59 research outputs found

    The Disk and Extraplanar Environment of NGC 247

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    The stellar content of the spiral galaxy NGC 247 is investigated. The main sequence turn-off (MSTO) in the inner 12 kpc of the disk corresponds to an age of 6 Myr. A mean star formation rate (SFR) of 0.1 solar masses per year during the past 16 Myr is computed from star counts. The color of the red supergiant plume does not change with radius, suggesting that the mean metallicity of young stars does not vary by more than 0.1 dex. The number of bright main sequence stars per local stellar mass density climbs towards larger radii out to a distance of 12 kpc; the scale lengths that characterize the radial distributions of young and old stars in the disk thus differ. The density of bright main sequence stars with respect to projected HI mass gradually drops with increasing radius. The population of very young stars disappears in the outer disk; the MSTO at galactocentric radii between 12 and 15 kpc corresponds to 16 Myr, while between 15 and 18 kpc the age is > 40 Myr. Red giant branch (RGB) stars are resolved at a projected minor axis galactocentric distance of 12 kpc. There is a broad spread in metallicity among the RGB stars, with a mean [M/H] = -1.2. The RGB-tip occurs at i' = 24.5 +/- 0.1, indicating that the distance modulus is 27.9 +/- 0.1. Luminous AGB stars with an age 3 Gyr are also seen in this field.Comment: Includes 16 eps figures; to appear in the Astrophysical Journa

    Postoperative Urinary Retention in Patients Undergoing Lung Resection: Incidence and Risk Factors

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    Background: The purpose of this study was to (1) determine the incidence of postoperative urinary retention (POUR) in patients undergoing lung resection at our institution, (2) identify differences in potential risk factors between patients with and without POUR, and (3) describe patient outcomes across POUR status. Methods: The medical records of 225 patients between 2016 and 2017 were reviewed, and 191 met criteria for inclusion. The institution's catheterization removal protocol was followed in all patients. Recatheterization was defined as requiring in-and-out catheterization or Foley catheter placement. Fisher exact and Wilcoxon tests were used for analysis. Results: POUR developed in 35 patients (18%). Patients with POUR were older (P = .01), had increased baseline creatinine (P = .04), and a higher prevalence of benign prostatic hyperplasia (P = .007). POUR patients were also less likely to get a Foley catheter intraoperatively (P = .0002). Other intraoperative factors, such as surgical approach and extent of resection, were not significantly different between patients with and without POUR. Postoperative factors (epidural use or days with chest tube) were similar. Although patients with POUR were more likely to be discharged with a Foley catheter (13% vs 0%, P = .002), no difference in length of stay, incidences of urinary tract infections, or 30-day readmission were observed. Conclusions: POUR develops in approximately 1 in 5 patients undergoing lung resection. Patients with POUR were more likely to not have a Foley catheter placed intraoperatively. However, patients who had POUR did not have worsened patient outcomes (urinary tract infections, length of stay, or 30-day readmission)

    Spin density wave induced disordering of the vortex lattice in superconducting La2−x_{2-x}Srx_xCuO4_4

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    We use small angle neutron scattering to study the superconducting vortex lattice in La2−x_{2-x}Srx_xCuO4_4 as a function of doping and magnetic field. We show that near optimally doping the vortex lattice coordination and the superconducting coherence length Ο\xi are controlled by a van-Hove singularity crossing the Fermi level near the Brillouin zone boundary. The vortex lattice properties change dramatically as a spin-density-wave instability is approached upon underdoping. The Bragg glass paradigm provides a good description of this regime and suggests that SDW order acts as a novel source of disorder on the vortex lattice.Comment: Accepted in Phys. Rev.

    Sex-Based Differences in Inpatient Burn Mortality

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    Background: Among burn patients, research is conflicted, but may suggest that females are at increased risk of mortality, despite the opposite being true in non-burn trauma. Our objective was to determine whether sex-based differences in burn mortality exist, and assess whether patient demographics, comorbid conditions, and injury characteristics explain said differences. Methods: Adult patients admitted with burn injury—including inhalation injury only—between 2004 and 2013 were included. Inverse probability of treatment weights (IPTW) and inverse probability of censor weights (IPCW) were calculated using admit year, patient demographics, comorbid conditions, and injury characteristics to adjust for potential confounding and informative censoring. Standardized Kaplan–Meier survival curves, weighted by both IPTW and IPCW, were used to estimate the 30-day and 60-day risk of inpatient mortality across sex. Results: Females were older (median age 44 vs. 41 years old, p < 0.0001) and more likely to be Black (32% vs. 25%, p < 0.0001), have diabetes (14% vs. 10%, p < 0.0001), pulmonary disease (14% vs. 7%, p < 0.0001), heart failure (4% vs. 2%, p = 0.001), scald burns (45% vs. 26%, p < 0.0001), and inhalational injuries (10% vs. 8%, p = 0.04). Even after weighting, females were still over twice as likely to die after 60 days (RR 2.87, 95% CI 1.09, 7.51). Conclusion: Female burn patients have a significantly higher risk of 60-day mortality, even after accounting for demographics, comorbid conditions, burn size, and inhalational injury. Future research efforts and treatments to attenuate mortality should account for these sex-based differences. The project was supported by the National Institutes of Health, Grant Number UL1TR001111

    Burn injury outcomes in patients with pre-existing diabetic mellitus: Risk of hospital-acquired infections and inpatient mortality

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    Background: Diabetes mellitus (DM) is a major cause of illness and death in the United States, and diabetic patients are at increased risk for burn injury. We therefore sought to examine the impact of pre-existing DM on the risk of inpatient mortality and hospital acquired infections (HAI) among burn patients. Methods: Adult patients (≄18 years old) admitted from 2004 to 2013 were analyzed. Weighted Kaplan–Meier survival curves – adjusting for patient demographics, burn mechanism, presence of inhalation injury, total body surface area, additional comorbidities, and differential lengths of stay – were used to estimate the 30-day and 60-day risk of mortality and HAIs. Results: A total of 5539 adult patients were admitted and included in this study during the study period. 655 (11.8%) had a pre-existing DM. The crude incidence of HAIs and in-hospital mortality for the whole burn cohort was 8.5% (n = 378) and 4.4% (n = 243), respectively. Diabetic patients were more likely to be older, female, have additional comorbidities, inhalational injury, and contact burns. After adjusting for patient and burn characteristics, the 60-day risk of HAI among patients with DM was significantly higher, compared to non-diabetic patients (RR 2.07, 95% CI 1.28, 6.79). However, no significant difference was seen in the 60-day risk of mortality (RR 1.34, 95% CI 0.44, 3.10). Conclusions: Pre-existing DM significantly increases the risk of developing an HAI in patients following burn injury, but does not significantly impact the risk of inpatient mortality. Further understanding of the immune modulatory mechanism of burn injury and DM is imperative to better attenuate the acquisition of HAIs

    The anti-NGF antibody muMab 911 both prevents and reverses pain behaviour and subchondral osteoclast numbers in a rat model of osteoarthritis pain

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    Objective: Nerve growth factor (NGF) has a pivotal role in peripheral hyperalgesia and inflammation; anti-NGF antibodies attenuate pain responses in inflammatory pain models, and in people with osteoarthritis (OA) or low back pain. The aim of this study was to characterise the peripheral mechanisms contributing to the analgesic effects of anti-NGF antibody treatment in an established model of joint pain, which mimics key clinical features of OA. Design: Effects of preventative vs therapeutic treatment with an anti-NGF antibody (monoclonal antibody 911: muMab 911 (10 mg/kg, s.c.)) on pain behaviour (weight bearing asymmetry and hindpaw withdrawal thresholds (PWT)), cartilage damage, synovitis and numbers of subchondral osteoclasts were investigated in the monosodium iodoacetate (MIA) model. Potential direct effects of NGF on receptor activator of nuclear factor kappa-B ligand (RANKL) mediated osteoclastogenesis were investigated in cultured human osteoclasts. Results: Intra-articular MIA injection resulted in significant pain behaviour, cartilage damage, synovitis and increased numbers of subchondral osteoclasts. Both preventative and therapeutic treatment with muMab 911 significantly prevented, or reversed, MIA-induced pain behaviour, but did not alter cartilage or synovial pathology quantified at the end of the treatment period. NGF did not facilitate RANKL driven osteoclast differentiation in vitro, but preventative or therapeutic muMab 911 reduced numbers of TRAP positive osteoclasts in the subchondral bone. Conclusions: We demonstrate that anti-NGF antibody treatment attenuates OA pain behaviour despite permitting cartilage damage and synovitis. Indirec

    Pain prediction by serum biomarkers of bone turnover in people with knee osteoarthritis: an observational study of TRAcP5b and cathepsin K in OA

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    Objectives: To investigate serum biomarkers, tartrate resistant acid phosphatase 5b (TRAcP5b) and cathepsin K, indicative of osteoclastic bone resorption, and their relationship to pain and pain change in knee osteoarthritis (OA). Methods: Sera and clinical data were collected from 129 people (97 with 3-year follow-up) with knee OA from the Prediction of Osteoarthritis Progression (POP) cohort. Knee OA-related outcomes in POP included: WOMAC pain, NHANES I (pain, aching and stiffness), subchondral sclerosis, and radiographically determined tibiofemoral and patellofemoral OA. Two putative osteoclast biomarkers were measured in sera: TRAcP5b and cathepsin K. Medial tibia plateaux were donated at knee arthroplasty for symptomatic OA (n=84) or from 16 post mortem controls from the Arthritis Research UK (ARUK) Pain Centre joint tissue repository. Osteoclasts were stained for TRAcP within the subchondral bone of the medial tibia plateaux. Results: Serum TRAcP5b activity, but not cathepsin K-immunoreactivity, was associated with density of TRAcP-positive osteoclasts in the subchondral bone of medial tibia plateaux. TRAcP-positive osteoclasts were more abundant in people with symptomatic OA compared to controls. Serum TRAcP5b activity was associated with baseline pain and pain change. Conclusions: Our observations support a role for subchondral osteoclast activity in the generation of OA pain. Serum TRAcP5b might be a clinically relevant biomarker of disease activity in OA
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