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Identifier |
000401709 |
Title |
Μελέτη γήρανσης σε μύες in-vivo, μέσω μικροσκοπίας Γένεσης Δεύτερης Αρμονικής ευαίσθητης στην Πόλωση |
Alternative Title |
Study of aging in muscles in-vivo, using Polarization sensitive Second Harmonic Generation microscopy |
Author
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Τσαφάς, Βασίλης Α.
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Thesis advisor
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Φωτάκης, Κώστας
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Reviewer
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Ταβερναράκης, Νεκτάριος
Λουκάκος, Παναγιώτης
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Scientific advisor
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Φιλιππίδης, Γιώργος
Ψιλοδημητρακόπουλος, Σωτήριος
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Abstract |
The need to understand basic biological mechanisms, such as aging, requires the
observation of living organisms at cellular level, therefore high resolution imaging
microscopy is required. In parallel, the form of microscopy to be used needs to be as
minimally invasive as possible, in order for the observation to be carried out in-vivo.
Furthermore, it is of great challenge to derive quantitative biological information, in
order to eliminate the nowadays qualitative analysis, based i.e. on the experienced eye
of an expert. A possible solution to the above could be the optical Polarization
sensitive Second Harmonic Generation (PSHG) imaging microscopy. Second
Harmonic Generation (SHG) is a non-linear scattering phenomenon (no energy
deposition in to the sample) which makes this method minimally invasive with very
high resolution (approximately 0.5 μm) giving us the ability for in-vivo observation of
biological samples at cellular level. In addition, this method is dependant to
polarization which gives the ability for quantitative information at molecular level.
In this study we investigated for the first time how aging affects the myosin molecules
in Caenorhabditis elegans (C. elegans) striated muscles using polarization sensitive
second harmonic generation (PSHG) microscopy. There are two ways to derive
quantitative information in molecular level from PSHG data. The first is by using an
iterative fitting procedure, while the second and much faster is by using the analytical
FFT (Fast Fourier Transform). It is worthwhile to note that in this study a new
filtering technique has been utilized for the first time for the FFT based PSHG data
analysis, which significantly increases FFT robustness and accuracy. Our results, after
utilizing this filtering technique, show significant changes in myosin structure
between young (1 day) and old (9 days) C. elegans. Specifically, we found that the
myosin SHG angle decreases upon aging. Our results encourage further experiments
e.g. in mutated C. elegans samples, towards the investigation of the exact mechanism
of aging in the myosin molecule. The long-term scope of this work is to develop a fast
and precise high-resolution optical diagnostic tool, able to quantitatively characterize
tissue pathologies in-vivo.
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Language |
Greek |
Subject |
C. elegans |
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Fast fourier transform (FFT) |
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Fitting |
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Μη-γραμμική μικροσκοπία |
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Προσαρμογή καμπύλης |
Issue date |
2016-07-22 |
Collection
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School/Department--School of Sciences and Engineering--Department of Physics--Post-graduate theses
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Type of Work--Post-graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/a/6/0/metadata-dlib-1467194201-812379-29902.tkl
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Views |
611 |