1,642 research outputs found

    Disability in young people and adults after head injury: 12-14 year follow up of a prospective cohort

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    Background: There is a need to establish how long term outcome evolves after head injury (HI) and factors related to this, to inform opportunities for intervention. Objective: To determine late outcome in adults 12-14 years after hospital admission for HI and to examine relationships between injury, early and late factors and disability. Methods: A prospective cohort with HI, whose outcome was reported previously at 1 and 5-7 years after injury were followed up after 12-14 years. Participants were assessed using structured and validated measures of disability (Glasgow Outcome Scale-Extended), psychological well-being, alcohol use and health status. Results: Of 219 survivors followed-up at 5-7 years, 34 (15.5%) had died by 12-14 years. Disability remained common in survivors at 12-14 years (51%), as found at one and 5-7 years (53%). For those disabled at 1 year, outcome was dismal, with 80% dead or disabled at 12-14 years. Older age at injury, a premorbid history of brain illness or physical disability and post-injury low self-esteem and stress were associated with disability at 12-14 years. Disability changed between 5-7 and 12-14 years in 55% of survivors, improving in 23%. Late changes in disability between 5-7 and 12-14 years were associated with self-perceptions of locus of control as being 'powerful others' at 5-7 years. Conclusions: Disability is common 12-14 years after hospital admission with a head injury. For some there is a dynamic process of change in disability over time that is associated with self-perceptions of control that could be a target for intervention based research

    Payload/orbiter signal-processing and data-handling system evaluation

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    Incompatibilities between orbiter subsystems and payload communication systems to assure that acceptable and to end system performamce will be achieved are identified. The potential incompatabilities are associated with either payloads in the cargo bay or detached payloads communicating with the orbiter via an RF link. The payload signal processing and data handling systems are assessed by investigating interface problems experienced between the inertial upper stage and the orbiter since similar problems are expected for other payloads

    Shuttle payload S-band communications system

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    The Shuttle payload S-band communications system design, operational capabilities, and performance are described in detail. System design requirements, overall system and configuration and operation, and laboratory/flight test results are presented. Payload communications requirements development is discussed in terms of evolvement of requirements as well as the resulting technical challenges encountered in meeting the initial requirements. Initial design approaches are described along with cost-saving initiatives that subsequently had to be made. The resulting system implementation that was finally adopted is presented along with a functional description of the system operation. A description of system test results, problems encountered, how the problems were solved, and the system flight experience to date is presented. Finally, a summary of the advancements made and the lessons learned is discussed

    Early recurrent ischemic stroke complicating intravenous thrombolysis for stroke: incidence and association with atrial fibrillation

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    <p><b>Background and Purpose:</b> Mechanisms of early neurologic deterioration after treatment with intravenous, recombinant, tissue-type plasminogen activator (IV rt-PA) include symptomatic intracerebral hemorrhage (SICH) and early recurrent ischemic stroke. We observed a number of cases of acute deterioration due to recurrent ischemic events.</p> <p><b>Methods:</b> We undertook a single-center, retrospective analysis of consecutive acute stroke patients treated with IV rt-PA between January 2006 and December 2008 to define the incidence of early neurologic deterioration (>= 4-point drop on the National Institutes of Health Stroke Scale within 72 hours) and its mechanism. Deterioration was attributed to SICH when associated with a PH1 or PH2 hemorrhage on postdeterioration computed tomography scans, to recurrent ischemic stroke when there was clinical and radiologic evidence of a new territorial infarction or new vessel occlusion, and otherwise to evolution of the incident stroke.</p> <p><b>Results:</b> Of 228 consecutive IV rt-PA-treated patients, 34 (15%) developed early neurologic deterioration, 18 (8%) secondary to incident strokes 10 (4.4%) due to SICH, and 6 (2.6%) due to early recurrent ischemic events, which were significantly associated with atrial fibrillation (present in 5 of 6 patients; 4 paroxysmal, 1 permanent). In 4 patients, sudden clinical deterioration developed during or shortly after IV rt-PA infusion, and in 2, deterioration developed 3 days later. All died 2 days to 2 weeks later. The single case without atrial fibrillation had a recurrent, contralateral, middle cerebral artery stroke during IV rt-PA infusion and multiple high-signal emboli detected by transcranial Doppler. Early recurrent ischemic stroke accounted for 5 of 12 (42%) cases of early neurologic deterioration in patients with atrial fibrillation.</p> <p><b>Conclusion:</b> In this single-center series, the incidence of early recurrent ischemic stroke after IV rt-PA was 2.6% and was associated with previous atrial fibrillation.</p&gt

    Secondary Metabolites Produced by the Marine Bacterium Halobacillus salinus That Inhibit Quorum Sensing-Controlled Phenotypes in Gram-Negative Bacteria

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    Certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. Here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. Isolate C42, a Halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by Vibrio harveyi in cocultivation experiments. With the use of bioassay-guided fractionation, two phenethylamide metabolites were identified as the active agents. The compounds additionally inhibit quorum sensing-regulated violacein biosynthesis by Chromobacterium violaceum CV026 and green fluorescent protein production by Escherichia coli JB525. Bacterial growth was unaffected at concentrations below 200 μg/ml. Evidence is presented that these nontoxic metabolites may act as antagonists of bacterial quorum sensing by competing with N-acyl homoserine lactones for receptor binding

    Antagonism of Quorum Sensing Phenotypes by Analogs of the Marine Bacterial Secondary Metabolite 3-Methyl-N-(2′-Phenylethyl)-Butyramide

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    Quorum sensing (QS) antagonists have been proposed as novel therapeutic agents to combat bacterial infections. We previously reported that the secondary metabolite 3-methyl-N-(2′-phenylethyl)-butyramide, produced by a marine bacterium identified as Halobacillus salinus, inhibits QS controlled phenotypes in multiple Gram-negative reporter strains. Here we report that N-phenethyl hexanamide, a structurally-related compound produced by the marine bacterium Vibrio neptunius, similarly demonstrates QS inhibitory properties. To more fully explore structure–activity relationships within this new class of QS inhibitors, a panel of twenty analogs was synthesized and biologically evaluated. Several compounds were identified with increased attenuation of QS-regulated phenotypes, most notably N-(4-fluorophenyl)-3-phenylpropanamide against the marine pathogen Vibrio harveyi (IC50 = 1.1 µM). These findings support the opportunity to further develop substituted phenethylamides as QS inhibitors

    Force production characteristics in Parkinson's disease

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    This experiment examined the preparation and the production of isometric force in Parkinson's disease (PD). PD patients, elderly, and young subjects generated force levels that were a percentage of their maximum (15, 30, 45, and 60%). Subjects were cued on the upcoming target force level and they were asked to produce the required response as fast as possible. PD patients showed a similar progression of force variability and dispersion of peak forces to that of control subjects, implying they have an accurate “internal model” of the required forces. Force production impairments were seen, however, at the within-trial level. PD patients had more irregular force-time curves that were characterized by changes in the rate of force production. The results suggest a more “noisy” output from the motor system and an inability to produce smooth forces. PD patients were also substantially slower in initiating a force production and the delay was localized in the pre-motor reaction time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46561/1/221_2004_Article_BF00253633.pd
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