250 research outputs found

    Sentry bioconvertible inferior vena cava filter: Study of stages of incorporation in an experimental ovine model

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    The Sentry inferior vena cava (IVC) filter is designed to provide temporary protection from pulmonary embolism (PE) and then bioconvert to become incorporated in the vessel wall, leaving a patent IVC lumen. Objective. To evaluate the performance and stages of incorporation of the Sentry IVC filter in an ovine model. Methods. Twenty-four bioconvertible devices and 1 control retrievable filter were implanted in the infrarenal IVC of 25 sheep, with extensive daily monitoring and intensive imaging. Vessels and devices were analyzed at early (≤98 days, n = 10) and late (180 ± 30 days, n = 14 study devices, 1 control) termination and necropsy time-points. Results. Deployment success was 100% with all devices confirmed in filtering configuration, there were no filter-related complications, and bioconversion was 100% at termination with vessels widely patent. By 98 days for all early-incorporation analysis animals, the stabilizing cylindrical part of the Sentry frame was incorporated in the vessel wall, and the filter arms were retracted. By 180 days for all late-incorporation analysis animals, the filter arms as well as frames were stably incorporated. Conclusions. Through 180 days, there were no filter-related complications, and the study devices were all bioconverted and stably incorporated, leaving all IVCs patent

    Animal models of hypertension: a scientific statement from the American Heart Association

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    Hypertension is the most common chronic disease in the world, yet the precise cause of elevated blood pressure often cannot be determined. Animal models have been useful for unraveling the pathogenesis of hypertension and for testing novel therapeutic strategies. The utility of animal models for improving the understanding of the pathogenesis, prevention, and treatment of hypertension and its comorbidities depends on their validity for representing human forms of hypertension, including responses to therapy, and on the quality of studies in those models (such as reproducibility and experimental design). Important unmet needs in this field include the development of models that mimic the discrete hypertensive syndromes that now populate the clinic, resolution of ongoing controversies in the pathogenesis of hypertension, and the development of new avenues for preventing and treating hypertension and its complications. Animal models may indeed be useful for addressing these unmet needs

    Allergen Sensitization and Asthma Outcomes among World Trade Center Rescue and Recovery Workers

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    A large number of World Trade Center (WTC) rescue and recovery workers are affected by asthma. While physical and mental health comorbidities have been associated with poor asthma control in this population, the potential role of allergen sensitization is unknown. This study examined the association of indoor sensitization and exposure as a risk factor for increased asthma morbidity in WTC workers. We used data from a prospective cohort of 331 WTC workers with asthma. Sensitization to indoor allergens was assessed by measurement of antigen-specific serum immunoglobulin E (IgE) levels. We used validated tools to evaluate the exposure to indoor allergens. Asthma morbidity outcomes included level of control (Asthma Control Questionnaire, ACQ), quality of life (Asthma Quality of Life Questionnaire, AQLQ) and acute resource utilization. The prevalence of sensitization to cat, dog, mouse, dust mite, cockroach, and mold allergens were 33%, 21%, 17%, 40%, 17%, and 17%, respectively. Unadjusted and regression analyses showed no significant relationship between sensitization and increased asthma morbidity (p \u3e 0.05 for all comparisons), except for sensitization to Aspergillus Fumigatus, cat and mouse epithelium, which were associated with decreased morbidity

    Use of antenatal corticosteroids prior to preterm birth in four South East Asian countries within the SEA-ORCHID project

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    BackgroundThere is strong evidence supporting the use of antenatal corticosteroids in women at risk of preterm birth to promote fetal lung maturation and reduce neonatal mortality and morbidity. This audit aimed to assess the use of antenatal corticosteroids prior to preterm birth in the nine hospitals in four South East Asian countries participating in the South East Asia Optimising Reproductive Health in Developing Countries (SEA-ORCHID) Project.MethodWe reviewed the medical records of 9550 women (9665 infants including 111 twins and two triplets) admitted to the labour wards of nine hospitals in four South East Asian countries during 2005. For women who gave birth before 34 weeks gestation we collected information on women's demographic and pregnancy background, the type, dose and use of corticosteroids, and key birth and infant outcomes.ResultsAdministration of antenatal corticosteroids to women who gave birth before 34 weeks gestation varied widely between countries (9% to 73%) and also between hospitals within countries (0% to 86%). Antenatal corticosteroids were most commonly given when women were between 28 and 34 weeks gestation (80%). Overall 6% of women received repeat doses of corticosteroids. Dexamethasone was the only type of antenatal corticosteroid used. Women receiving antenatal corticosteroids compared with those not given antenatal corticosteroids were less likely to have had a previous pregnancy and to be booked for birth at the hospital and almost three times as likely to have a current multiple pregnancy. Exposed women were less likely to be induced and almost twice as likely to have a caesarean section, a primary postpartum haemorrhage and postpartum pyrexia. Infants exposed to antenatal corticosteroids compared with infants not exposed were less likely to die. Live born exposed infants were less likely to have Apgar scores of ConclusionIn this survey the use of antenatal corticosteroids prior to preterm birth varied between countries and hospitals. Evaluation of the enablers and barriers to the uptake of this effective antenatal intervention at individual hospitals is needed.Pattanittum P, Ewens MR, Laopaiboon M, Lumbiganon P, McDonald SJ, Crowther CA and The SEA-ORCHID Study Grou

    Renal Replacement Therapy and Incremental Hemodialysis for Veterans with Advanced Chronic Kidney Disease.

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    Each year approximately 13,000 Veterans transition to maintenance dialysis, mostly in the traditional form of thrice-weekly hemodialysis from the start. Among >6000 dialysis units nationwide, there are currently approximately 70 Veterans Affairs (VA) dialysis centers. Given this number of VA dialysis centers and their limited capacity, only 10% of all incident dialysis Veterans initiate treatment in a VA center. Evidence suggests that, among Veterans, the receipt of care within the VA system is associated with favorable outcomes, potentially because of the enhanced access to healthcare resources. Data from the United States Renal Data System Special Study Center "Transition-of-Care-in-CKD" suggest that Veterans who receive dialysis in a VA unit exhibit greater survival compared with the non-VA centers. Substantial financial expenditures arise from the high volume of outsourced care and higher dialysis reimbursement paid by the VA than by Medicare to outsourced providers. Given the exceedingly high mortality and abrupt decline in residual kidney function (RKF) in the first dialysis year, it is possible that incremental transition to dialysis through an initial twice-weekly hemodialysis regimen might preserve RKF, prolong vascular access longevity, improve patients' quality of life, and be a more patient-centered approach, more consistent with "personalized" dialysis. Broad implementation of incremental dialysis might also result in more Veterans receiving care within a VA dialysis unit. Controlled trials are needed to examine the safety and efficacy of incremental hemodialysis in Veterans and other populations; the administrative and health care as well as provider structure within the VA system would facilitate the performance of such trials

    Chemical profiles of the oxides on tantalum in state of the art superconducting circuits

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    Over the past decades, superconducting qubits have emerged as one of the leading hardware platforms for realizing a quantum processor. Consequently, researchers have made significant effort to understand the loss channels that limit the coherence times of superconducting qubits. A major source of loss has been attributed to two level systems that are present at the material interfaces. We recently showed that replacing the metal in the capacitor of a transmon with tantalum yields record relaxation and coherence times for superconducting qubits, motivating a detailed study of the tantalum surface. In this work, we study the chemical profile of the surface of tantalum films grown on c-plane sapphire using variable energy X-ray photoelectron spectroscopy (VEXPS). We identify the different oxidation states of tantalum that are present in the native oxide resulting from exposure to air, and we measure their distribution through the depth of the film. Furthermore, we show how the volume and depth distribution of these tantalum oxidation states can be altered by various chemical treatments. By correlating these measurements with detailed measurements of quantum devices, we can improve our understanding of the microscopic device losses

    CHARMM at 45: Enhancements in Accessibility, Functionality, and Speed

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    Since its inception nearly a half century ago, CHARMM has been playing a central role in computational biochemistry and biophysics. Commensurate with the developments in experimental research and advances in computer hardware, the range of methods and applicability of CHARMM have also grown. This review summarizes major developments that occurred after 2009 when the last review of CHARMM was published. They include the following: new faster simulation engines, accessible user interfaces for convenient workflows, and a vast array of simulation and analysis methods that encompass quantum mechanical, atomistic, and coarse-grained levels, as well as extensive coverage of force fields. In addition to providing the current snapshot of the CHARMM development, this review may serve as a starting point for exploring relevant theories and computational methods for tackling contemporary and emerging problems in biomolecular systems. CHARMM is freely available for academic and nonprofit research at https://academiccharmm.org/program
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