353 research outputs found

    Kinematics of X‐Ray–Emitting Components in Cassiopeia A

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    We present high-resolution X-ray proper-motion measurements of Cassiopeia A using Chandra X-Ray Observatory observations from 2000 and 2002. We separate the emission into four spectrally distinct classes: Si-dominated, Fe-dominated, low-energy-enhanced, and continuum-dominated. These classes also represent distinct spatial and kinematic components. The Si- and Fe-dominated classes are ejecta and have a mean expansion rate of 0.2% yr-1. This is the same as for the forward shock filaments but less than the 0.3% yr-1 characteristic of optical ejecta. The low-energy-enhanced spectral class possibly illuminates a clumpy circumstellar component and has a mean expansion rate of 0.05% yr-1. The continuum-dominated emission likely represents the forward shock and consists of diffuse circumstellar material, which is seen as a circular ring around the periphery of the remnant as well as projected across the center

    Kinematics of X-ray Emitting Components in Cassiopeia A

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    We present high-resolution X-ray proper motion measurements of Cassiopeia A using Chandra observations from 2000 and 2002. We separate the emission into four spectrally distinct classes: Si-dominated, Fe-dominated, low-energy-enhanced, and continuum-dominated. These classes also represent distinct spatial and kinematic components. The Si- and Fe-dominated classes are ejecta and have a mean expansion rate of 0.2%/yr. This is the same as for the forward shock filaments but less than the 0.3%/yr characteristic of optical ejecta. The low-energy-enhanced spectral class possibly illuminates a clumpy circumstellar component and has a mean expansion rate of 0.05%/yr. The continuum-dominated emission likely represents the forward shock and consists of diffuse circumstellar material which is seen as a circular ring around the periphery of the remnant as well as projected across the center.Comment: 15 pages, 3 figures, accepted to Ap

    A prototype personal aerosol sampler based on electrostatic precipitation and electrowetting-on-dielectric actuation of droplets

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    This is an Open Access article, distributed under the terms of the Open Government Licence. http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved. The version of record (T. G. Foat, et al, 'A prototype personal aerosol sampler based on electrostatic precipitation and electrowetting-on-dielectric actuation of droplets', Journal of Aerosol Science, Vol. 95, pp. 43-53, May 2016) is available online at doi: https://doi.org/10.1016/j.jaerosci.2016.01.007.An electrostatic precipitator (ESP) based personal sampler with a laboratory based electrowetting-on-dielectric (EWOD) concentrator could provide a high concentration rate personal aerosol sampler system. A prototype system has been developed based on the concept of a lightweight personal ESP collecting aerosol particles onto a hydrophobic surface followed by the use of an EWOD actuated droplet system to transfer the deposited sample into a microlitre size water droplet.A personal sampler system could provide military or civilian personnel with a wide area biological monitoring capability supplying information on who has been infected, what they have been infected with, how much material they were exposed to and possibly where and when they were infected. Current commercial-off-the-shelf (COTS) personal sampler solutions can be bulky and use volumes of water to extract the sample that are typically a thousand times greater than the proposed method.Testing of the prototype ESP at a sample flow rate of 5Lmin-1 demonstrated collection efficiencies greater than 80% for sodium fluorescein particles larger than 4μm diameter and of approximately 50% at 1.5μm. The ESP-EWOD system collection efficiency measured for Bacillus atrophaeus (BG) spores with an air sample flow rate of 20L min-1 was 2.7% with a concentration rate of 1.9×105 min-1. This was lower than expected due to the corona ions from the ESP affecting the hydrophobicity of the collection surface and hence the EWOD efficiency. However, even with this low efficiency the concentration rate is more than an order of magnitude higher than the theoretical maximum of the best current COTS personal sampler. For an optimised system, ESP-EWOD system efficiency should be higher than 32% with a comparable increase in concentration rate.Peer reviewe

    How can healthcare professionals provide guidance and support to parents of adolescents? Results from a primary care-based study

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    Background: This study explored the rewards and difficulties of raising an adolescent and investigated parents' level of interest in receiving guidance from healthcare providers on parenting and adolescent health topics. Additionally, this study investigated whether parents were interested in parenting programs in primary care and explored methods in which parents want to receive guidance. Methods: Parents of adolescents (ages 12-18) who attended an outpatient pediatric clinic with their adolescent were contacted by telephone and completed a short telephone survey. Parents were asked open-ended questions regarding the rewards and difficulties of parenting and rated how important it was to receive guidance from a healthcare provider on certain parenting and health topics. Additionally, parents reported their level of interest in a parenting program in primary care and rated how they would like to receive guidance. Results: Our final sample included 104 parents, 87% of whom were interested in a parenting program within primary care. A variety of parenting rewards and difficulties were associated with raising an adolescent. From the list of parenting topics, communication was rated very important to receive guidance on (65%), followed by conflict management (50%). Of health topics, parents were primarily interested in receiving guidance on sex (77%), mental health (75%), and alcohol and drugs (74%). Parents in the study wanted to receive guidance from a pediatrician or through written literature. Conclusions: The current study finds that parents identify several rewarding and difficult aspects associated with raising an adolescent and are open to receiving guidance on a range of parenting topics in a variety of formats through primary care settings. Incorporating such education into healthcare visits could improve parents' knowledge. Healthcare providers are encouraged to consider how best to provide parenting support during this important developmental time period

    The spectrum of thyroid dysfunction in an Australian hepatitis C population treated with combination Interferon-α2β and Ribavirin

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    BACKGROUND: The study aims to assess the pattern of thyroid response to combination Interferon-α2β (IFN-α) and Ribavirin (RBV) anti-viral therapy in an Australian hepatitis C cohort. These include the prevalence of thyroid dysfunction (TD) including hyperthyroidism and hypothyroidism and their possible predictors, the common overall pattern of thyroid function tests whilst receiving therapy and TD outcomes, and the correlation with HCV status outcome. METHODS: A retrospective analysis of all medical records was performed to assess thyroid function in Hepatitis C Virus (HCV) patients who were treated at the Hunter Area hepatitis C treatment center between 1995 and March 2004. The centre is part of the John Hunter hospital, a major tertiary referral centre in New South Wales, Australia. RESULTS: There were 272 cases available for review. The prevalence of TD is 6.7 percent and is made up predominantly of females (80 percent). There were 3 (1.1 percent) cases of hyperthyroidism with 2 (67 percent) females. Thirteen out of fifteen (80 percent) cases of hypothyroidism were females with the overall prevalence of 5.5 percent. The majority of hypothyroid patients still required Thyroxine supplement at the end of follow up. CONCLUSION: Ninety three percent of HCV treated patients have intact thyroid function at the end of treatment. The predominant TD is hypothyroidism. The predominant pattern of thyrotoxicosis (TTX) is that of thyroiditis although the number is small. Graves' like disease was not observed. People with pre-existing thyroid auto-antibodies should be closely monitored for thyroid dysfunction, particularly hypothyroidism

    Development of a longitudinal integrated clerkship at an academic medical center

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    In 2005, medical educators at the University of California, San Francisco (UCSF), began developing the Parnassus Integrated Student Clinical Experiences (PISCES) program, a year-long longitudinal integrated clerkship at its academic medical center. The principles guiding this new clerkship were continuity with faculty preceptors, patients, and peers; a developmentally progressive curriculum with an emphasis on interdisciplinary teaching; and exposure to undiagnosed illness in acute and chronic care settings. Innovative elements included quarterly student evaluation sessions with all preceptors together, peer-to-peer evaluation, and oversight advising with an assigned faculty member. PISCES launched with eight medical students for the 2007/2008 academic year and expanded to 15 students for 2008/2009. Compared to UCSF's traditional core clerkships, evaluations from PISCES indicated significantly higher student satisfaction with faculty teaching, formal didactics, direct observation of clinical skills, and feedback. Student performance on discipline-specific examinations and United States Medical Licensing Examination step 2 CK was equivalent to and on standardized patient examinations was slightly superior to that of traditional peers. Participants' career interests ranged from primary care to surgical subspecialties. These results demonstrate that a longitudinal integrated clerkship can be implemented successfully at a tertiary care academic medical center

    A programme to spread eGFR graph surveillance for the early identification, support and treatment of people with progressive chronic kidney disease (ASSIST-CKD): protocol for the stepped wedge implementation and evaluation of an intervention to reduce late presentation for renal replacement therapy

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    Background Patients who start renal replacement therapy (RRT) for End-Stage Kidney Disease (ESKD) without having had timely access to specialist renal services have poor outcomes. At one NHS Trust in England, a community-wide CKD management system has led to a decline in the incident rate of RRT and the lowest percentage of patients presenting within 90 days of starting RRT in the UK. We describe the protocol for a quality improvement project to scale up and evaluate this innovation. Methods The intervention is based upon an off-line database that integrates laboratory results from blood samples taken in all settings stored under different identifying labels relating to the same patient. Graphs of estimated glomerular filtration rate (eGFR) over time are generated for patients 65 years with an incoming eGFR <40 ml/min/1.73 m2. Graphs where kidney function is deteriorating are flagged by a laboratory scientist and details sent to the primary care doctor (GP) with a prompt that further action may be needed. We will evaluate the impact of implementing this intervention across a large population served by a number of UK renal centres using a mixed methods approach. We are following a stepped-wedge design. The order of implementation among participating centres will be randomly allocated. Implementation will proceed with unidirectional steps from control group to intervention group until all centres are generating graphs of eGFR over time. The primary outcome for the quantitative evaluation is the proportion of patients referred to specialist renal services within 90 days of commencing RRT, using data collected routinely by the UK Renal Registry. The qualitative evaluation will investigate facilitators and barriers to adoption and spread of the intervention. It will include: semi-structured interviews with laboratory staff, renal centre staff and service commissioners; an online survey of GPs receiving the intervention; and focus groups of primary care staff. Discussion Late presentation to nephrology for patients with ESKD is a source of potentially avoidable harm. This protocol describes a robust quantitative and qualitative evaluation of a quality improvement intervention to reduce late presentation and improve the outcomes for patients with ESKD

    Novel strategies for targeting innate immune responses to influenza.

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    We previously reported that TLR4(-/-) mice are refractory to mouse-adapted A/PR/8/34 (PR8) influenza-induced lethality and that therapeutic administration of the TLR4 antagonist Eritoran blocked PR8-induced lethality and acute lung injury (ALI) when given starting 2 days post infection. Herein we extend these findings: anti-TLR4- or -TLR2-specific IgG therapy also conferred significant protection of wild-type (WT) mice from lethal PR8 infection. If treatment is initiated 3 h before PR8 infection and continued daily for 4 days, Eritoran failed to protect WT and TLR4(-/-) mice, implying that Eritoran must block a virus-induced, non-TLR4 signal that is required for protection. Mechanistically, we determined that (i) Eritoran blocks high-mobility group B1 (HMGB1)-mediated, TLR4-dependent signaling in vitro and circulating HMGB1 in vivo, and an HMGB1 inhibitor protects against PR8; (ii) Eritoran inhibits pulmonary lung edema associated with ALI; (iii) interleukin (IL)-1β contributes significantly to PR8-induced lethality, as evidenced by partial protection by IL-1 receptor antagonist (IL-1Ra) therapy. Synergistic protection against PR8-induced lethality was achieved when Eritoran and the antiviral drug oseltamivir were administered starting 4 days post infection. Eritoran treatment does not prevent development of an adaptive immune response to subsequent PR8 challenge. Overall, our data support the potential of a host-targeted therapeutic approach to influenza infection

    Wild Felids as Hosts for Human Plague, Western United States

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    Plague seroprevalence was estimated in populations of pumas and bobcats in the western United States. High levels of exposure in plague-endemic regions indicate the need to consider the ecology and pathobiology of plague in nondomestic felid hosts to better understand the role of these species in disease persistence and transmission
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