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Time resolved Small Angle X-ray Scattering (SAXS) experiments on detonating explosives have been conducted at Argonne National Laboratory's Advanced Photon Source Dynamic Compression Sector. The purpose of the experiments is to measure the SAXS patterns at tens of ns to a few ls behind the detonation front. Corresponding positions behind the detonation front are of order 0.1-10 mm. From the scattering patterns, properties of the explosive products relative to the time behind the detonation front can be inferred. This report describes how the time and distance from the x-ray probe location to the detonation front is calculated, as well as the uncertainties and sources of uncertainty associated with the calculated times and distances. [ABSTRACT FROM AUTHOR]

Exploding foil initiators (EFIs), also known as slapper initiators or detonators, offer clear safety and timing advantages over other means of initiating detonation in high explosives. This work outlines a new capability for imaging and reconstructing three-dimensional images of operating EFIs. Flyer size and intended velocity were chosen based on parameters of the imaging system. The EFI metal plasma and plastic flyer traveling at 2.5 km/s were imaged with short ∼80 ps pulses spaced 153.4 ns apart. A four-camera system acquired 4 images from successive x-ray pulses from each shot. The first frame was prior to bridge burst, the 2nd images the flyer about 0.16mm above the surface but edges of the foil and/or flyer are still attached to the substrate. The 3rd frame captures the flyer in flight, while the 4th shows a completely detached flyer in a position that is typically beyond where slappers strike initiating explosives. Multiple acquisitions at different incident angles and advanced computed tomography reconstruction algorithms were used to produce a 3-dimensional image of the flyer at 0.16 and 0.53mm above the surface. Both the x-ray images and the 3D reconstruction show a strong anisotropy in the shape of the flyer and underlying foil parallel vs. perpendicular to the initiating current and electrical contacts. These results provide detailed flyer morphology during the operation of the EFI. [ABSTRACT FROM AUTHOR]

The dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation endstation has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about -3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS. [ABSTRACT FROM AUTHOR]

Background: Fenestrated Endovascular Aneurysm Repair (fEVAR) involves deploying a covered stent into the aorta followed by multiple visceral stents through fenestrations in the main body of graft. The most commonly used large sheaths for cannulation of visceral vessels are the Gore DrySeal Flex, Cook Performer Check-Flo, and Medtronic Sentrant. None of these sheaths were designed for the insertion of multiple sheaths, and so a slow but steady leakage of blood occurs during the procedure. The aim of this paper is to assess in an in vitro setting which large bore sheath has the best valve for use when multiple smaller sheaths are inserted through it., Methods: Three large bore introducer sheaths (LBISs) were used for this study, The Gore DrySeal Flex LBIS, Medtronic Sentrant LBIS and Cook Performer Check-Flo LBIS. A test rig was constructed, made of an 18-liter fluid reservoir mounted vertically and receiving a constant supply of water from a domestic water supply which flowed into the reservoir and out of an overflow. The reservoir was connected to the LBIS by a vertical plastic pipe with an internal diameter of 40 mm and an isolation valve. The LBIS was connected to the isolation valve by inserting the LBIS up a flexible silicone tube connected to the isolation valve. The LBIS was subject to a constant column/pressure of water and fluid leakage from the LBIS was collected in a plastic pot/tray placed underneath the LBIS. The leakage rates through each LBIS were determined for the following smaller diameter sheath combinations inserted through the valve, one 6 French Sheath, two 6 French Sheaths, two 6 French Sheaths and one 7 French Sheath. This was done to closely mimic a fEVAR procedure in vitro. The procedure was to insert different sheath combinations through the nonreturn valves in the LBIS and measure the volume of fluid that leaked through the valves. The leaked fluid was weighed, and the weight was converted to volume using the density of water (1 g/ml)., Results: The average (mean) leakage rates for each LBIS and each sheath combination showed that leakage rates when only one sheath was inserted were very low. For all 3 LBIS's tested, the leakage rates increased dramatically when multiple sheaths were inserted. The Medtronic LBIS leaked the most, followed by Cook, followed by Gore. For the Cook LBIS, the leakage rates exhibited with 2 × 6 French sheaths were approx. 106 times greater than those for the Gore LBIS and 5 times greater for the 2 × 6 French +1 × 7 French sheath combination. A similar comparison for the Medtronic LBIS versus the Gore LBIS yields factors of 132 and 8., Conclusions: Leakage rates increase significantly when multiple sheaths are inserted and the Gore LBIS demonstrates significantly lower leakage than both the Cook and Medtronic during procedures that require simultaneous, multiple insertions of smaller sheaths. Although the Gore Dryseal has by far the lowest leakage rate when 3 small diameter sheaths are inserted (just under 1 ml/s), depending on the duration of the procedure this could still result in significant blood loss., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Oxymorphone, a semisynthetic μ-opioid receptor agonist, is the major active metabolite of oxycodone. It is a highly potent narcotic analgesic due to its high lipid solubility, which allows it to readily cross the blood-brain barrier and enter the central nervous system. It is available as both an immediate-release and extended-release (ER) formulation. Oxymorphone can be abused by injection or inhalation of crushed tablets; thus, in 2011, the manufacturer of ER oxymorphone reformulated the drug with crush-resistant technology to deter its misuse and abuse. We describe the case of a previously healthy, 24-year-old male who experienced reproducible acute subjective bilateral temporary hearing loss that occurred after inhalation of oxymorphone. He presented to the emergency department complaining of acute bilateral hearing loss after he reported snorting a crushed oxymorphone ER 30-mg tablet. Emergency department evaluation revealed obvious bilateral hearing loss as well as coincidental aspiration pneumonia. The patient's medical history revealed that he had experienced a similar episode of hearing loss after a previous episode of oxymorphone inhalation. His hearing loss began to improve 3 hours after presentation to the emergency department and was completely resolved by the following day. Use of the Naranjo adverse drug reaction probability scale revealed oxymorphone to be a probable cause of this patient's acute hearing loss (score of 6). The mechanism of action of opioid-associated hearing loss (OAHL) is not completely understood, but it is thought to be due to disturbances within the cochlea, such as cochlear ischemia. To our knowledge, this is only the second published case report of acute reversible hearing loss following oxymorphone inhalation and the first published case report of reproducible OAHL. Since opioid misuse continues to be prevalent despite attempts at reformulations to make the drugs crush resistant, a high degree of clinical suspicion is needed to evaluate and treat patients who present with unique findings after episodes of substance abuse, especially those related to tamper-resistant formulations., (© 2015 Pharmacotherapy Publications, Inc.)