2,082 research outputs found

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

    Get PDF
    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

    Stories from Around the Globe: Financing Catastrophic Health Expenditures in Selected Countries

    Full text link
    This study reviews literature on financing catastrophic health expenditures in selected countries to describe and synthesize the strategies of relatively successful health financing schemes. It begins with a review of basic concepts and definitions to set the stage for later discussions. This is followed by a country selection process, where countries were selected based on their income level, health outcomes, coverage outcomes, cost effectiveness, and the availability of information on their health financing strategies. Low-income, lower middle-income, and upper middle-income countries were selected, each one having above average outcomes and cost effectiveness relative to other countries within the same income level. The availability of information further limited the selection to three countries - Kyrgyz Republic, Sri Lanka, and Thailand - on which a desk review was conducted. The study presents the stories of each country and the common themes that emerged.The stories reveal that the causes behind catastrophic payments, specifically high out-of-pocket payments, vary, thus the strategies for addressing them also do. Health financing schemes were either set for the whole population or formulated to fit specific segments. All three countries increased the amount of funding available for health care, and did so mostly through taxation. Benefits are comprehensive, covering preventive, inpatient, and outpatient care with drugs and medicines. Payment methods were generally designed to use the available funds in a cost-effective manner by strengthening preventive primary care, and incentivizing efficiency in tertiary care facilities.Beyond that, change management factors that were common to most or all of the countries were: crises that created an impetus for change; strong public demand and participation; a political system that empowers the populace and creates political incentives for reform; commitment to a comprehensive, cohesive, and appropriate strategy; grit and responsiveness throughout the implementation period; monitoring and evaluation; and rapid but phased implementation

    Digital Watermarking Authentication and Restoration for Chinese Calligraphy Images

    Get PDF
    In this paper, a semi-fragile watermarking method for authentication and automatic restoration of Chinese calligraphy images is proposed using the pinned sine transform (PST). The watermarking system can locate the content of image that has been tampered maliciously with high accuracy. In particular, the watermarking scheme is very sensitive to any texture alteration in the watermarked images, which is crucial for calligraphy image analysis. The tampered portions could be approximately restored. Results of simulation experiments are presented to demonstrate the effectiveness of the proposed method.</p

    Atom-by-Atom Substitution of Mn in GaAs and Visualization of their Hole-Mediated Interactions

    Full text link
    The discovery of ferromagnetism in Mn doped GaAs [1] has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices [2-4]. A major hurdle for realistic applications of (Ga,Mn)As, or other dilute magnetic semiconductors, remains their below room-temperature ferromagnetic transition temperature. Enhancing ferromagnetism in semiconductors requires understanding the mechanisms for interaction between magnetic dopants, such as Mn, and identifying the circumstances in which ferromagnetic interactions are maximized [5]. Here we report the use of a novel atom-by-atom substitution technique with the scanning tunnelling microscope (STM) to perform the first controlled atomic scale study of the interactions between isolated Mn acceptors mediated by the electronic states of GaAs. High-resolution STM measurements are used to visualize the GaAs electronic states that participate in the Mn-Mn interaction and to quantify the interaction strengths as a function of relative position and orientation. Our experimental findings, which can be explained using tight-binding model calculations, reveal a strong dependence of ferromagnetic interaction on crystallographic orientation. This anisotropic interaction can potentially be exploited by growing oriented Ga1-xMnxAs structures to enhance the ferromagnetic transition temperature beyond that achieved in randomly doped samples. Our experimental methods also provide a realistic approach to create precise arrangements of single spins as coupled quantum bits for memory or information processing purposes

    One-step Preparation of ZnO Electron Transport Layers Functionalized with Benzoic Acid Derivatives

    Full text link
    We present a "one-step" approach to modify ZnO electron transport layers (ETLs) used in organic solar cells. This approach involves adding benzoic acid (BZA) derivatives directly to the ZnO precursor solution, which are then present at the surface of the resulting ZnO film. We demonstrate this approach for three different BZA derivatives, namely benzoic acid, chlorobenzoic acid, and 4-hydrazinobenzoic acid. For all molecules, improved device performance and stability is demonstrated in solar cells using an active layer blend of PTQ10 (donor) and ITIC-Br (non-fullerene acceptor) compared to such cells prepared using untreated ZnO. Furthermore, similar or improved device performance and stability is demonstrated compared to conventional PEIE treatment of ZnO. The presence of the BZA derivatives at the surface after processing is established using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine-structure spectroscopy. From atomic force microscopy analysis and X-ray diffraction studies, the addition of BZA derivatives appears to restrict ZnO grain growth; however, this does not negatively impact device performance. ZnO layers treated with BZA derivatives also exhibit higher water contact angle and lower work function compared to untreated ZnO. This approach enables simplification of device manufacture while still allowing optimization of the surface properties of metal oxide ETLs. Keywords: electron transport layers, zinc oxide, organic solar cells, surface modificationComment: Manuscript: 25 pages, 8 figures, 5 tables. Supplementary Material: 36 pages, 22 figures, 13 tables. Submitted to Solar Energy Materials and Solar Cell

    The effect of influenza virus on the human oropharyngeal microbiome

    Get PDF
    © The Author(s) 2018. Background. Secondary bacterial infections are an important cause of morbidity and mortality associated with influenza infections. As bacterial disease can be caused by a disturbance of the host microbiome, we examined the impact of influenza on the upper respiratory tract microbiome in a human challenge study. Methods. The dynamics and ecology of the throat microbiome were examined following an experimental influenza challenge of 52 previously-healthy adult volunteers with influenza A/Wisconsin/67/2005 (H3N2) by intranasal inoculation; 35 healthy control subjects were not subjected to the viral challenge. Serial oropharyngeal samples were taken over a 30-day period, and the V1-V3 region of the bacterial 16S ribosomal RNA sequences were amplified and sequenced to determine the composition of the microbiome. The carriage of pathogens was also detected. Results. Of the 52 challenged individuals, 43 developed proven influenza infections, 33 of whom became symptomatic. None of the controls developed influenza, although 22% reported symptoms. The diversity of bacterial communities remained remarkably stable following the acquisition of influenza, with no significant differences over time between individuals with influenza and those in the control group. Influenza infection was not associated with perturbation of the microbiome at the level of phylum or genus. There was no change in colonization rates with Streptococcus pneumoniae or Neisseria meningitidis. Conclusions. The throat microbiota is resilient to influenza infection, indicating the robustness of the upper-airway microbiome

    Property and Shape Modulation of Carbon Fibers Using Lasers

    Get PDF
    An exciting challenge is to create unduloid-reinforcing fibers with tailored dimensions to produce synthetic composites with improved toughness and increased ductility. Continuous carbon fibers, the state-of-the-art reinforcement for structural composites, were modified via controlled laser irradiation to result in expanded outwardly tapered regions, as well as fibers with Q-tip (cotton-bud) end shapes. A pulsed laser treatment was used to introduce damage at the single carbon fiber level, creating expanded regions at predetermined points along the lengths of continuous carbon fibers, while maintaining much of their stiffness. The range of produced shapes was quantified and correlated to single fiber tensile properties. Mapped Raman spectroscopy was used to elucidate the local compositional and structural changes. Irradiation conditions were adjusted to create a swollen weakened region, such that fiber failure occurred in the laser treated region producing two fiber ends with outwardly tapered ends. Loading the tapered fibers allows for viscoelastic energy dissipation during fiber pull-out by enhanced friction as the fibers plough through a matrix. In these tapered fibers, diameters were locally increased up to 53%, forming outward taper angles of up to 1.8°. The tensile strength and strain to failure of the modified fibers were significantly reduced, by 75% and 55%, respectively, ensuring localization of the break in the expanded region; however, the fiber stiffness was only reduced by 17%. Using harsher irradiation conditions, carbon fibers were completely cut, resulting in cotton-bud fiber end shapes. Single fiber pull-out tests performed using these fibers revealed a 6.75-fold increase in work of pull-out compared to pristine carbon fibers. Controlled laser irradiation is a route to modify the shape of continuous carbon fibers along their lengths, as well as to cut them into controlled lengths leaving tapered or cotton-bud shapes
    • …
    corecore