24,788 research outputs found
Discharge coefficients for thick-plate orifices
Investigation enables more accurate prediction of coolant flows within internally cooled turbine blades and vanes. The data is applicable for predicting flows in complex flow passages
Evaluation of a tumor microenvironment-based prognostic score in primary operable colorectal cancer
Purpose: The tumor microenvironment is recognized as an important determinant of progression and outcome in colorectal cancer. The aim of the present study was to evaluate a novel tumor microenvironmentâbased prognostic score, based on histopathologic assessment of the tumor inflammatory cell infiltrate and tumor stroma, in patients with primary operable colorectal cancer.
Experimental Design: Using routine pathologic sections, the tumor inflammatory cell infiltrate and stroma were assessed using KlintrupâMĂ€kinen (KM) grade and tumor stroma percentage (TSP), respectively, in 307 patients who had undergone elective resection for stage IâIII colorectal cancer. The clinical utility of a cumulative score based on these characteristics was examined.
Results: On univariate analysis, both weak KM grade and high TSP were associated with reduced survival (HR, 2.42; P = 0.001 and HR, 2.05; P = 0.001, respectively). A cumulative score based on these characteristics, the Glasgow Microenvironment Score (GMS), was associated with survival (HR, 1.93; 95% confidence interval, 1.36â2.73; P < 0.001), independent of TNM stage and venous invasion (both P < 0.05). GMS stratified patients in to three prognostic groups: strong KM (GMS = 0), weak KM/low TSP (GMS = 1), and weak KM/high TSP (GMS = 2), with 5-year survival of 89%, 75%, and 51%, respectively (P < 0.001). Furthermore, GMS in combination with node involvement, venous invasion, and mismatch repair status further stratified 5-year survival (92% to 37%, 93% to 27%, and 100% to 37%, respectively).
Conclusions: The present study further confirms the clinical utility of assessment of the tumor microenvironment in colorectal cancer and introduces a simple, routinely available prognostic score for the risk stratification of patients with primary operable colorectal cancer
First Lattice Study of the - Transition Form Factors
Experiments at Jefferson Laboratory, MIT-Bates, LEGS, Mainz, Bonn, GRAAL, and
Spring-8 offer new opportunities to understand in detail how nucleon resonance
() properties emerge from the nonperturbative aspects of QCD. Preliminary
data from CLAS collaboration, which cover a large range of photon virtuality
show interesting behavior with respect to dependence: in the region
, both the transverse amplitude, , and the
longitudinal amplitude, , decrease rapidly. In this work, we
attempt to use first-principles lattice QCD (for the first time) to provide a
model-independent study of the Roper-nucleon transition form factor.Comment: 4 pages, 2 figures, double colum
A dynamic model of Venus's gravity field
Unlike Earth, long wavelength gravity anomalies and topography correlate well on Venus. Venus's admittance curve from spherical harmonic degree 2 to 18 is inconsistent with either Airy or Pratt isostasy, but is consistent with dynamic support from mantle convection. A model using whole mantle flow and a high viscosity near surface layer overlying a constant viscosity mantle reproduces this admittance curve. On Earth, the effective viscosity deduced from geoid modeling increases by a factor of 300 from the asthenosphere to the lower mantle. These viscosity estimates may be biased by the neglect of lateral variations in mantle viscosity associated with hot plumes and cold subducted slabs. The different effective viscosity profiles for Earth and Venus may reflect their convective styles, with tectonism and mantle heat transport dominated by hot plumes on Venus and by subducted slabs on Earth. Convection at degree 2 appears much stronger on Earth than on Venus. A degree 2 convective structure may be unstable on Venus, but may have been stabilized on Earth by the insulating effects of the Pangean supercontinental assemblage
A projection method for statics and dynamics of lattice spin systems
A method based on Monte Carlo sampling of the probability flows projected
onto the subspace of one or more slow variables is proposed for investigation
of dynamic and static properties of lattice spin systems. We illustrate the
method by applying it, with projection onto the order-parameter subspace, to
the three-dimensional 3-state Potts model in equilibrium and to metastable
decay in a three-dimensional 3-state kinetic Potts model.Comment: 4 pages, 3 figures, RevTex, final version to appear in Phys. Rev.
Let
A controlled field experiment to investigate the deterioration of earthen heritage by wind and rain
Earthen heritage constitutes 10% of sites on the World Heritage List and many of these sites are experiencing extensive deterioration caused by environmental forces, such as wind and rain. This study used a well-established test wall to investigate the impact of environmental conditions on the deterioration of earthen heritage at the remote and under-studied site of Suoyang Ancient City, Gansu Province, China, which is exhibiting widespread deterioration. Test walls have previously been used in earthen heritage research as they allow controlled experiments to be undertaken on complex, realistic structures without risking damage or loss of value to the historic material. This study used portable wind and rain erosion simulation devices to investigate experimentally (i) the comparative effect of wind, sediment-laden wind and wind-driven rain in causing deterioration to earthen heritage and (ii) how the incipient deterioration features produced by wind, sediment-laden wind and wind-driven rain on the test wall relate to the deterioration features recorded on the historic city walls. The test wall was subjected to low, medium and high intensities of clean wind, sediment-laden wind and wind-driven rain. The extent of deterioration produced was measured using repeat, high resolution laser scans before and after each test run. The deterioration features caused by each environmental force were notably different with clean wind removing the loose surface material, sediment-laden wind causing pitting and wind-driven rain causing incipient gullying. These incipient features compare well with more developed features seen on the historic walls. Wind-driven rain caused the greatest amount of deterioration while clean wind caused the least. However, as the frequency and duration of wind events at Suoyang is much greater than those of rain events, wind is likely to play an important role in the deterioration of earthen heritage over annual timescales. These findings show that conservation strategies at rammed earth sites like Suoyang need to address the impact of multiple environmental forces, such as clean wind, sediment laden wind and wind-driven rain
Methanol masers reveal the magnetic field of the high-mass protostar IRAS 18089-1732
Context. The importance of the magnetic field in high-mass-star formation is
not yet fully clear and there are still many open questions concerning its role
in the accretion processes and generation of jets and outflows. In the past few
years, masers have been successfully used to probe the magnetic field
morphology and strength at scales of a few au around massive protostars, by
measuring linear polarisation angles and Zeeman splitting. The massive
protostar IRAS 18089-1732 is a well studied high-mass-star forming region,
showing a hot core chemistry and a disc-outflow system. Previous SMA
observations of polarised dust revealed an ordered magnetic field oriented
around the disc of IRAS 18089-1732. Aims. We want to determine the magnetic
field in the dense region probed by 6.7 GHz methanol maser observations and
compare it with observations in dust continuum polarisation, to investigate how
the magnetic field in the compact maser region relates to the large-scale field
around massive protostars. Methods. We reduced MERLIN observations at 6.7 GHz
of IRAS 18089-1732 and we analysed the polarised emission by methanol masers.
Results. Our MERLIN observations show that the magnetic field in the 6.7 GHz
methanol maser region is consistent with the magnetic field constrained by the
SMA dust polarisation observations. A tentative detection of circularly
polarised line emission is also presented. Conclusions. We found that the
magnetic field in the maser region has the same orientation as in the disk.
Thus the large-scale field component, even at the au scale of the masers,
dominates over any small-scale field fluctuations. We obtained, from the
circular polarisation tentative detection, a field strength along the line of
sight of 5.5 mG which appeared to be consistent with the previous estimates.Comment: 12 pages, 7 figures, accepted for publication in A&
The chemistry of Formycin biosynthesis
Remarkable progress has been made to elucidate the structural and mechanistic enzymology of the biosynthetic pathways that give rise to naturally occurring C-nucleosides. These compounds are generally cytotoxic and exhibit interesting antiviral, antibiotic and anti-parasitic activity. Here we review current knowledge concerning formycin biosynthesis and highlight deficiencies in our understanding of key chemical transformations in the pathway
Prognostic Value of Computed Tomography : Measured Parameters of Body Composition in Primary Operable Gastrointestinal Cancers
Professor Graeme Murray, Department of Pathology, University of Aberdeen provided us access to the colorectal cancer pathology databases from which the colorectal component of the research was based. Conflict of interest There are no conflicts of interest.Peer reviewedPublisher PD
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