100 research outputs found

    Performance of Fill Soils During the Loma Prieta Earthquake

    Get PDF
    The results of high quality in situ test results obtained at Hunter\u27s Point Naval Station both before and after the Lorna Prieta earthquake are presented. The interpretation of these tests and the results of subsequent numerical ground motion analyses are validated by the observed response at that site during the event. Data show that densification of the loose fill soils occurred as a result of the seismic activity and corroborate the observed surface deformations

    Endotracheal tube-induced sore throat pain and inflammation is coupled to the release of mitochondrial DNA

    Get PDF
    In the absence of infection, the pathophysiology of endotracheal tube-induced sore throat pain is unclear. Activated neutrophils release elastase, reactive oxygen species, and inflammatory cytokines known to contribute to neuropathic pain. Sterile tissue injury can cause the release of damage-associated molecular patterns such as mitochondrial DNA that promote neutrophil activation. We hypothesized that endotracheal tube-induced sore throat pain is linked to mitochondrial DNA-mediated neutrophil inflammation. A nonrandomized prospective survey for sore throat pain was conducted in 31 patients who required short-term intubation and had no evidence of upper airway infection. Patterns of neutrophil abundance, activation, and mitochondrial DNA levels were analyzed in tracheal lavage fluid following intubation and prior to extubation. Thirteen of 31 patients reported sore throat pain. Sore throat patients had high neutrophilia with elevated adhesion molecule and TLR9 expression and constitutive reactive oxygen species generation. Tracheal lavage fluid from sore throat patients accumulated mitochondrial DNA and stimulated neutrophils to release mediators associated with pain in a TLR9- and DNAse-dependent fashion. Endotracheal tube-induced sore throat is linked to the release of mitochondrial DNA and can drive TLR9-mediated inflammatory responses by neutrophils reported to cause pain. Mitigating the effects of cell-free mitochondrial DNA may prove beneficial for the prevention of endotracheal tube-mediated sore throat pain

    Cardiac surgery in a patient with retroperitoneal fibrosis and heart valvulopathy, both due to pergolide medication for Parkinson's disease

    Get PDF
    Retroperitoneal fibrosis is best described as a chronic inflammatory process which may be idiopathic, but can rarely be brought about by medications, such as pergolide, used for treating Parkinson's disease. Pergolide can produce a fibrotic process in heart valves, resulting in valve insufficiency in up to 25% of cases. Herein we describe the case of a 68-year-old man who received pergolide for 2 years for Parkinson's disease. The patient developed retroperitoneal fibrosis resulting in renal failure from ureteral obstruction necessitating ureteral stenting, as well as significant aortic and mitral valve insufficiency. He successfully underwent surgery for combined aortic valve, mitral valve and ascending aorta replacement because of severe valve insufficiency and dilated (d = 5.8 cm) ascending aorta. Retroperitoneal fibrosis improved with pergolide cessation and corticosteroid treatment. This is the second case reported in the literature, of a patient who had double valve and ascending aorta replacement surgery because he suffered from this rare but serious adverse effect of dopamine agonists used for managing Parkinson's disease

    Surgical Management of Cervical Spondyloarthropathy in Hemodialysis Patients

    Get PDF
    Dialysis-related spondyloarthropathy is a rare cause of spinal deformity and cervical myelopathy. Optimal management of cervical spine spondyloarthropathy often requires circumferential reconstructive surgery, because affected patients typically have both the anterior column and the facet joints compromised. The occasional presence of noncontiguous or "skip lesions" adds an additional level of complexity to surgical management, because decompression and fusion in an isolated segment of neural compression can worsen spine deformity by applying increased stress to adjacent cervical spine segments. We report two cases of hemodialysis patients who presented with cervical myelopathy and initially had anterior cervical discectomy or corpectomy. Because symptoms recurred due to hardware failure, both patients required posterior spine fusion as well. In retrospect, because of the hardware failure, both of these patients might have benefited from a circumferential (combined anterior and posterior) cervical spine reconstruction as their initial treatment

    Intravenous levosimendan-norepinephrine combination during off-pump coronary artery bypass grafting in a hemodialysis patient with severe myocardial dysfunction

    Get PDF
    This the case of a 63 year-old man with end-stage renal disease (on chronic hemodialysis), unstable angina and significantly impaired myocardial contractility with low left ventricular ejection fraction, who underwent off-pump one vessel coronary bypass surgery. Combined continuous levosimendan and norepinephrine infusion (at 0.07 μg/kg/min and 0.05 μg/kg/min respectively) started immediately after anesthesia induction and continued for 24 hours. The levosimendan/norepinephrine combination helped maintain an appropriate hemodynamic profile, thereby contributing to uneventful completion of surgery and postoperative hemodynamic stability. Although levosimendan is considered contraindicated in ESRD patients, this case report suggests that combined perioperative levosimendan/norepinephrine administration can be useful in carefully selected hemodialysis patients with impaired myocardial contractility and ongoing myocardial ischemia, who undergo off-pump myocardial revascularization surgery

    Ag colloids and arrays for plasmonic non-radiative energy transfer from quantum dots to a quantum well

    Get PDF
    Non-radiative energy transfer (NRET) can be an efficient process of benefit to many applications including photovoltaics, sensors, light emitting diodes and photodetectors. Combining the remarkable optical properties of quantum dots (QDs) with the electrical properties of quantum wells (QWs) allows for the formation of hybrid devices which can utilize NRET as a means of transferring absorbed optical energy from the QDs to the QW. Here we report on plasmon-enhanced NRET from semiconductor nanocrystal QDs to a QW. Ag nanoparticles in the form of colloids and ordered arrays are used to demonstrate plasmon-mediated NRET from QDs to QWs with varying top barrier thicknesses. Plasmon-mediated energy transfer. (ET) efficiencies of up to similar to 25% are observed with the Ag colloids. The distance dependence of the plasmon-mediated ET is found to follow the same d-4 dependence as the direct QD to QW ET. There is also evidence for an increase in the characteristic distance of the interaction, thus indicating that it follows a Frster-like model with the Ag nanoparticle-QD acting as an enhanced donor dipole. Ordered Ag nanoparticle arrays display plasmon-mediated ET efficiencies up to similar to 21%. To explore the tunability of the array system, two arrays with different geometries are presented. It is demonstrated that changing the geometry of the array allows a transition from overall quenching of the acceptor QW emission to enhancement, as well as control of the competition between the QD donor quenching and ET rates
    • …
    corecore