| 1. |
- Ellingsen, Pal Gunnar, et al.
(författare)
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Spectral correlation analysis of Amyloid beta plaque inhomogeneity from double staining experiments
- 2013
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Ingår i: Journal of Biomedical Optics. - : Society of Photo-optical Instrumentation Engineers (SPIE). - 1083-3668 .- 1560-2281. ; 18:10
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Tidskriftsartikel (refereegranskat)abstract
- A spectral correlation algorithm for the analysis of hyperspectral fluorescence images is proposed by Ellingsen et al. [J. Biomed. Opt. 18, 020501 (2013)]. Here, it is applied to the analysis of double-stained A beta amyloid plaques being related to the Alzheimers disease (AD). Sections of APP/PS1 AD mice model brains are double stained with luminescent-conjugated oligothiophenes, known to bind to amyloid protein deposits. Hyperspectral fluorescence images of the brain sections are recorded and by applying the correlation algorithm the spectral inhomogeneity of the double-stained samples is mapped in terms of radial distribution and spectral content. To further investigate the progression of A beta amyloid plaque formation, 19 AD mice of different ages up to 23 months are characterized, enabling a statistical analysis of the plaque heterogeneity. In accordance with recent findings by Nystrom et al. [ACS Chem. Biol. 8, 1128-1133 (2013)], the spectral distribution within A beta plaques is found to vary with age throughout the lifespan of the mouse. With the new correlation algorithm, it is possible to quantify the spectral abundance of the two stains depending on the relative distance from the plaque center and mouse age. Thus, we demonstrate the use of the correlation analysis approach in double-staining experiments and how it is possible to relate these to structural/spectral changes in biological samples. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
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| 2. |
- Kindahl, Tomas, et al.
(författare)
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Photophysical and DFT Characterization of Novel Pt(II)-Coupled 2,5-Diaryloxazoles for Nonlinear Optical Absorption
- 2012
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 116:47, s. 11519-11530
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Tidskriftsartikel (refereegranskat)abstract
- Several new bis-phosphine platinum(II) complexes with 2,5-diaryl-substituted oxazole-containing alkyne ligands have been synthesized and optically characterized in solution. Measurements of nonlinear absorption showed strong attenuation of laser light at 532 and 600 nm. The light absorption of the Pt complexes was shifted from the near-UV region for the ground state to the red region for the excited triplet state, and was associated with large extinction coefficients. The optical limiting effect can be explained by triplet-triplet excited state absorption in conjunction with fast excited singlet to-triplet intersystem crossing and slow triplet to-ground-state decay, in comparison with the pulse length of the laser. DFT calculations show good predictability of the S-0-S-1 and S-0-T-1 energy gaps and offer insight into the interaction strength between Pt and the alkyne ligands. The use of this type of ligand, with weak absorption for the Pt(II) complexes in the visual wavelength range as a key feature, enables the possibility to further improve these molecular systems for nonlinear absorption applications.
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| 3. |
- Lilledahl, Magnus B., et al.
(författare)
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Combined imaging of oxidative stress and microscopic structure reveals new features in human atherosclerotic plaques
- 2015
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Ingår i: Journal of Biomedical Optics. - : Society of Photo-optical Instrumentation Engineers (SPIE). - 1083-3668 .- 1560-2281. ; 20:2, s. 020503-
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Tidskriftsartikel (refereegranskat)abstract
- Human atherosclerotic samples collected by carotid endarterectomy were investigated using electronic paramagnetic resonance imaging (EPRI) for visualization of reactive oxygen species, and nonlinear optical microscopy (NLOM) to study structural features. Regions of strong EPRI signal, indicating a higher concentration of reactive oxygen species and increased inflammation, were found to colocalize with regions dense in cholesterol crystals as revealed by NLOM.
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| 4. |
- Nyström, Sofie, et al.
(författare)
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Evidence for Age-Dependent in Vivo Conformational Rearrangement within A beta Amyloid Deposits
- 2013
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Ingår i: ACS Chemical Biology. - : American Chemical Society. - 1554-8929 .- 1554-8937. ; 8:6, s. 1128-1133
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of aggregated A beta peptide in the brain is one of the major hallmarks of Alzheimers disease. Using a combination of two structurally different, but related, hypersensitive fluorescent amyloid markers, LCOs, reporting on separate ultrastructural elements, we show that conformational rearrangement occurs within A beta plaques of transgenic mouse models as the animals age. This important mechanistic insight should aid the design and evaluation of experiments currently using plaque load as readout.
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