We studied aspects of the birefringence in the human crystalline lens. With the use of Mueller-matrix ellipsometry in vivo on both accommodated and unaccommodated eyes, we found no difference between the associated retardations. We calculated form birefringence of the lens by interpreting the membranes of the lens fiber cells as Wiener bodies. The resulting retardation for a light beam that passes the lens as in the experiments exceeds by far the measured total retardation. We conclude that form and intrinsic birefringence of the lens cancel out.
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http://dx.doi.org/10.1364/josaa.8.001788 | DOI Listing |
Europace
January 2025
Division of Cardiology, McGill University Medical Center, Montreal, Quebec, Canada.
Background: Loss of bipolar electrograms immediately after pulsed field ablation (PFA) makes lesion durability assessment challenging.
Objective: The aim of this trial (NCT06700226) was to evaluate a novel ablation system that can optically predict lesion durability by detecting structural changes in the tissue during ablation.
Methods: Patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) using PFA (AblaView®, MedLumics).
Anal Chem
January 2025
Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3BX, U.K.
Reports of proteins in fossilized bones have been a subject of controversy in the scientific literature because it is assumed that fossilization results in the destruction of all organic components. In this paper, a novel combination of analytical techniques is used to address this question for an exceptionally well-preserved sacrum excavated from the Upper Cretaceous strata of the South Dakota Hell Creek Formation. Cross-polarized light microscopy (XPol) shows birefringence consistent with collagen presence.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Mechanical and Aerospace Engineering, Program of Materials Science and Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
Changes in the density and organization of fibrous biological tissues often accompany the progression of serious diseases ranging from fibrosis to neurodegenerative diseases, heart disease and cancer. However, challenges in cost, complexity, or precision faced by existing imaging methodologies and materials pose barriers to elucidating the role of tissue microstructure in disease. Here, we leverage the intrinsic optical anisotropy of the Morpho butterfly wing and introduce Morpho-Enhanced Polarized Light Microscopy (MorE-PoL), a stain- and contact-free imaging platform that enhances and quantifies the birefringent material properties of fibrous biological tissues.
View Article and Find Full Text PDFAim: Within the in vitro fertilization (IVF) process, to evaluate the possibility of using the state of the meiotic spindle of oocytes as an indicator of maturity in order to optimize the timing of vitrification.
Patients And Methods: In the presented report, the cause of couple infertility was a combination of a 38-year-old female and 43-year-old male with azoospermia, which was an indication for oocyte vitrification. Oocyte polar bodies and optically birefringent meiotic spindles were visualized by polarized light microscopy and their states and relative positions were used as indicators of oocyte maturation, i.
Sensors (Basel)
December 2024
Ophthalmic Instrumentation Development Lab, The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Wilmer 233, 600 N. Wolfe St., Baltimore, MD 21287, USA.
Signal amplitudes obtained from retinal scanning depend on numerous factors. Working with polarized light to interrogate the retina, large parts of which are birefringent, is even more prone to artifacts. This article demonstrates the necessity of using normalization when working with retinal birefringence scanning signals in polarization-sensitive ophthalmic instruments.
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