908 research outputs found
Comorbid conditions explain the association between posttraumatic stress disorder and incident cardiovascular disease
Background Posttraumatic stress disorder ( PTSD ) is associated with risk of cardiovascular disease ( CVD ). Biopsychosocial factors associated with PTSD likely account for some or all of this association. We determined whether 1, or a combination of comorbid conditions explained the association between PTSD and incident CVD . Methods and Results Eligible patients used 1 of 5 Veterans Health Affairs medical centers distributed across the United States. Data were obtained from electronic health records. At index date, 2519 Veterans Health Affairs ( VA ) patients, 30 to 70 years of age, had PTSD diagnoses and 1659 did not. Patients had no CVD diagnoses for 12 months before index date. Patients could enter the cohort between 2008 and 2012 with follow-up until 2015. Age-adjusted Cox proportional hazard models were computed before and after adjusting for comorbidities. Patients were middle aged (mean=50.1 years, SD ±11.0), mostly male (87.0%), and 60% were white. The age-adjusted association between PTSD and incident CVD was significant (hazard ratio=1.41; 95% CI : 1.21-1.63). After adjustment for metabolic conditions, the association between PTSD and incident CVD was attenuated but remained significant (hazard ratio=1.23; 95% CI : 1.06-1.44). After additional adjustment for smoking, sleep disorder, substance use disorder, anxiety disorders, and depression, PTSD was not associated with incident CVD (hazard ratio=0.96; 95% CI : 0.81-1.15). Conclusions PTSD is not an independent risk factor for CVD . Physical and psychiatric conditions and smoking that co-occur with PTSD explain why this patient population has an increased risk of CVD . Careful monitoring may limit exposure to CVD risk factors and subsequent incident CVD
Kinetics and Mechanism of Hydroxyapatite Crystal Dissolution in Weak Acid Buffers Using the Rotating Disk Method
The dissolution rates of synthetic hydroxyapatite pellets under sink conditions were measured using the rotating disk method. The experimental data were analyzed by means of a physical model that yielded an ionic activity product of KHAP = a10Ca2+ a6 PO4 3- a2OH- = 1 × 10-124.5±1.0 that was found to govern the dissolution reaction. Also, a surface resistance factor of k' equal to about 174 sec/cm was deduced from the data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67157/2/10.1177_00220345760550033201.pd
Managing marine disease emergencies in an era of rapid change
Infectious marine diseases can decimate populations and are increasing among some taxa due to global change and our increasing reliance on marine environments. Marine diseases become emergencies when significant ecological, economic or social impacts occur. We can prepare for and manage these emergencies through improved surveillance, and the development and iterative refinement of approaches to mitigate disease and its impacts. Improving surveillance requires fast, accurate diagnoses, forecasting disease risk and real-time monitoring of disease-promoting environmental conditions. Diversifying impact mitigation involves increasing host resilience to disease, reducing pathogen abundance and managing environmental factors that facilitate disease. Disease surveillance and mitigation can be adaptive if informed by research advances and catalysed by communication among observers, researchers and decision-makers using information-sharing platforms. Recent increases in the awareness of the threats posed by marine diseases may lead to policy frameworks that facilitate the responses and management that marine disease emergencies require
The Sloan Digital Sky Survey Quasar Catalog I. Early Data Release
We present the first edition of the Sloan Digital Sky Survey (SDSS) Quasar
Catalog. The catalog consists of the 3814 objects (3000 discovered by the SDSS)
in the initial SDSS public data release that have at least one emission line
with a full width at half maximum larger than 1000 km/s, luminosities brighter
than M_i^* = -23, and highly reliable redshifts. The area covered by the
catalog is 494 square degrees; the majority of the objects were found in SDSS
commissioning data using a multicolor selection technique. The quasar redshifts
range from 0.15 to 5.03. For each object the catalog presents positions
accurate to better than 0.2" rms per coordinate, five band (ugriz) CCD-based
photometry with typical accuracy of 0.05 mag, radio and X-ray emission
properties, and information on the morphology and selection method. Calibrated
spectra of all objects in the catalog, covering the wavelength region 3800 to
9200 Angstroms at a spectral resolution of 1800-2100, are also available. Since
the quasars were selected during the commissioning period, a time when the
quasar selection algorithm was undergoing frequent revisions, the sample is not
homogeneous and is not intended for statistical analysis.Comment: 27 pages, 4 figures, 4 tables, accepted by A
Colors of 2625 Quasars at 0<z<5 Measured in the Sloan Digital Sky Survey Photometric System
We present an empirical investigation of the colors of quasars in the Sloan
Digital Sky Survey (SDSS) photometric system. The sample studied includes 2625
quasars with SDSS photometry. The quasars are distributed in a 2.5 degree wide
stripe centered on the Celestial Equator covering square degrees.
Positions and SDSS magnitudes are given for the 898 quasars known prior to SDSS
spectroscopic commissioning. New SDSS quasars represent an increase of over
200% in the number of known quasars in this area of the sky. The ensemble
average of the observed colors of quasars in the SDSS passbands are well
represented by a power-law continuum with (). However, the contributions of the bump
and other strong emission lines have a significant effect upon the colors. The
color-redshift relation exhibits considerable structure, which may be of use in
determining photometric redshifts for quasars. The range of colors can be
accounted for by a range in the optical spectral index with a distribution
(95% confidence), but there is a red tail in the
distribution. This tail may be a sign of internal reddening. Finally, we show
that there is a continuum of properties between quasars and Seyfert galaxies
and we test the validity of the traditional division between the two classes of
AGN.Comment: 66 pages, 15 figures (3 color), accepted by A
Galaxy Clustering in Early SDSS Redshift Data
We present the first measurements of clustering in the Sloan Digital Sky
Survey (SDSS) galaxy redshift survey. Our sample consists of 29,300 galaxies
with redshifts 5,700 km/s < cz < 39,000 km/s, distributed in several long but
narrow (2.5-5 degree) segments, covering 690 square degrees. For the full,
flux-limited sample, the redshift-space correlation length is approximately 8
Mpc/h. The two-dimensional correlation function \xi(r_p,\pi) shows clear
signatures of both the small-scale, ``fingers-of-God'' distortion caused by
velocity dispersions in collapsed objects and the large-scale compression
caused by coherent flows, though the latter cannot be measured with high
precision in the present sample. The inferred real-space correlation function
is well described by a power law, \xi(r)=(r/6.1+/-0.2 Mpc/h)^{-1.75+/-0.03},
for 0.1 Mpc/h < r < 16 Mpc/h. The galaxy pairwise velocity dispersion is
\sigma_{12} ~ 600+/-100 km/s for projected separations 0.15 Mpc/h < r_p < 5
Mpc/h. When we divide the sample by color, the red galaxies exhibit a stronger
and steeper real-space correlation function and a higher pairwise velocity
dispersion than do the blue galaxies. The relative behavior of subsamples
defined by high/low profile concentration or high/low surface brightness is
qualitatively similar to that of the red/blue subsamples. Our most striking
result is a clear measurement of scale-independent luminosity bias at r < 10
Mpc/h: subsamples with absolute magnitude ranges centered on M_*-1.5, M_*, and
M_*+1.5 have real-space correlation functions that are parallel power laws of
slope ~ -1.8 with correlation lengths of approximately 7.4 Mpc/h, 6.3 Mpc/h,
and 4.7 Mpc/h, respectively.Comment: 51 pages, 18 figures. Replaced to match accepted ApJ versio
A randomized, placebo-controlled trial of cenicriviroc for treatment of nonalcoholic steatohepatitis with fibrosis
The aim of this study was to evaluate cenicriviroc (CVC), a dual antagonist of C-C chemokine receptor types 2 and 5, for treatment of nonalcoholic steatohepatitis (NASH) with liver fibrosis.
A randomized, double-blind, multinational phase 2b study enrolled subjects with NASH, a nonalcoholic fatty liver disease activity score [NAS] ≥4, and liver fibrosis (stages 1–3, NASH Clinical Research Network) at 81 clinical sites. Subjects (N = 289) were randomly assigned CVC 150 mg or placebo. Primary outcome was ≥2-point improvement in NAS and no worsening of fibrosis at year 1. Key secondary outcomes were: resolution of steatohepatitis and no worsening of fibrosis; improvement in fibrosis by ≥1 stage and no worsening of steatohepatitis. Biomarkers of inflammation and adverse events were assessed.
Full study recruitment was achieved. The primary end point of NAS improvement in the intent-to-treat population and resolution of steatohepatitis was achieved in a similar proportion of subjects on CVC (N = 145) and placebo (N = 144) (16% vs 19%, P = 0.52 and 8% vs 6%, P = 0.49, respectively). However, the fibrosis end point was met in significantly more subjects on CVC than placebo (20% vs 10%; P = 0.02). Treatment benefits were greater in those with higher disease activity and fibrosis stage at baseline. Biomarkers of systemic inflammation were reduced with CVC. Safety and tolerability of CVC were comparable to placebo.
Conclusions: After 1 year of CVC treatment, twice as many subjects achieved improvement in fibrosis and no worsening of steatohepatitis compared with placebo. Given the urgent need to develop antifibrotic therapies in NASH, these findings warrant phase 3 evaluation
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