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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.
481

A fully automated cell segmentation and morphometric parameter system for quantifying corneal endothelial cell morphology

Al-Fahdawi, Shumoos, Qahwaji, Rami S.R., Al-Waisy, Alaa S., Ipson, Stanley S., Ferdousi, M., Malik, R.A., Brahma, A. 22 March 2018 (has links)
Yes / Background and Objective Corneal endothelial cell abnormalities may be associated with a number of corneal and systemic diseases. Damage to the endothelial cells can significantly affect corneal transparency by altering hydration of the corneal stroma, which can lead to irreversible endothelial cell pathology requiring corneal transplantation. To date, quantitative analysis of endothelial cell abnormalities has been manually performed by ophthalmologists using time consuming and highly subjective semi-automatic tools, which require an operator interaction. We developed and applied a fully-automated and real-time system, termed the Corneal Endothelium Analysis System (CEAS) for the segmentation and computation of endothelial cells in images of the human cornea obtained by in vivo corneal confocal microscopy. Methods First, a Fast Fourier Transform (FFT) Band-pass filter is applied to reduce noise and enhance the image quality to make the cells more visible. Secondly, endothelial cell boundaries are detected using watershed transformations and Voronoi tessellations to accurately quantify the morphological parameters of the human corneal endothelial cells. The performance of the automated segmentation system was tested against manually traced ground-truth images based on a database consisting of 40 corneal confocal endothelial cell images in terms of segmentation accuracy and obtained clinical features. In addition, the robustness and efficiency of the proposed CEAS system were compared with manually obtained cell densities using a separate database of 40 images from controls (n = 11), obese subjects (n = 16) and patients with diabetes (n = 13). Results The Pearson correlation coefficient between automated and manual endothelial cell densities is 0.9 (p < 0.0001) and a Bland–Altman plot shows that 95% of the data are between the 2SD agreement lines. Conclusions We demonstrate the effectiveness and robustness of the CEAS system, and the possibility of utilizing it in a real world clinical setting to enable rapid diagnosis and for patient follow-up, with an execution time of only 6 seconds per image.
482

Detection of condom lubricants and starches in the presence of biologicals by diffuse reflectance infrared fourier transform spectroscopy and polarized light microscopy

Moody, Hannah Leigh January 2013 (has links)
Condoms have been used in sexual assaults as a means of preventing the transmission of biological fluids. Current sexual assault evidence collection kit processing protocols do not regularly take advantage of the information that can be gathered by examining residues left by condoms during intercourse. A biphasic liquid-liquid extraction technique was developed to separate polar and non-polar condom residues, which had been collected on cotton tipped swabs. This research involved the examination of twenty condom brands by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. Five brands were selected to examine the consistency of this technique when the lubricants were exposed to body and storage temperature conditions for various times and in the presence of oral, vaginal, and blood samples. Additionally, starches collected from the condoms under each of the above conditions were examined. Although all lubricants were identifiable using this IR technique, the nonoxynol-9 (spermicide) containing samples produced spectra which were not identical to those produced by nonoxynol-9 standards. Although there was a decrease in the percent transmittance within IR spectra as the time between the collection and the extraction of the swabs increased, the condom residues of interest remained identifiable at all time points examined. The use of vaginal and oral swabs in the collection caused a negligible amount of background interference, which could be eliminated through spectral subtraction of the swab.
483

Structural Transition During Fibrillogenesis of Amyloid β Peptide

Sidrak, George 01 January 2017 (has links)
Alzheimer’s Disease (AD) is a neurodegenerative disease marked by progressive neuronal cell death, leading to dementia. AD is the most common disease that results in dementia and largely affects the elderly, with five million people in the United States diagnosed with the disease as of 2015 and approximately 35 million people worldwide. Diseases resulting in dementia cost the US healthcare system an estimated $172 billion in 2010 and that cost is expected to increase as the population ages and as diagnostic techniques improve so that more people are treated (Holtzman, 2011). The disease was first reported by psychiatrist Alois Alzheimer at the onset of the 20th century, when one of his patients “suffered memory loss, disorientation, hallucinations and delusions and died at the age of 55,” then was found to have severe brain atrophy post-mortem (Cipriani, Dolciotti, Picchi, & Bonuccelli, 2011). There are palliative treatments available that marginally slow disease progression but there is currently no cure for the disease (Awasthi, Singh, Pandey, & Dwivedi, 2016). More research is needed to develop effective therapeutic strategies to combat the disease. Currently, AD cytotoxicity is believed to be caused by increased amyloid β (Aβ) peptide plaque deposition in the brain, as described by the amyloid cascade hypothesis (Barage & Sonawane, 2015). The current understanding is that oligomers of Aβ peptide lead to neuronal death through multiple mechanisms, most notably hyper-phosphorylation of the tau protein. Having a better understanding of the structural changes in the fibrillization process of Aβ will provide a broader insight into mechanisms of cell death and open new possibilities for pharmacological treatments, which is what this research intends to provide.
484

Evaluation of single-bounce attenuated total reflectanceFourier transform infrared and two-dimensional correlation spectroscopy in quantitative analysis

Cocciardi, Robert Arthur January 2003 (has links)
No description available.
485

Determination of peroxide value and anisidine value using Fourier transform infrared spectroscopy

Dubois, Janie January 1995 (has links)
No description available.
486

Infrared photophysics of gas phase ions in a Fourier transform ion cyclotron resonance mass spectrometer

Uechi, Guy Takeo January 1993 (has links)
No description available.
487

Shape Optimization for in Vitro and In Vivo Biomedical Sensing

Nair, Sumitha Parameswaran 31 March 2009 (has links)
No description available.
488

A Parametric Study to Quantify the Pressure Drop of Pulsating Flow through Blockages

Pappu, Suryanarayana 13 October 2014 (has links)
No description available.
489

DYNAMIC KERNEL FUNCTION FOR HIGH-SPEED REAL-TIME FAST FOURIER TRANSFORM PROCESSORS

Lee, Yu-Heng George 16 December 2009 (has links)
No description available.
490

Development of Liquid Crystal Infrared Imaging Sensors

Finnemeyer, Valerie A. 18 July 2016 (has links)
No description available.

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