No description available.

No description available.

Graduation date: 2001

A novel protocol for the study of protein-nucleic acid interactions is presented and demonstrated to be feasible. The protocol combines photochemical crosslinking techniques and mass spectrometric methods into a new strategy for identifying protein domains or amino acid residues that are in close contact with nucleic acid in protein-nucleic acid complexes. Identifying nucleic acid binding domains in proteins provides a starting point for understanding structure-function relationships in protein-nucleic acid complexes. The protocol can be divided into three parts: 1) Cross linking of the protein-nucleic acid complex by irradiation with ultraviolet light and subsequently verifying the crosslinking by mass spectrometry; 2) Mass spectrometric peptide mapping of crosslinked protein-nucleic acid complexes to identify crosslinked peptide-nucleic acid hybrids; 3) Tandem mass spectrometric sequencing of peptide-nucleic acid hybrids to localize the crosslinked amino acid residue(s). The experimental data described in this dissertation documents our efforts to establish and implement this analytical protocol. Using several different protein-nucleic acid systems and different crosslinking techniques, we have demonstrated the feasibility of a mass spectrometric based approach to structurally characterize UV-crosslinked protein-nucleic acid complexes. Matrix-assisted laser desorption/ionization mass spectrometry was for the first time demonstrated to be highly effective for detection and molecular weight determination of intact, UV-crosslinked protein-nucleic acid complexes and for molecular weight determination of synthetic and UV-crosslinked peptide-nucleic acid hybrids. Electrospray ionization mass spectrometry and tandem mass spectrometry was demonstrated to be effective for analysis of synthetic peptide-nucleic acid hybrids and, in conjunction with HPLC, for peptide mapping of a protein. The first application of MALDI mass spectrometry to the characterization of crosslinked peptide-nucleic acid hybrids isolated from a photochemically crosslinked protein-nucleic acid complex demonstrate that the new protocol can be used to identify nucleic acid binding domains in proteins. / Graduation date: 1995

No description available.

No description available.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Nov. 9, 2007). PDF text: iv, 129 p. : ill. ; 5 Mb. UMI publication number: AAT 3266778. Includes bibliographical references. Also available in microfilm and microfiche formats.

Made available in DSpace on 2014-06-12T22:56:59Z (GMT). No. of bitstreams: 2 arquivo2780_1.pdf: 3374117 bytes, checksum: 1ce7fdad8e74d2e26d55331aec8bb950 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Objetivos: Avaliar os resultados obtidos de pacientes portadores de ceratocone na forma inicial ou moderado, em fase de evolução, submetidos ao tratamento com a técnica do crosslinking do colágeno utilizando parâmetros reprodutíveis de concentração de riboflavina em gotas e exposição corneana aos raios ultra-violeta . Métodos: Em um estudo prospectivo, foram submetidos ao tratamento com crosslinking do colágeno 24 olhos de 24 pacientes, 13 do sexo feminino e 11 do sexo masculino. A idade média das mulheres foi 24,08 anos e dos homens de 21,27 anos. Quanto ao grau de ceratocone, 16 pacientes apresentavam ceratocone grau I e os outros 8 pacientes com ceratocone grau II. Foram tratados no período de dezembro de 2008 a abril de 2009 e acompanhados por um período de 6 meses com avaliações mensais da ceratometria , paquimetria pelo exame do ORBSCAN e AVCC ( acuidade visual com correção ) e refração ( avaliação do grau ). Resultados: Ao final do tratamento observou uma melhora estatisticamente significante ( p < 0,05 ) nas médias da ceratometria máxima (Kmáx), ceratometria média (Kmédio), AVCC ( acuidade visual com correção), paquimetria ( espessura da córnea ) e equivalente esférico. A média da acuidade visual corrigida com óculos (AVCC) antes do tratamento foi de 0.38 logMAR (20/50) com desvio padrão de ± 0,172 e no final do tratamento foi de 0.22 logMAR ( 20/30 ) com DP(desvio padrão) de ± 0,153 . Observamos também que a média do Kmédio antes do tratamento era 47.30 D com DP 2,723 e 6 meses após o tratamento diminuiu para 46.00 D com DP 2,595 o que confirma o aplanamento corneano com diminuição média de 1,30 D(dioptrias). Conclusão: O tratamento do crosslinking mostrou resultados significativamente positivos nos pacientes tratados principalmente nos pacientes portadores de ceratocone grau I . Concluímos que houve diferença significante entre a acuidade visual antes e pós-tratamento com melhora da visão

Indiana University-Purdue University Indianapolis (IUPUI) / Osteoarthritis affects millions of people of different age groups around the world. With very few treatment options and the highly restricted capacity of cartilage to repair, new treatment options are needed. The objective of this thesis was to develop a repeatable cartilage testing protocol, which could be used to test cartilage properties and determine if crosslinking can be used as a potential treatment for osteoarthritis. Previous studies have shown CASPc can be used as a photo-sensitizer to obtain collagen crosslinking through a secondary process. The ability to perform cartilage crosslinking by light-activation, which could be done arthroscopically is especially attractive as this would allow the surgery to be minimally invasive. The indentation protocol developed for a stress-relaxation test was able to achieve 95% repeatability, meaning the error in determining cartilage properties stayed within 5% of the average for tests performed at different times. Results of photo-chemical crosslinking demonstrated no change in cartilage stiffness when compared with control specimens. The spherical indenter chosen to indent the cartilage was suspected to apply less strain on cartilage as a result of its profile, which only compressed the cartilage instead of stretching its surface. The stiffness of CASPc control specimen was observed to be increasing when compared with no-CASPc control, as a result of added viscosity of CASPc solution. This elevated stiffness was observed to diminish over time due to the diffusion of CASPc from cartilage.

This study examined the mechanical and durable press properties of cotton 3/1 twill-woven fabrics finished with various concentrations of reactants in the BTCA/IA/AA combinations. The regression analysis was used to determine the relationship among each finishing variable, BTCA, IA, and AA concentrations, mole ratio of acid monomers to the sodium hypophosphite monohydrate catalyst, and curing times at 180°C, and the finished fabric's property variable, breaking strength, tear strength, wrinkle recovery angle whiteness index, and durable press rating. Based on the results of the reduced regression equations and range dispersion of mean values of finished fabric properties. The results of the study indicated the some BTCA/IA/AA combinations applied to cotton fabric provided good results in wrinkle recovery angle, breaking strength, and tear strength, comparable to those of the fabric finished with either BTCA only or DMDHEU reactant. The combinations of BTCA/IA/AA reactants did not provide as good whiteness index and durable press rating as the BTCA or DMDHEU reactant. / Ph. D.