Browsing by Author "Holmes, Hal R."

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    Application of sub-micrometer vibrations to mitigate bacterial adhesion
    Paces, Will R.; Holmes, Hal R.; Vlaisavljevich, Eli; Snyder, Katherine L.; Tan, Ee Lim; Rajachar, Rupak M.; Ong, Keat Ghee (2014-03-11)
    As a prominent concern regarding implantable devices, eliminating the threat of opportunistic bacterial infection represents a significant benefit to both patient health and device function. Current treatment options focus on chemical approaches to negate bacterial adhesion, however, these methods are in some ways limited. The scope of this study was to assess the efficacy of a novel means of modulating bacterial adhesion through the application of vibrations using magnetoelastic materials. Magnetoelastic materials possess unique magnetostrictive property that can convert a magnetic field stimulus into a mechanical deformation. In vitro experiments demonstrated that vibrational loads generated by the magnetoelastic materials significantly reduced the number of adherent bacteria on samples exposed to Escherichia coli, Staphylococcus epidermidis and Staphylococcus aureus suspensions. These experiments demonstrate that vibrational loads from magnetoelastic materials can be used as a post-deployment activated means to deter bacterial adhesion and device infection.
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    Focused ultrasound extraction (FUSE) for the rapid extraction of DNA from tissue matrices
    Holmes, Hal R.; Haywood, Morgan; Hutchison, Ruby; Zhang, Qian; Edsall, Connor; Hall, Timothy L.; Baisch, David; Holliday, Jason A.; Vlaisavljevich, Eli (2020-10-09)
    Rapid DNA extraction is a critical barrier for routine and fieldable genetics tests for applications in conservation, such as illegal trafficking and fraudulent mislabelling. Here, we develop a non-thermal focused ultrasound extraction (FUSE) technique that creates a dense cloud of high-pressure acoustic cavitation bubbles to disintegrate targeted tissues into an acellular debris, resulting in the rapid release of entrapped DNA. In this work, we demonstrate the proof-of-concept of the FUSE technique by obtaining species identifiable sequences and shotgun sequencing reads from DNA extracted from Atlantic salmon Salmo salar tissues. Having mitigated the key risks for this technique, we hypothesize future developments with this technology can be applied to accelerate and simplify DNA extraction from exceedingly difficult samples with complex tissue matrices (i.e. fibrous tissue and timber samples) in both laboratory and field settings.