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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Advancements in high throughput protein profiling using surface enhanced laser desorption/ionization time of flight mass spectrometry

Emanuele, Vincent A., II 15 November 2010 (has links)
Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI)is one of several proteomics technologies that can be used in biomarker discovery studies. Such studies often have the goal of finding protein markers that predict early onset of cancers such as cervical cancer. The reproducibility of SELDI has been shown to be an issue in the literature. There are numerous sources of error in a SELDI experiment starting with sample collection from patients to the signal processing steps used to estimate the protein mass and abundance values present in a sample. This dissertation is concerned with all aspects of signal processing related to SELDI's use in biomarker discovery projects. In chapter 2, we perform a comprehensive study of the most popular preprocessing algorithms available. Next, in chapter 3, we study the basic statistics of SELDI data acquisition. From here, we propose a quadratic variance measurement model for buffer+matrix only spectra. This model leads us to develop a modified Antoniadis-Sapatinas wavelet denoising algorithm that demonstrates superior performance when compared to MassSpecWavelet, one of the leading techniques for preprocessing SELDI data. In chapter 4, we show that the quadratic variance model 1) extends to real pooled cervical mucus QC data from a clinical study, 2) predicts behavior and reproducibility of peak heights, and 3) finds four times as many reproducible peaks as the vendor-supplied preprocessing programs. The quadratic variance measurement model for SELDI data is fundamental and promises to lead to improved techniques for analyzing the data from clinical studies using this instrument.
42

Collision velocity dependence of products formed via surface induced dissociation /

Beck, Jonathan R. January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
43

Investigation into the ionization mechanism occurring in matrix assisted laser desorption ionization and factors affecting ion flight time in MALDI time-of-flight mass spectrometry /

Holcomb, April M. Owens, Kevin G. January 2009 (has links)
Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 204).
44

On the velocities of ions produced at surfaces

Leigh, Nathan D. January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
45

The development of time-of-flight mass spectrometry techniques for studying the surface of Europa for astrobiology

Alvarez, David A. January 2009 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed Jan. 26, 2010). Includes bibliographical references (p. 40-43).
46

Collision velocity dependence of products formed via surface induced dissociation

Beck, Jonathan R. January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
47

Surface morphology and chemical composition of polymers studied by AFM, XPS and ToF-SIMS /

Lei, Yu-Guo. January 2002 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.
48

Analysis of clinically important compounds using electrophoretic separation techniques coupled to time-of-flight mass spectrometry /

Peterson, Zlatuše D. January 2004 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2004. / Includes bibliographical references.
49

On the velocities of ions produced at surfaces /

Leigh, Nathan D. January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
50

Explorations of electrothermal vaporization inductively coupled plasma time-of-flight mass spectrometry for isotopic analysis

Rowland, Adam Michael, 1982- 02 October 2012 (has links)
The application of inductively coupled plasma time-of-flight mass spectrometers (ICP-TOFMS) coupled to electrothermal vaporization (ETV) presents several unique analytical opportunities for isotopic analysis. This dissertation explores several subjects that utilize these characteristics in specific analytical applications. The viability of using the thermal programming abilities of the ETV in order to separate Rb and Sr is explored. These elements are isobaric at m/z 87, and must normally be separated prior to analysis for isotopic studies. Their disparate thermal properties allow them to be separated in time by the ETV allowing for simpler, faster isotope ratio analysis with less opportunity for contamination. A test case using standard potassium feldspar is found to produce moderately accurate and precise results. TOF instruments are of interest for isotope ratio analysis due to inherent isotope ratio precision. However, it has been observed that when operated in the analog data collection mode the isotope ratios observed possess a previously uncharacterized inaccuracy. This bias is rooted in variable detection efficiency of arriving ions, which can be corrected for with an algorithm described within. A method of determining the effective detector efficiency as a function of signal is presented, as well as an evaluation of the effectiveness of ratio correction. The use of ETV with TOF for isotope dilution analysis is explored. Correction of transient signals for efficiency effects is discussed, as well as the viability of using the autosampler for mixing of the solution and spike. A final study presents explores the combination of the ETV and TOF for analysis of a large number of elements from a brief transient signal. A library of peptide covered beads is analyzed for binding capacity to a variety of metals. Solutions containing metals stripped from the beads are analyzed to determine the binding capacity and specificity of the peptide sequence. The beads themselves are also analyzed for metal content using the ETV as an indicator of the efficiency of metal stripping off of the beads. / text

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