633 research outputs found
A clinical risk score to predict 3-, 5- and 10-year survival in patients undergoing surgery for Dukes B colorectal cancer
<p>Background: The prognosis of patients with Dukes stage B colorectal cancer is unpredictable and there is continuing interest in simply and reliably identifying patients at high risk of developing recurrence and dying of their disease. The aim of this study was to devise a clinical risk score to predict 3-, 5- and 10-year survival in patients undergoing surgery for Dukes stage B colorectal cancer.</p>
<p>Methods: A total of 1350 patients who underwent surgery for Dukes stage B colorectal cancer between 1991 and 1994 in 11 hospitals in Scotland were included in the analysis.</p>
<p>Results: On follow-up, 926 patients died of whom 479 died of their cancer. At 10 years, cancer-specific survival was 61% and overall survival was 38%. On multivariate analysis, age ≥75 (hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.15-1.82, P=0.001), emergency presentation (HR 1.59, 95% CI 1.27-1.99, P<0.001) and anastomotic leak (HR 2.17, 95% CI 1.24-3.78, P<0.01) were independently associated with cancer-specific survival in colon cancer. On multivariate analysis, only age ≥75 (HR 1.58, 95% CI 1.14-2.18, P<0.01) was associated with cancer-specific survival in rectal cancer. Age, presentation and anastomotic leak hazards could be simply added to form a clinical risk score from 0 to 2 in colon cancer. In patients with Dukes B stage colon cancer, the cancer-specific survival at 5 years for patients with a cumulative score 0 was 81%, 1 was 67% and 2 was 63%. The cancer-specific survival rate at 10 years for patients with a clinical risk score of 0 was 72%, 1 was 58% and 2 was 53%.</p>
<p>Conclusion: The results of this study, in a mature cohort, introduce a new simple clinical risk score for patients undergoing surgery for Dukes B colon cancer. This provides a solid foundation for the examination of the impact of additional factors and treatment on prediction of 3-, 5- and 10-year cancer-specific survival.</p>
Ultrasonic technique for non-destructive quality evaluation of oranges
Common techniques to monitor the quality of fruit at the time of harvest and in storage typically rely on destructive methods to measure physical properties such as firmness and hydration. The complex, inhomogeneous composition of most fruit mean that non-destructive ultrasonic methods for quality evaluation of fruit has typically been unsuccessful. A novel ultrasound method was developed which analyses the reflections at the transducer-fruit boundary to evaluate the quality of the fruit as a whole. Using a custom-built ultrasound device, the technique was applied to navel oranges to relate ultrasonic measurements with physical measurements taken via destructive methods. For a sample of randomly selected navel oranges, a high level of correlation was found between ultrasonic measurements and the density of the fruit, allowing the relative water content of oranges to be non-destructively determined regardless of individual physical characteristics such as size and maturity. When applied to a sample of navel oranges over a period of nine days, the ultrasonic measurements were found to be highly correlated to the firmness of the oranges, providing a non-destructive method to replace traditional destructive methods currently used to monitor orange maturation
Outcomes of a specialist weight management programme in the UK national health service: prospective study of 1838 patients
Objectives There is limited evidence on the effectiveness of weight management programmes provided within routine healthcare and inconsistent use of outcome measures. Our aim was to evaluate a large National Health Service (NHS) weight management service and report absolute and proportional weight losses over 12 months.<p></p>
Design Prospective observational study.<p></p>
Setting Glasgow and Clyde Weight Management Service (GCWMS), which provides care for residents of NHS Greater Glasgow and Clyde area (population 1.2 million).<p></p>
Participants All patients who began GCWMS between 1 October 2008 and 30 September 2009.<p></p>
Interventions Structured educational lifestyle programme employing cognitive behavioural therapy, 600 kcal deficit diet, physical activity advice, lower calorie diet and pharmacotherapy.<p></p>
Primary and secondary outcomes measures Baseline observation carried forward (BOCF), last observation carried forward (LOCF) and changes in programme completers reported using outcomes of absolute 5 kg and 5% weight losses and mean weight changes at a variety of time points.<p></p>
Results 6505 referrals were made to GCWMS, 5637 were eligible, 3460 opted in and 1916 (34%) attended a first session. 78 patients were excluded from our analysis on 1838 patients. 72.9% of patients were women, mean age of all patients at baseline was 49.1 years, 43.3% lived in highly socioeconomically deprived areas and mean weights and body mass indices at baseline were 118.1 kg and 43.3 kg/m2, respectively. 26% lost ≥5 kg by the end of phase 1, 30% by the end of phase 2 and 28% by the end of phase 3 (all LOCF). Weight loss was more successful among men, particularly those ≤29 years old.<p></p>
Conclusions Routine NHS weight management services may achieve moderate weight losses through a comprehensive evidence-based dietary, activity and behavioural approach including psychological care. Weight losses should be reported using a range of outcome measures so that the effectiveness of different services can be compared
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Implementation of a fully automated process purge-and-trap gas chromatograph at an environmental remediation site
The AQUASCAN, a commercially available, fully automated purge-and-trap gas chromatograph from Sentex Systems Inc., was implemented and evaluated as an in-field, automated monitoring system of contaminated groundwater at an active DOE remediation site in Pinellas, FL. Though the AQUASCAN is designed as a stand alone process analytical unit, implementation at this site required additional hardware. The hardware included a sample dilution system and a method for delivering standard solution to the gas chromatograph for automated calibration. As a result of the evaluation the system was determined to be a reliable and accurate instrument. The AQUASCAN reported concentration values for methylene chloride, trichloroethylene, and toluene in the Pinellas ground water were within 20% of reference laboratory values
The Elliptic curves in gauge theory, string theory, and cohomology
Elliptic curves play a natural and important role in elliptic cohomology. In
earlier work with I. Kriz, thes elliptic curves were interpreted physically in
two ways: as corresponding to the intersection of M2 and M5 in the context of
(the reduction of M-theory to) type IIA and as the elliptic fiber leading to
F-theory for type IIB. In this paper we elaborate on the physical setting for
various generalized cohomology theories, including elliptic cohomology, and we
note that the above two seemingly unrelated descriptions can be unified using
Sen's picture of the orientifold limit of F-theory compactification on K3,
which unifies the Seiberg-Witten curve with the F-theory curve, and through
which we naturally explain the constancy of the modulus that emerges from
elliptic cohomology. This also clarifies the orbifolding performed in the
previous work and justifies the appearance of the w_4 condition in the elliptic
refinement of the mod 2 part of the partition function. We comment on the
cohomology theory needed for the case when the modular parameter varies in the
base of the elliptic fibration.Comment: 23 pages, typos corrected, minor clarification
M2-branes on M-folds
We argue that the moduli space for the Bagger-Lambert A_4 theory at level k
is (R^8 \times R^8)/D_{2k}, where D_{2k} is the dihedral group of order 4k. We
conjecture that the theory describes two M2-branes on a Z_{2k} ``M-fold'', in
which a geometrical action of Z_{2k} is combined with an action on the branes.
For k=1, this arises as the strong coupling limit of two D2-branes on an O2^-
orientifold, whose worldvolume theory is the maximally supersymmetric SO(4)
gauge theory. Finally, in an appropriate large-k limit we show that one
recovers compactified M-theory and the M2-branes reduce to D2-branes.Comment: 16 pages, LaTeX, v2: typos corrected, included appendices on
Chern-Simons level quantization and monopole charge quantizatio
A Gaussian distribution for refined DT invariants and 3D partitions
We show that the refined Donaldson-Thomas invariants of C3, suitably
normalized, have a Gaussian distribution as limit law. Combinatorially these
numbers are given by weighted counts of 3D partitions. Our technique is to use
the Hardy-Littlewood circle method to analyze the bivariate asymptotics of a
q-deformation of MacMahon's function. The proof is based on that of E.M. Wright
who explored the single variable case.Comment: 11 pages and 3 figure
ASCA X-ray observations of the disk wind in the dwarf nova Z Camelopardalis
We present ASCA observations of the dwarf nova Z Camelopardalis during
outburst and during a transition from quiescence to another outburst.
At the beginning of the transition the X-ray count rate was an order of
magnitude higher and the spectrum much harder than during the outburst. As the
transition progressed, the spectrum remained hard as the X-ray flux decreased
by a factor of 3, with no spectral softening. Spectral modelling reveals an
optically-thin, high-temperature component (kT10 keV) which dominates
the transition observation and is also observed during outburst. This is
expected from material accreting onto the white dwarf surface. The outburst
spectra require additional emission at lower temperatures, either through an
additional discrete temperature component, or a combination of a cooling flow
model and an ionised absorber.
Fits to both observations show large amounts of absorption
(cm), two orders of magnitude greater than the
measured interstellar value, and consistent with UV measurements of the
outburst. This suggests that a disk wind is present even in the earliest stages
of outburst, possibly before the outburst heating wave has reached the boundary
layer.Comment: 9 pages, 9 figures, MNRAS Accepte
"Dark energy" in the Local Void
The unexpected discovery of the accelerated cosmic expansion in 1998 has
filled the Universe with the embarrassing presence of an unidentified "dark
energy", or cosmological constant, devoid of any physical meaning. While this
standard cosmology seems to work well at the global level, improved knowledge
of the kinematics and other properties of our extragalactic neighborhood
indicates the need for a better theory. We investigate whether the recently
suggested repulsive-gravity scenario can account for some of the features that
are unexplained by the standard model. Through simple dynamical considerations,
we find that the Local Void could host an amount of antimatter
() roughly equivalent to the mass of a typical
supercluster, thus restoring the matter-antimatter symmetry. The antigravity
field produced by this "dark repulsor" can explain the anomalous motion of the
Local Sheet away from the Local Void, as well as several other properties of
nearby galaxies that seem to require void evacuation and structure formation
much faster than expected from the standard model. At the global cosmological
level, gravitational repulsion from antimatter hidden in voids can provide more
than enough potential energy to drive both the cosmic expansion and its
acceleration, with no need for an initial "explosion" and dark energy.
Moreover, the discrete distribution of these dark repulsors, in contrast to the
uniformly permeating dark energy, can also explain dark flows and other
recently observed excessive inhomogeneities and anisotropies of the Universe.Comment: 6 pages, accepted as a Letter to the Editor by Astrophysics and Space
Scienc
Do we live in the universe successively dominated by matter and antimatter?
We wonder if a cyclic universe may be dominated alternatively by matter and
antimatter. Such a scenario demands a mechanism for transformation of matter to
antimatter (or antimatter to matter) during the final stage of a big crunch. By
giving an example, we have shown that in principle such a mechanism is
possible. Our mechanism is based on a hypothetical repulsion between matter and
antimatter, existing at least deep inside the horizon of a black hole. When
universe is reduced to a supermassive black hole of a small size, a very strong
field of the conjectured force might create (through a Schwinger type
mechanism) particle-antiparticle pairs from the quantum vacuum. The amount of
antimatter created from the vacuum is equal to the decrease of mass of the
black hole and violently repelled from it. When the size of the black hole is
sufficiently small, the creation of antimatter may become so fast, that matter
of our Universe might be transformed to antimatter in a fraction of second.
Such a fast conversion of matter into antimatter may look as a Big Bang. Our
mechanism prevents a singularity; a new cycle might start with an initial size
more than 30 orders of magnitude greater than the Planck length, suggesting
that there is no need for inflationary scenario in Cosmology. In addition,
there is no need to invoke CP violation for explanation of matter-antimatter
asymmetry. Simply, our present day Universe is dominated by matter, because the
previous universe was dominated by antimatter
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