187 research outputs found
The Structure of Liquid and Amorphous Hafnia.
Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an average Hf-O coordination number of ~7 exists in both the liquid and amorphous nanoparticle forms studied. The measured pair distribution functions are compared to those generated from several simulation models in the literature. We have also performed ab initio and classical molecular dynamics simulations that show density has a strong effect on the polyhedral connectivity. The liquid shows a broad distribution of Hf-Hf interactions, while the formation of low-density amorphous nanoclusters can reproduce the sharp split peak in the Hf-Hf partial pair distribution function observed in experiment. The agglomeration of amorphous nanoparticles condensed from the gas phase is associated with the formation of both edge-sharing and corner-sharing HfO6,7 polyhedra resembling that observed in the monoclinic phase
A microprocessor implementation of an image enhancement/transmission system
Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 147-148.by Raleigh Cedric Gallington.Elec.
Rapid calibration of seven-hole probes
This paper summarizes the major conclusions and some of the key supporting analyses resulting from the calibration and application of two small seven hole probes at NASA Lewis Research Center. These probes can produce reasonably accurate and rapid surveys of unknown steady flow fields which may include flow angles up to 70 degrees and Mach numbers up to 0.8. The probes were calibrated with both 'complete' and 'reduced' test matrices. Both types of test matrices produced similar results suggesting the the reduced matrices are adequate for most purposes. The average accuracy fo the calibration was about the same as that achieved in previous seven hole probe calibrations. At the higher Mach numbers, the calibration was sensitive to the diameter of the free jet in the calibration facility. Over a narrow angular range at the higher Mach numbers, the system had serious repeatability problems. This lack or repeatability apparently results from aliasing of high frequency (20 to 40 Hz) noise with the data acquisition system sampling frequency of 10 Hz. Analyses show that these noise frequencies are probably not related to airflow dynamics in the connecting tubing
Sleep disturbance among adults with overactive bladder: A cross-sectional survey
OBJECTIVE: To examine differences in sleep disturbance, nocturia, and depression among adults with overactive bladder (OAB) by treatment type.
METHODS: A cross-sectional survey of adults with OAB assessed sleep disturbance, nocturia, and depression using patient-reported outcome measures, including the Patient Reported Outcomes Measurement Information System (PROMIS)-29 Profile v2.1 (Sleep Disturbance and Depression domains), Lower Urinary Tract Dysfunction Research Network Symptom Index-10, and PROMIS Sleep Disturbance Short Form 8B. Treatment groups included antimuscarinics, β-3 adrenergic agonists, and no treatment. Analysis of covariance (ANCOVA) was used to test for differences in study endpoints; Bonferroni-adjusted pairwise tests (P \u3c .05/3) were performed to compare differences in least squares means between groups.
RESULTS: One hundred participants were included per treatment group. The overall mean (standard deviation) age across all groups was 47.8 (11.8) years. Symptom scores across all PROMIS domains in all three treatment groups were higher than the US general population. There were no statistically significant differences in outcomes across treatment groups.
CONCLUSION: Adults with OAB reported being affected by sleep disturbance and depression, regardless of treatment. The mirabegron group trended toward the lowest symptom impact across all outcomes, however, comparisons were not significant. Future research should examine temporal associations between OAB treatment, sleep disturbance, and outcomes
TLR2 Mediates Recognition of Live Staphylococcus epidermidis and Clearance of Bacteremia
Background: Staphylococcus epidermidis (SE) is a nosocomial pathogen that causes catheter-associated bacteremia in the immunocompromised, including those at the extremes of age, motivating study of host clearance mechanisms. SE-derived soluble components engage TLR2; but additional signaling pathways have also been implicated, and TLR2 can play complex, at times detrimental, roles in host defense against other Staphylococcal spp. The role of TLR2 in responses of primary blood leukocytes to live SE and in clearance of SE bacteremia, the most common clinical manifestation of SE infection, is unknown. Methodology/Principal Findings: We studied TLR2-mediated recognition of live clinical SE strain 1457 employing TLR2- transfected cells, neutralizing anti-TLR antibodies and TLR2-deficient mice. TLR2 mediated SE-induced cytokine production in human embryonic kidney cells, human whole blood and murine primary macrophages, in part via recognition of a soluble TLR2 agonist. After i.v. challenge with SE, early (1 h) cytokine/chemokine production and subsequent clearance of bacteremia (24-48 h) were markedly impaired in TLR2-deficient mice. Conclusions/Significance: TLR2 mediates recognition of live SE and clearance of SE bacteremia in vivo
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