3,626 research outputs found

    Attitudes of surgeons to the use of postoperative markers of the systemic inflammatory response following elective surgery

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    Background: Cancer is responsible for 7.6 million deaths worldwide and surgery is the primary modality of a curative outcome. Postoperative care is of considerable importance and it is against this backdrop that a questionnaire based study assessing the attitudes of surgeons to monitoring postoperative systemic inflammation was carried out. Method: A Web based survey including 10 questions on the “attitudes of surgeons to the use of postoperative markers of the systemic inflammatory response following elective surgery” was distributed via email. Two cohorts were approached to participate in the survey. Cohort 1 consisted of 1092 surgeons on the “Association of Coloproctology of Great Britain and Ireland (ACPGBI)” membership list. Cohort 2 consisted of 270 surgeons who had published in this field in the past as identified by two recent reviews. A reminder email was sent out 21 days after the initial email in both cases and the survey was closed after 42 days in both cases. Result: In total 29 surgeons (2.7%) from cohort 1 and 40 surgeons (14.8%) from cohort 2 responded to the survey. The majority of responders were from Europe (77%), were colorectal specialists (64%) and were consultants (84%) and worked in teaching hospitals (54%) and used minimally invasive techniques (87%). The majority of responders measured CRP routinely in the post-operative period (85%) and used CRP to guide their decision making (91%) and believed that CRP monitoring should be incorporated into postoperative guidelines (81%). Conclusion: Although there was a limited response the majority of surgeons surveyed measure the systemic inflammatory response following elective surgery and use CRP measurements together with clinical findings to guide postoperative care. The present results provide a baseline against which future surveys can be compared

    How and why systemic inflammation worsens quality of life in patients with advanced cancer

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    Introduction: The presence of an innate host systemic inflammatory response has been reported to be a negative prognostic factor in a wide group of solid tumour types in both the operable and advanced setting, both local and distant. In addition, this host systemic inflammatory response is associated with both clinician reported patient performance status and self-reported measures of quality of life in patients with cancer. Areas covered: A variety of mechanisms are thought to underlie this, including the influence of the host immune response on physical symptoms such as pain and fatigue, its effect on organ systems associated with physical ability and well being such as skeletal muscle, and bone marrow. Furthermore, this innate inflammatory response is thought to have a direct negative impact on mood through its action on the central nervous system. Expert commentary: It is clear that the host systemic inflammatory response represents a target for intervention in terms of both improving quality of life and prognosis in patients with advanced cancer. Based on this paradigm, future research should focus both on pathways which might be targeted by novel agents, but also on whether existing anti-inflammatory drugs might be of benefit

    Real and complex connections for canonical gravity

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    Both real and complex connections have been used for canonical gravity: the complex connection has SL(2,C) as gauge group, while the real connection has SU(2) as gauge group. We show that there is an arbitrary parameter β\beta which enters in the definition of the real connection, in the Poisson brackets, and therefore in the scale of the discrete spectra one finds for areas and volumes in the corresponding quantum theory. A value for β\beta could be could be singled out in the quantum theory by the Hamiltonian constraint, or by the rotation to the complex Ashtekar connection.Comment: 8 pages, RevTeX, no figure

    Measurement of nuclear effects in neutrino interactions with minimal dependence on neutrino energy

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    We present a phenomenological study of nuclear effects in neutrino charged-current interactions, using transverse kinematic imbalances in exclusive measurements. Novel observables with minimal dependence on neutrino energy are proposed to study quasielastic scattering, and especially resonance production. They should be able to provide direct constraints on nuclear effects in neutrino- and antineutrino-nucleus interactions.Comment: 7 pages, 9 figures, accepted version by PR

    Instability of the massive Klein-Gordon field on the Kerr spacetime

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    We investigate the instability of the massive scalar field in the vicinity of a rotating black hole. The instability arises from amplification caused by the classical superradiance effect. The instability affects bound states: solutions to the massive Klein-Gordon equation which tend to zero at infinity. We calculate the spectrum of bound state frequencies on the Kerr background using a continued fraction method, adapted from studies of quasinormal modes. We demonstrate that the instability is most significant for the l=1l = 1, m=1m = 1 state, for Mμ0.5M \mu \lesssim 0.5. For a fast rotating hole (a=0.99a = 0.99) we find a maximum growth rate of τ11.5×107(GM/c3)1\tau^{-1} \approx 1.5 \times 10^{-7} (GM/c^3)^{-1}, at Mμ0.42M \mu \approx 0.42. The physical implications are discussed.Comment: Added references. 27 pages, 7 figure

    First limits on the 3-200 keV X-ray spectrum of the quiet Sun using RHESSI

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    We present the first results using the Reuven Ramaty High-Energy Solar Spectroscopic Imager, RHESSI, to observe solar X-ray emission not associated with active regions, sunspots or flares (the quiet Sun). Using a newly developed chopping technique (fan-beam modulation) during seven periods of offpointing between June 2005 to October 2006, we obtained upper limits over 3-200 keV for the quietest times when the GOES12 1-8A flux fell below 10810^{-8} Wm2^{-2}. These values are smaller than previous limits in the 17-120 keV range and extend them to both lower and higher energies. The limit in 3-6 keV is consistent with a coronal temperature 6\leq 6 MK. For quiet Sun periods when the GOES12 1-8A background flux was between 10810^{-8} Wm2^{-2} and 10710^{-7} Wm2^{-2}, the RHESSI 3-6 keV flux correlates to this as a power-law, with an index of 1.08±0.131.08 \pm 0.13. The power-law correlation for microflares has a steeper index of 1.29±0.061.29 \pm 0.06. We also discuss the possibility of observing quiet Sun X-rays due to solar axions and use the RHESSI quiet Sun limits to estimate the axion-to-photon coupling constant for two different axion emission scenarios.Comment: 4 pages, 3 figures, Accepted by ApJ letter

    Dayem-Martin (SIS tunnel junction) mixers for low noise heterodyne receivers

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    Superconducting thin film tunnel junctions of small area (.1 → 1 μm^2) have properties which make them suitable for high frequency (≳100 GHz) heterodyne receivers. Both pair and single quasiparticle tunneling is present in these devices, but it is found that the mixing due to the pair effect is apparently excessively noisy, whereas the single quasiparticle effect has a low noise character which gives hope for near quantum limited performance. The physical effect involved is photon assisted quasiparticle tunneling and was first observed by Dayem and Martin[1]. We have made laboratory tests at 115 and 230 GHz which gave single side band (SSB) mixer noise temperatures of 60 and 300 K respectively. Also we have fabricated a 90-140 GHz receiver for the Caltech Owens Valley Radio Observatory which has an overall receiver noise temperature of about 300 K (SSB)

    New phase structure of the Nambu -- Jona - Lasinio model at nonzero chemical potential

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    It is shown that in the Nambu -- Jona - Lasinio model at nonzero chemical potential there are two different massive phases with spontaneously broken chiral symmetry. In one of them particle density is identically zero, in another phase it is not equal to zero. The transition between phases is a phase transition of the second order.Comment: 8 pages, LaTeX, no figures

    Polarised infrared emission from X-ray binary jets

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    Near-infrared (NIR) and optical polarimetric observations of a selection of X-ray binaries are presented. The targets were observed using the Very Large Telescope and the United Kingdom Infrared Telescope. We detect a significant level (3 sigma) of linear polarisation in four sources. The polarisation is found to be intrinsic (at the > 3 sigma level) in two sources; GRO J1655-40 (~ 4-7% in H and Ks-bands during an outburst) and Sco X-1 (~ 0.1-0.9% in H and K), which is stronger at lower frequencies. This is likely to be the signature of optically thin synchrotron emission from the collimated jets in these systems, whose presence indicates a partially-ordered magnetic field is present at the inner regions of the jets. In Sco X-1 the intrinsic polarisation is variable (and sometimes absent) in the H and K-bands. In the J-band (i.e. at higher frequencies) the polarisation is not significantly variable and is consistent with an interstellar origin. The optical light from GX 339-4 is also polarised, but at a level and position angle consistent with scattering by interstellar dust. The other polarised source is SS 433, which has a low level (0.5-0.8%) of J-band polarisation, likely due to local scattering. The NIR counterparts of GRO J0422+32, XTE J1118+480, 4U 0614+09 and Aql X-1 (which were all in or near quiescence) have a linear polarisation level of < 16% (3 sigma upper limit, some are < 6%). We discuss how such observations may be used to constrain the ordering of the magnetic field close to the base of the jet in such systems.Comment: Accepted to be published in MNRAS; 13 pages, 6 figure
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