598 research outputs found
Black chokeberry fruit polyphenols: A valuable addition to reduce lipid oxidation of muffins containing xylitol
The study aimed at assessing effects of black chokeberry polyphenol extract (ChPE) added (0.025–0.075%) to xylitol-containing muffins to reduce lipid oxidation, especially in preventing degradation of hydroperoxides throughout the storage period. Among polyphenolic compounds (3092 mg/100 g in total) in ChPE, polymeric procyanidins were the most abundant (1564 mg/100 g). ChPE addition resulted in a significantly increased capacity of scavenging free radicals and markedly inhibited hydroperoxides decomposition, as reflected by low anisidine values (AnV: 3.25–7.52) throughout the storage. On the other hand, sucrose-containing muffins had increased amounts of primary lipid oxidation products and differed significantly from other samples in conjugated diene hydroperoxides (CD values), which was in accordance with the decrease of C18:2 9c12c in those muffins after storage. In addition, sucrose-containing muffins were found to be those with the highest level of contamination with toxic carbonyl lipid oxidation products. Throughout the storage, no yeast or moulds contamination were found in higher enriched muffins. The incorporation of polyphenols to xylitol-containing muffins resulted in preventing decomposition of polyunsaturated fatty acids (PUFAs), and in reducing the content of some toxic aldehydes. ChPE could be regarded as a possible solution to xylitol-containing muffins to extend their shelf life. The results support the use of xylitol in muffin manufacture as being favourable in terms of suitability for diabetics
Virtual reality rehabilitation in patients with chronic obstructive pulmonary disease: A randomized controlled trial
Purpose: This study compared the effects of inpatient-based rehabilitation program of patients with chronic obstructive pulmonary disease (COPD) using non-immersive virtual reality (VR) training with a traditional pulmonary rehabilitation program. The aims of this study were to determine 1) whether rehabilitation featuring both VR as well as exercise training provides benefits over exercise training (ET) alone and 2) whether rehabilitation featuring VR training instead of exercise training provides equivalent benefits. Patients and Methods: The study recruited 106 patients with COPD to a 2-week high-intensity, five times a week intervention. Randomized into three groups, 34 patients participated in a traditional pulmonary rehabilitation program including endurance exercise training (ET), 38 patients participated in traditional pulmonary rehabilitation, including both endurance exercise training and virtual reality training (ET+VR) and 34 patients participated in pulmonary rehabilitation program including virtual reality training but no endurance exercise training (VR). The traditional pulmonary rehabilitation program consisted of fitness exercises, resistance respiratory muscle and relaxation training. Xbox 360® and Kinect® Adventures software were used for the VR training of lower and upper body strength, endurance, trunk control and dynamic balance. Comparison of the changes in the Senior Fitness Test was the primary outcome. Analysis was performed using linear mixed-effects models. Results: The comparison between ET and ET+VR groups showed that ET+VR group was superior to ET group in Arm Curl (p<0.003), Chair stand (p<0.008), Back scratch (p<0.002), Chair sit and reach (p<0.001), Up and go (p<0.000), 6-min walk test (p<0.011). Whereas, the comparison between ET and VR groups showed that VR group was superior to ET group in Arm Curl (p<0.000), Chair stand (p<0.001), 6-min walk test (p<0.031). Conclusion: Results suggest that pulmonary rehabilitation program supplemented with VR training is beneficial intervention to improve physical fitness in patients with COPD
Discovery of a high state AM CVn binary in the Galactic Bulge Survey
We report on the discovery of a hydrogen-deficient compact binary (CXOGBS
J175107.6-294037) belonging to the AM CVn class in the Galactic Bulge Survey.
Deep archival X-ray observations constrain the X-ray positional uncertainty of
the source to 0.57 arcsec, and allow us to uniquely identify the optical and UV
counterpart. Optical spectroscopic observations reveal the presence of broad,
shallow He i absorption lines while no sign of hydrogen is present, consistent
with a high state system. We present the optical lightcurve from Optical
Gravitational Lensing Experiment monitoring, spanning 15 years. It shows no
evidence for outbursts; variability is present at the 0.2 mag level on
timescales ranging from hours to weeks. A modulation on a timescale of years is
also observed. A Lomb-Scargle analysis of the optical lightcurves shows two
significant periodicities at 22.90 and 23.22 min. Although the physical
interpretation is uncertain, such timescales are in line with expectations for
the orbital and superhump periods. We estimate the distance to the source to be
between 0.5 - 1.1 kpc. Spectroscopic follow-up observations are required to
establish the orbital period, and to determine whether this source can serve as
a verification binary for the eLISA gravitational wave mission.Comment: Accepted for publication in MNRAS Letter
Spectroscopic classification of X-ray sources in the Galactic Bulge Survey
We present the classification of 26 optical counterparts to X-ray sources
discovered in the Galactic Bulge Survey. We use (time-resolved) photometric and
spectroscopic observations to classify the X-ray sources based on their
multi-wavelength properties. We find a variety of source classes, spanning
different phases of stellar/binary evolution. We classify CX21 as a quiescent
cataclysmic variable (CV) below the period gap, and CX118 as a high accretion
rate (nova-like) CV. CXB12 displays excess UV emission, and could contain a
compact object with a giant star companion, making it a candidate symbiotic
binary or quiescent low mass X-ray binary (although other scenarios cannot be
ruled out). CXB34 is a magnetic CV (polar) that shows photometric evidence for
a change in accretion state. The magnetic classification is based on the
detection of X-ray pulsations with a period of 81 2 min. CXB42 is
identified as a young stellar object, namely a weak-lined T Tauri star
exhibiting (to date unexplained) UX Ori-like photometric variability. The
optical spectrum of CXB43 contains two (resolved) unidentified double-peaked
emission lines. No known scenario, such as an AGN or symbiotic binary, can
easily explain its characteristics. We additionally classify 20 objects as
likely active stars based on optical spectroscopy, their X-ray to optical flux
ratios and photometric variability. In 4 cases we identify the sources as
binary stars.Comment: Accepted for publication in MNRA
Constraining the nature of the accreting binary in CXOGBS J174623.5-310550
We report optical and infrared observations of the X-ray source CXOGBS
J174623.5-310550. This Galactic object was identified as a potential quiescent
low-mass X-ray binary accreting from an M-type donor on the basis of optical
spectroscopy and the broad Halpha emission line. The analysis of X-shooter
spectroscopy covering 3 consecutive nights supports an M2/3-type spectral
classification. Neither radial velocity variations nor rotational broadening is
detected in the photospheric lines. No periodic variability is found in I- and
r'-band light curves. We derive r' = 20.8, I = 19.2 and Ks = 16.6 for the
optical and infrared counterparts with the M-type star contributing 90% to the
I-band light. We estimate its distance to be 1.3-1.8 kpc. The lack of radial
velocity variations implies that the M-type star is not the donor star in the
X-ray binary. This could be an interloper or the outer body in a hierarchical
triple. We constrain the accreting binary to be a < 2.2 hr orbital period
eclipsing cataclysmic variable or a low-mass X-ray binary lying in the
foreground of the Galactic Bulge.Comment: (9 pages, 5 figures, accepted for publication in MNRAS
Gaia transients in galactic nuclei
The high spatial resolution and precise astrometry and photometry of the Gaia
mission should make it particularly apt at discovering and resolving transients
occurring in, or near, the centres of galaxies. Indeed, some nuclear transients
are reported by the Gaia Science Alerts (GSA) team, but not a single confirmed
Tidal Disruption Event has been published. In order to explore the sensitivity
of GSA, we performed an independent and systematic search for nuclear
transients using Gaia observations. Our transient search is driven from an
input galaxy catalogue (derived from the Sloan Digital Sky Survey Release 12).
We present a candidate detection metric which is independent from the existing
GSA methodology, to see if Gaia Alerts are biased against the discovery of
nuclear transients, and in particular which steps may have an impact. Our
technique does require significant manual vetting of candidates, making
implementation in the GSA system impractical for daily operations, although it
could be run weekly, which for month-to-year long transients would make a
scientifically valuable addition. Our search yielded ~480 nuclear transients, 5
of which were alerted and published by GSA. The list of (in some cases ongoing)
transients includes candidates for events related to enhanced accretion onto a
super-massive black hole and TDEs. An implementation of the detection
methodology and criteria used in this paper as an extension of GSA could open
up the possibility for Gaia to fulfil the role as a main tool to find transient
nuclear activity as predicted in the literature.Comment: MNRAS accepted; full Table 2 attache
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