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Full-Text Articles in Physics
Stability Of Retinol In Liposomes As Measured By Fluorescence Lifetime Spectroscopy And Flim, Louis Sumrall, L. Smith, Elmukhtar Ehmed Alhatmi, Yekaterina G. Chmykh, D. Mitchell, Jay Nadeau
Stability Of Retinol In Liposomes As Measured By Fluorescence Lifetime Spectroscopy And Flim, Louis Sumrall, L. Smith, Elmukhtar Ehmed Alhatmi, Yekaterina G. Chmykh, D. Mitchell, Jay Nadeau
Physics Faculty Publications and Presentations
Retinol shows complex photophysical properties that make it potentially useful as an exogenous or endogenous probe of membrane microenvironment, but it has not been fully explored. In this study, we use bulk fluorescence lifetime measurements and fluorescence lifetime imaging microscopy (FLIM) to examine the stability of retinol in phosphatidylcholine (PC) multilamellar and unilamellar vesicles with and without cholesterol. We find that both light and exposure to ambient temperature and oxygen contribute to retinol degradation, with the addition of an antioxidant such as butylated hydroxytoluene (BHT) essential to provide stability, especially in the absence of cholesterol. With exposure to ultraviolet light …
Microbial Motility At The Bottom Of North America: Digital Holographic Microscopy And Genomic Motility Signatures In Badwater Spring, Death Valley National Park, Carl Snyder, Jakob P. Centlvre, Shrikant Bhute, Jay Nadeau, Multiple Additional Authors
Microbial Motility At The Bottom Of North America: Digital Holographic Microscopy And Genomic Motility Signatures In Badwater Spring, Death Valley National Park, Carl Snyder, Jakob P. Centlvre, Shrikant Bhute, Jay Nadeau, Multiple Additional Authors
Physics Faculty Publications and Presentations
Motility is widely distributed across the tree of life and can be recognized by microscopy regardless of phylogenetic affiliation, biochemical composition, or mechanism. Microscopy has thus been proposed as a potential tool for detection of biosignatures for extraterrestrial life; however, traditional light microscopy is poorly suited for this purpose, as it requires sample preparation, involves fragile moving parts, and has a limited volume of view. In this study, we deployed a field-portable digital holographic microscope (DHM) to explore microbial motility in Badwater Spring, a saline spring in Death Valley National Park, and complemented DHM imaging with 16S rRNA gene amplicon …
A Simple In Situ Method For Optimizing Settings For The Einzel Lens Elements In A Focused Ion Beam, Rich Swinford, Erik Sanchez
A Simple In Situ Method For Optimizing Settings For The Einzel Lens Elements In A Focused Ion Beam, Rich Swinford, Erik Sanchez
Physics Faculty Publications and Presentations
Ion beams have had an incredible impact on research in the past couple of decades. One major reason for this is the continued development of systems having optimal beam currents that allows one to image more clearly at different spot sizes to include higher currents that allow for faster milling. The advancements for Focused ion beam (FIB) columns have developed rapidly due to the computational optimization of lens designs. However, once a system has been produced, the optimal column settings for these lenses may change or simply become obscure. Our work involves regaining this optimization with the newly applied values …
Thin Film Deposition Of Mop, A Topological Semimetal, Robert Browning, Paul Plachinda, Raj Solanki
Thin Film Deposition Of Mop, A Topological Semimetal, Robert Browning, Paul Plachinda, Raj Solanki
Physics Faculty Publications and Presentations
MoP is a topological semimetal which has drawn attention due to its unique electrical and optical properties resulting from massless electrons. In order to utilize these properties for practical applications, it is necessary to develop a technique to produce high-quality, large-scale thin films of this 2D material. We report below our initial results of growth of MoP thin films using atomic layer deposition (ALD), where the film grows layer-by-layer. These films were grown on 5 cm × 5 cm silicon oxide coated Si wafers. Resistivity versus temperature measurements show that these films are metallic and includes a partial superconducting phase. …
Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau
Recent Advances In Experimental Design And Data Analysis To Characterize Prokaryotic Motility, Megan M. Dubay, Jacqueline Acres, Max Riekeles, Jay Nadeau
Physics Faculty Publications and Presentations
Bacterial motility plays a key role in important cell processes such as chemotaxis and biofilm formation, but is challenging to quantify due to the small size of the individual microorganisms and the complex interplay of biological and physical factors that influence motility phenotypes. Swimming, the first type of motility described in bacteria, still remains largely unquantified. Light microscopy has enabled qualitative characterization of swimming patterns seen in different strains, such as run and tumble, run-reverse-flick, run and slow, stop and coil, and push and pull, which has allowed for elucidation of the underlying physics. However, quantifying these behaviors (e.g., identifying …
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Physics Faculty Publications and Presentations
The electromagnetic fields generated from a static current source on a spherical surface are calculated in the framework of axion electrodynamics to first order in the coupling parameter. Comparisons of the results are made with reference to various results obtained in conventional Maxwell electrodynamics, as well as previous results obtained for point magnetic dipole source coupled to harmonic axion fields. Distinct features from the results so obtained are highlighted for possible experimental probing of the axions via electromagnetic interactions. In particular, electromagnetic radiation from sources with strong magnetic field is studied which may enable the detection of a cosmic …