with deregulated E2F activity, it is of great importance to study E2F targets that mediate these effects. In Part I of this manuscript, we identify the RhoBTB2 putative tumor suppressor gene as a direct physiological target of the E2F1 transcription factor. We find that RhoBTB2 is highly upregulated during mitosis due in part to E2F1, and that overexpression of RhoBTB2 increases the …

Antibiotic-Conjugated Polyacrylate Nanoparticles: New Opportunities For Development Of Anti-Mrsa Agents, Yang Wang

USF Tampa Graduate Theses and Dissertations

N-Thiolated β-lactams represent a novel family of antibacterial agents, whose in vitro activity is confined largely to Staphylococcus species, including multidrug-resistant forms of S. aureus. N-Thiolated β-lactams have recently been shown to possess intriguing biological activities which are addressed in Chapter II. Current development of nanoparticles as a new drug delivery vehicle is described in Chapter III. Chapter IV and V described the current research in our laboratories focusing on the synthesis and characterization of emulsified polyacrylate/polyacrylamide nanoparticle antibacterials for drug delivery of water-insoluble antibiotics. These nanoparticles can be prepared in aqueous media directly from acrylate/acrylamide monomers through free …

Evolutionary Genetics Of The Family Placobranchidae (Mollusca: Gastropoda: Opisthobranchia: Sacoglossa), Anna Lee Bass

USF Tampa Graduate Theses and Dissertations

Members of the family Placobranchidae have been the focus of numerous studies because of their interesting physiological adaptations (kleptochemistry and kleptoplasty) and ecological associations with marine algae. More than 100 species have been described since the 1800's, but no determination of phylogenetic relationships in the family has occurred. DNA sequences from two mitochondrial genes (large subunit ribosomal and cytochrome c oxidase subunit I) and one nuclear gene (Histone 3) were used to reconstruct relationships among 34 nominal species within the Placobranchidae. Strong support for terminal nodes was found using Bayesian phylogenetic methods; however, a "soft" polytomy was detected at internal …

Mapping Tampa Bay Cynoscion Nebulosus Spawning Habitat Using Passive Acoustic Surveys, Sarah Lyle Walters

USF Tampa Graduate Theses and Dissertations

Spotted seatrout, Cynoscion nebulosus, spawning locations as well as associated environmental variables were determined for Tampa Bay, Florida during the 2004 spawning season using a mobile hydrophone survey. Hydrophones, a type of underwater microphone, can be used to detect and record spawning sounds of soniferous fishes. During their spawning season in Tampa Bay which generally occurs between March and September, mature male spotted seatrout generate sounds associated with courtship in the crepuscular and evening periods by vibrating sonic muscles against the swim bladder. Active spawning sites can be located using hydrophones to find these calling males.

Using a random …

Chemical And Biological Investigation Of The Antarctic Red Alga Delisea Pulchra, Santhisree Nandiraju

USF Tampa Graduate Theses and Dissertations

Our interest in the red alga Delisea pulchra (=D.fimbriata) (Greville) Montagne 1844 (Rhodophyceae, Bonnemaisoniales, Bonnemaisoniaceace) was stimulated by its activity in the biosssays done at Wyeth Pharmaceuticals. Halogenated compounds from D. pulchra interfere with Gram-negative bacterial signaling systems, affect the growth of Gram-positive bacteria, inhibit quorum sensing and swarming motility of marine bacteria (inhibit bacterial communication). They also inhibit surface colonization in marine bacteria and exhibit antifouling properties against barnacle larvae and macroalgal gametes.

Chemical investigation of D.pulchra collected near Palmer Station, Antarctica yielded three new dimeric halogenated furanones, pulchralide A-C (41-43), along with previously reported …

N-Thiolated Β-Lactams: Chemistry And Biology Of A Novel Class Of Antimicrobial Agents For Mrsa, Timothy E. Long

USF Tampa Graduate Theses and Dissertations

N-Methylthio beta-lactams represent a promising new family of antibacterial agents whose in vitro activity is confined largely to Staphylococcus species, including multidrug-resistant forms of S. aureus. Originally developed in the 1980's for use as synthetic intermediates, N-methylthio beta-lactams have recently been shown in these laboratories to possess intriguing biological properties which are addressed in Chapters I-IV. In terms of the antibacterial activities, the structural features and species specificities exhibited by these compounds are unlike those of any existing family of beta-lactam drugs. The lactams seem to exert their effects intracellularly, requiring passage of the bioactive species through the …