Publications by authors named "Matthew J Crawford"

With the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR).

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Anticoagulation (AC) and antiplatelet (AP) therapy may increase the risk of gastrointestinal bleeding after double balloon enteroscopy (DBE); however, limited data are currently available regarding the incidence. The aim of this study was to assess the incidence and clinical characteristics of post-DBE bleeding in patients on AC and AP therapy. The medical records of patients who underwent DBE between 2009 and 2013 at Mayo Clinic, Florida, were retrospectively reviewed.

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In 1790, the Spanish Crown sent a "botanist-chemist" to South America to implement production of a chemical extract made from cinchona bark, a botanical medicament from the Andes used throughout the Atlantic World to treat malarial fevers. Even though the botanist-chemist's efforts to produce the extract failed, this episode offers important insight into the role of chemistry in the early modern Atlantic World. Well before the Spanish Crown tried to make it a tool of empire, chemistry provided a vital set of techniques that circulated among a variety of healers, who used such techniques to make botanical medicaments useful and intelligible in new ways.

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Conformationally preorganized peptide nucleic acids (PNAs) have been synthesized through backbone modifications at the γ-position, where R = alanine, valine, isoleucine, and phenylalanine side chains. The effects of these side-chains on the conformations and hybridization properties of PNAs were determined using a combination of CD and UV-Vis spectroscopic techniques. Our results show that the γ-position can accommodate varying degrees of sterically hindered side-chains, reaffirming the bimodal function of PNAs as the true hybrids of "peptides" and "nucleic acids.

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We have determined the structure of a PNA-DNA duplex to 1.7 A resolution by multiple-wavelength anomalous diffraction phasing method on a zinc derivative. This structure represents the first high-resolution 3D view of a hybrid duplex containing a contiguous chiral PNA strand with complete gamma-backbone modification ("gammaPNA").

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This paper presents the results of an NMR spectroscopy and distance-restrained molecular dynamics (MD) study of a gamma-methylated, palindromic, 8-base pair peptide nucleic acid (gamma-PNA) duplex. The goal of this study was to examine the impact of the gamma-backbone modification on the structure of the PNA duplex. The 2D NMR information involving the backbone methyl group, especially the NOEs between the methyl protons and those of the amide and methylene groups of the backbone, led to distance restraints useful in the elucidation of the structure of the backbone of gamma-PNA.

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Background: Injury of the acetabular labrum is a well recognized cause of hip pain in the young, active patient. The exact mechanism of these injuries remains a subject of speculation, although femoroacetabular impingement and twisting maneuvers have both been proposed as critical factors. We examined the hypothesis that torsional maneuvers of the morphologically normal hip joint generate mechanical strain within the acetabular labrum, particularly in areas that are prone to injury.

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We explored the mechanical factors leading to the formation of labral tears and the effect of these lesions on hip kinematics at the extremes of joint motion. Using a 3D motion analysis system, the stability of six cadaveric hips was measured during loading maneuvers known to impose anterior loads on the joint margin. These measurements were repeated following venting of the capsule, and after creation of a 15-mm tear in the intact labrum.

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Background: A review of multiple transplantations of human immunodeficiency virus-infected musculoskeletal allografts found that recipients of lyophilized (freeze-dried) bone or tendon from an infected donor all tested negative for human immunodeficiency virus. The finding that 75% of the recipients of fresh-frozen bone from the same donor contracted human immunodeficiency virus has led to speculation that freeze-drying may render retroviral-infected musculoskeletal allografts noninfectious.

Hypothesis: Lyophilization does not inactivate retrovirus in systemically infected bone and tendon.

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