668 research outputs found

    Characterization of health care utilization in patients receiving implantable cardioverter-defibrillator therapies: An analysis of the managed ventricular pacing trial.

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    BACKGROUND: Implantable cardioverter-defibrillators (ICDs) are effective in terminating lethal arrhythmias, but little is known about the degree of health care utilization (HCU) after ICD therapies. OBJECTIVE: Using data from the managed ventricular pacing trial, we sought to identify the incidence and types of HCU in ICD patients after receiving ICD therapy (shocks or antitachycardia pacing [ATP]). METHODS: We analyzed HCU events (ventricular tachyarrhythmia [VTA]-related, heart failure-related, ICD implant procedure-related, ICD system-related, or other) and their association with ICD therapies (shocked ventricular tachycardia episode, ATP-terminated ventricular tachycardia episode, and inappropriately shocked episode). RESULTS: A total of 1879 HCUs occurred in 695 of 1030 subjects (80% primary prevention) and were classified as follows: 133 (7%) VTA-related, 373 (20%) heart failure-related, 97 (5%) implant procedure-related, 115 (6%) system-related, and 1160 (62%) other. Of 2113 treated VTA episodes, 1680 (80%) received ATP only and 433 (20%) received shocks. Stratifying VTA-related HCUs on the basis of the type of ICD therapy delivered, there were 25 HCUs per 100 shocked VTA episodes compared with 1 HCU per 100 ATP-terminated episodes. Inappropriate ICD shocks occurred in 8.7% of the subjects and were associated with 115 HCUs. The majority of HCUs (52%) began in the emergency department, and 66% of all HCUs resulted in hospitalization. CONCLUSION: For VTA-related HCUs, shocks are associated with a 25-fold increase in HCUs compared to VTAs treated by ATP only. Application of evidence-based strategies and automated device-based algorithms to reduce ICD shocks (higher rate cutoffs, use of ATP, and arrhythmia detection) may help reduce HCUs

    Development and Optimization of Micro‐Nanotopographical Platforms for Surface Enhanced Raman Scattering Biomolecular Detection

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    Topologically designed micro‐ and nanostructured surface‐enhanced Raman scattering (SERS) substrates propel the advancements of innovative applications, including environmental and forensic point‐of‐care miniaturised devices via enhancing the localised electric fields for accurate analyte sensing. Herein, a method for designing, optimising and fabricating fine‐tuneable concentric hexagonal, triangular and rectangular SERS‐active micronano‐substrates is developed, with each unit yielding significant enhancement. Numerical simulations of the 3D near‐field electric field guided the optimal design process. While the coaxial SERS substrates consistently outperformed their solid counterparts, the hexagonal micro‐nano topologies exhibited ×21 higher signal than coaxial square arrays and a 12‐15‐fold increase over the triangle structures. Alternation of the topological designs from square to triangle lattice yielded more uniform plasmonic modes propagating along the 60°‐directions with various resonance modes playing key roles in light reflectance. This enables the engineering of platforms with tailor‐enhanced signals by changing the arrangement of micro‐nano patterned coaxial arrays. The fabricated SERS substrates are validated by detecting traumatic brain injury biomarkers, effectively yielding the characteristic fingerprint spectra of each neuro‐molecule. The straightforward development of sub‐micrometre tuneable SERS‐active architectures enables anelegant route for high‐throughput biochemical sensing, laying a platform for amplified bimolecular detection of disease biomarkers and integration in bioanalytical systems

    Development and Optimization of Micro‐Nanotopographical Platforms for Surface Enhanced Raman Scattering Biomolecular Detection

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    Topologically designed micro‐ and nanostructured surface‐enhanced Raman scattering (SERS) substrates propel the advancements of innovative applications, including environmental and forensic point‐of‐care miniaturised devices via enhancing the localised electric fields for accurate analyte sensing. Herein, a method for designing, optimising and fabricating fine‐tuneable concentric hexagonal, triangular and rectangular SERS‐active micronano‐substrates is developed, with each unit yielding significant enhancement. Numerical simulations of the 3D near‐field electric field guided the optimal design process. While the coaxial SERS substrates consistently outperformed their solid counterparts, the hexagonal micro‐nano topologies exhibited ×21 higher signal than coaxial square arrays and a 12‐15‐fold increase over the triangle structures. Alternation of the topological designs from square to triangle lattice yielded more uniform plasmonic modes propagating along the 60°‐directions with various resonance modes playing key roles in light reflectance. This enables the engineering of platforms with tailor‐enhanced signals by changing the arrangement of micro‐nano patterned coaxial arrays. The fabricated SERS substrates are validated by detecting traumatic brain injury biomarkers, effectively yielding the characteristic fingerprint spectra of each neuro‐molecule. The straightforward development of sub‐micrometre tuneable SERS‐active architectures enables anelegant route for high‐throughput biochemical sensing, laying a platform for amplified bimolecular detection of disease biomarkers and integration in bioanalytical systems

    Cellular Models of Aggregation-Dependent Template-Directed Proteolysis to Characterize Tau Aggregation Inhibitors for Treatment of Alzheimer's Disease

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    Copyright © 2015, The American Society for Biochemistry and Molecular Biology. Acknowledgements-We thank Drs Timo Rager and Rolf Hilfiker (Solvias, Switzerland) for polymorph analyses.Peer reviewedPublisher PD

    Mineralogy of sulfides

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    Metal sulphides are the most important group of ore minerals. As shown in this brief introduction, much is known about their compositions, crystal structures, phase relations and paragenesis. Much less is known about their surface chemistry and, in particular, about their biogeochemistry, and about the formation and behaviour of ‘nanoparticle’ sulphides, whether formed abiotically or biogenically. These are large and complex topics which can only be touched upon in this article which also serves to direct readers to more comprehensive accounts

    Dressings and securements for the prevention of peripheral intravenous catheter failure in adults (SAVE): a pragmatic, randomised controlled, superiority trial

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    Background: Two billion peripheral intravenous catheters (PIVCs) are used globally each year, but optimal dressing and securement methods are not well established. We aimed to compare the efficacy and costs of three alternative approaches to standard non-bordered polyurethane dressings. Methods: We did a pragmatic, randomised controlled, parallel-group superiority trial at two hospitals in Queensland, Australia. Eligible patients were aged 18 years or older and required PIVC insertion for clinical treatment, which was expected to be required for longer than 24 h. Patients were randomly assigned (1:1:1:1) via a centralised web-based randomisation service using random block sizes, stratified by hospital, to receive tissue adhesive with polyurethane dressing, bordered polyurethane dressing, a securement device with polyurethane dressing, or polyurethane dressing (control). Randomisation was concealed before allocation. Patients, clinicians, and research staff were not masked because of the nature of the intervention, but infections were adjudicated by a physician who was masked to treatment allocation. The primary outcome was all-cause PIVC failure (as a composite of complete dislodgement, occlusion, phlebitis, and infection [primary bloodstream infection or local infection]). Analysis was by modified intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12611000769987. Findings: Between March 18, 2013, and Sept 9, 2014, we randomly assigned 1807 patients to receive tissue adhesive with polyurethane (n=446), bordered polyurethane (n=454), securement device with polyurethane (n=453), or polyurethane (n=454); 1697 patients comprised the modified intention-to-treat population. 163 (38%) of 427 patients in the tissue adhesive with polyurethane group (absolute risk difference −4·5% [95% CI −11·1 to 2·1%], p=0·19), 169 (40%) of 423 of patients in the bordered polyurethane group (–2·7% [–9·3 to 3·9%] p=0·44), 176 (41%) of 425 patients in the securement device with poplyurethane group (–1·2% [–7·9% to 5·4%], p=0·73), and 180 (43%) of 422 patients in the polyurethane group had PIVC failure. 17 patients in the tissue adhesive with polyurethane group, two patients in the bordered polyurethane group, eight patients in the securement device with polyurethane group, and seven patients in the polyurethane group had skin adverse events. Total costs of the trial interventions did not differ significantly between groups. Interpretation: Current dressing and securement methods are commonly associated with PIVC failure and poor durability, with simultaneous use of multiple products commonly required. Cost is currently the main factor that determines product choice. Innovations to achieve effective, durable dressings and securements, and randomised controlled trials assessing their effectiveness are urgently needed

    Origins of the Highly Ionized Gas along the Line of Sight towards HD 116852

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    We present Hubble Space Telescope Imaging Spectrograph (HST/STIS) and Far Ultraviolet Spectroscopic Explorer (FUSE) observations of high ion interstellar absorption along the sight line to HD 116852. At a distance of 4.8 kpc, HD 116852 is an O9 III star lying in the low Galactic halo, -1.3 kpc from the plane of the Galaxy in the direction l = 304.9, b = -16.1. The STIS E140H grating observations provide high-resolution (FWHM = 2.7 km/s) spectra of the resonance doublets of Si IV, C IV, and N V. These data are complemented by medium-resolution (FWHM = 20 km/s) FUSE spectra of O VI. We find evidence for three distinct types of highly ionized gas present in the data. First, two narrow absorption components are resolved in the Si IV and C IV profiles, at approximate LSR velocities of -36 and -10 km/s. These narrow components appear to be produced in gas associated with the Norma and Sagittarius spiral arms, at approximate z-distances of -1.0 and -0.5 kpc, respectively. Second, we detect an intermediate-width component in C IV and Si IV, at 17 km/s, which we propose could arise at the conductive interface at the boundary between a low column density neutral or weakly ionized cloud and the surrounding hot medium. Finally, a broad collisionally ionized component of gas responsible for producing the smooth N V and O VI profiles is observed; such absorption is also present to a lesser degree in the profiles of Si IV and C IV. The broad O VI absorption is observed at a velocity displaced from the broad C IV component by almost 20 km/s, an amount large enough to suggest that the two ions may not co-exist in the same physical location.Comment: 39 pages, 6 figures; accepted for publication in January 10, 2003 edition of The Astrophysical Journa

    COLD GASS, an IRAM legacy survey of molecular gas in massive galaxies: I. Relations between H2, HI, stellar content and structural properties

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    We are conducting COLD GASS, a legacy survey for molecular gas in nearby galaxies. Using the IRAM 30m telescope, we measure the CO(1-0) line in a sample of ~350 nearby (D=100-200 Mpc), massive galaxies (log(M*/Msun)>10.0). The sample is selected purely according to stellar mass, and therefore provides an unbiased view of molecular gas in these systems. By combining the IRAM data with SDSS photometry and spectroscopy, GALEX imaging and high-quality Arecibo HI data, we investigate the partition of condensed baryons between stars, atomic gas and molecular gas in 0.1-10L* galaxies. In this paper, we present CO luminosities and molecular hydrogen masses for the first 222 galaxies. The overall CO detection rate is 54%, but our survey also uncovers the existence of sharp thresholds in galaxy structural parameters such as stellar mass surface density and concentration index, below which all galaxies have a measurable cold gas component but above which the detection rate of the CO line drops suddenly. The mean molecular gas fraction MH2/M* of the CO detections is 0.066+/-0.039, and this fraction does not depend on stellar mass, but is a strong function of NUV-r colour. Through stacking, we set a firm upper limit of MH2/M*=0.0016+/-0.0005 for red galaxies with NUV-r>5.0. The average molecular-to-atomic hydrogen ratio in present-day galaxies is 0.3, with significant scatter from one galaxy to the next. The existence of strong detection thresholds in both the HI and CO lines suggests that "quenching" processes have occurred in these systems. Intriguingly, atomic gas strongly dominates in the minority of galaxies with significant cold gas that lie above these thresholds. This suggests that some re-accretion of gas may still be possible following the quenching event.Comment: Accepted for publications in MNRAS. 32 pages, 25 figure

    Erythroid differentiation enhances RNA mis-splicing in SF3B1-mutant myelodysplastic syndromes with ring sideroblasts

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    Myelodysplastic syndromes with ring sideroblasts (MDS-RS) commonly develop from hematopoietic stem cells (HSC) bearing mutations in the splicing factor SF3B1 (SF3B1mt). Direct studies into MDS-RS pathobiology have been limited by a lack of model systems that fully recapitulate erythroid biology and RS development and the inability to isolate viable human RS. Here, we combined successful direct RS isolation from patient samples, high-throughput multiomics analysis of cells encompassing the SF3B1mt stem-erythroid continuum, and functional assays to investigate the impact of SF3B1mt on erythropoiesis and RS accumulation. The isolated RS differentiated, egressed into the blood, escaped traditional nonsense-mediated decay (NMD) mechanisms, and leveraged stress-survival pathways that hinder wild-type hematopoiesis through pathogenic GDF15 overexpression. Importantly, RS constituted a contaminant of magnetically enriched CD34+ cells, skewing bulk transcriptomic data. Mis-splicing in SF3B1mt cells was intensified by erythroid differentiation through accelerated RNA splicing and decreased NMD activity, and SF3B1mt led to truncations in several MDS-implicated genes. Finally, RNA mis-splicing induced an uncoupling of RNA and protein expression, leading to critical abnormalities in proapoptotic p53 pathway genes. Overall, this characterization of erythropoiesis in SF3B1mt RS provides a resource for studying MDS-RS and uncovers insights into the unexpectedly active biology of the “dead-end” RS. Significance: Ring sideroblast isolation combined with state-of-the-art multiomics identifies survival mechanisms underlying SF3B1-mutant erythropoiesis and establishes an active role for erythroid differentiation and ring sideroblasts themselves in SF3B1-mutant myelodysplastic syndrome pathogenesis
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