Hamburg, University, Diss., 2004.

Regensburg, Universiẗat, Diss., 2004.

No description available.

One of the main objectives of this thesis is to disperse double-walled carbon nanotubes (DWNT) in a polyvinylidene fluoride (PVDF) matrix, and to characterize the resulting composite using electrical, thermal, and mechanical characterization techniques. DWNTs are successfully dispersed in the PVDF, and this dispersion is assessed by using optical microscopy and both scanning and transmission electron microscopy. The second objective of this study is to investigate the morphology of the PVDF after adding the carbon nanotubes. The results using the x-ray diffraction technique do not show change in the PVDF morphology with addition of DWNTs. In Differential scanning calorimetry study the results show that the melting temperature does not vary much with addition of DWNTs. An increase in the crystallization temperature and a decrease in the percent crystallinity is also observed as DWNT content increases. The electrical and mechanical properties of the composites are measured and data is used to calculate the percolation volume fraction using electrical conductivity. The results show that the percolation threshold occurs at 0.23 vol%, which is a low volume fraction further indicating a good dispersion. The critical exponent implies a three dimensional dispersion. The predicted volume fraction at percolation using the excluded volume approach indicates that the DWNTs are dispersed in small bundles of seven hexagonally closed packed tubes. The mechanical properties are done using dynamic mechanical analysis to study the effect of the nanotubes on the mechanical properties. The results show that the storage modulus is enhanced 84% by adding 4.51 vol% DWNT-PVDF below the glass transition temperature which is in a -45°C region and it is increased by about 97% at 40°C. Electromechanical performance of the composites is assessed by testing the actuation behavior using DC voltage. The results show no actuation for volume contents below percolation, and a measurable actuation at volume contents above percolation. Results from the different characterization techniques indicate that the DWNTs are successfully dispersed. An enhancement in electrical conductivity and dielectric constant is achieved by addition of DWNTs. At DWNT volume content above percolation, both mechanical and electromechanical enhancements are observed, as evidenced by DMA and electroactive characterization techniques.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1972. / Bibliography: leaves 213-218. / xiv, 218 l illus., tables

Thesis (Ph.D.)--Tennessee Technological University, 2007. / Bibliography: leaves 182-193.

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 44-45).

Giessen, Universiẗat, Diss., 2001. / Dateiformat: tar.gz, Dateien im PDF-Format.

Indiana University-Purdue University Indianapolis (IUPUI) / The use of maternal urinary fluoride as a biomarker of prenatal fluoride exposure in epidemiology studies is increasing. However, the knowledge on maternal exposure to fluoride and its biomarkers, has not increased alongside. The objective of this dissertation was to improve our understanding of the dietary intake of fluoride (a major source of fluoride exposure), and spot urinary fluoride levels during pregnancy. Two secondary data analyses utilizing data from the Early Life Exposures in Mexico to ENvironmental Toxicants (ELEMENT) project were conducted, in a population of women living in a salt-fluoridated community. The first study estimated the dietary intake of fluoride over the course of pregnancy and assessed the influence of compliance with the dietary recommendations of intake of beneficial nutrients for pregnancy (calcium, iron, folate and protein) on the dietary intake of fluoride. The second study compared spot urinary fluoride in women during pregnancy and non-pregnancy (using one-year postpartum as a proxy for the non-pregnant state) and assessed associations between dietary factors (dietary fluoride intake, addition of table salt, calcium intake from diet and supplements, and dietary acid load) and urinary fluoride levels at each state. Results revealed that the median dietary intake of fluoride in pregnant women was 0.7 mg/day, increased with gestational age and in women who were moderately and highly compliant with recommendations of intake of beneficial nutrients for pregnancy. On the other hand, spot urinary fluoride levels during pregnancy did not significantly differ with those of women one-year postpartum, increased with gestational age, and decreased in calcium-supplemented women only during pregnancy. The dietary intake of fluoride, calcium, and dietary acid load were not associated with urinary fluoride in either state. Finally, reporting the addition of table salt to meals was associated with an increase in urinary fluoride only at one-year postpartum. The studies in this dissertation highlight the need for a deeper understanding of fluoride exposure and its biomarkers in the pregnant population. / 2022-07-01

Covalent antibody recruiting molecules (cARMs) are synthetic chemical tools that direct antibodies naturally present in human serum to tumor receptors leading to immune recognition and elimination. cARMs have three general features: an antibody binding domain (ABD), an antibody labelling domain (ALD), and a tumor binding domain. Proximal to the ABD, the ALD contains an electrophilic group which is attacked by a nucleophilic amino acid residue on the target antibody upon cARM binding. Previous cARMs use an acyl-imidazole (AL) ALD to successfully covalently recruit anti-dinitrophenyl IgG validated via fluorescence SDS-PAGE,and form immune complexes with PSMA+ HEK cells in ADCP flow experiments.1 Through MS analysis, AL cARMs were demonstrated to target lysine-59 of antiDNP.1 Problematically, there are several properties associated with AL chemistry that limit the therapeutic potential of associated cARMs. These limitations include limited stability in vivo, single amino acid (lysine) selectivity, and modest intramolecular protein labelling rates (10-5 s-1)1. To target novel antibody residues and possibly improve the rate of antibody labelling, a second generation of cARMs has been developed using sulfur fluoride exchange (SuFEx) chemistry as the ALD. Sulfur fluorides have been broadly used in academic and industrial applications due to intrinsically high stability and broad amino acid reactivity.2 SuFEx cARMs are hypothesized to have enhanced hydrolytic stability compared to AL cARMs. This thesis explores the synthesis, stability, binding, and labeling kinetics of SuFEx cARMs to advance cARM design and development for in vivo applications. This research contributes collectively to the design and development of novel therapeutics in chemical biology and immune-oncology research. / Thesis / Master of Science (MSc)