223 research outputs found

    Integral ribs formed in metal panels by cold- press extrusion

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    Metal panels with integral ribs are formed by the cold-press extrusion method without material loss. Integral ribs in aluminum-alloy panels are formed by this process

    Fibrinogen-Conjugated Gold-coated Magnetite Nanoparticles for Antiplatelet Therapy

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    Ischemic stroke is the world\u27s second leading cause of death and accounts for 2-4% of total worldwide healthcare costs. Ischemic stroke is caused by the occlusion of arteries responsible for supplying blood to the brain, which can result in disability or death. Arterial blood clots consist of aggregates of activated platelets wrapped in a mesh of fibrin. Tissue plasminogen activator, the only current FDA-approved treatment for ischemic stroke, functions by lysing fibrin in a blood clot. Unfortunately, tissue plasminogen activator significantly increases bleeding risks, which restricts its use. Alternatively, targeting and disrupting platelets within a clot could improve stroke outcome. To test this hypothesis, we have developed a targeting system utilizing fibrinogen to specifically target nanoparticles to activated platelets. Human fibrinogen was evaluated for targeting both human and murine platelets under conditions that are similar to an in vivo blood clot. Our results indicate that human fibrinogen conjugated to gold nanoparticles was capable of targeting activated human and murine platelets. Further, human fibrinogen conjugates bound to preformed platelet aggregates while in the presence of plasma levels of unconjugated fibrinogen. To disrupt platelets, we developed a system to cause localized hyperthermia to the platelet surface by utilizing inductively heated magnetic nanoparticles. Magnetic gold-coated magnetite nanoparticles were synthesized and characterized. The morphology of the gold-coated magnetite product differed substantially from the expected core-shell structure often reported for such nanoparticles. Despite the unexpected morphology, the nanoparticles could still be functionalized with protein and targeted to activated platelets. Localized hyperthermia was created when platelet-bound, fibrinogen-conjugated, gold-coated magnetite nanoparticles were exposed to an oscillating magnetic field. The effects of the hyperthermic treatment to surface-activated and aggregated platelets were evaluated by electron microscopy. The treated platelets demonstrated considerable structural damage, with the cell membrane showing significant disruption when compared to controls. A method to quantify platelet damage was developed and utilized to refine the length of exposure to the oscillating magnetic field and dose of nanoparticles. In the future, it may be feasible to use fibrinogen-conjugated, gold-coated magnetite to target and disrupt platelets in a thrombus in vivo, thereby restoring blood flow to ischemic brain

    Fiber glass dies speed forming of large metal sheets

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    Fiberglass tooling dies accelerate forming of large metal sheets. The dies, fabricated to fit over and fasten to the die bases, are lightweight, quickly replaced and have nongalling surfaces

    Sprayable low density ablator and application process

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    A sprayable, low density ablative composition is described consisting esentially of: (1) 100 parts by weight of a mixture of 25-65% by weight of phenolic microballoons, 0-20% by weight of glass microballoons, 4-10% by weight of glass fibers, 25-45% by weight of an epoxy-modified polyurethane resin, 2-4% by weight of a bentonite dispersing aid, and 1-2% by weight of an alcohol activator for the bentonite; (2) 1-10 parts by weight of an aromatic amine curing agent; and (3) 200-400 parts by weight of a solvent

    When REBOA grows wings: Resuscitative endovascular balloon occlusion of the aorta to facilitate aeromedical transport

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    BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a helpful adjunct in the control of non-compressible truncal hemorrhage. Concerns regarding ischemia time limits its applicability in transfer. We describe the first reported case of civilian transfer via aeromedical transport to a higher level of care with a zone 3 REBOA catheter deployed. CASE REPORT: We present the case of a patient in hemorrhagic shock with a complex pelvic fracture exceeding the capability of a rural level-two trauma center requiring the use of REBOA catheter to permit aeromedical transport to a level-one trauma center for definitive embolization. CONCLUSION: Deployment of REBOA catheter to facilitate aeromedical transport to an appropriate level of care may be considered if travel times can be kept brief and there is a process and training in place to empower flight medics to consider transporting with a REBOA deployed

    Continuous Selective Intra-Arterial Application of Nimodipine in Refractory Cerebral Vasospasm due to Aneurysmal Subarachnoid Hemorrhage

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    Background. Cerebral vasospasm is one of the leading courses for disability in aneurysmal subarachnoid hemorrhage. Effective treatment of vasospasm is therefore one of the main priorities for these patients. We report about a case series of continuous intra-arterial infusion of the calcium channel antagonist nimodipine for 1-5 days on the intensive care unit. Methods. In thirty patients with aneurysmal subarachnoid hemorrhage and refractory vasospasm continuous infusion of nimodipine was started on the neurosurgical intensive care unit. The effect of nimodipine on brain perfusion, cerebral blood flow, brain tissue oxygenation, and blood flow velocity in cerebral arteries was monitored. Results. Based on Hunt & Hess grades on admission, 83% survived in a good clinical condition and 23% recovered without an apparent neurological deficit. Persistent ischemic areas were seen in 100% of patients with GOS 1-3 and in 69% of GOS 4-5 patients. Regional cerebral blood flow and computed tomography perfusion scanning showed adequate correlation with nimodipine application and angiographic vasospasm. Transcranial Doppler turned out to be unreliable with interexaminer variance and failure of detecting vasospasm or missing the improvement. Conclusion. Local continuous intra-arterial nimodipine treatment for refractory cerebral vasospasm after aSAH can be recommended as a low-risk treatment in addition to established endovascular therapies

    Effects of iota-carrageenan on ocular Chlamydia trachomatis infection in vitro and in vivo

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    Ocular chlamydial infections with the ocular serovars A, B, Ba, and C of Chlamydia trachomatis represent the world's leading cause of infectious blindness. Carrageenans are naturally occurring, sulfated polysaccharides generally considered safe for food and topical applications. Carrageenans can inhibit infection caused by a variety of viruses and bacteria. To investigate whether iota-carrageenan (I-C) isolated from the red alga Chondrus crispus could prevent ocular chlamydial infection, we assessed if targeted treatment of the conjunctival mucosa with I-C affects chlamydial attachment, entry, and replication in the host cell. Immortalized human conjunctival epithelial cells were treated with I-C prior to C. trachomatis infection and analyzed by flow cytometry and immunofluorescence microscopy. In vivo effects were evaluated in an ocular guinea pig inclusion conjunctivitis model. Ocular pathology was graded daily, and chlamydial clearance was investigated. Our study showed that I-C reduces the infectivity of C. trachomatis in vitro. In vivo results showed a slight reduced ocular pathology and significantly less shedding of infectious elementary bodies by infected animals. Our results indicate that I-C could be a promising agent to reduce the transmission of ocular chlamydial infection and opens perspectives to develop prophylactic approaches to block C. trachomatis entry into the host cell

    Deletion of nuoG from the Vaccine Candidate Mycobacterium bovis BCG ΔureC::hly Improves Protection against Tuberculosis

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    The current tuberculosis (TB) vaccine, Mycobacterium bovis Bacillus Calmette-Guàérin (BCG), provides insufficient protection against pulmonary TB. Previously, we generated a listeriolysin-expressing recombinant BCG strain, which to date has successfully completed phase I and phase IIa clinical trials. In an attempt to further improve efficacy, we deleted the antiapoptotic virulence gene nuoG, encoding NADH dehydrogenase 1 subunit G, from BCG ΔureC::hly. In vitro, deletion of nuoG unexpectedly led to strongly increased recruitment of the autophagosome marker LC3 to the engulfed vaccine, suggesting that nuoG also affects xenophagic pathways. In mice, BCG ΔureC::hly ΔnuoG vaccination was safer than BCG and improved protection over that of parental BCG ΔureC::hly, significantly reducing TB load in murine lungs, ameliorating pulmonary pathology, and enhancing immune responses. Transcriptome analysis of draining lymph nodes after vaccination with either BCG ΔureC::hly or BCG ΔureC::hly ΔnuoG demonstrated earlier and stronger induction of immune responses than that with BCG SSI and suggested upregulation of inflammasome activation and interferon-induced GTPases. In summary, BCG ΔureC::hly ΔnuoG is a promising next-generation TB vaccine candidate with excellent efficacy and safety
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